Top Well Shut Down After Tests Tce Levels High Again; New Well Costs About Same As Treating Water

Groundwater pollution is prompting the city to shut down its most productive well, although a hot summer could force it back on line.

Spring tests showed an upsurge in trichloroethylene (TCE) in the Hanley Avenue well from 2 parts per billion to 7 parts per billion. A subsequent test by the Panhandle Health District turned up TCE at 8.26 parts per billion. This is the third successive year that TCE levels have spiked in the spring.

If the well has a minimum of 5 parts per billion for four consecutive quarters the city would have to either treat the water or shut down the well permanently. As it is, the city turned off the pump in late May.

The Hanley Avenue well is the city’s most productive, gushing 3,400 gallons of water per minute. It has the capacity to supply the entire city’s water needs during the winter.

The city shut down the well a few years ago, when the TCE problem first surfaced. But water pressure in north Coeur d’Alene was too low.

Last October, the city brought a booster pump on line that makes it possible to fill the Hanley area water tower with water from other city wells. “So this is the first time we’ve been able to shut (Hanley Avenue) off,” and maintain adequate water pressure in north Coeur d’Alene, said Jim Markley, the city water superintendent.

Coeur d’Alene consumes so much water in July and August, however, that Markley expects to have to restart the Hanley well for the hottest lawn-watering days. The city pumps between 18 and 20 million gallons of water a day in the summer and only about 5 million gallons in the winter.

The record was set in July 1994 - 22 million gallons in a single day.

The city will complete a new water well in September, on Honeysuckle Avenue. It will not produce enough water to make it possible to walk away from the Hanley Avenue well during the hottest months.

There is the possibility of drilling a new well in north Coeur d’Alene, but “the most logical sites are downstream from the Hanley well,” Markley said. “So we risk the same problem.

“I’m trying to postpone that until the problem can be resolved.”

The city could treat the water coming from the Hanley well. The cost is about the same as installing a new well.

The TCE plume is assumed to be migrating toward Post Falls. If the TCE plume moves and is diluted along the way, the city will save lots of money and headaches.

Drilling a new well or treating the current well “seems to be wasted money if the problem is short term,” Markley said.

Meanwhile, everyone is perplexed by the spring spike in TCE levels. And last year, TCE levels started dropping during the heaviest use of the well in late summer.

“It’s like herding cats to figure this out,” Markley said.

If the TCE levels drop in July and August, the city may just leave the Hanley well on-line to cover Coeur d’Alene this winter.

Some people believe the annual surge of TCE is caused by spring runoff washing TCE out of the soil and into the groundwater, said Brian Painter, of the Idaho Division of Environmental Quality. Others believe the pollution is primarily in one layer of the aquifer and that’s the strata most heavily used in spring, he said.

DEQ is concentrating on cleaning up the major source of TCE contamination upstream from the Hanley well. Deming Industries has been pulling water from underground since October, stripping out the TCE and returning the water to the aquifer.

“They are knocking the heck out of the TCE at Deming,” Painter said. “We are hoping, in a couple of years, it shows some benefit to the Hanley well.”

Work around Deming Industries seems to indicate there is another source of TCE contamination in Coeur d’Alene, but investigators cannot locate anything.

“We are remediating the highest concentration we could find,” Painter said.

Earlier investigations indicated some of the contamination could have come from chemicals dumped in septic tanks at Deming back in the days when that was legal. The company volunteered to clean up its Government Way metal-plating plant after the EPA announced the results of that probe.

While Deming doesn’t believe it’s the only source of the problem, “I would rather bring the contamination out from underground than to line a lawyer’s pocket,” Mike Deming said.

Deming has a personal interest in the project. His house is served by the Hanley Avenue well.

The company has invested about $150,000 to date. It paved the parking lot to prevent water from percolating through any potentially contaminated soil. Soil samples were taken, and while they yielded nothing significant, some of the earth was hauled off anyway.

Deming will continue to run the TCE-stripping well until well after the company meets the EPA requirements. “We want to have a significant disparity between what’s on our property and background levels,” Deming said.

To date, the stripper well has reduced TCE levels in the water under Deming from 1,000 parts per billion to 95 parts per billion, he said.

The company is holding an open house from 1 to 3 p.m. Saturday for the public to view its cleanup effort.

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