Title 18 . Environmental Conservation

Chapter 78 . Administrative Enforcement

Section 250. Corrective action plan

18 AAC 78.250. Corrective action plan

(a) At any time after reviewing the information submitted under 18 AAC 78.210 - 18 AAC 78.240, if the department determines that a threat to human health or safety, or to the environment exists, the department will require the owner or operator to

(1) submit additional information; or

(2) develop and submit a corrective action plan to respond to contaminated soil, surface water, and groundwater.

(b) If a corrective action plan is required under (a) of this section, the owner or operator shall submit the plan for approval according to a schedule and format established by the department. To obtain approval, the plan must

(1) provide for adequate protection of human health and safety, and of the environment, as determined by the department;

(2) include the elements listed in (e) of this section; and

(3) be prepared by a qualified, impartial third party; the owner or operator may request a waiver from the use of an impartial third party under the procedures of 18 AAC 78.090(f) .

(c) The owner or operator may, after fulfilling the requirements of 18 AAC 78.210 - 18 AAC 78.240, voluntarily submit a corrective action plan to respond to contaminated soil and groundwater. That corrective action plan must meet the requirements of (b)(1) and (b)(3) of this section. The owner or operator shall modify the plan is necessary to demonstrate that the plan meets the requirements of (b)(1) of this section.

(d) To minimize environmental contamination and perform more effective corrective actions, the owner or operator may begin corrective actions to respond to contaminated soil and groundwater, before the department approves a corrective action plan, if the owner or operator

(1) notifies the department of the intent to begin corrective actions;

(2) complies with any conditions imposed by the department, including halting corrective action or mitigating adverse consequences from corrective action activities; and

(3) incorporates any self-initiated corrective action measures in the corrective action plan, or as amendments to the plan.

(e) The corrective action plan must include the following elements:

(1) a schedule for conducting field work, monitoring, corrective action activities, and submittal of interim and final corrective action reports;

(2) sampling and analysis plan, including

(A) final verification sampling protocol; and

(B) provisions for handling, transporting, and disposing of investigation-derived wastes including

(i) purged water from a boring or monitoring well;

(ii) cuttings, mud, and other wastes from well or boring installation and development; and

(iii) contaminated equipment and materials;

(3) detailed specifications for each proposed corrective action technique, and copies of all previous communications with the department regarding the proposed technique;

(4) provisions for minimizing contaminant migration to previously unaffected areas, except under an approved corrective action technique under this section;

(5) provisions for transporting contaminated soil as a covered load in accordance with 18 AAC 60.015;

(6) provisions for the disposal of contaminated soil and groundwater, including the location and method of disposal;

(7) a list of chemical additives proposed for use, and their potential effects on

(A) the hazardous substances at the site; and

(B) human health and safety, and the environment;

(8) a site control plan, if necessary to protect the human health or safety, or the environment, including engineering measures, such as the installation of caps or liners, and provisions for restricting access, such as the use of fences, signs, or other barriers;

(9) a demonstration that site work and the corrective action will comply with the air quality standards and requirements of 18 AAC 50;

(10) a plan for ensuring that contaminated soil does not come in contact with uncontaminated soil during the corrective action process, except under an approved corrective action technique under this section or an approved operations plan under 18 AAC 78.273;

(11) a nondomestic wastewater system plan under 18 AAC 72.600, if the corrective action requires construction, alteration, installation, modification, or operation of a nondomestic wastewater treatment works or disposal system;

(12) for ex-situ corrective action techniques,

(A) provisions for containment and handling of leachate, if leachate is produced;

(B) a demonstration that site work and the corrective action will comply with soil storage, movement, and disposal requirements in 18 AAC 78.274;

(C) if using a hot asphalt batch plant, written certification by a registered engineer that processes incorporating contaminated soils meet current industry standards for asphalt paving;

(D) if combining contaminated soil with asphalt for the purposes of cold asphalt recycling, a cold asphalt recycling plan that includes

(i) a pavement structure design study for incorporating the excavated material; the study must be certified by a registered engineer;

(ii) approval for use of the specific leaching assessment or model used to determine contaminant migration; and

(iii) results of the pre-approved contaminant leaching assessment or model, referenced under (ii) of this subparagraph; those results must demonstrate that contaminant concentrations in the soil will not migrate;

(E) if using bioremediation, a bioremediation plan that includes detailed descriptions of

