ILLINOIS POLLUTION CONTROL BOARD
    November 7, 1991
    IN THE MATTER OF:
    )
    )
    GROUNDWATER QUALITY STANDARDS
    )
    R89-14(B)
    (35 ILL. ADM. CODE 620)
    )
    (Rulemaking)
    ADOPTED RULE.
    FINAL ORDER.
    OPINION AND ORDER OF THE BOARD (by R.C. Flemal):
    This matter comes before the Board pursuant to Section 8 of
    the Illinois Groundwater Protection Act (“IGPA”), Ill. Rev. Stat.
    1989, ch. 111½, pars. 7451 ~ ~g. Section 8 mandates inter alia
    that the Board promulgate “regulations establishing comprehensive
    water quality standards which are specifically for the protection
    of groundwater” (IGPA at Section 6(a)). The purpose of today’s
    action is make final adoption of these groundwater quality
    standards and the associated basic framework.
    PROCEDURAL HISTORY
    The Agency filed its original proposal on September 21,
    1989.
    On January 31, 1990 the Department of Energy and Natural
    Resources (“DENR”) filed the Economic Impact Statement (“EelS”),
    which pursuant to the IGPA was prepared concurrently with
    development of the Agency’s proposal.
    On March 26, 1990 an alternative proposal was filed by the
    McHenry County Defenders, Citizens for a Better Environment, and
    the Illinois Chapter of the Sierra Club (collectively as
    “Defenders”).
    On June 1, 1990 the Agency filed its second proposal within
    Public Comment (“PC”) #16.
    Hearings on the various proposals and the EcIS were held on
    December 12 and 13, 1989, and February 14, March 29, and May 7,
    1990k.
    1
    Transcripts of the December 1989 to May 1990 hearings, which
    are numbered consecutively, are herein cited in the form “Ri at
    I’
    The Board wishes to acknowledge the special contribution made
    by Michelle C. Dresdow, who has served as Hearing Officer
    throughout these proceedings.
    12 7—53
    —2—
    Based on the cumulative record then available, the Board on
    September 27, 1990 advanced its own proposed rule, which was
    published for First Notice on November 2, 19902. Hearings were
    held on this proposal on December 4 and 5, l990~.
    On February 19, 1991 the Agency filed its third amended
    proposal, which the Board on February 28, 1991 proposed for First
    Notice as Docket B4. Hearing was held on .the Docket B proposal
    on May 30, 1991g. At hearing the Agency offered further
    amendments to its proposal based on renewed discussions,
    conferences, and negotiation sessions with interested person~.
    The text of these amendments, which was entered as Exhibit T
    had been distributed to interested persons prior to the May 30,
    1991 hearing.
    On July 25, 1991 the Board proposed the Docket B
    regulations, with modifications, for Second Notice7. Given the
    magnitude of the changes, the Board withheld filing of the Second
    Notice proposal with the Joint Committee on Administrative Rules
    (“JCAR”) to allow for an additional comment period of 15 days.
    No comments filed during this periodpersuaded the Board to
    recede from its July 25 action, and the proposal was accordingly
    filed with JCAR.
    On October 22, 1991 JCAR issued a certificate of no
    objection to the proposed rules. Prior to the issuance of the
    certif.icate, JCAR staff alerted the Board to several non-
    substantive grammatical and typographical errors. In addition,
    The Board wishes to acknowledge the special contribution made
    by Michelle C. Dredow, who has served as Hearing Officer throughout
    these proceedings.
    2 14 Ill. Reg. 17822, November 2, 1990.
    ~ Transcripts of the December 1990 hearings are herein cited
    in the form “R2 at
    _____
    ‘~
    Publication occurred at 15 Ill. Reg. 4234, March 22, 1991.
    The transcript of the May 1991 hearing is herein cited in
    the form “R3 at
    _____“.
    6 The text of the proposed amendments entered as Exhibit T are
    often referred to in the transcript of the May 30, 1991 hearing as
    the “May 15. proposal”, based upon the date contained on that
    document.
    By the same Order the Board Closed Docket A and withdrew
    its provisions from further consideration, save fOr the amendment
    to 35 Ill. Adm. Code.Part 303 which was transferred to Docket B.
    12 7—54
    —3—
    JCAR staff recommended seven other changes involving sections
    620.110, 620.250(a) (2), 620.302(b) (1), 620.450(b) (3) (A) (ii),
    620.510(b) (1), 620.601(b) and 620.Appendix A(c) (1) (iii). These
    changes are discussed below in appropriate parts of this opinion
    and are incorporated into today’.s order.
    The Board is pleased with the high quality perspective that
    has been brought to bear on this matter, both in hearing
    testimony and public comments. The Board expresses its
    appreciation to the many persons who have contributed in on~form
    or another.
    STATUTORY FRAMEWORK
    The IGPA was enacted by the Illinois General Assembly as an
    outgrowth of long—standing concern by the General Assembly and
    the citizens of the State that the State’s rich and valued
    groundwater resources be protected. The IGPA is a multi—faceted
    policy and program statement designed to provide that protection
    and to assure the continued viability of the State’s groundwater
    resources. The policy statement of the IGPA is found at Section
    2(b) (Ill. Rev. Stat. 1989, ch. 111½, ¶7452(b)), and reads:
    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. The State
    recognizes the essential and pervasive role of
    groundwater in the social and economic well—being of
    the people of Illinois, and its vital importance to the
    general health, safety, and welfare. It is further
    recognized as consistent with this policy that the
    groundwater resources of the State be utilized for
    beneficial and legitimate purposes; that waste and
    degradation of the resources be prevented; and that the
    underground water resources be managed to allow for
    maximum benefit of the people of the State of Illinois.
    The particular mandate of the IGPA pertinent to today’s
    action occurs at Section 8 (Ill. Rev. Stat. 1989, ch. 111½,
    ¶7458). Section 8 reads:
    a. The Agency, after consultation with the Committee
    and the Council, shall propose regulations
    establishing comprehensive water quality standards
    which are specifically for the protection of
    groundwater. In preparing such regulations, the
    Agency shall address, to the extent feasible,
    those contaminants which have been found in the
    groundwaters of the State and which are known to
    cause, or suspected of causing, cancer, birth
    defects, or any other adverse effect on human
    health according to nationally accepted
    127—55
    —4—
    guidelines. Such regulations shall be submitted
    to the Board by July 1, 1989.
    b. Within 2 years after the date upon which the
    Agency files the proposed regulations, the Board
    shall promulgate the water quality standards for
    groundwater. In promulgating these regulations,
    the Board shall, in addition to the factors set
    forth in Title VII of the Environmental Protection
    Act, consider the following:
    1. recognition that groundwaters differ in many
    important respects from surface waters,
    including water quality, rate of movement,
    direction of flow, accessibility,
    susceptibility to pollution, and use;
    2. classification of groundwaters on an
    appropriate basis, such as their utility as a
    resource or susceptibility to contamination;
    3. preference for numerical water quality
    standards, where possible, over narrative
    standards, especially where specific
    contaminants have been commonly detected in
    groundwaters or where federal drinking water
    levels or advisories are available;
    4. application of nondegradation provisions for
    appropriate groundwaters, including
    notification limitations to trigger
    preventive response activities;
    5. relevant experiences from other states where
    groundwater protection programs have been
    implemented; and
    6. existing methods of detecting and quantifying
    contaminants with reasonable analytical
    certainty.
    c. To provide a process to expedite promulgation of
    groundwater quality standards, the provisions of
    this Section shall be exempt from the requirements
    of subsection (b) of Section 27 of the
    “Environmental Protection Act”, approved June 29,
    1970, as amended; and shall be exempt from the
    provisions of Sections 4 and 5 of “An Act in
    relation to natural resources, research, data
    collection and environmental studies”, approved
    July 1, 1978, as amended.
    127—56
    —5—
    d. The Department of Energy and Natural Resources,
    with the cooperation of the Committee and the
    Agency, shall conduct a study of the economic
    impact of the regulations developed pursuant to
    this Section. The study shall include, but need
    not be limited to, consideration of the criteria
    established in subsection (a) of Section 4 of “An
    Act in relation to natural resources, research,
    data collection and environmental studies”,
    approved July 1, 1978, as amended. This study
    shall be conducted concurrently with the
    development of the regulations developed pursuant
    to this Section. Work on this study shall
    commence as soon as is administratively
    practicable after the Agency begins development of
    the regulations. The study shall be submitted to
    the Board no later than 60 days after the proposed
    regulations are filed with the Board.
    The Department shall consult with the Economic
    Technical Advisory Committee during the
    development of the regulations and the economic
    impact study required in this Section and shall
    consider the comments of the Committee in the
    study.
    e. The Board may combine public hearings on the
    economic impact study conducted by the Department
    with any hearings required under Board rules.
    In the following sections of this Opinion the Board
    discusses the various provisions that comprise today’s adopted
    rules.
    PART 303
    CONFORMING AMENDMENT
    Although the principal regulations adopted today consist of
    new Part 620, the promulgation of Part 620 requires a conforming
    amendment to 35 Ill. Adm. Code: Subtitle C, Part 303. Since the
    proposed amendments to Part 303 were published in the Illinois
    Register on November 2, 1990, more than one year ago, the Board
    is required to return to first notice on the Part 303 amendments
    only. Therefore, under separate Opinion and Order, -the Boa’rd
    opens a docket C in this proceeding and again sends the Part 303
    amendments to first notice.
    PART 620
    SUBPART A: GENERAL PROVISIONS
    New 35 Ill. Adm. Code. Part 620 is designed to contain the
    principal provisions of today’s action. It consists of six
    12 7—5 7
    —6—
    Subparts plus two appendices. Subpart A sets out the general
    provisions applicable to the entire Part 620.
    Except for generally non—substantive changes within the
    definitions and incorporations sections made in response to post-
    First Notice public comments8, Subpart A remains essentially as
    proposed by the Agency in its third amended proposal.
    Purpose
    —-
    Section 620.105
    Section 620.105 sets forth the purpose of the Part. The
    Defenders had suggested insertion within this Section of the
    phrase
    “to
    assure that the groundwater resources of the State be
    utilized for beneficial and legitimate purposes, that waste and
    degradation of the resources be prevented, and that the
    underground water resource be managed to allow for maximum
    benefit of the people of the State of Illinois” (Def. Exh. 7 at
    proposed Section 620.101). This language comes from the policy
    statement found at Section 2(b) of the IGPA. While the Board
    fully stands behind this policy statement, the Board believes
    that today’s Section 620.105 language is a better descriptor of
    the contents of the Part 620 rules, and therefore opts to use
    this version. The Board believes that this narrow purpose
    statement more clearly alerts the public to what is being
    regulated.
    Definitions
    —-
    Section 620.110
    Section 620.110 contains definitions applicable to Part 620.
    The intent is to present those definitions necessary for a
    reading of Part 620, including both definitions that are
    particular to the Part and those that are statutory; statutory
    definitions are capitalized, pursuant to standard form.
    At second notice, JCAR recommended deletion of the phrase
    “unless otherwise provided” from the introductory statement at
    the beginning of this definitions section. The Board agrees to
    make this change.
    General Prohibitions
    -—
    Section 620.115
    Section 620.115 contains a general prohibition against
    threatening, causing or allowing a violation of the Illinois
    Environmental Protection Act, IGPA, or Board regulations,
    including this Part.
    Incorporations by Reference
    ——
    Section 620.125
    8 See discussion at p. 5—8 of Second Notice Opinion, July 25,
    1991.
    12 7—58
    —7—
    Section 620.125 sets forth incorporations by reference as
    used within Part 620.
    Exemptions from Subtitle C Standards
    -—
    Section 620.130
    Section 620.130 exempts groundwaters from the General Use
    Standards or Public and Food Processing Standards of Subparts B
    and C of 35 Ill. Adm. Code 302. This change, in combination with
    amendment to Section 303.203 (see above), clarifies the
    relation’ship between 35 Ill. Adm. Code.Subtitle C and today’s
    rules.
    Exclusion for Underground Water in Certain Man-Made Conduits
    -—
    Section 620.135
    Section 620.135 explicitly excludes any underground waters
    that occur in certain man—made conduits from the application of
    today’s regulations. The man-made conduits included are
    subsurface drains, tunnels, reservoirs, storm sewers, -tiles, and
    sewers9. Waters in such conduits do not have the conventional
    characteristics and properties of groundwater, and it is
    therefore inappropriate to apply to them water quality standards
    that are based upon groundwater characteristics and properties.
    It is perhaps arguable that Section 620.135 is not necessary
    since the definition of groundwater itself would seemingly
    exclude water in most, if not all, of the man-made conduits
    listed. Thus, if these waters are not groundwaters, groundwater
    standards would not apply to them. However, the record attests
    that there is sufficient confusion on this matter (see Agency
    Statement of Reasons, p. 11; PC #9; PC #10; PC #13) to warrant a
    definitive exclusion for water in man-made conduits.
    -
    It should be recognized that water in man—made conduits is
    not excused from
    ~
    water quality standards. To the extent that
    such waters are “Waters of the State”, they would be subject to
    the water quality standards of Subtitle C. As well, if such
    waters are discharged to the surface, they would be subject to
    water quality standards applicable to surface waters. The
    Illinois Department of Agriculture notes this conclusion with
    respect to drainage from agricultural field tiles:
    •. -
    It is inappropriate to apply any numbers or standards
    to water in a drainage tile except surface water
    standards at the point of discharge to a surface water,
    ~ Specifically ~ included are waters within wells or other
    structures designed to tap groundwater.
    -
    12 7—59
    —8—
    at which point one also must consider the effects of
    mixing. PC #9 at p. 1.
    127—60
    —9—
    PART 620
    SUBPART B: GROUNDWATER CLASSIFICATION
    Subpart B sets out today’.s general groundwater
    classification system, criteria for classifying specific
    groundwaters, the concept of management zones, and procedures for
    amending the classification of-any specific groundwater.
    Groundwater classification is a well—recognized tool for the
    optimizing of groundwater protection efforts. Among its many
    utilities are the opportunity of recognizing the different
    values, uses, and vulnerabilities of groundwaters (Defenders Exh.
    6). ToTay’s rules specifically accord with the mandate of the
    IGPA at Section 8(b) (2) that the Board consider “classification
    of groundwaters on an appropriate basis, such as their utility as
    a resource or susceptibility to contamination”.
    List of Groundwater Classes
    —-
    Section 620.201
    Section 620.201 establishes that there are four classes of
    groundwater. In addition, it establishes that some groundwaters
    may fall into groundwater management zones, pursuant to~Section
    620.201. Every groundwater in the State belongs to one of the
    four classes or to the waters in a groundwater management zone.
    The four classes of groundwater derive from concepts
    presented over.the full history of this proceeding, beginning
    with the Agency’s original proposal and the Defenders’ counter
    proposal, and culminating in the Agency’s third amended proposal
    (Docket B). Perhaps no other facet of this proceeding has
    focused as much effort as has determining how best to classify
    the State’s groundwaters.
    -
    Basic to the groundwater classification effort is the
    concept that groundwater constitutes a valued resource. This
    principle is articulated in the opening sentence of the State’s
    Groundwater Protection Policy:
    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. IGPA,
    Section 2(b).
    It is recognized, however, that not all groundw.aters
    constitute the same level of resource; some groundwaters have
    greater resource value by virtue of their higher quality,
    rjuantity, accessibility, etc. Moreover, it is generally agreed
    that the degree of protection required is in some measure a
    function of the nature of the particular groundwater resource.
    rhis concept constitutes one of the bases for groundwater
    classification, and the application of different water quality
    standards, monitoring and remedial requirements, etc., to the
    different classes.
    12 7—6 1
    —10—
    It is to be further recognized that potability’0 generally
    constitutes the “highest” use to which groundwaters are put.
    Potability, as a further generality, requires the highest degree
    of protection, including the most stringent standards, to
    maintain the use. Potable—use also is by far the largest use to
    which groundwaters in Illinois are put, and will be put in any
    foreseeable future. Given these circumstances, it is apparent
    that any successful program of groundwater management must give
    special focus to potable groundwaters. Emphasis on potable
    groundwaters is recognized in the declaration that the first
    class of Illinois groundwaters consists of the potable resource
    groundwaters.
    Potable Groundwaters Class
    -—
    Section 620.210
    • Section 620.210 establishes the definition of a Class I:
    Potable Resource Groundwater. Included are all groundwaters that
    are located 10 feet or more below the land surface and that, by
    any one of several tests, produce groundwater in quantities
    sufficient to sustain a potable use. In addition, Section
    620.210 specifically identifies that the Board may add
    groundwaters to Class I via the adjusted standards procedures
    spelled out at 620.260.
    -
    The tests used to determine potable quantities include
    demonstrated use, thicknesses associated with aquifers found in
    various rock types, or suitable hydrogeologic parameters. The
    latter include water in strata capable of a sustained yield of at
    least 150 gallons per day in a borehole of reasonable size and
    over a typical collection thickness11.
    Class I groundwaters clearly include a very broad range of
    groundwaters. This is fully intended. Moreover, it should be
    noted that Class I groundwaters include groundwaters of potential
    potable use as well as groundwaters currently experiencing
    potable use. A recurrent question regarding the resource—
    protection concept of groundwater protection has been whether
    potentially usable groundwaters should be afforded like
    10
    “Potable” is defined at in the IGPA as meaning “generally
    fit for human consumption in accordance with accepted water supply
    principles and practices” (Ill. Rev. Stat. 1989, ch. 111 1/2, par.
    7453 (h))
    11 The 150 gallons per day limit is that limit which the USEPA
    defines as a yield sufficient for a groundwater to serve as water
    source for a household unit (Defender’s Exh. 6, p. 39, 45; PC #16
    at p. 12-16). The qualifications regarding sustainability of yield
    and size of borehole plus the hydraulic conductivity condition were
    first proposed and discussed by the Agency at the May 30, 1991
    hearing (R3 at 18-23; Exh. T).
