Geochemistry of sulfur in the Florida Everglades: 1994 ...The Everglades ecosystem encompasses a...
59
U.S. DEPARTMENT OF THE INTERIOR U. S. GEOLOGICAL SURVEY Geochemistry of sulfur in the Florida Everglades: 1994 through 1999 By Anne L. Bates, William H. Orem, Judson W. Harvey, and Elliott C. Spiker U.S. Geological Survey, National Center, Reston, VA 20192 Open File Report 01-7 2000 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Transcript of Geochemistry of sulfur in the Florida Everglades: 1994 ...The Everglades ecosystem encompasses a...
U.S. DEPARTMENT OF THE INTERIOR
U. S. GEOLOGICAL SURVEY
Geochemistry of sulfur in the Florida Everglades: 1994 through 1999
By
Anne L. Bates, William H. Orem, Judson W. Harvey, and Elliott C. Spiker
U.S. Geological Survey, National Center, Reston, VA 20192
Open File Report 01-7
2000
This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Table of Contents
Page
Abstract.................................................... iv
Introduction ................................................... 1
Study Area ................................................... 4
Analytical Methods ............................................. 8
Results and Discussion .......................................... 11
Summary..................................................... 49
Acknowledgments.............................................. 51
References ................................................... 52
Tables
Table 1. Sulfur species concentrations and 534S values in sediment from WCA 1A(Loxahatchee National Wildlife Refuge), sites 1 and 7, April 1995 ..... 14
Table 2. Sulfur species concentrations and ffi^S values in sediment from WCA 2A, sites E1, F1, U3, and U3 (new) ................................ 16
Table 3. Total sulfur contents (percent dry weight) and S-^S values in the Everglades Agricultural Area at the Agricultural Research Center ...... 22
Table 4. Total sulfur contents (percent dry weight) for sediment cores from the center and the periphery of Lake Okeechobee ......................... 24
Table 5. Sulfur species contents (percent dry weight) and 534S values in sedimentcollected at the head and mid-section of Taylor Slough, May 1996 ...... 26
Table 6. Sulfate concentrations and 534S values in surface water, samples grouped by area .................................................. 30
Table 7. Sulfate concentrations and 834S values in rainwater, 1998 ......... 41
Table 8. Concentrations and 534S values of sulfate in groundwater collected in WCA 2A and the ENR, 1997 and 1998 ............................... 44
Figures
1. Study Areas in the Northern Everglades of South Florida ................ 6
2. Study Areas in the Southern Everglades of South Florida ............... 7
3. Sulfur Species in Loxahatchee Sediment: Percent Wet Weight and 834SValues.................................................. 15
4. Total Sulfur in EGA 2A Sediment at Sites E1 and U3, March 1994: Percent Dry Weight.................................................. 17
5. Sulfur Species in WCA 2A Sediment at Sites E1 and U3, March 1994: Percent Dry Weight and 534S Values .................................. 18
6. Total Sulfur in WCA 2A Sediment at Sites F1 and U3 (new): Percent DryWeight .................................................. 19
7. Sulfur Species in WCA 2A Sediment at Sites F1 and U3, April 1996: PercentDry Weight and 534S Values ................................... 20
8. Sulfur Species in WCA 2A Sediment at Sites F1 and U3 (new), March 1995:Percent Wet Weight and 534S Values ........................... 21
9. Agricultural Research Centers in the EAA, February 1994: 834S Values in TotalSulfur.................................................. 23
10. Total Sulfur Content in Lake Okeechobee Sediment: Percent Dry Weight. . 25
11. Total Sulfur Content in Sediment from Taylor Slough, May 1996: Percent DryWeight.................................................. 27
12. Sulfur Species in Taylor Slough Sediment at Sites 3 and 7, May 1996: Percent Dry Weight and 534S Values ................................. 28
13. Sulfate in Water in the Northern Everglades, 1995-1999 ................ 39
14. Comparison of Sulfate Concentration and 534S Values in Surface and GroundWater in WCA 2A and the ENR .............................. 48
Abstract
In this report, we present data on the geochemistry of sulfur in sediments and
in surface water, groundwater, and rainwater in the Everglades region in south
Florida. The results presented here are part of a larger study intended to determine
the roles played by the cycling of carbon, nitrogen, phosphorus, and sulfur in the
ecology of the south Florida wetlands. The geochemistry of sulfur in the region is
particularly important because of its link to the production of toxic methylmercury
through processes mediated by sulfate reducing bacteria.
ediment cores were collected from the Everglades Agricultural Area (EAA),
Water Conservation Areas (WCAs) 1A and 2A, from Lake Okeechobee, and from
Taylor Slough in the southern Everglades. Water collection was more widespread
and includes surface water from WCAs 1A, 2A, 3A, 2B, the EAA, Taylor Slough, Lake
Okeechobee, and the Kissimmee River. Groundwater was collected from The
Everglades Nutrient Removal Area (ENR) and from WCA 2A. Rainwater was collect
ed at two month intervals over a period of one year from the ENR and from WCA 2A.
Water was analyzed for sulfate concentration and sulfate sulfur stable isotopic ratio
(34S/32S). Sediment cores were analyzed for total sulfur concentration and/or for
concentrations of sulfur species (sulfate, organic sulfur, disulfides, and acid volatile
sulfides (AVS)) and for their stable sulfur isotopic ratio.
Results show a decrease in total sulfur content (1.57 to 0.61 percent dry
weight) with depth in two sediment cores collected in WCA 2A, indicating that there
has been an increase in total sulfur content in recent times. A sediment core from
the center of Lake Okeechobee shows a decrease in total sulfur content with depth
(0.28 to 0.08 percent dry weight). A core from the periphery of the lake (South Bay)
likewise shows a decrease in total sulfur content with depth (1.00 to 0.69 percent dry
weight), however, the overall sulfur content is greater than that near the center at all
iv
depths. This suggests input of sulfur in recent times, especially near the lake mar
gins. Sediments show a general decrease in sulfur concentration with depth, proba
bly because of increases in sulfur input to the marshes in recent times. Regional dif
ferences in the concentrations and stable isotopic ratios of sulfate sulfur in surface
water show that sulfur contamination to the northern Everglades likely originates from
canals draining the EAA.
Introduction
The Everglades region of south Florida is the subject of investigations to deter
mine the effects of agricultural and water management practices, and of urban devel
opment on the geochemistry of the ecosystem. The geochemistry of sulfur is of par
ticular interest because of the link between the reduction of sulfate to sulfide and the
production of toxic methylmercury (Hurley et al., 1998; Lambou et al., 1991), which is
known to be a problem in some areas of the Everglades. Our purposes have been
to determine if sulfur content has increased in recent times, to find the sources of sul
fur contamination to the northern Everglades, and to determine its relationship with
methylmercury content in sediments. To this end, sediment cores were collected and
analyzed for sulfur speciation and sulfur stable isotopic ratios (34S/32S, expressed as
834S in per mil units). We also collected water (surface, ground, and rainwaters) to
determine sulfate content and 834S values.
The Everglades ecosystem encompasses a large area, including the
Kissimmee River basin, Lake Okeechobee, the freshwater northern Everglades, the
Everglades National Park, and Florida Bay (Figs. 1 and 2). Most of our sampling for
sulfate in water was conducted in the northern Everglades, with emphasis on the
Water Conservation Areas (WCA 1 A, 2A, 2B and 3A), the Nutrient Removal Area
(ENR), the Everglades Agricultural Area (EAA), Lake Okeechobee, and the
Kissimmee River. Solid sediment was collected in the EAA, WCA 1A and 2A, and
Lake Okeechobee. To a lesser extent, sediment and water was also collected from
the southern Everglades in Taylor Slough (part of the Everglades National Park) and
from Florida Bay (Fig. 2).
There is widespread sulfur contamination in the northern Everglades. Marsh
areas near to canal discharge have surface water sulfate concentrations that average
about 0.50 meq/L and often exceed 1.0 meq/L, in contrast to background sites which
typically have surface water sulfate concentrations of about 0.05 meq/L or less. The
sources of water that are potentially major contributors of this sulfur contamination
include groundwater, rainwater, and water channeled from Lake Okeechobee through
canals traversing the Everglades Agricultural Area and released into the Water
Conservation Areas at pumping stations and spillways (Fig. 1). Sulfur enters the wet
lands as sulfate (SO4=) contained in groundwater, rainwater, and canal water. The
canal water consists of both irrigation drainage from the EAA and water from Lake
Okeechobee. Since 1995, we have collected surface water from the following areas:
the Hillsboro, North New River, and Miami Canals in the EAA, a buffer wetland con
structed on former agricultural land (the Everglades Nutrient Removal Area or ENR),
from WCA 1 A, 2A, 2B, 3A, and from the canals bordering or within these areas (Fig.
1). Nutrient-impacted WCA 2A was intensely investigated because it receives direct
discharge from the Hillsboro Canal that drains the EAA. More recently (since May
1997), we collected rainwater in the ENR, groundwater in WCA 2A and in the ENR,
and surface water from Lake Okeechobee and the Kissimmee River near where it
empties into the lake (Fig. 1).
The interpretation of stable isotope values (634S) of sulfate is complicated by
isotopic fractionation during bacterial reduction of sulfate to sulfide under anoxic con
ditions, primarily in sediments. The sulfide products are enriched in the isotopically
lighter 32S, relative to sulfate (Goldhaber and Kaplan, 1974), and the 534S values of
residual sulfate increase (Nakai and Jensen, 1964). Negative sulfide 534S values
are usually obtained where there is an essentially unlimited amount of sulfate avail
able (as in seawater); the 534S values in freshwater are usually positive. The 534S
values of the residual sulfate can become very high when the sulfate reservoir is lim
ited. The amount of sulfide produced and the rate of its production through bacterial
reduction are controlled by the availability of sulfate and biodegradable organic mat
ter (Berner, 1980; Berner and Raiswell, 1984; Boudreau and Westrich, 1984;
Canfield, 1991). Another complicating factor is that oxidation of isotopically light sul-
fide to sulfate will add isotopically light sulfate to a reservoir, thus decreasing the 834S
value of the sulfate in that reservoir (without changing the 834S values of the residual
sulfide). The formation of disulfide minerals (mostly pyrite) from sulfidic sulfur is lim
ited by reactive iron availability, assuming excess precursor sulfide availability.
Sulfidic sulfur can also react with organic matter, forming organic sulfur compounds,
or it can diffuse out of the sediments into the water column where it can become oxi
dized to sulfate. If this is the case, the sulfate reservoir in the water column will
increase and its 834S values will become lighter.
Study Area
Since implementation of the Central and Southern Florida Project for Flood
Control and Other Purposes, passed by the United States Congress in 1948, the his
toric Everglades has been divided by canals and levees into three major areas: the
Everglades Agricultural Area, the Water Conservation Areas, and Everglades
National Park (Fig. 1). Water in the northern Everglades (the EAA and WCAs) is
fresh and derived from rainfall and outflow from Lake Okeechobee. Water from Lake
Okeechobee irrigates the EAA and then flows into the WCAs via a network of canals
and pumping stations where it is impounded in wetlands and eventually released for
flood control and water supply needs. Recent studies (Craft and Richardson, 1993;
Koch and Reddy, 1992; DeBusk et al., 1994) indicate that agricultural runoff has
increased the input of nutrients in parts of the WCAs adjacent to canals draining the
EAA. Increased nutrient loading has resulted in changes in the type and amount of
vegetation growing in the impacted areas.
The surficial and ground waters of the freshwater Everglades are components
of a continuous, non-confined aquifer system, the uppermost unit of which is the
Biscayne Aquifer (Sonntag, 1987). Limestone bedrock underlies the Everglades peat
(Gleason and Stone, 1994). Recharge to the aquifer is mostly from rainwater, with
lesser amounts supplied by drainage from Lake Okeechobee and other areas to the
west and north (Fish, 1988; Waller and Earle, 1975). Groundwater flow patterns in
the WCAs vary seasonally and are not well known, although the WCAs and the
canals are known to be hydrostatic high points on a regional scale (Fish, 1988). The
surface waters are circum-neutral with pH values generally near 7 (unpublished data,
Orem).
Taylor Slough in the southern Everglades (Fig. 2) has freshwaters in its north
ern region. The head of the Slough is adjacent to agricultural fields and is nutrient
impacted (Orem et al., 1999). The dominant plants in the northern part of the
Slough are sawgrass, waterlily and periphyton algae. Marine water influence is felt in
the mangrove swamps in the near-coastal areas of the Slough. Freshwater flows
from the Slough into the marine waters of Florida Bay (Fig. 2).