(i) cultured microbes, unless using an indigenous microbe population;

(ii) electron acceptors and nutrient sources for microbes;

(iii) the expected rate of biodegradation;

(iv) intermediate and final breakdown products;

(v) the type and amount of contamination to be bioremediated;

(vi) any potential adverse effects on human health or safety, or on the environment; and

(vii) other information requested by the department; the department will request additional information if the department determines that the information is necessary to ensure protection of human health or safety, or of the environment;

(F) if using solidification, a solidification plan that includes

(i) a demonstration that contaminant concentrations in the contaminated media do not exceed 5,000 mg/kg for the total range of petroleum hydrocarbons described in the UST Procedures Manual and do not exceed 100 mg/kg of BTEX;

(ii) a demonstration that contaminant concentrations in the solidified material will not migrate;

(iii) results of structural testing on the solidified material to demonstrate that the solidified material has an unconfined compressive strength of 2,000 psi or more after 28 days;

(iv) results of leachability testing of the solidified material; and

(v) specifications for the ratio of the mass of contaminated media to the mass of reagent;

(G) if using soil contaminated with petroleum hydrocarbons as a base for a physical barrier, a physical barrier base plan that includes

(i) a demonstration that contaminant concentrations in contaminated soil used for the base do not exceed 5,000 mg/kg for the total range of petroleum hydrocarbons described in the UST Procedures Manual, or that do not exceed 100 mg/kg of BTEX;

(ii) a demonstration that the contaminated soil that is used for the base will be blended with uncontaminated soil only if necessary to meet design specifications;

(iii) a physical barrier design study, certified by a registered engineer;

(iv) approval for use of the specific leaching assessment or model used to determine contaminant migration;

(v) results of the pre-approved contaminant leaching assessment or model, as specified under (iv) of this subparagraph; those results must demonstrate that contaminant concentrations in the soil will not migrate;

(vi) a demonstration that the base under the physical barrier will use no more than 18 vertical inches of material containing contaminated soil;

(vii) a demonstration that the contaminated zone will be compacted to 95 percent or more of the maximum density as specified in American Society for Testing and Materials (ASTM) D 1557 - 91, Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort, updated January 1997 and adopted by reference, or (ASTM) D 4253 - 93, Standard Test Methods for Maximum Index Density and Unit Weight or Solids Using Vibratory Table, updated February 1993 and adopted by reference;

(viii) a demonstration that the material containing contaminated soil will be placed in a zone directly beneath the final base course with at least 18 inches of impervious pavement extending beyond the horizontal limit of the material containing contaminated soil;

(ix) a demonstration that at least six feet will separate the seasonal high groundwater point from the lowest point of the material containing contaminated soil; and

(x) as-built drawings, certified by a registered engineer, that show the final location of the material containing contaminated soil;

(H) if using soil contaminated with metals for a base as a physical barrier, and if that use is approved on a site-specific basis, the elements required by (G) of this paragraph; and

(I) if using an offsite or portable treatment facility, a demonstration that only an offsite or portable treatment facility with an operations plan approved under 18 AAC 78.273 will be used;

(13) for in-situ corrective action techniques:

(A) a site monitoring plan showing proposed locations of monitoring wells;

(B) a hydrogeologic description of the site, including

(i) soil and sediments present;

(ii) stratigraphy;

(iii) aquifer characteristics, including groundwater gradient, confining layers, perched water, permeability, and aquifer transmissivity;

(iv) percolation rates from precipitation; and

(v) other relevant factors;

(C) results of hydrogeologic modeling performed to address capture zones, effects of hydraulic loading, and plume migration; and

(D) if using bioremediation, a demonstration of compliance with (12)(E) of this subsection.

(f) The owner or operator shall submit and obtain approval for each of the applicable elements specified in (e) of this section before work on that element begins, and for additional approval if a modification to an element is anticipated.

History: Eff. 3/25/91, Register 118; am 11/3/95, Register 136; am 1/22/99, Register 149

Authority: AS 46.03.020

AS 46.03.050

AS 46.03.365

AS 46.03.740

AS 46.03.745

AS 46.04.020

AS 46.04.070

AS 46.09.020

Editor's note: The ASTM methods adopted by reference in 18 AAC 78.250 may be reviewed in the department's Anchorage, Fairbanks, Juneau, and Soldotna offices, and may be obtained from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103.