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                                   Supreme Court                               Date: 2019.12.10
                                                                               10:29:27 -06'00'



                 County of Will v. Pollution Control Board, 2019 IL 122798




Caption in Supreme      THE COUNTY OF WILL et al., Appellants, v. THE POLLUTION
Court:                  CONTROL BOARD, Appellee.



Docket Nos.             122798, 122813 cons.



Filed                   June 20, 2019



Decision Under          Appeal from the Appellate Court for the Third District; heard in that
Review                  court on review of order of Pollution Control Board.



Judgment                Appellate court judgment affirmed.
                        Board decision affirmed.


Counsel on              James W. Glasgow, State’s Attorney, of Joliet (Marie Quinlivan
Appeal                  Czech, Assistant State’s Attorney, of counsel), for appellants County
                        of Will and Will County Land Use Department.

                        Kwame Raoul, Attorney General, of Springfield (David L. Franklin,
                        Solicitor General, and Carl J. Elitz, Assistant Attorney General, of
                        Chicago, of counsel), for the People.

                        Marie E. Tipsord and J. Mark Powell, Special Assistant Attorneys
                        General, of Chicago, for appellee Illinois Pollution Control Board.
                              Howard A. Learner and Andrene E. Dabaghi, of Chicago, for amici
                              curiae Environmental Law & Policy Center et al.

                              Claire A. Manning and Daniel L. Hamilton, of Brown, Hay &
                              Stephens, LLP, of Springfield, for amicus curiae Illinois Clean
                              Construction and Demolition Debris (CCDD) Coalition.



     Justices                 JUSTICE THEIS delivered the judgment of the court, with opinion.
                              Chief Justice Karmeier and Justices Thomas, Garman, and Neville
                              concurred in the judgment and opinion.
                              Justice Kilbride dissented, with opinion.
                              Justice Burke took no part in the decision.



                                              OPINION

¶1        In 2010, the Illinois General Assembly directed the Pollution Control Board (Board) to
      adopt “rules for the use of clean construction or demolition debris [(CCDD)] and
      uncontaminated soil [(US)] as fill material at clean construction or demolition debris fill
      operations.” Pub. Act 96-1416 (eff. July 30, 2010). The legislature added that the rules must
      include “standards and procedures necessary to protect groundwater” and provided an
      inexhaustive list of 12 ways to do so that the Board may consider. Id. One of those ways was
      groundwater monitoring. Id. The rules ultimately promulgated by the Board required stronger
      “front-end” testing and certification requirements for CCDD and US but not a “back-end”
      groundwater monitoring requirement.
¶2        The sole issue in this appeal is whether the Board’s decision was arbitrary and capricious.
      The appellate court concluded that it was not and affirmed the Board’s decision. 2017 IL App
      (3d) 150637-U. For the reasons that follow, we affirm the appellate court’s judgment.

¶3                                         BACKGROUND
¶4        Construction and demolition projects produce materials that must be removed and
      discarded. In 1997, the General Assembly amended Illinois’s Environmental Protection Act
      (Act) (415 ILCS 5/1 et seq.) to distinguish between general materials and clean materials. See
      Pub. Act 90-475 (eff. Aug. 17, 1997). The amendment defined general materials or “general
      construction or demolition debris” (GCDD) as
              “non-hazardous, uncontaminated materials resulting from the construction,
              remodeling, repair, and demolition of utilities, structures, and roads, limited to the
              following: bricks, concrete, and other masonry materials; soil; rock; wood, including
              non-hazardous painted, treated, and coated wood and wood products; wall coverings;
              plaster; drywall; plumbing fixtures; non-asbestos insulation; roofing shingles and other
              roof coverings; reclaimed asphalt pavement; glass; plastics that are not sealed in a

                                                 -2-
              manner that conceals waste; electrical wiring and components containing no hazardous
              substances; and piping or metals incidental to any of those materials.” 415 ILCS 5/3.78
              (West 1998) (now codified at 415 ILCS 5/3.160(a) (West 2016)).
¶5        The amendment defined clean materials, or “clean construction or demolition debris”
     (CCDD), much more simply as “uncontaminated broken concrete without protruding metal
     bars, bricks, rock, stone, reclaimed asphalt pavement or soil generated from construction or
     demolition activities.” 415 ILCS 5/3.78a (West 1998) (now codified at 415 ILCS 5/3.160(b)
     (West 2016)). Under the Act, CCDD is not considered waste, to the extent allowed by federal
     law,
              “if it is *** used as fill material outside of a setback zone[, and] if the fill is placed no
              higher than the highest point of elevation existing prior to the filling immediately
              adjacent to the fill area, and if covered by sufficient uncontaminated soil to support
              vegetation within 30 days of the completion of filling or if covered by a road or
              structure, and, if used as fill material in a current or former quarry, mine, or other
              excavation, is used in accordance with the requirements of Section 22.51 of this Act
              and the rules adopted thereunder.” 415 ILCS 5/3.160(b)(i) (West 2016).
     Accordingly, sites that accept CCDD did not have to comply with costly regulatory
     requirements applicable to landfills that accept GCDD.
¶6        The following year, the General Assembly recognized that there were effectively no rules
     to prevent CCDD fill site operators from accepting GCDD and commingling general and clean
     materials. The legislature consequently amended the Act to prohibit the generation,
     transportation, or recycling of CCDD without documentation of its weight or volume, its
     origin, its hauler, and its destination. 415 ILCS 5/21(w) (West 2000). The legislature did not
     require operators to screen loads coming into their sites.
¶7        In 2005, the General Assembly closed that gap. The legislature amended the Act to require
     CCDD fill site operators to obtain permits from Illinois’s Environmental Protection Agency
     (Agency). 415 ILCS 5/22.51(b) (West 2006). That amendment also instructed the Agency to
     propose and the Board to adopt regulations for the use of CCDD as fill material in current and
     former quarries, mines, and other excavations. Id. § 22.51(c). The legislature wanted those
     regulations to include “standards for [CCDD] fill operations and the submission and review of
     permits.” Id. The Board soon promulgated such regulations as part 1100 of title 35 of the
     Illinois Administrative Code. See 35 Ill. Adm. Code 1100 (2012). Under part 1100, operators
     were required to screen loads and reject material that did not meet the statutory definition of
     CCDD.
¶8        In 2010, the General Assembly revisited the subject of CCDD. The legislature amended
     the Act to define uncontaminated soil (US) as soil from construction projects that does not
     contain contaminants harmful to human health or the environment. 415 ILCS 5/3.160(c)(1)
     (West 2010). Like CCDD, US is not considered “waste” to the extent allowed under federal
     law and regulations. Id. The amendment required fill site operators to obtain either a
     certification from the generator that the soil was “never *** used for commercial or industrial
     purposes and is presumed to be uncontaminated” or a certification from a licensed engineer
     that the soil is uncontaminated. Id. § 22.51(f)(2)(B). The amendment also required operators
     to confirm that the CCDD or US was not removed from a site “as part of a cleanup or removal
     of contaminants.” Id. § 22.51(f)(2)(C).


                                                   -3-
¶9        Additionally, the legislature for the first time voiced a concern about protecting
       groundwater and added sections 22.51(f)(1) and 22.51a(d)(1) to the Act. Section 22.51(f)(1)
       provided:
              “[T]he [Agency] shall propose to the [Board], and *** the Board shall adopt, rules for
              the use of [CCDD] and [US] as fill material at [CCDD] fill operations. The rules must
              include standards and procedures necessary to protect groundwater, which may
              include, but shall not be limited to, the following: requirements regarding testing and
              certification of soil used as fill material, surface water runoff, liners or other protective
              barriers, monitoring (including, but not limited to, groundwater monitoring), corrective
              action, recordkeeping, reporting, closure and post-closure care, financial assurance,
              post-closure land use controls, location standards, and the modification of existing
              permits to conform to the requirements of this Act and Board rules. The rules may also
              include limits on the use of recyclable concrete and asphalt as fill material at [CCDD]
              fill operations, taking into account factors such as technical feasibility, economic
              reasonableness, and the availability of markets for such materials.” Id. § 22.51(f)(1).
       Section 22.51a(d)(1) provided:
              “[T]he Agency shall propose to the Board, and *** the Board shall adopt, rules for the
              use of [US] as fill material at [US] fill operations. The rules must include standards and
              procedures necessary to protect groundwater, which shall include, but shall not be
              limited to, testing and certification of soil used as fill material and requirements for
              recordkeeping.” Id. § 22.51a(d)(1).

