ILLINOIS POLLUTION CONTROL BOARD
    November
    17,
    1988
    SHELL OIL COMPANY,
    Petitioner,
    )
    v.
    )
    PCB 88—188
    ILLINOIS ENVIRONMENTAL
    )
    PROTECTION AGENCY,
    )
    Respondent.
    ORDER OF THE BOARD
    (by 3. Anderson):
    On November
    16,
    1988, Shell Oil Company
    (Shell)
    filed
    a
    petition seeking variance from 35
    Ill.
    Adm.
    Code 901.102(a)
    and
    901.103 of the Board’s
    noise regulations.
    In
    its petition,
    Shell
    identifies
    the applicable Boar~’snoise regulations
    as those
    adopted
    in 1973
    in R72—2.
    Shell
    is advised that on January 22,
    1987,
    in R83—7, the
    Board adopted amendments
    to its noise regulations that affect the
    compliance requirements of
    35
    Ill.
    Adm.
    Code
    901.
    The R83—7
    Opinion and Order of the Board
    is enclosed.
    Shell’s petition
    is
    deficient insofar
    as
    it fails
    to reflect the amended measurement
    procedures applicable
    to Section 901
    as amended
    in R83—7.
    Unless an amended petition
    is
    filed within
    45 days of
    the
    date of this Order, curing the above—noted defects,
    this matter
    will be subject to dismissal.
    IT
    IS SO ORDERED.
    I,
    Dorothy M.
    Gunn, Clerk of Lhe Illinois Pollution Control
    Board,flç.xeby cer
    y that the above Order was adopted on
    the )7’~day of
    -
    ,
    1988,
    by
    a vote of
    7-~
    Dorothy M.Aunn,
    Clerk
    Illinois Pollution Control Board
    93—475

    ILLINOIS POLLUTION CONTROL BOARD
    January 22,
    1987
    IN THE MATTER OF:
    )
    )
    GENERAL MOTORS CORP.
    )
    PROPOSED AMENDMENTS
    )
    R83—7
    TO 35 ILL. ADM.
    CODE
    )
    900.103 AND 901.104
    )
    ADOPTED RULE.
    FINAL ORDER.
    FINAL OPINION AND ORDER OF THE BOARD (by J.
    Anderson):
    Procedural History
    This matter comes before the Board on the petition for
    change of the Board’s noise regulations, filed by General Motors
    Corporation
    (GM)
    February
    24,
    1983
    as amended April
    13, 1984.
    In
    summary,
    GM proposes amendments to
    35
    Iii.
    Adm.
    Code 900.103(b)
    “Measurement Procedures”
    applicable to Part 901 to require use of
    one hour Leq averaging in determining compliance with the
    regulations
    (except for blasting noise),
    as well as
    correction of
    measurements
    for ambient noise, and amendment to 35 Ill.
    Adm.
    Code 901.104
    “Impulsive
    Sound” by deletion of the required
    measurement by “fast dynamic characteristic”
    in conformance with
    the proposed amendment
    to Section 900.l03(b).*
    GM’s assertion is
    that these amendments are necessary to insure correct
    implementation
    of the Board’s intention
    in adopting the original
    noise regulations that sound measurements used to assess
    compliance
    be
    “in substantial conformity with standards
    established by the American National Standards Institute,
    Inc.
    (ANSI)”,
    See R72-2,
    In The Matter
    Of: Noise
    Pollution Control
    Regulations,
    Order of July 23,
    1973,
    Opinion of July
    31,
    1973,
    p.
    23.
    Merit hearings were held on this proposal on June
    22, and
    November
    22-23,
    1983,
    at which some economic data were
    presented.
    No separate economic impact hearings have been held,
    given
    the determination of the Department
    of
    Energy and Natural
    Resources
    (DENR) that:
    “While
    it may
    be
    possible
    to
    quantify some
    of
    the
    *This Opinion refers to the rules
    as renumbered upon
    codification;
    the record
    in part refers to the old rule
    numbers.
    The initial proposal referred to the applicable rules
    prior to codification,
    then numbered
    as Rules
    103 and 206 of the
    Chapter
    8:
    Noise Regulations.
    Prior to codification, Rule 206
    “Impulsive
    Sound” was renumbered to Rule 205
    in R76-14, and upon
    codification was renumbered
    to Section 901.104.
    Old Rule 103 was
    codified as
    901.103.
    75-106
    93—476

    -2-
    costs
    and benefits of R83-7,
    such a study would be
    costly
    and
    would
    probably
    not
    contribute
    much
    beyond
    what
    has
    already
    been
    entered
    into
    the
    record.
    Therefore,
    the
    following
    criterion
    specified
    in
    Section
    IV(d)
    of PA 83-468 applies
    in
    this matter:
    The
    cost
    of
    making
    a
    formal
    study
    is
    economically
    unreasonable
    in
    relation
    to
    the
    value of the study to the Board
    in determining
    the
    adverse
    economic
    impact
    of
    the
    regulation.”
    (DENR Letter of 12-23-83;
    see also DENR Letter of 3-12-
    84.)
    Post-hearing comments were filed by GM on April
    13 and June
    15,
    1984, and by the Illinois Environmental Protection Agency
    (Agency) on May
    3,
    1984.
    CM,
    the Agency,
    and DENR were the only
    active participants
    in this proceeding.
    Testimony on CM’s behalf
    was presented
    by
    Richard R. James, former Vice President of Total
    Environmental Systems,
    Inc.
    (TES),
    a noise consulting firm; James
    H.
    Pyne, CM Staff Engineer
    in Plant Engineering and Development,
    Advanced Product and Manufacturing Staff, who is responsible for
    overseeing and directing
    CM’s
    Noise Control Program; Roy F.
    Larson, Environmental Coordinator at the GM Central Foundry
    in
    Danville; and Woodford Van Tifflin, Supervisor of
    Engineering in
    Plant Engineering Programs.
    CM Central Office.
    Limited testimony
    in response
    to Board questions was given on behalf of the Agency
    by Major Hearn, Jr.
    By action on November
    7,
    1985,
    the Board proposed for first
    notice certain amendments
    to the Board’s
    rules and regulations
    governing noise; publication of the proposed amendments occurred
    in
    10 Illinois Register 4175,
    March
    7,
    1986.
    Subsequent to publication of the proposed amendments,
    the
    Board received three Public Comments
    (“PC”):
    PC
    #3 filed May 7,
    1986,
    by the Midwest Environmental Assistance
    Center;
    PC
    #4 filed
    May 12,
    1986,
    by Commonwealth Edison;
    and PC
    #5 filed June
    30,
    1986,
    by GM.
    Based on
    a review of the record,
    as augmented by these
    public comments,
    on December
    5,
    1986 the Board adopted Opinion
    and Order proposing amendments
    to
    35 Ill.
    Adm.
    Code Sections
    900.103(b) and 901.104.
    In so doing,
    the Board modified the
    first notice proposal to delete
    a proposed alternative
    measurement procedure
    (proposed
    Section 901.130)
    in response to
    public comments.
    As
    its meeting of January
    13,
    1987,
    the Joint Committee on
    Administrative Rules issued
    a certificate of no objection to the
    rules.
    Accordingly,
    the Board adopts amendments
    to
    35 Ill.
    Adm.
    75-107

