Contaminated groundwater from old Texfi site still threat to PWC water supply

Source: Fayetteville Observer (NC), November 6, 2011
Posted on: http://envfpn.advisen.com

Beneath an enormous storage tank, where almost 200,000 Fayetteville area residents get their drinking water, lies an elusive plume of groundwater contamination.

State officials have known about the contamination, which comes from an abandoned textile mill next to the city’s water treatment plant, since the mid-1990s.

The plume contains a toxic soup of industrial solvents — called tetrachlorothylene, or PCE — that can increase the risk of cancer and liver problems if ingested over many years.

The state estimates it would cost more than $50 million to clean up the former Texfi Industries site, but there isn’t enough money available to even properly monitor the contamination.

Money constraints forced state officials to reduce monitoring efforts until last year, when they were surprised to learn that the plume had sunk to 30 feet deep and bypassed a clay barrier built in 2001. The barrier, called a slurry wall, was supposed to stop the contamination’s spread toward the city’s stored supply of treated drinking water.

But Craig Hampton, the city’s special projects director, said in a public email in June that the barrier might be having the opposite effect, drawing the contaminants to the storage tank.

An October 2010 document from the state Department of Environment and Natural Resources shows that the tank now “sits in contact with contaminated groundwater.”

A state consultant’s report from May shows that a monitoring well dug next to the storage tank found concentrations of PCE at 2,300 times the acceptable limits.

Other public emails and records obtained by The Fayetteville Observer show that no contaminated groundwater has ever breached the storage tank, which has concrete walls between 12 and 22 inches thick that extend 7 feet below ground.

Fayetteville’s Public Works Commission tests the tank — known as a clear well — every month for the contaminants.

As a precaution, however, the city-owned utility in September began testing the nearby Cape Fear River, too. The sample came back negative, but it demonstrates the growing concerns of PWC officials.

Water source

The P.O. Hoffer water treatment plant off Ramsey Street draws water from the river at a point that’s a little more than the distance of three football fields from the main Texfi building, city records show. The underground plume appears to have migrated eastward to within a few hundred feet of the riverbank, according to an aerial map prepared this year by state officials.

Keith Snavely, a hydrogeologist for the state Division of Waste Management who is overseeing the Texfi pollution, said there is “minimal to no risk” that tainted groundwater will reach the river. Even if it did, he said, the river would dilute the hazardous material into harmless concentrations.

Snavely said river samples tested by the state and the Environmental Protection Agency in 2001 and 2002 were negative. So were soil samples taken along the riverbank, he said.

A nonprofit watchdog group called Clean Water for North Carolina said one potential risk is that contamination might reach the river during low-flow conditions, with little hope of the river diluting the pollution downstream, where the Hoffer plant draws water for treatment.

That’s why officials should monitor the groundwater near the river upstream, said Hope Taylor, executive director of Clean Water for North Carolina. She said PCE concentrations 30 feet below ground in the clay are less likely to seep into the river, but she is glad PWC has begun sampling it.

The state Department of Environment and Natural Resources has recognized the seriousness of the pollution. Of the more than 500 hazardous waste sites the agency has identified in the state, the Texfi land ranks as the 33rd worst. The rankings help establish cleanup priorities, but the state has an annual budget of only $500,000 to address the ranked sites.

“It is a lot harder for contaminated sites to get cleaned up, and the state is more and more likely to say, ‘Let’s just wait it out,’ unless there is a big outcry,” Taylor said.

This spring, state officials sent letters to more than 400 Texfi employees in an effort to understand the defunct company’s disposal practices. State officials said this fall that they reached only two former employees, and neither offered any useful information.

As a further precaution, the state plans to bury a 100-foot pipe about 10 feet deep to catch more contaminants below ground before they can reach the clear well. The contaminated liquid will then be pumped from the “interceptor trench” to a sewage treatment plant.

The trench, a sump pump and one year of maintenance on the new system will cost about $113,000, nearly depleting the money available for the Texfi contamination, state officials said in October.

A state consultant, in an April email to city officials, described the interceptor trench as a “Band-Aid remediation system” for the “remaining Band-Aid budget.”

Long-term solutions

Mick Noland, PWC’s chief operating officer for water resources, raised a concern in May that the state had no long-term remedial plan for the tainted groundwater.

“PWC is very concerned about the protection of the clear well,” Noland wrote to Snavely.

So far, the federal government has been unwilling to help through its Superfund program, which is used to clean up hazardous sites when the property owners or parties responsible for the contamination are unable to do the work themselves.

The city obtained title to the 96-acre Texfi property this year, long after the bankrupt company was liquidated, with the hopes of redeveloping some of it. City officials are negotiating a Brownfield agreement with the state that would essentially waive any future liability for contamination as the new owner.

City officials also have begun looking at other resources for help. In September, they received word that the Environmental Protection Agency has approved an in-kind grant for technical assistance evaluating the contamination and recommending additional steps to protect the clear well and reduce the pollution. The assessment could be completed by April, Hampton said.

