Source: http://books.nap.edu/openbook.php?record_id=12988&page=149
Timestamp: 2013-06-19 22:50:48
Document Index: 30647458

Matched Legal Cases: ['§ 62', '§62', '§373', '§ 62', '§ 373', '§ 62', '§ 62', '§ 62']

2011 ) / 5 Challenges in Restoring Water Quality Prev ChapterPrev Page Next PageNext Chapter Prev ChapterPrev Page Next PageNext Chapter Print
Front Matter R1-R14 Abstract 1-2 Summary 3-14 1 Introduction 15-22 2 The Restoration Plan in Context 23-61 3 Implementation Progress 62-111 4 Challenges in Restoring Water Timing, Flow, and Distribution 112-148 5 Challenges in Restoring Water Quality 149-204 6 Use of Science in Decision Making 205-243 References 244-262 Acronyms 263-265 Glossary 266-278 Appendixes 279-280 Appendix A: National Research Council Everglades Reports 281-286 Appendix B: Timeline of Significant Events in South Florida Ecosystem Management and Restoration 287-290 Appendix C: Status of Key Non-CERP Projects 291-300 Appendix D: Regulation Schedule for WCA-3A 301-302 Appendix E: Water Science and Technology Board; Board on Environmental Studies and Toxicology 303-304 Appendix F: Biographical Sketches of Committee Members and Staff 305-312 5
“Getting the water right” is a simple phrase that belies the inherent complexity of the overarching goal of the Comprehensive Everglades Restoration Plan (CERP). In Chapter 4, the committee discussed the challenges of water storage and distribution, and the necessity of making tradeoffs in the planning process to optimize the overall restoration benefits. Yet, water quality and water quantity are inextricably linked. Restoration planners cannot design projects to move large quantities of water south into the Everglades Protection Area to meet CERP goals without first ensuring that the water will meet established water quality criteria. Meanwhile, getting the water quality right has proven more difficult than originally imagined, and water quality has become a central technical, legal, and policy challenge that is affecting CERP progress.
In this chapter, the committee describes the legal context to water quality issues in the Everglades and analyzes the success of the water quality initiatives implemented to date. The committee also considers other possible water quality solutions and their cost implications. Water quality issues affecting aquifer storage and recovery (ASR) are not addressed in this chapter but are discussed briefly in Chapter 3.
PRE-DRAINAGE NUTRIENT CONDITIONS
Before construction of the canal and ditch networks began during the late 1900s, direct precipitation was the main source of water to much of the Everglades region. Although there are no water quality data extending back to that time, the general characteristics of the water quality can be reconstructed from measurements in the most interior sections of the marsh and from studies of the chemical composition of the dominant water sources. Recent hydroecological research, using a variety of methods including stable isotope analyses and chemical ratios (e.g., sulfate to chloride ratios), has demonstrated that under pre-drain-
5 Challenges in Restoring Water Quality ." Progress Toward Restoring the Everglades: The Third Biennial Review - 2010 . Washington, DC: The National Academies Press,
“Getting the water right” is a simple phrase that belies the inherent complex-
ity of the overarching goal of the Comprehensive Everglades Restoration Plan
(CERP). In Chapter 4, the committee discussed the challenges of water storage
and distribution, and the necessity of making tradeoffs in the planning process
to optimize the overall restoration benefits. Yet, water quality and water quantity
are inextricably linked. Restoration planners cannot design projects to move
large quantities of water south into the Everglades Protection Area to meet CERP
goals without first ensuring that the water will meet established water quality
criteria. Meanwhile, getting the water quality right has proven more difficult than
originally imagined, and water quality has become a central technical, legal,
and policy challenge that is affecting CERP progress.
In this chapter, the committee describes the legal context to water quality
issues in the Everglades and analyzes the success of the water quality initiatives
implemented to date. The committee also considers other possible water qual-
ity solutions and their cost implications. Water quality issues affecting aquifer
storage and recovery (ASR) are not addressed in this chapter but are discussed
briefly in Chapter 3.
Before construction of the canal and ditch networks began during the late
1900s, direct precipitation was the main source of water to much of the Ever-
glades region. Although there are no water quality data extending back to that
time, the general characteristics of the water quality can be reconstructed from
measurements in the most interior sections of the marsh and from studies of the
chemical composition of the dominant water sources. Recent hydroecological
research, using a variety of methods including stable isotope analyses and chemi-
cal ratios (e.g., sulfate to chloride ratios), has demonstrated that under pre-drain-
150 Progress Toward Restoring the Everglades
age conditions, surface water and groundwater were relatively small components
of the Everglades water inputs (see Table 4-1; Harvey and McCormick, 2009).
The rainfall input is characterized by low ionic strength (median specific
conductance of <20 microsiemens per centimeter [μS/cm]) and generally low
concentrations of all major ions (i.e., largely <1 parts per million [ppm, or mil-
ligrams per liter], except for sulfate and chloride, because of marine aerosol
influences). Rain-fed areas of the Everglades (e.g., the interior of the Arthur R.
Marshall Loxahatchee National Wildlife Refuge [LNWR]) have conductivities of
<100 μS/cm. Rainfall is also notably low in nitrogen and phosphorus; estimates
of phosphorus concentrations and loading in rainwater range from 30 parts per
billion (ppb) (Davis, 1994) to more recent measurements of 9 to 10 ppb (Ahn
and James, 2001; Richardson, 2008).
Water quality data going back to 1978 show that the interior portions of the
Water Conservation Areas (WCAs) and Everglades National Park are uniformly
at or below 10 ppb total phosphorus (TP). Water samples taken between 1978
and 2003 in Everglades National Park have geometric mean TP concentrations
of 4.5-5.6 ppb and geometric mean total nitrogen (TN) concentrations of 0.9-1.4
ppm (Payne and Weaver, 2004). A study conducted in 1953, prior to the intensive
agricultural development of the Everglades Agricultural Area (EAA) but after con-
struction of the major canals, showed “dissolved phosphorus” concentrations of
3–7 ppb in the Tamiami Trail canal and the lower portions of the canals bordering
what is now WCA-3B, with concentrations about an order of magnitude higher
in samples closer to Lake Okeechobee (Odum, 1953). In the absence of explicit
data from the pre-drainage period, one can assume that the rain-driven system
would have had similar water quality characteristics (i.e., low alkalinity, low total
nitrogen and phosphorus concentrations) derived primarily from atmospheric
deposition. Any phosphorus inputs from Lake Okeechobee overflows were gen-
erally thought to have been assimilated by the former pond apple swamp that
existed between the lake and the sawgrass plains (Noe et al., 2001).
