X-/EPA
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
DIRECTIVE NUMBER:
9283.1-1
TITLE: Recommendations for Ground Water Remediation
at the Mi liereek, PA Site
APPROVAL DATE:
EFFECTIVE DATE:
ORIGINATING OFFICE:
g FINAL
D DRAFT
STATUS:
REFERENCE (other documents):
March 24, 1986
March 24, 1986
OSWER/OERR
OSWER OSWER OSWER
E DIRECTIVE DIRECTIVE D
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&EPA
United States Environmental Protection Agency
Wasnmgton. DC 20460
OSWER Directive Initiation Request
Originator Information
Nam* of Contact P tr son
Betsy Shaw
Lead Office
Q OERR
D OSW
D
n
n
OUST
OWP6
AA-OSWEB
Mail Coda
WH-548E
Aooroveo
interim Directive Numoer
9283.1-1
Teleonone Numoer
382-3204
for Review
Signature of Office Director
Oaie
Tut*
Recommendations for Ground Water Remediation at the Millcreek, PA Site
Summary of Directive
Presents overall approach to decision-making regarding ground water
cleanup at Superfund sites under development by OERR. This strategy
will be further refined in the forthcoming Ground Water Evaluation
Manual scheduled for issuance in the summer of 1986.
Type of Directive iMtnutl. falter Oirtctiv*. Announcement. fte.J
Policy Directive
Status
D Draft
ED Final
l2SLNew
LJ Revision
Does trtis Directive Super s«M Previous Directives)? | | res M. No Does It Supoiarnem Previous Directive* s>> fj Yes jxj No
*^* . .' . . , ., «..„•- -c "lv "~*
If "Yes" to Eimer Quemton. What Directive (numtttr. triltl
Review Plan
G AA-OSWEA D OUST
D OERR O OWPE
D OSW U Regions
D OECM
O OGC
D OPP6
This Request Meets OSWER Directives System Format
Signature of Lead Office Directives Officer
Signature o< OSWER Directives Officer
I Date
Date
tO A. fnrrr,
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9283.1-1
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
MAR 2 4 1986
OFFICE OF
SOLID WASTE ANO EMtHGtNCY
MEMORANDUM
SUBJECT: Recommendations for Ground Water Remediation at
the Millcreek. PA Site
//^ £&
FROM: J. Wrnston Porter
Assistant Administrator
TO: James Seif, Regional Administrator
Region III
This is in response to your January 17 memorandum in which
you raised concerns about the national policy implications_on
the ground water remediation proposed for the Millcrouk, PA
site. The Office of Emergency and Remedial Response (OERR)
is developing a strategy which will articulate the general
framework in which we would like to soe ground water cleanup
decisions made nationwide. To assist you in addressing the
issues involved at the Millcreek site, wo are providing a
preview of some of the key features of the forthcoming strategy
below.
GERR's Hazardous Site Concrol Division (liSCD) is leading
the effort to develop a strategy for ground water cleanups
at Superfund sites. HSCD is being assisted in this effort
by a ground water work group/ comprised of representatives from
all relevant Agency offices, which has boon uxploring a widu
range of ground water issues since its formation last August.
HSCD's and the work group's efforts ultimately will culminate
in an overall guidance for Supurfund ground wutur cluunup.Si
scheduled for issuance late this spring. The guidance will
elaborate in detail on the general approach outlined below.
Preview of Forthcoming Superfund Ground Water Strategy
One of the premises of EPA's Ground Water Protection
Strategy (August 1984) is that ground water should be protected
for its highest beneficial use. Superfund's implementation of
EPA's Ground Water Protection Strategy will s&ufc rapid clounups
of all currant and potential drinking wutur (Class I, Class II A,
and Class II B ground waters) where it is cost-effective.
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9283.1-1
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For ground water remedial actions, at least one alternative
should be developed in the Feasibility.Study which would
attain applicable or relevant and appropriate health standards
for carcinogens where they are available or a 10~6 risk level
for carcinogens without standards for current and potential
exposure. This alternative should be designed to attain these
levels within a short period of time (for example one to five •
years) and should be used as a point of departure in analyzing
a range of alternatives.
A range of alternatives should be developed which would
achieve risk levels within the 10~7 to 10~4 risk range, within
a variety of timeframes, and through various remedial approaches
(e.g., pumping and treating, plume containment, natural attenuation).
