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U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF INSPECTOR GENERAL
Catalyst for Improving the Environment
Evaluation Report
EPA's Safety Determination for
Delatte Metals Superfund Site
Was Unsupported
Report No. 09-P-0029
November 19, 2008
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Report Contributors:
Carolyn Copper
Patrick Milligan
Kathryn Hess
Denise Rice
Martha Chang
Abbreviations
Delatte
DQO
EPA
LDEQ
O&M
OIG
ORD
PRB
QAPP
RAO
Review
ROD
SDMS
Site
Delatte Metals Superfund Site
Data Quality Objective
U.S. Environmental Protection Agency
Louisiana Department of Environmental Quality
Operation and Maintenance
Office of Inspector General
Office of Research and Development
Permeable Reactive Barrier
Quality Assurance Project Plan
Remedial Action Objective
Five-Year Review
Record of Decision
Superfund Document Management System
Delatte Metals Superfund Site
Cover photo:
New housing development built adjacent to the Delatte Metals Superfund
Site, Ponchatoula, Louisiana. (EPA OIG photo)
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,V16D Sr/|,
I
5
U.S. Environmental Protection Agency
Office of Inspector General
At a Glance
09 -P-0029
November 19, 2008
Catalyst for Improving the Environment
Why We Did This Review
The Office of Inspector
General (OIG) is testing long-
term monitoring results at
Superfund sites the U.S.
Environmental Protection
Agency (EPA) has deleted
from the National Priorities
List to ensure that EPA has
valid, reliable, and accurate
data on the conditions at these
sites. Delatte Metals
Superfund Site (Delatte),
Ponchatoula, Louisiana, is one
of eight sites that we are
evaluating.
EPA's Safety Determination for
Delatte Metals Superfund Site Was Unsupported
Background
Soil and water at Delatte were
contaminated with metals
from battery recycling and
smelting operations. EPA
deleted Delatte from the
National Priorities List in
2005, signifying clean-up
goals were achieved through
remedial action. In November
2007, EPA Region 6
completed a required review
(Five-Year Review) of the Site
to determine if it still
protected humans and the
environment from
unacceptable risks.
For further information,
contact our Office of
Congressional and Public
Liaison at (202) 566-2391.
To view the full report,
click on the following link:
www.epa.qov/oiq/reports/2009/
20081119-09-P-0029.pdf
What We Found
EPA's protection determination for the Delatte Metals Superfund Site was not
supported by its data. Despite evidence of potential remedy failure, EPA Region 6
determined in November 2007 that conditions at Delatte protect humans and the
environment in the short-term. Our review showed:
• The permeable reactive barrier (PRB) was not treating all of the shallow
contaminated groundwater before it discharges to surface water and
migration of metal contaminants was uncontrolled.
• Metal concentrations in surface water greatly exceeded site clean-up
standards.
• Site access was uncontrolled and public warning that the Site is restricted
to industrial use was limited.
• Region 6 did not perform sufficient testing of the groundwater and surface
water to determine whether contaminants were controlled.
• Region 6 did not perform the required inspection of the PRB.
EPA research scientists also raised concerns about the effectiveness of the PRB in
controlling the migration of all metals and recommended that Region 6 conduct
additional testing. The data available to Region 6 when it conducted its November
2007 Five-Year Review, combined with the OIG's results, show that the Site's
safety cannot be determined until the effectiveness of the PRB and the risk posed by
the migration of metals are assessed.
What We Recommend
We made eight final recommendations to Region 6. The Region agreed with
seven OIG recommendations to ensure that the Delatte clean-up remedy is
performing as intended and is protective to human health and the environment.
Region 6 disagreed with our recommendation to amend its 2007 Five-Year
Review determination to state that the protectiveness of the Delatte remedy cannot
be determined without further information and analysis. We believe this action is
needed. The recommendation is open and unresolved.
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\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
* WASHINGTON, D.C. 20460
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1
OFFICE OF
, -„„„ INSPECTOR GENERAL
November 19, 2008
MEMORANDUM
SUBJECT: EPA's Safety Determination for Delatte Metals Superfund Site
Was Unsupported
Report No. 09-P-0029
FROM: Wade Najj um ^ /^p / ///, ,1 ^ t
Assistant Inspector General /ft
Office of Program Evaluation -''
TO: Richard Greene
Region 6 Administrator
This is our report on the subject evaluation conducted by the Office of Inspector General (OIG)
of the U.S. Environmental Protection Agency (EPA). This report contains findings that describe
the problems the OIG has identified and corrective actions the OIG recommends. The OIG
responded to EPA Region 6's draft report comments by making changes to the report and
providing responses to EPA Region 6, as appropriate. This report represents the opinion of the
OIG and does not necessarily represent the final EPA position. Final determinations on matters
in this report will be made by EPA managers in accordance with established resolution
procedures.
The estimated cost of this report - calculated by multiplying the project's staff days by the
applicable daily full cost billing rates in effect at the time - is $398,750.
Action Required
In accordance with EPA Manual 2750, you are required to provide a written response to this
report within 90 calendar days. You should include a corrective action plan for agreed upon
actions, including milestone dates. For the recommendation over which we disagree, please
reconsider your position in your response to this final report. We have no objections to the
further release of this report to the public. This report will be available at
http://www.epa.gov/oig.
If you or your staff have any questions regarding this report, please contact Carolyn Copper,
Director for Program Evaluation, Hazardous Waste Issues, at (202) 566-0829, or
copper.carolyn@epa.gov: or Patrick Milligan, Project Manager, at (215) 814-2326, or
milligan.patrick@epa.gov.
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EPA's Safety Determination for Delatte Metals 09-P-0029
Superfund Site Was Unsupported
Table of Contents
Chapters
1 Introduction 1
Purpose 1
Background 1
Noteworthy Achievements 3
Scope and Methodology 3
2 OIG Sampling and Site Inspection Identified Site Safety Concerns 5
OIG Sampling Results Identified High Metal Concentrations 5
EPA Should Have Been Aware of Site Safety Concerns 8
Access to Site Was Not Controlled 9
Protection Level of Remedy Was Not Supported 10
Conclusions 14
Recommendations 14
EPA Region 6 Responses and OIG Evaluation 15
Status of Recommendations and Potential Monetary Benefits 18
Appendices
A Details on Scope and Methodology 19
B Relevant Documents Reviewed 21
C Results of OIG Sampling 22
D EPA Region 6 Responses and OIG Evaluation 27
E Distribution 55
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09-P-0029
Chapter 1
Introduction
Purpose
The Office of Inspector General (OIG) of the U.S. Environmental Protection
Agency (EPA) is evaluating long-term monitoring at Superfund sites deleted from
the National Priorities List. This is being done to ensure that EPA has valid,
reliable, and accurate data on the conditions of these sites. The Delatte Metals
Superfund Site (Delatte, or the Site), located in Ponchatoula, Louisiana, is one of
eight sites that we are evaluating. This report presents OIG findings related to
EPA's Five-Year Review determination, or "protectiveness determination," that
the remedy at Delatte is protective of human health and the environment.1 We
collected groundwater and surface water samples and conducted a site inspection.
We compared our results to past results reported by EPA and the Louisiana
Department of Environmental Quality (LDEQ).
Background
Delatte was added to EPA's Superfund National Priorities List in 1999. The Site
covers about 19 acres, although remedial activities extended beyond the Site
boundaries and encompassed a total of about 57 acres. Selsers Creek flows past
the northwest corner of the Site. Two tributaries to the creek drain the Site.
Soil, sediment, surface water, and shallow groundwater were contaminated with
lead, arsenic, cadmium and other metals from battery recycling and smelting
operations conducted at Delatte. Remedial action objectives identified in the
record of decision (ROD) included:
• Minimize or eliminate contaminant migration to the groundwater and
surface waters to levels that ensure beneficial reuse of these resources,
• Treat or remove the principal threat wastes at the site, and
• Reduce or eliminate the direct contact threats associated with
contaminated soil.
Remedial action included construction of a permeable reactive barrier (PRB) to
treat contaminated shallow groundwater. The PRB at Delatte (Figure 1-1)
extends 9 to 15 feet below ground and laterally about 720 feet across the direction
of groundwater flow to intercept the shallow groundwater. The PRB is composed
1 This report uses the terms "protective" and "safe" interchangeably. Our intent in using the word "safe," or
"safety," is to clarify a technical EPA term. An EPA publication used to communicate the purpose of Superfund
Five-Year Reviews also uses the words "protective" and "safe" interchangeably.
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09-P-0029
of limestone and cow manure to neutralize the acidity (raise the pH level) of the
groundwater that flows through it. The rise in pH immobilizes some metals in the
groundwater and limits the migration of metals off the Site. Remedial action also
included removing or stabilizing on- and off-site contaminated soil. Remedial
action was completed by Region 6 (Region) in 2003.
Figure 1-1: Aerial photograph of the northern portion of the Delatte Site, showing location
of the PRB and surface water features. This photograph was taken before houses (shown in
cover photograph) were constructed northwest of Selsers Creek. (Source: EPA, with labels
added by OIG)
In 2004 LDEQ initiated the required ongoing Operation and Maintenance (O&M)
phase that includes quarterly groundwater monitoring. In addition, research
scientists from EPA's Office of Research and Development (ORD) periodically
collected groundwater samples in the vicinity of the PRB.
EPA deleted the Site from the National Priorities List on August 8, 2005.
Deletion signifies an EPA decision that all response actions were successful and
no further Superfund response is required to protect human health and the
environment. The State of Louisiana concurred with this decision. Although the
Site is deleted, some waste remains, limiting the Site to industrial uses.
Therefore, reviews are required by law at least every 5 years to ensure that the
remedy continues to protect human health and the environment. Region 6
released its first Five-Year Review (Review) of the site on November 19, 2007,
which was 5 years after remedial construction began. The Region concluded that
the remedy protects in the short-term, but improvements were needed to ensure
long-term safety. The Region did not define what it meant by short-term
protection.
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09-P-0029
Noteworthy Achievements
The Region conducted remedial action during 2002 and 2003 to stabilize metals
in soil or remove the contaminated soil. Over 85,000 tons of contaminated soil
were excavated on- and off-site, treated, and disposed of at an off-site landfill.
About 20,000 tons of off-site soils meeting on-site industrial clean-up standards
were placed in the on-site excavations. Lime was applied to unexcavated areas to
reduce the soil's acidity. Because treated wastes were left on-site, an institutional
control in the form of conveyance notices were placed on the Site's property
deeds limiting the Site to industrial uses and excluding access to groundwater
under the Site for drinking water purposes.
Scope and Methodology
We conducted our work from May 2007 to August 2008 in accordance with
generally accepted government auditing standards. Those standards require that
we plan and perform the evaluation to obtain sufficient, appropriate evidence to
provide a reasonable basis for our findings and conclusions based on our
evaluation objectives. We believe that the evidence obtained provides a
reasonable basis for our findings and conclusions based on our evaluation
objectives.
We acquired a qualified contractor to take groundwater and surface water
samples, and conduct a site inspection at the Site during the week of February 4,
2008. On or near the site, the contractor collected samples from 22 groundwater
wells and 3 surface water locations. OIG staff members were present to ensure
that proper sampling and site inspection quality assurance protocols were
followed. The samples were analyzed at qualified laboratories.
We interviewed the EPA Remedial Project Manager, the Project Manager for
LDEQ, and others. We reviewed relevant site and guidance documents. On
March 6, 2008, we sent the Region information alerting it of potential issues we
identified at Delatte, along with a list of questions regarding those issues. The
Region provided this information to the EPA research scientists studying the
effectiveness of the PRB. On March 24, 2008, the Region, along with the EPA
research scientists, responded in writing. In May 2008, we followed up with the
Remedial Project Manager and the LDEQ Project Manager to determine whether
they implemented or planned corrective actions to address the issues we
identified.
A draft of this report was sent to the Region 6 Administrator on August 7, 2008.
We received comments from Region 6 on September 12, 2008, and met with
Region officials on October 9, 2008 to discuss their review of a draft of this
report. On October 15, 2008, the Region provided additional comments to their
September response. We reviewed and considered the Region's comments, and
made revisions to the report where appropriate.
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09-P-0029
Additional details on our Scope and Methodology are in Appendix A. A list of
relevant documents we reviewed is in Appendix B. OIG sampling results that
relate to issues discussed in this report are in Appendix C. Region 6's written
comments and the OIG's evaluation of those comments are in Appendix D.
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09-P-0029
Chapter 2
OIG Sampling and Site Inspection
Identified Site Safety Concerns
Results from our sampling and site inspection raise doubts about the safety of the
Delatte Site and the level of protection provided by EPA's clean-up actions.
Region 6 did not support its protectiveness determination based on data in its
November 2007 Five-Year Review. In particular, we question the effectiveness
of the PRB in preventing metals in the shallow groundwater from leaving the site.
We believe that groundwater is being re-contaminated after passing through the
PRB. In addition, the PRB does not extend far enough laterally to intercept all of
the contaminated groundwater. This resulted in some contaminated groundwater
bypassing the PRB and flowing from the Site untreated. Our site inspection and
sampling showed that high metal concentrations were:
• in the groundwater that had passed through the PRB,
• in the groundwater that bypassed the PRB, and
• in the surface water we sampled.
Similar information gathered by the Region and LDEQ confirm our groundwater
results and reinforce our doubts about the Region's determination that the remedy
protects in the short-term. We concur with EPA research scientists in questioning
the effectiveness of some characteristics of the PRB and recommending that
further study is needed. Also, physical access to the Site was not controlled.
Region 6 needs to conduct additional testing of groundwater and surface water
and determine the effectiveness of the PRB as a remedy before it can determine
whether the remedy protects human health and the environment.
OIG Sampling Results Identified High Metal Concentrations
Our results show high metal concentrations in parts of the shallow groundwater
and in surface water where concentrations should be low if the PRB is effectively
limiting the migration of metals off the Site. Discussion of these results follows.
High Metal Concentrations in Groundwater Beyond the PRB
Concentrations of some metals are reduced as the groundwater passes through
some sections of the PRB. However, the PRB is not preventing metals in the
groundwater from traveling beyond the PRB. Three monitoring wells tap
groundwater that has already traveled through the PRB (wells BA-09, DW-01,
and MW-01; see Figure 2-1 on page 7). We found high concentrations of metals
in these monitoring wells located beyond the PRB (see Table 2-1 on page 6).
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09-P-0029
Also, the groundwater pH values at these wells were low, which means that
acidity was high and metals were still mobile in this groundwater. The low pH
values and elevated concentrations of metals are evidence that the PRB was not
neutralizing the groundwater nor limiting the migration of all dissolved metals off
the Site. Therefore, we concluded that the PRB was not meeting its designed
remedial purpose.
Table 2-1: Selected OIG Groundwater and Surface Water Results
Groundwater Sampling
Beyond
PRB
Next to
PRB
Surface Water
Sampling
Sampling
Location
BA-09
DW-01
MW-01
DW-03
SW-03
Standards
Federal Drinking Water*
LDEQ Ecological **
ROD, Residential Groundwater
ROD, Ecological ***
Total Metal Concentration
(milligrams per liter)
Arsenic
0.019
0.29
0.11
O.01
<0.01
Cadmium
0.018
0.054
0.055
0.17
0.10
Lead
0.012
0.016
<0.05
0.41
0.53
Nickel
0.15
0.028
0.34
0.033
0.024
Zinc
0.25
0.16
<0.5
0.12
0.24
Field pH
(standard
units)
3.2
4.7
3.3
3.7
4.5
0.01
0.15
-
-
0.005
0.0005
-
0.0009
0.015
0.0007
0.015
0.0006
-
0.061
-
-
5
0.041
-
0.038
6.5-8.5
6.5-9
-
-
Source: EPA OIG
Metal concentrations in BOLD exceed the LDEQ ecological standard. pH values in BOLD are outside the federal ecological
standard range. The standards are also presented in BOLD.
< The sample concentration is below the method reporting limit. Therefore, the sample concentration could not be
measured. The value following the "<" sign is the method reporting limit for that analysis.
— Federal drinking water standard has not been set or clean-up standard was not specified in the ROD and its appendices.