LEGAL CONTEXT FOR WATER QUALITY IN THE SOUTH FLORIDA ECOSYSTEM
Water quality criteria and standards (see Box 5-1) in the South Florida eco-
system are governed by a mix of federal and state statutes, implementing regula-
tions, and judicial consent decrees. Current and proposed standards are fiercely
contested, and active litigation in federal courts continues to create uncertainty
as to which regulations will apply to future restoration plans. Because these
criteria and standards have important implications for the CERP as it moves
forward, the current legal and regulatory context is described in this section.
Current standards, including designated uses and supporting criteria, are
designed to limit the nutrient content of waters (especially phosphorus) flowing
Challenges in Restoring Water Quality 151
Definitions of Water Quality Criteria and Standards
Regulatory documents commonly use the terms “standards” and “criteria.” The two
terms are not synonymous. Water quality standards consist of three elements (EPA, 1998):
1) The designated use or uses of a water body or segment of a water body;
2) Water quality criteria necessary to protect the designated uses; and
3) An antidegradation policy.
Classes of designated uses are defined by states. In Florida, those classes are defined
in Florida Administrative Code (FAC) §§ 62-302.400 as:
CLASS I—Potable Water Supplies
CLASS II—Shellfish Propagation or Harvesting
CLASS III—Fish Consumption; Recreation, Propagation and Maintenance of a
Healthy, Well-Balanced Population of Fish and Wildlife
CLASS III-Limited—Fish Consumption; Recreation or Limited Recreation; and/or
Propagation and Maintenance of a Limited Population of Fish and Wildlife*
CLASS IV—Agricultural Water Supplies
CLASS V—Navigation, Utility, and Industrial Use
Water quality criteria are of two forms, numeric and narrative. Numeric criteria are
maximum acceptable concentrations of specific chemicals or acceptable ranges of
other parameters such as temperature that will protect human health and aquatic life
in a particular water body. Narrative criteria are qualitative statements such as those
in FAC §§62-302.500 that all waters shall be free of substances that cause specified
nuisance conditions and those that are acutely toxic.
*The Class III-Limited designation was added by the state of Florida in August 2010 and still
needs EPA review and approval.
into Lake Okeechobee and the Everglades Protection Area. In general terms, one
set of criteria was established for water quality within the Everglades and other
standards set limits on the actual discharges of phosphorus into water bodies.
The controlling federal statute is the Clean Water Act (CWA). It requires
states to establish water quality standards that will support designated uses of
waterways, and it establishes a permit program for discharges of wastewater and
stormwater into receiving waters of the United States. Although rather stringent
limits can be placed on point sources under authority of the CWA, nonpoint
sources are not subject to the federal permit program.
In 1987, the state of Florida exercised its authority to address nonpoint
sources by adopting the Surface Water Improvement and Management (SWIM)
152 Progress Toward Restoring the Everglades
program (Florida Statute Chapter 373.453). SWIM directed Florida’s water man-
agement districts to develop and implement plans to clean up and preserve
the state’s lakes, bays, estuaries, and rivers. SWIM also directed that the water
management districts’ operations not “adversely affect indigenous vegetation
communities or wildlife.” Thus, Florida set narrative regulatory criteria to ensure
that phosphorus concentrations would cause “no imbalance in flora or fauna,”
which is now formalized in Florida Administrative Code (FAC) 62-302.5301 (see
also Rizzardi, 2001).
Water Quality Standards for the Everglades Protection Area
In 1988, the United States sued the state of Florida and the South Florida
Water Management District (SFWMD), alleging that the state had failed to ade-
quately clean up waters flowing into Everglades National Park (ENP) and LNWR
(also known as WCA-1).2 After several years of litigation the parties entered into
a settlement agreement in 1991 that was implemented by a Consent Decree in
1992. The 1991 settlement agreement contained several provisions, including
• a general commitment on the part of the SFWMD and the Florida Depart-
ment of Environmental Protection (FDEP) to protect water quality in LWNR and
• adoption of interim and long-term total phosphorus limits,3
• certain remedial measures,
• a research and monitoring program, and
• contingencies for enforcement.
Remedial measures included a commitment by the SFWMD to construct 35,000
acres of stormwater treatment areas (STAs) and an interim and long-term regula-
tory program to require permits on all discharges from the EAA. Interim regula-
tions for the EAA were to require a 10 percent reduction in phosphorus loads,
Florida’s narrative water quality criterion for nutrients provides that “in no case shall nutrient
concentrations of a body of water be altered so as to cause an imbalance in natural populations of
aquatic flora or fauna.” (F.A.C. rule 62-302-530(47)(b)).
United States v. South Florida Water Management District, 847 F. Supp. 1567 (S.D. Fla. 1992).
Interim limits for phosphorus were to be achieved by July 1997 (later amended to October 2003),
including annual flow-weighted concentration goals in Shark River Slough of no more than 14 ppb
in a dry year and 9 ppb in a wet year. Long term limits were to be achieved by 2002 (later amended
to 2006) including annual flow-weighted concentration goals in Shark River Slough of no more than
13 ppb in a dry year and 8 ppb in a wet year, and the long-term concentration limit for Taylor Slough
and the Coastal Basins was set at 11 ppb. Interim and long-term limits for Everglades National Park
and LNWR were specified by complex formulas in Appendices A and B of the Settlement Agreement.
Interim levels for LNWR were to be between 8 and 22 ppb depending on water levels as measured.
Challenges in Restoring Water Quality 153
and the long-term regulations were to require source control efforts resulting in
a 25 percent reduction.
The state of Florida took action in 1994 to implement the primary features of
the 1992 Consent Decree with enactment of the Everglades Forever Act (Fla. Stat.
§373.4592). A crucial feature of the act directed the FDEP to develop numeric
criteria for phosphorus within the Everglades Protection Area, defined as WCAs 1
(LWNR), 2A, 2B, 3A, and 3B, and Everglades National Park (FAC §§ 62-302.540).
