The Critical Link between Aquifer Exemptions and the Sustainability of Water Resources as Part of Unconventional Resource Development

Transcription

1 GWPC s 2013 UIC Conference Sarasota, Florida The Critical Link between Aquifer Exemptions and the Sustainability of Water Resources as Part of Unconventional Resource Development Prepared by: J. Daniel Arthur, P.E., SPEC ALL Consulting Tulsa, Oklahoma

2 Abstract 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 development. 2

3 Outline Introduction Aquifer Exemptions Challenges to the AE Process GW Cycling as an Option Summary & Considerations 3

4 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! Source: 4

5 Why Grant an Aquifer Exemption? An aquifer may meet the definition of a USDW but: 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. 5

6 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. 6

7 Criteria for Exemption 40 CFR 146.4(b)(1)-(4) Aquifer produces mineral, hydrocarbon, or geothermal energy; Contains minerals or hydrocarbons in quantity and location that are expected to be commercially producible; 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. 7

8 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. 8

9 The Fight Against Aquifer Exemptions 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 exemptions. Source: 9

10 ProPublica Criticism Technology advances mean lower quality water can be made potable. Many exemptions are granted in arid or drought areas. Exemptions are almost never denied. Injectate can migrate outside the designated exemption area. EPA s decision criteria are outdated. 10

11 Support for Aquifer Exemptions Aquifer Exemptions_ States and EPA follow a well-defined analytical process with clear criteria in recommending and approving exemptions. 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. 11

12 Bakken Brackish Water Test Source UNDEERC (2012) 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 gpm. The Dakota Aquifer is also the main disposal zone in the region, making water cycling feasible. 13

13 Horn River Basin Groundwater Cycling Challenges: isolated location; lack of disposal option; limited access roads; lack of power; and harsh winter temperatures CAPP Environmental Award First Nation's concerns over use of surface water resources in the area has lead Apache/Encana to pursue brackish water from the DeBolt Aquifer. 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. 14

14 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 available 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 16

15 North Slope Aquifers Shublik Shale Outcrop Extensive and shallow. Brackish 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 17

16 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. 18

17 J. Daniel Arthur, P.E., SPEC ALL Consulting Citation Information: 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.