Environmental Health - Toxic Substances
U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12, 1999--Volume 3 of 3--Subsurface Contamination From Point Sources, Water-Resources Investigations Report 99-4018C
Ground-Water and Surface-Water Hydrology of the Norman Landfill Research Site
By Scott Christenson, Martha A. Scholl, Jamie L. Schlottmann, and Carol J. Becker
The Norman Landfill Research Site is a closed municipal landfill located south of Norman, Oklahoma. The landfill accepted municipal solid waste from the City of Norman from the early 1920's until 1985, when the landfill was closed. The landfill never utilized liners or leachate collection systems, and a leachate plume has developed and extends at least 225 meters from the edge of the landfill.
The landfill is located on the floodplain of the Canadian River. The Canadian River alluvial aquifer consists of fluvial sediments 10 to 12 meters thick. Alluvial sediments at the site range in size from coarse gravel to clay, although medium-grained sand dominates. Hydraulic conductivity measured by slug tests ranged from 2.37 x 10-7 meters per second to 2.81 x 10-4 meters per second, with a median of 6.72 x 10-5 meters per second. Below the alluvium are Permian-age clastic sediments of low permeability that act as a basal confining layer.
Recharge to the alluvial aquifer is infiltration from precipitation, small streams, and wetlands near the landfill. Ground water discharges to the small streams and wetlands, the Canadian River, and to evapotranspiration. The eastern edge of the leachate plume discharges to small streams near the base of the landfill. Further west, the leachate plume sinks to the bottom of the aquifer and flows under a wetland and stream.