REVIEW OF THE AQUIFER EXEMPTION PROCESS, HISTORY AND IMPLEMENTATION RELATED TO GROUNDWATER PROTECTION AND USE

Transcription

1 REVIEW OF THE AQUIFER EXEMPTION PROCESS, HISTORY AND IMPLEMENTATION RELATED TO GROUNDWATER PROTECTION AND USE GROUNDWATER PROTECTION COUNCIL ANNUAL UNDERGROUND INJECTION CONTROL CONFERENCE February, 2017; Austin, Texas Hal Demuth, M.S. and Ken Cooper, M.S., PE PETROTEK ENGINEERING CORPORATION

2 OBJECTIVES 2 Review the Safe Drinking Water Act (SDWA) and the Underground Injection Control (UIC) Program Under UIC regulations, what is an aquifer exemption? Review the history of UIC program Talk about concerns from NRDC, et. al and request for AE data Review the EPA Aquifer Exemption Database (what do the data show and what can we learn?)

3 SDWA UIC PROGRAM AND AQUIFER EXEMPTIONS 3 The primary focus of Safe Drinking Water Act (SDWA;1974) is protection of Underground Sources of Drinking Water (USDWs). Aquifer Exemptions (AEs) allow use of water bearing zones that are not USDWs for industrial/commercial purposes. Per 40 CFR (g), these aquifers have no real potential to be used as drinking water sources and therefore are not USDWs. They may be identified under 40 CFR and exempted under 40 CFR criteria.

4 4 WHAT IS AN AQUIFER EXEMPTION? A regulatory action that removes a portion of an aquifer with < 10,000 mg/l TDS water from qualification as an USDW EPA developed the aquifer exemption process to protect drinking water aquifers and meet industry needs. EPA evaluates the boundaries of the aquifer exemption proposed by the well owner/operator or state so that nearby drinking water sources remain protected (EPA, 2017).

5 HISTORY OF SDWA UIC PROGRAM AND AQUIFER EXEMPTIONS 5 Underground Injection Control (UIC) regulations promulgated in 1980 Program development and primacy granted to many states from State programs listed in 40 CFR 147 Many states requested Aquifer Exemptions as part of their original program development Most or all of those initial AE requests were for injection zones currently being used at that time

6 MARCH 2016 NRDC PETITION AND EPA FOIA 6 Natural Resources Defense Council (NRDC) and three other groups expressed concern about program implementation and lack of public information Requested all EPA data on aquifer exemptions (Freedom of Information Act [FOIA] on January 5, 2015)

7 EPA AQUIFER EXEMPTION DATABASE Preliminary Database 2017 Revised Database Updated AE data were released in January Interactive Online Aquifer Exemptions Map; GUI interface allows users to locate aquifer exemptions and sort by EPA UIC Well Class, Depth and Data Quality (related to location)

8 EPA AQUIFER EXEMPTION DATA Database 4,682 records 2017 Final Database 3,295 records 2017 Data do not include California Exempted aquifers in California are not shown on the maps. California is engaged in a process to digitize existing exemption locations and is also currently reviewing numerous requests for new or expanded aquifer exemptions that they expect to submit to EPA Region 9 for review. As this work progresses, the aquifer exemptions in California will be added to the national dataset (EPA, 2017)

9 EPA AQUIFER EXEMPTION DATA (2016 vs. 2017) : 4,682 Aquifer Exemptions (included AE data for California) 2016: No area data for 743 Aquifer Exemptions 2016: Data included AE requests, approvals, denials, withdrawn applications or permits 2016: Data sets contained 44 attributes 2017: Data sets contain only 19 attributes 2017: 3,295 Aquifer Exemptions (no California data) 2017: No area data provided for 529 Aquifer Exemptions

10 EPA AQUIFER EXEMPTION DATA (2016 vs. 2017) 10 Number Number % of total % of total Well Class Description I Industrial/E&P in WY II 4,484 3, O&G Production III ISR Uranium + other V Total 4,682 3,295 IID 1,155 1, Disposal IIR 3,179 2, Waterflood/P. Maint. II other Other