Figu
re 1
. St
udy
Area
s in
the
North
ern
Ever
glad
es
of S
outh
Flo
rida
A
N
Eve
rgla
des
Nat
iona
lP
ark
Tayl
or
Wes
t Palm
Be
ach
Mia
mi
\Flo
rida
Bay/
V..
./'
Ever
glad
es A
gricu
ltura
l Are
as (E
AAs)
ilj
Ever
glad
es W
ater
Con
serv
atio
n Ar
eas
(WCA
s)
Nutri
ent R
emov
al A
rea
(ENR
)
Sam
plin
g Si
tes - *
Scal
e, k
m
9
3?
Ever
glad
es
Nutri
ent
Rem
oval
Ar
ea (E
NR)
- EN
fl In
put
Fig
ure
2. S
tudy
Are
as in
the
Sou
ther
n E
verg
lade
s of
Sou
th F
lorid
a
Sou
th F
lorid
a
Eve
rgla
des
Nat
iona
l P
ark
Wes
t Pal
m
Beac
h
Mia
mi
The
Sou
ther
n E
verg
lade
s
Sca
le,
km:
030
Mia
mi
Sam
plin
g S
ites *
Analytical Methods
Sediment Sampling. Sediment cores were collected by piston coring using 9
cm inner diameter Plexiglas core tubes (Orem et al., 1997). The cores were sec
tioned into segments ranging from 2-10 cm thick. The core segments were placed in
zip-lock plastic bags, returned to the lab, and were then frozen until analysis. There
was brief exposure to air when the samples were transferred between containers.
Sulfur Speciation. Aliquots of selected freshly thawed core segments were
assayed gravimetrically for disulfides (DS), acid-volatile-sulfides (AVS), sulfate and
organic-sulfur (OS) after separation of these sulfur fractions by an HCI-CrCI2-Eschka
sequential extraction scheme (described in detail by Bates et al., 1993), similar to
methods were used by Tuttle et al. (1986) and Canfield et al. (1986). A brief
description is given here: acid-volatile sulfides were extracted from the samples
using hot 6N HCI under a nitrogen atmosphere in a sealed reaction vessel and then
reprecipitated as silver sulfide in a separate test-tube filled with 5% silver nitrate.
Disulfides within the HCI-insoluble residue were then reduced by chromous chloride
in hot 6N HCI under nitrogen and reprecipitated as silver sulfide. The sediment
residue was then filtered. Sulfate in the filtrate (including sulfate derived from both
pore-water and solid-phases in the sample) was precipitated as barium sulfate.
Organic-sulfur in the residual sediment was oxidized to sulfate by fusion with
Eschka's mixture (magnesium oxide and calcium carbonate) and then precipitated as
barium sulfate. The percentage by weight of each sulfur fraction in the sediment was
determined gravimetrically from the silver sulfide or barium sulfate recovered.
Water Sampling. All water samples were collected in clean, dry 500 milliliter
Nalgene bottles. Surface water was collected from about midway between the water
surface and the sediment surface. Most water sample bottles were topped off and
did not contain any air space. Samples were kept on ice during transit to the labora
tory, where they were continuously refrigerated. Usually no more than two weeks
elapsed between collection and the beginning of analysis.
Analysis of Sulfate Concentration. Water was filtered through 0.4 microme
ter Nuclepore filter pads before analysis in order to remove particulates. The volume
of the filtrate was measured to the nearest milliliter. The samples were then trans
ferred to volumetric flasks, and the contents were acidified to pH 4 with concentrated
HCI. Samples were then heated on a hot plate, ant barium chloride (10%) was
added after they began to boil. After the sample volume had been reduced to about
100 ml, the samples were filtered through 0.4 micrometer Nuclepore filter pads col
lect the precipitated barium sulfate. Recovery was determined after drying the filter
pads in a desiccator. The sulfate concentrations of the samples were calculated from
the mass of sulfate recovered and the measured volume of the water sample.
Analysis of Total Sulfur in Sulfur Fertilizer. Sulfur in elemental sulfur fertil
izer was oxidized to sulfate by fusion with Eschka's mixture for two hours at 800° C.
The dry fusion mixture was then slowly cooled and then suspended in boiling dis-
tilled-deionized water for 30 minutes. The suspension was filtered to remove solid
residue, and the recovered solution was then treated as described above for water
samples.
Sulfur Isotopic Ratio Determination. The recovered barium sulfate was
converted to SO2 by combustion on a vacuum line and was then isolated by vacuum
line methods. The 34S/32S of SO2 was determined using a Finnigan MAT 251 stable
isotope mass spectrometer, and the results are reported in delta notation (S^S) as
parts per thousand deviation from Canyon Diablo Triolite (CDT) reference standard
(Thode et al., 1961). Smaller samples (less than 1 milligram of sulfur) were concen
trated using liquid nitrogen for mass spectrometric analysis.
10
Results and Discussion
Solid Phase Sulfur Geochemistry
Solid phase cores were collected in the EAA, WCA 2A, WCA 1A (Loxahatchee
National Wildlife Refuge), Taylor Slough, and Lake Okeechobee (see Figures 1 & 2).
WCA1A. WCA 1A is a "pristine" area protected from canal discharge. Two
sediment cores were obtained from this area in April 1995, one near the Hillsboro
Canal at site 1, and one away from the canal at site 7 (Fig. 1). Sulfur species con
tents for these sampling sites were obtained only on a percent by wet weight basis
(Table 1, Fig. 3). These data shows that sulfur contents are about the same at both
sites except that organic sulfur is much higher at site 1. The 834S values are posi
tive at both sites (Tablel, Fig. 3), indicating freshwater levels of sulfate.
WCA 2A. Total sulfur content (percent dry weight) is similar in sediment col
lected in 1994 at two sites: one near the Hillsboro Canal (E1) and another far from
the canal (U3) (Table 2, Fig. 4). At each site, total sulfur shows a significant increase
in the upper part of the core, probably indicating an increase in sulfur loading in the
marsh in recent times. Sulfur speciation analyses (Table 2, Fig. 5) indicate that
most of the sulfur is in the form of organic sulfur, probably due to iron limitation of sul-
fide fixation. Positive 834S values for the sulfur species (Table 2, Fig. 5) show that
there is a relatively restricted supply of sulfate for reduction to sulfide, although one
negative 834S value for disufide sulfur (pyrite) at U3 could indicate an increase in sul
fate availability at the time of fixation (Bates et al., 1998).
11
Sediment collected in 1996 from site F1 (near the Hillsboro Canal) and from
site U3new ("new" U3-not the same as the site from 1994, see Fig. 1) has total sul
fur content slightly lower than in the sediment collected in 1994 (Table 2, Fig. 6).
Because the core lengths were shorter in 1996 (only the top 15 cm of sediment), it is
not possible to tell if there is a decrease with depth as there was in the sediment col
lected in 1994. Organic sulfur is the dominant species (Table 2, Fig. 7) near the top
of the sediment at F1 and U3, however, disulfides increase with depth. As in the
sediment samples collected in 1994, the 634S values are positive (Table 2, Fig. 7),
indicating a limited supply of sulfate.
Organic sulfur is the dominant sulfur species in another short core (top 15 cm)
collected in WCA 2A in 1995 (Table 2, Fig. 8), however the results are available only
on a percentage wet weight basis. More positive S^S values for disulfide sulfur and
organic sulfur are found in the near-surface sediment (top 3 cm) (Table 1, Fig. 8) near
the canal (F1) than far from the canal (U3new). This may be the result of higher
rates of sulfate reduction near the canal.
Everglades Agricultural Area. Agricultural soil at the U.S. Department of
Agriculture (USDA) Research Center at Canal Point and at the University of Florida
Agricultural Research Center was analyzed for total sulfur 634S values. These val
ues fall in a range from 12.63 to 19.37, with higher values in the top 5 cm of the three
cores sampled (Table 3, Fig. 9). Total sulfur was determined only on a dry weight
basis, and appears to increase with depth in the two meter core (Table 3).
Lake Okeechobee. Total sulfur as a percent of dry weight was obtained for
two cores from Lake Okeechobee, one from the center of the lake and the other from
South Bay at the southern tip of the lake (Table 4, Fig. 10). Total sulfur content is
12
higher at the periphery of the lake than at the center, and both cores show a general
decrease in sulfur content with depth.
Taylor Slough. Total sulfur contents (Table 5, Fig. 11) are higher in the upper
part of sediment collected at the head of Taylor Slough (Fig. 1) than in sediment col
lected in the middle part of the Slough (Fig. 1). This could be the result of the prox
imity of the head of the slough to agricultural fields and canal drainage (the head of
the Slough also has higher total phosphorus levels in the sediment (Orem et al.,
1999), possibly from agricultural runoff. Organic sulfur is the dominant sulfur species
at both sites (Table 5, Fig. 12). Sulfur species 634S values are positive at both sites
(Table 5, Fig. 12), indicating freshwater levels of sulfate. The 634S values of sulfate
sulfur are quite high (approaching 30 per mil) near the top of the core at the head of
the slough. This could be the result of a very restricted source of sulfate (not likely
considering that the sulfur content is relatively high near the top of the core) or to
high 634S values in the source sulfate.
13
Tab
le 1
. S
ulfu
r sp
ecie
s co
ncen
trat
ions
and
834
S va
lues
in
sedi
men
t fr
om W
CA
1A
(L
oxah
atch
ee N
atio
nal W
ildlif
e R
efug
e), s
ites
1 an
d 7,
Apr
il 19
95.
WC
A 1
A,
Site
1,
4-21
-95
(26
28.7
82'N
80
26.
565'
W)
Cor
e S
sgm
ent
0-5
cm5-
1010
-15
15-2
025
-30
35-4
5
WC
A 1
A,
0-5c
m5-
10
10-1
515
-20
25-3
040
-50
Av.
De
pth
S
ulfa
te
AV
S
DS
(c
m)
%W
et
Wt.
%W
et
Wt.
%W
et
Wt.
2.5
7.5
12.5
17.5
27.5
40.0
Site
7,
4-21
-95
2.5
7.5
12.5
17.5
27.5
45.0
0.00
9
0.00
20.
032
0.01
10.
015
0.01
00.
012
0.00
80.
009
0.00
60.
003
0.00
80.
004
0.00
40.
003
0.00
30.
006
(26
28.8
73'N
0.00
70.
009
0.00
30.
003
0.00
30.
001
0.02
00.
010
0.00
50.
005
0.00
50.
004
80
24
.
0.00
30.
004
0.00
20.
002
0.00
20.
002
OS
,W
et
Wt.
0.08
40.
055
0.03
30.
024
0.01
80.
012
,931
'W)
0.02
30.
017
0.00
80.
015
0.01
10.
007
Sul
fate
83
4S17
.89
14.5
514
.40
15.5
3
16.3
2-
15.1
914
.21
15.2
514
.19
14.8
3
AV
S
834S
21.4
022
.86
21.5
2
15.2
617
.11
22.4
421
.25
27.3
419
.58
19.9
3
DS
83
4S14
.87
17.8
012
.29
14.2
614
.13
15.0
3
15.4
312
.12
17.4
518
.80
10.5
65.
19
OS
83
4S13
.36
17.7
115
.78
16.1
715
.48
15.7
4
15.3
216
.10
16.5
715
.83
15.4
016
.51
Figure 3
Sulfur Species in Loxahatchee Sediment: Percent Wet Weight and 834S Values
Loxahatchee Sediment Core 1 April 1995
Loxahatchee Sediment Core 1
April 19950 -
10-
iQ.<u Q 30 -
40 -
50 -0
10
-g- 20 -
~
Q.«UQ 30
40
5(1 -
1
,
02 0.(
i
r/Vfl ^-'~*' -° ^'^
? 7 y\ ra <f 4
\ '. /
6 +v
i i i i 10 0.02 0.04 0.06 0.08 0.
Percent by Wet Weight
Loxahatchee Sediment Core 7
April 1995
° ^ 7
its > «I \\o v Y
\ 1i i 4
I!'
' I i; : .J,4
\j
10
O on ^^ 20 -
£ Q. (UQ2 30-
O
40-
50 0 (
- - AVS
-0--DS
-T-OS
-s?- SO4
0 -i
10
f 20fOQ 30-
40
SO
^S;-..^ \
^> \p-'V'V' jX
' <? Vt _/
\/O
(IV
\>l\
) 5 10 15 20 25 3(
Loxahatchee Sediment Core 7
April 1995
6"--/A <*^-^^ *"°-- _^* \ / V-- ' ~~~"^ /7 --"?*'^
o-"'" /i \
/ ! Ii (: \
^ Lo o V
-0.02 0.00 0.02 0.04 0.08 0.08 0.10
Percent by Wet Weightis 20 25 30
15
Table 2. Sulfur species concentrations and 534S values in sediment from WCA 2A, sites E1, U3, and U3 (new).
