Lead & Copper Content

Water is lead-free when it leaves the treatment plant, but lead can be released when the water comes in contact with pipes and plumbing fixtures that contain lead. Lead sources and lead levels vary between buildings, so it is important to identify and remove lead sources in every household.

Since August 2004, DC Water has undergone corrosion control treatment to inhibit the lead from entering the drinking water. The corrosion control measures have successfully reduced lead levels in the water. Since 2006, DC Water's lead and copper levels meet the drinking water standards established by the Environmental Protection Agency (EPA). The graphs below show lead and copper concentrations measured by DC Water over the past two years. The EPA limits for lead and copper are based on the 90th percentile of all samples collected during a sampling period. This means that at least 90 percent of over 100 homes sampled in each 6-month monitoring period must be below the action levels set by EPA. Lead and copper testing is conducted in a subset of District homes to assess the overall corrosion control treatment. DC Water recommends that each individual household identify and remove any lead sources on their property. To learn how to identify lead sources, click here. Customers may also request a lead test kit from the Drinking Water Division at 202-612-3440.

Lead concentration in drinking water
copper concentration in drinking water

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