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Stormwater Best Management Practices in Urban Development

Permanent Link: http://ufdc.ufl.edu/UFE0024257/00001

Material Information

Title: Stormwater Best Management Practices in Urban Development
Physical Description: 1 online resource (94 p.)
Language: english
Creator: Perrine, Kenneth
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: bmp, development, green, pavement, permeable, roof, stormwater, urban
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: 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 Science of Building Construction STORMWATER BEST MANAGEMENT PRACTICES IN URBAN DEVELOPMENT By Kenneth R. Perrine May, 2009 Chair: Robert J. Ries Cochair: R. Edward Minchin, Jr. Member: James G. Sullivan Major: Master of Science of Building Construction As the urban environment grows the need for comprehensive stormwater management grows with it. Federal, state, and local municipalities all have water management policies requiring various levels of retention for new developments. The conventional method or BMP, best management practice, has been the use of wet or dry retention basins. These basins rob developers of useful land. As the value of land increases the need for alternative BMPs is inevitable. The use of various BMPs such as underground retention vaults, permeable pavement, and green roofs have become more popular in the last few decades. These alternatives can be used to reduce or eliminate a conventional retention pond allowing owners increased use of their valuable land, not to mention the added environment benefit many provide. This study selected a pair of retail properties to determine what would be the most economical BMP over the life of the project. Case 1 is a fresh produce retail market in Titusville, FL. The area has period of high peak rainfalls requiring extensive stormwater retention efforts to mitigate flooding in the area. Case 2 is a large pharmacy chain located in Gainesville, FL. While the area has relatively high requirements for water retention, the retention volume required is only a fraction of those in Titusville. For each case study life-cycle costs and benefits were determined for each alternative. Once the life-cycle analysis was complete the developers of the projects were interviewed to obtain their opinion on alternative BMPs, why a specific BMP was chosen and if life-cycle costing was even a consideration in the decision making process. In Case 1, where stormwater policies require a very high volume of retention, the value of alternative methods becomes even greater. The use of alternative BMPs provides the site with an additional 43% of parking spaces. These extra spaces would allow the company to accommodate a higher volume of customers, facilitating growth. The use of permeable pavement in particular was the most beneficial, with initial cost similar to conventional methods, and low maintenance required over the life of the system. In Case 2, the project was considerable larger, and the volume of water retention needed was low. These factors dissipated the cost effectiveness of alternative BMPs. The area had less than optimal parking available but the added cost over the life of the project proved detrimental to the implementation of alternate methods. Developers of the projects along with several other commercial developers in the area were surveyed. The survey showed that the developers had a good understanding of alternative BMPs, though the use of life-cycle costing is seldom used in the decision making process in most of their projects. Though alternative BMPs are used in ultra-urban areas, the lack of life-cycle costs analysis results in low usage in intermediate areas.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Kenneth Perrine.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2009.
Local: Adviser: Ries, Robert J.
Local: Co-adviser: Minchin, Robert E.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024257:00001

Permanent Link: http://ufdc.ufl.edu/UFE0024257/00001

Material Information

Title: Stormwater Best Management Practices in Urban Development
Physical Description: 1 online resource (94 p.)
Language: english
Creator: Perrine, Kenneth
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: bmp, development, green, pavement, permeable, roof, stormwater, urban
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: 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 Science of Building Construction STORMWATER BEST MANAGEMENT PRACTICES IN URBAN DEVELOPMENT By Kenneth R. Perrine May, 2009 Chair: Robert J. Ries Cochair: R. Edward Minchin, Jr. Member: James G. Sullivan Major: Master of Science of Building Construction As the urban environment grows the need for comprehensive stormwater management grows with it. Federal, state, and local municipalities all have water management policies requiring various levels of retention for new developments. The conventional method or BMP, best management practice, has been the use of wet or dry retention basins. These basins rob developers of useful land. As the value of land increases the need for alternative BMPs is inevitable. The use of various BMPs such as underground retention vaults, permeable pavement, and green roofs have become more popular in the last few decades. These alternatives can be used to reduce or eliminate a conventional retention pond allowing owners increased use of their valuable land, not to mention the added environment benefit many provide. This study selected a pair of retail properties to determine what would be the most economical BMP over the life of the project. Case 1 is a fresh produce retail market in Titusville, FL. The area has period of high peak rainfalls requiring extensive stormwater retention efforts to mitigate flooding in the area. Case 2 is a large pharmacy chain located in Gainesville, FL. While the area has relatively high requirements for water retention, the retention volume required is only a fraction of those in Titusville. For each case study life-cycle costs and benefits were determined for each alternative. Once the life-cycle analysis was complete the developers of the projects were interviewed to obtain their opinion on alternative BMPs, why a specific BMP was chosen and if life-cycle costing was even a consideration in the decision making process. In Case 1, where stormwater policies require a very high volume of retention, the value of alternative methods becomes even greater. The use of alternative BMPs provides the site with an additional 43% of parking spaces. These extra spaces would allow the company to accommodate a higher volume of customers, facilitating growth. The use of permeable pavement in particular was the most beneficial, with initial cost similar to conventional methods, and low maintenance required over the life of the system. In Case 2, the project was considerable larger, and the volume of water retention needed was low. These factors dissipated the cost effectiveness of alternative BMPs. The area had less than optimal parking available but the added cost over the life of the project proved detrimental to the implementation of alternate methods. Developers of the projects along with several other commercial developers in the area were surveyed. The survey showed that the developers had a good understanding of alternative BMPs, though the use of life-cycle costing is seldom used in the decision making process in most of their projects. Though alternative BMPs are used in ultra-urban areas, the lack of life-cycle costs analysis results in low usage in intermediate areas.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Kenneth Perrine.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2009.
Local: Adviser: Ries, Robert J.
Local: Co-adviser: Minchin, Robert E.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024257:00001


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1 STORMWATER BEST MANAGEMENT PRACTICES IN URBAN DEVELOPMENT By KENNETH R. PERRINE 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 SCIENCE OF BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2009

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2 2009 Kenneth R. Perrine

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3 To my parents, thank you for a ll your support through all the years

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4 ACKNOWLEDGMENTS I thank my parents for their continued support thr oughout my years of education. I would also like to think my fiance for keeping me on tr ack while finishing my research. To Dr. Ries, thank you for giving me dire ction in my research.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4LIST OF TABLES................................................................................................................. ..........8LIST OF FIGURES................................................................................................................ .......10LIST OF ABBREVIATIONS........................................................................................................11ABSTRACT....................................................................................................................... ............12CHAPTER 1 INTRODUCTION..................................................................................................................14Statement of the Problem....................................................................................................... .14Objective of the Study......................................................................................................... ...14Research Methodology...........................................................................................................15Hypothesis Statement........................................................................................................... ..152 LITERATURE REVIEW.......................................................................................................17Introduction................................................................................................................... ..........17Conventional Ponds............................................................................................................. ...18Permeable Pavement............................................................................................................. ..20Green Roofing.................................................................................................................. ......21Underground Water Vault......................................................................................................23Industry Trends................................................................................................................ .......243 RESEARCH METHODOLOGY...........................................................................................27Introduction................................................................................................................... ..........27Case Study Analysis............................................................................................................ ...27Case Study Criteria..........................................................................................................27Project Selection..............................................................................................................28Information Collected......................................................................................................29Analysis Performed.........................................................................................................30Initial cost estimates.................................................................................................30Life-cycle cost estimates..........................................................................................31Sensitivity analysis...................................................................................................32Developer Survey............................................................................................................... ....32Limitations.................................................................................................................... ..........334 RESULTS........................................................................................................................ .......37

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6 Case 1 Life-cycle Cost......................................................................................................... ...37Case 2 Life-cycle Cost......................................................................................................... ...38Case 3 Life-cycle Cost......................................................................................................... ...40Sensitivity Analysis........................................................................................................... .....41Developer Survey............................................................................................................... ....425 CONCLUSIONS....................................................................................................................676 SUGGESTIONS FOR FUTURE RESEARCH......................................................................72APPENDIX A Developer Survey............................................................................................................... ....73B Life-Cycle Costs Used In Case 1............................................................................................76C Life-Cycle Costs Used In Case 2............................................................................................77D Life-Cycle Costs Used In Case 3............................................................................................78E Case 1 Conventional Pond Estimate.......................................................................................79F Case 1 Underground Vault Estimate......................................................................................80G Case 1 Permeable Pavement Estimate....................................................................................81H Case 1 Green Roof Estimate...................................................................................................82I Case 2 Conventional Pond Estimate.......................................................................................83J Case 2 Underground Vault Estimate......................................................................................84K Case 2 Permeable Pavement Estimate....................................................................................85L Case 2 Green Roof Estimate...................................................................................................86M Case 3 Conventional Pond Estimate.......................................................................................87N Case 3 Underground Vault Estimate......................................................................................88O Case 3 Permeable Pavement Estimate....................................................................................88P Case 3 Green Roof Estimate...................................................................................................89Q Survey Data.................................................................................................................... ........90R Mean Responses for Numerical Survey Questions................................................................91LIST OF REFERENCES............................................................................................................. ..92

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7 BIOGRAPHICAL SKETCH.........................................................................................................94

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8 LIST OF TABLES Table page 3-1 Case 1 Site specifications.............................................................................................. .....35 3-2 Case 1.1 Site specifications............................................................................................ ....35 3-3 Case 2 Site specifications.............................................................................................. .....35 3-4 Case 3 Site specifications.............................................................................................. .....36 4-1 Case 1 BMP initial costs................................................................................................ ....45 4-2 Case 1 Income........................................................................................................... .........46 4-3 Case 1.1 Income......................................................................................................... ........46 4-4 Case 1 Income growth.................................................................................................... ...47 4-5. Case 1 Income potential................................................................................................. ....47 4-6 Case 1 Life-cycle costs analysis........................................................................................48 4-7 Case 2 Available parking with BMP options.....................................................................49 4-8 Case 2 Life-cycle costs analysis....................................................................................... .49 4-9 Case 3 site specifications for each BMP............................................................................50 4-10 Case 3 income projections............................................................................................... ..50 4-11 Case 3 life-cycle cost analysis......................................................................................... ..51 4-12 Case 1 discount rate sensitivity analysis............................................................................52 4-13 Case 1 BMP bene fit sensitivity analysis............................................................................53 4-14 Case 2 discount rate sensitivity analysis............................................................................54 4-15 Case 2 BMP bene fit sensitivity analysis............................................................................55 4-16 Case 3 discount rate sensitivity analysis............................................................................56 4-17 Case 3 BMP bene fit sensitivity analysis............................................................................57 4-18 Discount rate sens itivity analysis summary.......................................................................58 4-19 BMP benefit sensi tivity analysis summary........................................................................59

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9 4-20 Survey group analysis summary........................................................................................59

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10 LIST OF FIGURES Figure page 4-1 Case 1 and Case 1.1 comparitive growth...........................................................................604-2 Case 1 growth vs. inflation................................................................................................614-3 BMP life-cycle cost vs. park ing space value in Case 2.....................................................614-4 Case 1 Conventional pon d sensitivity analysis..................................................................624-5 Case 1 Underground vault sensitivity analysis..................................................................624-6 Case 1 Permeable pavement sensitivity analysis...............................................................624-7 Case 1 Green roof sensitivity analysis...............................................................................624-8 Case 2 Conventional pon d sensitivity analysis..................................................................634-9 Case 2 Underground vault sensitivity analysis..................................................................634-10 Case 2 Permeable pavement sensitivity analysis...............................................................634-11 Case 2 Green roof sensitivity analysis...............................................................................634-12 Case 3 Conventional pon d sensitivity analysis..................................................................634-13 Case 3 Underground vault sensitivity analysis..................................................................644-14 Case 3 Permeable pavement sensitivity analysis...............................................................644-15 Case 3 Green roof sensitivity analysis...............................................................................644-16 LCC factor sensitivity.................................................................................................... ....654-17 Mean survey responses for each question group...............................................................66

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11 LIST OF ABBREVIATIONS CND Canadian dollar LCC Life-cycle cost BMP Best management practice sf Square feet cuft Cubic feet cy Cubic yard lcy Loose cubic yard lf Linear foot N/A Not applicable

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12 Abstract of Thesis Presen ted to the Graduate School of the University of Florida { TC ABSTRACT } in Partial Fulfillment of the Requirements for the Degree of Master of Science of Building Construction STORMWATER BEST MANAGEMENT PRACTICES IN URBAN DEVELOPMENT By Kenneth R. Perrine May 2009 Chair: Robert J. Ries Cochair: R. Edward Minchin, Jr. Major: Building Construction As the urban environment grows, the need for comprehensive stormwater management grows with it. The conventional method or best management practice (BMP), has been the use of wet or dry retention basins. However, these basins rob developers of useful land. As the value of land increases, the need for alternativ e BMPs is inevitable. The use of various BMPs such as underground retention vaults, permeable pavement, and green roofs have become more popular in the last few decades. These alterna tives can be used to reduce or eliminate a conventional retention pond allowing owners increas ed use of their valuable land; not to mention the added environmental benefits many provide. This study selected a pair of retail propert ies, along with an apartment complex, to determine what would be the most economical BM P over the life of each project. Case 1 is a fresh produce retail market in Titusville, FL. The area has periods of high peak rainfalls requiring extensive stormwater retention efforts to mitigate flooding in the area. Case 2 is a large pharmacy chain located in Gainesville, FL Case 3 is an apartment complex also in Gainesville, FL in a highly ur banized area of the city. For each case study, life-cycle costs (LCC) and benefits were determined for each alte rnative. Developers of the projects were

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13 interviewed to obtain their opinion on alternativ e BMPs, why a specific BMP was chosen, and if life-cycle costing was even a consideration in the decision making process. In Case 1, where stormwater policies require a very high volume of retention, the value of alternative methods becomes even greater. The use of alternative BMPs would provide the site with an additional 43% of parking spaces. These extra spaces would allow the company to accommodate a higher volume of customers, which would facilitate growt h. In particular, the use of permeable pavement would be the most bene ficial, with initial cost similar to conventional methods, and low maintenance requi red over the life of the system. In Case 2, the project was considerably larg er and the volume of water retention needed was low. These factors dissipate d the cost effectiveness of alternative BMPs. The area had less than optimal parking available but the added cost over the life of the project proved detrimental to the implementation of alternate methods. Case 3 employed underground stormwater storag e in the original development. The development did not offer vehicle parking for its residents. Because there was no parking area, the largest section for improvement was the stru cture itself. Green roofing allows for an additional 2,422 square feet of re sidential space, but the additional initial cost elim inates any lifecycle benefit over the test period. With the adde d complications that gr een roofs can bring, the best option is underground storage. Developers of the projects, along with several ot her developers in the state, were surveyed. The survey showed that the developers had a good understanding of alternative BMPs, but the use of life-cycle costing is seldom considered in the decision-making process for most of their projects. Although alternative BMPs are used in dense urban areas, the lack of LCC analysis results in low implementation in suburban areas.

