Source: Standard-Speaker (Hazleton, PA), October 5, 2015
Posted on: http://envfpn.advisen.com
Pouring a chemical into wells at a Superfund site in the Valmont Industrial Park is neutralizing a hazardous substance that leaked into ground water decades ago, the project manager overseeing the cleanup for the U.S. Environmental Protection Agency said.
Brad White, the manager, also said a consultant recently looked for ways to fine tune the treatment, which began four years ago.
In the treatment, a purple liquid called sodium permanganate flows down injection wells to mix with a cancer-causing chemical called trichloroethylene, which spilled from the former Chromatex plant between 1978 and 1988.
Because people living near the plant now drink municipal water, the groundwater doesn’t present a health risk to them currently. The EPA, however, wants to reduce the levels of trichloroethylene or TCE to 5 parts per million so the groundwater is suitable for future use, White said.
There is strong evidence that TCE causes kidney cancer in humans and limited evidence that it causes non-Hodgkin’s lymphoma and liver cancer, the U.S. Agency for Toxic Substances and Disease Registry said.
Injections of sodium permanganate began in Valmont in 2011 after the EPA tested a similar compound, potassium permanganate, in 2009.
The tests led EPA to conclude that underground injections would neutralize TCE.
When permanganate and TCE combine they yield neutral substances such as carbon dioxide, chloride, hydrogen and magnesium dioxide, which further breaks down into water and solid magnesium.
Treating TCE underground with permanganate would take five years and cost $821,000, whereas pumping the groundwater to the surface and treating it would take 20 years and cost $2.1 million, the EPA estimated before starting the injections.
Through March 31, 2012, the EPA said it spent $14.2 million on the site, according to a consent order entered last year with Chromatex and other parties potentially responsible for the spill. The parties agreed to pay $2.225 million toward the cleanup. In 1998, Chromatex also paid $823,000 to cover actions taken at the site up to then.
Chromatex made upholstery for furniture and used TCE in the process of applying Scotchguard on the fabric from 1978 to 1988.
The plant closed in 2001; the building is now used as a warehouse.
TCE leaked from underground tanks, and Chromatex also released 7,640 pounds of TCE into the air during operations.
Residents who drank and showered with groundwater before 1988 faced exposure to TCE.
“Exposures to ground water at the highest levels off-site could possibly have yielded adverse health effects (assuming 10 years of exposure),” the Agency for Toxic Substances said in a health assessment.
In 1988, the Hazleton City Authority installed public water to the affected residents living in West Hazleton and Hazle Township on Bent Pine Lane, Deer Run Road, Twin Oaks Lane and Jaycee Drive, and the risks decreased.
The health assessment, done in 2006, said the Agency for Toxic Substances and the Pennsylvania Department of Health concluded the site posed no apparent hazard then or in the future.
White said West Hazleton restricts people from drilling wells for drinking water in the affected area, and Hazle Township agreed to contact the EPA if anyone there seeks a permit for a well.
Since the discovery of the spill, the EPA has removed 18,000 tons of contaminated soil from beneath the underground tanks and other areas contaminated by air filters that captured TCE.
Beneath 16 homes, the EPA installed fans and pipes to divert fumes that might contain TCE from basements and create a “preferential pathway for the TCE to travel away from the homes,” White said.
He and other workers for the EPA inspect the vapor removal systems regularly and have replaced a few of them. Homeowners telephone if their systems quit or grow loud.
Also, the EPA checks about 50 monitoring wells in and around the former Chromatex plant, which is now used as a warehouse.
After injecting permanganate into the ground water three times since 2011, the levels of TCE in the monitoring wells have declined, White said.
“When we do an injection, we’ll see concentrations in TCE decrease wherever the oxidant is,” he said, referring to permanganate as the oxidant.
The bedrock below the area is sandstone, which absorbs TCE.
“As we neutralize TCE in cracks, more TCE will come out of the rock,” White said.
He calls that rise in TCE levels a rebound effect and has noticed the rebound in some, but not all, monitoring wells.
Last winter, before adding permanganate, the EPA drilled five more injection wells inside the warehouse so there are 14 injection wells all together.
Since then, the EPA hired a consultant to learn whether changes, such as putting permanganate into injection wells more frequently, would make the treatment work better.
The EPA will review the consultant’s report before adding permanganate to the wells again in the spring of 2016. Then the agency will advertise its plans to meet with residents at their homes and with government officials to gain feedback while preparing a five-year review of the treatment process.
“There are constant changes in the state of the science. We continue to look at ways to improve what we’re doing,” White said.