ILLINOIS
    RECEIVED
    CLERK’SOFF!CF
    MPR
    26
    2001
    STATE
    OF
    ILLINOIS
    Pollution
    Control Board
    IN THE MATTER OF:
    )
    )
    PROPOSED AMENDMENTS TO
    )
    RO1-26
    REGULATION OF PETROLEUM
    )
    (Rulemaking —
    Land)
    LEAKING
    UNDERGROUND STORAGE
    TANKS (35 ILL. ADM. CODE
    732)
    COMMENTS OF ROBERT CARSON
    Introduction
    My name is Robert
    Carson.
    I
    am a senior project manager at Goodwin
    Environmental Consultants, Inc.
    My
    responsibilities at GEC include geotechnical
    engineering and preparation of Leaking
    Underground Storage Tank reports and
    Corrective Action
    Plans.
    My professional experience consists of four years of work as a
    geotechnical engineer, seven
    years as a
    permit writer and remediation program
    supervisor
    in the Illinois
    Environmental
    Protection Agency Bureau of Land, three years
    as
    an
    environmental compliance manager
    in
    industry, 2-1/2 years of remediation
    experience at a Department
    of Energy site, and 3-1/2 years of experience with LUST
    projects in
    Illinois.
    My education includes a
    B. S. degree
    in Civil Engineering,
    B. S.
    degree in
    Earth
    Science, and
    M.
    S.
    degree in
    Civil
    Engineering (May 2001).
    I am
    licensed as a
    Professional Engineer in the State of Illinois.
    35111. Adm. Code
    s~
    732. ADgendix
    C.
    Backfill Volumes
    I wish to comment on the Board’sproposal to revise Appendix C of the
    regulation.
    In the past, this appendix provided guidance on the allowable volume of
    backfill that could
    be removed during
    early action. The
    amendment proposes the
    addition of tonnages associated with these backfill volumes. This
    addition to the
    appendix is
    beneficial because the weight of contaminated soil disposed at
    a landfill is
    routinely determined, but the volume of removed backfill is difficult to determine.
    My concern with the proposed regulation
    is that these tonnages are not
    representative of field conditions, and are inconsistent with the default soil bulk densities
    (Pb or
    Ps)
    identified
    in
    35
    III. Adm.
    Code § 742.
    The unit weight for removed backfill used
    in developing the table in the proposed
    regulation was
    100 lbs/ft
    3 (bulk density
    =
    1.60 g/cm3); the unit weight for replacement
    backfill used
    in the table was 103.7
    lbs/ft3 (bulk density
    =
    1.66 g/cm3).
    Presumably, the
    backfill material being removed is sand.
    This proposed bulk density is not
    representative
    of field conditions,
    and is inconsistent with
    the default value for sand bulk density
    in
    35
    Ill.
    Adm. Code § 742,
    Appendix
    C, Tables
    B and
    D.
    In Appendix
    C,
    Table B, the default
    ~
    bulk density for sand is 1.8 g/cm3.
    Even with
    no moisture content considered, the
    unit weight of the sand would be:
    Ydry
    1.8 x62.4 lbs/ft3
    =
    112.32 lbs/ft3
    where
    Ydi~,
    = dry unit weight of soil, lbs/ft3
    When the moisture content of the sand is considered, the discrepancy increases.
    A typical moisture content for sand excavated from a UST excavation is
    10%.
    Ywet =
    Pdry x 62.4 lbs/ft3 x
    (1
    +
    o)
    =
    1.8 x 62.4 x ~1+10%/i 00%)
    =
    123.55 lbs/ft
    where
    Ywet
    = moist unit weight of
    soil, lbs/ft3
    Pdiy
    =
    dry bulk density of
    soil, g/cm3
    =
    moisture content (weight basis), %
    The Board should adopt an as-excavated unit weight of between
    120 and 125
    lbs/ft3 for backfill removal
    in this
    table.
    Backfill (replacement)
    sand will typically be drier than the backfill sand
    removed
    from the excavation.
    A moisture content of 5% is probably representative.
    This would
    make the backfill (replacement) unit weight:
    YfiII
    Pdry
    x 62.4 lbs/ft
    3 x
    (1
    +
    =
    112.32 lbs/ft3 x 1.05
    =
    117.93 lbs/ft3
    The Board should adopt a
    unit weight of approximately 118 lbs/ft3 for
    backfill
    replacement
    in this table.
    My suggested corrections are shown
    in the following table.
    35 III. Adm.
    Code § 732, Appendix
    C
    Suggested Corrections
    Volume
    of Tank
    gallons
    Backfill
    Removal
    c.y.’
    Backfill
    Removal
    Tons2
    Backfill
    Removal
    Tons3
    Backfill
    Replacement
    c.y.4
    Backfill
    Replacement
    Tons5
    Backfill
    Replacement
    Tons6
    <285
    54 73 90 56 78 89
    285to299
    55 74
    91
    57 80
    91
    300to559
    56 76 93 58
    81
    92
    560to999
    67
    91
    111
    70 98
    112
    ..A,OOOtoi,049
    A,OSOtol,149
    ...±lSOtol,999
    2,OOOto2,499
    81
    109
    135
    87 122
    139
    89 120
    148
    96
    153
    94 127 156
    101 141 161
    112
    151
    186
    124
    174 198
    2,500 to 2,999
    128 173
    213
    143
    200 228
    3,OOOto3,999
    143 193
    237
    161
    225 256
    4,000 to 4,999
    175
    236
    291 198
    277 315
    5,000 to 5,999
    189
    255 314 219 307
    349
    6,000 to 7,499
    198
    267 329 235 329 374
    7,500 to 8,299
    206 278 342 250 350 398
    8,300 to 9,999
    219 296 364 268 375
    427
    10,000 to 11,999
    12,OOOto l~,999
    252 340 418 312 437 497
    286 386 475 357 500 569
    >1 5,000
    345 466 573 420 588 669
    NOTES
    1.
    Backfill removal volume from proposed regulation.
    2.
    Backfill removaltonnage from proposedregulation.
    3.
    Backfill removal tonnage based on unit weight of 123 lbs/ft3.
    4.
    Backfill replacement volume from proposed regulation.
    5.
    Backfill replacement tonnage from proposed regulation.
    6.
    Backfill replacement tonnage basedon unit weight of 118 lbs/f
    t3.
    Robert A. Carson,
    P.E.
    Goodwin
    Environmental
    Consultants,
    Inc.
    400 Bruns Lane
    Springfield,
    Illinois 62702-4617
    (217)
    698-0222
    (217) 698-0422 (fax)
    rcarson@goodwin-env.com

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