Citation
Life Cycle Analysis of the Deconstruction of World War II Army Barraks at Ft. McClellan in Anniston, Alabama

Material Information

Title:
Life Cycle Analysis of the Deconstruction of World War II Army Barraks at Ft. McClellan in Anniston, Alabama
Creator:
O'BRIEN, ELIZABETH ( Author, Primary )
Copyright Date:
2008

Subjects

Subjects / Keywords:
Barracks ( jstor )
Construction materials ( jstor )
Deconstruction ( jstor )
Demolition ( jstor )
Landfills ( jstor )
Lumber ( jstor )
Manuals ( jstor )
Pollutant emissions ( jstor )
Recycling ( jstor )
Wood ( jstor )

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright Elizabeth O'Brien. Permission granted to University of Florida to digitize and display this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Embargo Date:
7/24/2006
Resource Identifier:
496802405 ( OCLC )

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Full Text












LIFE CYCLE ANALYSIS OF THE DECONSTRUCTION OF MILITARY
BARRACKS: A CASE STUDY AT FT. MCCLELLAN, ANNISTON, ALABAMA















By

ELIZABETH O'BRIEN


A THESIS PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF ENGINEERING

UNIVERSITY OF FLORIDA


2006





























Copyright 2006

by

ELIZABETH O'BRIEN















ACKNOWLEDGMENTS

I would like to first acknowledge and thank the Department of Defense for the

grant funding that made this project possible. I am also grateful to Brad Guy and Timothy

Williams for their leadership and guidance of the deconstruction team and for their work

in collecting and organizing the data used in the life cycle assessment. I would also like

to thank Costello Dismantling Company for its help in the deconstruction and demolition

of the military barracks at Ft. McClellan.

I acknowledge and thank Dr. Angela S. Lindner, my supervisory committee

chairperson, for her time, hard work, leadership, and guidance during this project. I thank

my committee members Drs. Timothy Townsend and Charles Kibert for their direction,

time, and support. I am also very grateful to my research group for feedback and support

throughout this project. I acknowledge and thank my family, roommates and friends for

all of their support and guidance.
















TABLE OF CONTENTS

page

A C K N O W L E D G M E N T S ......... .................................................................................... iii

LIST OF TABLES ............. ..... ........................ ............. ............ vii

LIST OF FIGURES ............. .. ..... ...... ........ ....... .......................... viii

ABSTRACT ........ .............. ............. ...... .......... .......... ix

CHAPTER

1 IN TR OD U CTION ............................................... .. ......................... ..

A C ase for D econstruction................................................................................ 2
A dv antag es ....................................................... 2
D isadvantages ....................................................................... ... ..... . .........4.....4
Is R euse of N on-V irgin W ood Possible?.................................... ..................... 5
A C ase for V irgin W ood ........ .......... ............... ...................... ............... 8
Research Scope .......... .................. .......................... 12

2 REVIEW OF LITERA TURE ......... ................. ................................ ............... 14

A m ount of Construction Each Y ear ........................................ ....................... 14
Amount of Deconstruction/Demolition Each Year ............. .....................................15
Increased Availability of M materials .......... ........... .. ........... .. ............ 15
How are Virgin Trees Turned Into Usable Wood? ..........................................16
V irgin W ood Processes......................... ..........................................16
H arvesting ............................................. 16
S a w m ill ..................................................................................................... .. 1 7
The D construction Process ............................................... ............................ 18
R aw M material Extraction.............................................. ............................ 18
M material R efi n in g ....................................................................... ................ .. 2 1
U se/R eu se ................................................................. .................... 22
Disposal ....................................................... ........ 23
Disadvantages of Unlined Landfills .............. ............................................. 25
Costs of Deconstruction Verses Demolition.......................................................28









3 LIFE CYCLE ANALY SIS .......................................................... ............... 33

A b stract .................................................... ............................ 33
Introdu action ....................................... ........................................................ 34
M eth o d s ...................................... ..........................3 7
Description of Fort McClellan Barracks ..................................... .......37
The Deconstruction Process and Four Scenarios Studied ............... ................37
L ife C ycle A naly sis ..............................................................39
F functional U nit .................................. .................................................. ..........39
Scope and Goal Definition ................. ................. ............................ 39
F ig u re 3 -2 ................................................................3 9
F figures 3-3 and 3-4 .........................................................40
D ata Inventory ...................... ................ .............................. 41
Im pact A ssessm ent ................................................................................ 42
A ssum options and Lim stations .............................................................................. 42
Sensitivity A analysis ........................ ............ ................ ........... 44
R results and D discussion ........................ .................. .................. ........... 45
D ata Inventory .................................................. .. .... ..................... 45
Time Requirements for Removal of Barrack Components ..............................45
Labor and Machine Time and Mileage Requirements and Material Yields........47
Fuel and Electricity R equirem ents ........................................... .....................49
E m issio n s ................................51........... ...............
Im p act A n aly sis ................................................................53
Case 1: No Salvaging...................... .... ....... .. .......... .......... ........ 53
Case 2: Salvaging and No Long-Distance Transportation to a Storage Facility
(L local R eu se) ........................................ ...........................................55
Case 3: Salvaging and Transport to Austin, TX, for Reuse ............ ...............56
Sensitivity Analysis ................. ........ ............... ...... .... ........... ....57
Time for Deconstruction or Demolition Activities ..........................................57
Com m uting D instance ............................................................................ 58
Recycling ...................................................................... .......... 58
Transportation R equirem ents ........................................ ......................... 58
Time Required for Paint and Nail Removal ................................................59
C o n c lu sio n s..................................................... ................ 5 9

4 SUMMARY, CONCLUSIONS AND RECOMENDATIONS..............................76

S u m m a ry ............... ..... ............................................................................................... 7 6
C o n c lu sio n s........................................................................................................... 7 6
Recommendations................ ....... .. ... ......................79

APPENDIX

A DATA COLLECTION AND DAILY NARRRRATIVE ................ .................... 81

Introdu action to th e F orm ......... ................. .............................................................8 1
Key to Form .................... ................................83


v










T e a m .......................................................................................................8 3
C om p leted b y ...........................................................83
D a te ................................................................................................................. 8 3
T im e ...........................................................8 3
N a m e ............................................................................... 8 3
B u ild in g .....................................................................................................8 4
R o o m .............................................................................8 4
L o c a tio n .......................................................................................................... 8 4
A activity ....................................... ................................................... .............. 85
HDec (hand deconstruction) ................................ ............... 85
H D em (hand dem olition) ..................... .................... ................. 85
MDec (mechanically assisted deconstruction)................... .............87
MDem (mechanically assisted demolition) ...................................... 87
N (non-productive)..................... ........... ......... 87
P (processing)...................................88
S (su p e rv isin g ) ............................................................................................ 8 8
A ssem b ly ....................................................... 8 8
E quipm ent .............................................. 88

B INVENTORY OF EMISSIONS ....................................... .........90

L IST O F R EFE R EN C E S ............................................................................... 95

B IO G R A PH IC A L SK E T C H ........................................................................................ 99
















LIST OF TABLES


Table page

2-1. C&D W aste M material Categories and Sources .................................. ............... 19

2-2. Amount of Chemical Constituents in Wood Products (Construction and
D em olition W aste Landfills 1995)...................................................... ............... 26

3-1 Time Requirements for Removing Components of Barracks Using the Four
Scenarios Varying in Degree of Manual Deconstructiona' b........... ............... 61

3-2 Labor and Machine Requirements and Material Yields of the Four Scenarios
S tu d ie d .....................................................6 2

3-3 Fuel and Electricity Requirements for Associated Processesab ...............................63

3-4 Emissions from the Scenario Involving 100% Manual Methodsa.............................64

3-5 Emissions from the Scenario Involving 44% Manual Methodsa..............................65

3-6 Emissions from the Scenario Involving 26% Manual Methodsa............................66

3-7 Emissions from the Scenario Involving 100% Mechanical Methodsa, b...................67

B -l: R aw M material E m missions ............................................................................ ...... 90

B -2: Em missions to A ir .................. .................. ................. ........ .. ............ 91

B -3: Em missions to W after ....................................................... .. ............ 93

B -4 : E m missions to L and ............ ... .............................................................. ........ ....... 94
















LIST OF FIGURES


Figure pge

3-1 World War II Army Barracks at Fort McClellan ............................................... 68

3-2 Stages Involved in the Deconstruction Process............... ............. ............... 69

3-3 Total Impacts Calculated Using the EDIP Method Not Including Reuse of
Salvaged M materials. ........................ .............................. .. ........ .... ..... ...... 70

3-4 Total Impacts Calculated Using the CML Method Not Including Reuse of
Salvaged M materials. ..................... ................. .........................................71

3-5 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged
Materials But No Transportation to a Warehouse.................................................72

3-6 Total Impacts Calculated Using the CML Method Reuse of Salvaged Materials
But No Transportation to a W warehouse ........................................ ............... 73

3-7 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged
Materials and Transport to the Habitat for Humanity Warehouse in Austin,
T ex a s. ............................................................ ................ 7 4

3-8 Total Impacts Calculated Using the CML Method Including Reuse of Salvaged
Materials and Transport to the Habitat for Humanity Warehouse in Austin,
T ex a s. ............................................................ ................ 7 5















Abstract of Thesis Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Master of Engineering

LIFE CYCLE ANALYSIS OF THE DECONSTRUCTION OF MILITARY
BARRACKS: A CASE STUDY AT FT. MCCLELLAN, ANNISTON, ALABAMA


By

Elizabeth O'Brien

May 2006

Chair: Angela Lindner
Major Department: Environmental Engineering Sciences

Nearly 2.5 million ft2 of barracks must be removed from military facilities

throughout the U.S. Environmental Protection Agency Region 4. While manual

deconstruction offers promise for environmental, economic, and social benefits, the

combination of mechanical and manual methods for minimal impact to the environment

and public health is unknown. Here, life cycle analysis was used to determine an

optimum level of manual deconstruction of barracks at Ft. McClellan in Anniston,

Alabama. Four scenarios were compared with varying degrees of time required for

manual deconstruction, 100% Manual, 44% Manual, 26% Manual, and 100%

Mechanical, on the barracks. Data were collected directly from the site and applied using

SimaPro modeling software (Pre Associates, The Netherlands), considering three post-

deconstruction options. Materials salvaged using either 100% or 44% Manual

deconstruction and reused within a 20-mile radius of the deconstruction site yielded the

most favorable environmental and health impacts; however, given the significant impacts









involved in the life cycle of diesel fuel required for transportation, the need for

developing reuse strategies for deconstructed materials at the regional level is

emphasized.














CHAPTER 1
INTRODUCTION

Each year, the building industry in the United States is reported to generate nearly

136 million tons of construction and demolition (C&D) waste, amounting to 35-40

percent of the total amount of municipal solid waste (MSW) produced annually (Dolan et

al. 1999). Approximately 60 percent of this C&D waste originates from the demolition

of buildings, and 80-90 percent of this waste is estimated to be either reusable or

recyclable (McPhee 2002). While the reuse and recycling of C&D-related waste offers

potential environmental advantages, the building and deconstruction industry has not

fully embraced these practices (Lippiatt 1998).

Reuse and recycling of currently landfilled construction and demolition materials

offer potential benefits in terms of decreased landfill use and raw material extraction. A

reduced amount of raw material extraction is a benefit to the environment because the

extraction of raw materials may lead to resource depletion and biological diversity losses.

The extraction of raw materials normally occurs at sites far from manufacturing plants

and the transport of raw materials and manufacturing of building products consume

energy. The generation of this energy produces emissions linked to global warming, acid

rain and smog. Also the waste generated from the manufacture and transport of the raw

materials decreases the space available for disposal in landfills. All of these activities

from raw material extraction to landfilling are potential sources of air and water

pollution. The goal of this project is to discover the best way to lower building-related

contributions to environmental problems (Lippiatt 1998).









A Case for Deconstruction

Most buildings are removed using demolition processes. Demolition is an

equipment-intensive operation. Most of the crew is involved in operation of machinery

and have very little physical contact with the actual building materials. Larger materials

(usually metals, sometimes concrete and masonry) can be separated during demolition

using machinery (Falk and Lantz 1996). Deconstruction, on the other hand, "is the

systematic disassembly of buildings in order to reuse and recycle as many of the

component parts as possible, before or instead of standard mechanized demolition"

(Mcphee 2002). Deconstruction uses hand labor and physical contact with the building

by the workers and involves a methodical disassembly of building parts with similar care

taken in this process as devoted to its reverse process of construction. Because of this

physical contact with the building, deconstruction takes about twice as long as demolition

(Falk and Lantz 1996).

As an alternative to demolition, deconstruction has advantages and disadvantages:

Advantages

S Recycling building materials conserves resources by diverting used materials from

the landfill and avoiding use of virgin resources. For every recovered square foot

of wood used in new construction, a corresponding square foot of virgin wood is

not consumed. Therefore, salvaging reduces the use of natural resources. The

diversion of bulky and difficult-to-handle C&D waste from the municipal solid

waste (MSW) stream will increase the operating life of local landfills and will

result in fewer associated environmental impacts such as groundwater

contamination (Dolan et al. 1999).









* Deconstruction and the resulting reuse of building materials results in avoidance of

some of the costs of landfilling, primarily transportation and tipping fees.

* Recovering materials may generate a credit or otherwise subsidize the overall

building disposal costs. A generated credit would allow the owner of the

deconstructed building to receive money or materials from the user of the recovered

materials.

* Landfill failures can result in remediation costs being assigned to former landfill

contributors. By reducing landfill use, there could be a reduced future liability

(Falk and Lantz 1996).

* Due to the increasing cost of materials manufactured with virgin materials, recycled

materials are becoming much cheaper in comparison.

* Salvaging reduces the total cost of materials since only the cost of removal,

refurbishing, and transport is incurred by the salvage (NAHB 2003).

* The availability of high-quality virgin materials for the manufacture of building

materials is decreasing. In many cases, the sources of raw materials are great

distances from installations or building projects, and high transportation costs make

contractors look for a local replacement.

* Many state and regional waste authorities restrict the disposal of bulk waste, such

as furniture, appliances, and building equipment, to special solid waste handlers or

landfills. This, in turn, has driven up the disposal tipping fees. In most cases, any

level of salvage reduces the cost of disposal.

* Timber that is recovered properly from older buildings is gaining acceptance in

meeting the demand for large old-growth timber (Falk, R. and Lantz, S. 1996).









* Salvage recovers the highest percentage of the "embodied" resources in the

materials or subsystems. The energy and raw materials consumed in the original

manufacture of the materials or systems are not lost to landfill disposal (NAHB

2003).

Disadvantages

* Building disposal may be more management-intensive for the building owner if

multiple contracts are needed for the various types of abatement and disposal.

* Deconstruction takes twice as long as demolition.

* Demolition is more machine-intensive, while deconstruction is more labor-

intensive. Because of the increased number of workers on the deconstruction site,

there is an increase in the emphasis on site safety and coordination.

* The markets for nonvirgin building materials are very unstable. The acceptance of

salvaged material is still in transition from local markets to national and

international markets. Therefore, the value of the recovered materials is still

difficult to predict (Falk and Lantz 1996).

* Salvaged materials are harder to sell. As yet, they do not have a standard grading

system. So it is hard to tell for what application each board can be used.

* Before the deconstruction process, a determination of whether the materials and/or

assemblies can be removed in a cost-effective and safe manner must be made. This

is vital information in assessing the economic feasibility of the project.

* Even when markets for the material exist, deconstruction may not be financially

justifiable if there is not enough material.









* If there is too much material and not enough storage space the salvage operation

may not be able to occur. If the material has to be stored for an indefinite period of

time, some types of materials, such as wallboard, will lose their economic value. If

they are not stored properly, degradation of their material properties may occur

(Dolan et al. 1999).

* There are negative environmental impacts, such as dust generation, noise and

vibrations (Thormark 2002).

* Deconstruction discards different waste than construction or renovation and

demolition. Deconstruction is more likely to contribute contaminated materials to

landfills because all reusable materials are separated, leaving for disposal materials

contaminated by potentially toxic substances, such as lead paints, stains, and

adhesives (Dolan et al. 1999).

Is Reuse of Non-Virgin Wood Possible?

The U.S. Department of Defense (DOD) has 2,357,094 square feet of excess

buildings that are in need of removal from military bases throughout U.S. EPA Region 4,

encompassing the states of Alabama, Florida, Georgia, Kentucky, Mississippi, North

Carolina, South Carolina and Tennessee (Falk et al. 1999). The U.S. military is disposing

of these barracks because the federal procurement law and military regulations listed

under the U.S. Code of Federal Regulations, CFR 32 162.2, will not allow federal tax

dollars to be spent on the maintenance of facilities that are in surplus to its needs (Falk et

al. 1999). In response to these regulations, the U.S. Army is considering deconstruction

of its barracks and salvaging of materials in order to accomplish its minimization goals

and subsidize the overall disposal costs of the buildings, thus lowering funding









requirements (Falk et al. 1999). However, there is a question as to whether 100% manual

deconstruction of military barracks will yield optimum economic and environmental

savings, particularly for those barracks built before World War II.

The possibility of recovering timber and lumber from buildings is dependent on

both physical and economic factors, which include:

* wood condition, dimensions, and species

* type and number of fasteners per piece

* exposure or protection from the elements

* labor cost

* allowable building disposal period

* site configuration and building height

* allowable on site recovered materials storage time

The demand for nonvirgin timber and lumber can increase due to the following:

* Harvesting restrictions on high-quality, large-diameter, old-growth timber restrict

its availability at any price.

* Prices of forest products are steadily increasing.

* Exposed timber frame construction demands high-quality large timber.

* Older species-specific wood may be desired for use in new log home construction

and interior remodeling of older buildings.

* North American species may be considered "exotic" creating a demand in those

markets.

* The more nonvirgin timber and lumber is used the more familiar buyers, designers,

and builders will become with it.









The demand for nonvirgin timber and lumber is restricted by the following factors:

* There are no grading standards or design rules specifically for nonvirgin wood

materials; application of virgin material standards and rules on nonvirgin wood

may have the effect of downgrading nonvirgin materials.

* Lumber used at a site must be graded. Without a grade, a "timber grader" must be

present, or the materials will be rejected.

* Lack of consistent supplies and markets for nonvirgin timber and lumber.

* Owners and disposal contractors are not aware of the value of nonvirgin timber and

lumber so they make no attempt to recover them (Falk and Lantz 1996).

Variability of the Quality of Lumber

Service-related defects, such as drying checks, splits, bolt and nail holes, notches

from other framing members or utilities and exposure to weather and decay, can affect

the quality of recycled lumber. Depending on the building type and use, boards also may

have been exposed to chemicals and extreme temperatures. Most importantly, structural

members have often experienced an unknown load history (Green et al. 1999).

When timber is first cut it is full of water. Before the days of drying kilns in mills,

wood was allowed to dry naturally. This process takes several years for large timbers.

As the wood dries out, the timbers shrink. The location of the cut on the tree determines

the kinds of splits or checks that occur in the wood. A split is a separation of the wood as

a result of the tearing of the wood cells (Falk et al. 2000). "A separation of the wood that

occurs across or through the growth rings is a check. A separation that extends from one

surface of a piece to the opposite or adjoining surface is a through check" (Falk et al.

2000 73). If the timber was cut from the center (the "heart" of the tree), cracks (checks)









will form in a radial pattern outward from the center. If the timber was cut from the

outside part of the tree ("free of heart center"), there will be less checking. "Free of heart

center" timbers check less, but they cost more because they have to be cut from a much

bigger tree (Falk et al. 2000).

Heart checks have little effect on the strength of the recycled timber columns, but

they lower the modulus of rupture (Stress Grading of Recycled Lumber and Timber

1999). Checks also have little effect on column compressive strength. Although the

checks have little effect on the quality, the damage incurred during deconstruction lowers

the quality of dimensional lumber from the reconstructed buildings on average one grade

(Falk and Green 1999).

The direct reuse of wood materials as a construction product faces many obstacles.

The duration of loads, moisture cycling and fabrication changes during the service life of

the wood are difficult to determine but quantifying the remaining strength of the wood is

necessary. Currently, there is no way to grade wood except on an individual piece-by-

piece basis. This is a major obstacle to the reuse of timber. Typically, manufacturers

will reuse heavy timbers only for post and frame buildings because they are dry and

stable (Green et al. 1999). Another obstacle to the direct reuse of wood materials occurs

as a result of use or the dismantlement process. Defects often exhibited by recycled

lumber can include mechanical damage (broken ends and edges of members, splits due to

disassembly), damage from fasteners and hardware (bolt holes, clusters of nail holes),

and notches from other framing members or utilities (Green et al. 1999).

A Case for Virgin Wood

Since 1953, 16 million acres of southern yellow pine timberland have been lost in

the South. Suppression of wildfires, reduced prescribed burning, southern pine beetles,









urban development, high-grading, and a lack of artificial regeneration on privately owned

timberlands are all factors that have contributed to the decline of timberland. Tree-

planting programs on agricultural lands have slowed the decline of timberland. In

addition, according to the Southern Forest Resource Assessment, an increase in southern

yellow pine timberland could occur if 23 million acres of former cropland and

pastureland were planted to pines during the next four decades. This effort would

probably require subsidies (South and Buckner 2003).

Each American uses the equivalent of a 100-foot tree every year. The American

population has increased from 76 million in 1900 to more than 250 million people in

1990. Therefore, over 14-billion 100-foot trees were grown and used from 1900 to 1990.

And, due to good forest practices, two-thirds of the original forestland is left.

Many people believe that, to obtain environmental benefits from the forests, it is

best to leave the trees untouched. More often, the opposite is true. Forests with young

trees that are growing and healthy generally have more environmental benefits than older

forests whose trees are stagnant or dying. Tree farming using modern forestry knowledge

produces young healthy forests (Trees 1992).

Trees, unlike steel and aluminum, are a renewable resource. In 2002, forest

landowners planted nearly 1.7 billion seedlings. Besides planting new trees, forest

landowners managed the natural regeneration of millions of other trees giving America

nearly two and a half million acres of new, growing forests. For decades, America has

been growing more wood than is harvested or lost to insects and disease. And since the

beginning of the 1980s, the total amount of forestland in America has increased by 27

million acres (Trees 1992).









Trees produce 1.07 pounds of oxygen and use 1.47 pounds of carbon dioxide for

every pound of wood they grow. An acre of trees can grow approximately 4,000 pounds

of wood a year, using 5,880 pounds of carbon dioxide and giving off 4,280 pounds of

oxygen in the process (South and Buckner 2003).

Forests benefit our population in two ways. The first is by producing wood.

People use an average of 15,824 board feet of lumber and up to 10,893 square feet of

panels in each house that is built. Over 600 pounds of paper per a person are produced a

year for books, diapers, packaging, and all the other paper products. Trees are also a

benefit due to the oxygen they produce. One person needs 365 pounds of oxygen per

year, and that oxygen is manufactured through plants and trees (South and Buckner

2003). America is slowly becoming a paperless society as electronic copies become the

more cost and time-efficient way to do business. Before the industrialization of our

nation, tree harvesting was minimal. However, now that our nation is industrialized, the

harvesting of trees is one of the best ways to counteract the production of air pollution.

As trees age, they consume less carbon dioxide, so growing new trees allows more

carbon dioxide to be taken up and oxygen to be released making our air more breathable.

The harvesting of trees is important because it gives new trees room to grow and keeps

carbon dioxide stored in old wood.

As forests age and become more overcrowded, little growth occurs; however, trees

begin to use oxygen instead of releasing oxygen; and more wood may decay than grow.

For every pound of wood that decays (or combusts), 1.07 pounds of oxygen are used, and

1.47 pounds of carbon dioxide are released (South and Buckner 2003). As a result of this









reversal of CO2 removal/oxygen release, care must be taken to avoid wood decay or

combustion and to ensure that new trees are in abundance.

Besides creating more breathable air, trees cool the air by providing water

evaporation. Trees act like huge pumps cycling the water up from the soil and back into

the air (South and Buckner 2003). A 100-foot tree with 200,000 leaves, for example, can

remove 11,000 gallons of water from the soil and release it into the air in one growing

season. This cooling effect of water evaporation by latent heat transfer is said to be

equivalent to air conditioning for 12,168 square foot rooms. In fact, one solution to

combat global warming is forest regeneration and maintenance (South and Buckner

2003).

When a forest grows naturally, it goes through cycles. A wild forest may start out

with as many as 15,000 small seedlings per acre. Over a typical 60- to 100-year cycle, at

least 14,700 of the original trees 98 percent will die as the trees compete for space.

Modern forestry finds ways to use this natural mortality and improve and maintain forests

at the same time (South and Buckner 2003).

Modem forestry uses many different types of harvesting, depending on many

factors, including the terrain and the conditions that are needed to plant a forest (South

and Buckner 2003). More than half of the timber harvested each year in the United

States is used in some form of solid wood product: lumber, panels of veneer, or chips for

both structural and nonstructural applications, and miscellaneous products, such as posts,

poles, and pilings. Although a significant amount is used in manufacturing and shipping,

construction activity accounts for the majority of solid wood products consumption (more

than 60 percent of lumber and more than 80 percent of structural panels). As a result,









consumption and prices of lumber are highly sensitive to fluctuations in new housing and

other construction activity (Adams 2002). Therefore, use of virgin wood maintains the

production of trees, however, salvaging wood prevents the already harvested trees from

decaying in landfills.

Research Scope

The focus of this paper is the life cycle comparison of four identical barracks

located at Fort McClellan in Anniston, Alabama, deconstructed with varying degrees of

hand and mechanical methods, ranging from 100% mechanical demolition to 100%

manual deconstruction. Using data carefully collected during the deconstruction and

demolition processes, the specific emissions and resulting environmental impacts of the

four scenarios are compared using LCA methods and are reported herein.

Since steel and masonry building materials were being redirected to other parts of

the war effort, many of the army facilities that were built during the World War II era

were built of timber. Many of these facilities were classified as surplus to the nation's

defense requirements at the end of the Cold War era in the early 1990's. The current

situation in the military is contrary to the past trend of adding buildings to the industrial

inventory while continuing to use existing buildings. In the past, any disposal of

buildings was incidental to other ongoing operations and, as such, was often handled on

an individual basis. This disposal was based on administrative decisions and disposal

practices. The typical disposal practice for such facilities has been demolition, with the

debris placed in a landfill (Falk, R. and Lantz, S. 1996). Several army bases have been

closed since 1990, and many of the World War II barracks are no longer used (Falk, R.

and Lantz, S. 1996). Since federal tax dollars cannot be spent to maintain surplus

facilities, many of these army facilities must be demolished. In 1995, over 250,000,000









board feet (BF) of lumber were estimated to be available for reuse from the World War II

wood buildings then slated for demolition (Falk 2002).

At Ft. McClellan in Anniston, Alabama, deconstruction and demolition was

performed on three barracks on site with varying degrees of mechanical and manual

labor. This project involves a life cycle assessment (LCA) to determine if the reuse of

wood salvaged from the deconstruction of the barracks is a viable alternative to using

virgin wood. The Environmental Protection Agency states an LCA "examines the

environmental releases and impacts of a specific product by tracking its development

from a raw material, through its production and to eventual disposal." An LCA was

performed on all four scenarios to compare the inputs and outputs of each scenario in the

form of environmental impacts, energy consumed and labor required. This project was

completed to help the DOD determine the square footage of barracks that need removal

and to compare and contrast environmental impacts of deconstruction and demolition.

This project will have a direct impact on the ability to plan the most environmentally

effective deconstruction of the barracks contained in EPA Region 4. This plan is

intended to aid the U.S. Army to meet its waste minimization goals, to provide materials

at lower cost for new construction on bases on or close to deconstruction sites, and to

increase the number of civilian jobs. The hypothesis of the project is that 100% manual

deconstruction will have the lowest environmental impacts of any of the four scenarios

because it is assumed the machinery will be used for the least amount of time and fewer

materials will be landfilled. Therefore the least amount of emissions should be produced

in the 100% manual deconstruction scenario.














CHAPTER 2
REVIEW OF LITERATURE

Amount of Construction Each Year

Over the last three decades lumber consumption has increased by nearly one-third,

and structural panel use has more than doubled. The Resources Planning Act (RPA)

Timber Assessment projects that the consumption of solid wood products will continue to

grow in the future through the expansion of both construction and nonconstruction uses

due to America's growing population and increasing wealth (Adams 2002).

It is projected that, every year for the next 50 years, 1.43 million new households

will be constructed, thus creating approximately 71 million additional separate living

units. Approximately, 1.93 million houses will also be improved each year for the next

50 years. The primary driver of the new construction and improvements is an aging,

healthy, retired population acquiring second homes (Adams 2002).

Reflecting the trend of an aging population and the declining number of people per

household, the average size of new housing units is projected to stabilize over the next 40

years and then rise in the final decade of the projection. By 2050, the average size of a

single-family unit will increase from the current average of 2,160 square feet to 2,600

square feet. Multiple-family housing will expand from 1,000 to 1,200 square feet, and

mobile homes will grow from 1,350 to 1,950 square feet (Adams 2002). In 2004, single-

family houses had already increased to an average size of 2,225 square feet (CORRIM

2004). Since 1991, the consumption of lumber has been growing steadily. A historical

high of 68.2 billion board feet (bbf) consumed was reached in 1999 (Adams 2002).









Amount of Deconstruction/Demolition Each Year

The average age of housing in the United States is over 30 years, necessitating their

improvement or demolition. According to the Census Bureau, approximately 245,000

dwelling units and 45,000 non-residential units are demolished every year, creating

approximately 74 million tons of debris a year. Using deconstruction to remove

buildings can convert demolition waste into construction materials. For example, by

deconstructing one-fourth of the buildings instead of demolishing them, approximately

20 million tons of debris could be diverted from landfills each year (NAHB 2003).

Increased Availability of Materials

The past century has seen a major population boom in the United States. During

this time many new residential homes, commercial and industrial buildings, bridges, and

other structures were built from sawn lumber and timber. As these buildings become

ready to be torn down, much of this lumber may be available for reuse. Over three

trillion board feet of lumber and timber have been processed in the U.S. since 1900.

Much of this wood is still residing in existing structures. When these structures reach the

end of their service lives, become obsolete, or change use, contemporary practices

emphasize quick, cheap disposal in landfills (Green et al. 1999). Recently, public interest

has been expressed in finding environmentally acceptable and efficient material reuse

options that focus on deconstruction and reuse of materials in new construction and

remodeling activities (Green et al. 1999).

Along with growing public interest in increasing the amount of recycling/reuse of

C&D waste, federal agencies, such as the United States Environmental Protection

Agency (USEPA) and General Services Agency (GSA), have developed policies to

promote an increase in the use of recycled content products. Building materials have not









been emphasized in these procurement guidelines until recently. Increased recycling of

C&D waste promises to "close the loop" of material procurement and reuse by increasing

the amount of materials available (Dolan et al. 1999).

How are Virgin Trees Turned Into Usable Wood?

* The life cycle of timber products includes the following stages:

* Growing timber

* Harvesting timber/cutting it down

* Processing/making it into a useable product

* Installation into a building

* Maintaining, preserving, painting

* Replacement

* Disposal via landfill, incinerator/burning or recycling

* Transport at each stage

Virgin Wood Processes

Harvesting

Timber used for the construction of new houses and the renovation of old houses

all comes from one source-trees. The harvesting of trees occurs in three stages: the

felling and bunching of trees, the movement of the trees from the forest to the site where

they are loaded on the truck and the loading of the trees onto the truck (Long 2003).

A feller buncher is used in the first stage (felling and bunching of trees). The feller

buncher cuts down a group of trees using a saw blade that is located on the bottom of the

feller buncher between two clamps. There are also two more sets of clamps located

above the saw blade. All three sets of clamps are brought together at the same time. As









the saw blade cuts the tree, the two upper sets of clamps grab hold of the tree. Normally

feller bunchers cut trees that are between 8" and 18" in diameter. It cuts several trees at

a time, lays the trees down, and moves on to cut down the next tree (Long 2003). Photos

of feller bunchers can be accessed at

http://www.deere.com/enUS/cfd/forestry/deere forestry/fellerbunchers/tracked/703G

general.html, http://catused.cat.com/equipment/view-equipment-

detail.html?equipmentPK=Eq1.545735F, and http://www.franklin-

treefarmer.com/fellerbunchers/Fellerbunchers.html.