However, the Act provided that if no phosphorus criterion was adopted by the end
of 2003, a 10 ppb criterion would automatically take effect in 2004 (see Fla. Stat.
§ 373.4592(10)). Scientific support for that criterion, added to the administrative
code in July 2004, is discussed in Box 5-2. Modifications to the Consent Decree4
in 2001 deferred the compliance date for long-term phosphorus limits to 2006.
The state of Florida amended the Everglades Forever Act in 2003 and formally
adopted the revised phosphorus rule (FAC §§ 62-302.540).5 That rule states that
for Class III waters in the Everglades Protection Area, the phosphorus criterion is
a long-term geometric mean of 10 ppb, but not lower than natural conditions,
taking into account temporal and spatial variability. Achievement of the criterion
in Everglades National Park is governed by methods in Appendix A of the 1991
Settlement Agreement, and achievement of the criterion in the WCAs is evaluated
across a network of sampling stations using a four-part test6 to determine whether
a violation of Class III standards has occurred. Current methods for calculating
values for Consent Decree compliance in LWNR and Everglades National Park,
considering interannual variations in water levels, are described in the December
2009 report of the Technical Oversight Committee (SFWMD, 2009b).
Several important changes were also made in the 2003 Everglades For-
ever Act amendments. Long-term permit conditions were modified, and new
“Technology-based Effluent Limitations (TBELs) established through Best Avail-
able Phosphorus Reduction Technology (BAPRT)” were established to govern STA
discharges (FAC §§ 62.302.540). Water-quality-based effluent limitations were
held in abeyance until 2016. In addition, paragraph (6) allows net improvement
as a moderating provision for “impacted” areas, where those areas are defined
as being in the Everglades Protection Area with total phosphorus concentrations
in the upper 10 centimeters of the soils greater than 500 milligrams per kilogram.
See http://exchange.law.miami.edu/everglades/litigation/federal/usdc/88_1886/orders/2001_
amend_ Settlement_Agreement.pdf.
See also Miccosukee Tribe of Indians of Florida v. United States, 2008 WL 2967654 (S.D. Fla.).
The four-part test is used to assess compliance according to the following four provisions: (1) five-
year geometric mean is less than or equal to 10 ppb, (2) annual geometric mean averaged across
all stations is less than or equal to 11 ppb, (3) annual geometric mean averaged across all stations
is less than or equal to 10 ppb for three of five years, and (4) annual geometric mean at individual
stations is less than or equal to 15 ppb (FAC §§ 62.302.540).
154 Progress Toward Restoring the Everglades
Scientific Support for the 10 ppb Criterion
The determination of the 10 ppb total phosphorus (TP) criterion was based on
extensive research (McCormick et al.,1999; Payne et al., 2001, 2002, 2003; reviewed
in Noe et al., 2001; Richardson, 2008). The data overwhelmingly demonstrate that
even low levels of enrichment in total phosphorus concentrations result in elevated
phosphorus in macrophyte tissues, soil, the water column, and periphyton, leading
to undesirable changes in periphyton and macrophyte biomass and productivity and
Under pre-disturbance conditions, isolation of the surface-water system from bed-
rock meant that the only significant inputs of phosphorus were from atmospheric sourc-
es, estimated to be in the range of 0.03 grams per m2 per year (Noe et al., 2001). In
interior (undisturbed) portions of the Everglades, phosphorus concentrations in plant
and periphyton biomass and in soil are very low compared to other wetlands and other
peatlands, and the nitrogen:phosphorus ratios in these compartments suggest extreme
phosphorus limitation, which Noe et al. (2001) ascribe to several factors, including
• its occurrence on a limestone platform, which promotes removal and sequestra-
tion of phosphorus through abiotic chemical reactions;
• the very large spatial extent of the system, such that groundwater from other
regional sources are isolated from all but the periphery of the system and most of the
system receives the bulk of its nutrients from precipitation (ombrotrophic);
• conservative cycling of phosphorus by the dominant macrophytes;
• periphyton mats that maintain highly oxidized sediments, so that any phosphorus
becomes adsorbed to iron minerals and is not bioavailable; and
• the ability of Everglades plants (notably, Cladium, Eleocharis, and related spe-
cies) to grow at unusually low tissue phosphorus concentrations.
These changes were challenged by the Miccosukee Tribe in the U.S. Dis-
trict Court as violating both the 1992 Consent Decree and the federal CWA. In
July 2008, the court agreed that the changes (e.g., deferrals) violated the CWA,
enjoined the FDEP from issuing any permits under the revised program, and
ordered federal EPA to rigorously review the state program to ensure compliance
with the CWA. The effect of this ruling was to effectively reinstate the 10 ppb
rule and other features of the 1992 Consent Decree and the 1994 Everglades
Forever Act. Subsequently, in April, 2010, the court reaffirmed that deferring
compliance until 2016 violated federal law. New orders were issued for EPA to
issue instructions to compel the state of Florida to comply with the 10 ppb crite-
rion and for the State to complete new rulemaking to that effect in early 2011.7
Miccosukee Tribe of Indians of Florida v. United States of America, Lead Case No. 04-21448-CIV-
GOLD; Order Granting Plaintiffs’ Motions in Part; Granting Equitable Relief, Requiring Parties to
Take Action by Dates Certain, April 14, 2010.
Challenges in Restoring Water Quality 155
Water Quality Standards for Lake Okeechobee and Tributaries
Section 303(d) of the CWA requires that when a water body does not meet
applicable water quality standards, the state or U.S. Environmental Protection
Agency (EPA) must set numeric limits on point and nonpoint source discharges to
assure that the water body will satisfy the standards. Following a 1999 Consent
Decree,8 Florida enacted the Lake Okeechobee Protection Act in 2000 (Chapter
00-103, Laws of Florida), requiring limits on phosphorus inflows into the lake.
