Front Cover
 Division of Natural Resources
 Title Page
 Table of Contents
 Executive summary
 Historical perspective of peat...
 Accumulation of peat
 Mining technology
 Accumulations of peat in Flori...
 Inventory of peat in Florida
 Everglades agricultural area
 Industrial uses of peat
 Economic impact
 Potential environmental impacts...
 Endangered species associated with...
 Reclamation of mined peatlands
 Summary and conclusions
 Appendix A: Federal environmental...
 Appendix B: Classification of wetlands...
 AppendixC: Florida statutes concerning...
 Appendix D: Water quality
 Appendix E: Peatlands manageme...


An overview of peat in Florida and related issues ( FGS: Open file report 4 )
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00001003/00001
 Material Information
Title: An overview of peat in Florida and related issues ( FGS: Open file report 4 )
Series Title: Open file report (Florida. Bureau of Geology) ; no. 4
Physical Description: viii, 151 p. : ill. ; 23 cm.
Language: English
Creator: Bond, Paulette
Campbell, Kenneth M. (Kenneth Mark), 1949-
Scott, Thomas M.
Publisher: Florida Geological Survey
Publication Date: 1986.
Subjects / Keywords: Peat -- Florida
Peat industry -- Florida
Peatlands -- Florida
Abstract: Florida is currently faced with an inmediate expanding industrial interest in the explotation of its peat resources for fuel use. The study is primarily a compilation of literature pertinent to peats of Florida and their use for agriculture and energy applications. It is conceived as providing an information base for decisions concerning both the utilization and conservation of Florida's extensive peat resource.
General Note: Include bibliographical references (p. 95-101).
Funding: Digitized as a collaborative project with the Florida Geological Survey, Florida Department of Environmental Protection.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
System ID: UF00001003:00001


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Table of Contents
    Front Cover
        Front Cover
    Division of Natural Resources
        Unnumbered ( 3 )
    Title Page
        Page i
        Page ii
    Table of Contents
        Page iii
        Page iv
        Page v
        Page vi
        Page vii
        Page viii
        Page ix
    Executive summary
        Page x
        Page xi
        Page xii
        Page xiii
        Page xiv
        Page xv
        Page xvi
        Page xvii
        Page xviii
    Historical perspective of peat research in Florida
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    Accumulation of peat
        Page 20
        Page 21
        Page 22
    Mining technology
        Page 23
        Page 24
        Page 25
        Page 26
    Accumulations of peat in Florida
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
    Inventory of peat in Florida
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
    Everglades agricultural area
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
    Industrial uses of peat
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
    Economic impact
        Page 78
        Page 79
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
    Potential environmental impacts of peat mining
        Page 98
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
        Page 111
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
        Page 122
        Page 123
        Page 124
    Endangered species associated with areas of potential peat mining
        Page 125
        Page 126
        Page 127
        Page 128
        Page 129
        Page 130
        Page 131
        Page 132
        Page 133
        Page 134
        Page 135
    Reclamation of mined peatlands
        Page 136
        Page 137
        Page 138
        Page 139
        Page 140
        Page 141
        Page 142
        Page 143
        Page 144
        Page 145
        Page 146
    Summary and conclusions
        Page 147
        Page 148
        Page 149
        Page 150
        Page 151
        Page 152
        Page 153
        Page 154
        Page 155
        Page 156
        Page 157
        Page 158
        Page 159
        Page 160
        Page 161
        Page 162
        Page 163
        Page 164
        Page 165
        Page 166
        Page 167
        Page 168
        Page 169
    Appendix A: Federal environmental legislation
        Page 170
        Page 171
        Page 172
        Page 173
    Appendix B: Classification of wetlands in Florida
        Page 174
        Page 175
        Page 176
        Page 177
        Page 178
        Page 179
    AppendixC: Florida statutes concerning wetlands
        Page 180
        Page 181
        Page 182
        Page 183
        Page 184
        Page 185
        Page 186
        Page 187
        Page 188
        Page 189
        Page 190
        Page 191
        Page 192
        Page 193
        Page 194
    Appendix D: Water quality
        Page 195
        Page 196
        Page 197
        Page 198
        Page 199
    Appendix E: Peatlands management
        Page 200
        Page 201
        Page 202
        Page 203
        Page 204
        Page 205
        Page 206
        Page 207
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Full Text
cpE Fi ~eufr -4






Secretary of State


Commissioner of Education

Executive Di

Attorney General


Commissioner' of a oricuiture


Cover Drawing:

The cover drawing shows Water:Lilly (Nymphaea), the living
plant from which Water Lilly Peat ',ot s, characteristiic of,,.';
relatively deep, open waters '

r ~-~':: ~~I~II ~' I ""

Elton Gissendanner, Executive Director

Charles W. Hendry, Jr., Director

Steve R. Windham, Chief


Prepared by
Bureau of Geology
Paulette Bond, Principal Investigator

at the
direction of



Executive Summary. ................ ... .................... x

Acknowledgements.... .. d........ ............ .............. xviii

Purpose and Scope of the Study .............. ............. 1

Historical Perspective of Peat Research in Florida......... 1

Definition of Peat and the Significance of This

Definition ... .. ............... .... ........... ......... 4

Terminology Relating to the Peat Forming Environment.. 7

Peat: Agricultural or Mineral Resource?.............. 9

Harvesting or Mining ................................. 14

Classification Systems Applied to Peat ................ 16

The Accumulation of Peat... .... ..... ....... ... ............. 20

The Process of Peat Formation......................... 20

Geologic Conditions Associated with Peat

Accumulation ...................................... 21

Mining Technology .......... .............................. 23

Mining Methodology Associated with the Use of

Peat for Fuel................................. .. .. 23

Mining Methodology Associated with the

Agricultural Use of Peat ........................... 26

The Accumulation of Peat in Florida...................... 27

Rates of Peat Accumulation in Florida................. 27


Geologic Settings of Peat Accumulation in Florida..... 30

Inventory of Peat in Florida............................... 40

Mapping and Evaluating the Peat Resource.............. 40

Current Estimates of Peat in Florida.................. 42

The Everglades Agricultural Area.......................... 49

History of the Everglades Agricultural Area........... 49

Crops and Soils of the Everglades Agricultural Area... 51

Subsidence ............................................ 54

Conservation Measures. .......... . ............. 60

The Near Future of the Everglades Agricultural Area... 61

Industrial Uses of Peat .... ...... ........................ 65

Preparation of Peat for Industrial Utilization........ 65

Fuel Uses ............................................. 67

Direct Combustion ............................... 67

Gasification ................. ... ........ ........ 68

Biogasification .................................. 69

Industrial Chemicals... ............................... 70

Bitumens. ........... ............................ 70

Carbohydrates. ........................... ....... 72

Humic Acids ........ ...... ...................... 73

Peat Coke, Peat Tar and Activated Carbon......... 74

Use of Peat as a Growth Medium ............. .......... 75

Horticulture .......... .... ... ... ................ 75

Agriculture..... .............................. 76

Energy Crops ........... ........................ 76

Sewage Treatment. ....................................... 77

Economic Impact........................... .......... ..... 78

Production, Value, and Price of Peat.................. 78

Location of Peat Producers ........... ....... .......... 80

Location of Markets... ............................... 82

Use of Peat.................................. .. ........ 82

Permitting ................................................. 83

County Level Permits ... .............................. 83

State Level Permitting .............................. ..... 86

Department of Environmental Regulation........... 86

Water Management Districts....................... 87

Suwannee River Water Management District.... 87

St. Johns River Water Management District... 87

Southwest Florida Water Management

District ........................ ....... 93

South Florida Water Management District..... 94

Department of Community Affairs.................. 94

Federal Level Permitting............................... 95

Army Corps of Engineers.......................... 95

The Environmental Protection Agency............... 96

Peat Revenue and Taxation................................... 96

Potential Environmental Impacts of Peat Mining............. 98

The Effects of Peat Mining on Wetlands................ 98

The Effects of Peat Mining on Water Quality............ 102

The Effects of Peat Mining on Water Resources......... 107

Water Resources in an Undisturbed System......... 107

Water Resource Parameters Affected by Peat

Mining ........ ..... ........ ....... ........

The Effects of Peat Mining on Air Quality .............

The Effects of Peat Mining on Topography .............

Endangered Species Associated with Areas of Potential

Peat Mining............... .. .. ...........................

Reclamation of Mined Peatlands.............................

Peatland Reclamation in Minnesota.....................

Peatland Reclamation in North Carolina.......... .....

Peatland Reclamation in Finland........................

Peatland Reclamation in New Brunswick.................

Reclamation in Peatlands of Florida...................

Summary and Conclusions........................ ...... .....

References............ ....................................

Glossary of Technical Terms............................. ...

Appendices ...................... .......... ...............

Appendix A. Federal Environmental Legislation........

Appendix B. Classification of Wetlands in Florida....

Appendix C. Florida Statutes Concerning Wetlands......

Appendix D. Water Quality............................

Appendix E. Peatland Management......................






The process of coal formation...................

The relationship of peat types to fuel grade.....

A comparison of moisture content and heating

value for peat, wood and various coal types....




















4 Peat provinces of southern Florida............... 31

5 SW-NE cross-section from Cape Sable to vicinity

of Tamiami Trail ....... .......... ... ........... .. 32

6 Cross-section through a cypress hammock...c...... 33

7' Cross-section through a "Bay Head"............... 34

8 Cross-section through bay swamp and titi swamp... 35

9 Peat deposits bordering lakes.................. 36

10 Cross-section showing peat filling lake.......... 37

11 Cross-section using cores to show buried peat

layers at Eureka Dam site, Oklawaha River,

Marion County, Florida........................ 38

12 Isopach map of the Everglades region showing

thickness of peat and some muck areas........... 41

13 Peat deposits in Florida......................... 45

14 Fuel grade peat deposits in Florida.............. 46

15 Peat deposits in Florida........................ 47

16 Location map of the Everglades Agricultural

Area........................................... 53

17' Map of the Everglades Agricultural Area showing

the locations of profiles A-A' and B-B'........ 57

18 Profile A-A' across the upper Everglades showing

the original surface elevations and the

ground elevation in 1940 as shown by

topographical survey. Profiles for the years

1970 and 2000 are estimated .................... 58


19 Profile B-B' through the lower part of the

Everglades Agricultural Area show the original

surface elevation and the surface elevation as

determined in 1940 by topographic surveys.

Profiles for the years 1970 and 2000 are

estimated...... ............ ................. 59

20 Soil depths predicted (Stephens and Johnson,

1951) for the year 1980. Compare with

figure 17: ..................................... 62

21 Thicknesses of soils from the Everglades

Agricultural Area as determined in a recent

study .......................................... 63

22 Location of current peat producers............... 79

23 Production and value of peat in Florida.......... 81

24 Topographic profile of a karst basin peat

deposit in north Florida ...................... 119

25 Topographic profile of St. Johns River Marsh

peat deposit in southern Brevard County........ 120

26 Topographic profile of the Oklawaha River peat

deposit in northern Lake-southern Marion

counties ....................................... 121

27 Topographic profile of the Santa Fe Swamp peat

deposit in Alachua and Bradford counties....... 122

28 Topographic profile of the Everglades in Collier

and Dade counties............. ..... ...... .... 124



1 Estimated rates of peat accumulation in

Florida ......... ................... .......... 28

2 Proportions of the organic soils of the

Everglades Agricultural Area falling into

categories based on thickness.................. 64

3 Summary of county level permitting

requirements .. ............................... 84

4 Water quality issues associated with peat

mining ......................................... 104

5 Water resources issues associated with peat

mining........................................ 110

6 Air quality issues associated with peat mining... 115

7 Plant communities of concern ..................... 128

8 Endangered, threatened, and rare species

associated with areas of potential peat

accumulation ................................... 129

9 Independent factors governing site specific

reclamation programs........................... 138


Peat is a deposit of partially decayed plant remains which

accumulates in a waterlogged environment. It may contain some

proportion of inorganic material which is referred to as ash.