¶ 10                                       The Agency’s Proposal
¶ 11        The Agency went to work. In February 2011, the Agency published an overview of draft
       regulations and solicited input on them from “a diverse set of stakeholder groups.” According
       to the Agency, it received 88 pages of comments from 24 stakeholder groups in the public and
       private sector. On April 29, 2011, the Agency published an overview of revised draft
       regulations and requested further feedback from stakeholders. Three months later, on July 29,
       2011, the Agency filed its proposed regulations with the Board. The proposal contained eight
       subparts, labeled A through G. Subpart A contained general provisions, including revised and
       new definitions for terms used in part 1100. Subpart B concerned standards for CCDD at fill
       operations. Subpart C concerned permit application information for CCDD fill operations.
       Subpart D concerned procedural requirements for permitting CCDD fill operations. Subpart E
       concerned US fill operations. Subpart F concerned standards for US at fill operations. And
       subpart G concerned groundwater monitoring.
¶ 12        Subpart G required owners and operators of permitted CCDD and US fill sites to install
       groundwater monitoring systems—essentially, wells—and to collect water samples annually.
       Those samples could not exceed the groundwater quality standards listed in part 1100. See 35
       Ill. Adm. Code 620.410 (2012). In the event of an exceedance, an owner or operator would be
       required to notify the Agency, to prepare a remediation plan, and to implement and continue
       that plan until the fill site had no violations for three years. Subpart G applied for the “active
       life” of a fill site but exempted shuttered sites and sites undergoing “dewatering,” a process for
       removing excess water.



                                                    -4-
¶ 13        In its “STATEMENT OF REASONS” supporting its proposal, the Agency stated that its
       outreach efforts resolved significant concerns raised by interested parties. However, the
       Agency further stated that disagreements with its proposal remained. One area of disagreement
       was groundwater monitoring. On that subject, the Agency noted,
                    “Several parties oppose the groundwater monitoring requirements of proposed
                Subpart G of Part 1100. In their comments to [the Agency] they assert that the load
                checking requirements of Subpart B *** are sufficiently protective of groundwater and
                that the [Agency’s] proposed groundwater monitoring program will force many fill
                operations to shut down due to the high cost of installing and sampling monitoring
                wells.”
¶ 14        The Agency acknowledged that its proposal would increase costs for fill site operators but
       asserted that “the extent of the cost increase is unknown and may vary significantly between
       fill operations.” The Agency insisted that it tried to mitigate those costs and felt they were
       outweighed by the benefits of groundwater monitoring. Because the Agency “cannot be sure
       that the front-end screening process will keep 100% of contamination out of the fill operations,
       the groundwater monitoring requirement is necessary to detect any contamination of
       groundwater and provide timely corrective action and remediation.” Additionally, the Agency
       believed that “a groundwater monitoring program is important at fill operations because the
       facilities are not required to have a protective liner to control contaminant migration and
       because they are consolidating a large volume of offsite materials into one area with that
       material often placed directly into the groundwater flow.”

¶ 15                             The Board’s Base Docket Proceedings
¶ 16       The Board docketed the proposed regulations and held two hearings on them in late 2011.
       At the first hearing, the Agency presented testimony in support of its proposed regulations
       from Stephen Nightengale, manager of the Agency’s bureau of land permit section; Paul
       Purseglove, manager of the Agency’s bureau of land field operations section; Douglas Clay,
       manager of the Agency’s division of land pollution control; and Leslie Morrow, an Agency
       environmental toxicologist. At the second hearing, the Agency presented additional testimony
       from Nightengale and Thomas Hornshaw, manager of the Agency’s toxicity assessment unit.
       Eleven other public and private sector witnesses testified. The Board also received 20 written
       comments from various individuals, business entities, advocacy groups, and public bodies,
       including the Agency and the State of Illinois, as well as an official at the resource recovery
       division of the Will County Land Use Department.

¶ 17                                     The Board’s First Order
¶ 18      On February 2, 2012, the Board issued a 116-page, first-notice opinion and order. The
       Board stated that it had reviewed the record and then summarized the testimony and comments
       in meticulous detail. Regarding subpart G and the proposed groundwater monitoring
       requirement, the Board noted a lack of unanimity on that issue. The Board found:
              “[T]he record does not include evidence to demonstrate that CCDD or [US] sites are a
              source of groundwater contamination. Further, the record indicates requiring
              groundwater monitoring would impose potentially sizeable costs that may have adverse
              impacts on the fill operation. CCDD and uncontaminated soils are not classified as

                                                  -5-
               wastes, so do not require the stringent rules that exist for nonhazardous waste landfills.
               Therefore, *** the record does not support groundwater monitoring at this time.”
¶ 19       The Board was “disturbed” by the inconsistency between the Agency’s assertion that the
       costs of groundwater monitoring are unknown and its assurance that the fiscal impact of such
       a program would not be detrimental. Section 27 of the Act requires consideration of the
       economic reasonableness of any regulations. The Board concluded that groundwater
       monitoring is not economically reasonable because evidence indicated that monitoring is
       “costly and could potentially result in businesses closing.”
¶ 20       As detailed above, the Board noted that “the record does not include evidence to
       demonstrate that CCDD or [US] sites are a source of groundwater contamination,” and CCDD
       and US “are not classified as wastes, so do not require the stringent rules that exist for
       nonhazardous waste landfills.” The Board turned to the Act, which required the Board’s rules
       to include “standards and procedures necessary to protect groundwater.” According to the
       Board, the legislature listed 12 possible methods of doing so; one of those was groundwater
       monitoring. The Board surmised that “while groundwater protection is a legislative priority,
       this protection can be achieved without requiring groundwater monitoring.” The Board decided
       to strengthen “front-end” procedures, by requiring soil testing and certification by a licensed
       professional engineer or geologist whenever the source of CCDD or US is a “potentially
       impacted property” where the materials are more likely to be contaminated, but to delete
       subpart G of the Agency’s proposal.
¶ 21       During the first notice period, the Board held another hearing in early 2012. At that hearing,
       the Agency presented testimony from Clay and Richard Cobb, a licensed professional geologist
       and the Agency’s deputy manager of its bureau of water division of public water supplies.
       Thirteen other public and private sector witnesses testified. And the Board received written
       comments from 27 individuals, business entities, advocacy groups, and public bodies, again
       including the Agency, the State, and the Will County Land Use Department.

¶ 22                                      The Board’s Second Order
¶ 23        On June 7, 2012, the Board issued a 130-page, second-notice opinion and order. As it did
       in its first order, the Board stated that it had reviewed the record and then detailed the testimony
       and comments. The Board identified and discussed a number of issues that the participants
       raised, including groundwater monitoring. In that regard, the Board reiterated, “The Act does
       not require groundwater monitoring, but only that groundwater be protected.” The Board
       highlighted the options provided by the legislature for protecting groundwater and stated that
       its rules addressed several of those options—“testing and certification of soils to be deposited
       in CCDD and [US] fill operations, surface water control, recordkeeping and reporting, and
       closure and postclosure care.” The Board returned to the requirement of soil testing. If the
       source of materials is such a potentially impacted property, then “testing must be done” so
       materials do not exceed maximum allowable concentrations (MACs) of contaminants. The
       Board explained:
                 “If [materials] exceed the MACs[, they] are not ‘uncontaminated’ and cannot be used
                 as fill in a CCDD or [US] fill operation. Thus, the Board’s rules prohibit using
                 [materials] that are contaminated as fill material ***. As the rules do not allow for