    127—62
    —11—
    protection to groundwaters actually being used (e.g., Ri at 26,
    968-9; PC #6 and #8). The Board previously addressed this issue
    in R86-812. It there noted:
    -
    Resource groundwaters are, at the minimum, those
    groundwaters which are presently being put to
    conventional use by reason of being of suitable
    quality, having local demand, and having been actually
    developed. Much of the record also shows that resource
    groundwaters ought also to include those groundwaters
    which have the potential for being put to conventional
    use. This perspective is straightforward, in that it
    sug’gests that potential resources should be protected
    against the eventuality that at least some of them will
    find use in the future. The Board believes that this
    is a wholly correct perspective, and accordingly
    concludes that resource groundwaters should include
    groundwaters of potential use.
    ~
    at 11-3)
    The Board believes that this perspective remains correct
    today, and accordingly it is incorporated into today’s rules.
    Moreover, the Board believes that the General Assembly also
    endorsed this perspective by defining in the IGPA that a
    “‘resource groundwater’ means a groundwater that is presently
    being or in the future capable of being put to beneficial use”
    (IGPA at Section 3(j), Ill. Rev. Stat. 1989, ch. 111 1/2, par.
    7453(j); emphasis added). That is, the Board believes that among
    the most necessary facets of the State’s groundwater protection
    program is the need to protect
    ~jJ~
    drinkable water at a drinkable
    level. Similarly, the Board does not believe that current actual
    use should be the sole control of whether potable groundwater is
    afforded the protection necessary to maintain potability; we
    simply cannot allow the sullying of a resource that future
    generations may need. For the same reason the term “Potable
    Resource Groundwater”, rather than “Potable
    jj~
    Groundwater”, is
    employed in the title of this class.
    The Board also notes that today’s rules do not attempt to
    limit the definition of potability by qualifiers relating to time
    of travel to existing wells or stratigraphic position, as have
    some earlier proposals. This is in keeping with the position
    that all naturally potable groundwaters should be recognized as
    such, irrespective of whether they are currently experiencing use
    as a potable water supply.
    -
    Among the concepts not adopted to•day is the proposition
    espoused by the Defenders that to• Class I groundwaters should be
    added
    ~fl
    groundwaters hydrologically connected to and upgradient
    of potable resource groundwaters (R2 at 523; R3 at 269-70); under
    12 In the Matter
    of:
    A Plan
    for
    Protecting
    Illinois~
    Groundwater, R86-8, Report of the Board, August 28, 1986.
    127—63
    —12—
    the instant rules most such groundwaters would be Class II
    groundwaters. The Defender’s concept is not adopted because it
    offers little additional groundwater protection at a substantial
    increase in the regulatory burden.
    Lastly, the Board notes that the 10-foot rule arises from
    the need to recognize that- many surface activities can impact
    very shallow underground water without also impacting the great
    bulk of potable groundwaters. For example, the agricultural
    community has expressed substantial
    concern that establishing
    standards for groundwater would critically impact agriculture by.
    disallowing the chemical alteration of all subsurface waters,
    includin’g disallowing use of agricultural chemicals that operate
    through roots. To assure that this erroneous interpretation is
    not fostered, and to assure that legitimate use of agricultural
    chemicals or other legitimate activities are not proscribed, it
    was proposed at the December 4, 1990 hearing that the potable
    resource (Class I) groundwater standards specifically apply only
    to groundwaters below a depth of 10 feet, irrespective of whether
    these waters would otherwise qualify as potable waters;
    groundwaters shallower than 10 feet would always be Class II,
    III, or IV, depending upon the local circumstances.
    The Board today endorses the “10—foot” rule as a reasonable
    compromise between the need to protect potable groundwaters and
    the need to carry on legitimate surface activities, of which
    agriculture is but one.
    As a further observation on the “10—foot” rule, the Board
    notes that question has been raised whether potable groundwaters
    found below 10 feet, but located in a geologic unit that meets
    one of the thickness criteria only because a part of the unit is
    at a depth less- than 10 feet, would still be considered a Class I
    water (R3 at 300). The Board intends that the answer to this
    question be “yes”. Simply, if the water is below 10 feet and is
    naturally potable, it should be supported as a potable water
    resource. Prior to Second Notice a Board Note to this effect was
    added to Section 620.210 upon the recommendation of the Agency
    (PC #58 ¶4).
    The General Resource (Default) Class
    --
    Section 620.220
    Class II: General Resource Groundwater is, by definition at
    Section 620.220, the default groundwater class. That is, Class
    II consists of those groundwaters that are
    ia~
    Class I, III, or
    IV. For example, a groundwater occurring in a thin shale unit
    that is not actually producing potable g1oundwater and that has a
    hydraulic conductivity less than 1 x l0 cm/sec would fall into
    Class II unless one of the special conditions of Class III or IV
    should apply. In general, a groundwater would fall into Class II
    if it is not potable by virtue of quantity or quality
    limitations, if it has not been otherwise specially classified
    127—64
    —13—
    according to Class III procedures, or if it is not otherwise
    limited pursuant to Class IV qualifications.
    The Board anticipates that groundwaters in “tight”
    hydrogeologic units will constitute one of the most common
    •c~ccurrences of Class II groundwaters. These are groundwaters
    that are unavailable in quantities sufficient for most uses.
    Another common occurrence is likely to be groundwaters that are
    not so saline as to- warrant classification as Class IV: Other
    Groundwater, but that nevertheless are too saline to be pocable
    without treatment.
    GiVen the several ways that a groundwater may be classified
    as a Class II groundwater, in the long term it may be advisable
    to either subdivide Class II or split out additional classes from
    Class II. However, the Board believes that this endeavor, should
    it be undertaken, best awaits some experience with the more
    general classification adopted here.
    Special Resource Groundwater
    --
    Section 620.230
    Section 620.230, Class III: Special Resource Groundwater, is
    derived in concept from the Defenders’ proposal, which in turn is
    based on the United States Environmental Protection Agency’s
    (“USEPA”) groundwater classification strategies’
    .
    The Defenders
    contend that in certain circumstances a groundwater may take on
    an ecologically vital role, as for example when its discharge
    supports a vital wetland (Ri at 969-971). Other examples might
    include caves, lakes, ponds, streams, and perhaps even the more
    moist varieties of prairies and forests. In general, the Board
    believes that the concept of special treatment of unique or
    ecologically vital groundwaters via more stringent -standards is a
    meritorious concept.
    In its First-Notice form Section 620.230 provided -for the
    placement of a groundwater in Class III only though the formal
    action of the Board pursuant to Section 620.250. At the May 30,
    1991 hearing, with the support of the Illinois Nature Preserves
    Commission (PC #50) and the Illinois Department of Conservation
    (PC #52),~the Agency proposed that groundwaters that contribute
    to a dedicated nature preserve, as listed by the Agency, also be
    designated as Class III groundwaters via an alternate, more
    expeditious route found at subsection (b) (R3 at 24-7). As the
    Agency notes:
    This will provide a more expedited process to list
    sites that have already been designated by the Nature
    Preserve Commission, and also will allow for a review
    13 See Guidelines for Ground—Water Classification under the
    EPA Ground-Water Protection Strategy, USEPA Office of Ground-Water
    Protection, November 1986: Defender’s Exh. 6.
    -
    12 7—65
    —14—
    of these sites on a case—by—case basis. Sixty sites
    have been identified by the Commission as nature
    preserves that may have an important relationship to
    groundwaters. The review of this information on a
    case—by—case basis is important to help determine what
    relation groundwater has to these sites. (R3 at 26)
    The Board notes that any person who feels aggrieved by an
    Agency decision under subsection (b) would still have recourse to
    bring the action before the Board pursuant to subsection (a).
    Moreover, as the Defenders correctly observe, the listing process
    would “only resolve the question of which nature preserves would
    be desig’nated as containing Class III groundwater; there may
    still need to be a Board proceeding to determine the appropriate
    groundwater standards to apply” (PC #57 at p. 6).
    Other Groundwater
    --
    Section 620.240
    Section 620.240 sets out criteria for classifying Class IV:
    Other Groundwater. The purpose of the class is to accommodate
    certain waters that, due to particular practices or natural
    conditions, are limited in their resource potential. Included
    are groundwaters that are naturally saline, groundwaters that
    occur in the zone of attenuation surrounding a landfill,
    groundwaters in mining-disturbed areas, and affected groundwaters
    associated with potential primary or secondary sources, as
    defined in the IGPA. The class also would contain any
    groundwater designated by the Board as an exempt aquifer.
    Several modifications of Section 620.240 were made in
    response to First Notice comments. The interested person is
    direction to the Second Notice Opinion of July 25, 1991 at p. 13-
    15 for a description and discussion of these modifications.
    Groundwater Management Zones
    ——
    Section 620.250
    Section 620.250 provides for establishment of a management
    zone within each class of groundwater. A management zone is
    identified by the Agency for groundwaters that have become
    impaired due to contamination. In any management zone the goal
    is remediation, if practicable, of the groundwater to the level
    of the standards applicable to that class of groundwater (R3 at
    32).
    Unlike most of the other provisions of today’s rules, the
    concept of a management zone was first introduced into this
    proceeding in the Agency’s Docket B proposal. Previously the
    various proposals had entertained a “Remedial Groundwater” class
    into which various “substandard” but potentially remediable
    groundwaters were to reside temporarily or permanently (e.g., see
    Section 620.230 of the Board’s Docket A proposal, September 27,
    1990). As the Agency observes, a persistent problem with a
    remedial class of groundwater concerns the class to which
    12 7—66
    —15—
    remedial groundwaters return after remediation (R3 at 32). As an
    alternative to a separate remedial class, the Agency turned to
    the groundwater management zone
    (u.).
    Moreover, the management
    zone concept also provides a better coupling with RCRA and CERCLA
    regulations
    (~.
    at 33).
    At second notice, JCAR recommended that the form required
    for the confirmation of an adequate corrective action pursuant to
    35 Ill. Adm. Code 620.250(a) (2) be made an appendix to the rule.
    The Board has agreed to do so, and the form is placed at Appendix
    D in today’s order.
    Adlusted’ Standards
    —-
    Section 620.260
    Section 620.260 specifies that reclassification of any
    groundwater can occur as a result of an adjusted standard
    proceeding before the Board, in accord with the adjusted standard
    provisions of the Illinois Environmental Protection Act. The
    Section also specifies the level of justification required of a
    petitioner and other information to allow the Board to determine
    the adjusted standard, pursuant to Section 28.1 of the Act.
    The Board notes that, in addition to an adjusted standard,
    recourse to reclassification of a particular groundwater also
    would be available via the site—specific rulemaking process.
    Since, there are differences in proofs, conduct of hearings,
    etc., between adjusted standards proceedings and rulemaking
    proceedings, any interested person would be advised to consider
    both before choosing a course of action.
    PART 620
    SUBPART C: NONDEGRADATION AND PREVENTIVE NOTIFICATION/RESPONSE
    Subpart C contains nondegradation provisions and general
    preventive notification and response actions. These, in part,
    set the framework for the remainder of Part 620.
    Nondegradation
    --
    Section 620.301
    Section 620.301 states the basic nondegradation provision of
    today’s rules. Its essence is a prohibition against impairment
    of any existing or potential use of groundwaters.
    A principal area of contention in this proceeding has been
    whether nondegradation ought to encompass some more stringent
    -
    prohibition. Alternate proposals have included a prohibition
    against causing or allowing a statistically significant
    alteration in groundwater chemistry, or of causing or allowing
    ~ni
    change in groundwater chemistry.
    127—67
    —16—
    The Board today declines to generally extend nondegradation
    beyond the prohibition against loss of use14. The Board does
    this with some reluctance. Perhaps at some time in the future
    this step can be taken. However, today we simply- do not have the
    information base, or resources necessary to obtain the
    information base, upon which to found universal judgments of no
    (statistical) change in groundwater chemistry.
    It has sometimes been said that casting the nondegradation
    provision as it is today is equivalent to allowing pollution up
    to the standard. The Board believes that this characterization
    is too simplistic.
    -
    Among other matters, the whole preventive
    notification and response program (see following) is directed
    toward an early alert to, and staving off, of any increase in
    contamination in the most sensitive groundwater/potential source
    situations. Moreover, in other regulations, such as the Board’s
    landfill regulations at 35 Ill. Adm. Code 810-815 and the
    groundwater regulations at 35 Ill. Adm. Code 615 and 6l6’~,
    additional proscriptions against allowing of groundwater quality
    modifications also occur.
    The Board believes that the proper way to characterize
    today’s nondegradation provision is that it consists of the
    baseline, rule-of-general-applicability. In specific
    circumstances dictated both by today’s rule and by other
    regulations license to alter the State’s groundwaters is
    significantly more proscribed. Moreover, the Board also would
    anticipate, as we gain better understanding of the many dynamics
    of groundwater and sources of groundwater pollution, that these
    proscriptions also will expand. In fact, at subsection (d) the
    Board emphasizes its intention of providing for such different
    nondegradation provisions, including more stringent provisions,
    applicable under specific circumstances.
    Applicability of Preventive Notification/Response
    --
    Section
    620.302
    Section 620.302 sets forth the circumstance under which
    preventive notification and preventive response is applicable;
    the section is a prelude to the preventive notification and
    response provisions found in Section 620.305 and 620.310. In
    14 There is one area in which the Board has •previously
    determined that no statistical increase in groundwater contaminants
    is allowable. That is at the bounds of the zone of attenuation
    associated with landfills. The Board intends that nothing in
    today’s action overturn this prior determination.
    15 In the Matter of: Groundwater Protection: Regulations for
    Existing and New Activities Within Setback Zones and Regulated
    Recharge Areas, (35 Ill. Adm. Code 601, 615, 616, and 617), R89—
    5, currently in Second Notice.
    12 7—68
    —17—
    general, preventive notification and response is applicable only
    to persons who conduct groundwater monitoring pursuant to some
    other State or Federal program (R3 at 39). In addition,
    -
    preventive notification and response is associated only with the
    high-quality, high—use groundwaters, Class I and Class III
    groundwaters.
    At the recommendation of JCAR, the Board has agreed to
    insert the appropriate citations after the phrase “state or
    Federal law or regulation” at 620.302(b) (1).
    Preventive Notification Procedures
    --
    Section 620.305
    Preventive notification consists of (a) confirmation of
    results and (b) notification of interested persons. If it is the
    owner or operator who is required to monitor, the appropriate
    regulatory agency must be notified of the results. If it is a
    government agency that is required to monitor, it is the owner or
    operator who must be notified.
    The preventive notification procedures for Class I
    groundwaters are triggered when nunerical limits associated with
    either of two classes of contaminants is exceeded. These are the
    contaminants found at Section 620.310(a) (3) (A), which consist of
    the toxic heavy metals and the more common organic and
    petrochemical contaminants, and the contaminants identified as
    carcinogens at Section 620.410(b). For Class III groundwaters
    the preventive notification trigger is the detection of a
    contaminant for which there is a standard pursuant to Section
    620.430.
    It is important to note that these preventive notification
    triggers are generally much lower than the water quality standard
    for the same constituents. This is in keeping with the
    philosophy of becoming alert and reacting to potential problems
    in high—value groundwaters before these problems can grow to an
    unmanageable scale. It is further in keeping with the principle
    that in general it is much more expensive, including public
    expense, to remediate contaminated groundwater than it is to
    prevent the occurrence of groundwater contamination.
    Preventive Response Activities and Levels
    —-
    Section 620.310
    Section 620.310 describes preventive response activit~es
    that are required upon receipt of a preventive notification. The
    Section also specifies the preventive response levels16 used- to
    determine if a detected concentration requires a preventive
    response. In either case, the purpose of this Section to is to
    16 Prior to the submission of the Docket B proposal, these
    limits were called “corrective action levels” (e.g., Ri at 114—-
    129)
    12 7—69
    —18—
    provide a nexus between the body of today’s rules and existing
    and future regulatory programs that need triggers for corrective
    action. No new corrective action program is today adopted.
    The preventive response levels are set with several
    conditions in mind (R3 at 43). Among these are that all levels
    are at or above the practical quantitation limit (PQL);
    carcinogens, which have potable resources standards set, at PQLs
    (see Section 620.410), are not listed because there is no basis
    for establishing a preventive response level below a PQL (PC #47
    -at p. 15). Exceedence17 of background is employed for metals and
    the non—carcinogenic organic constituents.
    PART 620
    SUBPART D: GROUNDWATER QUALITY STANDARDS
    Subpart D constitutes the focus of the instant regulations.
    Within it are contained the actual groundwater standards as
    mandated by the IGPA. Since the groundwater standards are
    closely tied to the groundwater classification system of Subpart
    B, the form of Subpart D parallels that of Subpart B.
    Introduction
    --
    Sections 620.401 and 620.405
    Section 620.401 establishes the connection between the
    groundwater classification system presented in Subpart B and the
    groundwater standards of Subpart D, which is that all groundwater
    must meet the standards specified for the class to which the
    groundwater belongs. Section 620.405 provides a narrative
    standard that prohibits violation of the numeric standards of
    this Subpart.
    -
    Standards for Potable Resource Groundwater
    —-
    Section 620.410
    Section 620.410 contains the groundwater standards
    applicable to the Potable Resource Groundwater found in Class I
    (see discussion of Section 620.210, above). In general, the
    standards found in this Section are equal to the USEPA’s Maximum
    Concentration Levels (“NCLs)” applicable “at—the-tap” pursuant to
    the Safe Drinking Water Act (“SDWA”). The MCL- levels are
    specified as water quality standards under the principle that
    groundwaters that are naturally potable should be available for
    drinking water supply without treatment.
    The Board notes that within Section 620.310 and several
    subsequent sections of the First Notice proposal, the word
    exceedence
    was incorrectly spelled as exceed~nce.
    Exceedence
    is
    derived from the verb
    exceed,
    which in turn is derived from the
    Latin
    excedere
    via the Middle French
    exceder
    and the Middle English
    exceden;
    Latin infinitives ending in “ere” generate English nouns
    ending in “ence”.
