FIVE-YEAR REVIEW REPORT FOR
OMAHA LEAD SUPERFUND SITE
DOUGLAS COUNTY, NEBRASKA
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Prepared by
U.S. Environmental Protection Agency
Region 7
Lenexa, Kansas
Cecilia TaplaTThvision Director
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Date
The following Attachments are
available only on CD
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Table of Contents
LIST OF ABBREVIATIONS AND ACRONYMS 3
EXECUTIVE SUMMARY 4
FIVE-YEAR REVIEW SUMMARY FORM 6
I. INTRODUCTION 8
II. SITE CHRONOLOGY 9
III. BACKGROUND 14
Physical Characteristics : 14
Hydrology/ Geology 14
Land and Resource Use 15
History of Contamination 15
Initial Response 16
Basis for Taking Action 17
IV. REMEDIAL ACTIONS 19
Remedy Selection 19
Remedy Implementation 21
System Operation/Operation and Maintenance 21
Enforcement Activities 22
V. PROGRESS SINCE THE LAST REVIEW 22
VI. FIVE-YEAR REVIEW PROCESS 22
Administrative Components 22
Community Notification and Involvement 23
Document Review 23
Data Review 23
Site Inspection 24
Interviews 24
VII. TECHNICAL ASSESSMENT 24
Question A: Is the remedy functioning as intended by the decision documents? 24
Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action
objectives (RAOs) used at the time of the remedy section still valid? 24
Question C: Has any other information come to light that could call into question the
protectiveness of the remedy? 27
Technical Assessment Summary 27
VIII. ISSUES/RECOMMENDATIONS AND FOLLOW-UP ACTIONS 27
IX. PROTECTIVENESS STATEMENT 27
X. NEXT REVIEW 28
Page 1 of 30
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Tables
Table 1 - Chronology of Site Events
Table 2 - Issues and Recommendations/Follow-up Actions
Figures
Figure 1 - Site Locator Map
Figure 2 - Site Status Map
Attachments
Site Maps
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LIST OF ABBREVIATIONS AND ACRONYMS
AMSL
Above Mean Sea Level
AO
Administrative Order
ARAR
Applicable or Relevant and Appropriate Requirement
CA
Cooperative Agreement
CD
Consent Decree
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act
CFR
Code of Federal Regulations
DCHD
Douglas County Health Department
EPA
United States Environmental Protection Agency
FS
Feasibility Study
FYR
Five-Year Review
IA
Interagency Agreement (new term)
IAG
Interagency Agreement (old term)
ICs
Institutional Controls
IEUBK
Integrated Exposure Uptake Biokinetic Model
NCP
National Contingency Plan
NDEQ
Nebraska Department of Environmental Quality
NPL
National Priorities List
OLS
Omaha Lead Superfund Site
O&M
Operation and Maintenance
OU
Operable Unit
ppm
parts per million
PRG
Preliminary Remediation Goal
PRP
Potentially Responsible Party
RAO
Remedial Action Objectives
RI
Remedial Investigation
ROD
Record of Decision
RPM
Remedial Project Manager
SDMS
SEMS Document Management System
SEMS
Superfund Enterprise Management System
SOW
Statement of Work
UAO
Unilateral Administrative Order
USACE
United States Army Corps of Engineers
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EXECUTIVE SUMMARY
This is the First Five-Year Review (FYR) for the Omaha Lead Superfund Site (Site) located in Omaha,
Douglas County, Nebraska. The purpose of this FYR is to review information to determine whether the
remedy is and will continue to be protective of human health and the environment. The triggering action
for this statutory review is the on-site construction start date of the OU2 remedial action of May 2009.
The general boundary of the site encompasses residential and non-residential property. However, the site
is defined to include only residential and residential-type properties where the concentration of lead in
the surface soil is determined to be 400 ppm or greater. Residential-type properties include parks,
churches, schools and other properties used extensively by children. Other commercial properties are
specifically excluded from the definition of the site.
