Toxic Chemical Prompts Warnings at Lake Wateree

Posted on Wed, Aug. 25, 2010

Some of Lake Wateree’s most popular game fish are polluted with a cancer-causing material that has made them unsafe to eat in more than moderate amounts.

The state Department of Health and Environmental Control has issued a health advisory for striped bass, blue catfish and largemouth bass after finding PCBs in those species at Lake Wateree. The advisory tells people to limit consumption of those fish.

DHEC’s warning makes Lake Wateree only the second lake in South Carolina — and the first in the Midlands — to carry a fish consumption advisory for PCBs, which have persisted in the environment decades after production of the toxic industrial material stopped.

PCBs, or polychlorinated biphenyls, are considered probable human carcinogens and have been linked to liver cancer in rats. People can be exposed by consuming food and water containing PCBs, as well as breathing airborne particles of the toxic material. Industrial spills into water and air can send the material into rivers and lakes.

DHEC issued the fish advisory for PCBs this past spring on its website but has not yet posted warning signs at boat landings and other areas along the lake where people fish.

Agency spokesman Adam Myrick said DHEC is working with the Department of Corrections to produce the signs. He could not predict when they would be posted, but he said there should be about eight signs.

“We have identified the boat landings where they will go up,’’ he said.

State data showing the level of PCBs in each fish species were not available Tuesday.

Lake Wateree, about 30 minutes north of Columbia, is one of the most popular recreational lakes in the state, attracting anglers and boaters alike.

But the lake is among 17 percent of the country’s reservoirs with elevated PCB levels in fish, a 2009 federal study said.

Last fall, a U.S. Environmental Protection Agency report found PCBs in Lake Wateree’s largemouth bass at nearly six times a public health safety standard. The report also noted elevated mercury levels in some Lake Murray fish.

After the EPA report came out last fall, DHEC tested Lake Wateree’s fish for PCBs for the first time in years. Results of the testing prompted DHEC to issue the advisories, which have not been reported widely in the media. Myrick said his agency continues to investigate the PCB problem at Lake Wateree.

David Merryman, the riverkeeper for the Catawba River basin, said he’s glad DHEC tested Lake Wateree’s fish. The lake is the southernmost in the Catawba River basin and just above the Wateree River.

“People are eating and consuming these fish, and they need to know what’s in them,’’ Merryman said. “We need to know there is a problem and move forward. We have to recognize that this is a chronic pollutant.’’

According to DHEC, people should not eat more than one meal per month of blue catfish or striped bass. People also should not eat more than one meal per week of largemouth bass, the agency says. Each advisory is based on a meal of about eight ounces of fish.

There are no restrictions on black crappie, another popular fish, according to the health and environmental agency.

PCBs that wash into rivers and lakes build up in the fat or tissue of some longer-lived fish species. While the water itself remains relatively free of the pollutants, the contamination settles to the bottom of lakes and binds to soils. It can slowly accumulate in fish that suck in microscopic amounts of the pollutant over time. Unlike with mercury in fish, DHEC says, some threats from PCBs can be reduced if people carefully cut the fatty tissue away from fish they catch.

Manufactured decades ago as coolants, lubricants and fire retardants, PCBs are made up of some 209 compounds and were once relied upon extensively by industry.

Among other things, they were used as insulating fluids in electrical transformers and as fluids in vacuum pumps and compressors, according to the EPA. PCBs haven’t been produced since the late 1970s because of evidence that they build up in the environment and pose health risks. They get into lakes and rivers through both air and water pollution.

DHEC’s finding of PCB contamination in fish at Lake Wateree reflects a broader concern in the Catawba River basin, which extends from north of Charlotte to near Congaree National Park southeast of Columbia. Sprawling Charlotte often is cited as a reason for contamination in the river system south of there.

Earlier this year, Merryman’s Catawba Riverkeeper organization found PCBs at Mountain Island Lake, a North Carolina reservoir also on the Catawba River chain.

Dan Tufford, a USC water quality researcher familiar with Lake Wateree, said he suspects industrial pollution has contributed to the PCB findings in fish.

“There is a lot of industry upriver from Lake Wateree,’’ said Tufford, who tracks water quality issues at the lake. “The potential for this kind of contamination has always been there.’’

Lake Wateree also has had questions about PCBs before. Sometime in the 1940s, workers for a power company used PCBs in an attempt to kill mosquitoes on the lake, former employees have said.

Dick Foote, who heads a citizens’ committee studying water quality at Lake Wateree, said it could be difficult to rid the popular reservoir of PCBs in fish.

“I don’t know that there’s anything you can do about it,’’ he said. “You could dredge the entire lake, which you might as well say is impossible, or you could cover it all with something. That also is practically impossible. I think it’s just a fact of life.’’

Foote said the key is for people to know about the fish consumption advisories at Lake Wateree. He noted that the advisories do not prohibit eating certain fish, only to be careful about the amount eaten.

“It’s like lots of things — lots of things you do in moderation,’’ he said. “Just be aware of what you can do and what you can’t do.’’