Calculator is Closed for Maintenance
NOTE: DEC recently adopted revisions to the Oil and Other Hazardous Substances Pollution Control regulations in 18 AAC 75. The adoption package is currently undergoing a legal review and could become law as early as October 2008.
We highly recommend that sites currently undergoing cleanup use the proposed cleanup levels during this time of transition to the new regulations.
The Method Three and Cumulative Risk web calculator has not been updated to reflect the proposed cleanup levels and equations. For Method 3 Cleanups, see the proposed revised Cleanup Levels Guidance (July 2008) or contact Jill Taylor by phone at 907-465-5209, or by email at jill.taylor@alaska.gov. We anticipate the Method 3 web calculator to be operational by October 2008.
See our regulations update page.
If you are a consultant currently working on a cleanup project, please contact your assigned DEC project manager regarding implementation of the revised cleanup levels.
If you would like to be notified when the calculator is operational again, please email the SPAR Webmaster.
The Method Three & Cumulative Risk Calculator was designed to assist consultants, potential responsible parties, and regulators in evaluating soil analytical results with respect to ADEC's 18 AAC 75 regulations.
18 AAC 75 provides four methods of evaluating analytical data against regulatory guidelines. Method one and two provide look up tables to compare analytical results versus regulatory cleanup levels. Method four involves development of a risk assessment. Method three is described below.
Method Three Cleanup Levels
Method three was developed to provide flexibility in determining alternative cleanup levels for soil and groundwater. This method allows for the use of site-specific soil data, aquifer data or both, and it also allows for the use of commercial/industrial exposure values without performing a full risk assessment under method four.
Method three provides methods of determining site-specific alternative cleanup levels for three soil exposure pathways: inhalation, ingestion, and migration to groundwater. In this web calculator, the following site-specific soil and aquifer parameters may be modified.
- Dry bulk density;
- Total soil porosity;
- Air-filled soil porosity;
- Water-filled soil porosity;
- Average soil moisture content;
- Organic carbon content of soil;
- Aquifer hydraulic conductivity;
- Hydraulic gradient;
- Infiltration Rate;
- Aquifer Thickness; and
- Source length parallel to groundwater flow.
In addition, the user has the choice between selecting the residential and commercial/industrial land use scenarios.
The soil and aquifer parameter values used to develop the Department's default cleanup levels may not be reflective of soil or aquifer conditions at a particular site. Therefore, method three allows for the use of site specific data for selected parameters. The Department requires submittal of the parameters proposed for modification, the site specific values for those parameters proposed for use and a description of the basis for each site specific value prior to calculating site-specific cleanup levels.
For details on the methodology and equations used in this calculator, please refer to ADEC's Cleanup Levels Guidance.
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