    -3—
    Code 900.103 and 901.104 as proposed at second notice and set
    forth
    in the Order below.
    Factual Background Prompting the GM Proposal
    GM’s
    Illinois operations include
    a gray iron foundry located
    partially
    in Danville and partially in Tilton,
    a Fisher Body
    plant
    in Willow Springs which fabricates and assembles automobile
    bodies,
    and two Electro-Motive plants:
    Plant
    #1
    in
    La Grange,
    which fabricates and assembles diesel-electric powered railroad
    locomotives, power generating units
    for petroleum drilling rigs,
    and diesel power sources for various applications, and Plant
    #2
    in Chicago, which primarily fabricates and welds primary engine
    and electric motor components.
    Data from noise surveys at the
    Danville plant were those primarily used
    to exemplify CM’s
    concerns with the wording and implementation of the existing
    rules, although some data from the other plants was also
    discussed.
    The Agency began an investigation of noise emissions
    at GM’s
    Danville facility in
    1978,
    as
    a result of
    a complaint
    in
    February,
    1978 from
    a Tilton resident,
    Mr. Wayne
    H.
    Powers,
    who
    complained of
    a
    “high pitch tone soundingl
    like very large
    electric motors”.
    As
    a
    follow-up to the complaint
    the Agency
    contacted eight other residents,
    5 of whom shared
    Mr. Powers’
    complaint.
    See Agency Comments of 5-3-84,
    p.
    6 and Attach.
    3-4.
    The
    record of Agency monitoring activities
    at Danville shows
    that there were at least seven field trips to acquire data.
    Measurements were taken pursuant
    to the criteria adopted by the
    Agency pursuant
    to Section 900.103(b)
    on February
    8, 1980
    (Exh.
    C).
    The first trip was on May
    17,
    1978,
    and the most recent was
    on January
    29,
    1981.
    Exhibit
    “L” summarizes the first
    six trips,
    which covers eight
    tests.
    The ninth test was on January
    29,
    1981.
    Exhibit
    “L” shows each of the test dates,
    the time spent
    by the Agency staff on site,
    the type of analyzer used,
    the total
    sample length
    (period of observation), range of levels
    (or
    “average” level)
    in the 160 Hz 1/3 octave band, and the delta
    (or
    range
    of deltas) used
    to define the presence of
    a prominent
    discrete tone.
    The January
    29,
    1981,
    test was conducted between
    the hours of 11:30 a.m.
    and 1:30 p.m.
    Visual observations
    of
    levels were made with
    a B&K 2209 SLM and
    1/3 octave filter set.
    The data was also tape recorded
    for subsequent analysis.
    This
    analysis consisted of
    3 sample periods covering 116 seconds of
    data
    from the
    B&!
    2131,
    which was
    set to an averaging time
    of one
    second.
    The range
    of levels
    in the 160 Hz 1/3 octave band was
    62
    to
    66 dB, with the deltas ranging from
    7
    to
    14 dB.
    Data collection and analysis
    followed one of two methods.
    Exhibit
    “L” shows the method used by the Agency for each test,
    by
    referring to
    “Filter and SLM (Fast or
    Slow),” or
    “Taped B&K
    2131.”
    The
    first method involved visual reading
    of the sound
    level in each
    1/3 octave band directly
    from the readout meter of
    the B&K 2209 sound
    level meter, equipped with
    a
    B&F( 1616 1/3
    75-108
    93—478

    -4—
    octave band filter set.
    No record was provided of the period of
    observation or methodology used
    to determine the reported
    levels.
    The second method involved tape recording the community
    noise at the test sites.
    This recording was subsequently
    analyzed at an Agency laboratory.
    The typical analysis procedure,
    as described on page
    5 of
    the Agency’s
    Noise Survey Report,
    is shown
    in Exhibit
    “M.”
    It
    documents the Agency’s data collection and analysis procedures
    for the testing conducted on July
    18,
    1979,
    as.
    follows:
    “The data
    was accumulated using
    the Nagra IV-
    SJ
    taperecorder
    and
    magnetic
    tape
    at
    7.5
    inches
    per
    second
    tape
    speed
    on
    fast
    channel
    #1.
    The data was analyzed by playback of the
    magnetic
    tape
    on
    the same recorder
    (Nagra IV-
    SJ)
    at the same speed
    (7.5 ips)
    into the Bruel
    and Kjaer model
    2131
    Digital
    Frequency third-
    octave
    analyzer.
    The
    2131
    supplies
    the
    information
    to
    the
    Hewlett
    Packard
    9825A
    calculator.
    The
    calculator
    has
    been
    programmed
    to accept the information and apply
    all correction factors, except those necessary
    due
    to
    ambient
    SPL’s
    and
    print
    the corrected
    data
    in
    1/3
    octaves
    and
    summed
    octave bands.
    The
    HP
    9825A
    printouts
    are
    included
    in
    this
    report.
    Several averaging
    times were used
    on
    the noise
    source.
    The important
    fact
    is that
    over
    a
    32 second averaging time the prominent
    discrete
    tone
    is
    still
    present.
    Thereby
    indicating,
    the pure tone can be characterized
    as constantly present.”
    Two different averaging
    times were used.
    Three
    sets of data
    samples were each averaged for one second, and one set of data
    was averaged over
    a 32-second period.
    The 32-second
    sample was
    in compliance with both Rules 202 and 207.
    The physical noise environm~nt is complex.
    In addition
    to
    noise produced by GM,
    there are noise emissions from motor
    vehicles on
    1-74,
    which at that point has a major on-off ramp and
    is elevated on a high berm,
    as well as in-town traffic, and noise
    emissions from the railroad lines
    and one switchyard
    located
    to
    the east and south.
    The
    source of the “high pitch tone” was determined
    to be the
    cupola fume control systems
    at stacks
    1,
    2
    &
    3.
    The schematic
    provided as
    Exhibit
    “H” shows
    the
    2000 HP fan which draws cupola
    emissions through
    the scrubbers.
    The fundamental tone of
    this
    fan
    is related
    to the fan RPM and the number of fan blades.
    For
    this
    fan,
    which
    is used on all three
    stacks, this tone is at 158
    Hz.
    75-109

