Clean Water In the News

Plant operators suspect customer improperly disposed of chemical

By Asher Price
AMERICAN-STATESMAN STAFF
Thursday, March 30, 2006

A wastewater treatment plant just outside Georgetown pumped excessive amounts of mercury into the Brazos River basin as recently as June 2005, according to a review of U.S. Environmental Protection Agency records by the Austin American- Statesman.

The Dove Springs Wastewater Treatment Plant exceeded its acceptable amounts for mercury by as much 3,371 percent while racking up violations for five consecutive reporting periods from April 2004 to June 2005. Each reporting period is three months long.

At high levels, mercury may damage the brain, kidneys and a developing fetus, according to the Agency for Toxic Substances and Disease Registry.

State officials said the level of mercury discharged by the plant did not pose an immediate health threat.

"Mercury cycles through the environment very easily," said Gerald Carney, a Dallas-based EPA toxicologist, "and it has the potential for bioaccumulation. It can make its way into tissues and then make its way into animals higher up the food chain."

At its worst, the mercury content amounted to 0.00059 parts per billion; the acceptable EPA drinking level for drinking water is 2 parts per billion, according to an EPA consumer fact sheet.

The Texas Department of State Health Services uses 0.7 parts per million in fish tissue as a rough trigger to issue consumption advisories for fish, said Doug McBride, a department spokesman.

"Just because you got mercury in the water doesn't mean you got mercury in fish," McBride said. "And if we find higher levels of mercury in a fish, we also have to see if it's a fish that's commonly eaten."

The Dove Springs plant has no cleaning procedure for mercury.

"We think that someone, a customer, was disposing of a mercury-containing substance into the system," said Glenn Dishong, the water services manager for the City of Georgetown, which owns the Dove Springs plant. "It has nothing to do with plant's design or operation."

Dishong said the plant serves fewer than a dozen industrial or medical customers.

"We took a look at dentists' offices and industrial customers and sampled at strategic locations," Dishong said. "It's hard to know exactly where it comes from. We went business to business in certain areas, asked them if they use mercury compounds and told them they can't dispose of it down the sewer."

No mercury has been discharged from the plant for nine months.

"All it takes is someone to dump mercury down the toilet, and I've got this problem again," Dishong said.

The plant has no pre-treatment for mercury, Dishong said.

Other similarly sized plants, including the two dozen or so operated by the Lower Colorado River Authority and the handful operated by the City of Austin, also do not treat for mercury, according to city and LCRA officials.

"A pre-treatment for mercury is available, but a plant is not required to implement it unless it's the only way to get below permitted levels," Andrea Morrow, a spokeswoman for the Texas Commission on Environmental Quality, said.

The Dove Springs plant, which came online in 1993, treats sewage in the southern part of Georgetown.

The current capacity of the plant is 1.24 million gallons a day; an expansion under way would more than double capacity to 2.5 million gallons. Sewage is pumped through the facility, treated and sent into an unnamed tributary of the Mankins Branch tributary of the San Gabriel River, which is in the Lower Brazos River basin.

The facility tests the effluent, or cleaned water, twice a week to make sure the water falls within environmental commission standards.

Dove Springs is permitted to emit a daily average of up to 0.0171 milligrams of mercury per liter of water, according to the state commission.

At its highest, during the reporting period ending in March 2005, 0.593541 milligrams of mercury per liter of water was detected in the treatment plant's effluent.

Between July 2003 and December 2004, more than 58 percent of industrial and municipal water facilities in Texas discharged more pollution into waterways than their Clean Water Act permits allow, according to "Troubled Waters," a report released last week by Environment Texas that prompted the American-Statesman review.

In Texas, at least 19 percent of rivers and 29 percent of lakes are unsafe for swimming and fishing, according to Luke Metzger, who runs Environment Texas, an arm of Texas Public Interest Research Group.

asherprice@statesman.com; 445-3643