County pins hopes on aeration plan

By Jenna Portnoy, Intelligencer, November 2, 2008

Bucks County and the state are close to finalizing a plan to treat liquid from the county-owned landfill that once flowed into a tributary of Gallows Run.

 

Earlier this month, commissioners agreed to pay Penn E&R of Hatfield $281,500 to build a drip irrigation system to treat the liquid, called leachate, from Hidden Valley, a defunct dump in Nockamixon.

 

The county only obtained one quote to avoid the added time and costs associated with putting the project out to bid, said special projects coordinator Joe Bush.

 

The landfill attracted attention in April after this newspaper reported that four years' worth of testing showed liquid discharged into the stream consistently exceeded permitted levels of ammonia and iron. In December, the state Department of Environmental Protection issued a violation notice against the county and began talks on a treatment plan.

 

The state is conducting a technical review of the county's plan to treat the liquid using drip irrigation, instead of the earlier spray-irrigation proposal, said spokesman Dennis Harney.

 

The county plans to repair two pump stations last used to treat leachate in the 1990s and add new equipment.

 

Harney explained how drip irrigation works: First, leachate flowing down two sides of the landfill is collected in piping and pumped to the treatment station.

 

After aeration and settling at the treatment center, the leachate travels to the second pumping station nearby, where it is pushed to the top of the landfill.

 

From there, it flows through hoses called drip lines. Tiny holes in the hoses allow the liquid to drip out slowly over a large area, instead of one concentrated spot.

 

The liquid is then absorbed by vegetation, a process that distributes and dilutes the contaminants.

 

The cycle is continuous with pipes at the bottom of the sloping landfill constantly collecting liquid to feed the treatment center.

 

Bush said it's too early to know how much running the system, including electricity and maintenance, will cost.

 

Although the state has yet to issue the county a permit to operate the treatment center, Bush said site work could begin as early as this week. The county hopes to finish by the end of the year, if the weather cooperates.

 

After that the state will have a role in determining how long the center must be operational. Back in the early '90s, leachate tests showed liquid coming out of the landfill was clean enough to stop treatment.

 

“It got so good they didn't need it anymore so they shut it down,” Bush said. “And that could happen again.”

 

Stephen Donovan, a local chemist who sits on the Bridgeton-Nockamixon-Tinicum Joint Groundwater Committee, said drip irrigation would allow some compounds to evaporate instead of entering the groundwater.

 

Old dumps like Hidden Valley were utilized to get rid of everything and anything with zero regard for the environmental impact, he said.

 

“It's sort of like shoveling sand in the tide,” he said. “You throw it back and it comes down again.”

 

In addition to the 130-acre landfill, the county owns an adjacent 124 acres that it leases to Bucks County Horse Park Inc.

 

Commissioners on Oct. 15, decided to purchase 23 acres near the horse park from Paul and Kim Havis for $640,000. The county bought the land with open space dollars set aside for parkland preservation out of the first referendum in 1997.

 

The land will be added to the park if the county enters into a formal contract with the equestrian group.

 

The current deal, a one-page document issued by Parks Director Bill Mitchell in 2005, requires the park to submit quarterly financial reports to the county, pay liability insurance and utility costs and maintain the land, equipment and buildings.

 

Twenty-five acres of trails wind through the horse park and adjoining properties where the county has purchased easements.

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