Initial EPA response was conducted under the Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA) removal authority. The first removal action addressed child daycare
centers and residences where children with elevated blood lead reside. A second removal action was
conducted to address the most highly contaminated residential-type properties with maximum mid-yard
soil lead levels exceeding 2,500 ppm. As cleanups were completed at the most highly contaminated
residential properties, the soil lead action level was sequentially reduced to 1,200 ppm and eventually
800 ppm so that soil cleanups could continue under CERCLA removal authority at the properties
remaining with the highest mid-yard soil lead levels.
Following completion of the CERCLA removal response, the EPA organized the remaining work into
two operable units. Operable Unit 1 (OU1) is the response at child high impact areas such as child
daycare facilities, and the most highly contaminated site properties exceeding 800 ppm. Operable Unit 2
(OU2) is the response at the remaining residential and residential-type properties that exceed risk-based
soil lead levels established during the final remedy selection process.
The lead in the soil is attributed to air emissions from the former ASARCO smelter which operated for
about 125 years in downtown Omaha and the former Aaron Ferer & Sons Company (Aaron Ferer) /
Gould Electronics Inc. (Gould) facility which operated a smaller smelter as part of a battery recycling
facility. The former ASARCO smelter ceased operation in 1997, and the former Aaron Ferer / Gould
facility ceased operation in the 1980s. In addition, NL Industries was found to be a corporate successor
to companies that produced lead in the downtown Omaha area including the former Carter White Lead
facility.
Groundwater and surface water are not impacted by the emissions from the former facilities and the
remedy does not address these media.
The remedy for the site includes:
Excavation of soils that exceeds 400 ppm lead in the upper 1 foot of surface soil at residential
and residential-type properties
Replacing excavated soil with clean soil and revegetating the clean soil with sod
Stabilization of deteriorating exterior lead-based paint
Response to lead-contaminated interior dust
Health Education
Operation of a local lead hazard registry as a type of institutional control
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The Remedial Action Objective (RAO) specified in the Record of Decision (ROD) for OU2 is to reduce
the risk of exposure of young children to lead in (or derived from) outdoor yard soil such that, given
typical exposures to lead in air, water and food, there is no greater than a 5 percent chance that an
individual child, or group of similarly exposed children, will develop a blood-lead concentration
exceeding 10 |ig/dL. The cleanup value selected for the site for lead in soil is 400 ppm.
Participation in a comprehensive remedy addresses identified lead exposure sources. The construction of
the remedy is continuing and is anticipated to be complete by December 31, 2015. Activities to date
have effectively addressed exposure to lead-contaminated surface soils. It is expected that the remedy
will be protective upon completion of construction activities in 2015.
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FIVE-YEAR REVIEW SUMMARY FORM
Lead agency: EPA
[If "Other Federal Agency," enter Agency name]'. Click here to enter text.
Author name (Federal or State Project Manager): Steve Kemp
Author affiliation: U.S. EPA Region 7
Review period: 4/1/2014 - 8/31/2014
Date of site inspection: N/A
Type of review: Statutory
Review number: 1
Triggering action date: 5/13/2009
Due date (fiveyears after triggering action date):. 9/30/2014
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Kmh s Ru-oiiuiu-iul.ttioiis
OU(s) without Issues/Rect»iiieiii»tloiis ideatffied in the Five-Year Review:
S-'A
Kmii'n and i(h utiiivi* in ilu' S i\r S v.if
N/A
Protect »>i'IH'nn Stiilciitinl(s)
Operable Unit: Protectiveness Determination: Addendum Due Date
01 Will be Protective (if applicable):
Protectiveness Statement:
The remedy at OU1 is expected to be protective of human health and the environment upon
completion. In the interim, remedial activities completed to date have adequately addressed all
exposure pathways that could result in unacceptable risks in these areas.