Ash content is a critical parameter if peat is to be used as a

fuel and may not exceed 25 percent of the material by dry weight.

In addition, fuel grade deposits must be at least four feet thick

with a surface area of at least 80 contiguous acres per square

mile. Fuel grade peat must yield at least 8000 BTU per moisture-

free pound.

Peat is removed from the ground in an excavation process.

The procedure is alternatively referred to as harvesting or

mining. "Harvesting" when used in conjunction with peat

correctly refers to the nearly obsolete practice of harvesting

Living Sphagnum from the surface of a bog. In this process, the

Sphagnum was allowed to grow back so that repeated harvests were

possible in a given area. Very little or no true harvesting

occurs today. Thus, the extraction of peat is properly termed


An important implication of the definition of peat is its

classification as an agricultural resource as opposed to a

mineral resource. This classification may have ramifications

with respect to the sorts of regulations which are applied to

peat mining. Peat does not comply with the conditions set forth

in the academic definition of the term mineral. It is, however,

considered a mineral resource by the United States Geological

Survey and the United States Bureau of Mines. Peat is an

ancestor of the mineral graphite and is also viewed by earth

science professionals as nonrenewable. Thus it is considered

appropriate to term peat a mineral resource.

Peat-accumulates and is preserved in wetlands, such as the

Everglades, marshes and mangrove swamps, river-valley marshes

(St. Johns river-valley marsh), and in sinkhole lakes. This

strong association of peat with wetlands occurs because the

presence of water serves to inhibit the activity of decomposing

organisms which would normally metabolize plant matter and

prevent its accumulation.

Earth science professionals consider peat to be

nonrenewable. In Florida an average rate of peat accumulation

is 3.62 inches per 100 years. Using this average rate, a deposit

4 feet thick (minimum thickness of a fuel grade deposit) could

accumulate in approximately 1,326 years or approximately 18 human

lifetimes (average lifetime of 7'2 years).

Florida is estimated as having 677,688 acres of fuel grade

peat or 606 million tons. This estimate is based on material

thought to contain no more than 25 percent ash. Other estimates

are much greater (1.7'5 billion tons and 6.9 billion tons). These

estimates include organic soils whose ash content exceeds ASTM

standards for material defined as peat and U.S. Department of

Energy standards for fuel grade peat.

The Everglades Agricultural Area was delineated based on

scientific analysis of soils to determine their suitability as a

growth medium. The drainage necessary for successful agriculture

has been accompanied by subsidence primarily because soils are no

longer protected from decomposing organisms which require oxygen

for their metabolizm. Soil loss continues to occur at about 1

inch each.year. It is predicted that by the year 2000

approximately 250,000 acres in the Agricultural Area will have

subsided to depths of less than one foot. The fate of soils less

than one foot thick is uncertain. They may be used for pasture

land or abandoned for agricultural purposes.

Peat currently is used in Florida for a variety of

horticultural and agricultural purposes. The United States

Bureau of Mines reports that in 1982, 120 thousand short tons was

produced at a value estimated at 1.5715 million dollars. These

data reflect voluntary information supplied to the Bureau of

Mines and do not include responses from all of Florida's peat

producers. Most peat sales in Florida are currently wholesale

and for agricultural purposes and are thus exempt from sales tax.

Records are not maintained which detail sales tax on retail sale

of peat products specifically, and thus there is no way of esti-

mating the current tax income derived from the exploitation of

peat resources in the State of Florida.

The peat permitting process as it applies to peat mining is

complex. County level permits may be required, although in many

cases zoning regulations are the only regulations which apply to

opening a peat mine. At the state level, the Department of


Environmental Regulation and Water Management Districts

containing peat may require permits. The Department of Community

Affairs has jurisdiction over Developments of Regional Impact

(DRI). Certain peat mining operations could come under federal

jurisdiction. The agencies concerned would include the

Environmental Protection Agency and the Army Corps of Engineers.

The environmental impacts associated with peat mining for

energy purposes depend strongly on the size of the prospective

operation. Environmental impacts are also extremely site

specific. Small operations would consume 26 acres of peat mined

to a depth of 6 feet, over 4 years, moderate operations 3500

acres mined to a depth of 6 feet, over a 20 year period and a

large operation would require 125,000 acres of peat, mined to a

depth of 6 feet to operate for 20 years. Peat mining will occur

largely in wetlands and the functions of each individual wetland

must be weighed against the value of peat to be removed. The

wetland habitat will be severely affected. Fauna will be

displaced and possibly destroyed and flora will be destroyed when

the peatland is cleared for mining. Water quality impacts may

be major, even for small operations and are related to chemical

characteristics of the discharge waters. Water resource

parameters are not expected to be severely affected by small

scale operations but may be more seriously impacted by larger

scale development. The impacts of mining on air quality arise

from mining, processing, and utilizing peat as a fuel. They are

specific to an operation's size, mining method, and the intended


use for the product. Endangered species, both plant and animal,

may inhabit peatlands. The change in habitat brought about by

peat mining might lead to the destruction of members of stressed

species associated with a mined area.

Research in Minnesota, North Carolina, Finland and New

Brunswick, Canada, show that reclamation techniques can be

successfully applied to peatlands. Reclamation techniques are

specific to those areas and do not address difficulties inherent

to Florida peatlands. Reclamation of Florida's peatlands will

involve a change from wetland systems to other systems (probably

aquatic systems). Restoration of mined peatlands (for the most

part wetlands) will, in all probability, be financially



Mineral Versus Non-Mineral

Peat, like coal, petroleum and natural gas, does not comply

with the principal conditions set forth in the academic defini-

tion of the term mineral. Peat represents an early stage in a

series of products resulting in the conversion of vegetable

matter to pure carbon (peat-lignite-coal-graphite), the end pro-

duct of which fits all the requirements of a true mineral. In

classifying peat as a mineral or non-mineral, there has been a

tendency toward allowing use to play an important role in the


classification, that is, if used as an agricultural product peat

would be treated as a non-mineral or if used as an energy source

or fossil fuel peat would be treated as a mineral. Classifica-

tion based on use can create considerable confusion especially

with mineral products used as fertilizers. Peat has been

historically classified by the U.S. Bureau of Mines and the U.S.

Geological Survey as a mineral resource, a somewhat broader

category than just "mineral," along with coal, oil and natural

gas. Peat is generally regarded as nonrenewable by earth science

professionals, requiring in excess of 1,000 years to generate a

commercially extractable deposit of fuel grade peat.

This study would conclude that because of peat's genetic

relationship to the mineral graphite, its general classification

by the U.S. Bureau of Mines and the U.S. Geological Survey as a

mineral resource, and emphasizing its nonrenewability, peat

should be classed as a mineral, mineral resource, or mineral pro-

duct. Consequently, any classification based on use should be


Harvesting versus Mining

Harvesting and mining have been used synonymously to refer

to the extraction of peat. Literature searches reveal the term

harvesting correctly refers to the nearly obsolete practice of

selectively removing living Sphagnum from the surface of the bog.

In this practice, Sphagnum was allowed to grow back, permitting

successive harvests in a single location. Peat (unlike living

Sphagnum) is considered nonrenewable and the term harvesting is

inappropriate when applied to peat extraction. Additionally, the

method and equipment utilized in peat extraction and the environ-

mental impacts of peat extraction are synonymous with those com-

monly attributed to mining, not harvesting.

This.study would conclude that harvesting should be applied

only to the removal of living Sphagnum or other living plants and

that the extraction of peat should be categorized as mining.

Environmental Impacts of Peat Mining

Peat occurrence in Florida is, in nearly every case exa-

mined, coexistent in and beneath a current wetland area. For

this reason, peat mining and wetland mining are virtually synony-

mous terms in Florida. The environmental impacts associated with

peat mining may vary widely depending on the type of wetland, the

location of the wetland, the function of the wetland, the extent

of mining, the type of mining, and other physical parameters of

the site.

This study would conclude that an accurate assessment of the

environmental impacts of peat extraction will be site specific

and can be anticipated to range from minor to severe.

Reclamation of Peat Mining

Reclamation or the return of mined land to a beneficial use

is applicable to most mining operations and would be so with peat

mining. Restoration or the return of mined land to the pre-


mining function is only partially applicable to most mining

operations and would not be practical with peat mining. The

higher the ratio of overburden to the mined product, the higher

the percentage of original landform and contour that can be

achieved in reclamation. In peat mining, where the mined product

typically-has no overburden, the extraction leaves a void space

with no material available for filling, and therefore, no origi-

nal landform and contour can be achieved in reclamation.

This study would conclude that reclamation of mined

peatlands to a beneficial use as an aquatic or uplands system is

achievable, however, the restoration of mined peatlands to pre-

mining contour and function is not feasible.

Agricultural Use of Peat

The inplace use of peat and related organic for agri-

cultural purposes such as the Everglades Agricultural Area appear

to be a nonconsumptive use of peat. In fact, the exposure of

peat to air allows aerobic bacteria to oxide the peat causing a

gradual loss of peat accompanied by subsidence of the land sur-

face. It is predicted that by the year 2000, approximately

250,000 acres in the Everglades Agricultural Area will have sub-

sided to depths of less than one foot.

This report would conclude that agricultural uses of inplace

peat be viewed as a consumptive use of peat and that companion to

the use, research and planning be carried out to determine the

systems impact resulting from peat loss and land subsidence for

management to better transition into future land uses.



The initial outline for this study was read and improved by

David Gluckman, representing the Florida Chapter of the Sierra

Club; Charles Lee, representing the Florida Audubon Society; and

Katherine Ewel, Helen Hood, John Kaufmann, and Marjorie Carr,

representing the Florida Defenders of the Environment.

Richard P. Lee, Florida Department of Environmental Regulation

offered helpful comments on the outline and sent valuable

references concerning wetlands. Irwin Kantrowitz, United State

Geological Survey read the outline and offered assistance.

Ronnie Best of the Center for Wetlands, University of Florida

provided an excellent perspective on the values attributed to

wetlands and proved to be a most useful reference. Roy Ingram,

Professor of Geology at the University of North Carolina, Chapel

Hill, provided work space, access to his personal collection of

peat reference works and the benefit of his research experience

through numerous informal conversations concerning various

aspects of peat.



This study was undertaken in response to a directive from the

Florida Legislature originating in the Natural Resources

Committee of the Florida House of Representatives. Florida is

currently faced with immediate expanding industrial interest in

the exploitation of its peat resources for fuel use. The study

is primarily a compilation of literature pertinent to peats of

Florida and their use for agriculture and energy applications.

It is conceived as providing an information base for decisions

concerning both the utilization and conservation of Florida's

extensive peat resource.



Interest in Florida's peat deposits has fluctuated since the

Florida Geological Survey published a "Preliminary Report on the

Peat Deposits of Florida" in its Third Annual Report (Harper,

1910). This early work was basically a reconnaissance study of

peat resources in the state. The author acknowledged that as

population density in the state increased a detailed report would

be required. In light of current environmental awareness, it is

especially interesting that Harper (1910) recommended studies by

both an engineer and an ecologist.

The historical perspective of peat use in Florida is not

complete without mention of the work of Robert Ransom, a civil

engineer, who came to Florida from Ipswich, England in 1884.

Ransom viewed Florida's peat deposits as a readily exploitable

resource and was especially interested in energy production from

peat. For thirty-five years Ransom experimented with peat, even-

tually even opening a test plant near Canal Point (Palm Beach

County) which produced power gas, tars, oils, methyl alcohol and

various by-products. He was not able to gain acceptance for his

radical projects within his lifetime (Davis, 1946).

In 1946, John H. Davis published The Peat Deposits of

Florida, Their Occurrence, Development and Uses. This study

categorized peat-forming environments in the state and treated

individual deposits in detail. It extended Harper's work and

included chemical characterization of various Florida peats.

Chemical characteristics were related to the use of peat for

agricultural purposes and also to its use as a fuel source.

A number of studies treating the peats of south Florida have

been prepared by W. Spackman in conjunction with co-workers.

