Leaking septic tanks threatening tap water

Published 4:00 am Sunday, November 4, 2001

Failing and leaking septic systems remain a threat to drinking water in southern Deschutes County, but authorities said they are making progress in efforts to protect the aquifer and the Deschutes and Little Deschutes rivers.

Septic systems around La Pine and another community farther north are causing high volumes of nitrates to leak into the aquifer that supplies the area’s drinking water and eventually leads to rivers.

Officials said there is no current health hazard, and they are spending $5.5 million and taking other steps to correct the problem.

Among the recent developments:

Researchers have nearly completed installation of innovative septic systems at 50 homes in La Pine as part of a national experiment to reduce septic tank nitrate pollution.

A three-dimensional computer model is being created to predict how fast nitrate pollutants are seeping toward the aquifer.

A citizens advisory committee has been appointed to come up with better ideas for handling sewage.

Officials have stepped up their campaign to teach homeowners about the cost and health benefits of preventing septic problems before they happen.

At least $1 million in low-interest loans will be available to southern Deschutes County homeowners to replace or relocate their failing septic systems with one of the innovative systems. Loans could range from $8,000 to $12,000. The innovative systems cost from $8,000 to $20,000, several thousand dollars more than standard systems.

And the Oregon Water Wonderland neighborhood, which is two miles south of Sunriver along Highway 97, is working out a plan to buy land from the Forest Service to build a $7 million sewage system on 240 acres of nearby land. The project would be funded by federal and state government grants and loans. The DEQ has cited the subdivision in the past for violating state wastewater regulations.

La Pine’s potential groundwater problem has its roots in the 1960s and 1970s, when the area was subdivided into more than 13,600 half-acre and acre lots. Some of these are located in areas where shallow groundwater and porous soils make individual septic systems untenable and the communities’ drinking water vulnerable to contamination.

By the 1970s and early 1980s, La Pine’s downtown drinking water had nitrate contamination levels above federal health standards. Officials considered the levels enough of a potential health hazard that they made an an exception to state land use laws prohibiting sewer systems in unincorporated areas.

A sewage system installed in the core area in the mid-1980s cut those nitrate levels in half. The major health risk from nitrates in drinking water is methemoglobinemia, also known as ”blue baby syndrome,” a blood disorder that can cause lethargy, diarrhea, vomiting and trouble breathing.

State authorities, who have sampled hundreds of wells in recent years, have found nitrate concentrations as high as 8.6 milligrams per liter in parts of the La Pine area, close to the U.S. Environmental Protection Agency’s (EPA) maximum level of 10 milligrams per liter for public water supplies.

And a 1998 Portland State University study said growing nitrate pollution in the aquifer could force the state to require the entire area to add sewer and water systems, possibly as soon as 2003.

State and local government authorities are unsure how widespread the problems is, but they said they have no reports of sewage-related illnesses and nitrate levels are still below thresholds established by the EPA.

Still, if nothing is done and nitrate levels continue to rise, southern Deschutes County’s water table will be polluted within several years, officials predicted.

But maybe not as fast as they first thought.

Although no firm research results will be available until spring, officials said preliminary results indicate the innovative septic systems could be effective throughout the area and that contaminants originally expected to filter through the soil into the aquifer in 2003 could take longer to arrive.

That delay could give researchers, homeowners, septic system installers and community officials more time to repair or replace ailing septic systems and develop new ways to protect drinking water.

”We’re making progress, but we’re not there yet,” said Barbara Rich, coordinator of the La Pine National Demonstration Project and a water quality specialist at the Oregon Department of Environmental Quality (DEQ).

The demonstration project, which involves the DEQ, Deschutes County Environmental Health Division and the United States Geological Survey, is intended to protect water quality in the La Pine area.

Most southern Deschutes County homes have standard septic systems using a tank and a drain field or sand filter.

The tanks collect solid waste, filter liquid waste underground into soil or sand, and use bacteria to decompose organic material and destroy disease-causing germs.

The innovative systems are similar but remove more nitrogen and provide more advanced treatment that uses both bacteria that thrive in oxygen and bacteria that thrive without it. Standard septic systems use one kind of bacteria.

The $5.5 million demonstration project involves installing and testing 13 kinds of experimental septic systems at 50 homes where people live year-round. Installation started last fall and will be complete within the next eight weeks.

In the spring, a three-dimensional computer model will help evaluate soil porosity, groundwater depths, nitrate levels and other factors to predict the rate at which sewage contamination will reach the aquifer in La Pine and the rest of southern Deschutes County. Data is being entered into the model, but it is not fully operational.

The experts will not rely solely on innovative septic tanks and high-tech modeling. They also want to persuade homeowners to take responsibility for their septic systems through a public education campaign.

”We’re trying to minimize the health threat by being pro-active, which is hard because people don’t actually see a problem until it’s too late,” Rich said.

As part of the campaign, a citizens advisory committee meets monthly to discuss ways to prevent the deterioration of the area’s drinking water. The committee includes septic system companies, property owners, real estate agents, utility companies and others.

Kim Russell, chairman of the citizens maintenance advisory committee, said many southern Deschutes County homeowners are unfamiliar with septic tanks, but many are interested in learning about preventative maintenance.

And getting homeowners to maintain their systems could help officials get over one of the biggest hurdles, said Roger Everett, director of the Deschutes County Environmental Health Division.

Some new homeowners moved from urban and suburban communities with public drinking water and sewer systems rather than the well water and septic tanks that are common in rural areas.

”They used to just flush away, and if there was a problem, they just called the city sewer department,” Everett said. ”Well, in the country, you are the sewer department.”

If a septic system becomes plugged, the homeowner faces not only expensive repairs but possible contamination of well water, Everett said.

”The whole neighborhood could be hurt,” he said. ”Your neighbors will share your neglect.”

More than 25 percent of American homes have septic systems that are not operating at peak efficiency, often because of owner neglect.

”We’d like neighbors to sit around the kitchen table, having a cup of coffee and chatting about their septic systems,” Everett said, chuckling. ”We know that’s not going to happen, but it would benefit everybody if people used their common sense” and checked their septic systems as often as their cars, furnaces, hot water heaters and other machinery.