In this chapter:
(1) “Commission” means the Texas Commission on Environmental Quality.
(2) “Department” means the Department of State Health Services.
(3) “Federal superfund site” means a site defined by the federal Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (42 U.S.C. § 9601 et seq.), as amended.
(4) “Immediately surrounding area” means an area determined by the commission to have been significantly exposed to one or more pollutants from the identified site.
(5) “Institute” means the Texas Environmental Health Institute.