In addition, the city will apply for an EPA Brownfields grant worth up to $200,000 over three years. The grants may be the city’s best chance at reducing the pollution and risk to the drinking supply, according to public emails.

“We are on our own for the Brownfields grant to finish the cleanups,” Hampton told his colleagues in an email last fall. “Shouldn’t take more than a decade or so.”

The Texfi plant was used in yarn preparation and weaving, fabric dyeing and finishing. Dyeing added color to polyester fabric, and finishing involved a final coating to the fabric. Chlorinated solvents, such as PCE, were used in the process, because some cloths and fabrics soaked up dye more easily than others. Officials suspect that plant operations led to the release of chlorinated solvents into the ground.

About seven years ago, a bankruptcy court set aside $941,000 for the Texfi contamination. The fund, administered by the state, will have about $57,000 left after the interceptor trench is installed and maintained for one year. In addition, the legislature appropriated $50,000 this summer for monitoring and cleanup at Texfi.

In an interview in September, Noland said the steps PWC already has taken to protect the clear well and the interceptor trench are important safeguards — as long as nothing fails.

“As you know, sometimes things happen that weren’t anticipated,” Noland said. “There is always something that can happen.”

In 1995, PWC installed a plastic liner on the inside of the clear well and dug a french drain about 8 feet deep along the perimeter to collect groundwater. After the contamination was discovered, PWC began keeping the clear well at least half full, creating enough pressure to repel any groundwater from seeping through the walls, Noland said.

Noland said he is not too concerned that the contamination is now 30 feet below ground, near or under the bottom of the clear well. He said the clay at that depth acts as a sponge, and the french drain around the clear well is supposed to catch groundwater moving at more shallow depths.

Carla Raineri Padilla, director of the Southeastern Center for Environmental Excellence at Methodist University, said she and her students have toured the Hoffer plant many times.

“They do a really good job,” she said of the plant workers. “I know they are constantly inspecting and constantly monitoring everything.”

According to emails, Snavely asked PWC officials in February if they had ever considered abandoning the clear well and building storage tanks above ground.

PWC officials told him they “have investigated their options” but decided it was too expensive to mothball the clear well.

When the compartments that make up the clear well were last evaluated in 2008, inspectors found the tanks to be “sound structurally,” needing only minor upgrades to the mechanical gates inside, according to PWC emails.

The clear well holds as much as 12 million gallons of water.

The city’s other water treatment plant draws water from Glenville Lake, off Filter Plant Road next to Mazarick Park. The Glenville plant also draws water from the Cape Fear River. Both plants supply the city as a whole.

Water plant’s history

Construction started on the Hoffer plant and a smaller clear well in 1967 — a year before the Texfi mill began operation. The Hoffer plant, dedicated in 1969, has been expanded three times.

In September, PWC officials unveiled a $59.1 million, six-year plan to increase the treatment capacity at Hoffer and upgrade the clear well.

In 2008 and 2009, a state consultant injected a liquid compound into the ground at the Texfi site that served as a food supply for bacteria, which in turn neutralized some of the contamination into a harmless material. The project helped reduce the pollution that lingered only about 10 feet below ground. State officials said they can’t afford to do anything for the pollution at 30-foot depths.

Cathy Akroyd, a spokeswoman for the state Department of Environment and Natural Resources, said removing all the contaminated groundwater at Texfi and the Hoffer property would be a cost-prohibitive tab exceeding $50 million.

Akroyd said the state will quickly address any imminent pollution threats to drinking water or homes.

Padilla, the environmental director at Methodist University, said the state and the city are following a basic strategy of trying to contain the pollution rather than doing the arduous task of removing it. But she said officials need to be vigilant about the potential spread of contamination.

“I would worry about it contaminating the river and the life forms in the river,” Padilla said. “The problem here is the type of pollutants are extremely dangerous, carcinogenic and volatile.”

While the state says there are no private wells in use near the Texfi site, there is evidence that some contamination has seeped to the surface. According to the city’s application in April with the EPA, low levels of another type of degreasing solution, called DCE, were detected in six of seven temporary streams that spring up during rainfalls. The streams, or drainage ditches, are west of the abandoned Texfi building. One of the streams is to the north on city property at Clark Park.

Snavely said the streams drain into a pond in Clark Park and eventually into the Cape Fear River.

DCE is a byproduct of PCE. Both are chlorinated solvents, Akroyd said.

Akroyd said industrial chemicals found at Texfi, such as PCE and DCE, don’t normally linger on the surface. They are heavier than water and often sink deep below ground into aquifers, where they can remain in the environment for a long time.

Noland, who heads PWC’s water operations, said he hopes the state will test samples from monitoring wells on the site at least once a year to gauge the contamination’s movement.

Akroyd said the state will evaluate how to use limited funding for the Texfi site and decide when to sample more monitoring wells in the future.

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