Spackman and others (1964) presented a summary of various coal

forming environments associated with the Everglades. This work

includes a large number of geologic cross sections which document

the relationship of peats to bedrock and surrounding materials.

The plant communities currently associated with peats in the

various coal forming environments are also carefully documented.

Cohen and Spackman (1977', 1980) present detailed descriptions of

peats from southern Florida along with discussions of their ori-

gin, classifications and consideration of the alteration of plant

material. Spackman and others (1976) present an updated and

augmented edition of the original guidebook. The format of

these works (Spackman, et. al., 1964 and Spackman, et. al., 1976)

makes them particularly useful to scientists in various disci-

plines whose interests converge on the various wetland environ-

ments of south Florida.

In 1979, the U. S. Department of Energy began its "Peat

Development Program." The assessment of fuel grade peat deposits

was part of an effort to define energy resources in the United

States exclusive of petroleum. The Florida Governor's Energy

Office subcontracted with the University of Florida's Institute

of Food and Agricultural Sciences to survey the peat resources of

Florida. This study resulted in a literature survey of peat

deposits of Florida combined with detailed work in the Everglades

Agricultural Area (Griffin, et al., 1982).

The current study was undertaken in response to a directive

from the Florida Legislature originating in the Natural Resources

Committee of the Florida House of Representatives. It provides a

compilation of information concerning the location and amount of

Florida's peat resources. In addition, the various aspects of

the Everglades Agricultural Area are described in some detail and

implications of subsidence of peats in this region are con-

sidered. Emphasis is also placed on existing information rela-

tive to potential effects of peat mining on Florida's

environment. Legislation which may be applied to peat mining,

water quality parameters monitored in conjunction with various

phases of peat mining and methods of regulation applied to the

peat resource by Minnesota, New Brunswick and North Carolina are

included as appendices to this report.


Peat is defined by workers in a variety of disciplines

(geology, botany, soil science, and horticulture among others).

These definitions proliferate in response to the specific

interest of researchers and also in response to the multiple uses

of peat. The American Geological Institute defines peat as, "An

unconsolidated deposit of semicarbonized plant remains of a

watersaturated environment, such as a bog or fen and of per-

sistently high moisture content (at least 7'5 percent). It is

considered an early stage or rank in the development of

coal..." (Gary, et al., eds., 1974). This extremely general

definition notes several essential points. Peat is composed of

plant remains which accumulate in a wet environment. It is con-

sidered to be an early product of the coal-forming process.

In a definition which will be published in an upcoming

volume (A. Cohen, personal communication, 1984), the American

Society for Testing and Materials (ASTM) defines peat as a

naturally occurring substance derived primarily from plant

materials. Peat is distinguished from other organic soil

materials by its lower ash content (less than 25 percent ash by

dry weight IASTM Standards D2974]) and from other phytogenic

material of higher rank (i.e. lignite coal) by its lower BTU

value on a water saturated basis. This very specific definition

is designed so that peats may be classified objectively and

distinguished from both organic soils and also coals.

Griffin and others (1982) note the definition of fuel grade

peat which is used by the United States Department of Energy.

Fuel grade peat is defined as an organic soil consisting of

greater than 75 percent organic matter in the dry state. In

order for a peat deposit to be classified as fuel grade, the

deposit must be at least 4 feet thick, with a surface area of not

less than 80 contigous acres per square mile and yield not less

than 8000 BTU per pound (moisture free). The definition for fuel

grade peat establishes minimum standards for organic matter con-

tent and also for heating value (BTU per pound). It further com-

ments on the deposits itself, stipulating minimum thickness and

contiguous acreage requirements.

The three definitions of peat presented here respond to the

specific purposes of individuals and agencies who prepared them.

Varied user groups and professionals who work with peat may for-

mulate additional definitions directly suited to their needs. It

is thus necessary to determine the way in which an author defines

peat in order to fully understand the implications of his work.

In the state of Florida, the definition of peat may take on

special significance if it is used as criteria for classification

of peat as either a mineral resource or an agricultural

(vegetable) resource. It has been argued that if peat is not

classified as a mineral then its excavation might constitute a

harvesting process. Harvesting may not be subject to the regula-

tory procedures that govern mining of a legally-defined mineral


The usage of the term harvesting to describe the mining of

peat follows Kopstein (1979). "Harvesting" when used in conjunc-

tion with peat correctly refers to the nearly obsolete practice

of harvesting living Sphagnum (peat moss) from the surface of a

bog. In this process, the Sphagnum was allowed to grow back so

that repeated harvests were possible in a given area. Thus, a

crop was in actuality "harvested." Very little or no true har-

vesting occurs today (A. Cohen, personal communication, 1984).

In the carbonization process, the carbon content of the

plants' cellulose is proportionally increased as water, carbon-

dioxide and methane are evolved. Carbonization can be generally

described by the following equation:

072H120060 = C62H72024 + 2CH4 + 8C02 + 20H20

Cellulose Peat Methane Carbon Dioxide Water

The expressions for cellulose and peat were taken from U.S.

Geological Survey Bulletin 7'28 (Soper and Osbon, 1922).

Two major considerations arise from the definition of peat.

One of these considerations involves the classification of peat

as a vegetable or mineral and the second consideration follows

from the first. If peat is viewed as being a vegetable material,

then its excavation might be termed a harvesting process.

Harvesting practices would not be subject to the regulatory pro-

cedures that govern mining of a legally-defined mineral material.


Peat can only accumulate in a waterlogged environment. The

terms which refer to these environments take on different defini-

tions according to author preference. The American Geological

Institute distinguishes between bogs and fens on the basis of

chemistry. Bogs and fens are both characterized as waterlogged,

spongy groundmasses. Bogs, however, contain acidic, decaying

vegetation consisting mainly of mosses while fens contain alka-

line, decaying vegetation, mainly reeds (Gary, et al., eds.,

1974). The terms "bog" and "fen" are not usually applied to

peatlands in the southeastern United States. They are included

in this discussion because they occur frequently in the litera-

ture associated with peatlands extraneous to Florida. Although

a significant body of research specific to the peats of Florida

exists (Cohen and Sparkman, 1980; Cohen and Spackman, 1977;

Griffin et al., 1982 Spackman et al., 1976), much information

concerning mining techniques, reclamation methods and hydrologic

aspects of peatlands pertains directly to areas remote to Florida

where the terms "bog" and "fen" may be used.

The concepts of minerotrophy and ombrotrophy are based on

the quality of water feeding a peatland (Heikurainen, 1976) and

are perceived as separate from the series eutrophy, mesotrophy

and oligotrophy. The latter series describes nutrient resources

of peatlands using plant composition with eutrophy being richer

in nutrients and oligotrophy being poorer. The eutrophy oli-

gotrophy series is difficult to apply since it may be expanded to

include additional extreme and transitional groups. The boun-

daries between these various groups are not clear (Heikurainen,

1976) and they will not be considered further in this document.

Bogs are said to be ombrotrophic, which implies that the bog

is isolated from the regional groundwater system and receives its

moisture mainly from precipitation. Minerotrophic peatlands, or

fens, are defined as being connected with the regional ground-

water system and are nourished both by precipitation and ground-

water flow (Brooks and Predmore, 1970).

The U.S. Department of Energy in its Peat Prospectus avoids

the usage of fen and characterizes peat as forming in swamps,

bogs and saltwater and freshwater marshes (Kopstein, 1979). The

extent of this confusion becomes clear on examination of the

American Geological Institute's definition of swamp (Gary, et

al., sds., 1974) which is characterized as "A water saturated

area..., essentially without peatlike accumulation." It should

be noted that most workers in the field do not concur with the

portion of the American Geological Institute's definition that

addresses the accumulation of peat in swamps (A. Cohen, personal

communication, 1984). Moore and Bellamy (1974, p. 84) use the

term "mire" to cover all wetland ecosystems in which peat

accumulates in the same area where its parent plant material

lived and grew. Thus, the meaning of specific names assigned to

the peat-forming environment must be derived from an author's


In the southeastern United States, the most commonly used

terms for.peat-forming environments are swamps and marshes.

Swamps refer to forested wetlands and marshes refer to aquatic,

herbaceous wetlands (A. Cohen, personal communication, 1984).


In Florida, peat may eventually be viewed as a mineral

resource or an agricultural resource. The United States Bureau

of Mines has long considered peat a mineral resource for the

reporting of commodity statistics. In deference to the formal

definition of the term "mineral," the greatest majority of earth

science professionals would not classify peat as a mineral. Peat

more properly might be likened to a rock in that it contains a

number of minerals (quartz, pyrite, and clay minerals among

others) as well as macerals which are the organic equivalents of


If, however, the formal and most restricted definition of

mineral is compared with a definition of mineral that reflects

current usage, it is noted that "minerals" adhere to the specifi-

cations of the formal definition in varying degrees. The intent

of this discussion is not to establish that peat is a mineral,

but rather to illustrate the extent to which the formal defini-

tion has been expanded in the realm of common usage.

A standard mineralogy textbook for university students,

Elements of Mineralogy (Mason and Berry, 1968), gives the

following definition of a minerals "A mineral is a naturally

occurring, homogeneous solid, inorganically formed, with a defi-

nite chemical composition and an ordered atomic arrangement."

This definition is useful because its authors continue by

expanding on each part of their definition, taking into account

the complexity of the group of compounds classified as minerals.

According to this definition, a mineral must be naturally

occurring. This eliminates materials which are synthesized in

the laboratory or are formed as by-products of various manufac-

turing processes. Since peat is indisputably naturally

occurring, this aspect of the definition will not be considered


A mineral must also be a homogeneous solid. This qualifica-

tion eliminates liquids and gases from consideration and implies

that a mineral cannot be separated into simpler compounds by any

physical means (Mason and Berry, 1968). In the coalification

process by which plant material (i.e., cellulose) becomes peat,

water, carbon dioxide and methane are evolved with time

(Kopstein, 1979). Kopstein (1979) is referring to a generali-

zation of the peat-forming process in which all initial plant

material is referred to as cellulose. In actuality, peat con-

tains many types of plant material and may possibly contain no

cellulose at all. It is important here to note that many mineral

substances evolve water or gaseous by-products when subjected to

changed conditions of pressure or temperature. Gypsum dehydrates

(evolves water) forming anhydrite. The mineral talc evolves

water and forms enstatite and quartz at elevated temperatures.

Thus, minerals commonly contain water as an integral part of

their crystal structures.

The term mineral is restricted by definition (Mason and

Berry, 1968) to refer to inorganically formed substances. It

eliminates homogeneous solids formed by plants and animals such

as oyster shells, pearls and gallstones. Ostensibly, this

qualification could eliminate peat from consideration.

The American Geological Institute in its Glossary of Geology

(Gary, et al., eds., 1974) includes the following reference in

its definition of the term mineral: "A mineral is generally con-

sidered to be inorganic, though organic compounds are classified

by some as minerals." Thus, organic compounds are not automati-

cally eliminated from consideration as minerals. This suggests

that'the term mineral has come to be used in a sense that is less

restricted than might be supposed from examination of the defini-

tion presented to beginning students of mineralogy.

Minerals are defined as having definite chemical composition

(Mason and Berry, 1968). This implies that their composition

must be readily expressible using a chemical formula. It does

not preclude variation in chemical composition. Variation within

definite limits is allowed, thus, the composition is definite but

not fixed (Mason and Berry, 1968). The compositions of cellulose

and the peat derived from it are frequently cited using the

appropriate chemical formulae (Soper and Osbon, 1922, pp. 6-7;

Kopstein, 1979, pp. 5-6; Cameron, 1973, p. 506). (As noted pre-

viously, the formulae cited here are based on a generalization of

the peat-forming process in which peat is derived from a

starting material of cellulose. For most peats, this simplified

approximation is not realistic.)

