The threat to human health by urban runoff is not only due to materials scoured from surfaces, but also from the infrastructure of the sewer system itself. Storm water systems are often combined with sanitary sewer systems enroute to sewage treatment plants. Excessive storm water can cause this joint system to overflow, resulting in sewage contamination of waterways. Urban runoff is usually collected by storm sewers and discharged directly into waterways so, many sources of discharge go uncontrolled and untreated. Combined systems are cheaper, but the potential to harm health is higher.
Some systems have diversions to accommodate heavy flow.
Forty-six percent of the population is served by separate systems. The goal here is to protect public health and aquatic life, and to assure that every facility treats waste water. Nonconventional pollutants which may require regulation such as nitrogen and phosphorus . Target specific enterprises that have opportunities to control run-off Conduct education projects to teach students how to prevent pollution Nonpoint Source Pollution Control Program Pollution Prevention Management Management Measures for Urban Areas Industrial Storm water Home Topics FAQsHome References 1. Environmental Protection Agency, Non-point source pollution fact sheet.