                                                    -6-
               contaminated material to be placed in a fill operation, the Board is unconvinced that
               groundwater monitoring is required.”
¶ 24       The Board also engaged the State’s argument that CCDD and US are waste and should be
       regulated in the same manner as other materials that pose a risk to the public. The Board quoted
       section 3.160(b) of the Act, which states that, to the extent allowed by federal law, CCDD
       “shall not be considered ‘waste’ ” under certain circumstances. The Board rejected the State’s
       position:
                   “The Board is unconvinced by the [State’s] argument that CCDD and [US] as
               defined by Section 3.160(b) of the Act are always waste. Federal law has no rule or
               statute directly on point. The [State] would have the Board search federal law to find
               federal language that specifically provides that CCDD and [US] are not waste. The
               Board instead will rely on the plain language of the statute in which the Illinois General
               Assembly found that CCDD and [US] used as fill material are not a waste. The Board
               will not usurp the General Assembly without specific evidence that federal law will be
               circumvented.”
¶ 25       The Board noted that the record lacked any evidence that fill sites “operating within the
       law are currently contaminating wells or are likely to contaminate the wells.” Although the
       Agency and the State insisted that such evidence is not required before implementing
       groundwater monitoring, the Board believed that “something more is required in this case
       where the record merely reflects that groundwater contamination is possible if the rules are not
       followed.” The Board remained unconvinced because the evidence adduced at the second
       hearing had not “added sufficient information to change the Board’s position.” Several
       participants, including the Agency, provided conflicting information on the costs of
       groundwater monitoring. The Board reviewed that evidence and concluded, “in view of the
       Board’s decision that soil certification and testing sufficiently protects groundwater, the costs
       information does not alter the Board finding.” The Board ultimately refused to restore subpart
       G to its regulations.
¶ 26       The Board sent its proposed regulations to the legislature’s Joint Committee on
       Administrative Rules (JCAR). On August 22, 2012, JCAR certified that it had considered the
       Board’s order and did not object to the Board’s regulations. JCAR offered 25 stylistic changes
       to the regulations and, more importantly, recommended that the Board revisit the issue of
       groundwater testing. According to JCAR, “[t]his would give the Board the opportunity to
       receive further comment from parties who may not have submitted their supportive views when
       groundwater monitoring was an element of this proposal and who may have opinions and
       information to offer in light of the Board’s decision to remove that requirement before going
       to 1st Notice on this rulemaking.” The next day, the Board adopted the regulations with the
       nonsubstantive changes suggested by JCAR and opened subdocket B “to continue to examine
       the issue of groundwater monitoring at CCDD or [US] fill operation[s].”

¶ 27                               The Board’s Subdocket Proceedings
¶ 28       The Board solicited public comments regarding groundwater monitoring. Eighteen public
       and private sector entities and individuals responded, including the Agency, the State, Will
       County State’s Attorney James Glasgow, two state senators, and four state representatives, all
       of whom requested that the Board include groundwater monitoring in its final decision. The


                                                   -7-
       Agency agreed with the Board’s conclusion that the Act did not specifically require
       groundwater monitoring but emphasized that such monitoring is “the single most important
       measure for achieving groundwater protection.” According to the Agency, certification and
       screening procedures were of limited effectiveness; “they could provide a basic level of
       protection but could not be relied upon to provide a consistently high level of protection by all
       soil generators at all fill operations for all potential contaminants and all soil accepted at fill
       operations over an indefinitely long period of time.” The Agency added that “groundwater
       monitoring was an important ‘back-end’ control that would serve as an early warning of any
       groundwater contamination that might result from the quantities of soil deposited in unlined
       quarries, mines or other excavations.”
¶ 29       After reviewing those comments, the Board held another hearing, where individuals and
       representatives of some entities that filed comments testified. At the close of the hearing, the
       Board’s hearing officer set forth a series of questions raised by the testimony and opened an
       additional comment period. Fill industry groups and public bodies—namely, the Agency, the
       State, and Will County—answered those questions.

¶ 30                                      The Board’s Third Order
¶ 31       On August 6, 2015, the Board issued a 66-page order, stating that it “remains unconvinced
       that groundwater monitoring for permitted CCDD and [US] fill[ ] sites is required for the
       protection of groundwater.” In fact, the Board found that the subdocket proceedings provided
       additional support for its earlier decision to reject subpart G. The Board repeated its earlier
       finding that CCDD and US used as fill material in accordance with section 22.51 of the Act
       are not waste. The Board rejected the State’s argument that CCDD and US have characteristics
       similar to waste disposed in landfills so that those materials should be considered “inert waste.”
       The Board stated its position:
                    “The Board notes that the record indicates some confusion may still exist with
               regard to CCDD and [US] that is placed in permitted facilities regulated under Part
               1100 and material that are considered ‘waste.’ The Board notes that several
               commenters referred to CCDD and [US] as ‘waste’ in their comments. The Board
               disagrees with this reference. *** This distinction was made by the General Assembly
               in deciding to allow CCDD and [US] facilities to operate under the statute and the
               Board rules implementing the statute. Therefore, the Board cannot treat CCDD and
               [US], regulated under Part 1100, as waste.
                    In addition to this confusion in the record, the [State] reiterate[s] arguments that
               CCDD and [US] fill operations regulated under Part 1100 will include materials that
               have characteristics similar to waste disposed of in inert landfills ***. The Board
               remains unconvinced that CCDD and [US] regulated under Part 1100 should be
               regulated as if the materials are inert waste. As stated above CCDD and [US] regulated
               under Part 1100 are not waste, and the General Assembly made that clear. *** The
               General Assembly did not intend CCDD that is regulated under Section 22.51 to be
               treated as waste, even inert waste.”
¶ 32       The Board then addressed sites exempt from part 1100, so-called “borrow pits.” Borrow
       pits are sites associated with public road construction projects that use CCDD or US as fill in
       compliance with Illinois’s Department of Transportation (IDOT) regulations. IDOT


                                                    -8-
       determines whether CCDD and US are “clean” by using procedures that are similar to those in
       part 1100; those procedures do not include groundwater monitoring. The Board noted that
       CCDD and US fill sites have stricter requirements than borrow pits. The Board rejected
       arguments that those requirements would fail. The Board remained unconvinced that
       groundwater monitoring is required to protect groundwater and closed the subdocket. The State
       and Will County appealed from the Board’s decision. See Ill. S. Ct. R. 335 (eff. July 1, 2017);
       415 ILCS 5/29(a), 41(a) (West 2016).
¶ 33        A split panel of the appellate court confirmed the Board’s decision. 2017 IL App (3d)
       150637-U. The appellate court majority observed that the Board employs its expertise in
       promulgating regulations. Id. ¶ 52. Consequently, a reviewing court will invalidate such
       regulations only when an objecting party demonstrates that they are arbitrary, capricious, or
       unreasonable. Id. The appellate court majority addressed three arguments from the State and
       Will County.
¶ 34        The State and Will County first argued that the Board’s decision not to adopt subpart G
       and its groundwater monitoring requirement was arbitrary because the Board considered a
       factor that the legislature did not intend it to consider—namely, whether CCDD and US
       constitute “waste” under the Act. The appellate court majority rejected that argument. The
       majority referred to sections 22.51(f)(1) and 22.51a(d)(1) of the Act, which directed the Board
       to adopt rules that would protect groundwater at CCDD and US fill sites. Id. ¶ 60. Because the
       State equated subpart G to inert waste landfill regulations, the Board had to consider whether
       those materials should be treated as waste or inert waste. Id. ¶ 62. “Whether CCDD and [US]
       constitute ‘waste’ or ‘inert waste’ is relevant to determining what prospective regulations are
       necessary to protect groundwater ***.” Id. ¶ 61. The Board could not decide which rules are
       necessary without determining whether those materials are waste. Id.
¶ 35        The State and Will County next argued that the Board’s decision was arbitrary because the
       Board failed to consider important aspects of the problem targeted by the legislature—namely,
       the dangers posed by preregulation materials deposited at fill sites, fill site operators’ history
       of “scofflaw” behavior, and the cost of groundwater monitoring. The appellate court majority
       rejected that argument. According to the majority, “[t]he Board considered operators’ past
       practices; it simply did not attribute as much weight to this issue as the [State] and Will County
       would have liked.” Id. ¶ 66. The record further indicated that the Board thoroughly investigated
       site operators’ costs. Id. ¶ 68. The majority concluded:
                “Participants in these proceedings provided more than enough information for the
                Board to make its decision. The record indicates that the Board considered all
                significant issues presented by the evidence. The objecting parties’ disagreement with
                the Board’s final determination and the weight it assigned to certain evidence, does not
                compel this court to reweigh the evidence on review. We hold that the Board did not
                fail to consider any important aspect of protecting groundwater from CCDD and [US]
                at fill site operations.” Id. ¶ 69.
¶ 36        Finally, the State and Will County argued that the Board’s decision was arbitrary because
       it ran counter to the evidence. The State and Will County specifically pointed to sampling data
       that showed groundwater contamination at several fill sites. Id. ¶ 72. The majority again
       rejected their argument, concluding:



                                                   -9-
                   “We find that the Board’s decision was adequately supported by the record of
               proceedings. Participants presented substantial evidence and testimony during multiple
               dockets, hearings, and public comment periods. According to the Board, Subpart G’s
               proponents did not show that compliant CCDD and [US] materials pose a threat to
               groundwater that justifies implementing Subpart G. Even without considering Subpart
               G’s economic reasonableness, the thorough record sufficiently supported the Board’s
               determination. Therefore, we cannot find the Board’s determination to be arbitrary,
               capricious, or unreasonable.” Id. ¶ 77.
¶ 37       Justice Wright dissented, disagreeing with nearly every aspect of the Board’s decision to
       reject subpart G. She opined, “The Board’s conclusion, that front-end regulations are sufficient
       to provide prospective protection for groundwater, represents a result-driven theory that favors
       industry without a sound, evidentiary basis.” Id. ¶ 82 (Wright, J., dissenting). She concluded
       that that decision was not only arbitrary, capricious, and unreasonable but also contrary to the
       legislature’s directions in the 2011 amendment to the Act. Id.
¶ 38       The State and Will County filed petitions for leave to appeal. See Ill. S. Ct. R. 315(a) (eff.
       Nov. 1, 2017). This court granted those petitions and consolidated the cases for review.

