Using the CL Calculator
Although we believe that using the CL web-based calculator is generally intuitive, click on the steps below for detailed instructions.
- Select Hazard Quotient
- Select Target Risk
- Select Scenario
- Select Cleanup Level Type
- Select Chemical Info Type
- Select Risk Output
- Select RfD/RfC Type
- Select Individual Chemicals
- Click Retrieve
- Site-specific Parameters
- View Results
1. Select Hazard QuotientChoose the appropriate hazard quotient.
2. Select Target RiskChoose the appropriate target risk.
3. Select ScenarioChoose one of the 5 landuse scenarios and then select which precipitation zone to assess for soils under the "Select Precipitation Zone" list that is displayed (except for "Groundwater" and "Migration to Groundwater").
4. Select Cleanup Level TypeSelect the type of cleanup level desired. "Defaults" is the pre-selected choice and calculates the Cleanup Levels using the standard eqauations, toxicity, chemical parameters, and suggested inputs from the guidance document. "Site Specific" will allow users to change parameters for some equations using a tailored approach for the site. If "Site Specific" is selected go to Step 5. If "Defaults" is selected go to step 7.
5. Select Chemical Info TypeThe "Select Chemical Info Type" drop down menu will appear. Select either "Database hierarchy defaults" or "User-provided". "Database hierarchy defaults" uses the toxicity values and the chemical-specific parameters as selected by the hierarchies described in ADEC CL guidance. "User-provided" gives the option to add extra chemicals and enter toxicity values and chemical-specific parameters. The toxicity Metadata option will be disabled if "User-provided" is selected.
6. Select Risk OutputSelect yes if risk output is desired. Selecting risk output requires the calculator to be run in "Site Specific" mode. The "Migration to Groundwater" medium does not have risk output and will become disabled when risk output is selected. Risk output does not apply the one-hit rule to cancer risk results.
7. Select RfD/RfC TypeSelect either "Chronic" or "Subchronic" types of RfD and RfC values. As a general rule of thumb, ADEC considers an exposure duration of more than 7 years to be chronic. Shorter durations may be considered subchronic. In some instances some risk assessors will consider a shorter exposure duration to still be chronic if the exposures occur frequently. We recommend you contact a toxicologist or risk assessor in ADEC for your site. Chronic and Subchronic toxicity values are selected according to the hierarchy presented in ADEC cleanup level guidance.
8. Select Individual ChemicalsSelect one or more contaminants for CL calculation. Select a contaminant by highlighting it in the left box and click the ">>" button to move it to the box on the right. Contaminants in the box on the right will be used for CL calculation. Highlight multiple contaminants at once by using the "Shift" key. Remove a contaminant from the right box by highlighting it and clicking the "<<" button. You may choose all contaminants by checking the "ALL" box. Chemicals can also be added via their CAS number. Below the pick list is an option to add extra chemicals. The calculator run time will correspond with the number of contaminants selected.
9. Click RetrieveClick the "Retrieve" button at the bottom of the page. If "Default" CLs are being calculated go to step 9. If "Site Specific" CLs are being calculated go to step 8.
10. Site-specific ParametersIf risk output was selected, enter media concentrations. Enter site-specific toxicity values and chemical-specific parameters for the extra chemicals added. Adjust exposure parameters for all chemicals. Click the "Retrieve" button at the bottom of the page.
If you have consulted with the community around a contaminated site and agreed to exposure scenarios or exposure assumptions which differ from the default values initially identified on the CL website, you can change those in the calculator. If changing any of these inputs it is important to review which media (e.g. soil or groundwater) you want to change. Note that changing toxicity values or risk levels for one media, does not automatically change the other media. If you are working on an actual or potential contaminated site, we recommend discussing the use of non-default inputs with a toxicologist or risk assessor at ADEC. If you are using CLs on a contaminated site, consider placing a hard copy in the Administrative Record for your site decision.
11. View ResultsReview your results. In order to save a copy of your input parameters and CL results choose from the following options:
- Click "Output to PDF" to save in PDF (.pdf) format
- Select "Print" from the File Menu or press CTRL+P to print from your browser.