In assessing how frequently hydraulic fracturing takes place close to a public water supply, a 2016 EPA report said that drinking water supplies located near hydraulic fracturing sites are more likely to be impacted should a contamination event occur.
The investigators amassed a large database of private drinking water wells and compared their locations to hydraulic fracturing sites.
This knowledge is important to maintaining high-quality water in many domestic wells," said co-author Jasechko, an assistant professor at UCSB’s Bren School of Environmental Science & Management.
"Our results underscore the importance of increased water monitoring efforts near both hydraulically fractured and conventional oil and gas wells in ascertaining the risk of contamination and in protecting water well quality."
"These hotspots are areas where, in light of potential contamination mechanisms, limited resources for assessing spill frequency and well integrity could be used more effectively and efficiently," explained Perrone, an assistant professor in UCSB’s environmental studies program.
Perrone noted that some hotspot areas include not only hydraulically fractured but also conventional oil and gas wells, which are more abundant.
"We can consider stronger policies that include requirements for repeated groundwater quality testing of the many domestic self-supply wells that exist close to hydraulic fracturing."
In fact, the scientists found vast differences in how states collect groundwater data.
"One policy recommendation would be to have a national standard for data collection on groundwater well construction," Perrone said.
More information: Scott Jasechko el al., "Hydraulic fracturing near domestic groundwater wells," PNAS (2017).