Wastewater movement near four treatment and disposal sites in Yellowstone National Park, Wyoming
The U.S. Geological Survey, in cooperation with the National Park Service, studied the effects on nearby streams and lakes of treated wastewater effluents that percolate from sewage lagoons at four sites in Yellowstone National Park. A network of observation wells has been established near the sites, and water level and water quality data were collected from 1974 through 1982. Groundwater mounds occur under the lagoons as percolation of effluents occurs. The percolating effluents mix with groundwater and form plumes of water that contain chemical constituents from the effluents. These plumes move down the hydraulic gradient toward groundwater discharge areas. The directions of movement of percolating effluents have been determined by analyzing water samples from wells near the lagoons for specific conductance, chloride concentration, and nitrite plus nitrate concentration. Other constituents and properties also were determined. The percolating effluents are diluted by groundwater and have no discernible effects on the quality of water in the nearby streams and lakes. (USGS)