    -5-
    In response
    to discussions with the Agency in
    1978,
    CM
    installed on an experimental basis
    a corrosion-resistant
    Industrial Acoustic Silencer
    in the No.
    2 cupola.
    This did not
    correct
    the violation noted by the Agency and completely
    disintegrated
    in the stack within
    14 months after installation.
    Testimony of
    W. Van Tifflin,
    p.
    6, and Exh.
    E.
    According to the
    Agency,
    (comments,
    p.
    7)
    “several”,
    unspecified
    operational
    changes
    were
    also
    unsuccessfully
    implemented.
    On
    May
    23,
    1980,
    the Agency issued
    a
    “Notice of Enforcement”
    (Exh.
    E) alleging
    violations
    of
    then
    Rules
    101,
    202,
    and
    207
    concerning
    noise
    nuisance, emission of sounds from Class
    C to Class
    A land,
    and
    prominent discrete tones.
    No enforcement action has ever been
    brought before the Board.
    This does not reflect Agency judgment
    that any problem has been solved, but instead reflects the severe
    cutback
    in the Agency’s Noise Control
    Staff which
    is the result
    of the demise of the Federal Noise Program and its funding for
    state enforcement efforts.
    See Agency Comments,
    p.
    13-19.
    The
    Agency has
    “pressed” for installation by CM of stack silencers
    (~Lc~~~•
    p.
    7).
    CM has investigated this option, and believes that stainless
    steel silencers produced by TLT Babcock are the most feasible
    option.
    Capital, installation and maintenance costs will require
    an expenditure of $142,358 per year
    (in
    1983)
    for every year in
    which GM continues to operate,
    due to the need to replace the
    silencers every five years due
    to corrosion.
    The silencers are
    designed
    to hypothetically achieve
    a 24 dB reduction at the
    cupola.
    Based on extension measurements
    in Mr.
    Power’s yard
    (described
    in more detail below),
    GM asserts that the effective
    reduction of noise to that receiving source is
    4 dB, due to the
    masking of the sound
    from the cupola by ambient, non-GM noise
    sources.
    CM further asserts that installation of such equipment
    to achieve compliance with the numerical limits Part
    901
    (as
    opposed to the noise nuisance of Section 900.102)
    is economically
    unreasonable, based on its belief that the Agency’s noise
    measurement and analysis procedures do not correctly measure
    noise emissions as
    intended by the Board
    in adopting the noise
    regulations.
    See, generally,
    testimony of W. Van Tifflin.
    GM notes
    that,
    based on sound measurements
    in 1981 at
    its
    two Electromotive and its Fisher Body plant, by using the Agency
    measurement techniques
    as employed at the Danville plant,
    that
    a
    measurer could find violations of the Board’ prominent discrete
    and impulsive
    sound
    rules.
    GM does not seek site specific relief
    for each of its four plants, believing
    that non-ANSI complying
    flaws
    in the measurement affect not only GM, but the rest
    of the
    regulated community as well.
    GM’s basic position,
    then,
    is
    that
    as
    a
    “good corporate citizen”
    the responsible position for
    it
    to
    take
    is
    to correct
    the generally applicable
    flaws
    it perceives,
    rather than
    to attach only its specific
    “compliance” problems.
    75-110
    93—480

    -6-
    CM’s Asserted Flaws
    In Agency Measurement and Analysis Techniques
    ANSI S1.13-1971
    (Exhibit D) requires that the measuring
    technician
    measure
    sound
    over
    a
    sufficient
    period
    of
    observation
    to obtain a statistically representative sound level;
    it does not
    specify
    the
    length
    of
    the
    observation
    period.
    It
    also
    requires
    corrections for ambient sounds which are measured along with the
    source
    in
    question.
    ANSI
    S1.13-1971
    provides
    methods
    for
    determining
    the
    true
    root
    mean
    square
    (rms)
    values
    of
    the
    sound
    level
    for
    a
    specified
    period
    of
    observation.
    The
    rms
    sound
    pressure
    level
    is
    also
    known as the “log average
    sound pressure level,”
    “equivalent
    continuous
    sound
    pressure
    level,”
    and
    “Leq”
    when
    referring
    to
    the
    equivalent continuous
    sound level.
    For reasonably steady sounds
    this value is indicated by the position of the meter needle or
    digital readout
    value of the sound level meter.
    When
    fluctuations
    in the meter readout due to variations
    in the
    sound’s amplitude preclude direct readout, ANSI Sl.13 provides
    procedures
    for estimating
    the true rms value
    that work well,
    when
    the variation
    in the sound level over the period of observation
    is reasonably stable and sinusoidal.
    ANSI’s formula for
    averaging independent samples
    is:
    N
    (L./l0)
    L
    =
    10
    *
    LOG
    ~-
    ~
    10
    dB
    Eq.
    1
    j=1
    Where:
    N
    =
    total number of observations
    L1
    =
    the level at each observations.
    ANSI S1.13 recommends
    that if
    the time scale of the
    fluctuations
    is such as
    to make this procedure impractical, other
    techniques,
    such as direct computation of the rms value by analog
    or digital means, are required.
    The digital method utilizes an
    algorithm conceptually similar
    to
    the above
    formula.
    CM asserts that the Agency’s measurement procedures,
    adopted
    February
    8,
    1980,
    under Rule
    103(a) Exhibit
    “C”,
    follow ANSI
    Sl.l3 very closely,
    often paraphrasing whole sections of the
    standard
    --
    except at one very important point.
    The Agency
    modified Equation
    1 to make the input values for L~the maximum
    levels observed, not the statistically independent samples
    intended by ANSI.
    This means that value
    “L”
    is no longer the
    true mean rms level.
    Now “L”
    is instead the log average of the
    maximum values.
    It will thus always be greater than the rms
    value desired, with the discrepancy increasing as
    the magnitude
    of the fluctuations increase and
    as
    the pattern of the variation
    in level deviates from sinusoidal.
    CM further asserts
    that there was also
    a discrepancy
    in
    Agency laboratory procedures.
    This deviation occurs
    in the HP
    9825A computer program, where the sample output levels from the
    B&K 2131 are averaged and printed
    Out.
    This deviation occurs
    75-111
    93—481

    —7—
    because the HP 9825A computer program is written to
    arithmetically average
    the levels.
    Thus, equation
    1 was changed
    to read,
    for the Agency’s measurements
    at Danville,
    to the
    following:
    1
    N
    L
    =
    i=l
    L~)
    Eq.2
    Where:
    N
    =
    total
    number
    of
    samples
    =
    the level of the sample
    output from the B&K 2131.
    This equation
    is not
    in agreement with either the published
    Agency measurement procedures
    of February
    8, 1980,
    or the ANSI
    Sl.l3-l971 methods
    for determining the true rms sound pressure
    level.
    GM/TES FINDINGS AT DANVILLE
    A comprehensive study of the impact of the Danville plant’s
    noise emissions on the Tilton community environment was conducted
    jointly by General Motors’ and TES personnel.
    Data were
    collected jointly by CM representatives and analyzed by TES.
    The
    last completed test
    sequence documented noise levels over a
    24
    hour period,
    at the primary
    test site that was also used by the
    Agency
    -
    Mr.
    Power’s yard.
    Exhibit
    “N” presents the results
    of the 1980 Power’s yard
    tests as log-mean-average
    sound pressure levels, plus or minus
    one standard deviation.
    The data representing each cupola’s
    noise emissions has been separated into two tables.
    The upper
    table
    shows the cupola noise emissions in conjunction with
    traffic and railroad activities.
    The lower table
    shows
    the
    average
    levels
    in each 1/3 octave band
    from the data analysis
    conducted
    to separate
    the plant ,noise from other ambient noise
    sources.
    This table presents the levels
    in the bands adjacent to
    the
    cupola
    noise
    out
    of
    context
    of
    the
    ambient
    environment.
    However,
    this
    is
    a necessary
    step
    in
    defining
    the
    1/3
    octave
    band
    containing cupola noise components, to judge the effect of noise
    control changes.
    A method similar to that used by the Agency was
    used
    in analysis, although the GM/TES averaging was done
    logarithmically, typically over periods of 16
    seconds
    or
    more,
    and was not limited
    to only the maximum levels observed.
    When GM/TES sampled
    for the “with-ambient” condition,
    they
    typically averaged uninterrupted periods of
    3.4 minutes or 6.8
    minutes.
    Mr. James used an
    ‘ear and eye’
    judgment
    to select
    single
    samples
    to make up
    a composite,
    “without-ambient-noise”
    period.
    This was done by sampling when he both heard the tone
    and could
    see that
    the 158 Hz spike was not affected by other
    noise
    components
    in
    the
    160 Hz 1/3 octave band.
    These tables
    75-112
    93—482

