Residents above contaminated plume alarmed at cleanup plan

Some North Jersey residents who live above one of the largest vapor intrusion sites in the country are so worried about a proposal to flush away the contaminated groundwater beneath their homes by pumping clean water into the ground that they have lobbied the state to hold a public hearing on the plan.

Pompton Lakes residents are worried about a plan to clean contaminated groundwater by pumping more water into the ground through a pipe to be buried along this railroad bed.

The groundwater under about 450 homes in Pompton Lakes is contaminated with PCE and TCE, cancer-causing solvents that were dumped at a DuPont munitions facility decades ago and spread through groundwater to the adjacent neighborhood.

In 2008, officials discovered the solvents were vaporizing up through the soil in some of the basements in the area.

The pilot test will involve a process called hydraulic surcharging, to see if pumping clean water into the ground at various points in the neighborhood can dilute or flush out the contamination.

Residents are worried that pumping more water into the ground will raise the water table enough to flood their basements with contaminated water, bringing more pollution into their homes.

And after talking with a number of insurance companies, residents say they would not be able to obtain homeowners insurance policies that would cover damages that could occur from this sort of project.

“I don’t think hydraulic surcharging is the answer,” said Lisa Riggiola, a former borough councilwoman and member of a residents' advocacy group. “There are better ways to tackle this.”

The group sent a letter to the state Department of Environmental Protection requesting a public hearing. Riggiola said she was told the request will be granted, but no date has been set.

This Pompton Lakes neighborhood sits above a plume of groundwater contaminated with solvents from the former DuPont munitions plant in background.

The work will be conducted by Chemours, a spinoff company that has taken on responsibility for cleanup at dozens of contaminated sites across the country formerly owned by DuPont.

Workers will install a horizontal pipe about 20 to 25 feet deep and running for about 600 feet along a railroad bed behind homes along Barbara Drive, just south of the DuPont property. Clean water will be pumped through the perforated pipe, which will act like an oversized soaker hose to let the water escape into the surrounding soil, theoretically diluting the pollution in the groundwater.

The federal Environmental Protection Agency has said field tests show the water level would not rise to flood basements, but residents are not convinced.

They want the state or EPA to make Chemours provide the homeowners with a blanket insurance policy to cover any potential damages from the pilot study.

The Pompton Lakes cleanup has been a long time coming. As far back as 1989, the DEP expressed impatience with DuPont's failure to clean up the groundwater. “The off-site migration of the contaminated groundwater is a threat to human health,” the DEP said at the time, and “requires the most immediate action.”

In 2009, the state Health Department found significantly elevated levels of kidney cancer and non-Hodgkin's lymphoma among residents of the affected neighborhood — cancers that have been linked in lab studies to TCE and PCE. The state did not definitively link the elevated cancer rates to the solvents in the groundwater, but did not rule that out as a cause.

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The pollution has stigmatized the neighborhood, leaving some unable to sell their houses and many worried about their health.

“We need to get this cleanup done,” Riggiola said. “It’s unacceptable that it has been more than 30 years and we’re still in a pilot study mode.

“These residents are living in an area with elevated cancer rates, their homes are devalued, and now they’re getting another worry over this pilot study without any blanket insurance policy.”

Chemours received approval from the DEP for the hydraulic surcharging study in late March, and the company is in the process of obtaining necessary permits. There was a public comment period during April.

Once the DEP evaluates all the public comments, it will make a decision on how and if the pilot study moves forward.

The former DuPont plant in Pompton Lakes manufactured explosives and is now an environmental threat to the surrounding residential area.  Part of the original plant that produced detonator caps shown in 1943.

DuPont installed a pump-and-treat system in 1998 to capture groundwater before it leaves the DuPont site, to keep even more contamination from spreading into the neighborhood. The water is cleaned of contaminants and pumped back into the ground.

In 2008, when the state determined that the solvents in the groundwater plume were vaporizing into basements, DuPont began installing vapor mitigation systems on homes. To date 335 systems have been installed.

According to measurements taken by DuPont at test wells in the neighborhood in 2008, the highest readings showed PCE at 260 parts per billion, while the state threshold for cleanup is 1 part per billion. The highest level of TCE found was 100 parts per billion, while the state threshold is 1.

The company did a pilot test of a different cleanup method in 2011 and 2012, when it injected soybean oil and then sodium lactate into the soil as a food source to stimulate growth of naturally occurring microbes that could break the PCE and TCE down into non-harmful substances. The results were disappointing because the groundwater didn't distribute the food evenly or quickly through the plume.

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Chemours is also planning another pilot test, to take place on the former DuPont property, to see if a process called in situ chemical oxidation could render the solvents harmless.

Liquid chemical compounds will be injected into the soil in the hope it will break down the contaminants. When the oxidants are injected, a chemical reaction occurs that destroys the contaminants and produces less-harmful byproducts, according to the EPA.

Chemours received approval for the in-situ work plan in September, and started design testing in December to collect information about how best to run the full-scale pilot test.

As part of the design testing, Chemours installed 10 injection wells and 14 monitoring points at five different areas on the former DuPont property. A Chemours spokesman said. Then, workers injected a complex solution of sodium persulfate and hydrogen peroxide at varying depths over five days.

After looking at the data, the company decided it needed more information to properly design the full scale pilot study. The company planned to collect more data in the early spring, and will then evaluate it.

The EPA has approved the use of chemical oxidants for cleanup of at least 40 Superfund sites, as well as many other contaminated sites across the country.