PB97-963109
EPA/541/R-97/015
November 1997
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
Tonolli Corp.,
Nesquehoning, PA
1/7/1997
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JflN 0 7 1997
SECOND EXPLANATION OF SIGNIFICANT DIFFERENCES
TONOLLI CORPORATION SUPERFUND SITE
NESQUEHONING, PENNSYLVANIA
A. Introduction
The Environmental Protection Agency, Region HI (EPA) is issuing this Second Explanation of
Significant Differences (ESD), pursuant to its authority in Section 117(c) of the Comprehensive
Environmental Response, Compensation and Liability Act of 1980, as amended (CERCLA), 42
U.S.C. § 9617(c), and the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP), 40 C.F.R. § 300.435(c)(2)(i), for the September 30, 1992, Record of Decision (ROD) (no.
189, Section III, in the Administrative Record Index for the Site) issued for the Tonolli
Corporation Superfund Site (Site) in Nesquehoning, Pennsylvania. EPA is the lead agency for
the Site and the Pennsylvania Department of Environmental Protection (PADEP) is the support
agency. EPA has determined that this change does not fundamentally alter the remedy selected
in the ROD with respect to scope, performance, or cost.
The Coi.jnonwealth of Pennsylvania does not concur with the issuance of this ESD as described
in Section E below.
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B. Summary of Site History. Contamination Problems, and Selected Remedy
For a summary of site history and contamination problems, see Sections II (page 1) and IV
(page 8) of the ROD. For a description of the remedy as set forth in the ROD, see Section IX
(page 63). The first ESD was issued February 17, 1995 (1995 ESD ). The 1995 ESD addressed
the Technical Issues Appendix attached to the RD/RA Consent Decree and whether the
Pennsylvania hazardous and residual waste regulations were Applicable or Relevant and
Appropriate Requirements ("ARAR") under Section 121(d) of CERCLA, 42 U.S.C. § 962 l(d).
The major concern addressed in the 1995 ESD was the condition of the onsite landfill and the
design criteria required to meet the Pennsylvania Hazardous Waste Regulations for landfills.
C. Significant Differences; Rationale
The 1995 ESD recognizes 25 PA Code § 264.302(b) as an ARAR to the response actions at the
onsite landfilL
This ARAR requires that "a minimum distance of 4 feet shall be maintained between the top of
the subbase [of the landfill] and any seasonal high water table without the use of any artificial
or manmade groundwater drainage or dewatering systems" and that the "distance between the top
of the subbase and the regional groundwater table shall be a minimum of 8 feet". The 1995 ESD
also required further data collection to determine if the ARAR was being achieved or if the need
to evaluate an artificial system existed. If after data collection it was apparent that the ARAR
was not met, the 1995 ESD provided for a waiver thereof based upon an achievement of an
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equivalent standard of performance. Specifically, the 1995 ESD stated the following:
" • If EPA determines during remedial design that the minimum distance set forth
in the groundwater isolation distance requirement regulation is not present at the
landfill, the ROD is hereby clarified to require that a manmade groundwater
drainage or dewatering system be evaluated to determine if an artificial system can
be installed to ensure that the landfill waste is not in direct contact with the
groundwater during any part of the hydrogeologic cycle. "
The Tonolli Site Technical Committee, through their consultant, Advanced GeoServices
Corporation, has submitted a Technical Memorandum (October 1996) which presents the findings
of the data collection required by the 1995 ESD. The data shows that the minimum 4 feet
ground water isolation distance is not achieved during all seasons. However, the data also show
that the groundwater did not contact the liner during the remedial design investigation.
Therefore, EPA believes an equivalent standard of performance to that required by the
groundwater isolation distance regulation presently exists and has determined that an evaluation
of a manmade groundwater drainage or dewatering system is unnecessary. Additionally, in order
to ensure landfill stability and groundwater protectiveness, the groundwater elevation will again
be considered in the final design of the landfill closure. Post remedial groundwater monitoring
will be conducted and if at any time it becomes apparent that the groundwater quality is being'
adversely impacted by the landfill, additional remedial action may be required.
D. Affirmation of Statutory Determinations
Considering the new information that has been developed and the changes that have been made
to the selected remedy, EPA believes that the remedy, as modified by this ESD, remains
protective of human health and the environment, complies with Federal and State requirements
that are applicable or relevant and appropriate to this remedial action, and is cost-effective. In
addition, the revised remedy utilizes permanent solutions and alternative treatment (or resource
recovery) technologies to the maximum extent practicable for this Site.
E. Support Agency Comments
Nothing in this ESD shall be deemed to waive or nullify any rights that the Commonwealth of
Pennsylvania may have under Section 121(e)(2) and (f)(2) of CERCLA, 42 U.S.C. § 9621(e)(2)
and (f)(2). EPA acknowledges that the Commonwealth of Pennsylvania has whatever rights are
provided for by Section 121(e)(2) and (f)(2) of CERCLA, 42 U.S.C. § 9621(e)(2) and (f)(2). The
Commonwealth of Pennsylvania does not concur with the issuance of this ESD. The
Commonwealth disagrees with EPA's conclusion that an equivalent standard of performance to
. that required by 25 Pa. Code § 264.302(b), as described above, has been met for purposes of
waiver of that ARAR under 42 U.S.C. § 9621(d)(4)(D). However, at this point, the
Commonwealth believes the remedy as a whole, as set forth in the ROD and the 1995 ESD, will
upon full implementation nonetheless be protective of human health and the environment,
specifically in consideration of the remedial provisions calling for dewatering, closure, and
maintenance of the landfill, ongoing leachate removal, installation of a downgradient vertical
chemical barrier with possible gradient controls and routine groundwater monitoring.
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F. Public Participation Activities
This ESD becomes part of the administrative record file for this Site and the record is available
for review at the two locations identified below:
Nesquehoning Borough
427 West Catawissa Street
Nesquehoning, Pennsylvania 18240
(717) 669-9588
Hours: 8:00 a.m. to 4:00 p.m.
Monday through Friday
United States Environmental Protection
Agency, Region in
841 Chestnut Building
Philadelphia, Pennsylvania 19107
(215) 566-3157
Hours: 8:30 a.m. to 5:00 p.m.
Monday through Friday
Date Thomas C.
Hazardous Waste Management Division
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