Administrative Rules of Montana › Department 17 - ENVIRONMENTAL QUALITY › Chapter 17.56 - UNDERGROUND STORAGE TANKS PETROLEUM AND CHEMICAL SUBSTANCES › Subchapter 17.56.6 - Release Response and Corrective Action for Tanks Containing Petroleum or Hazardous Substances › Rule 17.56.607 - RELEASE CATEGORIZATION

Current through Register Vol. 13, July 5, 2024
(1) The
				department shall categorize all releases from USTs and PSTs regulated under
				this chapter as active, transferred, resolved, ground water management, or
				resolved with a petroleum mixing zone releases.
(2) Releases that do not meet the criteria
				set forth in (3), (4), (7), or (10) must be categorized as active.
(3) The department may categorize a release
				as transferred if another state or federal program assumes jurisdiction over
				the facility and all releases and threatened releases of hazardous or
				deleterious substances from USTs or PSTs regulated under this chapter are to be
				addressed by that program at the facility. The department shall notify the
				owner or operator before categorizing the release as transferred. The notice
				must state which state or federal program has jurisdiction over the
				release.
(4) The department may
				categorize a release as resolved if the department has determined that all
				cleanup requirements have been met and that conditions at the site ensure
				present and long-term protection of human health, safety, and the environment.
				The following requirements must also be met before a release may be categorized
				as resolved:
(a) documented investigations,
				conducted in accordance with ARM
				17.56.604, identify the extent or
				absence of contamination in the soil, ground water, surface water, and other
				environmental media relevant to the release;
(b) risks to human health, safety and the
				environment from residual contamination at the site have been evaluated using
				methods listed in (4)(b)(i) or (ii) and the evaluation indicates that
				unacceptable risks do not exist and are not expected to exist in the future.
				The department considers a total hazard index that does not exceed 1.0 for
				noncarcinogenic risks, and a total cancer risk that does not exceed 1 x
				10-5, to be an acceptable risk level. Owners or
				operators, or other persons may, with department approval, use either of the
				following methods to evaluate risks from a release:
(i) Tier 1 evaluation using Montana
				Risk-based Correction Action Guidance for Petroleum Releases (RBCA) for
				evaluation of risks to human health, safety and the environment associated with
				surface and subsurface soil and ground water contamination; or
(ii) a site-specific risk assessment method
				approved by the department for evaluation of risks to human health, safety, and
				the environment associated with contamination, or likely contamination, that
				demonstrates to the department's satisfaction that current and potential future
				exposure pathways are incomplete;
(c) all appropriate corrective actions
				associated with the release and required by the department, including
				compliance monitoring and confirmatory sampling, have been completed;
(d) all free product has been removed to the
				maximum extent practicable; and
(e)
				all applicable environmental laws associated with the release have been met.
				These applicable requirements may include, but are not limited to, air quality,
				drinking water and monitoring well requirements, solid waste management
				requirements, hazardous waste management requirements, national pollutant
				discharge elimination system (NPDES) and Montana pollutant discharge
				elimination system (MPDES) requirements, underground injection controls and
				standards, UST requirements, noxious weed control, ground water and surface
				water quality standards, nondegradation requirements, storm water requirements,
				and requirements for the protection of endangered species, historic sites,
				wetlands and floodplains.