Trinity River fish still not safe for eating
High levels of toxic compound continue to be found in tests along the Trinity River
02/03/2010 11:46 PM
07/07/2010 12:41 PM
Fish in the Trinity River likely won't be safe to eat for many more years because of the continued presence of a toxic compound in the water, officials said Wednesday.
And some of the highest poisonous readings of polychlorinated biphenyls -- or PCBs -- were found at sample sites in Tarrant County.
"I think we've done irreparable damage," Brian Smith, who owns about 700 acres of preserved ranchland along the river in Navarro County south of Dallas, said during a Texas Commission on Environmental Quality meeting Wednesday in Arlington.
The meeting was held to update the public on the state's effort to clean up the water in a 150-mile stretch of the river in Fort Worth, Arlington, Dallas and south toward Corsicana. A fish consumption advisory was issued in 2002 by Texas Department of Parks and Wildlife, and a ban on the possession and consumption of fish on some portions of the Trinity was also issued.
In Tarrant County, the effort includes restoring the water quality to 22 miles of the West Fork below Lake Worth, and one mile of the Clear Fork below Lake Benbrook.
Among the highest PCB readings were results at testing sites in Fort Worth -- one near North Beach Street, the other near Handley Road -- and another near Farm Road 157 near the Fort Worth/Arlington border, a consultant explained during the Arlington meeting.
PCBs were commonly used in caulk, cooling and insulating fluids for transformers and capacitors, flame retardant, floor finish and paint from the 1930s through 1977.
The compound was banned after being linked to severe skin problems and possibly liver damage. Some studies have also linked PCBs to an increased risk of cancer.
One characteristic that made PCBs so desirable in 20th-century manufacturing also makes it a modern-day environmental nightmare -- the stuff is extremely durable and refuses to break down, often remaining in the environment for decades.
As a result, PCBs continue to leak into the Trinity River from mostly unknown sources, although scientists believe more than 60 percent of the PCBs being found in the fish are coming from creek and river sediment.
In other words, the dangerous material is clinging to the river bottom and only gets into the water -- and, as a result, into the fish -- when it's stirred up.
Other likely sources of contamination include pretreated wastewater from industrial sites that feed into the Trinity River and stormwater from surrounding cities.
It's still a major mystery where specifically the PCBs are coming from, said Kirk Dean, a principal scientist with Parsons, a firm hired to produce a technical report on PCBs in the river.
"Coming into this, I think we were hoping to find a hot spot that nobody had found out about, and maybe that one spot could be addressed and take care of the problem," Dean said. "But we didn't find any hot spots to speak of. Yeah, there are some areas that are hotter than others, but it didn't look like a smaller area that we might be able to do something about."
But the Texas Commission on Environmental Quality is making progress on its plan to eventually clean up a 150-mile stretch of the river from Benbrook and Lake Worth to Cedar Creek Reservoir south of Corsicana. The idea is to prevent more PCBs from getting into the river, and allowing the PCBs already in the sediment to break down over time, until PCB levels fall below harmful levels.
"It's not expected this is something that could happen overnight, or even over the next few years," said Dania Grundmann, project manager. "This is a long-term effort. It's been there 25 years. It might be there another 25."
About 50 people attended the meeting, which was held at the North Central Texas Council of Governments office in Arlington.
One woman in the audience asked if drinking water was at risk.
State officials and their consultant explained that their report focused on fish tissue and didn't go into detail about drinking water, but that generally PCB does not mix with water and tends to either stick to fish or sink to the bottom.
As a result, the levels of PCB weren't expected to immediately threaten drinking water.
Oakhurst Neighborhood Association president Libby Willis is concerned that Riverside Park would be excavated to store river water as part of the Central City/Trinity Uptown project. The nature of Willis’ concern was incorrectly reported in a story Thursday about a toxic compound in the Trinity River that had made fish unsafe to eat.
"If there are PCBs in the soil, why would you put it in a park, of all places?" she asked.
Willis also noted that signs warning that fish in the Trinity River should not be eaten had been removed. Texas Commission on Environmental Quality said the signs most likely had been stolen.
GORDON DICKSON, 817-390-7796
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