¶ 39                                            ANALYSIS
¶ 40       Environmental protection is a cornerstone of the 1970 Illinois Constitution. Article XI,
       section 1, provides, “The public policy of the State and the duty of each person is to provide
       and maintain a healthful environment for the benefit of this and future generations.” Ill. Const.
       1970, art. XI, § 1. The General Assembly was given the authority to implement and enforce
       that policy (id.), which resulted in the passage of the Act (415 ILCS 5/1 et seq. (West 2016)).
       The Act established “a unified statewide program to restore, protect and enhance the quality
       of the environment in the State.” People v. NL Industries, 152 Ill. 2d 82, 90-91 (1992).
¶ 41       To carry out that program, the Act created the Board as an independent body of five
       “technically qualified members.” 415 ILCS 5/5(a) (West 2016). The Board is charged with
       determining and defining environmental protection standards through rules and regulations.
       Id. § 5(b); see also id. § 27(a) (“The Board may adopt substantive regulations as described in
       this Act.”). Sections 22.51(f)(1) and 22.51a(d)(1) instructed the Board to adopt rules regarding
       the use of CCDD and US as fill material that include “standards and procedures necessary to
       protect groundwater.” 415 ILCS 5/22.51(f)(1), 22.51a(d)(1) (West 2016). The Board did so
       but chose to omit the groundwater monitoring provisions proposed by the Agency in subpart
       G. The only question before us is whether that decision was arbitrary and capricious.
¶ 42       The Board has both quasi-judicial and quasi-legislative functions. Landfill, Inc. v. Pollution
       Control Board, 74 Ill. 2d 541, 554 (1978). When the Board conducts hearings on complaints
       charging putative violations of the Act, it acts in a quasi-judicial capacity. Id. When it
       promulgates regulations, it acts in a quasi-legislative capacity. Id. The Board’s regulations have
       the force and effect of laws, and they are presumptively valid. Celotex Corp. v. Pollution
       Control Board, 94 Ill. 2d 107, 126 (1983).
¶ 43       Judicial review of the Board’s decision to adopt certain regulations is necessarily limited.
       Granite City Division of National Steel Co. v. Illinois Pollution Control Board, 155 Ill. 2d 149,
       162 (1993). Because the Board is composed of technically qualified individuals, their expertise
       is essential in crafting regulations. Central Illinois Public Service Co. v. Pollution Control

                                                   - 10 -
       Board, 116 Ill. 2d 397, 412 (1987). “The Board, unlike this court, is well equipped to determine
       the degree of danger which a pollutant will cause, and then to balance the public threat against
       an alleged individual hardship ***.” Monsanto Co. v. Pollution Control Board, 67 Ill. 2d 276,
       290 (1977). We do not judge the wisdom of a decision by the Board, only whether it is arbitrary
       and capricious. Central Illinois Public Service, 116 Ill. 2d at 412. The party challenging the
       decision bears a heavy burden to establish that it was clearly arbitrary and capricious. Id.;
       People v. Pollution Control Board, 103 Ill. 2d 441, 448 (1984) (“any further review of the
       Board’s action must be based on whether it abused its statutory authority by acting arbitrarily
       or capriciously”); Illinois Coal Operators Ass’n v. Pollution Control Board, 59 Ill. 2d 305, 310
       (1974) (“administrative action taken under statutory authority will not be set aside unless it has
       been clearly arbitrary, unreasonable or capricious”).
¶ 44        The parties, however, stray from that familiar standard. Relying upon Greer v. Illinois
       Housing Development Authority, 122 Ill. 2d 462, 495-96 (1988), the parties assert that whether
       the Board’s decision was arbitrary and capricious is a threefold inquiry. In Greer, we stated:
                    “While it is probably not possible to enumerate all the kinds of acts or omissions
                which will constitute arbitrary and capricious conduct, the following guidelines apply.
                Agency action is arbitrary and capricious if the agency: (1) relies on factors which the
                legislature did not intend for the agency to consider; (2) entirely fails to consider an
                important aspect of the problem; or (3) offers an explanation for its decision which runs
                counter to the evidence before the agency, or which is so implausible that it could not
                be ascribed to a difference in view or the product of agency expertise.” Id. at 505-06.
¶ 45        The appellate court here, as well as in other cases (see, e.g., Environmental Protection
       Agency v. Pollution Control Board, 308 Ill. App. 3d 741, 751 (1999); Waste Management of
       Illinois, Inc. v. Pollution Control Board, 231 Ill. App. 3d 278, 284 (1992)), has applied Greer
       in reviewing decisions by the Board. While we have never done so, the parties exclusively
       discuss the Greer guidelines in their briefs. Thus, that approach provides a useful rubric in this
       case where the parties’ arguments would be otherwise difficult to cabin analytically.
       Accordingly, we will address each of the guidelines in turn.

¶ 46                       1. Did the Board Rely on Factors That the Legislature
                                   Did Not Intend the Board to Consider?
¶ 47        The State contends that the Board relied on an improper factor when it focused on “the
       status” of CCDD and US as “non-waste.” The Board has both the authority and the obligation
       to protect groundwater from not only waste but all pollution. The State points to the definition
       of “water pollution” under the Act, which refers to the discharge of “contaminants,” not the
       presence of waste. 415 ILCS 5/3.545 (West 2016); see also id. § 3.165 (defining “contaminant”
       broadly as “any solid, liquid, or gaseous matter, any odor, or any form of energy, from
       whatever source”). The State then points to title II of the Act, concerning water pollution.
       Section 11(b) provides, “It is the purpose of this Title to restore, maintain and enhance the
       purity of the waters of this State in order to protect health, welfare, property, and the quality
       of life, and to assure that no contaminants are discharged into the waters of the State ***.” Id.
       § 11(b). Section 2(b) of the Illinois Groundwater Protection Act further provides that “it is the
       policy of the State of Illinois to restore, protect, and enhance the groundwaters of the State, as
       a natural and public resource.” 415 ILCS 55/2(b) (West 2016).