    127—70
    —19—
    An historical difficulty with incorporation of numeric
    standards within regulations is the need to constantly revise the
    numbers as new information is developed. This difficulty has a
    particular presence in the instant matter because the USEPA is in
    the process of a major MCL promulgation effort. Even over the
    short course of this proceeding the Agency has had to several
    times revise its standards recommendations in keeping with
    USEPA’s action on MCL5- (e.g., PC #47 at p. 17—9; R3 at 49-50;
    Exh. T; PC #52 at p. 25, 27); it is to be expected that the
    current MCL list will continue to experience changes within the
    coming years.
    At the First Notice of Docket A the Board proposed to
    address the matter of changing standards/MCLs of Section 620.410
    in what it considered a novel and advantageous method. The Board
    noted:
    Ordinarily the USEPA promulgation of new
    -
    standards/MCLs would imply that Part 620 regulations
    would have to be regularly reopened and updated to
    accommodate new MCLs. However, the Board today
    -
    proposes a stratagem that both forestalls the need to
    constantly update the MCL list-at Section 620.410 and
    also assures that the MCLs of Section 620.410 remain
    current. The stratagem consists of identifying the
    groundwater standards that apply to Potable Resource
    Groundwaters as being identical with the MCLs found at
    35 Ill. Adm. Code 611.Subpart F. 35 Ill. Adm. Code
    6li.Subpart F contains the “identical in substance”
    MCLs promulgated pursuant to the SDWA and the Act. As
    such, 611.Subpart F is subject to updates every six
    months, pursuant to the Board’s SDWA “identical in
    substance” update program. (Docket A, Opinion p. 17)
    At Second Notice of the instant rules the Board receded from
    this stratagem in the interest of moving this proceeding forward.
    However, the Board there noted and here continues to note that it
    expects from the Agency regular18 updates of the groundwater
    standards’, parallel to those undertaken for the Public Water
    Supply Standards at 6li.Subpart F.
    General Resource Groundwater Standards
    ——
    Section 620.420
    Section 620.420 establishes standards for Class II: General
    Resource Groundwaters. Because groundwaters are placed in Class
    II because they are quality-limited, quantity-limited, or both
    (see Subpart B discussion above), it is necessary that the
    18 The Board notes that the Defenders urge a regular (perhaps
    every three years) review of both the Class I and Class II
    standards (e.g., R3 at 257).
    -
    12 7—7 1
    —20—
    standards that apply to these waters reflect this range of
    possible attributes. Among the factors considered in determining
    the Class II numbers are the capabilities of treatment
    technologies to bring Class II waters to qualities suitable for
    potable use (R3 at 75). Thus, many Class II standards are based
    on MCL5 as modified to reflect treatment capabilities.
    •
    For some
    parameters the Class II standards are based on support of a use
    other than potability (e.g., livestock watering, irrigation,
    industrial use) where the different use requires a more stringent
    standard (R3 at 114-8).
    Standards Applicable to Special Resource Groundwaters
    ——
    Section
    620.430
    Section 620.430 specifies that the standards applicable to
    Class III: Special Resource Groundwater are the same standards
    applicable to Class I groundwater, except as may be provided by
    the Board in a proceeding pursuant to Section 620.260.
    Accordingly, the default values of the standards are the Class I
    standards, with more stringent standards possible if a
    justification is made for them.
    Standards Applicable to Other Groundwater
    --
    Section 620.440
    The existing concentration is the basic standard to be
    applicable to Class IV Groundwater. It is also provided that
    specific exceptions apply to groun-dwaters within a zone of
    attenuation of a landfill, as defined pursuant to 35 Ill. Adm.
    Code 811 and 814, and within a previously mined area as defined
    at Section 620.110. Within a zone of attenuation existing
    concentrations are not to be exceeded except as caused by
    leachate. Within a previously mined area existing concentrations
    are not to be exceeded except for pH, total dissolved solids, and
    those major ions (chloride, iran, manganese, and sulfate), which
    are typically disturbed as a result of coal mining.
    Alternate Groundwater Standards
    --
    Section 620.450
    Section 620.450 recognizes that special groundwater
    standards are necessarily associated with certain activities, as
    contrasted to native types of groundwater. These activities
    today are identified to include sites undergoing corrective
    action or equivalent corrective processes and sites for surface
    and underground coal mining activities.
    - -
    At the recommendation of JCAR, the Board agreed to cite the
    appropriate citation to 62 Ill. Adm. Code 1780.21(f) and (g) at
    620.450(b) (3) (A) (ii)
    12 7—7 2
    —21—
    •
    PART 620
    SUBPART E: GROUNDWATER MONITORING AND ANALYTICAL PROCEDURES
    Subpart E sets out some minimal conditions associated with
    groundwater monitoring and analytical procedures. These
    constitute rules-of-general-applicability; in ~other regulations
    further conditions and proscriptions may be added to these. It
    is to be particularly noted that today’s rules contain no new
    required monitoring program.
    An important part of Subpart E is found in the Compliance
    Procedures of Section 620.505. This Section specifies where
    complian’ce determinations may be made. As the Agency notes, this
    Section “recognizes the practical limitations associated with
    groundwater monitoring and cleanup under a building, landfill, or
    tank” (PC #47 at p. 23). Also specified in Section 620.505 are
    the conditions necessary for a water or monitoring well to serve
    as a compliance point.
    For Section 620.510(b) (1), at the recommendation of JCAR,
    the Board inserted the word “regulatory” after the word
    “appropriate”, to make it clear that what is referred to ia. the
    appropriate regulatory agency.
    -
    PART 620
    -
    SUBPART F: HEALTH ADVISORIES
    Subpart F establishes procedures for developing and issuing
    a Health Advisory. A Health Advisory is a means for the Agency
    to establish a guidance level for a chemical substance or a
    mixture of chemical substances for which a standard has not yet
    been set under Subpart D. This advisory process is intended to
    mirror the procedure used by USEPA to account for substances
    detected in groundwater that do not: have a promulgated standard.
    Also, the Agency notes that this Subpart would codify existing
    practice by the Agency (Statement of Reasons, p. 28—36).
    Because the Health Advisory provision and its attendant
    Appendices have been presented to the Board without apparent
    controversy, and because the Board has not itself proposed
    substantive amendment to the Agency’s version, the Board will not
    here discuss these-matters further. The interested person is
    directed to the Agency’s Statement of Reasons, p. 28—36, for more
    discussion and explanation.
    Two changes to the Health Advisory material were recommended
    by JCAR and accepted by the Board. These are to update certain
    phraseology and citations connected with the change in public
    water supply regulations cited in Section 620.601(b); and to
    delete the term “approximately” and add the terms “at least 5”
    in Section 620.Appendix A(c) (1) (iii).
    12 7—73
    —22—
    ECONOMIC IMPACT
    EcIS Document
    On January 31, 1990, •DENR filed the EcIS in this matter,
    titled: “Economic Impact Study for Proposed Groundwater Quality
    Standards, 35 IL. Admin. Code 620” (DENR Exh. 5). The EcIS was
    prepared by Camp Dresser & McKee, Inc. The study evaluated
    groundwater remediation costs using historical data on
    -
    groundwater contamination in the State and also examined benefits
    consisting of reduced health risks through decreased exposure to
    contamirfants in groundwater. Pursuant to Section 8 of the IGPA
    and in an effort to expedite the promulgation of the regulations,
    the EcIS was conducted concurrently with the development of the
    -
    regulations. Therefore, the EcIS document focused on various
    options under consideration during the development of the
    origir~alAgency proposal, over two years prior to today’s action.
    Cost Analysis
    The EcIS investigators determined that the most significant
    costs of the regulations can be expected to be groundwater
    remediation costs; i.e.-, those costs associated with returning
    contaminated groundwater to compliance with the standards.
    To estimate -remediation costs, the EcIS investigators used
    historical data on groundwater contamination in the State. The
    analysis focused on costs for prototypical remediation of six
    parameters representing organic, inorganic, and pesticide
    contaminants. Cleanup cost estimates ranged from $8.83-$8.85
    million for the organic contaminants, $l2.84-$13.64 million for
    the pesticides, and $9.10 million for the inorganic contaminants,
    per incident over a 20 year period. To derive statewide cleanup
    costs, the estimated per facility costs were multiplied by an
    estimated number of sites of contamination (24 volatile organic
    compound incidents and four pesticide incidents). The estimated
    costs for these remedial actions would range from $263—$267
    million.
    By using data on existing incidence of groundwater
    contamination, the EcIS investigators further assumed that costs
    could be higher for three reasons. These are that although the
    Agency did not report an incidence for inorganic contamination -of
    public water supply facilities, it is highly probable that the
    incidence would be greater than zero. Also, since the
    regulations could include a greater number of VOC’s than the Safe
    Drinking Water Act MCL5, a greater incidence of contamination can.
    be expected. Lastly, the EcIS investigators believe that the
    actual number of cleanups required would more likely be closer to
    the number of facilities that exceed the detection limit than the
    number that exceed an MCL. The statement is based on their
    belief that once a contaminant is detected, groundwater
    I 2 7—74
    —23—
    contamination is already likely to e~ceedenforcement or potable
    use standardsGiven
    thesesomewhereconsiderations,at
    the siteand1
    based upon estimates derived
    from existing contamination incidences, the EcIS investigators
    reported estimated costs of $1,141 million for VOC remediation,
    $238 million for pesticide remediation, and $610 million for
    inorganic remediation, leading to a total estimated state—wide
    cleanup cost of $1.99 billion. This was calculated only for
    sites within 3000 feet of community water supply wells, since the
    proposed Class I standards at the time of EcIS development were
    proposed to be applied only within the 3000-foot distance.
    In its most recent comments, DENR estimates that the costs
    under today’s version of the rules could be higher since Class I
    has been expanded to include a larger volume of the State’s
    groundwaters. The EcIS investigators estimated costs 50 higher
    should Class I (as defined sometime before the completion of the
    EcIS in January 1990) include all groundwaters rather than the
    3000-foot zone. Therefore DENR states that costs for the entire
    State would be $3.1 billiOn. DENR recognizes that the addition
    of provisions for groundwater management zones and adjusted
    standards options could offset the increase (PC #55).
    Benefits Analysis
    The EcIS investigators report that the primary benefit of
    groundwater standards is “reduced health risks through decreased
    exposure to contaminants in grou-ndwater”. They explain the
    benefits thusly:
    These benefits can be expressed as decreased health
    care expenses, lower health insurance premiums,
    reduction in pain and suffering, and a better quality
    of life for Illinois citizens. Reductions in excess
    cancer risks
    . . .
    and although not examined
    quantitatively, a corresponding decrease in non—
    carcinogenic health risks also can be anticipated as a
    result of the proposed regulations.
    A second major benefit of the proposed regulations is
    preservation of groundwater as a resource for future
    generations. By preventing contamination where
    possible through preventive management practices and by
    19 For the same reasons, the EcIS investigators believe that
    the economic impact of trigger limits which would be somewhere
    between detection levels and potable use standards would not result
    in cost savings due to early detection of contamination. That is,
    they believe that once there is detection, there would most likely
    already be contamination above potable use standards somewhere on
    the site, which would require remediation.
    127—75
    —24—
    addressing existing contamination through groundwater
    remediation, the value of the resource is preserved and
    the availability of groundwater for future use is
    greatly enhanced.
    Other non-quantifiable benefits include avoided
    decreases in property- values proximal to sites of
    groundwater contamination, avoided restrictions in
    siting for private and community potable wells, and
    avoided negative impact on wildlife and ecology of
    areas served by groundwater base flow. Additionally,
    the aesthetic value of the state’s groundwater reserves
    will be enhanced by the proposed regulations. Finally,
    a major portion of the costs of cleanups can
    actually be considered benefits for engineering firms,
    construction firms, water utilities, and other parties
    involved in groundwater remediation.
    (EcIS at 6—8 to 6-10)
    In Appendix D to the EcIS the EcIS investigators listed
    information on the toxicological effects of substances to be
    regulated. Section 5.2.4 of the EcIS disbusses calculations of
    carcinogenic risk factors based on USEPA risk levels defined in
    terms of excess cancer risks.
    Discussion and Comments
    One of the major points brought out in comments surrounding
    and at the March 29, 1990 EcIS hearing is that the EcIS authors
    did not base analysis upon what was then the Agency’s proposal
    (R. 697—702; PC #16, R89-14 Board First Notice Opinion and Order,
    September 27, 1990). This was mainly because the EcIS was
    statutorially required to be conducted concurrently with the
    development of the proposal. This was done in an effort to
    inject economic analysis into the process at an early stage.
    However, it did not anticipate that the proposal would undergo a
    series of major revisions after completion of the EcIS. Thus,
    even had the EcIS been conducted on the Agency’s proposal as it
    stood in March 1990, the EcIS could not have addressed the
    changes in subsequent proposals, including the rules today
    adopted. Therefore, any examination of economic impact that
    includes the EcIS must consider the context in which the study
    was developed and the lack of availability to the Ec-IS
    investigators of subsequent revisions.
    With that preface, the Board recognizes that if remediation
    to the level of today’s standards is subseguently required
    through other programs, costs of remediation of groundwater could
    be substantial. It is important to remember, however, that these
    are groundwater quality standards, not cleanup standards or
    requirements. As the EcIS authors realized, site specific
    considerations can and most likely will determine the nature of
    12 7—76
    —25—
    required remediation and what actual cost ~s to be borne by any
    particular entity, industry, or government
    ~.
    As stated
    concerning the concurrent R89-5 proceeding, there is difficulty
    in applying economic analysis to a rule of general applicability.
    This is especially true where there are as many varied conditions
    and unknown circumstances as are likely to be encountered here.
    It also must be borne in mind that exception procedures
    associated with adjusted standards and features such as the
    groundwater management-zones must temper any attempt to broadly
    cast cost estimates.
    Another factor in consideration of the EcIS’ cost estimates
    is that the instant regulations do 1iQ~create or require any new
    corrective action program; all such programs are part of other
    -
    regulations already in place or proposed (e.g., RCRA, CERCLA,
    LUST, waterwell setback regulations, etc.). It is accordingly
    not appropriate to attribute to today’s regulations the cost of
    corrective actions that are not prompted by today’s regulations.
    The EcIS investigators recognized that the remedial costs
    -
    properly associated with the instant rules should be “incremental
    costs over and above the costs associated with the currently
    applicable regulations for water quality standards and cleanup
    criteria”, but further stated that they did not consider the
    costs of these other programs because of “the limited number of
    remediations brought under the current regulatory scheme” (EcIS
    at ii).
    The fact that the EcIS investigators attributed to today’s
    groundwater quality standards all the costs of any potential
    future remedial action is a serious flaw in the EcIS analysis.
    Cleanup of contaminants to the levels stated in these rules as
    required by an appropriate agency during remediation does not
    mean that all the costs of cleanup should be attributed to
    adoption of today’s rules. The remediation programs already
    require cleanup of most of the parameters listed in the- instant
    regulations21, in some cases to levels more stringent than in
    today’s rules. That to date there have been few such cleanups in
    Illinois does not make the cost of all further cleanups
    attributable to today’s rules.
    -
    20 Much discussion at hearing and in subsequent comments
    concerned different treatment techniques and their costs (See
    generally, Ri at 889—97, 760—1; PC #5).
    21 Some of the parameters in the instant regulations,
    including iron, total dissolved solids, and boron, are not
    regulated under RCRA and CERCLA. However, the EcIS investigators
    observe that it would be unlikely that these parameters could be
    exceeded -without a simultaneous exceedence of one or more
    parameters which are regulated under RCRA and CERCLA (Ri at 759).
    127—77
    —26—
    A comprehensive list of benefits was included in the EcIS,
    though the EcIS investigators did not attempt to quantify them,
    save for the carcinogenic health risks. Additional benefits
    identified at hearing include reduced expenses to obtain
    alternate water supplies necessary to replace contaminated
    current supplies, and reduced expenses for treatment of water at
    well heads to render it potable or suitable for industrial use
    (Ri at 820, 830-2). It is important to note that although the
    benefits currently cannot be quantified, they are thereby no less
    real or substantial; it is only that they cannot be identified in
    terms
    of reliable, specific dollar figures.
    ORDER
    The Clerk of the Board is directed to submit the text of the
    following amendments to the Secretary of State for final notice
    pursuant to Section 6 of the Illinois Administrative Procedures
    Act.
    12 7—78
    —27—
    TITLE 35: ENVIRONMENTAL PROTECTION
    SUBTITLE F: PUBLIC WATER SUPPLIES
    CHAPTER I: POLLUTION CONTROL BOARD
    PART 620
    GROUNDWATER QUALITY
    SUBPART A: GENERAL
    Section
    620.105
    620.110
    620.115
    620.125
    620. 130
    620. 135
    Section
    620.201
    620.210
    620.220
    620.230
    620.240
    620. 250
    620. 260
    Purpose
    Definitions
    Prohibition
    Incorporations by Reference
    Exemption from General Use Standards and Public
    and Food Processing Water Supply Standards
    Exclusion for Underground Water in Certain
    Man-Made Conduits
    SUBPART B: GROUNDWATER CLASSIFICATION
    Groundwater Designations
    Class I: Potable Resource Groundwater
    Class II: General Resource Groundwater
    Class III: Special Resource Groundwater
    Class IV: Other Groundwater
    Groundwater Management Zone
    -
    Reclassification of Groundwater by Adjusted
    Standard
    SUBPART C: NONDEGRADATION PROVISIONS FOR
    APPROPRIATE GROUNDWATERS
    General Prohibition Against Use Impairment of
    Resource Groundwater
    Applicability of Preventive Notification and
    Preventive Response Activities
    Preventive Notification Procedures
    Preventive Response Activities
    SUBPART D: GROUNDWATER QUALITY STANDARDS
    Applicability
    General Prohibitions Against Violations of
    Groundwater Quality Standards
    Groundwater Quality Standards for Class I: Potable
    Resource Groundwater
    Groundwater Quality Standards for Class II:
    General Resource Groundwater
    Section
    620.301
    620. 3 02
    620.305
    620.310
    Section
    620.401
    620.405
    620.410
    620. 420
    127—79
    —28—
    620.430
    Groundwater Quality Standards for Class III:
    Special Resource Groundwater
    620.440
    Groundwater Quality Standards for Class IV: Other
    Groundwater
    620.450
    Alternative Groundwater Quality Standards
    SUBPART E: GROUNDWATER MONITORING AND ANALYTICAL PROCEDURES
    Compliance Determination
    Monitoring and Analytical Requirements
    SUBPART F: HEALTH ADVISORIES
    Purpose of a Health Advisory
    Issuance of a Health Advisory
    Publishing Health Advisories
    Additional Health Advice for Mixtures of
    Similar-Acting Substances
    Appendix A
    Procedures for Determining Human Threshold
    Toxicant Advisory Concentration for Class I:
    Potable Resource Groundwater
    Appendix B
    Procedures for Determining Hazard Indices for
    -
    Class I: Potable Resource Groundwater for Mixtures
    of Similar-Acting Substances
    Appendix C
    Guidelines for Determining When Dose Addition of
    Similar-Acting Substances in Class I: Potable
    Resource Groundwaters is Appropriate
    Appendix D
    Confirmation of an Adequate Corrective Action
    Pursuant to 35 Ill. Adm. Code 620.250 (a) (2).
