An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

EPA's Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources

Scenario Analysis of the Impact on Drinking Water Intakes from Bromide in the Discharge of Treated Oil and Gas Wastewater

Weaver, J., Xu, J., and Mravik, S. Journal of Environmental Engineering. August 2015. 


EPA scientists developed a model to evaluate the impact from bromide in discharges by conventional commercial wastewater treatment plants (CWTP) that treat oil and gas (including hydraulic fracturing) wastewaters into the Allegheny River (faster flow rate) and the Blacklick Creek (slower flow rate) on drinking water resources. The study’s authors created different scenarios for CWTPs including a steady flow of discharge and a pulsed flow to account for plants that might not operate continuously. Bromide concentrations downstream depend on factors such as the volume, timing and concentration of effluent; the effluent discharge rate; the flow rate of the receiving river or creek; and the distance to the drinking water intake. The study found that discharging treated hydraulic fracturing wastewaters can contribute to elevated levels of bromide downstream at drinking water intakes. Mitigation measures to help reduce bromide concentrations at drinking water plants include reducing the effluent concentration or discharge rate/volume, pulsing discharges, or limiting discharges during low flow conditions in the stream/river. This work was done as part of EPA’s Study of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources.