Environmental Services
Information on Perchlorate in Drinking Water
Perchlorate is a naturally occurring as well as man-made compound. Its presence in drinking water is currently unregulated and utilities are not required to monitor for it. In 2007, the Washington Aqueduct began voluntarily participating in a nonregulatory perchlorate sampling project for the Potomac River funded by the Environmental Protection Agency (EPA).
EPA has established a reference dose of 24.5 parts per billion (ppb) for perchlorate in water. A reference dose is a scientific estimate of a daily exposure level that is not expected to cause adverse health effects in humans. The reference dose will be used in EPA’s on-going efforts to address perchlorate in drinking water.
The samples collected in 2007 from our Potomac River water filtration plant source and treated water show trace amounts of perchlorate at levels 3.1 ppb or less, far below the EPA reference dose level. We consider the occurrence of perchlorate at levels observed in our Potomac plant water to be insignificant and not a health concern. If you have special health concerns, you can get additional information from the EPA or contact the EPA’s Safe Drinking Water Hotline at 1-800-426-4791.
Learn more about the Washington Aqueduct’s participation in the nonregulatory perchlorate sampling project.