* Drinking water standards for pH and zinc are secondary standards. The drinking water standard for lead is an action level
above which acidity control is required.
** The ecological standards for chronic exposure to cadmium, lead, nickel, and zinc are dependent on the hardness of the
water. The standards given here are based on the median hardness of water in Selsers Creek at the LDEQ monitoring site
downstream of the Delatte Site. The pH range is a federal ecological standard.
*** The ROD reports the clean-up standard for lead. Standards for cadmium and zinc are recommended in an appendix to
the ROD.
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09-P-0029
Figure 2-1: Map of Northern Portion of Delatte Metals Superfund Site
Housing in Place Before Remedial Actions
SCALE IN FEET
Hew Housing Development
Constructed After Remedial
Actions
Source: EPA Region 6, with labels added by OIG.
Many of our results from these three wells exceeded ecological standards
(Table 2-1). These high metal concentrations raise concerns about the quality of
the surface water on and near the Site, because the shallow groundwater in the
vicinity of these wells is thought to discharge to Selsers Creek and a tributary
(Tributary 1 in Figure 2-1). However, Region 6 has not investigated groundwater
discharge to these surface waters nor required LDEQ to sample Selsers Creek and
its tributaries as part of the quarterly O&M monitoring at the Site.
Results from three wells located beyond the PRB also show that concentrations of
lead cannot be used as the Region's sole measure of remedial success at the Site.
We found elevated arsenic, cadmium, nickel, and zinc concentrations in areas
where lead concentrations were low. This contradicts the Region's assumption in
the ROD that the clean-up of lead will effectively clean up the other metals as
well.
High Metal Concentrations in Groundwater Bypassing the PRB
Not all of the shallow groundwater with high metal concentrations at the Site
flows through the PRB. Some groundwater flows to the east of the PRB, possibly
discharging into Tributary 1 or Selsers Creek. The highest lead concentration we
found in groundwater was in a well next to the PRB (well DW-03). Several other
metal concentrations also were elevated and the pH of this water was low. These
sample results further support our conclusion that the PRB was not meeting its
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09-P-0029
designed remedial purpose, in this case because the PRB was not laterally
extensive enough to treat all of the contaminated water.
High Metal Concentrations in Surface Water
The PRB was not preventing cadmium, lead, nickel, and zinc from migrating to
the surface water. The highest lead concentration we measured was in a surface
water sample (see SW-03 in Table 2-1) taken from the tributary that feeds into
Selsers Creek near the western end of the PRB (Tributary 2 in Figure 2-1). The
concentration is about 800 times the ecological clean-up level for lead in surface
water specified in the ROD. As with the groundwater beyond and bypassing the
PRB, we again found low pH levels.
One of the residents living adjacent to the Site informed us that children play in
Selsers Creek. During our February 2008 site inspection, we also observed pets
of the nearby residents in the creek and its tributaries. In evaluating the safety of
the Site, Region 6 needs to assess how prevalent metals are in the creek and its
tributaries, and determine possible human and ecological exposures.
One of the Region's recommendations in the Five-Year Review is to add surface
water sampling to the O&M monitoring. LDEQ, in responding to a draft of the
Five-Year Review, recommended in October 2007 that surface water sampling
occur in an area of the creek near the PRB and also downstream of the PRB.
However, the recommended action in the Review is limited to sampling in Selsers
Creek in the vicinity of one of the monitoring wells (MW-01) located beyond the
PRB. We concluded from our results that surface water sampling should be more
extensive and include areas of the surface water possibly receiving groundwater
that bypassed the PRB.
EPA Should Have Been Aware of Site Safety Concerns
Site information similar to our results was available to Region 6 when it
conducted its November 2007 Five-Year Review. However, the Region did not
raise concerns about uncontrolled migration of metals in the shallow groundwater,
even though it had the data to suggest the PRB was not treating all of the
contaminated groundwater. For example, sampling data collected by LDEQ and
EPA research scientists showed that arsenic concentrations in groundwater in and
beyond the PRB were as high as nine times the ecological standard.
LDEQ's O&M sampling also showed lead concentrations rising at well DW-03
located to the east of the PRB. This is the well in which we measured the highest
groundwater concentration of lead. In its 2007 Review, Region 6 misidentified
this well as being located ahead of rather than next to the PRB. As a result, EPA
did not recognize that groundwater with high metal concentrations bypassed the
PRB.
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09-P-0029
Region 6 had groundwater flow maps and analyses of contaminant transport that
were gathered for the 1999-2000 remedial investigation before the PRB was
designed. From this information, we concluded that the PRB does not extend far
enough laterally to intercept all of the contaminated groundwater, some of which
appears to discharge to the creek and its tributaries. We believe that the Region
should have made these same conclusions and evaluated the magnitude of the
migration of metals that would bypass the PRB and the potential risks to human
health and the environment posed by that bypass.
Another source of information was LDEQ's sampling results when it tested the
water quality of the creek downstream of the Site. LDEQ sampled the creek four
times in 2007. All four water samples had lead concentrations that exceeded the
ROD's clean-up standard for lead in surface water.
Access to Site Was Not Controlled
The Site is currently restricted to industrial use because wastes were left on-site at
concentrations not appropriate for residential or ecological uses. During our site
inspection in February 2008, we observed access to the site was not controlled:
• the perimeter fence was damaged in two locations by fallen trees;
• the fence had been cut and rolled back, providing access to one monitoring
well;
• a chain on an access gate through the fence had been cut but was left to
appear that the gate was still locked; and
• no signs were posted with warnings about the Site being limited to
industrial use or with contact information.
Poor fence maintenance gives the perception that the Site is not maintained and
allows unauthorized Site access. A resident whose property borders the site
expressed concern about the damaged fence. The Region's Site manager stated
that the fence belongs to the site owners and is not necessary to protect human
health and the environment. In addition, the Region stated that a combination of
existing land use controls on the Site and quarterly LDEQ inspections ensures that
unauthorized activities are not occurring at the Site. However, quarterly
inspections cannot prevent unauthorized access year-round. The Region stated in
its response to the draft of this report that access to the Site will be controlled and
signs posted. LDEQ told us it plans to repair and maintain the fence as part of its
O&M responsibilities.
Although land use classification has not changed, residential density surrounding
the site has changed. This change further emphasizes the need to review site
access controls. Since the completion of remedial activities, subdivision housing
has been constructed northwest of the Site (see cover photograph); another
subdivision is planned next to the eastern fence. The growth in the population
surrounding the Site increases the likelihood of trespassers entering through the
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09-P-0029
damaged perimeter fence. During the remedial investigation, risk assessments for
on-site trespassers were not performed. EPA's Five-Year Review guidance
specifically identifies changes in land use as a factor to consider in evaluating the
protection provided by the remedy. We consider the increase in the housing
density to be a change in land use. The Region stated that the residents in the new
developments were protected because they were served by public water.
However, this explanation does not account for the clean-up level of the soil. The
soil on the Site was cleaned to an industrial-use standard, not to the more
protective residential or ecological standards. As a result, the Site has restrictions
and unauthorized people are not permitted. An evaluation of the risk to on-site
trespassers, particularly in the absence of a secure perimeter fence, should have
been conducted during the Five-Year Review.
The uncontrolled access may also result in damage to the remedy or the
monitoring network in and around the PRB. The monitoring wells in this network
were installed by the EPA research scientists without tamper-resistant casings that
are standard and are installed on the wells in the O&M monitoring network at this
Site. Instead, the plastic casings of the PRB monitoring wells are exposed above
ground. These casings provide an unsecured route for tampering with the
subsurface PRB, whether intentional or unintentional. The plastic casings above
ground also could be easily damaged. While at the Site, we observed that several
of the casings were already damaged.
Protection Level of Remedy Was Not Supported
EPA's determination in its November 2007 Five-Year Review that the remedy
protects human health and the environment in the short-term was not supported by
the information the Region included in the Review. The Region did not
completely evaluate the performance of the PRB in meeting the remedial goal of
controlling the migration of metals in the shallow groundwater. In addition, the
Region did not comply with all ROD requirements, nor did it consider all human
and ecological exposure pathways and their resulting risks. The Region needs to
revise its protectiveness statement to indicate protectiveness cannot be determined
until further information is obtained.
EPA guidance for conducting a Five-Year Review calls for a technical assessment
that answers three questions:
• Is the remedy functioning as intended by the decision documents?
• Are the exposure assumptions, toxicity data, clean-up levels, and remedial
action objectives used at the time of remedy selection still valid?
• Has any other information come to light that could call into question the
protectiveness of the remedy?
How the Region answers these questions establishes whether EPA determines that
the site remedy protects human health and the environment. In making its
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determination, we found that the Region did not collect enough relevant
information to answer these questions. Also, the Region did not use all of the
available data or assess whether its assumptions were still valid. The Region cited
monitoring results that indicated the remedy was functioning effectively.
However, the Region also had data that indicated the remedy was not functioning
as intended, and had received recommendations that further testing and
investigation were needed. Region 6 did not cite these problematic results when
determining the protection level. As a result, Region 6 did not identify all
contaminant exposure pathways or assess the risks to human health and the
environment in the Five-Year Review.
Incomplete Evaluation of Remedy
The Region did not conduct a full evaluation of the PRB, which is the remedy
intended to treat the shallow contaminated groundwater to prevent the metal
contaminants from leaving the Site and entering the surface water. The Region
had evidence that the PRB was not fully preventing the migration of metals when
it conducted the Site's Five-Year Review in 2007. The Review stated that with
the exception of total lead, metal concentrations tended to be significantly higher
in groundwater beyond the PRB than before it. This evidence should have
prompted the Region to question the PRB's ability to limit the migration of all
metals.
The Review stated that due to excessive vegetative growth, the Region and LDEQ
were unable to inspect the area above the PRB in June 2007 when they inspected
the Site as part of the Five-Year Review process. Inspecting the area above the
PRB for irregularities at land surface (i.e., subsidence, cracks, and erosion) that
might indicate problems below ground with the PRB is part of the quarterly O&M
site inspection. The Region, through its oversight authority, could have requested
that the area above the PRB be mowed so that a proper inspection could occur for
the Five-Year Review, but did not take this step. Rather, it concluded that the
ground showed no evidence of gross subsidence even though the area above the
PRB had not been inspected. The Region did recommend in the Review that
within 1 year LDEQ remove trees and mow routinely to facilitate inspection of
the PRB. We found in our February 2008 site inspection evidence of the ground
sinking over the PRB.
EPA research scientists are studying whether the PRB at Delatte operates as
designed to increase the pH and decrease the concentration of metals in the
groundwater that passes through the PRB. The scientists sent to the Region in
February 2007 an evaluation of the PRB2 based on 3 years of monitoring results.
The scientists found high arsenic concentrations in groundwater that had passed
through the PRB. They concluded that the groundwater may have become
re-contaminated after it passed through the PRB. This groundwater is thought to
2 In February 2007, EPA's ORD provided Region 6 its evaluation of the PRB performance. Region 6 included this
evaluation as an attachment to its November 2007 Five-Year Review.
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09-P-0029
discharge into Selsers Creek and the tributary flowing to the north of the PRB.
The PRB was installed across an area that had been used for many years to hold
acid wastes in an unlined pond. High concentrations of arsenic and other metals
were detected in the soils in this area during the Region's remedial investigation
conducted in 1999-2000. However, we found no evidence in the 2007 Review
that the Region considered the implications of high arsenic concentrations in
groundwater beyond the PRB or other issues with the PRB raised by the scientists
when determining whether the remedy protects human health and the
environment.
In response to issues we raised in March 2008, the EPA research scientists
provided an update to their 2007 PRB evaluation. They restated that groundwater
is picking up arsenic after it passes through the PRB. Moreover, the scientists
acknowledged that the PRB is not functioning completely as designed and some
groundwater is flowing around the PRB. The scientists recommended
investigating the source of the arsenic and possibly extending the PRB to intercept
more contaminated groundwater. In responding to the same March 2008 OIG
request, the Region did not account for the scientists' findings and instead
responded that the PRB is functioning as designed.
The Region further responded in March 2008 that it had stated in the Review that
the remedy is protective to human health and the environment in the short-term
and it had recommended actions that needed to be taken for the remedy to be
protective in the long-term. The Region's recommended actions do not focus on
improved control of metals migrating in the shallow groundwater. The Region
recommended improving evaluation of groundwater data and implementing
surface water monitoring. Depending on the results of these efforts, the Region
may need to then focus on improving control of metals migrating in the shallow
groundwater.
In February 2008, LDEQ's consultant recommended in review of the December
2007 O&M monitoring results that additional remediation alternatives be
considered in the shallow groundwater.
Region 6 Did Not Follow All ROD Requirements
Site deletion proceeded based on the assumption that the Site's clean-up actions
were adequate for meeting the human health and environment clean-up standards
specified in the ROD. However, no surface water samples were collected as part
of the O&M monitoring and the Region did not account for the problematic
groundwater data it had in assessing the effectiveness of the PRB. In addition,
ROD conditions incorrectly state that clean-up of lead would also address other
metals of concern.
The mobile lead in the shallowest groundwater at the Site was identified in the
ROD as a "principal threat waste." The PRB was intended to treat this principal
threat waste by neutralizing the acidity of the shallow groundwater and limiting
12
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09-P-0029
the migration of the dissolved metals that would otherwise discharge to the
surface water. However, no surface water samples were taken at the Site to
confirm that the ROD clean-up standard in surface water was being met. The
Region stated in its March 2008 response to the OIG that the ROD does not
include groundwater or surface water clean-up goals. However, the ROD
identifies specific clean-up standards for all appropriate media for lead, including
groundwater and surface water. We concluded that the Region has misinterpreted
the clean-up requirements in the ROD.
The conditions of the ROD incorrectly state that the clean-up of lead would also
address other metals of concern, such as cadmium, nickel, and zinc. This
assumption was not supported by our sampling results and those from LDEQ and
the EPA research scientists. These results show that while the concentrations of
lead have been effectively reduced in the shallow groundwater beyond the PRB,
the concentrations of other metals remain high. Region 6 cannot continue to
assume that if lead concentrations are low other metals also are low. The
concentrations of other metals in addition to lead should be evaluated and
considered in decisions regarding the effectiveness of the PRB and the protection
level provided by the remedy.
Region 6 Did Not Consider All Exposures and Risks
The Region did not consider all human and ecological exposures and risks when
conducting the Five-Year Review. The Review identifies air, soil and
groundwater as the media for potential contamination exposure to humans. Not
recognizing problematic results and the potential migration of dissolved metals to
the surface water prevents the Region from assessing exposure assumptions and
identifying other potential exposure media, such as surface water. EPA has not
evaluated human health risks to surface water for lead. In addition, unacceptable
ecological risks may still exist at Selsers Creek and its tributaries because clean-
up assumptions were contingent upon the remedy controlling metal migration in
the groundwater.
Protection Determination Should Be Revised
The Region determined in November 2007 that the Delatte remedy was protective
in the short-term. The Region added the emphasis to "/'« the short-term" in its
March 2008 response to OIG questions. The response explained that the Region
recognized that the groundwater data set was not robust due to issues related to
detection limit variability and therefore made this short-term protectiveness
determination. The Region recommended in its 2007 Review several actions that
needed to be taken for the remedy to be protective in the long-term. These
included adding surface water sampling, reviewing the adequacy of the
groundwater monitoring program, and improving Site maintenance. However,
none of these actions address PRB effectiveness or the possible risk to human
health or the environment posed by uncontrolled migration of metals.
13
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09-P-0029
Based on information the Region disclosed in its Five-Year Review, along with
the results of the recent OIG sampling and site inspection, an appropriate
statement at this time would be that "protectiveness cannot be determined until
further information is obtained." Such a statement would reflect an understanding
by the Region of:
• limitations in its monitoring and site inspection data,
• potential problems raised by some of the data,
• doubts as to the effectiveness of the PRB remedy to control the migration
of some metals in the shallow groundwater, and
• EPA's responsibility to protect human health and the environment.
EPA guidance on conducting a Five-Year Review establishes the determination
"protectiveness cannot be determined until further information is obtained" as an
option among the types of protectiveness determinations that can be made.
