There are many sources of pollution in our waters. In addition to point sources such as sewage and industrial waste, a great deal of water pollution comes from non-point sources such as agricultural runoff, and stormwater drainage. Common water pollutants include pesticides, lead, arsenic and polychlorinated biphenyls (PCBs). The protection of our water sources from these and other pollutants is one of the EPA's most important challenges. Under the Clean Water Act, the Agency regulates discharges of pollutants into the waters of the United States and sets effluent standards. The EPA also works with state and local authorities to control the pollution from non-point sources.

Recommended EPA Web pages

• What Contaminants May Be Found in Drinking Water?
  This page discusses the different ways in which ground water and drinking water can become contaminated.
• Drinking Water Contaminants
  This page lists current drinking water standards (Maximum Contaminants Levels) for regulated contaminants.
• Drinking Water Contaminant Candidate List and Regulatory Determinations
  The Safe Drinking Water Act requires EPA to establish a list of contaminants to aid in priority-setting for the Agency's drinking water program.

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