    —8—
    represent
    the
    average
    of all the 1980 data (representing normal
    operations)
    that they have analyzed from TES test site tapes at
    Power’s
    yard.
    There
    are
    significant
    differences
    between
    Exhibit
    N
    values
    and those documented by the Agency.
    The
    1981
    data
    is
    the
    most
    comprehensive of all.
    This test
    involved
    8-1/2
    hours
    of
    tape-recorded
    data,
    taken
    beginning
    the
    evening
    of
    June
    30,
    1981,
    and
    ending
    approximately
    24
    hours
    later,
    late
    in
    the
    afternoon
    of
    July
    1,
    1981.
    The
    taping
    sessions
    were
    usually
    1-1/2
    to
    3
    hours
    long,
    and
    were
    timed
    so
    as
    to
    record
    significant
    operating
    periods.
    Taped
    data
    included
    samples from early evening,
    late night through
    to
    shut
    down
    after
    midnight, early morning start-up, midday, and late afternoon.
    These tapes were analyzed
    to determine the 15-minute equivalent
    continuous
    sound pressure levels
    in
    the frequency bands of
    interest.
    Environmental conditions
    during data acquisition placed the
    test site downwind of the plant.
    This condition favors
    propagation of plant
    sounds toward the test site.
    GM asserts
    that the importance of
    the results
    of
    this test
    period
    is
    in the observed short-term variations in the community
    sounds and the acceptable degree of contribution from the foundry
    cupolas when evaluated over
    a
    longer period of observation.
    The
    level of the
    160Hz 1/3 octave band varies from
    a low of 55 dB at
    4:15 p.m.
    on July
    1,
    to
    a high of
    69 dB at 11:30 p.m.
    on June
    30.
    Corresponding differences
    show up
    in the values of the delta
    used to judge prominence of the fan tone at 158 Hz.
    This
    variation over
    a
    day
    makes
    it extremely unlikely that levels
    resulting
    from
    analysis
    of
    the
    short-term
    sampling
    times,
    of
    one
    second
    to
    15
    seconds,
    as
    used
    by
    the Agency, bear any
    relationship
    to
    the
    equivalent
    continuous
    sound
    pressure
    level
    over
    a
    longer
    and
    more
    reasonable
    period
    of
    observation.
    Using
    the 8-1/2 hours
    of test data,
    for the periods
    of the day and
    night when the plant was operating,
    we see average daily noise
    levels of
    63 dB for the 160Hz
    1/3 octave band,
    66 dB for the 125
    Hz octave band,
    and
    a delta of 7.5 for the 160 Hz 1/3 octave band
    containing
    the fan tone.
    GM asserts that the plant’s
    sound
    emissions clearly comply with Rule 207,
    based upon
    a
    “reasonable”
    period of observation as permitted by ANSI.
    GM’s position,
    then,
    is that the Agency’s tests of foundry
    and other community noises
    in Tilton produced skewed data.
    The
    data samples were too short
    to accurately evaluate whether the
    plant’s
    sound levels violate
    Part
    901, and that the misleading
    nature of
    the data was
    then compounded by the Agency’s inaccurate
    version of the ANSI formula
    for determining equivalent continuous
    (or rms)
    sound pressure levels.
    75-113 93—483

    -9-
    HISTORY OF THE BOARD’S NOISE REGULATIONS,
    USEPA NOISE STUDIES AND THE PROPOSAL
    FOR ONE-HOUR Leg AVERAGING
    On July
    26,
    1973, the Board adopted
    Former Chapter
    8 of the
    Illinois
    Pollution
    Control
    Board
    Rules
    and
    Regulations,
    Illinois’
    first
    comprehensive
    noise
    pollution
    control
    regulations.
    In
    its
    July
    31,
    1973
    Opinion
    in
    support
    of
    the
    noise
    regulations,
    the
    Board described
    the regulations as
    “designed
    to
    protect
    people
    in
    the
    State
    from
    the
    unreasonable
    exposure
    to
    environmental
    noise
    burdens.”
    Opinion
    of
    the
    Board,
    R72-2
    at
    20
    (July
    31,
    1973).
    The
    entire
    record
    in
    R72-2
    reflects
    a
    concern
    for
    establishing
    maximum
    noise
    levels
    based
    upon
    anticipated
    community
    response
    (“a regulation should be based on the likelihood of compliant”),
    as well as
    a concern that the standards adopted be economically
    and technically feasible.
    See Opinion
    R72-.-2,
    at 35-39
    (extensive
    analysis of technical feasibility and economic reasonableness
    of
    proposed regulations).
    The limits presently contained
    in Part 901 were established
    following an examination and analysis of community noise
    annoyance.
    In addition to the protection afforded to the general
    public by Part
    901,
    Part 900 accommodated
    the
    specific individual
    by entitling that person to bring
    a complaint,
    under Section
    900.102,
    that
    a particular noise
    source is emitting sound
    “so as
    to cause noise pollution in
    Illinois....”
    Specific measurement procedures were not established by the
    Board
    in R72-2.
    In explaining the measurement procedure
    established
    in Rule 103,
    the Board stated:
    “This rule establishes the basic techniques
    to
    be used
    in measuring sound levels by reference
    to specific published
    standards
    such
    as those
    of
    the
    American
    National
    Standards
    Institute,
    Inc.
    (ANSI).
    Much
    testimony
    appears
    in
    the
    record,
    mainly from
    industry,
    urging that
    the
    techniques be specified
    in more detail
    as part
    of
    the
    regulation.
    This
    was
    felt
    to
    be
    impractical
    given
    the
    uniqueness
    of
    each
    measuring
    location
    in
    the
    state
    and
    the
    periodic development
    of new and more advanced
    techniques.
    Filing
    the
    techniques
    with
    the
    Secretary of State before applying them should
    give
    sufficient
    notice
    of
    their
    nature
    and
    provisions
    to interested persons.
    Application
    of
    the
    measurement
    techniques
    to
    specific
    situations must be done on
    an individual basis
    and
    could
    be
    a
    subject
    to
    challenge
    in
    an
    enforcement
    proceeding.”
    Opinion,
    R72-2,
    at
    23.
    More specifically,
    the problem of measuring varying, non-
    steady noise emissions was not resolved
    in R72-2, primarily due
    75-114
    93—484

    -10-
    to
    the
    absence
    of
    accurate
    and
    efficient
    instrumentation
    to
    measure such noise at that time.
    Indeed,
    the Board recognized
    the
    difficulty
    of measuring fluctuating sound in its Opinion on
    R72-2.
    At page
    19 of
    the
    Board’s Opinion,
    the following
    observation
    is
    found:
    “One
    last
    type
    of
    sound
    is
    fluctuating
    sound,
    where
    the
    sound
    pressure
    level
    varies
    with
    time.
    Some
    sirens
    emit
    noise
    that
    could
    be
    classified
    as
    fluctuating
    and
    there
    is
    also
    machine
    and
    process
    noise
    that
    varies
    regularly
    in
    sound
    level
    with
    time.
    Little
    information
    is
    available
    to
    determine
    its
    relative
    annoyance
    to
    non—fluctuating
    noise.”
    (Emphasis supplied).
    George
    W.
    Kamperman,
    the Agency’s acoustical consultant
    in R72-2,
    confirmed the absence
    of available technology to measure non-
    steady,
    fluctuating noise
    at the time the Board considered R72-2
    in
    a recent letter
    to Petitioner,
    in which Kamperman noted:
    “In
    1972,
    I
    had
    independently
    developed
    laboratory instrumentation for determining the
    average
    sound
    level
    (Leq)
    for
    time
    varying
    sounds.
    There were
    no commercially
    available
    instruments
    for determining the average
    sound
    level
    when
    the
    proposed
    noise
    regulations
    became
    effective.”
    Letter
    to
    Woodford
    Van
    Tifflin
    (April 13,
    1981)
    at
    2.
    The availability of
    that instrumentation today
    is
    reflected
    not
    only in the testimony presented by Petitioner during the public
    hearings on R83-7, but is also noted by
    Karnperman:
    “In
    the
    past
    two
    years,
    several
    instrument
    manufacturers
    have
    started
    marketing
    portable
    microprocessor
    controlled
    sound
    level
    meters
    capable
    of
    computing
    average
    sound
    level.”
    Id.
    There
    was
    no
    evidence
    presented
    to the Board
    in R72-2 that
    community
    annoyance
    or community response to noise
    is best
    determined by measuring short duration maximum level noise
    emissions.
    Research completed subsequent
    to
    the
    adoption
    of the
    original noise regulations provides evidence
    to the contrary.
    Such documentation is contained
    in the report of the United
    States Environmental Protection Agency (USEPA)
    entitled “Public
    Health and Welfare Criteria for Noise,” published July 27, 1973
    (“Criteria
    Document”)
    (Exhibit P);
    a report of USEPA entitled
    “Information on Levels of Environmental Noise Requisite to
    Protect Public Health and Welfare with an Adequate Margin of
    Safety”
    (“Levels Document”), published
    in April,
    1974
    (Exhibit
    MM);
    a report of USEPA’s former Office of Noise Abatement and
    Control (“ONAC”) entitled “Toward
    a National
    Strategy for
    Noise
    75-115
    93—485