A rubber-tired skidder delimbs the downed trees by directing them through steel

grates and then moves them from the forest to the loading area (Long 2003). Photos of

rubber-tired skidders can be accessed at http://www.vannattabros.com/skidderl.html.

Log loaders are used to sort the wood by size and to pick the trees up from the ground

and load them on eighteen-wheeler trucks, which carry the logs to the mill (Long 2003).

Photos of log loaders can be observed at http://www.vannattabros.com/drott.html and

http://www.madillequipment.com/loaders.html.

Sawmill

Logs are converted into lumber in a sawmill after they are unloaded from the

eighteen- wheeler truck. The first step is to cut the logs to specified log lengths, and then

the logs are sawn by a chipping saw or a bandsaw, edgers, a trimmer and a resaw. The

focus of these processes is to maximize the lumber extraction. The timber is cut into two-

inch thick boards of varying widths and lengths, and sorted by size before it is kiln-dried.

The lumber is then planed using a plane saw and graded by graders. The kilns, which are

controlled by computers, dry rough, green lumber with a moisture content of about 50%

to a desired moisture content of about 10% in approximately 24 hours. Lumber is planed









to the desired size and finished in the planermill. Then the lumber is shipped to

consumers (Long 2003).

The Deconstruction Process

Raw Material Extraction

Deconstruction is used to extract materials that will be reused in new construction

and remodeling activities. The main raw material that comes from deconstruction is

reusable wood. Other raw materials that can be salvaged include showers, urinals,

mercury ballasts, and doors.

Before deconstruction begins, the building is surveyed to determine what can and

cannot be salvaged. Visible defects, subtle signs of wear and tear, and the ease with

which materials can be removed are observed. Deconstruction is both labor-intensive

and time-consuming, comparable to building a new structure only in reverse order

(Yeung and David 1998). Deconstruction starts with removing the shingles from the roof

and pulling out nails to take out the sheathing. The roof boards are then pried loose,

handed down, further denailed, sized and stacked. Next, workers take nails from the

rafters, knock the boards apart, and hand them down to be denailed and sorted. Then the

ceiling joists are knocked off and lowered down (Block 1998). This process continues

throughout the whole building.

Deconstruction can be contrasted with the sorting and salvaging of demolition

debris. The biggest problem with sorting and salvaging of demolition debris is that,

during demolition, the debris is mixed. Even during the deconstruction process, when the

structure is carefully dismantled by manual labor, the mixing of different types of

materials is still possible. For example, removing the exterior wall in a load-bearing

masonry system will result in a combination of masonry materials including concrete









blocks or bricks, reinforcing steel, metal ties and grout (Dolan et al. 1999). These

dissimilar materials must be separated if they are to be recycled or reused.

The composition of C&D waste varies depending on the type of project and the

method of construction and demolition. In general, wood comprises one-quarter to one-

third of the C&D waste stream. As shown in Table 2-1, C&D waste can be divided into

sixteen categories of materials, which can be further- divided into several different

subcategories of materials. The information listed in Table 2-1 includes all of the

individual components that may be found in a building. Many of these classes of

materials, such as concrete, masonry, and ceramics are inert and thus not susceptible to

degradation by bacterial activity once landfilled. There are, however, several components

of C&D waste that are not inert in nature and, therefore, are putrescible. The best

example of a material the will putrefy under the proper conditions in a landfill is wood.

Also several types of these materials can be considered chemically-reactive, such as paint

and paint thinner, and they must be handled in a special manner (Dolan et al. 1999).

Table 2-1. C&D Waste Material Categories and Sources
Waste Material Demolition Source Construction Source
Asphalt Roads, bridges, parking lots, roofing materials, Same
flooring materials
Brick Masonry building equipment white goods, Same
appliances installed equipment
Ceramics/clay Plumbing fixtures, tile Same
Concrete Foundation, reinforced concrete frame, Same
sidewalks, parking lots, driveways
Contaminants Lead-based paint, asbestos insulation, fiberglass, Paints, finishes
fuel tanks
Fiber-based Ceiling systems materials, insulation Same
Glass Windows, doors N/A
Gypsum/plaster Wall board, interior partitions Same









Table 2-1 continued
Waste Material Demolition Source Construction Source
Metals, ferrous Structural steel, pipes roofing, flashing, iron, Same
stainless steel
Metals, nonferrous Aluminum, copper, brass, lead Same
Paper/cardboard N/A Corrugated cardboard,
packaging
Plastics Vinyl siding, doors, windows, signage, plumbing Same
Soil Site clearance Same, packaging
Wood, treated Plywood: pressure- or creosote-treated, laminates Same
Wood, untreated Framing, scraps, stumps, tops, limbs Same

The amount of C&D waste produced in the United States depends on several

variables including:

* The extent of growth and overall economic development that will drive the levelof

construction, renovation, and demolition;

* Periodic special projects, such as urban renewal, road construction and bridge

repair, and unplanned events, such as natural disasters;

* Availability and cost of hauling and disposal options;

* Local, state and federal regulations concerning separation, reuse, and recycling of

C&D waste;

* Availability of recycling facilities and the extent of end-use markets (Dolan et al.

1999).

The composition and quality of waste materials will vary greatly from building to

building. Any of the 16 categories of waste found in Table 2-1 is expected to be found in

a typical residential, commercial or institutional project. The physical composition of

building materials changes dramatically depending on the age of the project (for

renovation and demolition projects), resource availability and construction/demolition

practices used. There are three main factors that affect the characteristics of C&D waste:









the structure type (e.g., residential, commercial or industrial building, road, bridge),

structure size (e.g., low-rise, high-rise), and activity being performed (e.g., construction,

renovation, repair, demolition). Some additional factors that influence the type and

quantity of C&D waste produced are the size of the project (e.g., custom built residence

versus tract housing), the location of the project (e.g, waterfront versus inland, rural

versus urban), materials used in the construction (e.g., brick versus wood), the demolition

practices (e.g., manual verses mechanical), schedule (e.g., rushed versus paced), and the

way the contractor keeps track of and takes care of materials (Dolan et al. 1999).

Salvaging materials has several advantages for both the construction industry and

solid waste management. It recovers the most resources and the initial energy and raw

materials used for the virgin manufacture are not lost to landfill disposal. Also, salvaging

materials reduces the overall cost of the materials since only the cost of removal,

refurbishing and transport are included in the final price of the material. Salvaging

materials also reduces the cost of disposal (Dolan et al. 1999).

Material Refining

Once the wood is removed from the building, it must be cleaned before it can be

reused. The first step taken to make the wood reusable is denailing. Denailing is

accomplished using a denailing gun, which operates reverse of a nail gun. Removal of

nails without damaging the wood using a denailing gun requires approximately 30% of

the time necessary to remove the boards from the building (Guy 2005). At a typical

deconstruction site, a denailing gun is powered by a generator and runs approximately 8

hours a day (Guy 2005).

Painted wood is not stripped unless it is covered in lead-based paint (LBP). Wood

covered with paint containing no lead can be stripped by the consumer if needed. If the









end of the wood is rotten, it is still resold and the consumer can remove the end. If

however, nails are clustered at the rotten end, it is cut off before sale to a customer (Guy

2005).

The processing of lumber after a deconstruction process takes approximately 0.008

labor hours per linear foot of lumber. Processing the lumber involves 3 steps: moving the

lumber from an original pile to the denailing station, denailing the boards using a

compressor and a denailing gun, and restacking the boards (Guy 2005).

Use/Reuse

The wood salvaged from deconstruction is ideally reused in new construction and

renovation projects; however, several barriers exist to making this practice a reality. The

largest barrier is the difficulty project managers and solid waste authorities have in

identifying markets for the debris. Another barrier is the accurate characterization of

C&D waste due to the high variability of the content and quantity of C&D waste. "This

variability is due to the nature of the waste, the dispersion of C&D activities, inconsistent

waste management regulations, range of disposal options, and the variance in cost of

disposal options (Dolan et al. 1999 58)." Damage is incurred on C&D waste as a result

of 1) the original construction process (nail hoes, bolt hoes, saw cuts, notches), 2)

building use (drying defects, decay and termite damage), and/or 3) the deconstruction

process (edge damage, end damage, end splitting, and gouges). The main reason for the

inconsistencies in reusable wood is damage during the deconstruction process (Falk and

Green 1999).

Joists, particularly those located on the first floor, decay more frequently than other

timbers because of their proximity to the ground. Water leakage causes the joists in

bathroom areas to decay most often (Falk et al. 1999). Larger timbers (such as support









columns) command a high price and are regularly recycled, whereas dimensional lumber

is not often reused (Falk and Green 1999).

There are several potential advantages of reusing recycled lumber. First, a

significant quantity of recycled lumber is derived from old-growth timber and may have a

tighter grain structure. Second, recycled lumber is relatively dry, with less tendency to

warp on the job site (Falk et al. 1999). Third, salvage yards sell recycled lumber at about

50% of retail lumber prices (Falk 2002).

Disposal

The Florida Administrative Code (FAC) allows the use of C&D debris facilities in

addition to Class I, II and III landfills. Rule 62-701.200 (25) defines C&D debris as:

* Discarded materials generally considered to be not soluble in water and non-

hazardous in nature, including but not limited to steel, glass, brick, concrete,

asphalt material, pipe, gypsum wallboard, and lumber, from the construction or

destruction of a structure as part of a construction or demolition project or from the

renovation of a structure, including such debris from construction of structures at a

site remote from the construction or demolition project site. The term includes

rocks, soils, tree remains, trees, and other vegetative matter (that normally result

from land clearing or land development operations for a construction project), clean

cardboard, paper, plastic, wood, and metal scraps from a construction project;

* Effective January 1, 1997, except as provided in Section 403.707(13)(j), F.S.,

unpainted, nontreated wood scraps from facilities manufacturing materials used for

construction of structures or their components and unpainted, non-treated wood

pallets provided the wood scraps and pallets are separated from other solid waste









where generated and the generator of such wood scraps or pallets implements

reasonable practices of the generating industry to minimize the commingling of

wood scraps or pallets with other solid waste; and

* De minimis amounts of other non-hazardous wastes that are generated at

construction or demolition projects, provided such amounts are consistent with best

management practices of the construction and demolition industries;

* Mixing of construction and demolition debris with other types of solid waste will

cause it to be classified as other than construction and demolition debris (FAC 62-

701.200).

Landfills are typed as Class I, II and III. Class I landfills receive an average of 20

tons or more of solid waste per day. Class II landfills receive an average of less than 20

tons of solid waste per day. Class I and II landfills receive general, non-hazardous

household, commercial, industrial and agricultural wastes, following Rules 62-701.300

and 62-701.520, F.A.C. C&D waste is disposed of in a Class III landfill. In rule 62-

701.200 of the Florida Administrative Code (FAC) Class III landfills are defined as those

that receive only yard trash, construction and demolition debris, waste tires, asbestos,

carpet, cardboard, paper, glass, plastic, furniture other than appliances, and any other

materials approved by the Florida Department of Environmental Protection (FDEP). Any

materials approved by the FDEP for disposal are not expected to produce leachate that

endangers public health or the environment. Putrescible household waste is not accepted

in Class III landfills.

Since Class III landfills do not receive MSW for disposal, they are not required to

be lined automatically. Special requirements for Class III landfills are contained in Rule









62-701.340(3)(d), F.A.C., which states that Class III landfills can be exempt from some

or all requirements for landfill liners, leachate controls and water quality monitoring it

that no significant threat to the environment will result from the exemption. The

language in this rule results in the need for a liner in a Class III landfill to be determined

on a case-by-case basis by each department district office. The determination of each

case will be made by the Department in a way that will protect both human health and the

environment (ICF 1995).

The average cost of disposal of C&D waste in Florida is $32.06/ton, ranging

anywhere from $5.00/ton in Okaloosa County to $92.00/ton in Monroe County (ICF

1995). This average cost of disposal is seemingly high, most likely because disposal

costs at private facilities, which are significantly lower, were not included.

Disadvantages of Unlined Landfills

Leachate is formed when water washes over garbage in landfills, soaks through the

landfilled material, and exits the other side carrying contaminants. The fate of hazardous

constituents in C&D materials, such as acrylic acid, styrene, vinyl toluene, nitrile and

copper (Table 2-2) may include leaching into nearby groundwater aquifers or

volatilization into the surrounding air. As a result, potential impacts of C&D waste

disposal in unlined landfills may include drinking water contamination and fire hazards.













Table 2-2. Amount of Chemical Constituents in Wood Products (Construction and
Demolition Waste Landfills 1995)
Wood Product Chemical Constituent Amount of Note
Chemical(s) in
Wood
Product
pallets and skids, pentachlorophenol < 10 ppm a
(hardwood/softwood) lindane dimethylphthalate
copper-8-quinolinolate
copper naphthenate
pallets, plywood phenolic resins 2-4% a
pallets, glued epoxy 2-4%
painted wood, lead-based paint lead 1400-20,000 ppm b
(before 1950)
painted wood, acrylic-based acrylic acid, styrene, vinyl
paint toluene, < 0.01%
nitriiles
painted wood, "metallic" aluminum powder, copper
pigments acetate, < 0.01%
phenyl mercuric acetate, zinc
chromate, titanium dioxide,
copper ferrocyanide
plywood, interior grade urea formaldehyde (UF) resins 2-4% c
plywood, exterior grade phenol formaldehyde (PF) resins 2-4% c
oriented strandboard phenol formaldehyde resins, or 2-4%
PF/isocynate resins
waterboard urea formaldehyde resins, or 5-15% UF d
"Aspenite phenolic resins 2.5% PF, 2% wax













Table 2-2. continued
4-8%,
overlay panels phenol formaldehyde resins sometimes
up to 10%
plywood/PVC laminate urea fomaldehyde 2.5% UF
polyvinyl chloride 10% PVC
particleboard urea formaldehyde resins 5-15% UF d
UF resins with polyvinyl
particleboard with PVC laminate chloride 4.5%UF
10% PVC
hardboard phenolic resins 1.50%
fencing and decks: pressure CCA or ACA 1-3% e
treated southern pine CCA or ACA 1-3% e
fencing and decks: surface
treated pentachlorophenol 1.2-1.5% f
utility poles, laminated
beams,
freshwater pilings, bridge
timbers,
decking, fencing
creosote containing
railroad ties, utility poles 85% PAHs 14-20% g
freshwater pilings, docks creosote coal tar 15-20%
marine pilings, docks creosote/chlorpyrifos 15-20%
a. Hardwood pallets are used primarily in the eastern U.S.; softwood and plywood pallets are used
primarily in the western U.S.
b. Lead level is highly dependent on the age of the paint; before 1950 lead comprised as much as
50% of the paint film. Legislation in 1976 reduced the standard to 0.06% by weight.
c. Plywood may be surface-coated with fire retardants, preservatives and insecticides, or pressure-
treated with CCA.
d. May be sealed with polyurethane or other sealant to prevent off gassing of formaldehyde.
e. Dominant wood preservative; actual levels will be lower due to evaporation or leaching after
treatment.
f. Restricted use due to industry change and concern over dioxin linkage; not permitted
for residential uses.
g. Losses after treatment estimated to be 20-50% over 10-25 years; not recommended for
residential use.











Costs of Deconstruction Verses Demolition

When well-trained crews are employed for the deconstruction of buildings,

deconstruction is very competitive with demolition because deconstruction companies are

relatively inexpensive to start and multiple streams of revenue occurring during each

deconstruction job. These revenue streams are the job contract, reduced tipping fees, a

percentage of the resale of materials, and tax deductions for the donation of materials to

nonprofit organizations. The most successful deconstruction companies either own or

partner with a retail yard that sells salvaged materials (high-value architectural pieces,

dimensional lumber, windows, doors, hardware, and more) at affordable, but profitable

prices (Mcphee 2002). A well-trained deconstruction team can contend with the price of

mechanical demolition. For example in Hartford, Connecticut, deconstruction teams

deconstructed a building at a cost of $2/square foot this was a 33 percent savings over

mechanical demolition. Also deconstruction projects can reduce tipping costs by as

much as 50 to 85 percent (Mcphee 2002).

Due to the decreased amount of available landfill space and the increasing costs of

managing landfill tipping fees, recycling C&D waste not only recovers valuable

resources, it saves money. Because of these changes in cost, C&D waste recovery and

reuse of waste is becoming economically feasible (Dolan et al. 1999).

The cost of buying these recycled materials on the market depends on the cost of

storage, collection, transportation, and other costs for the processor. The most important

driving force of cost is the demand for these materials. This depends on short-term

demand for and availability of virgin material. The scarcer a resource is, the higher the









resale cost and thus the more feasible deconstruction will be considered. There are at

least six key factors that drive the supply, demand, and pricing of recycled materials:

1. Export markets. The Far East, where fiber is in short supply, represents a

particularly strong export market for recycled materials.

2. Virgin capacities and recycled capacities. When the price and availability of virgin

commodities change, the price and availability of recycled commodities follow.

3. Geography. A West Coast generator with access to markets in the Pacific Rim has

different marketing opportunities than a generator in the Midwest.

4. Transportation costs. The distance to market plays a role in the pricing of all

commodities, whether recycled or virgin.

5. Endproduct demand. Recycled materials serve three key sectors of the economy:

automobiles, housing and retail. When the auto industry booms, so do the steel and

plastic industries. When housing booms, business increases for suppliers of steel,

paper, plastic and other virgin and recycled materials. Likewise, when retail sales

climb, so do paper and plastic packaging material sales.

6. Natural disasters around the world. When a community begins to rebuild after a

natural disaster, demand for recycled materials in all areas of the world spike

(Dolan et al. 1999).

To reduce the uncertainty associated with recycling/reusing the materials gathered

from large-scale or long-term projects, an explicit commitment among the general

contractor or project manager, hauler and market should be established (Dolan et al.

1999). This will ensure a market for the materials and guarantee that the deconstruction

is worth the extra time and effort.









The most critical component for reuse of C&D waste is the identification of a

market for the waste material. Once a market is found to exist, the material becomes a

commodity not a waste. For reuse of materials to be economically successful, there must

be a stable, profitable market. The Solid Waste Association of North America (SWANA)

suggests that, to have a market for the C&D waste, there are five requirements that must

be met and agreed upon by both the buyer and the seller: (1) specifications, (2) quantity,

(3) delivery conditions, (4) price, and (5) commitment (Dolan et al. 1999).

For most Army facilities, an extensive C&D waste reuse operation will require a

large investment of both time and money. Denison and Ruston (1990) listed factors that

should be considered by solid waste and project managers before beginning any type of a

reuse operation to ensure that the reuse project is both financially and technically

feasible:

1. quantity of waste generated

2. composition of the waste

3. materials targeted for recycling and the methods of recovery

4. expected value

5. necessary additional processing required to prepare the recovered materials for the

market

6. costs of recycling, handling, collecting, and processing

7. financial and logistical risks and uncertainties

8. availability of markets for recovered materials, current market prices, price

instability, and the potential effect of market development programs (Dolan et al.

1999).









Army Technical Manual Rule 5-634 states that the added costs (increased time,

effort, and equipment) plus the sales revenue of a recycling program will determine its

economic feasibility (TM 5-634, p 4-79). If the added costs exceed the avoided costs

plus revenue, the operation should not be performed (Dolan et al. 1999).

Many contractors are doubtful of the time and cost effectiveness of deconstruction,

thus hampering its general acceptance. When savings in disposal costs and the resale

value of building materials are considered, deconstruction becomes more attractive. An

even more appealing aspect of salvage and deconstruction is the environmental benefits,

including reduction of waste materials which may be incinerated or landfilled. This may

improve air and water quality and will reduce landfill use. Also sometimes lumber

recovered from deconstruction projects is vintage or priceless. Building materials yards

may have old growth timbers, architectural trimmings and antique doorknob (Yeung and

David 1998). Salvageable materials include plywood, lumber, hardwood flooring, bricks,

windows, concrete, plumbing fixtures, doors and knobs, hinges, paneling, insulation,

stairs and railings, asphalt roof tiles, moldings and baseboards and countertops. The

recycling of building materials gives its greatest benefit to the consumer, who purchases

the material at incredibly low prices (Yeung and David 1998).

The following equation can be used to determine the net deconstruction cost:

(Deconstruction + Disposal + Processing) (Contract Price + Salvage Value) = Net

Deconstruction Costs. The net cost for demolition use is calculated by the equation

(Demolition + Disposal) (Contract Price) = Net Demolition Costs. When the salvaged

materials are not resold or redistributed on-site or reused by the deconstruction contractor

in new construction, transportation and storage costs may be additional costs for









deconstruction. For deconstruction to be cost effective and competitive with traditional

demolition and disposal the sum of the savings from disposal, revenues from resale of

materials must be greater than the incremental increase in labor costs. To increase the

percentage of time spent in deconstruction activity and decrease overall time costs, a

building's materials should be deemed worth salvaging and with efficient resale

mechanisms and markets. Removing and reselling materials as quickly as possible can

overcome the disincentive for deconstruction created by the time costs of development

and building loans. Deconstruction is also more cost effective when the site is large

allowing the unwanted structure to be isolated from the other construction activity and be

deconstructed without delaying the site development. On the other hand when the new

construction will take place on the footprint of the existing structure, the time for removal

of the existing structure by deconstruction is a significant economic impediment (Guy

2001).














CHAPTER 3
LIFE CYCLE ANALYSIS

Abstract

Nearly 2.5 million ft2 of barracks must be removed from military facilities

throughout the U.S. Environmental Protection Agency Region 4. While manual

deconstruction offers promise for environmental, economic, and social benefits, the

combination of mechanical and manual methods for minimal impact to the environment

and public health is unknown. Here, life cycle analysis was used to determine an

optimum level of manual deconstruction of barracks at Ft. McClellan in Anniston,

Alabama. Four scenarios were compared with varying degree of time required for

manual deconstruction, 100% Manual, 44% Manual, 26% Manual, and 100%

Mechanical, on the barracks. Data were collected directly from the site and applied using

SimaPro modeling software (Pre Associates, The Netherlands), considering three post-

deconstruction options. Materials salvaged using either 100% or 44% Manual

deconstruction and reused within a 20-mile radius of the deconstruction site yielded the

most favorable environmental and health impacts; however, given the significant impacts

involved in the life cycle of diesel fuel required for transportation, the need for

developing reuse strategies for deconstructed materials at the regional level is

emphasized.









Introduction

Each year, the building industry in the United States is reported to generate nearly

136 million tons of construction and demolition (C&D) waste, amounting to 35-40

percent of the total amount of municipal solid waste (MSW) produced annually (Dolan et

al. 1999). Approximately 60 percent of this C&D waste originates from the demolition

of buildings, and 80-90 percent is estimated to be either reusable or recyclable (McPhee

2002). While reuse and recycle of C&D-related waste offers potential environmental

advantages, the building and deconstruction industry has not fully embraced these

practices (Lippiatt 1998).

There are two different methods for the removal of buildings-deconstruction and

demolition-and the method used greatly influences the amount of salvaged (reusable)

material gained. Demolition, the most often used means of building removal, is

equipment-intensive, requiring machinery throughout the process for leveling the

building and separating the larger materials. Because most of the labor involves

machinery operation, the crew has very little physical contact with the actual building

materials (Falk and Lantz 1996). Deconstruction, on the other hand, involves the

methodical disassembly of buildings in order to reuse or recycle as many of the

component parts of the building as possible, before or instead of demolition (McPhee

2002). Deconstruction can involve hand labor only and always involves actual physical

contact with the building by the workers, thus resulting in time requirements that are

approximately twice that of demolition (Falk and Lantz 1996).

The additional time burden and perception of associated increased costs

accompanying deconstruction have hampered its practice. Another potential drawback of

deconstruction is the need to tend to a greater level of detail at every stage of the removal









process. For example, increased planning is required in order to assess the type and

amount of materials that can potentially be salvaged. The actual deconstruction phase

must involve greater oversight of the labor, while recovered materials must be stored and

protected on site before removal to their final destination. Also, most of the salvaged

lumber can only be used for non-structural applications, such as in decks and non-

supporting walls, unless the materials are re-graded (Falk et al. 1999). In order to

minimize the time and cost burdens of deconstruction while still ensuring gain of

salvaged materials, this practice can be combined with demolition. However, the degree

at which this combination of building removal practices becomes economically and

environmentally beneficial is not known.

This work presents results of a case study performed on military barracks at Ft.

McClellan in Anniston, Alabama, for the purpose of determining the benefits of

combining deconstruction and demolition. Military buildings in need of removal

throughout the U.S. offer tremendous potential for materials recovery and reuse. The

U.S. Department of Defense (DOD) has 2,357,094 square feet of excess buildings that

are in need of removal from military bases throughout U.S. EPA Region 4 alone,

encompassing the states of Alabama, Florida, Georgia, Kentucky, Mississippi, North

Carolina, South Carolina and Tennessee (Falk et al. 1999). The U.S. military is disposing

of these barracks because the federal procurement law and military regulations listed

under the U.S. Code of Federal Regulations (CFR 32 162.2) will not allow federal tax

dollars to be spent on the maintenance of facilities that are in surplus of its needs (Falk et

al. 1999, CFR 2004). In response to these regulations, the U.S. Army is considering

deconstruction of its barracks and salvaging of materials in order to accomplish its









minimization goals and subsidize the overall disposal costs of the buildings, thus

lowering funding requirements (Falk et al. 1999). However, there is a question as to

whether 100% manual deconstruction of military barracks will yield optimum economic

and environmental savings, particularly for those barracks built before World War II.

This project, funded by the U.S. DOD, sought to determine the optimum levels of

manual deconstruction and mechanical demolition of pre-World War II barracks using a

life cycle approach. Life cycle analysis (LCA) is a method that enables quantification of

the environmental and public health impacts of an activity or product throughout its

entire life. This "cradle-to-grave" approach is based on the knowledge that each stage in

a product's life has potential to contribute to its environmental impacts. Considering a

building's life cycle, these stages include raw material extraction and processing, material

manufacture (e.g., wood harvesting and milling), transportation, installation (e.g.,

construction), operation and maintenance, and, ultimately, recycling and waste

management (e.g., salvaging of materials for recycling or reuse) (Lippiatt 1998).

The focus of this paper is the life cycle comparison of four identical World War II-

era barracks. Data were carefully collected from a previous study on three Ft. McClellan

barracks, deconstructed using different methods of manual effort that were accompanied

by different time requirements for manual involvement. The specific emissions and

resulting environmental impacts and cost savings or burdens of the three scenarios are

compared to traditional mechanical demolition using LCA methods and are reported

herein.









Methods

Description of Fort McClellan Barracks

U.S. Army facility, Ft. McClellan, in Anniston, Alabama, was established in 1917,

with a primary mission of training for combat, a service it fulfilled during World War I,

World War II, and the Vietnam War. This facility was also the home of the Women's

Army Corps School, the U.S. Army Chemical Center and School, the Military Police

School, and the Training Brigade. The base was decommissioned in 1995; and, upon its

official closing on May 20, 1999, it occupied 45,679 acres of land with 100 barracks of

approximately 415 m2 each in need of removal (Fort McClellan 2005). Figure 3-1 shows

a typical row of barracks at Ft. McClellan. They are identical, two-story, wood-frame,

World War II-era barracks similar in typology and construction to thousands of older

barracks found on military installations throughout the United States.

The barracks in the U.S. EPA Region 4 were typically built with Southern yellow

pine, a strong wood readily available in the Southeast and considered salvageable. Other

components with potential resale value in the barracks include showers, urinals, toilets,

windows, doors, electrical wiring, lighting, emergency exit signs, a brick fireplace, and

the metals associated with the air conditioning ducts and the large structural support

columns. The metals were removed by hand before the demolition of the building, and it

was found that the structural support columns were salvageable under careful demolition

practices.

The Deconstruction Process and Four Scenarios Studied

The deconstruction and demolition of the barracks were conducted from April-June

of 2003. Personnel involved in this project participated in either a deconstruction team or

an LCA team. The deconstruction team was responsible for hiring a dismantling









contractor, coordinating the dismantling of each barrack in a systematic approach, and

collecting data during the deconstruction process. With the aid of Costello Dismantling

Co., Inc. (Boston, MA, USA), contracted in the early stages of the project, the

deconstruction team carefully documented in 15-minute intervals at the deconstruction

site the following information: type and amount of material salvaged or disposed, method

of material removal (manual or mechanical), time required to salvage and/or demolish,

time required for machine operation, total labor time and transportation requirements, as

previously described in detail (Guy and Williams, 2004). The LCA team transferred the

data collected from the site and applied these data to the modeling efforts.

As stated previously, the primary goal of this project was to assess the optimum

combination of manual and mechanical methods of barracks removal, as measured by

minimum environmental/public health life cycle impacts. To this end, four scenarios

were designed and compared. The first scenario involved removal of one barrack using

entirely manual deconstruction (labeled as "100% Manual"). The second and third

scenarios involved manual deconstruction only 44% and 26% of the total time required

for removal, respectively, with the remainder of the time involving traditional mechanical

methods. These two scenarios are labeled henceforth as "44% Manual" and "26%

Manual," respectively. The fourth scenario involved removing a barrack using only

mechanical methods of demolition, as traditionally used, and this scenario is denoted as

"100% Mechanical." The percentages of time used for mechanical demolition and

manual deconstruction were determined by dividing the total time required for building

removal into the total time required for machine operation and/or labor.









Life Cycle Analysis

All data collected from the deconstruction phase were carefully databased for use in

the life cycle analysis (LCA) modeling that followed ISO 14000 guidelines (Guinee et.

al., 2002). The ultimate objective of the LCA effort was to guide the Department of

Defense (DOD) in the best management practices for removing the WWII-era barracks

that remain in EPA Region 4. The scenario yielding lowest environmental impacts would

be considered the most preferable option in this study. The development of the LCA

model and its relevant stages are discussed in more detail below.

Functional Unit

The four scenarios were compared using a functional unit of "per square foot of

barracks." This functional unit allowed comparison of inputs and outputs and the

ultimate impacts from each scenario. All results presented herein are based on this

functional unit.

Scope and Goal Definition

The relevant stages included in this LCA are the deconstruction/demolition process,

representing "raw material extraction"; disposal of materials by landfilling; transportation

between the stages; and recycling and reuse of salvaged materials by replacing virgin

materials.

Figure 3-2

Figure 3-2 shows these stages divided into individual steps, starting with

preparation for deconstruction by transportation of equipment and labor to the site and

removing asbestos (Steps la and 1) and hazardous waste (Step 2). Each rectangle (Steps

1, 2, 5, 13-16) represents an activity that is involved in preparation for demolition of the

barracks, preparation of salvaged materials for reuse, and the processes in the outer









avoided virgin wood production loop. Each oval (Steps 3, 4, 6-12) represents a part of

the barrack disposed of in the landfill or salvaged for reuse. Time requirements for each

relevant step under each scenario were collected at the site for subsequent LCA

development. The only steps shown in Figure 3-2 relevant to the 100% Mechanical

scenario are transportation of labor and equipment to the site, asbestos and hazardous

waste removal and transportation to disposal sites (Steps 1, la, lb, 2 and 2a), whereas all

subsequent steps apply only to the other three scenarios.

Figures 3-3 and 3-4

In this LCA, three options were considered for salvaged material. The first option

was performed from the perspective of savings in landfill volume requirements and

reduction of leachate production that occurred when materials were salvaged. No reuse

of salvaged materials was considered in this first option and represents a case where no

reuse options are available. The second option was also performed from the perspective

of savings in landfill volume requirements and reduction of leachate that was produced

when materials were salvaged. However, this option also included the reuse of the

materials by transporting them to a local storage facility within 20 miles of the

deconstruction site for their reuse or recycle, thus assessing impacts of a regional market

for these materials. The third option considered reuse and recycle of the salvaged

materials beyond the deconstruction and landfill sites by incorporating transportation to

the Habitat for Humanity (HfH) warehouse in Austin, TX, thus assessing impacts of a

national market for these materials. For both the second and third options, if use of the

salvaged material avoided the production and preparation of the virgin wood that it

replaced, then the avoided virgin wood production loop (Steps 13a-16) and the recycling

of MEP materials (Step 5a) were involved.









