340-094-0080 Groundwater Monitoring and Corrective Action If a municipal solid waste landfill is subject to 40 CFR, Part 258 as provided in 40 CFR, §258.1, the owner or operator shall comply with groundwater monitoring and corrective action requirements in 40 CFR, Part 258, Subpart E. Consistent with those requirements, all municipal solid waste landfill owners and operators shall also comply with this rule: (1) Groundwater: (a) Each landfill permittee shall ensure that: (A) The introduction of any substance from the landfill into an underground drinking water source does not result in a violation of any applicable federal or state drinking water rules or regulations beyond the solid waste boundary of the landfill or an alternative boundary specified by the Department; (B) The introduction of any substance from the landfill into an aquifer does not impair the aquifer’s recognized beneficial uses, beyond the solid waste boundary of the landfill or an alternative boundary specified by the Department, consistent with OAR 340, division 40 and any applicable federal or state rules or regulations. (b) Where monitoring is required, monitoring wells shall be placed at Department-approved locations between the solid waste boundary and the property line if adequate room exists; (c) The Department may specify an alternative boundary based on a consideration of all of the following factors: (A) The hydrogeological characteristics of the facility and surrounding land; (B) The volume and physical and chemical characteristics of the leachate; (C) The quantity and directions of flow of groundwater; (D) The proximity and withdrawal rates of groundwater users; (E) The availability of alternative drinking water supplies; (F) The existing quality of the groundwater including other sources of contamination and their cumulative impacts on the groundwater; and (G) Public health, safety, and welfare effects. (2) Monitoring: (a) Where the Department finds that a landfill’s location and geophysical condition indicate that there is a reasonable probability of potential adverse effects on public health or the environment, the Department may require a permittee to provide monitoring wells at Department-approved locations and depths to determine the effects of the landfill on groundwater; (b) In addition to the requirements in 40 CFR, Part 258, Subpart E, if the Department determines that monitoring wells are required at a landfill, the permittee shall provide and maintain the wells at the locations specified by the Department and shall submit a copy of the geologic log and record of well construction to the Department within 30 days of completion of construction; (c) In addition to the requirements in 40 CFR, Part 258, Subpart E, where the Department determines that self-monitoring is practicable, the Department may require that the permittee collect and analyze samples of surface water and/or groundwater, at intervals specified and in a manner approved by the Department, and submit the results in a format and within a time frame specified by the Department; (d) The Department may require permittees who do self-monitoring to periodically split samples with the Department for the purpose of quality control. (3) Corrective action. The Department may require action to remediate releases of constituents above the levels specified in 40 CFR, §258.56 or OAR 340, division 40, whichever is more stringent. This authority is in addition to any other authority granted by law. Statutory/Other Authority: ORS 459.045, 459A.100 - 459A.120 & 468.020 Statutes/Other Implemented: ORS 459.015, 459.045 & 459.248 History: DEQ 10-1994, f. & cert. ef. 5-4-94 DEQ 5-1993, f. & cert. ef. 3-10-93, Renumbered from 340-061-0040 DEQ 2-1984, f. & ef. 1-16-84 DEQ 26-1981, f. & ef. 9-8-81 DEQ 41, f. 4-5-72, ef. 4-15-72