Nonpoint source effects on water quality

Results of a project to define the nature and extent of nonpoint source water quality responses are reported. Included are some details of a procedure to construct instrumentation that can automatically collect water samples in a way that reflects field conditions, water quality response curves related to point and nonpoint sources, and development of loading rates from nonpoint sources for urban and non-urban basins. A pollutant mass standard is proposed where appropriate, in addition to concentration standards The work is useful as an aid to establish field measuring programs to determine the characteristics and extent of nonpoint and point source pollution. Results for two basins in central Florida are presented. A comparison of these results considered with other data indicates the necessity of site-specific studies.