Water management technologies used by Marcellus Shale Gas Producers.

Advances in Membrane Distillation for Water Desalination and Purification Applications

“…One of the challenges on using produced water for agricultural applications is the high levels of salinity and the excess of sodium, when present in the water, which can reduce the hydraulic conductivity of soils and prevent plant growth. Industrial applications include process water for hydraulic fracturing operations at oil and gas well sites, water for power generation, dust control, and fire protection and control [317,318]. Pretreatment is required but it is not as extensive as it is for agricultural purposes.…”

Impacts of Shale Gas Wastewater Disposal on Water Quality in Western Pennsylvania

“…3,9 Pennsylvania has historically managed wastewater from conventional oil and gas wells (i.e., vertical wells drilled into an oil/gas reservoir) by hauling it to industrial brine treatment facilities, which then discharge treated effluent to surface waters. 10 In 2010 there were 74 oil and gas water pollution control facilities, including both private brine treatment facilities and publicly owned treatment works (POTWs) permitted or awaiting permit approval to accept wastewater in Pennsylvania (Figure 1; Supporting Information (SI) text). 10 Ferrar et al (2013) 11 showed that treatment of wastewater by three of these facilities releases elevated concentrations of Cl, Br, Sr, and Ba to streams at concentrations above U.S. Environmental Protection Agency (USEPA) maximum contaminant levels, secondary maximum contaminant levels, criterion maximum concentrations, or criterion chronic concentrations.…”

“…10 In 2010 there were 74 oil and gas water pollution control facilities, including both private brine treatment facilities and publicly owned treatment works (POTWs) permitted or awaiting permit approval to accept wastewater in Pennsylvania (Figure 1; Supporting Information (SI) text). 10 Ferrar et al (2013) 11 showed that treatment of wastewater by three of these facilities releases elevated concentrations of Cl, Br, Sr, and Ba to streams at concentrations above U.S. Environmental Protection Agency (USEPA) maximum contaminant levels, secondary maximum contaminant levels, criterion maximum concentrations, or criterion chronic concentrations. 11 The disposal of Marcellus wastewater through treatment facilities was also suggested to be linked to an overall increase of 5% in chloride concentrations at downstream surface water monitoring sites in western Pennsylvania 12 and likely increased the salt intake at downstream water treatment facilities.…”

Challenges and Opportunities of Shale Gas Extraction via Hydraulic Fracturing

“…Wastewater After the fracturing period, the pressure on the well is released, and a fraction of the fluid migrates back to the surface as "flowback," a process which can occur over the course of several weeks [36] . The amount of fluid recovered is estimated at about 25 to 75% in some areas, such as the Barnett shale play, [37][38][39] and 10 to 30% in others, such as the Marcellus shale play [40] . The volume of flowback is not reported to any state agencies, however, meaning these estimates could be very inaccurate.…”

“…While a CWT may be specially equipped to handle known contaminants in the wastewater, this is not the case with POTWs. The sodium chloride content, for instance, damages equipment [38,41] , bromides lead to toxic brominated disinfection byproducts, and POTWs lack treatment methods for radionuclides. For these reasons, the state of Pennsylvania has limited the disposal of hydrofracking wastewater at POTWs to less than 1% of the POTW's average daily flow [42] .…”