Background

The Michigan Department of Environmental Quality (DEQ) is required under Part 201, Environmental Remediation, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended (Act 451), to identify and track locations of environmental contamination in Michigan, and to rank these sites according to the risk each poses to human health and the environment. Since 1990, an environmental risk model, identified as the Site Assessment Model, has been used by the DEQ to score all Part 201 sites of environmental contamination, except for sites regulated under part 213, Leaking Underground Storage Tanks, of Act 451.  Scores can range from 0‑48, with 48 posing the greatest risk.

Purpose

The Site Assessment Model evaluates the existing and potential chemical substance exposure to determine a site score reflecting the hazard of the site relative to other sites in Michigan. It is a structured value assessment system based upon the perceived risk and value of the actual and potential affected resources.  There are six categories within the model, for which points are assigned to reflect the value of the perceived risks:

1.      Environmental Contamination:  This category is designed to reflect the threats and impacts contaminants may pose to various environmental media (soils, groundwater, surface water, and air) and human receptors.

2.      Mobility Rating:  This category is designed to reflect the variable risks associated with a contaminant's ability to migrate in the environment; and thereby, impact additional resources (e.g. soil to groundwater, groundwater to surface water).

3.      Sensitive Environmental Resource:  This category considers the potential risk contaminants in the environment may have on resources, particularly plants and animals which are especially sensitive due to their rarity or declining populations.

4.      Population:  The category takes into consideration the human population that has or may be exposed to hazardous substances from the site.

5.      Institutional Population:  This category considers the added risk posed to certain populations like children at schools or elderly at nursing homes which because of their age or health could be more susceptible to environmental health problems.

6.      Chemical Hazard:  This category is designed to reflect the relative risks associated with sites based on the types and quantities of hazardous substances which have been or may be released to the environment.

Site scores are used by the DEQ, along with other criteria, to help determine where limited state funding resources should be utilized.

For questions about the Site Assessment Model, please contact Soheil Ghavami at 517-373-9541.  Detailed information about the Site Assessment Model can be found in the link to the Part 201 rules.

You can find out how sites of environmental contamination rank in your area by searching the database.  If you have questions about specific sites, please contact the DEQ office serving the site.