FDEP developed and EPA approved a phosphorus total maximum daily load
(TMDL) for Lake Okeechobee of 140 metric tons (mt) annually (105 mt from
nonpoint surface runoff and 35 mt from atmospheric deposition; FDEP, 2001;
Chapter 62-304, Laws of Florida). In addition, the rules prescribed a 40 ppb TP
goal for the pelagic zone in the lake, and a target of 113 ppb was established
for the lake’s tributaries, as recommended by FDEP, to provide protection of
aquatic life within each tributary while maintaining consistency with the Lake
Okeechobee TMDL (EPA, 2008a). The 113 ppb target was selected for the
Lake Okeechobee tributaries as a numerical interpretation of Florida’s narrative
criterion until a numeric criterion was developed. In March 2009 a group of
environmental organizations filed suit challenging the EPA action and arguing
that the “interim” TMDL violates the CWA.9 This case is pending.
Statewide Numeric Limits for Nutrients
Recent actions have been taken to establish statewide numeric criteria for
nutrients (i.e., phosphorus and nitrogen) in Florida’s waters. In 1998 EPA for-
mulated a national strategy for development of regional nutrient criteria (EPA,
1998). In doing so it cited evidence that nutrients were among the leading causes
of impairment in rivers, lakes, and estuaries, and noted that 51 percent of lakes
and 57 percent of the nation’s estuaries were impaired by over-enrichment of
nutrients (EPA, 1996). At the time the only national criterion for nitrogen was a
health-based limit for the protection of domestic water supplies, and the only
national phosphorus criterion was based on “a conservative estimate to protect
against the toxic effects of the bioconcentration of elemental phosphorus to
estuarine and marine organisms.” That strategy was revisited in 2007 (EPA, 2007).
A 2008 national status report on numeric nutrient criteria showed that 31 states
had no numeric criteria for nutrients in lakes and reservoirs, 36 had none for
rivers and streams, and half of the 24 states with estuaries had none (EPA, 2008b).
See Florida Wildlife Federation v. Carol Browner, No. 4:98CV356-WS (N.D. Fla. Tallahassee
Div., April 22, 1998).
Florida Wildlife Federation, et al v. The United States Environmental Protection Agency, Case
4:09-cv-00089-SPM-WCS (N.D. Fla.).
156 Progress Toward Restoring the Everglades
FDEP began development of statewide numeric nutrient criteria in 2002,
soon after reaching agreement with EPA on a plan for the process. A technical
advisory committee was appointed and met 22 times between 2002 and 2010
(FDEP, 2009). A lawsuit over the lack of progress prompted EPA to intervene,
and in August 2009, EPA entered into a phased Consent Decree to settle the
suit.10 EPA committed to propose numeric nutrient criteria for lakes and flowing
waters in Florida by January 14, 2010. Proposed criteria for lakes, flowing waters,
springs, and South Florida canals were published in the Federal Register on Janu-
ary 26, 2010 (75 FR 4174-4226). The approach and the criteria are summarized
in Box 5-3. EPA intends to issue a final rule for lakes and flowing water (outside
of South Florida) by November 15, 2010, and by August 2012 for estuarine and
coastal waters and South Florida canals, unless Florida submits and EPA approves
state numeric nutrient criteria before a final EPA action.
The implications of the new statewide numeric nutrient criteria are uncer-
tain at the time of this report, most importantly because the proposed criteria
for lakes, flowing waters, springs, and canals are subject to change during the
public comment period. Proposed criteria for estuaries are not scheduled for
publication until 2011. Additional determinations will also be needed regarding
which data are to be used in analyses and evaluated against the criteria.
Proposed nutrient limits for South Florida canals (42 ppb TP, 1.6 ppm TN,
4 ppb chlorophyll a) could present yet another challenge to management of
the system, depending upon how these criteria are enforced and how the Class
III-limited designation (see Box 5-1) is applied. A requirement for all canals to
achieve these nutrient concentrations would require significant changes in cur-
rent nutrient control and treatment efforts at immense cost.
Water Quality Standards: Attainability and Cost
The CWA established water quality standards to protect aquatic life and
human health without regard to available technology and the cost associated
with attaining the standards. The cost of attaining and maintaining the standards
may be considered during formulation and implementation of water quality
management programs, but options for doing so are quite burdensome.
As discussed later in this chapter, attaining water quality standards in the
Everglades system may take decades of sustained effort at very substantial costs.
In proposing numeric nutrient criteria for Florida, EPA requested comments
on a possible new option, a “restoration water quality standard” for impaired
waters that would enable the state to take incremental steps toward attainment
Florida Wildlife Federation et al. v. Stephen L. Johnson and the U.S. Environmental Protection
Agency, No. 4:08-cv-324-RH-WCS (N.D. Fla.).
Challenges in Restoring Water Quality 157
EPA Proposed Numeric Nutrient Criteria
for Lakes and Flowing Waters
The U.S. Environmental Protection Agency (EPA) used correlations between nu-
trients and biological response parameters to derive nutrient criteria for lakes using
stressor-response models. EPA concluded that relationships between nutrients and
chlorophyll-a in Florida’s rivers and streams were affected by so many variables that
derivation of reliable criteria using models was not possible. EPA chose instead to use
the statistical distribution-reference site approach for those water bodies as the bet-
ter basis for setting criteria. Numeric criteria were also derived for springs and clear
streams. They were derived from laboratory and field investigations that supported
development of a dose-response model for nuisance algal and periphyton responses
to doses of nitrite and nitrate nitrogen. Criteria for canals in South Florida were derived
using the statistical distribution approach (see 75 FR 4174-4226 and EPA [2010] for
Proposed criteria for the Peninsula watershed region, which includes the Caloosa-
hatchee, St. Lucie, and Kissimmee watershed, are instream limits of 0.107 ppm for total
phosphorus (TP) and 1.205 ppm for total nitrogen (TN) based on an annual geometric
mean not to be surpassed more than once in a three-year period. In addition, the pro-
posed criteria state that the long-term average of annual geometric mean values shall
not surpass the listed concentration values. The 10 ppb TP criterion for the Everglades
Protection Area was not affected by the proposed rule. A protective TN and TP load
for Lake Okeechobee also was not calculated, because a total maximum daily load
(TMDL) is in effect for TP. Numeric criteria for canals in the South Florida bioregion
were proposed as 42 ppb TP, 1.6 ppm TN, and 4 ppb chlorophyll a (75 FR 4174-4226).
Criteria for canals are applicable to all Class III canals in the South Florida bioregion
as shown in Figure 5-1 except for canals within the Everglades Protection Area, where
the TP criterion of 10 ppb currently applies.
FIGURE 5-1 South Florida bioregion.
