Water Quality Reports > Washington DC Drinking Water Quality Report
Water Quality Score
Washington DC Drinking Water Quality
Water Quality Factors
  • Passed All Health Guidelines
  • Passed All Legal Limits
  • Met all Reporting and Monitoring Requirements
  • Uses Chlorine plus Ammonia (Chloramines) disinfectant

The Washington Aqueduct draws surface water from the Potomac River and is responsible for treating the water at the Dalecarlia and McMillan Treatment Plants. The treatment process includes sedimentation, filtration, fluoridation, pH adjustment, disinfection using free chlorine and chloramine (chlorine + ammonia) and orthophosphate as a corrosion control. DC Water is then responsible for distributing water to Washington DC residents. DC Water advises that chloramine must be removed from water used for kidney dialysis and aquarium. Due to some mining activities around the Potomac River, radioactive chemicals may be present in the water from the Potomac River. The 2013 DC Water Quality Report cautions that “Customers are responsible for ensuring that water quality is maintained on private property” once it has left the treatment plant.

Data Sources:
EPA 2012 SDWIS Report

Washington, DC Water Quality Recent Violations

There were no health violations for in the 2010-2012 reporting periods

There were no reporting, montioring or other reported violations for in the 2010-2012 reporting periods

To see the latest EPA monitoring report for visit the EPA at SDWIS Report

Washington, DC Water Quality Historical Violations

Above Legal Limit
Above Health Limits
Below Limits
ContaminantTotal Tests Positive ResultsAbove Health LimitsAbove Legal LimitsEPA RegulatedMax ResultHealth Limit Legal Limit
Arsenic (total) 1 1 0 0 Yes 0.34 2 10
Nitrate 1 1 0 0 Yes 1.65 10 10
Total haloacetic acids (HAAs) 7 7 0 0 Yes 41.20 70 60
Total trihalomethanes (TTHMs) 7 7 0 0 Yes 68 - 80

0 Water Contaminants were tested for in the Washington, DC area but not found in drinking water between 2004 and 2009.

Data Source: NYTimes.com

The scores and results above reflect a summary of the historical drinking water testing results that has been documented by the EPA and other sources. The color coding of the symbols was developed by WaterFilterComparisions.com as an easy way for individuals to gauge the historical effectiveness of Washington water suppliers in meeting legal and health regulations in providing clean drinking water. This should only be used as a guide, and WaterFilterComparisons recommends you contact Washington water suppliers to better understand the quality of the drinking water in Washington, .