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14 CHAPTER 1 INTRODUCTION Statement of the Problem As cities grow, the need for stormwater co ntrol grows. The building of parking lots, asphalt roads, roofs, and other impermeable surfaces cause water to travel from where it falls to areas where it can be accepted by the surrounding soil. As the to tal area of these impermeable surfaces grow, the accumulation of water increa ses, causing flooding and water pollution. Over the last half-century, methods have been put into place to try to control stormwater runoff in new development. These methods have commonly been retention ditches and ponds, which rob developments of useful land. Ol der cities throughout the United States have little or no runoff systems and must be retrofitted to manage stormwater flow. As more and more developments are construc ted, available land becomes a premium. In many renovation projects and crowde d cities, extra land for water rete ntion is often unavailable. Retention methods that do not rely on setting la nd aside are needed now more than ever. The aim of this study is to analyze th e cost effectiveness of some of these methods in various forms of development. Specific case studies of project s in the central Florida area are analyzed to determine the best method of water retention for e ach case. The developers of the projects will also be surveyed to gain insight on the d ecision-making process used while choosing a BMP. Objective of the Study This research will test the hypothesis that a lternate BMPs are being progressively accepted and implemented by developers in urban envi ronments. Additionally, the research will investigate the role that life-cycle costing play s in the decision making of developers regarding stormwater BMPs.

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15 Some BMPs are relatively new, especially in the United States. These innovative methods can be effective even if they are not as time-tested as convent ional methods. Possible problems of alternative methods include permeable pavements and underground pipes becoming clogged and a green roof dying, reducing their effectiven ess to retain and disp erse water slowly. Conventional retention ponds use gravity to fill depressions; a method as old as the oceans. Every method has certainly has limitations. Where newer methods may be less dependable, conventional methods require a large area of land. Research Methodology Initial costs and the life-cycle costs of each alternative will be analyzed, including maintaining BMPs, in order to determine their valu e. The potential benefits of each alternative will be determined and included in the LCC an alysis. The economic benefit of each BMP will be discounted to the date of c onstruction. Initial costs, annual costs, and benefits will be analyzed to determine life-cycle costs. A full LCC analysis ov er a study period of 20 years will be conducted for each case study for each altern ative: conventional ponds, underground vaults, green roofs, and permeable pavement. A sensitiv ity analysis will be conducted to establish how variations on various aspects of the LCC analys is will affect the overall LCC in each case. A survey will be conducted to gain insight on de velopers opinions regard ing stormwater BMPs. Hypothesis Statement The null hypothesis is that the application of one of the alte rnative BMPs would result in a lower 20 year LCC than the conventional method would. The alternate h ypothesis is that the conventional method results in the lowest life-cycle cost and other methods do not result in a net benefit. The focus of this study is to determ ine what the most economical BMP would be in each case study, and why the method used was chosen. This research will also help establish whether or not alternative BMPs should be pus hed for wide-spread use in new developments

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16 throughout central Florida. As developers enco unter new stormwater problems, they need an array of options to discover which one best suit their needs. This study aims to determine what the most economical method woul d be in various situations.

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17 CHAPTER 2 LITERATURE REVIEW Introduction Many areas of the United States have repl aced forest and other natural areas with substantial urbanization. The resu lting impervious areas of urba nization and development, such as rooftops and parking areas, do not allow water to absorb into the land. Rainfall in such areas accumulates much faster than pervious areas. As the water drains from these areas, it gathers pollutants and heat. Natural waterways are the ev entual receptacles for the pollutants and heat acquired from urban runoff. These can result in a variety of ecological detriments including overgrowth of fungus and algae, k illing of local species, and cont amination of drinking water. Along with ecological damage, stormwater from de veloped areas contributes to high volumes of water deposited into waterways. This causes increased erosion and amplifies the potential for flooding. Due to these factors, developments require the use of impoundments to control stormwater runoff (Thrasher, 1985). Controlling in this sense is both lessening the volume and the rate of runoff, along with re moving pollutants at their source. Up to 90 percent of the water that falls in urbanized regions ends up becoming runoff (Snoonian, 2001). Of course, this depends on the percentage of the area that is pervious or impervious. The higher the percentage of impe rvious surfaces, the more rainwater becomes runoff. Two basic approaches are taken to help alleviate the runoff pr oblem: building areas to collect runoff or lowering the amount of imperv ious surfaces. These methods can certainly be used in conjunction whenever possible. Conve ntional retention ponds receive water from these runoff areas and allow it to be slowly emptied into existing systems. Conventional retention ponds are also permeable surfaces themselves. Th eir two basic purposes ar e to collect runoff and to provide permeable surfaces. Retention ponds reduce peak outflows of stormwater, allowing

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18 runoff to be transported to existing bodies of water through smaller pathways. Localized retention efforts slow the release of stormwater runoff, and greatly reduce the need for large civil projects. By implementing localized stormwat er regulations, municipa lities are putting the burden of stormwater runoff from new developments on to the de velopers themselves. This approach saves tax dollars by re ducing the need for large-scale infrastructure spending by government agencies (Chambers and Tottle, 1980). Of course, every site is unique and requires various amounts of stormw ater retention. For example, in some areas if a site adds no new impervious areas then no additional stormwater retainage that must be added. Projects that do require new rete ntion may require anywhere from 0.05 to 2.10 cubic feet of stormwater retention for every square foot of non-pervious area. The amount of water required various based on several factors: amount of pervious area, frequency of storms, intensity of storms, peak outflow rate, po tential pollutants from th e site, permeability of the site, and size of watershed site is draining into (Clar et al, 2004). There are a number of methods that can be used to achieve the goal of stormwater retention. As mentioned previously, the conve ntional method is to use basins to retain stormwater. However, alternative stormwater BMPs have been develo ped over the years that accomplish the same goals of a conventional pond Many of these BMPs require less land, or even no land to be devoted solely to the purpose of retaining stormwater. By taking stormwater retention underground or on rooftops, alternative BM Ps allow for greater land use of a given site. Although many unconventional methods are more cost ly than typical means, the use of the additional land can result in increased income which could add value to a project. Conventional Ponds The conventional approach to managing stormw ater runoff is to remove the water from the development areas as quickly as possible. Wa ter is diverted from the building to retention

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19 ponds or canals and taken away from the site. Channeling water aw ay from buildings lowers the structures risk of flooding. This is due to the long-standing attitude th at water in developed areas is unwanted, unless possessing aesthetic or recreational value (Williams, 2003). This attitude was developed because stormwater is often seen as a destru ctive force within the construction industry. On the contrary, collected stormwater can serve many useful purposes if handled wisely. For the most part, stormwater should be kept out of the overall building envelope. However, rainwater harvesters can be installed on buildings to collect rainwater and use it for non-potable uses such as flushing toilet s and watering plants. Also, stormwater can be retained on the site and used to k eep moisture in surrounding landscaping. In most developments, the site is steeply gr aded away from buildings to quickly remove water from structures to high-flow storm sewers. However, this approach pays no regard to peak flow during storms, the transfer of pollutants, or total volume reduction (Coffman et al., 1998, 2000). Alternative methods, such as underground retention areas and gree n roofs, allow for a much slower release of the water into the st orm drain system or ground. These methods keep peak volumes down and pollutants filtered at the source. Permeable pavement allows water to naturally permeate to aquifers help to reduce th e total volume of stormwater released into stormwater systems. Stormwater control met hods, such as conventiona l retention ponds, also allow for a large percentage of the water retain ed to be evaporated back into the sky, again reducing total stormwater volume. Local regulati ons, in areas such as Alachua County, Florida, require developers to make efforts to mitigat e peak flows (Alachua County Board of County Commissioners [ACBCC], 2002). Stormwater retention areas require a large area of land to be effective. The lowest point of a retention pond must be at a greater elevation than the outlet to the conduit used to drain it. This

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20 basic principle of retention ponds keeps their overa ll depth minimal. These shallow depths mean their overall footprint must be large in order to create th e volume needed. Conventional retention ponds require large areas of land and are also easy to build and maintain. This ease of use makes the conventional pond a popular choice in areas where land is more abundant. For years, engineers have employed this simple met hod for water retention. However, this practice cannot be implemented in urban ar eas, where land is at a premium. Therefore, it is clear that alternative retention methods must be used (Roberts, 1996). Permeable Pavement Pavement makes up the largest percentage of impermeable surfaces throughout the United States. A way to help alleviate this pr oblem is a technology that is over 2,000 years old. Permeable pavement was first used by early ci vilizations in the form of cobblestone roads (Green, 2007). Cobblestone roads are created by f itting stones together to create a hard surface that is easy to travel. The voids between the st ones allow water to penetrate the system. While conventional pavements result in runoff, the porous nature of permeable pavements allows stormwater to seep through the pavements and pe netrate the earth below (F HWA, undated). This effectively reduces the area for runoff, allowing for the use of other BMPs or smaller wet ponds to detain the remaining runoff created by buildings. Though the use of permeable paving has cont inued, the process of creating permeable roadways has changed. Stones are still an accep table method of permeable pavement but a number of alternatives have been created. Brick pavers can also be used by leaving small gaps between the pavers. The cutting-edge of perm eable pavement technology however, lies in pervious concrete paving. Permeable concrete contains a system of interconnected voids running throughout. The voids surround the la rge aggregate within the concrete mix. Pervious concrete paving is applied much in the way conventional pa ving is, but with the addition of an aggregate

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21 sub-base to allow drainage. It s implementation has been tested during use in recent American highway projects (Hossain and Scofield, 1991). On e test determined that average infiltration rates for permeable concrete over one year were 2.5 inches per hour. An acceptable infiltration rate is 1.5 inches per hour. Th is study was conducted at a rest area for Interstate 4 in central Florida. The site was primarily used by trucks a nd tractor trailers. Even in an area with heavy traffic, the system showed no visual signs of wear and continued to perform above design requirements (Wanielista and Chopra, 2007). Although there are obvious benefits to this me thod, permeable concrete can cost between 15 and 25 percent more than conventional concrete paving. The cost of the aggregate drainage layer also increases the total cost of the system. Higher initial cost can be offset by the removal of curbs and underground storm pipes, which are no longer needed to channel runoff. Even though material costs are higher, by removing curbi ng on a project, the use of pervious concrete may result in net savings (Field et al., 1982). Anot her additional cost of permeable pavement is the costs of maintenance. Without proper ma intenance, permeable surfaces may become clogged, greatly reducing their drai nage capacity (Tan et al, 2003). Small debris from high traffic areas, along with grease and oil, may clog the system a nd greatly reduce its drainage capacity. These effects can be resolved by vacu uming the area. (Stormwater/Nonpoint Source Management Section, 1988). Sand however, will not clog the system. This is because sand will not be compressed and naturally contains voids allowing continued drainage. Green Roofing In addition to paving, the second non-permeable area of a project is usually the building itself. The best way to negate the runoff of thes e areas is with a green roof. A green roof is a roof which holds vegetation growing in severa l inches of growing medium. The vegetation naturally collects both sunlight and water. The growing medium needed for vegetated green