    —11—
    Control,” published
    in April,
    1977;
    ANSI S3.23-1980 entitled
    “Sound Level Descriptors
    for Determination of Compatible Land
    Use”;
    ANSI S12.4-198X
    (June
    1983 Draft) entitled
    “Method for
    Assessment
    of
    High-Energy
    Impulsive Sounds with Respect to
    Residential
    Communities”;
    and
    ISO
    Recommendation
    R1996
    entitled
    “Assessment of Noise with Respect to Community Response,” ISO/R
    1996-1971
    (before
    the
    Board
    in
    R72-2).
    Each
    of
    these
    documents
    provides
    support
    for Petitioner’s claim that Leg averaging is
    clearly the most accurate descriptor of community response to
    noise.
    The USEPA Criteria Document was prepared pursuant to the
    directive to the Agency contained
    in the
    Noise
    Control
    Act,
    42
    U.S.C.
    §4904(a),
    to
    develop
    and
    publish
    criteria
    with
    respect
    to
    noise
    which
    reflects
    “the scientific knowledge most useful in
    indicating
    the
    kind
    and
    extent
    of all identifiable effects on the
    public
    health
    or
    welfare
    which
    may
    be
    expected
    from
    differing
    quantities
    and
    qualities
    of
    noise.”
    The
    Criteria Document stated
    that:
    “in
    terms assessing
    the effects
    of noise
    on
    humans,
    Leq
    is
    one
    of
    the
    most
    important
    measures
    of
    environmental
    noise,
    since
    there
    is
    experimental
    evidence
    that
    it
    accurately
    describes
    the onset and progression of hearing
    loss.
    There
    is
    also
    considerable
    evidence
    that
    it
    applies
    to
    human
    annoyance
    due
    to
    noise.”
    Criteria Document at
    2-7.
    After reviewing
    a number of other criteria used to rate community
    response to noise,
    the Report concluded that “to date
    the
    one
    measure of noise that appears
    to be emerging as one of the most
    important measures of environmental noise in terms of the effects
    on man
    is the Energy Mean Noise Level,
    Leq,
    ...“
    Id.
    at
    2-10.
    This conclusion was based
    in part on
    a study undertaken by Task
    Group
    #3 of the USEPA on Aircraft/Airport Noise Study,
    which
    found
    that:
    “The
    ‘energy’
    equivalent,
    or
    average
    A-
    weighted
    sound
    level
    taken
    over
    a
    24-hour
    period,
    with
    a
    10-decibel
    penalty
    applied
    to
    nighttime
    sound
    levels,
    is
    the simplest noise
    measure
    that
    provides
    a
    high
    degree
    of
    correlation
    with
    annoyance,
    complaint
    behavior, and overt community reaction.”
    This conclusion was reinforced by the subsequently published
    Levels Document.
    This
    document, which was more concerned with
    establishing maximum levels rather than measurement procedures,
    nevertheless
    noted
    that criteria for describing time-varying
    community noise must take into account both the level and
    duration of the noise.
    The Levels Document concluded that:
    93—486
    75-116

    -12-
    “ijin
    order
    to
    describe
    the
    effects
    of
    environmental
    noise
    in
    a
    simple,
    uniform
    and
    appropriate
    way,
    the
    best
    descriptors
    are
    the
    long-term
    equivalent
    A-weighted
    sound
    level
    (Leq)
    and
    a
    variation
    with
    a
    nighttime
    weighting,
    the
    day-night
    sound
    level
    (Ldn)
    ...“
    Levels
    Document
    at
    2.
    The USEPA’s recommended criteria levels are found
    in ONAC’s
    report
    entitled
    “Toward
    a
    National
    Strategy
    for
    Noise
    Control.”
    Here,
    the USEPA has
    proposed
    maximum
    levels
    represented
    in
    terms
    of the day-night average
    sound
    level
    (Ldn),
    measured
    over a 24-
    hour period.
    Numerous federal agencies have adopted maximum
    noise
    levels
    for
    projects
    under
    their
    jurisdiction
    expressed
    in
    terms
    of
    an
    average
    equivalent
    sound
    level,
    including
    the
    Department of Housing and Urban Development,
    see
    24 C.F.R.
    §51.103
    (1982),
    the Federal Highway Administration,
    see 23 C.F.R.
    §772 et
    seq,
    and the Federal Aeronautics Administration,
    see
    14
    C.F.R.
    §KI~O.1O1(d) (1982).
    The most recent ANSI publications
    on this point also
    recommend
    a
    time-varying measurement standard for establishing
    the appropriate noise level descriptors
    for determination of
    community response to noise.
    In ANSI S3.23-l980 (Exhibit
    Q),
    a
    day-night average sound level
    is adopted
    as the appropriate
    “acoustical measure
    to be used
    in assessing compatibility between
    various
    land uses and
    an outdoor environment.”
    ANSI S3.23-l980
    proposes
    a period of observation of twenty-four
    (24)
    hours.
    In
    a
    recent
    draft
    proposal
    providing
    for
    a
    method
    of
    assessment
    of
    high-energy
    impulsive
    sounds
    with
    respect
    to
    residential
    communities,
    ANSI
    reaffirms that “A-weighted day-night average
    sound
    level
    is
    the
    primary
    descriptor
    of
    environmental
    noise.”
    See
    ANSI
    S12.4-l98X
    (June
    1983
    DraFt),
    at
    1.
    The International Organization for Standarization published
    ISO Recommendation
    P.1996
    in
    1971.
    This document, which was
    introduced as an exhibit
    in the original proceedings
    on R72-2 and
    is referred to in several parts pf the Board’s Opinion on R72-2,
    suggests methods
    of measuring and rating noise in
    a manner
    “suitable for predicting approximately the public reaction likely
    to be caused by noise.”
    ISO/R 1996-1971
    at
    3
    (Exhibit S).
    At
    Section
    3.1.5 the ISO document states:
    “If
    the
    noise
    varies
    with
    time
    in
    a
    more
    complicated manner than
    is appropriate for the
    use of Table
    1,
    the equivalent
    sound level
    Leq
    should
    be
    obtained,
    for
    example
    from
    a
    statistical
    analysis
    of
    the
    time
    history
    of
    the A-weighted
    sound level.”
    When reviewing
    the existing national and international
    standards
    it
    is clear
    that the Leq and day-night average
    sound
    level
    (Ldn) measurement criteria are the most widely accepted
    75-117
    93—487