Another EPA region recently released a Five-Year Review for one of its deleted
Superfund sites where that Region concluded it could not make a protectiveness
determination because site monitoring had been inadequate and new potential
issues had been observed.3
Conclusions
Our review disclosed that the Region could not support its November 2007 Five-
Year Review determination that the Delatte remedy protects human health and the
environment in the short-term. From results of our work, we concluded that the
PRB remedy at Delatte was not fully meeting its purpose of limiting the off-site
migration of metals in the shallow groundwater, which may give rise to additional
exposures and risks. A similar conclusion can be drawn from information available
to the Region in 2007 when it conducted its Five-Year Review and made its
protection determination. Accurate and balanced communication to the public on
this Site should state that the Site's protectiveness cannot be determined until
further information is obtained.
Recommendations
We recommend that the Region 6 Administrator:
2-1 Amend the Region's November 2007 Five-Year Review to state that
protectiveness of the Site remedy in both the short- and long-term cannot
be determined without further analysis of the effectiveness of the remedy
and the risk posed by the migration of metals.
See http://www.epa. gov/superfund/sites/fivevear/f200703OOP 1720.pdf. page vi.
14
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09-P-0029
2-2 Publish EPA's milestones for obtaining the information required to make
an accurate determination on the effectiveness of the Site's remedy and on
the risk associated with continued metal migration.
2-3 Investigate, quantify, and publicly report on the discharge of metals from
shallow groundwater at the Site to Selsers Creek and its tributaries and
implement an appropriate response.
2-4 Implement a comprehensive evaluation of the effectiveness of the PRB to
minimize the migration of metals in groundwater off the Site and
implement an appropriate response. Also, evaluate the impact of
groundwater bypassing the PRB.
2-5 Examine the source and mobility of arsenic in shallow groundwater in the
vicinity of the PRB and implement an appropriate response.
2-6 Require LDEQ to modify quarterly water quality sampling to include
analyses for all metals of concern, including arsenic, cadmium, lead,
nickel, and zinc.
2-7 Require LDEQ to control and restrict Site access by repairing and
maintaining the fence and gates, and posting clearly visible signs
describing Site use restrictions and hazards.
2-8 Conduct a new analysis of Site safety that properly considers information
on metal concentrations in groundwater and surface water, and other
evidence of whether the remedy is functioning.
EPA Region 6 Responses and OIG Evaluation
The OIG reviewed and considered two sets of Region 6 comments, and made
revisions to the report where appropriate. Region 6's comments and the OIG's
evaluation of those comments are in Appendix D. Region 6 did not agree with
Recommendations 2-1 and 2-9 in the draft report, but did agree with
Recommendations 2-2 through 2-8 and provided proposed corrective actions.
The corrective actions for Recommendations 2-2, 2-6, and 2-7 meet the intent of
our recommendations. However, Region 6's response and proposed corrective
actions for Recommendations 2-3, 2-4, 2-5, and 2-8 do not fully address the
recommendations.
In its response to Recommendation 2-1, the Region stated that it continues to
believe that the Delatte remedy remains protective in the short-term. The Region
added that no new information that would affect short-term protectiveness has
come to light since the ROD was signed in September 2000, including the
information provided in the OIG report. We do not agree. The OIG's
recommendation is not contingent on presenting "new" information. Region 6's
evaluation of the Delatte remedy was incomplete when it made its protectiveness
15
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09-P-0029
determination. OIG's work confirmed several of the results that EPA has seen at
this site but did not act on. Additionally, the OIG was the first to sample surface
water at this site during the O&M period. More information is needed to
determine whether the Delatte remedy is protective to human health and the
environment.
Regarding Recommendation 2-3, Region 6 has agreed to conduct surface water
monitoring to better understand the groundwater to surface water migration
pathway to guide the future direction of the site. However, the Region further
stated that it did not find an unacceptable risk to human health from direct contact
or ingestion of contaminated surface water during the remedial investigation.
We found that the 2004 human health risk assessment report stated, "potential
exposure to contaminated shallow groundwater may be possible if contamination
were to discharge to surface water . . . ." This statement implies that there was
limited information in 2004 to assess potential risk from exposure to
contaminated groundwater discharging to surface water. As a result, Region 6
needs to use the data it collects to assess the risks to human health and the
environment. In its response to the final report, the Region will need to describe
actions taken or planned to ensure sufficient risk assessments are performed at the
site.
Regarding Recommendation 2-4, Region 6 responded that EPA's ORD is
currently conducting an independent evaluation of the PRB. Region 6 said it will
consider the results of that evaluation and take appropriate action to improve the
performance of the PRB if warranted. We agree that Region 6 needs to continue
to work with ORD to evaluate the effectiveness of the existing PRB. However
the Region also needs to determine whether the existing PRB is sufficient to
ensure the site is protective of human health and the environment. For example,
Region 6 needs to determine whether the PRB is of adequate length to ensure that
the remedy is effective. In its response to the final report, the Region will need to
describe actions taken or planned to ensure the PRB is protective of human health
and the environment.
Regarding Recommendation 2-5, the Region responded that it will continue to
monitor for arsenic in the groundwater, and that if unacceptable exposures occur,
the Region will take whatever action is needed to address that exposure. We
believe that monitoring alone is not sufficient because arsenic in the groundwater
is a new condition. As such, this condition has not been included in the analyses
conducted to date of potential exposure and risk. In its response to the final
report, the Region will need to describe actions taken or planned to conduct an
investigation to understand the magnitude and extent of the source of the mobile
arsenic.
Regarding Recommendation 2-8, Region 6 responded that EPA and LDEQ will
continue to collect data to evaluate the performance of the remedy, but that it
continues to conclude that the remedy is protective in the short term. We believe
that the protectiveness determination is unsupported.
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09-P-0029
In its response to the draft report's Recommendation 2-9, Region 6 responded that
protectiveness determinations are made following the Five-Year Review
Guidance. The Region added that the OIG's report does not support the need for
implementing a quality assurance process to ensure that protectiveness
determinations are made in accordance with Five-Year Review Guidance. The
Region concluded that additional procedures would be redundant and
unwarranted. We do not agree that the Region made the protectiveness
determination in accordance with the Five-Year Review Guidance. The Region
did not collect relevant information in answering the three technical questions that
define protectiveness. The Region has not provided any additional information in
its current response to address the problems identified by the OIG. This includes
the fact that no surface water samples were taken at the Site and that the Region
did not account for the problematic groundwater data it had in assessing the
effectiveness of the remedy. The Region did not do a complete evaluation of the
remedy during the Five-Year Review process. We concluded that the Region
does not have adequate management controls to assure that EPA guidance on
conducting Five-Year Reviews is followed. Consequently, the Region cannot
provide a reasonable assurance that resulting protectiveness determinations are
properly supported by the available data and analyses.
In December 2006, the OIG had issued a report titled, "EPA Has Improved Five-
Year Review Process for Superfund Remedies, But Further Steps Needed."
Recommendations were made to expand the scope of quality assurance reviews of
Five-Year Review reports and revise guidance to more clearly define short- and
long-term protectiveness determinations. OIG plans to address issues that pertain
to Recommendation 2-9 in a follow-up review of this earlier report; therefore,
Recommendation 2-9 has been removed from this report.
17
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09-P-0029
Status of Recommendations and
Potential Monetary Benefits
RECOMMENDATIONS
Rec.
No.
Page
No.
Subject
Status1
Action Official
Planned
Completion
Date
POTENTIAL MONETARY
BENEFITS (in $OOOs)
Claimed Agreed To
Amount Amount
2-1 14 Amend the Region's November 2007 Five-Year
Review to state that protectiveness of the Site
remedy in both the short- and long-term cannot be
determined without further analysis of the
effectiveness of the remedy and the risk posed by
the migration of metals.
2-2 15 Publish EPA's milestones for obtaining the
information required to make an accurate
determination on the effectiveness of the Site's
remedy and on the risk associated with continued
metal migration.
2-3 15 Investigate, quantify, and publicly report on the
discharge of metals from shallow groundwater at
the Site to Selsers Creek and its tributaries and
implement an appropriate response.
2-4 15 Implement a comprehensive evaluation of the
effectiveness of the PRB to minimize the migration
of metals in groundwater off the Site and
implement an appropriate response. Also,
evaluate the impact of groundwater bypassing the
PRB.
2-5 15 Examine the source and mobility of arsenic in
shallow groundwater in the vicinity of the PRB and
implement an appropriate response.
2-6 15 Require LDEQ to modify quarterly water quality
sampling to include analyses for all metals of
concern, including arsenic, cadmium, lead, nickel,
and zinc.
2-7 15 Require LDEQ to control and restrict Site access
by repairing and maintaining the fence and gates,
and posting clearly visible signs describing Site use
restrictions and hazards.
2-8 15 Conduct a new analysis of Site safety that properly
considers information on metal concentrations in
groundwater and surface water, and other
evidence of whether the remedy is functioning.
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
Region 6 Administrator
0 = recommendation is open with agreed-to corrective actions pending
C = recommendation is closed with all agreed-to actions completed
U = recommendation is undecided with resolution efforts in progress
18
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09-P-0029
Appendix A
Details on Scope and Methodology
We initially visited the Delatte Metals Superfund Site in October 2007 to plan our sampling and
conduct a preliminary inspection. We acquired a qualified contractor from the list of General
Services Administration contractors to take groundwater and surface water samples, and conduct
a site inspection. The contractor collected water samples during the week of February 4, 2008,
to verify the results obtained in the quarterly O&M sampling. The OIG evaluation team was
present to ensure that proper protocols were followed as part of the quality assurance program
established for our sampling. Our sampling included, but was not limited to, eight monitoring
wells screened within the shallow groundwater and three surface water samples - two in Selsers
Creek and one in a tributary to the creek.
The contractor sampled groundwater using the protocol in the 2004 Site O&M manual. The
contractor collected samples from the monitoring wells with peristaltic pumps using low-stress
sampling techniques. Dedicated tubing already installed in the monitoring wells was used. The
contractor monitored basic water quality parameters with calibrated electrodes in a flow-through
cell (pH, conductivity, temperature, oxidation-reduction potential, and dissolved oxygen) or with
grab samples measured on site (turbidity). The contractor monitored the water level in the
monitoring well periodically during purging. The contractor collected groundwater samples after
the parameters had stabilized. The flow-through cell was disconnected prior to collecting the
samples.
Because Region 6 had not been collecting surface water samples, we had no site specific
protocol to use. We used generally accepted surface water sampling methods appropriate for
initial screening of site conditions. This included taking pH measurements along the stream by
submerging a calibrated pH electrode. Samples were taken by a dip method at the location of the
lowest pH measured along the creek or tributary and at a location upstream of the most northern
groundwater monitoring well (see Figure 2-1).
Both unfiltered and filtered samples were collected for analysis of total and dissolved metals at
all locations in clean, plastic bottles containing enough nitric acid to lower the pH of the sample
to 2. These bottles were supplied by the analytical laboratories. Filtering of groundwater
samples was done inline using disposable, 0.45 micron filters. For the surface water samples,
water from the collection vessel was filtered using a hand-filtering unit.
Duplicate samples were taken at all locations, except for one surface-water location (SW-03).
The duplicate samples were sent to separate laboratories for independent analyses.
All sample bottles were checked to make sure the sampling location designation matched the
bottle labels, unfiltered samples were put in bottles labeled unfiltered, and filtered samples were
put in bottles labeled filtered. All metal and cyanide bottles were checked for evidence of proper
preservation by observing that the correct chemical was listed on the label and that liquid was in
the bottles received from the laboratories.
19
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09-P-0029
Our sample collection was more extensive than that usually done during the O&M sampling.
Typically only field pH, turbidity and concentrations of arsenic, lead, manganese, nickel, and
thallium are analyzed. Filtered samples for analysis of dissolved metal concentrations are
generally collected under the Site's O&M plan only when the turbidity exceeds 10
Nephelometric Turbidity Units. However, we collected filtered and unfiltered samples at all
locations regardless of the turbidity measurement.
Samples were kept chilled and sent overnight to the laboratory. Chain of custody was
maintained. Samples were analyzed by approved methods (EPA 105.1, pH; EPA 200.7/200.8,
metals; EPA 245.1, mercury; EPA 355.4 or SM4500-CN C,E, cyanide) at two laboratories
licensed by the National Environmental Laboratory Accreditation Conference and the Arizona
Department of Health Services.
The resulting field and laboratory data were validated internally by performing the following:
• The laboratory reporting packages were checked to determine whether all samples, raw
data, calibration curves, continuing calibration verification standards, interference checks
and other batch quality control measures were present.
• All calibration and batch quality control measures were reviewed to determine if they
were within the acceptance parameters specified in the method or contract statement of
work and, if not, were flagged. The flagged data were determined as not impacting the
data quality.
• Laboratory holding times were checked to determine whether they were analyzed within
method-required holding times.
• Method, field, and rinse blanks were checked to make sure they were clean or had no
impact if a compound was detected.
• A transcription check from raw data to final laboratory report was performed on
approximately 25 percent of the groundwater data. All surface water samples (SW-01,
SW-02, and SW-03) were checked because there was limited historical data for the
surface water samples and they were the basis for many of our concerns.
• A sensibility check across the analyses was performed.
• Data were reviewed to determine whether the two sets of laboratory data matched, within
the expected scientific variation of approximately 25 percent, except for low levels where
greater variance is expected.
20
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Relevant Documents Reviewed
09-P-0029
Appendix B
Year
1993
1999
1999
2000
2000
2000
2000
2000
2001
2004
2004
2004
2004
2004-2007
2005
2007
2007
2008
Year
2000
2001
Site-Specific Documents (EPA except where noted otherwise)
Hazard Ranking System, Delatte Metals, Ponchatoula, Louisiana, Superfund Document
Management System (SDMS) 914705
Community Involvement Plan, Delatte Metals, Ponchatoula, Louisiana, July 1999, SDMS
136511
Remedial Investigation and Feasibility Study for Delatte Metals, Ponchatoula, Louisiana,
Field Sampling Plan, SDMS 105307
Delatte Metals Remedial Investigation Report, Ponchatoula, Louisiana, January 2000,
SDMS 138215
Delatte Metals Remedial Investigation and Feasibility Study for Delatte Metals,
Ponchatoula, Louisiana, Baseline Ecological Risk Assessment, March 2000, SDMS
136507
Delatte Metals Human Health Risk Assessment, March 2000 SDMS 136506
Delatte Metals Feasibility Study Report, Ponchatoula, Louisiana, May 2000, SDMS
136509
Superfund Record of Decision: Delatte Metals,
EPA ID: LAD052510344, OU 01, Ponchatoula, LA, September 2000
Delatte Metals Final Design Report, Ponchatoula, Louisiana, January 2001, SDMS
903141
Final Close Out Report, Delatte Metals Superfund Site, Ponchatoula, Louisiana,
March 2004, SDMS 183879
Remedial Action Report, Delatte Metals Superfund Site, Ponchatoula, Louisiana,
September 2004, SDMS 175105
Explanation of Significant Differences: Delatte Metals Superfund Site,
Ponchatoula, Louisiana, December 2004, SDMS 179805
Public Health Assessment for Delatte Metals, prepared by Louisiana Office of Public
Health, SDMS 207457
Quarterly Monitoring Reports, various, LDEQ
Direct Final Notice of Deletion: Delatte Metals Superfund Site, Tangipahoa Parish,
Louisiana, May 2005, SDMS 188689
PRB performance evaluation update for the Delatte Metals site, Ponchatoula, Louisiana,
memo from Ludwig and others, EPA's Ground Water and Ecosystems Restoration
Division, National Risk Management Research Laboratory, Office of Research and
Development, Ada, OK, to Region 6, February 2007, attachment 10 to the First Five-Year
Review Report
First Five-Year Review Report for the Delatte Metals Superfund Site, Ponchatoula,
Tangipahoa Parish, Louisiana, November 2007
EPA Region 6 and EPA research scientist responses to OIG questions
Guidance Documents (EPA)
Close Out Procedures for National Priorities List Sites, Office of Solid Waste and
Emergency Response Directive 9320.2-09A-P, EPA 540-R-98-016
Comprehensive Five-Year Review Guidance, Office of Solid Waste and Emergency
Response Directive 9355.7-03B-P, EPA 540-R-01-007
21
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Results of OIG Sampling
09-P-0029
Appendix C
Table C-1.a: Shallow groundwater results, Delatte Metals Superfund Site, February, 2008 (Wells BA-03, BA-09, DW-01, and DW-02).
