Ouachita River Study

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Use Attainability Analysis and Water Quality Assessment of Coffee Creek, Mossy Lake, and the Ouachita River.

The purpose of this investigation was to perform a water quality assessment of the Ouachita River, which is the receiving water of the Georgia-Pacific (GP) Crossett paper mill discharge, and to determine if the current “no aquatic life use designation” for Coffee Creek and Mossy Lake is appropriate. The area of the Ouachita River for this study is located in southern Arkansas below the Felsenthal Lock and Dam and upstream of the Louisiana state line. The study area consisted of Coffee Creek, Mossy Lake, and a portion of the Ouachita River, a short  distance upstream and downstream of the confluence with Coffee Creek. From the biological data collected it was apparent that a diverse and abundant, though seasonal, aquatic community existed in the Reference Site stream. The fish and macroinvertebrate samples from the Reference Site were indicative of an aquatic community that is seasonally variable and tied to flood flows from the Ouachita River. Coffee Creek had very few fish and was dominated by a highly pollution-tolerant macroinvertebrate community. The same was true for the Mossy Lake biological community with the exception of a slightly more diverse macroinvertebrate assemblage. The Coffee Creek site below Mossy Lake had higher numbers of large predatory fish, due to the proximity of the Ouachita River, but otherwise exhibited an aquatic community much like the other effluent-dominated sites. From this evidence it was concluded that the waters of Coffee Creek and Mossy Lake have the potential to support aquatic life indicative of streams in the ecoregion. They also show evidence of degradation from the effluent of the Georgia Pacific Outfall 001.There were exceedances of several numeric GCER standards in these water bodies, and signs of ecological impairment, including loss of habitat and toxicity to aquatic organisms from both the water column and sediment.

Parsons Engineering and Funding from US Environmental Protection Agency partnered with this study.