This web site provides operators with an estimate of casing depths to assist in obtaining the Groundwater Protection Determination Letter (pdf).

All estimates derived from this Web site must be verified by the RRC Groundwater Advisory Unit Team and final recommendations will be provided in the Groundwater Protection Determination Letter.

Railroad Commission of Texas regulations require that anyone drilling for oil and gas or reentering an existing oil and gas well must have a plan for the well design that is approved by the RRC. Part of the plan must include use of surface casing and cement to protect fresh water (generally a salinity of less than 1000 mg/l TDS) and useable quality water (generally a salinity of less than 3000 mg/l TDS). Surface casing also helps protect the well from caving in and blowing out.

The well operator must have a letter from the RRC Groundwater Advisory unit, which is then provided to the RRC, which outlines where fresh and usable-quality water is located. The RRC uses the recommendations in the Groundwater Protection Determination Letter for designing well requirements.

For a full explanation of the procedures and available resources for obtaining the Groundwater Protection Determination Letter, please visit the RRC Groundwater Advisory Unit page that includes sample application forms, surface casing rules, expedited application procedures, and contact information.

To proceed in acquiring surface casing information click the arrow below or click the question mark for help on how to use the site:

Prepared in cooperation with the Railroad Commission of Texas.
The preparation of this site was financed through funds from the Railroad Commission of Texas and the Texas Commission on Environmental Quality.

Effective September 1, 2011, the Surface Casing Estimator project is coordinated through the RRC Groundwater Advisory Unit. Prior to September 1, 2011, the Surface Casing Estimator project was coordinated through the Texas Commission on Environmental Quality.