Analyte Identifier
Sampling Date
Laboratory
Total Aluminum
Dissolved Aluminum
Total Antimony
Dissolved Antimony
Total Arsenic
Dissolved Arsenic
Total Barium
Dissolved Barium
Total Beryllium
Dissolved Beryllium
Total Cadmium
Dissolved Cadmium
Total Calcium
Dissolved Calcium
Total Chromium
Dissolved Chromium
Total Cobalt
Dissolved Cobalt
Total Copper
Dissolved Copper
Total Iron
Dissolved Iron
Total Lead
Dissolved Lead
Total Magnesium
Dissolved Magnesium
Total Manganese
Dissolved Manganese
Total Nickel
Dissolved Nickel
Total Potassium
Dissolved Potassium
Total Selenium
Dissolved Selenium
Total Silver
Dissolved Silver
Total Sodium
Dissolved Sodium
Total Thallium
Dissolved Thallium
Total Vanadium
Dissolved Vanadium
Total Zinc
Dissolved Zinc
Total Mercury
Dissolved Mercury
Total Cyanide
Laboratory Measured pH
Field Measured pH
Groundwater Level
BA-03
6-Feb-08
1
44.5
47.1
<0.01
<0.01
O.01
O.01
0.0224
0.0240
0.00570
0.00640
0.239
0.254
59.9
62.0
0.0165
0.0179
0.0820
0.0874
0.160
0.169
3.17
3.26
0.360
0.366
30.4
32.2
2.66
2.78
0.0968
0.104
6.21
6.31
<0.01
<0.01
<0.005
<0.005
201
213
<0.01
<0.01
<0.02
<0.02
0.616
0.645
<0.0002
<0.0002
<0.005
4.60 H
2
48
48
< 0.025
< 0.025
< 0.010
< 0.010
0.025
0.025
0.0064
0.0062
0.27
0.26
67
66
0.019
0.020
0.092
0.092
0.17
0.17
3.4
3.3
0.36
0.35
34
34
3.0
3.1
0.12
0.12
6.2
6.1
< 0.025
< 0.025
< 0.0050
< 0.0050
210
200
< 0.0500
< 0.0500
< 0.010
< 0.010
0.70
0.69
< 0.0002
< 0.0002
< 0.010
4.2 H
4.37
8.47
BA-09
5-Feb-08
1
172
129
<0.01
<0.01
0.0193
0.0169
0.0157
0.0143
0.0178
0.0167
0.0177
0.0113
59.7
56.5
0.0427
0.0362
0.112
0.103
<0.01
<0.01
108
95.7
0.0115
<0.005
58.3
52.3
2.52
2.19
0.152
0.137
7.44
5.89
<0.01
<0.01
<0.005
<0.005
382
360
<0.01
<0.01
0.0658
0.0659
0.254
0.216
<0.0002
<0.0002
<0.005 A
3.70 H
2
180
200
< 0.025
< 0.025
0.020
0.024
0.017
0.022
0.020
0.024 B7
< 0.0030
< 0.0030
68
81
0.067
0.078
0.12
0.14
< 0.010
< 0.010
120
140
< 0.010
< 0.010
67
80
2.6
3.1
0.16
0.20
7.4
9.0
< 0.025
< 0.025
< 0.0050
< 0.0050
370
430
< 0.0500
< 0.0500
0.076
0.093
0.27
0.32
< 0.0002
< 0.0002
< 0.010
3.5 H
3.24
2.01
DW-01
7-Feb-08
1
7.21
5.50
<0.01
<0.01
0.289
0.128
0.0276
0.0293
<0.004
0.00450
0.0540
0.0559
45.4
47.3
<0.005
<0.005
0.0945
0.0981
0.126
0.106
1.96
2.28
0.0161
0.0151
8.00
8.93
7.31
7.38
0.0282
0.0317
1.92
2.34
<0.01
<0.01
<0.005
<0.005
75.8
82.9
O.01
<0.01
<0.02
<0.02
0.160
0.164
<0.0002
<0.0002
<0.005
5.30 H
2
7.4
5.2
< 0.0200
< 0.0200
0.261
0.0908
0.029
0.029
< 0.0050
0.0059
0.0507
0.0493
46
46
< 0.0500
< 0.0500
0.094
0.096
0.124
0.0934
1.8
1.8
< 0.0200
< 0.0200
7.9
8.4
7.7
7.7
< 0.0500
< 0.0500
<2.0
2.3 B1
< 0.0200
< 0.0200
< 0.01 00
< 0.0100
65
65
< 0.0050
< 0.0050
< 0.010
< 0.010
0.16
0.16
< 0.0002
< 0.0002
< 0.010
4.8 H
4.72
3.49
DW-02
6-Feb-08
1
667 MHA
677 MHA
<0.01 M2
0.01 00 M2
0.0327 M2
0.0252
0.01 15 M2
0.0127
0.0344 M2
0.0356
0.0558 M2
0.0563 M2
133
131
0.0900 M2
0.0957 M2
0.383 M2
0.385
<0.01 M2
<0.01 M2
339 MHA
326 MHA
0.0270 M2
0.0294
111
113
16.9 MHA
16.4 MHA
0.458 M2
0.480 M2
6.88
6.75
<0.01
<0.01
<0.005 M2
<0.005 M2
674
655
O.01 M2
O.01 M2
0.197M2
0.204 M2
1 .53 M2
1.55
<0.0002
<0.0002
<0.005
3.10 H
2
640
650
< 0.025
< 0.025
0.054
0.044
0.014
0.016
0.051
0.051
0.025
0.028
200
200
0.21
0.21
0.56
0.56
< 0.010
< 0.010
320
320
< 0.010
< 0.010
180
180
16
16
0.73
0.74
8.2
8.4
< 0.025
< 0.025
< 0.0050
< 0.0050
560
520
< 0.0500
< 0.0500
0.29
0.30
2.2
2.3
< 0.0002
< 0.0002
< 0.010
3.0 H
2.50
10.27
22
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09-P-0029
Table C-1.b: Shallow groundwater results, Delatte Metals Superfund Site, February, 2008 (Wells DW-03, MW-01, MW-02, and PW-04).
Analyte Identifier
Sampling Date
Laboratory
Total Aluminum
Dissolved Aluminum
Total Antimony
Dissolved Antimony
Total Arsenic
Dissolved Arsenic
Total Barium
Dissolved Barium
Total Beryllium
Dissolved Beryllium
Total Cadmium
Dissolved Cadmium
Total Calcium
Dissolved Calcium
Total Chromium
Dissolved Chromium
Total Cobalt
Dissolved Cobalt
Total Copper
Dissolved Copper
Total Iron
Dissolved Iron
Total Lead
Dissolved Lead
Total Magnesium
Dissolved Magnesium
Total Manganese
Dissolved Manganese
Total Nickel
Dissolved Nickel
Total Potassium
Dissolved Potassium
Total Selenium
Dissolved Selenium
Total Silver
Dissolved Silver
Total Sodium
Dissolved Sodium
Total Thallium
Dissolved Thallium
Total Vanadium
Dissolved Vanadium
Total Zinc
Dissolved Zinc
Total Mercury
Dissolved Mercury
Total Cyanide
Laboratory Measured pH
Field Measured pH
Groundwater Level
DW-03
7-Feb-08
1
23.7
25.6
0.0310
0.0310
<0.01
<0.01
0.0909
0.0995
<0.004
0.00410
0.174
0.194
22.7
23.5
<0.005
<0.005
<0.02
0.0213
0.169
0.188
16.9
18.8
0.406
0.427
10.1
10.8
0.515
0.541
0.0326
0.0374
2.92
3.13
<0.01
<0.01
<0.005
<0.005
21.9
23.4
<0.01
<0.01
<0.02
O.02
0.116
0.124
<0.0002
<0.0002
<0.005
3.30 H
2
23
27
0.0305
0.0312
< 0.0300
< 0.0300
0.097
0.099
< 0.0050
0.0060
0.161
0.193
23
25
< 0.0500
< 0.0500
0.021
0.023
0.159
0.177
16
21
0.406
0.432
10
11
0.53
0.59
< 0.0500
< 0.0500
3.0
3.2 B1
< 0.0200
< 0.0200
< 0.0100
< 0.0100
22
23
< 0.0050
< 0.0050
< 0.010
< 0.010
0.13
0.13
< 0.0002
< 0.0002
< 0.010
3.7 H
3.73
6.50
MW-01
6-Feb-08
1
331
363
<0.100
<0.100
0.108
<0.10
<0.100
<0.100
0.0460
0.0490
0.0550
0.0550
144
150
<0.0500
<0.0500
0.307
0.341
<0.100
<0.100
418
446
<0.0500
<0.0500
153
166
8.71
9.23
0.344
0.387
17.6
19.8
<0.100
O.100
<0.0500
<0.0500
835
926
<0.100
<0.100
0.212
0.240
O.50
0.414
<0.0002
<0.0002
<0.005
3.80 H
2
340
350
< 0.025
< 0.025
0.093
0.077
0.017
0.017
0.049
0.050
0.0071
0.0041
140
140
0.12
0.12
0.32
0.32
< 0.010
< 0.010
430
430
< 0.010
< 0.010
160
160
9.0
9.1
0.40
0.41
23
23
< 0.025
< 0.025
< 0.0050
< 0.0050
710
720
< 0.1 00
< 0.1 00
0.22
0.22
0.45
0.44
< 0.0002
< 0.0002
< 0.010
3.4 H
3.33
1.97
MW-02
7-Feb-08
1
22.3
23.9
<0.01
<0.01
<0.01
<0.01
0.0137
0.0148
0.0117
0.0125
0.126
0.137
15.5
16.1
<0.005
<0.005
0.0906
0.0932
0.0107
0.0122
24.3
24.7
<0.005
0.00501
30.6
31.1
1.16
1.20
0.120
0.128
5.45
5.68
<0.01
<0.01
<0.005
<0.005
164
162
<0.01
<0.01
<0.02
O.02
0.416
0.434
<0.0002
<0.0002
<0.005
3.30 H
2
22
24
< 0.0200
< 0.0200
< 0.0300
< 0.0300
0.015
0.014
0.0123
0.0137
0.116
0.128
16
16
< 0.0500
< 0.0500
0.091
0.085
< 0.0200
< 0.0200
25
25
< 0.0200
< 0.0200
32
30
1.2
1.3
0.111
0.106
5.1
5.1 B1
< 0.0200
< 0.0200
< 0.01 00
< 0.01 00
170
160
< 0.0050
< 0.0050
< 0.010
< 0.010
0.43
0.43
< 0.0002
< 0.0002
< 0.010
3.2 H
3.06
7.61
PW-04
6-Feb-08
1
13.8
14.3
<0.01
<0.01
<0.01
<0.01
0.0199
0.0207
0.0130
0.0138
0.00730
0.00740
74.9
76.9
0.0444
0.0456
0.0430
0.0454
<0.01
<0.01
40.2
41.5
<0.005
<0.005
37.8
39.2
2.05
2.11
0.0548
0.0593
3.23
3.24
<0.01
O.01
<0.005
<0.005
120
120
<0.01
<0.01
0.0806
0.0821
0.147
0.152
<0.0002
<0.0002
<0.005
4.50 H
2
14
14
< 0.025
< 0.025
< 0.010
< 0.010
0.022
0.021
0.014
0.014
< 0.0030
< 0.0030
80
78
0.058
0.057
0.045
0.046
< 0.010
< 0.010
43
42
< 0.010
< 0.010
40
39
2.2
2.2
0.061
0.061
3.4
3.2
< 0.025
< 0.025
< 0.0050
< 0.0050
120
120
< 0.0500
< 0.0500
0.082
0.080
0.16
0.16
< 0.0002
< 0.0002
< 0.010
4.1 H
3.92
7.83
All concentrations are reported in milligrams per liter.
pH is reported in standard pH units.
Groundwater level, as measured on February 5, 2008, is reported in feet above the National Geodetic Vertical Datum.
Note: These tables present results of OIG sampling conducted at the Delatte Metals Superfund Site in February 2008. Only results from the
shallowest groundwater are given in line with the focus of this report.
23
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Code Explanation
< Analyte not detected at method reporting limit, the value that follows the less than sign.
A Sample pH was less than or equal to 12 upon receipt. pH was adjusted in the lab to greater than 12 prior to analysis.
B1 Target analyte detected in method blank at or above the method reporting limit.
B7 Target analyte detected in method blank at or above method reporting limit. Concentration in sample was 10 times above the
concentration found in the method blank.
H This test is specified to be performed in the field within 15 minutes of sampling; sample was received and analyzed past the
regulatory holding time.
M2 The matrix spike (and/or matrix spike duplicate) was below the acceptance limits due to sample matrix interference.
MHA Due to high levels of analyte in the sample, the matrix spike calculation does not provide useful spike recovery information.
Source: DIG
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09-P-0029
Table C-2: Surface water results, Delatte Metals Superfund Site, February, 2008.
Analyte Identifier
Sampling Date
Laboratory
Total Aluminum
Dissolved Aluminum
Total Antimony
Dissolved Antimony
Total Arsenic
Dissolved Arsenic
Total Barium
Dissolved Barium
Total Beryllium
Dissolved Beryllium
Total Cadmium
Dissolved Cadmium
Total Calcium
Dissolved Calcium
Total Chromium
Dissolved Chromium
Total Cobalt
Dissolved Cobalt
Total Copper
Dissolved Copper
Total Iron
Dissolved Iron
Total Lead
Dissolved Lead
Total Magnesium
Dissolved Magnesium
Total Manganese
Dissolved Manganese
Total Nickel
Dissolved Nickel
Total Potassium
Dissolved Potassium
Total Selenium
Dissolved Selenium
Total Silver
Dissolved Silver
Total Sodium
Dissolved Sodium
Total Thallium
Dissolved Thallium
Total Vanadium
Dissolved Vanadium
Total Zinc
Dissolved Zinc
Total Mercury
Dissolved Mercury
Total Cyanide
Laboratory Measured pH
Field Measured pH
SW-01
4-Feb-08
1
1.54
0.193
<0.01
<0.01
<0.01
<0.01
0.0550
0.0446
<0.004
<0.004
<0.001
<0.001
6.29
5.40
<0.005
<0.005
<0.02
O.02
O.01
<0.01
1.78
0.413
<0.005
<0.005
1.60
1.45
0.111
0.0996
<0.01
<0.01
1.78
1.96
<0.01
<0.01
<0.005
<0.005
13.9
13.9
<0.01
<0.01
<0.02
<0.02
<0.05
<0.05
<0.0002
<0.0002
<0.005
6.40 H
2
2.2
0.18
< 0.0020
< 0.0020
< 0.0030
< 0.0030
0.057
0.038
< 0.0005
< 0.0005
< 0.0020
< 0.0020
6.0
5.2
< 0.0050
< 0.0050
< 0.010
< 0.010
0.0046
0.0032
1.8
0.38
0.0036
< 0.0020
1.6
1.4
0.10
0.090
< 0.0050
< 0.0050
2.1
2.1
< 0.0020
< 0.0020
< 0.0010
< 0.0010
14
13
< 0.0005
< 0.0005
< 0.010
< 0.010
0.11
< 0.050
< 0.0002
< 0.0002
< 0.010
6.9 H
6.26
SW-02
4-Feb-08
1
1.62
0.266
<0.01
<0.01
<0.01
<0.01
0.0534
0.0402
<0.004
<0.004
<0.001
<0.001
6.02
5.75
<0.005
<0.005
<0.02
<0.02
<0.01
<0.01
1.88
0.459
0.00846
<0.005
1.70
1.56
0.143
0.124
<0.01
<0.01
1.70
1.68
<0.01
<0.01
<0.005
<0.005
15.7
15.3
<0.01
<0.01
<0.02
<0.02
<0.05
<0.05
<0.0002
<0.0002
<0.005
7.80 H
2
2.2
0.27
< 0.0020
< 0.0020
< 0.0030
< 0.0030
0.054
0.039
< 0.0005
< 0.0005
< 0.0020
< 0.0020
5.7
5.2
< 0.0050
< 0.0050
< 0.010
< 0.010
0.0042
0.0033
1.8
0.67
0.0080
0.0023
1.7
1.5
0.13
0.12
< 0.0050
< 0.0050
<2.0
<2.0
< 0.0020
< 0.0020
< 0.0010
< 0.0010
15
15
< 0.0005
< 0.0005
< 0.010
< 0.010
< 0.050
< 0.050
< 0.0002
< 0.0002
< 0.010
6.8 H
5.82
SW-03
7-Feb-08
1
7.05
7.26
<0.01
<0.01
O.01
O.01
0.0528
0.0581
<0.004
<0.004
0.101
0.108
40.5
41.5
<0.005
<0.005
0.0275
0.0312
0.0114
0.0119
1.68
1.61
0.532
0.552
11.2
11.8
1.18
1.20
0.0241
0.0292
2.98
3.21
<0.01
<0.01
<0.005
<0.005
41.2
43.4
<0.01
O.01
O.02
<0.02
0.239
0.247
<0.0002
<0.0002
NA
NA
4.48
All concentrations are reported in milligrams per liter.
pH is reported in standard pH units.
