RAILROAD COMMISSION OF TEXAS Norman Gearhart, P.G. Manager Groundwater Advisory Unit

Groundwater Advisory Unit Purpose Provide recommendations for groundwater to be protected during oil and gas drilling and production. Evaluate Saltwater Disposal Well applications for geologic isolation from the base of usable- quality water and injection below the underground source of drinking water. Hydrogeological evaluation concerning groundwater contamination.

Protected Aquifers For oil and gas wells Freshwater (less than 1,000 mg/l total dissolved solids, TDS), and Usable-quality water (less than 3,000 mg/l TDS, waters known to be used, and waters identified by the Texas Water Development Board for use in desalination) For saltwater injection wells in addition to the above Underground source of drinking water (less than 10,000 mg/l TDS)

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Types of Applications Surface Casing Applications Microseismic Applications Seismic Applications (shot holes) Saltwater Disposal Applications (W-14)

What Requires a Surface Casing Letter New Drills Well Integrity Test Plugging and Abandoning Cathodic Protection Microseismic Boreholes Re-entering a Well

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Seismic Letter Send a Dated letter Including – Company Name and Address – Contact Person and Phone Number – Project Name – County Name(s) – Shot Hole Depth – Map Showing Shot Points Receive a Seismic Groundwater Protection Letter (Base of Usable-Quailty Water )

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14 Base of Usable-Quality Water Base Underground Source of Drinking Water Carrizo

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Contact Information 18 Milton Rister, Executive Director Gil Bujano, Director, Oil & Gas Division Ramon Fernandez, Deputy Director, Field Operations, Oil & Gas Division Gaye Greever McElwain, Public Outreach Information Officer Norman Gearhart, P.G., Manger Groundwater Advisory Unit

Contact Information 19 Barry T. Smitherman, Chairman David Porter, Commissioner Christi Craddick, Commissioner 1701 N. Congress Ave. P.O. Box Austin, TX