WCA 2A,Core
Segment0-55-10
10-1515-2025-3035-4055-6065-7076-80
WCA 2A,0-55-10
10-1520-2530-3550-5563-73
WCA-2A,0-3 cm
3-66-9
12-16
WCA 2A,0-3 cm
3-66-99-12
12-15
Ste El, 3-1-94 Average Sulfate Depth (cm) %DryWt.
2.575
12.517.527.537.557.567.5
78
0.1600.0500.1400.1500.1200.0900.0300.1800.100
(26 21 .090'N 80 21 .200'W) AVS OS OS TS
%DryWt. %DryWt. iDryW %DryWt.0.0200.0100.0100.0100.0100.0100.0000.0000.000
Ste U3, 3-1-942.57.5
12.522.532.552.5
68
0.3100.3900.2600.1600.0900.0000.060
0.0100.0100.0100.0000.0000.0000.000
Ste F1, 3- 27- 951.54.57.514
0.0040.0180.0150.016
0.0050.0040.0050.005
Site U3 (new), 3-27-951.54.57.510.514
0.0080.020
0.0270.021
0.0010.0020.0020.0030.002
WCA 2A, Site F1, 4-26-960-55-10
10-15
WCA 2A.0-55-10
10-15
2.57.5
12.5
0.1300.0900.000
0.0100.0100.070
Site U3 (new), 4-25-962.57.5
12.5
0.0800.1100.000
0.0010.0250.019
0.2200.2200.2700.2500.1500.1300.1500.1700.120
0.8701.0901.0900.8000.6100.5400.5700.4800.470
1.261.361.521.210.890.760.750.830.69
Sulfate 834S15.7214.7814.2114.5114.3515.7222.5717.1414.31
AVS 834S14.1913.6914.0015.8216.0820.2421.0121.2819.60
OS 834S13.6212.0610.7810.7611.4415.9718.7811.166.97
OS 834S
14.0812.2112.0514.0815.3116.8915.0116.1013.82
(2617.270'N 8024.680'W)0.4400.3900.3700.4200.2200.1000.080
0.8000.9400.7600.7600.6100.5500.470
1.571.741.401.340.920.650.61
18.1715.4618.5119.5722.21
9.3121.8619.7623.61
6.84-1.0915.2419.9322.2117.0213.28
8.1912.5216.9316.1515.6114.5315.55
(26 21 .580'N 80 22.230'W)0.0060.0160.0200.024
0.0320.0470.1120.105
18.12715.19616.66319.788
7.7810.7017.3416.07
7.9439.6914.2314.19
10.6110.429.9010.43
(26 17.250'N 80 24.680'W)0.0060.0140.0110.0190.018
0.0020.020
0.0670.065
(2621.580'N 800.1600.2000.980
0.5700.6100.000
22.230'W)0.870.911.04
14.7017.78
18.0217.67
17.7920.18
17.8015.7016.3416.7717.95
18.3218.9819.73
7.936.646.529.9212.53
11.913.94
15.691
8.356.80
13.1115.21
10.99813.72617.873
(2617.250'N 8024.680'W)0.4700.7500.700
0.6300.0000.000
1.180.890.72
19.934 16.57718.09719.044
8.77610.81316.186
16.33815.26211.861
16
Figure 4
Total Sulfur in WCA 2A Sediment at Sites E1 and U3, March 1994:Percent Dry Weight
WCA 2A Sediment at Site E1, March 1994: Total Sulfur, Percent Dry Weight
20 -
40 -
CL <D Q 60 -
80-
100
o
20 -
40-
CL <Da eo
80 -
100
Total Sulfur
00 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Percent Dry Weight
WCA 2A Sediment at Site U3, March 1994: Total Sulfur, Percent Dry Weight
Total Sulfur
"I r-
0.0 0.2 0.4 0.6 0.8 1.0 1.2Percent Dry Weight
1.4 1.6 1.8 2.0
17
Figure 5
Sulfur Species in WCA 2A Sediment at Sites E1 and U3 March 1994: Percent Dry Weight and 534S
20
40
.c o.Q 60
60
100-0.2
20
g- 40
,0,
o. cu Q 60
80
100
WCA 2A Sediment at Site E1
March 1994
TO
0.0 0.2 0.4 0.6 0.8
Percent by Dry Weight
i.o
WCA 2A Sediment at Site U3
March 1994
a- ' O '
Q
20
40
60
60 -
20 -
40-
o.OJQ 60 -
60 -
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2
Percent Dry Weight
WCA 2A Sedimemt at Site E1
March 1994
10 15 20 25
WCA 2A Sediment at Site U3
March 1994
n
a' /
10
834S
20 25
18
Figure 6
Total Sulfur in WCA 2A Sediment at Sites F1 and U3 (new):Percent Dry Weight
WCA 2A Sediment at Site F1 April 1996
E 6J
.cQ.
8H
10 H
12 H
14
Total Sulfur
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Percent Dry Weight
WCA 2A Sediment at Site U3 (new) April 1996
_o_
.cQ.
6^
8H
10 H
12 ^
14
Total Sulfur
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4Percent Dry Weight
1.6 1.8 2.0
19
Figure 7
Sulfur Species in WCA 2A Sediment at Sites F1 and U3, April 1996:Percent Dry Weight and 534S Values
WCA 2A Sediment Core F1 .1,
x: o.
0 -
2
4 -
6 -
8 -
10 -
12 -
14 -
-C
0
2
4
6
8
10
12
14 -
-0
i
.2 0.
i
//
I\\\
fcJ
2 O.C
WOA ^A seaiment uore at M
April 1996
P \
/ \} \1 I
/\/ '- -.... /
\ /'""-- '
3K3 0.2 0.4 0.8 0.8 1.0 1
Percent Dry Weight
WCA 2A Sediment Core U3
April 1996
1 ^"' \\/^
i * 6
/
/ . ' :'
6
0.2 0.4 0.8 0.8 1.0 1
Percent Dry Weight
0 -i
2 -
4 -
"E" e .H.c a.8 *-
10 -
12 -
14 -
.2 £
AVS -o- DS -- OS 7 SO4
0 -
2-
4 -
^ 6-.0.
Q.Q 8 -Q
10 -
12-
14 2
April 1996
*\X '
\ \ . 1\\ I^ I\ \ "
^' X \
' X \
i \ 1
10 15 20 2S
WCA 2A Sediment Core U3
April 1996
\ [\/ \/ \
b / <(/ \
/ \' / \/ ' \
/ \
/ ""o i
> 10 15 20 2
6^3 ;
20
Figure 8
Sulfur Species in WCA 2A Sediment at Sites F1 and U3 (new), March 1995: Percent Wet Weight and 634S
Q. (U Q
WCA 2A Sediment Core F1
March 1995
WCA 2A Sediment Core F1
March 1995
0
2
4
6 -
6
10
12
14
0 -
2
4
6
6 -
10 -
12 -
14
<
0.00
.
I
0.00
K ( \ \^
Q7 T ̂
A ^^-^1 n A!l fi i /i I /i? 6 V
0.02 0.04 0.06 0.06 0.10 0.
Percent Wet Weight
WCA 2A Sediment Core U3 (new)
March 1995
O^t
\\
O ^tti
/ \ x\* \ x\ \\ \
O C" T
i / \
u /0.02 0.04 0.06 0.08 0.10 0.
u -
2
4
6
£ 6 -Q.(B
Q 10-
12
14-
16 -
12
- AVS -o- DS-T-- OS-<?- SO4
0 y
2 -
4 -
6 -E^'o.
Q 10-
12 -
14 -
16 -
12 0
\ I S\.\ /^^\.
1 '"' ^^^^\
1 ' ^\t ° \Xi \
i A./ \
i / \i 6 * '(7
3 5 10 15 20 2
WCA 2A Sediment Core U3 (new)
March 1995
/T *^'')<f
K { \
\ x\ \\\ i\ !
o. \ V f\ \ .-
\ \ I
5 10 15 20 25
Percent Wet Weight
21
Tab
le 3
. T
otal
sulfu
r co
nten
ts (
perc
ent
dry
wei
ght)
and
534
S va
lues
in
the
Eve
rgla
des
Agr
icul
tura
l Are
a at
the
Dep
artm
ent
of A
gric
ultu
re R
esea
rch
Cen
ter
at C
anal
Poi
nt (
A1)
and
The
Uni
vers
ity
of F
lorid
a R
esea
rch
Sta
tion
at B
elle
glad
e (G
1 an
d G
2).
EA
A,
Site
A1,
2-2
8-94
(Lat
and
long
coo
rdin
ates
unk
now
n)
Cor
e S
egm
ent
0-1
ft.
2-3
ft.
4-5
ft.
6-7
ft.
Ave
rage
D
epth
(cm
)15
.24c
m
76.2
0 cm
13
7.2c
m
198.
1 cm
Sul
fate
%
Dry
Wt.
I
AV
S
%D
ry W
t.D
S
%D
ry W
t.O
S
iDry
WTS
%
Dry
Wt.
0.10
0.
88
2.02
2.
27
Sul
fate
83
4SA
VS
83
4SD
S 83
4SO
S
834S
TS
S34S
17.6
3 12
.63
17.2
3 15
.55
EA
A, S
ited,
2-28
-94
0-5
cm
10-1
5 cm
20
-25
cm
30-3
5 cm
EA
A,
Site
G2,
2-2
8-94
0-5
cm
20-2
5 cm
40
-45
cm
(Lat
and
long
coo
rdin
ates
unk
now
n)
0.50
0.53
0.60
0.48
(Lat
and
long
coo
rdin
ates
unk
now
n)
0.56
0.44
0.57
18.7
518
.82
13.5
117
.12
19.3
718
.82
19.2
3
Total Sulfur 834S Values at the U.S. Department of Agricultural Research Center
at Canal Point, February 1994Figure 9
50
£ 100
Q. CDD 150
200-
25010 15 5MS Total Sulfur
20 25
Total Sulfur 834S Values at the University of Florida Cane Field
at Belle Glade, February 1994
so -
-? 100
Q.
D 150
200
2505 10 15 20
S^S Total Sulfur
Total Sulfur 834S Values at the University of Florida
Unused Field, February 1994
25
u
50
g- 100 -
Q.to D 150
200
250-
C
(
5 10 15 20 2;
5MS Total Sulfur
23
Table 4. Total sulfur contents (percent dry weight) for sediment cores from the center and the periphery of Lake Okeechobee.
Lake Okeechobee, Center CoreCore Average
Ssgment Depth (cm)0-22-44-66-88-10
10-1212-1414-1616-1818-2020-2222-2424-2626-2828-3030-3232-3434-36
13579
11131517192123252729313335
(2657.783'N 80 49.931 'W) TS
%Dry Wt.
0.250.280.330.350.240.280.270.220.250.130.130.170.200.200.200.190.140.08
Lake Okeechobee, Periphery0-22-44-66-8
8-10
10-1212-1414-1616-1818-2020-2222-2424-2626-2828-3030-3232-3434-3636-38
38-42.5
13579
1113151719212325272931333537
40.25
(2644.179'N 80 45.595'W) 0.601.001.010.970.900.911.110.850.840.790.650.630.650.800.730.730.830.840.760.69
24
Figu
re 1
0. T
otal
Sulfu
r Con
tent
in L
ake
Oke
echo
bee
Core
s: P
erce
nt D
ry W
eigh
t
Cent
er o
f Lak
ePe
riphe
ry o
f Lak
e
i 10
co CD "53
.E 5 I C/D "c T3
CD
C/D I
CD
-Q Q.
CD
Q
20 30 40
,0 0.
2 0.
4 0.
6 0.
8 1.
0 1.
2
Tota
l Sulf
ur, P
erce
nt o
f Dry
Wei
ght
Or
10 20 30 40 Q|_
__
__
|__
__
_|_
__
__
|__
__
_|_
__
__
|__
__
_|
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Tota
l Sulf
ur,
Perc
ent o
f Dry
Wei
ght
Tab
le 5
. S
ulfu
r sp
ecie
s co
nte
nts
(p
erc
en
t dr
y w
eig
ht)
and
834
S v
alue
s in
sedim
ent
colle
cte
d a
t the
hea
d an
d m
id-s
ect
ion
of
Tayl
or
Slo
ug
h,
May
199
6.
Hea
d o
f T
ayl
or
Slo
ugh,
Cor
e 19
, 5-
22-9
6(2
5 24.3
06'N
80 3
6.3
77'W
)
Cor
e A
vera
ge
Sul
fate
A
VS
S
ag
me
nt
De
pth
(cm
) %
Dry
Wt.
