Water-Related Document Number 484

To Members of IERG’s Water-Related Issues Workgroup:

On August 9, 2012, the Illinois Pollution Control Board advanced its rulemaking to amend the groundwater quality standards contained in 35 Ill. Admin. Code Part 620 to Second Notice.  Members likely recall that the rulemaking, initially proposed by the Illinois EPA in 2008, and as advanced by the Board to First Notice in October of 2011, would, among other things:

  • Add Class I (Potable Resource Groundwater) and Class II (General Resource Groundwater) groundwater quality standards for perchlorate and vanadium, as well as 29 additional organic chemical constituents;
  • Revise the existing Class I groundwater quality standard for arsenic from 0.05 mg/L to 0.010 mg/L based on the federal MCL;
  • Add a new category of chemical constituents (with corresponding Class I and Class II groundwater quality standards) called “explosive constituents;”
  • Add the eight explosive constituents for which the Class IV (Other Groundwater) groundwater quality standards within a previously mined area would be the existing concentrations of the constituents; and
  • Provide alternative groundwater quality standards for the eight explosive constituents after completion of reclamation at a coal mine.

The Board made no major changes from the First Notice version of the proposal.  Procedurally, the proposal will be transmitted to JCAR for its review and approval (a 45 day period under the Administrative Procedure Act) and can then be finalized by the Board.

Should Members have any questions or comments on this rulemaking, please contact IERG Staff at iergstaff@ierg.org or 217-522-5512.