Lake Worth Watershed: A TMDL Project for PCBs in Fish Tissue
Photograph courtesy of the
Fort Worth Water Department
County: Tarrant
Parameter: polychlorinated biphenyls (PCBs) in fish tissue
River Basin: Trinity
Segment: 0807, 0808
On this page:
Background and Goals
Lake Worth (Segment 0807) is a 3,558-acre impoundment of the West Fork Trinity River located in northwest Tarrant County. The lake has a conservation capacity of approximately 37,000 acre-feet, and drains a 2,064 square-mile watershed. Water quality testing found that fish in Lake Worth (Segment 0807) are contaminated with polychlorinated biphenyls (PCBs), resulting in an advisory to the public in 2002 to limit their consumption of fish caught in the lake.
The goal of this project is to reduce PCBs to levels that will make it safe to eat fish from the lake. The goal of a TMDL is to restore the full use of a water body that has limited quality in relation to one or more of its uses. The TMDL defines an environmental target by determining the extent to which a certain pollutant must be reduced in order to attain and maintain the affected use. Based on this environmental target, the state develops an implementation plan to mitigate anthropogenic sources of pollution within the watershed and restore full use of the water body.
Back to topStatus
The TMDL I-Plan relies heavily on cleanup efforts at Air Force Plant No. 4 (AFP4), located on the south side of the lake. AFP4 is undergoing cleanup under the federal Resource Conservation and Recovery Act (RCRA) program. Also under the I-Plan, fish tissue in Lake Worth is sampled periodically to monitor the effectiveness of cleanup efforts.
The DSHS conducted the first fish tissue monitoring under the I-Plan in October 2008. Based on that monitoring data, the DSHS extended the advisory to include Segment 0808. The second fish tissue monitoring effort under the I-Plan was conducted November 2016. In March 2018, the DSHS issued advisory ADV-60, limiting consumption of seven fish species due to dioxins and PCBs.
However, the overall mean concentration of PCBs in all fish has declined. The mean concentration for the 80 samples collected in 2008 was .064 milligrams per kilogram (mg/kg) PCBs. The mean concentration for the 80 samples collected in 2016 was .032 mg/kg PCBs.
Total Maximum Daily Load
The commission adopted this TMDL on August 10, 2005. The EPA approved it on October 13, 2005, at which time it became part of the state's Water Quality Management Plan.
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One Total Maximum Daily Load for Polychlorinated Biphenyls (PCBs) in Fish Tissue in Lake Worth
Segment 0807 - Response to Public Comment on the TMDL June 2005
Revisions to TMDLs
From time to time, it is necessary to revise TMDLs to account for changing conditions in the watershed. Revisions to the load allocations in TMDLs are made via the state’s Water Quality Management Plan (WQMP), which is updated quarterly. Revisions are made to TMDLs in one of two ways:
- Updates are made to account for changing conditions in the watershed, such as new or revised wasteload allocations, permits that have been canceled or have expired, or changed facility names.
- Addenda are created to add load allocations for assessment units that are impaired by the same pollutant or condition, within the same watershed as in the original TMDL report.
Both updates and addenda are provided in the same units of measure used in the original TMDL.
Addendum
An additional TMDL for Lake Worth has been added by addendum, submitted as an update to the state’s Water Quality Management Plan.
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TMDL Addendum One: One Total Maximum Daily Load for PCBs in Fish Tissue in West Fork Trinity River Below Eagle Mountain Lake
Segment 0808. July 2014 WQMP Update, Approved by EPA November 2014
Implementation Plan
The Commission approved this I-Plan on August 23, 2006.
- Implementation Plan for One Total Maximum Daily Load for Polychlorinated Biphenyls (PCBs) in Fish Tissue in Lake Worth, Segment 0807
- Response to Public Comment on the Implementation Plan, July 2006
For More Information
For further information regarding the TMDLs or I-Plan, please email tmdl@tceq.texas.gov and mention the Lake Worth PCB project in the subject line. Or call us at 512-239-6682.