                                                   - 11 -
¶ 48       According to the State, sections 22.51(f)(1) and 22.51a(d)(1) of the Act are in line with that
       policy. Those sections expressed a concern about the risks to groundwater from CCDD and
       US, and they “directed the Board to address potential contamination in whatever form that
       contamination might take.” Consequently, the State insists that the Board injected into its
       decision an irrelevant and inappropriate consideration by focusing on whether those materials
       are waste. Will County echoes the State’s argument and contends that, even with “clean” debris
       and soil, some contaminants will enter unlined fill sites.
¶ 49       We hold that the State and Will County failed to establish that the Board’s decision was
       arbitrary and capricious for relying upon an improper factor when it considered whether CCDD
       and US are waste. First, the State was the architect of the purported error of which it now
       complains. That is, the State repeatedly and forcefully injected into these administrative
       proceedings the issue of whether CCDD and US are, or should be, considered waste. In public
       comments submitted two months before the Board’s first order, the State pressed several “over-
       arching principles,” one of which was its belief that “various classes of materials, which pose
       the same or similar risks to public health, safety and the environment” should be regulated in
       a consistent manner. Accordingly, the State urged the Board to adopt regulations that are “at
       least as comprehensive and protective as the regulations previously adopted by the Board for
       the disposal of inert wastes.” The Board’s 116-page first order rejected the State’s argument in
       two sentences. The Board stated that “CCDD and [US] are by statutory definition clean and
       uncontaminated and not a waste.” The Board further stated that “CCDD and [US] are not
       classified as wastes, so do not require the stringent rules that exist for nonhazardous waste
       landfills.”
¶ 50       Again, in prefiled testimony submitted a month after the Board’s first order, the State
       repeated its view that “CCDD has always been and continues to be a waste,” unless it meets
       the exceptions provided in section 3.160(b) of the Act. “Moreover,” the State continued,
       “CCDD is at a minimum ‘inert waste.’ ” The Board’s 130-page, second order rejected the
       State’s argument over two pages. The Board reviewed the statutory definition of CCDD, which
       provides that that material shall not be considered waste to the extent allowed by federal law.
       Because “[f]ederal law has no rule or statute directly on point,” the Board relied instead upon
       “the plain language of the statute in which the Illinois General Assembly found that CCDD
       and [US] as used as fill material are not a waste.”
¶ 51       In responses to questions from the Board during the subdocket B proceedings, the State
       tried another approach. Rather than claiming that CCDD is waste, the State asserted that it is
       “not actually ‘clean,’ as CCDD by its very definition may lawfully contain carcinogenic
       compounds in the form of PNAs (i.e. reclaimed or other asphalt) without reference to any
       regulatory levels.” The Board’s 66-page final order rejected that argument over two pages.
       According to the Board, the General Assembly distinguished between GCDD, which is waste,
       and CCDD and US, which are not. The General Assembly clearly did not intend CCDD and
       US to be treated as waste, inert or not. The Board’s three orders reflect the fact that it was the
       State who raised the “waste” issue. The Board disposed of it succinctly in each order and did
       not misdirect its focus from sections 22.51(f)(1) and 22.51a(d)(1).
¶ 52       Second, and more importantly, the question of whether CCDD and US constitute waste is
       relevant to determining what regulations are necessary to protect groundwater. The first Greer
       guideline suggests that an administrative agency’s decision may be arbitrary and capricious if


                                                   - 12 -
       the agency relied upon an improper factor. That inquiry hinges on what the legislature intended
       the administrative agency to consider, so our analysis begins with the statutes at issue. In
       sections 22.51(f)(1) and 22.51a(d)(1), the legislature instructed the Board to adopt “rules for
       the use of CCDD and [US] as fill material” that include “standards and procedures necessary
       to protect groundwater.” Contrary to the State’s position, the legislative aim was not new
       regulations for protecting groundwater generally from all pollution but new regulations for
       protecting groundwater specifically from CCDD and US at fill sites. The definitions of those
       materials are an inherent part of the legislature’s directive, so they are a factor in the Board’s
       rulemaking.
¶ 53        The Board announced that its “first concern is that the CCDD and [US] to be deposited
       into quarries, mines, and other excavations be clean and uncontaminated as those terms are
       defined by the rules and the statute.” To address that concern, the Board repeatedly referred to
       the statutory definitions of CCDD and US, both of which mention that those materials are not
       waste. See 415 ILCS 5/3.160(b), (c)(1) (West 2016). The Board used the legislature’s own
       distinction between clean materials, which are not waste, and general materials, which are
       waste, in order to limit the scope of its regulations to the explicit instructions provided by the
       General Assembly. The Board believed that it could protect groundwater by ensuring, through
       enhanced “front-end” certification and screening requirements, that fill site operators abide by
       the statutory definitions of CCDD and US. The Board reasoned that if materials dumped at fill
       sites meet those definitions, they are not waste and need not be deposited in landfills, where
       stricter regulatory requirements apply. As the Board stated, “if the regulations provide
       assurances that the materials being deposited are indeed clean and uncontaminated and are
       adhered to, protection will be provided to public health and the environment, including
       groundwater.” We cannot say that the Board’s decision was arbitrary and capricious for
       reiterating that CCDD and US are not waste.

¶ 54                    2. Did the Board Fail to Consider an Important Aspect
                             of the Problem Targeted by the Legislature?
¶ 55       The State and Will County contend that the Board ignored two important aspects of the
       groundwater protection problem—the costs of groundwater monitoring and the hazards of
       older and noncompliant fill. We reject both contentions.

¶ 56                              A. The Costs of Groundwater Monitoring
¶ 57       The State acknowledges that the Board’s first order referred to the “potentially sizeable
       costs” for the fill industry if groundwater monitoring were required, but its final order did not
       mention costs. The State surmises that the Board abandoned its earlier statement because
       participants in the subdocket B proceedings generally agreed that any costs could be borne by
       generators of CCDD and US, who could be charged more on a per-unit basis by haulers or
       operators. Even industry representatives acknowledged that the costs of implementing
       groundwater monitoring were not onerous, while the costs of remediation were a much greater
       concern.
¶ 58       Will County also observes that the Board failed to address costs in its final order, despite
       divergent estimates from participants. Will County asserts that the Board’s solution to “the
       quandary about cost” was to avoid it. Will County labels the Board’s approach as “fear of an


                                                   - 13 -
       unknown cost,” which ran afoul of its statutory duty to consider the economic reasonableness
       of its decision. See id. § 27(a) (“In promulgating regulations under this Act, the Board shall
       take into account the *** economic reasonableness of measuring or reducing the particular
       type of pollution.”). Like the State, Will County observes that the fill industry’s biggest
       concern was the cost of possible remediation. Will County insists that that concern is
       premature. The only issue before the Board was whether to test groundwater, not how to
       apportion the cost of remediation.
¶ 59        We hold that the State and Will County failed to establish that the Board’s decision was
       arbitrary and capricious for failing to consider the costs of groundwater monitoring. The Board
       did not ignore the costs of groundwater monitoring. In its first order, the Board discussed costs
       at length. The Board summarized the concerns of some participants with “the high costs
       associated with groundwater monitoring and the consequences of requiring such expenditures,
       including the potential closure of CCDD and [US] fill operations.” According to those
       participants, those higher costs would adversely affect businesses, municipalities, and
       ultimately taxpayers. The Board was disturbed by the inconsistency of the Agency’s
       acknowledgement that the costs of groundwater monitoring are unknown and its view that the
       fiscal impact will not be detrimental. The Board declined to impose a “costly groundwater
       monitoring program to protect against a perceived problem that the record does not support.”
¶ 60        The Board also mentioned section 27(a) of the Act, which provides that the Board must
       consider the economic reasonableness of any regulations. The Board stated that it received
       “numerous public comments addressing the economics of [the Agency]’s proposal” and heard
       testimony on the costs of complying with that proposal from fill industry representatives, as
       well as representatives from state and local governments. According to the Board, “[t]he cost
       of groundwater monitoring and particularly of testing samples was one area of concern.” The
       Board concluded, “The evidence in this record demonstrates that groundwater monitoring is
       costly and could potentially result in businesses closing. Therefore, the Board finds that
       groundwater monitoring is not economically reasonable.”
¶ 61        In its second order, the Board stated that several participants provided “cost break downs
       for groundwater monitoring.” The Board further stated that it appreciated that information, but
       it did not alter the decision that “soil certification and testing sufficiently protects groundwater”
       and monitoring is not required. And in its final order, the Board provided a summary of the
       first two orders. The Board noted that “participants provided information on the cost of
       groundwater monitoring” and “the record indicated that requiring groundwater monitoring
       would impose potentially sizable costs that may have adverse impacts on fill operations.” The
       Board also summarized comments from the State and the Agency, which offered their views
       on the costs of groundwater monitoring. While the Board’s third order did not repeat every
       finding in its prior orders, it did state that the Board had reviewed the entire record and
       considered additional comments and testimony in the subdocket B proceedings.
¶ 62        The Board devoted considerable attention to the costs of groundwater monitoring and
       balanced those costs against other considerations—namely, the potential closure of some
       CCDD and US fill sites, which could have a negative economic impact on not only the fill
       industry but also the public. We cannot say that the Board’s decision was arbitrary and
       capricious for failing to consider the costs of groundwater monitoring.