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22 roofs acts as an excellent insula tor as well as an area for stormw ater to collect. By retaining moisture within the soil, water is slowly releas ed into the attached stormwater system. The growing medium and vegetation on a green roof act in conjuncti on to reduce stormwater runoff and lower energy cost (Getter, 2006). As water is retained by the green ro of soil or in the plant vegetation, most of the moisture is evaporated back into the atmosphere Close to half of stormwater that falls on a green roof can be re cycled in this manner, cutting down on municipal stormwater holding areas (Kolb, 2004). One study s hows that if six percent of the buildings in a town like Toronto, Canada, were to employ green r oofing systems, it would be the equivalent of constructing a 60 million dollar (CND) water serv ice pipe (Peck, 2005). Obviously, this option could greatly reduce the infrastructure cost of a new development. One example of a successful use of a green roofing system is The American Society of Landscape Architects' in Washington, D.C. The facility has installed a green roof, to lower energy cost and set an example for the nation (E NR, 2007). This 3,000 square foot roof reduced runoff by 27,500 gallons of stormwater per hour during peak storms. Along with the added aesthetic and environmental bene fits, the green roof can be us ed as an educational tool. Some of the obvious costs associated with conventional roofs, su ch as insulation and shingles can be eliminated. This removal could make a gree n roof a more viable option. Another benefit is the reduction of the heat island effect, altho ugh it may be difficult to quantify by developers and owners. The he at island effect is a phenomenon in which heat is accumulated and retained in urban areas. Therefore, it ra ises ambient temperatures and increases cooling costs. While many conventional roofing systems in crease the heat island effect, green roofs can be used to decrease it. But, no matter how be neficial, the complex natu re of a green roof may

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23 scare away some potential users. While quite popular in areas of Eu rope and Canada, green roofs are slow to catch on in the United States (Parrott, 2007). Although green roofs can be an exceptional method of stor mwater retention, there are several drawbacks. Designing a project with a green roof can be complicated. The additional load of soil, vegetation, and reta ined water must be considered when designing such a building. Another concern in the implementation of a gree n roof is owner prefer ences and prejudices. Some owners may welcome the additional green space and stormwater benefits. However, some owners may see a green roof as an area requiring ex tra maintenance, as well as an area that could be prone to problems such as leaking. The need for additional structural support, along with the costs of green roofing materials, can make the green roof option an expensive one. Underground Water Vault Another consideration for wa ter retention in urban areas is the use of an underground water vault. Underground water retention vaults can be built by using creating concrete caverns, specifically designed boxes, perf orated polyethylene pipes, or steel pipes. Every method of underground vault has benefits and detriments, which depend on site specific conditions. Underground vaults work in the same way as an above-ground rete ntion pond, by holding the collected stormwater until the surrounding soil can accept it (Metropoli tan Council, 2003). Though they use a similar method to conve ntional ponds, underground vaults allow for courtyards, paving, or light struct ures to be constructed above them. By enabling construction above, underground vaults can greatly increase th e amount of useable land on a project site. Underground vaults are popular in densely populated areas because they allow for nearly full use of the land.

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24 Since they are constructed underground, vaults can be designed to allow for natural filtration through mediums such as sand or peat to remove small particles. Source particulate filtration is a key objective of any stormwater BMP (Roberts, 1996). In addition to reducing peak flows and filtering source pollutants, underg round vaults can also help lower the overall volume of potential runoff. Reducing total vol ume is accomplished by allo wing water within the vault to absorb into the surrounding soil, which reduces the total water outflow into municipal systems. One downfall of underground vaults is their need for regular maintenance. By filtering particles out of the runoff that flows through, th e system gradually accumulates sediment and debris. Once they become clogged, underground vaults lose their ability to affectively retain and filter the amount of runoff require d. Some extreme cases even require cleaning once a week to maintain efficiency (North ern Virginia District Pla nning Commission, 1992). Also, initial costs for underground vaults are often higher than conventional met hods. Higher costs are incurred because, essentially, a conventiona l pond must be excavated and fitte d with the required drainage connections. The system supporting the ground above must then be installed, drainage pipes must be mounted to direct stormwater to the vault, and access points must be put in place for monitoring and maintenance. The high requirem ent for maintenance, al ong with high initial costs, can make underground vaults non-feasible in many applications (Wiegand et al., 1986). Even though underground vaults have their downfa lls, their similarity to conventional methods makes them a popular choice. Industry Trends There are ever-growing options for developers when considering BMPs. This growth is due to a competitive commercial market that is em erging to meet the demands of urban areas. As the use of alternative BMPs grows, the fam iliarity and costs of such methods decrease.

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25 Companies that create products used in unconve ntional BMPs are becoming more and more popular. As the industry grows, there is an in creased force pushing for the adoption of new BMPs. These companies are pushing their prod ucts by promoting their benefits, and lowering associated material costs (Fassman, 2006). Some municipalities and developers are l ooking into the future when considering stormwater BMPs. Land values will continue to increase, driving up the actual cost of conventional ponds. As the parties responsible for implementing alternative BMPs focus more on the future, they increasingly se e the benefit of such methods. Another driving factor for using BMPs is the federally mandated National Polluta nt Elimination Program, which will require a separate stormwater discharge permit system. Requiring a permit guarantees that the EPA will review every new development. The EPA will re view the potential chemicals, sediment and other pollutants that could advers ely affect water quality if runoff is untreated and/or released into natural waterways (Urbonas, 1995). This legislation requires more and more developers to adopt unconventional BMPs. Although many municipalities see the benefit of alternative stormwater BMPs, and push for their use, there are several that do not r ecognize the benefit. Se veral Florida counties, including Broward County, will not allow a project s use of permeable paving to lower the total site retention volume needed. Such counties cl aim to recognize the benefit of such methods however, since many alternative methods require re gular maintenance to remain effective, these districts do not recognize their use and require a more time tested method. Some districts however, will allow the use of alternative stormw ater BMPs if the operator of the facility demonstrates the capability to maintain the methods employed (DeWiest and Livingston, 2002).

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26 By requiring an operating permit from two to five years, stormwater authorities are allowed to inspect the site regular to monitor the effec tiveness of maintenance, and BMP performance. The growth of the green building movement, al ong with increased life-cycle cost analysis will highlight the benefits of many alternative BMPs. The construction industry has been notorious for slowly adopting emerging technologie s. New methods will only be accepted is if they are easy-to-use, durable, well-known, and most importantly, economically beneficial. Because some BMPs are scarcely used by American contractors, Virginia Tech University is developing software to help c hoose the best BMP for a given a pplication (Landers, 2007). This program will promote alternative BMP awarenes s and educate contractors who are unfamiliar with these techniques. Software like this will promote the adoption of BMPs in urban North America by streamlining the decision-making process.

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27 CHAPTER 3 RESEARCH METHODOLOGY Introduction The primary aim of this thesis is to determ ine the stormwater management method with the greatest economical benefit in specific case studies. Also, this research will determine the reasons specific stormwater pr actices are used on projects. The methodology of this research was determined by the purpose and hypothesis se t out in Chapter 1. The following steps were taken to obtain the necessary information: An extensive literature review was conducted on material rela ting to stormwater BMPs and their use in development projects. The data needed for the analysis was identified. Projects that may lend themselves to the use of alternative BMPs were selected. The information needed from each case study was collected. The information collected from the case studies was analyzed to determine life-cycle costs. The life-cycle costs were analyzed to select the BMP with the highest economical benefit. A sensitivity analysis was conducted to gauge th e effect variations on determining factors would have on life-cycle cost. The data was analyzed to draw the necessary conclusions on the use of BMPs in these case studies. A developer survey was created to obtain opinions and outlooks of developers. The survey was administered to the developers selected. Surveys were collected and analyzed; conclusions were drawn from the results. Case Study Analysis Case Study Criteria First, the criteria for persp ective case studies were determin ed. The project should be an income-producing property so the benefits could be easily identified with a monetary value. The site must be in an area with a population densit y of 200 people per square mile or more. Site improvement information, along with the inform ation on the income-producing ability of the project is acquired to perform the necessary analysis.

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28 Project Selection Case 1 is a retail fresh produce market near downtown Titusville, FL. The project was essentially a new development with little remn ants of previous construction. In 1998, a new building and new parking area were constructe d on site. The site had been built with a conventional retention pond to the specifications shown in Table 3-1. The total area of the lot, along with the amount of permeable and non-permeable surfaces, is presented in the table. The table also includes the retention pond volume with various ratios of interest about the property. The case study selected to assist in the anal ysis of Case 1 in Titusville, FL was the companys sister store in New Smyrna Beach, FL entitled Case 1.1. Case 1.1 is approximately 32 miles away from Case 1, in an area w ith similar population density and population demographics. The project in Case 1.1 consisted of the renovation of two historical buildings, along with the addition of necessary equipmen t for conducting business as a fresh produce market. Because the site had been previously developed and used for retail purposes, there was already ample room for parking. Since there we re no new impervious areas placed, there was no need for new water retention. Th is project was selected solely to analyze the income-producing potential for Case 1. The project had been built with the specificati ons shown in Table 3-2. Another project selected for cas e study, was a large retail pharmacy chain in Gainesville, FL, referred to as Case 2. The project is a new development in a heavily populated portion of urban Gainesville. The site sits at the intersectio n of two busy streets, so access from both streets is necessary. The site had previous development that had to be demolished before construction could begin. Since the entir e site was completely cleared, the area was considered new development. As a new development, the projec t could not use the stormw ater retention already in place and must abide by all current stor mwater regulations. The project utilized a

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29 conventional retention pond to meet local stormw ater policies. Case 2 was built to the site specifications shown in Table 3-3. Case 3 is an apartment complex located two blocks from the University of Florida in Gainesville, FL. The proximity to the school ma kes the land very desirable, and thus very valuable. Most of the surrounding properties are similar rental properties built three to five stories tall. In Case 3, the project is three stories tall and employs an underground vault as its stormwater BMP. There is a central grassy common area constructed on top of the underground vault. City parking available near the location allows tenants to park on the street and free up valuable space on the site. Because there is no parking area, the only pavement areas on site are sidewalks. Case 3 was built to the s ite specifications shown in Table 3-4. Information Collected The necessary information for the analysis of each case study was obtained. For all cases, the information collected included: land ar ea, permeable area, retention pond volume, nonpermeable area, amount of concrete curbing, and available parking. This site information was needed to estimate initial and maintenance costs for each alternative stormwater BMP. The use of any BMP not utilized in th e original site plan change d the site specifications. In addition to cost estimates, th e site plans for Case 1 were us ed to calculate the additional parking that could be created by using each stor mwater method. Annual income totals for both Case 1 and Case 1.1 were collected dating back to 1999. The income totals were acquired to compare growth between the two sites and determine the benefits of additional parking. The information needed for this analysis was made available by the owner of both projects. For Case 2 in Gainesville, FL, the plans we re acquired and the needed information was calculated. By using this information, estimates could be made for initial and life-cycle costs on the project. As in Case 1, site plans were al so needed to determine the amount of additional

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30 parking that could be added by using each stor mwater method. The annual value of additional parking was obtained from the project owner. Increased income could be generated by the property with the addition of more parking. The plans for Case 3 were obtained and pertinen t figures were also calculated. The effect of the various BMPs included the addition and rem oval of available rental space. Other areas of the site were impacted by the changing building f ootprint. These changes were determined so initial cost, LCC, and potential income could be calculated. To generate potential gross income, data on rental rates, vacancy rates, efficiency ratios, and square footage of the building were collected or determined as needed. To conduct a sensitivity analysis data was collected to dete rmine a conceivable range of both land value and discount rate. These figures were estimated as accurately as possible, but must be broad enough to draw conclusions. The pur pose of the sensitivity analysis is to provide additional information to assist in the deci sion making process while choosing a stormwater BMP. Analysis Performed Initial cost estimates Once the data was collected, estimates of the in itial cost were devel oped. These estimates were made for the construction of each alterna tive for each case study. The BMPs selected for this analysis were green r oofs, permeable pavement, underg round vaults, and conventional retention ponds. RSMeans build ing construction cost data 2007 was used to estimate all construction expenses. By usi ng a common source for determining costs, comparisons could be made between the construction methods utilized, a nd the other methods analyzed in this study. It was assumed that project costs not associ ated with the BMP methods selected would remain the same. This assumption allowed only the systems in study to be estimated and

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31 compared. The estimated costs were discounted to 1998 for Case 1, and 2008 for Case 2 and Case 3. The location factor given by RSMeans building construction cost data 2007 for each project location was also used to further modify estimated costs. For each case study, the use of each BMP affect ed the site plan differently. Each BMP would change the water retenti on requirements, thusly changing the size of the retention volume needed. As a result, some BMPs allowed for more parking or more building to be built. Each of these changes had to be calculate d to estimate initial costs. Life-cycle cost estimates The life-cycle cost software NIST BLCC 5.3 was used to estimate tota l life-cycle cost. Annually recurring costs, such as maintenance, were included as pos itive numbers. Annual benefits, such as income generated from additional parking or rental area, were included as negative numbers. Negative numbers in the model indicate a negative cash outflow, or savings. By using the available data, estimates of LC C were determined for each alternative. Potential income variations of each alternativ e were projected to s upport the LCC analysis. The use of actual income data from the different projects were used to project potential income using alternative BMPs. Income projections were developed for Case 1 by comparing the income totals, growth, and available parking of both Case 1 and Case 1.1. The developer of Case 2 gave the annual value of a dditional parking for projects of th is type. By using the values given, the economic benefit of a dditional parking could be calculated for each BMP. Income projections for Case 3 were determined by cal culating the possible rent generated using each alternative. The economic benefit of each BMP, if any, wa s determined. If using an alternative BMP would create a cost benefit over the 20 year life of the buildi ng, then the null hypothesis set in