The cost-effectiveness of all alternatives will be analyzed as
reouired by statute and the National Contigency Plan (NCP), and
as laid out in the Feasibility Study Guidance.
The determination of the appropriate risk level and the
timeframe for reaching it will be based on the class of the
ground water and other appropriate factors. In many situations,
the most important factors will include:
o Site and ground water characteristics;
o Cost, reliability, speed, and technical feasibility-
of each alternative;
o Effectiveness and reliability of institutional controls
which might be used as part of a remedy;
o Degree of risk reduction each alternative may obtain;
o Puhlic acceptability of the options;
o Anticipated future need for the ground water (e.g., timing
and extent of need);
o Ability to provide an alternative water supply; and
o Environmental considerations including indirect public
health consequences.
These various factors will have different emphasis depending
upon the characteristics or class of ground water. For Class I
ground waters, which are special by virtue of being an irreplaceable
source of drinking water or ecologically vital (i.e., having the
characteristics of a Class I aquifer), the desire for rapid
restoration will be given primary emphasis in the determination
of cost-effectiveness. Also for Class I ground waters, emphasis
should be qiven to achieving levels at the more protective end
of the risk management range.
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9283.1-1
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When evaluating the cost-effectiveness of remedies for
currently used (typically Class II A) ground waters, the
following factors are important: the ability to provide an
alternate water supply, the anticipated future need of the
ground water, the cost of proposed response actions, and the
effectiveness of institutional controls during ground water
remediation, in addition to the desire for rapid restoration
to the target risk range of 10~7 to 10~4.
For aquifers with the characteristics of Class II B ground
water, which may be used as drinking water some time in the
future, the Superfund program is more willing to accept longer-
term remedies and higher risk levels within the risk range.
EPA is currently uncertain about the long-term effectiveness
of institutional controls as a means of restricting ground water
use. This posture stems from the Agency's limited experience
with such controls and the current lack of criteria against
which their effectiveness can be judged, as well as uncertainty
o^er the ability of a PRP or state to maintain or continue
extended response actions, and uncertainty regarding Superfund's
ability to oversee and fund additional response actions in
the future. As a result, the Superfund program generally does
not encourage ground water remedies with long timeframes. EPA
is establishing a workgroup to develop criteria for evaluating
the effectiveness and appropriateness of institutional controls,
and guidelines for their use. This effort will examine time-
frames beyond a rapid restoration period over which institutional
controls can be effective.
The analysis of the cost-effectiveness of remedial ground
water alternatives may determine that it is not possible to
implement a remedy within the preferred timeframe or to attain
a cleanuo taraet within the 10"^ to 10"^ risk range because
of technical impracticality or Fund-balancing. The NCP provides
exceptions to accommodate such circumstances.
Source control measures need to be consistent with long-term
ground water remedies. The cost-effectiveness of source control
alternatives can be analyzed separately from the cost-effectiveness
of ground water options, but the response goals of both operable
units should be considered together in selecting the source control
remedy. A range of source control actions should be considered:
1. Closure to prevent direct contact;
2. Measures necessary to meet short-term ground water
objectives; and
3. Actions necessary to achieve long-term ground water
aoals. • .
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In general, source control measures should facilitate the
achievement of the long-term objectives and goals for the
ground water.
Site Description
The Millcreek site is a 72 acre parcel of land which
was used as a landfill from 1941 to 1981. The unpermitted
landfill received trash, foundry sand, furnace slag, waste
refuse, and an undetermined amount of bulked and drummed
liauid hazardous wastes.
Surface soils and sediments are contaminated with PCBs,
PAHs, phthalates, volatile organics, copper, and lead. A
contaminant plume exists. The main contaminant in the plume
is vinyl chloride with 1,1-dichloroethane, 1,1-dichloroethene,
1,2-dichloroethene, trichloroethylene (TCE), 1,1,1-trichloroethane
also present. Ground water flows northeast and discharges into
Lake Erie. To date the plume has migrated 1000 feet from the
site and is 5,500 feet from Lake Erie. Assuming effective
source control action is taken, it would take approximately
125 years for the contaminants in the plume to reach the lake
and for levels in the around water to naturally attenuate to
health-based levels. The ground water downgradient of the
Millcreek site probably has the characteristics of Class II B
(potential use) around water, although there are public supply
wells located 1600 - 2100 feet upgraclient of the site, a situation
which could be viewed as a Class II A setting.