                                                    - 14 -
¶ 63                           B. The Hazards of Older and Noncompliant Fill
¶ 64        The State contends that the Board did not give sufficient attention to the fact that materials
       placed at fill sites between 1997 and 2010 pose a current threat to groundwater. Even after the
       legislature distinguished between general and clean materials and allowed the latter to enter
       fill sites, adherence to the definition of CCDD was often lax. According to the State, the
       Board’s obligation to protect groundwater includes an obligation to do so even when the
       contamination is from older fill. The State adds that newer fill may not comply with
       regulations, either. The State mentions “many recent enforcement actions” against fill industry
       members, as well as “growing numbers of load rejections.” The State concludes that negligent
       and scofflaw generators and haulers continue to direct noncompliant CCDD and US into fill
       sites.
¶ 65        Further, the State asserts that the Board did not understand that its certification and
       screening requirements check for only certain contaminants and not other harmful compounds
       that are likely in CCDD and US. The State insists that the Board abrogated its mandate to
       protect groundwater by refusing to consider the dangers posed by older fill and even newer fill
       that may contain contaminants. Will County brings up the “Lynwood facility,” which operated
       from 1997 to 2003. At that site, the Agency tested groundwater and found exceedances for a
       variety of contaminants. Will County states that the site may be closed but fill deposited there
       continues to affect groundwater.
¶ 66        We hold that the State and Will County failed to establish that the Board’s decision was
       arbitrary and capricious for failing to consider the hazards of older and noncompliant fill. The
       second Greer guideline suggests that an administrative agency’s decision may be arbitrary and
       capricious if the agency failed to consider an important aspect of the problem targeted by the
       legislature. As we have discussed, the legislature sought to protect groundwater from CCDD
       and US at fill sites. That is, the legislature was concerned with materials that met the statutory
       definitions, not with older and noncompliant materials that may not have.
¶ 67        Thus, the Board properly focused on evidence from CCDD and US fill sites. The Board
       reviewed the extensive record in these administrative proceedings and found no evidence that
       a CCDD or US fill site operating within regulatory guidelines had caused groundwater
       contamination. In its first order, the Board noted “the lack of documented evidence of CCDD
       or [US] fill operations being a source of groundwater contamination.” The Board added that
       “the record does not include evidence to demonstrate that CCDD or [US] sites are a source of
       groundwater contamination.” Contamination from clean materials was a “perceived problem”
       for the Board, not a real one. In its second order, the Board noted that the State and the Agency
       argued evidence of groundwater contamination is not required. The Board disagreed, stating
       that “something more is required in this case where the record merely reflects that groundwater
       contamination is possible if the rules are not followed.” The Board recognized that mistakes
       are possible and some operators may ignore the law, but “the rules do provide checks at the fill
       sites to alleviate the potential” for mistakes. And in its final order, the Board stated that, despite
       evidence of enforcement actions and evidence regarding unregulated sites, “the record still
       does not provide indications of groundwater contamination at sites that are permitted under
       Part 1100.”
¶ 68        Moreover, subpart G exempted shuttered fill sites, so even the Agency’s proposal would
       not have protected groundwater from historical contamination at sites like Lynwood. And, as


                                                    - 15 -
       the Board notes, testing at the Lynwood site, which is closed, may have shown contamination,
       but testing at another site called Reliable Lyons, which is still operational, did not. Again, we
       cannot say that the Board’s decision was arbitrary and capricious for failing to consider the
       hazards of older and noncompliant fill.

¶ 69                     3. Did the Board Offer an Explanation for Its Decision That
                                Was Counter to the Evidence or Implausible?
¶ 70       The State contends that the Board’s decision not to adopt subpart G and its groundwater
       monitoring requirement runs counter to “nearly all of the evidence presented.” The State refers
       to evidence from the Agency that there were exceedances in contaminants at 10 of the 12 fill
       sites where it tested soil in 2012 and to evidence from a fill industry representative whose tests
       at 4 fill sites showed contaminants. Additionally, the State mentions the Lynwood site, which
       operated before the Board adopted the part 1100 rules, where exceedances were also
       discovered. The State called the Board’s comparison of CCDD and US fill sites with borrow
       pits inapt because borrow pits are small and fill sites can be “enormous.” The State concludes
       with the Agency’s comment that groundwater monitoring is “the single most important
       measure for achieving groundwater protection.”
¶ 71       Will County tracks most of the State’s argument, adding that groundwater is at risk because
       CCDD and US fill deep unlined pits, which lie close to the water table. Will County adds that
       there is evidence that groundwater in Illinois is being degraded. Agency studies show that 33%
       of community wells have been negatively impacted by volatile organic compounds.
¶ 72       We hold that the State and Will County failed to establish that the Board’s decision was
       arbitrary and capricious for offering an explanation for its decision that was counter to the
       evidence or implausible. When acting in its quasi-legislative capacity, the Board has no burden
       to support its conclusions with a given quantum of evidence. Granite City, 155 Ill. 2d at 180.
       The base docket and subdocket proceedings here generated an extensive record. The Board’s
       orders were built on and supported by that record. In each of its three orders, the Board
       summarized the evidence and explained why it did not support groundwater monitoring. The
       Board considered the results of Agency soil testing as well as groundwater testing at the
       Lynwood site. According to the Board, an Agency witness testified in the subdocket B
       proceedings that the Lynwood site, which closed before the adoption of the part 1100
       regulations, accepted both general and clean materials. See People ex rel. Madigan v. J.T.
       Einoder, Inc., 2015 IL 117193, ¶ 7 (“Sometime in 1995, the [Lynwood] site began accepting
       [GCDD] and [CCDD].”). Further, in responses to questions from the Board during subdocket
       B proceedings, the State acknowledged that the only other sites where groundwater testing
       occurred, Reliable Lyons and “the Kane County” facility, did not exhibit exceedances of
       groundwater standards. The Board found the lack of evidence of contamination at operational
       CCDD and US sites persuasive, noting that, “[w]hile evidence of enforcement actions and
       evidence regarding sites not regulated under Part 1100 were offered, the record still does not
       provide indications of groundwater contamination at sites that are permitted under Part 1100.”
¶ 73       The State asserts that “it is not the Board’s prerogative to dismiss the need for rules
       protecting groundwater where the General Assembly has directed otherwise.” That argument
       is specious. At no point in this process did the Board dismiss the need for groundwater
       protection rules. At every point in this process, the Board returned to the language of the Act.


                                                   - 16 -
       The legislature directed the Board to adopt rules to protect groundwater from CCDD and US,
       providing an inexhaustive list of 12 ways to do so that the Board may consider, only one of
       which was monitoring. The Board exercised its rulemaking authority in three lengthy and well-
       supported orders in which it concluded that “back-end” groundwater monitoring was
       unnecessary because “front-end” certification and screening would keep contaminants out of
       CCDD and US fill sites and, thus, satisfy the legislature’s directions in sections 22.51(f)(1) and
       22.51a(d)(1). We cannot say that the Board’s decision was arbitrary and capricious for offering
       an explanation that was counter to the evidence or implausible.
¶ 74       In closing, we return to the language of our constitution. Under the 1970 Illinois
       Constitution, a foundational public policy in this state is providing and maintaining a healthy
       environment. Determining how best to do that is not the responsibility of this court, however,
       but of the General Assembly and the Board. If the legislature believes that the Board’s decision
       to drop the subpart G groundwater monitoring requirement runs counter to the mandate to
       protect groundwater, the legislature may direct the Board to adopt a groundwater monitoring
       program for CCDD and US fill sites. And any person, including the State and Will County,
       may present a written proposal regarding groundwater monitoring to the Board. See 415 ILCS
       5/28 (West 2016).

¶ 75                                      CONCLUSION
¶ 76      For the reasons that we have stated, the judgment of the appellate court affirming the
       decision of the Board is affirmed.

¶ 77      Appellate court judgment affirmed.
¶ 78      Board decision affirmed.

¶ 79        JUSTICE KILBRIDE, dissenting:
¶ 80        Despite the Agency’s strong and repeated entreaties, a majority of this court concludes that
       the Board’s exclusion of mandatory “back-end” groundwater monitoring in its CCDD and US
       fill site rules did not fail to consider any important aspect of the problem the legislature
       intended to target in sections 22.51(f)(1) and 22.51a(d)(1) of the Act (415 ILCS 5/22.51(f)(1),
       22.51a(d)(1) (West 2010)). I disagree. Sections 22.51 and 22.51a expressly require the Board
       to adopt “standards and procedures necessary to protect groundwater”—without any limitation
       on the timeframe of the potential groundwater harm. (Emphasis added.) 415 ILCS
       5/22.51(f)(1), 22.51a(d)(1) (West 2010). The Board’s final order does not comport with that
       statutory mandate. Both our legislature and our constitution have adopted a proactive approach
       to environmental protection. See Ill. Const. 1970, art. XI, § 1 (declaring the state’s policy is
       “to provide and maintain a healthful environment for the benefit of this and future
       generations”); 415 ILCS 55/2(b) (West 2010) (Illinois Groundwater Protection Act) (stating
       that preventing the “waste and degradation of the [groundwater] resources” is consistent with
       expressed state policy). In my view, the Board’s errors can be traced to its focus on the wrong
       question, considering whether there was evidence of groundwater contamination rather than
       how to protect groundwater from potential contamination.
¶ 81        The Board relies in part on a purported distinction between the risk to groundwater
       presented by “current” and “historic” fill. That reliance, however, is inconsistent with the

