Alaska Administrative Code › Title 18 - Environmental Conservation › Chapter 78 - Underground Storage Tanks › Article 6 - Cleanup Levels › 18 AAC 78.600 - Cleanup levels: General requirements

Current through May 31, 2024
(a) Soil
				samples from an excavation or stockpile created as part of a corrective action
				must be collected as required by
				18 AAC 78.605, analyzed in
				accordance with Chapter 2 of the
UST Procedures
				Manual,
analyzed by a laboratory approved by the department under
				18 AAC 78.800 -
				18 AAC 78.815, and reported as
				required by
				18 AAC 78.276. If laboratory
				results indicate that the concentrations of a contaminant are below the
				applicable soil cleanup levels determined under
				18 AAC 75.340 and
				18 AAC 75.341, the department will
				determine soil corrective actions to be adequate, unless subsequent evidence
				shows that the testing was not representative or that sampling did not detect
				all contamination.
(b) The identity
				of a released refined petroleum product must be assumed to be unknown unless
				the owner or operator demonstrates, by analysis done as required by the
UST Procedures Manual,
that the product is only gasoline, or
				only a refined nongasoline product. The department will waive the requirement
				that a product be identified by analysis if the owner or operator demonstrates
				that only one type of product was stored or distributed during the facility's
				operational life.
(c) Soils
				additionally contaminated with a hazardous substance other than a petroleum
				product are subject to 18 AAC 75 and, as applicable, 18 AAC 60, 18 AAC 62, 18
				AAC 70, and 18 AAC 72, or another chapter of this title.
(d) If using method two or method three for
				determining the applicable soil cleanup levels as described in
				18 AAC 75.340 and
				18 AAC 75.341, or if applying the
				groundwater cleanup levels at Table C in
				18 AAC 75.345, the owner or
				operator shall ensure that, after completing site corrective action activities,
				the risk from contaminants does not exceed a cumulative carcinogenic risk
				standard of 1 in 100,000 across all exposure pathways and a cumulative
				noncarcinogenic risk standard at a hazard index of one, reported to one
				significant figure, across all exposure pathways. Instructions for determining
				on cumulative risk are provided in the department's Procedures fol' Calculating
				Cumulative Risk, dated September 15, 2016, and adopted by reference.
(e) If proposing an alternative cleanup level
				for soil or groundwater, based on a site- specific risk assessment under method
				four in 18 AAC 75.340(f)
				or under the provisions of
				18 AAC 75.345(b)(2), the owner or operator
				shall ensure that the risk from contaminants does not exceed a cumulative
				carcinogenic risk standard of 1 in 100,000 across all exposure pathways and a
				cumulative noncarcinogenic risk standard at a hazard index of one, reported to
				one significant figure, across all exposure pathways. Instructions for
				determining cumulative risk are provided in the department's Pl'ocedures for
				Calculating Cumzilative Risk, adopted by reference in (d) of this section.
(f) An owner or operator
				requesting approval of a cleanup level for soil or groundwater based on a
				site-specific risk assessment under
				18 AAC 75.340(f)
				or 18 AAC 75.345(b) (2) shall reimburse the department for its
				expenses to hire a contractor to review a risk assessment report.
(g) An owner or operator shall provide for
				long-term care and management of a site subject to corrective action under this
				chapter, including proper operation and maintenance of
(1) corrective action techniques and
				equipment;
(2) monitoring wells and
				equipment, if required; and
(3)
				institutional controls, if required under
				18 AAC 78.625.