HomeMy WebLinkAbout20041012Response to DEQ Comments.pdfGARY L. HONEYMAN
Manager Environmental Site Remediation
UNION PACIFIC RAILROAD CO
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Mailing Address:
221 Hodgeman
Laramie, Wyoming 82072
Phone: (307) 745-6532
Fax: (307) 745-3042
GLHONEYM~UP.COM
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Wty, Health and Environment
f4'1P Dodge Street, Room 930
Omaha, NE 68179-0930
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October 8, 2004
Idaho Public Utilities Commission
O. Box 83720
Boise, ID. 83720-0074
RE:Idaho PUC Case No. UPR-O4-01 - Response to Comments by Idaho
Department of Environmental Quality Relative to Proposed Abandonment Coeur
d' Alene Industrial Lead Line
Dear Madam or Sir:
This letter is provided in response to the comments submitted by the Idaho Department of
Environmental Quality (IDEQ) relative to the proposed abandonment of portions of the
Coeur d' Alene Industrial Lead line (the Line) located in northern Idaho. These
comments were submitted by IDEQ to the Idaho Public Utility Commission (IPUC) in a
letter dated June 15, 2004.
The IDEQ letter raised concerns relative to the potential for creosote and herbicide
contamination along the rail bed of the Line and the potential for human exposure as a
result of access to the Line from the nearby, populated areas. The IDEQ letter
recommended that additional testing and a risk based assessment be performed to ensure
that there are no public health issues.
Based on the discussion presented below, we believe that the proposed abandonment of
the ROW does not pose any human health related concerns related to creosote or
herbicides and that the sampling program recommended by IDEQ is unnecessary.
IDEQ's concerns relative to creosote presumably arises from the presence of creosote
treated ties within the rail bed and the potential for this creosote to migrate into the ballast
or underlying rail bed material. It should be pointed out that creosote treated ties and
utility poles are used extensively throughout the country and we are unaware of a
situation where evaluations such as those suggested by IDEQ have been requested by a
regulatory agency as part of an abandonment proceeding.
October 8, 2004
Page 2
Creosote treated ties are routinely used in residential settings for landscape purposes
without any regulatory restriction. The potential for non-occupational, human contact
with ties located within the rail bed would be significantly less than that associates with
the common use of treated ties in residential settings.
Creosote consists of a mixture of polycyclic aromatic hydrocarbons (P AHs). Previous
studies have indicated that there is minimal migration of P AHs associated with creosote
and other treatment compounds from treated wood to the surrounding media. One such
study, reported by Brooks (2000) 1, provides a summary of the literature on the
environmental fate ofP AHs as well as the results of a field evaluation of the migration of
P AHs from newly treated as well as weathered ties. Those observations and conclusions
reported within the Brooks study that are pertinent to the issues raised in IDEQ's letter
are as follows:
The migration of creosote from newly treated ties to the surrounding ballast is
minimal and occurs primarily in the first few years.
There is a rapid decrease in P AH concentrations with time. In the case of ballast
this decrease is attributed to photochemical degradation within the ballast
environment.
The Brooks study reported maximum observed average concentrations of 1.5 mg/kg total
PARs within the ballast adjacent to weathered ties over the 555 day study period.
provide a perspective on how low this concentration is we have made a comparison with
IDEQ's Tier 1 Risk Based Criteria. The Tier 1 criteria represent risk based thresholds
that consider the ingestion, inhalation, and dermal contact exposure pathways for
contaminants. Concentrations of contaminants in soils below these thresholds have been
determined by IDEQ to not represent an excessive risk for these pathways and do not
require any remedial action. As a separate point of reference, the comparison has also
been made to generic risk based criteria for protection of human health adopted by the
Michigan Department of Environmental Quality (~EQ).
The risk based criteria provided by IDEQ and ~EQ are for individual P AH compounds
(there are no criteria for total P AHs). Accordingly we extrapolated the total P
concentration (1.5 mg/kg) found in the Brooks study into estimated concentrations that
would be expected for those individual P AH compounds that would commonly be
associated with weathered creosote. This extrapolation is based on information reported
in the Brooks study. The result of the comparison of the extrapolated P
concentrations with the risk based criteria is presented below.
