PB95-963123
EPA/ESD/R09-91/129
March 1995
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
Beckman Instruments,
Porterville, CA
3/6/1991
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Beckman Instruments Sunerfund Site
Porterville, California
EXPLANATION OP SIGNIPICANT DIPPERENCES
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I.
INTRODUCTION
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On September 26, 1989, .the United States' Environmental
Protection Agency (EPA) signed a Record of Decision (ROD) for the
final remedy at the Beckman Instruments Inc. Superfund Site.
("Beckman Site") in Porterville, California. The purpose of this
document is to explain the significant differences between the
description .of the remedy selected in the ROD signed on September
26, 1989 and the remedy that will be implemented at the Beckman
Site. This difference is not a fundamental alteration of the
remedy described in the 1989 ROD.
Unqer Section 117 of the Comprehensive Environmental
Response, Comp~sation and Liability Act of 1980, as amended,
(CERCLA), 42 U.S.C. 55 9617, and pursuant to 40 C.F.R. Section
300.435(c) (2)(i) (55 Fed.Reg. 8666, 8852 (March 8, 1990», EPA is
required to publish an Explanation of Significant Difference
(ESD) whenever a significant (but not fundamental) change is made
to a final remedial action plan as described in a ROD.l
This document provides a
Site, a summary of the remedy
of the change to the ROD that
the change affects the remedy
1989 ROD), and an explanation
to the ROD.
brief background of the Beckman
selected in the ROD, a description
EPA is now making (including how
originally selected by EPA in the
of why EPA is making these changes
Based on the technical data in the administrative record, .
EPA is changing the ROD to provide that the contaminant-specific
numerical levels characterized as "goals" in the 1989 ROD are
established as final cleanup "standards" to be achieved by the
selected remedy. Specifically, EPA is revising language in the
1989 ROD that states that the remedy for groundwater is "pumping . .
and treating of all three units, to the extent practicable" by
deleting the phrase "to the extent practicable." This change is
mad~ to clarify and ensure that EPA has selected in the ROD a
specific remedial action for groundwater cleanup rather' than
deferring the selection of cleanup standards to a later date.
1 If the changes made after the ROD was signed had
fundamentally altered the nature of the selected remedy, then a
ROD amendment would have been required. 40 C.F.R.
S 300.435(c) (2) (ii) (1990) (55 Fed. Reg. 8666,8852 (March 8,
1990».
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The technical data in the administrative record supports this
remedy. There is not sufficient information in the record to
indicate that it is currently technically impracticable to
implement the remedy selected.
EPA has provided a fifteen (15) day comment period to the
state of California (in accordance with 40 C.F.R.
S 300.515(h) (3» and the state has concurred on this ESD.
Pursuant to 40 C.F.R. S 300.435(6) (2) (i) (1990), a public comment
period is not required for an ESD.
II.
BACKGROUND
The following is a brief background of the Beckman site and
a short summary of the remedy selected in the ROD. Additional
background information can be found in the September 26, 1989 ROD
and in the Beckman Administrative Record.
A.
site Backaround and Descriction
The: Beckman Site, which includes the Beckman Plant and
surrounding study area, is located near the southern limit of the
City of porterville, California. porterville is located in
Tulare County about 25 miles southeast of Visalia on the eastern
fringe of California's Central Valley. The Beckman Plant is
located at 167 West Poplar Avenue and occupies approx~mately 12.5
acres of a 30.95 acre parcel of land owned by Beckman
Instruments, Inc. The Site study area is generally bounded by
the Tule River to the north, plant property to the east, Poplar
ditch to the south and Newcombe Drive to the west. Land use
within the study area includes residential, field crop, orchard,
grazing land, Tule River floodway, commercial, industrial and
vacant land. . .
The Beckman Plant has manufactured electronic instrument
assemblies, subassemblies and printed circuit boards in
Porterville since 1967.. Its industrial processes include.
electroplati~g and degreasing. The waste streams from these
processes have included spent halogenated solvents, inorganic and
acid solution, salts, metal-laden solutions and plating bath
sludge.
Wastewater from the industrial processes conducted at the
site was discharged to the city of porterville sewer system
between 1967 and 1974. From 1974 until early 1983, various waste
streams were discharged to an on-site solar evaporation pond.
Wastes also may have been placed in other areas near the plant.
Since 1983, waste streams have been treated on-site and treated
liquids are discharged to the City of porterville sewer system.
Beckman initiated groundwater monitoring in the vicinity of
the solar pond in 1982. Water samples analyzed in May 1983
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revealed the presence of some organic compounds and metals in
groundwater below the unlined solar pond and in domestic wells
downgradient of the plant. The pond was closed in 1983.
In Karch 1985, the California Department of Health Services
(DHS) placed the Site on California's Superfund state Priority
Ranking List. On October 9, 1985 EPA received an official
request by DHS to assume the lead role in overseeing remedial
studies and cleanup activities at the Site. The Site was added \
to the Federal Superfund National Priorities List (NPL) by EPA on "\
June 10, 1986, by notice in the Federal Register, Volume 51, No. '
111.
