Growing Pains

Managing the Smelly Side of Growth

By Tad Sooter, 2-28-06

	Photo by Chris Lombardi

No matter where you live in western Montana, it’s a good bet that at least part of what you flush down your toilet is going to end up in a river or reservoir. How it gets there can be the difference between clean or skuzzy water.

The dramatic impact of nutrients on our ground and surface water makes septic use a dynamic measure of growth, showing not only how fast a region is growing, but how well it is prepared to manage growth to protect water quality.

Septic systems, dotted across rural parts of Montana and clustered in subdivisions on the outskirts of towns, are a quiet threat to water. Neglected systems leak their smelly contents, and poorly placed drainfields can flood or fail to filter properly. This nutrient-rich soup seeps into groundwater – and eventually rivers like the Clark Fork, where it fertilizes dense algae blooms that can stagnate water and impede the river’s flow.

“You don’t have to be an ecologist to see it in the Clark Fork,� Missoula City/County Environmental Health Director Jim Carlson said. “Sometimes in the summer the entire bottom will be coated in green algae. From the air it looks like a long green snake. That’s not what a Rocky Mountain trout stream should look like.�

There are 157,000 septic users in the 10 counties in the Clark Fork basin of Montana and 144,000 on municipal sewer systems. Septic systems are by no means the only culprits in the nutrient overload problem, but because they are so widely used and necessary in rural areas, they present a challenge in the fight to lower nutrients.
The goal of counties like Missoula is to match septic demands with sewage hookups to keep the number of septic installations steady and keep the nutrient problem reined in.

In Missoula County, 2005 was a year of modest success in the septic wars, Carlson said.

“Even though the number of housing units went up, the number of septic permits has remained steady because we’ve had more sewer hookups,� he said.

Those sewer hookups were made possible by high-density housing added near town, where municipal sewer hookups are available. The county approved 262 septic systems in 2005, on par with the 280 that was average for the previous four years. Septic growth in neighboring Ravalli County has been heavier (385 new permits in 2005) but still close to average for the county.

Success in matching septic permits with sewage hookups in Missoula County has been inspired in part by the Voluntary Nutrient Reduction Program, a partnership agreement between city and private organizations in the Clark Fork basin who have worked together to reduce the nutrient load on the river since 1988. The Missoula Growth Management Plan has also been effective in ensuring that sewer expansion matched growth around the city.

One project urged by the Voluntary Nutrient Reduction Program was an $18 million remodel of the Missoula Wastewater Treatment plant, concluded in October of 2004. Improvements included a biological treatment system with ultraviolet instead of chlorine disinfection. The impact was dramatic: Nitrogen output was cut by more than 50 percent and phosphorous dropped from an average of 266 pounds per day in 2003 to just 41 in 2005. Ammonia and coliform bacteria were virtually eliminated. The remodel also increased plant capacity from 8 million to 12 millions gallons of average annual input, enough to handle future expansions.

“Given current growth ... this plant will be good through 2020 or 2025,� Missoula Wastewater Director Starr Sullivan said.
The city has been putting the improved plant to good use – since 2004, Missoula has been able to integrate growing East Missoula and large developments west of Reserve Street, along with other neighborhoods around the city.

Missoula's attempts to add sewage in the Rattlesnake Valley, however, illustrated the challenges often faced in sewer expansion. In 2004, septic systems along the crowded Clark Fork tributary were failing and overflowing. Households had to cut back on water use and some even resorted to installing porta-potties in their yards to tide them over until the sewer could be expanded. In response, the city proposed a Special Improvement District to expand the sewer up the valley; Sen. Conrad Burns found federal funding for the project and residents in three of the four proposed sewage areas approved.

But a majority of citizens in a fourth area were vehemtly opposed to the proposal and joined together as the Rattlesnake Coalition to block the expansion. The Coalition sued the Environmental Protection Agency and the city over the treatment plant expansion as well as the planned hookup, claiming that proper environmental impact studies had not been done. In October their suit was thrown out by a federal judge but was subsequently appealed to the 9th Circuit Court. Another Coalition lawsuit against the Montana Department of Environmental Quality is pending, city attorney Jim Nugent said.

The Coalition grabbed the spotlight, but the Rattlesnake got its sewer. Three areas quietly re-submitted for Special Improvement Districts and the sewer expansion got underway in the central and western areas of the valley. The only thing missing was the federal funding, which was tied up by the lawsuit, according to Nugent.

City officials are skeptical whether the Coalition’s protests are really about environmental health and not about growth and money.

“If people have had good luck with their septic systems and they’re not concerned about the impact they are having on their aquifer, then their main concern is the cost of putting in the sewer, which is substantial,� Carlson said.

Several neighborhoods around Missoula, including Orchard Homes and Target Range, are still slated for sewer connection, but the feeling is that Missoula has done well at keeping up with demands for sewer.

For areas too far from the city for sewage hookups, more advanced septic systems can help cut down on nutrient pollution. Individual biological treatment systems, like mini versions of the large scale one used in the Missoula Wastewater plant, can be employed. The bio-systems are costly to buy and maintain, with a unit costing roughly $12,000 rather than the $3,000 needed for a regular septic system.

Despite the challenges presented by rural growth, the Clark Fork watershed is showing signs of slow improvement said Will McDowell, Missoula coordinator of the Tri-State Water Quality Council, a group created to coordinate the Voluntary Nutrient Reduction Program in Montana, Idaho and Washington.

“In 2005, we looked at water quality in the river from the nutrient perspective, and we looked at it in terms of a 10-year period,� McDowell said. “We found, in most sites we tested on the river, consistently lower nutrient levels.�

One exception is a section of river below Missoula, where the river is still high in nutrients. McDowell said that the improvements to the sewer plant have not had time to manifest in the water quality downstream but “the data we have seen so far suggests that it will have a large positive impact.�

In McDowell's view, with more development looming, it’s important for planners to understand the problems related to septic systems and the need to add sewers to match growth.

“It’s coming fast and furious," he said. "That’s a big concern.�

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