ABSTRACT
This chapter summarizes the initial phases of United State Environmental Protection Agency's Risk Reduction Engineering Laboratory sponsored research project. The long range goal of the research project is to develop a Manual of Practice that will assist local governments to identify the magnitude and source of nonstormwater entries into their separate storm drainage systems. Drainage area increases in size, the probability also increases that dry-weather entries associated with individual intermittent activities would appear more continuous at the outfall. The preparation and study of drainage and land-use maps are an important step in a nonstormwater contamination investigation; therefore, before field activities can be started, a mapping effort must be undertaken. Drainage maps should identify: predevelopment streams that may have been converted to storm drains. Further drainage area investigations must be conducted if outfall screenings indicate the presence of dry-weather discharge. These include drainage system and industrial and commercial site studies to locate specific nonstormwater entries.