Beckman submitted the Remedial Investigation (RI) report to
EPA in December 1988. The Feasibility Study (FS) report'prepared
by Beckman, and as amended by ~A, was released for public
comment in Karch 1988. EPA's Proposed Plan was released for
public review in June 1989.
Th~ RI report indicated the existence of a multilayer
aquifer system beneath and downgradient of the plant. The
aquifer system is comprised of an "upper aquifer", "upper
aquitard" and "lower aquifer", based on the order of occurrence
of the units below ground surface and the hydraulic
characteristics of the units. Five primary contaminants have
been identified in groundwater at the Site. These volatile
organic compounds (VOCs) include 1,1,1-trichloroethane (TCA),
1,1-dichloroethylene (DCE), freon 113,1~1-dichloroethane (1,1-
DCA), and trichloroethylene (TCE). other contaminants such as .
1,2-dichloroethane and benzene have been sporadically detected in
groundwater in and surrounding the Site. Soil samples were
identified with lead concentrations above the cleanup level
established in the ROD. .
Prior to the discovery of chemicals in the groundwater,
groundwater below the site area was used for domestic and
agricultural purposes. After discovery of chemicals in
groundwater, Beckman provided alternate water supplies to
approximately 300 residences in the study area. Eight private
wells which were completed in the upper and lower aquifers were
also sealed or replaced with wells screened in the lower aquifer
to prevent further spread of contamination.
Beckman began extraction and treatment via air stripping of
groundwater in July 1985 to contain western migration of the
plume, control water level gradients in the upper aquifer, and
reclaim upper aquifer groundwater. Beckman commenced operation
of a second containment and reclamation system in the eastern
portion of the Site in July 1987.
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B.
REMEDY SELECTED IN THE 1989 ROD
1. Groundwater. The selected remedy for qroundwater in the
upper aquifer, upper aquitard, and lower aquifer is extraction
and treatment. Extracted groundwater is to be treated using air
stripping towers. The air stripping towers will meet substantive
permitting requirements set by the local Air Quality Management
District to regulate emissions. i Treated groundwater will be
discharged to on-site infiltration ponds. These discharges will \
be regulated by the National Pollutant Discharge Elimination. '.
System (NPDES) under the Clean Water Act. \
EPA set groundwater cleanup goals for the upper aquifer,
upper aquitard and lower aquifer at federal Maximum Contaminant
Limits (MCLs), except where state MCLs are more stringent (as is
the case for 1,1-DCA). Where no federal or state MCL exists for
a contaminant, state action levels (SALs) were selected as the
cleanup goal (this is the case for Freon-113). The specified
cleanup goals are as follows: .
Contaminant
CleanU"D Goal
1,1,1-TCA
1,1-DCE
Freon-113
1,1-DCA
TCE
200 ppb2
6 ppb
1,200 ppb
5 ppb
5 ppb
2. Soils. This ESD does not affect the soils remediation
component of the September 26, 1989 ROD.
III.
EXPLANATION OF SIGNIFICANT DIFFERENCES
This ESD is intended to clarify two points relating to EPA's
ROD dated September 26, 1989. For the reasons explained below,
this ESD amends two sentences in the ROD:
1.
The sentence in the ROD (Section IX, page 22) that
stated: "The remedy specified in this Record of
Decision is pumping and treating of all three units, to
the extent practicable," is amended to read:.
"The remedy specified in this Record of Decision
is pumping and treating of all three units."
2.
Language in the ROD (Section IX, page 23) that stated:
"This decision will be reviewed after the remedy has
been in place five years to determine the feasibility
2
ppb = parts per billion
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of cleaning up the aquitard to MCLs," is amended to
read:
"The remedial action selected in this Record
Decision shall be reviewed pursuant to the
requirements of Section 121(c) of CERCLA, 42
V.S.C. S 9621(c)~"
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A. CleanuD Standards. The amendment to the first sentence,
above, is to make clear that the numerical "goals" set forth in
the ROD for both qroundwater. and soil remediation at the Beckman
Site constitute "cleanup standards" to be attained at the
completion of the remedial action. EPA selected qroundwater
extraction and treatment to address the qroundwater ....
contamination. It specified five cleanup "goals" for qroundwater
in the upper and. lower aquifers and the upper aquitard: 200ppb
1,1,1-TCA; 6ppb 1,1-DCE; 1200 ppb Freon 113; Sppb TCE; Sppb 1,1-
DCA.
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The. ROD expressed these numerical levels as "goals",
recognizing that it may not be possible to state with certainty
the extent to which actual cleanup levels could be achieved in
the more impermeable zones of the aqui tard. As noted above, the
~OD states that the remedy specified therein is "pumping and
treating of all three units, to the extent practicable." The
qualifying phrase "to the extent practicable" acknowledges the
inherent uncertainty (that the remedial action will achieve
cleanup levels3) that exists at the time a groundwater
extraction treatment remedy or innovative treatment technology is
selected.
