TX-1 Address Hotspots of Contamination in the Bay
OBJECTIVE:
Identify and remediate priority “hotspots” of contamination in the bay.
STATUS:
Ongoing. Using the Tampa Bay Benthic Index, eight priority hotspots were identified in Tampa
Bay. A Sediment Quality Action Plan was developed for the highest priority site, McKay Bay,
and initial assessment has been completed.
BACKGROUND:
Monitoring of benthic, or bottom habitats, has been ongoing since 1993 with more than 1500
samples analyzed for environmental characteristics, including contamination and benthic
community composition. The Environmental Protection Commission of Hillsborough County
coordinates the monitoring program, with participation from Manatee and Pinellas Counties.
Over the last 20 years, the condition of Tampa Bay benthic communities baywide has been
“Fair” to “Poor”, with “Good” conditions in Middle and Lower Tampa Bay in most years.
Increased monitoring of major river systems (e.g., Hillsborough, Palm, Alafia and Little Manatee
Rivers) and minor tidal tributaries is needed (See BH-8), and benthic community targets should
be incorporated into tidal stream habitat management plans (see BH-1 and BH-9).
Benthic monitoring is important for identifying hotspots of sediment contamination. Using
monitoring data, the Tampa Bay Benthic Index (TBBI) provides a tool for assessing the health of
benthic habitats. This index assesses the severity of contamination based on lack of diversity or
abundance of benthic organisms, low dissolved oxygen, or high levels of contaminants of
concern (COCs). COCs include toxic chemicals like heavy metals, polycyclic aromatic
hydrocarbons (PAHs), polychlorinated biphenols (PCBs) and organic pesticides. Because COCs
can persist for decades in aquatic sediments and some can bioaccumulate in the food web, these
hotspots pose health risks to wildlife and humans.
In 2007, the Sediment Quality Assessment Group identified nine priority “hotspot” areas in
Tampa Bay with low TBBI scores, indicating elevated contamination and reduced diversity of
organisms. These include:
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McKay Bay
East Bay
Ybor Channel
West Davis Island
Largo Inlet
Westshore
Bayboro Harbor/Port of St. Petersburg
Apollo Beach/Big Bend
Through a 2011 cooperative effort of TBEP partners, a Sediment Quality Action Plan (SQAP)
was developed for the highest-ranking hotspot, McKay Bay, where 46% of sediments are
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contaminated enough to threaten the organisms living in the bay. Despite its urban location and
impacted sediments, McKay Bay provides important wildlife habitat with its diversity of
mudflats, mangroves, saltmarshes and oyster bars. The McKay Bay SQAP recommends initial
steps to 1) identify and control external sources of COCs from upland sites with known soil or
groundwater contamination and from stormwater run-off, and 2) assess ecological and human
health risks from contaminated sediments.
If awarded in 2016, an EPA Brownfields Coalition Assessment Grant will allow TBEP, EPC and
Pinellas County to perform assessments at multiple upland sites with known contamination that
drain into McKay Bay and Largo Inlet. With this information, TBEP and partners can move
towards appropriate clean-up efforts. Sediment Quality Action Plans are still needed for other
priority hotspots in Tampa Bay.
Follow-up studies in 2014, funded by the Tampa Bay Environmental Restoration Fund, showed
McKay Bay sediments are indeed toxic to animals. In tests of a variety of fish and shellfish,
contaminants found in the animal tissue exceeded thresholds for environmental and human
health, highlighting the need for continuing risk assessments and tracking of updated standards.
The last baywide risk assessment for COCs was 20 years ago.
Figure ES-4 Conceptual ecosystem model of sediment contamination impacts in McKay
Bay. From TBEP Technical Report #03-14 page 30.
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STRATEGY:
Activity 1
Continue benthic monitoring program to analyze sediments for contaminants and
assess the health of benthic communities. Expand monitoring in rivers and tidal
tributaries.
Responsible Parties: EPCHC (lead), Pinellas County, Manatee County
Timeframe: Ongoing; river and stream sites added as funding available
Cost and potential funding sources: $$$ Current benthic program funded
by EPC; new sites could be funded internally via EPC budget or through
external grants
Location: Baywide
Benefit/Performance Measure: Number of monitoring sites analyzed
Results: Expanded benthic monitoring in rivers and tidal tributaries will
help identify additional hotspots.
Deliverable:
Annual benthic monitoring reports, incorporating additional sampling
in rivers and tidal streams as feasible
Activity 2
Incorporate benthic community targets in tidal stream habitat management plan.
Responsible Parties: TBEP Sediment Quality Assessment Group
Timeframe: Following initiation of benthic sampling in tidal streams
Cost and potential funding sources: $ CWA Section 320 funds
Location: Baywide
Benefit/Performance Measure: Targets of benthic health established for
tidal streams
Results: Targets will help track progress in maintaining or restoring
ecological health and diversity of tidal tributaries
Deliverable:
Tidal tributary management plan incorporating benthic targets
Activity 3
Continue implementation of Sediment Quality Action Plan through EPA
Brownfields Grant, if awarded.
Responsible Parties: EPCHC, Pinellas County
Timeframe: 2016
Cost and potential funding sources: $$$
Location: McKay Bay and Largo Inlet
Benefit/Performance Measure: Risk assessment of toxic contaminants at
upland sites draining to McKay Bay and Largo Inlet
Action plans addressing two priority hotspots
Results: Identification of land-based sources and relative contributions of
toxic contaminants at two priority hotspots
Deliverable:
Reports assessing ecological and human health associated with upland
sites
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Activity 4
Continue development and implementation of action plans addressing priority hot
spots of contamination (as determined by the Tampa Bay Benthic Index). Identify
most appropriate options to restore sediment quality in impacted areas, including
in-bay remediation such as capping with clean fill or dredged material, as well as
upland restoration.
Responsible Parties: EPCHC, Pinellas County, Hillsborough County,
SWFWMD, TBEP, Port Tampa Bay, U.S. Army Corps of Engineers
Timeframe: Ongoing
Cost and potential funding sources: $$-$$$$ Potential funding from
external grants, or as part of broad multi-partner initiatives to restore
habitat and use dredge material beneficially
Location: East Bay,Ybor Channel,West Davis Island, Westshore,
Bayboro Harbor/Port of St. Petersburg, Apollo Beach/Big Bend
Benefit/Performance Measure: Development and implementation of
Action plans addressing eight priority hotspots
Results: Identification of site-specific strategies for restoring or
remediating sediment quality in degraded areas
Deliverable:
Comprehensive action plans addressing priority hot spots of contamination
Activity 5
Update risk assessments for priority areas of contamination. Track new indicators
and standards for human and ecological health and incorporate those into updated
risk assessments.
Responsible Parties: EPCHC, Pinellas County, Hillsborough County,
TBEP Sediment Quality Assessment Group
Timeframe: Following completion of McKay Bay-Largo Inlet
Brownfields project, to incorporate applicable results and sampling
techniques from that research in assessing additional bay sites with
known or suspected toxic contamination
Cost and potential funding sources: $$-$$$ Potential funding from
external grants
Location: Baywide, beginning with remaining priority hotspots
Benefit/Performance Measure: Risk assessment of toxic contaminants at
all eight priority hotspots
Results: Updated assessments of bay sediments will identify
ongoing or new contaminants and quantify threats to ecological and
human health
Deliverable:
Updated risk assessments utilizing revised standards for allowable levels
of toxics deemed harmful for aquatic organisms and/or human health
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