                                                   - 17 -
       language of the Act. In section 22.51(f)(1), our legislature expressly enumerated a series of
       options the Board could adopt to fulfill its obligation to craft “standards and procedures
       necessary to protect groundwater.” Among the action items listed was “corrective action.” 415
       ILCS 5/22.51(f)(1) (West 2010). Applying the plain and ordinary meaning of “corrective,”
       “corrective action” means conduct designed “to make or set right” or “to alter or adjust so as
       to bring to some standard or required condition.” Webster’s Collegiate Dictionary 260 (10th
       ed. 1997). Thus, any “corrective action” taken by the Board would necessarily modify a
       preexisting, or “historic,” condition needing remediation. Here, that condition is groundwater
       contamination due to the use of CCDD or US in unlined quarry sites.
¶ 82        Notwithstanding this obvious connection between “historic” fill and the need for
       “corrective action,” the Board insists its statutory mandate is limited to developing rules to
       protect against groundwater risks arising from only current CCDD and US. In making this
       claim, the Board relies, in its brief, on the statute’s reference to “the use of CCDD and [US] as
       fill material at CCDD operations and [US] operations.” (Emphases in original.) In defending
       this interpretation, the Board protests that “the People, Will County, and Amici attempt to
       shoehorn a comprehensive rule to protect groundwater from historical contamination into a
       rulemaking proposed to protect groundwater from potential contamination by the use of CCDD
       and [US].” The Board is effectively arguing that it has not been asked to “protect groundwater”
       from all contamination due to the use of CCDD and US even though the plain language of the
       statute requires its rules to address both ongoing and future groundwater harm from the use of
       CCDD and US. Reading the Board’s mandated duty under section 22.51(f)(1) as being to
       create “standards and procedures to protect groundwater” that include the adoption of
       “corrective action” when warranted, I reject the Board’s claim that the petitioners are somehow
       improperly “attempt[ing] to shoehorn” additional measures not authorized by law into the
       rules.
¶ 83        By enacting the plain language of section 22.51(f)(1), the legislature unambiguously
       expressed its intent to protect groundwater from all CCDD and US used in disposal
       operations—without any limitation on the relevant timeframe. Contrary to the Board’s
       assertion in this court, the legislature did not “provide[ ] the Board with a specific context for
       CCDD operations and [US] operations that included a requirement to protect groundwater on
       a prospective, not retrospective, basis.” Section 22.51(f)(1) simply does not draw a sharp
       distinction between the need to protect groundwater from current versus historic fill. The
       Board’s unduly narrow reading of its statutory duty to establish the “standards and procedures
       necessary to protect groundwater” is not supported by the statute.
¶ 84        On the other hand, the State and county’s understanding of the scope of the Board’s
       statutory directive is consistent with the language chosen by the legislature. It is a fundamental
       precept of statutory construction that courts must review statutes as a whole, bearing in mind
       the subject matter they address and the apparent intent of the legislature. Van Dyke v. White,
       2019 IL 121452, ¶ 46. Here, the rules adopted by the Board failed to comport with the broad
       directive legislatively conferred on it to protect this state’s groundwater resources.
¶ 85        Our state constitution also explicitly champions the Act’s environmental goals by declaring
       that a cornerstone of this state’s public policy is “to provide and maintain a healthful
       environment for the benefit of this and future generations.” (Emphasis added.) Ill. Const. 1970,
       art. XI, § 1. The Board’s actions “entirely fail[ ] to consider an important aspect of the


                                                   - 18 -
       problem” (Greer v. Illinois Housing Development Authority, 122 Ill. 2d 462, 495 (1988))
       constituting an unreasonable abuse of its statutory authority. See supra ¶¶ 43-44 (citing the
       reviewing standards in People v. Pollution Control Board, 103 Ill. 2d 441, 448 (1984), and
       Greer, 122 Ill. 2d at 495-96). Because the Board’s interpretation of the relevant statutory
       language fails to give effect to the statute as a whole, instead selectively disregarding a key
       portion of it, the Board has failed to act in accordance with both its statutory mandate and this
       state’s express public policy. For those reasons alone, I cannot agree with the conclusion that
       the Board properly exercised its statutory rulemaking authority in this case.
¶ 86       My dissent is further prompted by the Board’s insistence that it merely “declined to impose
       what the evidence showed were costly groundwater monitoring programs to protect against ‘a
       perceived problem’ that the record did not support as even being a problem.” The record refutes
       both the Board’s contention that groundwater harm presents only a “perceived problem”
       unsupported by the record and that monitoring programs are unduly costly.
¶ 87       The record in this case shows the problem being addressed in sections 22.51 and 22.51a is
       very real. The simple fact that the legislature directed the Board to adopt rules protecting
       groundwater from CCDD and US deposited into disposal sites shows it believed the risk of
       groundwater contamination, inadvertent or otherwise, was not just “a perceived problem” but
       a sufficiently serious actual “problem” to require specialized oversight.
¶ 88       As discussed below, even properly run sites in full compliance with existing regulations
       have been discovered to have levels of dangerous polynuclear aromatic hydrocarbons (PNAs)
       and metals above the maximum allowable concentrations (MACs) as well as a variety of other
       hazardous materials present at levels somewhat below the MACs. Thus, even purportedly
       compliant CCDD and US endanger this state’s groundwater resources and citizens’ health. As
       the Agency concludes, despite “even the best intentions and following the screening and soil
       acceptance procedures, soils with contamination above the MAC are being accepted at the
       operating sites.” The use of CCDD and US as fill in unlined quarry sites presents an actual
       problem that the legislature directed the Board to address in its rulemaking. The adequacy of
       the Board’s decision to require only front-end screening to satisfy that mandate, without any
       back-end groundwater monitoring, is the subject of this appeal.
¶ 89       The record is replete with evidence that front-end screening is imperfect at best,
       particularly since large volumes of fill are frequently at issue. Mandatory visual and odor
       inspections of that fill have long been in place, even though those approaches have obvious
       limitations. And those limitations necessarily increase with the size of the load being
       monitored. Along with visual screenings, the Board has required screening for dangerous
       volatile organic chemical compounds with photo ionization detectors (PIDs) since 2016, when
       it adopted the part 1100 CCDD regulations. The use of PIDs, however, is frustrated by a
       number of limitations similar to those impeding visual inspections of large waste streams.
       Indeed, PIDs suffer from a multitude of other accuracy and reliability issues as well when
       employed under many common conditions, such as exposure to electrical interference from
       power lines, transformers, and other electrical fields or even to routine weather phenomena,
       including high wind, humidity, and rain. PIDs are also designed to detect only some types of
       toxic chemicals and will not alert operators to the presence of many other hazardous chemicals
       that can create serious health risks or environmental damage.



