?/EPA
United States
Environmental Protection
Agency
Office of Water
EPA 821-F-16-001
June 2016
Pretreatment Standards for the
and Gas Extraction Point Source
Category
Summary
EPA finalized a rule, on June 13, 2016, establishing pretreatment standards for discharges of wastewater from
onshore unconventional oil and gas (DOG) extraction facilities to municipal sewage treatment plants (also
known as publicly owned treatment works, or POTWs). The rule protects human health and the environment
by preventing the discharge of pollutants in these wastewaters. The rule also protects POTWs from disruptions
in their operations that can be caused by these wastewaters.
Background
Responsible development of America's oil and gas resources offers important economic, energy security, and
environmental benefits. EPA has been working with states and other stakeholders to understand and address
potential impacts of hydraulic fracturing, an important process involved in producing DOG, so the public has
confidence that oil and natural gas production will proceed in a safe and responsible manner.
DOG extraction wastewater can be generated in large quantities and may contain pollutants that are
potentially harmful to human health and the environment. Because they are not typical of POTW influent
wastewater, some DOG extraction wastewater constituents can be discharged, untreated, from the POTW to
the receiving stream; can disrupt the operation of the POTW (e.g., by inhibiting biological treatment); can
accumulate in biosolids (sewage sludge), limiting their use; and can facilitate the formation of harmful
disinfection by-products (DBPs). Based on the information collected by EPA, current industry practice is to not
send these wastewaters to POTWs. EPA is issuing a zero discharge pretreatment standard that will ensure that
such current industry best practice is maintained over time. EPA does not project that the final rule will
impose any costs on the industry or lead to pollutant removals.
This final rule fills a gap in existing federal wastewater regulations to ensure that the current industry practice
of not sending DOG extraction wastewater discharges from this sector to POTWs continues into the future.
Are there existing regulations that apply to this industry?
Direct discharges of oil and gas extraction wastewater pollutants from onshore oil and gas facilities to waters
of the U.S. have been regulated since 1979 under the existing Oil and Gas Effluent Limitations Guidelines and
Standards (40 CFR part 435), the majority of which fall under subpart C, the Onshore Subcategory. The
limitations for direct dischargers in the Onshore Subcategory represent Best Practicable Control Technology
Currently Available (BPT). The BPT-based limitations for direct dischargers require zero discharge of pollutants
to waters of the U.S. However, there are currently no requirements in subpart C that apply to onshore oil and
gas extraction facilities that are indirect dischargers, i.e., those that send their discharges to POTWs that treat
the water before discharging it to waters of the U.S. Requirements that apply to indirect dischargers are
referred to as pretreatment standards.
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What part of the industry is addressed by this rule?
This final rule includes pretreatment standards for wastewater pollutants from a subset of oil and gas
extraction facilities. This rule applies to onshore extraction from shale and/or tight geologic formations
(referred to as unconventional oil and gas extraction resources).
This final rule does not include pretreatment standards for wastewater pollutants associated with
conventional oil and gas extraction facilities or coalbed methane extraction facilities. EPA is reserving such
standards for a future rulemaking, if appropriate.
This rule does not address the practice of underground injection of wastewater discharges from this sector
since such activity is not subject to the Clean Water Act but rather the Safe Drinking Water Act.
Why did EPA require zero discharge of pollutants from DOG extraction facilities to POTWs?
Most POTWs are designed to treat pollutants found in municipally-generated, not industrial, wastewater. They
typically provide at least secondary level treatment and, thus, are designed to remove suspended solids and
organic material using biological treatment. Wastewater from DOG extraction can contain high concentrations
of dissolved solids (or salts), as well as pollutants such as radioactive elements, metals, chlorides, sulfates, and
other dissolved inorganic constituents that POTWs are not designed to remove. Because they are not typical
of POTW influent wastewater, some DOG extraction wastewater constituents can be discharged, untreated,
from the POTW to the receiving water; can disrupt the operation of the POTW (e.g., by inhibiting biological
treatment); can accumulate in biosolids (sewage sludge), limiting their use; and can facilitate the formation of
harmful DBPs.
Where DOG extraction wastewaters have been indirectly discharged to POTWs in the past, there have been
documented cases of elevated levels of chloride and bromide occurring in the receiving waters. The
concentration of TDS in DOG extraction wastewater can be high enough that if discharged untreated to
surface water, the potential exists to adversely affect a number of designated uses of surface water, including
drinking water, aquatic life support, livestock watering, irrigation, and industrial use. There have also been
documented cases where discharges of bromide upstream of drinking water intakes have led to the formation
of carcinogenic disinfection by-products at drinking water utilities.
When will this rule take effect?
Because the requirements of the final rule are based on current practice, EPA determined that the standards
apply on the effective date of the final rule, which is 60 days after publication in the Federal Register.
Where can I find more information?
You can view the Federal Register Notice on EPA's website for Unconventional Extraction in the Oil and Gas
Industry at https://www.epa.gov/eg/unconventional-oil-and-gas-extraction-effluent-guidelines. In addition,
the final rule will be available at regulations.gov under Docket ID: EPA-HQ-OW-2014-0598. You may also email
Ms. Karen Milam at Milam.Karen@epa.gov.
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