The last criterion in the definition of a mineral is that of

an ordered atomic arrangement; that is, a mineral should be a

crystalline solid. Mason and Berry (1968) note a group of com-

pounds which are considered minerals even though the crystalline

state is not initially attained: "A few minerals, the commonest

being opal, are formed by the solidification of a colloidal gel

and are noncrystalline initially; many such minerals become

crystalline during geologic time." The mineral opal may attain

an ordered atomic arrangement only in the course of geologic


The coal-forming process is illustrated in figure 1. As

organic matter (originally deposited as peat) is subjected to

conditions of increasing temperature and pressure it undergoes

the changes associated with coalification. The end-product of

this process is the mineral graphite (Press and Siever, 1974,

p. 468). Graphite crystallizes in the hexagonal system and its

formula is simply carbon (C). It is found in a number of

occurrences including metamorphosed coal beds (Quinn and Glass,





l i I
-- - -~~ --- - - -

........... OF M TERS ...........
.::::::::::OF METERS OF.-
la- .- ,


Plant litter accumulates at
the surface
Buried plant litter decays
partially and is compacted
forming peat

Underlying sediments in -rida
typically consist of limestone
clay and unconsolidated sand.

With shallow burial peat is
compressed to form brown

Additional burial transforms
the brown coal to lignite if
burial is comparatively shallow
and bituminous coal if depth of
burial is greater.

Coal is metamorphosed to anthracite
or graphite with continuing burial
and metamorphism.

The process of coal formation. (Modified from Press and Siever,
1974, Figure 13-18, p. 468)

Figure 1.

I L __

-- I ,, = I

1958). The parallels with the case of opal seem apparent.

Neither opal nor peat initially attain the internal atomic

ordering referred to in Mason and Berry's definition of a

mineral. Opal will presumably achieve internal atomic ordering

in the course of geologic time (Mason and Barry, 1968). The

transformation of peat into the mineral graphite requires, in

addition to the passage of time, increases in temperature and

pressure (Press and Siever, 1974).

Geologists do not universally include crystalline form as a

prerequisite to classification of a material as a mineral. This

is demonstrated in the continuation of the AGI Glossary's defini-

tion of mineral. "Those who include the requirement of

crystalline form in the definition of a mineral would consider an

amorphous compound such as opal to be a 'mineraloid'" (Gary, et

al., eds., 1974).

The United States Geological Survey in its volume entitled

United States Mineral Resources (Brobst and Pratt, eds., 1973),

devotes a chapter to peat as well as chapters to petroleum,

natural gas and coal. The United States Bureau of Mines also

considers peat to be a mineral resource in addition to coals,

petroleum and natural gas. These resources including peat are

all non-renewable.


Harvesting and mining are both terms which are applied to

the extraction of peat. As was discussed in the section of this

report "The Definition of Peat and Significance of this

Definition" the term "harvesting" properly refers to the

practically obsolete procedure of literally harvesting living

Sphagnum from the surface of a bog. In this procedure, Sphagnum

is allowed to continue its growth subsequent to harvesting (A.

Cohen, personal communication, 1984).

Currently, the choice of "harvesting" as opposed to "mining"

for terms to describe the excavation process of peat is

arbitrary. The nature of the distinction is demonstrated in the

following quotation taken from Peat Prospectus: "Thus, the reco-

very of peat is a surface mining or harvesting process,"

(Kopstein, 1979, p. 18). It may be significant that surface

mining carries with it certain negative environmental connota-

tions. Harvesting is largely free of environmentally negative

connotations but this is perceived to be due to a lack of

understanding since harvesting is frequently used as synonymous

with surface mining.

The equipment utilized in the peat removal process is not

associated with harvesting in its commonly accepted sense. Peat

operations which are currently active in Florida utilize earth

moving and excavating machinery. In drained bogs such machinery

commonly includes shovels, bulldozers and front-end loaders

while draglines, clamshells and dredges are used in undrained

bogs (Searls, 1980).

Harvesting originally referred to removal of living Sphagnum

which was allowed to replenish itself after harvesting. Peat is

not considered renewable due to its slow rate of accumulation

(Kopstein, 1979; Moore and Bellamy, 197'4).

The process of harvesting in its usual sense does not imply

the necessity of extensive land reclamation. However, reclama-

tion of peatlands which have been excavated is acknowledged as

necessary.(Minnesota Department of Natural Resources, 1981) and

is discussed more thoroughly in the section of this report

entitled "Reclamation of Peatlands of Florida."


Peat, like many materials, is classified for the convenience

of persons using it. Since peat use in the United States has

been largely agricultural, most classification schemes are based

on properties of peat pertinent to agricultural applications. As

one might expect, classification schemes devised for agricultural

application do not necessarily indicate peat quality for energy

purposes. However, there is a general relationship between peat

decomposition and its energy value with respect to direct com-

bustion. This is illustrated in figure 2.

The American Society of Testing and Materials (ASTM) has

established maximum and minimum particle sizes for peat (ASTM,

1969). They additionally specify fiber content requirements for

various types of peat. The maximum particle size for fibers is

0.5 inch (1.25 cm) and the minimum is 0.006 inches (0.15 mm).

Peat is subdivided into five types and each type must contain a







0 10 20 30 40 50 60 70 80 90 100

Figure 2. The relationship of peat types to fuel grade. (Modified from
Kopstein, 1979)

certain percentage of the characteristic fiber. These percen-

tages are based on an oven-dried weight at 105 OC as opposed to

volume. The types of peat recognized by the ASTM include: 1)

Sphagnum moss peat which must contain 66.66 percent Sphagnum

fibers by weight, 2) Hypnum moss peat which must contain 33.33

percent fibers with one-half of those identifiable as Hypnum

moss, 3) reed-sedge peat which must contain 33.33 percent fibers,

half of which are reed-sedge and other nonmosses, 4) peat-humus

must contain less than 33.33 percent fiber, and 5) other peat,

which accounts for all peat not previously classified in ASTM

Designation D-2607-69 (ASTM, 1969).

The ASTM classification as discussed in the previous

paragraph is currently under revision. Two major factors were

considered in this revision. The classification of peat should

meet the needs of three major user groups including engineers,

energy users and agricultural users. In addition, the

classification should be based on parameters which may be

measured objectively. These parameters include ash, botanical

composition, pH, and water holding capacity. In order to be

called peat, a material will have to contain 75 percent or more

organic material. Although peats will still be categorized as

fibric, hemic or sapric, these general terms will be modified by

ash content, botanical composition, pH and water holding capacity

(A. Cohen, personal communication, 1983).

One essential parameter that is characteristic of all peat

is moisture level, but there are no current regulated standards

for moisture in peat. The United States Bureau of Mines con-

siders a commonly accepted value in the United States to be 55

percent moisture by weight for air dried peat (Searls, 1980).

The U.S. Department of Agriculture divides peat into three

categories (Searls, 1980). Fibric peat must contain more than

66.66 percent plant fibers. Hemic peats are more decomposed than

fibric peats. They must have a fiber content which ranges

between 33.33 percent and 66.66 percent fibers. Sapric peat con-

sists of the most extensively decomposed plant material. Sapric

peat contains less than 33.33 percent recognizable plant

fragments of any type.

Peat in the United States has often been classified into

three general categories (Searls, 1980; Kopstein, 1979). Moss

peat comprises Sphagnum, Hypnum and other mosses. Reed-sedge

peat is mainly the product of reeds, sedges and other swamp

plants. Humus is simply too decomposed for evidence of its ori-

gin to be retained.

The parameters which bear most directly on peat's usefulness

as a fuel source are measured by proximate analysis. In this

procedure, peat is analyzed in the laboratory for its volatile

content, fixed carbon, ash content and moisture. The volatile

content of peat refers to substances other than moisture which

are emitted as gas and vapor when peat is burned. Peat has a

very high volatile content compared to coal. This is a positive

attribute for peat which is to be gasified since the reactivity

of peat in the gasification process increases with increased

volatile content. The fixed carbon content of the peat is

responsible for much of its combustion energy.

Ash is the amount of material in a fuel which remains after

combustion. The amount of ash varies for different types of

peat. Peats which receive their moisture primarily from precipi-

tation are usually lower in ash than those which are nourished by

surface waters. In times of flood, surface waters may carry

large sediment loads onto the peatlands where it is trapped in

the peat.

Peat's high moisture content can be a major problem which

must be considered in its utilization. Even a drained and soli-

dified bog may contain 70-95 percent moisture and for some uses

peat will require additional drying which will, in turn, require




Peat forms when the rate of accumulation of plant matter

exceeds the rate at which decomposing organisms metabolize it.

The conversion of fresh plant material to peat takes place over

a period of time as peat becomes enriched in fixed carbon while

evolving water, carbon dioxide and methane (Kopstein, 1979).

Peat is comparatively increased in fixed carbon as opposed to

cellulose and the process by which this takes place is referred

to as carbonization. It is this enrichment of carbon which makes

peat desirable as a fuel source (figure 3). The Peat Prospectus

(Kopstein, 1979) compares peat with wood and various grades of

coal in terms of fixed carbon and the heating value (in British

Thermal Units, BTU). The following values are taken from figure

3 of the Peat Prospectus and are approximate (Kopstein, 1979).

One pound-of wood with a fixed carbon content of approximately 20

percent, generates 9,300 BTU on a moisture and mineral free

basis. An equivalent amount of peat containing 28 percent fixed

carbon may generate approximately 10,600 BTU. These values for

peat and wood contrast with values for lignite which yields about

12,400 BTU at a fixed carbon content of approximately 47' percent.

These figures demonstrate that peat is a material distinguishable

from wood in its fuel-producing characteristics.


As was previously noted, peat forms when the accumulation of

plant material exceeds its destruction by the organisms which

decompose it. Since plant matter is usually decomposed before

significant accumulations develop, it is instructive to examine

the set of circumstances which allow peat to form. Certain

geologic, hydrologic and climatic conditions serve to inhibit

decomposition by organisms. Ideally, areas should be continually

waterlogged, temperatures generally low and pH values of asso-

ciated waters should be low (Moore & Bellamy, 1974). It should

noted that Moore and Bellamy (1974) primarily treat peats asso-

14 i
#A 60


2i 40 .

. 30o.



Figure 3.





A comparison of moisture content and heating value for peat, wood
and various coal types. (Modified from Kopstein, 1979)

ciated with northern cold climates.

Certain geologic characteristics are associated with

waterlogged surface conditions. The tendency toward waterlogging

is enhanced if topographic relief is generally low and topographic

barriers exist which restrict flow and allow water to pond.

Additionally, waterlogging is encouraged if highly permeable

bedrock is covered with material of low permeability (Olson, et

al., 1979).

The chemical nature of the plant litter may also serve to

reduce its susceptibility to decomposition. Moore and Bellamy

(1974) note the association of cypress and hardwood trees with

peats characteristic of the hammocks or tree islands of the

Everglades. These hammocks occur on peat deposits which are

situated on limestone bedrock. The trees, which are responsible

for the peat beneath them, contain enormous amounts of lignin.

Lignin is very resistant to decay (Moore and Bellamy, 1974). It

is alternatively suggested that hammock peats in Florida may be

controlled by the persistence of water (A. Cohen, personal com-

munication, 1984).



Recently, several potential commerical users have been

investigating Florida's peat as a fuel source. This interest is

prompted by the rising cost of traditional fuels. Preliminary

proposals for the use of peat as a fuel in Florida suggest that

peat will be air dried and burned directly. This usage will

require comparatively large amounts of peat which must be dried

before it is burned (this drying is in addition to the moisture

reduction which accompanies bog drainage) (Kopstein, 1979). The

drainage of a peatland is an integral and necessary first step in

any large-scale peat mining operation utilizing milled peat or

sod peat mining methods. Moisture must be reduced to approx-

imately 90 percent for the bog to be considered workable (i.e.,

able to bear the weight of machinery).

Drainage is accomplished by construction of a system of

ditches and waterways which are designed to capture water and

route it away from the portion of the bog to be mined (Kopstein,

1979). If surface streams traverse the bog, they are diverted

around it. Eventually, surface vegetation and stumps must be


There are several mining methods in common use in Europe.

The manual method is one in which peat is cut into blocks by

hand, removed from the bog for air drying and finally burned for

home heating and cooking (Kopstein, 1979). Manual peat har-

vesting is labor intensive and probably will not become important

in Florida.