Data Inventory

Both primary (derived directly from the deconstructed and demolished barracks)

and secondary (derived from literature and regulatory agency publications and databases)

data were collected and databased in LCA software, SimaPro 5.1 (PRe Consultants,

Ameersfort, The Netherlands). SimaPro contains inventory data that has already been

gathered for common products and processes in databases created by ETH-ESU (Uster,

Switzerland), Buwal 250 (Bern, Switzerland), and Franklin Associates (Prairie Village,

Kansas, USA), among others (Goedkoop and Oele 2001). As previously described, the

primary data collected included the amounts of hazardous, salvaged, recycled and

landfilled materials, the amount of time each piece of equipment was used, the number of

workers, and the worker labor time. In addition, the weights of salvaged and landfilled

materials were found by weighing the hauling trucks before and after filling. The

secondary data included types of equipment and materials used (site-specific for project),

fuel type and requirements of each piece of equipment (JLG 2004, Bobcat 2004,

Caterpillar 2004, Grove 2004, Homelite 2004, Stihl 2004, DeWalt 2004), amount and

composition of leachate from all deconstruction materials (Jamback 2004), equipment

usage for production of virgin wood in the forest and at the sawmill (Long 2003),

emissions for production of bricks used in the barracks construction (EPA 1997),

recycling and producing steel (EPA 1986), diesel and gasoline fuel combustion emissions

(EPA 1995), data for the production of diesel fuel and gasoline (EPA 1995) and for the

U.S. electricity mix (SimaPro 5.1). The LCA compared the inputs and outputs of each

alternative scenario in terms of emissions, the value of the material, and requirements of

dollars, energy, and labor.









Impact Assessment

While a number of weightings schema used in LCA impact assessment have been

developed and are available to LCA practitioners, the need for an increased

understanding of how these metrics are developed, their uncertainty and variability, and

potential limitations and benefits of their application has been recently identified

(Thomas et al. 2003). In this study, two methods, Centrum Voor Milieukunde Leiden

(CML) and Environmental Design of Industrial Products (EDIP), were chosen for

calculation of the relative impacts of Global Warming, Ozone Depletion, Acidification,

Eutrophication, Human Toxicity, and Ecotoxicity (Guinee and Heijungs 1993; Goedkoop

et al. 1998; Goedkoop and Spriensma 1999; CML 2001; Goedkoop and Oele 2001).

Each method, included in the SimaPro software, uses a different approach for calculating

impacts but consider similar contributing factors for each impact. Comparing the results

of these two approaches will enable determination of the reliability of the observed

trends. A detailed description of these methods can be obtained in Sivaraman and

Lindner (2004).

Assumptions and Limitations

The following is a list of assumptions made throughout this assessment to enable

comparison of the four scenarios:

1. Each barrack contains the same quantity of hazardous material, asbestos, and wood

coated with lead-based paint that must be disposed; therefore, these emissions were

not accounted for in the LCA.

2. Transportation: Note that all assumptions of distances traveled were considered for

their effect on the results in the sensitivity analysis.









3. The workers made a 20-mile roundtrip to and from work each day in a 1995 model

midsize car. Each worker drove his/her own car; however, carpooling was

considered for its effect on the results in the sensitivity analysis. A 20-mile

distance served as a worst-case scenario because this represents approximately

twice the distance most workers travel to work (Khattak et. al. 2005, Demographia

2005).

4. Equipment was transported to the site on a flat bed truck from within a 20-mile

radius. Because this distance varies for every site, this mileage was tested in the

sensitivity analysis (transport distance).

5. A 30-mile distance for transport of equipment to and from the site of harvesting

was assumed (Long 2003), and harvested wood was assumed to be transported 60

miles to the sawmill (Long 2003). A transport distance of finished lumber of 100

miles was assumed to exist from the sawmill to the construction site for virgin

wood (Long 2003).

6. Salvaged wood was transported 80 miles from the deconstruction site to the new

construction site. While a 500-mile radius is considered to be a cutoff point for

environmental savings for delivery of materials to a construction site, this lower

value was assumed to ensure that the expense of transporting and buying the

salvaged material does not exceed that of the virgin materials (Smith 2003).

7. Except for small equipment (chainsaws, chopsaws, and weedeaters), each piece of

equipment used at the barracks site required a separate flat bed truck for hauling.

8. The capacity of each truck was at least capable of handling 5,500 lbs of wood,

equal to a cord of wood.









9. Other than the use stage, the life cycle stages of the machinery used throughout the

deconstruction or demolition process were not considered.

10. Sources of emissions included from the creation of virgin timber were harvesting,

transporting the wood, milling the wood, and transporting the lumber to the

construction site.

11. The data collected at the barracks in Ft. McClellan are applicable to all other

barracks within U.S. EPA Region 4.

12. Methods for asbestos abatement and lead assessment are the same whether for

demolition or deconstruction. The wood deposited into the landfill was untreated

chemically, but most of it was painted with lead-based paint. Wood coated with

lead-based paint produces lead-contaminated leachate; however; the effects of this

wood were not accounted for in the leachate because there was the same amount in

each barrack. Because the landfill is unlined, the leachate from all other materials

contained within the barracks was accounted for using data reported in Jamback

and Townsend (2004), the only available resource for this type of data.

13. The source of electricity was assumed to be the average U.S. mixture of 56% coal,

21% nuclear, 10% hydropower, 10% natural gas, and 3% crude oil. The safety

concerns of spent nuclear fuel were not considered.

Sensitivity Analysis

Assumptions and variables that were tested for their sensitivity to model impacts

included the time spent to both deconstruct and demolish the barracks, the distances the

workers traveled, the distances the materials and machinery were transported, the

recycling of the steel, and the time requirements for preparation of the materials for reuse.









Results and Discussion

Data Inventory

Time Requirements for Removal of Barrack Components

As shown in Table 3-1, each of the barrack components was partitioned into broad

categories of windows and doors, interior partitions, hazardous waste (composed

primarily of mercury thermostat switches, lead-acid batteries in exit lights and emergency

light fixtures, fluorescent tubes and ballasts), mechanical, electrical and plumbing (MEP)

materials (including sinks, toilets, showers, light fixtures, wiring and conduit, ducts, and

air handlers), interior finishes and framing, roof, walls and floors, and foundation. The

time required to remove each building component following the relevant set of steps

conducted in each scenario is also provided in Table 3-1. Asterisks in Table 3-1 denote

all components that were removed involving some degree of mechanical methods.

Removal of hazardous materials (fluorescent lights and exit signs) and the

foundation of each of the barracks, mechanically performed in all scenarios, required the

same amount of time (5.0 and 3.3 hrs, respectively). Removal of windows and doors,

interior partitions, and MEP materials required the same amount of time for the three

scenarios that involved hand deconstruction (100% Manual, 44% Manual, and 26%

Manual) but a significantly lower time for the 100% Mechanical scenario. The windows

and door frames coated with lead-based paint and the MEP materials were manually

removed from the barracks involving hand deconstruction. The wood containing lead-

based paint was not considered hazardous waste because of the low concentrations of the

paint, and, therefore, it was disposed of in a C&D landfill. The windows and door frames

from the 100% mechanically demolished barrack were disposed of thus yielding no time

requirement, whereas the time for removing MEP materials under this scenario was lower









than the other three because only the light fixtures, electrical wiring and conduits were

removed before the demolition of the building. The 3.1 hours required to remove interior

partitions from the 100% mechanically demolished barrack involved recovery of the

large support columns only.

The same amount of time was needed for the salvaging of the interior finishes and

framing for the 100% Manual and the 44% Manual scenarios but a decreased amount of

time was needed in the 26% Manual scenario. This decreased time is explained by the

fact that the columns and wall studs were cut using chainsaws to speed the process of

deconstruction and so that the second story floor could be dropped onto the first story

floor for deconstruction.

As shown in Table 3-1, less time was required for removal of the roof, walls and

floors of the barracks with increasing use of mechanical methods. This is true with the

exception of the removal of the second story floor. The removal of the second story floor

took longer in the 26% manual scenario than in the 44% manual scenario although it still

took less time than the 100% manual scenario. In the 44% Manual scenario, the second-

story floor was cut into ten-by-ten foot pieces and dismantled on the ground, whereas the

second-story floor in the barrack subjected to 26% Manual methods was dropped onto the

first-story floor and dismantled. The two different methods of removal for the second

story floor in the 26% and 44% manual scenarios were experimental to determine the

fastest way to deconstruct the second story floor. It was found that it is faster to remove

the second story floor in ten-by-ten foot pieces because it is easier to remove the wood

when it is in smaller pieces. The time for the removal of the first- story wall also varied

greatly between the 44% Manual and 26% Manual scenarios. The former, involving









manual removal of sheathing and siding, required approximately 62 hours, and the latter,

involving cutting at the floor base and direct disposal in a dumpster for ultimate

landfilling, required approximately 9 hours. For more information on the methods used

to deconstruct and demolish the barracks and the time differences for the removal of the

different components of the building please refer to Guy and Williams (2004).

Labor and Machine Time and Mileage Requirements and Material Yields

Table 3-2 presents the total labor and machine time and transportation requirements

for the material yields from each of the four scenarios. As expected, the scenario

involving all manual deconstruction demanded the greatest number of work days and

mileage requirements of the work crew, 17.7 days and 2160 miles, respectively,

compared to the range of 12.7 to 1.5 days and 1440 to 120 miles for the other scenarios,

decreasing with less manual deconstruction. Interestingly, the time requirement for

machine operation and mileage requirements for delivery of machinery were maximum

in the 44% Manual scenario (277.8 hrs, 140 miles, respectively) because an additional

piece of equipment, a crane, was used in this scenario to lift the roof off the building so

that the salvageable pieces of the roof could be saved while the rest of the building was

demolished. It is important to note that machines were necessary in the 100% Manual

scenario for collection, movement and cleaning of materials.

The 100% mechanical demolition scenario required the least amount of transport

mileage of equipment and machine hours because only two pieces of equipment were

involved, the Bobcat T200 Turbo (Bobcat, West Fargo, ND) and Caterpillar 320C

excavator (Caterpillar, Inc. Pleasanton, CA), to simply topple the building with no

manual removal processes. Also, unlike the three scenarios with manual involvement

where materials were separated and moved to various locations on site, the 100%









Mechanical scenario resulted in materials transferred directly to an on-site dumpster for

subsequent disposal.

The amount of recycled material was the same for each barrack that used hand

deconstruction (Table 3-2). In 100% mechanical demolition, the building was knocked

down and put in the C&D landfill without removing the recyclable steel. As anticipated,

the yield of salvageable material decreased with diminishing levels of manual labor. The

weight of salvaged material ranged from 2,552 lbs from the barrack that was entirely

mechanically deconstructed to 59,089 lbs from the entirely manually deconstructed

barrack. The barrack that was mechanically deconstructed yielded salvaged material in

the form of large wood columns, the foundation of the building and plumbing and

electrical fixtures. This is a total of 2,552 lbs of salvaged wood, which is 1.8% of the

total weight of the building. Additional components salvaged with manual methods

included non-damaged wood, showers, urinals, toilets, air conditioning ducts, and some

of the bricks from the chimney (if clean of mortar).

The amount of hazardous material (141 lbs) was the same for each barrack, as each

barrack contained the same components, including primarily mercury thermostat

switches, lead-acid batteries in exit lights and emergency light fixtures, fluorescent tubes

and ballasts. As salvaged material yields increased, the amount of material sent to the

landfill decreased. Therefore, as also anticipated, the amount oflandfilled material

decreased with increasing manual labor rates. The amount of material landfilled ranged

from 140,055 lbs for 100% mechanical demolition to 82,486 lbs for 100% manual

deconstruction.









Fuel and Electricity Requirements

The hourly fuel and electricity requirements for transportation of the labor force

and machinery and for the operation of each of the machines are provided in Table 3-3,

along with the relevant stages of their involvement, previously introduced in Figure 3-2.

Seven different pieces of machinery that were used during the deconstruction and

demolition of the military barracks are also listed in Table 3-3. Each of these pieces of

equipment was used for a different purpose and for varying amounts of time depending

on the scenario. The JLG Lift 600S (JLG Industries, Inc., McConnellsburg, PA) was

used to raise the workers above the roof in order to cut and remove panelized sections in

the 100% Manual and 26% Manual scenarios. The Bobcat T200 Turbo was used to move

the loose salvaged material and floor panels to the designated places for pick up and

disposal in all 4 scenarios. The Caterpillar 320C (excavator) was used to knock down the

100% mechanically demolished building and to push over the building in the 26%

Manual scenario. In all the other scenarios, the Caterpillar excavator was used to pick up

the floor panels from the second floor and flip over the first floor panels. The Crane

Grove TMS 760E (Grove, Pensacola, FL) was used for the removal of the roof in the

44% Manual scenario. The Homelite Chainsaw (Homelite, Port Chester, NY) and Stihl

Chopsaw (Stihl Inc., Jacksonville, FL) were used to cut the roof into panelized sections

either on the ground or in the air with the help of the JLG Lift 600S. The chopsaw was

also used to cut the first and second floor panels in the Manual scenarios. The chainsaw

was used to cut the roof rafter for roof panelizations, the second floor joists and beams

for panelization, and the columns and wall studs in the 26% Manual scenario so that the

second floor could be dropped onto the first floor and dismantled there. The DeWalt









DG7000E (generator) (DeWalt Industrial Tool Company, Baltimore, MD) was used to

remove nails and paint from the salvaged wood with attached tools in all four scenarios.

The 100% Manual scenario required operation of the lift, bobcat, excavator and

chopsaw for 4, 4, 0.5 and 3 total hours, respectively (data not shown). The same

equipment was used in the 26% Manual scenario, requiring increased times for use of the

lift, bobcat, excavator and chopsaw of 5, 1, 6 and 7 hours, respectively. In the 44%

Manual scenario, the lift, bobcat, and excavator were also used in addition to the

chainsaw and crane (for a total of 6, 9.5, 1, 3, and 4.5 hours, respectively). Only the

bobcat and excavator were required in the 100% Mechanical scenario, both used for 2

hours total. As shown in Table 3-3, the chopsaw, chainsaw, and generator required

gasoline (0.20, 0.12, and 0.63 gallons/hr, respectively) (Stihl 2004, Homelite 2004,

DeWalt 2004), whereas the other equipment required diesel fuel in larger volumes

(ranging from 2.50 to 8.10 gallons/hr) (Bobcat 2004, Caterpillar 2004, Grove 2004, JLG

2004).

The fuel and electricity requirements for harvesting and processing virgin wood are

also provided in Table 3-3. The primary equipment pieces involved in harvesting of

wood are feller bunchers, rubber-tired skidders, and log loaders. The 29 gallons of diesel

fuel used during the transportation of this equipment to and from the forest was

overwhelmingly greater than in-use fuel consumption. In fact, the consumption during

transportation of the equipment to the forest for harvesting was greater than any of the

other diesel fuel consumption requirements incurred during transportation, including

transport of the downed trees to the sawmill, of the lumber to the construction site, of the

recycled steel to the recycling facility, and of the waste materials to the landfill.









Electricity requirements for sawmill operation (6.2E-03 kWh per pound of wood) and

recycling of steel (2.1 kWh per pound of recycled steel) were also accounted for, as

shown in Table 3-3. It is important to note that, for every pound of salvaged wood, one

pound of virgin wood is avoided. Thus, the values provided in Table 3-3 represent

"savings" in relation to using all virgin materials in reconstruction applications, and their

resulting emissions will be considered as "emissions savings" rather than contributions.

Emissions

Tables 3-4, 3-5, 3-6 and 3-7 show the primary environmental emissions that result

from each of the four scenarios per square foot of barrack. The emissions shown in these

tables represent the second option where material salvaged is reused or recycled within

20 miles of the deconstruction site. Emissions from the other two options-no salvaging

or reuse and transportation of all reusable materials to Austin, TX-are considered in the

discussion of impact analysis results below. While the SimaPro modeling software

included hundreds of emissions from the included life cycle stages, only those in highest

quantity and/or risk to the public and environment were considered. These emissions

have been broken down into four categories-criteria pollutants, greenhouse gases,

metals, and miscellaneous chemicals-which have been further separated by life cycle

stage, during salvaging of material (Stage 13 in Figure 3-2), disposal (Stages lb, 2a and

the waste from stages 3-12), use of equipment during deconstruction (Stages 3, 4 and 6-

12), and transport of equipment and labor to and from the site (Stage la). The emissions

with negative values in Tables 3-4, 3-5, 3-6 and 3-7 represent savings as a result of

replacing virgin materials with salvaged materials.

The most highly emitted species from all four scenarios were carbon monoxide

(CO), carbon dioxide (C02), volatile organic compounds (VOCs), nitrogen oxides (NOx),









and methane (CH4). The remaining chemical emissions, dioxin, arsenic, lead, and

mercury, are listed in the tables because of their known toxicity. Total CO2 and CH4

emissions increased and VOC and CO emissions decreased with decreasing degree of

manual involvement. Despite small increases in emissions of CO from the disposal

stages from the 100% Manual to the 100% Mechanical scenario, the decrease in CO and

VOC emissions from equipment (resulting from decreasing use of the generator used to

clean salvaged materials) and transportation (resulting from the decreasing transportation

mileage from the commute to/from the site by the labor) overwhelmingly influence the

total CO and VOC values. As expected, the C&D landfill contributed the largest

emissions of CO2 and CH4 regardless of the scenario, and the increases in materials

disposed of in the landfill resulted in an increase in these emissions with decreasing

degree of manual involvement. Also, emissions of arsenic, lead, and mercury in leachate

from the landfill increased as manual involvement in the deconstruction decreased

because the amount of materials that are landfilled increased. These metals in particular

leach from the wood and the joists (Tables 3-4 3-7).

Total emissions of NOx are highest in the 100% Mechanical scenario (87.7 g/ft2

barrack, Table 3-7) and lowest in the 44% Manual scenario (46.9 g/ft2 barrack, Table 3-

5), with total emissions from the 100% Manual and 26% Manual scenarios (74.6 and 49.5

g/ft2) falling in between these values. The lower emissions of NOx as the amount of

manual involvement in the manual deconstruction scenarios decreased can be explained

by the decreased usage of cars for transportation of workers. The number of days the

workers drove to the site decreased as fewer manual methods were used which, in turn,

decreased the NOx production from the combustion of the gasoline. The 100%









Mechanical scenario yielded the highest NOx emissions because the steel was not

recycled. The recycling of steel produced negative emissions of NOx (emissions savings)

for the manual deconstruction scenarios, thus allowing 100% manual deconstruction to

yield lower NOx emissions than 100% mechanical demolition.

Impact Analysis

An impact assessment was performed on each of the four scenarios to determine

their effects on Global Warming, Ozone Depletion, Acidification, Eutrophication, Human

Toxicity, and Ecotoxicity. As stated earlier two published impact assessment methods,

CML and EDIP, were used for this LCA to compare and contrast the results of three

hypothetical cases-1) where no reuse was considered, 2) where reuse but no

transportation to a salvage warehouse was considered, and 3) where both salvage and

transportation to the Habitat for Humanity warehouse in Austin, TX were considered.

Case 1: No Salvaging

Figures 3-3 and 3-4 show impacts (calculated using EDIP and CML 2000,

respectively) resulting from the scenarios where no reuse was considered. In this option,

all salvaged materials are disposed of in a landfill. All scenarios that involve manual

deconstruction show comparable or larger contributions to all impact categories

calculated by the EDIP method (Fig. 3-3) compared to the mechanical demolition

scenario. All of the environmental impacts were lowest for the 100% Mechanical

scenario because of the significantly lower emissions resulting from lower total mileage

for transportation of the employee's to/from the site and the lowest total hours of

equipment use. Specifically, ecotoxicity and human toxicity impacts are higher in the

scenarios involving manual methods because of the increased need of diesel fuel and

gasoline for machine and automobile operation, respectively. These impacts are most









affected by the emissions of mercury and lead during the production of the fuels, not

emissions resulting from their use in the associated equipment. The global warming

potential is higher for higher percentages of manual deconstruction because of the

increased transportation of workers and corresponding production- and use-related

emissions of CO and CO2. The increase in machine and transportation requirements in

all of the manual scenarios also yielded increased SOx and NOx emissions that increased

acidification and eutrophication impacts. Most of the SOx emissions were released in the

production of the diesel fuel and gasoline required by the machines and automobiles,

whereas the NOx was released primarily during the use of these fuels. The ozone

depletion potential was elevated because of the increased production requirements of

diesel fuel, needed in larger quantities in the manual scenarios. The production of diesel

fuel involves CFC emissions, thus yielding increased ozone depletion impacts.

The CML 2000 impact analysis method results revealed less significant influence

of 100% Mechanical methods on impacts (Fig. 3-6) and, in most cases, comparable

impacts among all of the scenarios. The reason for this difference from the EDIP results

is because the impact assessment categories are normalized by CML 2000, whereas EDIP

does not normalize the impact assessment results. Normalization attempts to achieve the

expression of impacts on a global or regional basis, and the CML 2000 approach

normalized the impacts to the most problematic species that is known for each impact

category. Global warming is expressed as kg of C02, ozone depletion, as kg of CFC-11,

human toxicity and ecotoxicity, as kg of 1,4-DB, acidification, as kg of SO2, and

eutrophication, as kg of PO4-3. The impacts for EDIP are expressed based on the

environmental emissions that occur and their effects on the local area. Regardless of the









differences in results from the CML 2000 and EDIP impact assessment methods, both

show that, if the salvaged materials are not reused, then manual methods of

deconstruction yield potential for increased or comparable impacts compared to

traditional demolition methods.

Case 2: Salvaging and No Long-Distance Transportation to a Storage Facility (Local
Reuse)

Figures 3-5 and 3-6 show the impacts calculated using the EDIP and CML 2000

impact analysis methods for each of the four scenarios where material is salvaged and

delivered to local reuse and recycling facilities. The EDIP impact results (Fig. 3-5)

showed that, unlike when no salvaging is considered, the 100% Mechanical scenario

yielded significantly higher impacts compared to the scenarios involving manual

methods. Differences observed in impacts from the manual scenarios were not large.

However, of the manual methods, the 100% Manual scenario yielded the least impacts to

global warming and ozone depletion. Acidification and toxicity impacts were lowest in

the 44% Manual scenario, with the latter resulting in a negative value because of

emissions savings. Eutrophication impacts were lowest in the 44% and 26% Manual

scenarios, whereas ecotoxicity impacts were the lowest in the 100% and 44% Manual

scenarios, both yielding negative impact values. These small differences in impacts

involving manual methods were directly related to the amount of wood salvaged and to

the amounts of diesel fuel, gasoline and electricity used in the processes. Manual

deconstruction avoided the production of virgin wood, thus avoiding electricity emissions

from this stage and yielding decreases in the ecotoxicity, ozone depletion and global

warming impacts. The 100% Manual scenario, involving increased use of machinery and









cars, yielded higher human toxicity, acidification and eutrophication impacts than its

other manual counterparts.

Like the EDIP method results, the CML 2000 method revealed that impacts from

the 100% Mechanical scenario were the highest when salvaging but no long-distance

transport of the salvaged materials was involved. The CML 2000 approach also showed

that the 100% Manual scenario yielded the lowest impacts in all categories except

acidification, which was lowest (and negative) in the 44% Manual scenario (Fig. 3-6). In

comparing only the impacts from the manual scenarios, the 26% Manual scenario was

largest in all cases and yielded no negative impacts using the CML 2000 method.

Case 3: Salvaging and Transport to Austin, TX, for Reuse

The impacts determined by the EDIP and CML methods for each of the four

scenarios that included transportation of the salvaged materials to the Habitat for

Humanity warehouse in Austin, TX, (approximately 885 miles) are shown in Figures 3-7

and 3-8, respectively. The 100% Mechanical scenario yielded the lowest impacts in all

instances because of its significantly lower transportation requirements. The

transportation of the salvaged material to Austin, Texas increased the environmental

impacts for each of the scenarios in which materials were salvaged. Likewise, impacts

increased with increasing manual involvement because of the greater emissions related to

fuel production and use during transportation accompanying the larger weight of

salvaged materials. The results of both the EDIP (Fig. 3-6) and CML 2000 (Fig. 3-7)

impact assessment methods showed that the negative impacts of transport distance of the

salvaged materials far outweigh the savings in emissions that occur by reusing the

materials.









Sensitivity Analysis

The previous results show the influence of both material salvaging for reuse and

transportation to a storage warehouse on the environmental and health impacts of each

scenario compared. Other variables tested for their influence on impacts were time for

deconstruction or demolition activities, driving distance carpoolingg), degree of recycling,

transport distance of equipment, and time for material preparation.

Time for Deconstruction or Demolition Activities

The importance of the pace of dismantling and demolishing the barrack by each of

the four scenarios on the environmental and health impacts was determined by increasing

and decreasing the baseline rates achieved. Baseline rates of dismantling achieved by the

deconstruction team were 105.5, 182.4, 231.7, and 388.4 lbs/hr for 100%, 44%, 26%

manual deconstruction and 100% mechanical demolition, respectively. The demolition

rates achieved were 1028.5, 608.2, 729.3, and 600.1 lb/hr for the 100%, 44%, 26%

manual deconstruction and 100% mechanical demolition scenarios, respectively. These

rates were found by dividing the lbs of material salvaged and landfilled by the labor

hours minus the machine hours and machine hours respectively.

The rate of dismantling material for salvage was observed to influence the

emissions much more than the disposal rate because the slower rate of hand demolition

greatly increased the amount of time the workers spent at the site and thus the times

required for driving to work and using the generator. For the scenarios involving manual

deconstruction, decreasing the rate of dismantling by 5 lb/hr increased human toxicity by

21%, acidification by 4%, and eutrophication and ozone depletion by 3%, whereas very

little change in the impacts was observed in the 100% Mechanical scenario because no

salvaging of materials was performed. Increasing the rate of dismantling by 5 lb/hr









showed that human toxicity was also most sensitive by resulting in a decrease of 27.4%,

while acidification and eutrophication decreased by 6% and ozone depletion by 4.0%.

Increasing and decreasing the rate of demolition resulted in no significant change in

impacts.

Commuting Distance

Decreasing and increasing the commuting distance of 20 miles assumed in the

baseline case by 5 and 10 miles and in the number of people/car from 1 in the baseline

case to 4 tested for their sensitivity on the impacts from the 100% Manual scenario. The

importance of carpooling to the site by increasing the number of occupants to four was

evident by a decrease in eutrophication by 561%, in acidification by 77.5%, and in

human toxicity by 39%. Less dramatic results were observed with increasing the driving

distance by 5 miles, where the largest changes were observed in impacts on

eutrophication, acidification and human toxicity (2.12%, 0.290% and 0.146% increases,

respectively).

Recycling

When recycling was removed from the scenarios involving manual methods,

acidification, eutrophication, and ecotoxicity decreased as much as 23.5%, 36.4% and

77.9%, respectively (for the 100% Manual scenario).

Transportation Requirements

Driving distances for transportation of demolition equipment, salvaged material,

recycled material and landfill material, for moving equipment to the woods, felled wood

from the woods to the mill and boards from the mill to the store or site were increased

and decreased by 5 and 10 miles from their assumed transport distances (listed in the

Assumptions and Limitations section). Most of the emissions categories did not increase









or decrease significantly. Global warming, ozone depletion, acidification and

eutrophication changed the most as a result of elevated emissions resulting from

increased diesel fuel requirements. For example, when the mileage of an eighteen-wheel

truck was increased by 5 miles, eutrophication increased by 18.3%, acidification

increased by 2.38%, global warming increased by 2.11%, and ozone depletion increased

by 1.25%.

Time Required for Paint and Nail Removal

According to the deconstruction team's past experience, 30% of the total time for

manual deconstruction involves paint stripping and denailing the wood and thus use of

the generator. However, this time percentage was increased and decreased by 5 and 10%

to account for differences in methods and experience levels of deconstruction teams. The

results show that large changes in acidification, eutrophication and human toxicity occur

when the generator times for paint stripping and denailing runs were altered.

Acidification increased the most, 106%, when the time for material preparation was

increased by 5%, while eutrophication and human toxicity impacts increased by 48.5%

and 26.1%, respectively. Thus, the amount of time spent on material preparation can

greatly affect the environmental impacts that occur from manual deconstruction.

Conclusions

Of the three options considered, that involve salvaging and reuse within a 20-mile

distance yielded the lowest impacts. Both the CML 2000 and EDIP methods resulted in

significantly lower environmental and health impacts when manual methods of

deconstruction were used. Of the three manual scenarios considered with salvaging, the

100% and 44% Manual scenarios yielded, for the most part, the lowest impacts.

Compared to the scenarios involving manual methods of deconstruction, the 100%









Mechanical scenario was the fastest option, as anticipated, and, if the salvaged wood does

not replace virgin wood in other building applications, this traditional means of building

removal was shown to be the best option in terms of environmental emissions and

resulting impacts. However, if the reuse of salvaged wood is assumed to avoid the

production of virgin wood then either the 100% Manual or 44% Manual scenario would

be preferred because of the decrease in environmental emissions and thus impacts. The

LCA model presented herein is most sensitive to changes in car mileage and the amount

of time the generator runs. It is recommended, therefore, that the deconstruction occur on

or near the site where the materials will be reused, for the workers to live near the site,

and for the amount of time spent on material preparation to be minimal.

Social and economic impacts of deconstruction and demolition processes were not

quantified in this study. Economic impacts of deconstruction have been discussed by

Guy and Williams (2004), however. Because deconstruction takes longer and is more

labor-intensive, it provides work for a crew for several days. Deconstruction also

provides lower-cost building materials, which, in turn, can lower the cost of new

construction or can allow people who cannot afford virgin materials to buy materials of

good quality to make repairs on their own homes. Given that the Department of Defense

must dispose of nearly 2.5 million square feet of army barracks in the U.S. EPA Region 4

alone, incorporating some degree of manual deconstruction offers potential benefits well

beyond those quantified in this study. Given the influence of transportation of salvaged

materials for reuse applications, it is recommended, however, that a strategy be

developed to foster reuse within the deconstruction site region.












Table 3-1 Time Requirements for Removing Components of Barracks Using the Four Scenarios Varying in Degree of Manual
Deconstructiona, b


100% Manual


Component


Windows and
Doors
Interior
Partitions
Hazardous
MEP
Interior
Finishes and
Framing
Roof
2Wall
2Floor
lWall
1Floor
Foundation


Time
(hours)


44% Manual


% Total Time
Time (hours)


26% Manual


% Total Time
Time (hours)


100% Mechanical


% Total Time
Time (hours)


% Total
Time


9.57 1.46% 9.57 2.01% 9.57 2.64% 0.00 0.00%


18.97
5.05
9.54


73.55
137.15
52.75
147.69
64.30
133.07
3.26*


2.90%
0.77%
1.46%


11.23%
20.94%
8.05%
22.55%
9.82%
20.32%
0.50%


18.97
5.05
9.54


73.55
95*
45.28
71.92*
62.27
80.84*
3.26*


3.99%
1.06%
2.01%


15.48%
19.99%
9.53%
15.13%
13.10%
17.01%
0.69%


18.97
5.05
9.54


50
77*
29.12*
84.4*
9.29*
65.9*
3.26*


5.24%
1.39%
2.63%


13.81%
21.26%
8.04%
23.31%
2.57%
18.20%
0.90%


3.09*
5.05
1.03*


3.09*
6.18*
2.06*
5.15*
2.06*
4.12*
3.26*


8.81%
14.39%
2.94%


8.81%
17.61%
5.87%
14.68%
5.87%
11.74%
9.29%


aAll of the sections of the barrack within which machines were used are indicated with an asterisk (*), and all sections that do not have
an asterisk next to them used hand deconstruction only.
bMEP = Mechanical, electrical and plumbing materials, 2Wall = Second story wall, 2Floor = Second story floor, lWall = First-story
wall, 1Floor = First-story floor.












