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Groundwater Management Zones List

Groundwater Management Zones
As of January 1, 2026

**Illinois EPA ID No. Facility Name                Closest Municipality County

*Ill. Adm. Code 620.450(a)(5) List of concentrations of constituents above applicable GWQS per Section 620.450(a)(4)(B) [as of 1/1/26]:

  • Class II GWQS: 
    • tetrachloroethylene 1.1 mg/L
    • trichloroethylene 0.42 mg/L
    • dichloroethylene 0.57 mg/L
    • vinyl chloride 0.145 mg/L
**W indicates Bureau of Water Facilities. Bureau of Land Facilities are numerals only.