Operable Unit: Protectiveness Determination: Addendum Due Date
02 Will be Protective (if applicable):
(lick here to utiier a dale,
Protectiveness Statement:
The remedy at OIJ2 is expected to be protective of human health and the environment upon
completion. In the interim, remedial activities completed to date have adequately addressed all
exposure pathways that could result in unacceptable risks in these areas.
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I. INTRODUCTION
The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy
in order to determine whether the remedy will continue to be protective of human health and the
environment. The methods, findings and conclusions of reviews are documented in five-year review
reports. In addition, FYR reports identify issues found during the review, if any, and document
recommendations to address them.
The U.S. Environmental Protection Agency (EPA) prepares FYRs pursuant to the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Section 121 and the National
Contingency Plan (NCP). CERCLA 121 states:
"If the President selects a remedial action that results in any hazardous substances, pollutants, or
contaminants remaining at the site, the President shall review such remedial action 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. In addition, if
upon such review it is the.judgment of the President that action is appropriate at such site in
accordance with section [104] or [106], the President shall take or require such action. The
President shall report to the Congress a list of facilities for which such review is required, the
results of all such reviews, and any actions taken as a result of such reviews. "
The EPA interpreted this requirement further in the NCP; 40 Code of Federal Regulations (CFR)
Section 300.430(f)(4)(ii), which states:
"If a remedial action is selected that results in hazardous substances, pollutants, or contaminants
remaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead
agency shall review such actions no less often than every five years after the initiation of the
selected remedial action."
The EPA conducted a FYR on the remedy implemented at the Omaha Lead Superfund site in Omaha,
Douglas County, Nebraska. The EPA is the lead agency for developing and implementing the remedy
for the Site. The Nebraska Department of Environmental Quality (NDEQ), as the support agency
representing the State of Nebraska, has reviewed all supporting documentation and provided input to the
EPA during the FYR process.
This is the First FYR for the Omaha Lead Superfund site. The triggering action for this statutory review
is the on-site construction start date for OU2 of May 13, 2009. The FYR is required due to the fact that
hazardous substances, pollutants, or contaminants remain at the site above levels that allow for unlimited
use and unrestricted exposure. The Site consists of two Operable Units, both of which are addressed in
this FYR.
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II. SITE CHRONOLOGY
A chronology of significant site events and dates is included in Table 1.
Table !: i linun>l<,g\ nt Site I M ills
DCHD compiles statistics regarding elevated blood lead levels in
the Omaha area.
1973 -1998
Omaha City Council requests EPA assistance to address the high
incidence of children with blood lead concentrations greater than
lOggdl.
ms
EPA began collecting soil samples from residential properties that
were being used as child day-care facilities. Sample collection and
response action was conducted under CERCLA removal authority.
March 199M
IAG with USACE to "implement a removal action on child care
properties, and properties where children with elevated blood lead
levels reside," Excavation and soil replacement was completed at
257 properties by the USACE.
! A(i If):
DW96952155-01 -0
August 1999
2047710
IAG was later amended in 2001 to increase funding and extend the
project period.
IAG was amended several times to adjust funding and the period of
performance.
DW969S2155-01-1
DW-96-952155-01 -2
DW-96-952155-01-3
DW-96-952155-01-4
DW-96-952155-01-5
FPA executes an Action Memorandum for a Time-Critical removal
action.
August 2. 1999
95704
1 PA ordered ASARCO to perform the necessary removal action
pursuant to a UAO.
ASARCO responded that they would not comply.
Docket Number-
CERCLA-7-99-0029
August 2,1999
30202152
EPA initiates an apportionment investigation.
April 5, 2000
Final Preliminary Assessment/Site Inspection Report completed.
August I, 2001
40051879
Omaha Lead site proposed for the NPL.
February 24, 2002-1
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i|g|gl||Migag
M)MS
Document
BMHIiljlM
30070051
2Mii Time Critical removal action executed to address all other
residential-type properties where the maximum non-foundation soil
lead concentration exceeded an action level of 2.500 ppm.
