Illinois Pollution Control Board Reconsiders Ruling on Groundwater Management Zones, Affirms Remainder of Order on Coal Ash Violations

This post updates the October 15, 2019, blog post regarding the citizen enforcement proceeding against Midwest Generation, LLC (“MWG”) launched by several environmental advocacy groups (“Environmental Groups”). (That post can be read here.)

On February 6, 2020, the Illinois Pollution Control Board (“Board”) issued an order in Sierra Club, et al. v. Midwest Generation, LLC (PCB13-15) (“Reconsideration Order”) reconsidering its June 20, 2019, interim opinion and order (“Interim Order”). As addressed in greater detail in the earlier post, MWG owns four coal-fired power plants in Illinois, each of which contains coal ash disposal ponds. After Illinois EPA (“IEPA”) issued MWG violation notices in 2012 under Section 31(a) of the Illinois Environmental Protection Act (“Act”) (415 ILCS 5/31(a)), MWG negotiated with IEPA and entered into Compliance Commitment Agreements (“CCAs”) to address the alleged violations at the four sites and forestall litigation. The CCAs for three of those sites incorporated a regulatory mechanism called a Groundwater Management Zone (“GMZ”)—a three-dimensional zone using monitored natural attenuation to mitigate impairment caused by the release of contaminants from a site subject to a corrective action process. These GMZs were created by Part 620 of the Board’s rules (35 Ill. Adm. Code Part 620, et seq.).

During this negotiated CCA effort with the Agency, several Environmental Groups filed suit, alleging MWG caused or contributed to groundwater contamination at the coal ash pond sites. The proceeding was bifurcated into liability and remedy portions, and the Board ultimately issued its Interim Order finding MWG liable for groundwater contamination from these four sites. In addition to finding these violations, the Board ruled that the GMZs had expired with the conclusion of active remedial work, even though the GMZ mechanism prescribes passively monitoring for natural attenuation of contaminants. On September 9, 2019, MWG sought reconsideration of both the Board’s finding of violations at the site and its GMZ ruling.

On October 14, 2019, a coalition of industry groups that rely on GMZs for their own compliance efforts intervened in support of MWG, including the Illinois Environmental Regulatory Group, the Chemical Industry Council of Illinois, the Illinois Coal Association, and the Illinois Chapter of the National Waste & Recycling Association (“the Associations”). The Associations sought leave to file an Amicus Brief supporting reconsideration on that date as well, with HeplerBroom LLC attorneys representing several of the parties in this amici coalition.

Amicus Brief in Support of MWG Allowed

The Environmental Groups vigorously contested the Associations’ right to file any such brief, and the parties engaged in motion practice around this issue. In its Reconsideration Order, the Board drew on Part 101.110(c) of its rules, stipulating that “[a]micus curiae briefs may be filed in any adjudicatory proceeding by any interested person, provided permission is granted by the Board.” The Board found that members of the Associations “regularly use GMZs in Illinois and depend upon a consistent interpretation of their duration,” and granted the Associations leave to file their brief. Although it granted the Environmental Groups’ motion to strike an exhibit attached to the Associations’ brief, the Board otherwise rejected efforts to strike portions of the amicus filing in support of MWG.

Groundwater Management Zones Did Not Expire with the End of Active Remediation

The Board then turned to the merits of MWG’s reconsideration motion. Regarding the GMZ issue, the Board quoted the following at Part 620.250 of its rules, establishing GMZs:

“a) Within any class of groundwater, a groundwater management zone may be established as a three dimensional region containing groundwater being managed to mitigate impairment caused by the release of contaminants from a site:

1)   That is subject to a corrective action process approved by the Agency or

2)   For which the owner or operator undertakes an adequate corrective action in a timely and appropriate manner and provides a written confirmation to the Agency. Such confirmation must be provided in a form as prescribed by the Agency.


  1. c) A groundwater management zone expires upon the Agency’s receipt of appropriate documentation which confirms the completion of the action taken pursuant to subsection (a) and which confirms the attainment of applicable standards as set forth in Subpart D….”

35 Ill. Adm. Code 620.250(a), (c) (emphasis added).

In their reconsideration briefs, MWG and the Associations argued that the Board’s Interim Order erroneously construed Part 620.250(c). They first argued that a GMZ continues until (1) the Agency receives appropriate documentation confirming completion of corrective action, and (2) the applicable groundwater quality standards have been attained, and that in the instant case, these requirements had not been met. Second, they argued that the timeliness requirement in Part 620.250(a)(2) cannot be read-into a GMZ negotiated with the Agency under Part 620.250(a)(1). In short, the Interim Order misconstrued these rules, effectively stripping GMZs of their value by finding that monitored natural attenuation was not an ongoing remedy.

The Board reversed its earlier GMZ ruling and broadly agreed with this reasoning. First, it held that “MWG is proceeding at the Stations under CCAs approved by the Agency,” i.e. as part of 620.250(a)(1). As part of the CCAs, MWG submits compliance statements to the Agency, but has not submitted “appropriate documentation which confirms the completion” of corrective action. Thus, the first condition of Part 620.250(c) has not been met. It then noted “[n]or has the second condition,” in that “MWG has not submitted documentation confirming that the applicable groundwater quality standards…have been attained.” The Board acknowledged that “the process of monitored natural attenuation can be, by its nature, a long one [and] can conceivably last for many years;” therefore, “[f]or a GMZ to expire two weeks after it had been established (as in Powerton) risks rendering them effectively meaningless.”

Remainder of Interim Order Affirmed, including Finding of Violations

With the exception of the GMZ ruling and these minor clarifications, the Board affirmed the remainder of its rulings in the Interim Order. It then directed “the parties and the hearing officer to proceed expeditiously to hearing on remedy.”

Although regulated industries across the state—particularly those that rely on GMZs in their corrective action efforts—can rest a little easier than they did at the issuance of the Interim Order, this proceeding certainly warrants careful attention as it moves into the remedy determination phase.

Search Blog




Kerri Forsythe

Jump to Page

This website uses cookies to analyze site usage and to store information about a visitors' session. These cookies allow us to distinguish you from other visitors of our website. We use these cookies purely for analytical purposes and for our own statistical research into the success of our website.

We Encourage You To View Our PRIVACY STATEMENT