11 EPA AQUIFER EXEMPTION MAP

12 EPA AQUIFER EXEMPTION MAP DATA QUALITY/DETAIL 12

13 13 3,295 3,295 exemptions (without (without CA) CA) Note: Boundary is the surface outline of AE, typically with a small vertical thickness

14 14 3,295 exemptions (without CA) Note: AE locations shown are the centroid of the AE, not the AE boundary outline

15 15 65 Class I exemptions (without CA) Note: AE locations shown are the centroid of the AE, not the AE boundary outline

16 16 3,145 Class II exemptions (without CA) Note: AE locations shown are the centroid of the AE, not the AE boundary outline

17 17 82 Class III exemptions (without CA) Note: AE locations shown are the centroid of the AE, not the AE boundary outline

18 18 AE Depth (TVD) and Number 10,000-15,000: 22 5,000-10,000: 741 2,500-5,000: 1,249 1,000-2,500: : : 78 Note: AE locations shown are the centroid of the AE, not the AE boundary outline; depth data are incomplete

19 EPA AQUIFER EXEMPTION BY WELL CLASS 19

20 20

21 21 UIC Program development

22 22 UIC Program development

23 23 UIC Program development

24 EXEMPTION AREA AND VOLUME TYPICALLY ARE SMALL Powder River Basin Class I Example (Johnson County WY) 24 Estimated depth to saline water = 10,000 feet (18% porosity) Aquifer exemption zone = 100 feet thick; porosity = 18% Volume of exempted water = 100 x 0.18 x ππ(1,320 2 ) x 7.48 = x 10 6 gallons Volume of water in place = 9,800 x 0.18 x ππ(1,320 2 ) x 7.48 = 72.2 x 10 9 gallons (depth to water = 200 ) Percent of exempted water in ¼-mile AOR cylinder = 1.0% Land area for Johnson County, WY = 4,175 mi 2 Assume an average saturated thickness of 5,000 feet For 10 AEs, AE volume = % of the water in place

25 REGULATORY REVIEW AND TECHNICAL REQUIREMENTS HAVE INCREASED OVER TIME 25 Initial requirements in UIC regulations (1980); 40CFR criteria for exempted aquifers Additional requirements agreed upon by EPA and States during State primacy approvals EPA Guidance 34: General and Specific requirements for demonstrating consistency with 40 CFR July 24, 2014 Letter from EPA HQ to EPA Regional Directors 5 pages of requirements to demonstrate regulatory and technical consistency with regulations As the UIC program matured, EPA and States generally have approved smaller AE areas and vertical thicknesses, and required more justification

26 SUMMARY AND CONCLUSIONS 26 Most Aquifer Exemptions (2,005; 61% of the total) were issued during UIC program development ( ) 3,145 exemptions (95.4% of the total excluding CA) are related to Oil and Gas production and allow injection into zones that were never a potential water supply (they were producing hydrocarbons) Those zones never would have been used for a public water supply, are not fresh water, and were already being used at the time For the past 30 years, few AEs (1,094; 33%) have being approved The annual approval rate has remained consistently low

27 SUMMARY AND CONCLUSIONS 27 Current EPA UIC regulations (1) adequately protect USDWs and (2) allow use of aquifers that have no potential to be used as drinking water sources for other purposes State program requirements for AE application to EPA have become more systematic, detailed and consistent EPA requirements for aquifer exemption demonstration have increased Industry awareness and technical detail in exemption applications increased EPA has provided aquifer exemption data in a useful manner with easy access available to the public

28 Questions and Discussion 28 Contact Hal Demuth, M.S. Principal, Senior Technical Team Manager Ken Cooper, M.S., PE Principal, Engineering Manager Petrotek Engineering Corporation 5935 South Zang Street, Suite 200 Littleton, Colorado (303) x all rights reserved