Table 3-2 Labor and Machine Requirements and Material Yields of the Four Scenarios Studied
Labor and Machine Requirements Material Yields
Hazardous
Labor Equipment Salvage Recycle Material Landfilled
Scenario Labor Machine Transportation Transportation Weight Weight Weight Weight
(Days) (Hours) (Miles) (Miles) (Lbs) (Lbs) (Lbs) (Lbs)

100% Manual 13.64 80.22 2160 120 59089 1032 141 82486

44% Manual 9.74 146.59 1440 140 57291 1032 141 84284

26% Manual
7.32 139.75 1080 120 48134 1032 141 93441

100% Mechanical 1.46 23.42 120 40 2552 0 141 140055









Table 3-3 Fuel and Electricity Requirements for Associated Processesab
Processes Involved Gasoline Diesel Electricity
Stagesc (gal) Fuel (gal) (kWh)


Labor
Transportation (1 laborer, 1 day of
work)
Deconstruction
Transportation To and From the Site
Lift (hr)


Bobcat (hr)
Excavator (hr)
Crane (hr)
Chopsaw (hr)

Chainsaw (hr)
Generator (hr)
End-of-Life Stages
Salvaging Wood (1 lb)
Harvesting
Transportation of Equipment to and
from the Forest
Feller Buncher (1 lb)
Rubber Tired Skidder (1 lb)
Log Loader (1 lb)
Transport from Site to Sawmill (1 lb)
Sawmill
Electricity (1 lb)
Transportation from the Sawmill to
Construction the Site (1 lb)
Recycling Steel (1 lb)
Electricity (1 lb)
Transportation to Recycling Facility
Landfill (1 lb)
Transportation to Landfill


8.0E-01 --


7,8
6,7,9,
10, 11,
12
7, 12
7
7, 11
7, 8, 9,
10, 11
13


6.4E+00
2.5E+00


5.0E+00
8.1E+00
4.0E+00
2.0E-01 --

1.2E-01 --
6.3E-01 --


2.9E+0 1
1.7E-03
2.8E-03
3.1E-03
9.OE-03


6.2E-03


3.OE-03


2.1E+00
1.6E-02 --


1.6E-02


aValues of fuel requirements by the equipment are presented on an hourly basis, and
values of electricity.
bAll fuel usage values were obtained by contacting the manufacturers of the machines
and asking for average fuel usage values.
CStage numbers refer to the specific stages involved and shown in Figure 3-2.
dMileage workers drove to/from the site was assumed to be 20 miles, equipment
transported from within a 20 mile radius to site, 30 miles to/from the forest, 60 mile
transport for harvested wood to sawmill, 100 mile transport from sawmill to construction
site and an 80 mile transport distance for salvaged material to new construction site.









Table 3-4 Emissions from the Scenario Involving 100% Manual Methodsa


Salvaged
Material Disposal


Recycled
Material


Equipmentb Transportation'


Criteria Pollutants
Carbon
Monoxide
(CO) 3.52E+03 -8.29E+01 6.94E+01 9.36E-01 1.94E+03


Nitrogen
Oxides (NOx) 7.46E+01
Air Toxics
Dioxin -8.16E-12


-7.06E+01 4.79E+01 -9.59E-01 5.55E+01

-2.76E-11 1.50E-11 1.87E-13 3.17E-12


Greenhouse Gases
Methane
(CH4) 8.49E-01 -2.29E+00 2.43E+00 3.03E-02 5.09E-01


Carbon
Dioxide (C02) 3.45E+02
Metals
Arsenic (As) 1.62E-05
Lead (Pb) -4.72E-04
Mercury (Hg) 3.05E-06


-1.46E+03 1.57E+03 -2.72E+02 3.86E+02


-4.49E-05
-7.08E-05
-1.71E-05


4.73E-05
8.38E-05
1.56E-05


5.92E-07
-5.09E-04
1.95E-07


9.88E-06
1.76E-05
3.26E-06


1.59E+03


4.28E+01

1.08E-12




1.70E-01


1.11E+02

3.32E-06
5.92E-06
1.09E-06


Miscellaneous Chemicals
Volatile
Organic
Compounds
(VOCs) 1.69E+02 -2.61E-01 0.00E+00 -2.46E-02 9.40E+01 7.53E+01
aThe functional unit is per ft2 of barrack removed. The emissions in this table are
expressed in terms of g/ft2 of barrack removed.
bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw andweedeater.
cTransportation includes labor and equipment.


Emission


Total









Table 3-5 Emissions from the Scenario Involving 44% Manual Methodsa

Salvaged Recycled
Emission Total Material Disposal Material Equipment Transportation'


Criteria Pollutants
Carbon
Monoxide
(CO) 2.22E+03 -8.04E+017.09E+01 9.36E-01


Nitrogen
Oxides (NOx) 4.69E+01
Air toxics
Dioxin -6.96E-12


-6.84E+014.90E+01 -9.59E-01

-2.68E-11 1.53E-11 1.87E-13


Greenhouse Gases
Methane
(CH4) 9.87E-01 -2.22E+00 2.48E+00


Carbon
Dioxide (C02) 5.38E+02
Metals
Arsenic (As) 6.68E-05
Lead (Pb) -3.00E-03
Mercury (Hg) 3.98E-06

Miscellaneous Chemicals
Volatile
Organic
Compounds
(VOCs) 1.04E+02


3.03E-02


-1.42E+031.61E+03 -2.72E+02


-1.46E-04 1.97E-04
-7.50E-05 9.49E-05
-1.66E-05 1.60E-05


5.92E-07
-3.04E-03
1.96E-07


-2.53E-01 0.00E+00 -2.46E-02


1.17E+03


3.83E+01

3.46E-12


5.57E-01


5.22E+02

1.09E-05
2.13E-05
3.58E-06






5.38E+01


1.06E+03


2.90E+01

8.65E-13


1.37E-01


8.92E+01

2.67E-06
5.28E-06
8.79E-07






5.02E+01


aThe functional unit is per ft2 of barrack removed. The emissions in this table are
expressed in terms of g/ft2 of barrack removed.
bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw andweedeater.
cTransportation includes labor and equipment.









Table 3-6 Emissions from the Scenario Involving 26% Manual Methodsa
Salvaged Recycled Equipment Transportation
Emission Total Material Disposal Material b c


Criteria Pollutants
Carbon
Monoxide
(CO) 1.62E+03 -6.76E+017.85E+01 9.36E-01


Nitrogen
Oxides (NOx) 4.95E+01


Air toxics
Dioxin


-5.75E+01 5.43E+01 -9.59E-01


-5.68E-13 -2.25E-11 1.70E-11 1.87E-13


Greenhouse Gases
Methane
(CH4) 1.69E+00 -1.86E+002.75E+00 3.03E-02


Carbon
Dioxide (C02) 9.69E+02
Metals
Arsenic (As) 1.13E-04
Lead (Pb) -2.97E-03
Mercury (Hg) 8.86E-06

Miscellaneous Chemicals
Volatile
Organic
Compounds
(VOCs) 7.38E+01


-1.19E+03 1.78E+03 -2.72E+02


-1.22E-04 2.20E-04
-6.30E-05 1.05E-04
-1.40E-05 1.77E-05


5.92E-07
-3.04E-03
1.96E-07


-2.13E-010.00E+00 -2.46E-02


8.15E+02


3.20E+01

4.13E-12


6.67E-01


5.75E+02

1.30E-05
2.55E-05
4.29E-06


3.64E+01


7.94E+02


2.18E+01

6.49E-13


1.03E-01


6.70E+01

2.00E-06
3.96E-06
6.60E-07






3.76E+01


aThe functional unit is per ft2 of barrack removed. The emissions in this table are
expressed in terms of g/ft2 of barrack removed.
bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw andweedeater.
'Transportation includes labor and equipment.













Table 3-7 Emissions from the Scenario Involving 100% Mechanical Methodsa, b


Disposal Equipment'


Transportationd


Criteria Pollutants


Carbon Monoxide (CO) 2.52E+02 -3.58E+00


Nitrogen Oxides (NOx) 8.77E+01 -3.05E+00
Air toxics
Dioxin 2.62E-11 -1.19E-12


1.18E+02 4.85E+01 8.92E+01


8.13E+01 6.40E+00 3.04E+00

2.54E-11 1.70E-12 2.66E-13


Greenhouse Gases
Methane (CH4)


4.34E+00 -9.87E-02


4.12E+00 2.75E-01


Carbon Dioxide (C02) 2.19E+03 -6.63E+00
Metals
Arsenic (As) 8.46E-05 -1.94E-06
Lead (Pb) 1.50E-04 -3.06E-06
Mercury (Hg) 2.77E-05 -7.40E-07


1.99E+03 1.79E+02 2.78E+01


8.03E-05
1.42E-04
2.64E-05


5.36E-06
9.51E-06
1.77E-06


8.34E-07
1.48E-06
2.74E-07


Miscellaneous Chemicals


Volatile Organic
Compounds (VOCs) 6.18E+00 -1.13E-02 0.00E+00 2.01E+00 4.18E+00
aThe functional unit is per ft2 of barrack removed. The emissions in this table are
expressed in terms of g/ft2 of barrack removed.
bRecycled Material is not applicable for 100% mechanical. Hazardous waste not
accounted for in all 4 scenarios.
cEquipment includes a bobcat, excavator and weedeater.
dTransportation includes labor and equipment.


Emission


Total


Salvaged
Material


4.28E-02





































Figure 3-1World War II Army Barracks at Fort McClellan










































Avoided
16. Sawmill Virgin 14. Transp
Wood ofMachin
Production

.... ." / 15. Harvesting


13a.
.......... Salvaged
Material
Avoids
Virgin
Wood


Figure 3-2 Stages Involved in the Deconstruction Process


















100%


90%


80%-


70%


60%-


50%-


40%-


30%-


20%-


10%


0%
Global Warming Ozone Depletion Acidification Eutrophication Human Toxicity


Impacts


0100% Mechanical

E26% Manual

044% Manual

3100% Manual


Ecotoxicity


Figure 3-3 Total Impacts Calculated Using the EDIP Method Not Including Reuse of Salvaged Materials.


I
















100%


80% -




S 60%- U 100% Mechanical
.l 026% Manual
S- 0 44% Manual
0
0 40%- E3100% Manual




20%




0%
Global Ozone Acidification Eutrophication Human Ecotoxicity
Warming Depletion Toxicity
Impacts


Figure 3-4 Total Impacts Calculated Using the CML Method Not Including Reuse of Salvaged Materials.
























100% Mechanical
0
20%- 26% Manual
E44% Manual
00.. 100% Manual

L -200/..

-400/..

-60%

-80%-

100%
Global Ozone Acidification Eutrophication Human Toxicity Ecotoxicity
Warming Depletion

Impacts


Figure 3-5 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged Materials But No Transportation to a
Warehouse.


























0 i100% Mechanical
n 40% U 26% Manual
[] 44% Manual
CM 100% Manual
O 20o/..


00/..


-200/..


-40%
Global Ozone Acidification Eutrophication Human Toxicity Ecotoxicity
Warming Depletion

Impacts


Figure 3-6 Total Impacts Calculated Using the CML Method Reuse of Salvaged Materials But No Transportation to a Warehouse.

















































Global Warming Ozone Depletion Acidification Eutrophication Human Toxicity
Impacts


S100% Mechanical
*26% Manual
044% Manual
S100% Manual


Ecotoxicity


Figure 3-7 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged Materials and Transport to the Habitat for
Humanity Warehouse in Austin, Texas.


100%


80%-


60%




40%-


20%-




0%-



























S100% Mechanical
S26% Manual
O 44% Manual
S100% Manual


Global Warming


100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%


Impacts





Figure 3-8 Total Impacts Calculated Using the CML Method Including Reuse of Salvaged Materials and Transport to the Habitat for
Humanity Warehouse in Austin, Texas.


Ozone Acidification Eutrophication Human Toxicity Ecotoxicity
Depletion













CHAPTER 4
SUMMARY, CONCLUSIONS AND RECOMMENDATIONS

Summary

An LCA was performed comparing deconstruction and demolition of World War II

army barracks to determine the contribution of each life cycle stage to the total

environmental impacts and to compare impacts of material reuse and disposal. Before

this LCA was conducted, a combination of deconstruction and demolition was performed

on three barracks. Once the time requirements for each stage of these processes were

found, four modeled scenarios were produced. An LCA was then performed on these

four scenarios using SimaPro. The four life cycle stages considered for the

deconstruction process were deconstructing the building, cleaning the salvaged materials,

salvaged material reuse, and disposal. The four life cycle stages considered for the

demolition process were harvesting of trees, processing of trees to boards at the sawmill,

use of materials in buildings, and disposal. The LCA was performed according to ISO

14040 standards and included scope and goal definition, inventory analysis, impact

assessment, and interpretation. Impact assessment was performed using two published

impact methods-CML and EDIP.

Conclusions


Results from the inventory analysis have shown that demand for virgin material is

highest for 100% mechanical demolition. The largest amount of emissions to water, air

and soil is derived from the disposal of the materials into landfills when compared to all

the other process considered throughout this LCA. In fact, in most cases the salvaging of









the materials had an almost opposite effect on the environment than did the disposal of

the materials into landfills. This is due not only to the effects of disposal of materials into

the landfill but also to impacts resulting from reproduction of that material. Salvaging

materials circumvented both landfilling and reproduction of new virgin materials, thus

yielding environmental savings.

The impact assessment methods used showed some variation based on the chosen

model. According to the EDIP method of analysis, the 100% Manual and 44% Manual

deconstruction scenarios were shown to be superior when material was salvaged and

transported nearby. The largest emissions that occurred for 100% manual deconstruction

scenario, shown in Table 3-4, were C02, CO, NOx, and VOCs, ranging from 7.46E+01

g/ft2 NOx to 3.52E+03 g/ft2 CO. Both CO and CO2 emissions were greater than observed

in the 100% mechanical deconstruction scenario, primarily because of increased

generator operation and labor transportation requirements. The transportation of labor

and the use of the generator were also the largest contributors to the nitrogen oxides and

VOC's in this scenario. Table 3-5 illustrates that in the 44% manual scenario, the largest

emissions were CO2, CO, NOx, and VOCs ranging from 2.22E+03 to 4.69E+01. The

major sources of these emissions are also transportation of labor to/from the site and

generator operation. An increased amount oflandfilled material contributes to increased

CH4 emissions and, in part, to increased CO2 and CO emissions when compared to the

100% manual deconstruction scenario. With less time spent at the site less transportation

of workers occurred to and from the site and with less salvaged material the generator

was used for a smaller amount of time thus all of the emissions for this scenario were less

than the 100% manual emissions. As seen in Table 3-6 the 26% manual scenario had the









same top 4 emissions and the same contributing processes to the emissions ranging from

4.95E+01 to 1.62E+03. Due to the higher transportation of machinery and the lower

amount of salvaged materials, the largest producer of carbon dioxide was the

transportation of equipment, followed closely by the transportation of labor and the use of

the generator. As with the 44% manual scenario the emissions were lower than the 100%

manual and the 100% mechanical scenario due to less material being landfilled and less

time being spent in transportation of labor and cleanup of the salvaged materials. Table

3-7 provides emissions resulting from 100% mechanical demolition of a barrack. The

highest total emissions in this scenario were greenhouse gases, carbon dioxide (CO2,

3.40E+02 g/ft2) and carbon monoxide (CO, 2.52E+02 g/ft2). Also high were emissions

of nitrogen oxides (NOx), volatile organic compounds (VOCs) and methane (CH4). The

greatest contributor of C02, CO, NOx and CH4 was the landfill used for disposal of waste

materials, whereas the main source of VOC's was the transportation of labor and

equipment to and from the site. Equipment operation was also a significant contributor to

CO2 emissions.

A sensitivity analysis was performed on the results from the impact assessment to

determine the influence of variables on the environmental impacts considered. The

model produced in SimaPro was most sensitive to changes in the mileage driven by

workers onsite machine use and the operation time of the generator. It was shown that

environmental impacts decrease with higher levels of materials salvaged. However,

detrimental impacts were shown to rise with transportation distance to the new

construction site or to a storage facility. Impacts also increased with increasing

deconstruction time because of the increased number of days workers drove their cars to









the site. Ideally, salvaged materials would be reused at a construction site located on or

near the property where the building is deconstructed.

The results found from this project will be used by the DOD to aid in development

of best management practices for the 2,357,094 square feet of army barracks, slated for

removal within EPA Region 4 and the countless more square footage of buildings in need

of removal on bases throughout the U.S. The implementation of these practices by the

DOD will decrease the impact of the disposal of these buildings on both public health and

the environment through decreased environmental impacts.

While cost and societal impacts of deconstruction were not considered in this study,

some discussion of these aspects is worth mention. While increases in environmental

savings were shown herein, the availability of materials for reuse has tremendous social

implications. Jobs are created by deconstruction, and companies and individuals unable

to afford large amounts virgin materials would be able to access materials at a decreased

cost. With careful planning and execution, deconstruction costs less than demolition

considering the resale value of the materials and decreased landfill disposal costs and

certainly provides greater positive contributions to society.

Recommendations


The most significant limitation to this study was the small number of scenarios

studied. Because the most efficient way to take down a building in terms of time and

environmental impacts is a combination of hand deconstruction and mechanical

demolition, it would have been beneficial to have more scenarios that combined the two.

This would give a more accurate representation of the most effective way to take down a

building. It is recommended that for each building, contractors should determine the






80


amount of available materials that could be salvaged and the worth of these salvageable

materials. In doing so, the building can be removed using a combination of

deconstruction and demolition methods, resulting in maximum environmental savings

from prevention of disposal of the reusable materials and production the new replacement

materials.















APPENDIX A
DATA COLLECTION AND DAILY NARRRRATIVE

Introduction to the Form

The heart of the data collection method is the data collection form. The form

guides the documentation of each worker. It gives information on where they are

working, what they are doing, and what equipment they are using. Since each form

covers 15 minutes of activity, one is completed every 15 minutes from the start to the end

of each workday. Later, the forms are entered into a spreadsheet format that allows the

data to be sorted in different ways. This information was collected by the deconstruction

team.










Team : Deconstruction

Completed by: Date Time: 7:30-7:45


Name Building Room Location Activity Assembly Equipment

1

2

3

4

5

6

7

8

9

10









Key to Form

Team

Starting in the upper left hand corner, the first box identifies the team which is

going to be recorded on the form. For this project, we had two main teams. The first one

was the Deconstruction Team, which was primarily composed of the demolition

contractor and crew. This was the team that was responsible for removing the materials

from the building. The other was the Processing Team. This Team was composed of

Americorp and Habitat for Humanity (HfH) volunteers. This Team was responsible for

taking the deconstructed materials, getting them into a ready-for-use state, and

transporting them to the HfH storage facility.

Completed by

Record of who completed the data form.

Date

Date form was completed.

Time

15-minute interval that the form documents. When a worker changes activity, the

amount of time is rounded to the nearest quarter hour.

Name

Recording the name of each worker organizes the data collection and allows

someone who wasn't present at the deconstruction site to follow an individual worker's

activity through a day in order to get a mental picture of the deconstruction process.

Additionally, when the labor hours are reported, it is possible to break down the labor by

skill level and pay-rate. The name entry will be used to sort the data for this part of the

analysis.









Building

To begin with buildings 839, 840, and 841 were deconstructed. Each building was

basically identical, so it was important to write down which building was being worked

on. No one reading the data forms later would be able to infer the building number solely

by the description of what was taking place that day. In the event that work was being

done simultaneously on two or more buildings, it became difficult to always notice who

was working on which building, but at the same time it remained critical to be accurate in

assigning the correct building number to the entry for the analysis and comparison of

methods.

Room

On the back of each data collection clipboard, there was a small plan of each floor

of the building. Each room was numbered. To track the progression of work, a record

was kept of where each person was working. If the worker is inside the building, the

number of the room where they were working was recorded. Other designations included

roof, ext for exterior and site for work not occurring specifically on the building.

Location

This column was used to more specifically record where work was being done. If

the worker was on the roof, the slope he or she is on (north or south) was recorded. If the

worker was on the exterior, the side of the building was recorded (north, south, east, or

west). If the worker was inside, records were kept of which surface was being worked

on. Data was kept by using such designations as "F" for floor, "C" for ceiling, and N, S,

W, or E for wall surfaces.









Activity

This column was used to identify what type of work was being done. While the

activity categories were simplified as much as possible, they still encompass the variety

of tasks that will occur during the project. An attempt was made to explain the range of

tasks that can fall under each category. In completing this column the data collector

needed to exercise careful observation and good judgment in order to understand what

each worker was doing and into which category that activity fell. If the collector was not

sure what someone was doing, he was to obtain clarification from the worker. If the

collector was not sure which category to use, a supervisor was to be consulted.

HDec (hand deconstruction)

This category includes all work associated with removing materials that had

potential for processing and salvage from the building using hand labor. It includes

the use of hammers, crowbars, or hand-held power tools such as circular saws or

sawzalls. It would also include the use of a man-lift, forklift, or crane provided that

this equipment is being used to transport workers or individual pieces of building

materials. The key to differentiating between "Hand" and "Mechanically-Assisted"

work is that hand methods are directed towards removing the materials piece-by-

piece from the building and mechanically-assisted methods are directed towards

removing large sections or assemblies from the building with separation into

individual pieces occurring later.

HDem (hand demolition)

This category includes all work associated with removing materials from the

building by hand for disposal. It includes the use of hammers, crowbars, or hand-

held power tools such as circular saws or sawzalls. The key to differentiating









between deconstruction and demolition is that with deconstruction the materials are

handled with a level of care sufficient to preserve their condition and suitability for

reuse. Demolition will generally be faster and less gentle than deconstruction.

This project is primarily directed towards research into the methods, labor, and

costs involved in deconstruction. Actual salvage of building materials is a

secondary benefit. Also, the amount of actual salvage will be limited by the

widespread use of lead-based paint on the wooden building materials, making them

unsuitable for reuse. In the case of most of the smaller pieces of dimensional

lumber, stripping the lead-based paint is simply not cost effective or

environmentally beneficial. For these reasons, many of the parts of the building

will be dismantled using deconstruction techniques in order to document the

process, while still eventually ending up in the dumpster. 2x4 small wall studs for

instance are typically salvageable. In this project, since they are painted they will

be disposed in a landfill. However, since the information on salvage time and costs

will be needed in the accurate planning of future projects, the wall studs were

deconstructed rather than demolished. Generally, meetings were held at the start of

each day, to discuss the planned activities for the day, what methods were used, and

which materials were being demolished or deconstructed. Any worker who was

unsure about any activity was told to ask for clarification immediately, because the

accurate distinction between how much time was spent on each building

deconstructing for theoretical salvage or demolishing for theoretical disposal was

critical.









MDec (mechanically assisted deconstruction)

This category includes all work associated with removing materials with

potential for processing and salvage from the building with mechanical assistance.

This includes both mechanical labor time and any hand labor time that is needed to

prepare for the mechanical work. For instance, on one of the buildings, the

deconstruction method involved removing large panels of the roof using a crane.

The time spent actually lifting the panels off by crane is MDec, and so is any time

spent bracing a panel by hand so that it will stay in one piece while being lifted off,

cutting the panel free from surrounding materials, and attaching the lifting

mechanism.

MDem (mechanically assisted demolition)

This category includes work associated with removing materials from the

building with mechanical assistance for disposal.

N (non-productive)

Non-productive time includes all "on-the-clock" time that is not spent in any of

the other categories. Activities such as water breaks (though not lunch), discussing

what to do next, receiving instruction, tool and work station set-up at the beginning

of the day and break-down at the end, miscellaneous clean-up (though not disposal

of an individual material that has just been demolished getting materials to the

roll-offs is part of demolition), building ramps or sawhorses, running caution tape,

and many other activities that do not directly contribute to the removal or

processing of the building materials are non-productive.









P (processing)

Processing includes all the work done to prepare the materials for reuse after

they have been removed from the building. This includes denailing, cleaning,

trimming, sorting, bundling, and loading for transport.

S (supervising)

Supervisory work is time spent by a job supervisor instructing, directing,

coordinating, etc.

Assembly

This column is used to record which part of the building is being worked on. When

the labor time is analyzed, this column will be used to describe how much effort is

needed to salvage each part of the building as well as the whole. For the purpose of data

collection, the buildings are divided into the following assemblies:

R (Roof)

2W (Second floor walls)

2F (Second floor).

1W (First floor walls)

1F (First floor)

Fnd (Foundation)

MEP (Mechanical, Electrical, and Plumbing systems)

Equipment

This column is used to record what tools were used for the work. To be sure, the

most critical tools to record are the tools that require energy to operate (electric saws or

drills, as well as heavy equipment such as cranes, manlifts, forklifts, bobcats, etc.). Some

workers will change hand tools often, switching between a crowbar and a flatbar as they









work. In these cases, it is more important to document that they are using a set of prying

tools, rather than exactly which one they use at any given time. The equipment

information is useful to provide an image of what was being done at any given time for

someone who was not present and to help calculate energy consumption for the life-cycle

analysis component of the project. Keeping these goals in mind will help simplify what

can become the most tedious section of data collection. Generally, it allows future

project decision makers to know what type of work was being done and to calculate how

long energy consuming equipment was being operated.















APPENDIX B
INVENTORY OF EMISSIONS

(When accounting for the recycling of steel and subtracting emissions for the

production of virgin materials using EDIP.)

Table B-l: Raw Material Emissions


44% Manual


26% Manual 100% Mechanical


water kg 3.61E+04 3.61E+04 3.61E+04 O.00E+00
coal kg -9.97E+01 -9.37E+01 -6.86E+01 3.39E+00
crude oil kg -2.22E+03 -2.02E+03 -1.38E+03 4.27E+02
energy MJ 3.34E+03 3.35E+03 3.37E+03 -5.57E+00
lignite kg 4.47E+01 4.47E+01 4.47E+01 .00OE+00
limestone kg -7.39E+00 -7.03E+00 -5.59E+00 1.98E-01
natural gas kg -1.70E+02 -1.56E+02 -1.09E+02 2.90E+01
oil kg 3.60E+00 3.60E+00 3.60E+00 O.00E+00
steel scrap kg 5.50E+02 5.50E+02 5.50E+02 .00OE+00
uranium kg 1.64E+00 1.64E+00 1.64E+00 1.43E-05
wood/wood
wastes kg 1.65E+00 -1.51E+00 -1.04E+00 3.03E-01


Substance


Unit


100%
Manual




Full Text

PAGE 1

LIFE CYCLE ANALYSIS OF THE DE CONSTRUCTION OF MILITARY BARRACKS: A CASE STUDY AT FT MCCLELLAN, ANNISTON, ALABAMA By ELIZABETH OBRIEN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENGINEERING UNIVERSITY OF FLORIDA 2006

PAGE 2

Copyright 2006 by ELIZABETH OBRIEN

PAGE 3

iii ACKNOWLEDGMENTS I would like to first acknowledge and th ank the Department of Defense for the grant funding that made this project possible. I am also grateful to Brad Guy and Timothy Williams for their leadership and guidance of the deconstruction team and for their work in collecting and organizing the data used in th e life cycle assessment. I would also like to thank Costello Dismantling Company for its help in the deconstruction and demolition of the military barracks at Ft. McClellan. I acknowledge and thank Dr. Angela S. Lindner, my supervisory committee chairperson, for her time, hard work, leadersh ip, and guidance during th is project. I thank my committee members Drs. Timothy Townsend and Charles Kibert for their direction, time, and support. I am also very grateful to my research group for feedback and support throughout this project. I acknowledge and tha nk my family, roommates and friends for all of their support and guidance.

PAGE 4

iv TABLE OF CONTENTS page ACKNOWLEDGMENTS.................................................................................................iii LIST OF TABLES............................................................................................................vii LIST OF FIGURES.........................................................................................................viii ABSTRACT....................................................................................................................... ix CHAPTER 1 INTRODUCTION........................................................................................................1 A Case for Deconstruction............................................................................................2 Advantages............................................................................................................2 Disadvantages........................................................................................................4 Is Reuse of Non-Virgin Wood Possible?...............................................................5 A Case for Virgin Wood...............................................................................................8 Research Scope...........................................................................................................12 2 REVIEW OF LITERATURE.....................................................................................14 Amount of Construction Each Year...........................................................................14 Amount of Deconstruction/Demolition Each Year....................................................15 Increased Availability of Materials.....................................................................15 How are Virgin Trees Turned Into Usable Wood?.............................................16 Virgin Wood Processes...............................................................................................16 Harvesting............................................................................................................16 Sawmill................................................................................................................17 The Deconstruction Process.......................................................................................18 Raw Material Extraction......................................................................................18 Material Refining.................................................................................................21 Use/Reuse............................................................................................................22 Disposal...............................................................................................................23 Disadvantages of Unlined Landfills....................................................................25 Costs of Deconstruction Verses Demolition...............................................................28

PAGE 5

v 3 LIFE CYCLE ANALYSIS.........................................................................................33 Abstract.......................................................................................................................33 Introduction.................................................................................................................34 Methods......................................................................................................................37 Description of Fort McClellan Barracks.............................................................37 The Deconstruction Process and Four Scenarios Studied...................................37 Life Cycle Analysis....................................................................................................39 Functional Unit....................................................................................................39 Scope and Goal Definition..................................................................................39 Figure 3-2............................................................................................................39 Figures 3-3 and 3-4..............................................................................................40 Data Inventory.....................................................................................................41 Impact Assessment..............................................................................................42 Assumptions and Limitations.....................................................................................42 Sensitivity Analysis....................................................................................................44 Results and Discussion...............................................................................................45 Data Inventory.....................................................................................................45 Time Requirements for Remova l of Barrack Components.................................45 Labor and Machine Time and Mileage Requirements and Material Yields........47 Fuel and Electricity Requirements......................................................................49 Emissions....................................................................................................................51 Impact Analysis..........................................................................................................53 Case 1: No Salvaging..................................................................................................53 Case 2: Salvaging and No Long-Distan ce Transportation to a Storage Facility (Local Reuse)..........................................................................................................55 Case 3: Salvaging and Transport to Austin, TX, for Reuse........................................56 Sensitivity Analysis....................................................................................................57 Time for Deconstruction or Demolition Activities.............................................57 Commuting Distance...........................................................................................58 Recycling.............................................................................................................58 Transportation Requirements..............................................................................58 Time Required for Paint and Nail Removal........................................................59 Conclusions.................................................................................................................59 4 SUMMARY, CONCLUSIONS AND RECOMENDATIONS..................................76 Summary.....................................................................................................................76 Conclusions.................................................................................................................76 Recommendations.......................................................................................................79 APPENDIX A DATA COLLECTION AND DAI LY NARRRRATIVE...........................................81 Introduction to the Form.............................................................................................81 Key to Form................................................................................................................83

PAGE 6

vi Team....................................................................................................................83 Completed by.......................................................................................................83 Date......................................................................................................................83 Time.....................................................................................................................83 Name....................................................................................................................83 Building...............................................................................................................84 Room...................................................................................................................84 Location...............................................................................................................84 Activity................................................................................................................85 HDec (hand deconstruction)............................................................................85 HDem (hand demolition).................................................................................85 MDec (mechanically assi sted deconstruction).................................................87 MDem (mechanically assisted demolition).....................................................87 N (non-productive)...........................................................................................87 P (processing)...................................................................................................88 S (supervising).................................................................................................88 Assembly.............................................................................................................88 Equipment............................................................................................................88 B INVENTORY OF EMISSIONS.................................................................................90 LIST OF REFERENCES...................................................................................................95 BIOGRAPHICAL SKETCH.............................................................................................99

PAGE 7

vii LIST OF TABLES Table page 2-1. C&D Waste Material Categories and Sources..........................................................19 2-2. Amount of Chemical Constituen ts in Wood Products (Construction and Demolition Waste Landfills 1995)...........................................................................26 3-1 Time Requirements for Removing Co mponents of Barracks Using the Four Scenarios Varying in Degree of Manual Deconstructiona, b.....................................61 3-2 Labor and Machine Requirements and Ma terial Yields of the Four Scenarios Studied......................................................................................................................62 3-3 Fuel and Electricity Require ments for Associated Processesa,b.................................63 3-4 Emissions from the Scenario Involving 100% Manual Methodsa.............................64 3-5 Emissions from the Scenario Involving 44% Manual Methodsa................................65 3-6 Emissions from the Scen ario Involving 26% Manual Methodsa...............................66 3-7 Emissions from the Scenario In volving 100% Mechanical Methodsa, b.....................67 B-1: Raw Material Emissions...........................................................................................90 B-2: Emissions to Air........................................................................................................91 B-3: Emissions to Water...................................................................................................93 B-4: Emissions to Land.....................................................................................................94

PAGE 8

viii LIST OF FIGURES Figure page 3-1 World War II Army Barr acks at Fort McClellan...................................................... 68 3-2 Stages Involved in the Deconstruction Process.........................................................69 3-3 Total Impacts Calculated Using the EDIP Method Not Including Reuse of Salvaged Materials...................................................................................................70 3-4 Total Impacts Calculated Usin g the CML Method Not Including Reuse of Salvaged Materials...................................................................................................71 3-5 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged Materials But No Transportation to a Warehouse....................................................72 3-6 Total Impacts Calculated Using th e CML Method Reuse of Salvaged Materials But No Transportation to a Warehouse....................................................................73 3-7 Total Impacts Calculated Using the EDIP Method Including Reuse of Salvaged Materials and Transport to the Habitat for Humanity Warehouse in Austin, Texas........................................................................................................................74 3-8 Total Impacts Calculated Using th e CML Method Including Reuse of Salvaged Materials and Transport to the Habita t for Humanity Warehouse in Austin, Texas........................................................................................................................75

PAGE 9

ix Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Engineering LIFE CYCLE ANALYSIS OF THE DE CONSTRUCTION OF MILITARY BARRACKS: A CASE STUDY AT FT MCCLELLAN, ANNISTON, ALABAMA By Elizabeth OBrien May 2006 Chair: Angela Lindner Major Department: Environmental Engineering Sciences Nearly 2.5 million ft2 of barracks must be remove d from military facilities throughout the U.S. Environmental Protec tion Agency Region 4. While manual deconstruction offers promise for environmental, economic, and social benefits, the combination of mechanical and manual methods for minimal impact to the environment and public health is unknown. Here, life cycle analysis was used to determine an optimum level of manual deconstruction of barracks at Ft. McClellan in Anniston, Alabama. Four scenarios were compared with varying degrees of time required for manual deconstruction, 100% Manual, 44% Manual, 26% Manual, and 100% Mechanical, on the barracks. Data were collect ed directly from the site and applied using SimaPro modeling software (Pr Associates The Netherlands), considering three postdeconstruction options. Materials salv aged using either 100% or 44% Manual deconstruction and reused within a 20-mile ra dius of the deconstruction site yielded the most favorable environmental and health im pacts; however, given the significant impacts

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x involved in the life cycle of diesel fuel required for transpor tation, the need for developing reuse strategies for deconstruc ted materials at the regional level is emphasized.

