All of those “Do Not Dump—Drains to Lake” signs on storm drains and the programs to collect household hazardous waste in many communities really do have an effect, as one of EPA’s nonpoint success stories shows.
Fosdic Lake in Fort Worth, TX, was so polluted that the state banned the possession of fish taken from it, concerned about harmful chemicals at concentrations high enough to be dangerous to people who consumed them. Although many of the chemicals had long since been banned by the time the Texas Department of State Health Services made that move in 1995, leaks, spills, and illegal application of chlordane, PCBs, and various pesticides and coolants were keeping levels high in the lake and surrounding soils.
Five years after the ban, a TMDL went into effect. The city of Fort Worth opened a facility that accepts household hazardous waste from local residents—carefully tracking how much of what came in matched the “legacy pollutants” affecting the lake. Over six years, more than 8,000 pounds of such substances were collected. In combination with public education efforts and continual sampling of the water, soils, and fish tissue, these efforts allowed the state to lift the fish ban in 2007 and to remove the impairment designation for many of the chemicals; only PCB levels remain elevated, but are improving.
EPA maintains a site highlighting water bodies affected by nonpoint-source pollution that have been improved, often with the help of a federal Section 319 Grant and usually with other funding sources as well. Strategies and funding sources are listed for each site.
On November 17, 2000, TCEQ and the U.S. Environmental Protection Agency (EPA) approved a total maximum daily load (TMDL) for Fosdic Lake to address legacy pollutants in fish tissue. The endpoint of the TMDL was to restore the fish consumption use by meeting the DSHS' criteria for contaminant levels.
Project Highlights
The Fort Worth Environmental Management Department (FWEMD) operates the Environmental Collection Center (ECC), a permanent, year-round facility that accepts household hazardous waste from residents of Fort Worth and other areas. In consultation with TCEQ and EPA, the ECC modified its record-keeping system to track the amounts of legacy pollutants collected at the center. The city used the information as a measure for evaluating its pollution prevention program and targeting its educational efforts.
As part of the TMDL effort, TCEQ collaborated with the U.S. Geological Survey (USGS) in 2004 to collect and analyze sediment and runoff samples from the watershed to evaluate the loading of legacy pollutants and to identify trends and sources of the pollutants. The TMDL collaboration effort also included collecting fish tissue samples, an effort funded in part by a CWA section 319 grant. The goal was to develop the quantitative risk characterization that eventually became the basis for the revised health risk assessment that DSHS adopted in 2008.
Results
Pollution prevention and source control practices such as the public education and household hazardous waste collection programs implemented by the City of Fort Worth contributed to the reduction of pollutants. The City's educational program resulted in an overall 21 percent increase in the use of its permanent household hazardous waste facility. As of 2006, the ECC had collected and logged more than 8,000 pounds of materials containing legacy pollutants. The educational program was also highly successful in informing the public about the quality of urban lakes and the possible public health and environmental risks of potential contaminants. The combination of these investigations, management activities, and the natural attenuation of the pollutants has proven to be effective for Fosdic Lake.
Through 2006, sampling of residential stormwater outfalls showed that legacy pollutants continued to be present in urban runoff. Recent fish tissue monitoring data, however, indicated that the pollutant levels in fish from Fosdic Lake had diminished sufficiently to allow for their safe consumption, prompting DSHS to lift the fish possession ban in 2007. According to a January 15, 2008, DSHS article, fish tissue monitoring showed that, with the exception of PCBs, concentrations of legacy pollutants were in compliance with the target health assessment comparison (HAC) values in the TMDL (Figure 2). As a result, TCEQ removed the impairment designation for chlordane, dieldrin and DDE in 2008. Although there has been a distinct downward trend in PCB concentrations, levels remain sufficiently elevated to warrant a consumption advisory and impairment designation.