Rule 17.74.519 - SAMPLING PROCEDURES(1) The following sampling procedures must be followed to assess contamination and to verify the attainment of the decontamination standards within inhabitable structures:(2) The department may approve an equivalent method, in advance if the method is at least as stringentas the method in (1).(3) Each sampling event shall include a minimum of one laboratory blank, identified in a manner that avoids identification as a blank.(4) Each sampling plan shall include a minimum of two discretionary samples, to be utilized at the methamphetamine certified contractor's discretion based on updated field observations. When utilized these samples will be incorporated into the chain of custody, analysis by the laboratory, and final report.(5) An assessment or clearance plan shall incorporate a sampling plan that follows an authoritative sampling approach, which uses professional judgment to target areas suspected to have the highest levels of contamination within the inhabitable property and unless otherwise approved by the department, shall include:(a) samples from each room or area within the inhabitable property known, based on credible evidence or documentation, to have contained a CML or to have been exposed to contamination from methamphetamine smoking;(b) at least two samples from each room or area within the inhabitable property where methamphetamine manufacturing or smoking is suspected to have occurred;(c) at least one sample from each heating, ventilation, and air conditioning (HVAC) system's return side when such systems are present in the inhabitable property; and(d) at least one sample from each exhaust fan when exhaust fans are present in the inhabitable property, unless assumed to be contaminated by the contractor.(6) Each assessment plan shall include a minimum of two discretionary samples, to be collected and utilized at the methamphetamine certified contractor's discretion based on updated field observations.(7) If the encountered site conditions at an inhabitable property are different from the expected site conditions, the methamphetamine certified cleanup contractor may complete sampling in accordance with a modified plan An explanation of the unexpected conditions and sampling plan deviations shall be submitted to the department in the final report.Mont. Admin. r. 17.74.519
NEW, 2022 MAR p. 1812, Eff. 9/24/2022AUTH: 75-10-1304, MCA; IMP: 75-10-1304, MCA