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32 the introduction is true. If the most economical option over the life of th e building is to use a conventional retention pond, then th e alternative hypothesis is true. Sensitivity analysis To better assist in the decision making proce ss, a sensitivity analysis was conducted to determine the effect factor va riation would have on the total LCC of the stormwater methods selected. The discount rate used during the research was altere d to a conceivable minimum and maximum to study how the value of money over the life of the project would change the present value of each BMP studied. This research also predicted how the present value of the LCC of each method could vary by studying a range of proj ected benefits. If land values were to increase or decrease, the valu e of the benefits would change accordingly. By studying the impact that variation of each f actor would have on the selected methods, the sensitivity to each factor could be determined. Developer Survey A structured interview of the project devel opers, along with other local developers, was created and administered to obtain opinions on various areas of BMP ap plication. Developers were selected from a list of the top developers in the central Flor ida area. The subjects of the study were required to give consent to the survey before the survey could be sent. A total of 40 surveys were sent to the developers from this lis t, and three sent to th e developers of the case studies. Of the 40 surveys distri buted, a total of 18 responses we re returned and collected for analysis. All responses were given a numeri cal code to keep the names of respondents confidential. The survey used a five point Likert scale, ranging from negative two to positive two, to rate responses. Open ended and multiple choice questions were summarized for analysis. The survey included questions designed to gauge developers familiarity with each BMP and

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33 frequency of use for each BMP. Also, inquiries were aimed at determining the difficulty of drawing permits for each BMP. Questions were us ed to gain insight on the use of LCC within the industry in the applic ation of stormwater BMPs. Developers were also asked to express their preference between various forms of stormwater management. A copy of the entire survey, as given to the developers in th e study, is in Appendix A. An analysis of the survey was done by calculating the mean of each numerical response. A mean with a positive value represents a posit ive position on the proposed subject matter. Conversely, a mean with a negative value repr esents a negative posit ion on the subject. Questions focusing on similar information were placed into groups to assist in developing conclusions. Questions with no numerical value, such as preferences, were analyzed to determine which response was chosen the most a nd least frequently. Comp lete results of this analysis are presented in Chapter 4. The study has also drawn conclusions from the data, and this information is presented in Chapter 5. Limitations This research was done to gain insight on a sp ecific area of both the construction industry and construction projects in gene ral. By focusing the study, the re sults of the research cannot be applied to general industry practices. The study was conducted in a specific region; therefore, conclusions can only be applied to developers in the area, not the entire population of developers. If a national or in ternational study had been conduc ted, then conclusions could be made for a much broader arena. The surv ey portion of the study only focused on land developers. To gain a full industry perspec tive on stormwater BMPs, a survey must be administered to members of all disciplines. Every case study has specific cr iteria that must be consider ed during analysis. Because every project is unique, a standard ized method cannot be established to account for all variations.

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34 What applies to the projects sele cted, will not apply to every proj ect. The method of income for projects varies from one to the next requiring various factors to c onsider in a LCC analysis. For example, a housing development in a suburban ar ea will have different needs and requirements than that of one in an urban environment. An apartment complex will generate income by having long-term residents, as opposed to a retail store that requires a larg e number of short term customers. Project owners value different things, so certain cond itions will appeal to some more than others. During the development of estimates and projec tions, certain assumptions had to be made; this is yet another limitation to this study. Th ese were made as accurately as possible to minimize the margin of error. Accurate assu mptions keep all estimates and projections as realistic as possible. Assumptions also had to be made to create models designed to predict cost 20 years into the future. The use of RSMeans bu ilding construction cost data 2007 as a source of project costs can also result in varia tions from actual figures. RSMeans building construction cost data 2007 dete rmines its cost data by taking averages of generalized work across the country. Though location and time factor s were applied to modify costs closer to reality, estimates are never 100 percent accurate.

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35 Table 3-1. Case 1 Site specifications Quantity Units Total land area: 18924 Sf Non-permeable Area: 10797 Sf Permeable area 8127 Sf Pavement area: 7053 Sf Permeable % of Total: 43 % Non-permeable % of Total: 57 % Pond 1 volume 11608 Cuft Pond 2 volume 2230 Cuft Total pond volume: 13838 Cuft Pond volume/Non-permeable area: 1.28 Cuft/Sf Table 3-2. Case 1.1 Site specifications Quantity Units Total land area: Non-permeable area: Permeable area Pavement area: Permeable % of total: Non-permeable % of total: Total pond volume: Pond volume/non-permeable area: 34,907 21,490 13,417 18,762 38 62 Sf Sf Sf Sf % % Cuft Cuft/Sf Table 3-3. Case 2 Site specifications Quantity Units Total land area Permeable area Non-permeable area Pavement area Pond area Permeable % of total Non-permeable % of total Total pond volume Pond volume/non-permeable area 65557 45890 19667 31400 14000 30 70 7012 0.15 Sf Sf Sf Sf Sf % % Cuft Cuft/Sf

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36 Table 3-4. Case 3 Site specifications Quantity Units Total land area Permeable area Non-permeable area Pavement area Pond area Permeable % of total Non-permeable % of total Total pond volume Pond volume/non-permeable area 12,003 8,029 3,974 1,706 33 67 3,768 0.47 Sf Sf Sf Sf Sf % % Cuft Cuft/Sf

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37 CHAPTER 4 RESULTS Case 1 Life-cycle Cost Using the plans for Case 1 and RSMeans build ing construction cost data 2007, estimates of initial costs were created for each BMP met hod: conventional, underground vault, permeable pavement, and green roof. The estimates are summarized in Table 4-1 with the available number of parking spots each alternative allows. The va lues used to determine LCC are presented in Appendix B and detailed estimates for each of th e methods are presented in Appendices E-H. Case 1.1 did not undergo the full analysis as there were no stormwater retention requirements for the project. Case 1.1 was onl y used as a comparison to generate income projections for its sister store in Titusville. Case 1.1 has 35 parking spots compared to 12 in Case 1. This larger parking area allowed for gr eater growth. Income totals for each store were obtained and discounted back to 1998 dollar amounts. Annual growth and average growth for each store were determined and presented in Ta ble 4-2 through 4-3 and Figures 4-1 through 4-2. Growth projections were applied to the income totals of Case 1 to estimate the annual benefit that additional parking would provide. These in come totals and projectio ns are shown in Table 4-4 through 4-5. The growth analysis of Case 1 shows that there was little to no actual growth over the study period. Annual income totals were 0.0037 per cent lower than if the initial annual income had grown by inflation alone. This stalemate dem onstrates that Case 1 ha d maximized its growth potential with the current parking scenario. If additional parking had been available, growth could have continued on a rate similar to its sister store. Since the parkin g area in Case 1 would still not be on par with that of Case 1.1, growth could only be assumed for the additional parking

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38 alternative BMPs would create. The benefit of the additional pa rking was estimated to be an additional $28,000 in annual income to the project. Using the estimated initial cost, projected income benefits, and projected maintenance costs, a life-cycle analys is was conducted for each BMP alternative. The study period chosen for this research was 20 years, beginning in 1998. The study shows that the permeable pavement option had the lowest LCC of ($153,676) over 20 years. The conventional retention pond that was used had a total life-cycle cost of $30,383. The difference in LCC between permeable pavement and conventional concrete is $184,059. This benefit is attained from lower initial and annual cost, along with the added benefit of additional parking. Th e BMP with the second lowest LCC was the green roof option was ($121,234) over 20 years. Even though initial costs of green roofing were higher th an those of conventional methods the value of the additional parking would overcome the cost differential over th e life of the project. The full results of this LCC analysis are shown in Table 4-6. Case 2 Life-cycle Cost The next case study, Case 2, was the pharmacy in Gainesville, FL. Site plans and RSMeans building construction cost data 2007 were used to estim ate the total initial cost for all BMP options. Initial cost and the number of available pa rking spaces are presented by BMP type in Table 4-7. The option with the lowest in itial costs is the option employed in the current site plan. The initial cost of this option is $79,138. After the initial option, the second least expensive option is the underground vault met hod with a total cost of $170,469. The most influential factor in the price of these two options is the use of asphalt paving. Asphalt paving has very low initial cost for paving of large area s. The other options of permeable pavement and green roofs result in initial cost of $182,690 and $214,274, respectfully. LCC used in the

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39 analysis are in Appendix C and the full initial cost of these estimates is presented in Appendices I-J. The pharmacy chains real estate department gave the following description for choosing a potential new location: A new location with the highest probability for approval by the Real Estate Committee will have the following characteristics: Site criteria: A new Walgreen Drug Store location with the highest probability for approval by the Real Estate Committee will have the following characteristics: Freestanding location at si gnalized intersection of two main streets with significant traffic counts. Direct access to service the site. 75,000 square feet +/of land to accommodate parking for 70+ cars and a pharmacy drive thru. Building criteria: 112' x 130' = 14,560 square feet. Trade area population of 20,000. (Walgreens, 2009) The current site plan has met all of the criter ia except for one; parking for 70+ cars. Use of a conventional pond only allowed for 53 spaces on site. By employing either permeable pavement or an underground vault the total number of parking spaces could be increased to 73. The use of a green roof also increased the av ailable parking to a to tal of 63, a gain of 18.87 percent, but it would still not meet the recommended number. The results of the life-cycle analysis for the BMP methods in this case are presented in Table 4-8. It was determined by the project de veloper that the benef it of additional parking would be $380 annually (Spock, personal communi cation). A conventional retention pond with normal asphalt paving has the lowest life-cycle cost of $91,351. The lowest alternative method was the installation of an underground vault and the life-cycle cost of the vault option is $127,660. Green roofing was the most expensiv e option because the total LCC was $204,982.

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40 The initial cost of a green roof was higher than the ot her options, and offere d less than 50 percent of the additional parking ot her alternatives allowed. Case 3 Life-cycle Cost Case 3 is a three story apartment complex c onsisting of two separate buildings connected with a covered walkway. Land usage and wate r retention specifications such as retention volume needed, permeable area, and non-permeable area, are shown in Table 4-9 for each alternative. This table displays how the land would be utilized for each situation. Needing a relatively small retention volume of 800 cuft, the green roof option creates the most permeable area on site. This is compared to the volume of 3,768 cuft needed for an underground vault, creating a difference in volume of 2,967 cuft. With an average depth of five feet, the green roof option could add an additional 594 sqft of constructible space. Table 4-10 show how each alternative would affect retention volume needed, building area, and total rentable area. By using these numbers, along with rent rates and vacancy rates, the gross annual income each option could produce was determined. The annual income figures for the various alternatives were compared to the method used, which is an underground vault. BMPs that resulted in a larger rentable space allowed for more income to be produced, while those that required additional land lowered the tota l rentable space. Annual income varied from $352,430 for the green roof option to $278,440 with the conventional method. Using the areas defined in Tables 4-8 and 4-9, initial costs of each method were estimated. The figures determined for the LCC are in Appe ndix D and detailed initial cost estimates are presented in Appendices M-P. An LCC analysis was performed with the initial cost, annual cost, and life-cycle costs shown in Table 4-11. This anal ysis determined that the most cost efficient method would be the underground vault method, with a total 20 year LCC of $52,763. The green roof option would allow for additional building area, thus more rent, however this option

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41 has the highest initial cost. The high initia l cost makes the green roof option the least economical. The conventional method is less economical compared with the underground method, though initial costs would be the lowest The area needed for the pond would remove 2,069 sf of building space, re sulting in an annual loss of $34,079 in annual income. Sensitivity Analysis The factors of discount rate and BMP benef it were chosen to study how the LCC for each method would be affected if these factors were to change. A discount rate of 4.7 percent was used for the baseline study. The baseline rate was determined by the U.S. Department of Energy in the NIST BLCC 5.3 software. It was determined that the rate could conceivably drop as low as 1.0 percent, or could rise as high as 7.0 percent. The present value of LCC cost was determined for each stormwater control method with these high and low rates. Benefits of the BMPs were calculated at 25.0 percent above and below the baseline case to gauge how changes in potential benefits woul d impact LCC. The benefits of the additional land made available by the use of alternative BMPs would vary according to the value of the land. The sensitivity analysis showed that the cha nge in discount rate w ould have the greatest impact over the 20 year life of the study. The average variation for each method from the low to high discount rate, was $139,000 for Case 1, $27,000 for Case 2, and $180,000 for Case 3. Compare these to the difference that varia tions in benefit would cause of $67,000, $16,000, and $86,000 respectively. For both factors studied, the projects where alternative BMPs had the greatest economical impact were affected the most dramatically by changes in the sensitivity factors. Figure 4-3 illustrates a direct correlation of land value and the economic benefit of alternative BMPs. As the value of parking space s increases, the life-cycle cost of alternative BMPs decreases as well, show ing at what point alternativ e methods would become more

