Alaska Administrative Code › Title 18 - Environmental Conservation › Chapter 75 - Oil and Other Hazardous Substances Pollution Control › Article 3 - Discharge Reporting, Cleanup, and Disposal of Oil and Other Hazardous Substances › 18 AAC 75.341 - Soil cleanup levels; tables

Current through May 31, 2024
(a) If a
				responsible person uses method one for petroleum hydrocarbons for a non-Arctic
				zone under
				18 AAC 75.340, the soil cleanup
				levels must be based on Table A1 in this subsection. 

                 TABLE A1. METHOD ONE - PETROLEUM HYDROCARBON

                    SOIL CLEANUP LEVELS IN NONARCTIC ZONES

                (See notes to table for further requirements)

Part A: Determine score for each item*
1. Depth to Groundwater
Less than 5 feet                           (10)

           5 feet to 15 feet                          (8)

           More than 15 feet to 25 feet               (6)

           More than 25 feet to 50 feet               (4)

           More than 50 feet                          (1)
2. Mean Annual Precipitation
More than 40 inches                        (10)

           More than 25 inches to 40 inches           (5)

           15 inches to 25 inches                     (3)

           Less than 15 inches                        (1)
3. Soil Type (Unified Soil Classification)
Clean, course-grained soils                (10)

           Coarse-grained soils with fines            (8)

           Fine-grained soils (low organic 

carbon)     (3)

           Fine-grained soils (high organic 

carbon)    (1)
4. Potential Receptors

  (Select the most applicable category)
a. Public water system within 

1000

           feet, or private 

water system within

           500 feet                                   (15)

           b. Public/private water system 

within

           1/2 mile                                   (12)

           c. Public/private water system 

within

           one mile                                   (8)

           d. No water system within one mile         (4)

           e. Nonpotable groundwater                  (1)
5. Volume of Contaminated Soil
More than 500 cubic yards                  (10)

           More than 100 cubic yards to 

500 cubic

           yards                                      (8)

           More than 25 cubic yards to 

100 cubic

           yards                                      (5)

           10 cubic yards to 25 cubic yards           (2)

           Less than 10 cubic yards                   (0)
*The items to be scored are defined in note 1 to this
				  table.
Part B: Add scores from Part A to determine matrix
				  score and cleanup level
Cleanup Level in mg/kg

                     Gasoline     Diesel     Residual

  Matrix Score for     Range       Range       Range

   Each Category     Organics    Organics    Organics

Category A: More          50        100        2000

   than 40

Category B: 26 - 40      100        200        2000

Category C: 21 - 26      500       1000        2000

Category D: Less        1000       2000        2000

   than 21
Notes to Table A1:
1. The following definitions for items 1 - 5
				in Part A apply for purposes of using method one:
a. "depth to groundwater" means the
				measurement from the lowest point of the zone of soil contamination to the
				seasonal high groundwater table; a responsible person may not claim a lower
				matrix score for soil by moving contaminated soil to a higher elevation
				relative to the groundwater table;
b. "mean annual precipitation" is defined at
				18 AAC 75.990;
c. "soil type" means the predominant Unified
				Soil Classification (USC) soil type between the deepest point of contamination
				and the seasonal high groundwater table; a responsible person may seek to
				demonstrate that otherwise coarse-grained soil has an organic carbon content
				that might enable a lower point classification. Soil types using the USC system
				are further defined as shown in Figure 1: 

                                 Figure 1

     SOIL TYPE                           UNIFIED SOILS CLASSIFICATIONS

       Clean coarse-grained                             GW, GP, SW, SP

     Coarse-grained with fines         GM, GC, SM, SC, GP-GC, SP-SM,

                                       GW-GM, SW-SM, SW-SC

Fine-grained with low organic

carbon                                                  ML, CL, HM, CH

Fine-grained with high organic

carbon                                                      OL, OH, Pt
d. for the
				"potential receptors" categories,
(i) "public
				water system" and "private water system" have the meaning given those terms in
				18 AAC 80.1990;
(ii) "nonpotable" means unusable for drinking
				water due to a water quality condition, such as salinity, that was not caused
				by or that does not arise from contamination at the site;
e. "volume of contaminated soil" means the
				total estimated volume of soil that is contaminated above the applicable
				cleanup level before a responsible person begins a removal or cleanup
				action.