SOURCE: ftp.epa.gov/wed/ecoregions/fl/fl_eco_lg.pdf.
158 Progress Toward Restoring the Everglades
of permanent standards over a stated time period. EPA provided an example
of an interim standard that would require progress during years 1-5, a more
stringent interim standard during years 6-10, and attainment of the permanent
standard beginning in year 11 (EPA, 2010). That particular option would not be
applicable to the phosphorus standard in the Everglades Protection Area, which
is explicitly excluded under EPA’s current proposal for Florida. Implementing
a similar strategy in the Everglades Protection Area would require significant
The CWA offers to states two options to address an unattainable standard,
namely the use of attainability analysis and discharge-specific variances, neither
of which may be appropriate to the Everglades ecosystem. A state can remove
a designated use, other than an existing use, if it can demonstrate through a
formal use attainability analysis that attaining the standard is not feasible for
one of several reasons, including cost and widespread economic impacts.
When implementing changes through a use attainability analysis, a designated
use for a particular water body is changed, not the criteria applicable to the
original class of uses. Because criteria are specific to designated uses, however,
a change in use may trigger a change in applicable criteria. In August 2010,
FDEP amended FAC Rules 62-302.400 and 62-302.530 to refine the existing
surface-water classification system, creating a new sub-classification of waters,
Class III-Limited would applicable to wholly artificial waters or altered waters:
Thus, a new set of criteria applicable to the new class of waters will have to be
established. The implications of this change for water quality management in
the Everglades system are not clear at this time. Discharge-specific variances,
normally applied to municipal and industrial point source discharges, have not
been applied to discharges from permitted sources within the Everglades and
are therefore an untested option. Under Florida rules, an affected party may also
petition for site-specific alternative criteria (SAC) when “a water body, or portion
thereof, may not meet a particular ambient water quality criterion specified for
its classification, due to natural background conditions or man-induced condi-
tions which cannot be controlled or abated” (FAC 62.302.800). No such petition
has been requested for phosphorus in the Everglades Protection Area (E. Marks,
FDEP, personal communication, 2010).
TOWARD A SYSTEMWIDE PHOSPHORUS BUDGET
Phosphorus is the primary nutrient of concern in the Everglades system.
Therefore, it is especially important that the storage and transport of phosphorus
through the system be understood in considerable detail if water quality concerns
are to be addressed effectively and comprehensively.
Challenges in Restoring Water Quality 159
Stored Phosphorus in the South Florida Ecosystem
Phosphorus retention is an important function in basin nutrient cycling.
Phosphorus can be stored over the short term in above- and below-ground
plant tissues, microorganisms, periphyton, and detritus. Over the long term,
phosphorus can be stored in inorganic and organic soil particles and organic
matter. The fate of phosphorus in these long-term storage compartments needs
to be considered in any comprehensive water quality management approach. In
the Lake Okeechobee basin, Reddy et al. (2010) estimated TP storage in upland
and wetland soils to be 215,000 mt.11 Approximately 80 percent of the stored
phosphorus (or 169,800 mt) is located in soils and stream sediments, with the
remainder stored in lake sediments in the Upper Chain of Lakes, Lake Istokpoga,
Reddy et al. (2010) performed a thought experiment that illuminates the
long-term role of stored (or legacy) phosphorus on loading to Lake Okeechobee.
Based on chemical extraction tests, they assumed that approximately 35 percent
of the phosphorus stored was stable (i.e., not able to be released) because it was
not soluble either in acid or base or both. Reddy et al. (2010) conservatively esti-
mated that 10 to 25 percent of the reactive phosphorus in the soils was available
to be exported from the system (see Figure 5-2). Given estimates of phosphorus
leaching rates from stored phosphorus in the Lake Okeechobee basin of 500 mt
per year (estimated based on assessments of long-term phosphorus discharges
into Lake Okeechobee) and the estimates of stored reactive phosphorus, legacy
phosphorus could maintain a phosphorus load to the lake of 500 mt per year
for the next 22 to 55 years. This loading rate only considers legacy phosphorus
stored in the soils and sediments and does not take into account new phosphorus
additions in the basin. A recent report suggests that 11,000 mt of phosphorus
is currently imported annually into the basin, and 6,700 mt is exported out of
the basin, resulting in 5,300 mt net phosphorus accumulation in the system
(SFWMD, 2010b).
Internal loads from sediments in Lake Okeechobee to the water column
are also significant, especially from the mud zone sediments. These sediments
are fine grained and are readily suspended into the water column. Based on
several earlier research reports, internal flux from mud sediments to the water
column was estimated at 112 mt of phosphorus per year. Based on the available
reactive phosphorus in the sediments (using the assumptions described above),
this supply will continue for 12 to 31 years (Figure 5-2). Managing internal load
through chemical amendments may not be cost-effective considering the size of
One metric ton equals 2,200 pounds.
194 Progress Toward Restoring the Everglades
Sources of Sulfur in the Everglades
There have been few studies on the sources of sulfate to the Everglades (Wright
et al., 2008; Gabriel, 2009). Potential sources include atmospheric deposition, deep
groundwater, and sulfur supplied from the Everglades Agricultural Area (EAA). Inputs
of atmospheric sulfate deposition are small compared to fluxes in canals. Therefore,
atmospheric deposition is a limited component of sulfate contamination in the Ever-
glades. Deep groundwater exhibits high sulfate concentrations and could potentially
be an important source of sulfate. However, deep groundwater is not geochemically
consistent with canal water, and it is not thought to be an important source. There have
been few mass balances of sulfur for the Everglades. Schueneman (2001) concluded
that Lake Okeechobee and soil mineralization (the degradation of soil organic sulfur)
were the largest sources of sulfate to the Everglades. Gabriel (2009) conducted a pre-
liminary mass balance of sulfur for Lake Okeechobee, the EAA, Water Conservation
Area (WCA)-1, and WCA-2 for wet (2004), dry (2007), and intermediate (2003) years.
