Section 18 AAC 78.600 - Cleanup levels: General requirements(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.(h) An owner or operator shall obtain approval before disposing of soil or groundwater from a site (1) that is subject to this chapter; or(2) for which the owner or operator has received a written determination from the department under 18 AAC 78.276(f).(i) The collection, interpretation, and reporting of data under this section must be conducted or supervised by a qualified environmental professional.Eff. 1/22/99, Register 149; am 8/27/2000, Register 155; am 1/30/2003, Register 165; am 6/17/2015, Register 214, July 2015; am 7/1/2017,Register 222, July 2017 The department's procedures for Calculating Cumulative Risk, adopted by reference in 18 AAC 78.600(d), may be viewed at or obtained from the department's offices in Anchorage, Fairbanks, Juneau, and Soldotna or the department's Internet website at http://dec.alaska.gov/spar/csp/guidanceforrns/csguidance.htm.
As of Register 188 (January 2009), the regulations attorney made technical revisions under AS 44.62.125(b)(6), to 18 AAC 78.600(e) and (f), reflecting the Department of Environmental Conservation's renumbering of paragraphs in 18 AAC 78.345(b), effective 10/9/2008 (Register 188).
Authority:AS 46.03.020
AS 46.03.050
AS 46.03.365
AS 46.03.710
AS 46.03.740
AS 46.03.745
AS 46.03.822
AS 46.04.020
AS 46.04.070
AS 46.09.020