The sod peat mining method is one in which a trench is cut

into a previously prepared field. These trenches are cut by

excavator/macerators which are specifically designed to cut,

macerate, and extrude sods onto a conveyor which deposits them

onto the field for air drying. At a moisture content of about

75 percent the sods are windrowed. Windrows are periodically

split and turned to facilitate drying and at about 55 percent

moisture sods are considered dry and removed for storage

(Aspinall, 1980).

The milled peat mining method is one in which a peat layer

1/4 to 2 inches thick is milled or shredded from the prepared

surface of the bog. The peat is periodically harrowed to

expedite drying. At a moisture content of 50 to 55 percent, the

dried peat is pushed into ridges where it is collected for

transportation to storage facilities (Aspinall, 1980).

Several methods of hydraulic peat mining are in development.

Examples of these processes are the slurry ditch, hydro peat and

slurry pond methods (Aspinall, 1980). In each of these methods,

the surface must be cleared; but drainage is not necessary.

The slurry ditch and hydro peat methods utilize high

pressure water guns to cut peat from a ditch face. The dif-

ference between the methods lies in the post-mining dewatering

process. The slurry ditch method utilizes a dewatering

apparatus; whereas, the hydro peat method is dewatered by pumping

the slurry to a drying field where it spread to dry (Minnesota

DNR, 1981). The slurry pond method utilizes mechanical

excavators or a dredge to remove peat. Mining equipment is

mounted on a barge which floats on a pond excavated within the

peat deposits as the mining progresses.

The ultimate success of wet mining methods will depend on

the successful development of very large scale dewatering

processes and upon the environmental impacts of the mining

process (Kopstein, 1979). These may be the preferred methods,

however, in areas where drainage of the peat deposit will be



In order to obtain current information on Florida's active

peat operations for the present study, the staff of the Bureau of

Geology designed and conducted a survey of producers. In the

first stage of this survey, a list of peat producers was

compiled. In an effort to make this list as comprehensive as

possible, a number of sources were consulted including: existing

lists of producers (Florida Bureau of Geology, United States

Bureau of Mines, United States Mines Safety and Health

Administration); agencies contacting peat producers in

conjunction with regular professional services (county

agricultural agents, Florida Department of Agriculture); and

numerous telephone directories. In the second stage of the

survey, peat producers were contacted by telephone and field

visits were arranged. The information which follows was

contributed on a voluntary basis by producers'who were contacted

during field visits.

Peat extraction methods vary with the size and nature of the

deposit being mined. Most deposits are mined using conventional

types of earth-moving and excavating equipment. The machinery

used includes draglines, backhoes, grade-alls, front-end loaders

and hydraulic excavators. The majority of companies use a

dragline for mining. A shredder is used to pulverize the peat.

Most-companies drain the immediate area of mining by

pumping and ditching, which enables the deposit to be mined by

dry processes. Approximately one-third of the companies con-

tacted conduct all or part of their mining below the watertable.

Two companies utilize a variety of the milled peat mining

process. After surface clearing and ditching is complete, the

surface peat is pulverized with a rotovater. The pulverized

material is dried in the sun and is turned by discing to help

promote drying. The dried material is mechanically windrowed

using a front-end loader or bulldozer and is then stockpiled or

loaded for transport. There are no companies currently mining

peat by the sod peat method in Florida.



Knowledge of the rate of peat accumulation is important in

that it allows various extractive uses for the resource to be

weighed in light of the amount of time it takes for the material

to accumulate. Rates of peat accumulation are usually deter-

mined using the carbon-14 method of dating organic materials.

This method is subject to a number of difficulties when applied

to peat. The following problems are enumerated by Moore and

Bellamy (1974). 1) Wide errors may be introduced since young

roots may penetrate material at depth. This problem could result

in apparently rapid rates for the accumulation of peat. 2) Older

layers are compacted as new ones are deposited. This could cause

rates of deposition to appear anomalously low. 3) Rates of peat

formation vary with climate and climate varies with time. Thus,

an accumulation rate probably reflects a sort of average rate for

some given amount of peat. Several estimates of peat accumulation

rates in Florida are presented in Table 1.


Author Estimated Rate Comments
Davis (1946, p. 74) 5.2in/100 years This rate is computed based on the
amount of Si02 fixed by a standing crop
of sawgrass from the Everglades. It
is widely quoted, but a recent analysis
of the method (Gleason, et al., 1974)
indicates that certain of the assump-
tions necessary to the calculation must
be in error. This difficulty is dis-
cussed more completely in the accom-
panying text.

Kuehn (1980, p. 49) 4.24in/100 years This rate was computed from a core
which penetrated peat formed alter-
nately in marine, brackish and fresh
water environments from southwest
Florida. The computations were based
on radiocarbon ages.

Kuehn (1980, p. 49) 3.64in/100 years This rate was computed for a single
type of peat, red mangrove (Rhizophora),

from southwest Florida using measured
thickness and radiometric ages.

Stephens (1974, 3 in/100 years Rates were computed from the Everglades
p. 356) using radiocarbon ages which were not
specifically referenced in the text.

The variation in rate presented here for peat accumulation

may be attributed to a number of factors. Gleason and others

(1974) used Davis' (1946) data to compute a value of productivity

for the sawgrass environment. Productivity refers to the amount

of dry organic matter (measured in pounds) which is formed on an

acre of ground in a year. When this productivity is compared to

the dry weight of an acre-foot of peat as estimated by Davis

(1946), a discrepancy is apparent. According to these com-

putations, more material accumulates as peat than is originally

formed in the sawgrass environment (Gleason, et al., 1974).

Factors which may account for this difficulty include possible

low estimates of productivity and inadequate estimates of silica

content or peat density. It is also possible that silica in the

peat might not be entirely derived from sawgrass (Gleason, et

al., 1974). Rates of peat accumulation computed from radiocarbon

age are grouped about an average of 9.1 cm/100 years. The rate

of peat accumulation can vary with climate (which also varies

with time), the position of the water table and nutrient supply

(Moore and Bellamy, 1974). Data are not available which would

allow rate variation in different environments to be evaluated.

The rates presented here were calculated from peats produced from

varying plant communities which thrive in different environments.

In addition, peat has been lost by fire during various

prehistoric dry periods (Cohen, 1974). Failure to recognize

evidence of fire could alter the rate at which peat is calculated

to accumulate.


The conditions under which peat can occur in Florida are

highly variable. While geologic and hydrologic relations of peat

to its neighboring materials have been thoroughly documented in

the Everglades of south Florida, numerous small deposits in the

central peninsula remain unmapped. Davis (1946, p. 114), con-

sidered the peat deposits of Florida as falling into a number of

groups based on their locations. These groups include: 1)

coastal associations, including marshes and mangrove swamps,

lagoons and estuaries as well as depressions among dunes;

2) large, nearly flat, poorly-drained areas as exemplified by the

Everglades illustrated in figures 4, 5, 6, and 7; 3) river-valley

marshes such as the marsh adjacent to the St. Johns River; 4)

swamps of the flatland region (figure 8); 5) marshes bordering

lakes and ponds (figure 9); 6) seasonally flooded shallow

depressions; 7) lake bottom deposits (figure 10); 8) peat layers

buried beneath other strata (figure 11).

Cohen and Spackman (1977) have devised a more comprehensive

classification of south Florida's phytogenic (of plant origin)

sediments based on micropetrological studies. They first divide




Figure 4. Peat Provinces of Southern Florida. (Modified from Spackman et
al., 1976)


PEAT "10 3
-Mi. WATER 0

Figure 5.

SW-NE cross-section from Cape Sable to vicinity of Tamiami Trail
and map showing line of section. (Modified from Spackman, et al.,
1964 and Spackman, et al., 1976)

SW -

"Moat "Moat"


Figure 6. Cross-section through a cypress hammock. (Modif*ed from Spackman
et al., 1964)




Figure 7.



Cross-section through a "Bay Head". (Modified from Spackman et
al., 1964)








I --


--------- ----------
---------- ------------- -- --------- ----1
- -- -e - - - -- --- - -
----- - - - --- -- -
---~------------- ---------- ------------ ------
-- -- -- -- -- -- -- ---- -- -
-------------------------- --- ------- ----
I----- -_-------------------------- -
--11--------------- ---- 11 ---------
-- 111--- ----- --------- ----- -
- -- - - ----- -
____-II-------- --------
-- -- ----- ---------
------ --------




Fige 8. Cross-section trough bay swamp and titi swamp. (Modified from
Cameron et al.,i 19771).

I /

:!I ,,,.I

' I



Figure 9. Peat deposits bordering lakes. (Taken from Davis, 1946)





Figure 10. Cross-section showing peat filling lake. (Taken from Davis, 1946)

SAND : 2
i MARL I- I- -


Figure 1 cross-section using cores to show buried peat layer! (at eka

Dam Site, Oklawaa River, Marion County, Florida. ( fom
Davis, 1946)

phytogenic sediments into two groups based on whether the plant

material is transported from the site of growth or deposited at

or near the growth sites of their source plants. Transported and

nontransported phytogenic sediments are subdivided as occurring

in marine to brackish water or fresh water. Specific environ-

ments are enumerated for both marine to brackish water deposits

and also fresh water deposits. Peats of these deposits are dif-

ferentiated based mainly on their botanical composition.

In Florida, peat deposits occur above or below the water-

table (Davis, 1946; Gurr, 1972). Wet peat deposits occur if the

watertable remains relatively high. Peat may be actively accumu-

lating in these deposits. Certain areas within the Everglades,

the coastal mangrove peats, and some lake-fringing peat deposits,

such as the one associated with Lake Istokpoga, are examples of

deposits which occur below the watertable. In other instances,

peat deposits are located above the watertable. This drainage

may have been instigated to enhance the land for agricultural

use. The Everglades agricultural region contains numerous tracts

drained'for this purpose. Other deposits have apparently been

drained as a result of regional lowering of the watertable. Most

peatlands in Florida occur at or below the watertable and, thus,

are very frequently also wetlands.



There is no comprehensive inventory of Florida's peat de-

posits currently in print. Until recently, peat was not even

remotely considered as a fuel source in Florida; and several

scattered deposits were adequate to satisfy the state's agri-

cultural and horticultural needs. Thus, neither interest nor

funding were available for a complete peat inventory in the

recent past.

It is important to point out that a comprehensive inventory of

Florida's peat resource is, of necessity, a massive undertaking.

The reasons for this difficulty are manifold. Florida is currently

estimated to have 6.8 billion tons of peat contained in 4,700

square miles (U.S. Soil Conservation Service). This peat occurs

in a variety of geologic settings which are both discontinuous

and widely distributed across the breadth and length of the

state. The various geologic settings of peat in Florida are

discussed in a previous section, "Geologic Settings of Peat

Accumulation in Florida."

These difficulties are compounded by the inaccessibility of

many peat-producing areas. Peat actively accumulates in wetland

situations typified by marshes, swamps, and mangrove islands.

Much of Florida's peat occurs in the Everglades region (figure

12). Due to extensive drainage in the Everglades the exact



II ~-9 I;





Figure 12. Isopach maps of the Everglades region showing thickness of peat
and some muck areas. (Taken from Davis, 1946)

thickness and extent of the peat has decreased since figure 12

was prepared. Many of these areas are not accessible to

conventional vehicles. Their size and character may render foot

travel unfeasible. Some, but not all, sites may be accessible to

boats. Coring apparatus for taking samples and measuring

thickness must, in addition, accompany any field party charged

with assessing peat reserves.

A realistic appraisal of Florida's peat resource is further

complicated by the variability of the material. Peat may be

classified as fibric, hemic or sapric depending on the extent to

which it has decomposed (see section entitled "classification

systems applied to peat"). It also varies with respect to

chemical properties that affect its viability as a fuel source.

Complete assessment of the peat resource requires laboratory

analysis in addition to time-consuming field studies.

Attempts to assess the amount and locations of peat in

Florida are hampered by an additional factor. Peat deteriorates

by oxidizing when the wetlands where it accumulates are drained.

