County to investigate source of bacteria in Frenchtown groundwater

Martin Kidston

(Missoula Current) Missoula County looks to drill a monitoring well in Frenchtown to better understand the source of bacteria in area groundwater and replace a second test well at the Wye.

Commissioners approved a $60,000 contract with Jerome’s Drilling to drill the two monitoring wells. The project is funded through savings in the Water Quality District, according to Travis Ross with the City-County Health Department.

He added that water quality in the Two Shed Lane area in Frenchtown has been an issue for decades.

“It’s been a special management area for about 30 years under health code, which restricts development in that area because of higher than expected bacteriological amounts in groundwater wells out there,” Ross said. “We’re attempting to reverse engineer the problem and see if we can isolate where that is coming from.”

Ross said the monitoring well will be sealed from the surface down to the water source in hopes of isolating the source of contamination in the area.

As it stands, he said, shallow ground water may be the issue.

“I think it’s a combination of irrigation. When the ditch comes on the groundwater levels come up. It’s probably interacting with shallow ponds in the area, and also the septic systems,” Ross said. “We’re hoping to isolate all those contamination sources and rule out the issue, that it’s actually seasonal inputs.”

Ross said the second well will be drilled near Waldo Road at the Wye. It’s intended to replace one of the county’s failing monitoring wells.

“We have 40 monitoring wells around the county that are part of our long-term monitoring network,” said Ross. “We have one in the Wye area that’s not functioning correctly. It’s silted in and not giving us much data.”