At properties determined to be eligible for response under either of
the removal actions where the maximum mid-yard soil lead level
exceeded the action level, soils exceeding the cleanup level of 400
ppm were excavated and replaced with clean soil and excavated
areas were revegetated.
August 22, 20<
EPA began directly implementing the removal action and
remediated a total of 144 properties through 2003.
2002
Omaha Lead site listed on the NPL.
April 30. 2003
The action level which triggered response for typical residential
properties under the second removal action was reduced to 1,200
ppm in November 2003.
November 4, 2003
40118805
1AG with the US ACE to conduct a time-critical removal action at
approximately 300 residential yards in Omaha. Nebraska.
1AG ID:
[)\V-%-l)5222(>o|-0
May 1. 2004
40278505
Amended to adjust funding and time period.
DW-96-95222601 -3
40278504
Initial Rl completed.
June. 2004
Interim ROD completed.
December 15, 2004
30023102
Action Memorandum Amendment to allow the removal actions so
be combined and funded as one action.
March 31. 2005
30034335
I AG with the I :SACE to complete the remedial actions at
approximately 350 residential yards in Omaha. NE through a
perlbrmance based contract task order.
LAG ID:
D W-96-95224201 -0
July 20, 2005
30050389
State Super-fund Contract between the State of Nebraska. The City
of Omaha, and the EPA for the Interim Remedial Action at the
Omaha Lead site. P' vear of interim remedial action.
September 29, 2005
OA between (he City of Omaha and EPA to allow the city to
oversee exterior lead-based paint and interior dust activities-
Extended July 2010 to June 2012
CA:
V-98767501
September 29, 2005
30055594
Page 10 of 30
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Kuni
Final L AO with Union Pacific Railroad Company for Remedial
Design and Remedial Action. There were eight amendments to the
UAO to allow additional time for negotiation.
Agreement ii)
1
CERl'LA
020?
07-2005-
IjjgilttlllM
December 16, 2005
SDMS
Document
i!)
IAG will! the USAO: to complete the remedial actions at
approximately 425 residential yards in Omaha Nebraska through a
performance based linn fixed price contract task order.
IACJ ID:
DW-96-95224601
February 15, 2006
P1 amendment to the Slate Superfund Contract, To allow (he second
year of interim remedial action.
2riff amendment to the S^^ o allow the third
vear of interim remedial action.
March 29, 2006
February 26, 2007
30056994
3'" amendment to the State Superfund Contract to revise the cost
estimate for the third year of interim remedial action.
May 10, 2007
4th amendment lo the State Superfund Contract to revise the cost
estimate for the fourth year of interim remedial action.
Final Remedial Investigation Report completed.
April 17, 2008
April 2009
30056992
Four
volumes:
30024422,
30024423,
30024424,
30022200
The Record of Decision for Ol ;2 was issued.
May 13, 2009
30022233
Superfund State Contract between the State of Nebraska, The City
of Omaha, and EPA for the Filial Remedial Action at the site OU2
June 4, 2009
30047075
AOs for access (multiple).
multiple
Bankruptcy Settlement Agreement - The claim against ASARCO
for the site was resolved by the court on July 5, 2009. As a result of
the settlement. ASARCO paid SI 86 million to ii PA.
In subsequent court actions the amount was increased to include
interest in the amount of S33 million and was then reduced by
S15 million to a total of S204 million.
Case 05-21207
June 5,2009
1047
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Agreement ID
^Hi-
Dociisiii-iit
m
1st Amendment to the 4Ui Supei fund State Contract to allow the
DC'HL) and the Metropolitan C ommunity College to perform
portions of the remedial action.
March 26. 20is)
CA with IX'I ID to provide financial support for the education of
the owner, residents of homes, within the site boundary which are
determined to contain lead dust contamination, in the use of proper
cleaning techniques and to conduct dust inspections per the ROD.
Grant end date May 31, 2017,
Amount $3,8 million
CA:
V-7717501-0
May 27. 2010
30023602
CA with DC 1 i t) to reduce lead hazards through blood-lead
screening analysis, education and collaboration. Health education
activities and collaboration will be on-going under this cooperative
agreement.
