1. Issues and Opportunities in Evaluating Water Sources for Oil and Gas Operations Wade Oliver, PG Gerry Grisak, PG

2. Houston and T.C. Railroad Co. vs. East 1904 Texas Supreme Court “…the existence, origin, movement, and course of such waters, and the causes which govern and direct their movements, are so secret, occult, and concealed that an attempt to administer any set of legal rules in respect to them would be involved in hopeless uncertainty, and would, therefore, be practically impossible.”

4. Groundwater Data Sources TWDB Groundwater Database – Most detailed – 138,000 wells TWDB Submitted Drillers Reports Database – After 2001 – 336,000 wells TCEQ Drillers Reports – Before 2001 – 800,000+ wells? – Limited location data Groundwater Availability Models BRACS Database and Studies Texas Railroad Commission Disposal Wells Geophysical Logs from BEG, RRC, and Commercial Sources Groundwater Conservation Districts Published Reports * Basic Groundwater Hydrology: Heath (1983) – WSP 2220 http://pubs.usgs.gov/wsp/wsp2220

5. Confining Unit Unconfined Aquifer (fresher) Confined Aquifer (brackish) Types of Aquifers

6. One Aquifer – Two Types UnconfinedConfined NorthwestSoutheast Measured Water Level

7. Major Aquifers Carrizo-Wilcox Gulf Coast

8. Minor Aquifers Yegua-Jackson Queen City Sparta

9. Gulf Coast Aquifer Geochemistry Study

10. Groundwater Conservation Districts GCDs, DFCs, MAGs, GAMs, GMAs, RWPGs Groups of groundwater districts in 16 groundwater management areas decide every 5 years on management goals (desired future conditions) for next 50 years. These goals are used to define groundwater availability throughout TX. Drilling or Exploration Operations Exemption Law related to whether wells for hydraulic fracturing require a permit is ambiguous and unevenly applied throughout the state.

11. Rig Supply Water Wells 2001 - 20072008 - 2013 Source: TWDB Submitted Drillers Reports

12. Water Wells Exceeding 1000 mg/L TDS

13. Percent of Fresh Water Use for Hydraulic Fracturing by County for 2011 McMullen (55%) La Salle (17%) Dimmit (24%) Karnes (31%) DeWitt (18%) Sources: TWDB Water Use Survey Total Est. GW and SW Use Nicot and others (2012) HF Water Consumption Does not include brackish or recycled/reused water

14. Opportunities Benefit from better understanding of groundwater source options Deeper brackish resources – Less impact on local fresh water supplies – Increased understanding of brackish aquifers Cooperation with GCDs – Can benefit both GCDs and O&G companies – Data sharing (well logs, water production, water quality, etc.) – Jointly funded studies?

15. Contact: Wade Oliver, PG woliver@intera.com 512-425-2058