Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River

A water quality sampling station was installed at the Washington County Road 195 Bridge on the West Fork of the White River just above the confluence of the three main forks of the Upper White River in December 2001. The Quality Assurance Project Plan (QAPP) was approved by EPA Region Six on March 2002 and sampling was begun at that time. This station is coordinated with a USGS gauging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into the upper end of Beaver Lake from the West Fork of the White River. The West Fork is listed on Arkansas’ 1998 303d list as impaired from sediment. The Upper White was designated as the states highest priority watershed in the 1999 Unified Watershed Assessment. Accurate determination of stream nutrients and sediment is critical for future determinations of TMDLs, effectiveness of best management practices and trends in water quality. This project is a cooperative effort between AWRC and the ADEQ Environmental Preservation and Planning Divisions. All aspects of the project are coordinated with and subject to technical review and comments from ADEQ. This report is for 2002 water quality sampling, water sample analysis and annual pollutant load calculations at the Washington County Road 195 Bridge on the West Fork of the White River. The parameters measured from collected samples were nitrate-nitrogen, ammonia-nitrogen, total Kjeldahl nitrogen, total phosphorus, dissolved reactive phosphorus and total suspended solids. In addition turbidity, conductivity and pH were measured in-situ and recorded in thirty-minute intervals. Also, the AWRC in conjunction with the USGS conducted cross-section sampling to determine the relationship between autosampler concentrations and cross-section concentrations.