Note: This table presents results of OIG sampling conducted at the Delatte Metals Superfund Site in February 2008.
All laboratory results from surface water samples collected are included.
25
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Code Explanation
< Analyte not detected at method reporting limit, the value that follows the less than sign.
H This test is specified to be performed in the field within 15 minutes of sampling; sample was
received and analyzed past the regulatory holding time.
NA Not applicable
Source: DIG
26
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09-P-0029
Appendix D
EPA Region 6 Responses and OIG Evaluation
September 12, 2008
MEMORANDUM
TO: Carolyn Cooper
Director for Program Evaluation
Hazardous Waste Issues
FROM: Richard E. Greene fs/RichardE. Greene
Regional Administrator
SUBJECT: Draft Evaluation Report: Delatte Metals Superfund Site
On August 7, 2008, you provided me with a summary of concerns which led you to
conclude that the Environmental Protection Agency (EPA) could not support its recent
determination regarding the protectiveness of the remedy in place at the Delatte Metals
Superfund site in Ponchatoula, Louisiana.
Attached is the Region 6 response to your draft evaluation report. I believe that that the
overall conclusion of your report is misleading and does not present an accurate evaluation of
EPA's past and future activities at the site. EPA made the determination that the remedy is
currently protective based on several years of monitoring and observation at the site. Your
evaluation suggests that the remedy in place at the site had no impact on human health and the
environment and that exposure to contaminants is occurring. The determination of "protective in
the short term" is based on the facts that there are no known exposures to ground water
contamination, there are institutional controls in place to restrict land use and ground water use,
any trespasser access will not result in an immediate health risk, and no cancer or non-cancer
excess lifetime risk was identified for surface water that exceeded the EPA risk ranges.
I look forward to your assistance in resolving any concerns regarding the review that
EPA conducted at the site in making its determination of protectiveness.
Attachments
27
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09-P-0029
OIG Response 1
The OIG's conclusion correctly conveys Region 6's past and future activities at the site. The
OIG has not been misleading, and has fairly and transparently evaluated and communicated the
conditions and activities at the Delatte Site. Region 6 continues to conclude that the Delatte Site
is safe, or protective, in the short-term. The OIG's data, as well as several years of Region 6
and LDEQ sampling data at the Site, show that the PRB was not treating all of the shallow
contaminated groundwater before it discharges to surface water, and migration of metals was
uncontrolled. Our review concluded that more information is needed to determine whether the
remedy is protective to human health and the environment.
As stated in our report and reiterated in EPA's current response, EPA guidance for conducting a
Five-Year Review calls for a technical assessment that answers three questions:
A. Is the remedy functioning as intended by the decision documents?
B. Are the exposure assumptions, toxicity data, clean-up levels, and remedial action
objectives used at the time of remedy selection still valid?
C. Has any other information come to light that could call into question the protectiveness
of the remedy?
The answers to these questions are part of the basis for EPA's determination that the site remedy
is protective of human health and the environment. In making its determination, we found that
the Region did collect enough relevant information to answer these questions. Also, the Region
did not use all available data. The Region cited monitoring results that indicated the remedy
was functioning effectively. However, the Region also had data that indicated the remedy was
not functioning as intended and had been advised that further testing and investigation were
needed. Region 6 did not cite these problematic results when making its determination. The
Region has not provided any additional information in its current response to address the issues
raised in our report. The Region still has not collected surface water samples to confirm that the
clean-up standard in the decision document (i.e., ROD) for surface water was being met. The
Region did not account for the problematic groundwater data it had in assessing the
effectiveness of the PRB. In addition, Region 6's data, as well as OIG data, show that the
decision document had an incorrect assumption that clean-up of lead would also address other
metals of concern. These conditions raise serious concerns regarding the Region's safety
determination for the Site. Specifically, we found that the PRB is not functioning sufficiently to
control the migration of metals in the shallow groundwater. EPA guidance for answering the
question on remedy function (Question A) states that when conducting a Five-Year Review, the
region should "investigate and identify problems that could lead to the remedy being not
protective."
The Region's belief that there are no known exposures to groundwater contamination does not
serve as evidence of no exposure. However, the Region has not investigated all exposures
resulting from contaminated groundwater discharging to surface water. The risk imposed by
this discharge depends on the magnitude and location of the discharge. Region 6 has not
investigated this discharge or determined whether human and environmental exposures are
occurring. Therefore, it is inappropriate for the Region to conclude that there are no exposures.
28
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09-P-0029
Region 6 Response to the Office of Inspector General's (OIG) Draft Report on the
Protectiveness Determination in the Delatte Metals Superfund Site
Five Year Review
This document transmits the Region 6 response and comments on the OIG's draft
evaluation report on the protectiveness determinations made in the November 2007 Five Year
Review for the Delatte Metals Superfund Site in Ponchatoula, Louisiana. Our comments are
limited to the findings regarding the protectiveness determination and the recommendations in
the evaluation directed at Region 6.
In the November 2007 Five Year Review, EPA made recommendations to address site
maintenance issues and to revise future sampling plans to evaluate the migration of
contamination through a ground water to surface water pathway.
OIG Response 2
It has been nearly a year since Region 6 made these recommendations. The Region has not yet
evaluated the migration of contaminants through a groundwater to surface water pathway. The
Region recently addressed certain Site maintenance issues.
The OIG evaluation raises several concerns regarding the ability of the remedy at Delatte
Metals to provide long-term protectiveness to human health and the environment. These
concerns are similar to those identified in the Five Year Review. As part of the Five Year
Review process, Region 6 is working with the Louisiana Department of Environmental Quality
LDEQ) to include additional sampling in future site monitoring and tko procure a contractor to
repair the damaged fences and gates and post informational signs at the site.
OIG Response 3
The OIG report addresses the protectiveness of the remedy. The Five-Year Review discusses
surface-water sampling in the vicinity of well MW-01 to better understand the effectiveness of
the PRB in limiting migration of metals. We believe that the surface water sampling should be
more extensive to better understand the migration of metals that bypass the PRB. In the past,
the Region did not support repairs to the damaged fence because it believed it was not necessary
for safety. The Region recently agreed to address the damaged fence.
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09-P-0029
Region 6 would like to offer comments on a few specific issues that you raised in your
evaluation.
Region 6 Response
Report Title: EPA's Safety Determination for Delatte Metals Superfund Site Was
Unsupported
Narrative Response: The title of the evaluation is very misleading, including the use of the term
"safety". The title of the OIG report is misleading and should be revised. The title suggests that
EPA has done no remediation at the site, does not monitor the site, and that human exposure to
contaminants is occurring. The determination of "protective in the short term" is based on the
following facts: 1) there are no known exposures to ground water contamination, 2) there are
institutional controls (1C) in place to restrict land use and ground water use, 3) any trespasser
access will not result in an immediate health risk, and 4) no cancer or non-cancer excess lifetime
risk was identified for surface water that exceeded the EPA risk ranges. LDEQ will continue to
monitor the ground water quarterly as well as enforce the ICs, and EPA will continue to evaluate
the site every five years. Data are reviewed continuously, and should monitoring data indicate
the potential for exposure, EPA and/or LDEQ will take whatever action is needed to address that
exposure. In addition, for the remedy to remain protective in the long-term, follow-up actions
were identified in the five-year review and include continued site maintenance, continued ground
water sampling, and the addition of surface water sampling. Long term monitoring and
maintenance activities and continued five-year reviews of the effectiveness of the remedy will
provide the information necessary for EPA to ensure protectiveness in the long-term.
The conclusions drawn in the Five Year Review were based on several years of monitoring data
and site observations, whereas the conclusions drawn in your evaluation are based on one field
investigation conducted in February 2008. The data requirements for monitoring the operation
of the remedy are defined in the site Operation and Maintenance Plan.
CERCLA §121(c) requires reviews no less often than each five years after the initiation of such
remedial action to assure that human health and the environment are being "protected" by the
remedial action being implemented. The NCP also discusses the five-year review in terms of
evaluating whether the remedy continues to provide adequate "protection" of human health and
the environment. Further, EPA's guidance specifically uses the terms "protectiveness
determination" and "protectiveness statement." Your use of the term "safety" implies imminent
risk and endangerment to the surrounding community.
Proposed Revision: The title of the evaluation should be re-written. "EPA's Short-
Term Protectiveness Determination for the Delatte Metals Superfund Site is Appropriate."
30
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OIG Response 4
The current title accurately captures OIG's conclusion that Region 6 did not support its recent
protectiveness determination with data and analyses. The OIG conclusion is not based on one
field investigation, but instead is based on the entire body of data available for the site.
The Region proposed a title revision, stating that the OIG's report title is misleading because it
implies that "EPA has done no remediation at the site, does not monitor the site, and that human
exposure to contaminants is occurring." The OIG's report includes discussion of the clean-up
actions EPA and others have taken at Delatte (see Noteworthy Achievements). We also include
discussion of the actions that EPA and others have taken to monitor the Site. As stated in its
current response, Region 6 does not currently know whether adverse human and environmental
exposures are occurring because the Region has not yet evaluated the migration of groundwater
contaminants to surface water.
OIG Finding: High Metals Concentrations in Ground Water Beyond the Permeable
Reactive Barrier (PRB), Page 4, Paragraph 1
Narrative Response: In the second sentence, you refer to the shallow ground water contaminated
with metals as a principal threat waste. EPA does not generally consider contaminated ground
water to be a principal threat (A Guide to Principal Threat and Low Level Wastes, November
1991, Attachment A).
Proposed Revision: "In particular, we question the effectiveness of the PRB in treating the
shallow ground water contaminated with metals."
OIG Response 5
Regardless of whether EPA generally considers contaminated groundwater not to be a principal
threat waste, in the ROD for Delatte (p. 32), Region 6 identified the "mobile lead source
contaminants" in the shallow groundwater as a principal threat waste. The ROD stated that these
contaminants "must be resolved by treatment and permanent solutions to the maximum extent
practicable."
OIG Finding: High Metals Concentrations in Ground Water Beyond the PRB, Page 4,
Paragraph 4
Narrative Response: The sentence, "The PRB is not preventing metals in the ground water from
traveling beyond the PRB," suggests that the Permeable Reactive Barrier is not removing any
contamination from the shallow ground water at the site. The PRB was designed to minimize the
migration of contamination from the site by reducing the concentrations of metals as ground
water passed through the PRB. Based on the data collected from monitoring wells upgradient
and downgradient of the PRB by EPA and its Office of Research and Development (ORD) and
provided to you on March 28, 2008, Region 6 concluded that the migration of metals is being
controlled, although not eliminated by the PRB at the site. These data indicated that lead,
cadmium, and arsenic contamination was reduced and that pH values were raised in ground
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09-P-0029
water passing through the PRB. From these data, EPA concludes that the PRB is working as
intended (Attachment B, Page 3, General Comment 4).
OIG Response 6
EPA ORD's evaluation of the PRB (Attachment B, Page 3, General Comment 4) states, "With
the exception of TEPA-8, Figures 5, 6, and 7 indicate lead, cadmium, and nickel are very
effectively removed by the PRB." TEPA-8 is the line of six monitoring wells that crosses the
eastern flank of the PRB. As such, the quoted statement implies that the eastern flank of the
PRB does not effectively remove lead, cadmium, and nickel. In addition, ORD's results show
that arsenic concentrations are elevated beyond the PRB in each line of monitoring wells.
Therefore, we do not agree with the Region's conclusion that the PRB is working as intended.
The PRB is intended to raise the pH and immobilize metals in the shallow groundwater.
The concentrations of metals found in the ground water samples collected during your evaluation
do not affect the short term protectiveness determination made by EPA because the shallow
ground water is not used as a drinking water supply and EPA has no evidence of exposure to
ground water contamination.
The shallow ground water is not considered suitable for drinking water due to the high
concentrations of Total Dissolved Solids (TDS). In EPA's ground water classification system
ground water with greater than 10,000 micrograms per liter (ug/1) TDS is not considered suitable
for drinking water (Attachment C, Page iv). EPA does not expect any impact to human health
from exposure to the ground water. Also, EPA's risk assessment, conducted as part of the
remedial investigation for the site, indicated that exposure to surface water from site
contaminants would not pose an unacceptable risk to human health.
OIG Response 7
The Region stated that the remedy (PRB) is functioning as designed because it has no current
evidence of exposures to contaminated groundwater, and previous investigations did not reveal
unacceptable health risks from exposure to "surface water from site contaminants." We believe
Region 6 has misinterpreted, or ignored the procedures that form the basis for making a decision
about remedy functioning. Our data and EPA's data show that the PRB is not treating the
shallow groundwater contaminated with metals. The mobile lead in this groundwater was
identified in the ROD as a principal threat waste to be treated to the maximum extent
practicable. Our site inspection and sampling showed that high metal concentrations were in the
groundwater that had passed through the PRB, in the groundwater that bypassed the PRB, and in
the surface water we sampled. Similar groundwater information was gathered by EPA and
LDEQ and confirms OIG results. Even EPA's own research scientists questioned the
effectiveness of some characteristics of the PRB and recommended that further study is needed.
Proposed Revision: "Although the PRB is not preventing metals in the ground water from
traveling beyond the PRB, data indicates the PRB is reducing the metals concentrations and
raising the pH of the shallow ground water at the site."
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PIG Response 8
We do not agree with the proposed revision. The Region's declarations of PRB success focus
on the western flank of the PRB, where most of ORD's monitoring wells are located. However,
one transect of wells across the eastern flank (TEPA-8) has consistently yielded data that points
to problems in that area of the PRB. As ORD research scientists have reported, the elevated
arsenic levels may be resulting from a residual source located downgradient of the PRB. The
Five-Year Review, based on an analysis of the Site's long-term monitoring data, noted that most
recently (2005-2006) lead concentrations show a decreasing trend. However, the Review also
stated that over the entire monitoring period (2004-2006) "none of the tested constituents
exhibited a significant decrease in concentration downgradient of the PRB" (page 29). If these
conditions exist, then the PRB does not limit the migration of all metals of concern.
OIG Finding: High Metals in Ground Water Bypassing the PRB, Page 6, Paragraph 3
Narrative Response: As noted in our March 28, 2008, response to you, EPA does believe that
some ground water may be flowing around the western end of the PRB (Attachment B, Page 1,
General Comment 1), but had no data to suggest that ground water was flowing around the
eastern end of the PRB. We agree that additional data is needed to assess the potential for
ground water bypassing the east end of the PRB. We note that you collected ground water and
surface water data near the west end of the PRB and that you concluded that ground water
discharges may be affecting the tributary at the west end of the PRB. The OIG cited the results
of a sample that was collected from a tributary near the western end of the PRB, which had a
lead concentration of 530 ug/1, and a shallow ground water sample you collected in the
immediate vicinity of the surface water sample that had a lead concentration of less than 5 ug/1.
