Storm water discharges are generated by precipitation and runoff from land, pavements, building rooftops and other surfaces. Storm water runoff accumulates pollutants such as oil and grease, chemicals, nutrients, metals, and bacteria as it travels across land. Heavy precipitation or snowmelt can also cause sewer overflows which, in turn, may lead to contamination of water sources with untreated human and industrial waste, toxic materials, and other debris. EPA controls storm water and sewer overflow discharges through its National Pollutant Discharge Elimination System. NPDES provides guidance to municipalities and state and federal permitting authorities on how to meet stormwater pollution control goals as flexibly and cost-effectively as possible.

Recommended EPA Web pages

• National Pollutant Discharge Elimination System (NPDES): Stormwater Program
  Provides information about the NPDES storm water program.
• National Pollutant Discharge Elimination System (NPDES)
  The National Pollutant Discharge Elimination System permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States.
• Urban Watershed Management Research
  Technological approach of managing the stormwater runoff generated from rainfall in an urban environment.

Drinking Water
Drinking Water System, Protection

Ground Water
Discharge, Hydrogeology, Protection, Runoff, Wells

Storm Water
Combined Sewer Overflows (CSOs), Industrial Storm Water, Permits, Sanitary Sewer Overflows (SSOs), Wet Weather Programs

Surface Water
Dumping, Marine Debris

Wastewater
Animal Feeding Operations (AFOs), Biosolids, Discharges, Effluent Guidelines, Effluents, Industrial Wastewater, Municipal Wastewater Treatment, National Pollutant Discharge Elimination System (NPDES), Permits, Publicly Owned Treatment Works (POTWs), Standards, Treatment, Wastewater Systems

Water Infrastructure

Water Pollution
Community Involvement, Cost Benefit Analysis, Data, Nonpoint Sources, Point Sources, Reporting, Testing, Transboundary Pollution

Water Pollution Control
Pretreatment, Remediation, Trading, Wastewater Treatment

Water Pollution Effects
Economic Effects, Environmental Effects, Health Effects

Water Pollution Legal Aspects
Compliance, Enforcement, Guidance, Legislation, Permits, Public Comment, Regulations, Standards, Total Maximum Daily Loads (TMDLs)

Water Quality Monitoring
Bioassessment, Criteria, Health Advisories, Models, Standards