The Critical Link Between Aquifer Exemptions and teh Sustainability of Water Resources as Part of Unconventional Resource Development
The Critical Link between
Aquifer Exemptions and the
Sustainability of Water
Resources as Part of
J. Daniel Arthur, P.E., SPEC
GWPC’s 2013 UIC
Development of Unconventional Resources in the United States is likely to require
one to three million additional wells to be drilled and completed. Each of these
wells will require hydraulic fracturing and it’s likely that the vast majority will
require the use of water for drilling and fracturing activities. Although current
development leverages highly on fresh water for these activities, it is likely that
poorer quality water will assume a larger role as development progresses.
Sourcing, recycling, and disposal of this water requires innovation, such as has
been undertaken already in several plays around the world and in the United
States. Technically innovative and sustainable concepts, such as “Groundwater
Cycling” has gained considerable attention as a solution. In the Horn River Basin
of British Columbia, the DeBolt Aquifer is being used as both a water source and
disposal zone as is the Dakota Aquifer in the Bakken play. The concept is also
being assessed in the Shublik on Alaska’s North Slope, the Mississippi-Lime play
in Kansas, the Eagle Ford Shale play in south Texas, as well as other plays. Many
of these sustainable alternatives, as well as other concepts, require current
aquifers meeting the definition of an Underground Sources of Drinking Water
(USDWs) to be exempted. This paper will describe the critical role of aquifer
exemptions with regard to water sustainability and unconventional resource
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Challenges to the AE Process
GW Cycling as an Option
Summary & Considerations
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Defining a USDW
• An aquifer which
– Supplies any public water system, or
– Contains sufficient quantity of ground water to
supply a public water system, and
– Currently supplies drinking water, or
– Contains fewer than 10,000 mg/L TDS, AND
– Which is not an exempted aquifer
• Note that aquifer exemptions are part of the
definition of a USDW!
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Why Grant an Aquifer Exemption?
An aquifer may meet the definition of a
• The likelihood of its being used for
drinking water is extremely remote.
• It contains commercially producible
mineral or hydrocarbon resources.
• There are nearby abundant, fresher
drinking water resources.
• It is contaminated.
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Defining an Exempted Aquifer
• Meets the standard for a USDW but has
been exempted because:
– It does not currently provide water for
human consumption, and
– It cannot serve as a source of drinking water
now or in the future, OR
– It has TDS >3,000 mg/L and <10,000 mg/L,
AND is not reasonably expected to supply a
public water system.
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Criteria for Exemption
40 CFR 146.4(b)(1)-(4)
• Aquifer produces mineral, hydrocarbon, or
• Contains minerals or hydrocarbons in
quantity and location that are expected to be
• Depth or location that makes the recovery of
the ground water for drinking water
economically or technologically impractical;
• So contaminated that rendering the water fit
for human consumption would be
economically or technologically impractical.
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Decision Process: Options
• Non-substantial program revision
– Based on the >3,000 and <10,000 mg/L criterion
– Requires public notice and public hearing
– State director submits exemption to EPA RA
– Becomes final after 45 days unless disapproved
• Commercially producible hydrocarbons
– Demonstrate feasibility of production
• Substantial program revision
– <3,000 mg/L TDS
– Approval by EPA Administrator
• Exemption is a final EPA action.
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The Fight Against
• The “idea” that the energy industry is unregulated has gained
significant traction as shale development has spread.
• Any industry exemption, regardless of justification, is used as
a tool to derail development and support further regulation.
• Perhaps the biggest issue is defining the term “Reasonably
Expected” as intended by EPA and Congress.
• The ability to treat lower and lower quality waters is not
necessarily a justification to re-define USDWs or limit aquifer
9Copyright (c), ALL Consulting, January 2013Source: www.propublica.org
• Technology advances mean lower
quality water can be made potable.
• Many exemptions are granted in arid
or drought areas.
• Exemptions are almost never
• Injectate can migrate outside the
designated exemption area.
• EPA’s decision criteria are outdated.