%D
ryW
t.0-
2 cm
2-5
5-8
8-11
11-1
414
-17
17-2
020
-25
25-3
030
-35
35-4
04
0-5
050-6
0
Mid
Ta
ylo
r
0-5
cm5-
1010
-15
15-2
020
-30
30-4
040
-50
50
-60
60-7
0
1.0
3.5
6.5
8.5
12.5
15.5
18.5
22.5
27.5
32.5
37.5
45.0
55.0
Slo
ugh,
2.5
7.5
12.5
17.5
25
.035.0
45
.055.0
65.0
0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
190
29
03
80
07
012
018
00
70
04
00
20
01
00
20
0.0
10
0.
Cor
e 5, 0. 0. 0. 0. 0. 0. 0. 0. 0.
02
0
5-1
7-9
6
05
02
80
23
02
20
22
011
010
00
70
03
0
0.0
45
0.03
10.0
09
0.0
06
0.0
08
0.0
05
0.0
03
0.0
04
0.00
10.
001
0.00
10.0
00
0.0
03
0.01
10.0
04
0.00
10.
001
0.00
10
.00
20.0
02
0.0
00
0.0
00
DS
% D
ry W
t0.
660
0.43
00.
140
0.07
00.
080
0.0
70
0.0
60
0.0
60
0.0
30
0.0
40
0.0
40
0.0
40
0.0
20
0.3
00
0.1
30
0.0
70
0.0
80
0.0
70
0.0
90
0.0
60
0.0
50
0.0
30
OS
. o
Dry
Wt.
0.6
70
0.6
70
0.6
10
0.4
00
0.3
70
0.2
30
0.1
90
0.1
70
0.1
10
0.0
70
0.0
40
0.0
30
0.0
20
(25
17
.23
1'N
0.7
70
0.6
60
0.5
90
0.4
80
0.5
40
0.7
60
0.5
30
0.3
50
0.3
90
Sulfa
te
534S
28 28 29 23 20 20 20 20
.85
.45
.19
.92
.48
.94
.43
.43
19.9
219 18
.56
.80
n.d.
n.d.
AV
S
53
4S
24
.28
26
.02
25
.55
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d
14.5
1
DS
83
4S22
.31
22.8
52
2.4
718
.77
17.0
918
.43
20
.20
19.1
823.0
420.1
621
.91
17.3
52
0.9
6
OS
5
34
S
22.6
322.8
523.1
319
.56
18.4
218
.91
18.9
918
.82
18
.38
18.0
317
.79
17.3
51
4.1
6
80 3
8.7
80
'W)
21 18 18 18 19 20 20 20 n.
.13
.51
.52
.45
.63
.29
.08
.62
d.
13.9
613
.77
12.3
810
.62
9.6
411
.61
13.3
013
.32
14.3
016
.97
14.9
315
.14
15.0
115
.18
15.1
415
.02
15.5
416
.03
18
.10
Figure 11
Total Sulfur Contents in Sediment from Taylor Slough, May 1996:Percent Dry Weight
Head of Taylor Slough at Site 3, May 1996: Percent Dry Weight
a.
10 -
20 -
30 -
40 -
50 -
60 -
70
10 -
20 -
t.r: "a.
40 H
50 -
60 -
700.0
Total Sulfur
0.0 0.5 1.0 1.5 Total Sulfur, Percent Dry Weight
Middle of Taylor Slough at Site 7, May 1996
2.0
Total Sulfur
0.5 1.0 1.5 Total Sulfur, Percent Dry Weight
2.0
27
Figure 12
Sulfur Species in Taylor Slough Sediment at Sites 3 and 7, May 1996:Percent Dry Weight and 534S
20
| 30^
Q.0) 40 O
SO
60
70-0.2
Head of Taylor Slough, Core 19
May 1996
" 0
v<o
IFit
0.2 0.4Percent Dry Weight
0.8
10
20 -
^
£
50 -
60
70
Head of Taylor Slough, Core 19
May 1996
-o
IS 20 25 30
10
20
| 30^
& 40 H
SO
60-
Middle of Taylor Slough, Site 3, Core 5
May 1996
o 6
V j
-0.2 0.0 0.2 0.4 0.6
Percent Dry Weight
o.a
.cI-Q
Middle of Taylor Slough, Core 5, Site 3
May 1996
10 -
20
30 -
40 -
SO
60 -
7n -
.-°' r f1 i0 * *
1'> i
: \"? T
. \o V' -. \
" o\
r-^
T
\\it\
10 IS 20 25 30
28
Dissolved Sulfate Concentrations and Isotopic Compositions
Surface waters were collected in the EAA, the ENR, WCA 1A, 2A, 2B, and 3A,
Lake Okeechobee, and Taylor Slough (Figs. 1 and 2). Groundwater and rainwater
were collected in WCA 2A and in the ENR. The concentrations and sulfur isotopic
ratio data were determined for samples from each area (Tables 6, 7, 8; Figs. 13 and
14).
Surface Water. Regional patterns in sulfate concentration and 534S values
obtained from March 1995 through July 1998 are shown in (Fig. 13a-g). Surface
waters collected from the canals in the EAA tend to have higher sulfate concentra
tions with lower 534S values compared to water samples from the Hillsboro Canal
where it is adjacent to WCA 2A. Sulfate concentrations of water from the Kissimmee
River and Lake Okeechobee (Fig. 13a) are low compared to water collected from the
EAA canals. Surface water in WCA 2A, which receives discharge from the Hillsboro
Canal through the S-10 spillways, tends to be somewhat lower in sulfate concentra
tion with higher 534S values than water collected from the canal. These changes are
probably due to progressive reduction of sulfate and to dilution with rainwater or
groundwater. Surface waters from WCA 3A and 2B have relatively low sulfate con
tent. WCA 2B receives water from the southern part of WCA 2A but not directly from
the canals, and WCA 3A is a very large area, most of which is far from canal dis
charge sites. The Loxahatchee National Wildlife Refuge (WCA 1A), with little direct
input of water from the Hillsboro Canal, also has very low sulfate content although
the S^S values are in the same range as the canals in the EAA. In contrast, the
S^S values of water from WCAs 3A and 2B are in the same range as water from
WCA 2A, suggesting that similar sulfate processing is occurring in these areas.
29
Tabl
e 6.
S
ulfa
te c
on
centr
atio
nsa
nd
534
S v
alue
sin
sur
face
wat
er,
sam
ples
gro
uped
by
area
.
Mon
th/ Y
ear
of C
olle
ctio
n
Sam
plin
g Lo
catio
n La
t Lo
ng
3/9
53
/95
3/9
53
/95
3/9
53
/95
3/9
53
/95
3/9
53
/95
3/9
53
/95
3/9
54
/95
4/9
54
/95
4/9
54
/95
4/9
54
/95
7/9
57
/95
7/9
57
/95
7/9
57
/95
7/9
512/9
512/9
512/9
512/9
5
Wat
er C
onse
rvat
ion
Are
a 2A
:
R> R> F1 E1 E2 F2 E4 F3 R F5 U1 U2 U3 F1 E1 R R R R U3 R> R.I
of
2F
1,2
of2
R E1 E4 U3 U1 U3 E1 E4
26
22
.52
0'N
80
21
.86
0'W
2622.5
20'N
80
21
.86
0'W
2621.5
80'N
80
22
.23
0'W
26
21
.09
0'N
80
21
.20
0'W
2620.5
20'N
80
21
.16
0'W
2618.5
50'N
80
21
.43
0'W
2619.7
90'N
80
23
.29
0'W
2619.0
00'N
80
23
.12
0'W
26
14
.45
0'N
80
21
.39
0'W
26
15
.75
0'N
80
23
.05
0'W
2617.2
50'N
80
24
.68
0'W
26
21
.58
0'N
80
22
.23
0'W
26
21
.09
0'N
8021.2
00'W
26
19
.00
0'N
80
23
.12
0'W
2619.0
00'N
80
23
.12
0'W
26 1
9.00
0'N
8023.1
20'W
2619.0
00'N
8023.1
20'W
26
17
.25
0'N
80
24
.68
0'W
26
22
.52
0'N
8021.8
60'W
2621.5
80'N
8022.2
30'W
2621.5
80'N
80
22
.23
0'W
2619.0
00'N
8023.1
20'W
26
21
090
'N 8
02
1.2
00
'W26
18.
550'
N 8
02
1.4
30
'W2617.2
50'N
80
24
.68
0'W
26
14
.45
0'N
80
21
.39
0'W
26
17
.25
0'N
80
24
.68
0'W
26
21
.09
0'N
80
21
.20
0'W
26 1
8.55
0'N
8021.4
30'W
SO
4 S
O4
mg
/l
meq/l
93.9
981
.30
61.9
423
.77
37.0
930
.85
44.2
955
.19
67.7
958
.61
58.3
457
.32
41.8
625
.13
9.19
59.5
154
.53
53.9
960
.59
47.0
177
.42
59.4
157
.65
36.1
543
.21
24.0
452
.31
37.5
350
.87
42.9
737.4
9
1.96
1.69
1.29
0.50
0.77
0.64
0.92
1.15
1.41
1.22
1.22
1.19
0.87
0.52
0.19
1.24
1.14
1.12
1.26
0.98
1.61
1.24
1.20
0.75
0.90
0.50
1.09
0.78
1.06
0.90
0.78
S0
4
534S 20
.47
20.5
323.0
421
.35
22.5
824
.05
22.2
721
.71
20.7
524.4
823.4
823
.40
20.7
025.5
017
.49
23.7
923
.44
n.d.
n.d.
22.8
320.6
925.3
9n.
d.21.5
725
.91
22.1
321.0
025
.02
23.8
324.9
023
.85
Table
6.
Sul
fate
co
nce
ntr
atio
ns a
nd
534
S v
alu
es
in s
urf
ace
wate
r,
sam
ple
s g
rou
pe
d b
y are
a.
Month
/ Ye
ar
of C
olle
ctio
n
Sa
mp
ling
Lo
catio
n
' La
t Lo
ng12/9
512/9
512/9
512/9
53
/96
3/9
63
/96
6/9
66
/96
6/9
66
/96
6/9
61
2/9
612/9
612/9
63
/97
3/9
76
/97
6/9
77
/97
7/9
78
/97
9/9
79
/97
9/9
71/
981
/98
6/9
86
/98
6/9
86
/98
6/9
86
/98
FD F1 F1 R F1 R U3
EO F1 E1 U1
U3
F1 U3
BO U3
F1 R U3
U3
F1 E1 F1 U3
R F1 U3
U3
U1 E4 R F1 E1
26
22
.52
0'N
8021.8
60'W
2621.5
80'N
80
22
.23
0'W
26 2
1 .5
80'N
80
22.
230'
W2
61
9.0
00
'N 8
02
3.1
20
'W26
21
,580
'N 8
0 22
.230
'W2
61
9.0
00
'N 8
023.1
20'W
2617.2
50'N
8024.6
80'W
26
22
.28
0'N
8
02
1.0
90
'W2
62
1.5
80
'N 8
02
2.2
30
'W2
62
1.0
90
'N 8
02
1.2
00
'W26
14.
450'
N
80
21
.39
0'W
2617.2
50'N
80
24
.68
0'W
26
21
.58
0'N
8022.2
30'W
26
17
.25
0'N
8
02
4.6
80
'W2
62
2.2
80
'N 8
02
1.0
90
'W26
17.
250'
N 8
02
4.6
80
'W2
62
1.5
80
'N 8022.2
30'W
26 1
9.00
0'N
8023.1
20'W
2617.2
50'N
8
02
4.6
80
'W2
61
7.2
50
'N 8
02
4.6
80
'W2
62
1.5
80
'N 8
02
2.2
30
'W2
62
1.0
90
'N 8
02
1.2
00
'W2
62
1.5
80
'N
80
22
.23
0W
26
17
.25
0'N
8024.6
80'W
2619.0
00'N
8
02
3.1
20
'W2
62
1.5
80
'N 8
02
2.2
30
'W26
17.
