A. The vadose zone shall be abated as follows:

(1) water contaminants in the vadose zone shall not be capable of contaminating ground water or surface water, in excess of the standards in Subsections B and C below, through leaching, percolation or as the water table elevation fluctuates; and

(2) any constituent listed in 20.6.2.3103 NMAC or any toxic pollutant in the vadose zone shall be abated so that it is not capable of endangering human health due to inhalation of vapors that may accumulate in structures, utility infrastructure, or construction excavations.

E. Alternative Abatement Standards: If the person abating water pollution pursuant to an approved abatement plan, or pursuant to the exemptions of 20.6.2.4105 NMAC, is unable to fully meet an abatement standard set forth in Subsections A and C of this section, the person may file a petition with the commission seeking approval of an alternative abatement standard.

1. (1) A petition for an alternative abatement standard shall demonstrate at least one of the following criteria:

   1. (a) compliance with the standard set forth in Subsections A and B of this section would not be feasible by the maximum use of commercially accepted abatement technology;
   2. (b) compliance with the standard set forth in Subsections A and B of this section would not be feasible by the maximum use of technology within the economic capability of the person;
   3. (c) there is no reasonable relationship between the economic and social costs and benefits of attainment of the standard set forth in Subsections A and B of this section; or
   4. (d) compliance with the standard set forth in Subsections A and B of this section is technically infeasible following the maximum use of commercially accepted abatement technology, as demonstrated by a statistically valid extrapolation of the decrease in concentration of any water contaminant over a twenty (20) year period, such that projected future reductions during that time would be less than 20 percent of the concentration at the time technical infeasibility is proposed. Technical infeasibility proposals that involved the use of experimental abatement technology shall be considered at the discretion of the commission. A statistically valid decrease cannot be demonstrated by fewer than eight (8) consecutive sampling events. Sampling events demonstrating a statistically valid decrease shall be collected with a minimum of ninety (90) days between sampling events and shall not span a time period greater than four (4) years.

2. (2) A petition for alternative abatement standards shall specify, in addition to the information required by Subsection A of 20.6.2.1210 NMAC the following:

   1. (a) the water contaminant for which the alternative abatement standard is proposed;
   2. (b) the alternative abatement standard proposed;
   3. (c) the three-dimensional body of water pollution for which approval is sought;
   4. (d) a summary of all actions taken to abate water pollution to standards; and
   5. (e) other information as deemed necessary, which may include a transport, fate and risk assessment in accordance with accepted methods.

3. (3) The commission may approve an alternative abatement standard if the petitioner demonstrates that:

   1. (a) at least one of the criteria set forth in Paragraph 1 of Subsection E of this Section has been met;
   2. (b) the proposed alternative abatement standard is technically achievable and cost benefit justifiable; and
   3. (c) compliance with the proposed alternative abatement standard will not create a present or future hazard to public health or undue damage to property.
4. (4) An alternative abatement standard shall only be granted after a public hearing, as required by NMSA 1978, Section 74-6-4(H) of the water Quality Act.
5. (5) The commission shall review petitions for alternative abatement standards in accordance with the procedures for review of variance petitions provided in the commission’s adjudicatory procedures, 20.1.3 NMAC.

F. For a site where abatement activities include post-completion monitoring, maintenance of engineering controls, remediation systems, affirmation of non-residential use, or port-closure care, institutional controls such as well drilling restrictions under 19.27.5 NMAC, deed restrictions, easements or other legal restrictions binding on successors in interest to the site may be required by the secretary.

[12-1-95, 11-15-96; 20.6.2.4103 NMAC - Rn, 20 NMAC 6.2.IV.4103, 1-15-01; A, 12-21-18]