Watershed Management Plan
As a result of citizen concerns about increased aquatic weeds and algae in the Clark Fork River and Pend Oreille Lake, language was added to the 1987 Clean Water Act that directed the EPA to study the sources of pollution in the watershed. A comprehensive 3-year study led to the development of the Clark Fork- Pend Oreille Management Plan, which was finalized in early 1993 and designed to protect and restore water quality in the watershed from nutrient pollution.The Tri-State Water Quality Council is responsible for implementing numerous specific actions to achieve these objectives. (To review the Plan document, click on the link in the headline below.)
1993 CLARK FORK - PEND OREILLE BASIN WATER QUALITY STUDY
A SUMMARY OF FINDINGS AND A MANAGEMENT PLAN
Conducted Under SECTION 525 OF THE CLEAN WATER ACT OF 1987 January 1993 U.S. Environmental Protection Agency, Regions 8 and 10 State of Montana State of Idaho State of WashingtonIntroduction and Acknowledgements
This document summarizes three years of water quality research in the Clark Fork-Pend Oreille Basin and provides a Management Plan for protection of the basin's water quality. All work was conducted pursuant to Section 525 of the 1987 amendments to the federal Clean Water Act as a cooperative effort among the states of Montana, Idaho, and Washington and with assistance from the U.S. Environmental Protection Agency. This report is a synthesis of the following three documents completed for the Clark Fork-Pend Oreille Basin Water Quality Study: A Rationale and Alternatives for Controlling Nutrients and Eutrophication Problems in the Clark Fork River Basin, by G. L. Ingman, Montana Department of Health and Environmental Sciences, Helena, 1992 Phase I Diagnostic and Feasibility Analysis: A Strategy for Managing the Water Quality of Pend Oreille Lake, Bonner and Kootenai Counties, Idaho, 1988-1992, by B. Hoelscher, J. Skille, G. Rothrock, Idaho Department of Health and Welfare, Division of Environmental Quality, Boise, 1993. Pend Oreille River Management Plan, by R. Coots, Washington State Department of Ecology, Olympia, 1992. State reports are available from each state's steering committee members. This report is the fourth and final annual progress report for the Clark Fork-Pend Oreille Water Quality Study. The first, second, and third annual reports are available from any member of the Steering Committee.
Clark Fork-Pend Oreille Basin Water Quality Study Steering Committee
Gary
Ingman
Loren Bahls
Montana Department of Health and Environmental Sciences
Water Quality Bureau
P.O. Box 200901
Helena, MT 59620-0901
(406) 444-2406, fax (406) 444-1374
Brian
Hoelscher
Jack Skille
Idaho Department of Health and Welfare
Idaho Division of Environmental Quality
2110 Ironwood Parkway Coeur d'Alene, ID 83814
(208) 667-3524, fax (208) 667-4869
Will Kendra Randy Coots
Washington Department of Ecology
Watershed Assessments Section
P.O. Box 47710
Olympia, WA 98504-7710
(206) 586-0803, fax (206) 586-5497
Judith Leckrone
U.S. EPA, Region 10
1200 Sixth Ave, WD-139
Seattle, WA 98101
(206) 553-6911, fax (206) 553-0165
William Roberts
U.S. EPA, Region 8
Montana Office
301 South Park Drawer 10096
Helena, MT 59626
(406) 449-5414, fax (406) 449-5434
The Steering Committee acknowledges the important contributions of previous Steering Committee members:
Mike Beckwith, U.S. Geological Survey, Idaho
Gwen Burr, Idaho Division of Environmental Quality
Mason Hewitt, EPA Environmental Monitoring Systems Laboratory,Las Vegas
Sally Marquis, EPA, Region 10, Seattle
Don Martin, EPA, Idaho Operations Office
Lee Shanklin, EPA, Region 8, Montana Office
Lynn Singleton, Washington Department of Ecology.