His analysis showed that atmospheric deposition was a small input, and evasion of
reduced sulfur gases was a minor loss. During the intermediate and wet years, Lake
Okeechobee was a net source of sulfate. The WCAs were generally net sinks for sulfate
inputs. Based on canal water fluxes, the EAA was a large net source of sulfate during
the wet and intermediate years and a slight sink during the dry year. Gabriel’s analysis
suggests that soil sulfur mineralization and direct agricultural application were important
sulfur sources for the EAA and the annual harvest of sugar cane was an important sulfur
loss. Although soil sulfur oxidation is clearly an important source of sulfate to down-
stream drainage waters, relatively little is known about controls on this source and how
it has varied over time. Using sulfur stable isotope measurements, it appears that sulfur
applied for agriculture is a major contributor to the excess sulfate concentrations in the
Everglades (Bates et al., 2002). However, the relative contribution of recent vs. legacy
sulfur additions to sulfate concentrations in the Everglades is not clear.
(<10-20 ppm) methylation is sulfate limited (Figure 5-15), and under these condi-
tions increases in sulfate will stimulate methylation of ionic mercury (Gilmour et
al., 2009). This sulfate-limited condition coincides with sulfide concentrations
below 0.2-0.3 ppm in sediment porewaters. At high concentrations of surface-
water sulfate (>10-20 ppm) and/or high concentrations of sulfide (>0.2-0.3 ppm),
production of methyl mercury becomes curtailed because of immobilization of
ionic mercury by sulfide (Benoit et al., 2003). In the northern Everglades the
high supply of sulfate coupled with reducing conditions result in high concen-
trations of sulfide in wetland porewaters (often exceeding 1 ppm), which may
limit methyl mercury concentrations (Scheidt and Kalla, 2007). With decreases
in sulfate and sulfide concentrations there is an increase in methyl mercury pro-
duction rate in WCA-2B and -3A with subsequent decreases through Everglades
National Park toward the south (Gilmour et al., 2007).
An additional factor that may influence the spatial patterns in fish mercury
Challenges in Restoring Water Quality 195
FIGURE 5-15 Conceptual diagram showing the response of methylation of mercury to varying sulfate con-
centrations. At low concentrations of sulfate, methylation is stimulated; at higher sulfate concentrations, the
production of high concentrations of sulfide inhibits methylation.
Figure 5-15.eps
SOURCE: Modified from Gilmour et al. (2009).
in the Everglades is phosphorus supply. Water concentrations of phosphorus
exhibit a distinct decreasing gradient north to south due to inputs from the EAA
(Scheidt and Kalla, 2007). This elevated supply of phosphorus increases aquatic
productivity, which may result in “biodilution” of fish mercury (Pickhardt et al.,
2002; Chen and Folt, 2005). However, it does not appear that this hypothesis
has ever been tested for the Everglades.
The Everglades mercury problem arises from the convergence of two con-
taminant sources (mercury and sulfate). Ecosystem-wide sampling indicates that
zones of elevated methyl mercury production appear to be controlled by sulfate
transport, which varies in time and space. Increases in water discharge since
196 Progress Toward Restoring the Everglades
the mid-1990s appear to have increased sulfate transport southward, resulting in
mercury contamination in the southern portions of the Everglades (Krabbenhoft
Possible Approaches to Decrease Sulfur Contamination and Research Needs
Previous mass balance studies have demonstrated the importance of the
EAA as a major source of sulfate to the Everglades. Transport of sulfate south-
ward largely occurs via canal discharge. To date there has been limited effort
to control or restrict sulfate contamination in the Everglades. Watershed BMPs
could be implemented in the EAA to decrease sulfate loads. Recently, Ye at al.
(2009) found that rates of sulfur application commonly used in the EAA do not
significantly decrease the pH of soils and may not be effective in enhancing the
availability of phosphorus. Application of sulfur could be limited in the EAA to
the minimum quantity needed for sustained crop yields. Sulfur application (e.g.,
gypsum [CaSO4] for pH adjustment, sulfur based fungicides, sulfur containing
fertilizers) could also be minimized.
An opportunity to mitigate sulfur contamination may result from the pur-
chase of land in the EAA from the U.S. Sugar Corporation. Taking EAA land out
of cultivation should decrease both land application of sulfur and soil oxidation
of sulfur associated with soil mineralization, limiting two of the most impor-
tant sources of sulfate to the Everglades. The initial flooding of lands that were
formerly in agriculture could likely result in a very large flux of phosphorus,
sulfate, mercury, and other contaminants in drainage waters, creating a short-
term environmental problem. If EAA soils are re-wetted, detailed monitoring
should be conducted to characterize the extent of this disturbance. However,
over the long-term prolonged flooding and saturation of soil should stimulate
the accumulation of soil carbon and reducing conditions and limit the mobili-
zation of sulfate.
Restoration of sheet flow within the Everglades ecosystem will help pro-
tect sensitive areas like the WCAs, Everglades National Park, and Big Cypress
National Park from the effects of sulfate contamination. Canals promote distant
transport of sulfate under oxidizing conditions. The re-establishment of sheet
flow should promote sequestration of sulfur (as sulfide) under more reduced
conditions and should decrease the transport of sulfate.
STAs have not been designed to remove sulfate, and, in fact, monitoring
data suggest that STAs have limited effectiveness in removing sulfate. Research
could be conducted to investigate how STAs can better remove sulfate, within the
context of the primary objective of removing phosphorus. Possible approaches
might include increasing the hydrologic residence time in STAs, using plants
Challenges in Restoring Water Quality 197
that are more effective in sequestering sulfur, and using chemical amendments
It appears that some planned hydrologic improvements in the CERP may
have the undesired consequence of enhancing transport of sulfate to the south-
ern more pristine portions of the Everglades, increasing mercury contamination
in these areas. For example, within the proposed eastern flow-way, water from
WCA-2 is transferred to Lake Belt storage areas prior to discharge into Everglades
National Park south of Tamiami Trail. As a consequence, increasing (or changing)
discharge patterns without considering associated water quality may exchange
CALCIUM, ALKALINITY, AND SPECIFIC CONDUCTANCE
The related issues of the supply of calcium concentrations, alkalinity, and
specific conductance in the water quality of the Everglades have received some
attention, but they may deserve more careful consideration as factors in eco-
system restoration. The effects of elevated conductivity on native vegetation
and the implications of changing calcium concentrations on phosphorus are
Effects on Wetland Biota
Waters draining the Everglades are thought to be historically soft. Harvey
and McCormick (2009) found that the development of thick, low-hydraulic-
conductivity peats isolated surface water and shallow groundwater from deep
groundwater with higher ionic strength.