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42 economical than the conventional method used. The full results from the sensitivity analysis are in Table 4-12 through 4-19 and Figures 4-4 thro ugh 4-16. This analysis shows that as the discount rate decreases, and futu re money becomes more valuable today, alternatives with high potential benefits were given a great advantage. In both Case 2 and Case 3, options that were originally less economical than others became the mo st beneficial as the in terest rate decreased. These methods had a high initial cost, but their benef it over time would overcome the cost if the future value of money was relatively high. As the value of future money decreased, Case 3 saw the conventional method become the most econo mical. This method had the lowest income producing potential, but also had th e lowest initial cost. The low initial cost was more preferred in this scenario where future money has little value. Developer Survey The purpose of the survey is to obtain opini ons on alternative stormwater retention methods, along with the use of LCC analysis in th e implementation of stormwater BMPs. In the scored portion of the developer survey, there is a range of (2) to 2 points. A positive number represents a positive perception of alternative BMP use, and a negative number represents the opposite. There was also a multiple choice section of the survey. To analyze the multiple choice questions, the responses for each choice were co unted and summed to draw conclusions. The responses of the survey are pr esented in Appendices Q and R. After gathering and evaluating developer res ponses, conclusions could be developed by following a particular method of analysis. By grouping together questions on general alternative BMP use, LCC use, and permitting, the study could focus on these certain points of interest. Additionally, questions regardi ng a specific BMP were put into their respective BMPs group. The full results of this group an alysis are in Table 4-12 and Fi gure 4-17. The questions were grouped as follows:

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43 General alternative BMPs 1, 8, and 14 LCC 13 and 18 Permitting 15, 16, and 17 Permeable pavement 2, 10, and 19 Green roof 3, 11, and 20 Underground vault 4, 12, and 21 Once the questions were grouped, a mean score for each group was determined. The mean score for general alternative BMP use was 0.11. This score showed a positive perception on the use of alternative stormwater retention methods. Although de velopers viewed alternative methods favorably, there are still benefits to using conventional methods The survey showed that the biggest reason for choos ing conventional BMPs over others was first cost, and not lack of awareness of the alternatives. Developers surv eyed rarely used life-cy cle costing to determine what method of stormwater retention to empl oy. Questions regarding LCC analysis received a mean score of (0.08), representing a lack of LCC in the industry today. The survey also exemplified that permitting can be a problem w ith the implementation of alternative BMPs. Every permitting question received a negative mean score with the entire group receiving a mean of (0.11). There were several questions designed to evaluate the developers attitudes on the alternative stormwater retention methods studied in this research. Arithmetic means of the responses for the alternative BMP groups are as follows: permeable pavement 0.21, underground vault 0.19, and green roof with (0.33). The data from the numerical portion of the survey is supported by the information acquired in the multiple choice portions. By calculating the number of multiple choice responses regard ing the most preferred method, the permeable pavement option was determined to be the mo st popular. The multiple choice section of the survey showed that the permeable pavement was selected by 10 out of the total 18 respondents. The option chosen second most was the use of underground vaults, which was selected 7 times.

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44 Green roofing proved to be the least preferred method, with one respondent who chose it as their preference. In regards to whic h methods the respondents would be least likely to use, green roofing was selected 16 times. Permeable pa vement and underground vaults were each chosen once as the least preferred method.

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45 Table 4-1. Case 1 BMP initial costs Conventional Total initial cost $ 24,277 Parking spots 12 $/Parking spot 2,023 Permeable pavement Total initial cost $ 26,016 Parking spots 17 $/Parking spot 1,530 Underground vault Total initial cost $ 97,736 Parking spots 17 $/Parking spot 5,749 Green roof Total initial cost $ 56,547 Parking spots 17 $/Parking spot 3,326

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46 Table 4-2. Case 1 Income Year Annual income Annual growth Growth by inflation only Annual inflation rate 1999 $ 764,584 $764,584 2.19% 2000 $ 764,863 0.04% $790,427 3.38% 2001 $ 735,543 -3.83% $812,796 2.83% 2002 $ 799,998 8.76% $825,719 1.59% 2003 $ 935,537 16.94% $844,463 2.27% 2004 $ 963,634 3.00% $867,095 2.68% 2005 $ 847,888 -12.01% $896,489 3.39% 2006 $ 873,922 3.07% $925,536 3.24% 2007 $ 924,863 5.83% $951,913 2.85% 2008 $1,046,399 13.14% $988,562 3.85% Avg $ 865,723 3.88% $866,759 2.83% Table 4-3. Case 1.1 Income Year Annual income Annual growth Growth by inflation only Annual inflation rate 1999 $544,631 $544,631 2.19% 2000 $604,409 10.98% $563,040 3.38% 2001 $602,962 -0.24% $578,974 2.83% 2002 $758,706 25.83% $588,179 1.59% 2003 $886,947 16.90% $601,531 2.27% 2004 $831,533 -6.25% $617,652 2.68% 2005 $806,978 -2.95% $638,590 3.39% 2006 $837,986 3.84% $659,281 3.24% 2007 $870,607 3.89% $678,070 2.85% 2008 $1,078,357 23.86% $704,176 3.85% Avg $782,312 8.43% $617,412 2.83%

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47 Table 4-4. Case 1 Income growth Year Titusville Titusville in 1998 $ Titusville growth Titusville growth discounted 1999 $ 764,584 $ 747,840 2000 $ 764,863 $ 717,365 0.04% -4.25% 2001 $ 735,543 $ 678,171 -3.83% -5.78% 2002 $ 799,998 $ 719,438 8.76% 5.74% 2003 $ 935,537 $ 816,256 16.94% 11.86% 2004 $ 963,634 $ 808,103 3.00% -1.01% 2005 $ 847,888 $ 683,567 -12.01% -18.22% 2006 $ 873,922 $ 679,649 3.07% -0.58% 2007 $ 924,863 $ 683,659 5.83% 0.59% 2008 $ 1,046,399 $ 773,498 13.14% 11.61% Avg $ 865,723 $ 730,755 3.88% 0.0037% Table 4-5. Case 1 Income potential Year Case 1 in 1998 $ Case 1 potential in 1998 $ Case 1 capacity with alt. BMPs BMP benefit 1999 $ 747,840 $ 731,462 $ 1,036,238 $ (16,378) 2000 $ 717,365 $ 732,847 $ 1,038,200 $ 15,482 2001 $ 678,171 $ 738,265 $ 1,045,876 $ 60,095 2002 $ 719,438 $ 752,878 $ 1,066,577 $ 33,440 2003 $ 816,256 $ 762,661 $ 1,080,436 $ (53,595) 2004 $ 808,103 $ 769,444 $ 1,090,045 $ (38,660) 2005 $ 683,567 $ 770,824 $ 1,092,000 $ 87,256 2006 $ 679,649 $ 773,362 $ 1,095,597 $ 93,713 2007 $ 683,659 $ 778,925 $ 1,103,478 $ 95,267 2008 $ 773,498 $ 776,739 $ 1,100,381 $ 3,241 Avg $ 730,755 $ 758,741 $ 1,074,883 $ 27,986 Sum $ 7,307,546 $ 7,587,407 $ 10,748,827 $ 279,861

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48 Table 4-6. Case 1 Life -cycle costs analysis Present value Annual value Conventional Initial capital costs $ 24,277 Annually recurring costs $ 6,106 $ 478 Total life-cycle cost $ 30,383 Underground vault Initial capital costs $ 97,736 Annually recurring costs $ (12,147) $ (951) Total life-cycle cost $ (81,585) Permeable pavement Initial capital costs $ 26,016 Annually recurring costs $ (179,692) $ (14,071) Total life-cycle cost $ (153,676) Green roof Initial capital costs $ 56,547 Annually recurring costs $ (177,781) $ (13,922) Total life-cycle cost $ (121,234)

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49 Table 4-7. Case 2 Available parking with BMP options Conventional Total initial cost: $ 79,139 Parking spots 53 $/Parking spot 1,493 Underground vault Total initial cost: $ 170,469 Parking spots 74 $/Parking spot 2,304 Permeable pavement Total initial cost: $ 182,690 Parking spots 74 $/Parking spot 2,469 Green roof Total initial cost: $ 214,274 Parking spots 63 $/parking spot 3,401 Table 4-8. Case 2 Life -cycle costs analysis Present value Annual value Conventional Initial capital costs $ 79,139 Annually recurring costs $ 12,212 $ 955 Total life-cycle cost $ 91,351 Underground vault Initial capital costs $ 170,469 Annually recurring costs $ (42,810) $ (3,349) Total life-cycle cost $ 127,660 Permeable pavement Initial capital costs $ 182,690 Annually recurring costs $ (40,898) $ (3,200) Total life-cycle cost $ 141,793 Green roof Initial capital costs $ 214,274 Annually recurring costs $ (9,292) $ (727) Total life-cycle cost $ 204,982.

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50 Table 4-9. Case 3 site specifications for each BMP Conventional UndergroundPermeable Green roof Quantity Quantity Quantity Quantity Units Total land area: 12,003 12,003 12,003 12,003 Sf Non-permeable area: 7,346 8,029 6,323 1,706 Sf Permeable area 4,657 3,974 5,680 10,297 Sf Pavement area: 1,706 1,706 1,706 1,706 Sf Permeable % of total: 39 33 47 86 % Non-permeable % of total: 61 67 53 14 % Total pond volume: 3,448 3,768 2,967 801 Cuft Pond volume/ non-permeable area: 0.47 0.47 0.47 0.47 Cuft/Sf Table 4-10. Case 3 income projections Conventional Underground Permeable Green roof Quantity Quantity Quantity Quantity Units Building 5,633 6,323 5,730 7,131 Sf Pond area 690 754 593 160 Sf Pond gallons 25,789 28,187 22,198 5,989 gallons Total building area 16,900 18,969 17,189 21,392 sf Efficiency factor 0.82 0.82 0.82 0.82 Rentable area 13,858 15,555 14,095 17,541 sf Rent $/sf/yr $ 22 $ 22 $ 22 $ 22 Vacancy rate 0.93 0.93 0.93 0.93 Gross annual income $ 278,440 $ 312,518 $ 283,186 $ 352,430 Rent difference $ (34,079) $ (29,333) $ 39,911

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51 Table 4-11. Case 3 life-cycle cost analysis Present value Annual value Conventional Initial capital costs $ (168,259) Annually recurring costs $ 239,361 $ 18,727 Total life-cycle cost $ 71,102 Underground vault Initial capital costs $ 38,088 Annually recurring costs $ 14,675 $ 1148 Total life-cycle cost $ 52,763 Permeable pavement Initial capital costs $ (142,747) Annually recurring costs $ 206,790 $ 16,178 Total life-cycle cost $ 64,043 Green roof Initial capital costs $ 294,686 Annually recurring costs $ (170,154) $ (13,312) Total life-cycle cost $ 124,532

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52 Table 4-12. Case 1 discount rate sensitivity analysis Low 1% High 7% Present Value Present Value Conventional Conventional Initial Capital Costs $ 24,277 Initial Capital Costs $ 4,277 Annually Recurring Costs $ 10,640 Annually Recurring Costs $ 4,391 Total Life-Cycle Cost $34,917 Tota l Life-Cycle Cost $ 28,668 Underground vault Underground vault Initial Capital Costs $ 97,736 Initial Capital Costs $ 97,736 Annually Recurring Costs $ (312,476) Annually Recurring Costs $ (128,965) Total Life-Cycle Cost $ (214,740) Total Life-Cycle Cost $ (31,229) Permeable Pavment Permeable Pavment Initial Capital Costs $ 26,016 Initial Capital Costs $ 26,016 Annually Recurring Costs $ (313,124) Annually Recurring Costs $ (129,232) Total Life-Cycle Cost $ (287,108) Total Life-Cycle Cost $ (103,216) Green roof Green roof Initial Capital Costs $ 56,547 Initial Capital Costs $ 56,547 Annually Recurring Costs $ (309,793) Annually Recurring Costs $ (127,858) Total Life-Cycle Cost $ (253,246) Total Life-Cycle Cost $ (71,311)

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53 Table 4-13. Case 1 BMP benefit sensitivity analysis Low -25% High +25% Present Value Present Value Conventional Conventional Initial Capital Costs $ 24,277 Initial Capital Costs $ 24,277 Annually Recurring Costs $ 6,106 Annually Recurring Costs $ 6,106 Total Life-Cycle Cost $ 30,383 Total Life-Cycle Cost $ 30,383 Underground vault Underground vault Initial Capital Costs $ 97,736 Initial Capital Costs $ 97,736 Annually Recurring Costs $ (132,887) Annually Recurring Costs $ (225,759) Total Life-Cycle Cost $ (35,151) Total Life-Cycle Cost $ (128,023) Permeable Pavment Permeable Pavment Initial Capital Costs $ 26,016 Initial Capital Costs $ 26,016 Annually Recurring Costs $ (133,259) Annually Recurring Costs $ (226,131) Total Life-Cycle Cost $ (107,243) Total Life-Cycle Cost $ (200,115) Green roof Green roof Initial Capital Costs $ 56,547 Initial Capital Costs $ 53,262 Annually Recurring Costs $ (131,347) Annually Recurring Costs $ (224,220) Total Life-Cycle Cost $ (74,800) Total Life-Cycle Cost $ (167,673)