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1 CHAPTER 1 INTRODUCTION Each year, the building industr y in the United States is re ported to generate nearly 136 million tons of construction and de molition (C&D) waste, amounting to 35-40 percent of the total amount of municipal solid waste (MSW ) produced annually (Dolan et al. 1999). Approximately 60 percent of this C&D waste originates from the demolition of buildings, and 80-90 percent of this waste is estimated to be either reusable or recyclable (McPhee 2002). While the reuse and recycling of C&D-related waste offers potential environmental advantages, the bui lding and deconstruction industry has not fully embraced these practices (Lippiatt 1998). Reuse and recycling of currently landf illed construction and demolition materials offer potential benefits in terms of decrease d landfill use and raw material extraction. A reduced amount of raw material extraction is a benefit to the environment because the extraction of raw materials may lead to resour ce depletion and biologi cal diversity losses. The extraction of raw materials normally occurs at sites far from manufacturing plants and the transport of raw materials and manufacturing of building products consume energy. The generation of this energy produ ces emissions linked to global warming, acid rain and smog. Also the waste generated from the manufacture and transport of the raw materials decreases the space available for dis posal in landfills. A ll of these activities from raw material extraction to landfilling are potential sources of air and water pollution. The goal of this proj ect is to discover the best way to lower bu ilding-related contributions to environmental problems (Lippiatt 1998).

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2 A Case for Deconstruction Most buildings are removed using demolition processes. Demolition is an equipment-intensive operation. Most of the crew is involved in operation of machinery and have very little physical contact with the actual building materials. Larger materials (usually metals, sometimes concrete and masonry) can be separated during demolition using machinery (Falk and Lantz 1996). D econstruction, on the other hand, is the systematic disassembly of buildings in or der to reuse and recycle as many of the component parts as possible, before or instead of standard mechanized demolition (Mcphee 2002). Deconstruction uses hand la bor and physical contact with the building by the workers and involves a methodical disass embly of building parts with similar care taken in this process as devoted to its reve rse process of construction. Because of this physical contact with the building, deconstruc tion takes about twice as long as demolition (Falk and Lantz 1996). As an alternative to demo lition, deconstruction has adva ntages and disadvantages: Advantages Recycling building materials conserves reso urces by diverting us ed materials from the landfill and avoiding use of virgin resources. For ev ery recovered square foot of wood used in new construction, a corres ponding square foot of virgin wood is not consumed. Therefore, salvaging redu ces the use of natural resources. The diversion of bulky and difficult-to-handl e C&D waste from the municipal solid waste (MSW) stream will increase the operating life of local landfills and will result in fewer associated environm ental impacts such as groundwater contamination (Dolan et al. 1999).

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3 Deconstruction and the resulting reuse of bu ilding materials results in avoidance of some of the costs of landfilling, prim arily transportation and tipping fees. Recovering materials may generate a cred it or otherwise subsidize the overall building disposal costs. A generated credit would allow the owner of the deconstructed building to receive money or materials from the user of the recovered materials. Landfill failures can result in remediation costs being assigned to former landfill contributors. By reducing landfill use, there could be a reduced future liability (Falk and Lantz 1996). Due to the increasing cost of materials manuf actured with virgin materials, recycled materials are becoming much cheaper in comparison. Salvaging reduces the total cost of mate rials since only the cost of removal, refurbishing, and transport is incurred by the sa lvage (NAHB 2003). The availability of high-quality virgin materials for the manufacture of building materials is decreasing. In many cases, th e sources of raw materials are great distances from installations or building projects, and hi gh transportation costs make contractors look for a local replacement. Many state and regional waste au thorities restrict the dis posal of bulk waste, such as furniture, appliances, and building equipm ent, to special solid waste handlers or landfills. This, in turn, has driven up th e disposal tipping fees. In most cases, any level of salvage reduces the cost of disposal. Timber that is recovered properly from older buildings is gaining acceptance in meeting the demand for large old-growth timber (Falk, R. and Lantz, S. 1996).

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4 Salvage recovers the highest percentage of the embodied resources in the materials or subsystems. The energy and raw materials consumed in the original manufacture of the materials or systems are not lost to landfill disposal (NAHB 2003). Disadvantages Building disposal may be more manageme nt-intensive for the building owner if multiple contracts are needed for the various types of abatement and disposal. Deconstruction takes twice as long as demolition. Demolition is more machine-intensive, while deconstruction is more laborintensive. Because of the increased numb er of workers on the deconstruction site, there is an increase in the emphasi s on site safety and coordination. The markets for nonvirgin building materials are very unstable. The acceptance of salvaged material is still in transi tion from local markets to national and international markets. Therefore, the va lue of the recovered materials is still difficult to predict (Falk and Lantz 1996). Salvaged materials are harder to sell. As yet, they do not have a standard grading system. So it is hard to tell for what application each board can be used. Before the deconstruction process, a dete rmination of whether the materials and/or assemblies can be removed in a cost-effective and safe manner must be made. This is vital information in assessing the economic feasibility of the project. Even when markets for the material exis t, deconstruction may not be financially justifiable if there is not enough material.

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5 If there is too much material and not enough storage space the salvage operation may not be able to occur. If the material has to be stored for an indefinite period of time, some types of materials, such as wa llboard, will lose their economic value. If they are not stored properly, degradation of their material properties may occur (Dolan et al. 1999). There are negative environmental impact s, such as dust generation, noise and vibrations (Thormark 2002). Deconstruction discards different wast e than construction or renovation and demolition. Deconstruction is more likely to contribute contaminated materials to landfills because all reusable materials are separated, leaving for disposal materials contaminated by potentially toxic substan ces, such as lead paints, stains, and adhesives (Dolan et al. 1999). Is Reuse of Non-Virgin Wood Possible? The U.S. Department of Defense (DOD) has 2,357,094 square feet of excess buildings that are in need of removal from military bases throughout U.S. EPA Region 4, encompassing the states of Alabama, Flor ida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina and Tennessee (Falk et al. 1999). The U.S. military is disposing of these barracks because the federal procurement law and military regulations listed under the U.S. Code of Federal Regulations CFR 32 162.2, will not allow federal tax dollars to be spent on the maintenance of facilit ies that are in surplus to its needs (Falk et al. 1999). In response to these regulations, th e U.S. Army is considering deconstruction of its barracks and salvaging of materials in order to accomplish its minimization goals and subsidize the overall disposal costs of the buildings, thus lowering funding

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6 requirements (Falk et al. 1999). However, th ere is a question as to whether 100% manual deconstruction of military barracks will yi eld optimum economic and environmental savings, particularly for those barracks built before World War II. The possibility of recovering timber and lumber from buildings is dependent on both physical and economic factors, which include: wood condition, dimensions, and species type and number of fasteners per piece exposure or protection from the elements labor cost allowable building disposal period site configuration and building height allowable on site recovered materials storage time The demand for nonvirgin timber and lumber can increase due to the following: Harvesting restrictions on high-quality, large-diameter, old-growth timber restrict its availability at any price. Prices of forest products are steadily increasing. Exposed timber frame construction demands high-quality large timber. Older species-specific wood may be desired for use in new log home construction and interior remodeling of older buildings. North American species may be consider ed exotic creating a demand in those markets. The more nonvirgin timber and lumber is used the more familiar buyers, designers, and builders will become with it.

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7 The demand for nonvirgin timber and lumber is restricted by the following factors: There are no grading standards or de sign rules specifically for nonvirgin wood materials; application of virgin materi al standards and rules on nonvirgin wood may have the effect of downgrading nonvirgin materials. Lumber used at a site must be graded. Without a grade, a timber grader must be present, or the materials will be rejected. Lack of consistent supplies and markets for nonvirgin timber and lumber. Owners and disposal contract ors are not aware of the va lue of nonvirgin timber and lumber so they make no attempt to recover them (Falk and Lantz 1996). Variability of the Quality of Lumber Service-related defects, such as drying checks, splits, bolt and nail holes, notches from other framing members or utilities and exposure to weather and decay, can affect the quality of recycled lumber. Depending on the building type and use, boards also may have been exposed to chemicals and extreme temperatures. Most im portantly, structural members have often experienced an unknow n load history (Green et al. 1999). When timber is first cut it is full of water. Before the days of drying kilns in mills, wood was allowed to dry naturally. This pro cess takes several years for large timbers. As the wood dries out, the timbers shrink. Th e location of the cut on the tree determines the kinds of splits or checks that occur in th e wood. A split is a separation of the wood as a result of the tearing of the wood cells (Fal k et al. 2000). A separation of the wood that occurs across or through the growth rings is a check. A separation that extends from one surface of a piece to the opposite or adjoining surface is a through check (Falk et al. 2000 73). If the timber was cut from the center (the heart of the tr ee), cracks (checks)

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8 will form in a radial pattern outward from th e center. If the timber was cut from the outside part of the tree (free of heart center), there will be less checking. Free of heart center timbers check less, but they cost more because they have to be cut from a much bigger tree (Falk et al. 2000). Heart checks have little effect on the stre ngth of the recycled timber columns, but they lower the modulus of rupture (Stress Grading of Recycled Lumber and Timber 1999). Checks also have little effect on column compressive strength. Although the checks have little effect on th e quality, the damage incurred during deconstruction lowers the quality of dimensional lumber from the reconstructed buildings on average one grade (Falk and Green 1999). The direct reuse of wood materials as a construction product faces many obstacles. The duration of loads, moisture cycling and fabrication changes durin g the service life of the wood are difficult to determine but quantif ying the remaining strength of the wood is necessary. Currently, there is no way to grade wood except on an individual piece-bypiece basis. This is a majo r obstacle to the reuse of tim ber. Typically, manufacturers will reuse heavy timbers only for post and frame buildings because they are dry and stable ( Green et al. 1999). Another obstacle to the direct reuse of wood materials occurs as a result of use or the dismantlement pro cess. Defects often e xhibited by recycled lumber can include mechanical damage (broken ends and edges of members, splits due to disassembly), damage from fasteners and hard ware (bolt holes, clusters of nail holes), and notches from other framing member s or utilities (Green et al. 1999). A Case for Virgin Wood Since 1953, 16 million acres of southern yellow pine timberland have been lost in the South. Suppression of wildfires, reduced prescribed burning, sout hern pine beetles,

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9 urban development, high-grading, and a lack of artificial regenerati on on privately owned timberlands are all factors that have contri buted to the decline of timberland. Treeplanting programs on agricultural lands have slowed the decline of timberland. In addition, according to the Southern Forest Reso urce Assessment, an increase in southern yellow pine timberland could occur if 23 million acres of former cropland and pastureland were planted to pines during the next four decades. This effort would probably require subsidies (South and Buckner 2003). Each American uses the equivalent of a 100-foot tree every year. The American population has increased from 76 million in 1900 to more than 250 million people in 1990. Therefore, over 14-billion 100-foot tr ees were grown and used from 1900 to 1990. And, due to good forest practices, two-thirds of the original forestland is left. Many people believe that, to obtain environm ental benefits from the forests, it is best to leave the trees untouched. More of ten, the opposite is true Forests with young trees that are growing and hea lthy generally have more enviro nmental benefits than older forests whose trees are stagnant or dying. Tree farming using modern forestry knowledge produces young healthy forests (Trees 1992). Trees, unlike steel and aluminum, are a renewable resource. In 2002, forest landowners planted nearly 1.7 billion seedlings. Besides planting new trees, forest landowners managed the natural regeneration of millions of other trees giving America nearly two and a half million acres of new, growing forests. For decades, America has been growing more wood than is harvested or lost to insects and di sease. And since the beginning of the 1980s, the total amount of forestland in America has increased by 27 million acres (Trees 1992).

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10 Trees produce 1.07 pounds of oxygen and use 1.47 pounds of carbon dioxide for every pound of wood they grow. An acre of trees can grow approximately 4,000 pounds of wood a year, using 5,880 pounds of car bon dioxide and giving off 4,280 pounds of oxygen in the process (South and Buckner 2003). Forests benefit our population in two wa ys. The first is by producing wood. People use an average of 15,824 board feet of lumber and up to 10,893 square feet of panels in each house that is built. Over 600 pounds of paper per a person are produced a year for books, diapers, packaging, and all the other paper products. Trees are also a benefit due to the oxygen they produce. One person needs 365 pounds of oxygen per year, and that oxygen is manu factured through plants and trees (South and Buckner 2003). America is slowly becoming a paperless society as electronic copies become the more cost and time-efficient way to do busin ess. Before the industrialization of our nation, tree harvesting was minimal. However, now that our nation is industrialized, the harvesting of trees is one of the best ways to counteract the produc tion of air pollution. As trees age, they consume less carbon di oxide, so growing new trees allows more carbon dioxide to be taken up and oxygen to be released making our air more breathable. The harvesting of trees is important because it gives new trees room to grow and keeps carbon dioxide stored in old wood. As forests age and become more overcrowd ed, little growth occurs; however, trees begin to use oxygen instead of releasing oxygen; and more wood may decay than grow. For every pound of wood that decays (or combusts), 1.07 pou nds of oxygen are used, and 1.47 pounds of carbon dioxide are released (South and Buckner 2003). As a result of this

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11 reversal of CO2 removal/oxygen release, care must be taken to avoid wood decay or combustion and to ensure that new trees are in abundance. Besides creating more breathable air, trees cool the air by providing water evaporation. Trees act like huge pumps cycling the water up from the soil and back into the air (South and Buckner 2003). A 100-foot tree with 200,000 leaves, for example, can remove 11,000 gallons of water from the soil and release it into the air in one growing season. This cooling effect of water evapora tion by latent heat tran sfer is said to be equivalent to air conditioning for 12,168 square foot rooms. In fact, one solution to combat global warming is forest regene ration and maintenance (South and Buckner 2003). When a forest grows naturally, it goes thr ough cycles. A wild forest may start out with as many as 15,000 small seedlings per acre. Over a typical 60to 100-year cycle, at least 14,700 of the original trees 98 percent will die as the trees compete for space. Modern forestry finds ways to use this natural mortality and improve and maintain forests at the same time (South and Buckner 2003). Modern forestry uses many different types of harvesting, depending on many factors, including the terrain a nd the conditions that are need ed to plant a forest (South and Buckner 2003). More than half of the timber harvested each year in the United States is used in some form of solid wood product: lumber, panels of veneer, or chips for both structural and nonstructural applications and miscellaneous products, such as posts, poles, and pilings. Although a significant amount is used in manufacturing and shipping, construction activity accounts for the majority of solid wood products consumption (more than 60 percent of lumber and more than 80 pe rcent of structural pa nels). As a result,

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12 consumption and prices of lumber are highly sensitive to fluctuations in new housing and other construction activity (Adams 2002). Th erefore, use of virg in wood maintains the production of trees, however, salvaging wood pr events the already harvested trees from decaying in landfills. Research Scope The focus of this paper is the life cycle comparison of four identical barracks located at Fort McClellan in Anniston, Alab ama, deconstructed with varying degrees of hand and mechanical methods, ranging from 100% mechanical demolition to 100% manual deconstruction. Using data carefully collected during th e deconstruction and demolition processes, the specific emissions and resulting environmental impacts of the four scenarios are compared using LC A methods and are reported herein. Since steel and masonry building materials we re being redirected to other parts of the war effort, many of the army facilities that were built during the World War II era were built of timber. Many of these facilities were classified as surplus to the nations defense requirements at the end of the Cold War era in the early 1990s. The current situation in the military is contrary to the pa st trend of adding buildings to the industrial inventory while continuing to use existing bui ldings. In the past, any disposal of buildings was incidental to other ongoing ope rations and, as such, was often handled on an individual basis. This disposal was ba sed on administrative decisions and disposal practices. The typical disposal practice for such facilities has been demolition, with the debris placed in a landfill (Falk, R. and Lant z, S. 1996). Several army bases have been closed since 1990, and many of the World Wa r II barracks are no longer used (Falk, R. and Lantz, S. 1996). Since federal tax dolla rs cannot be spent to maintain surplus facilities, many of these army facilities must be demolished. In 1995, over 250,000,000

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13 board feet (BF) of lumber were estimated to be available for reuse from the World War II wood buildings then slated for demolition (Falk 2002). At Ft. McClellan in Anniston, Alabam a, deconstruction and demolition was performed on three barracks on site with varying degrees of mechanical and manual labor. This project involves a life cycle a ssessment (LCA) to determine if the reuse of wood salvaged from the deconstruction of the barracks is a viable alternative to using virgin wood. The Environm ental Protection Agency states an LCA examines the environmental releases and impacts of a specific product by tracking its development from a raw material, through its production and to eventual disposal. An LCA was performed on all four scenarios to compare the inputs and outputs of each scenario in the form of environmental impacts, energy consum ed and labor required. This project was completed to help the DOD determine the square footage of barracks that need removal and to compare and contrast environmental impacts of deconstruction and demolition. This project will have a direct impact on th e ability to plan the most environmentally effective deconstruction of the barracks c ontained in EPA Region 4. This plan is intended to aid the U.S. Army to meet its waste minimization goals, to provide materials at lower cost for new construction on bases on or close to deconstruction sites, and to increase the number of civili an jobs. The hypothesis of the project is that 100% manual deconstruction will have the lowest environmental impacts of any of the four scenarios because it is assumed the machinery will be used for the least amount of time and fewer materials will be landfilled. Therefore the least amount of emissions should be produced in the 100% manual deconstruction scenario.

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14 CHAPTER 2 REVIEW OF LITERATURE Amount of Construction Each Year Over the last three decades lumber consumption has increased by nearly one-third, and structural panel use has more than doubled. The Resources Planning Act (RPA) Timber Assessment projects that the consump tion of solid wood products will continue to grow in the future through the expansion of both construction and nonconstruction uses due to Americas growing population and increasing wealth (Adams 2002). It is projected that, every year for th e next 50 years, 1.43 million new households will be constructed, thus creating approxima tely 71 million additional separate living units. Approximately, 1.93 million houses will al so be improved each year for the next 50 years. The primary driver of the new construction and improvements is an aging, healthy, retired population acquiri ng second homes (Adams 2002). Reflecting the trend of an aging populati on and the declining number of people per household, the average size of new housing units is projected to stabil ize over the next 40 years and then rise in the final decade of the projection. By 2050, the average size of a single-family unit will increase from the cu rrent average of 2,160 square feet to 2,600 square feet. Multiple-family housing will expand from 1,000 to 1,200 square feet, and mobile homes will grow from 1,350 to 1,950 sq uare feet (Adams 2002). In 2004, singlefamily houses had already increased to an average size of 2,225 square feet (CORRIM 2004). Since 1991, the consumption of lumber ha s been growing stead ily. A historical high of 68.2 billion board feet (bbf) c onsumed was reached in 1999 (Adams 2002).

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15 Amount of Deconstruction/Demolition Each Year The average age of housing in the United St ates is over 30 years, necessitating their improvement or demolition. According to the Census Bureau, approximately 245,000 dwelling units and 45,000 non-residential uni ts are demolished every year, creating approximately 74 million tons of debris a year. Using deconstruction to remove buildings can convert demolition waste into construction materials. For example, by deconstructing one-fourth of the buildings instead of demolishing them, approximately 20 million tons of debris could be dive rted from landfills each year (NAHB 2003). Increased Availability of Materials The past century has seen a major populat ion boom in the United States. During this time many new residential homes, commerc ial and industrial build ings, bridges, and other structures were built from sawn lumb er and timber. As these buildings become ready to be torn down, much of this lumber may be available for reuse. Over three trillion board feet of lumber and timber ha ve been processed in the U.S. since 1900. Much of this wood is still residing in existing structures. When these structures reach the end of their service lives, become obsole te, or change use, contemporary practices emphasize quick, cheap disposal in landfills (Gre en et al. 1999). Recently, public interest has been expressed in finding environmentally acceptable and efficient material reuse options that focus on deconstruction and re use of materials in new construction and remodeling activities (Green et al. 1999). Along with growing public interest in incr easing the amount of recycling/reuse of C&D waste, federal agencies, such as th e United States Environmental Protection Agency (USEPA) and General Services Agen cy (GSA), have developed policies to promote an increase in the use of recycled content products. Building materials have not

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16 been emphasized in these procurement guidelines until recently. Increased recycling of C&D waste promises to close the loop of material procurement and reuse by increasing the amount of materials avai lable (Dolan et al. 1999). How are Virgin Trees Turned Into Usable Wood? The life cycle of timber products includes the following stages: Growing timber Harvesting timber/cutting it down Processing/making it into a useable product Installation into a building Maintaining, preserving, painting Replacement Disposal via landfill, incinerator/burning or recycling Transport at each stage Virgin Wood Processes Harvesting Timber used for the construction of ne w houses and the renovation of old houses all comes from one source-trees. The harvesting of trees occurs in three stages: the felling and bunching of trees, the movement of th e trees from the forest to the site where they are loaded on the truck and the load ing of the trees onto the truck (Long 2003). A feller buncher is used in the first stage (felling and bunching of trees). The feller buncher cuts down a group of trees using a saw blade that is located on the bottom of the feller buncher between two clamps. There are also two more sets of clamps located above the saw blade. All three sets of clamps are brought together at the same time. As

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17 the saw blade cuts the tree, the two upper sets of clamps grab hold of the tree. Normally feller bunchers cut trees that are between 8 and 18 in diameter. It cuts several trees at a time, lays the trees down, and moves on to cut down the next tree (Long 2003). Photos of feller bunchers can be accessed at http://www.deere.com/en_US/cfd/forestry/d eere_forestry/feller _bunchers/tracked/703G_ general.html, http://catused. cat.com/equipment/view-equipmentdetail.html?equipmentPK=Eq1.545735F, and http://www.franklintreefarmer.com/fellerbunchers/Fellerbunchers.html. A rubber-tired skidder delimbs the downe d trees by directing them through steel grates and then moves them from the forest to the loading area (Long 2003). Photos of rubber-tired skidders can be accessed at http://www.vanna ttabros.com/skidder1.html. Log loaders are used to sort the wood by si ze and to pick the trees up from the ground and load them on eighteen-wheeler trucks, whic h carry the logs to the mill (Long 2003). Photos of log loaders can be observed at http://www.vannattabros.com/drott.html and http://www.madillequipment.com/loaders.html. Sawmill Logs are converted into lumber in a sa wmill after they are unloaded from the eighteenwheeler truck. The first step is to cut the logs to specified log lengths, and then the logs are sawn by a chippi ng saw or a bandsaw, edgers, a trimmer and a resaw. The focus of these processes is to maximize the lumber extraction. The tim ber is cut into twoinch thick boards of varying wi dths and lengths, and sorted by size before it is kiln-dried. The lumber is then planed using a plane saw and graded by graders. The kilns, which are controlled by computers, dry rough, green lumb er with a moisture content of about 50% to a desired moisture content of about 10% in approximately 24 hours. Lumber is planed

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18 to the desired size and finished in the planermill. Then the lumber is shipped to consumers (Long 2003). The Deconstruction Process Raw Material Extraction Deconstruction is used to extract materials that will be reused in new construction and remodeling activities. The main raw material that comes from deconstruction is reusable wood. Other raw materials that ca n be salvaged include showers, urinals, mercury ballasts, and doors. Before deconstruction begins, the building is surveyed to determine what can and cannot be salvaged. Visible defects, subtle signs of wear and tear, and the ease with which materials can be removed are observed. Deconstruction is both labor-intensive and time-consuming, comparable to buildi ng a new structure only in reverse order (Yeung and David 1998). Deconstruction starts with removing the shingles from the roof and pulling out nails to take out the sheathing. The roof boards are then pried loose, handed down, further denailed, si zed and stacked. Next, workers take nails from the rafters, knock the boards apart, and hand them down to be denailed and sorted. Then the ceiling joists are knocked off and lowered dow n (Block 1998). This process continues throughout the whole building. Deconstruction can be contrasted with the sorting and salvaging of demolition debris. The biggest problem with sorting and salvaging of demolition debris is that, during demolition, the debris is mixed. Even during the deconstruction process, when the structure is carefully dismantled by manual labor, the mixing of different types of materials is still possible. For example, removing the exterior wall in a load-bearing masonry system will result in a combination of masonry materials including concrete

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19 blocks or bricks, reinforcing steel, metal ties and grout (Dolan et al. 1999). These dissimilar materials must be separated if they are to be recycled or reused. The composition of C&D waste varies depe nding on the type of project and the method of construction and demolition. In ge neral, wood comprises one-quarter to onethird of the C&D waste stream. As shown in Table 2-1, C&D waste can be divided into sixteen categories of materials, which can be furtherdivided into several different subcategories of materials. The informa tion listed in Table 2-1 includes all of the individual components that may be found in a building. Many of these classes of materials, such as concrete, masonry, and cer amics are inert and thus not susceptible to degradation by bacterial activity once landfilled. There are, ho wever, several components of C&D waste that are not inert in nature and, therefore, are putrescible. The best example of a material the will putrefy under th e proper conditions in a landfill is wood. Also several types of these materials can be considered chemically-reactive, such as paint and paint thinner, and they must be handled in a special manner (Dolan et al. 1999). Table 2-1. C&D Waste Materi al Categories and Sources Waste Material Demolition Source Construction Source Asphalt Roads, bridges, parking lots, roofing materials, Same flooring materials Brick Masonry building equipment white goods, Same appliances installed equipment Ceramics/clay Plumbing fixtures, tile Same Concrete Foundation, reinforced concrete frame, Same sidewalks, parking lots, driveways Contaminants Lead-based paint, asbestos insulation, fiberglass, Paints, finishes fuel tanks Fiber-based Ceiling systems materials, insulation Same Glass Windows, doors N/A Gypsum/plaster Wall board, interior partitions Same

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20 Table 2-1 continued Waste Material Demolition Source Construction Source Metals, ferrous Structural steel, pipe s roofing, flashing, iron, stainless steel Same Metals, nonferrous Aluminum, copper, brass, lead Same Paper/cardboard N/A Corrugated cardboard, packaging Plastics Vinyl siding, doors, wi ndows, signage, plumbing Same Soil Site clearance Same, packaging Wood, treated Plywood: pressureor creosote-treated, laminates Same Wood, untreated Framing, scraps, stumps, tops, limbs Same The amount of C&D waste produced in th e United States depends on several variables including: The extent of growth and overall economic development that will drive the levelof construction, renovation, and demolition; Periodic special projects, such as urban renewal, road construction and bridge repair, and unplanned events, such as natural disasters; Availability and cost of ha uling and disposal options; Local, state and federal regulations concer ning separation, reuse, and recycling of C&D waste; Availability of recycling facilities and the extent of end-use markets (Dolan et al. 1999). The composition and quality of waste materi als will vary greatly from building to building. Any of the 16 categories of waste foun d in Table 2-1 is expected to be found in a typical residential, commercial or institutional project. The physical composition of building materials changes dramatically de pending on the age of the project (for renovation and demolition projects), resour ce availability and construction/demolition practices used. There are three main factors th at affect the characte ristics of C&D waste:

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21 the structure type (e.g., reside ntial, commercial or industr ial building, road, bridge), structure size (e.g., low-rise, high-rise), a nd activity being perform ed (e.g., construction, renovation, repair, demolition). Some additi onal factors that influence the type and quantity of C&D waste produced are the size of the project (e.g., custom built residence versus tract housing), the loca tion of the project (e.g, wate rfront versus inland, rural versus urban), materials used in the cons truction (e.g., brick versus wood), the demolition practices (e.g., manual verses mechanical), sc hedule (e.g., rushed versus paced), and the way the contractor keeps track of and take s care of materials (Dolan et al. 1999). Salvaging materials has several advantag es for both the construction industry and solid waste management. It recovers the mo st resources and the initial energy and raw materials used for the virgin manufacture are not lost to landfill disposal. Also, salvaging materials reduces the overall cost of the ma terials since only the cost of removal, refurbishing and transport are included in the final price of the material. Salvaging materials also reduces the cost of disposal (Dolan et al. 1999). Material Refining Once the wood is removed from the building, it must be cleaned before it can be reused. The first step taken to make the wood reusable is dena iling. Denailing is accomplished using a denailing gun, which opera tes reverse of a nail gun. Removal of nails without damaging the wood using a de nailing gun requires approximately 30% of the time necessary to remove the boards from the building (Guy 2005). At a typical deconstruction site, a denailing gun is powered by a generator and runs approximately 8 hours a day (Guy 2005). Painted wood is not stripped unless it is covered in lead-based paint (LBP). Wood covered with paint containing no lead can be stripped by the consumer if needed. If the

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22 end of the wood is rotten, it is still resold and the consum er can remove the end. If however, nails are clustered at the rotten end, it is cut off before sale to a customer (Guy 2005). The processing of lumber after a decons truction process takes approximately 0.008 labor hours per linear foot of lumber. Proce ssing the lumber involves 3 steps: moving the lumber from an original pile to the de nailing station, denailing the boards using a compressor and a denailing gun, and restacking the boards (Guy 2005). Use/Reuse The wood salvaged from deconstruction is ideally reused in new construction and renovation projects; however, several barriers ex ist to making this practice a reality. The largest barrier is the difficu lty project managers and solid waste authorities have in identifying markets for the debris. Another barrier is the accurate characterization of C&D waste due to the high variability of the content and quantity of C&D waste. This variability is due to the nature of the waste, the dispersion of C&D activities, inconsistent waste management regulations, range of dis posal options, and the variance in cost of disposal options (Dolan et al. 1999 58). Da mage is incurred on C&D waste as a result of 1) the original construction process (nail hoes, bolt hoes, saw cuts, notches), 2) building use (drying defects, decay and term ite damage), and/or 3) the deconstruction process (edge damage, end damage, end splitting, and gouges). The main reason for the inconsistencies in reusable wood is damage during the deconstruction process (Falk and Green 1999). Joists, particularly those lo cated on the first floor, decay more frequently than other timbers because of their proxi mity to the ground. Water l eakage causes th e joists in bathroom areas to decay most often (Falk et al. 1999). Larger timbers (such as support

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23 columns) command a high price and are regular ly recycled, whereas dimensional lumber is not often reused (Falk and Green 1999). There are several potential advantages of reusing recycled lumber. First, a significant quantity of recycled lumber is de rived from old-growth timber and may have a tighter grain structure. Second, recycled lumb er is relatively dry, with less tendency to warp on the job site (Falk et al. 1999). Thir d, salvage yards sell recycled lumber at about 50% of retail lumber prices (Falk 2002). Disposal The Florida Administrative Code (FAC) allo ws the use of C&D debris facilities in addition to Class I, II and III landfills. Rule 62-701.200 (25) defines C&D debris as: Discarded materials generally considered to be not soluble in water and nonhazardous in nature, including but not limited to steel, glass, brick, concrete, asphalt material, pipe, gypsum wallboar d, and lumber, from the construction or destruction of a structure as part of a construction or demolition project or from the renovation of a structure, including such de bris from construction of structures at a site remote from the construction or demolition project site. The term includes rocks, soils, tree remains, trees, and othe r vegetative matter (that normally result from land clearing or land development ope rations for a construc tion project), clean cardboard, paper, plastic, wood, and meta l scraps from a construction project; Effective January 1, 1997, except as pr ovided in Section 403.707(13)(j), F.S., unpainted, nontreated wood scraps from fac ilities manufacturing materials used for construction of structures or their components and unpainte d, non-treated wood pallets provided the wood scraps and palle ts are separated from other solid waste

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24 where generated and the generator of su ch wood scraps or pallets implements reasonable practices of the generating i ndustry to minimize the commingling of wood scraps or pallets with other solid waste; and De minimis amounts of other non-hazardous wa stes that are generated at construction or demolition projects, provided such amounts are consistent with best management practices of the cons truction and demolition industries; Mixing of construction and demolition debris with other types of solid waste will cause it to be classified as other than construction and demolition debris (FAC 62701.200). Landfills are typed as Class I, II and III. Class I landfills receive an average of 20 tons or more of solid waste per day. Class II landfills receive an average of less than 20 tons of solid waste per day. Class I and II landfills receive ge neral, non-hazardous household, commercial, industrial and ag ricultural wastes, following Rules 62-701.300 and 62-701.520, F.A.C. C&D waste is disposed of in a Class III landf ill. In rule 62701.200 of the Florida Administrative Code (FAC ) Class III landfills ar e defined as those that receive only yard trash, construction and demolition debr is, waste tires, asbestos, carpet, cardboard, paper, glass, plastic, fu rniture other than app liances, and any other materials approved by the Florida Department of Environmental Protection (FDEP). Any materials approved by the FDEP for disposal are not expected to produce leachate that endangers public health or the environment. Putrescible household waste is not accepted in Class III landfills. Since Class III landfills do not receive MSW for disposal, they are not required to be lined automatically. Special requirements fo r Class III landfills are contained in Rule

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25 62-701.340(3)(d), F.A.C., which states that Clas s III landfills can be exempt from some or all requirements for landfill liners, leachat e controls and water quality monitoring it that no signifigant threat to the enviro nment will result from the exemption. The language in this rule results in the need for a liner in a Class III landf ill to be determined on a case-by-case basis by each department di strict office. The determination of each case will be made by the Department in a wa y that will protect both human health and the environment (ICF 1995). The average cost of disposal of C& D waste in Florida is $32.06/ton, ranging anywhere from $5.00/ton in Okaloosa C ounty to $92.00/ton in Monroe County (ICF 1995). This average cost of disposal is seemingly high, most likely because disposal costs at private facilities, which are significantly lower, were not included. Disadvantages of Unlined Landfills Leachate is formed when water washes over garbage in landfills, soaks through the landfilled material, and exits th e other side carrying contaminan ts. The fate of hazardous constituents in C&D materials, such as acry lic acid, styrene, vinyl toluene, nitrile and copper (Table 2-2) may include leachi ng into nearby groundwater aquifers or volatilization into th e surrounding air. As a result potential impacts of C&D waste disposal in unlined landfills may include drin king water contamination and fire hazards.

