Baseline monitoring is sampling that is repeated within the same watershed at the same locations. It is more geographically extensive than Source Identification monitoring.
Baseline Monitoring Objectives help determine if water quality standards are met in watersheds that previously have not been sampled or need additional sampling. For each major water quality parameter, determine the range of variation (by geomorphic and land use category) characteristic of Island County surface waters as necessary to help assign possible causes to exceedances and trends.
Washington State Department of Ecology - A Citizens Guide to Understanding Monitoring
Washington State Department of Ecology - Water Topics