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54 Table 4-14. Case 2 discount rate sensitivity analysis Low High Present Value Present Value Conventional Conventional Initial Capital Costs $ 79,139 Initial Capital Costs $ 79,139 Annually Recurring Costs $ 21,280 Annually Recurring Costs $ 8,783 Total Life-Cycle Cost $ 100,419 Total Life-Cycle Cost $ 87,922 Underground vault Underground vault Initial Capital Costs $ 170,469 Initial Capital Costs $ 170,469 Annually Recurring Costs $ (74,597) Annually Recurring Costs $ (30,788) Total Life-Cycle Cost $ 95,872 Total Life-Cycle Cost $ 139,681 Permeable Pavment Permeable Pavment Initial Capital Costs $ 182,690 Initial Capital Costs $ 182,690 Annually Recurring Costs $ (71,266) Annually Recurring Costs $ (29,413) Total Life-Cycle Cost $ 111,424 Total Life-Cycle Cost $ 153,277 Green roof Green roof Initial Capital Costs $ 214,274 Initial Capital Costs $ 214,274 Annually Recurring Costs $ (16,192) Annually Recurring Costs $ (6,683) Total Life-Cycle Cost $ 198,082 Total Life-Cycle Cost $ 207,591

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55 Table 4-15. Case 2 BMP benefit sensitivity analysis Low High Present Value Present Value Conventional Conventional Initial Capital Costs $ 79,139 Initial Capital Costs $ 79,139 Annually Recurring Costs $ 12,212 Annually Recurring Costs $ 12,212 Total Life-Cycle Cost $ 91,351 Total Life-Cycle Cost $ 91,351 Underground vault Underground vault Initial Capital Costs $ 170,469 Initial Capital Costs $ 170,469 Annually Recurring Costs $ (29,561) Annually Recurring Costs $ (56,063) Total Life-Cycle Cost $ 140,908 Total Life-Cycle Cost $ 114,406 Permeable Pavment Permeable Pavment Initial Capital Costs $ 182,690 Initial Capital Costs $ 182,690 Annually Recurring Costs $ (27,650) Annually Recurring Costs $ (54,152) Total Life-Cycle Cost $ 155,040 Total Life-Cycle Cost $ 128,538 Green roof Green roof Initial Capital Costs $ 214,274 Initial Capital Costs $ 214,274 Annually Recurring Costs $ (2,987) Annually Recurring Costs $ (15,597) Total Life-Cycle Cost $ 211,287 Total Life-Cycle Cost $ 198,677

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56 Table 4-16. Case 3 discount rate sensitivity analysis Low High Present Value Present Value Conventional Conventional Initial Capital Costs $ (168,259) Initial Capital Costs $ (168,259) Annually Recurring Costs $ 417,099 Annually Recurring Costs $ 172,145 Total Life-Cycle Cost $ 248,840 Tota l Life-Cycle Cost $ 3,886 Underground vault Underground vault Initial Capital Costs $ 38,088 Initial Capital Costs $ 38,088 Annually Recurring Costs $ 25,571 Annually Recurring Costs $ 10,554 Total Life-Cycle Cost $ 63,659 Total Life-Cycle Cost $ 48,642 Permeable Pavment Permeable Pavment Initial Capital Costs $ (142,747) Initial Capital Costs $ (142,747) Annually Recurring Costs $ 360,343 Annually Recurring Costs $ 148,721 Total Life-Cycle Cost $ 217,596 Tota l Life-Cycle Cost $ 5,974 Green roof Green roof Initial Capital Costs $ 294,686 Initial Capital Costs $ 294,686 Annually Recurring Costs $ (418,845) Annually Recurring Costs $ (172,866) Total Life-Cycle Cost $ (124,159) Total Life-Cycle Cost $ 121,820

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57 Table 4-17. Case 3 BMP benefit sensitivity analysis Low High Present Value Present Value Conventional Conventional Initial Capital Costs $ (168,259) Initial Capital Costs $ (168,259) Annually Recurring Costs $ 211,841 Annually Recurring Costs $ 344,291 Total Life-Cycle Cost $ 43,582 Total Life-Cycle Cost $ 176,032 Underground vault Underground vault Initial Capital Costs $ 38,088 Initial Capital Costs $ 38,088 Annually Recurring Costs $ 14,675 Annually Recurring Costs $ 14,675 Total Life-Cycle Cost $ 52,763 Total Life-Cycle Cost $ 52,763 Permeable Pavment Permeable Pavment Initial Capital Costs $ (142,747) Initial Capital Costs $ (142,747) Annually Recurring Costs $ 181,749 Annually Recurring Costs $ 294,838 Total Life-Cycle Cost $ 39,002 Total Life-Cycle Cost $ 152,091 Green roof Green roof Initial Capital Costs $ 294,686 Initial Capital Costs $ 294,686 Annually Recurring Costs $ (121,485) Annually Recurring Costs $ (218,824) Total Life-Cycle Cost $ 173,201 Total Life-Cycle Cost $ 75,862

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58 Table 4-18. Discount rate se nsitivity analysis summary Case 1 Low 1% Base 4.7% High 7% Difference Conventional $ 34,917 $ 30,383 $ 28,668 $ 6,249 Underground vault $ (214,740) $ (81,585) $ (31,229) $ 183,511 Permeable Pavment $ (287,108) $ (153,676) $ (103,216) $ 183,892 Green Roof $ (253,246) $ (121,234) $ (71,311) $ 181,935 Average $ 138,897 Case 2 Low 1% Base 4.7% High 7% Difference Conventional $ 100,419 $ 91,351 $ 87,922 $ 12,497 Underground vault $ 95,872 $ 127,660 $ 139,681 $ 43,809 Permeable Pavment $ 111,424 $ 141,793 $ 153,277 $ 41,853 Green Roof $ 198,082 $ 204,982 $ 207,591 $ 9,509 Average $ 26,917 Case 3 Low 1% Base 4.7% High 7% Difference Conventional $ 248,840 $ 71,102 $ 3,886 $ 244,954 Underground vault $ 63,659 $ 52,763 $ 48,642 $ 15,017 Permeable Pavment $ 217,596 $ 64,043 $ 5,974 $ 211,622 Green Roof $ (124,159) $ 116,806 $ 121,820 $ 245,979 Average $ 179,393

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59 Table 4-19. BMP benefit sens itivity analysis summary Case 1 Low -25% Base High +25% Difference Conventional $ 30,383 $ 30,383 $ 30,383 $ Underground vault $ (35,151) $ (81,585) $ (128,023) $ 92,872 Permeable Pavment $ (107,243) $ (153,676) $ (200,115) $ 92,872 Green Roof $ (74,800) $ (121,234) $ (167,673) $ 92,873 Average $ 69,654 Case 2 Low -25% Base High +25% Conventional $ 91,351 $ 91,351 $ 91,351 $ Underground vault $ 140,908 $ 127,660 $ 114,406 $ 26,502 Permeable Pavment $ 155,040 $ 141,793 $ 128,538 $ 26,502 Green Roof $ 211,287 $ 204,982 $ 198,677 $ 12,610 Average $ 16,404 Case 3 Low -25% Base High +25% Conventional $ 43,582 $ 71,102 $ 176,032 $ 132,450 Underground vault $ 52,763 $ 52,763 $ 52,763 $ Permeable Pavment $ 39,002 $ 64,043 $ 152,091 $ 113,089 Green Roof $ 173,201 $ 116,806 $ 75,862 $ 97,339 Average $ 85,720 Table 4-20. Survey group analysis summary Question category Mean score Frequency most preferred Frequency least preferred General alternative BMPs 0.11 LCC (0.08) Permitting (0.11) Permeable pavement 0.21 10 1 Green roof (0.33) 1 16 Underground vault 0.19 7 1

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60 Figure 4-1. Case 1 and Case 1.1 comparitive growth

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61 Figure 4-2. Case 1 growth vs. inflation $(50,000) $$50,000 $100,000 $150,000 $200,000 $250,000 LCCParking space value Underground Permeable Green roof Conventional Figure 4-3. BMP life-cycle cost vs parking space value in Case 2

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62 Figure 4-4. Case 1 Conventiona l pond sensitivity analysis Figure 4-5. Case 1 Underground vault sensitivity analysis Figure 4-6. Case 1 Permeable pa vement sensitivity analysis Figure 4-7. Case 1 Green r oof sensitivity analysis

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63 Figure 4-8. Case 2 Conventiona l pond sensitivity analysis Figure 4-9. Case 2 Underground vault sensitivity analysis Figure 4-10. Case 2 Permeable pavement sensitivity analysis Figure 4-11. Case 2 Green roof sensitivity analysis Figure 4-12. Case 3 Conventi onal pond sensitivity analysis

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64 Figure 4-13. Case 3 Underground vault sensitivity analysis Figure 4-14. Case 3 Permeable pavement sensitivity analysis Figure 4-15. Case 3 Green roof sensitivity analysis

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65 Figure 4-16. LCC factor sensitivity

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66 0.11 (0.08) (0.11) 0.21 (0.33) 0.19 (0.40) (0.30) (0.20) (0.10) 0.00 0.10 0.20 0.30 0.40 General alternative BMPs LCC Permitting Permeable pavement Green roof Underground Figure 4-17. Mean survey responses for each question group

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67 CHAPTER 5 CONCLUSIONS In Case 1, the most economical choice would have been to employ the use of permeable pavement. Permeable pavement allowed for a 43 pe rcent increase in available parking with little additional maintenance cost over the life of the project. The initial costs were $26,016 compared to $24,277 for conventional concrete paving, creating an initial co st burden of $1,739. Similar costs were realized by having less of a retenti on pond to dig and sod, even though material cost of permeable pavement is considerably more than regular concrete. The 43 percent increase in parking would allow for store income to grow by allowing more customers at one time, along with easier ingress and egress for customer vehicl es. Because the store relies on a high volume of customers spending relatively small amounts of money, additional parking is very beneficial. Though each alternate BMP allows for the same increase in available parking area, the green roof and underground vault option have highe r initial and LCC than permeable pavement. The BMP options rated by lowest LCC are perm eable pavement, green roof, underground vault, and lastly, a conventional pond. Case 2 was considerably larger than Case 1, and the relative volum e of water retention needed was considerably lower. These factors dissipated the cost effec tiveness of alternative BMPs. The area had less than optimal parking av ailable but, the added cost of alternatives over the life of the project proved detrimental to their implementation. Though the parking area was less than the recommended amount, there is not a great financial benefit of additional parking. The parking area was still quite la rge at 53 spots, along with a driv e thru area for the pharmacy. The only times the parking capacity is predicted to be inadequate woul d be during peak shopping periods throughout the year.

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68 Case 2 used asphalt paving instead of concre te paving due to the large parking area. Asphalt is much cheaper than concrete for larg e areas throughout the lif e of the project. Permeable concrete had an initial cost that was much too great to overcome, even with additional parking made available. An underground vault al lowed for greater park ing, but again a high initial cost was detrimental. The use of a green roof had the highest initia l cost and with little economic benefit, the option was unsatisfactory. Case 3 is in a highly developed area, very close to the Univers ity of Florida. The value of land in this area is high, with rent al properties drawing very expens ive rates. For this reason, the need to maximize land use is essential. A c onventional water retention pond was not used on this project, instead an underground vault was us ed to maximize available land. The green roof option would allow for a greater rental area to be built. However, higher initial and maintenance costs erase any benefit of additional income. Even though the green roof option would allowed for increased income, the added design complex ity and possible complications make the option less attractive compared to simpler alternatives. Since there was no on-site parking required, the use of permeable pavement would add little benefit to stormwater management on the site The only paved areas of the project were the sidewalks. If a conventional pond would have been used, the area needed for the pond would remove available land currently used for construc tion of a large portion of the apartments. This land is too valuable to be used as a retent ion pond and not as inco me producing property. The selection of an underground water storage vault was the correct selection because it allows for the lowest LCC. It also has relatively easy maintenance and greatly increases available land compared to the conventional method. Many apartment complexes immediately surrounding the area also use underground vaults. Th is further strengthens the assumption that