    -13-
    measurement
    criteria
    utilized
    today
    for
    the
    measurement
    of
    community response
    to noise.
    The Model Community Noise Control Ordinance was developed by
    The
    National
    Institute
    of
    Municipal
    Law
    Enforcement
    Officers
    and
    the
    Environmental
    Protection
    Agency,
    Office
    of
    Noise
    Abatement
    Control
    September,
    1975.
    The
    Model
    Community
    Noise
    Control
    Ordinance,
    which
    sets
    forth
    guidelines
    for
    localities
    that
    are
    developing
    noise
    regulations,
    advocates
    averaging
    by
    utilizing
    the
    equivalent
    A-weighted
    sound
    level
    (Leq)
    over
    a
    time
    period
    of
    twenty-four
    (24)
    hours.
    The
    24-hour
    averaging
    period
    suggested
    by
    the
    Model
    Community
    Noise
    Control
    Ordinance
    permits
    the
    exceedence
    of
    the
    prescribed
    decibel
    limits
    as
    long
    as
    the
    decibel
    level,
    as
    averaged
    over
    a
    twenty-four
    (24)
    hour
    period,
    does not exceed those limits.
    As previously noted, CM has proposed
    a
    1 hour, rather than
    a
    24 hour Leq averaging system.
    This does not reflect CM’s
    disagreement with the
    24 hour method, but is proposed to aid
    enforcement by reducing sampling time by enforcement
    authorities.
    The Board also notes
    that,
    since the
    1 hour Leq
    averaging could be enforced for a period of maximum hourly
    measurements,
    it could be more stringent than
    a
    24 hr. Leq.
    THE ECONOMIC RECORD
    No separate economic hearings have been held.
    In addition
    to the previously mentioned
    cost data presented by GM concerning
    the enforcement scheme,
    the Agency’s comments present data
    concerning the costs
    to the Agency of the rule change.
    These
    relate primarily to equipment costs and manpower costs.
    Due
    to truncation of the Agency’s noise control staff, an
    integral part
    of its program is the training of local enforcement
    officials
    to investigate noise complaints, through
    the use of
    sound monitoring equipment loaned them by the Agency free of
    charge.
    The Agency owns some 35-plus
    sound level meters,
    15 of
    which were then on loan, none of which were capable of measuring
    Leq.
    CM presented evidence
    (Exh’.
    CC)
    that adapters for existing
    equipment were available for about $1,000 per unit, which
    presumably would be borne by the Agency.
    The Agency is
    also concerned about the increase in time
    spent in investigation of complaints.
    Using the fast scale
    measurement technique,
    the Agency asserts
    that 10-20 minutes
    are
    occupied
    in measurements; one hour or more could be spent
    in
    obtaining an accurate Le
    reading.
    In
    1984,
    the Agency employed
    only two noise inspector~, responsible for investigating the 250
    noise complaints filed with the Agency between September,
    1982,
    and May,
    1984.
    The Agency asserts that any additional time spent
    investigating complaints
    “could be terminal to the already
    extremely fragile
    -
    program.”
    75.118
    93—488

    —14—
    The
    final
    source
    of
    economic
    information
    is
    the
    DENR’s
    letter
    determining
    that
    the
    cost
    of
    making
    a
    formal
    EelS
    is
    unreasonable
    in
    relation
    to
    the
    value
    of
    a
    study
    to
    the
    Board.
    DENR
    made
    clear
    that
    this
    determination
    was
    made
    on
    the
    basis
    of
    review
    of
    the
    1973
    USEPA
    document
    “Public
    Health
    and
    Welfare
    Criteria
    for
    Noise,”
    and
    ANSI
    S3.23-1980
    (each
    of
    which
    were
    reviewed
    supra,
    p.
    8).
    DENR
    agrees
    with
    GM’s
    contention
    that:
    “(1)
    IEPA’s
    ‘grab
    sample’
    noise
    measurement
    technique
    is
    incorrect,
    and
    (2)
    the
    ‘grab
    sample’
    technique
    is
    not
    an
    adequate
    descriptor
    for
    community
    annoyance.”
    DENR
    further
    stated
    that:
    “The
    conclusion
    that
    IEPA has been
    measuring
    noise
    incorrectly,
    i.e.,
    not
    is
    substantial
    conformity
    with
    ANSI
    under
    Rule
    103(b),
    has
    had
    a
    significant
    impact
    on
    our
    analysis
    of
    the economic consequences
    of R83-7.
    Consider
    the following:
    if IEPA measurement procedures
    were in substantial conformity with ANSI,
    then
    R83-7
    would
    redefine
    compliance
    for
    certain
    firms which were out of compliance because of
    their
    marginal
    short-term
    excursions
    of
    the
    noise
    standards.
    Because
    the IEPA procedures
    used
    to
    determine
    compliance
    are
    apparently
    erroneous,
    R83-7
    does
    not
    redefine
    compliance;
    it
    specifies
    procedures
    for
    determining
    compliance
    which
    are
    in
    accordance
    with
    ANSI
    and
    USEPA
    recommendations.
    R83-7
    merely
    clarifies
    Rule
    103(b)
    because
    the
    Board
    intended measurement
    procedures
    to track ANSI
    and
    intended
    noise
    regulation
    to
    reflect
    community annoyance.
    With
    this
    interpretation
    in
    mind,
    an
    assessment
    of
    the
    ec9nomic
    consequences
    of
    R83-7
    is
    relatively
    straightforward.
    The
    costs of the proposed regulation will be borne
    in
    large
    part
    by
    the
    IEPA.
    GM
    presented
    testimony on 11/22/83,
    which clearly delineate
    the
    cost
    of
    adapting
    IEPA
    noise
    level
    meters
    and other
    equipment
    to accommodate
    the 1 hour
    Leq measurement
    technique.
    The Department’s
    independent
    calculations
    agree
    with
    those
    presented
    by
    CM.
    The
    IEPA
    will
    also
    bear
    added
    manpower
    costs
    because
    data
    collection
    in enforcement
    cases will require at
    least one
    hour of staff
    time.
    However, we believes that
    the unquantifiable
    benefit
    of having reliable
    data
    on
    noise
    emissions
    far
    outweighs
    the
    added manpower and other costs
    to the IEPA.
    75-119