In the northern portions of the Everglades Protection Area (i.e., LNWR,
WCA-2), water near the perimeter canals is elevated in specific conductance,
with values in the range of 1,000 μS/cm (Surratt et al., 2008; Harvey and McCor-
mick, 2009). Canal water discharging into the LNWR has specific conductance
values up to two times greater than interior waters (231.5 μS/cm vs. 121.8 μS/
cm) (USFWS, 2009e). This condition creates a zone of elevated surface-water
specific conductance extending up to 2.8 miles into the LNWR and is associ-
ated with the absence of yelloweyed grass (Xyris spp.), a key indicator plant for
undisturbed communities. The conductivity of water in the interior of WCA-2A
is generally in the range of 1,000 μS/cm; in contrast, within Everglades National
Park, specific conductances are rarely above 600 μS/cm, despite thin peat and
greater surface water-groundwater exchange in that region. The input of waters
with high concentrations of cations from the EAA into the northern WCAs has
been demonstrated in spatial analyses of calcium concentration in the soil
(Rivero et al., 2007) and occurred as far back as the 1940s.
198 Progress Toward Restoring the Everglades
There is some evidence to indicate that elevated mineral content in the
surface waters of the areas receiving canal waters from the EAA may have sig-
nificant impacts on the ecology of these areas. Experimental work suggests that
some characteristic species, including Rhynchospora spp., Xyris smalliana., and
Eriocaulon aquaticum germinate and grow better under unenriched (low cal-
cium, phosphorus) conditions and are typically found only in softwater areas (R.
Gibble, USFWS, and P. McCormick, SFWMD, personal communication, 2009).
In northern peatlands, species’ distributions are well known to be strongly influ-
enced by calcium concentrations (Glaser, 1992; Bridgham et al., 1996; Payette
and Rochefort, 2001), with large changes in plant community composition as
calcium concentrations decrease below 10 ppm. However, the role of calcium
in Everglades plant ecology has received very little attention, and so it is not
clear whether the patterns observed in the northern peatlands is relevant here.
There is stronger evidence that periphyton communities are altered by
changes in water hardness. Swift and Nicholas (1987) showed that calcium-
enriched waters affected by canal and agricultural drainage had a lower overall
diversity of algae and cyanobacteria than the softwater interior-marsh sites and
were dominated by filamentous cyanobacteria and other characteristic “pollu-
tion indicators,” in contrast to the desmid and acid-preferring species of diatoms
found in the softwater sites. Harvey and McCormick (2009) reported similar
results in the LNWR. Paleoecological data (Slate and Stevenson, 2000) show
that diatom species preferring acidic conditions were more widespread in the
pre-drainage Everglades than currently. Contemporary data also show that cal-
careous communities are more common in the more minerotrophic waters of the
southern Everglades. Studies of food web relationships suggest that a transition
from the diatom-desmid community to a calcareous community has effects on
fish species and food web structure (Williams and Trexler, 2006), although these
authors found that the dominant detritivores appear to be feeding on a mixture
of periphyton species from both diatoms and cyanobacteria.
Calcium Trends and Implications
In contrast to the pattern of elevated calcium and alkalinity observed in the
WCAs in association with inputs from the EAA, Lake Okeechobee has shown
trends of decreasing calcium concentrations since the 1970s (Figure 5-16). Cal-
cium concentrations in the lake have decreased from 45-50 ppm in the 1970s
to 30-35 ppm in 1999, a trend correlated with a slight decrease in pH and
alkalinity and an increase in temperature. This pattern is likely due to a decrease
in back-pumping of calcium-enriched water from the EAA and a trend toward
wetter conditions, which lead to lower concentrations of lake calcium (Walker,
2000; Zhang et al., 2007).
Challenges in Restoring Water Quality 199
FIGURE 5-16 Monthly average values of (A) calcium, (B) specific conductivity, and (C) sulfate
Figure 5-16.eps
at eight long-term monitoring stations in Lake Okeechobee.
SOURCE: Zhang et al. (2007).
200 Progress Toward Restoring the Everglades
The role of calcium in the lake is strongly linked to the fate of phosphorus,
as 58-70 percent of the phosphorus accumulating in the bottom sediments is
bound to calcium and magnesium, and the fraction of phosphorus in the benthic
sediments that is bound to calcium also shows a decreasing trend (Walker, 2000).
The settling rate of phosphorus in the lake is strongly correlated with calcium
concentrations (Figure 5-17), so decreasing inputs of calcium to the lake results
in higher quantities of total phosphorus maintained in the lake water column.
Calcium loading would appear to be an important component of the phosphorus
management of the lake (Walker, 2000). This mechanism is likely associated
with precipitation of calcium carbonate and the immobilization of phosphorus
by sorption and flocculation. Precipitation of calcite likely facilitates the removal
of turbidity, but long-term declines in calcium carbonate precipitation could
enhance the persistence of phosphorus and turbidity in the lake.
Changes in the dynamics of calcium may also have implications for the
long-term success of the STAs. Short-term immobilization of phosphorus in the
STAs seems to occur by biological removal by periphyton and macrophytes and
FIGURE 5-17 Relationship of phosphorus settling rate in Lake Okeechobee to calcium con-
centration in the water column, based on data from 1973 to 1999.
Figure 5-17.eps
SOURCE: Walker (2000).
Challenges in Restoring Water Quality 201
particulate settling. However, over the longer term it is likely that immobilization
by calcium is important. STAs exhibit net retention of alkalinity, probably largely
as a result of calcite precipitation (W. Walker, consultant, personal communica-
tion, 2009), and phosphate is readily co-precipitated with calcite (Wetzel, 2001;
Reddy and Delaune, 2008). Walker (2009) reported outflow TP concentrations
from the STAs that were highly correlated with inflow calcium concentrations,
showing the importance of calcium as a control on water column TP. Long-term
decreases in the inflow of calcium to STAs associated with changes in agricul-
tural activities in the EAA will likely decrease the formation of calcite and may
limit associated immobilization of phosphorus.