    AUTHORITY: Implementing and authorized by Section 8 of the
    Illinois Groundwater Protection Act (Ill. Rev. Stat. 1989, ch.
    lii 1/2, par. 7458).
    SOURCE: Adopted in R89-l4(B) at
    Ill. Reg.,
    __________,
    effective ________________________
    NOTE: Capitalization denotes statutory language.
    Section
    620. 505
    620. 510
    Section
    620. 601
    620. 605
    620. 610
    620. 615
    12 7—80
    —29—
    SUBPART A: GENERAL
    Section 620.105
    Purpose
    This Part prescribes various aspects of groundwater quality,
    including method of classification of groundwaters,
    nondegradation provisions, standards for quality of groundwaters,
    and various proc2dures and protocols for the management and
    protection of groundwaters.
    -
    Section 620.110
    Definitions
    The defi’nitions of the Environmental Protection Act (Ill. Rev.
    Stat. 1989, ch. lii 1/2, par. 1001 et seq.) and the Groundwater
    Protection Act (Ill. Rev. Stat.- 1989, ch. lii 1/2, pars. 7451 et
    seq.) apply to this Part. The following definitions also apply
    to this Part.
    “Act” means the Environmental Protection Act (Ill. Rev.
    Stat. 1989, ch. iii 1/2, pars. 1001 et seq.).
    “Agency” means the Illinois Environmental Protection
    Agency.
    “AQUIFER” MEANS SATURATED (WITH GROUNDWATER) SOILS AND
    GEOLOGIC MATERIALS WHICH ARE SUFFICIENTLY PERMEABLE TO
    READILY YIELD ECONOMICALLY USEFUL QUANTITIES OF WATER
    TO WELLS, SPRINGS, OR STREAMS UNDER ORDINARY HYDRAULIC
    GRADIENTS. (Section 3(b) of the IGPA)
    -
    “BETX” means the sum of the concentrations of benzene,
    ethylbenzene, toluene, and xylenes.
    “Board” means the Illinois Pollution Control Board.
    “Carcinogen” means a chemical, or complex mixture of
    closely related chemicals, which has been listed or
    classified in the Integrated Risk Information System or
    as specified in a final rule adopted by USEPA in
    accordance with USEPA Guidelines for Carcinogenic Risk
    Assessment, incorporated by reference at Section
    620.125, to be a group A, B1, or B2 carcinogen.
    “COMMUNITY WATER SUPPLY” MEANS A PUBLIC SUPPLY WHICH
    SERVES OR IS INTENDED TO SERVE AT LEAST 15 SERVICE
    CONNECTIONS USED BY RESIDENTS OR REGULARLY SERVES --AT
    LEAST 25 RESIDENTS. (Section 3.05 of the Act)
    “CONTAMINANT” MEANS ANY SOLID, LIQUID, OR GASEOUS
    MATTER, ANY ODOR, OR ANY FORM OF ENERGY, FROM WHATEVER
    SOURCE. (Section 3.06 of the Act)
    12 7—8 1
    —30—
    “Corrective action process” means those procedures and
    practices that may be imposed by a regulatory agency
    when a determination has been made that contamination
    of groundwater has taken place, and are necessary to
    address a potential or existing violation of the
    standards set forth in Subpart D.
    “Cumulative impact area” means the area, including the
    coal mine area permitted under the Surface Coal Mining
    Land Conservation Act (Ill. Rev. Stat. 1989, ch. 96
    1/2, pars. 7901.01 et seq., as amended) and 62 Ill.
    Adm. Code 1700 through 1850, within which impacts
    resulting from the proposed operation may interact with
    the impacts of all anticipated mining on surface water
    and groundwater systems.
    “Detection” means the identification of a contaminant
    in a sample at a value equal to or greater than the:
    “Method Detection Limit” or “MDL” which means the
    minimum concentration of a substance that can be
    measured as reported with 99 percent confidence
    that the true value is greater than zero, pursuant
    to 56 Fed. Reg. 3526-3597, incorporated by
    reference at Section 620.125; or
    “Method Quantitation Limit” or “MQL” which means
    the minimum concentration of a substance that can
    be measured and reported pursuant to “Test Methods
    for Evaluating Solid Wastes, Physical! Chemical
    Methods”, incorporated by reference at Section
    620.125.
    “Department” means the Illinois Department of Energy
    and Natural Resources.
    “GROUNDWATER” MEANS UNDERGROUND WATER WHICH OCCURS
    WITHIN THE SATURATED ZONE AND GEOLOGIC MATERIALS WHERE
    THE FLUID PRESSURE IN THE PORE SPACE IS EQUAL TO OR
    GREATER THAN ATMOSPHERIC PRESSURE. (Section 3.64 of
    the Act)
    -
    “Hydrologic balance” means the relationship between the
    quality and quantity of water inflow to, water outflow
    from, and water storage in.a hydrologic unit such as a
    drainage basin, aquifer, soil zone, lake, or reservoir.
    It encompasses the dynamic relationships among
    precipitation, runoff, evaporation, and- changes in
    ground and surface water storage.
    “IGPA” means the Illinois Groundwater Protection Act.
    (Ill. Rev. Stat. 1989, ch. 111 1/2, pars. 7451 et seq.)
    12 7—82
    —31—
    “LOAEL” or “Lowest observable adverse effect level”
    means the lowest tested concentration of a chemical or
    substance which produces a statistically significant
    increase in frequency or severity of non—overt adverse
    effects between the exposed population and its
    appropriate control. LOAEL may be determined for a
    human population (LOAEL-H) or an animal population
    (LOAEL-A).
    “NOAEL” or “No observable adverse effect level” means
    the highest tested concentration of a chemical or
    substance which does not produce a statistically
    significant increase in frequency or severity of non—
    overt adverse effects between the exposed population
    and its appropriate control. NOAEL may be determined
    for a human population (NOAEL-H) or an animal
    population (NOAEL-A)
    “NON-COMMUNITY WATER SUPPLY” MEANS A PUBLIC WATER
    SUPPLY THAT IS NOT A COMMUNITY WATER SUPPLY. (Section
    3.05)
    “Off—site” means not on—site.
    “On—site” means on the same or geographically
    contiguous property which may be divided by public or
    private right—of—way, provided the entrance and exit
    between properties is at a crossroads intersection and
    access is by crossing as opposed to going along the
    right-of-way. Noncontiguous properties owned by the
    same person but connected by a right—of-way which he
    controls and to which the public does not have access
    is also considered on—site property.
    “Operator” means the person responsible for the
    operation of a site, facility or unit.
    “Owner” means the person who owns a site, facility or
    unit or part of a site, facility or unit, or who owns
    the land on which the site, facility or unit is
    located.
    “POTABLE” MEANS GENERALLY FIT FOR HUMAN CONSUMPTION IN
    ACCORDANCE WITH ACCEPTED WATER SUPPLY PRIN.CIPLES AND
    PRACTICES. (Section 3.65 of the Act)
    “POTENTIAL PRIMARY SOURCE” MEANS ANY UNIT AT A FACILITY
    OR SITE NOT CURRENTLY SUBJECT TO A REMOVAL OR REMEDIAL
    ACTION WHICH:
    IS UTILIZED FOR THE TREATMENT, STORAGE, OR
    DISPOSAL OF ANY HAZARDOUS OR SPECIAL WASTE NOT
    GENERATED AT THE SITE; OR
    i
    27—83
    —32—
    IS UTILIZED FOR THE DISPOSAL OF MUNICIPAL WASTE
    NOT GENERATED AT THE SITE, OTHER
    THAN LANDSCAPE
    WASTE AND CONSTRUCTION AND DEMOLITION DEBRIS; OR
    IS UTILIZED FOR THE LANDFILLING,
    LAND
    TREATING,
    SURFACE IMPOUNDING OR PILING OF ANY HAZARDOUS OR
    SPECIAL WASTE THAT IS GENERATED ON THE SITE OR AT
    OTHER SITES OWNED, CONTROLLED OR OPERATED BY THE
    SAME PERSON; OR
    STORES OR ACCUMULATES AT ANY TIME MORE THAN 75,000
    POUNDS ABOVE GROUND, OR MORE THAN 7,500 POUNDS
    BELOW GROUND, OF ANY HAZARDOUS SUBSTANCES.
    (Section 3.59 of the Act)
    “POTENTIAL ROUTE” MEANS ABANDONED AND IMPROPERLY
    PLUGGED WELLS OF ALL KINDS, DRAINAGE WELLS, ALL
    INJECTION WELLS, INCLUDING CLOSED LOOP HEAT PUMP WELLS,
    AND ANY EXCAVATION FOR THE DISCOVERY, DEVELOPMENT OR
    PRODUCTION OF STONE, SAND OR GRAVEL. (Section 3.58 of
    the Act)
    “POTENTIAL SECONDARY SOURCE” MEANS ANY UNIT AT A
    FACILITY OR A SITE NOT CURRENTLY SUBJECT TO A REMOVAL
    OR REMEDIAL ACTION, OTHER THAN A POTENTIAL PRIMARY
    SOURCE, WHICH:
    -
    IS UTILIZED FOR THE LANDFILLING, LAND TREATING, OR
    SURFACE IMPOUNDING OF WASTE THAT IS GENERATED ON
    THE SITE OR AT OTHER SITES OWNED, CONTROLLED OR
    OPERATED BY THE SAME PERSON, OTHER THAN LIVESTOCK
    AND LANDSCAPE WASTE, AND CONSTRUCTION AND
    DEMOLITION DEBRIS; OR
    STORES OR ACCUMULATES AT ANY TIME MORE THAN 25,000
    BUT NOT MORE THAN 75,000 POUNDS ABOVE GROUND, OR
    MORE THAN 2,500 BUT NOT MORE THAN 7,500 POUNDS
    BELOW GROUND, OF ANY HAZARDOUS SUBSTANCES; OR
    STORES OR ACCUMULATES AT ANY TIME MORE THAN 25,000
    GALLONS ABOVE GROUND, OR MORE THAN 500 GALLONS
    BELOW GROUND, OF PETROLEUM, INCLUDING CRUDE OIL OR
    ANY FRACTION THEREOF WHICH IS NOT OTHERWISE
    SPECIFICALLY LISTED OR DESIGNATED AS A HAZARDOUS
    SUBSTANCE; OR
    STORES OR ACCUMULATES PESTICIDES, FERTILIZERS, OR
    ROAD OILS FOR PURPOSES OF COMMERCIAL APPLICATION
    OR FOR DISTRIBUTION TO RETAIL SALES OUTLETS; OR
    STORES OR ACCUMULATES AT ANY TIME MORE THAN 50,000
    POUNDS OF ANY DE-ICING AGENT: OR
    127—84
    —33—
    IS UTILIZED FOR HANDLING LIVESTOCK WASTE OR FOR
    TREATING DOMESTIC WASTEWATERS OTHER THAN PRIVATE
    SEWAGE DISPOSAL SYSTEMS AS DEFINED IN THE PRIVATE
    SEWAGE DISPOSAL LICENSING ACT, Ill. Rev. Stat.
    1989, ch. 111 1/2, par. 116.301 et seq. (Section
    3.60 of the Act)
    “Practical Quantitation Limit” or “PQL” means the
    lowest concentration or level that can be reliably
    measured within specified limits of precision and
    accuracy during routine laboratory operating conditions
    in accordance with “Test Methods for Evaluating Solid
    Wastes, Physical/Chemical Methods”, EPA Publication No.
    SW—846, incorporated by reference at Section 620.125.
    “Previously mined area” means land disturbed or
    affected by coal mining operations prior to February 1,
    1983.
    (Board Note: February 1, 1983, is the effective date of
    the Illinois permanent program regulations implementing
    the Surface Coal Mining Land Conservation and
    Reclamation Act (Ill. Rev. Stat.. 1989, ch. 96 1/2,
    pars. 7901.1 et seq., as amended) as codified in 62
    Ill. Adm. Code 1700 through 1850.)
    “Property class” means the class assigned by a tax
    assessor to real property for purposes of real estate
    taxes.
    -
    (Board Note: The property class rural property,
    residential vacant land, residential with dwelling,
    commercial residence, commercial business, commercial
    office, or industrial is identified on the property
    record card maintained by the tax assessor in
    accordance with the Illinois Real Property Appraisal
    Manual February 1987, published by the Illinois
    Department of Revenue, Property Tax Administration
    Bureau.)
    “PUBLIC WATER SUPPLY” MEANS ALL MAINS, PIPES AND
    STRUCTURES THROUGH WHICH WATER IS OBTAINED AND
    DISTRIBUTED TO THE PUBLIC, INCLUDING WELLS AND WELL
    STRUCTURES, INTAKES AND CRIBS, PUMPING STATIONS,
    TREATMENT PLANTS, RESERVOIRS, STORAGE TANKS AND
    APPURTENANCES, COLLECTIVELY OR SEVERALLY, ACTUALLY USED
    OR INTENDED FOR USE FOR THE PURPOSE OF FURNISHING WATER
    FOR DRINKING OR GENERAL DOMESTIC USE AND WHICH SERVE AT
    LEAST 15 SERVICE CONNECTIONS OR WHICH REGULARLY SERVE
    AT LEAST 25 PERSONS AT LEAST 60 DAYS PER YEAR. A
    PUBLIC WATER SUPPLY IS EITHER A “COMMUNITY WATER
    SUPPLY” OR A “NON-COMMUNITY WATER SUPPLY”. (Section
    3.28 of the Act)
    12 7—85
    —34—
    “Regulated entity” means a
    facility or unit regulated
    for groundwater protection by any state or federal
    agency.
    “Regulatory agency” means the Illinois
    Environmental
    Protection Agency, Department of Public
    Health,
    Department of Agriculture,
    Department of Mines and
    Minerals, and the Office of State Fire Marshal.
    “REGULATED RECHARGE AREA” MEANS A COMPACT GEOGRAPHIC
    AREA, AS DETERMINED BY THE BOARD pursuant to Section
    17.4 of the Act, THE GEOLOGY OF WHICH RENDERS A POTABLE
    RESOURCE GROUNDWATER PARTICULARLY SUSCEPTIBLE
    TO
    CONTAMINATION.
    (Section 3.67 of the Act)
    “RESOURCE GROUNDWATER” MEANS GROUNDWATER THAT IS
    PRESENTLY BEING, OR IN THE FUTURE IS CAPABLE OF BEING,
    PUT TO BENEFICIAL USE BY REASON OF BEING OF SUITABLE
    QUALITY.
    (Section 3.66 of the Act)
    “SETBACK ZONE” MEANS A GEOGRAPHIC AREA,
    DESIGNATED
    PURSUANT TO THIS ACT, CONTAINING A POTABLE WATER SUPPLY
    WELL OR A POTENTIAL SOURCE OR POTENTIAL ROUTE HAVING A
    CONTINUOUS BOUNDARY, AND WITHIN WHICH CERTAIN
    PROHIBITIONS OR REGULATIONS ARE APPLICABLE IN ORDER TO
    PROTECT GROUNDWATERS. (Section 3.61 of the Act)
    “Site” MEANS ANY LOCATION, PLACE, TRACT OF LAND, AND
    FACILITIES, INCLUDING BUT NOT LIMITED TO, BUILDINGS AND
    IMPROVEMENTS USED FOR PURPOSES SUBJECT TO REGULATION OR
    CONTROL BY the ACT OR REGULATIONS THEREUNDER. (Section
    3.43 of the Act)
    “Spring” means a natural surface discharge of an
    aquifer from rock or soil.
    “Threshold dose” means the lowest dose of a
    chemical at
    which a specified measurable effect is observed and
    below which it is not observed.
    “Treatment” means the technology, treatment techniques,
    or other procedures for compliance with 35 Ill. Adm.
    Code: Subtitle F.
    “UNIT” MEANS ANY DEVICE, MECHANISM, EQUIPMENT, OR AREA
    (EXCLUSIVE OF LAND UTILIZED ONLY FOR AGRICULTURAL
    PRODUCTION). (Section 3.62) of the Act)
    “USEPA” or “U.S. EPA” means the United States
    Environmental Protection Agency.
    Section 620.115
    Prohibition
    12 7—8 6
    —35—
    No person shall cause, threaten or allow a violation of the Act,
    the IGPA or regulations adopted by the Board thereunder,
    -
    including but not limited to this Part.
    Section 620.125
    Incorporations
    by Reference
    a)
    The Board incorporates
    the ~ollowing
    material by
    reference:
    ASTM. American Society for Testing and Materials,
    1976 Race Street,
    Philadelphia,
    Pa. 19103 (215)
    299—5585
    -
    “Standard Practice for Description and
    Identification of Soils (Visual Manual
    Procedure)” D2488-84
    GPO. Superintendent of Documents, U.S. Government
    Printing Office, Washington, D.C. 20401, (202)
    783—3238)
    Maximum Contaminant Level Goals and National
    Primary Drinking Water Regulations for Lead
    and Copper; Final Rule, 56 Fed. Reg. 26460—
    26564 (June 7, 1991).
