ARM 17.50.720. MONITORING DURING CLOSURE

(1) The ground water monitoring plan must include a discussion of the anticipated ground water monitoring system and schedule of sampling for closed portions of the facility. (2) If a facility specified in 75-10-207(1) , MCA, undergoes closure prior to January 1, 1993, the department will require a minimum of 6 semi-annual sampling episodes for Table 1 [ARM 17.50.708] parameters prior to approving final closure. These sampling events must occur after the last date the facility received waste. If no exceedence of preventative action limits or enforcement standards occurs for any Table 1 [ARM 17.50.708] constituent, then ground water monitoring at the closed landfill may be discontinued contingent upon written approval obtained from the department. Depending on the site-specific hydrogeology study, the department reserves the right to increase or decrease the number of ground water sampling events required during closure approval.