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26 Table 2-2. Amount of Chemical Constituen ts in Wood Products (Construction and Demolition Waste Landfills 1995) Wood Product Chemical Constituent Amount of Note Chemical(s) in Wood Product pallets and skids, pentachlorophenol < 10 ppm a (hardwood/softwood) lindane dimethylphthalate copper-8-quinolinolate copper naphthenate pallets, plywood phenolic resins 2-4% a pallets, glued epoxy 2-4% painted wood, lead-based paint lead 1400-20,000 ppm b (before 1950) painted wood, acrylic-based paint acrylic acid, styrene, vinyl toluene, < 0.01% nitriiles painted wood, "metallic" pigments aluminum powder, copper acetate, < 0.01% phenyl mercuric acetate, zinc chromate, titanium dioxide, copper ferrocyanide plywood, interior grade urea formaldehyde (UF) resins 2-4% c plywood, exterior grade phenol form aldehyde (PF) resins 2-4% c oriented strandboard phenol form aldehyde resins, or 2-4% PF/isocynate resins waterboard urea formaldehyde resins, or 5-15% UF d "Aspenite phenolic resins 2.5% PF, 2% wax

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27 Table 2-2. continued overlay panels phenol formaldehyde resins 4-8%, sometimes up to 10% plywood/PVC laminate urea fomaldehyde 2.5% UF polyvinyl chloride 10% PVC particleboard urea formaldehyde resins 5-15% UF d particleboard with PVC laminate UF resins with polyvinyl chloride 4.5%UF 10% PVC hardboard phenolic resins 1.50% fencing and decks: pressu re CCA or ACA 1-3% e treated southern pine CCA or ACA 1-3% e fencing and decks: surface treated pentachlorophenol 1.2-1.5% f utility poles, laminated beams, freshwater pilings, bridge timbers, decking, fencing railroad ties, utility poles creosote containing 85% PAHs 14-20% g freshwater pilings, docks creoso te coal tar 15-20% marine pilings, docks creosote/chlorpyrifos15-20% a. Hardwood pallets are used primarily in the east ern U.S.; softwood and plywood pallets are used primarily in the western U.S. b. Lead level is highly dependent on the age of the paint; before 1950 lead comprised as much as 50% of the paint film. Legislation in 1976 reduced the standard to 0.06% by weight. c. Plywood may be surface-coated with fire reta rdants, preservatives and insecticides, or pressuretreated with CCA. d. May be sealed with polyurethane or other sealant to prevent off gassing of formaldehyde. e. Dominant wood preservative; actual levels will be lower due to evaporation or leaching after treatment. f. Restricted use due to industry change and concern over dioxin linkage; not permitted for residential uses. g. Losses after treatment estimated to be 20-50% over 10-25 years; not recommended for residential use.

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28 Costs of Deconstruction Verses Demolition When well-trained crews are employed for the deconstruction of buildings, deconstruction is very competitive with de molition because deconstruction companies are relatively inexpensive to start and multiple streams of revenue occurring during each deconstruction job. These revenue streams ar e the job contract, reduced tipping fees, a percentage of the resale of materials, and tax deductions for the donation of materials to nonprofit organizations. The most successful deconstruction companies either own or partner with a retail yard that sells salvaged materials (h igh-value architectural pieces, dimensional lumber, windows, doors, hardware and more) at affordable, but profitable prices (Mcphee 2002). A well-tr ained deconstruction team can contend with the price of mechanical demolition. For example in Hartford, Connecticut, deconstruction teams deconstructed a building at a cost of $2/squa re foot this was a 33 percent savings over mechanical demolition. Also deconstruction projects can reduce tipping costs by as much as 50 to 85 percent (Mcphee 2002). Due to the decreased amount of availabl e landfill space and the increasing costs of managing landfill tipping fees, recycling C&D waste not only recovers valuable resources, it saves money. Because of thes e changes in cost, C&D waste recovery and reuse of waste is becoming economica lly feasible (Dolan et al. 1999). The cost of buying these recycled material s on the market depends on the cost of storage, collection, transportati on, and other costs for the processor. The most important driving force of cost is the demand for thes e materials. This depends on short-term demand for and availability of virgin material The scarcer a resource is, the higher the

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29 resale cost and thus the more feasible dec onstruction will be cons idered. There are at least six key factors that dr ive the supply, demand, and pric ing of recycled materials: 1. Export markets The Far East, where fiber is in short supply, represents a particularly strong export mark et for recycled materials. 2. Virgin capacities and recycled capacities When the price and availability of virgin commodities change, the price and availability of recycled commodities follow. 3. Geography A West Coast generator with access to markets in the Pacific Rim has different marketing opportunities than a generator in the Midwest. 4. Transportation costs The distance to market plays a role in the pricing of all commodities, whether recycled or virgin. 5. End product demand Recycled materials serve three key sectors of the economy: automobiles, housing and retail. When th e auto industry booms, so do the steel and plastic industries. When housing booms, bus iness increases for suppliers of steel, paper, plastic and other virgin and recycled materials. Likewise, when retail sales climb, so do paper and plastic packaging material sales. 6. Natural disasters around the world When a community begi ns to rebuild after a natural disaster, demand for recycled mate rials in all areas of the world spike (Dolan et al. 1999). To reduce the uncertainty associated with recycling/reusing the materials gathered from large-scale or long-term projects, an explicit commitment among the general contractor or project manager, hauler and market should be established (Dolan et al. 1999). This will ensure a market for the mate rials and guarantee that the deconstruction is worth the extra time and effort.

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30 The most critical component for reuse of C&D waste is the identification of a market for the waste material. Once a market is found to exist, the material becomes a commodity not a waste. For reuse of materi als to be economically successful, there must be a stable, profitable market. The Solid Waste Association of North America (SWANA) suggests that, to have a market for the C&D waste, there are five requirements that must be met and agreed upon by both the buyer and th e seller: (1) specifications, (2) quantity, (3) delivery conditions, (4) price, an d (5) commitment (Dolan et al. 1999). For most Army facilities, an extensive C&D waste reuse operation will require a large investment of both time and money. De nison and Ruston (1990) listed factors that should be considered by solid waste and projec t managers before beginning any type of a reuse operation to ensure that the reuse pr oject is both financia lly and technically feasible: 1. quantity of waste generated 2. composition of the waste 3. materials targeted for recycling a nd the methods of recovery 4. expected value 5. necessary additional processing required to prepare the recovered materials for the market 6. costs of recycling, handli ng, collecting, and processing 7. financial and logistical risks and uncertainties 8. availability of markets for recovered ma terials, current market prices, price instability, and the potential effect of ma rket development programs (Dolan et al. 1999).

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31 Army Technical Manual Rule 5-634 states that the adde d costs (increased time, effort, and equipment) plus the sales revenue of a recycling program will determine its economic feasibility (TM 5-634, p 4-79). If the added costs exceed the avoided costs plus revenue, the operation should not be performed (Dol an et al. 1999). Many contractors are doubtful of the time a nd cost effectiveness of deconstruction, thus hampering its general acceptance. When savings in disposal costs and the resale value of building materials are considered, d econstruction becomes more attractive. An even more appealing aspect of salvage and deconstruction is the environmental benefits, including reduction of waste materials which may be incinerated or landfilled. This may improve air and water quality and will redu ce landfill use. Also sometimes lumber recovered from deconstruction proj ects is vintage or priceles s. Building materials yards may have old growth timbers, architectur al trimmings and anti que doorknob (Yeung and David 1998). Salvageable materials include plywood, lumber, hardwo od flooring, bricks, windows, concrete, plumbing fixtures, door s and knobs, hinges, paneling, insulation, stairs and railings, asphalt roof tiles, moldings and ba seboards and countertops. The recycling of building materials gives its grea test benefit to the consumer, who purchases the material at incredibly lo w prices (Yeung and David 1998). The following equation can be used to determine the net deconstruction cost: (Deconstruction + Disposal + Processing) (Contract Price + Salvage Value) = Net Deconstruction Costs. The net cost for demolition use is calculated by the equation (Demolition + Disposal) (Contract Price) = Net Demolition Costs. When the salvaged materials are not resold or re distributed on-site or reused by the deconstruction contractor in new construction, transportation and st orage costs may be additional costs for

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32 deconstruction. For deconstruction to be cost effective and competitive with traditional demolition and disposal the sum of the savings from disposal, revenues from resale of materials must be greater than the incremental increase in labor costs. To increase the percentage of time spent in deconstruction activity and decrease overall time costs, a buildings materials should be deemed wo rth salvaging and with efficient resale mechanisms and markets. Removing and rese lling materials as quickly as possible can overcome the disincentive for deconstruction created by the time costs of development and building loans. Deconstruction is also more cost effective when the site is large allowing the unwanted structure to be isolated from the other construction activity and be deconstructed without delaying the site deve lopment. On the other hand when the new construction will take place on the footprint of the existing structure, the time for removal of the existing structure by deconstruction is a significant economic impediment (Guy 2001).

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33 CHAPTER 3 LIFE CYCLE ANALYSIS Abstract Nearly 2.5 million ft2 of barracks must be remove d from military facilities throughout the U.S. Environmental Protec tion Agency Region 4. While manual deconstruction offers promise for environmental, economic, and social benefits, the combination of mechanical and manual methods for minimal impact to the environment and public health is unknown. Here, life cycle analysis was used to determine an optimum level of manual deconstruction of barracks at Ft. McClellan in Anniston, Alabama. Four scenarios were compared with varying degree of time required for manual deconstruction, 100% Manual, 44% Manual, 26% Manual, and 100% Mechanical, on the barracks. Data were collect ed directly from the site and applied using SimaPro modeling software (Pr Associates The Netherlands), considering three postdeconstruction options. Materials salv aged using either 100% or 44% Manual deconstruction and reused within a 20-mile ra dius of the deconstruction site yielded the most favorable environmental and health im pacts; however, given the significant impacts involved in the life cycle of diesel fuel required for transpor tation, the need for developing reuse strategies for deconstruc ted materials at the regional level is emphasized.

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34 Introduction Each year, the building industr y in the United States is re ported to generate nearly 136 million tons of construction and de molition (C&D) waste, amounting to 35-40 percent of the total amount of municipal solid waste (MSW ) produced annually (Dolan et al. 1999). Approximately 60 percent of this C&D waste originates from the demolition of buildings, and 80-90 percent is estimated to be either reusable or recyclable (McPhee 2002). While reuse and recycle of C&D-rela ted waste offers potential environmental advantages, the building and deconstructi on industry has not fully embraced these practices (Lippiatt 1998). There are two different methods for the removal of buildingsdeconstruction and demolitionand the method used greatly influen ces the amount of salvaged (reusable) material gained. Demolition, the most ofte n used means of building removal, is equipment-intensive, requiring machiner y throughout the process for leveling the building and separating the larger material s. Because most of the labor involves machinery operation, the crew has very little physical contact with the actual building materials (Falk and Lantz 1996). Deconstr uction, on the other hand, involves the methodical disassembly of buildings in or der to reuse or recycle as many of the component parts of the building as possible, before or instead of demolition (McPhee 2002). Deconstruction can invol ve hand labor only and alwa ys involves actual physical contact with the building by the workers, t hus resulting in time requirements that are approximately twice that of de molition (Falk and Lantz 1996). The additional time burden and percep tion of associated increased costs accompanying deconstruction have hampered its practice. Another pot ential drawback of deconstruction is the need to tend to a greater level of detail at every stage of the removal

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35 process. For example, increased planning is required in order to assess the type and amount of materials that can potentially be salvaged. Th e actual deconstruction phase must involve greater oversight of the labor, while recovered ma terials must be stored and protected on site before removal to their fi nal destination. Also, most of the salvaged lumber can only be used for non-structural applications, such as in decks and nonsupporting walls, unless the materials are re-g raded (Falk et al. 1999). In order to minimize the time and cost burdens of dec onstruction while stil l ensuring gain of salvaged materials, this practice can be comb ined with demolition. However, the degree at which this combination of building re moval practices becomes economically and environmentally beneficial is not known. This work presents results of a case study performed on military barracks at Ft. McClellan in Anniston, Alabama, for the pur pose of determining the benefits of combining deconstruction and demolition. Military buildings in need of removal throughout the U.S. offer tremendous potential for materials recovery and reuse. The U.S. Department of Defense (DOD) has 2,357,094 square feet of excess buildings that are in need of removal from military bases throughout U.S. EPA Region 4 alone, encompassing the states of Alabama, Flor ida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina and Tennessee (Falk et al. 1999). The U.S. military is disposing of these barracks because the federal procurement law and military regulations listed under the U.S. Code of Federal Regulations (CFR 32 162.2) will not allow federal tax dollars to be spent on the maintenance of facilit ies that are in surplus of its needs (Falk et al. 1999, CFR 2004). In response to these regulations, the U.S. Army is considering deconstruction of its barracks and salvaging of materials in orde r to accomplish its

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36 minimization goals and subsid ize the overall disposal cost s of the buildings, thus lowering funding requirements (Falk et al. 1999 ). However, there is a question as to whether 100% manual deconstruction of military barracks will yield optimum economic and environmental savings, particularly for those barracks built before World War II. This project, funded by the U.S. DOD, sought to determine the optimum levels of manual deconstruction and mechanical demolition of pre-World War II barracks using a life cycle approach. Life cycl e analysis (LCA) is a method th at enables quan tification of the environmental and public health impact s of an activity or product throughout its entire life. This cradle-to-grave approach is based on the knowledge that each stage in a products life has potential to contribute to its environmental impacts. Considering a buildings life cycle, these stages include ra w material extraction a nd processing, material manufacture (e.g., wood harvesting and m illing), transportatio n, installation (e.g., construction), operation and maintenance, and, ultimately, recycling and waste management (e.g., salvaging of materials fo r recycling or reuse) (Lippiatt 1998). The focus of this paper is the life cycl e comparison of four identical World War IIera barracks. Data were caref ully collected from a previ ous study on three Ft. McClellan barracks, deconstructed using different methods of manual effort that were accompanied by different time requirements for manual i nvolvement. The specific emissions and resulting environmental impacts and cost savi ngs or burdens of the three scenarios are compared to traditional mechanical demo lition using LCA methods and are reported herein.

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37 Methods Description of Fort McClellan Barracks U.S. Army facility, Ft. McClellan, in Anniston, Alabama, was established in 1917, with a primary mission of training for combat a service it fulfilled during World War I, World War II, and the Vietnam War. This facility was also the home of the Womens Army Corps School, the U.S. Army Chemical Center and School, the Military Police School, and the Training Brigade. The base was decommissioned in 1995; and, upon its official closing on May 20, 1999, it occupied 45,679 acres of land w ith 100 barracks of approximately 415 m2 each in need of removal (Fort McClellan 2005). Figure 3-1 shows a typical row of barracks at Ft. McClellan. They are identical, tw o-story, wood-frame, World War II-era barracks similar in typol ogy and construction to thousands of older barracks found on military in stallations throughout the United States. The barracks in the U.S. EPA Region 4 we re typically built with Southern yellow pine, a strong wood readily available in the Southeast and considered salvageable. Other components with potential resale value in th e barracks include shower s, urinals, toilets, windows, doors, electrical wiri ng, lighting, emergency exit signs, a brick fireplace, and the metals associated with the air conditio ning ducts and the large structural support columns. The metals were removed by hand before the demolition of the building, and it was found that the structural support column s were salvageable under careful demolition practices. The Deconstruction Process and Four Scenarios Studied The deconstruction and demolition of the barracks were conducted from April-June of 2003. Personnel involved in th is project participated in ei ther a deconstruction team or an LCA team. The deconstruction team was responsible for hiring a dismantling

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38 contractor, coordinating the di smantling of each barrack in a systematic approach, and collecting data during the dec onstruction process. With th e aid of Costello Dismantling Co., Inc. (Boston, MA, USA), contracted in the early stages of the project, the deconstruction team carefully documented in 15-minute intervals at the deconstruction site the following information: type and amount of material salvaged or disposed, method of material removal (manual or mechanical), time required to salvage and/or demolish, time required for machine operati on, total labor time and tran sportation requirements, as previously described in detail (Guy and W illiams, 2004). The LCA team transferred the data collected from the site and applied these data to the modeling efforts. As stated previously, the primary goal of this project was to assess the optimum combination of manual and mechanical met hods of barracks removal, as measured by minimum environmental/public health life cycle impacts. To this end, four scenarios were designed and compared. The first scen ario involved removal of one barrack using entirely manual deconstructi on (labeled as % Manual ). The second and third scenarios involved manual dec onstruction only 44% and 26% of the total time required for removal, respectively, with the remainde r of the time involving traditional mechanical methods. These two scenarios are labeled henceforth as % Manual and % Manual, respectively. The f ourth scenario involved removing a barrack using only mechanical methods of demolition, as traditiona lly used, and this scenario is denoted as % Mechanical. The percentages of time used for mechanical demolition and manual deconstruction were determined by di viding the total time required for building removal into the total time required fo r machine operation and/or labor.

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39 Life Cycle Analysis All data collected from the deconstruction phase were carefully databased for use in the life cycle analysis (LCA) modeling th at followed ISO 14000 guidelines (Guinee et. al., 2002). The ultimate objective of the LCA effort was to guide the Department of Defense (DOD) in the best management pr actices for removing the WWII-era barracks that remain in EPA Region 4. The scenario yielding lowest environmental impacts would be considered the most preferable option in this study. The development of the LCA model and its relevant stages are di scussed in more detail below. Functional Unit The four scenarios were compared using a functional unit of per square foot of barracks. This functiona l unit allowed comparison of inputs and outputs and the ultimate impacts from each scenario. All results presented herein are based on this functional unit. Scope and Goal Definition The relevant stages included in this LCA are the deconstruction/demolition process, representing raw material extraction; dispos al of materials by landfilling; transportation between the stages; and recycling and reuse of salvaged materials by replacing virgin materials. Figure 3-2 Figure 3-2 shows these stages divided into individual steps, starting with preparation for deconstruction by transportati on of equipment and la bor to the site and removing asbestos (Steps 1a and 1) and hazardous waste (Step 2). Each rectangle (Steps 1, 2, 5, 13-16) represents an activity that is involved in preparation for demolition of the barracks, preparation of salvaged materials for reuse, and the processes in the outer

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40 avoided virgin wood production l oop. Each oval (Steps 3, 4, 612) represents a part of the barrack disposed of in the landfill or salv aged for reuse. Time requirements for each relevant step under each scenario were co llected at the site for subsequent LCA development. The only steps shown in Fi gure 3-2 relevant to the 100% Mechanical scenario are transportation of labor and equipment to the site, asbestos and hazardous waste removal and transportation to disposal sites (Steps 1, 1a, 1b, 2 and 2a), whereas all subsequent steps apply only to the other three scenarios. Figures 3-3 and 3-4 In this LCA, three options were considered for salvaged material. The first option was performed from the perspective of savings in landfill volume requirements and reduction of leachate production that occurred when materials were salvaged. No reuse of salvaged materials was considered in this first option and represents a case where no reuse options are available. The second opti on was also performed from the perspective of savings in landfill volume requirements and reduction of leachate that was produced when materials were salvaged. However, this option also incl uded the reuse of the materials by transporting them to a local storage facility within 20 miles of the deconstruction site for their reuse or recycle, thus assessing impact s of a regional market for these materials. The third option cons idered reuse and recycle of the salvaged materials beyond the deconstruc tion and landfill sites by inco rporating transportation to the Habitat for Humanity (HfH) warehouse in Austin, TX, thus assessing impacts of a national market for these materials. For bot h the second and third op tions, if use of the salvaged material avoided the production a nd preparation of the virgin wood that it replaced, then the avoided virgin wood produc tion loop (Steps 13a16) and the recycling of MEP materials (Step 5a) were involved.

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41 Data Inventory Both primary (derived directly from th e deconstructed and demolished barracks) and secondary (derived from literature and re gulatory agency publications and databases) data were collected and da tabased in LCA software, Si maPro 5.1 (PR Consultants, Ameersfort, The Netherlands). SimaPro contai ns inventory data th at has already been gathered for common products and processes in databases created by ETH-ESU (Uster, Switzerland), Buwal 250 (Bern, Switz erland), and Franklin Asso ciates (Prairie Village, Kansas, USA), among others (Goedkoop and Oele 2001). As previously described, the primary data collected included the amount s of hazardous, salvaged, recycled and landfilled materials, the amount of time each piece of equipment was used, the number of workers, and the worker labor time. In a ddition, the weights of sa lvaged and landfilled materials were found by weighing the hauling trucks before and after filling. The secondary data included types of equipment and materials used (site-specific for project), fuel type and requirements of each piece of equipment (JLG 2004, Bobcat 2004, Caterpillar 2004, Grove 2004, Homelite 2004, Stihl 2004, DeWalt 2004), amount and composition of leachate from all deconstr uction materials (Jamback 2004), equipment usage for production of virgin wood in th e forest and at the sawmill (Long 2003), emissions for production of bricks used in the barracks construction (EPA 1997), recycling and producing steel (E PA 1986), diesel and gasoline fuel combustion emissions (EPA 1995), data for the production of diesel fuel and gasoline (EPA 1995) and for the U.S. electricity mix (SimaPro 5.1). The LC A compared the inputs and outputs of each alternative scenario in terms of emissions, th e value of the material, and requirements of dollars, energy, and labor.

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42 Impact Assessment While a number of weightings schema used in LCA impact assessment have been developed and are available to LCA pract itioners, the need for an increased understanding of how these metr ics are developed, their uncer tainty and variability, and potential limitations and benefits of thei r application has been recently identified (Thomas et al. 2003). In this study, two methods, Centrum Voor Milieukunde Leiden (CML) and Environmental Design of Industr ial Products (EDIP), were chosen for calculation of the rela tive impacts of Global Warming, Oz one Depletion, Acidification, Eutrophication, Human Toxicit y, and Ecotoxicity (Guin e and Heijungs 1993; Goedkoop et al. 1998; Goedkoop and Spriensma 1999; CML 2001; Goedkoop and Oele 2001). Each method, included in the SimaPro software uses a different a pproach for calculating impacts but consider similar contributing fact ors for each impact. Comparing the results of these two approaches will enable determ ination of the reliability of the observed trends. A detailed description of these methods can be obtained in Sivaraman and Lindner (2004). Assumptions and Limitations The following is a list of assumptions made throughout this assessment to enable comparison of the four scenarios: 1. Each barrack contains the same quantity of hazardous material, asbestos, and wood coated with lead-based paint that must be disposed; therefore, these emissions were not accounted for in the LCA. 2. Transportation: Note that all assumptions of distances traveled were considered for their effect on the results in the sensitivity analysis.

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43 3. The workers made a 20-mile roundtrip to and from work each day in a 1995 model midsize car. Each worker drove hi s/her own car; howev er, carpooling was considered for its effect on the results in the sensitivity analysis. A 20-mile distance served as a worst-case scenario because this represents approximately twice the distance most workers travel to work (Khattak et. al. 2005, Demographia 2005). 4. Equipment was transported to the site on a flat bed truck from within a 20-mile radius. Because this distance varies for ev ery site, this mileage was tested in the sensitivity analysis (transport distance). 5. A 30-mile distance for transport of equipm ent to and from the site of harvesting was assumed (Long 2003), and harvested wood was assumed to be transported 60 miles to the sawmill (Long 2003). A transport distance of finished lumber of 100 miles was assumed to exist from the sawmill to the construction site for virgin wood (Long 2003). 6. Salvaged wood was transported 80 miles fr om the deconstruction site to the new construction site. While a 500-mile radius is considered to be a cutoff point for environmental savings for delivery of mate rials to a construction site, this lower value was assumed to ensure that th e expense of transporting and buying the salvaged material does not exceed that of the virgin materials (Smith 2003). 7. Except for small equipment (chainsaws, c hopsaws, and weedeaters), each piece of equipment used at the barracks site require d a separate flat bed truck for hauling. 8. The capacity of each truck was at leas t capable of handling 5,500 lbs of wood, equal to a cord of wood.

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44 9. Other than the use stage, the life cycle st ages of the machinery used throughout the deconstruction or demolition process were not considered. 10. Sources of emissions included from the cr eation of virgin timber were harvesting, transporting the wood, milling the wood, and transporting the lumber to the construction site. 11. The data collected at the barracks in Ft McClellan are applicable to all other barracks within U.S. EPA Region 4. 12. Methods for asbestos abatement and lead assessment are the same whether for demolition or deconstruction. The wood de posited into the landfill was untreated chemically, but most of it was painted w ith lead-based paint. Wood coated with lead-based paint produces lead-contaminated leachate; however; th e effects of this wood were not accounted for in the leachat e because there was the same amount in each barrack. Because the landfill is unlin ed, the leachate from all other materials contained within the barracks was account ed for using data reported in Jamback and Townsend (2004), the only available resource for this type of data. 13. The source of electricity was assumed to be the average U.S. mixture of 56% coal, 21% nuclear, 10% hydropower, 10% natural gas, and 3% crude oil. The safety concerns of spent nuclear fuel were not considered. Sensitivity Analysis Assumptions and variables that were tested for their sensitivity to model impacts included the time spent to both deconstruct a nd demolish the barracks, the distances the workers traveled, the distances the materi als and machinery were transported, the recycling of the steel, and the time requirements for preparation of the materials for reuse.

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45 Results and Discussion Data Inventory Time Requirements for Removal of Barrack Components As shown in Table 3-1, each of the barrack components was partitioned into broad categories of windows and doors, interior partitions, hazardous waste (composed primarily of mercury thermostat switches, lead -acid batteries in exit lights and emergency light fixtures, fluorescent tube s and ballasts), mechanical, electrical and plumbing (MEP) materials (including sinks, toil ets, showers, light fixtures, wiring and conduit, ducts, and air handlers), interior finishes and frami ng, roof, walls and floors, and foundation. The time required to remove each building component following the relevant set of steps conducted in each scenario is also provided in Table 3-1. Asterisks in Table 3-1 denote all components that were removed involvi ng some degree of mechanical methods. Removal of hazardous materials (fluor escent lights and exit signs) and the foundation of each of the barrack s, mechanically performed in all scenarios, required the same amount of time (5.0 and 3.3 hrs, resp ectively). Removal of windows and doors, interior partitions, and MEP materials required the same am ount of time for the three scenarios that involved hand deconstruction (100% Manual, 44% Manual, and 26% Manual) but a significantly lo wer time for the 100% Mechanical scenario. The windows and door frames coated with lead-based paint and the MEP materials were manually removed from the barracks involving hand deconstruction. The wood containing leadbased paint was not considered hazardous wast e because of the low concentrations of the paint, and, therefore, it was disposed of in a C&D landfill. The windows and door frames from the 100% mechanically demolished barrack were disposed of thus yielding no time requirement, whereas the time for removing ME P materials under this scenario was lower

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46 than the other three because only the light fi xtures, electrical wi ring and conduits were removed before the demolition of the building. The 3.1 hours required to remove interior partitions from the 100% mechanically demo lished barrack involved recovery of the large support columns only. The same amount of time was needed for the salvaging of the interior finishes and framing for the 100% Manual and the 44% Ma nual scenarios but a decreased amount of time was needed in the 26% Manual scenario. This decreased time is explained by the fact that the columns and wall studs were cu t using chainsaws to speed the process of deconstruction and so that the second stor y floor could be dropped onto the first story floor for deconstruction. As shown in Table 3-1, less time was requi red for removal of the roof, walls and floors of the barracks with incr easing use of mechanical methods This is true with the exception of the removal of the second story floor. The removal of the second story floor took longer in the 26% manual scenario than in the 44% manual scen ario although it still took less time than the 100% manual scenario. In the 44% Manual scenario, the secondstory floor was cut into tenby-ten foot pieces and dismantled on the ground, whereas the second-story floor in the barrack subjected to 26% Manual methods was dropped onto the first-story floor and dismantled. The two di fferent methods of removal for the second story floor in the 26% and 44% manual scen arios were experimental to determine the fastest way to deconstruct the second story floor It was found that it is faster to remove the second story floor in ten-by-ten foot piec es because it is easier to remove the wood when it is in smaller pieces. The time for the removal of the firststory wall also varied greatly between the 44% Manual and 26% Ma nual scenarios. The former, involving

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47 manual removal of sheathing and siding, requir ed approximately 62 hours, and the latter, involving cutting at the floor base and dire ct disposal in a dumpster for ultimate landfilling, required approximately 9 hours. For more information on the methods used to deconstruct and demolish the barracks and the time differences for the removal of the different components of the building pl ease refer to Guy and Williams (2004). Labor and Machine Time and Mileage Requirements and Material Yields Table 3-2 presents the total labor and m achine time and transportation requirements for the material yields from each of the four scenarios. As expected, the scenario involving all manual deconstruction demanded th e greatest number of work days and mileage requirements of the work crew, 17.7 days and 2160 miles, respectively, compared to the range of 12.7 to 1.5 days a nd 1440 to 120 miles for the other scenarios, decreasing with less manual deconstruction. Interestingly, the time requirement for machine operation and mileage requirements for delivery of machinery were maximum in the 44% Manual scen ario (277.8 hrs, 140 miles, respec tively) because an additional piece of equipment, a crane, was used in this scenario to lift the roof off the building so that the salvageable pieces of the roof could be saved while the rest of the building was demolished. It is important to note that machines were necessary in the 100% Manual scenario for collection, movement and cleaning of materials. The 100% mechanical demolition scenario re quired the least amount of transport mileage of equipment and machine hours b ecause only two pieces of equipment were involved, the Bobcat T200 Turbo (Bobcat, West Fargo, ND) and Caterpillar 320C excavator (Caterpillar, Inc. Pleasanton, CA ), to simply topple the building with no manual removal processes. Also, unlike th e three scenarios with manual involvement where materials were separated and move d to various locatio ns on site, the 100%

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48 Mechanical scenario resulted in materials transferred directly to an on-site dumpster for subsequent disposal. The amount of recycled material was the same for each barrack that used hand deconstruction (Table 3-2). In 100% m echanical demolition, the building was knocked down and put in the C&D landfill without removi ng the recyclable steel. As anticipated, the yield of salvageable material decreased wi th diminishing levels of manual labor. The weight of salvaged material ranged from 2,552 lbs from the barrack that was entirely mechanically deconstructed to 59,089 lbs fr om the entirely manually deconstructed barrack. The barrack that was mechanically deconstructed yielded salvaged material in the form of large wood columns, the f oundation of the building and plumbing and electrical fixtures. This is a total of 2,552 lbs of salvaged wood, which is 1.8% of the total weight of the building. Additional components salvaged with manual methods included non-damaged wood, showers, urinals, toilets, air conditioning ducts, and some of the bricks from the chimne y (if clean of mortar). The amount of hazardous material (141 lbs) was the same for each barrack, as each barrack contained the same components, including prim arily mercury thermostat switches, lead-acid batteries in exit lights and emergency lig ht fixtures, fluorescent tubes and ballasts. As salvaged material yields increased, the amount of material sent to the landfill decreased. Therefore, as also anticipated, the amount of landfilled material decreased with increasing ma nual labor rates. The amount of material landfilled ranged from 140,055 lbs for 100% mechanical demolition to 82,486 lbs for 100% manual deconstruction.

