DNREC announces release of preliminary data from USGS unconfined aquifer water quality study
DOVER – The Department of Natural Resources and Environmental Control’s Division of Water today announced the release of preliminary data from the ongoing United States Geological Survey (USGS) unconfined aquifer water quality study in Delaware.
The USGS is in the process of completing the third in a series of ongoing studies conducted over the past 20 years. These studies focused on the ground water quality in a selection of public water systems statewide. Started in 2000, the USGS studies have been designed to assess existing raw-water quality relative to established drinking water standards and emerging interests. In each iteration, the study has included analytes beyond the standard regulatory scope with the addition of per- and poly-fluorinated substances (PFAS) in the current effort.
Consistent with the previous studies, specific compounds were detected above standards at a few locations. DNREC’s review of this preliminary data indicates that overall water quality in the State of Delaware is generally good in respect to the broad suite of compounds detected. PFAS were detected in isolated locations which shows similar distribution to other emerging compounds in the past. Of the 30 sampling locations, PFAS was identified in the unconfined aquifer water above the current Federal Health Advisory Limit (HAL) of 70 parts per trillion in only two isolated locations. In both instances, DNREC, in conjunction with the Department of Health and Social Service’s Office of Drinking Water (DHSS-ODW), and the water providers, confirmed that treated water quality meets the drinking water standards, including the unregulated compounds. While the sampling was done at locations of public wells, the USGS results reflect unconfined aquifer water prior to any treatment supplied by water utilities, and do not reflect served water quality.
While the USGS is in the process of finalizing the report, verified preliminary data can now be accessed by the public through the National Water Information System (NWIS). It is anticipated that the USGS study summarizing the results of their analysis of over 500 compounds will be completed in the spring of 2020. This data, in comparison with the results from the 2000 and 2008 studies, will provide a detailed baseline of water quality in the unconfined aquifer throughout the state that can be used by DNREC and partnering agencies in making water resource management decisions.
CONTACT: Michael Globetti or Joanna Wilson, DNREC Public Affairs, 302-739-9902