This brief review suggests that calcium and alkalinity may play a larger role
in controlling both phosphorus management and the composition of the biota
than has been previously recognized. It is important to determine the extent to
which changes in conductivity alone, separately from phosphorus enrichment,
cause undesirable changes in both the periphyton mat and in the macrophyte
communities. In addition, research should be directed toward understanding
the co-variation and dynamics of conductivity and other pollutants (phospho-
rus, sulfate) to verify the suggested utility of conductivity alone as an indicator
of polluted water impact (Harwell et al., 2008; Surratt et al., 2008). Most of
the research on the extent and impacts of high-conductivity water on plant
and periphyton communities has been done within the LNWR; it is important
to understand the extent of impact of high-conductivity canal waters on other
receiving areas. Finally, the potentially important role of calcium as a control
on phosphorus chemistry both within Lake Okeechobee and the STAs deserves
further attention, as tradeoffs in water quality management may be necessary.
Ten years after the CERP was launched, “getting the water right” is proving to
be more difficult and expensive than originally anticipated. It has taken decades
(more than 60 years) for the ecosystem to degrade to its current state, and it will
likely take a similar timeframe or longer to restore. Legacy phosphorus storages
in the Lake Okeechobee watershed, the lake itself, and the EAA suggest that cur-
rent phosphorus release rates into the system will persist for decades. Attaining
water quality goals throughout the system is likely to be very costly and take
several decades of continued commitment to a systemwide, integrated planning
and design effort that simultaneously addresses source controls, storage, and
treatment over a range of timescales.
202 Progress Toward Restoring the Everglades
Additional information on phosphorus mass balances, particularly within
the EAA, are needed to support effective decision making. NRC (2008) recom-
mended a systemwide accounting for phosphorus and other contaminants such
as sulfur, nitrogen, calcium, and mercury, and this remains a pressing need.
There are notable gaps in the published phosphorus budgets between Lake
Okeechobee and the inflows to the STAs and also in the contributions from
atmospheric deposition for phosphorus and other elements. The lack of informa-
tion synthesis of inputs and pathways of phosphorus and other contaminants in
key areas, such as the Everglades Agricultural Area, hinders the development of
targeted strategies to improve water quality management.
The current acreage of STAs, as managed, is not sufficient to treat exist-
ing water flows and phosphorus loads into the Everglades Protection Area.
Although new construction of STAs is underway in Compartments B and C,
these STAs are located far from where the recent Consent Decree violations have
occurred. With increased volumes of water planned for the CERP, substantially
more water quality treatment and/or additional load reductions will be needed if
the new flows are to meet the water quality criteria. If these new CERP loads are
addressed with STAs alone, an estimated 54,000 additional acres of STAs will be
required, costing approximately $1.1 billion to construct, $27 million per year
to operate and maintain, and approximately $1.1 billion to refurbish every 20
to 25 years (2010 dollars). Additional STAs will further increase the large cost of
restoration (last estimated at nearly $13 billion) and add to the fiscal challenges
of federal and state agencies, although additional source control measures could
reduce the magnitude of this cost increase. EPA’s recently announced phospho-
rus and nitrogen water quality standards for lakes, rivers, and canals introduce
additional technical and financial challenges.
The SFWMD should complete a comprehensive scientific, technical, and
cost-effectiveness analysis as a basis for assessing potential short- and long-term
restoration alternatives and for optimizing restoration outcomes given state and
federal financial constraints. This analysis is needed to facilitate management
decisions that focus on improving systemwide water quality, bringing the water-
shed into compliance with the Lake Okeechobee TMDL, and addressing recent
violations of the Consent Decree. In addition to considering additional treat-
ment and source control, this analysis should evaluate urban and agricultural
water supply management approaches and accelerated sequencing for seepage
management projects to determine whether changes could address water quality
and water quantity concerns in a more efficient manner.
A rigorous research, analysis, and modeling program is needed to develop
improved best management practices and to examine the long-term sustain-
ability and performance of STAs to meet the desired outflow water quality. To
Challenges in Restoring Water Quality 203
support the comprehensive scientific, technical, and cost-effectiveness analysis
recommended above, additional research is needed in the following areas:
• STA sustainability and performance. The SFWMD’s extensive STA soil and
water quality monitoring program should be supported by a systematic research
program that evaluates the long-term ability of STAs to sustain or improve upon
their current level of functioning. Further research should examine the biogeo-
chemistry, vegetation dynamics, and hydrology of the STAs, and should couple
the resultant data with predictive models to improve performance and support
management decisions. Useful improvements could also be realized through an
external peer review of the STA research and monitoring program, including the
design criteria and modeling efforts.
• Source control effectiveness. A rigorous research, monitoring, and mod-
eling program focused on developing improved BMPs is needed to improve the
efficiency of phosphorus source control efforts and to inform systemwide phos-
phorus management decisions. Long-term monitoring of the efficacy and costs
of BMP implementation across multiple sites will be required to evaluate source
control practices across variable hydrologic, geomorphologic, and soil regimes
present in the South Florida ecosystem and to validate and build confidence in
Given that restoration as originally envisioned in the CERP remains decades
away and the ecosystem continues to decline, CERP agencies should conduct
a rigorous scientific analysis of the short- and long-term tradeoffs between
water quality and quantity for the Everglades ecosystem. The committee does
not endorse such tradeoffs at this time, because scientific analyses to explain
the repercussions of such decisions are lacking. However, the scientific analysis
of potential tradeoffs is critical to inform future water management decisions,
including the prioritization of projects. In particular, the analysis should address
• What are the short- and long-term consequences of providing too little
water to the Everglades ecosystem but maintaining sufficient quality?
• What are the short- and long-term consequences of providing water of
lower quality to the Everglades ecosystem but maintaining sufficient flows?
• Are the negative consequences reversible, and if so, within what
Effective water quality management would be best served by consideration
of a multi-contaminant approach in the future. Water quality conditions in the
Everglades are affected not only by the input of contaminants, but also by the
204 Progress Toward Restoring the Everglades
inputs of other elements that alter their behavior. For example, the bioavail-
ability of mercury and its accumulation in fish and other wildlife appears to
be controlled not only by inputs of mercury, but also by the supply of sulfate,
phosphorus, and dissolved organic carbon. Likewise the transport and removal
of phosphorus may be coupled with the supply of calcium in Lake Okeechobee,
the STAs, and other portions of the Everglades. Additional research is also needed
to clarify the linkages between water quality constituents to support sound multi-
contaminant water management decisions.