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WATER QUALITY IN THE GARRISON REACH OF THE MISSOURI RIVER, ND: PRELIMINARY EMAP FINDINGS
Citation:
Angradi, T., E. W. Schweiger, AND D W. Bolgrien. WATER QUALITY IN THE GARRISON REACH OF THE MISSOURI RIVER, ND: PRELIMINARY EMAP FINDINGS. Presented at 2003 Missouri River Natural Resources Center, Benedictine College, Atchison, Kansas, June 1-4, 2003.
Description:
In 2001 and 2002, summer water quality (WQ) sampling was conducted on open waters (flowing waters of the river channel) and backwaters of the Missouri River between Garrison Dam and Lake Oahe as part of the EPA's Environmental Monitoring and Assessment Program Upper Missouri River Pilot Project (EMAP-UMR). Sampling was conducted using a probabilistic sample design so that robust, unbiased estimates of water quality conditions can be made at the Garrison Reach scale at the completion of sampling in 2003. Study analytes included nutrients, metals, anions, pH, alkalinity, chlorophyll a, turbidity and others. Possible sources of variation in open-water WQ include distance from the dam, cumulative downstream effects of backwaters, and proximity to Bismarck. Sources of variation in backwater WQ include connectivity to the river channel, backwater size, and local non-point source effects. Preliminary data analysis indicates that backwater WQ is much more variable that open water WQ. Unconnected floodplain backwaters were usually chemically distinct from connected backwaters. EMAP WQ data will be used to select reference and test (impaired) sites in the Garrison Reach so that indices of biotic integrity (IBIs) based on benthic macroinvertebrates can be developed for use as assessment tools for the Missouri River ecosystem. This abstract does not necessarily reflect EPA policy. In 2001 and 2002, summer water quality (WQ) sampling was conducted on open waters (flowing waters of the river channel) and backwaters of the Missouri River between Garrison Dam and Lake Oahe as part of the EPA's Environmental Monitoring and Assessment Program Upper Missouri River Pilot Project (EMAP-UMR). Sampling was conducted using a probabilistic sample design so that robust, unbiased estimates of water quality conditions can be made at the Garrison Reach scale at the completion of sampling in 2003. Study analytes included nutrients, metals, anions, pH, alkalinity, chlorophyll a, turbidity and others. Possible sources of variation in open-water WQ include distance from the dam, cumulative downstream effects of backwaters, and proximity to Bismarck. Sources of variation in backwater WQ include connectivity to the river channel, backwater size, and local non-point source effects. Preliminary data analysis indicates that backwater WQ is much more variable that open water WQ. Unconnected floodplain backwaters were usually chemically distinct from connected backwaters. EMAP WQ data will be used to select reference and test (impaired) sites in the Garrison Reach so that indices of biotic integrity (IBIs) based on benthic macroinvertebrates can be developed for use as assessment tools for the Missouri River ecosystem. This abstract does not necessarily reflect EPA policy.