In the Beckman ROD, Applicable or Relevant and Appropriate
Requirements (ARARs) were used to establish the numerical cleanup
"goals" (either as federal or state MCLs or state Action Levels).
As required by section 121(d) (2) (A) of CERCLA, these levels,
referred to as "cleanup goa1s", are established as cleanup
standards which must be attained by the completion of the
remedial action. Accordingly, after re-evaluation of the
administrative record and in light of the promulgation of the
National Contingency Plan, by this ESD, EPA now unequivocally
reaffirms that the qroundwater remedy selected in the ROD shall
attain all ARARs, i.e., the contamination concentra~ion levels
set forth as "cleanup goals" in Table 4 of the ROD.
As was true at the time the ROD was signed, there is still
insufficient information to invoke any type of waiver of these
3 Final cleanup levels are established either from ARARs,
or by consideration of other factors, in the determination of
final Remediation Goals. 40 C.F.R. Section 300.430(e).
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statutorily required cleanup levels, pursuant to section
121(d)(4) of CERCLA. Adequate data for an informed decision
about any technical impracticability of the selected groundwater
remedial action will not exist until the extraction and treatment
system has become fully operational for a significant period of
time.
Under Section 121 of CERCLA, 42 U.S.C. S 9621, and the NCP,
EPA is required to select a remedy that is protective of human
health and the environment and that meets all ARARs. EPA can
only select a remedy that does not meet an ARAR if it formally
makes a finding based on at least one of the six factors set
forth in Section 121(d) (4) of CERCLA, 42 U.S.C. S 9621(d) (4).
One of these six factors allows EPA to select a remedy that does
not meet an ARAR if the remedy originally selected is found to be
"technically impracticable from an engineering perspective" [See
Section 121(d) (4) (c) of CERCLA, 42 V.S.C. S 9621(d)(4)(c)].
The authority of EPA to invoke an "ARAR waiver" based on
"technical impracticability" is limited under CERCLA. This
waiver $hould be used in cases where: (i) neither existing nor
innovative technologies can reliably attain the ARAR in question,
or (ii) attainment of the ARAR in question would be illogical or
infeasible from an engineering perspective [53 Federal Register
51439 (December 21, 1988)]. While cost may be considered in
determining practicability,. it should generally playa
subordinate role in determining practicability from an
engineering perspective [55 Federal Register 8748 (March 8,
1990)]. Accordingly, based on its re-evaluation of the
administrative record,EPA has determined that there is presently
insufficient information upon which to waive any ARARs at the
.' Beckman Site. .
At the time EPA selected the remedial action for the Beckman
Site, EPA responded to comments on the Feasibility Study (which
are included in the administrative record) that objected to
proposed cleanup levels which were more stringent than ARARs
(MCLs or SALs). In the ROD, EPA selected ARARs as the cleanup
levels for groundwater. Comments to the Feasibility Study
indicated satisfaction with ARAR levels and no waiver of these
ARARs was sought at that time. While the ROD acknowledged
ci~umstances that could affect the practicability of the
selected remedy, through this ESD EPA is clarifying that it will
cQnsider technical practicability or impracticability as a factor
in evaluating whether, in the future, it should formally invoke a
waiver of an ARAR. EPA will make such an evaluation, as required
by CERCLA and the NCP, on the basis of information generated
during the Remedial Action phase of the remedy.
B. Process for Future Amendments to the ROD. EPA
recognizes that new information may be generated during the
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ongoing Remedial Design/Remedial Action process that could affect
the remedy selected in the ROD. This information, which may be
developed by Beckman, support agencies, the general public, or
EPA, may form the basis for a proposed amendment to the ROD or an
ESD. In determining whether a change to the ROD is appropriate,
EPA will consider all legally applicable requirements.
In addition, under Section;121(c) of CERCLA, 42 U.S.C.
S 9621(c), EPA is required to review every five years all
Superfund sites where hazardous substances remain on the site to
ensure that human health and the environment are protected.
Therefore, it is possible that EPA may determine that a remedy
selected in the ROD should be changed to provide for even greater
protection to human health and the environment.
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If new information is submitted by the general public,
Beckman, the support agencies, or developed by EPA during
implementation of the remedial action, EPA may reconsider the
hazardous substance management approach selected in the ROD. If
EPA determines that the ROD should be changed, it will follow all
applicable requirements under CERCLA, including those of Section
117 of CERCLA, 42 U.S.C. S 9617, and under the National oil and
Hazardous Sub~ances Pollution Contingency Plan (NCP), 40 C.F.R.
Part 300, including those required by 40 C.F.R. Subpart I,
Section 300.S25(c).
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i5an1 W. McGovern ~
Regional Administrator
3.C,.Cl1
Date
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