250'
N 8
02
4.6
80
'W2617.2
50'N
80
24
.68
0'W
26
14
.45
0'N
8
02
1.3
90
'W2
61
8.5
50
'N
8021.4
30'W
26
19
.00
0'N
80
23
.12
0'W
2621.5
80'N
80
22
.23
0'W
26
21
.09
0'N
8021.2
00'W
90
4
90
4
mg
/l
me
q/l
31.4
149
.55
50.8
046
.98
39.7
933
.82
5.95
32.4
148
.27
48.3
736
.36
43.4
364
.65
67.0
836
.14
3.91
50.8
559
.55
42.4
810
0.21
50.8
181
.09
67.1
766
.59
79.8
863
.16
82.8
752
.27
38.2
440
.55
36.1
832
.94
53.9
3
0.65
1.03
1.06
0.98
0.83
0.70
0.12
0.68
1.01
1.01
0.76
0.90
1.35
1.40
0.75
0.08
1.06
1.24
0.88
2.09
1.06
1.69
1.40
1.39
1.66
1.32
1.73
1.09
0.80
0.84
0.75
0.69
1.12
S0
4
534S 20
.14
26.2
226
.20
23.8
522
.15
29.8
124
.87
22.2
721
.23
22.5
722
.60
22.4
522
.74
28.1
821
.53
25.6
317
.52
33.4
822
.14
22.6
621
.58
23.6
024
.02
23.6
823
.09
23.3
323
.28
23.2
822
.00
22.7
521
.66
19.3
422
.05
Tab
le 6
. S
ulfa
te c
on
cen
tra
tion
san
d 5
34S
va
lue
sin
sur
face
wate
r,
sam
ple
sgro
up
ed
by
are
a.
u>
10
Mo
nth
/Ye
ar
of C
olle
ctio
n
Sam
plin
g Loca
tion
3/95
3/95
3/95
3/9
53
/95
7/9
57
/95
7/9
512/9
56
/96
7/9
79
/97
9/9
76
/98
6/9
8
Hill
sbor
o C
anal
Sam
ples
:
S10
ES
10D
S10
DS
10C
S10
CS
10C
S10
DS
IDE
SID
ES
IDE
Hill
soro
Canal b
etw
ee
n E
AA
& W
CA
2A
SI O
C.
he
ad
SI O
C, ta
ilS
IOC
.Head
SI O
C. T
ail
SO
4 S
O4
Lat
Long
m
g/l
me
q/l
96.0
611
7.94
121.
9983
.10
80.0
165
.32
88.1
498
.19
36.2
948
.99
26 2
8.36
2'N
80
26.8
39'W
87
.08
67.2
858
.43
25.8
524
.76
2.00
2.46
2.54
1.73
1.67
1.36
1.84
2.05
0.76
1.02
1.81
1.40
1.22
0.54
0.52
SO
4 53
4S 18.0
318
.79
18.8
020
.25
20.6
021
.11
20.2
620
.14
21.1
122
.79
21.4
122
.21
21.4
718
.11
18.0
8
Lox
a ha
tehee W
ildlif
e R
efug
e:
4/95
C
2(3
te7
)4/
95
C2
(Ste
7)
4/95
C
2 (S
te 7
)4/
95
C3
4/95
C
41/
98
Lo
xah
atc
he
e
Rum
e
2628
.873
'N 8
0 24
.931
'W
2628
.873
'N 8
0 24
.931
'W
2628
.873
'N 8
024.
931'
W
26 2
8.87
'N
80 2
4.93
'W
4.23
2.96
2.42
5.40
14.7
90.
00
0.09
0.06
0.05
0.11
0.31
0.00
21.1
9 19
.36
n.d
. 16
.46
14.8
2n
.d.
Tab
le 6
. S
ulfa
te c
on
cen
tra
tion
san
d S
34S
va
lue
sin
sur
face
wate
r,
sam
ple
sgro
uped b
y are
a.
U)
U)
Mo
nth
/Ye
ar
of C
olle
ctio
n
Sam
plin
g Loca
tion
3/95
3/9
57
/95
7/9
5
7/9
51
2/9
5
6/9
61
2/9
6
7/9
58
/97
8/9
7
8/9
71
/98
1/9
81
/98
1/9
8
12
/95
12
/95
12
/95
12
/96
3/9
6
6/9
63
/97
8/9
71
/98
L67
Canal:
L6
7@
S1
51
L67
@ S
333
L67
@ S
333
L6
7@
S1
51
Mia
miC
anal@
L67(S
151)
L67
L6
7@
15
1L6
7
Mia
mi
Canal:
Mia
miC
an
al@
L6
7(S
15
1)
Mia
miC
anal#
1M
iam
iCa
na
l #
2M
iam
i Ca
na
l# 3
Mia
mi C
anal o
ff 2
7M
iam
i Canala
t 6
mile
sM
iam
i Canai a
t 12
mi ©
pum
p s
tatio
nM
iam
iCanal
@ R
t 75
Wat
er C
onse
rvatio
n A
rea
2 a
WC
A2B
Nor
thW
CA
2B S
outh
WC
A2B
WC
A2B
Sou
thW
CA
2B
Sou
thW
CA
2B
WC
A2B
Sou
thW
CA
2B
Sou
thW
CA
2B
Sou
th
Lat
Long
26 0
0.9
00'N
80
30
.34
2'W
25
46
.11
6'N
8040.3
80'W
25
46
.11
6'N
80
40
.38
0'W
26
00.9
00'N
80
30
.34
2'W
26 0
0.9
00'N
80
30
.34
2'W
26 0
0.9
00
'N 8
0 3
0.3
42'W
26 0
0.9
00'N
80
30.3
42'W
26
41
.78
3'N
80
48
.37
6'W
26
37.4
34'N
8
0 4
9.9
94'W
26
19
.91
5'N
8046.4
79'W
26
41
.78
3'N
80
48.3
76'W
26 3
7.4
34
'N
80 4
9.9
94
'W2
61
9.9
15
'N 8046.4
79'W
26
08.7
69'N
80
37
.98
3'W
26
12
.00
0'N
8
02
2.5
00
'W2
6 0
9.5
80'N
80
22.6
80'W
26
09
.58
0'N
80
22
.68
0'W
26 0
9.5
80'N
80
22
.68
0'W
26 0
9.5
80
'N
80 2
2.6
80
'W
26 0
9.5
80
'N
80 2
2.6
80
'W
26 0
9.5
80'N
80
22
.68
0'W
S04
S
04
mg
/l
me
q/l
28.1
82
1.2
31
8.3
016
.61
7.6
2
24
.48
6.4
9
22
.59
7.6
2147.8
9
62.7
166.7
4102.1
613
4.51
20.9
86.
71
47
.82
6.0
74.1
3
11
.36
20
.85
6.9
72
1.3
2
7.0
42
6.7
7
0.5
9
0.4
40.3
8
0.3
5
0.1
60.
51
0.1
4
0.4
7
0.1
6
3.0
81.
311.
39
2.1
32.8
00.4
40.1
4
1.00
0.1
30.0
90.2
4
0.4
30.1
5
0.4
40
.15
0.5
6
SO
4 534S
20.1
2
23.5
52
0.5
9
20.2
8
25.0
6
25
.33
20.5
2
24
.23
25.0
6
16
.27
20.6
1
18.6
11
5.8
41
7.4
22
2.5
32
1.1
3
24
.74
25.3
12
2.5
428.5
9
33.9
92
5.5
9
20.5
2
24.1
028
.51
Tab
le 6
. S
ulfa
te c
on
cen
tra
tion
s an
d 83
4S v
alue
s in
sur
face
wat
er,
sam
ples
gro
uped b
y a
rea
.
Mo
nth
/Ye
ar
of
Colle
ctio
n
Sam
plin
g Lo
catio
n
12/9
53/
963/
966/
966
/96
12
/98
12/9
612/9
63/9
77
/97
8/9
71
/98
4/9
84/9
84
/98
4/9
84
/98
4/9
84/9
8
12/9
51
2/9
512/9
53/9
73
/97
6/9
66
/96
12/9
612/9
612/9
612/9
69
/97
Wa
ter
Conserv
ation A
rea 3
A:
WC
A3
A ©
hyd
ro 1
5W
CA
3A
90 93 WC
A3A
3A-T
T3A
-15
3A-3
3A-1
53A
@
(1.9
97
3A
-15
3A
-15
3<in
ner
Isla
ndH
ead
Hg
e E
ast.3
AN
IN
utho
use
Hea
dM
arsh
Wes
t. 3A
N1
Nut
Hou
se M
arsh
9<in
ner
Isla
nd,
mar
sh e
ast
Gki
nnern
eart
rail
Nut
rient
Rem
oval
Are
a:
BM
R10
2(9/
V)
BM
RG
253E
B^R
G25
0B
MR
102
BM
R30
3B
MR
103
BM
R30
3B
MR
P12
BM
RP
5B
MR
G'w
ater
. 11
AB
^RG
'wate
r, 1
1AE
NR
012
(Pro
ject
ou
tflo
w)
Lat
Long
2558.4
55'N
8040.1
27'W
25 4
5.7
20
'N
80 3
0.4
60
'W2558.4
55'N
8040,1
27'W
26 1
6.16
4'N
8036.8
16'W
2558.4
55'N
8040.1
27'W
2556.7
36'N
80
26.
601
'W2558.4
55'N
8
04
0.1
27
'W2558.4
55'N
80
40.1
27'W
2551.6
15'N
8043.9
26'W
2611.2
00'N
80
44.3
51 'W
25 5
3.3
45'N
80
33
.75
0'W
26 1
1 .2
09'N
80
44
.40
5'W
25 5
3.3
65'N
80
33
.67
4'W
25
51
36
.88
8
04
35
5.5
7255029.7
7
80
44
18
.34
26
38
48
.30
7
802451.4
67
26
38
48
.30
7 8
02
45
1.4
67
26 3
6.6
60
'N 8
0 2
6.3
64
'W26
38.2
44'N
80
25
.36
2'W
26 3
6.6
60
'N 8
0 2
6.3
64
'W2
63
81
1.2
76
802442.9
26
26 3
827.9
25
80 2
64
0.8
54
26 3
75
0.8
92
80
26
00
.50
426
37
50
.89
2
80 2
600.
504
SO
4 S
O4
mg/l
me
q/l
0.0
02
.58
6.78
5.4
00
.60
0.18
1.30
11.8
80.
812
6.1
71.
980.4
90.0
02
.49
11.3
34
.90
10.9
70
.00
0.1
7
32.2
13
4.8
232
.31
101.
378
0.8
857.4
83
1.1
829.3
24
0.7
350.0
545.6
970.5
3
n.d
.0.
050.
140.
110.
010.
000
.03
0.25
0.02
0.55
0.04
0.01
0.00
0.05
0.2
4010
0.23
0.00
0.00
0.67
0.73
0.67
2.11
1.69
1.20
0.65
0.61
0.85
1.04
0.95
1.47
SO
4 &
34S n.d.
22.9
32
8.1
52
5.5
924.1
7n.d
.n.
d.27
.90
n.d.
21.6
6n.
d.n.
d.n.
d.20
.62
25
.00
19.6
924.6
0n.
d.n.
d.
18.3
12
0.3
417
.43
22
.66
23.1
72
1.8
82
3.0
631
.84
25.3
028
.93
28
.32
24
.46
Tab
le 6
. S
ulfa
te c
on
cen
tra
tion
s a
nd
534
S v
alu
es
in s
urf
ace
wa
ter,
sa
mp
les
gro
up
ed
by
are
a.
Mo
nth
/Ye
ar
of C
olle
ctio
n
Sam
plin
g L
oca
tion
9/9
79
/97
9/97
9/9
79
/97
6/98
6/98
6/9
86
/98
6/98
6/9
86/
986
/98
6/98
6/98
6/9
8
8/9
612
/96
12/9
612
/96
12/9
63
/97
3/9
73/
973
/97
3/9
77
/97
7/9
77
/97
7/9
77
/97
1/98
1/98
EN
RG
259
(head o
f se
ep
ag
e C
.)E
NR
002
(pro
ject
inflo
w)
EN
R01
1 (s
ee
pa
ge
Canal
retu
rn)
EN
R1
03
9/V
(1)
EN
R1039/V
(2)
EN R
004
EN
R01
1E
NR
G25
9E
NR
012
EN
R00
2M
103
M10
2M
203
M20
4M
303
M40
1
Eve
rgla
des
Agricu
ltura
l Are
a:
Ca
na
lsu
rfa
ce w
ate
rE
AA
3te
1E
AA
3te
4E
AA
ate
2E
AA
ate
3E
AA
3te
1E
AA
ate
2E
AA
ate
3E
AA
ate
4C
anal 3
te 1
Canal
3te
2C
an
al a
te 3
Ca
na
l 3te
4H
illso
ro C
anal,
be
tw'n
EAA
& W
CA
2A
N.
New
Rve
rCa
na
l, b
etw
'n E
AA
and
2A
N.
New
Rve
rCa
na
l at
Gol
f C
ours
eN
. N
ew R
verC
an
al
Lat
26 3
8.24
4'N
26 3
8.24
4'N
26 3
8.24
4'N
26 3
848.
