Treated sewage seeping into Central Ore. groundwater

BEND, Ore. (AP) The urban-like density of rural subdivision lots in La Pine is feeding increasing levels of sewage contaminants into the groundwater.

The Bend Bulletin reports a committee commissioned by the Oregon Department of Environmental Quality found that 85 percent of the Deschutes County lots and 75 percent of the Klamath County lots are at risk of having groundwater comprised of at least 25 percent of partially treated sewage.

The combination of thousands of septic systems close together, permeable soil and a shallow water table led to the sewage contaminants entering the groundwater. The potential groundwater contamination around La Pine starts in septic systems, but it's not raw sewage or the typical hazards connected to human waste.

Instead, chemicals and pharmaceuticals with unknown impacts on groundwater are the chief concern.

John Blakinger, co-chair of the South Deschutes North Klamath Groundwater Protection Steering Committee, said a future study would examine concentrations of nitrates, which are a tracer showing that other contaminants from septic systems are making it into the water.

"The concentration of houses became a concern," Blakinger said. "That is why we need an urban-type solution like a sewer or cluster systems."

Blakinger said tap water in La Pine is safe to drink, with either contamination lower than state health guidelines or their wells drawing water from sources deeper than the tainted groundwater.

Officials said the situation is not yet a public-health risk, but the committee has called for further study on the potential impacts to the Little Deschutes River, and say the rural areas require solutions for dealing with sewage contaminants more like what is used in urban areas.

"There is a risk, but we don't know how big it is," said Eric Nigg, water quality manager with the agency in Bend. "We believe there is an increasing contamination of the groundwater, but we believe we are in a position to head it off before it becomes a widespread public health risk."

Nigg agrees with the call for more study of what is seeping down into the water and what might be draining into the Little Deschutes River.