Nearly one third of homes in Minnesota use on-site systems to treat household wastewater. And the number is growing, as baby boomers retire to northern lakes. Many on-site systems, especially in northern Minnesota, don't protect groundwater and nearby lakes from contamination. Now, people are trying new technologies that may cost more but may work a lot better. And health officials are gradually moving toward new ways of monitoring the performance of on-site septic systems.

	A worker builds a mound septic system, commonly used in northeastern Minnesota. Because of the bedrock on the hillside, dirt was trucked in to build a leaching field. In many areas, even expensive mound systems don't do a good job of treating household wastewater. (MPR Photo/Stephanie Hemphill)

Summer in Minnesota brings kids to the lake. But what else is in the water with the kids? Many of Minnesota's lakes are miles from a sewer line. The cabins and retirement homes overlooking the lake have septic systems built to handle waste from toilets, showers, and washing machines. A lot of the septic systems don't work properly, especially in northeastern Minnesota, where bedrock is close to the surface and much of the soil is heavy clay.

But most people don't like to spend lots of money fixing broken systems or building new ones.

St. Louis County Commissioner Mike Forsman says he gets more calls from people with septic system problems than about any other issue.

"We have literally half-million and million dollar homes going up on some of our lakes," Forsman says. "But when the time comes for the septic system, because you don't see it, it doesn't have that same importance - but yet it does. For the neighbors, it actually has more importance than what your building looks like across the lake or from the road."

	Spring runoff stands in a yard near Grand Lake. The water table is so close to the surface, there's no room for wastewater to be purified before it reaches the groundwater. (MPR Photo/Stephanie Hemphill)

No one wants untreated sewage running into the lake.

Forsman says people often run into problems when they convert a cabin to a year-round home.

"They finally found that dream house on the lake," he says. The septic system may have worked perfectly well when it was only used in the summer. "They got out there, insulated it, moved their family into the nicest home they could possibly afford, and then found out that the system that was there wouldn't do the job. And it happens more times that you think!"

Many people take their septic systems for granted. They don't realize the system may require a little attention now and then. Septic system installer Bruce Dudley offers a few simple precautions to keep systems running better and longer:

"Keep the chemicals out of your septic tank," he advises. "Figure out what your pumping schedule could be. If you're not certain, I always say, every time they elect a president, pump your septic tank!"

Currently, state rules say if you build your septic system according to certain guidelines, the health department assumes it will work. No one comes to inspect to make sure it's working - until you sell the house. Then you or the buyer could be in for an unpleasant surprise - and a big bill to fix the system or install a new one.

Several counties in Northeastern Minnesota have been working together to design a different approach. Jeff Crosby works for the St. Louis County Health Department. He says eventually the county will require renewable permits for septic systems.

"After a period of time, perhaps three years or five years or ten years, somebody would have to demonstrate that they've adequately maintained the system, Crosby says. "And it probably is a logical time to say if you haven't taken care of it, now would be the time to do that in order to renew the permit."

But Crosby says homeowners, and the county, can keep track of maintenance fairly easily. New technologies and computer programs can help.

	NRRI researcher Barb McCarthy inspects a tub of fiber chips. Fiber filters are one of several alternative sewage treatment methods that could work on difficult sites in Northeastern Minnesota. (MPR Photo/Stephanie Hemphill)

Crosby says most modern systems are equipped with monitors, "some method of saying, 'is everything working properly?' And by looking at those, you can say that if the homeowner's use of the system is within acceptable norms, we'll assume that it works well."

Some of those same advances in technology are also making it possible to build homes and cabins in places where they couldn't be built before. And Crosby says that's posing a new challenge for the county - controlling growth.

"Eventually we're going to get to a point that we can find an on-site solution to any property," says Crosby. "Historically the on-site solutions have been somewhat restrictive, so they've been used as a de-facto zoning tool. And we need to come back and say, 'where do we want to put people and how do we want to allow development to proceed?'"

Citizens in some parts of St. Louis County, especially around major lakes, are working on plans to guide growth.

The county is working with the Minnesota Pollution Control Agency to tweak the state code to move toward renewable permits for septic systems.