1. (a) Detection monitoring at the frequency established under 18 AAC 60.825(i) is required in all groundwater monitoring wells at facilities required to conduct groundwater monitoring under this chapter. At a minimum, except as provided in (1) of this subsection, detection monitoring requires monitoring for the analytes and parameters required for the facility by the department under 18 AAC 60.840. Upon the request of the owner or operator of the facility, the department may

   1. (1) remove any of the analytes and parameters required under 18 AAC 60.840 if the owner or operator of the facility demonstrates that the removed constituents are not reasonably expected to be in or derived from the waste stored, treated, or disposed in the facility; and

   2. (2) establish an alternative list of inorganic indicator analytes for the facility, instead of some or all of the heavy metals identified in 40 C.F.R. Part 258, Appendix I, as amended through August 1, 2005, adopted by reference; if the owner or operator of the facility demonstrates to the department's satisfaction that the alternative analytes provide a reliable indication of inorganic releases from the facility to the groundwater; the department will determine an alternative list with consideration given to the

      1. (A) types, amounts, and concentrations of constituents in wastes managed at the facility;
      2. (B) mobility, stability, and persistence of waste constituents or their reaction products in the unsaturated zone beneath the facility;
      3. (C) detectability of indicator analytes or parameters, waste constituents, and reaction products in the groundwater; and
      4. (D) concentration of, or values and coefficients-of-variation for, inorganic analytes in the groundwater background.

2. (b) If the owner or operator determines under 18 AAC 60.830(i) that there is a statistically significant increase over background values for one or more monitored constituents in any downgradient monitoring well, the owner or operator of the facility

   1. (1) shall, not later than 14 days after making the determination, place a notice in the operating record of the facility indicating which constituents have shown statistically significant changes over background values, and submit written notification to the department that this notice was placed in the operating record; and

   2. (2) shall, not later than 90 days after making the determination, either

      1. (A) establish an assessment monitoring program that meets the requirements of 18 AAC 60.860, including a revised and approved monitoring plan; or

      2. (B) receive department approval of, and enter into the operating record, a report certified by either a qualified groundwater scientist or another person preapproved by the department that proves that an assessment monitoring program is not necessary because

         1. (i) a source other than the monitored waste management area caused the pollution; or
         2. (ii) the statistically significant increase determination resulted from an error or from a natural variation in groundwater quality.

(Eff. 1/28/96, Register 137; am 10/29/98, Register 148; am 2/25/2022, Register 241)

Authority: AS 44.46.020, AS 46.03.020, AS 46.03.110, AS 46.03.010, AS 46.03.100