Leachate treatment system works

WILLMAR –– Initial test results indicate that a too-good-to-be-true method of filtering out hazardous chemicals and contaminants from liquid that seeps from the Kandiyohi County landfill may indeed be good and true.

The Kandiyohi County Board of Commissioners heard an update Tuesday on a pilot project underway at the landfill that engineers say can turn contaminated water into drinking water. And the process is more environmentally sound than the county’s current system of trucking leachate to Willmar’s wastewater treatment facility.

On top of that, they said the technology will save the county $3 million over the next 20 years.
The board will consider a proposal on September 16 on whether or not to install the equipment permanently for the first-of-its kind system in the United States.

Commissioner Doug Reese said the ability to save money and turn “nasty, nasty water” into water that’s cleaner than the Minnesota Pollution Control Agency’s standards for drinking water is hard to envision.

“I believe you, but it sounds too good to be true,” said Reese, quickly adding that he’s “impressed” with the test results and the “great possibilities for our county.”

“That’s why the MPCA is so excited,” said Vladimir Scheglowski, an engineer with Clark Engineering Corporation of Minneapolis.

“Our results aren’t made up,” he said. “The MPCA has been watching over our shoulder.”

Commissioner Harlan Madsen said he would like to hear from an MPCA official to have the information corroborated prior to taking a vote later this month.

After a preliminary trial run last year at the landfill, engineers from Clark Engineering and Apex, a Coon Rapids company, conducted a large-scale demonstration project this summer.

Thousands of gallons of leachate –– the liquid that is collected in a drainage tank every day at the landfill — was pumped through a filtering system to remove contaminants.

The cleaned water was tested for 140 different compounds by independent testing laboratories.

Almost 90 percent of the compounds tested were completely removed, according to information from the engineers.

Any remaining contaminants are well below the MPCA’s “intervention” level, which is even better than the limits for drinking water, said Greg Ackerson, an engineer with Apex.

Ackerson said the Department of Health establishes how many parts per million of a specific compound are allowed in drinkable water.

In an effort to ensure there is no harm to groundwater, Ackerson said the MPCA wants discharged leachate to be at one-fourth of that level.

The treated leachate is “cleaner than drinking water” standards “by a factor of four,” he said.

Testing for perfluorochemicals, or PFCs, was done at a level of parts per trillion at a California laboratory, Scheglowski said. “We’re cleaning that to that level,” he said.

Every year the county spends about $200,000 to transport more than 3 million gallons of leachate from the landfill to Willmar’s wastewater treatment facility, where it’s treated and then discharged into a ditch system that eventually flows to the Minnesota River and Mississippi River.

Although the city is a “good partner” with the county, Scheglowsi said the cost of transporting and treating leachate is expected to increase 7 percent a year.

He also said the traditional treatment system relies partly on simply diluting compounds to meet standards, while the filters now used in the pilot project actually remove the contaminants.

Treating leachate on site will give the county more economic and environmental control of the process.

Scheglowsi said the technology will allow the county to meet new, stricter environmental discharge standards the MPCA may require in the future.

Information about the proposal, including final pricing from contractors, will be presented to the commissioners on September 16.

If the project is approved, construction would begin in November.

This type of filtering system has been used for the last decade in Europe and Asian countries, but Scheglowsi said this would be the first of its kind in the United States.

Ackerson said, however, as the MPCA gears up to tighten regulations for discharging leachate, the Kandiyohi County project has been generating phone calls from engineers working with other landfills in the region.