    National Primary Drinking Water Regulations,
    Final Rule, 56 Fed. Req. 3526-3597 (January
    30, 1991).
    -
    USEPA Guidelines for Carcinogenic Risk
    Assessment, 51 Fed. Req. 33992—34003
    (September 24, 1986).
    NCRP. National Council on Radiation Protection,
    7910 Woodmont Ave., Bethesda, MD (301) 657—6252
    “Maximum Permissible Body Burdens and Maximum
    Permissible Concentrations of Radionuclides
    in Air and in Water for Occupational
    Exposure”, NCRP Report Number 22, June 5,
    1959.
    NTIS. National Technical Information Service,
    5285 Port Royal Road, Springfield,
    VA 22161 (-703)
    487—4600.
    “Methods for Chemical Analysis of Water and
    Wastes,” EPA Publication No. EPA—600/4—79—
    020, (March 1983), Doc. No. PB 84—128677
    127—87
    —36-
    “Methods for the Determination of Organic
    Compounds in Drinking Water”, EPA, EMSL, EPA-
    600/4—88/039 (Dec. 1988), Doc. No. PB 89—
    220461
    “Practical
    Guide for Ground-Water Sampling”,
    EPA Publication
    No. EPA/600/2’-85/104
    (September 1985), Doc. No. PB 86—137304
    “Test Methods for Evaluating Solid Wastes,
    Physical/Chemical
    Methods”, EPA Publication
    No. SW-846 (Third Edition,
    1986, as amended
    by- Revision I (December 1987), Doc.
    No. PB
    89—148076
    USGS. United States Geological Survey, 1961 Stout
    St., Denver, CO 80294 (303) 844—4169
    “Techniques of Water Resources Investigations
    of the
    United States Geological Survey,
    Guidelines for
    Collection and Field Analysis
    of Ground—Water Samples for Selected Unstable
    Constituents”, Book I, Chapter D2 (1981).
    b) This Section incorporates no later editions or
    amendments.
    Section 620.130
    Exemption from General Use Standards and
    Public and Food Processing
    Water Supply
    Standards
    Groundwater
    is not required
    to meet the general use standards and
    public and food- processing water supply standards of 35 Ill. Adm.
    Code 302.Subparts B and C.
    Section 620.135
    Exclusion for Underground Waters in Certain
    Man-Made Conduits
    This Part does not apply to underground waters contained
    in
    man—made
    subsurface drains, tunnels, reservoirs,
    storm sewers,
    tiles or sewers.
    12 7—8 8
    —37—
    SUBPART B: GROUNDWATER CLASSIFICATION
    Section 620.201
    Groundwater Designations
    All groundwaters of the
    State are designated as:
    a) One
    of the following four classes of groundwater in
    accordance with Sections 620.210 through 620.240:
    1)
    Class
    I: Potable Resource Groundwater
    2) Class II: General Resource Groundwater;
    3) Class III: Special Resource Groundwater;
    4) Class
    IV: Other Groundwater; or
    -
    b)
    A groundwater management zone
    in accordance with
    Section 620.250.
    -
    Section 620.210
    Class
    I: Potable Resource
    Groundwater
    Except as provided in Sections 620.230,
    620.240, or 620.250,
    Potable Resource Groundwater is:
    -
    a) Groundwater located 10 feet or more below the land
    surface and within:
    -
    1) The minimum setback zone of a well which serves as
    a potable water supply and to
    the bottom of such
    well;
    2) Unconsolidated sand, gravel or sand and gravel
    which is 5 feet or more in thickness and that
    contains 12 percent
    or
    less of fines (i.e. fines
    which pass through a No. 200
    sieve tested
    according to ASTM Standard Practice D2488-84,
    incorporated by reference at Section 620.125);
    3) Sandstone which is 10 feet or more in thickness,
    or fractured- carbonate which is 15 feet of more in
    thickness; or
    4) Any geologic material which is capable of a:
    A)
    Sustained groundwater yield, from up
    to a 12
    inch borehole, of 150 gallons per day or more
    from a thickness of 15 feet or less;
    or
    B) Hydraulic conductivity of
    1 x 10~ cm/sec or
    greater using one of the following test
    methods or its
    equivalent:
    127—89
    —38—
    i)
    Permeameter;
    ii)
    Slug test; or
    iii)
    Pump test.
    b)
    Any groundwater which is determined by the Board
    pursuant to petition procedures set forth in Section
    620.260, to be capable of potable use.
    (Board Note: Any portion of the thickness associated
    with the geologic materials as described in
    subsections
    620.210(a)
    (2), (a)(3) or (a) (4) should be designated as
    Class I: Potable Resource Groundwater if located 10
    feet or more below the land surface.)
    Section 620.220
    Class II: General Resource Groundwater
    Except as provided in Section 620.250, General Resource
    Groundwater is:
    a)
    Groundwater which does not-meet the provisions
    of
    Section
    620.210 (Class I),
    Section 620.230 (Class III),
    or Section 620.240 (Class IV)..
    b) Groundwater which is found by the Board, pursuant to
    -
    the petition procedures -set forth in Section 620.260,
    to be capable of agricultural, -industrial, recreational
    or other beneficial uses.
    Section 620.230
    Class
    III: Special Resource Groundwater
    Except as provided in Section 620.250, Special Resource
    Groundwater is:
    a)
    Groundwater
    that is determined by the Board, pursuant
    to the procedures set forth in Section 620.260, to be:
    1) Demonstrably unique (e.g., irreplaceable sources
    of groundwater) and suitable for application of a
    water quality standard more stringent than the
    otherwise applicable water quality standard
    specified in Subpart D; or
    2) Vital for a particularly sensitive ecological
    system.
    b)
    Groundwater that contributes to a dedicated nature
    preserve
    that is
    listed by the Aciencv as set forth
    below:
    12 7—90
    —39—
    1)
    •
    A written request to list
    a dedicated nature
    preserve under this
    subsection must contain,
    at a
    minimum, the following information:
    A)
    A generaldescription
    of the site and the
    surrounding land use;
    B)
    A topographic map or other map of suitable
    scale denoting the location of the dedicated
    nature preserve;
    C) A general description of the existing
    groundwater quality at and surrounding the
    dedicated nature preserve;
    D)
    A general geologic profile of the dedicated
    nature preserve based upon the most
    reasonably available information, including
    but not limited to geologic maps and
    subsurface groundwater flow
    directions; and
    E)
    A description of the interrelationship
    between groundwater and the nature of the
    site.
    2)
    Upon confirmation by the Agency of the technical
    -
    adequacy of a written request, the Agency shall
    publish the proposed listing of the dedicated
    nature preserve in the Environmental Register for
    a 45-day public comment period. Within 60 days
    after the close of the public comment period, the
    Agency shall either publish a final listing of the
    dedicated nature preserve in the Environmental
    Register or provide a written response to the
    requestor specifying- the reasons for not listing
    the dedicated nature preserve.
    3)
    At least once annually, the Agency shall publish
    in the Environmental Register a complete listing
    of all dedicated nature preserves listed under
    this subsection.
    4)
    For purposes of this Section the term “dedicated
    nature preserve” means a nature preserve that i-s
    dedicated pursuant to the Illinois Natural Areas
    Preservation Act (Ill. Rev. Stat. 1989, ch. 105,
    pars. 701 et seq.).
    •
    Section 620.240
    Class IV: Other -Groundwater
    Except as provided in Section 620.250, Other Groundwater is:
    12 7—9 1
    —40—
    a) Groundwater within a zone of attenuation as provided in
    35 Ill. Adm. Code 811 and 814;
    b) Groundwater within a point of compliance as provided in
    35 Ill. Adm. Code 724, but not to exceed a distance of
    200 feet from a potential primary or secondary source.
    c) Groundwater that naturally contains more than 10,000
    mg/L of total dissolved solids;
    d) Groundwater which has been designated by the Board as
    an exempt aquifer pursuant to 35 Ill. Adm. Code
    730.104; or
    e)
    Groundwater which underlies a
    potential primary or
    secondary source, in which contaminants may be present
    from a release, if the owner or operator of such source
    notifies the Agency in writing and the following
    conditions are met:
    1)
    The outermost edge is the closest practicable
    distance from such source, but does not exceed:
    A)
    A lateral distance of 25 feet from the edge
    of such potential source or the
    property
    boundary, whichever is less; and
    B)
    A depth of 15 feet from the bottom of such
    potential source or the land
    surface,
    whichever is greater;
    2) The source of any
    release of contaminants to
    groundwater has been controlled;
    3)
    Migration of contaminants within the- site
    resulting from a
    release to groundwater has been
    minimized;
    4)
    Any on—site release of contaminants to groundwater
    has been managed to prevent migration off-site;
    and
    5) No potable water well exists within the outermost
    edge as provided in subsection (e) (1).
    f)
    Groundwater which underlies a coal mine refuse disposal
    area not contained within an area from which overburden
    has been removed, a coal combustion waste disposal area
    at a surface coal mine authorized under Section 21(s)
    of the Act, or an impoundment that contains sludge,
    slurry, or precipitated
    process material at a coal
    preparation plant, in which contaminants may be
    present, if such area or impoundment was placed into
    12 7—92
    —41—
    operation after February 1, 1983, if the owner and
    operator notifies the Agency in writing, and if the
    following conditions are met:
    -
    1)
    The outermost edge is the closest practicable
    distance, but does not exceed:
    A)
    A lateral distance of 25 feet from the edge
    of such area or impoundment, or the property
    boundary, whichever is less; and
    B)
    A depth of 15 feet from the bottom of such
    area or impoundment, or the land surface,
    whichever is greater;
    2) The source of any release of contaminants to
    groundwater has been controlled;
    3)
    Migration of contaminants within the site
    resulting from a
    release to groundwater has been
    minimized;
    4)
    Any on—site release of contaminants to groundwater
    has been managed to prevent migration off—site;
    and
    5) No potable water well exists within the outermost
    edge as provided in subsection (e) (1).
    g) Groundwater within a previously mined area, unless
    monitoring demonstrates that the groundwater is capable
    of consistently meeting the standards of Sections
    620.410 or 620.420. If such capability is determined,
    groundwater within the previously mined area shall not
    be Class IV.
    Section 620.250
    Groundwater Management Zone
    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.
    127 —9 3
    —42—
    b)
    A groundwater management zone is established upon
    concurrence by the Agency that the conditions as
    specified in subsection (a) are met and groundwater
    management continues for a period of time consistent
    with the action described in that subsection.
    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. The Agency
    shall
    review the on—going adequacy of controls and continued
    management at the site if concentrations of
    chemical
    constituents,
    as specified in Section 620.450(a) (4) (B),
    remain in groundwater at the site following completion
    of such action. The review must take
    place no less
    often than every
    5 years and the results must be
    presented to the Agency in a
    written report.
    Section 620.260
    Reclassification of Groundwater by
    Adjusted
    Standard
    Any person may petition the Board to reclassify a groundwater in
    accordance with the procedures
    for adjusted standards specified
    in Section 28.1 of the Act and 35 Ill. Adm. Code l06.Subpart G.
    In any proceeding to reclassify
    specific groundwater by adjusted
    standard, in addition to the
    requirements of
    35 Ill. Adm. Code
    106.Subpart G, and Section 28.1(c) of the Act, the petition
    shall, at a minimum,
    contain information to allow the Board to
    determine:
    a)
    The specific groundwater for which reclassification
    is
    requested, including but not
    limited to geographical
    extent of any aquifers, depth of groundwater, and rate
    and direction of groundwater flow and that the specific
    groundwater exhibits the characteristics
    of the
    requested class as set forth in
    Sections 620.2i0(b),
    620.220(b), 620.230, or 620.240(b);
    b)
    Whether the proposed change or use restriction
    is
    necessary for economic or social development, by
    providing information including, but
    not limited to,
    the impacts of the standards on the regional economy,
    social benefits such as loss of jobs or closing of
    facilities,
    and economic analysis contrasting the
    health and environmental
    benefits with -costs likely to
    be incurred in
    meeting the standards would be
    beneficial or necessary;
    c)
    Existing and anticipated uses of the specific
    groundwater;
    12 7—94
    —43—
    d) Existing and anticipated quality of the specific
    groundwater;
    e) Existing and anticipated contamination, if any, of the
    -
    specific groundwater;
    f)
    Technical feasibility
    and economic reasonableness of
    eliminating or reducing contamination of the specific
    groundwater or of maintaining existing water quality;
    g)
    The anticipated time period over which contaminants
    will continue to affect the
    specific groundwater;
    h) Existing and anticipated impact on any potable water
    supplies due to
    contamination;
    1)
    Availability and cost of alternate water
    sources o’r
    of
    treatment for those users adversely affected;
    j)
    Negative or positive effect on property values; and
    k) For special resource groundwater, negative or positive
    -
    effect on:
    -
    1) The quality of surface waters; and
    2)
    Wetlands, natural areas, and the life contained
    therein, including endangered or threatened
    species of plant, fish or wildlife listed pursuant
    to the Endangered Species Act, 16 U.S.C. 1531 et
    seq., or the Illinois Endangered Species
    Protection Act (Ill. Rev. Stat. 1989, ch. 8, par.
    331 et seq.).
    12 7—95
    —44—
    SUBPART C:
    NONDEGRADATION PROVISIONS FOR APPROPRIATE
    GROUNDWATERS
    Section 620.301
    General Prohibition Against Use Impairment of
    Resource Groundwater
    a)
    No person shall cause, threaten or
    allow the release of
    any contaminant to a resource groundwater such that:
    1)
    Treatment or additional treatment is necessary to
    continue an existing use or to assure a potential
    use of such groundwater; or
    2)
    An existing or potential use of such groundwater
    is precluded.
    b) Nothing in this
    Section shall prevent the establishment
    of a
    groundwater management zone pursuant to Section
    620.250 or a cumulative impact area within a permitted
    site.
    c) Nothing in this Section shall
    limit underground
    injection pursuant to a permit issued by the Agency
    under the Act or issued by the Department of Mines and
    Minerals under “An Act in relation to oil, gas, coal
    and other surface and
    underground resources and to
    repeal an Act
    herein named”
    (Ill. Rev Stat. 1989, ch.
    96 1/2, pars. 5401 et seq., as amended).
    d) Nothing
    in this Section shall limit the Board from
    promulgating nondegradation provisions applicable to
    particular types of facilities
    or activities which
    impact upon groundwater, including but not limited to
    landfills regulated pursuant to 35 Ill. Adm.
    Code.Subtitle G.
    Section 620.302
    Applicability of Preventive
    Notification and
    Preventive Response Activities
    a) Preventive notification and
    preventive response as
    specified in Sections 620.305 through 620.310 applies
    to:
    1)
    Class I groundwater under Section 62Q.210(a)(1),
    (a) (2), or (a) (3)
    which
    is monitored by the
    persons listed in subsection (b); or
    2)
    Class III groundwater which is monitored by the
    persons listed in subsection (b).
    b)
    For purposes of subsection (a), the persons that
    conduct groundwater monitorinq are:
    12 7—96
    —45—
    1)
    An owner or operator of a regulated entity for
    which groundwater quality monitoring must be
    performed pursuant to State or Federal law or
    regulation (e.g. Sections 106 and 107 of the
    Comprehensive Environmental Response, Compensation
    and Liability Act, (42 U.S.C. 9601, et seq.);
    Sections 3004 and 3008 of the Resource
    Conservation and Recovery Act, (42 U.S.C. 6901, et
    seq.); Sections 4(q), 4(v), 12(g), 21(d), 21(f),
    22.2(f), 22.2(m) and 22.18 of the Act; 35 Ill.
    Adm. Code 724, 725, 730, 731, 750, 811 and 814.)”
    2) An owner or operator of a public water supply well
    who conducts groundwater quality monitoring; or
    3) A state agency which is authorized to conduct, or
    is the recipient of, groundwater quality
    monitoring data (e.g., Illinois Environmental
    Protection Agency, Department of Public Health,
    Department of Conservation, Department of Mines
    and Minerals, Department of Agriculture, Office of
    State Fire Marshall or Department of Energy~and
    Natural Resources).
    c) If a contaminant exceeds a standard set forth in
    Section 620.410 or Section 620.430, the appropriate
    remedy is corrective action and Sections 620.305 and
    620.310 do not apply.
    Section 620.305
    Preventive Notification Procedures
    a) Pursuant to groundwater quality monitoring as described
    in Section 620.302, a preventive notification must
    occur whenever a contaminant:
    1) Listed under Section 620.310(a) (3) (A) is detected
    (except due to natural causes) in Class I
    groundwater; or
    2) Denoted as a carcinogen under Section 620.410(b)
    is detected in Class I groundwater; or
    3)
    Subject to a standard under Section 620.430 is
    detected (except due to natural causes) in Class
    III groundwater.
    b)
    When a preventive notification is required for
    groundwater which is monitored by a regulated entity
    for the subject contaminant, the owner or operator of
    the site shall confirm the detection by resampling the
    monitoring well. This resampling shall be made within
    30 days of the date on which the first sample analyses
    are received. The owner or operator shall provide a
    127—97
    —46-
    preventive notification to the appropriate regulatory
    agency of the results of the resampling analysis within
    30 days of the date on which the sample analyses are
    received, but no later than 90 days after the
    results
    of the first samples were received.
    c)
    When a preventive notification
    is required for
    groundwater which is monitored by a regulatory agency,
    such agency shall notify the owner or operator of
    the
    site where the detection has occurred.
    The owner or
    operator shall confirm the detection by resampling
    within 30 days of the date of the notice by the
    regulatory agency. The owner or operator shall provide
    preventive notification to the
    regulatory agency of the
    results of the resampling analysis within 30 days of
    -
    the date on
    which the sample analyses are received,- but
    no later than 90 days after the results of the first
    samples were received.
    d) When a preventive notification of a confirmed detection
    has been provided by an owner or operator pursuant to
    this Section, additional detections of the same
    contaminant do not require further notice, provided
    that the groundwater quality conditions are
    substantially unchanged or that preventive .response is
    underway for such contaminant.