                                                  - 19 -
¶ 90       As for the Board’s suggestion that it refused to adopt groundwater monitoring because it
       is too “costly,” that assertion is inconsistent with the evidentiary record. When addressing
       industries as lucrative as disposal operations, the acceptable costs must be viewed in light of
       the value and profitability of the relevant operations. After citing a Chicago Sun-Times article
       that reported a CCDD site in Will County had been sold for $17.7 million, Director Dean Olson
       of the Will County Land Use Department noted the sale price “indicates that a significant
       amount of profit is anticipated by the operator,” making it “difficult to understand ‘why a
       CCDD owner or operator cannot afford to install a groundwater monitoring system and sample
       groundwater.’ ” Naturally, the cost of groundwater monitoring must be considered in light of
       disposal operations’ high degree of profitability. Evaluating the cost of measures needed to
       fulfill the Board’s mandate to protect groundwater must consider all the relevant factors and
       circumstances, including the potential remediation costs if screening alone is not effective. The
       final order in this case, however, did not even mention the potentially enormous cost of
       groundwater remediation if monitoring is not required.
¶ 91       As for the actual costs at issue, the record reveals that the Board was presented with a range
       of possible monitoring costs and scenarios. The consensus of most industry testimony was that
       designing, installing, and maintaining monitoring wells, along with groundwater sampling and
       analysis, was economically feasible when viewed as only a slight increase in cost per cubic
       yard of fill deposited over the lifespan of each disposal site. The additional cost would
       constitute only a small increase in the tipping fees already being charged to disposers. While
       it was possible that some sites would close if faced with the up-front expense of monitoring
       wells, industry members also testified that remediation costs presented a far bigger concern—
       one that could easily put operators out of business. Although the impact of high remediation
       costs due to delays in discovering groundwater contamination undoubtedly represented a
       significant factor in evaluating the feasibility of back-end monitoring, the Board’s orders never
       discussed any potential remediation costs or the impact of those costs on the viability of
       industry entities—or on taxpayers who would have to foot that bill because the source of the
       contamination was later untraceable. Because the Board’s final order did not consider all of
       the relevant costs, it failed, again, to consider an important aspect of the problem, making it
       arbitrary and capricious under the Greer test.
¶ 92       Finally, the Board asserts its order fulfilled its statutory duty because it was not charged
       with adopting rules to protect groundwater from “noncompliant” CCDD and US. Instead, the
       Board asserts it chose to focus on “ensur[ing] that CCDD and [US] deposited in quarries met
       the definitions in Sections 22.51 and 22.51a of the Act.” That focus, however, presupposes an
       overly optimistic view of the effectiveness of front-end regulations alone, particularly given
       the historic realities of disposal site contamination and the potential for serious harm to the
       environment and to Will County residents. The actual state of the grounds surrounding current
       CCDD disposal sites does not engender that optimism.
¶ 93       Even though MAC limits had already been imposed on fill, the Agency’s 2012 test of soil
       samples from 12 CCDD sites revealed that 10 of those sites exceeded the MACs for metals
       and semivolatile organic compounds or applicable pH limits. In other words, the vast majority
       of sites already subject to regulation by the Board contained serious contamination problems.
       In addition, the record shows that, even after the enactment of the latest amendments to the
       Act, 13 enforcement actions have been brought for violations of the regulations governing
       CCDD facilities. That evidence proves that the prospect of industry noncompliance is far from

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       speculative. The Board also heard about an industry analysis of samples from 44 borings taken
       from around 3 CCDD fill sites. That study revealed levels of both PNAs and metals above the
       MACs, as well as concentrations of volatile chemicals, PCBs, and pesticides. That testimony
       is further evidence of the reality of underground contamination permeating CCDD sites,
       contamination that is likely to implicate groundwater quality since CCDD and US are
       deposited below ground level—often directly in the saturated zone, where groundwater flows.
¶ 94       While the Board argues that none of this soil testing has established groundwater
       contamination at any regulated CCDD or US site, that argument ignores two critical facts.
       First, no evidence of groundwater contamination is available precisely because the Board has
       never required back-end groundwater monitoring. Quite obviously, no testing necessarily
       equates to no evidence of contamination. Second, it defies logic to assert that, even with the
       prior adoption of preventative front-end regulations, dangerous, even carcinogenic, chemicals
       have already leached into the soil around unlined CCDD and US sites but that those chemicals
       have no implications for the groundwater underlying those sites.
¶ 95       The Board’s stated reliance on CCDD and US being inherently “clean” is also
       unpersuasive. For example, “clean construction or demolition debris,” by definition, includes
       “reclaimed or other asphalt pavement.” 35 Ill. Adm. Code 1100.103 (2012). Asphalt, in turn,
       routinely contains debris from vehicles, road salts, oils, and seal coating—materials that can
       endanger the quality of this state’s groundwater. Thus, even fill that meets the technical
       definition of “CCDD” can threaten the safety of our groundwater. Indeed, sound scientific
       evidence suggests that asphalt itself may pose a serious groundwater threat since it can contain
       PNAs that are known to cause cancer. Nonetheless, the Board’s second-notice order concluded
       that, “[a]s the rules do not allow for contaminated material to be placed in a fill operation, the
       Board [was] unconvinced that groundwater monitoring is required.” That statement ignores
       the nature of the “compliant” materials that may be deposited in CCDD and US fill sites
       throughout Illinois.
¶ 96       The Board’s rulemaking also permitted entities seeking to dispose of material in CCDD
       and US fill sites to self-certify that those waste streams presumptively comply with established
       standards because they come from properties that are not “potentially impacted” by hazardous
       materials—without any third-party confirmation. As evidenced in the record, however, self-
       certification is often ineffectual. Despite the existence of mandatory fill certification
       procedures, disposal sites submitted 417 load rejection sheets between September 2012 and
       June 2013, with 65% of the self-certified loads being rejected for high PID readings, indicating
       hazardous levels of toxic chemicals. In other words, through error, inadvertence, or perhaps
       intentional deception, each of those 417 purportedly “clean” fill loads violated the safety
       standards put in place by the Board even after being certified as being in compliance with those
       regulations by the very entities charged with verifying their safety.
¶ 97       Economic factors further undermine the adequacy of self-certification requirements.
       Disposal at CCDD and US fill sites provides enormous cost savings over disposal in landfills.
       In fact, disposal at CCDD and US fill sites costs about 75% less than dumping at landfills, a
       savings that greatly benefits disposers’ bottom lines. Along with those financial incentives, of
       course, come vastly increased pressures and temptation for cost-conscious disposers and site
       operators alike to overlook problems with incoming fill or to cut corners on measures intended
       to ensure the quality of material being deposited at CCDD and US fill sites. While in a perfect


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        world, front-end regulations would ensure that fill consisted of only “compliant” material
        meeting the statutory definitions of “clean” CCDD and US, in the real world, it is a virtual
        certainty that noncompliant material will, intentionally or not, make its way into unlined
        disposal sites. The Board’s belief that front-end-only regulations can adequately protect Will
        County’s groundwater resources and ensure compliance from both disposers of fill and CCDD
        and US site operators is, at best, naïve. The Board has effectively put on blinders to the realities
        presented in the record, ignoring evidence of industry noncompliance and unduly minimizing
        the risk presented by continuing noncompliance.
¶ 98         In the absence of any evidence of a foolproof means of detecting noncompliant materials
        before they contaminate the groundwater relied on by 71% of the residents of Will County, the
        Board’s final order both seriously undermines the safety goals underlying sections 22.51 and
        22.51a and defies the preventative approaches to protecting groundwater mandated in the
        Illinois Groundwater Protection Act (415 ILCS 55/2 (West 2010)). As the Agency notes,
        “without groundwater monitoring, there will be no mechanism to identify groundwater
        contamination at an early stage to take preventive action.” The United States Supreme Court
        has also recognized the critical need for early action. In United States v. Riverside Bayview
        Homes, Inc., 474 U.S. 121, 132-33 (1985), the Court declared that the “[p]rotection of aquatic
        ecosystems *** demanded broad federal authority to control pollution, for ‘[w]ater moves in
        hydrologic cycles and it is essential that discharge of pollutants be controlled at the source.’
        [Citation.]” Because the hydrologic cycle results in groundwater being transported
        unpredictably through seepage and flow paths in the earth, the destructive effects of
        groundwater contamination are pervasive (see Thomas C. Winter, Judson W. Harvy, O. Lehn
        Franke, & William M. Alley, Ground Water and Surface Water: A Single Resource, U.S.
        Geological      Survey      Circular      1139    (1998),     https://pubs.usgs.gov/circ/circ1139
        [https://perma.cc/M57X-TBTF]).
¶ 99         Here, the evidence shows that, acting alone, the Board’s front-end regulations cannot
        realistically provide effective control of pollution at the source before it infiltrates Will
        County’s groundwater. Although back-end monitoring would provide a vital early check on
        the efficacy of front-end screening procedures, it was rejected. Thus, the Board failed to fulfill
        its statutory mandate by not considering all aspects of the problem addressed in sections 22.51
        and 22.51a. While the majority suggests that the legislature could intervene and “direct the
        Board to adopt a groundwater monitoring program for CCDD and US fill sites,” the far
        superior, and legally required, solution is for the Board to fulfill its statutory duty. To do so, it
        must first comply with the broadly protective plain language of statutes such as sections 22.51
        and 22.51a. It must then apply those mandates with an eye toward solving the real-world
        problems evidenced in the record to achieve real-world results, consistent with Illinois’s
        express policy to protect its natural resources.
¶ 100        Because the Board misapprehended its statutory mandate and adopted a laissez-faire “wait-
        and-see” approach that required only front-end screening, with all its inherent limitations, in
        lieu of back-end groundwater monitoring, it ignored important aspects of sections 22.51 and
        22.51a. For those reasons, I respectfully dissent from the majority opinion.

¶ 101       JUSTICE BURKE took no part in the consideration or decision of this case.



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