Landfill Leachate Polluting Groundwater

Chemicals from Keystone Sanitary Landfill are Contaminating Groundwater

A trend of increasing concentrations of ammonia-nitrogen, chloride, nitrate, sodium and total dissolved solids in one of the landfill's groundwater monitoring wells indicate the contamination comes from the landfill's leachate treatment plant, a DEP geologist told Keystone manager Joseph Dexter in a Sept. 11 letter. The letter and other DEP documents were recently made available to the newspaper, which filed a Right to Know Law request to review them.

After reviewing Keystone's annual groundwater reports, the newspaper found that the landfill has experienced off-and-on problems with its leachate treatment plant dating back about 12 years.

Though the state's Clean Streams Law makes it unlawful to discharge any polluting substance to groundwater, Keystone received no violations from DEP for any of these issues, spokeswoman Colleen Connolly said.

"A lot of the reason for that is if they work with us to correct the problem, that goes a long way," she said. "There's still a good-faith effort to remedy the problem. It's not like they're just ignoring it."

Mark Szybist, staff attorney for environmental group PennFuture, said any confirmed discharges would surely violate the state's Clean Streams Law. He found it "problematic" that they don't show up on eFacts, the DEP's enforcement tracking tool.

"You can't fault the DEP for taking a non-adversarial approach with a cooperative violator," he said, "but it's another matter when the public doesn't know a facility's true environmental record because it doesn't show up on eFacts."

Leachate is liquid that passes through a landfill, picking up chemicals and dissolved particles from the waste. Some call it "landfill tea."

Keystone's leachate contains a wide and ever-changing variety of contaminants, according to documents in its February application to the DEP for permission to expand skyward 220 feet from its current peak. The expansion would extend the life of the landfill by almost 50 years.

In various tests in 2013 and 2014, DEP found acetone, t-Butyl alcohol, tetrachloroethene, toluene, tetrahydrofuran and methyl ethyl ketone in groundwater wells drilled on Keystone property.

Each of these chemicals are industrial solvents, typically found in paint or varnish thinners. Tetrachloroethene is widely used in dry cleaning. In high enough concentrations, they are all toxic to humans, according to the National Institute for Occupational Safety and Health.

Acetone is a "common laboratory contaminant," according to DEP, and may not have come from the landfill.

The other chemicals are volatile organic compounds, "a key indicator of landfill contamination," according to a report prepared for Keystone by Hydro-Geo Services Inc. of New Cumberland.

Drainage from abandoned coal mines already affects groundwater below the landfill, according to the landfill's reports. Landfill and DEP tests show consistent high levels of iron and manganese, among other metals.

The leachate contamination is not likely to affect local drinking water, Pennsylvania American Water spokeswoman Susan Turcmanovich said. Drinking water comes from Lake Scranton, Williams Bridge, Elmhurst, Curtis and Hollister reservoirs for the 160,000 people from Archbald down through the valley to Old Forge, the Abingtons and Scott Twp..

Dunmore No. 1, a reservoir across Route 6 about 800 feet from part of the landfill, is only used in emergencies, she said. Its last use was 2006. The utility would have to test the reservoir and consult with DEP before using it as a drinking water source, she said.

When all goes according to plan, Keystone keeps chemicals out of the groundwater via a leachate collection and pre-treatment system.

Keystone collects leachate in a set of pipes running below the waste but above the liners meant to separate waste from the ground, the landfill's application states.

Leachate flows from the pipes to a lined lagoon, then to a pump station. The pumps feed the leachate into a pre-treatment plant, which can treat between 70,000 and 100,000 gallons per day.

From there, the leachate flows to sewers owned by the Scranton Sewer Authority through a dedicated line that feeds into the authority's Roaring Brook trunk line, according to a March 2012 agreement between the landfill and the sewer authority. The agreement includes limits on chemical concentrations the sewer will accept, among other conditions.

The pre-treated leachate then enters the Scranton Wastewater Treatment Plant, where it's treated again, then discharged to the Lackawanna River.

At least occasionally, Keystone's leachate escapes this controlled system, the newspaper found in its review of records. DEP testing found leachate-associated chemicals in three monitoring wells in May 2014. The department also found chemicals in three wells in May 2013. The department returned in August 2013 to test the same wells again and did not find those chemicals.

Yet, the Sept. 11, 2014 letter indicates the problem is not resolved, particularly with one well, labeled MW-15A. DEP geologist Lisa Hannigan wrote "The groundwater quality at MW-15A is a concern. ... As seen in the past, concentration trends in MW-15A point to further leachate treatment plant deficiencies."

In emails, Ms. Connolly explained how the DEP views the contamination and promised continued monitoring. The department does not believe the contamination poses a threat to drinking water or the ecosystem, she said.

"The department believes the (volatile organic compounds) would dissipate upon entering the mine pool, and hence, the Lackawanna River," she said, adding the leachate issue is not a factor in the DEP's review of Keystone's expansion.

"We believe Keystone is remediating the problem," Ms. Connolly said. "However, if tests show increased levels of leachate again, it would be an issue we could not ignore."

Acetone, the only volatile organic reported in August, showed up in low concentrations from MW-15A and was flagged as a laboratory contaminant in another well, she said. DEP will continue tracking it.

Since May, DEP has not detected tetrachloroethene (dry-cleaning fluid) or the chemicals it forms when it breaks down, Ms. Connolly said.

DEP also suspects some of the chemicals that showed up in the May 2013 tests came from well construction. "(Methyl ethyl ketone), toluene and tetrahydrafuran were reported in wells that I believe had undergone repairs," she said. "Cement for PVC pipe (used in well construction) contains these products."

Source: The Times Tribune

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• Environment
• Pollution
• Groundwater Recharge