Voluntary Nutrient Reduction Measures Make a Major Impact

What if you could get major dischargers to make major reductions in their pollution levels...voluntarily? Sounds like a major undertaking. River Network congratulates our Idaho Partner the Tri-State Water Quality Council for its role in establishing, implementing and monitoring a truly volunteer, stakeholder-led process for reducing nutrient discharges and improving water quality in the Clark Fork River, part of the 16-million acre Clark Fork-Pend Oreille watershed that traverses Montana, Idaho, and Washington.

In the late 1980s, studies produced evidence that one of the two most significant water quality problems facing the Clark Fork River and many waters of Montana was nutrient pollution. These nutrients, nitrogen and phosphorus, serve as food for algae. When excessive algae grows in rivers it degrades aquatic habitats, depletes levels of dissolved oxygen, puts stresses on native fish populations and contributes to the loss of diversity in aquatic invertebrate communities, among other impacts.

After the Environmental Protection Agency published the Clark Fork-Pend Oreille Basin Water Quality Study and Management Plan in 1993, the collaborative Tri-State Water Quality Council formed to implement this plan which focused on excessive nutrient pollution that was impacting water quality in all three states and thus catalyzed efforts towards reducing levels of nitrogen and phosphorus entering their waters.

In 1994, the Tri-State Water Quality Council approached Montana’s four largest nutrient point-source dischargers to the Clark Fork River (municipal wastewater treatment plants in Butte, Deer Lodge and Missoula and the Smurfit Stone Container pulp mill), the Montana Dept. of Environmental Quality, the Missoula City-County Health Dept. (non-point nutrient sources) and the Clark Fork Coalition (a Montana citizen group and River Network Partner) and began to negotiate a voluntarily agreement that would reduce levels of nutrients discharged into the river and its downstream watershed.

In October 1998, the participant entities signed the Voluntary Nutrient Reduction Program (VNRP), a formal agreement which established in-stream numeric nutrient water quality targets and committed each discharger to specific measures that would be taken to reduce nitrogen and phosphorus inputs to the Clark Fork. Such measures included spending millions of dollars to upgrade wastewater treatment plants with Biological Nutrient Removal systems, revising wastewater operations, banning phosphate-containing laundry detergents, and connecting septic systems from thousands of homes to city sewer.

Water quality was monitored annually under the Tri-State Water Quality Council’s existing basin-wide monitoring program and progress towards reaching the VNRP’s in-stream water quality targets was reviewed every three years. When the VNRP program sunsetted in 2008 the results were impressive:

• Total phosphorus discharge reduced by 72% from 1990 levels.
• Total nitrogen discharge reduced by 32%.
• Missoula Valley cut its nitrogen input by 260 pounds per day by expanding the sewer to thousands of homes previously using septic systems.
• Average summer phosphorus concentrations in the Clark Fork River near Deer Lodge and Missoula were cut in half.
• Stringent algae targets were met 30% of the time in the upper and middle river, and 70% of the time in the lower river.

Additionally, and just as impressive, the State of Montana eventually adopted the in-stream targets for nutrients set by the VNRP as water quality standards for the river, establishing one of the nation’s first numeric nutrient water quality standard.

What more needs to be done? Well, managing the sources of non-point pollution from stormwater runoff, livestock, forestry and septic systems is an ongoing but not insurmountable challenge. River Network salutes the Tri-State Water Quality Council and its partners for the completion of this successful program and on their future work.

For more information, please contact: Diane Williams, Executive Director, Tri-State Water Quality Council, dianetristatecouncil@sandpoint.net.

Article sources include:

Tri-State Water Quality Council VNRP Committee. The Clark Fork River: Voluntary Nutrient Reduction Program Final Report. August 21, 2009.

Clark Fork Coalition. Nutrient Pollution: A Slippery Problem. Currents, Fall 2009.