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49 Fuel and Electricity Requirements The hourly fuel and electricity requirement s for transportation of the labor force and machinery and for the operation of each of the machines are provided in Table 3-3, along with the relevant stages of their invol vement, previously introduced in Figure 3-2. Seven different pieces of machinery that were used during the deconstruction and demolition of the military barracks are also listed in Table 3-3. Each of these pieces of equipment was used for a different purpose and for varying amounts of time depending on the scenario. The JLG Lift 600S (JLG Industries, Inc., McConnellsburg, PA) was used to raise the workers above the roof in or der to cut and remove panelized sections in the 100% Manual and 26% Manual scenarios. The Bobcat T200 Turbo was used to move the loose salvaged material and floor panels to the designated places for pick up and disposal in all 4 scen arios. The Caterpillar 320C (ex cavator) was used to knock down the 100% mechanically demolished building a nd to push over the building in the 26% Manual scenario. In all the other scenarios, the Caterpillar excavator was used to pick up the floor panels from the second floor and flip over the first floor panels. The Crane Grove TMS 760E (Grove, Pensacola, FL) was us ed for the removal of the roof in the 44% Manual scenario. The Homelite Chainsaw (Homelite, Port Chester, NY) and Stihl Chopsaw (Stihl Inc., Jacksonville, FL) were used to cut the roof into panelized sections either on the ground or in the air with the help of the JLG Lift 600S. The chopsaw was also used to cut the first and second floor pa nels in the Manual scenarios. The chainsaw was used to cut the roof raft er for roof panelizations, the second floor joists and beams for panelization, and the columns and wall studs in the 26% Manual scenario so that the second floor could be dropped onto the first floor and dismantled there. The DeWalt

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50 DG7000E (generator) (DeWalt Industrial Tool Company, Baltimore, MD) was used to remove nails and paint from the salvaged wood w ith attached tools in all four scenarios. The 100% Manual scenario required operati on of the lift, bobcat, excavator and chopsaw for 4, 4, 0.5 and 3 total hours, resp ectively (data not shown). The same equipment was used in the 26% Manual scenar io, requiring increased times for use of the lift, bobcat, excavator and chopsaw of 5, 1, 6 and 7 hours, respectively. In the 44% Manual scenario, the lift, bobcat, and excavat or were also used in addition to the chainsaw and crane (for a total of 6, 9.5, 1, 3, and 4.5 hours, respectively). Only the bobcat and excavator were required in the 100% Mechanical scenario, both used for 2 hours total. As shown in Table 3-3, the chopsaw, chainsaw, and generator required gasoline (0.20, 0.12, and 0.63 gallons/hr, respectively) (Stihl 2004, Homelite 2004, DeWalt 2004), whereas the other equipment re quired diesel fuel in larger volumes (ranging from 2.50 to 8.10 gallons/hr) (Bobc at 2004, Caterpillar 2004, Grove 2004, JLG 2004). The fuel and electricity requirements for harvesting and processing virgin wood are also provided in Table 3-3. The primary equipment pieces involved in harvesting of wood are feller bunchers, rubber-tired skidders, and log loaders. The 29 gallons of diesel fuel used during the transportation of th is equipment to and from the forest was overwhelmingly greater than in-use fuel c onsumption. In fact, the consumption during transportation of the equipment to the forest for harvesting was greater than any of the other diesel fuel consump tion requirements incurred duri ng transportation, including transport of the downed trees to the sawmill, of the lumber to the construction site, of the recycled steel to the recycling facility, a nd of the waste materials to the landfill.

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51 Electricity requirements for sawmill opera tion (6.2E-03 kWh per pound of wood) and recycling of steel (2.1 kWh per pound of recycl ed steel) were also accounted for, as shown in Table 3-3. It is important to note that, for every pound of salvaged wood, one pound of virgin wood is avoided. Thus, th e values provided in Table 3-3 represent savings in relation to using all virgin mate rials in reconstruction applications, and their resulting emissions will be considered as emi ssions savings rather than contributions. Emissions Tables 3-4, 3-5, 3-6 and 3-7 show the prim ary environmental emissions that result from each of the four scenarios per square f oot of barrack. The emissions shown in these tables represent the second option where material salvaged is reused or recycled within 20 miles of the deconstruction site. Emissi ons from the other tw o optionsno salvaging or reuse and transportation of all reusable ma terials to Austin, TXare considered in the discussion of impact an alysis results below While the SimaPro modeling software included hundreds of emissions from the includ ed life cycle stages, only those in highest quantity and/or risk to the public and environment were c onsidered. These emissions have been broken down into four categorie scriteria pollutants, greenhouse gases, metals, and miscellaneous chemicalswhich have been further separated by life cycle stage, during salvaging of material (Stage 13 in Figure 3-2), disposal (S tages 1b, 2a and the waste from stages 3-12), use of equipm ent during deconstruction (Stages 3, 4 and 612), and transport of equipment and labor to a nd from the site (Stage 1a). The emissions with negative values in Tabl es 3-4, 3-5, 3-6 and 3-7 repres ent savings as a result of replacing virgin materials with salvaged materials. The most highly emitted species from all four scenarios were carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOCs), nitrogen oxides (NOx),

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52 and methane (CH4). The remaining chemical emissions, dioxin, arsenic, lead, and mercury, are listed in the tables beca use of their known toxicity. Total CO2 and CH4 emissions increased and VOC and CO emissi ons decreased with de creasing degree of manual involvement. Despite small increase s in emissions of CO from the disposal stages from the 100% Manual to the 100% Mech anical scenario, the decrease in CO and VOC emissions from equipment (resulting from decreasing use of the generator used to clean salvaged materials) and transportation (resulting from the decreasing transportation mileage from the commute to/from the site by the labor) overwhelmingly influence the total CO and VOC values. As expecte d, the C&D landfill contributed the largest emissions of CO2 and CH4 regardless of the scenario, and the increases in materials disposed of in the landfill resulted in an increase in these emissions with decreasing degree of manual involvement. Also, emissions of arsenic, lead, a nd mercury in leachate from the landfill increased as manual invol vement in the deconstruction decreased because the amount of materials that are landf illed increased. These metals in particular leach from the wood and the joists (Tables 3-4 3-7). Total emissions of NOx are highest in the 100% Mech anical scenario (87.7 g/ft2 barrack, Table 3-7) and lowest in the 44% Manual s cenario (46.9 g/ft2 barrack, Table 35), with total emissions from the 100% Manual and 26% Manual scenarios (74.6 and 49.5 g/ft2) falling in between these values. The lower emissions of NOx as the amount of manual involvement in the manual deconstructi on scenarios decreased can be explained by the decreased usage of cars for transporta tion of workers. The number of days the workers drove to the site decreased as fewe r manual methods were used which, in turn, decreased the NOx production from the combustion of the gasoline. The 100%

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53 Mechanical scenario yielded the highest NOx emissions because the steel was not recycled. The recycling of steel produced negative emissions of NOx (emissions savings) for the manual deconstruction scenarios, thus allowing 100% manua l deconstruction to yield lower NOx emissions than 100% mechanical demolition. Impact Analysis An impact assessment was performed on each of the four scenarios to determine their effects on Global Warming, Ozone Depl etion, Acidification, Eutrophication, Human Toxicity, and Ecotoxicity. As stated earlier two publishe d impact assessment methods, CML and EDIP, were used for this LCA to compare and contrast the results of three hypothetical cases) where no reuse was considered, 2) where reuse but no transportation to a salvage warehouse was c onsidered, and 3) where both salvage and transportation to the Habitat for Humanity warehouse in Austin, TX were considered. Case 1: No Salvaging Figures 3-3 and 3-4 show impacts (calculated using EDIP and CML 2000, respectively) resulting from the scenarios wh ere no reuse was consider ed. In this option, all salvaged materials are disposed of in a landfill. All scenarios that involve manual deconstruction show comparable or larger contributions to al l impact categories calculated by the EDIP method (Fig. 3-3) compared to the mechanical demolition scenario. All of the environmental imp acts were lowest for the 100% Mechanical scenario because of the significantly lower em issions resulting from lower total mileage for transportation of the employees to/from the site and the lowest total hours of equipment use. Specifically, ecotoxicity a nd human toxicity impacts are higher in the scenarios involving manual methods because of the increased need of diesel fuel and gasoline for machine and automobile operati on, respectively. These impacts are most

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54 affected by the emissions of mercury and l ead during the producti on of the fuels, not emissions resulting from their use in the a ssociated equipment. The global warming potential is higher for higher percentages of manual deconstruc tion because of the increased transportation of workers and corresponding productionand use-related emissions of CO and CO2. The increase in machine and transportation requirements in all of the manual scenarios also yielded increased SOx and NOx emissions that increased acidification and eutrophication impacts. Most of the SOx emissions were released in the production of the diesel fuel and gasoline required by the machines and automobiles, whereas the NOx was released primarily during the use of these fuels. The ozone depletion potential was elevated because of the increased produc tion requirements of diesel fuel, needed in larger quantities in the manual scenario s. The production of diesel fuel involves CFC emissions, thus yielding increased ozone depletion impacts. The CML 2000 impact analysis method resu lts revealed less significant influence of 100% Mechanical methods on impacts (Fi g. 3-6) and, in most cases, comparable impacts among all of the scenarios. The reas on for this difference from the EDIP results is because the impact assessment categories are normalized by CML 2000, whereas EDIP does not normalize the impact assessment results. Normalization attempts to achieve the expression of impacts on a global or regional basis, and the CML 2000 approach normalized the impacts to the most problema tic species that is known for each impact category. Global warming is expressed as kg of CO2, ozone depletion, as kg of CFC-11, human toxicity and ecotoxicity, as kg of 1,4-DB, acidification, as kg of SO2, and eutrophication, as kg of PO4 -3. The impacts for EDIP are expressed based on the environmental emissions that occur and their e ffects on the local area. Regardless of the

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55 differences in results from the CML 2000 and EDIP impact assessment methods, both show that, if the salvaged materials ar e not reused, then manual methods of deconstruction yield potential for increased or comparable impacts compared to traditional demolition methods. Case 2: Salvaging and No Long-Distance Tran sportation to a Storage Facility (Local Reuse) Figures 3-5 and 3-6 show the impacts calculated using the EDIP and CML 2000 impact analysis methods for each of the four scenarios where material is salvaged and delivered to local reuse and recycling facili ties. The EDIP impact results (Fig. 3-5) showed that, unlike when no salvaging is c onsidered, the 100% Mechanical scenario yielded significantly higher impacts comp ared to the scenarios involving manual methods. Differences observed in impacts fr om the manual scenarios were not large. However, of the manual methods, the 100% Manu al scenario yielded the least impacts to global warming and ozone depletion. Acidifi cation and toxicity impacts were lowest in the 44% Manual scenario, with the latter re sulting in a negative value because of emissions savings. Eutrophication impacts we re lowest in the 44% and 26% Manual scenarios, whereas ecotoxicity impacts we re the lowest in the 100% and 44% Manual scenarios, both yieldi ng negative impact values These small differences in impacts involving manual methods were directly relate d to the amount of wood salvaged and to the amounts of diesel fuel, gasoline and el ectricity used in the processes. Manual deconstruction avoided the production of virg in wood, thus avoiding electricity emissions from this stage and yielding decreases in the ecotoxicity, ozone depletion and global warming impacts. The 100% Manual scenario, involving increased us e of machinery and

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56 cars, yielded higher human toxi city, acidification and eutr ophication impacts than its other manual counterparts. Like the EDIP method results, the CML 2000 method revealed that impacts from the 100% Mechanical scenario were the highest when sa lvaging but no long-distance transport of the salvaged ma terials was involved. The CML 2000 approach also showed that the 100% Manual scenario yielded the lowest impacts in all categories except acidification, which was lowest (and negative) in the 44% Manua l scenario (Fig. 3-6). In comparing only the impacts from the manual scenarios, the 26% Manual scenario was largest in all cases and yielded no ne gative impacts using the CML 2000 method. Case 3: Salvaging and Transport to Austin, TX, for Reuse The impacts determined by the EDIP and CML methods for each of the four scenarios that included transportation of the salvaged materials to the Habitat for Humanity warehouse in Austin, TX, (approxima tely 885 miles) are shown in Figures 3-7 and 3-8, respectively. The 100% Mechanical sc enario yielded the lowest impacts in all instances because of its significantly lo wer transportation requirements. The transportation of the salvaged material to Austin, Texas increased the environmental impacts for each of the scenarios in which ma terials were salvaged. Likewise, impacts increased with increasing manual involvement b ecause of the greater emissions related to fuel production and use during transportati on accompanying the larger weight of salvaged materials. The results of both the EDIP (Fig. 3-6) and CML 2000 (Fig. 3-7) impact assessment methods showed that the negative impacts of tran sport distance of the salvaged materials far outweigh the savings in emissions that occur by reusing the materials.

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57 Sensitivity Analysis The previous results show the influence of both material salvaging for reuse and transportation to a storage warehouse on the environmental and health impacts of each scenario compared. Other variables tested for their influence on impacts were time for deconstruction or demolition activities, drivi ng distance (carpooling), degree of recycling, transport distance of equipment, a nd time for material preparation. Time for Deconstruction or Demolition Activities The importance of the pace of dismantling and demolishing the barrack by each of the four scenarios on the environmental and health impacts was determined by increasing and decreasing the baseline rates achieved. Baseline rates of dismantling achieved by the deconstruction team were 105.5, 182.4, 231.7, and 388.4 lbs/hr for 100%, 44%, 26% manual deconstruction and 100% mechanical demolition, respectively. The demolition rates achieved were 1028.5, 608.2, 729.3, and 600.1 lb/hr for the 100%, 44%, 26% manual deconstruction and 100% mechanical demolition scenarios, respectively. These rates were found by dividing the lbs of material salvaged and landfilled by the labor hours minus the machine hours and m achine hours respectively. The rate of dismantling material for salvage was observed to influence the emissions much more than the disposal rate because the slower rate of hand demolition greatly increased the amount of time the work ers spent at the site and thus the times required for driving to work and using the ge nerator. For the s cenarios involving manual deconstruction, decreasing the rate of disman tling by 5 lb/hr increased human toxicity by 21%, acidification by 4%, and eutrophication and ozone depletion by 3%, whereas very little change in the impacts was observed in the 100% Mechanical scenario because no salvaging of materials was performed. Increasing the rate of dismantling by 5 lb/hr

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58 showed that human toxicity wa s also most sensitive by resu lting in a decrease of 27.4%, while acidification and eutr ophication decreased by 6% and ozone depletion by 4.0%. Increasing and decreasing the rate of demolition resulted in no significant change in impacts. Commuting Distance Decreasing and increasing the commuting di stance of 20 miles assumed in the baseline case by 5 and 10 miles and in the num ber of people/car from 1 in the baseline case to 4 tested for their sensitivity on th e impacts from the 100% Manual scenario. The importance of carpooling to the site by increa sing the number of occupants to four was evident by a decrease in eutrophicati on by 561%, in acidification by 77.5%, and in human toxicity by 39%. Less dramatic results were observe d with increasing the driving distance by 5 miles, where the largest changes were observed in impacts on eutrophication, acidification and human toxi city (2.12%, 0.290% a nd 0.146% increases, respectively). Recycling When recycling was removed from the scenarios involving manual methods, acidification, eutrophication, and ecotoxicity decreased as much as 23.5%, 36.4% and 77.9%, respectively (for the 100% Manual scenario). Transportation Requirements Driving distances for transportation of demolition equipment, salvaged material, recycled material and landfill material, fo r moving equipment to the woods, felled wood from the woods to the mill and boards from th e mill to the store or site were increased and decreased by 5 and 10 miles from their as sumed transport distances (listed in the Assumptions and Limitations section). Most of the emissions categories did not increase

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59 or decrease significantly. Global warmi ng, ozone depletion, acidification and eutrophication changed the most as a result of elevated emissions resulting from increased diesel fuel requirements. For exam ple, when the mileage of an eighteen-wheel truck was increased by 5 miles, eutrophi cation increased by 1 8.3%, acidification increased by 2.38%, global warming increas ed by 2.11%, and ozone depletion increased by 1.25%. Time Required for Paint and Nail Removal According to the deconstruction teams past experience, 30% of the total time for manual deconstruction involves paint stripping and denailing the wood and thus use of the generator. However, this time percen tage was increased and decreased by 5 and 10% to account for differences in methods and expe rience levels of deconstruction teams. The results show that large changes in acidifi cation, eutrophication and human toxicity occur when the generator times for paint stri pping and denailing runs were altered. Acidification increased the most, 106%, wh en the time for material preparation was increased by 5%, while eutrophication and human toxicity impacts increased by 48.5% and 26.1%, respectively. Thus, the amount of time spent on material preparation can greatly affect the environmental impacts th at occur from manual deconstruction. Conclusions Of the three options considered, that invol ve salvaging and reuse within a 20-mile distance yielded the lowest impacts. Both the CML 2000 and EDIP methods resulted in significantly lower environm ental and health impacts when manual methods of deconstruction were used. Of the three manua l scenarios considered with salvaging, the 100% and 44% Manual scenarios yielded, for the most part, the lowest impacts. Compared to the scenario s involving manual methods of deconstruction, the 100%

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60 Mechanical scenario was the fastest option, as anticipated, and, if the salvaged wood does not replace virgin wood in other building applic ations, this traditi onal means of building removal was shown to be the best option in terms of environmental emissions and resulting impacts. However, if the reuse of salvaged wood is assumed to avoid the production of virgin wood then either the 100% Manual or 44% Manual scenario would be preferred because of the decrease in envi ronmental emissions and thus impacts. The LCA model presented herein is most sensitiv e to changes in car mileage and the amount of time the generator runs. It is recommende d, therefore, that the deconstruction occur on or near the site where the materials will be re used, for the workers to live near the site, and for the amount of time spent on material preparation to be minimal. Social and economic impacts of deconstr uction and demolition processes were not quantified in this study. Economic impacts of deconstruction have been discussed by Guy and Williams (2004), however. Because deconstruction takes longer and is more labor-intensive, it provides work for a crew for several days. Deconstruction also provides lower-cost building materials, whic h, in turn, can lower the cost of new construction or can allow people who cannot affo rd virgin materials to buy materials of good quality to make repairs on their own homes. Given that the Department of Defense must dispose of nearly 2.5 million square feet of army barracks in the U.S. EPA Region 4 alone, incorporating some degr ee of manual deconstruction o ffers potential benefits well beyond those quantified in this study. Given the influence of transportation of salvaged materials for reuse applications, it is r ecommended, however, that a strategy be developed to foster reuse within the deconstruction site region.

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61Table 3-1 Time Requirements for Removing Components of Barr acks Using the Four Scenarios Varying in Degree of Manual Deconstructiona, b 100% Manual 44% Manual 26% Manual 100% Mechanical Component Time (hours) % Total Time Time (hours) % Total Time Time (hours) % Total Time Time (hours) % Total Time Windows and Doors 9.57 1.46% 9.57 2.01% 9.57 2.64% 0.00 0.00% Interior Partitions 18.97 2.90% 18.97 3.99% 18.97 5.24% 3.09* 8.81% Hazardous 5.05 0.77% 5.05 1.06% 5.05 1.39% 5.05 14.39% MEP 9.54 1.46% 9.54 2.01% 9.54 2.63% 1.03* 2.94% Interior Finishes and Framing 73.55 11.23% 73.55 15.48% 50 13.81% 3.09* 8.81% Roof 137.15 20.94% 95* 19.99% 77* 21.26% 6.18* 17.61% 2Wall 52.75 8.05% 45.28 9.53% 29.12* 8.04% 2.06* 5.87% 2Floor 147.69 22.55% 71.92* 15.13% 84.4* 23.31% 5.15* 14.68% 1Wall 64.30 9.82% 62.27 13.10% 9.29* 2.57% 2.06* 5.87% 1Floor 133.07 20.32% 80.84* 17.01% 65.9* 18.20% 4.12* 11.74% Foundation 3.26* 0.50% 3.26* 0.69% 3.26* 0.90% 3.26* 9.29% aAll of the sections of the barrack within which machines were us ed are indicated with an asterisk (*), and all sections that do not have an asterisk next to them us ed hand deconstruction only. bMEP = Mechanical, electrical and plumbing ma terials, 2Wall = Second story wall, 2Floor = Second story floor, 1Wall = First-stor y wall, 1Floor = First-story floor.

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62Table 3-2 Labor and Machine Requirements and Mate rial Yields of the Four Scenarios Studied Labor and Machine Require ments Material Yields Scenario Labor (Days) Machine (Hours) Labor Transportation (Miles) Equipment Transportation (Miles) Salvage Weight (Lbs) Recycle Weight (Lbs) Hazardous Material Weight (Lbs) Landfilled Weight (Lbs) 100% Manual 13.64 80.22 2160 120 59089 1032 141 82486 44% Manual 9.74 146.59 1440 140 57291 1032 141 84284 26% Manual 7.32 139.75 1080 120 48134 1032 141 93441 100% Mechanical 1.46 23.42 120 40 2552 0 141 140055

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63 Table 3-3 Fuel and Electricity Requ irements for Associated Processesa,b Processes Involved Stagesc Gasoline (gal) Diesel Fuel (gal) Electricity (kWh) Labor Transportation (1 laborer, 1 day of work) -8.0E-01--Deconstruction Transportation To and From the Site --6.4E+00 -Lift (hr) 7, 8 -2.5E+00 -Bobcat (hr) 6, 7, 9, 10, 11, 12 -5.0E+00 -Excavator (hr) 7, 12 -8.1E+00 -Crane (hr) 7 -4.0E+00 -Chopsaw (hr) 7, 11 2.0E-01--Chainsaw (hr) 7, 8, 9, 10, 11 1.2E-01--Generator (hr) 13 6.3E-01--End-of-Life Stages Salvaging Wood (1 lb) Harvesting Transportation of Equipment to and from the Forest 14 -2.9E+01 -Feller Buncher (1 lb) 15 -1.7E-03 -Rubber Tired Skidder (1 lb) 15 -2.8E-03 -Log Loader (1 lb) 15 -3.1E-03 -Transport from Site to Sawmill (1 lb)15 -9.0E-03 -Sawmill Electricity (1 lb) 16 --6.2E-03 Transportation from the Sawmill to Construction the Site (1 lb) 16 -3.0E-03 -Recycling Steel (1 lb) Electricity (1 lb) 5a --2.1E+00 Transportation to Recycling Facility 5a -1.6E-02 -Landfill (1 lb) Transportation to Landfill 1b -1.6E-02 -aValues of fuel requirements by the equipm ent are presented on an hourly basis, and values of electricity. bAll fuel usage values were obtained by cont acting the manufacturer s of the machines and asking for average fuel usage values. cStage numbers refer to the specific st ages involved and shown in Figure 3-2. dMileage workers drove to/from the site was assumed to be 20 miles, equipment transported from within a 20 mile radius to site, 30 miles to/from the forest, 60 mile transport for harvested wood to sawmill, 100 m ile transport from sawmill to construction site and an 80 mile transport distance for salvaged material to new construction site.

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64 Table 3-4 Emissions from the Scenario Involving 100% Manual Methodsa aThe functional unit is per ft2 of barrack removed. The emissions in this table are expressed in terms of g/ft2 of barrack removed. bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw and weedeater. cTransportation includes labor and equipment. Emission Total Salvaged Material Disposal Recycled Material Equipmentb Transportationc Criteria Pollutants Carbon Monoxide (CO) 3.52E+03 -8.29E+016.94E+01 9.36E-01 1.94E+03 1.59E+03 Nitrogen Oxides (NOx) 7.46E+01 -7.06E+014.79E+01 -9.59E-015.55E+01 4.28E+01 Air Toxics Dioxin -8.16E-12 -2.76E-111.50E-11 1.87E-13 3.17E-12 1.08E-12 Greenhouse Gases Methane (CH4) 8.49E-01 -2.29E+002.43E+00 3.03E-02 5.09E-01 1.70E-01 Carbon Dioxide (CO2) 3.45E+02 -1.46E+031.57E+03 -2.72E+023.86E+02 1.11E+02 Metals Arsenic (As) 1.62E-05 -4.49E-054.73E-05 5.92E-07 9.88E-06 3.32E-06 Lead (Pb) -4.72E-04 -7.08E-058.38E-05 -5.09E-041.76E-05 5.92E-06 Mercury (Hg) 3.05E-06 -1.71E-051.56E-05 1.95E-07 3.26E-06 1.09E-06 Miscellaneous Chemicals Volatile Organic Compounds (VOCs) 1.69E+02 -2.61E-010.00E+00 -2.46E-029.40E+01 7.53E+01

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65 Table 3-5 Emissions from the Scenario Involving 44% Manual Methodsa Emission Total Salvaged Material Disposal Recycled Material Equipmentb Transportationc Criteria Pollutants Carbon Monoxide (CO) 2.22E+03 -8.04E+017.09E+019.36E-011.17E+03 1.06E+03 Nitrogen Oxides (NOx) 4.69E+01 -6.84E+014.90E+01-9.59E-013.83E+01 2.90E+01 Air toxics Dioxin -6.96E-12 -2.68E-111.53E-111.87E-133.46E-12 8.65E-13 Greenhouse Gases Methane (CH4) 9.87E-01 -2.22E+002.48E+003.03E-025.57E-01 1.37E-01 Carbon Dioxide (CO2) 5.38E+02 -1.42E+031.61E+03-2.72E+025.22E+02 8.92E+01 Metals Arsenic (As) 6.68E-05 -1.46E-041.97E-045.92E-071.09E-05 2.67E-06 Lead (Pb) -3.00E-03 -7.50E-059.49E-05-3.04E-032.13E-05 5.28E-06 Mercury (Hg) 3.98E-06 -1.66E-051.60E-051.96E-073.58E-06 8.79E-07 Miscellaneous Chemicals Volatile Organic Compounds (VOCs) 1.04E+02 -2.53E-010.00E+00-2.46E-025.38E+01 5.02E+01 aThe functional unit is per ft2 of barrack removed. The emissions in this table are expressed in terms of g/ft2 of barrack removed. bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw and weedeater. cTransportation includes labor and equipment.

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66 Table 3-6 Emissions from the Scen ario Involving 26% Manual Methodsa Emission Total Salvaged Material Disposal Recycled Material Equipmentb Transportationc Criteria Pollutants Carbon Monoxide (CO) 1.62E+03 -6.76E+017.85E+019.36E-018.15E+02 7.94E+02 Nitrogen Oxides (NOx) 4.95E+01 -5.75E+015.43E+01-9.59E-013.20E+01 2.18E+01 Air toxics Dioxin -5.68E-13 -2.25E-111.70E-111.87E-134.13E-12 6.49E-13 Greenhouse Gases Methane (CH4) 1.69E+00 -1.86E+002.75E+003.03E-026.67E-01 1.03E-01 Carbon Dioxide (CO2) 9.69E+02 -1.19E+031.78E+03-2.72E+025.75E+02 6.70E+01 Metals Arsenic (As) 1.13E-04 -1.22E-042.20E-045.92E-071.30E-05 2.00E-06 Lead (Pb) -2.97E-03 -6.30E-051.05E-04-3.04E-032.55E-05 3.96E-06 Mercury (Hg) 8.86E-06 -1.40E-051.77E-051.96E-074.29E-06 6.60E-07 Miscellaneous Chemicals Volatile Organic Compounds (VOCs) 7.38E+01 -2.13E-010.00E+00-2.46E-023.64E+01 3.76E+01 aThe functional unit is per ft2 of barrack removed. The emissions in this table are expressed in terms of g/ft2 of barrack removed. bEquipment includes a lift, bobcat, excavator, chopsaw, chainsaw and weedeater. cTransportation includes labor and equipment.

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67 Table 3-7 Emissions from the Scenario Involving 100% Mechanical Methodsa, b Emission Total Salvaged Material Disposal Equipmentc Transportationd Criteria Pollutants Carbon Monoxide (CO) 2.52E+02 -3.58E+00 1.18E+02 4.85E+01 8.92E+01 Nitrogen Oxides (NOx) 8.77E+01 -3.05E+00 8.13E+01 6.40E+00 3.04E+00 Air toxics Dioxin 2.62E-11 -1.19E-12 2.54E-11 1.70E-12 2.66E-13 Greenhouse Gases Methane (CH4) 4.34E+00 -9.87E-02 4.12E+00 2.75E-01 4.28E-02 Carbon Dioxide (CO2) 2.19E+03 -6.63E+00 1.99E+03 1.79E+02 2.78E+01 Metals Arsenic (As) 8.46E-05 -1.94E-06 8.03E-05 5.36E-06 8.34E-07 Lead (Pb) 1.50E-04 -3.06E-06 1.42E-04 9.51E-06 1.48E-06 Mercury (Hg) 2.77E-05 -7.40E-07 2.64E-05 1.77E-06 2.74E-07 Miscellaneous Chemicals Volatile Organic Compounds (VOCs) 6.18E+00 -1.13E-02 0.00E+00 2.01E+00 4.18E+00 aThe functional unit is per ft2 of barrack removed. The emissions in this table are expressed in terms of g/ft2 of barrack removed. bRecycled Material is not applicable for 100% mechanical. Hazardous waste not accounted for in all 4 scenarios. cEquipment includes a bobcat, excavator and weedeater. dTransportation includes labor and equipment.