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Support for Aquifer Exemptions
• States and EPA follow a well-defined analytical
process with clear criteria in recommending and
– Extensive geologic and hydrologic investigation
– Both technical and economic analysis
– Areal limits of the exemption are clearly defined
• Congress’s intent was not to interfere with oil and gas
development unless “absolutely essential to assure
that USDWs will not be endangered.”
• Improving technology can also make other nearby
non-exempt water sources potable.
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Lifecycle Water Considerations in
A lifecycle approach is needed to address
the many issues important to managing
water on a lifecycle basis for
unconventional resource development:
• Regulatory Challenges
• Legislative changes
• Public opposition
• Historical Activities
• Competition for resources
• Flowback recovery
• Regulatory Uncertainty
• Environmental risks
• Cumulative Impacts
• Pre-Development Assessment
• Water Sourcing Availability & Issues
• Well Site Construction & Drilling
• Water Conditioning/Pre-Treatment
• Well Completion/Fracturing
• Flowback/Produced Water
• Reuse/Disposal/Beneficial Use
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• EERC partnered with Hess to pilot test the
use of reverse osmosis (RO) treatment on
brackish water from the Dakota Aquifer
(~10,000 mg/L TDS).
• Site located near Tioga at an existing water
production well used for EOR.
• GE Water Process and Technologies was
contracted to provide the RO treatment.
• Currently at ~70% efficiency with permeate
production at 80-160 gpm.
• The Dakota Aquifer is also the main
disposal zone in the region, making water
cycling feasible.Source UNDEERC (2012)
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Horn River Basin
• First Nation's concerns over use of
surface water resources in the area
has lead Apache/Encana to pursue
brackish water from the DeBolt
• Water from the DeBolt (500-1,000
meters) is brackish (15,000-40,000
mg/L TDS) and sour (65 mg/L H2S).
• A $60 million treatment plant was built
to sweeten water for use in HF.
• Produced water after HF is re-injected
back to the brackish DeBolt aquifer.2011 CAPP Environmental Award
Challenges: isolated location; lack of disposal option; limited access
roads; lack of power; and harsh winter temperatures.
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Sourcing & GW Cycling
• Water sourcing can be challenging in the MLP.
Drought has impacted surface water sources and
restrictions have arisen in some areas.
• Fresh water costs of $0.25/BBL are common (far less
• Common water sourcing options have been fresh
water from creeks, farm ponds, impoundments, and
the blending of water captured during the flowback
• Groundwater combined with groundwater cycling is an
option for the MLP as the play moves north (AE
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Alaska’s Shublik Shale
• Resource comparable to Bakken and Eagle Ford
• Source rock for Kuparik and Northstar
• Great Bear has leased 500,000 acres.
• Development will depend on sufficient water being
– Up to 6 million gallons per well
– Surface water is limited
– Sourcing and disposal are concerns
– Treated Beaufort Sea water is one option
– Ground water cycling in local aquifers would
address both issues
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North Slope Aquifers
• Extensive and shallow.
• Total thickness 2000 to 3000 feet
• Parts are below 10,000 mg/L TDS
• Some areas have exemptions
– Kuparuk River
– Milne Point
• Good candidate for GW cycling
– But could require aquifer exemptions
17Copyright (c), ALL Consulting, January 2013Shublik Shale Outcrop
Considerations for the Future
• Achieving our overall goals of fully developing U.S.
shales will mean something on the order of 1-3
million additional wellbores. This will NOT be easy!
• Need 2 to 6 million gallons of water per well
• Sourcing and disposal will be big issues
• Water cycling will be a valuable option
• May require aquifer exemptions in some areas
• Opposition to exemptions is forming
• Industry and states will have to work together to
justify exemptions based on the law, Congressional
intent, and economic necessity.
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J. Daniel Arthur, P.E., SPEC
J. Daniel Arthur, P.E., SPEC. “The Critical Link between Aquifer Exemptions and the Sustainability of Water
Resources as Part of Unconventional Resource Development”. Presented at the Ground Water Protection
Council’s 2013 UIC Conference, January 22-24, 2013, Sarasota, Florida.