307
26 3
835.
054
26 3
902.
993
26 3
6.66
0'N
26
37
46
.31
2
26 3
6.59
3'N
26 3
8.74
5'N
26 4
2.09
3'N
2641.8
65'N
26 3
6.59
3'N
26 4
2.09
3'N
26
41
.86
5'N
26 3
8.74
5'N
26 3
6.59
3'N
26 4
2.09
3'N
26
41
.86
5'N
26 3
8.74
5'N
26 2
8.36
2'N
26
20
.14
3'N
26 4
2.09
1 'N
26 3
6.57
5'N
U>n
g
80 2
5.36
2'W
80 2
5.36
2'W
80 2
5.36
2'W
8024
51.4
67802601.5
48
80 2
524.
223
80 2
6.36
4'W
80
26
24
.11
0
80 4
2.61
7'W
80 3
4.89
0'W
8042.4
18'W
80
41
.46
9'W
80 4
2.61
7'W
80
42
.41
8'W
80
41
.46
9'W
80 3
4.89
0'W
80 4
2. 6
1 7'
W8
04
2.4
18
'W8
04
1.4
69
'W80
34.
890'
W80
26.
839'
W80
32.
333'
W80
42.
91 5
'W80
42.
679'
W
S0
4
SO
4 m
g/l
me
q/l
36.2
814
4.35
45.7
045
.31
46.5
930
.14
56.8
449
.55
30.6
924
.72
32.2
733
.18
29.1
828
.54
30.7
924
.37
124.
8634
.97
34.9
634
.98
35.5
942
.81
44.7
034
.57
43.3
812
4.87
119.
8518
2.24
142.
0087
.08
44.6
680
.68
115.
71
0.76
3.01
0.95
0.94
0.97
0.63
1.18
1.03
0.64
0.51
0.67
0.69
0.61
0.59
0.64
0.51
2.60
0.73
0.73
0.73
0.74
0.89
0.93
0.72
0.90
2.60
2.50
3.80
2.96
1.81
0.93
1.68
2.41
SO
4 53
4S 30.4
121
.13
26.0
426
.18
26.4
418
.80
24.6
024
.95
18.7
716
.69
18.8
317
.79
20.8
520
.18
21.7
120
.94
19.0
117
.27
17.5
117
.35
17.3
117
.54
16.9
617
.14
17.4
818
.72
17.5
816
.58
18.1
321
.41
19.6
118
.23
19.7
2
Tabl
e 6.
S
ulfa
te c
once
ntr
atio
nsa
nd 5
348
valu
es in
sur
face
wat
er,
sam
ples
gro
uped
by
area
.
Mon
th/Y
ear
of C
olle
ctio
n S
ampl
ing
Loca
tion
1/98
1/9
87
/98
7/9
87
/98
7/9
87
/98
7/9
87
/98
7/9
85
/99
5/9
95
/99
5/9
95
/99
5/9
95
/99
5/9
95
/99
5/9
95
/99
5/9
9
W.
Ca
na
l 9.. S
Hill
sbor
o C
an
al
@ F
t. 88
0M
iam
i Ca
na
l, 6
mi.
Mia
miC
anal,
12 m
i.N
orth
New
Hve
rCanal
@ R
27
& 82
7N
. N
ew R
verC
anal
©G
olf
Cou
rse
N.
New
Rve
rCa
nal
near
Hol
ey L
and
Hill
sbor
o C
anal
, Ju
nkya
rdH
illsb
oro
Can
al.
@ R
& 8
27 &
880
Hill
sbor
o C
anal
, @
R
.827
#1,
Bel
ow b
ridge
, P
alm
Bea
ch &
Oce
an C
an
al
#2, 8
80 &
B^R
, O
cean C
an
al a
long
880
bef
ore
#3,
Alo
ng 8
80 @
-9m
ibe
nd
,Se
nte
rRd
.#4
. H
illsb
oro
C ,
near
880-
827
inte
rsec
tion
#5.
Off
plat
form
end
of
dirt
roa
d (8
27)
#6,
Junk
yard
off
W.
Ca
na
l Stre
et#7
, Gol
f C
ours
e nearp
um
p s
tatio
n#8
. N.
New
Hve
rCanal
@ R
s. 3
27-2
7#9
, R
27
at H
oly
Land
Wild
life
Ref
uge
#10,
Mia
mi C
an
al o
ff R
. 27
#11,
Mia
mi C
an
al a
t 6
mi b
ridge
#12,
Brid
ge a
t pu
mp
St. a
bout
21 m
i.
Lat
26
41
.83
7'N
26 3
8.73
9'N
26 3
7.43
4'N
Long
80
41
.47
4'W
80 3
4.88
3'W
80 4
9.99
4'W
26 1
9.9
15'N
80460479'W
26 3
6.58
6'N
26 4
2.09
1'N
26
20
.11
8'N
26
41
.83
7'N
26 3
8.7
48
'N26
28.
363'
N2
64
1.0
59
'Nbric2
641.0
77'N
26 4
0.6
90
'N26
38.
748'
N26
28.
406'
N2
64
1.8
37
'N26
42.
091
'N26
36
.60
8'N
2620.1
32'N
26
41
.78
3'N
26 3
7.43
4'N
26 1
9.95
7'N
80 4
2.66
7'W
80 4
2.91
5'W
80 3
2.31
0'W
8041.4
74'W
80
34
.89
1'W
80 2
6.80
9'W
80 2
3.42
2'W
80 2
3.49
0'W
80
32
.12
6'W
8034.8
91'W
80 2
6.81
3'W
80
41
.47
4'W
80 4
2.91
5'W
80 4
2.60
6'W
80 3
2.31
6'W
80 4
8.37
6'W
80 4
9.99
4'W
80 4
6.38
9'W
S0
4
S0
4
mg/l
me
q/l
127.
5679
.77
22.9
523
.76
25.4
326
.80
31.9
629
.88
28.6
540
.70
38.5
738
.86
36.6
770
.58
65.6
671
.16
57.9
566
.27
53.0
913
2.90
74.0
149
.46
2.66
1.66
0.48
0.5
00
.53
0.56
0.67
0.62
0.60
0.85
0.80
0.81
076
1.47
1.37
1.48
1.21
1.38
1.11
2.77
1.54
1.03
S0
4
534S 18
.49
22.1
016
.37
16.4
817
.33
17.0
118
.16
17.2
717
.08
18.9
017
.26
17.4
517
.52
15.0
1n
.d.
n.d
.15
.10
18.6
819
.45
14.6
118
.88
17.6
0
Lake
Oke
ech
obee a
nd T
ribut
ary
Riv
ers
and
Cre
eks:
7/97
7/98
7/9
87
/98
7/9
87
/98
7/9
87/9
87
/98
7/9
8
Wss
imee
Riv
erLa
ke O
., 3t
e 1,
Mid
-poi
nt,
Sur
face
Lake
O.,
9te
1, M
id-d
epth
Lake
O.,
9te
1, B
otto
mLa
ke 0
., 3
te 2
, C
ente
r, S
urfa
ceLa
ke O
., si
te 2
, M
id -d
ep
thLa
ke O
.,3
te 2
, B
otto
m (
111)
Lake
O.,
9te
3, S
outh
Bay
, S
urfa
ceLa
ke O
., at
e 3,
Bot
tom
, (3
.51)
Wsa
mm
ee R
iver
27 0
8.9
30'N
26
51
.04
2'N
26
51
.04
2'N
26 5
1 .0
42'N
26 5
7.7
83
'N26
57.
783'
N26
57.
783'
N2
64
4.1
79
'N2
64
4.1
79
'N27
08
.93
0'N
80 5
2.2
73'W
80 5
2.37
2'W
80
52.
372'
W80
52.
372'
W80
49.
931
'W8
04
9.9
31
'W8
04
9.9
31
'W80
45.
595'
W80
45.
595'
W80
52.
273'
W
9.4
224
.82
26.6
023
.66
23.9
326
.17
24
.43
23.7
324
.72
22.7
5
0.2
00.
520!
550.
490.
500.
550.
510.
490.
510.
47
17.1
516
.89
17.0
116
.57
16.8
016
.73
16.5
616
.70
16.5
417
.01
Tab
le 6
. S
ulfa
te c
once
ntr
atio
ns
and
5348
val
ue s
in s
urfa
ce w
ater
, sa
mpl
es g
roup
ed b
y ar
ea.
Mon
th/Y
ear
of C
olle
ctio
n
Sam
plin
g Lo
catio
n La
t Lo
ng7/
987/
985/
995
/99
5/9
95/9
95
/99
5/9
9
Reh
eatin
g C
reek
Ta y
lo r
C re
e k
Tay
lor C
reek
Kss
imm
ee R
iver
off
78R
shea
ting
Cre
ek,
off
78L
Ok.
, ce
nte
rL
Ok.
. M
id -p
oint
L O
k.,
Sou
th B
ay
26 5
7.78
8'N
81
07.2
23'W
27
12
.59
6'N
80
47.8
66'W
27
12
.59
6'N
80
47.8
66'W
27 0
8.9
30
'N 8
0 5
2.2
73
'W26
57.
788'
N
81 0
7.2
23'W
26
57
.78
3'N
80
49.9
31'W
26
51
.04
2'N
8052.3
72'W
26
44
.17
9'N
80
45.5
95'W
S0
4
304
mg/l
me
q/l
11.7
932
.13
30.2
114
.65
10.6
230
.28
29.2
530
.99
0.25
0.67
0.63
0.31
0.22
0.63
0.61
0.65
SO
4
53
45
22
.79
17.0
616
.75
15.1
724
.01
16.0
616
.47
15.9
9
Tay
lor
Slo
ugh,
Nor
th:
5/96
T
aylo
r S
ough
, nearp
um
p s
tatio
n (1
S1)
5/96
T
aylo
r S
ough
, ce
nte
r (T
S7)
5/96
T
aylo
r S
ough
, ce
nte
r (T
S7)
5/96
H
ead
of T
aylo
r S
ough
, near
brid
ge (
TS2)
5/96
T
aylo
rSou
gh,
mid
-wes
t (T
S7W
)5/
96
Tay
lor
Sou
gh,
mid
-eas
t (T
57§
5/96
T
aylo
r S
ough
, D
elta
, w
este
rn e
dge
(TS1
1)7/
98
TS4
7/98
TS
57/
98
TS7
7/99
TS
77/
99
TS9
Tay
lor
Slo
ugh,
Sou
th:
5/96
1.
5 m
i. no
rth
of M
adie
ra B
ay (
1C2)
5/96
M
angr
ove
swam
p, b
ehin
d sp
ide
ralle
y (1
C1)
5/96
Ta
ylor
Cre
ek,
Skl
ar (1
C 1 A
)5/
96
Tay
lorC
reek
, N
orth
(1C
3)
25 2
5.01
0'N
80
35.6
68'W
3.
2425
1 7
.231
'N 8
0 38
.780
'W
0.00
25 1
7.23
1 'N
80
38.7
80'W
0.
3325
24.
306'
N 8
0 36
.377
'W
6.64
25 1
7.41
9'N
804
0.49
6'W
0.
0025
17.
258'
N 8
0 38
.235
'W
0.18
2512
.786
'N 8
044.
170'
W
58.9
625
20.
310'
N 8
0 38
.670
'W
0.00
25 2
0.03
0'N
80
37.0
40'W
0.
6525
1 7
.231
'N 8
0 38
.780
'W
0.00
25 1
7.2
31 'N
80
38.7
80'W
0.
0025
14.
230'
N 8
040.
936'
W
0.08
25 1
2.70
9'N
80
38.8
89'W
12
9.64
25 1
1.7
73'N
80
38.2
16'W
10
65.7
525
11.8
63'N
803
8.59
8'W
18
95.6
325
12.7
22'N
80
38.8
77'W
14
45.8
1
0.07
0.00
0.01
0.14
0.00
0.00
1.23
0.00
0.01
0.00
0.00
0.00
2.70
22.2
039
.49
30.1
2
n.d.
n.d.
n.d.
29.9
5n.
d.n.
d.26
.95
n.d.
n.d.
n.d.
n.d.
n.d.
23.0
320
.60
20
.77
20
.98
Tab
le 6
. S
ulfa
te c
on
cen
tra
tion
san
d 5
34S
val
ue s
in s
urfa
ce w
ater
, sa
mpl
es g
roup
ed b
y ar
ea.