    Section 620.310
    Preventive Response Activities
    a) The following preventive assessment must be undertaken:
    1) If a preventive notification under Section
    620.3.05(c) is provided by a community water
    supply:
    A) The Agency shall notify the owner or operator
    of any identified potential primary source,
    potential secondary source, potential route,
    -
    or community water supply well that is
    located within 2,500 feet of the wellhead.
    B) The owner or operator notified under
    subsection (a) (1)
    (A) shall, within 30 days of
    the date of issuance of such notice, sample
    each water well or monitoring well-for the
    contaminant identified in the notice if the
    cOntaminant or material containing such
    contaminant is or has been stored, disposed,
    or otherwise handled at the site.
    If a
    contaminant identified under Section
    620.305(a) is detected, then the well must be
    resampled within 30 days of the date on which
    the first sample analyses are received. If a
    12 7—98
    —47—
    contaminant identified under Section
    620.305(a) is detected by the resampling,
    preventive notification must be given as set
    forth in Section 620.305.
    C) If the Agency receives analytical results
    under subsection (a) (1) (B) that show a
    contaminant identjfied under Section
    620.305(a) has been detected, the Agency
    shall:
    i) Conduct a well site survey pursuant to
    Section 17.1(d) of the Act, if such a
    survey has not been previously conducted
    within the last 5 years; and
    ii) Identify those sites or activities which
    represent a hazard to the continued
    availability of groundwaters for public
    use unless a groundwater protection
    -needs assessment has been prepared
    pursuant to Section 17.1 of the Act.
    2) If a preventive notification is provided under
    Section 620.305(c) by a non-community water supply
    or for multiple private water supply wells, the
    Department of Public Health shall conduct a
    sanitary survey within 1,000 feet of -the wellhead
    of a non-community water supply or within 500 feet
    of the wellheads for multiple private water supply
    wells.
    3) If a preventive notification under Section
    620.305(b) is provided by the owner or operator of
    a regulated entity and the applicable standard in
    Subpart D has not been exceeded:
    A) The appropriate regulatory agency shall
    determine if any of the following occurs for
    Class I: Potable Resource Groundwater:
    i) The levels set forth below are exceeded
    or are changed for pH:
    Constituent
    Criterion
    (mg/L)
    para—Dichlorobenzene
    0.005
    ortho—Dichlorobenzene 0. 01
    Ethylbenzene
    0.03
    Phenols
    0.001
    Styrene
    0.01
    Toluene
    0.04
    127—99
    —48—
    Xylenes
    0.02
    ii) A statistically
    significant increase
    occurs above background (as determined
    pursuant to other regulatory procedures
    (e.g., 35 Ill. Adm. Code 616, 724, 725
    or 811)) for arsenic, cadmium, chromium,
    cyanide, lead or mercury (except due to
    natural causes); or for aldicarb,
    atrazine, carbofuran, endrin, lindane
    (gamma—hexachlor cyclohexane), 2,4-D,
    -
    1, i—dichloroethylene,
    cis-l, 2—dichloroethylene,
    trans-i, 2-dichloroethylene,
    methoxychlor, monochlorobenzene,
    2,4,5—TP (Silvex) and
    1, 1, l-trichloroethane.
    iii) For a chemical constituent of gasoline,
    diesel fuel, or heating fuel, the
    constituent exceeds the following:
    Constituent
    Criterion
    (mg/L)
    BETX
    0.095
    iv) For pH, a statistically
    significant
    change occurs from background.
    (Board Note: Constituents that are
    carcinogens have
    not been listed in subsection (a)
    (3)
    (A) because the
    standard is set at the PQL and any exceedence thereof
    is a violation subject to corrective action.)
    B) The appropriate
    agency shall determine if, for
    Class III:
    Special Resource Groundwater, the
    levels as determined by the Board are
    exceeded.
    C)
    The appropriate regulatory agency shall consider
    whether the owner or operator reasonably
    demonstrates that:
    I)
    The contamination is a result of contaminants
    remaining in groundwater from a prior release
    for which appropriate action was taken in
    accordance with laws and regulations in
    existence at the time of the release;
    ii)
    The source of contamination is not due to the
    on—site release of contaminants; or
    12 7—100
    —49—
    iii) The detection resulted from error in
    sampling, analysis, or evaluation.
    D)
    The appropriate regulatory agency shall consider
    actions necessary to
    minimize the degree and
    extent of contamination.
    b)
    The appropriate regulatory agency shall determine whether a
    preventative response must be undertaken based on relevant
    factors including, but not limited to, the considerations in
    subsection (a) (3).
    c)
    Aft~r completion of preventive response pursuant to
    authority of an appropriate regulatory agency, the
    concentration of a contaminant listed in subsection
    (a) (3) (A) in groundwater may exceed 50
    percent of the
    applicable numerical standard
    in
    Subpart D only if
    the
    -
    following conditions are met:
    1) The exceedence has
    been minimized to the extent
    practicable;
    2)
    Beneficial use, as appropriate for the class of
    groundwater, has been assured; and
    3) Any threat to public health or the environment has
    been
    minimized.
    -
    d)
    Nothing in this Section shall in any way limit the authority
    of the State or of the United States to require or perform
    any corrective action process.
    127—101
    —50—
    SUBPART D: GROUNDWATER QUALITY STANDARDS
    Section 620.401
    Applicability
    Groundwaters must meet the standards appropriate to the
    groundwater’s class as specified in this Subpart and the
    nondegradation provisions of Subpart C.
    Section 620.405
    General Prohibitions Against Violations of
    Groundwater Quality Standards
    No person shall cause, threaten or allow the release of any
    contamir~ant to groundwater so as to cause a groundwater quality
    standard set forth in this Subpart to be exceeded.
    Section 620.410
    Groundwater Quality Standards for Class I:
    Potable Resource Groundwater
    a) Inorganic Chemical Constituents
    Except due to natural causes or as provided in Section
    620.450, concentrations of-the following chemical
    constituents must not be exceeded in Class I
    groundwater:
    -
    Constituent
    Units
    Standard
    Arsenic
    mg/L
    -
    0.05
    Barium
    mg/L
    2
    Boron
    mg/L
    2
    Cadmium
    mg/L
    0.005
    Chloride
    mg/L
    200
    Chromium
    -
    mg/L
    0.1
    Cobalt
    mg/L
    1
    Copper
    mg/L
    0.65
    Cyanide
    mg/L
    0.2
    Fluoride
    mg/L
    4.0
    Iron
    mg/L
    5
    Lead
    -
    mg/L
    0.0075
    Manganese
    mg/L
    0.15
    Mercury
    mg/L
    0.002
    Nickel
    mg/L
    0.1
    Nitrate as N
    mg/L
    10
    Radium—226
    pCi/L
    20
    Radium—228
    pCi/L
    20
    Selenium
    mg/L
    0.05
    Silver
    mg/L
    0.05
    Sulfate
    mg/L
    400
    Total Dissolved
    Solids (TDS)
    mg/L
    1,200
    Zinc
    -
    mg/L
    5
    127—102
    —51—
    b) Organic Chemical Constituents
    Except due to natural causes or as provided in Section
    620.450 or subsection (c), concentrations of the
    following organic chemical constituents must not be
    exceeded in Class I groundwater:
    Constituent
    Standard
    (mg/L)
    Alachlor*
    0.002
    Aldicarb
    0.003
    Atrazine
    0.003
    Benzene*
    0.005
    Carbofuran
    0.04
    Carbon Tetrachloride*
    0.005
    Chlordane*
    0.002
    Endrin
    0.002
    Heptachlor*
    0.0004
    Heptachior Epoxide*
    0.0002
    Lindane (Gamma—Hexachlor
    cyclohexane)
    0.0002
    2,4—D
    0.07
    ortho-Dichlorobenzene
    0
    .
    6
    para-Dichlorobenzene
    0.075
    1, 2-Dichloroethane*
    0.005
    1, i-Dichloroethylene
    0. 007
    cis-l, 2-Dichloroethylene
    0.07
    trans-i
    ,
    2-Dichloroethylene
    0.1
    1, 2—Dichloropropane*
    0.005
    Ethylbenzene
    0.7
    Methoxychlor
    -
    0.04
    Monochlorobenzene
    -
    0.1
    Pentachlorophenol*
    0.001
    Phenols
    -
    0.1
    Polychlorinated Biphenyls (PCB’
    5)
    (as decachloro—bipehnyl)*
    0.005
    Styrene
    0.1
    2,4,5—TP (Silvex)
    0.05
    Tetrachloroethylene*
    0.005
    Toluene
    1
    Toxaphene*
    0.003
    1,1, 1-Trichloroethane
    0.2
    Trichloroethylene*
    0 .005
    Vinyl Chloride*
    0.002
    Xylenes
    10
    *Denotes a carcinogen.
    127—103
    —52—
    c) Complex Organic Chemical Mixtures
    Concentrations of the following chemical constituents
    of gasoline, diesel fuel, or heating fuel must not be
    exceeded in Class I groundwater:
    Constituent
    Standard
    (mg/L)
    Benzene*
    0.005
    BETX
    11.705
    *Denotes a carcinogen.
    d)
    pH
    Except due to natural causes, a pH range of 6.5
    —
    9.0
    units must not be exceeded in Class I groundwater.
    e)
    Beta Particle and Photon Radioactivity
    1)
    Except due to natural causes, the average annual
    concentration of beta particle and photon
    radioactivity
    from man—made radionuclides shall
    not exceed a dose equivalent to the total body
    organ greater than
    4 inrem/year in Class I
    groundwater. If two or
    more radionuclides are
    present, the sum of their dose equivalent to the
    total body, or to any internal organ shall not
    exceed 4 mrem/year in Class I groundwater except
    due to natural causes.
    2)
    Except for the radionuclides listed in subsection
    (e) (3), the concentration of man—made
    radionuclides causing 4 mrem total body or organ
    dose equivalent must be calculated on the basis of
    a 2 liter per day drinking water intake using the
    168—hour data in accordance with the procedure se-t
    forth in NCRP Report Number 22, incorporated by
    reference at in
    Section 620.125(a).
    3)
    Except due to natural causes, the
    average annual
    concentration assumed to produce a total body or
    organ dose of 4 mrem/year of the following
    -
    chemical constituents shall not be exceeded in
    Class I groundwater:
    Critical
    Standard
    Constituent
    Organ
    (pCi/i)
    Tritium
    Total body
    20,000
    Strontium—gO
    Bone marrow
    8
    12 7—104
    —53—
    Section 620.420
    Groundwater Quality Standards for Class II:
    General Resource Groundwater
    a)
    Inorganic Chemical Constituents
    1) Except due to natural causes or as provided in
    Section 620.450 or subsection (a)(3) or (d),
    concentrations of the iollowing chemical
    constituents must not be exceeded in Class II
    groundwater:
    Constituent
    Standard
    (mg
    / L)
    Arsenic
    0.2
    Barium
    -
    2
    Cadmium
    0.05
    Chromium
    1
    Cobalt
    1
    Cyanide
    0.6
    Fluoride
    4.0
    Lead
    0.1
    Mercury
    0.01
    Nitrate as N
    100
    2) Except as provided in Section 620.450 or
    subsection (a)
    (3) or (d), concentrations of the
    following chemical constituents must not be
    exceeded in Class II groundwater:
    Constituent
    Standard
    (mg/L)
    Boron
    2.0
    Chloride
    200
    Copper
    0.65
    Iron
    5
    Manganese
    10
    Nickel
    2
    Selenium
    0.05
    Total Dissolved Solids
    (TDS)
    1,200
    Sulfate
    400
    Zinc
    10
    3)
    The standard for any inorganic chemical
    constituent listed in subsection (a) (2), for
    barium, or for pH does not apply to groundwater
    within fill material or within the upper 10 feet
    of parent material under such fill material on a
    site not within the rural property class for
    which:
    12 7—105
    —54—
    A)
    Prior to the effective date of this Part,
    surf icial characteristics
    have been altered
    by the placement of such fill material so as
    to impact the concentration of the parameters
    listed in subsection (a) (3), and any on-site
    groundwater monitoring of such parameters is
    available for review by the Agency.
    B)
    On the effective date of this Part, surficial
    characteristics
    are in the process of being
    altered by the placement of such fill
    material, which proceeds in reasonably
    continuous manner to completion, so as to
    impact the concentration of the parameters
    listed in subsection (a) (3), and any on-site
    groundwater monitoring of such parameters is
    available for review by the Agency.
    4)
    For purposes of subsection (a) (3), the term “fill
    material” means clean earthen materials, slag,
    ash, clean demolition debris, or other similar
    materials.
    b) Organic Chemical Constituents
    1)
    Except due to natural causes or as provided in
    Section 620.450 or subsection (b) (2) or (d),
    concentrations of the following organic chemical
    constituents must not be exceeded in Class II
    groundwater:
    Constituent
    Standard
    (mg/L)
    Alachlor*
    0.010
    Aldicarb
    0.015
    Atrazine
    0.015
    Benzene*
    0.025
    Carbofuran
    0.2
    Carbon Tetrachloride*
    0.025
    Chlordane*
    -
    0.01
    Endrin
    0.01
    Heptachlor*
    0.002
    Heptachlor Epoxide*
    0.001
    Lindane (Gamma-Hexachior
    cyclohexane)
    0.001
    2,4—D
    0.35
    ortho-Dichlorobenzene
    1.5
    para-Dichlorobenzene
    0.375
    1, 2-Dichloroethane*
    0.025
    1, i-Dichloroethylene
    0. 035
    cis—1, 2 —Dichloroethylene
    0.2
    trans—i, 2-Dichloroethylene
    0.5
    12 7—106
    —55—
    1, 2—Dichioropropane*
    0. 025
    Ethylbenzene
    1.0
    Methoxychlor
    0.2
    Monochlorobenzene
    0. 5
    Pentachlorophenol*
    0.005
    Phenols
    0.1
    Polychlorinated Biphenyls (PCB’s)
    (as decachloro-biphenyl)*
    0.0025
    -
    Styrene
    0.5
    2,4,5—TP.
    0.25
    Tetrachloroethylene*
    0.025
    Toluene
    2.5
    Toxaphene*
    0.015
    1,1, l-Trichloroethane
    1.0
    Trichloroethylene*
    0.025
    Vinyl Chloride*
    0.01
    Xylenes
    10
    *Denotes a carcinogen.
    2)
    The standards for pesticide chemical constituents
    listed in subsection (b) (1) do not apply to
    groundwater within 10 feet of the land surface,
    provided that the concentrations of such
    constituents result from the application of
    pesticides in a manner consistent with the
    requirements of the Federal Insecticide, Fungicide
    and Rodenticide Act (7 U. S. C. 136 et seq.) and
    the Illinois Pesticide Act (Ill. Rev. Stat. 1989,
    ch. 5, pars. 801 et seq.).
    c) Complex Organic Chemical Mixtures
    Concentrations of the following organic chemical
    constituents of gasoline, diesel fuel, or heating fuel
    must not be exceeded in Class II groundwater:
    Constituent
    Standard
    -
    (mg/L)
    Benzene*
    0.025
    BETX
    13.525
    *Denotes a carcinogen.
    d)
    pH
    Except due to natural causes, a pH range of 6.5
    —
    9.0
    units must not be exceeded in Class II groundwater that
    is within 5 feet of the land
    surface.
    Section 620.430
    Groundwater Quality Standards for Class III:
    Special Resource Groundwater
    127—1(7
    —56—
    Concentrations of inorganic and organic chemical constituents
    must not exceed the standards set forth in Section 620.410,
    except for those chemical constituents for which the Board has
    adopted a standard pursuant to Section 620.260.
    Section 620.440
    Groundwater Quality Standards for Class IV:
    Other Groundwater
    a)
    Except as provided in subsections (b) or (c), Class IV:
    Other Groundwater standards are equal to the existing
    concentrations of constituents in groundwater.
    b)
    For groundwater within a zone of attenuation as
    provided in 35 Ill. Adm.- Code 811 and 814, the
    standards specified in Section 620.420 must not be
    exceeded, except for concentrations of contaminants
    within leachate released from a permitted unit.
    c) For groundwater within a previously mined area, the
    standards set forth in Section 620.420 must not be
    exceeded, except for concentrations of TDS, chloride,
    iron, manganese, sulfates, or pH. For concentrations
    of TDS, chloride, iron, manganese, sulfates, or pH, the
    standards are the existing concentrations.
    Section 620.450
    Alternative Groundwater Quality Standards
    -a)
    Groundwater Quality Restoration Standards
    1) Any chemical constituent in groundwater within a
    groundwater management zone is subject to this
    Section.
    2) Except as provided in subsections (a) (3) or
    (a) (4), the standards as specified in Sections
    620.410, 620.420, 620.430, and 620.440 apply to
    any chemical constituent in groundwater within a
    groundwater management zone.
    3) Prior to completion of a corrective action
    described in Section 620.250(a), the standards as
    specified in Sections 620.410, 620.420, 620.430,
    and 620.440 are not applicable to such released
    chemical constituent, provided that the initiated
    action proceeds in a timely and appropriate
    manner.
    -
    4) After completion of a corrective action as
    -
    described in Section 620.250(a), the standard for
    such released chemical constituent is:
    12 7—108
    —57—
    A) The standard as set forth in Section 620.410,
    620.420, 620.430, or 620.440, if the
    concentration as determined by
    groundwater
    monitoring of such constituent is less than
    or equal to the standard for the appropriate
    class set forth in those sections; -or
    -
    B) The concentration as determined by
    groundwater monitoring, if such concentration
    exceeds the standard for the appropriate
    class set forth in Section 620.410, 620.420,
    620.430, or 620.440 for such constituent,
    and:
    i) To the extent practicable, the
    exceedence has been minimized and
    beneficial use, as appropriate for the
    class of groundwater, has been returned;
    and
    ii) Any threat to public health or the
    environment has been minimized.