    —15—
    R83-7
    may
    impose
    some
    costs
    on private
    firms
    which
    monitor
    their
    own
    noise
    emissions
    with
    noise meters which are incompatible with the
    1
    hour
    Leq.
    However
    few
    industries
    and
    especially
    few
    small businesses monitor their
    own
    noise.
    If
    an
    industry or
    small business
    wanted to monitor noise,
    an independent
    noise
    consultant
    would
    normally
    be
    hired.
    Municipalities will
    not
    be
    effected
    by
    R83-7
    because
    the
    proposed
    regulation
    is
    only
    applicable
    to
    measurement
    techniques
    in
    enforcement cases
    (Part
    2 of Chapter 8).
    With
    respect
    to
    the
    benefits
    of
    R83-7,
    the
    principal benefit will accrue
    to
    the citizens
    of
    Illinois
    because
    the
    IEPA will
    be
    able
    to
    concentrate on those noise emitters which have
    an
    impact
    on
    health
    and
    welfare
    of
    the
    population.
    Other
    benefits
    will
    accrue
    to
    some
    noise
    emitters
    which
    the
    IEPA
    have
    determined
    to
    be
    non-compliant
    because
    of
    marginal
    short-term
    noise
    excursions,
    i.e.,
    certain
    firms
    will
    not
    be
    required
    to
    implement
    controls
    because
    their
    noise
    does
    not
    violate
    the
    standards
    set
    forth
    by
    the
    Board”
    (DENR
    Letter of
    December
    20,
    1983,
    pp.
    2-3).
    RATIONALE FOR
    THE PROPOSED AMENDMENTS
    When the Board originally promulgated regulations
    in 1973 to
    control
    noise
    pollution
    (In
    The
    Matter
    Of:
    Noise
    Pollution
    Control Regulations, R72-2,
    8 PCB 653 and
    8 PCB 703),
    it did
    so
    under
    the
    premise
    that
    community
    response
    constituted
    the
    principal test against which
    a noise was to be judged as
    polluting
    or
    non-polluting.
    The
    Board
    believes
    today,
    as
    it
    did
    in
    1973,
    that
    community
    response
    is
    indeed
    the
    appropriate
    test.
    Several factors are involved
    in the level of community
    response
    to
    a
    given
    noise.
    An
    obvious
    factor
    is
    the
    loudness
    of
    the noise.
    The Board gave recognition to this factor when it
    established the current regulations by promulgating the maximum
    loudness
    limits
    found
    at
    35
    Ill.
    Adm.
    Code
    901.102
    and
    901.103;
    these
    are
    unaltered
    under
    the current proposed amendments.
    A
    second
    factor
    is
    the
    frequency
    of
    sounds,
    or
    pitch,
    with
    certain frequencies having greater negative community response at
    given
    loudness levels
    than others.
    This factor
    is also
    recognized
    in
    §~9O1.1O2
    and
    901.103
    and
    remains
    unaltered
    under
    the current proposed amendments.
    It
    is also recognized
    in
    restrictions on prominent discrete tones
    (S901.l06),
    which
    likewise are not altered under the current proposal.
    75.120
    93—490

    —16—
    A third factor
    is the duration of the noise.
    For example,
    some
    noises
    have
    little
    negative
    community
    response
    even
    when
    the
    noise
    is moderately
    loud
    if
    the
    noise
    occurs
    only
    rarely
    and
    for
    short
    intervals.
    Examples
    which
    have
    been
    cited
    are
    a
    dog
    bark,
    a
    slammed
    car
    door,
    and
    a
    noon-hour
    factory
    whistle.
    However,
    the
    same
    noises
    may
    become
    highly
    objectionable
    if
    repeated
    too
    often.
    Therefore,
    regulations
    based
    on
    community
    response
    should
    correctly
    include
    provisions
    limiting
    the
    duration
    of
    noises.
    Current
    Board
    noise
    regulations
    do
    recognize
    some
    aspects
    of
    time-variation
    of
    sounds.
    These
    include
    limitations
    on
    impulsive
    sound
    (5901.104),
    including,
    by
    separate
    amendments
    in
    1982
    and
    1983
    respectively,
    special
    considerations
    for
    blasting
    noise
    (5901.109);
    and impact forging operations
    (5901.105); these
    provisions
    remain
    unaltered
    under
    the
    current
    proposed
    amendments.
    However,
    current Board
    regulations fail to give
    consideration to the general issue of fluctuating,
    time-variant
    noises.
    The reason
    is historical.
    At the time of the 1973
    rulemaking the state of acoustical
    science and technology was
    such that the ability to identify and quantify certain types
    of
    noises to accurately reflect community response,
    specifically
    steady-state
    noises,
    was generally agreed upon.
    This state of
    conditions was reflected
    in
    the standards as then recommended by
    the American National Standards Institute,
    Inc.
    (“ANSI”)
    for
    noise control.
    In promulgating its noise regulations,
    the Board
    relied upon ANSI and adopted its then current recommendations,
    and these remain the basis of the Board’s current noise
    regulations.
    At that time the Board,
    as did ANSI, also
    recognized
    that
    the instrumentation had not yet been fully
    developed and available to properly reflect community response to
    fluctuating noise.
    However,
    in ensuing years acoustical science and technology
    has advanced such that
    a new and more broadly encompassing method
    of identifying and quantifying noise that better reflects
    community response has evolved.
    Specifically,
    the ANSI
    measurement procedure now reflects community response not only
    for steady-state noise, but also for fluctuating,
    time-variant
    noise,
    after
    correcting for ambient,
    or background,
    noise.
    It
    is
    updating of the existing regulations to reflect
    this new
    methodology which is the principal impetus
    for CM’s proposal and
    the Board’s proposed amendments.
    In
    so doing,
    the Board believes
    that
    compliance
    expectations
    and enforcement are enhanced by
    utilizing current ANSI based methodology and instrumentation for
    fluctuating noise.
    THE LEQ MEASUREMENT
    The major proposed amendment
    to existing regulations
    Consists
    of identification of the Leq (as defined
    at
    35
    Ill. Adm.
    Code 900.101), with
    a one-hour reference time,
    as the measurement
    which shall
    be utilized
    to determine compliance
    with the sound
    75.121
    93—491

    —17—
    emission
    standards
    of
    Part
    901*.
    The
    rationale
    for
    this
    amendment
    is the determination that Leq
    is the most comprehensive
    measurement of community response to noise because it best
    combines
    consideration
    of
    both
    steady-state
    and
    time-variant
    noise.
    This
    determination
    was
    detailed
    in
    the
    the
    First
    Notice
    Proposed
    Opinion
    and
    Order,
    p.
    9-12,
    and
    therefore
    will
    not
    be
    repeated
    here.
    It
    is
    significant
    to
    note
    that
    the
    loudness
    standards
    of
    Part
    901,
    including
    both
    broad
    spectrum
    noises
    and
    noise
    of
    limited
    frequency
    range,
    are
    not
    altered
    by
    the
    proposed
    amendments.
    Moreover,
    for
    steady-state
    noises,
    measurement
    via
    either
    present
    procedures
    or
    Leq
    will
    produce
    the
    same
    results.
    It
    is
    only
    for
    fluctuating
    noises
    that
    the
    Leq
    measurement
    provides
    a
    deviation
    from
    the
    present
    rule.
    This
    is
    done
    by
    giving
    weight
    to
    both
    loudness
    and
    duration
    of
    the
    noise,
    commensurate with considerations
    of community response.
    THE FIRST NOTICE PROPOSAL AS ADOPTED BY THE BOARD
    Based on the record amassed by then,
    the Board adopted for
    first
    notice
    a
    modified
    version
    of
    GM’s
    proposal.
    This
    reflected
    the
    Board’s
    basic
    agreement
    with
    CM’s
    contention
    that
    this
    is
    not
    a site-specific issue, and that current Agency noise measurement
    techniques are not in substantial conformity with ANSI,
    as
    intended by the Board
    in adopting
    the
    noise
    regulations.
    The
    Board’s
    proposal tracked that of GM to the extent that it
    included
    a
    1 hour Leq
    averaging,
    except
    as applied to blasting
    noise; the blasting noise exception is important to maintain
    relative consistency with federal mining regulations.
    See
    Opinion,
    R80-9/lO.
    Ambient sound correction was provided for.
    The impulsive noise rule was amended to delete the required use
    of noise measurement by
    a fast dynamic characteristic,
    to conform
    with the amendments
    to the measurements rule.
    The Board, however, added
    a procedure to allow for
    justification of use of alternative measurement procedures where
    it can be demonstrated that such alternative procedures provide
    a
    higher degree of correlation of the characteristics of the sound
    emission to human response.
    This provision was included,
    in
    part,
    to allow for adjustments in situations
    such as those
    “noise
    sources about which the Agency receives complaints operating
    as
    little as 1/2 hour per week.”
    See Agency Comments,
    p.
    12.
    However, it also reflected concerns not fully addressed
    in the
    record,
    which dealt mainly with prominent discrete tones
    as an
    example,
    concerning possible unintentional blunting of the
    impulsive noise rules, particularly as they relate to noises of
    high magnitude but short duration.
    *
    An exception is made for the sound emission standards of
    901.109 due
    to the special characteristics of noises
    considered
    there.
    75.122
    93—492

