Groundwater at Rocky Flats is routinely monitored to identify changes in contaminant concentration, location and direction of movement. The sitewide Groundwater Monitoring Program was expanded in 1986 to accomplish "Superfund" characterization requirements, although routine groundwater monitoring activities have been ongoing since 1953. The primary RFCA intent of the groundwater monitoring network is to protect surface water quality because there is no existing or anticipated future domestic use of Site groundwater.

During Fiscal Year 99, Rocky Flats collected groundwater samples from 98 wells to characterize groundwater quality. Monitoring wells are located within and down-gradient of known areas of contamination, as well as at the Site boundary. Groundwater samples are analyzed for metals, volatile organic compounds, anions, and radionuclides. Known groundwater plumes are entirely contained on Site and exist in several locations associated with historical disposal and waste handling practices. However, groundwater at Rocky Flats is typically found near the surface, is present in small volumes, and is slow-moving. All these factors have helped to keep the chemicals in groundwater on-site and away from regional drinking water sources.

Groundwater plumes with chemical concentrations above reporting requirements are scheduled to be remediated as part of the Site closure and cleanup mission. Although volatile organic compounds (VOCs) are present in Rocky Flats groundwater, no groundwater VOC contamination has been found off-site.

Additional background information on Rocky Flats groundwater monitoring programs is outlined in the Integrated Monitoring Plan and the Integrated Monitoring Plan - Groundwater - 2002