    5) The Agency shall develop and maintain a listing of
    concentrations derived pursuant to subsection
    (a) (4) (B). This list shall be made available to
    -
    the public and be updated periodically, but no
    less frequently than semi-annually. This listing
    shall be published in the Environmental Register.
    b) Coal Reclamation Groundwater Quality Standards
    1) Any inorganic chemical constituent or pH in
    groundwater, within an underground coal mine, or
    within the cumulative impact area of groundwater
    for which the hydrologic balance has been
    disturbed from a permitted coal mine area pursuant
    to the Surface Coal Mining Land Conservation and
    Reclamation Act (Ill. Rev. Stat. 1989, ch. 96 1/2,
    pars. 7901.1 et seq., as amended) and 62 Ill. Adm.
    Code 1700 through 1850, is subject to this
    Section.
    2) Prior to completion of reclamation at a coal mine,
    the standards as specified in Sections 620.410(a)
    and (d), 620.420(a) and (e), 620.430 and 620.440
    are not applicable to inorganic constituents and
    pH.
    3) After completion of reclamation at a coal mine,
    the standards as specified in Sections 620.410(a)
    and (d), 620.420(a), 620.430, and 620.440 are
    127—109
    —58—
    applicable to inorganic constituents and pH,
    except:
    A)
    The concentration of total dissolved solids
    (TDS) must not exceed:
    i) The post—reclamation concentration or
    3000 mg/L, whichever is less, for
    groundwater within the permitted area;
    or
    ii) The post—reclamation concentration ot
    TDS must not exceed the post—reclamation
    concentration or 5000 mg/L, whichever is
    less, for groundwater in underground
    coal mines and in permitted areas
    -
    reclaimed after surface coal mining if
    the Illinois Department of Mines and
    Minerals and the Agency have determined
    that no significant resource groundwater
    existed prior to mining (62 Ill. Adm.
    Code 1780.21(f) and (g)); and
    B) For chloride, iron, manganese and sulfate,
    the post—reclamation concentration within the
    permitted area must not be exceeded.
    C) For pH, the post—reclamation concentration
    within the permitted area must not be
    exceeded within Class I: Potable Resource
    Groundwater as specified in Section
    620.210 (a) (4)
    4) A refuse disposal area (not contained within the
    area from which overburden has been -removed) is
    subject to the inorganic chemical constituent and
    pH requirements of:
    A)
    35 Ill. Adm. Code 303.203 for such area that
    was placed into operation after February 1,
    1983, and before the effective date of this.
    Part, provided that. the groundwater is a
    present or a potential source of water for
    public or food processing;
    B) Section 620.440(c) for such area that was
    placed into operation prior to February 1,
    1983, and has remained in continuous
    operation since that date; or
    C) Subpart D for such area that is placed into
    operation on or after the effective date of
    this Part.
    127—110
    —59—
    5) For a refuse disposal area (not contained within
    the area from which overburden has been removed)
    that was placed into operation prior to February
    1, 1983, and is modified after that date to
    include additional area, this Section applies to
    the area that meets the requirements of subsection
    (b) (4) (C) and the follqwing applies to the
    additional area:
    A) 35 Ill. Adm. Code 303.203 for such additional
    refuse disposal area that was placed into
    operation after February 1, 1983, and be-fore
    the effective date of this Part, provided
    that the groundwater is a present or a
    potential source of water for public or food
    processing; and
    B) Subpart D for such additional area that was
    placed into operation on or after the
    -
    effective date of this Part.
    6) A coal preparation plant (not located in an area
    from which overburden has been removed) which
    contains slurry material, sludge or other
    precipitated process material, is subject to the
    inorganic chemical constituent and pH requirements
    of:
    A) 35 Ill. Adm. Code 303.203 for such plant that
    was placed into operation after February 1,
    1983, and before the effective date of this
    Part, provided that the groundwater is a
    present or a potential source of water for
    public or food processing;
    B) Section 620.440(c) for such plant that was
    placed into operation prior to February 1,
    1983, and has remained in continuous
    operation since that date; or
    C) Subpart D for such plant that is placed into
    operation on or after the effective date of
    this Part.
    7) For a coal preparation plant (not located in--an
    area from which overburden has been removed) which
    contains slurry material, sludge or other
    precipitated process material, that was placed
    into operation prior to February 1, 1983, and is
    modified after that date to include additional
    area, this Section applies to the area that meets
    L~_I—_L
    111~l..L.
    —60—
    the requirements of subsection (b) (6) (C) and the
    following applies to the additional area:
    A)
    35 Ill. Adm. Code 303.203 for such additional
    area that was placed into operation after
    February 1, 1983, and before -the effective
    date of this Part, provided that the
    groundwater is a present or a potential
    source of water for public or food
    processing; and
    B)
    Subpart D for such additional area that was
    placed into operation on or after the
    effective date of
    this Part.
    127—112
    —61—
    SUBPART E: GROUNDWATER MONITORING AND ANALYTICAL PROCEDURES
    Section 620.505
    Compliance Determination
    a) Compliance with standards at a site is to be determined
    as -follows:
    1) For a structure (e.g., buildings), at the closest
    practical distance beyond the outermost edge for
    the structure.
    2) For groundwater that underlies a potential primary
    or secondary source, the outermost edge as
    -
    specified in Section 620.240(e) (1).
    3) For groundwater that underlies a coal mine refuse
    disposal area, a coal combustion waste disposal
    area, or an impoundment that contains sludge,
    slurry, or precipitated process material at a coal
    preparation plant, the outermost edge as specified
    in Section 620.240(f) (1) or location of monitoring
    wells in existence as of the effective -date of
    this Part on a permitted site.
    4) For a groundwater management zone, as specified in
    a corrective action process.
    5) At any point at which groundwater monitoring is
    conducted using any water well or monitoring well
    that meets the following conditions:
    A) For a potable well other than a community
    water supply well, a construction report has
    been filed with the Department of Public
    Health for such potable well, or such well
    has been located and constructed (or
    reconstructed) to meet the Illinois Water
    Well Construction Code (Ill. Rev. Stat. 1989,
    ch. 111 1/2, pars. 116.111 et seq., as
    amended) and 35 Ill. Adm. Code 920.
    B) For a community water supply well, such well
    has been permitted by the Agency, or has been
    constructed in accordance with
    as
    Ill. Adm.
    -
    Code 602.115.
    C) For a water well other than a potable water
    well (e.g., a livestock watering well or an
    irrigation well), a construction report has
    been filed with the Department of Public
    Health or the Department of Mines and
    Minerals for such well, or such well has been
    located and constructed (or reconstructed) to
    12 7—113
    —62—
    meet the Illinois Water Well Construction
    Code (Ill. Rev. Stat. 1989, ch. 111 1/2,
    pars. 116.111 et seq., as amended) and 35
    Ill. Adm. Code 920.
    D) For a monitoring well, such well meets the
    following requirements:
    i) Construction must be done in a manner
    that will enable the collection of
    groundwater samples;
    ii) Casings and screens must be made from
    durable material resistant to expected
    chemical or physical degradation that do
    not interfere with the quality of
    groundwater samples being collected; and
    iii) The annular space opposite the screened
    section of the well (i.e., the space
    between the bore hole and well screen)
    must be filled with gravel or sand if
    necessary to collect groundwater
    samples. The annular space above and
    below the well screen must be sealed to
    prevent migration of water from adjacent
    formations and the surface to the
    sampled depth.
    -
    b) For a spring, compliance with this Subpart shall be
    determined at the point of emergence.
    Section 620.510
    Monitoring and Analytical Requirements
    a) Representative Samples
    A representative sample must be taken from locations as
    specified in Section 620.505.
    b) Sampling and Analytical Procedures
    1) Samples must be collected in accordance with the
    procedures set forth in the documents pertaining
    to groundwater monitoring and analysis, -“Methods
    for Chemical Analysis of Water and Wastes,
    “Methods for the Determination of Organic
    Compounds in Drinking Water”, “Practical Guide for
    Ground—Water Sampling”, “Test Methods for
    Evaluating Solid Wastes, Physical/Chemical
    Methods” (SW—846), “Techniques of Water Resources
    Investigations of- the United States Geological
    Survey, Guidelines for Collection and Field
    Analysis of Ground-Water Samples for Selected
    127—114
    —63—
    Unstable Constituents”, incorporated by reference
    at Section 620.125 or other procedures adopted by
    the appropriate regulatory agency.
    2) Groundwater elevation in a groundwater monitoring
    well must be determined and recorded when
    -
    necessary to determine the gradient.
    3)
    The analytical methodology used for the analysis
    of constituents in Subparts C and D must be
    consistent with both of the following:
    A) The methodology must
    have a PQL at or below
    the preventive response levels of Subpart C
    or the
    groundwater standard set forth in
    Subpart D, whichever is applicable; and
    B) The methodology must be consistent with
    methodologies contained in “Methods for
    Chemical Analysis of Water and Wastes”,
    “Methods for the Determination of Organic
    Compounds in Drinking Water”, “Practic~1
    Guide for Ground-Water Sampling”, “Test
    Methods for Evaluating Solid Wastes,
    Physical/Chemical Methods” (SW—846),
    “Techniques of Water Resources
    Investigations
    of the United States Geological Survey,
    Guidelines for Collection and Field Analysis
    of Ground—Water Samples for Selected Unstable
    Constituents”,
    incorporated by reference at
    Section 620.125.
    c)
    Reporting Requirements
    At a minimum, groundwater monitoring analytical results
    must include information, procedures and techniques
    for:
    1)
    Sample collection (including but not limited to
    name of sample collector, time and date of the
    sample, method of collection, and identification
    of the monitoring location);
    2) Sample preservation and shipment (including but
    not limited to field quality control);
    3) Analytical procedures (including but not limited
    to the method detection limits and the PQLs); and
    4) Chain of custody control.
    127—115
    —64—
    SUBPART F: HEALTH ADVISORIES
    Section 620.601
    Purpose of a Health Advisory
    This Subpart establishes procedures for the issuance of a Health
    Advisory that sets forth guidance levels that, in the absence of
    standards under Section 620.410, must be considered by the Agenc~
    in:
    -
    a)
    Establishing groundwater cleanup or action levels
    whenever there is a release or substantial threat of a
    release of:
    1)
    A hazardous substance or pesticide; or
    2)
    Other contaminant that represents a significant
    -
    hazard to public health or the environment.
    b) Determining whether the community water supply is
    taking its raw water from a site or source consistent
    with the siting and source water requirements of 35
    Ill. Adm. Code 611.114 and 611.115.
    c) Developing Board rulemaking proposals for new or
    revised numerical standards.
    -
    d) Evaluating mixtures of chemical substances.
    Section 620.605
    Issuance of a Health Advisory
    a) The Agency shall issue a Health Advisory for a chemica
    substance if all of the following conditions are met:
    1) A community water supply well is sampled and a
    substance is detected and confirmed -by resampling;
    2) There is no standard under Section 620.410 for
    such chemical substance; and
    3) The chemical substance is toxic or harmful to
    human health according to the procedures of
    Appendix A, B, or C.
    b) The Health Advisory must contain a general description
    of the characteristics of the chemical substance, the
    potential adverse health effects, and a guidance level
    to be determined as follows:
    1) If disease or functional impairment is caused due
    to a physiological mechanism for which there is a
    threshold dose below which no damage occurs, the
    guidance level for any such substance is the
    Maximum Contaminant Level Goal (“MCLG”), adopted
    127—116
    —65—
    by USEPA for such substance, 56 Fed. Reg. 26460-
    26564, and 56 Fed. Reg. 3526-3597, incorporated by
    reference at Section 620.125. If there is no MCLG
    for the substance, the guidance level is the Human
    Threshold Toxicant Advisory Concentration for such
    substance as determined in accordance with
    Appendix A, unless the concentration for such
    substance is less than the lowest appropriate PQL
    specified in “Test Methods for Evaluating Solid
    Wastes, Physical/Chemical Methods”, EPA
    Publication No. SW-846 (SW-846), incorporated by
    reference at Section 620.125 for the substance.
    If the concentration for such substance is less
    than the lowest appropriate PQL for the substance
    specified in SW-846, incorporated by reference at
    Section 620.125, the guidance level is the lowest
    appropriate PQL.
    2) If the chemical substance is a carcinogen, the
    guidance level for any such chemical substance is
    the lowest appropriate PQL specified in SW-846,
    incorporated by reference at Section 620.125 for
    such substance.
    Section 620.610
    Publishing Health Advisories
    a)
    The Agency shall publish the full text of each Health
    Advisory upon issuance and make the document available
    to the public.
    -
    b)
    The Agency shall publish and make available to the
    public, at intervals of not more than 6 months, a
    comprehensive and up-to-date summary list of all Health
    Advisories.
    Section 620.615
    Additional Health Advice for Mixtures of
    Similar-Acting Substances
    a) The need for additional health advice appropriate to
    site-specific conditions shall be determined by the
    Agency when mixtures of chemical substances are
    detected, where two or more of the chemical substances
    are similar-acting in their toxic or harmful
    physiological effect on the same specific -organ or
    organ system.
    b)
    If mixtures of similar—acting chemical substances are
    present, the procedure for evaluating the
    mixture of
    such substances is specified in accordance with
    Appendices A, B, and C.
    127—117
    —66—
    Section 620.Appendix A Procedures for Determining Human
    Threshold Toxicant Advisory
    Concentration for Class I: Potable
    Resource Groundwater
    a)
    Calculating the Human Threshold Toxicant Advisory
    Concentration
    For those substances for which USEPA has not adopted a
    Maximum Contaminant Level Goal (“MCLG”), the Human
    Threshold Toxicant Advisory Concentration is calculated
    as follows:
    HTTAC
    =
    RSC x ADE/W
    Where:
    HTTAC
    =
    Human Threshold Toxicant Advisory
    Concentration in milligrams per liter (mg/L);
    RSC
    =
    Relative contribution of the amount of
    the exposure to a chemical via drinking water
    when compared to the total exposure to that
    chemical from all sources.
    Valid chemical—
    specific data shall be used if available.
    If
    valid chemical—specific data are not
    available, a value of 20
    (=0.20) must be
    used;
    ADE
    =
    Acceptable Daily
    Exposure of substance
    in milligrams per day (mg/d) as determined
    pursuant to subsection (b); and
    W
    =
    Per capita daily water consumption equal
    to 2 liters per day (L/d).
    b)
    Procedures for Determining Acceptable Daily Exposures
    for Class I:
    Potable Resource Groundwater
    1)
    The Acceptable Daily Exposure (ADE) represents the
    maximum amount of a threshold toxicant in
    milligrams per day (mg/d) which if ingested daily
    for a lifetime results in no adverse
    effects to
    humans. Subsections (b) (2) through (b) (6) list,
    in prescribed order, methods for determining the
    ADE in Class I: Potable Resource Groundwater.
    2)
    For those substances for which the- USEPA has
    derived a Verified Oral Reference Dose for humans,
    USEPA’s Reference Dose given in milligrams per
    kilogram per day (mg/kg/d), as determined in
    accordance with methods provided in
    National
    Primary and Secondary Drinking Water Regulations;
    127—118
    —67—
    Final Rule, 56 Fed. Reg. 3526—3597, (January 30,
    1991), incorporated by reference at Section
    620.125, must be used. The ADE equals the product
    of multiplying the Reference Dose by 70 kilograms
    (kg), which is the assumed average weight of an
    adult human.
    3)
    For those substances for which a no observed
    adverse-effect
    level for humans (NOAEL-H) exposec~
    to the substance has been derived, the ADE equals
    the product of multiplying one-tenth of the
    NOAEL-H given in milligrams of toxicant per
    kilogram of body weight per day (mg/kg/d) by the
    average weight of an adult human of 70 kilograms
    (kg).
    If two or more studies are available, the
    lowest NOAEL-H must be used in the calculation of
    the ADE.
    4)
    For those substances for which only a lowest
    observed adverse effect level for humans (LOAEL—H)
    exposed to the substance has been derived,
    one-tenth the LOAEL-H must be
    substituted for the
    NOAEL—H in subsection (b) (3).
    5)
    For those substances for which a no
    observed
    adverse effect level has been derived from studies
    of mammalian test species (NOAEL-A)
    exposed to the
    substance, the ADE equals the
    product of
    multiplying 1/100 of the NOAEL-A given in
    milligrams toxicant per kilogram of test species
    weight per day (mg/kg/d) by the average weight of
    an adult human of 70 kilograms -(kg). Preference
    will be given to animal studies having High
    Validity, as defined in subsection (c), in the
    order listed in that subsection.
    Studies having a
    Medium Validity must be considered if no studies
    having High
    Validity are available. If studies of
    Low Validity must be used, the ADE must be
    calculated using 1/1000 of the NOAEL-A having Low
    Validity instead of 1/100 of the NOAEL-A of High
    or Medium Validity, except as described in
    subsection (b) (6).
    If two or more studies among
    different animal species are equally valid, the
    lowest NOAEL—A among animal species must be used
    in the calculation of the ADE. Additional
    considerations in selecting the NOAEL—A
    include:
    A)
    If the NOAEL-A is given in milligrams of
    toxicant per liter of water consumed (mg/L),
    prior to calculating the ADE the NOAEL-A must
    be multiplied by the
    average daily volume of
    water consumed by the mammalian test species
    in liters per day (l/d) and divided by the
    127—119
    —68—
    average weight of the mammalian test species
    in kilograms (kg).
    B)
    If the NOAEL—A is given in milligrams of
    toxicant per kilogram of food consumed
    (mg/kg), prior to calculating the ADE, the
    NOAEL-A must be multiplied by the average
    amount in kilograms of food consumed daily by
    the mammalian test sp?cies (kg/d) and divided
    by the average weight of the mammalian test
    species in kilograms (kg).
    C)
    If the mammalian test species was not exposed
    to the toxicant each day of the test period,
    the NOAEL-A must be multiplied by the ratio
    of days of exposure to the total days of the
    test period.
