(a) The commission adopts by reference 40 Code of Federal Regulations (CFR) §257.94 (Detection monitoring program) as amended through the April 17, 2015, issue of the Federal Register (80 FR 21301), subject to the additions in this section.
(b) After making a determination of a statistically significant increase (SSI) over the background value for any Appendix III constituent adopted by reference in §352.1421 of this title (relating to Appendix III - Constituents for Detection Monitoring) at any monitoring well, the owner or operator shall notify the executive director, and any local pollution agency with jurisdiction that has requested to be notified, in writing within 14 days of this determination.
(c) After making a determination of an SSI over the background value for any Appendix III constituent adopted by reference in §352.1421 of this title at any monitoring well, the owner or operator may submit an alternative source demonstration in accordance with 40 CFR §257.94(e)(2) to the executive director for review. In making a demonstration under this section, the owner or operator must:
  (1) notify the executive director, and any local pollution agency with jurisdiction that has requested to be notified, in writing within 14 days that the owner or operator intends to make an alternative source demonstration under this section; and
  (2) within 90 days of making a determination of an SSI over the background value for any Appendix III constituent adopted by reference in §352.1421 of this title, submit a report prepared and certified in accordance with §352.4 of this title (relating to Engineering and Geoscientific Information), to the executive director, and any local pollution agency with jurisdiction that has requested to be notified, demonstrating that a source other than a coal combustion residuals unit caused the SSI or that the SSI resulted from error in sampling, analysis, statistical evaluation, or natural variation in groundwater quality.
(d) If the owner or operator does not make an alternative source demonstration under this section satisfactory to the executive director, then the owner or operator shall initiate an assessment monitoring program as required in 40 CFR §257.94(e). The executive director may require the owner or operator to install additional monitoring wells to determine whether the demonstration is satisfactory. If the owner or operator does make an alternative source demonstration under this section that is satisfactory to the executive director, then the owner or operator may continue to monitor in accordance with the detection monitoring program established under this section.

Source Note: The provisions of this §352.941 adopted to be effective May 28, 2020, 45 TexReg 3464