(a) Production zone monitoring. Designated production zone monitor wells shall be spaced no greater than 400 feet from the production area, as determined by exploratory drilling. The distance between adjacent mine area monitor wells shall be no greater than 400 feet. The angle formed by lines drawn from any production well to the two nearest monitor wells will not be greater than 75 degrees. Changes or adjustments in designated production zone monitor well locations may be authorized by the executive director so as to assure adequate containment. These wells shall be subject to the sampling, corrective action, and reporting requirements in §331.105 of this title (relating to Monitoring Standards) and §331.106 of this title (relating to Remedial Action for Excursion).
(b) Nonproduction zone monitoring. At a minimum, designated nonproduction zone monitor wells shall be completed in the production area in any freshwater aquifer overlying the production zone. These wells shall be located not more than 50 feet on either side of a line through the center of the production area with a minimum of one per every four acres of production area for wells completed in the first overlying freshwater aquifer and one per every eight acres for wells completed in any additional overlying freshwater aquifers. Changes or adjustments in designated nonproduction zone monitor well locations may be authorized by the executive director so as to assure adequate containment. Those wells completed in the first overlying freshwater aquifer shall be subject to sampling, remedial action, and reporting requirements of §331.105 of this title (relating to Monitoring Standards) and §331.106 of this title. Monitor wells completed in any additional overlying freshwater aquifers shall be subject to monitoring, remedial action, and reporting requirements specified in the permit.

Source Note: The provisions of this §331.103 adopted to be effective May 13, 1986, 11 TexReg 1985; amended to be effective March 12, 2009, 34 TexReg 1638