    D) If more than one
    equally valid NOAEL-A is
    available for the same mammalian test
    species, the best available data must be
    used.
    -
    6)
    For those substances for which a NOAEL-A is not
    available but the lowest observed adverse effect
    level (LOAEL-A) has been derived from studies of
    mammalian test species exposed to the substance,
    one-tenth of the LOAEL-A may be substituted for
    the NOAEL-A in subsection (b) (5). The LOAEL-A must
    be selected in the same manner as that specified
    in subsection (b) (5).
    One-tenth the LOAEL-A from
    a study determined to have Medium Validity may be
    substituted for a NOAEL-A in subsection (b) (3) if
    the NOAEL-A is from a study determined to have Low
    Validity, or if the toxicity endpoint measured in
    the study having the LOAEL-A of Medium Validity is
    determined to be more biologically relevant than
    the toxicity endpoint measured in the study having
    the NOAEL-A of Low Validity.
    C)
    Procedures for Establishing Validity of Data from
    Animal Studies
    1)
    High Validity Studies
    -
    A)
    High validity studies use a route of exposure
    by ingestion or gavage, and are based upon:
    i)
    Data from animal carcinogenicity studies
    with a minimum of 2 dose levels and a
    control- group, 2 species, both sexes,
    with 50 animals per dose per sex, and at
    least 50 percent survival at 15 months
    12 7—120
    —69—
    in mice and 18 months in rats and at
    least 25 percent survival at 18 months
    in mice and 24 months in rats;
    ii)
    Data from animal chronic studies with a
    minimum of 3 dose levels and a control
    group., 2 species, both sexes, with 40
    animals per dose per sex, and at least
    50 percent survival at 15 months in mice
    and 18 months in rats and at least 25
    percent survival at 18 months in mice
    and 24 months in rats, and a
    well-defined NOAEL; or
    iii) Data from animal subchronic studies with
    a minimum of 3 dose levels and control,
    2 species, both sexes, 4 animals per
    dose per sex for non—rodent species or
    10 animals per dose per sex for rodent
    species, a duration of at least 5 of
    the test species’ lifespan, and a
    well-defined NOAEL.
    --
    B) Supporting studies which reinforce the
    conclusions of a study of Medium Validity may
    be considered to raise such a study to High
    Validity.
    2)
    Medium Validity Studies
    -
    Medium validity studies are based upon:
    A) Data from animal carcinogenicity, chronic, or
    subchronic studies in which minor deviations
    from the study design elements required for
    a High Validity Study are found, but which
    otherwise satisfy the standards for a High
    Validity Study;
    B) Data from animal carcinogenicity and chronic
    studies in which at least 25 percent survival
    is reported at 15 months in mice and 18
    months in rats (a lesser survival is
    permitted at the conclusion of a longer
    duration study, but the number of surviving
    animals should not fall below 20 percent per
    dose per sex at 18 months for mice and 24
    months for rats), but which otherwise satisfy
    the standards for a High Validity Study;
    C) Data from animal subchronic or chronic
    studies in which a Lowest Observable Adverse
    Effect Level (LOAEL) is determined, but which
    12~—121
    —70—
    otherwise satisfy the standards for a High
    Validity Study; or
    D) Data from animal subchronic or chronic
    studies which have an inappropriate route of
    exposure (for example, intraperitoneal
    injection or inhalation) but which otherwise
    satisfy the standards for a High Validity
    Study, with correction factors for conversion
    to the oral route.
    3) Low Validity Studies
    Low validity studies are studies not meeting the
    standards set forth in subsection (c) (1) or
    (c) (2)
    .
    -
    12 7—122
    —71—
    Section 620.Appendix B Procedures for Determining Hazard
    Indices for Class I: Potable Resource
    Groundwater for Mixtures of
    -
    Similar-Acting Substances
    a)
    This appendix describes procedures -for evaluating
    mixtures of similar—acting substances which may be
    present in Class I: Potable ~Resource Groundwaters.
    Except as provided otherwise in subsection
    (C),
    subsections (d) through (h) describe the procedure for
    determining the Hazard Index for mixtures of
    similar—acting substances.
    b)
    For the purposes of this appendix, a “mixture” means
    two or more substances which are present in Class I:
    Potable Resource Groundwater which may or may not be
    related either chemically or commercially, but which
    are not complex mixtures of related isomers and
    congeners which are produced as commercial products
    (for example, PCB5 or technical grade chlordane).
    c) The following substances listed in Section 620.410 are
    mixtures of similar acting substances:
    1) Mixtures of ortho—Dichlorobenzene and
    para-Dichlorobenzene. The Hazard Index (“HI”) for
    such mixtures is determined as follows:
    HI
    =
    ortho-Dichlorobenzene\0.6
    +
    para-Dichlorobenzene \0.075
    2) Mixtures of l,1-Dichloroethylene and
    l,l,1-trichloroethane. The Hazard Index (“HI”)
    for such mixtures is determined as follows:
    HI
    =
    ~l,1-Dichloroethy1ene)\0.007 +
    1,1, l—trichloroethane\O.2
    d) When two or more substances occur together in a
    mixture, the additivity of the toxicities of some or
    all of the substances will be considered when
    determining health-based standards for Class I: Potable
    Resource Groundwater. This is done by the use of a
    dose addition model with the development of a Hazard
    Index for the mixture of substances with similar—acting
    toxicities. This method does not address synergism or
    antagonism. Guidelines for determining when the dose
    addition of similar—acting substances is appropriate
    are presented in Appendix C.
    127—123
    —72—
    The Hazard Index is calculated as follows:
    HI
    =
    A\ALA + B\ALB
    + . . .
    I)\ALI
    Where:
    HI
    =
    Hazard Index, unitless.
    A), (B, I)
    =
    Concentration of each
    similar-acting substance in groundwater in
    milligrams per liter (mg/L).
    ALA, ALB, ALl
    =
    The acceptable level of each
    similar—acting substance in the mixture in
    milligrams per liter (mg/L).
    e) For substances which are considered to have a threshold
    mechanism of toxicity, the acceptable level is:
    1) The standards listed in Section 620.410; or
    2) For those substances for which standards have not
    been established in Section 620.410, the Human
    Threshold Toxicant Advisory Concentration (HTTAC)
    as determined in Appendix A.
    -
    f) For substances which are carcinogens, the acceptable
    level is:
    1) The standards listed in Section 620.410; or
    2) For those substances for which standards have not
    •been established under Section 620.410, the lowest
    appropriate PQL of USEPA-approved analytical
    methods specified in SW-846, incorporated by
    reference at Section 620.125, for each substance.
    g) Since the assumption of dose addition is most properly
    applied to substances that induce the same effect by
    similar modes of action, a separate HI must be
    generated for each toxicity endpoint- of concern.
    h) In addition to meeting the individual substance
    objectives, a Hazard Index must be less than or equal
    to 1 for a mixture of similar—acting substances.
    12 7—124
    —73—
    Section 620.Appendix C
    Guidelines for Determining When Dose
    Addition of Similar-Acting Substances in
    Class I: Potable Resource Groundwaters
    is Appropriate
    -a)
    Substances must be considered similar—acting if:
    1)
    The substances have the same target in an organism
    (for. example, the same organ, organ system,
    receptor, or enzyitte).
    2)
    The substances have the same mode of toxic action.
    These actions may include, for example, central
    nervous system depression, liver
    toxicity, or
    cholinesterase inhibition.
    b)
    Substances that have fundamentally different mechanisms
    of toxicity (threshold toxicants vs. carcinogens) must
    not be considered similar—acting. However, carcinogens
    which also cause a threshold toxic effect should be
    considered in a mixture with other similar—acting
    substances having the same threshold toxic effect. In
    such a case, an Acceptable Level for the carcinogen
    must be derived for its threshold effect, using the
    procedures described in Appendix A.
    c) Substances which are components-of a complex mixture of
    related compounds which are produced as commercial
    products (for example, PCBs or technical grade
    chlordane) are not mixtures, as defined in Appendix B.
    Such complex mixtures are equivalent to a single
    substance. In such a case, the Huma-n Threshold
    Toxicant Advisory Concentration may be derived for
    threshold effects of the complex mixture, using the
    -
    procedures described in Appendix A, if valid
    -
    toxicological or epidemiological data are available for
    the complex mixture. If the complex mixture is a
    carcinogen, the Health Advisory Concentration is the
    lowest appropriate PQL of USEPA-approved analytical
    methods specified in SW-846, incorporated by reference
    at Section 620.125.
    12 7—125
    —74—
    Section 620.Appendix D
    Confirmation of an Adequate Corrective
    Action Pursuant to 35 Ill. Adm. Code
    620.250 (a)(2).
    Pursuant to 35 Ill. Adm. Code 620.250(a) if an owner or operator
    provides a written confirmation to the Agency that an adequate
    corrective action, equivalent to a corrective action process
    approved by the Agency, is being undertaken in a timely and
    appropriate manner, then 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. This document provides the form in
    which th’e written confirmation is to be submitted to the Agency.
    Note 1. Parts I and II are to be submitted to IEPA at the time
    that the facility claims the alternative groundwater
    standards. Part III is to be submitted at the
    completion of the site investigation. At the
    completion of the corrective process, a final report is
    to be filed which includes the confirmation statement
    included in Part IV.
    Note 2. The issuance of a permit by IEPA’s Division of Air
    Pollution Control or Water Pollution Control for a
    treatment system does not imply that the Agency has
    approved the corrective action process.
    Note 3. If the facility is conducting a cleanup of a unit which
    is subject to the requirements of the Resource
    Conservation and Recovery Act (RCRA) or the 35 111.
    Adm. Code 731 regulations for Underground Storage
    Tanks, this confirmation process is not applicable and
    cannot be used.
    Note 4. If the answers to any of these questions require
    explanation or clarification, provide such in an
    attachment to this document.
    Part I. Facility Information
    Facility Name
    ____________________________________________
    Facility Address
    -
    County
    -
    -
    Standard Industrial Code (SIC)
    ______________________________
    1. Provide a general description of the type of industry,
    products manufactured, raw materials used, location and
    size of the facility.
    2. What specific units (operating or closed) are present
    at the facility which are or were used to manage waste,
    hazardous waste, hazardous substances or petroleum?
    12 7—126
    —75—
    YES
    NO
    Landfill
    Surface Impoundment
    Land Treatment
    Spray Irrigation
    -
    Waste Pile
    -
    Incinerator
    Storage Tank (above ground)
    Storage Tank (underground)
    Container
    Storage Area
    Injection Well
    Water Treatment Units
    Septic Tanks
    French Drains
    Transfer Station
    Other Units (Please describe)
    3. Provide an extract from a USGS topographic or county
    map showing the location of the site and a more
    --
    detailed scaled map of the facility with each waste
    management unit identified in Question 2 or
    known/suspected source clearly identified. Map scale
    must be specified and the location of the facility must
    be provided with respect to Township, Range and
    Section.
    4. Has the facility ever conducted operations which
    involved the generation, manufacture, processing,
    transportation, treatment, storage or handling of
    “hazardous
    substances” as defined by the Illinois
    Environmental Protection Act? Yes
    _____
    No
    _____
    If
    the answer to this question is “yes” generally describe
    these operations.
    5. Has the facility generated, stored or treated hazardous
    waste as defined by the Resource Conservation and
    Recovery Act? Yes
    _____
    No
    ______
    If the answer to
    this question is “yes” generally describe these
    operations.
    6. Has the facility conducted operations which involved
    the processing, storage or handling of petroleum?
    Yes
    _____
    No
    _____
    If the answer to this questions is
    “yes” describe these operations.
    7. Has the facility ever held any of the following
    permits?
    a. Permits for any waste storage, waste treatment or
    waste disposal operation. Yes
    _____
    No
    _____
    If
    127—127
    —76—
    the answer to this question is “yes”, identify the
    IEPA permit numbers.
    b.
    Interim Status under the Resources Conservation
    and Recovery Act (filing of a RCRA Part A
    application).
    Yes
    _____
    No
    _____
    If the answer
    to this question is “yes”, attach a copy of the
    last approved Part A application.
    -
    -
    c. RCRA Part B Permits. Yes
    _____
    No
    _____
    If the
    answer to this question is “yes”, identify the
    permit log number.
    8. Has the facility ever conducted the closure of a RCRA
    hazardous waste management unit? Yes
    ______
    No
    9. Have any of the following State or federal government
    -
    actions taken place for a release at the facility?
    a. Written notification regarding known, suspected or
    alleged contamination on or emanating from the
    property (e.g., a Notice pursuant to Section 4(q)
    of the Environmental Protection Act)? Yes
    _____
    No
    _____
    If the answer to ths question is “yes”,
    identify the caption and date of issuance.
    b. Consent Decree or Order under RCRA, CERCLA, EPAct
    Section 22.2 (State Superfund), or EPAct Section
    21(f) (State RCRA). Yes
    ____
    No
    ____
    c. If either of Items a or b were answered by
    checking “yes”, is the notice, order or decree
    still in effect? Yes
    _____
    No
    _____
    10. What groundwater classification will the facility be
    subject to at the completion of the remediation?
    Class I
    _____
    Class II
    _____
    Class III
    _____
    Class IV
    _____
    If more than one Class applies, please-
    explain.
    11. Describe the circumstances which the release to
    groundwater was identified.
    -
    Based on my inquiry of those persons directly responsible for
    gathering the information, I certify that the information
    submitted is, to the best of my knowledge and belief, true and
    accurate.
    Facility Name
    Signature of Owner/Operator
    Location of Facility
    Name of Owner/Operator
    12 7—128
    —77—
    EPA Identification Number
    Date
    PART II: Release Information
    1.
    Identify the chemical constituents released to the
    groundwater.
    Attach additional documents as necessary.
    Chemical Description
    -
    Chemical Abstract No.
    2. Describe how the site will be investigated to determine
    the source or
    sources of the release.
    3. Describe how groundwater will be monitored to determine
    the rate and extent of the release.
    4. Has the
    release been contained on-site at the facility?
    5. Describe the groundwater monitoring network and
    -
    groundwater
    and soil sampling protocols in
    place at the
    facility.
    6. Provide the schedule for investigation and monitoring.
    7. Describe the laboratory quality assurance progra-m
    utilized for the investigation.
    8. Provide a summary of the results of available soil
    testing and groundwater monitoring associated with the
    release at the facility. The summary of results should
    provide the following information: dates of sampling;
    types of samples taken (soil or water); locations and
    depths of samples; sampling and analytical methods;
    analytical laboratories used; chemical constituents for
    which analyses were performed; analytical detection
    limits; and concentrations of chemical constituents in
    ppm (levels below detection should be identified as
    “ND”).
    Based on my inquiry of those persons directly responsible for
    gathering the information, I certify that the
    information
    submitted is, to the best of knowledge and belief, true and
    -
    accurate and confirm that the actions identified herein will be
    undertaken in accordance with the schedule set forth herein.
    Facility Name
    Signature of Owner/Operator
    12 7—129
    —78—
    Location of Facility
    Name of Owner/Operator
    EPA Identification
    Number
    Date
    Part III:
    Remedy Selection Information
    1.
    Describe the selected remedy.
    2.
    Describe other remedies which were considered and why
    -
    they were rejected.
    3.
    Will waste, contaminated soil or contaminated
    groundwater be removed from the site in the course of
    this remediation?
    Yes
    _____
    No
    _____
    If the answer
    to this question is “yes”, where will the contaminated
    material be taken?
    4.
    Describe how the selected remedy will accomplish the
    maximum practical restoration of beneficial use of
    groundwater.
    5. Describe how the selected remedy will minimize any
    threat to public health or the environment.
    - -
    6.
    Describe how the selected remedy will result in
    compliance with the applicable groundwater standards.
    7.
    Provide a schedule for design, construction and
    operation of the remedy, including dates for the start
    and completion.
    -
    8.
    Describe how the remedy will be operated and
    maintained.
    9.
    Have any of the following permits been issued for the
    remediation?
    a.
    Construction or Operating permit from the Division
    of Water Pollution Control.
    Yes
    _____
    No
    _____
    b.
    Land treatment permit from the Division of Water
    Pollution Control. Yes
    _____
    No
    _____
    If the
    answer to this question is “yes”, identify the
    permit number.
    c.
    Construction or Operating permit from the Division
    of Air Pollution Control.
    Yes
    _____
    No
    _____
    If
    the answer to this question is “yes”, identify the
    permit number.
    12 7—130
    —79—
    10. How will groundwater at the facility be monitored
    following completion of the remedy to ensure that the
    -
    groundwater standards have been attained?
    Based on my inquiry of those persons directly responsible for
    gathering the information, I certify that the information
    submitted is, to the best of my knowledge and belief, true and
    accurate and confirm that the actions identified herein will be
    undertaken in accordance with the schedule set forth herein.
    Facility Name
    Location of Facility
    Signature of Owner/Operator
    Name of Owner/Operator
    EPA Identification Number
    Date
    PART IV: Completion Certification
    This certification
    must accompany documentation which includes
    soil and groundwater monitoring data demonstrating successful
    completion of the corrective process described in Parts I—Ill.
    Facility Name
    Facility Address
    County ______________________
    Standard Industrial Code (SIC)
    Date
    Based on my inquiry of those
    persons directly responsible for
    gathering the information, I certify that an adequate corrective
    action, equivalent to a corrective action process approved by the
    Agency, has been undertaken and that the following restoration
    concentrations are being met:
    Chemical Name
    -
    Chemical
    Abstract No.
    Concentration
    (mg
    /1)
    Facility Name
    Signature of Owner/Operator
    Location of Facility
    Name of Owner/Operator
    127— 13 1
    —80—
    EPA Identification Number
    Date
    IT IS SO ORDERED.
    Board Member J.D. Dumelle concurred.
    I, Dorothy M. Gunn, Clerk of the Illinois Pollution Control
    Board, hereby certify that the above. 0 inion and Order was
    adopted on the
    7Z1
    day of
    _____________________,
    1991, by
    a vote of
    7-o
    I
    Control Board
    127—132

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