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69 areas of high population density and land value are better candida tes for alternat ive stormwater BMPs. The sensitivity analysis exhibits that as th e price of land increase s, alternative methods become more viable. The results of the sensi tivity analysis show that in Case 3 the most economical option would change from an underground vault, as in the base case, to permeable paving as the value of benefits de crease. Benefit value in Case 3 would decrease if the value of the land were to decrease. This is why developers are much more likely to employ unconventional BMPs in areas of high land value as hypothesized. As the discount rate changes from high to low and the value of future money increases, options with higher future financial benefits become the most economical. In Case 3 the most economical option with a discount rate of 1.0 percent was the green roof. The green roof would have the lowest present value LCC because future money would be most valued and the increased income would make a greater impact. Conversely, the conventional pond method w ould have the lowest present value LCC if the discount rate was as high as 7.0 percent. This scenario favors immediate cost savings over increased income over the life of the project. The survey helped to conclude that many project owners have a limited construction budget and must use the least costly method. Mo st alternate practices are more expensive initially, though the long term be nefit of the additional useable land can make up for high initial cost. The developers surveyed rarely use LCC to determine what method of stormwater retention to employ. This exemplifies that alternative BMPs face the same problem many emerging construction technologies face. There is little to no LCC analysis employed while choosing the subsystems of a project. Without LCC analysis, many systems are incorrectly written off as impractical due to high first costs. Most emerging technologies only see a

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70 financial payoff after years of service. The lack of LCC analysis by developers suggests there is much room for improvement in the area. Green roofs are the least popular option among the developers su rveyed due to their highly unconventional nature. The effect of a green roofing system on th e total site can be hard to qualify within the entire stormw ater management system of a particular project. Another deterrent of green roofing adoption is the interdisciplinary effort that must be taken between the architect, landscape architect, and ci vil engineer. A truly diverse t eam must be utilized to fully integrate a green roof into a stormwater retenti on system. High initial costs are also a major drawback to widespread use of green roofing. Permeable paving, on the other hand, requires li ttle to no maintenance over the life of the project compared to green roofing. For this reason, permeable paving was the most preferred choice among those surveyed. The application of pe rvious concrete is very similar to that of conventional concrete. With its long life a nd high durability, the only major drawbacks to permeable pavement are high upfront and maintena nce costs. Permeable paving is not a viable choice for application in very densely populated areas. This is because many developments in highly urbanized areas do not have parking lots, but rather parki ng structures or basements. Permeable concrete is most useful when it is applied on gr ade with no cover. Underground vaults were preferred sec ond after permeable pavement. Underground vaults, like permeable pavements, are more simila r to the conventional method than green roofs. Municipal stormwater systems ar e connected to underground vau lts much in the way regular retention ponds are connected. This makes them popular within the developer community. To reduce the size needed for an underground retention vault, this method can be used in conjunction with other traditional and non-traditional practices. Reducing the size of the vault

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71 needed would also reduce the associated cost. Not only can an underground vault be used with permeable pavement, but any of these methods can be used together to incr ease effectiveness. A project site utilizing a green roof and permeable pavement would have little to no post development runoff. The little runoff that ma y be created could be controlled by a small retention pond or underground vault. The survey shows that permits for alternativ e methods are reasonably easy to obtain, with those for green roofs being the most difficult. Responses also expressed that permits for permeable pavements have become increasingly easier to obtain over the last decade. This is due to a push from state and local municipalities for the adoption of more BMP alternatives. This study determined that alternative stormwater BMPs should be pressed to be used more frequently in urban development. Benefits of additional la nd use outweigh the extra initial and maintenance cost. Central Florida has seen so me of the most rapid growth in the nation over the last several years. As a result, the area must learn to succes sfully control development and its consequences.

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72 CHAPTER 6 SUGGESTIONS FOR FUTURE RESEARCH The potential to expand on this study is vi rtually infinite. One area that may be particularly beneficial would be the investigation of the industr y, outside of developers, on their opinions of alternative stormwater BMPs. Re search could also be conducted to study how particular methods are being pushed for increase d use. Another area of interest would be investigating the use of LCC analysis regard ing areas of constructi on besides stormwater management. A study determining trends of use for various areas of the nation would also be highly beneficial. By studying what types of BMPs are used in certain areas, one could determine trends for BMP use. These tende ncies could be based on geological areas, geographical areas, population density, and the ag e of the city devel opments are built in. The primary aim of this study was focused on economical benefits, but another important issue is the ecological and environmental benefits of various stormwater BMPs. Ecological and environmental aspects are more important now th an ever, especially in conjunction with the current green building movement. An aspect beyond the scope of this study would be investigating a green roof s benefit of lowering cooling loads in warm climates. Another area of study would be the investigation of cutting-e dge BMP applications that are either in developmental or early-use stages. By res earching new technologies, studies could help determine what the future of stormwater management will be.

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73 APPENDIX A DEVELOPER SURVEY The following is a survey designed to assess your opinions on various forms of stormwater best management practices in urban developments The conventional method of stormwater management is with a wet/dry storm basin or retention pond. Permeable pavements are paving materials with voids that allow water to penetrat e freely. Underground vaults store stormwater in underground cavities allowing slow release, which is similar to a conventional pond. Green roofs consist of soil and vegetation on a buildings rooftop. These roofs are designed to accept rainwater and slowly release it, mini mizing peak flows from rooftops. 1. Do you consider any alternative water retention methods during the design of your projects? No Yes 2. How interested would you be in using permeable pavement? Little Some Great 3. How interested would you be in using green roofs? Little Some Great 4. How interested would you be in using underground vaults? Little Some Great 5. Are there any other methods you would consider using? 6. Which alternative method are you MOST likely to use? 1. Permeable 2. Underground 3. Green Roof 4. Other ______________________

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74 7. Which alternative method are you LEAST likely to use? 1. Permeable 2. Underground 3. Green Roof 4. Other ______________________ 8. How many projects have you used alternative methods? None Some Many 9. What is the biggest reason you choose the conventional method? 1. Familiarity 2. Code 3. First Cost 4. Life-cycle Cost 5. Other ___________________ 10. How likely would it be for you use to permeable pavement in an urban development project? Very Unlikely Very Likely 11. How likely would it be for you use to green roofing in an urban development project? Very Unlikely Very Likely 12. How likely would it be for you to use underground vaults in an urban development project? Very Unlikely Very Likely 13. On how many projects do you perform a life-cycle analysis for stormwater best management practices? None Some All 14. Why are alternative methods not employed? Unknown Not Possible

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75 15. How difficult is permitting for permeable paving? Very Difficult Very Easy 16. How difficult is permitting for underground vaults? Very Difficult Very Easy 17. How difficult is permitting for green roofs? Very Difficult Very Easy 18. How often would you use the method with the lowest life-cycle cost? None Some All 19. How familiar are you in using permeable pavement? None Some Very 20. How familiar are you in using green roofs? None Some Very 21. How familiar are you in using underground vaults? None Some Very

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76 APPENDIX B LIFE-CYCLE COSTS USED IN CASE 1 Conventional pond Initial costs Construction $ 24,277 Annual costs Maintenance $ 120 Clean filter $ 240 Cut grass $ 560 Net annual $ (920) Permeable pavement Initial costs Construction $ 26,016 Annual costs Maintenance $ 144 Clean filter $ 288 Cut grass $ 480 Annual benefits Additional parking $ 27,986 Net annual $ 27,074 Green roof Initial costs Construction $ 56,547 Annual costs Plant maintenance $ 520 Clean filter $ 200 Cut grass $ 480 Annual benefits Additional parking $ 27,986 Net annual $ 26,786 Underground vault Initial costs Construction $ 97,736 Annual costs Maintenance $ 288 Cut grass $ 480 Annual benefits Additional parking $ 27,986 Net annual $ 27,218

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77 APPENDIX C LIFE-CYCLE COSTS USED IN CASE 2 Pond Initial costs Construction $ 79,135 Annual costs Maintenance $ 240 Clean filter $ 480 Cut grass $ 1,120 Net annual $ (1,840) Permeable pavement Initial costs Construction $ 182,690 Annual costs Maintenance $ 288 Clean filter $ 576 Cut grass $ 960 Annual benefits Additional parking $7,986.12 Net annual $ 6,162 Green roof Initial costs Construction $ 214,274 Annual costs Plant maintenance $ 39,833 Clean filter $ 420 Cut grass $ 960 Annual benefits Additional parking $ 3,800 Net annual $ (36,993) Underground vault Initial costs Construction $ 170,469 Annual costs Maintenance $ 351 Clean filter $ 370 Cut grass $ 815 Annual benefits Additional parking $7,986.12 Net annual $ 6,820

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78 APPENDIX D LIFE-CYCLE COSTS USED IN CASE 3 Pond Initial Costs Construction $ (168,259) Annual Costs Maintenance $ 265 Clean Filter $ 490 Cut Grass $ 1,230 Lost Rent $ 34,079 Net annual $ (1,985) Permeable Pavement Initial Costs Construction $ (142,747) Annual Costs Maintenance $ 288 Clean Filter $ 576 Cut Grass $ 960 Lost Rent $ 29,333 Net annual $ (31,157) Green Roof Initial Costs Construction $ 282,483 Annual Costs Plant maintenance $ 2,160 Clean Filters $ 576 Cut grass $ 960 Annual Benefits Additional Rent $ 39,911 Net annual $ 36,215 Underground Vault Initial Costs Construction $ 38,088 Annual Costs Maintenance $ 576 Cut Grass $ 960 Clean Filter $ 675 Net annual $ (2,211)

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79 APPENDIX E CASE 1 CONVENTIONAL POND ESTIMATE Sub System Quantity Units $/unit Total Sod 8,127 Sf 0.47 $ 3,779 Excavate Pond: 513 Cy 9.70 $ 4,971 Haul excavated soil: 615 Lcy 11.00 $ 6,765 Total pond $ 15,516 Paving 522 Sy 38.00 $ 19,853 Strait curbs 246 Lf 22.50 $ 5,541 Curved curbs 62 Curved 25.00 $ 1,544 Stripes 12 Stalls 10.30 $ 124 Total lot $ 27,061 Total site costs w/ conventional: $ 42,576 Location factor 82.40% Time factor 30.80% $ 24,277

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80 APPENDIX F CASE 1 UNDERGROUND VAULT ESTIMATE Sub system Quantity Units $/unit Total Sod 7,339 Sf 0.47 $ 3,413 Excavate pond: 82 Cy 9.70 $ 795 Haul excavated soil: 177 Lcy 1.00 $ 1,952 Vault tank 1 Ea $ 131,500 Total vault $ 137,661 Paving 581 Sy 45.60 $ 26,484 Strait curbs 246 Lf 22.50 $ 5,541 Curved curbs 62 Curved 25.00 $ 1,544 Stripes 17 Stalls 10.30 $ 175 Total lot $ 33,743 Total site costs w/ underground vault: $ 171,404 Location factor 82.40% Time factor 30.80% $ 97,736

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81 APPENDIX G CASE 1 PERMEABLE P AVEMENT ESTIMATE Sub System Quantity Units $/unit Total Sod 7,339 Sf 0.47 $ 3,413 Excavate Pond: 82 Cy 9.70 $ 795 Haul excavated soil: 98 Lcy 11.00 $ 1,083 Total pond $ 5,291 Paving 581 Sy 45.60 $ 26,484 Aggregate drainage 581 Sy 11.35 $ 6,592 Strait curbs 246 Lf 22.50 $ 5,541 Curved curbs 62 Curved 25.00 $ 1,544 Stripes 17 Stalls 10.30 $ 175 Total lot $ 40,335 Total site costs w/ permeable: $ 45,626 Location factor 82.40% Time factor 30.80% $ 26,016

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82 APPENDIX H CASE 1 GREEN ROOF ESTIMATE Sub system Quantity Units $/unit Total Sod 7,339 Sf 0.47 $ 3,413 Excavate pond: 372 cy 9.70 $ 3,610 Haul excavated soil: 447 Lcy 11.00 $ 4,913 Total pond $ 11,936 Green roof 3744 Sf 17.00 $ 63,648 Shingles 4980 Sf 2.04 $ 10,158 Total green roof $ 53,490 Paving 581 Sy 45.60 $ 26,484 Strait curbs 246 Lf 22.50 $ 5,541 Curved curbs 62 Curved 25.00 $ 1,544 Stripes 17 Stalls 10.30 $ 175 Total lot $ 33,743 Total site costs w/ permeable: $ 99,168 Location factor 82.40% Time factor 30.80% $ 56,547

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83 APPENDIX I CASE 2 CONVENTIONAL POND ESTIMATE Sub system Quantity Units $/unit Total Sod 19,667 sf 0.47 $ 9,145 Excavate pond: 260 cy 9.70 $ 2,519 Haul excavated soil: 312 lcy 11.00 $ 3,428 Total pond $ 15,093 Paving 1 1/2"binder course 2,326 sy 5.20 $ 12,095 2" wearing course 2,326 sy 7.00 $ 16,281 10" limestone base 307 sy 12.15 $ 3,731 6" limestone base 2,019 sy 7.85 $ 15,848 Strait curbs 995 lf 22.50 $ 22,388 Curved curbs 260 lf 25.00 $ 6,500 Stripes 53 stalls 10.30 $ 546 Total lot $ 77,389 Total site costs w/ conventional: $ 92,481 Location factor 82.40% Time factor 3.85% $ 79,139