This drainage may be due to the activities of man or by natural

lowering of the water table in times of drought. Any data base

for peat will require periodic updating if it is to remain



The total peat resources available in Florida are difficult

to estimate and published values vary widely. The paucity of

actual peat resource investigations is an important hindrance to

the development of accurate figures. A few published studies are

concerned with the entire state (Davis, 1946; Griffin, et al.,

1982). Several others concentrate on limited areas (Stephens and

Johnson, 1951; Gurr, 1972).

Individual county soil surveys vary in their usefulness due

to apparent inconsistencies in the terminology relating to

organic and organic-rich soils. The more recent studies were

used by Griffin, et al. (1982) to estimate fuel grade peat

resources. Unfortunately, these studies are not complete for

every county in the state. As a result, Griffin, et al. (1982)

were unable to provide a comprehensive inventory of the peat

resources for the entire state.

Another possible reason for the variation between resource

estimates may be the result of the specific material studied.

Griffin, et al. (1982) investigated "fuel-grade peats" while

Davis (1946) inventoried a variety of organic materials

classified as peats. The United States Soil Conservation Service

(1981) studies soils in general and describes their organic con-

tent in addition to other characteristics.

Griffin, et al. (1982) report the discrepancies among the

figures from various studies but were unable to determine the

reason for the differences. Griffin, et al. (1982) also state

that verbal reports from other Department of Energy peat

researchers indicate that they have found similar discrepancies

between the resource figures from the Soil Conservation Service

and their own figures in other states.

Published estimates of Florida's peat resources vary nearly

by an order of magnitude. Griffin, et al. (1982) provide the

lowest figure of 677',688 acres (1,059 square miles) consisting of

606 million tons of peat. Davis (1946) estimated 2,240,000 acres

(3,500 square miles), comprising 1,750,000,000 tons of peat. The

highest figure is provided by the Soil Conservation Service and

is 3,000,000 acres (4,700 square miles), or 6,900,000,000 tons of


The published resource estimates vary significantly and thus

should be used with reservation. The U.S. Bureau of Mines

currently uses the Soil Conservation Service figure (C. Davis,

personal communication, 1983).

The determination of a more accurate resource figure for

Florida peats would require a significant investment of time and

money to complete. The scattered nature of the deposits in north

and central Florida (figure 13) is such that there are literally

thousands of sites to be investigated. In south Florida, peat

deposits cover broad areas which would have to be examined in

order for accurate estimates to be prepared.

The greatest potential peat resources in Florida lie predo-

minantly in south Florida (figures 13, 14, and 15). The vast

majority of this peat lies in the Everglades and associated

swampy areas. It is interesting to note that while Davis (1946)

(figure 13) and the Department of the Interior (Christ et al.,

1981) (Figure 15) show similar areas of peat in south Florida,

I .- .
_", ,.. I

-. ,- EVERGLADS- -

MostlycSaw-9 ssPeo--,. l
A an I-'tt >.. : -', .Muck. and-T -. A at
8 Loxahatchee Peat
Mostly Sowoross Peat -
A Muck and *oat -oq
B Loxahatche. Peat ^ --*---f'H 1

+ E CORKSCREW MARSH o + -, r---c- -
C.L A'< ,- U D
S--- UI- ,- -. ,-.I -- --

7 x x 1 .0
,I^ ..L .
GtvLP oF MXxILo rC(\
1. :

Peat Deposits in Florida. (Taken from Davis, 1946)

Figure 13.


* No Survey Avoilable
; I I 1


Z\ e/ f1

Figure 14. Fuel Grade Peat in Florida. (Taken from Griffin, et al., 1982)

Figure 15. Peat deposits in Florida. (Taken from Christ, et al., 1981)

("7" r-'

k~ I

,e ,d~P~L

Griffin et al. (1982) (figure 14) show a significantly smaller

area. This discrepancy may be due to subsidence and high ash

content which would render peat unsuitable for fuel use.

Griffin, et al. (1982) show peat deposits in Collier and Lee

counties that are not included on the other maps.

Figures 13, 14, and 15 indicate the presence of large depo-

sits in the St. Johns River Valley (Indian River, Brevard and

Ocange counties), and the Oklawaha River Valley (Marion and Lake

counties). Other relatively large deposits include: Lake Apopka

(Orange and Lake counties), near Lake Arbuckle (Highlands

County), Orange Lake area (Marion and Alachua counties) and the

Florahome deposit (Putnam County). Smaller deposits are also

indicated on Davis' (1946) map (figure 13) and Griffin, et al.

(1982) map (figure 14).

It is interesting to note that while Davis (1946) (figure

13) shows scattered samples taken from small peat areas in the

panhandle, Griffin, et al. (1982) (figure 14) show a number of

deposits including a large deposit in Leon County and smaller

deposits in Bay, Jackson, and Santa Rosa counties. The

Department of the Interior map (Christ et al., 1981) (figure

15) does not indicate any deposits in the panhandle.

Peat associated with mangrove and coastal swamps generally

occur in a narrow band paralleling Florida's coastline. The zone

occupied by these environments is widest in southwest Florida.

These peats are not generally shown on the maps of peat resources

due to the scale of the maps.

Until a more detailed investigation of our peat resources is

undertaken the published resource estimates must suffice. It

must, however, be kept in mind that the figures are estimates of

the available resources and vary from one investigator to




The Everglades Agricultural Area is a part of an immense

natural drainage system that begins in the northernmost reaches

of the Kissimmee River drainage basin near Orlando. The

Kissimmee River flows to the southeast into Lake Okeechobee. In

its natural state, the level of Lake Okeechobee fluctuated within

a range of approximately 8 feet, that is, between 12 to 20 feet

above mean sea level (M.S.L.) (Parker, 1974). The water level in

the upper Everglades rose and fell in response to the

fluctuations of Lake Okeechobee.

In the wet season, most of the Everglades was inundated

much of the time. When the water level of Lake Okeechobee

reached about 14.6 feet (M.S.L.), two separate segments of the

lake shore would begin overflowing into the Everglades. At about

18 feet (M.S.L.), the entire southern shore (30 miles) overflowed

pouring a flood into the upper Everglades (Parker, 1974). It is

important to note, however, that losses to evapotranspiration are

estimated to have been as high as 82 percent. Thus, flood water

from Lake Okeechobee most probably did not travel the entire

length of the Everglades, but rather local precipitation caused

the inundation (Parker, 1974). This mass of water flowed

sluggishly to the Gulf and has come to be described as sheet flow

(Parker, 1974). The chronic inundation allowed the accumulation

and preservation of the organic soils which characterize the

highly productive Everglades Agricultural Area.

In about 1880, Hamilton Disston entered into a contract by

which he would drain land on the upper Kissimmee River and

receive as compensation half of the land he drained. His success

was debatable (Tebeau, 1974). The history of early drainage

efforts is a history of inadequate technical expertise and inse-

cure funding. The scope of the drainage issue was continually

underestimated. Disasterous floods associated with hurricanes in

1926 and 1928 moved the Federal Government to take action. The

extensive floods of 1947 and 1948 made it obvious that water

control had not yet been established and set the stage for the

intervention of the Army Corps of Engineeers (Tebeau, 1974).

In 1947, most of south Florida was flooded for several

months. The U.S. Congress, in response to the continuing water-

control problems, passed the Flood Control Act of June 30, 1948.

This action directed the Army Corps of Engineers to plan, design

and construct a massive project which would ultimately solve

water problems in all or parts of 18 counties in central and

south Florida (Snyder, et al., 1978). In the plan proposed by

the Army Corps of Engineers, major concern was devoted to the

protection of life and property along the lower east coast of

Florida. The first phase of the project involved building an

artificial levee from Lake Okeechobee to about Homestead in order

to confine flood waters to the Everglades. The project was also

designed to provide water control for soil, water conservation

and farming (Snyder, et al., 1978).

After studies by both the United States Department of

Agriculture and the University of Florida, the lands of the pre-

sent "Everglades Agricultural Area" were set aside for agri-

cultural development. The organic soils of the Agricultural Area

were the only soils of sufficient depth and of the proper type to

support cultivation for a period of time sufficient to justify

development (Snyder, et al., 1978). It is important to note that

when the Everglades Agricultural Area was being planned it was

recognized that subsidence of organic soil would occur and that

the area could not support cultivation indefinitely (Snyder,



The Florida Everglades comprises the single largest body of

organic soils in the world, 1,976,800 acres (Shih, 1980). The

Everglades Agricultural Area consists of 1,892,811 acres of fer-

tile organic soil. Winter vegetables from the Agricultural Area

include sweet-corn, celery, radishes, leaf crops, carrots and

beans. In addition, lands of the agricultural tract are used for

sugar cane, pasture and turf (Shih, 1980). Sugar cane is the

dominant crop with cash receipts of $215 million in 1977-1978

(Snyder, et al., 1978).

The proximity of the Florida Agricultural Area to the south

shore of Lake Okeechobee is not coincidence (figure 16). Before

the activities of man altered the tendency of Lake Okeechobee to

overflow along it southern edge silt, clay, and organic colloids

were mixed with dead plants to form muck. In this way, the mucks

became enriched in the microelements that peat lacks (Stephens,

1974), enchancing the mucks as an agricultural growth medium.

The soils of the Everglades Agricultural Area are classified

by soil scientists on the basis of the percentage of inorganic

matter they contain and their thickness. The Torry Series soils

occur within two to five miles of Lake Okeechobee. They contain

black organic layers more than 51 inches thick and are

characterized by a range of 35 percent to 70 percent mineral

matter (mostly the clay minerals sepiolite and montmorillonite)

(Snyder, 1978) and are not considered peats according to ASTM

standards. The Terra Ceia, Pahokee, Lauderhill and Dania soils

are dark organic soils which are differentiated from one another

based on their thickness above bedrock. The Terra Ceia soils are

the thickest with the Pahokee, Lauderhill and Dania becoming

successively thinner. As the process of subsidence occurs, Terra

Ceia soils will become Pahokee soils since Pahokee soils differ

from Terra Ceia soils only in their thickness (Snyder, 1978).




Figure 1 6.

Location map of the Everglades Agricultural Area. (Modified from
Snyder et al., 1978)


L` J


Subsidence refers to the loss of thickness which is incurred

by organic soils when they are drained. A group of physical pro-

cesses are responsible for subsidence, including 1) shrinkage due

to dessication, 2) consolidation by loss of the buoyant force of

groundwater and loading, or both, 3) compaction by tillage, 4)

wind erosion, 5) burning and 6) biochemical oxidation (Stephens,

1974). The processes of drying, consolidation and compaction do

not result in actual loss of soil (Shih, 1980). Stephens and

Johnson (1951) documented an increase of oven dried weight for

Everglades peat from about 9 pounds to about 16 pounds per cubic

foot after cultivation. This increase in density corresponds to

a decrease in soil volume. In this manner, the volume of the

soil decreases although there is little actual loss of soil.

The processes of wind erosion, burning and oxidation do,

however, result in the actual loss of organic soils (Shih, 1980).

Wind erosion is thought to have minor effects in the Everglades

Agricultural Area. Numerous charcoal rich lenses which represent

ancient fires have been found at depth in cores through the

organic soils of the Everglades and coastal swamps (Cohen, 1974).

Attempts to correlate charcoal layers from core to core were

futile suggesting that fires were not widespread geographically.

The fires were confined mainly to sawgrass-dominated peats.

Modern observation indicated that fires are very common in

sawgrass communities and it is suggested that sawgrass may be

especially well-adapted to survival of fires (Cohen, 1974).

The most serious cause of long term subsidence in the

Everglades is biochemical oxidation. Biochemical oxidation has

been responsible for 55 to 75 percent of the total soil loss in

the upper Everglades Agricultural Area (Stephens, 1974).

