Groundwater contamination discovered around old landfill site

Under a benign-looking lush green hill in Hubbard County lurks a
growing toxic concern.

The 9-acre former Pickett Landfill, which borders the Heartland Trail
and is west of County Road 4, is about to become a household word once
again. It now is a massive area of groundwater contamination that
stretches from 204th Street on the north, then south and east of
Ferndale Loop. It once held 93,269 cubic yards of municipal solid
waste.

It opened in 1973 and closed in 1987. Since then state pollution
control officials have been monitoring the site for methane gas
migration and ground water quality.

Now, leaching chemicals have reached the point of concentration where
public notification is necessary and mandated by law.

Those notices will go out to affected property owners soon.

“We want to get the word out there,” said Minnesota Pollution Control
Agency land manager Tom Newman, who addressed the Hubbard County board
Wednesday. “It’s been off everybody’s radar since 1996.”

That was the year after the landfill became part of the Closed
Landfill Program, begun in 1994 to voluntarily shut down unlined
landfills throughout the state. The landfills, once accepted into the
state program, then came under state monitoring and were eligible for
state financing to clean up the site. To date 112 landfills are in the
program.

It was then covered with a synthetic membrane impervious layer topped
by 30 inches of cover soils, according to the MPCA. Gas vents were
installed and are monitored.

Demolition debris was relocated and a gravel pit nearby was reclaimed
and re-vegetated, according to the MPCA, in 1995.

“We’re required statutorally to give notice of off-site drift, the
non-point source pollution,” Newman said.

In addition to monitoring the groundwater for higher than normal
concentrations of arsenic, MPCA hydrologist Kate Rolf said she has
identified 68 organic compounds in the area surrounding the landfill
itself.

There is no reason to panic, the MPCA officials noted, but the county
needs to be aware there would be limitations for future development
and notification to prospective buyers of what those limitations will
be.

But Environmental Services Officer Eric Buitenwerf said Hubbard County
doesn’t have countywide planning and zoning ordinances. The only
regulations in place govern shoreland development, he told the MPCA.
So there’s a limit to what the county can do to prevent development in
the area.

Pollution control officials said the number of wells drawing off the
aquifer that serves the region need to be monitored as the
contamination spreads to the southeast. Schweitzer Lake, to the east,
has not been affected, the MPCA officials said.

If the area becomes wetter, the groundwater flow changes, the
officials said. Different demands on the groundwater resources could
alter the chemical makeup of the region as well.

“We can’t preclude building there but we can warn” people about the
potential risks, Newman said.

“Some of the waste is pretty old,” he said. “We don’t know what’s in it.”

“We put a slug of wells out there during the closing process,” said
Hubbard County Solid Waste administrator Vern Massie.

Those wells have served as the testing points to monitor any
pollution. Six deep wells are used to detect any gas.

Since the landfill’s inclusion in the state program, constant
monitoring has occurred, Rolf told the board.

MPCA officials have only sporadically detected seeping methane above
ground, but Newman warns it can be explosive.

In larger landfills, the methane and landfill gases are captured for
energy use or burned off, he said. The Pickett Landfill is too small
and old to be an effective energy source, Newman said.

If building is to occur near the site, deep water wells will likely
need to be installed, the MPCA officials said. Or special well
construction guidelines will have to be implemented.

The notification to the county is to “make sure it’s developed
responsibly,” Newman told the board.

“It alerts you to the pitfalls” of building in the area, Rolf said.

The county board took no action on the matter but asked Buitenwerf to
monitor the situation.

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