Lewis and Clark County commissioners, bucking overwhelming opposition voiced at a meeting last week, on Tuesday approved a yearlong extension of the county’s controversial and litigated interim zoning regulations.

Commissioners said an eightfold increase in nitrate levels in Helena Valley wells in the past quarter-century, coupled with the 2006 discovery of trace amounts of pharmaceuticals and personal-care products in about 30 wells, prompted their decision to extend the zoning regulations.

The rules, initially approved a year ago, require landowners installing or replacing septic systems on lots smaller than five acres to use a Level II system, which can cost between $13,000 and $18,000, including installation costs.

Those systems remove at least 60 percent of nitrates from wastewater before it flows into the drain field, where soils continue to filter the effluent.

But commissioners said they’ll consider amending the rules once officials bring forward proposals to drop the requirement for expensive Level II septic systems in favor of Level I-b systems, which cost between $7,000 and $8,000, and to create a grandfathering clause for some existing homeowners who have standard septic systems.

County Administrator Ron Alles said he will review drafts of those proposals Wednesday and get them to the commission as quickly as possible.

In a public hearing last week, real-estate agents, engineers, attorneys and residents told commissioners they didn’t believe the Helena Valley faces a groundwater-quality crisis.

Several brought in well-test results that showed nitrate levels well below the U.S. Environmental Protection Agency’s public-water standard of 10 parts per million, which doesn’t apply to private wells.

Some said zoning rules aren’t the appropriate way to regulate septic systems. Most of the speakers asked commissioners to allow the interim zoning rules to expire.

Commissioner Andy Hunthausen today said data shows there is a water-quality issue in the valley, and said it’s the commission’s responsibility to act.

“No one can tell me that we should not be concerned about our water in the valley,” he said. “No one can tell me that. We have to be concerned. As a leader in this community, to make a responsible decision about where we go in the future, I have to look through a … long-term lens. There are going to be people here long after you’re gone and long after I’m gone. We have to act on this stuff.”

While the valley’s average nitrate level of 4 ppm doesn’t exceed the EPA’s standard for public water systems, it — and the projections that the county’s population will grow by 50 percent by 2030 — is significant enough to cause concern, he said.

“I don’t think that it’s necessarily all perfect and all rosy. I know there are impacts on people’s lives,” Hunthausen added, referring to the more than 30 homeowners who’ve had to install Level II systems, at a cost between $13,000 and $18,000, in the past year.

Hunthausen said in the future he would support applying the rules only to areas that are more susceptible to groundwater contamination. The county is finalizing a study that shows which areas of the valley are more likely to be impacted by contamination.

Commissioner Mike Murray echoed Hunthausen’s comments and asked landowners to bring their well test results to the county’s Environmental Health Division. The data would be included in the county’s ongoing study and could help officials refine zoning regulations in the future. Private well tests cannot be viewed by the county without the landowner’s permission.

“I’m asking you to help us,” he said. “You have the information.”

Commission Chair Ed Tinsley said he was proud of commissioners and officials for having the courage to face the controversial issue head-on.

“Our goal is simple,” he said. “We’re trying to protect the future of this valley, of this county.

“What this valley looks like 30 years from now depends on what we do today,” Tinsley said.

His opponent in this year’s county commission race, Derek Brown, said commissioners have painted themselves into a corner.

“To me, their action (Tuesday) was predictable,” Brown said. “I think they made a mistake to begin with and now they can’t get out of it.”

He said commissioners never had the scientific basis to create the zoning rules and said the water-quality crisis doesn’t exist.

Brown believes sanitarians should decide what type of septic system is required at a specific location based on conditions on the ground.

“There’s no blanket, one-size-fits-all for any of these things,” he said.

Reporter Larry Kline: 447-4075 or larry.kline@helenair.com