Water Quality Regulations and Portland's Drinking Water
Portland's primary water supply is surface water from the Bull Run Watershed. Restricted access to the watershed and a watershed protection program have allowed Portland to meet stringent requirements for remaining an unfiltered water system.
Groundwater has been available as a back-up supply since 1986. The system is used to meet peak water demand during hot summer months. It is also used as an emergency source of supply when the Bull Run is not available. During the February 1996 flood, groundwater was used to meet water demands for several days due to increased turbidity in Bull Run reservoirs. All groundwater served to customers meets or surpasses drinking water standards.
All water supplied by Portland's public water system meets or surpasses federal and state drinking water standards. The Portland Water Bureau performs approximately 54,400 analyses on 11,800 water samples each year. Samplers collect water from the watershed reservoirs, in-town reservoirs, the distribution system , groundwater and consumers' taps. Monitoring schedules for Bull Run water and groundwater follow federal and state regulations. Records of analyses are available to the public.