1. Select Scenario

Choose one of the 4 landuse scenarios and then select which precipitation zone to assess under the "Select Precipitation Zone" list that is displayed (except for "Groundwater").

2. Select Chemical Info Type

The "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 in step 7.

3. Select RfD/RfC Type

Select 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.

4. Select Individual Chemicals

Select 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.

5. Click Retrieve

Click the "Retrieve" button at the bottom of the page. Media concentrations will be entered on the next page.

6. Site-specific Parameters

Enter media concentrations and 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 Risk 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.

7. View Results

Review your results. In order to save a copy of your input parameters and risk 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.

Once this has been done, you will have a preliminary record of your calculations, including all of the inputs and cleanup levels. You now have a dated record of your site-specific risk results, including the inputs. Consider placing a hard copy in the Administrative Record for your site.