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84 APPENDIX J CASE 2 UNDERGROUND VAULT ESTIMATE Sub system Quantity Units $/unit Total Sod 10,317 sf 0.47 $ 4,797 Excavate pond: 313 cy 9.70 $ 3,033 Haul excavated soil: 375 lcy 11.00 $ 4,127 Water vault 1 ea 90,500.00 $ 90,500 Total vault $ 102,457 Paving 1 1/2"binder course 3,019 sy 5.20 $ 15,696 2" wearing course 3,019 sy 7.00 $ 21,130 10" limestone base 307 sy 12.15 $ 3,731 6" limestone base 2,711 sy 7.85 $ 21,285 Strait curbs 1,140 lf 22.50 $ 25,650 Curved curbs 340 lf 25.00 $ 8,500 Stripes 74 stalls 10.30 $ 762 Total lot $ 96,754 Total site costs w/ underground: $ 199,211 Location factor 82.40% Time factor 3.85% $ 170,469

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85 APPENDIX K CASE 2 PERMEABLE PAVEMENT ESTIMATE Sub system Quantity Units $/unit Total Sod 10,317 sf 0.47 $ 4,797 Excavate pond: 82 cy 9.70 $ 795 Haul excavated soil: 98 lcy 11.00 $ 1,083 Total pond $ 6,675 Paving 3,019 sy 45.60 $ 137,644 Aggregate drainage 3,019 sy 11.35 $ 34,260 Strait curbs 1,140 lf 22.50 $ 25,650 Curved curbs 340 lf 25.00 $ 8,500 Stripes 74 stalls 10.30 $ 762 Total lot $ 206,816 Total site costs w/ permeable: $ 213,492 Location factor 82.40% Time factor 3.85% $ 182,690

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86 APPENDIX L CASE 2 GREEN ROOF ESTIMATE Sub system Quantity Units $/unit Total Sod 21,331 sf 0.47 $ 9,919 Excavate pond: 187 cy 9.70 $ 1,815 Haul excavated soil: 225 lcy 11.00 $ 2,470 Total vault $ 14,204 Paving 1 1/2"binder course 2,449 sy 5.20 $ 12,736 2" wearing course 2,449 sy 7.00 $ 17,144 10" limestone base 307 sy 12.15 $ 3,731 6" limestone base 2,142 sy 7.85 $ 16,815 Strait curbs 1,045 lf 22.50 $ 23,513 Curved curbs 280 lf 25.00 $ 7,000 Stripes 63 stalls 10.30 $ 649 Total lot $ 81,588 Green roof 14,490 sf 14.00 $ 202,860 3 ply roofing 14,490 sf 2.33 $ 33,762 Insulation 14,490 sf 1.00 $ 14,490 Total green roof $ 154,608 Total site costs w/ green roof: $ 250,401 Location factor 82.40% Time factor 3.85% $ 214,274

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87 APPENDIX M CASE 3 CONVENTIONAL POND ESTIMATE Sub system Quantity Units $/unit Total Sod 4,657 sf 0.47 $ 2,165 Excavate pond: 128 cy 9.70 $ 1,239 Haul excavated soil: 153 lcy 11.00 $ 1,685 Total pond $ 5,089 Concrete Paving 190 sy 38.00 $ 7,203 Total paving $ 7,203 Less building (2,069) sf 101.00 $ (208,920) Total site costs w/ conventional: $ (196,628) Location factor 82.40% Time factor 3.85% $ (168,259)

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88 APPENDIX N CASE 3 UNDERGROUND VAULT ESTIMATE Sub system Quantity Units $/unit Total Sod 3,974 sf 0.47 $ 1,848 Excavate pond: 140 cy 9.70 $ 1,354 Haul excavated soil: 167 lcy 11.00 $ 1,842 Water vault 1 ea 32,265.00 $ 32,265 Total vault $ 37,309 Concrete Paving 190 sy 38.00 $ 7,203 Total lot $ 7,203 Total site costs w/ underground: Location factor 82.40% Time factor 3.85% $ 38,088 APPENDIX O CASE 3 PERMEABLE PAVEMENT ESTIMATE Sub system Quantity Units $/unit Total Sod 3,974 sf 0.47 $ 1,848 Excavate pond: 110 cy 9.70 $ 1,066 Haul excavated soil: 132 lcy 11.00 $ 1,451 Total pond $ 4,365 Concrete Paving 190 sy 45.60 $ 8,644 Total lot $ 8,644 Less building -1,780 sf 101.00 $ (179,823) Total site costs w/ permeable: $ (166,814) Location factor 82.40% Time factor 3.85% $ (142,747)

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89 APPENDIX P CASE 3 GREEN ROOF ESTIMATE Sub system Quantity Units $/unit Total Sod 3,167 sf 0.47 $ 1,472 Excavate pond: 30 cy 9.70 $ 288 Haul excavated soil: 36 lcy 11.00 $ 391 Total vault $ 2,151 Concrete Paving 190 sy 38.00 $ 7,203 Total lot $ 7,203 Green roof 7,131 sf 16.00 $ 114,088. 3 ply roofing 7,131 sf 2.33 $ 16,614 Insulation 7,131 sf 1.00 $ 7,131 Total green roof $ 90,343 Additional building 2,423 sf 101.00 $ 244,673 Total site costs w/ green roof: $ 344,371 Location factor 82.40% Time factor 3.85% $ 294,686

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90 APPENDIX Q SURVEY DATA Respondent Code: Question: Mean: A B C D E F G H I J K L M N O P Q R 1 (0.28) 2 (1) 1 (1)(2)0 (2)1 (1)(2)1 (1) (2) 1 0 1 0 0 2 0.72 0 0 1 1 2 1 2 0 1 2 2 0 2 0 (1)(1)(1)2 3 0.33 1 (1) (1) 0 2 2 0 0 2 (1)2 1 2 (2) (2)0 (1)2 4 0.44 0 (1) 1 1 1 (1)1 0 1 0 1 2 1 0 2 0 0 (1) 5 N/A N/A 6 N/A 2 1 2 1 2 2 1 1 2 1 2 1 2 1 1 3 1 1 7 N/A 3 3 3 3 3 3 3 3 2 3 3 3 3 3 3 1 3 3 8 0.50 2 0 1 1 2 1 2 1 1 (1)(1)1 0 (2) (1)0 2 0 9 N/A 4 3 2 3 2 3 3 3 1 4 3 5 2 3 3 2 5 4 10 0.06 (1) 0 2 0 0 (2)(2)0 2 2 0 2 1 0 1 (1)(1)(2) 11 (1.00) (1) (1) (2) (2)(2)0 (1)1 (1)(1)(2)(1) 0 (2) (2)(2)(1)2 12 0.06 1 (1) (1) 0 (1)(1)(1)2 1 0 (1)1 (1) (1) 2 (2)2 2 13 0.22 (2) 1 0 0 (1)(2)1 1 2 2 2 (2) 1 (1) (1)1 2 0 14 0.50 2 1 1 1 (1)0 (1)2 1 (1)1 1 1 0 1 0 (1)1 15 (0.06) (1) 0 0 0 2 (2)0 (2)(1)2 1 1 2 2 (2)(1)(1)(1) 16 (0.11) 1 0 1 1 (1)1 1 0 0 (2)(2)1 0 (2) (1)1 (1)0 17 (0.17) (2) 0 (1) (1)0 1 (1)1 0 1 (2)(1) 1 (2) 1 (1)2 1 18 (0.39) (1) (2) (1) (1)(2)(1)(2)(2)2 (2)2 2 1 (1) 1 (1)(1)2 19 0.11 2 2 1 1 (1)2 (1)1 (2)1 (1)1 (2) 2 (1)(1)(2)0 20 (0.50) 0 (2) (2) (2)0 (1)0 (2)(1)(1)1 1 (2) 1 0 (2)2 1 21 0.39 2 0 1 1 1 0 (2)2 (2)0 0 2 1 1 0 0 2 (2)

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91 APPENDIX R MEAN RESPONSES FOR NUMERICAL SURVEY QUESTIONS 1 2 3 4 8 10 11 12 13 14 15 16 17 18 19 20 21 Mean: (0.28)0.72 0.33 0.44 0.50 0.06 (1.00)0.06 0.22 0.50 (0.06)(0.11)(0.17)(0.39)0.11 (0.50)0.39 (1.20) (1.00) (0.80) (0.60) (0.40) (0.20) 0.00 0.20 0.40 0.60 0.80 1.00 1.20

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92 LIST OF REFERENCES Chambers, G. M. and Tottle, C. H. (1980) Evaluation of Stormwater Impoundments in Winnipeg. Winnipeg: CMHC Clar M.L., Barfield, B.J., and OConnor, T.P. (2004). Stormwater Best Management Practice Design Guide. National Risk Management Research Laboratory Office of Research and Development. DeWiest, D.R. and Livingston, E.H. (2002) The Florida Stormwater, Erosion, and Sedimentation Control Inspectors Manual. Florida Department of Environmental Protection. Fassman, Elizabeth A. (2006). Improving E ffectiveness and Evaluation Techniques of Stormwater Best Management Practices. Journal of Environmental Science and Health: Part A 41:1247. Field, R., H. Masters, and M. Singer. (1982) Porous Pavement: Research; Development; and Demonstration. Transportation Engineering Journal of ASCE 108.TE3. Getter, Kristin Louise. (2006) Extensive Green Roofs: Plant Evaluations and the Effect of Slope on Stormwater. Diss. Michigan State University. Green, Elizabeth Weiss. (2007). Hol es That Make for Better Roads. U.S. News & World Report 142.11. Hossain, M., and L.A. Scofield. (1991). Porous Pavement for Control of Highway Run-off. Final Report. FHWA-AZ91-352. Arizona Trans portation Research Center, Phoenix, AZ. Kolb, W. (2004). Good Reasons for Roof Planting Green Roofs and Rainwater. Acta Hort 643: 295-300. Landers, Jay. (2007). Software Will Help Determine Appropriate Storm-Water Practice. Civil Engineering 77.10: 36-37. Metropolitan Council. (2007). Ret ention Systems: Wet Vaults. Minnesota Urban Small Sites BMP Manual Nov. 5, 2007 www.metrocouncil.org/Environment/Watershed/BMP Northern Virginia District Planning Commission. (1992). Underg round Detention Tanks (UDTs) As A Best Management Practice (BMP). Nort hern Virginia Distri ct Planning Commission, Annandale, VA. Parrott, Jeff. (2007). The Ins and Ou ts of Stormwater Management. Planning 73.10 2007:2631 Nov. 3, 2007 http://search.ebscohost.com/l ogin.aspx?direct=true&db=ap h&AN=27192349&site=ehost-live

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93 Peck, S.W. P. (2005). Green Roofs: Ecologica l Design and Construction Atglen, P.A.: Schiffer Books,. Real Estate Inquiries (2009). Walgreens February 12, 2009 https://www.walgreens.com/contactus/real_estate.jsp. Roberts, Brian (1996). Stormwater Treatment goes Underground. Civil Engineering 66.7 1996:56. Waier, Phillip R. (2007). RSMeans build ing construction cost data 2007. Kingston, Massachusetts Snoonian, Deborah. (2001). Drain It Right: Wetlands for Managing Runoff. Architectural Record 189.8 2001: 127. Federal Highway Admi nistration. (2007). Stormwater Best Management Practices in an Ultra-Urban Setting: Selection and Monitoring Nov. 5, 2007 http://www.fhwa.dot.gov/environment/ultraurb/index.htm Study Shows Big Advantages. (2007). Engineering News Record 259.12 2007:17. Tan, Siew-Ann, Fwa, Tien-Fang, and Han, Chong-Teng. (2003). Clogging Evaluation of Permeable Bases Journal of Transportation Engineering 129.3 (2003): 309. The Stormwater/Nonpoint Source Management Section "Florida Development Manual: A Guide to Sound Land and Water Management" (1988): Volume 2 Chapter 6, 721 www.dep.state.fl.us/water/nonpo int/docs/nonpoint/erosed_bmp.pdf Thrasher, Mark H. (1982). Highway Imp acts on Wetlands: Assessment, Mitigation, and Enhancement Measures. Floodplains Erosion and Stormwater Pumping Transportation Research Board, National Resear ch Council, 17. Washington D.C. Urbonas, Ben R. (1995). Recommended Paramete rs to Report with BMP Monitoring Data Journal of Water Resour ces Planning & Management 121.1 1995: 23. Wanielista, Marty and Chopra, Manoj. (2007). Performance Assessment of Portland Cement Pervious Pavement Stormwater Management Academy University of Central Florida Wiegand, C., T. Schueler, W. Chittenden, and D. Jellick. (1986). Urban Runoff Quality Impact and Quality Enhancement Technology. American Society of Civil Engineers 1986: 366-382. Williams, Evan Shane. (2003). Hydrologic and Economic Impacts of A lternative Residential Land Development Methods. Di ss. University of Florida

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94 BIOGRAPHICAL SKETCH Kenny Perrine was born in Cape Canaveral, FL, and was the youngest of four children. He grew up in Titusville, Florida, where he acquired his high school education at Astronaut High School. Afterwards, he enrolled in the University of Florida a nd entered the M.E. Rinker Senior School of Building Construction two years later. Af ter four years of college, he graduated with a Bachelor of Science in Building Construction. He completed his Masters of Science in Building Construction the following year. After school, he married his college sw eetheart and moved to Houston, Texas, to begin his career.