1 Brooks, K.2000. Migration of Polycyclic Aromatic Hydrocarbons (P AH) from New and Used Railway
Crossties into Ballast and Adjacent Wetland Environments. American Wood-Preservers' Association 96
Annual Meeting, May 8, 2000
October 8, 2004
Page 3
Comparison with Risk Based Corrective Action Guidance for PADs Associated with
Weathered Creosote
Individual P AH Compounds IDEQ Tier 1 Risk Based MDEQ Extrapolated.
Commonly Associated with Screening Levels for Generic Risk Concentration Based
Weathered Creosote Surficial Soils (mgIkg)Based on Total Avg. PAH
Criteria(2)Concentration of 1.5
'mg/kg )mgIkg in Ballast
Residential Commerciall ResidentiaV %of mgIkgIndustrialCommercialTotal (4)
Benzo(b )Fluoranthene 1.22 1,1)20(3)
Benzo(k )F1uoranthene 4.4(1)4.4(1)200(3)
Benzo( a)Anthracene 1.22 19.3(1)20(3)
Chrysene 0.5(1)0.5(1)000
Fluoranthene 9(1)9(1)000
Phenanthrene 15(1)15(1)600
Pyrene 10(1)10(1)000
(1) Risk-based value exceeds Soil Saturation Limit (SSL). RBSL equals the SSL.(2) MDEQ lowest criteria for particulate inha1ation, dermal contact, or ingestion pathway.(3) MDEQ indicates insufficient data for inhalation pathway
(4) The extrapolated concentration of the individual compounds is based on the spectnun of individual
P AH compounds found in weathered in creosote as reported in the Brooks study
As indicated in the above table, the extrapolated concentrations of the individual P
compounds within the ballast adjacent to weathered ties are significantly less than either
the IDEQ or MDEQ risk based criteria. The ties located on the Line are generally more
than four years old; therefore, the results reported in the Brooks study for weathered ties
would be representative of the conditions found on the Line.
The above analysis indicates that any concentrations of creosote that made be found
within the rail bed of the Line would be minimal and would not represent a risk to the
general public.
The IDEQ letter also makes reference to potential environmental controls if tie washing
occurs as part of the tie removal. Washing of ties as part of the tie removal process is not
a common occurrence. IDEQ may have raised this issue due to familiarity with the
activities associated with a CERCLA response action conducted by UPRR on an
abandoned branch line (the Wallace-Mullan Branch) in the Coeur d' Alene Valley. This
response action addressed metals associated with mine waste contamination that existed
along portions of the rail bed. Due to the presence of these metals, the scope of the
response action required decontamination of the ties prior to salvage. This
decontamination involved the removal of visually identifiable accumulations of surface
material on the ties. In this unique situation, high pressure washing was used in the
decontamination process.
During the course of the Wallace-Mullan Branch response action, IDEQ requested that
the solid residuals removed from the ties as well as the wash water be analyzed for
October 8, 2004
Page 4
creosote compounds. The analysis did not fmd any detectable concentrations of creosote.
This indicates that, even under the aggressive conditions represented by the pressure
washing, migration of creosote from railroad ties did not occur.
The IDEQ letter also raised the issue of herbicides. Any herbicides that would be present
within the rail bed would occur as a result of routine weed spraying. Any such weed
spraying would have occurred by a licensed contractor and would not represent any more
risk than that which normally occurs along any public transportation corridor that would
be subject to such spraying.
Based on the above discussion, there is no significant potential of human health risk
associated with the presence of creosote or herbicides within the ROW. Accordingly, we
do not believe that either the field investigation suggested by IDEQ or any further
evaluation of this issue is warranted.
If you have any questions pertaining to this letter please do not hesitate to contact Gary
Honeyman at (307) 745-6532.
Sincerely,
L-'4~
Gary L. Honeymat'i
Manager, Environmental Site Remediation
cc:Joel Strafelda - UPRR
Mack Shumate - UPRR
Bob Bylsma - UPRR
Gwen Fransen - IDEQ