Although original plans for drainage in the Everglades recognized

that subsidence would occur, the causes were apparently

misunderstood (Stephens and Johnson, 1951). Shrinkage of

original peat due to drainage was taken into account, but the

slow continual loss of peat due to biochemical oxidation was not


The organic soils of the Everglades are a collection of

organic particles and mineral particles which are interspersed

with void spaces or pores. When these pores are filled with

water the micro-organisms which actively decompose the organic

soil are unable to function or function at a greatly reduced rate

(Snyder, et al., 1978). This is the condition that allowed

organic soils to accumulate before modification of natural

drainage patterns. Biochemical oxidation of organic soils is

facilitated by warm temperatures, low water tables, high pH and

high organic content (Stephens, 1974).

Drained organic soils of the Florida Everglades Agricultural

Area subside at an average rate of approximately 1 inch/year

(Stephens, 1974). This rate varies with variation of depth to

the water table. Rates of subsidence for experimental plots with

water table depths of 12 inches, 24 inches and 36 inches were

measured to be 0.6 inches per year, 1.4 inches per year and 2.3

inches per year, respectively.

Subsidence has been documented in the Everglades using

repeated surveys of ground elevation along certain lines. In

figures 17, 18 and 19 (Stephens and Johnson, 1951), the solid

lines represent the original elevation of the surface of the

ground and the elevation as measured in 1940. The dashed lines

indicate the topographic elevations predicted from subsidence

rates. Stephens (1974) notes that subsidence was measured to be

33.5 inches between 1941 and 1966 in the upper Everglades which

may be compared to a predicted subsidence loss of 33.0 inches in

25 years (Stephens and Johnson, 1951).

Rates of subsidence in the Everglades Agricultural Area vary

with the depth to which the water table is maintained. The depth

at which the water table is maintained depends on optimum con-

ditions for each land use. Snyder and others (1978) note that

most vegetable crops produce high yield when the water table is

maintained at 24 inches below the surface. Sugar cane normally

requires a water table depth which is greater than 24 inches; and

in certain organic soils, a water table depth of 30 to 36 inches

greatly improves sugar cane quality. Water tables for cattle and

sod production may be maintained at levels which would be con-

sidered too high for most crops. It is important to note that

extremely high water tables may cause problems specifically

related to crop land use even though high water tables allow

maximum soil preservation (Snyder, et al., 1983).

Figure 17.

Map of the Everglades Agricultural Area showing the locations of
profiles A-A' and B-B'. (Modified from Stephens and Johnson,

A A'

0 5 10 15 20 25 30 35

Figure 18.

Profile A-A'across the upper Everglades showing the original
surface elevations and the ground elevation in 1940 as shown by
topographical survey. profiles for the years 1970 and 2000 are
estimated. (Modified from Stephens and Johnson, 1951).


5 10 15 20 25 30

Figure 19.

Profile B-B' through the lower part of the Everglades Agricultural
Area show the original surface elevation and the surface elevation
as determined in 1940 by topographic surveys. Profiles for the
years 197 and n 2000 are estimated. (Modified from Stephens and
Johnson, 1951) 1 ,


Researchers who have worked in the Everglades Agricultural

Area suggest that maintenance of high water tables is the most

effective measure available for conservation of organic soils.

Tate (1980) notes that the only feasible means of controlling

subsidence is knowledgeable manipulation of the water table.

Snyder and others (1978) recommend: "For best conservation

organic soils should be kept flooded whenever not in use. When

soils are used, the water table should be maintained as high as

is possible for that use." Stephens (1974) lists a number of

suggestions geared toward conservation of organic soil: "(1)

provide adequate water control facilities for keeping water

tables as high as crop and field requirements will tolerate; (2)

make productive use of drained lands as soon as possible; and (3)

intensify research studies to develop practices to prolong the

life of the soils."

It has been suggested that extending the life of organic

soils by plowing under cover crops or litter (Snyder, et al.,

1978; Stephens, 1974) is probably not an effective conservation

measure. The rate at which peat forms is extremely slow and the

volume of plant litter produced is very small. Snyder and others

(1978) discuss an example which clarifies this relationship.

Sugar cane produces an amount of top growth exceeded by few, if

any, plants. An average cane crop (30 tons/acre) is estimated to

contain approximately 8 tons of dry matter. If all of the dry

matter from an entire crop were added to the soil, it could be

assumed that about half of it would be decomposed rapidly. One

acre-inch of top soil is about the amount lost to subsidence

each year in the Everglades Agricultural Area. That amount of

soil weighs approximately 50 tons. Thus, 4 tons are replaced each

year, which is still only approximately 1/12 the amount which is



Snyder and others (1978) have included a discussion of land

use in the Everglades Agricultural Area through the year 2000.

It is noted that the predictions of Stephens (1951) have proved

reliable (compare figures 20 and 21). These predictions are pre-

sented in Table 2 (Snyder, et al., 1978). Although land eleva-

,tions are shown through the year 2000, subsidence will continue.

By the year 2000, only approximately 80,000 acres of soil three

feet in depth or deeper will remain. It is predicted that sugar

cane acreage will decrease, pasture acreage will increase signi-

ficantly and vegetable acreage will remain essentially unchanged

assuming the economic viability of such operations. By the year

2000, over 500,000 acres will be less than 3 feet in thickness.

Approximately half of this will be less than a foot in depth

(Snyder, et al., 1978). The depth of 3 feet is significant

because, at depths of less than 3 feet, the use of mole drains

becomes impractical. The soils which have subsided to depth of




0 2 4 6 8 10 MILES

Figure 20. Soil depths predicted for the year 1980. (Modified from Stephens
and Johnson, 1951) Compare with Figure 17. (Taken from Griffin,
et al., 1982)



1 ,- .. .' MARTIN CO. 0


S- ... *
f. *:.:-:.': :. '. :*:** 10




Figure 21, Thicknesses of soils from the Everglades Agricultural Area as
determined in r recent study. (Modified from Griffin et al.,


Proportions of the Organic soils of the Everglades Agricultural
Area falling into categories based on thickness (after Snyder,
19 7).

YEAR 0 to 1 ft. 1 to 3 ft. 3 to 5 ft. over 5 ft.

1912 0 1 3 95
1925 1 3 7, 89
1940 1 7' 14 85
1950 2 7 28 76
1960 4 12 28 55
1970 11 16 41 45
1980 17' 28 41 14
1990 27' 28 39 7
2000 45 42 9 4

less than one foot face an uncertain fate. Snyder and others

(1978) suggest that while some of those soils may be suitable for

pasture, the soils may be abandoned for agricultural uses. It is

also suggested that the remaining soils and the existing water-

control structures be used to produce aquatic crops. The authors

suggest that such a usage could greatly extend the useful agri-

cultural life of the soils.


Industrial use of peat can be divided into two major

categories: extractive and non-extractive (Minnesota DNR, 1981).

The extractive uses include direct combustion, gasification,

industrial chemicals, horticultural products and sewage

treatment. The non-extractive uses include agriculture, energy

crops and again sewage treatment (Minnesota DNR, 1981).


For most applications, peat must be dewatered before pro-

cessing. Biogasification and some energy crops and sewage treat-

ment processes do not require dewatering.

Solar drying in the field is energy efficient but is not

suitable to wet mining processes or to all mining plans.-

Alternative dewatering processes include mechanical presses and

thermal dryers, in addition to pretreatment processes such as wet

carbonization, wet oxidation and solvent extraction.

Mechanical methods are limited in the amount of water they

can remove. Most of the water contained in peat is held in

chemical bonds, colloidal suspensions and small pores in the

organic matter. Mechanical methods may reduce water content to

70 percent at best (Minnesota DNR, 1981). Thermal dryers can be

utilized to reduce the moisture content further. The efficiency

of mechanical dewatering is greatly enhanced by pretreatment

processes such as wet carbonization, wet oxidation and solvent

extraction. Peat can be mechanically dewatered to approximately

30 percent water content after wet oxidation (Mensinger, et al.,

1980 in Minnesota DNR, 1981, p. 30).

Wet carbonization consists of heating a slurry of peat and

water (approximately 3 percent solids) to 300-400F.at 50-100

atmospheres of pressure for 30 minutes. A "peat coal" with a

heat value of 12,000-14,000 BTU/lb dry weight is obtained after

the liquid is removed (Kopstein, 1979).

Wet oxidation is an established process for the oxidation of

many wet organic materials. Air or oxygen is pressure fed to wet

peat in a closed, heated vessel. Combustion is rapid and is

controlled by the rate of supply of the oxygen or air. The pro-

cess can be stopped after enough heat has been generated to car-

bonize the remaining peat or can be carried to completion to

produce energy (Kopstein, 1979).

Solvent extraction reacts a heated peat-water slurry under

pressure with an organic solvent. The water is extracted from

the peat by the solvent. Subsequent to cooling, the absorbed

water is stripped from the solvent and after treatment is

disposed of as waste.


Direct Combustion

Direct combustion of peat is a method of producing energy

which has been utilized on a commercial scale in Ireland, Finland

and the Soviet Union for several decades. The Soviet Union had

installed an electric power station fueled entirely by peat as

early as 1914 (Kopstein, 1979).

The U. S. Department of Energy has developed several cri-

teria for fuel-grade peat. The criteria are: 1) heat value

greater than 8000 BTU/lb (dry weight), 2) greater than 80 acres

of peat per square mile, 3) peat depth greater than 4 feet, and

4) ash content less than 25 percent (Minnesota DNR, 1981). Hemic

and sapric peats are the most suitable for direct combustion

useage. The more decomposed peats (sapric) have been carbonized

to a greater extent but often have larger ash contents which

reduces their fuel value. Hemic peats generally are the most

suitable for fuel use (Minnesota DNR, 1981).

Direct combustion of peat is accomplished in boilers

designed or retrofitted for either peat fuel entirely or mixed

fuel feed. Boiler design must accommodate the characteristics of

peat fuel: low energy density, high moisture content. Both of

these characteristics result in increased cost (approximately 50

percent greater) of the boiler and feed system compared with a

coal or oil fired boiler of the same capacity (Kopstein, 1979).

Grate fired and fluidized-bed boilers require pelletized or bri-

quetted feed. Pulverized-fired boilers require peat ground to

the particle size compatible with the combuster design.

Direct combustion techniques can result in partial oxidation

of the peat and generation of synthetic fuel gases. Reduced oxy-

gen input and/or water vapor injection are required to generate

the fuel gases.


Peat is very reactive during gasification. Gasification can

yield low to medium BTU fuel gases, synthesis gases (those which

can be further upgraded by hydrocracking) fuel liquids, ammonia,

sulfur and oil byproducts (napthalene, benzene and phenol)

(Kopstein, 1979; Minnesota DNR, 1981).

Several basic designs of gasifiers are feasible for peat

gasification, however, data for peat gasification is primarily

limited to laboratory scale operations (Kopstein, 1979).

Entrained flow and fluid bed gasifiers appear attractive. An

example is the PEAT GAS process developed by the Institute of Gas

Technology. Dry peat is fed to the gasifier, and heated under

pressure with a hydrogen rich gas. The carbon in the peat reacts

with the hydrogen to form hydrocarbon gases (primarily methane

and ethene). The gases produced can be upgraded to pipeline

quality (Minnesota DNR, 1981). Byproduct oils (benzene,

napthalene and phenols), ammonia and sulfur are extracted in turn

from the liquids which are condensed during various gas upgrading

processes.(Minnesota DNR, 1981).

The ratio of gaseous to liquid products is controlled by

changes in temperature, pressure and length of reaction time.

Increased temperature and reaction time lead to gaseous product

increases. With higher temperature and longer reaction times,

the large hydrocarbon molecules comprising the liquid products

are hydrocracked into lighter gaseous molecules (Kopstein, 1979).


Biogasification is an anerobic fermentation process. An

important advantage of biogasification is that dewatering is not

required. -Biogasification is a two-stage process. In the first

step, the peat-water slurry is partially oxidized to break it down

to simple compounds. Aldehydes, ketones, organic acids and

esters are the main products at this stage. The pH is adjusted

and the mixture is transferred to the fermenter (anerobic biolo-

gical reactor) where bacteria catalyze methane production.