Mo
nth/
Yea
r of
Col
lect
ion
Sam
plin
g Lo
catio
n
5/96
5/96
5/96
5/96
1/1/
981/
1/98
1/1/
984/
98
Ror
ida
Bay
:
Pass
Key
, Fb
rida
Bay
Whi
p R
ay K
ey,
Ror
ida
Bay
Bob
Alie
n B
ank,
Ror
ida
Bay
Rus
sel K
ey,
Ror
ida
Bay
Rus
sel K
ey,
Ror
ida
Bay
Pas
sKey
, Fb
rida
Bay
Bob
Alie
n B
ank,
Ror
ida
Bay
Eag
le K
ey P
ond
3
904
Lat
Long
m
g/l
2508.8
66'N
8034.4
71'W
17
60.9
62
50
4.3
09
'N 8
0 44
.31
2'W
28
32.7
32501.3
78'N
8039.3
71'W
27
53.6
8250.3
841'N
80
37.5
1 1'
W
2409
.00
25
0.3
84
1'N
80
37.
51 1
'W
1698
.29
2508.8
66'N
80
34
.47
1'W
14
14.8
72501.3
78'N
8039.3
71'W
21
86.4
623
36.2
2
904
me
q/l
36.6
959
.02
57.3
750
.19
35.3
829.4
845
.55
48.6
7
90
4
534S 20
.48
20.2
420
.37
20.3
920
.22
20.3
420
.20
19.9
2
Figure 13. Sulfate in Water in the Northern Everglades, 1995-1999
4.0
3.5
3.0
|2.5
if- 2.0TT
8 1-5
1.0
0.5
0.0{
4.0
3.0
OJ
=-2.08*
1.0
r\ r\' C
4.0
3.0
I «2- 2.0
8
, 1.0
0.0,
4.0
t o f\3.0Ms-
82.0
1.0
nn
! Hillsboro, Miami 40'< and N. New River
Vj Canals in the EAA 3-°
"M -\ ' * 2.0
5iI'B (834S of Elemental SJLj Fertilizer =15.7, 15.9 & 20.3) 1.0
Kissimee River andf ^J"Lake Okeechobee 1p o *
3 5 10 15 20 25 30 35 40 U 'U C 834S(permil)
Hillsboro Canal at Spillways 40Bordering WCA2A
. 3.0
(b)30.Sm, ^S-10C
/A 18m, ; 9m, 1.0Rainwater in \ S-10C ] m s5'^ ~ ~~^_South Florida A \X. A ~~" - A
) 10 -.20 30 40 50 ( 834S(permil)
4.0
WCA2A3.0
-<C)
mlm
' flflj . 1 '°
fr) 5 10 15,. 20 25 30 35 40 0-0C
834S(permil)
WCA2B"
M\-
* , . * . i
WCA3A and Canals
Q\e/
"
PI.J ) 5 10 15,, 20 "5 30 35 40
834S(permil)
WCA1A,
Loxahatchee National Wildlife Refuge-
(f)- * '
-
H1 1 1 B ^ ! , | ,
) 5 10 15. .20 25 30 35 40 834S(permil)
EvergladesNutrient inflow tram EAA,
' Removal Area " Sepl ' 97
- (n) Outflow from ENR,Va/ /Sept. 97
Seepage canal return. ^Xsept.97
) 5 10 15,, 20 25 30 35 40 834S(permil)
~ Surface Water (SW)
O - Water from Lake Okeechobeeand the Kissimee River
A - Groundwater, 9.0 m or greaterdepths below the sediment surface
834S(permil)
39
In the Taylor Slough of the southern Everglades (Fig. 2) sulfate concentrations
are low and 534S values are high in the northern part of the Slough (Table 6). The
mangrove swamps of the southern part of Taylor Slough have very high sulfate con
centrations, reflecting marine influence from Florida Bay. Interestingly, Taylor Creek,
in the mangrove swamps, had high sulfate concentrations in 1996 and relatively low
sulfate concentrations in 1998 and 1999, probably reflecting differences in freshwater
discharge.
Bay waters near small islands (keys) in Florida Bay have sulfate concentra
tions near seawater levels (56 meq/L) and 534S values at the seawater value (-20
per mil) (Table 6; Fig 2). Sulfate concentrations slightly greater than that of seawater
are probably caused by evaporation of the shallow waters of the Bay, while sulfate
concentrations lower than that of seawater are caused by dilution with water from
Taylor Slough. Proximity to the coastline determines the amount of dilution (Pass
Key>Russell Key>Bob Alien Key>Whipray Basin).
Rainwater. Rainwater could cause dilution trends in surface water, but cer
tainly not trends of increase in 634S values. Analysis of rainwater collected in the
ENR from January through March 1998 gives a 534S value of 10.7 per mil (Table 7);
rainwater samples collected from the same site in approximately two month intervals
from March through September 1998 show a range of 834S values from 2.1 to 3.2
per mil. Rainwater collected in WCA 2A in July 1998 had a 534S value 5.9 per mil.
These values are much lower than 534S values for sulfate from surface water that we
have analyzed in any part of the northern Everglades. The rainwater that we collect
ed had sulfate concentrations (0.04 to 0.09 meq/L), that are low in comparison to
sulfate concentrations in surface water and quite similar to sulfate concentrations
40
Table 7. Sulfate concentrations and 834S values In rainwater, 1998.
Month/Year SO4 SO4 SO4 of Collection Sampling Location mg/l meq/l 834S
3/98
6/98
7/98 7/98
9/98 9/98
ENR atG253
ENR atG253
ENR atG253A WCA2A atS10-C
ENR atG253A WCA2A atS10-C
3.38
4.27
1.73 1.71
3.06 0.65
0.07
0.09
0.04 0.04
0.06 0.01
10.742
3.158
2.721 5.892
2.059 n.d
found in rainwater from the northern Everglades region in the early to mid 1970's
(Waller and Earl, 1975).
Groundwater. Surface and groundwater were collected in WCA 2A (Table 8;
Fig. 14a, b) and at the head and tail of the S-10C spillway (Table 8; Fig. 13b) on the
Hillsboro Canal in September, 1997. The sulfate concentration and 534S values from
all of the surface water samples collected at this time fall in range typical of surface
water in WCA 2A (Figs. 13c and 14a). Groundwater beneath WCA 2A (Fig. 14b) is
generally much lower in sulfate concentration compared to surface water (particularly
at 4.5 m depth, and is variable with respect to 634S values. Groundwater collected at
S-10C at 30.5 m depth (Fig. 14b) and at F1 at 9 m depth (Fig. 14b) have sulfate con
centrations as high or higher than surface water. However, their S^S values are sig
nificantly different from surface water; this is also true of groundwater collected at 9 m
depth at all sites. All of these results suggest that groundwater was not the major
source of sulfate to surface water in WCA 2A at the time of collection, although there
does appear to be a greater potential for at least some groundwater influence near
41
the Hillsboro Canal (sites E1, F1, and S-10C; see figure 1) than at sites away from
the canal (Harvey et al., 1998).
Groundwater collected in WCA 2A (Fig. 14c) and at S-10C (Fig. 13b) in June
1998 displays a similar pattern, with sulfate concentrations low in comparison to sul
fate concentrations in surface water except for a very high sulfate concentration for
groundwater at 9 m at site F1 in WCA 2A. The 534S values for groundwater in June
1998 have a greater range of values in comparison to the 534S values obtained from
samples collected in September 1997 (five of the groundwater samples collected at
that time are not included in figure 14c because they had sulfate concentrations
insufficient for isotopic analysis). The very high 534S values in three of the water
samples (40 per mil or greater) are probably due to nearly complete reduction of a
limited sulfate reservoir in groundwater at these sites, possibly the result of drought
conditions during this season (summer of 1998). The 534S values in groundwater
collected at this time are all very different than those obtained in surface water (Fig.
14a).
Groundwater hydrology in the ENR appears to be more complex, and definite
conclusions cannot be drawn concerning its influence on surface water. Groundwater
was collected at five sites along a transect across the ENR (see figure 1), parallel to
the direction of groundwater flow (south-east to north-west). In September 1997, the
near-surface groundwaters (at or above 8 m depth) at these sites fall in the same
[SO4--]--534S field as the surface water samples in the ENR (Figs. 14d,e,f). In June
1998, the concentrations of sulfate in groundwater at these same sites (Fig. 14f) were
not much changed compared to 1997, but the 534Svalues of sulfate tended to be
higher. Groundwater collected at greater depths at these sites tends to have higher
sulfate concentrations, similar to values found in water from the EAA canals.
Groundwater taken at 58 m at the northernmost site on the transect in the ENR
42
(Fig. 1) had sulfate concentrations of 31.99 meq/L (1997) and 33.58 meq/L (1998)
with 834S values of 24.68 and 25.11 per mil, respectively (not shown in figures 14e or
14f).
43
Table 8. Sulfate concentrations and 5348 values in groundwater,samples grouped by area. Data from surface water taken at the same time at the same collection sites is included.
Month/Year SO4 SO4 SO4 of Collection Sampling Location______mg/l meg/1 &34S
Hillsboro Canal:
9/97 S10C,head 67.28 1.40 22.219/97 S10C,tail 58.43 1.22 21.479/97 S-10C.WA 42.79 0.89 9.639/97 S10C.WB 7.79 0.16 21.719/97 S10C.WC 14.94 0.31 24.256/98 SIOC.Head 25.85 0.54 18.116/98 SIOC, Tail 24.76 0.52 18.086/98 S10C-WA 15.61 0.33 14.336/98 S10C-WB 4.30 0.09 20.276/98 S10C-WC 13.51 0.28 48.50
WCA 2A:
6/97 F4, GW4 2.47 0.05 21.956/97 F4. Surface 59.55 1.24 33.486/97 F4.GW3 1.29 0.03 8.136/97 U3, Gw 3 0.99 0.02 6.386/97 U3, Surface 42.48 0.88 22.148/97 E1.GW4 ' 2.45 0.05 21.358/97 E1.GW3 17.82 0.37 16.788/97 E1, Surface 81.09 1.69 23.609/97 WCA-2A. F1.SW 67.17 1.40 24.029/97 WCA-2A, F1.GW4 1.08 0.02 25.059/97 WCA-2A.F1.GW3 187.26 3.90 11.809/97 WCA-2A.U3, SW 66.59 1.39 23.689/97 WCA-2A, U3, GW4 0.67 0.01 31.469/97 WCA-2A, U3, GW3 3.36 0.07 0.949/97 WCA-2A, F4, SW 79.88 1.66 23.099/97 WCA-2A. F4, GW4 0.92 0.02 19.60
44
Table 8. Sulfate concentrations and 534S value sin groundwater,samples grouped by area. Data from surface watertaken at the same time at the same collection sites is included.
Month/ Year of Collection
6/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/98
12/9612/969/979/979/979/979/979/979/979/979/979/979/979/97
Sampling LocationWCA2A, U3, GW3WCA2A, U3, GW4WCA2A, U3, Surface WaterWCA2A, U1.GW3WCA2A. U1.GW4WCA2A, U1, Surface WaterWCA2A, E4, GW3WCA2A, E4, GW4WCA2A, E4, Surface WaterWCA2A, F4. GW3WCA2A, F4, GW4WCA2A, F4, Surface WaterWCA2A, F1.GW3WCA2A, F1.GW4WCA2A, F1, Surface WaterWCA2A, E1.GW3WCA2A, E1.GW4WCA2A, E1, Surface Water
Nutrient Removal Area:
12-5-96, ENR, G'water, 11A12-5-96, ENR, G'water, 11AENR 102ENRG259ENR 002ENR 011ENR103SW{1)ENR103SW{2)MP3-AMP3-BMP3-CMP3-DMP1-AMP1-B
S04 mg/l
2.000.34
40.010.163.03
38.243.6115.8740.551.620.3436.18185.240.00
32.944.400.2553.93
50.0545.6962.0536.28144.3545.7045.3146.59
1535.5179.1139.5961.6440.2854.41
S04 meq/l0.040.010.830.000.060.800.080.330.840.030.010.753.860.000.690.090.011.12
1.040.951.290.763.010.950.940.9731.991.650.821.280.841.13
S04 834S
0.09n.d.
23.21n.d.
43.9622.0045.8515.5122.758.58n.d.
21.6612.60n.d.
19.3439.88n.d.
22.05
28.9328.3228.6730.4121.1326.0426.1826.4424.6819.6523.7827.7927.7727.22
45
Table 8. Sulfate concentrationsand 5348 value sin groundwater,samples grouped by area. Data from surface watertaken at the same time at the same collection sites is included.