These data suggests that ground water discharging into the tributary is not likely having a
significant impact on surface water quality in this area of the site.
OIG Response 9
The Region's response concludes that groundwater discharging into the tributary is not likely
having a significant impact on surface water quality in this area. Based on historical
information on the variability of concentrations in groundwater, we do not accept this
conclusion. The 2000 Feasibility Study report includes a map that shows a variable distribution
of lead in the shallow groundwater. As part of the report, modelers projected the direction of
transport from three "hot spots" of high lead concentrations. One of the flow arrows points
directly to the location where we found high lead concentrations in the surface water. The
varied distribution of lead in the groundwater may explain why we obtained low concentrations
in the groundwater near where we obtained high concentrations in the surface water. The
Region should conduct additional sampling to fully understand conditions at the site and the
source of the high metals in the tributary.
EPA will work with the LDEQ to revise the existing site Operation and Maintenance Plan to
assess the impact of ground water flowing around the ends of the PRB and discharging into the
tributaries to Selser's Creek. The need for additional monitoring to assess the ground water to
surface water migration pathway was identified in the November 2007 Five Year Review.
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PIG Response 10
The Five-Year Review implies that monitoring to assess the groundwater to surface water
migration pathway will be in the vicinity of well MW-01. OIG findings show that monitoring
needs to be more extensive than sampling in the vicinity of MW-01. Well MW-01 is the area
identified by the EPA research scientists as being downgradient of the part of the PRB that is
working the best. Monitoring needs to include areas where problems have been identified.
OIG Finding: High Metals Concentrations in Surface Water, Page 7, Paragraph 1
Narrative Response: The sentence, "The PRB was not preventing cadmium, lead, nickel, and
zinc from migrating to the surface water" does not consider that the Remedial Action Objective
in the Record of Decision (Attachment D, Page 20) was written to "minimize or prevent
contaminant migration." In the Five Year Review, EPA recognized the need to increase surface
water sampling to ensure satisfaction with the Remedial Action Objectives and ensure the long
term protectiveness of the remedy. EPA will work with the LDEQ to revise the existing site
Operation and Maintenance Plan to assess the prevalence of metals in the surface water at the
site.
This conclusion appears to be based on one round of sampling and the collection of three surface
water samples, two of which are located within Selsers Creek and one from a drainage ditch that
runs along the western boundary on the adjacent property. A single sampling event must be used
in conjunction with other Site data and should be based on sound scientific data collected from
multiple samples under a site-specific plan and evaluated relative to site-specific circumstances
over a specified period of time to assist in understanding the site. These data should be collected
in accordance with an established QAPP to address the site-specific data quality objectives. As
no QAPP or DQOs were proved for EPA's review, the validity of the surface water data cannot
be determined. In addition, the two samples collected from Selsers Creek are consistent with
data collected during the RI and are consistent with upstream concentrations; therefore, these
conclusions appear to be based on one sample taken from a drainage ditch located just west of
the site.
OIG Response 11
We agree that a Quality Assurance Project Plan (QAPP) and Data Quality Objectives (DQOs)
need to be established for the long-term monitoring at this site. Our sampling protocol was to
use the Region's QAPP and DQOs, as we did with our groundwater sampling. However,
because Region 6 and LDEQ have not conducted surface water sampling as part of the quarterly
monitoring at Delatte, there were no QAPP and DQOs that we could use to guide our sampling.
See Appendix A, Details on Scope and Methodology, for further information on our methods.
Screening samples, such as the ones that we collected in February 2008, provide valuable
information to the team tasked with establishing a QAPP and DQOs for the site. Region 6
should collect more screening samples to fully inform decisions needed for the design and
quality of the surface water monitoring program, including finalizing a QAPP and DQOs.
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OIG Finding: Access to the Site Was Not Controlled, Page 8, Paragraph 2
Narrative Response: The LDEQ is taking steps to address site access issues raised in this
evaluation. The LDEQ is in the process of procuring a contractor repair the damaged fences and
gates and post informational signs at the site. It should be noted that these findings were in
EPA's November 2007 Five Year Review.
OIG Response 12
We had been informed of the Region's plans to discuss site access issues with LDEQ, as well as
LDEQ's plans to repair and maintain the fence as part of its O&M responsibilities. We included
this on page 8 of the draft report. We had not been told until this current response that
informational signs would be posted.
The finding that the perimeter fence was damaged in several places is included in the Region's
November 2007 Five-Year Review. However, the Review states that the ownership of the fence
was turned over to the property owners. Region 6 did not recommend repair and maintenance of
the perimeter fence in the November 2007 Five-Year Review. It was not until the OIG issued
findings in this area that the Region committed to action.
OIG Finding: Protectiveness Determination Was Not Supported, Page 9, Paragraph 2
Narrative Response: EPA's protectiveness was made following guidelines published in EPA's
"Comprehensive Five-Year Review Guidance," June 2001. Examples of protectiveness
determinations are provided in Exhibit 4-5 (Attachment E) of this guidance. The guidance
indicates that protectiveness is generally defined by the risk range and hazard index (HI) and
information obtained through answers to Questions A, B, and C should be considered to
determine possible impacts to the protectiveness of the remedy. The determination of
"protective in the short term" is based on the facts that there are no known exposures to ground
water contamination, there are institutional controls in place to restrict land and ground water
use, and any trespasser access due to site security issues will not result in an immediate health
risk. The remedial action addressed all soil contaminated with metals above concentrations that
would allow for future industrial use. This level of clean-up also addresses the risk of direct
contact with the soil by a trespasser.
EPA recognizes, as identified in the November 2007 Five Year Review, that additional actions
need to be taken to ensure that the remedy is protective in the long term and recommend that
ground water continue to be monitored and that surface water monitoring be included to ensure
that the Remedial Action Objectives for the remedy are met.
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PIG Response 13
The OIG's data, as well as several years of EPA and LDEQ sampling data at the site, confirm
that more information is needed to determine whether the remedy is protective to human health
and the environment. We remain concerned that the Region does not account for the
uncertainties regarding the Site's current safety. See OIG Response 1 for further information on
our concerns.
The risk imposed by metals continuing to discharge to surface water depends on the magnitude
and location of the discharge, as well as other factors. While the Five-Year Review recommends
that surface water sampling be added to the quarterly monitoring "to evaluate the groundwater to
surface water migration pathway in the vicinity of MW-01," we discuss in our report the need for
more extensive surface water sampling. In addition, we conclude that the ecological standard for
total lead (the freshwater chronic continuous criteria) reported in the Five-Year Review is
incorrect for the surface waters found on and near the Site. The appropriate standard is about
three times lower, as shown in Table 2-1 of our report.
Recommendations, Pages 12 and 13
2-1. Amend the November 2008 Five-Year Review to state that the safety of the site in both
the short- and long-term cannot be determined without further analysis of the remedy and
the risk posed by migration of the metals.
Narrative Response: As discussed above, EPA continues to believe that the Delatte Metals
remedy remains protective in the short term. No new information that would affect short-term
protectiveness has come to light since the ROD was signed in September 2000, including the
information provided in the OIG report.
OIG Response 14
The OIG's recommendation is not contingent on new information. The OIG demonstrated that
Region 6 did not act on the problematic information it had when it made its safety
determination. Region 6's evaluation of the Delatte remedy was incomplete when it made its
determination. OIG's work confirmed several of the results that Region 6 has seen at this site
but did not act on. Information on hand, at best, supports a determination that more information
is needed before making a safety decision.
The OIG was the first to sample surface water at this Site during the O&M period. We report
those results here. Our limited results, showing high metal concentrations in one of the
tributaries to the creek, are evidence that more information is needed to determine whether the
Delatte remedy is protective to human health and the environment. See OIG Response 1 for
further information on our concerns regarding the protectiveness determination.
EPA recognized in the November 2007 Five Year Review that additional actions need to be
taken to ensure that the remedy provides long-term protectiveness. Additional sampling to
assess potential impacts from ground water bypassing the east end and, possibly, the west end of
the PRB is needed. Additional monitoring is also needed to better understand the ground water
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to surface water migration pathway and ensure that surface water quality criteria for the site are
achieved. Work to improve site security and minimize site access, to maintain warning signs
with contact information about the site, and to clear and grub the site and address settling in the
area of the PRB needs to be completed.
EPA will work with the LDEQ to ensure that monitoring beginning in Spring 2009 will provide
the data necessary to address issues raised in your evaluation. The data collected in future
monitoring will be evaluated in accordance with statistical procedures outlined in the existing
Operation and Maintenance Plan for the site (Attachment F).
2-2. Publish EPA's milestones for obtaining the information required to make an accurate
determination on the effectiveness of the site's remedy and on the risk associated with
continued metal migration.
Narrative Response: EPA will continue to collect data to evaluate the effectiveness of the PRB.
As noted in this response, EPA will work with the LDEQ over the next several months to
develop a plan for collecting the additional data needed to monitor the potential impacts from
ground water bypassing the PRB, to understand the overall ground water to surface water
migration pathway, and to ensure that exposure to surface water does not present a long term
threat.
Once a plan is developed, EPA and/or the LDEQ will provide public availability of the plan,
including facts sheets and be available to discuss the plan and site progress.
2-3. Investigate, quantify, and publicly report on the discharge of metals from shallow
ground water at the site to Selser's Creek and its tributaries and implement an appropriate
response.
Narrative Response: As identified in the Five Year Review, EPA recommended that more
ground water and surface water monitoring is needed to ensure that the Remedial Action
Objectives for the remedy are satisfied. EPA will use the data collected to better understand the
ground water to surface water migration pathway to guide the future direction of the site. EPA
will continue to make these data available to the public. As discussed in this response, EPA did
not find an unacceptable risk to human health from direct contact or ingestion of contaminated
surface water during the remedial investigation conducted for this site. Based on this finding,
EPA did not select a component of the remedy to specifically address metals in surface water.
These activities will be carried out in concert with the responses to number 2-2 above.
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PIG Response 15
The State human health risk assessment report for Delatte stated in 2004 (page 2) "potential exposure
to contaminated shallow groundwater may be possible if contamination were to discharge to surface
water . . . ." From this statement we conclude that the potential exposure pathway and the risk to
human health from exposure to contaminated groundwater discharging to surface water had not been
investigated. In addition, the ecological exposure pathways are numerous as mobile metals in ground
water are discharging to surface water. The ecological risk assessment conducted for the remedial
investigation noted low species diversity and abundance in the creek and tributaries and hypothesized
that this observed poor ecological health could have resulted from a number of factors, including the
discharge of low pH waters and the contaminants of concern.
2-4. Implement an independent evaluation of the effectiveness of the PRB to minimize
migration of metals in ground water off the site and implement an appropriate response.
Also, evaluate the impact of ground water bypassing the PRB.
Narrative Response: The EPA Office of Research and Development is currently conducting an
independent evaluation of the PRB. EPA will consider the results of this evaluation and take
appropriate action to improve the performance of the PRB, if warranted. As part of EPA's effort
to conduct additional ground water and surface water monitoring, the resulting data will be used
to evaluate the impact of ground water bypassing the east end of the PRB.
OIG Response 16
We agree that the Region can evaluate the effectiveness of the existing PRB by continuing to work
with ORD research scientists. However, this evaluation needs to be extensive enough to determine
whether the PRB is sufficiently controlling the migration of metals to ensure the Site is protective of
human health and the environment. For example, the Region needs to determine whether the PRB is
of adequate length to ensure that the remedy is effective.
2-5. Examine the source and mobility of arsenic in the shallow ground water in the vicinity
of the PRB and implement an appropriate response.
Narrative Response: As EPA and LDEQ continue to monitor the site, data will be collected to
ensure that unacceptable exposures to arsenic from the ground water do not occur. Should future
monitoring data indicate the potential for exposure to arsenic in ground water to occur, EPA will
take whatever action is needed to address that exposure.
OIG Response 17
Monitoring alone is not sufficient. An elevated concentration of arsenic in the groundwater is a new
condition. As such, this condition has not been included in the analyses conducted to date of potential
exposure and risk. Region 6 needs to conduct an investigation to understand the magnitude and extent
of the source of the mobile arsenic, as this source was not identified in the remedial investigation.
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Narrative Response: EPA recognized in the November 2007 Five Year Review the need for
additional monitoring data. EPA will work with the LDEQ to include the analyses for all metals
of concern in future sampling at the site.
2-7. Require LDEQ to control and restrict site access by repairing and maintaining the
fences and gates and posting clearly visible signs describing site use restrictions and
hazards.
Narrative Response: The LDEQ is currently in the process of acquiring a contractor to address
these site security and information issues.
2-8. Conduct a new analysis of Site safety that properly considers information on metals
concentrations in ground water and surface water, evidence of remedy functioning, and
changes in land use around the site.
Narrative Response: EPA and LDEQ will continue to collect data to evaluate the performance
of the remedy at the site. Based on all of the information available for the site, EPA continues to
conclude that the remedy is protective in the short term and that some followup activities need to
be undertaken by EPA and the LDEQ.
PIG Response 18
No new information is provided in Region 6's response to support its current protectiveness
determination. Evidence shows that metal migration in the shallow groundwater is not
controlled. Region 6 has not quantified the amount of this migration.
Land use around the site has not changed since the ROD was signed in September 2000. Land
use in the area surrounding the site was identified in the ROD as residential; land use on the site
was identified as industrial. The remedy for the site was selected considering the possibility that
residential use around the site may increase over time. Also, EPA is not aware of any changes in
the use of the shallow ground water for drinking water at the site.
PIG Response 19
Land use density has changed even though the land use classification has not. As a result,
increased population density leads to a higher probability of increased trespasser activity,
particularly if site access is not controlled. We have seen no indication in the site records in
SDMS that an increase in the residential density around the site was considered when the risk
assessments were conducted.
As new data becomes available, EPA and LDEQ will continue to evaluate the effectiveness of
the remedy at the site and determine if any adjustments to the operation of the remedy need to be
considered. EPA will also continue to conduct five year reviews of the remedy at the Delatte
Metals site, as required under Superfund law.
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PIG Response 20
We concluded that the evaluation of the effectiveness of the remedy conducted for the
November 2007 Five-Year Review was incomplete. Not all of the available data was accounted
for and the Region was missing other needed data. Region 6 did not have groundwater data for
all of the contaminants of concern. Region 6 also did not collect any surface water samples to
verify that the clean-up level for lead in surface water had been achieved. Finally, the
evaluation did not fully incorporate the results reported by ORD scientists.
2-9. Implement a quality assurance process to ensure that safety determinations for future
Five Year Reviews within the Region are conducted and supported with EPA guidance.
Narrative Response: The current Five Year Reviews are conducted in accordance with EPA's
Five Year Review Guidance and protectiveness determinations are made following this
guidance. Draft Five Year Review documents are reviewed by a site team in the Region. This
team includes the Remedial Project Manager, the site attorney, the site risk assessor, an
independent technical reviewer, Regional Superfund program management, staff from EPA
Headquarters, and the State project manager. There are no supporting facts in the report that
justify this recommendation. Our comments demonstrate that additional monitoring is also
needed to better understand the ground water to surface water migration pathway and ensure that
surface water quality criteria for the site are achieved, and that LDEQ is currently in the process
of acquiring a contractor to address these site security issues. These issues were identified as
part of the Five Year Review process. Additional procedures would be redundant and
unwarranted.
OIG Response 21
EPA guidance for conducting a Five-Year Review calls for a technical assessment that answers
three questions (see OIG Response 1). How Region 6 answers these questions establishes
whether the Region can determine the site remedy to be protective of human health and the
environment. We conclude that the Region did not completely evaluate the remedy during the
Five-Year review process at Delatte.
The OIG issued a report titled, "EPA Has Improved Five-Year Review Process for Superfund
Remedies, But Further Steps Needed," in December 2006. Recommendations were made to
expand the scope of quality assurance reviews of five-year review reports and revise guidance to
more clearly define short- and long-term protectiveness determinations. OIG plans to address
issues that pertain to Recommendation 2-9 in a follow-up review of this earlier report; therefore,
Recommendation 2-9 has been removed from this report.