    -18-
    CHANCES FROM THE FIRST NOTICE PROPOSAL
    In its First Notice Opinion,
    the Board specifically
    requested comments on the alternative justification procedure
    embodied
    in proposed Sections 900.101, 900.103(b)(2) and
    901.130.
    GM responded at length.
    The Board is persuaded,
    based
    on GM’s response and its own further reflection,
    to remove the
    alternative justification procedure from the proposed rule.
    The proposed procedure reflected the Board’s concern as to
    whether there might be value in creating
    a separate procedural
    mechanism, utilizing the adjusted standard mechanism embodied
    in
    Section
    28.1 oF the Act.
    The mechanism was potentially useful
    for possible special noise situations, where
    a person might wish
    to show that a different measurement procedure better correlates
    to human response, notwithstanding the ANSI approach of
    correlating sound emission to community response.
    CM asserted that the alternative measurement procedure may
    have hidden pitfalls.
    It pointed out that any procedure should
    reflect community response;
    to do otherwise
    is “likely to do what
    the single-exceedence rule now does:
    measure emissions for
    compliance with an arbitrary standard not based on community
    response”.
    (P.C.
    #5,
    p.
    10)
    GM pointed out that
    a correlation with human response will
    always
    be inferior to the collective human testimony which forms
    the basis
    of community response, which in turn the Leq measures
    numerically.
    CM further asked the question: “in the presence of
    a one-hour Leq,
    what will Rule 901.130 the
    alternative
    procedure
    do for citizens that cannot be achieved in
    a nuisance
    case under Rule 900.102?”
    (P.C.
    #5,
    p.
    10)
    The Board acknowledges that utilizing “human response” would
    impart an inconsistent overlay on the Board’s regulations,
    regulations which have always defined compliance in terms of
    community response.
    And, if the Board were to change the
    alternate demonstration
    so as
    to be based on
    community response,
    rather than human response,
    ther,e would be an even greater
    question as
    to whether the procedure
    is
    a useful tool.
    Leq is
    the generally accepted best measurement of community response at
    present.
    If future developments and/or circumstances change
    this
    situation,
    such a change would require
    a full rulemaking
    proceeding,
    since the change would be of general applicability.
    On reflection,
    the Board believes that the procedure would
    not be a useful tool,
    especially as measured against the Board’s
    existing procedural mechanisms already available to any person
    seeking a remedy, e.g. by way of an enforcement action (based on
    nuisance or otherwise),
    a regulatory amendment,
    or
    a variance.
    Therefore,
    the Board has deleted the proposed First Notice
    language
    in Sections 900.101, 900.103(b)(2), and 901.130.
    75.123
    93—493

    —19—
    ECONOMIC CONSIDERATIONS
    Two economically-based arguments
    in opposition to the
    proposed amendments were reasserted
    in the public comments during
    the first notice period.
    These relate
    to the cost of replacing
    and/or adapting existing noise meters such that these can measure
    Leq, and added manpower needed to make noise measurements.
    The Agency reasserted that the noise meters presently owned
    by the Agency,
    and presumably at least some of those owned by
    other entities who measure noise, are not equipped to measure
    Leq.
    Some confusion has existed throughout the record
    in this
    matter as to the costs which would
    be involved
    in adapting these
    meters to Leq measurement.
    The latest estimate
    is that the cost
    per meter would be approximately $610 (PC
    #5,
    p.
    14).
    The Board
    does not believe that this cost is prohibitive.
    Moreover, as
    existing meters require replacement, they would be expected to be
    replaced by Leq-capable meters anyway since these are the current
    standard of the industry.
    The Board also notes that the updated
    meters need be used only for enforcement, not for
    routine
    assessment.
    The gathering
    of one-hour Leq data suitable for enforcement
    actions
    may, under some circumstances, require longer measurement
    times than required under the present rule.
    Thus, manpower needs
    may be larger.
    However, the Board believes that this
    is
    a small
    price to pay relative to the gains
    to be made with respect to
    strengthening the noise regulations both as to enforceability and
    compliance expectations.
    ORDER
    The Board directs the Clerk to cause the following adopted
    final rules to be filed with the Secretary of State.
    Title
    35:
    Environmental Protection
    Subtitle
    H:
    Noise
    Chapter
    I:
    Pollution Control Board
    Section 900.103
    Measurement Procedures
    (a)
    No change
    (b)
    Procedures Applicable Only to
    35 Ill. Adm. Code 901
    All measurements and all Mmeasurement procedures
    to
    determine whether emissions of sound comply with 35 Ill.
    Adm.
    Code 901 shall
    be in substantial conformity with
    ANSI
    S1.6-l967, ANSI S1.4-l971
    --
    Type
    I Precision, ANSI
    S1.11-1966 and ANSI S1.13-1971
    Field MethodT, and shall,
    with the exception of measurements to determine whether
    emissions of sound comply with
    35 Ill. Adm. Code
    901.109, be based on Leg averaging,
    as defined
    in 35
    Ill.
    Adm.
    Code 900.101, using
    a reference time of one
    75-124
    93—494

    -20-
    hour.
    All such measurements
    and measurement
    procedures
    shall
    correct
    or provide
    for the correction of such emissions
    for the
    presence of ambient noise as defined
    in ANSI Sl.l3-l971.
    (c-e)
    No change
    Section 901.104
    IMPULSIVE SOUND
    Except as elsewhere
    in this Part provided, no person shall
    cause or allow the emission of impulsive
    sound from any
    property-line-noise-source
    located on any Class
    A,
    B,
    or
    C
    land to any receiving Class
    A or
    B land which exceeds
    the
    allowable A-weighted
    sound levels1
    ~easu~ee wi~ ~as~
    ~yfia1~ie
    e~ae~er~st~e1 specified
    in the following table when
    measured at any point within such receiving
    Class
    A or B
    land, provided,
    however,
    that no measurement of sound levels
    shall
    be made less than 25 feet such from property-line--
    noise-source.
    IT IS
    SO ORDERED.
    J.
    D.
    Dumelle and
    B.
    Forcade dissented.
    I, Dorothy
    M.
    Gunn,
    Clerk of the Illinois Pollution Control
    Board, hereby certify that the
    abcrc’~e Final Opinion and Order was
    adopted on the ~~~--day
    of ______________________,
    1987,
    by
    a
    vote of
    _________.
    /
    /~-
    //
    _~/
    //
    /L
    ~
    ~
    /
    Dorothy N.
    Gi.(nn,
    Clerk
    Illinois Pollution Control Board
    75-125
    93_4~~

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