Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Retrofits in Roberts Bay Result in Removal of Nutrient Impairment v
Wqtprhnrlv Imnrnvprl Nutrient loading from both point and nonpoint sources led the
' ' '' -'* ' r " ' ' " Florida Department of Environmental Protection (DEP)to add
Roberts Bay to Florida's 1998 Clean Water Act (CWA) section 303(d) list of impaired waters
for exceedances of the historical minimum chlorophyll-a value threshold. Project partners
implemented numerous nonpoint source pollution management strategies, including install-
ing nutrient-separating baffle boxes and promoting the "Florida-Friendly Landscaping" (FFL)
education program. Chlorophyll-a levels dropped as a result, prompting Florida DEP to
remove Roberts Bay from the state's impaired waters list (for nutrient impairment) in 2010.
Problem
Roberts Bay (Figure 1) is in the Sarasota Bay-Peace-
Myakka River watershed in northwest Sarasota
County, Florida. Roberts Bay is a Class III marine
water body, designated for recreation and the
propagation and maintenance of a healthy, well-
balanced population offish and wildlife. It receives
drainage from a 65-square-mile area, including the
urbanized Philippi Creek Basin and urbanized areas
of Sarasota County. Predominant land uses in the
Roberts Bay watershed are residential (50 percent),
urban (17 percent) and agriculture (11 percent).
The U.S. Environmental Protection Agency desig-
nated the Sarasota Bay system, including Roberts
Bay, an Estuary of National Significance in 1988
and initiated the Sarasota Bay National Estuary
Program in 1989. DEP designated the estuary an
Outstanding Florida Water, and the South Florida
Water Management District placed Sarasota Bay on
its Surface Water Improvement and Management
(SWIM) Program list of priority water bodies for
protection or restoration in 1995.
In 1998 DEP included Roberts Bay on the state's
CWA section 303(d) list for nutrient impairment.
Key point sources of nutrients in the basin included
four domestic wastewater treatment facilities;
nonpoint sources included atmospheric deposition,
ground water discharge to streams, ground water
seepage, septic systems and surface water runoff.
In 2001, in accordance with Florida's Identification
of Impaired Surface Waters Rule (IWR), the state's
Environmental Regulation Commission adopted
a new methodology to verify water body impair-
ments. The IWR listing methodology verifies estu-
ary nutrient impairment if (1) the annual average
Raima
Sola Bay
Figure 1. The Roberts Bay Basin (orange) lies along
the Gulf of Mexico in Florida's Sarasota County.
chlorophyll-a (a measure of algal biomass) values
exceed the estuarine threshold of 11 micrograms per
liter (jUg/L) in any year within the verification period
(1/1/1997-6/30/2004) or (2) the annual average chloro-
phyll-a values during the verification period increase
by more than 50 percent over the historical minimum
value (the lowest average chlorophyll-a value from
1992-1996) for at least two consecutive years.
Roberts Bay was verified as impaired for nutrients
in 2005 because annual mean chlorophyll-a values
in the verification period were more than 50 percent
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Roberts Bay— WBID1968D
Annual Average Chlorophyll-o
2-
V
^^™ Chlorophyll-a Threshold
^^~ Historical Chlorophyll-a Thre
+ Annual Average Chlorophyll
V
V
shold(|jg/L)(50%ofHist
a(ug/L)
1 V
V
Chl-a Value)
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
Figure 2. Annual average chlorophyll-a values in Roberts Bay
(1997-2007).
above the historical minimum value of 4.8/jg/L in
1997, 1998, 1999, 2001, 2003 and 2004 (Figure 2).
In 2005 DEP developed a total maximum daily load
(TMDL) for nutrients in Roberts Bay. The objective
of the TMDL was to reduce the chlorophyll-a annual
average to below 50 percent above the historical
minimum value, or to below 7.2/jg/L. In 2009, DEP
increased the assessment threshold from 7.2 jug/L
to 7.5/jg/L as a result of updated monitoring data.
Project Highlights
Sarasota County implemented two CWA section
319(h) projects (FY2002 and FY2004, both completed
in 2006) to install 13 nutrient-separating baffle boxes,
which capture and separate organic matter (including
vegetation and litter) and sediment from runoff in the
stormwater system. These projects also funded the
installation of pump station/sewer enlargements and
inlet traps (to filter solids such as trash and organic
debris). Implementing these best management
practices (BMPs) resulted in the following estimated
pollutant load reductions: 267 pounds per year (Ib/yr)
total nitrogen (TN), 186 Ib/yr total phosphorus (TP),
and 53,892 Ib/yr total suspended solids (TSS). A
SWIM project completed in 2004 also funded the
installation of two additional nutrient-separating
baffle boxes. One additional CWA section 319(h)
project, expected to be completed in 2013, is funding
the installation of eight nutrient-separating baffle
boxes and bioretention junction boxes. These BMPs
will lead to additional estimated load reductions of
2,607 Ib/yr TN, 242 Ib/yr TP, and 135,882 Ib/yr TSS.
In 1992 Sarasota County began its FFL program (for-
merly known as "Florida Yards & Neighborhoods"),
an educational campaign designed to improve water
quality by integrating landscaping BMPs in home-
owners' and green industries' fertilizer/pesticide use
and irrigation practices. This highly successful and
popular statewide program has been funded with
base CWA section 319(h) funds since 1994. In 2009
the Florida Legislature designated the program the
official state landscaping BMP program. Legislators
find the program so critical to the public welfare that
deed restrictions, covenants and local ordinances
are void if they prohibit an owner from implementing
FFL practices on their land. The FFL program has
led to a significant cultural change to more environ-
mentally friendly landscaping throughout the state,
including Sarasota County, thus preventing further
nutrient loading in Roberts Bay.
Results
Thanks to the effort of numerous stakehold-
ers, pollutant loads have dropped in Roberts
Bay (see Figure 2). Water quality data show that
the bay's chlorophyll-a annual average did not
exceed 50 percent of the historical chlorophyll-
a threshold of 7.5/jg/L in three consecutive
years—2005 (7.5jug/L), 2006 (5jug/L), and
2007 (3.6jug/L). As a result, DEP removed Roberts
Bay from Florida's impaired waters list (for nutri-
ent impairment) in 2010. Additional improvements
can be seen regionally: Five other water bodies
in nearby Sarasota Bay, Little Sarasota Bay and
Blackburn Bay were delisted for chlorophyll-a or
historical chlorophyll-a between 2005 and 2010.
Partners and Funding
The Sarasota County Environmental Services,
Sarasota County Drainage Operations Division,
City of Sarasota, City of Venice, Sarasota County
Cooperative Extension Service, FFL Program,
Sarasota Bay National Estuary Program, Sarasota
County Neighborhood Environmental Stewardship
Team, Southwest Florida Water Management
District, and numerous other partners and partici-
pants contributed to improvements in Roberts Bay
and surrounding estuaries. A total of $1.6 million
in CWA section 319(h) funds and $5.2 million in
local funds were directed to projects to imple-
ment BMPs, monitor post-construction loading,
and implement education components. Between
FY2002 and FY2009, an additional $3.8 million in
CWA section 319(h) funds supported the statewide
FFL program, with an official match of $3.3 million
and a significantly higher unofficial match (including
Sarasota County funds).
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-12-001B
February 2012
For additional information contact:
Kristine P. Jones
Nonpoint Source Management Section
Florida Department of Environmental Protection
850-245-8682 • Kristine.P.Jones@dep.state.fl.us
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