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ATTACHMENT A
A Guide to Principal Threat and Low level Threat Wastes
Superfund Publication 9380.3-06FS
November 1991
ATTACHMENT B
EPA Office of Research and Development Response to OIG Comments/Questions
Regarding PRB Performance at the Delatte Metals Site
Ponchatoula, Louisiana
March 20, 2008
ATTACHMENT C
Guidelines for Ground Water Classification under the
EPA Ground Water Strategy
November 1986
ATTACHMENT D
Delatte Metals Superfund Site Record of Decision
September 2000
ATTACHMENT E
Comprehensive Five Year Review Guidance, June 2001
ATTACHMENT F
Operation and Maintenance Manual
Delatte Metals Superfund Site
Ponchatoula, Tangipahoa Parish, Louisiana
February 2004
OIG Response 22
The Region attached six documents to its response memorandum. The titles are listed
here, but the documents are too large to include in this report. Five of these documents
are public EPA documents. The sixth, Attachment B, is available on request.
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PIG Response 23
We received comments from Region 6 on September 12, 2008, and met with Region officials
on October 9, 2008, to discuss their review of a draft of the final report. We provided Region
officials draft responses to their comments ahead of this meeting. On October 15, 2008, the
Region sent a second set of comments. We reviewed and considered both sets of Region 6
comments, and made revisions to the report where appropriate. Below is the second set of
comments, much of which has been previously presented by Region 6 and responded to by the
OIG. Therefore, we only responded to new information presented by Region 6.
DELATTE METALS OIG REPORT
REGION 6 COMMENT CLARIFICATIONS
PRESENTED
DURING THE VIDEO CONFERENCE
ON
9 OCTOBER 2008
During the video conference, Region 6 and ORD presented several explanations and
clarifications to explain why Region 6 could not and should not agree with the
Recommendation 2-1 of the Draft OIG Report concerning the Delatte Metals Five Year
Review. My staff compiled the reference materials from the ROD and the Five Year
Review. As you can see from this information, the ROD anticipated that some contaminants
and potentially some minor exposure could continue to exist at the site. Both the human
health and ecological risk assessments dealt with these scenarios in the establishment of
remedial action objectives and in the remedial action that was achieved.
OIG Response 24
One remedial action objective (RAO) of the ROD requires the remedy to "minimize or
eliminate contaminant migration to the ground water and surface water to levels that ensure
beneficial reuse of these resources." The ROD explicitly defines how the RAO will be
achieved - by maintaining or attaining specific numerical clean-up levels in the soil, sediment,
groundwater, and surface water. The OIG recognizes that some minor exposure may exist at
the site, but EPA cannot claim that the site remedy is protective, either in the short-term or
long-term, if it has never sampled the surface water to ensure that the RAO has been achieved.
The Five Year Review did reveal some issues that needed to be addressed in the "short
term." The definition of "short term" was a topic of discussion during our call on October 9.
In its Annual Report to Congress, EPA defined short term protectiveness as follows: "This
statement is generally used when the remedy is protective but requires further actions or
institutional controls to remain protective in the long term."
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PIG Response 25
The OIG continues to believe that the Region's protectiveness determination was
unsupported. The Region indicates, in reference to the definition it cites, that determining that
a site remedy is protective in the short-term is the same as determining that the remedy is
protective. According to the Region, the only difference between determining that a remedy
is protective in the short- or long-term is the addition of a time-frame. Both indicate that the
remedy protects human health and the environment from unacceptable risk at the time the
determination is made. Our work has demonstrated that the Region did not have enough
information at the time it made its November 2007 determination to state that the site remedy
was protective - either in the short- or long-term. In addition, information that the Region did
have indicated that problems existed with the overall effectiveness of the remedy in meeting
the RAOs.
The Five Year Review included a milestone date of 1 year after report submittal in
Table 14. In other words, Region 6 anticipated that a number of additional measures
including the additional monitoring would be in place before November 2008. Region 6
recognizes that the actual implementation has been delayed by the ongoing responses to
Hurricanes Gustav and Ike. Efforts to assure timely implementation are underway.
Currently, the plan is to begin the additional monitoring before the end of December 2008.
Our position remains that, based on the ROD, the decision to consider the short term
protectiveness continues to be sound.
OIG Response 26
On May 20, 2008, more than 3 months before either Hurricane Gustav or Ike, the Site
manager updated the OIG on the progress Region 6 made in implementing the additional
measures at the Site. We were informed that no action had been taken because the Site
manager had other priorities.
We recognize that Region 6 has competing responsibilities and priorities, including potentially
significant responsibilities during hurricane season. However, the Region should then modify
its current determination if the Region is aware that its competing responsibilities have caused
it to delay the "short-term" period for which it has designated that the site remedy is protective
(i.e., up through November 2008). The Region should factor the likely impact that
unexpected events and competing priorities will have on its ability to address issues it
designates as necessary in the "short-term" to ensure the protectiveness of Superfund sites. If
the Region, or other involved parties have demonstrated an inability to fulfill their
commitments according to the timelines they established, the Region should be conservative
in its decisions about site remedy protectiveness.
"Evidence of current land use suggests that the future land use of the DMI
[Delatte Metals, Inc.] Site will consist of the continuation of
industrial/commercial activities in the facility area with off-facility residential
and ecological use. The RAOs [Remedial Action Objectives]presented in this
ROD [Record of Decision] have been developed for protection of activity within
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these facility (industrial) and off-facility (residential and ecological) areas"
(ROD, page 17).
See OIG Response 27 (below)
"Three distinct and local water-bearing zones are beneath the DM [Delatte
Metals] Site. According to the Louisiana Risk Evaluation/Corrective Action
Program analysis of hydrology and water quality, the uppermost water-bearing
zone is considered Class 3B (a source of a moderate quantity of water, with total
dissolved solids concentration greater than 10,000 mg/1 [milligramsper liter]);
the middle is Class 2C (a source that could potentially supply drinking water in
sufficient quantity for a domestic water supply, but since it has a total dissolved
solids concentration between 1,000 mg/1 and 10,000 mg/1, it is not of sufficient
drinking water quality); and the lowest is Class IB (a source that could
potentially or currently does supply drinking water to a domestic water supply
and has less than 1000 mg/1 total dissolved solids) " (ROD, page 15). "For
purposes of this ROD and ground water protection, the third identified water
bearing zone at the DM Site is equivalent to the Shallow Aquifer" (ROD, page
16).
See OIG Response 28 (below)
"... a HHRA [Human Health Risk Assessment] and ERA [Ecological Risk
Assessment] [were] also performed to determine the current and future effects of
contaminants on human health and the environment" (ROD, page 18). "In
conclusion, for both the on-site and off-site child scenarios, the IEUBK
[Integrated Exposure Uptake Biokinetic] Model estimated blood lead levels to be
greater than 10 ug/dL [micrograms per deciliter] for all children between 0.5
years and 7 years of age." (HHRA, C- 7). "The Adult Lead Model was used to
predict soil screening levels for lead for non-residential exposure Pathways" and
".. .produced a screening level of 1,697 fig/g or mg/kg,.." (HHRA, page 49)
which was adjusted to 1700 mg/kg (ROD, page 21 and Appendix C). "The
conclusions of the Adult Lead Model and the IEUBK Model indicate that there
will be unacceptable health risks and blood lead concentrations to both an adult
worker in the facility areas of the DM Site and the child in the residential off-
facility areas. Therefore,
cleanup of these areas designated for industrial and residential use will have to
be addressed" (ROD, pages 19-20).
All other noncancer and cancer risks for the resident child related to exposure to
offsite soil and for the industrial worker related to exposure to onsite soil were
below the benchmark ofl and were within or below the acceptable risk range
(1E-04 to 1E-06), respectively. In addition, the Human Health Risk Assessment,
evaluated the trespasser/visitor scenario for an adult and child exposed to surface
water and sediment in Selsers Creek. The cancer and noncancer risks were
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below the benchmark ofl and the cancer risks were within or below the
acceptable risk range (1E-04 to 1E-06) (HHRA, Section 5, Tables 7.5- 7.6; 7.9
7.14; 7.15 - 7.16; 7.23 - 7.24; 8.5- 8.6; 8.9- 8.14; 8.15- 8.16; and 8.23 - 8.24).
See PIG Response 29 (below)
According to the ecological risk assessment, risks were evaluated for site soil,
sediment and surface water. Soil "Risk to plants was based on the exceedance of
soil toxicological benchmarks and on evidence of plant uptake" (ERA, page 132).
"Terrestrial invertebrates are at risk from multiple COCs [contaminants of
concern] in soil, surface water, and ground water" (ERA, page 132). "By every
measure, the ditch habitat was more contaminated than the creek habitat" (ERA,
page 133). "None of the creek samples were toxic to this species [Hyallela]. In
the ditches, three samples were extremely toxic, and one moderately toxic, to
Hyallela" (ERA, page 116). "Sediment HQs in the ditch for cadmium and lead
are considered to indicate significant risk to benthic invertebrates, including
crayfish" and "Surface water HQs for lead exceeded 500" (ERA, page 133).
"Fish and amphibians contained levels of aluminum, cadmium, and lead
indicating adverse effects on survival and growth. Levels were highest in the
ditches, but of concern in creek populations also" (ERA, page 133). "The
surface water and sediment in the area ditches and ground water that discharges
to Selsers Creek are the prime candidates for remedial action. If these existing
sources of contaminants are removed or reduced, concentrations of COCs in
sediment and surface water in Selsers Creek will likely be diluted and
redistributed by seasonal flooding, making active remediation of the creek
unnecessary" (ERA, page 137-138).
"EPA has identified lead as the one COC that poses the greatest potential risk to
human health at this Site" (ROD, page 18) and ".... is the most abundant and
widespread COC at the DM Site. Since lead has been detected (co-located) at the
points where the few other identified heavy metals have been detected, lead will
be used as the basis for measuring numerical cleanup goals" (ROD, page 20).
"...the cleanup of lead will address the other few metal contaminants
(aluminum, antimony, cadmium, manganese, selenium, and zinc) because these
contaminants have been found at the same sampling points where lead was
found" (ROD, page 19). "Because of seasonal variations and the presence of
sediment and soil mixed together in many pails of the off-facility areas, whenever
this ROD addresses soil, it is with the understanding that it includes both soil and
sediment (when present). It is anticipated that the cleanup of soil thus will of
necessity include the cleanup of sediment" (ROD, page 19).
See OIG Response 30 (below)
"The numerical cleanup goals were developed from the Adult Lead Model, the
IEVBK Model, and the Ecological Risk Model. These models form the basis for
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determination of cleanup levels that will ensure protection of human health and
the environment in both facility (industrial) and off-facility (residential and
ecological) areas " (ROD, page 20). "... since the source of the contamination is
mainly in surficial and subsurface soils, the selected remedy was designed to
primarily address the soil contamination. It is expected that when the soil
cleanup levels are achieved, the other forms of cleanup measurements (such as
Sediment: Ecological; 100 mg/kg lead; Ground Water; Residential: 15 ug/1 lead;
and. Surface Water: Ecological: 0.6 ug/1 lead) will also be achieved (ROD, page
21). Therefore, the measurement of success at accomplishing the RAOs will be
based on the media-specific numerical cleanup goals to be achieved in the
various designated areas of soil contamination. These are:
1. Industrial (Adult Lead Model basis): 1,700 mg/kg lead in soil;
2. Residential (IEVBKModel basis): 500 mg/kg lead in soil; and,
3. Ecological: (Ecological Risk Model basis): 80 mg/kg lead in soil."
"The remedy at the DM Site will protect human health and the environment by:
Immobilization to address the principal threat wastes within the soil (thus
eliminating the source of contamination for sediment, surface water, ground
water);
Off-site disposal to transport immobilized wastes to a disposal facility;
Permeable treatment walls to neutralize the acidity of the shallow ground water
and limit the migration of dissolved metals;
Institutional controls in the form of deed notices to inform the public of Site
conditions; and,
Ground water monitoring to ensure the effectiveness of the cleanup remedy.
More specifically, the implementation of the selected remedy will achieve the DM
Site RAOs, as determined by numerical cleanup goals formulated from the basis
of the Adult Lead Model, IEVBK Model, and the Ecological Risk Model" (ROD,
page 35).
"Excavation of soils and waste pits began in December 2002 and was completed
in July 2003. Following soil excavation, surface restoration activities were
conducted for on-site and off-site areas. Installation of the PRB began in
February 2003 and was completed in June 2003. On September 22, 2004, LDEQ
filed two institutional controls for three on-facility properties. The third
institutional control was filed by one of the property owners" (Five Year Review,
page 10).
Based on these actions, the site was determined to be protective in the short-term.
1. "Based on the risk models, a total of 44,000 cubic yards of contaminated soil
would have to be addressed at the DM Site. Included in this total are areas where
lead contaminants were found well above acceptable risk levels even for
industrial workers (the approximately 25,000 cubic yards of highly mobile lead
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source materials, also referred to in this ROD as the principal threat wastes) "
(ROD, page 19 and 32). "On- and off-facility contaminated soil exceeding the
industrial criteria were addressed by removal, solidification/stabilization (S/S),
and off-site disposal; Off-facility soil exceeding the residential or ecological
criteria were excavated and consolidated on the facility; and, Sediment exceeding
the ecological criteria was also excavated and consolidated on the facility" (Five
Year Review, page 9). "Approximately 41,000 cubic yards (cy) of on-facility and
1,400 cy of off-facility soil were excavated, treated, and disposed of at an off-site
landfill. The total weight of soil disposed of at the landfill was 85,444 tons.
Approximately 10,000 cy of off-facility soil meeting on-facility cleanup levels
were placed in the on-facility excavations" (Five Year Review, Page 10).
"Confirmation sampling was completed to verify sufficient excavation and soil
treatment" (Five Year Review, page 9).
Five Year Review Recommendation and milestone date for follow-up actions
supporting long-term protectiveness (page 42 and Table 14): "The ROD states
that the "...the measurement of success at accomplishing the RAOs will be based
on the media-specific numerical cleanup goals to be achieved in the various
designated areas of soil contamination..." because "... it is expected that when
soil cleanup levels are achieved,..." that the A WQ criteria and Groundwater
criteria for lead will be met" (ROD, page 21 and Five Year Review, page 43).
The remedy called for "Immobilization to address the principal threat wastes
within the soil (thus eliminating the source of contamination for sediment,
surface water, ground water) " (ROD, page 35).
See OIG Response 31 (below)
"Groundwater monitoring is currently conducted; however, surface water
sampling is not. According to the trend analysis, there is no identifiable
increasing or decreasing trend for any of the COCs [regarding MW-01];
however, these values exceed the current 2.5 fig/L freshwater chronic continuous
criteria for lead. "... to evaluate the groundwater to surface water migration
pathway in the vicinity of MW-01 surface water samples should be collected to
ensure satisfaction of the RAO" Five Year Review, page 43).
2. "There have been no changes in land use that bear on the protectiveness of
the selected remedy. There have been no changes [in exposure pathways] that
bear on the protectiveness of the selected remedy. There have been no new
contaminants or contaminant sources identified at the Site. No new laws or
regulations have been promulgated or enacted that would call into question the
effectiveness of the remedy at the Site to protect human health and the
environment" (Five Year Review, page 38).
3. "Since there is no evidence of drinking water use from the first two identified
water-bearing zones (Class 3B and 2C), permeable treatment walls will be
installed in the first water-bearing zone to aid in the overall immobilization
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treatment process of the contaminated soils in order to prevent any migration of
lead contaminants to the usable third water-bearing zone/Shallow Aquifer (Class
IB) " (ROD, page 17). "A Permeable Reactive Barrier (PRB) was installed to
raise the pH of the groundwater as it migrates north and west toward Selsers
Creek and its tributaries" (Five Year Review, page 9). "In general, the PRB is
performing well in reducing the lead concentrations and treating the low pH
impacted groundwater in the shallow WBZ" (Five Year Review, page 31 and
Attachment 10).
4. "Ground water monitoring to ensure the effectiveness of the remedy is also a
component of each alternative, except the "no action " alternative. This ground
water component of Alternatives 2 through 6, requires the monitoring of ground
water to ensure that contaminants have not migrated into the third water-bearing
zone/Shallow Aquifer" (ROD, page 22).