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68 Figure 3-1World War II Army Barracks at Fort McClellan

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69 Figure 3-2 Stages Involved in the Deconstruction Process Avoided Virgin Wood Production 16. Sawmill 15. Harvesting 14. Transportation of Machinery Deconstruction on Site 1a. Transportation of Labor and Machinery 1. Asbestos Removal 1b. C&D Landfill 2. Hazardous Waste Removal 2a. Hazardous Waste Disposal 5. MEP 5a. Recycled Steel 13. Mechanical Cleaning and Preparation of Salvaged Material 3. Interior Partitions 4. Windows and Doors 6. Interior Finishes and Framing 7. Roof 8. Second Story Wall 9. Second Stor y Floo r 10. First Stor y Wall 11. First Stor y Floo r 12. Foundation 13a. Salvaged Material Avoids Virgin Wood

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70Figure 3-3 Total Impacts Calculated Using the EDIP Method Not Including Reuse of Salvaged Materials. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%% Contribution Global WarmingOzone DepletionAcidificationEutrophicationHuman ToxicityEcotoxicityImpacts 100% Mechanical 26% Manual 44% Manual 100% Manual

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71 0% 20% 40% 60% 80% 100%% Contribution Global Warming Ozone Depletion AcidificationEutrophicationHuman Toxicity EcotoxicityImpacts 100% Mechanical 26% Manual 44% Manual 100% Manual Figure 3-4 Total Impacts Calculated Using the CML Method Not Includi ng Reuse of Salvaged Materials.

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72 -100% -80% -60% -40% -20% 0% 20% 40% 60% 80% 100%% Contribution Global Warming Ozone Depletion AcidificationEutrophicationHuman ToxicityEcotoxicity Impacts 100% Mechanical 26% Manual 44% Manual 100% Manual Figure 3-5 Total Impacts Calculated Using the EDIP Method Including Re use of Salvaged Materials But No Transportation to a Warehouse.

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73 -40% -20% 0% 20% 40% 60% 80% 100%% Contribution Global Warming Ozone Depletion AcidificationEutrophicationHuman ToxicityEcotoxicity Impacts 100% Mechanical 26% Manual 44% Manual 100% Manual Figure 3-6 Total Impacts Calculated Usi ng the CML Method Reuse of Salvaged Materi als But No Transportation to a Warehouse.

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74 0% 20% 40% 60% 80% 100%% Contribution Global WarmingOzone DepletionAcidificatio nEutrophicationHuman ToxicityEcotoxicityImpacts 100% Mechanical 26% Manual 44% Manual 100% Manual Figure 3-7 Total Impacts Calculated Using the EDIP Method Including Reus e of Salvaged Materials and Transport to the Habitat f or Humanity Warehouse in Austin, Texas.

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75 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%% Contributio n Global WarmingOzone Depletion AcidificationEutrophicationHuman ToxicityEcotoxicityImpacts 100% Mechanical 26% Manual 44% Manual 100% Manual Figure 3-8 Total Impacts Calculated Using the CML Method Including Reuse of Salvaged Materials and Transpor t to the Habitat fo r Humanity Warehouse in Austin, Texas.

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76 CHAPTER 4 SUMMARY, CONCLUSIONS AND RECOMENDATIONS Summary An LCA was performed comparing deconstr uction and demolition of World War II army barracks to determine the contributi on of each life cycle stage to the total environmental impacts and to compare impacts of material reuse a nd disposal. Before this LCA was conducted, a combination of deconstruction and demolition was performed on three barracks. Once the time requirement s for each stage of these processes were found, four modeled scenarios were produce d. An LCA was then performed on these four scenarios using SimaPro. The four life cycle stages considered for the deconstruction process were deconstructing th e building, cleaning the salvaged materials, salvaged material reuse, and disposal. The four life cycle stages considered for the demolition process were harvesting of trees, proc essing of trees to boards at the sawmill, use of materials in buildings and disposal. The LCA was performed according to ISO 14040 standards and included scope and goal definition, inventory analysis, impact assessment, and interpretation. Impact a ssessment was performed using two published impact methodsCML and EDIP. Conclusions Results from the inventory analysis have shown that demand for virgin material is highest for 100% mechanical demolition. The largest amount of emissions to water, air and soil is derived from the disposal of the ma terials into landfills when compared to all the other process considered throughout this LCA. In fact, in most cases the salvaging of

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77 the materials had an almost opposite effect on the environment than did the disposal of the materials into landfills. This is due not only to the effect s of disposal of materials into the landfill but also to impacts resulting fr om reproduction of that material. Salvaging materials circumvented both landfilling and re production of new virgin materials, thus yielding environmental savings. The impact assessment methods used showed some variation based on the chosen model. According to the EDIP method of analysis, the 100% Manual and 44% Manual deconstruction scenarios were shown to be superior when material was salvaged and transported nearby. The largest emissions that occurred for 100% manual deconstruction scenario, shown in Table 3-4, were CO2, CO, NOx, and VOCs, ranging from 7.46E+01 g/ft2 NOx to 3.52E+03 g/ft2 CO. Both CO and CO2 emissions were greater than observed in the 100% mechanical deconstruction s cenario, primarily be cause of increased generator operation and labor transportation requirements. The transportation of labor and the use of the generator were also the la rgest contributors to the nitrogen oxides and VOCs in this scenario. Table 3-5 illustrate s that in the 44% manual scenario, the largest emissions were CO2, CO, NOx, and VOCs ranging from 2.22E+03 to 4.69E+01. The major sources of these emissions are also tr ansportation of labor to/from the site and generator operation. An increased amount of landfilled material cont ributes to increased CH4 emissions and, in part, to increased CO2 and CO emissions when compared to the 100% manual deconstruction scenario. With less time spent at the site less transportation of workers occurred to and from the site and with less salvaged material the generator was used for a smaller amount of time thus all of the emissions for this scenario were less than the 100% manual emissions. As seen in Table 3-6 the 26% manual scenario had the

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78 same top 4 emissions and the same contribu ting processes to the emissions ranging from 4.95E+01 to 1.62E+03. Due to the higher tran sportation of machinery and the lower amount of salvaged materials, the la rgest producer of carbon dioxide was the transportation of equipment, followed closely by the transportation of labor and the use of the generator. As with the 44% manual scen ario the emissions were lower than the 100% manual and the 100% mechanical scenario due to less material being landfilled and less time being spent in transportation of labor a nd cleanup of the salvaged materials. Table 3-7 provides emissions resulting from 100% mechanical demolition of a barrack. The highest total emissions in this scenario were greenhouse gases, carbon dioxide (CO2, 3.40E+02 g/ft2) and carbon monoxide (CO, 2.52E+02 g/ft2). Also high were emissions of nitrogen oxides (NOx), volatile organic compounds (VOCs) and methane (CH4). The greatest contributor of CO2, CO, NOx and CH4 was the landfill used for disposal of waste materials, whereas the main source of VOCs was the transportation of labor and equipment to and from the site. Equipment ope ration was also a significant contributor to CO2 emissions. A sensitivity analysis was performed on the results from the impact assessment to determine the influence of variables on the environmenta l impacts considered. The model produced in SimaPro was most sensi tive to changes in the mileage driven by workers onsite machine use and the operation tim e of the generator. It was shown that environmental impacts decrease with higher levels of mate rials salvaged. However, detrimental impacts were shown to rise with transportation distance to the new construction site or to a storage facilit y. Impacts also increased with increasing deconstruction time because of the increased num ber of days workers drove their cars to

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79 the site. Ideally, salvaged materials would be reused at a constructi on site located on or near the property where the building is deconstructed. The results found from this project will be used by the DOD to aid in development of best management practices for the 2,357,094 s quare feet of army barracks, slated for removal within EPA Region 4 and the countless more square footage of buildings in need of removal on bases throughout the U.S. The implementation of these practices by the DOD will decrease the impact of the disposal of these buildi ngs on both public health and the environment through decreased environmental impacts. While cost and societal impacts of deconstr uction were not considered in this study, some discussion of these aspects is worth mention. While increas es in environmental savings were shown herein, the availability of materials for reuse has tremendous social implications. Jobs are created by deconstr uction, and companies a nd individuals unable to afford large amounts virgin materials would be able to access mate rials at a decreased cost. With careful planning and executi on, deconstruction costs less than demolition considering the resale value of the materials and decreased landfill disposal costs and certainly provides greater positiv e contributions to society. Recommendations The most significant limitation to this study was the small number of scenarios studied. Because the most efficient way to take down a building in terms of time and environmental impacts is a combination of hand deconstruction and mechanical demolition, it would have been beneficial to have more scenarios that combined the two. This would give a more accurate representation of the most effective way to take down a building. It is recommended that for each building, contractors should determine the

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80 amount of available materials that could be salvaged and the worth of these salvageable materials. In doing so, the building can be removed using a combination of deconstruction and demolition methods, resu lting in maximum e nvironmental savings from prevention of disposal of the reusable materials and producti on the new replacement materials.

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81 APPENDIX A DATA COLLECTION AND DAILY NARRRRATIVE Introduction to the Form The heart of the data collection method is the data collection form. The form guides the documentation of each worker. It gives information on where they are working, what they are doing, and what e quipment they are using. Since each form covers 15 minutes of activity, one is complete d every 15 minutes from the start to the end of each workday. Later, the forms are entered into a spreadsheet format that allows the data to be sorted in different ways. This information was collected by the deconstruction team.

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82Team : Deconstruction Completed by: Date Time: 7:30-7:45 Name Building Room Location Activity Assembly Equipment 1 2 3 4 5 6 7 8 9 10

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83 Key to Form Team Starting in the upper left hand corner, the first box identifies the team which is going to be recorded on the form. For this pr oject, we had two main teams. The first one was the Deconstruction Team, which was primarily composed of the demolition contractor and crew. This wa s the team that was responsible for removing the materials from the building. The other was the Proce ssing Team. This Team was composed of Americorp and Habitat for Humanity (HfH) vol unteers. This Team was responsible for taking the deconstructed materials, getti ng them into a ready-for-use state, and transporting them to the HfH storage facility. Completed by Record of who completed the data form. Date Date form was completed. Time 15-minute interval that the form documents When a worker changes activity, the amount of time is rounded to the nearest quarter hour. Name Recording the name of each worker orga nizes the data collection and allows someone who wasnt present at the deconstructi on site to follow an individual workers activity through a day in order to get a mental picture of the deconstruction process. Additionally, when the labor hour s are reported, it is possible to break down the labor by skill level and pay-rate. The name entry will be used to sort the data for this part of the analysis.

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84 Building To begin with buildings 839, 840, and 841 we re deconstructed. Each building was basically identical, so it was important to write down which building was being worked on. No one reading the data forms later would be able to infer the building number solely by the description of what was taking place that day. In the event that work was being done simultaneously on two or more buildings, it became difficult to always notice who was working on which building, but at the same time it remained critical to be accurate in assigning the correct building number to the entry for the analysis and comparison of methods. Room On the back of each data co llection clipboard, there was a small plan of each floor of the building. Each room was numbered. To track the progression of work, a record was kept of where each person was working. If the worker is inside the building, the number of the room where they were worki ng was recorded. Other designations included roof, ext for exterior and site for work not occurring specifically on the building. Location This column was used to more specifically record where work was being done. If the worker was on the roof, the slope he or she is on (north or south) was recorded. If the worker was on the exterior, the side of the building was recorded (north, south, east, or west). If the worker was inside, records were kept of which surface was being worked on. Data was kept by using such designations as F for floor, C for ceiling, and N, S, W, or E for wall surfaces.

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85 Activity This column was used to identify what type of work was being done. While the activity categories were simplified as much as possible, they still encompass the variety of tasks that will occur during the project. An attempt was made to explain the range of tasks that can fall under each category. In co mpleting this column the data collector needed to exercise careful observation and good judgment in order to understand what each worker was doing and into which category th at activity fell. If the collector was not sure what someone was doing, he was to obtai n clarification from the worker. If the collector was not sure which category to use, a supervisor was to be consulted. HDec (hand deconstruction) This category includes all work associat ed with removing ma terials that had potential for processing and salvage from the building using hand labor. It includes the use of hammers, crowbars, or hand-held power tools such as circular saws or sawzalls. It would also incl ude the use of a man-lift, fork lift, or crane provided that this equipment is being used to transpor t workers or individual pieces of building materials. The key to differentiating be tween Hand and Mechanically-Assisted work is that hand methods are directed towards removing the materials piece-bypiece from the building and mechanically-a ssisted methods are directed towards removing large sections or assemblies fr om the building with separation into individual pieces occurring later. HDem (hand demolition) This category includes all work associat ed with removing materials from the building by hand for disposal. It includes the use of hammers, crowbars, or handheld power tools such as ci rcular saws or sawzalls. The key to differentiating

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86 between deconstruction and demolition is that with deconstruction the materials are handled with a level of care sufficient to preserve their conditi on and suitability for reuse. Demolition will generally be fast er and less gentle than deconstruction. This project is primarily directed toward s research into the methods, labor, and costs involved in deconstr uction. Actual salvage of building materials is a secondary benefit. Also, the amount of actual salvage will be limited by the widespread use of lead-based paint on th e wooden building materials, making them unsuitable for reuse. In the case of most of the smaller pieces of dimensional lumber, stripping the lead-based paint is simply not cost effective or environmentally beneficial. For these r easons, many of the parts of the building will be dismantled using deconstruction techniques in order to document the process, while still eventually ending up in the dumpster. 2x4 small wall studs for instance are typically salvageable. In this project, since they are painted they will be disposed in a landfill. However, sin ce the information on salvage time and costs will be needed in the accurate planning of future projects, the wall studs were deconstructed rather than demolished. Genera lly, meetings were held at the start of each day, to discuss the planned activities for the day, what methods were used, and which materials were being demolished or deconstructed. Any worker who was unsure about any activity was told to ask for clarification immediately, because the accurate distinction betw een how much time was spent on each building deconstructing for theoretical salvage or demolishing for theoretical disposal was critical.

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87 MDec (mechanically assisted deconstruction) This category includes all work associ ated with removing materials with potential for processing and salvage from th e building with mechanical assistance. This includes both mechanical labor time a nd any hand labor time that is needed to prepare for the mechanical work. For instance, on one of the buildings, the deconstruction method involved removing large panels of the roof using a crane. The time spent actually lifting the panels off by crane is MDec, and so is any time spent bracing a panel by hand so that it will stay in one piece while being lifted off, cutting the panel free from surrounding ma terials, and attaching the lifting mechanism. MDem (mechanically assisted demolition) This category includes work associated with removing materials from the building with mechanical assistance for disposal. N (non-productive) Non-productive time includes all on-the-cloc k time that is not spent in any of the other categories. Activi ties such as water breaks (though not lunch), discussing what to do next, receiving instruction, t ool and work station set-up at the beginning of the day and break-down at the end, mi scellaneous clean-up (though not disposal of an individual material that has just been demolished getting materials to the roll-offs is part of demolition), building ramps or sawhorses, running caution tape, and many other activities that do not dire ctly contribute to the removal or processing of the building materials are non-productive.

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88 P (processing) Processing includes all the work done to prepare the materials for reuse after they have been removed from the build ing. This includes denailing, cleaning, trimming, sorting, bundling, and loading for transport. S (supervising) Supervisory work is time spent by a j ob supervisor instructing, directing, coordinating, etc. Assembly This column is used to record which part of the building is being worked on. When the labor time is analyzed, this column will be used to describe how much effort is needed to salvage each part of the building as well as the whole. For the purpose of data collection, the buildings are divide d into the following assemblies: R (Roof) 2W (Second floor walls) 2F (Second floor) 1W (First floor walls) 1F (First floor) Fnd (Foundation) MEP (Mechanical, Electrical, and Plumbing systems) Equipment This column is used to record what tools were used for the work. To be sure, the most critical tools to record are the tools th at require energy to opera te (electric saws or drills, as well as heavy equipment such as cr anes, manlifts, forklifts, bobcats, etc.). Some workers will change hand tools often, switchi ng between a crowbar and a flatbar as they

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89 work. In these cases, it is more important to document that they ar e using a set of prying tools, rather than exactly which one they use at any given time. The equipment information is useful to provide an image of what was being done at any given time for someone who was not present and to help ca lculate energy consumption for the life-cycle analysis component of the project. Keepi ng these goals in mind w ill help simplify what can become the most tedious section of da ta collection. Generally, it allows future project decision makers to know what type of work was being done and to calculate how long energy consuming equipment was being operated.

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90 APPENDIX B INVENTORY OF EMISSIONS (When accounting for the recycling of st eel and subtracting emissions for the production of virgin materials using EDIP.) Table B-1: Raw Material Emissions Substance Unit 100% Manual 44% Manual 26% Manual100% Mechanical water kg 3.61E+04 3.61E+04 3.61E+04 0.00E+00 coal kg -9.97E+01 -9.37E+01 -6.86E+01 3.39E+00 crude oil kg -2.22E+03 -2.02E+03 -1.38E+03 4.27E+02 energy MJ 3.34E+03 3.35E+03 3.37E+03 -5.57E+00 lignite kg 4.47E+01 4.47E+01 4.47E+01 0.00E+00 limestone kg -7.39E+00 -7.03E+00 -5.59E+00 1.98E-01 natural gas kg -1.70E+02 -1.56E+02 -1.09E+02 2.90E+01 oil kg 3.60E+00 3.60E+00 3.60E+00 0.00E+00 steel scrap kg 5.50E+02 5.50E+02 5.50E+02 0.00E+00 uranium kg 1.64E+00 1.64E+00 1.64E+00 1.43E-05 wood/wood wastes kg -1.65E+00 -1.51E+00 -1.04E+00 3.03E-01

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91 Table B-2: Emissions to Air Substance Unit 100% Manual 44% Manual 26% Manual 100% Mechanical acrolein kg -4.44E-06-4.23E-06-3.35E-061.31E-07 aldehydes kg -1.10E-01-5.44E-02-2.36E-022.63E-02 ammonia kg -3.22E-02-3.12E-02-2.77E-022.20E-03 As kg -3.37E-05-3.14E-05-2.30E-053.96E-06 Be kg -2.86E-06-2.68E-06-2.02E-062.54E-07 benzene kg -8.68E-06-8.16E-06-6.23E-066.54E-07 Cd kg -3.74E-05-3.42E-05-2.37E-056.62E-06 Cl2 kg -4.37E-04-3.99E-04-2.72E-048.40E-05 CO kg 2.27E+031.58E+031.06E+039.51E+01 CO2 kg -1.32E+03-1.14E+03-8.92E+021.34E+02 cobalt kg -3.60E-05-3.30E-05-2.31E-055.99E-06 Cr kg -2.11E-04-2.08E-04-1.98E-044.29E-06 Cu kg -2.12E-05-2.12E-05-2.12E-050.00E+00 CxHy kg 2.12E+002.12E+002.12E+000.00E+00 cyanides kg -5.73E-04-5.73E-04-5.73E-040.00E+00 dichloromethane kg -1.91E-05-1.82E-05-1.44E-056.14E-07 dioxin (TEQ) kg -2.40E-11-2.29E-11-1.82E-116.77E-13 dust (SPM) kg 3.72E-013.72E-013.72E-010.00E+00 F2 kg 1.40E-041.40E-041.40E-040.00E+00 fluoride kg -7.91E-01-7.67E-01-6.44E-01-3.42E-02 formaldehyde kg -1.63E-05-1.55E-05-1.21E-057.34E-07 H2SO4 kg -6.37E-04-6.37E-04-6.37E-040.00E+00 HCl kg -1.95E-01-1.89E-01-1.59E-01-6.54E-03 HF kg -3.10E-03-2.95E-03-2.34E-039.23E-05 Hg kg -1.34E-05-1.26E-05-9.49E-061.20E-06 kerosene kg -1.07E-04-1.02E-04-8.19E-052.22E-06 metals kg -7.64E-04-6.98E-04-4.81E-041.38E-04 methane kg -1.71E+00-1.59E+00-1.17E+002.04E-01 Mn kg -4.71E-03-4.70E-03-4.69E-034.66E-06

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92 Table B-2: Emissions to Air Continued n-nitrodimethylamine kg -9.37E-07-8.92E-07-7.08E-07 2.74E-08 N2O kg 7.48E-027.52E-027.70E-02 -2.82E-04 naphthalene kg -2.20E-06-2.02E-06-1.40E-06 3.85E-07 Ni kg -6.10E-04-5.64E-04-4.14E-04 9.34E-05 non methane VOC kg -7.92E+03-6.95E+03-4.73E+03 1.25E+03 NOx kg -3.95E+00-1.77E+01-1.83E+01 5.17E+00 organic substances kg -8.81E-02-8.05E-02-5.51E-02 1.68E-02 particulates kg -7.86E+00-8.75E+00-7.98E+00 -1.01E-01 Pb kg -5.61E-04-5.57E-04-5.43E-04 7.40E-06 phenol kg -4.31E-05-3.97E-05-2.83E-05 6.37E-06 Sb kg -1.25E-05-1.14E-05-8.01E-06 2.07E-06 Se kg -4.27E-05-4.02E-05-3.07E-05 3.10E-06 Sox kg -1.90E+01-1.89E+01-1.57E+01 1.10E+00 tar kg 4.21E-044.21E-044.21E-04 0.00E+00 tetrachloroethene kg -4.27E-06-4.06E-06-3.22E-06 1.31E-07 tetrachloromethane kg -1.03E-05-9.67E-06-7.33E-06 8.58E-07 trichloroethene kg -4.18E-06-3.98E-06-3.16E-06 1.21E-07 VOC kg 1.12E+027.59E+015.02E+01 4.27E+00 Zn kg -4.73E-03-4.73E-03-4.73E-03 0.00E+00

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93 Table B-3: Emissions to Water Substance Unit 100% Manual 44% Manual 26% Manual 100% Mechanical Acid as H+ kg -2.46E-06 -2.24E-06-1.53E-064.70E-07 As kg 4.15E-05 4.79E-05 8.03E-05 2.44E-04 B kg -1.64E-02 -1.54E-02-1.18E-021.21E-03 BOD kg -3.86E-02 -3.52E-02-2.41E-027.24E-03 calcium ions kg 1.06E-01 1.23E-01 2.06E-01 6.25E-01 Cd kg -4.17E-04 -3.82E-04-2.66E-047.12E-05 chromate kg -3.06E-05 -2.80E-05-1.94E-055.40E-06 Clkg -3.70E-01 -3.30E-01-1.84E-013.11E-01 COD kg -2.65E-01 -2.42E-01-1.67E-014.82E-02 Cr kg -4.02E-04 -3.63E-04-2.26E-042.36E-04 crude oil kg 9.36E-05 9.36E-05 9.36E-05 0.00E+00 Cu kg 1.94E-05 2.42E-05 4.87E-05 1.84E-04 cyanide kg -1.27E-04 -1.26E-04-1.26E-041.04E-07 dissolved solidskg -1.10E+01 -1.00E+01-6.98E+001.91E+00 dissolved substances kg 4.27E-01 4.27E-01 4.27E-01 0.00E+00 F2 kg 9.89E-03 9.89E-03 9.89E-03 0.00E+00 Fe kg 2.91E-02 2.99E-02 3.34E-02 5.37E-04 fluoride ions kg -4.32E-04 -4.12E-04-3.29E-049.46E-06 H2SO4 kg -4.07E-03 -3.83E-03-2.93E-032.97E-04 HCl kg 9.36E-01 9.36E-01 9.36E-01 0.00E+00 Hg kg -3.15E-08 -2.89E-08-2.01E-085.36E-09 K kg 1.00E-01 1.16E-01 1.94E-01 5.90E-01 metallic ions kg -5.28E-02 -4.81E-02-3.28E-021.01E-02 Mg kg 2.04E-02 2.35E-02 3.94E-02 1.20E-01 Mn kg -1.01E-02 -9.56E-03-7.31E-033.01E-03 N a kg 4.69E-02 5.41E-02 9.08E-02 2.76E-01 N H3 kg -3.99E-03 -3.63E-03-2.42E-037.78E-04 N i kg -3.59E-05 -3.59E-05-3.59E-050.00E+00 nitrate kg 1.49E-02 1.72E-02 2.87E-02 8.69E-02 oil kg -2.51E-01 -2.29E-01-1.59E-014.47E-02 other organics kg -2.87E-02 -2.64E-02-1.86E-024.59E-03 Pb kg -5.83E-05 -5.79E-05-5.67E-058.40E-07 p henol kg -1.70E-04 -1.55E-04-1.06E-043.25E-05 p hosphate kg -2.05E-03 -1.93E-03-1.47E-031.51E-04 sulphate kg -3.53E-01 -3.22E-01-2.13E-011.45E-01 sulphide kg 4.07E-04 4.70E-04 7.88E-04 2.39E-03 suspended solids kg -3.82E-01 -3.58E-01-2.67E-013.77E-02 suspended substances kg 1.41E-01 1.41E-01 1.41E-01 0.00E+00 TOC kg 1.13E+00 3.10E+00 2.70E+00 0.00E+00 Zn kg -7.00E-04 -6.82E-04-6.25E-043.58E-05

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94 Table B-4: Emissions to Land Substance Unit 100% Manual 44% Manual 26% Manual 100% Mechanical ammonia kg -3.18E-04 -3.18E-04-3.18E-040.00E+00 Cr kg -1.06E-03 -1.06E-03-1.06E-030.00E+00 Cu kg -1.11E-04 -1.11E-04-1.11E-040.00E+00 Mn kg -5.92E-02 -5.92E-02-5.92E-020.00E+00 N i kg -5.52E-04 -5.52E-04-5.52E-040.00E+00 Pb kg -2.48E-03 -2.48E-03-2.48E-030.00E+00 Zn kg -4.25E-02 -4.25E-02-4.25E-020.00E+00

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95 LIST OF REFERENCES Adams, DM. (2002). Solid Wood Products: Ri sing consumption and imports, modest price growth. Journal of Forestry, 100(2),14-19. Block, D. (1998). Deconstructing Buildings at Former Army Base. BioCycle, 39(11), 46-49. Centrum Voor Milieukunde Leiden (CML). (2001) Part 3: Scientific Background. In: Guine et al., eds., Life Cycle Assessment: An Operational Guide to the ISO Standards, A Report for the Ministri es of Housing, Spatial Planning and the Environment, Economic Affairs, Transpor t, Public Works and Water Management, Agriculture, Nature Management and Fi sheries, CML, Leiden University, The Netherlands. (October 4, 2004). Consortium for Research on Renewable Industrial Material s CORRIM (2004). Understanding the Value of Wood, (January 17, 2005). Demographia Smart Growth and Urban Cont ainment: Misguided Urban Policy. (2005). (March 6, 2005). Dolan, P., Lampo, R. and Dearborn, J. (1999) Concepts for Reuse and Recycling of Construction and Demolition Waste. USACERL Technical Report, 99/58. Environmental Protection Agency AP 42. (1986). Iron and Steel Production. (January 10, 2003). Environmental Protection Agency AP 42. (1995). Transportation and Marketing of Petroleum Liquids. (January 8, 2003). Environmental Protection Agency AP 42. ( 1997). Brick and Structural Clay Product Manufacturing. (January 2, 2003). Falk, R. (2002). Wood-Framed Building D econstruction: A Source of Lumber for Construction? Forest Products Journal, 52(3), 8-15.

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96 Falk, R. and Lantz, S. (1996). Feasibility of Recycling Timber from Military Industrial Buildings. Proceedings for Use of R ecycled Wood and Paper in Building Applications, Madison, WS. Sponsored by the USDA and the Forest Products Society. Falk, R., Devisser, D., Cook, S. and Stans bury, D. (1999). Effect of Damage on the Grade Yield of Recycled Lumber. Fore st Products Journal, 49(7/8), 71-79. Falk, R. and Green, D. (1999). Stress Gradi ng of Recycled Lumber and Timber. In: 1999 Structures Congress: Structural Engi neering In The 21 Century; 1999 April 18-21; New Orleans, LA. Reston, VA: Sponsor ed by the American Society of Civil Engineers. 650-653. Falk, R., Green, D., Rammer, D. and Lantz, S. (2000). Engineering Evaluation of 55Year-Old Timber Columns Recycled from an Industrial Military Building. Forest Products Journal, 50(4), 71-76. Florida Administrative Code 62-701.200. (2003). (August 1, 2003). Fort McClellan Pelham Range. ( 2005). Global Security.org. (April 22, 2005). Franklin Associates. (1998). Characteri zation of Building-related Construction and Demolition Debris in the United States. Report No. EPA 530-R-98-010. Prarie Village, KS. Goedkoop, M., Hoffstetter, P., Muller-Wenk, R. and Spriensma, R. (1998). The Ecoindicator 98 Explained. International Journal of LCA, 3, 352-260. Goedkoop, M.J. and Spriensma, R. (1999). T he Eco-indicator 99 a Damage Oriented Approach for LCIA. Ministry VROM, The Hague, Amersfoot, The Netherlands: PR Consultants. Goedkoop, M., Oele, M. and Effting, S., (2003). PRe Consultants, SIMAPRO 5.1, Database Manual. Amersfoot, The Netherlands: PR Consultants. Green, D., Falk, R. and Lantz, S. (1999). E valuation of Lumber Recycled from an Industrial Military Building. Fore st Products Jour nal, 49(5), 49-55. Guinee, J. and Heijungs, R. (1993). A Pr oposal For The Classification Of Toxic Substances Within The Frame Work Of Life Cycle Assessment Of Products. Centre of Environmental Science, Leid en University. Chemosphere, 26, 19251944.

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97 Guine, J.B., ed., M. Gorre, R. Heijungs, G. Huppes, R. Kleijn, A. de Koning, L. van Oers, A.W. Sleeswijk, S. Suh, H.A. Udo de Haes, H. de Bruijn, R. van Duin, M.A.J. Huijbregts, E. Lindeijer, A.A.H. Roorda, B.L. van der Ven and B.P. Weidema. (2002). Handbook on Life Cycle Assessment: Operational Guide to the ISO Standards. Dordrecht, The Netherlands: Kluwer Academic Publishers. Guy, B. (2001). How Cost Effective Is D econstruction? (Statisti cal Data Included). BioCycle. 42(7), 75. Guy, B. and Williams, T., (2004). Polluti on Prevention through the Optimization of Building Deconstruction for DoD Facil ities: Ft. McClellan Deconstruction Project. Final Report for the Department of Defense Regional P2 Program Region 4, administered by the University of Sout h Carolina. Columbia, South Carolina. ICF Incorporated. (1995). Construction and Demolition Waste Landfills. Contract No. 68-W3-0008. (July 25, 2003). Jambeck, J., Townsend, T. and Solo-Gabriele, H. (2004). Leachate Quality from Simulated Landfills Containing CCA-Treated Wood. Environmental Impact of Preservative-Treated Wood Conference, The Florida Interdisciplinary Center for Environmentally Sound Solutions (FIC ESS). Orlando, FL. February 8-11. Khattak, A., Amerlynck, V. and Quercia, R., (2005). Are Traveling Times And Distances To Work Greater For Resi dents Of Poor Urban Neighborhoods? (November 10th, 2005). Lippiatt, B. (1998). Balancing Environmental and Economic Sustainability. The Construction Specifier. April 1998. 35-42. Mcphee, M. (2002). Latest Trends in Dec onstruction: Interview with a Pioneer. BioCycle, 28-32. Murray, C. and Lopez, A., (1996). The Global Burden of Disease. WHO, World Bank, and Harvard School of Public Health, Boston, MA, USA National Association Of Home Builders (NAHB ) Research Center. Materials Salvaged Through Deconstruction. (2003). Case St udy: Riverdale Village Apartments. (September 15, 2005). Rammer, Douglas R. (1999). Evaluation of Recycled Timber Members In: Bank, Lawrence C., ed. Materials and cons truction--Explori ng the connection. Proceedings, 5th ASCE materials en gineering congress; 1999 May 10-12; Cincinnati, OH. Reston, VA: Sponsored by the American Society of Civil Engineers, 46-51.

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98 Sivaraman, D. and Lindner, A. (2004). A Comparative Life Cycle Analysis of Gasoline-, Battery-, and Electricity Po wered Lawn Mowers. Environmental Engineering Science, 21(6), 768-785.

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99 BIOGRAPHICAL SKETCH Elizabeth OBrien received her Bachelor of Science in environmental engineering from the University of Florid a in 2003 and her Master of Engineering in environmental engineering sciences from the University of Florida in 2006. Ms. OBrien is currently working at BCI Engineers and Scientists in Minneola, Florida, designing stormwater treatment systems. From January 2004 A ugust 2004 she worked with Jones, Edmunds and Associates as a consultant to the St. Johns River Wate r Management District on the Lake Apopka Clean Up Project. This projec t uses a constructed wetland to decrease the phosphorus levels in Lake Apopka.