The Steering Committee thanks the following people for their assistance:
Diana Boquist, U.S. Environmental Protection Agency
Bronwyn Echols, Technical Writer
David Haire, Confederated Salish and Kootenai Tribes of the Flathead Reservation
Glen Rothrock, Idaho Division of Environmental Quality
Christopher Moffett, U.S. Environmental Protection Agency
Peter Nielsen, Clark Fork-Pend Oreille Coalition
Connie Robinson, U.S. Environmental Protection Agency
Ed Tulloch, Idaho Division of Environmental Quality
Ruth Watkins, Clark Fork-Pend Oreille Coalition
Executive Summary
The Clark Fork-Pend Oreille Basin lies within western Montana, northern Idaho and northeastern Washington. The basin encompasses about 25,000 square miles and is the source of waters that enter and leave Pend Oreille Lake in Idaho. The Clark Fork River begins near Butte, Montana and drains an extensive area of western Montana before entering Pend Oreille Lake. The lake is the source of the Pend Oreille River in northeastern Washington which in turn drains into the Columbia River. In response to concerns and complaints about the growing presence of algae and water weeds in the Clark Fork-Pend Oreille Basin, Congress mandated the United States Environmental Protection Agency (EPA) to conduct a comprehensive water quality study in the basin, and to report study findings and recommendations to Congress. This mandate appeared as Section 525 of the 1987 amendments to the federal Clean Water Act. The main objectives of the study were to characterize water quality problems, identify sources and recommend actions for maintaining and enhancing water quality throughout the basin. This report and management plan are intended to meet the study and reporting requirements mandated in Section 525.
Regions 8 and 10 of the EPA had the primary federal responsibility for implementing the Clark Fork-Pend Oreille Basin Water Quality Study. The States of Montana, Idaho and Washington identified research objectives within their boundaries, conducted the research, wrote reports and recommended state-specific management actions that would meet the basin-wide study objectives. The Clark Fork-Pend Oreille Basin Water Quality Study Steering Committee, consisting of representatives from EPA and the three states, oversaw the study and reviewed and summarized the three state plans into this document, the Clark Fork-Pend Oreille Basin Water Quality Study: A Summary of Findings and a Management Plan. The Steering Committee invited all interested persons and agencies to comment on individual state management plans and the basin-wide management plan. The Committee sponsored four public workshops in Deer Lodge and Missoula, Montana, Sandpoint, Idaho and Newport, Washington. The Committee also requested comments by mail from over five hundred individuals, agencies and other groups on the mailing list. (Responses to these public comments are included as Appendix C.)
Research Findings and Conclusions
The three-year Clark Fork-Pend Oreille Water Quality Study yielded the following major research findings and conclusions:
Clark Fork River
Excessive levels of algae caused water use impairment in up to 250 miles of the Clark Fork River. About half of the soluble phosphorus derives from wastewater discharges, with the other half contributed by nonpoint sources in tributary watersheds. Three-fourths of the soluble nitrogen comes from tributaries, with the remaining quarter from wastewater discharges. The most critical point sources are the municipal wastewater treatment plants, particularly at Butte, Deer Lodge and Missoula. The Stone Container Corporation's Missoula Mill is a major source of industrial wastewater nutrient loading to the river, although the levels of nutrients in its effluent over the past six years have been reduced several fold. Phosphate detergent bans in several communities along the river have decreased the phosphorus content of the effluent of the municipal wastewater treatment plants. The largest nonpoint sources of nutrient loading to the Clark Fork River are the Flathead, Bitterroot, and Blackfoot rivers. A nonpoint source stream reach assessment found that of 99 basin streams with suspected problems, 65 percent have an impaired ability to support designated beneficial water uses.
Pend Oreille Lake
Open lake water quality has not changed statistically since the mid-1950s. There is a high correlation between total phosphorous loading from nearshore and local tributaries and the degree of urban development. The greatest share (more than 90 percent) of water entering the lake comes from the Clark Fork River inflow, as does about 85 percent of the total loading of phosphorus, the nutrient that limits algae growth in the lake. Maintenance of open lake water quality is largely dependent on maintaining nutrient loadings from the Clark Fork River at or below their present levels. Pack River, followed by Sand Creek, are the tributaries discharging the highest phosphorus loads per unit of land area to the lake. Lightning Creek, Pack River, and Sand Creek have the highest nitrogen levels.
Pend Oreille River
The mainstem Pend Oreille River has water quality that is generally good and in the oligo-mesotrophic range. The primary water quality concern on the Pend Oreille River is the proliferation of Eurasian watermilfoil, an invasive and adaptable plant. Roughly 75 percent of the external nitrogen and phosphorus loading to this reach of the river comes from the Newport wastewater treatment plant, Calispell Creek, and Trimble Creek. Several tributaries exceed standards for fecal coliform bacteria content. Nonpoint sources of pollutants in the Pend Oreille River basin that potentially affect the river are animal keeping practices, agriculture, on-site sewage disposal, stormwater and highway runoff, forest practices, land development, landfills, and gravel extraction.