Peqional Position on Millcreek
Region III prepared a draft Record of Decision (ROD) in
early December, 1985. Performance criteria for remedial
activities addressing contaminated soils, sediments, and
around water- were established using a health-based risk
approach. The Region's preferred alternative consists of:
o Grading, soil cover, revegetation;
o Excavation of soils and sediments to protect ground
water at a 10~^ risk level;
o Consolidation of soils and sediments followed by
construction of a RCRA cap;
o Ground water pumping and treating to recommended
cleanup levels (10~4 risk level).
The capital cost r- the preferred remedy as outlined in
the Feasibility Study is $14.8 million - $20.9 million of which
$3.1 million is to pump and treat the ground water. Operation
and maintenance costs cor the pump and treat system are estimated
at $611,000/year for the first two years, and $187,000 annually
for cap maintenance and ground water monitoring for years 3 - 30.
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9283.1-1
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The total cost range accounts for the uncertainty related to the
amount of contaminated soil which needs to be consolidated under
the cap.
Position of Potentially Responsible Parties (PRPs)
The PRPs have met with Region III representatives and have
raised several concerns regarding the proposed remedy. The
PRPs also sent a letter to the Administrator on January 10, 1986
requesting a meeting with him to discuss the policy implications
of response actions proposed for the Millcreek site. The PRPs
auestion the need for both active source control and ground
water actions.
The PRPs urge EPA to consider that there are/is:
1. No current users of the ground water downgradient from
the site;
2. An abundance of high guality drinking water in the area
from other sources; and
3. A willingness on the part of at least some local
government officials to install institutional
controls on ground water use in.the vicinity.
The PRPs believe the Remedial Investigaton/Feasibility
Study (RI/FS) prepared for the Millcreek site contains insufficient
information to justify the Region's proposed remedy. In dis-
cussions with you and your staff, the PRPs have indicated that
they believe the contaminated plume should be allowed to naturally
attenuate and permanent institutional controls should be established
to prevent ground water use.
Consistency of Proposed Millcreek Response Action with OERR's
Ground Water Strategy
Region III began their analysis of the cost-effectiveness
of remedial alternatives for the Millcreek site by looking at
remedies which could achieve a 10~^ risk level within a short
period of time. The Region determined the 10~6 risk level to
be desirable and theoretically attainable, but impracticable
to measure because it would involve reducing levels of vinyl
chloride (the major contaminant) to .015 ppb, well below its
detection limit of 1 ppb. According to the proposed MCL for
vinyl chloride, the risk level associated with 1 ppb is approxi-
mately 7 x 10~5. Region III is recommending a one to two y-^ar
program of active pumping and treatment to reduce vinyl chloride
levels to the detection limit resulting in an overall risk level
of 10~4 for all constituents in ground water. The Region expects
the aauifer to reach the 10~*> risk level for all constituents as
the contamination naturally attenuates after pumping and treating,
although the detection limit for vinyl chloride will prevent
the Region from measuring this further reduction in vinyl chloride
concentrations.
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9283.1-1
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Reqion Ill's proposed ground water remedy for the Millcreek
site is consistent with the Superfund ground water strategy
under development. The Region has evaluated a number of alter-
natives within the 10~7 to 10~4 risk range, including a 10~6
option, and has arrived at a remedy which will attain a target
risk range rapidly, well within an acceptable period of time.
We agree with your preference'for rapid restoration since the
long-term remedy would take 125 years to complete by natural
attenuat ion.
Region III has done an analysis for source control and
has determined that a 10~6 risk level will meet the long-term
goals for ground water remediation at Millcreek. This also
is consistent with the strategy under development.
We hope this preview of the forthcoming Superfund ground
water cleanup strategy assists you in preparing the final
Record of Decision for the Millcreek site. OERR will be
soliciting regional comments on subsequent drafts of the
evolving strategy and will also call upon your assistance in
reviewing the overall ground water guidance later in the spring.
If you have any questions, please call Bill Hanson (FTS 382-2345)
or Lisa Woodson (FTS 475-8246).
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