LOUISVILLE, Ky. (WDRB) – Kentucky wants to remove the lower half of the Ohio River from a list of state waterways with warnings against eating fish possibly contaminated with mercury.

The state Division of Water's proposal includes about 370 miles of the river from Jefferson County west to where the Ohio flows into the Mississippi River, said Randy Payne, an agency environmental scientist.

Mercury, along with other pollutants, has led Kentucky officials to caution against consuming fish from the Ohio. The type of mercury that people absorb when eating contaminated fish has been linked to neurological problems in infants and children, according to the U.S. Environmental Protection Agency.

The section of the river west of Louisville is considered to be impaired because of mercury levels in fish tissue. Payne said the upper half of the river isn't deemed impaired, although a statewide advisory cautions women of childbearing age and children younger than six years old to eat freshwater fish no more than once per week due to mercury concerns.

The state took a different approach to gauging mercury in the Ohio during its most recent review last year, sampling the substance in fish tissue instead of overall levels in river water, said Randy Payne, a Division of Water environmental scientist.

Payne said a national standard involves the fish tissue measurements.

“Those data tell us that the fish are below the criterion (and) are indeed safe to consume based on those results,” he said.

The state agency's plan, released earlier this month, is part of a federal review done every two years. The Division of Water is taking public comment on it until July 13.

The proposal doesn't necessarily signal it's safe to eat fish from the river. Kentucky still considers hundreds of miles to be tinged with PCB and other toxic chemicals and urges people not to eat fish in 11 of the 25 counties on the Ohio.

Judy Petersen, executive director of the Kentucky Waterways Alliance, said she was caught off guard by the state proposal.

“I'm pretty concerned about it, because as far as I know we have no new data that says that the mercury in fish tissue is getting any less in the Ohio River,” she said. “As a matter of fact, everything I've seen points the other direction.”

Peterson noted data from a regional agency that monitors water quality showing that, as recently as last year, portions of the river in Kentucky exceeded the safe threshold for mercury in fish tissue.

“It still seems to me like we have a considerable amount of data showing that there is reason for concern,” she said.

But the agency, the Ohio River Valley Water Sanitation Commission, reported last year that the average levels of mercury in fish tissue sampled in 19 river pools all fell below the amount the EPA says not to exceed when eating fish.

As a result, “the entire river is classified as fully supporting the fish consumption use for methyl mercury,” according to the report.

At the same time, the commission tested Ohio River water at 11 locations and found higher-than-allowed levels of mercury in more than 10 percent of the samples. In Louisville, scientists noted violations in three of 18 samples, or 17 percent.

The most contaminated water – 20 percent of all samples -- was at the J.T. Myers Locks and Dam in Union County.

The Ohio River commission is currently reviewing changes to rules on “mixing zones” where discharges of mercury are diluted in the river before being measured for compliance with allowed standards. It also is weighing possible changes to the criteria for safe levels of mercury in water.

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