ILLINOIS POLLUTION CONTROL BOARD
    August
    22,
    1991
    VILLAGE OF MATTESON,
    )
    )
    Complainant,
    )
    V.
    )
    PCB 90—146
    )
    (Enforcement)
    WORLD MUSIC THEATRE,
    )
    JAN
    PRODUCTIONS, LTD.,
    )
    DISCOVERY SOUTH GROUP,
    LTD.,
    )
    and GIERCZYK DEVELOPMENT,
    INC.,
    )
    )
    Respondents.
    ORDER OF THE BOARD
    (by B. Forcade):
    On July 22,
    1991, the Village of Matteson filed a Petition
    for Interim Relief.
    That Petition asserted various continuing
    nuisance and numerical sound violations and noted an instanta-
    neous radio feedback loop between the sound monitoring
    technicians and the World Music Theatre.
    In response to that
    motion the Board Order of July 25,
    1991,
    stated:
    Because
    of the dispute that has arisen
    regarding the
    legitimacy
    of
    the
    data
    being
    collected, the Board will require World Music
    Theatre
    to
    ensure
    that
    all
    raw uncorrected
    data acquired
    in
    this
    monitoring
    effort
    be
    preserved and that copies of such raw data be
    provided to Matteson and included in the final
    report...
    On August
    6,
    1991, the final report was filed with the Board.
    By
    Order of August
    8,
    1991, the Board stated:
    The Board
    will allow
    the Theatre
    until
    August 20,
    1991 to provide copies of the one-
    hour
    Leq
    spectra
    (which
    must
    include
    instantaneous values prior
    to any correction
    or averaging over time),
    the log of time and
    content of any conversation, and any actions.
    taken by Theatre as a result.
    On August 20,
    1991, Theatre filed a response to the Board Order
    which included an Addendum to the World Music Theatre Final
    Report prepared by the Sound consultant EISA.
    That addendum
    states,
    “No instantaneous spectrum levels were collected nor was
    this data subjected to any post-process averaging or manipula-
    tion.”
    The Board finds this failure to acquire and maintain
    instantaneous spectrum levels disturbing.
    125—3 19
    2
    Theatre has stated in the final report that:
    The Leq,
    or equivalent sound pressure
    level
    (SPL)
    based
    on
    time
    averaged
    energy
    or
    intensity, can be a very useful environmental
    metric.
    However,
    the
    one—hour
    measurement
    period stipulated in Section 900.103 proved to
    be
    unrealistically
    long
    for
    the
    conditions
    encountered
    at
    these
    measurement
    sites.
    Averaged over
    an hour,
    sound
    energy emitted
    from the Theatre tended to become “submerged”
    in the time-averaged ambient sound energy.
    Final Report p.
    5
    Theatre has also stated, “.~weobserved the sound emitted from
    Theatre to change from totally inaudible to clearly audible,
    to
    totally inaudible again in
    a matter of 10 or 15 minutes.”
    (Final
    Report, p.9).
    Clearly this type of information is essential for
    informed decision making on sound impacts during monitoring.
    Yet,
    it was not provided to the Board.
    It would thus appear the failure to acquire and maintain
    instantaneous values for future averaging has, by Theatre’s
    own
    admission, resulted in the submission of unrealistic data where
    the sound energy from Theatre is submerged in the single time-
    averaged value submitted to the Board.
    The Board notes that
    Theatre’s reference to a “one—hour measurement” period
    is
    incorrect.
    Section 900.103 provides for measurement of sound,
    “...based on Leq averaging,
    as defined in 35
    Ill.
    Adm. code
    900.101, using
    a reference time of one hour.”
    It
    is the time
    period for data averaging which is specified as one—hour.
    As recited in Section 3.1.5 of the ISO document quoted
    in
    the Board Opinion adopting the one-hour Leq:
    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.
    R83-7, Opinion at p.
    12
    (January 22, 1987)
    Here,
    Theatre’s measurements have failed to acquire and maintain
    this time history of sound levels for each octave band.
    The Board today Orders Theatre to immediately ensure that
    all sound measurements acquire, maintain, and preserve a complete
    time history of the sound levels during each monitoring period,
    for each octave band (i.e.,
    a time-varying sound level or Leq
    Spectra).
    This data shall be preserved and copies conveyed to
    the Board and to Matteson on a weekly basis.
    Also,
    the
    125—320
    3
    monitoring process shall record sufficient narrative information
    to allow the Board to determine whether sound from Theatre is
    inaudible,
    audible, clearly audible,
    etc.
    The Board requests that the data collected on July 19,
    1991,
    “measured ambient all evening”, be provided to the Board.
    IT IS SO ORDERED.
    I, Dorothy M.
    Gunn,
    Clerk of the Illinois Pollution Control
    Board,
    hereby cert’
    y that the above Order was adopted on the
    ‘~?1t’!
    day of
    __________________,
    1991, by a vote of
    7~)
    227.
    ~
    /AZ
    p.
    Dorothy M.
    nn, Clerk
    Illinois Pollution Control Board
    125—32 1

    Back to top