Methane and carbon dioxide are produced in stoichometric propor-

tions (Kopstein, 1979) with up 95 percent of the material being

converted to methane or carbon dioxide (Minnesota DNR, 1981).

The resulting gas can be upgraded to substitute natural gas (SNG)

by scrubbing the carbon dioxide and hydrogen sulfide from the

methane gas (Kopstein, 1979).

The waste material from the fermentation process contains

undigested peat components, inorganic residues and residual bac-

teria. These materials can be utilized for soil conditioners,

animal feeds, or can be concentrated for disposal. Excess water

is recycled to the fermenter (Kopstein, 1979).


Peat has been utilized as a raw material for the production

of industrial chemicals for many years in Europe and the Soviet

Union. U. S. interest has developed only recently. Peat bitu-

mens, carbohydrates and humic acids are extracted by processes at

low to moderate temperatures. Peat coke, peat tar and activated

charcoal are produced by pyrolysis. The use of peat for

industrial chemicals does not pose major technical problems. The

technology has been developed in Europe and the Soviet Union.

The chemicals produced are similar to petroleum derived products.

As petroleum becomes more expensive, the incentives to utilize

peat will increase (Minnesota DNR, 1981).


Peat bitumens are those peat components which are soluble

in nonpolar organic solvents. The yield of bitumens depends on

the extracting solvent chosen. Yield increases from low to high

in the following list of solvents: petroleum ether, gasoline,

dichloroethane, benzene, ethanol:benzene (1:1) (Fuchsman,1978).

Although various solvents are utilized for analytical purposes,

gasoline is the solvent used in commercial processes. Benzene is

not used because of health hazards (Bel'Kevich, 1977'). The peat

bitumens of commercial interest are peat waxes and resins. The

waxes are the most important commercially (Fuchsman, 1978).

Peat, suitable for commercial wax production, contains at

least 5 percent gasoline extractable material and has an ash con-

tent less than 10 percent (Lishtvan and Korol', 1975). The wax

content of peat is higher in more highly decomposed peats

(Naucke, 1966) particularly those with remains of shrubs and

trees (Fuchsman, 1978).

Dried peat particles in the size range of 0.02 inches 0.2

inches are required for efficient solvent extraction. Wax

extraction-utilizes gasoline as the solvent and extracts most of

the wax but relatively few of the resins (Bel'Kevich, 1977).

Gasoline and peat are mixed at 20:1. Approximately 5 percent of

the gasoline is lost in the process, with the rest being recycled

after wax removal by solvent evaporation.

The crude wax contains some resins. Resins are partially

removed by treatment with an appropriate solvent (cold acetone,

alcohol and ethyl acetate) (Fuchsman, 1976). Further purifica-

tion is accomplished by treatment with potassium dichromate and

sulfuric acid at 1670F-230F. The result is a fairly hard, light

tan wax (Bel'Kevich, 1977').

Peat waxes are produced commercially only in the Soviet

Union where they are used as release agents in foundary castings

and on polyethylene surfaces. Peat waxes are similar to montan

wax which is derived from lignite. Montan wax is a substitute

for beeswax and carnuba wax and is used as an industrial lubri-

cant and as an ingredient in shoe and furniture polish, electri-

cal insulating materials and in candles (Minnesota DNR, 1981).

Peat resins are the primary byproducts of peat wax produc-

tion. The resins are of importance as a source of steroids for

use by the pharmaceutical industry (Minnesota DNR, 1981).


Peat carbohydrates consist primarily of cellulose and

related materials such as hemicellulose and starches (Fuchsman,

1978). Sugars are produced by acid hydrolysis for use in yeast

culture. Yeast culture can be optimized for the production of

single cell protein or for the fermentation of alcohol (Fuchsman,


Peat suitable for carbohydrate hydrolysis, according to

Soviet criteria are: Spagnum peat with degree of decomposition

less than 20 percent, ash content less than 5 percent and at

least 24 percent of the dry weight of the peat recoverable as

fermentable sugars from the easily hydrolyzable carbohydrates (or

45 percent if difficultly hydrolyzable carbohydrates are

included) (Fuchsman, 1978). Cellulose is classified as being

difficult to hydrolyze. The preferred Soviet process (Ishino,

1976) is as follows: peat with a maximum grain size of 0.4

inches is.slurried with water to 7-20 percent solids and mixed.

The suspension is then pumped at 5-7 atmospheres of pressure and

concentrated sulfuric acid is added to give an overall acid con-

centration of 0.25-1 percent. The slurry is heated to

2840F-338*F by steam injection and discharged to atmospheric

pressure and reacted for 10-30 minutes. Volatile matter is

flashed off, the fluid is diluted and reacts for an additional 10

minutes at 2840F to allow hydrolysis completion. Solids are then

removed by sedimentation centrifuge or filtration. Yield by this

process is 34-40 percent of the peat dry weight.

Humic Acids

Fuchsman (1978) describes humic acid as "alkali-soluble,

acid-insoluble organic compounds, excluding bitumens and

carbohydrates." There are several lines of chemical modification

of humic acid: pyrolysis, oxidation and reduction (Fuchsman,


To date, there are no large scale commercial uses for humic

acid. Present industrial uses for humic acids include sizing

for paper, tanning agents, in fertilizers and as viscosity modi-

fiers for oil well drilling mud (Fuchsman, 1978). Potential uses

include the production of plastics and synthetic fibers, com-

ponents for paints and adhesive formulations and flocculants or

thickeners in water purification systems. These uses are based

primarily on the adsorption and ion exchange properties of humic

acids (Fuchsman, 1978).

Peat Coke, Peat Tar and Activated Carbon

Peat coke, tar and activated carbon are produced by the pro-

cess of pyrolysis. Pyrolysis consists of decomposition of orga-

nic substances by heat in the absence of air. When carried to a

high enough temperature and for long enough time, the process

yields a carbon residue (peat coke), a water immiscible conden-

sate (peat tar) and non-condensable gases which can be utilized

as fuel gases.

Peat suitable for coking requires a relatively high carbon

content (high level of decomposition), low ash content and low

phosphorous content (Fuschman, 1978). High carbon content is

necessary for acceptable yields. Phosphorous and ash degrade the

product quality.

Several factors influence the yield of pyrolysis products.

Coke yields are increased with more highly decomposed peats and

slower rates of heating. Peat tar and gases generated by the

pyrolysis process are often recycled as fuel for the coking pro-


Activated carbon is produced from peat coke by treating coke

with steam at 16320F-2012*F. The reaction forms hydrogen gas and

carbon monoxide which has the physical effect of expanding the

pores in the peat coke, greatly increasing the surface area

available for adsorption (Norit, N.V.).

Peat-coke is utilized to form high purity silicon for the

electronics industry and as a reducing agent in electric smelting

furnaces especially in the production of ferrochrome and ferrosi-

licon alloys (Eckman, 1975). Peat tars are refined for pesticide

and wood preservative use. The primary use, however, is as fuel

recycled to the peat coke production process. (Minnesota DNR).

Activated carbon is utilized for a variety of purposes, all

of which take advantage of the large surface area available for

adsorption. Uses include removal of pollutants from industrial

waste gases, as a gas absorber, deodorizer, and for purification

of water and sugar (Fuchsman, 1978).



Essentially all of the peat mined in Florida, at the present

time, is used for horticultural purposes. Peat is used by home

owners'for soil enhancement, by nurseries and landscapers for

potting soils and growing media for plants, and also as a

medium for mushroom and earthworm culture.


Agricultural uses of peat are similar to horticultural uses.

The peat is utilized as a growing medium (soil) for agricultural

crops. The material is not mined, however, drainage is generally

necessary to provide the proper moisture conditions.

Hemic and sapric peats, as well as mucks, are utilized for

agricultural purposes. Fibric peats, typically are not suitable

due to the low pH (acidic) which makes nutrients unavailable to

many plants (Farnam and Levor, 1980). Large areas of Florida

peats and mucks are utilized for agricultural purposes.

Energy Crops

Growing energy crops for plant biomass production allows

peatlands to be utilized to produce renewable energy sources.

Plant biomass can be harvested and burned directly or can be

gasified to produce liquid and gaseous fuels. Energy crops can

be an alternative to conventional mining (using the peat as a

growing medium) or can be utilized as a reclamation technique on

mined out peatlands (Minnesota DNR, 1981).

Plants which may be suitable for energy crop use in wetlands

include; cattails, reeds and sedges, willow and alder (Minnesota

DNR). These wetland species have two distinct advantages over

conventional crops for use in biomass energy production: 1) the

biomasss productivity of wetland species is often higher than

conventional crops (corn, soybeans, etc.) and 2) they can be

grown in wetlands unsuitable for conventional crop plants and

thus do not compete with conventional crop production (Minnesota

DNR, 1981).


Peat has been utilized in the tertiary treatment of waste

water both in the U. S. and in Europe. The primary objective is

to reduce nutrient levels, primarily phosphorous and nitrogen

(Minnesota DNR, 1981).

Phosphorous is removed from solution by bacteria present in

that portion of the peat exposed to air. Bacterial metabolism

converts the phosphorous to insoluable forms. Chemical reactions

with calcium, aluminum and iron present in the peat also remove

phosphorous from solution (Nichols, 1980).

Nitrogen is metabolized by anerobic bacteria, converting

nitrate in the waste water to gaseous nitrogen which is released

to the atmo-sphere (Nichols, 1980). Additional nutrients are

removed through uptake by plants growing on the peat surface.

Three methods are commonly used for the tertiary treatments

of waste water. Two utilize the peat in place, the third utili-

zes excavated peat (Minnesota DNR 1981). The waste water can be

introduced directly to the bog surface and allowed to filter

through the peat or may be introduced to a ditched and drained

peat deposit. This would increase the volume of peat exposed to

the waste water, increasing residence time and allowing more

efficient nutrient uptake (Nichols, 1980). The third method

involves a built up filter bed of peat, sand and gravel. The

effluent is applied to the filter surface by sprinklers.

Generally, the surface of the filter would be seeded with a

suitable sedge or grass to remove additional nutrients (Minnesota

DNR, 1981).

Peat water treatment systems and experimentation has not

been conducted for enough time to determine the period of time

over which it can effectively remove nutrients before it becomes

saturated. Environmental effects, therefore, must be strictly

monitored (Minnesota DNR, 1981).


Peat is currently mined in twelve Florida counties (figure

22). In each of these counties, the mining companies provide

jobs, pay state and local taxes, require the services of various

support industries and provide a valuable product to nurseries

and individuals.


The U. S. Bureau of Mines reports an average 1982 price for

Florida peat of $13.12 per short ton. 1983 prices quoted by

mining companies range from $8.50 to $18.00 per cubic yard of


9 o ,--
*' -S

Figure 22. Location of Current Peat Producers. (Bureau of Geology survey for
this study)

peat with the most common price being $10.00 to $10.50 per cubic

yard. Blended topsoils range from $11.00 to $20.00 per cubic

yard. If one ton of peat is assumed to occupy 2.3 cubic yards,

the $10.50 per cubic yard price is equivalent to $24.15 per short

ton. Bagged peat prices are higher and are in the range of

$45.00 per ton.

Florida ranked second in peat production nationally in 1982

(Boyle and Hendry, in press, 1984). The U. S. Bureau of Mines

(B.O.M.) reported peat production in 1982 as 120,000 short tons,

with a value of $1,575,000 dollars (figure 23). The average

price in 1982 was $13.12 per short ton. The above figures repre-

sent a 25 percent drop in production and a 47' percent drop in

value from 1981.

The B.O.M. production and value figures do not represent the

complete picture. The B.O.M. reported peat production from four

counties in 1982. Of the ten companies on the B.O.M. peat

producer list, only six are still active. The authors have com-

piled a list of 21 peat producers, located in 12 counties. The

actual peat production in the state must be significantly higher

than reported by the B.O.M.


Peat production is concentrated in central peninsular

Florida, in Sumter, Lake, Orange, Pasco, Hillsborough, Polk and

Highlands counties. Additional producers are located in Madison