Five Year Review Recommendation and milestone date for follow-up actions
supporting long-term protectiveness (page 37 and 42 and Table 14): "Generally,
metals concentrations in the third WBZ are not increasing. Although all of the
third WBZ [water bearing zone] and water wells had metals concentrations
which exceeded comparison criteria (e.g., MCLs), only three of these monitoring
wells were located outside the area under institutional controls (in the form of
conveyance notices). Based on the most recent data available (i.e., December
2006), the data show that monitoring wells maintain drinking water integrity and
no detected constituents are above comparison criteria" (Five Year Review, page
3 7). "The groundwater dataset was not robust enough to form definitive
conclusions about the functionality or efficacy of the PRB. Although, year 2006
concentrations remain below MCLs or EPA Region 6 MSSLs [medium-specific
screening levels], trend analyses for wells located in the third WBZ show
significant increasing trends: two for lead and two for nickel. Based on these
findings, groundwater monitoring as outlined in the O&M Manual should
continue using low-level reporting limits. In addition, the need for institutional
controls restricting groundwater use of the third WBZ should be evaluated. The
groundwater monitoring programs should be reviewed to ensure adequate data
are collected which may include altering sampling frequency, altering sampling
parameters, and plugging and/or installing wells" (Five Year Review, page 42).
5. "Institutional controls (in the form of conveyance notices) were placed on
affected properties " Five Year Review, page 10). "The notice provided the
following requirements: (1) That the property has been the subject of a CERCLA
response; (2) That hazardous substances remain at specified locations on the
property above levels that allow for unrestricted exposure; limit site use to
industrial/commercial use; and prohibit the use of groundwater within the first
and second WBZs; (3) That disturbing or moving soil in these locations may pose
a threat to human health or the environment, and may subject the property
owner and the party causing the disturbance to liability under CERCLA or other
laws; (4) That structures including permeable treatment walls and monitoring
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wells, and any other feature necessary for protectiveness of the remedy or for its
successful operation and maintenance, remain on the property at specified
locations; (5) That disturbing or moving these features of the remedy may pose a
threat to human health or the environment, and my subject the property owner
and the party causing the disturbance to liability under CERCLA or other laws;
and, (6) That the property may be subject to restrictions under LAC 33. V.
Chapter 35 (Five Year Review, page 40). "No future land uses have been
established or are anticipated for the Site that would require an adjustment to the
institutional controls currently being implemented" (Five Year Review, page 41).
Five Year Review actions supporting long-term protectiveness (page 46): The
remedy will remain protective of human health and the environment in the long-
term provided recommendations for improvement are made, O&M activities
continue, and the institutional controls restricting the Site to
commercial/industrial use remain in place.
5. "A review of the latest O&M Quarterly Report from the June 2006
groundwater monitoring event (McDonald Construction 2006) and groundwater
monitoring data through December 2006 indicates that the O&M Manual (Tetra
Tech 2004a) is being followed and the Remedial Action Objectives are generally
being met" (Five Year Review, page 16).
Five Year Review actions supporting long-term protectiveness (page 46): The
remedy will remain protective of human health and the environment in the long-
term provided recommendations for improvement are made, O&M activities
continue, and the institutional controls restricting the Site to
commercial/industrial use remain in place.
See OIG Response 32 (below)
As you can see from the Record of Decision, the future land use of the Site was evaluated
and it was determined that the site would continue to be used for industrial/commercial activities
in the facility area with off-facility residential and ecological use. The remedial action objectives
presented were developed for protection of activity within the facility (industrial) and off-facility
(residential and ecological) areas.
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PIG Response 27
OIG has not raised an issue with the soil clean-up levels at Delatte, which were within the
numerical clean-up levels established in the ROD. However, as shown in our report and
previous responses, metal contaminants may be migrating off-site through the uncontrolled
groundwater, and may be entering surface water. The ROD states that to meet the RAO to
"minimize or eliminate contaminant migration to the ground water and surface water to levels
that ensure beneficial reuse of these resources," numerical clean-up levels must be maintained
in surface water. This is how the ROD defines protection of activity in off-facility (residential
and ecological) areas. EPA has not collected surface water data to show that the RAO has
been achieved prior to making its statement of protection.
Likewise, the ground water use was investigated. The Louisiana Risk
Evaluation/Corrective Action Program analysis of hydrology and water quality, identifies the
first water-bearing zone as Class 3B [(a source of a moderate quantity of water, with total
dissolved solids concentration greater than 10,000 milligrams per liter (mg/1)], the second water-
bearing zone as Class 2C (a source that could potentially supply drinking water in sufficient
quantity for a domestic water supply, but since it has a total dissolved solids concentration
between 1,000 mg/1 and 10,000 mg/1, it is not of sufficient drinking water quality, and the third
water-bearing zone as Class IB (a source that could potentially or currently does supply drinking
water to a domestic water supply and has less than 1,000 mg/1 total dissolved solids).
OIG Response 28
The OIG is aware that the first water-bearing zone (Class 3B) is not intended to supply
drinking water, and as such, human ingestion of groundwater from the first water-bearing
zone is not an anticipated exposure pathway. However, groundwater from the contaminated
first water-bearing zone discharges to the surface water of the nearby Selsers Creek and
tributaries. EPA has not explored the impacts of this discharge, which may potentially
re-contaminate the underlying sediment, and result in potential human and ecological
exposure of metal contaminants. The OIG does not believe EPA can make a statement of
protectiveness, either in the short-term or long-term, without further analysis on the risks
posed by the migration of metals.
Based on these uses, site exposures were evaluated through a human health risk
assessment and an ecological risk assessment. According to the Human Health Risk
Assessment, unacceptable risks related to lead exposure were found to exist for the child resident
and the industrial worker. Exposure to lead presented a potential for adverse health effects in
children currently living near the Site and any children living on or near the site in the future and
presented a potential for adverse health effects in the developing fetus of an adult woman. All
other noncancer and cancer risks for the resident child related to exposure to offsite soil and for
the industrial worker related to exposure to onsite soil were below the benchmark of 1 and were
within or below the acceptable cancer risk range for Superfund sites (1E-04 to 1E-06),
respectively. In addition, the Human Health Risk Assessment evaluated the trespasser/visitor
scenario for an adult and child exposed to surface water and sediment in Selsers Creek. The
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noncancer risks were below the benchmark of 1 and the cancer risks were within or below the
acceptable risk range (1E-04 to 1E-06).
PIG Response 29
The OIG is not focusing on potential contaminant exposure from soil. Therefore, we are not
addressing the cancer and non-cancer soil exposure risks for the off-site resident child or the
on-site industrial worker. However, because metal contaminants in the groundwater are not
controlled and the contaminated groundwater discharges to surface water, there may be risks
associated with surface water exposure to trespassers and visitors.
Trespassers and visitors are defined in the Human Health Risk Assessment as any adult or child
with limited exposure, whether that exposure is through hunting, fishing, hiking, or swimming
in areas surrounding the site. During the remedial investigation, lead was found in the surface
water and sediments in tributaries to Selsers Creek off-site at concentrations a couple of orders
of magnitude greater than the ecological clean-up levels specified in the ROD. The reason for
lead not being identified as non-cancer or cancer risks in the Human Health Risk Assessment
was because toxicity values were not available for lead for the calculations to be performed.
Instead, lead risk was calculated in the models for soil only. As a result, EPA never
characterized the risk of lead for surface water and sediment exposure.
Region 6 has not recognized all contaminant exposure pathways, particularly human and
ecological exposure to the surface water and sediments. As a result, EPA has not fully
evaluated the effectiveness of the remedy to conclude that the remedy is protective of human
health and the environment.
According to the ecological risk assessment, risks were evaluated for site soil, sediment
and surface water. Risks related to exposure for all three media were found to exist, and the
primary contaminants were identified as lead and cadmium. As presented in the ROD and
supported by the risk assessments, lead has been identified as the most abundant and widespread
contaminant based on concentration and associated risks for both human health and the
environment. This contaminant of concern was also identified as being co-located with other
metals. Therefore, addressing source material and lead concentrations in the soil and sediment
will also address other detected metals.
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PIG Response 30
The Ecological Risk Assessment assumes that sediment and surface water contamination will
resolve itself once the source of the contamination (i.e., groundwater) has been controlled. The
ROD assumes that (1) groundwater contamination would be controlled when soil clean-up
levels are achieved, and (2) the clean-up of lead will address the other metal contaminants. As
demonstrated in our report, both of the ROD's assumptions have been proven incorrect by EPA,
LDEQ, and OIG data. Migration of metals in groundwater has not been controlled. Therefore,
concentrations of lead and other metals may exceed ecological standards. Continued
contamination may be adversely affecting benthic invertebrates, fish, and amphibians. The OIG
believes that EPA cannot make its statement of protectiveness until it assesses whether the
current discharge of metals to surface water poses an acceptable level of risk to the environment.
In order to be protective, remedial action objectives and cleanup levels were set for the
soil, sediment, and ground water to address the human health (industrial onsite and residential
offsite) and ecological risks (sediment and surface water). During remedial action, soil and
sediment exceeding the cleanup levels were excavated and disposed offsite. This removed the
risks associated with the soil to an acceptable level for industrial use onsite and residential use
offsite. This also removed the ecological risks associated with the sediments to an acceptable
level and removed the source of contamination for the surface water.
OIG Response 31
The ROD states, "... in order to achieve these RAOs, certain numerical cleanup levels would
have to be maintained or attained in the various environmental media.... It is expected that when
the soil cleanup levels are achieved, the other forms of cleanup measurements (such as
Sediment: Ecological: 100 mg/kg lead; Ground Water: Residential: 15 ug/1 lead; and, Surface
Water: Ecological: 0.6 ug/1 lead) will also be achieved. Therefore, the measurement of success
at accomplishing the RAOs will be based on the media-specific numerical cleanup goals to be
achieved in the various designated areas of soil contamination." As discussed in the report,
post-remedial action data from EPA, LDEQ, and OIG has shown that migration of metals in
groundwater has not been controlled even though the contaminated soil has been removed.
Therefore, the ROD assumption that the clean-up of contaminated soil will resolve the other
contaminated media is incorrect. Because groundwater contamination is not controlled, the
ecological risks associated with the contaminated sediments and surface water cannot be
assumed to have been alleviated to acceptable levels. The OIG recognizes the considerable
efforts by EPA in removing and treating the contaminated soil during remedial action.
However, the measurement of remedy success cannot be based on achieving the soil clean-up
goals alone. EPA needs to ensure that numerical clean-up levels have been maintained in
sediment, groundwater, surface water, and soil prior to concluding that the remedy is protective,
either in the short-term or long-term.
The first two identified water-bearing zones (Class 3B and 2C) were identified as non-drinking
water sources and no current use was identified. Therefore, permeable treatment walls were
installed in the first water-bearing zone to aid in the overall immobilization treatment process of
the contaminated soils in order to prevent any migration of lead contaminants to the usable third
water-bearing zone/Shallow Aquifer (Class IB). For continued protection of the permeable
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reactive walls and from ground water exposure, an institutional control was placed on the
property to restrict land use and ground water use.
PIG Response 32
The OIG is not addressing the second or third water-bearing zones in this report, nor is it
questioning the adequacy of the institutional controls. The intended purpose of the PRB, as
stated in the ROD, is "to neutralize the acidity of the shallow ground water and limit the
migration of dissolved metals," whether it is to the potable third water-bearing zone or to the
surface water nearby. The installation of the PRB serves to meet the RAO to "minimize or
eliminate contaminant migration to the ground water and surface waters to levels that ensure
beneficial reuse of these resources."
An additional item of concern includes the one surface water sample taken from the
drainage ditch southwest of the site. During the site visit, three surface water samples were
collected by the IG, two of which are located within Selsers Creek and one from a drainage ditch
that runs along the western boundary, on the adjacent property, eventually discharging into
Sellers Creek. A single sampling event must be used in conjunction with other Site data and
should be based on sound scientific data collected from multiple samples under a site-specific
plan and evaluated relative to site-specific circumstances over a specified period of time to assist
in the understanding the site. These data should also be collected in accordance with an
established Quality Assurance Project Plan (QAPP) to address the site-specific data quality
objectives. As no QAPP or Data Quality Objectives were approved for review, the validity of
the surface water data cannot be determined.
OIG Response 33
See OIG Response 11 to address comment on the QAPP and DQOs. LDEQ had collected
groundwater data over multiple sampling events in accordance with the QAPP. These data were
available to Region 6 for its Five-Year Review. As demonstrated in our report, Region 6's data
raises questions regarding the effectiveness of the remedy in minimizing contaminated
groundwater discharge to Selsers Creek and its tributaries. In addition, our surface water
samples were not taken to satisfy Region 6's responsibility to confirm that the RAOs have been
met. Our surface water samples support our analysis of historic data.
We note that you collected ground water in the vicinity of the surface water sample
location near the west end of the PRB and that you concluded that ground water discharges may
be affecting the tributary at the west end of the PRB. You cited the result of the surface water
sample as having a lead concentration of 530 jig/1 and the shallow ground water sample as
having a lead concentration less than 5 jig/1. These data suggests that ground water discharging
into the tributary is not likely having a significant impact on surface water quality in this area of
the site. As noted above, under Bullet 1, the Five Year Review noted the ground water
concentrations as they relate to the surface water criteria needs additional review.
Based on these actions, the site was determined to be protective in the short-term:
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1. All principal threat wastes, soil, and sediment exceeding the cleanup levels have been
excavated, treated and disposed offsite. All soil and sediment cleanup levels have been met and
the site is available for industrial use. No residential development was identified on the site, and
portions of the site are being used for industrial use only. No unacceptable risks were identified.
2. The PRB has been installed in the first-water bearing zone and data gathered by EPA/ORD
show the PRB is functioning as intended by neutralizing the ground water and reducing metals
concentrations. Therefore, the removal of the source material and the PRB are minimizing
contaminant migration to the surface water.
3. Ground water data, though not robust enough for definitive conclusions regarding the PRB
influence on upgradient verses downgradient concentrations, were significant enough to allow
for statistical evaluations within individual wells. Many wells show significant decreasing trends
for metals evaluated while others show increasing trends. For many, no significant trend was
identified. Although concentrations appear to be 'stable', this water bearing zone is not a
drinking water zone, and there are no receptors exposed to concentrations in the ground water.
Ground water flow in the first-water bearing zone continues to flow towards and through the
PRB.
4. Current ground water data do not indicate that the third-water bearing zone exceeds drinking
water criteria; therefore, the removal of the source material and the PRB are minimizing
contaminant migration to the ground water.
PIG Response 34
The OIG currently does not anticipate contamination of the third-water bearing zone, nor does it
anticipate an adverse direct human exposure to groundwater. However, as demonstrated in this
report and the OIG responses, removal of large amounts of source material (i.e., contaminated
soil) and the installation of the PRB have not controlled metal migration in the shallow
groundwater.
5. The source of contamination for the ground water and surface water has been removed.
6. Institutional Controls have been placed on the property to restrict land use to industrial,
prohibit activities that could affect long-term monitoring, and prohibit the use of the first-and
second-water bearing zones.
7. O&M activities and ground water monitoring is conducted quarterly by LDEQ to ensure the
1C are enforced, and site activities are restricted.
8. The assumptions used to evaluate the site and human and ecological risks were unchanged
during the time of the Five-Year Review.
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Appendix E
Distribution
Office of the Administrator
Assistant Administrator, Office of Solid Waste and Emergency Response
Assistant Administrator, Office of Research and Development
Regional Administrator, Region 6
Office of General Counsel
Agency Follow-up Official (the CFO)
Agency Follow-up Coordinator
Associate Administrator for Congressional and Intergovernmental Relations
Associate Administrator for Public Affairs
Audit Follow-up Coordinator, Office of Solid Waste and Emergency Response
Audit Follow-up Coordinator, Office of Research and Development
Audit Follow-up Coordinator, Region 6
Public Affairs Officer, Region 6
Director, Superfund Division, Region 6
Deputy Inspector General
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