Month/Year of Collection
9/979/979/97
.9/979/979/979/979/979/976/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/986/98
Sampling LocationMP1-CMP1-DMP2-A(1)MP2-A (2)MP2-BM203PM203PZM103PM103PZBJR004BvJR011BvJRG259BvJR012BvJR002MP1-AMP1-BMP1-CMP1-DMP2-AMP2-BMP2-CMP2-DMP3-AMP3-BMP3-CMP3-DMP3-TWMP3-HWMOP3-AMOP2-AMOP2-BMOP2-CMOP1-AMOP1-BM103PZM103P
S04 mg/l
35.8926.67118.4170.53164.2338.38114.10174.0951.1630.1456.8449.5530.6924.7234.8816.976.999.7792.93175.5361.75n.d.
1611.3056.4566.4741.1342.1755.91
1857.7052.2616.919.79
69.001.65
36.60135.65
S04 meq/l
0.750.562.471.473.420.802.383.631.070.631.181.030.640.510.730.350.150.201.943.661.29n.d.
33.571.181.380.860.881.16
38.701.090.350.201.440.030.762.83
SO4 534S
26.0622.1917.5124.4617.3614.2130.9419.4127.9418.8024.6024.9518.7716.6932.7838.5325.2536.2219.3524.6931.53n.d.
25.1124.2736.1328.5825.7820.4615.5231.1240.6925.6218.2336.7139.7730.52
46
Table 8. Sulfate concentrations and 534S value sin groundwater,samples grouped by area. Data from surface water taken at the same time at the same collection sites is included.
Month/Year of Collection
6/986/986/986/986/986/986/986/986/986/986/986/98
Sampling LocationM103 Surface WaterM102PM 102 Surface Water ,M203PZM203PM203 Surface WaterM204PM204 Surface WaterM303PM303 Surface WaterM401PM401 Surface Water
804 mg/l
32.27221.4533.18119.9029.6229.1859.0928.5467.0230.7932.1024.37
804 meq/I0.674.610.692.500.620.611.230.591.400.640.670.51
804 534S
18.8323.8917.7931.6419.3220.8525.1920.1828.8321.7132.5320.94
47
Figure 14. Comparison of Sulfate Concentrations and 834S Values in Surface and Ground Water in WCA2A and the ENR
WCA2A ENR
4.0
3.5
3.0
1" 2.52
& I-5
1.0
0.5
0.0,
" Surface Water,' September 1 997 and June 1 998-_.(a)
\ ^
iii i i i i) 5 10 15 20 25 30 35 40
Surface Water
4-° " Surface Water,3-5 ' September 1 997 and June 1 9983.0 -
2.5 -
2.0 - (d)
1.5 -
1.0 - *m0.5 - "n n . , i , iU-U 0 5 10 15 20 25 30 35 40
D Ground Water, 4.5 to 9.0 m depth below sediment surfaceA Ground Water, 9.0 m or greater depths
4.0
3.5
_ 3.0
<u 25 s. "n- 2.0 *r
0 1.5en
1.0
0.5
Fi,9m A Groundwater,September 1997
---(b).-
A
°-°0 5 10 15 2D~ 25 3CT 35 40
4.0
3.5
_ 3.0*"o'l-Sen
1.0
0.5
o.oj
F1,9m AGroundwater,June 1998
--(c)--
nA A , i A n Ar no 20 so 40
534S(permil)
4'° " A Groundwater,3 - 5 ~ A September 19973.0 -
2.5 - A n2.0 - (B)
1.5 - 4 n1-0 - n nf
0.5 - A
°'°0 5 10 15 20 25 30 35 40
4-° " Groundwater,3-5 - June 1998 A3.0- A2.5 - n2.0 - (fl D
1 '5 " A A AA ^
1.0 - A n U A nn /A LJ 0.5 - R A
. 00 . , , : D . ,A A .50 "'U0 5 10 15 20 25 30 35 40
5^S (per mil)
48
Summary
The results of analysis of solid phase sediment samples from the Everglades
indicate that there has been an increase in sulfur input to the Everglades in recent
times. This is particularly evident in sediment from WCA 2A that receives direct
runoff from the Hillsboro Canal. Concentrations of sulfur species show that organic
sulfur is usually the dominant species in the core sediments, probably because sul-
fide fixation is limited by reactive iron availability. The organic sulfur is likely pro
duced by reaction of sulfide with the organic matter-rich sediment. Positive 834S val
ues for almost all sulfur species in all sediment samples indicate that there is a rela
tively restricted supply of sulfate. Variations in the 834S values with depth in the sedi
ment are the result of changes in the amount of sulfate available, variations in the
rate of reduction of sulfate to sulfide, and/or to changes in the 834S values of the
source sulfate.
We conclude from our data that much of the dissolved sulfate in the northern
Everglades is coming from the EAA by way of the canals that drain the agricultural
lands. The origin of this sulfate could be sulfur from fertilizer used in the EAA, rain
water, Lake Okeechobee water, groundwater, or a combination of these sources.
The sulfate concentration in rainwater is far too low to account for the concentration
of sulfate found in the canals in the EAA. Lake Okeechobee is certainly the origin of
much of the water in the EAA canals (Bottcher and Izuno, 1994). During seasons of
normal rainfall, the sulfate concentration was low in surface water collected from
Lake Okeechobee and from the Kissimmee River as it enters the lake (Fig. 1; Fig.
2a) in comparison to the sulfate concentrations in water collected from the canals in
the EAA (Fig. 2a). In contrast, during the Spring-Summer 1998 drought season, sul
fate concentrations in canal water in the EAA plummeted to values only a little higher
49
than in the Lake. It is likely that during a dry season the water in the canals is domi
nated by discharge from the lake with limited contributions from rainfall runoff from
EAA fields (Bottcher and Izuno, 1994). Sulfate concentrations during periods of
drought therefore largely reflect Lake Okeechobee discharge. Three separate batch
es of elemental sulfur fertilizer (98% S°), usually referred to as agricultural sulfur,
were purchased in the EAA and analyzed for total sulfur 534S values. The values
obtained were 15.7 (purchased in 1996), 20.3 (purchased in 1997), and 15.9 per mil
(purchased in 1999). We found that sulfate extracted from agricultural soil had a
534S value of 15.6 per mil. These values are at least consistent with agricultural sul
fur being a major contributor to sulfate content in the agricultural lands and the adja
cent canals. However, concentrations of sulfate from groundwater (>9 m) beneath the
ENR are as high as sulfate in the canals in the EAA, and some of the 634S values
for sulfate in groundwater in the ENR are close to the values for sulfate in the EAA
canals (15 to 22 per mil). If groundwater beneath the ENR (formerly a part of the
EAA) is representative of groundwater beneath the EAA, then pumping or natural dis
charge of groundwater to the EAA canals cannot be excluded as contributors of sul
fate to the canals that drain the EAA. An analysis of groundwater from within the
EAA is planned for in the future.
50
Acknowledgments
The USGS Place Based Studies Program funded this project. The South
Florida Water Management District (SFWMD) provided logistical support. We thank
Tom Fontaine, Larry Fink, Steve Krupa, Cynthia Greenlaw, Pete Rawlik (SFWMD),
Dave Krabbenhoft (USGS), Tom Atkinson (Florida Department of Environmental
Protection), Cindy Gilmour (Benedict Marine Lab), and other members of the Aquatic
Cycling of Mercury in the Everglades Project for many helpful discussions and for
field support. Special thanks to Robert Mooney (SFWMD) for providing rainwater for
analysis and to Margo Corum, Ann Boylan, and Sharon Fitzgerald (USGS) who
helped with surface water collection. Special thanks and appreciation also to Aaron
Higer and Sarah Gerould for their support of this project and their faith in our vision.
51
References
Bates, A.L., Spiker, E.G., Orem, W.H., Burnett, W.C. (1993) Speciation and isotopic composition of sulfur in sediments from Jellyfish Lake, Palau. Chem. Geol. 106: 63-76.
Bates, A.L., Spiker, E.G., and Holmes, C.W. (1998) Speciation and isotopic
composition of sedimentary sulfur in the Everglades, Florida, USA. Chem. Geol. 146: 155-170.
Berner, R.A. (1980) Early Diagenesis, A Theoretical Approach. Princeton Univ. Press, Princeton, NJ, 241 pp.
Bemer, R.A., Raiswell, R. (1984) C/S method for distinguishing freshwater from
marine sedimentary rock. Geology 12:365-368.
Bottcher, A.B and Izuno, FT. (eds) (1994) Everglades Agricultural Area (EAA) -
Water, Soil Crop, and Environmental Management. University Press of
Florida, Gainesville, Florida, 318 pp.
Boudreau, B.P. and Westrich, J.T. (1984) The dependence of bacterial sulfate reduc
tion on sulfate concentration in marine sediment. Geochim. Cosmochim. Acta
48:2503-2516.
Canfield, D.E., Raiswell, R., Westrick, J.T, Reaves, C.M., Berner, R.A. (1986) The use of chromium reduction in the analysis of reduced inorganic-sulfur in sedi ments and shales. Chem. Geol. 54: 149-155.
Canfield, D.E. (1991) Sulfate reduction in Deep-sea sediments. Am. J. Sci. 291: 177-
189.
Craft, C.B. and Richardson, CJ. (1993) Peat accretion and phosphorus
accumulation along a eutrophication gradient in the northern Everglades.
Biogeochemistry, 22: 133-156.
52
DeBusk, W.F., Reddy, K.R., Roch, M.S. and Want, Y. (1994) Spatial distribution of soil
nutrients in a Northern Everglades Marsh: Water Conservation Area 2A. Soil Sci. Soc. Am. J., 58: 543-552.
Fish, J.E. (1988) Hydrology, aquifer characteristics, and groundwater flow of the sur
ficial aquifer system, Broward County, Florida. US Geological Survey Water- Resources Investigation Report 87-4034, Tallahassee, FL, p. 92.
Gleason, J.P. and Stone, P. (1994) Age, origin, and landscape evolution of the
Everglades peatland. In: Davis, S.M., Ogden, J.C. (Eds.), Everglades-The Ecosystem and its Restoration. St. Lucie Press, Delray Beach, FL, pp. 149-
197.
Goldhaber, M.B. and Kaplan, I.R. (1974) The sulfur Cycle. In: Goldberg, E.D. (Editor)
The Sea. J.Wiley & Sons. 5: 569-655.
Hurley, J.P., Krabbenhoft, D.P., Cleckner, L.B., Olson, M.L, Aiken, H.R. and Rawlik, P.S. Jr. (1998)) System controls on the aqueous distribution of mercury in the
northern Florida Everglades. Biogeochem. 40: 293-31. Koch, M.S. and Reddy, K.R. (1992) Distribution of soil and plant nutrients
along a trophic gradient in the Florida Everglades. Soil Sci. Soc. Am. J., 56:
1492-1499.
Lambou, V.W., Barkay, T, Braman, R.S., Delfino, J.J., Jansen, J.J., et al. (1991) Mercury Technical Committee Interim Report to the Florida Governor's Mercury in Fish and Wildlife Task Force. Environmental Monitoring and Wet Environments Research Program, Center for Biomedical and Toxicological Research and Waste Management, Florida State University, Tallahassee, FL,
60 pp.
Nakai, N. and Jensen, M.L. (1964) The kinetic isotope effect in the bacterial reduction and oxidation of sulfur. Geochem. et Cosmochim. Acta. 28: 1893-1912.
Orem, W.H., Lerch H.E. and Rawlik P. (1997) Geochemistry of surface and pore
water at USGS coring sites in wetlands of south Florida. USGS Open-File
Report 97-454, 55 pp.
53
Orem, W.H., Lerch, H.E., Zielinski, R.A., Bates, A.L., Boylan, A., and Corum, M.
(1999) Nutrient geochemistry of the south Florida wetlands ecosystem:
Sources, accumulation, and biogeochemical cycling. U.S. Geological Survey
Program on the South Florida Ecosystem, Proceedings of the South Florida Restoration Science Forum, Boca Raton, FL, May 1999, U.S. Geological Survey Open-File Report 99-181, p. 80-81.
Sonntag, W.H. (1987) Chemical characteristics of water in the surficial aquifer sys
tern, Dade County, Florida. US Geological Survey Water Resources
Investigations Report 87-4080, Tallahassee, FL, 42 pp.
Thode, H.G., Monster, J. and Dunford, H.B. (1061) Sulfur isotope geochemistry. Geochim. Cosmochim. Acta. 25: 159-174.
Tuttle, M.L., Goldhaber, M.D., Williamson, D.L (1986) An analytical scheme for deter
mining forms of sulphur in oil shales and associated rocks. Talanta 33 (12): 956-961.
Waller, B.C. and Earle, J.E. (1975) Chemical and biological quality of water in part of the Everglades, Southeastern Florida. US. Geological Survey Water- Resources Investigations Report 56-75, Tallahassee, Florida, pp. 156.
54