Grant end date March 31. 2017.
Amount $1.6 million.
CA:
V-97725601
March 1,2011
CD with Union Pacific Railroad Company and the I :nion Pacific
Corporation - The company paid S3.15 million to finance the work
in accordance with the CD. ROD. SOW. etc. to fund the Omaha
Healthy Kids Alliance and paid S21.35 million to FPA.
8:1 l-cY-00195-L.SC-
FG3
August 9, 2011
CD with Gould Electronics Inc. - the company paid FPA M . 1
million.
K: 11-cv-00195-LSC-
FG3
August 10, 2011
CA with DCHD to conduct Lead Health Education and Intervention
Grant end date August 14. 2014.
Amount $233,838.00
CA:
V-97726501
August 15, 2011
CA with the City of Omaha to conduct exterior lead-based paint
stabilization.
CA:
V-97733501
December 29, 2011
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S \L-nf Viivi-mfiil il> M;»u- SDMS
Grant to the Cily of Omaha tor $5.2 million.
Grant will enable the City of Omaha, under the current cooperative
agreement, to assist the I:PA in obtaining access to properties lor
the purpose of conducting sampling for lead contamination while
continuing its efforts to reduce lead hazards by providing exterior
lead based paint stabilization where deteriorating lead based paint
would cause reeontamsnation of soil. This work will include
working with communities, targeted populations and those at risk
due to potential adverse health effects from hazardous waste
contamination.
CA:
V-97733501-1
January !. 2012
in
CD with NL Industries, NL paid $624,000.00 to EPA.
8:12 -cv-00059-J M G -
CRZ
March 23. 2012
CA with the City of Omaha to develop an existing lead registry
database into an institutional control that will educate and inform
public and private agencies; focus on lead issues; act as an
enforcement tool; be interconnected with many city and county
departments and activities; act as a repository of lead contamination
and mitigation data for the public as well as for the city ;
be inexpensive to operate and maintain; act as a useful land reuse
and revitali/ation tool; and, protect and promote city, EPA and
community investments into the future, www.omahalead.org
Grant end date May 30, 2019.
Amount $987,000.00
CA:
V-97734901-0
May 29, 2012
I:PA begins deleting properties that haw been remediated from the
NPL. 1J 54 properties deleted.
December 6, 2013
CD with Aaron Ferer the company paid $480,000 to EPA.
8; 12-CV-0G406-RGK-
CRX
February 4, 2013
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III. BACKGROUND
Physical Characteristics
The city of Omaha covers an area of approximately 130 square miles. According to the 2010 census the
city has a population of 409,000. The site encompasses 27 square miles with a population of
approximately 130,000. (Figure 1 - Site Location) While the city of Omaha is not an environmentally
sensitive area, the city and the Site are bordered on the east by the Missouri River. For a description of
the river please refer to the following discussion.
Hydrology/Geology
The 2009 RI included an evaluation of the hydrology and geology at the site.
Surface Water: Surface waters within the site, including major streams such as Papillion Creek, flow
southeast toward the Missouri River. The storm water runoff control system for the City of Omaha flows
into the tributary to the Missouri River or directly into the river via a series of discharge points. The
Missouri River supports recreational fishing and boating. There are wetlands located along the river. The
Missouri River is the habitat location for the blacknose shiner (Notropis heterolepis), finescale dace (P.
neogaeus), lake sturgeon (Acipenser fulvescens), northern redbelly dace (P. eos), pallid sturgeon
(Scaphirhynchus albus), and pearl dace (Margariscus margarita), which are designated as threatened
and/or endangered species. The majority of the site is located outside the 500-year flood plain of the
Missouri River.
Groundwater: Groundwater under the site varies in depth based on the amount of precipitation but is
generally shallow, 10-20 feet below the ground surface in the low lying areas of the site closest to the
Missouri river. At the higher elevations west, and north of the downtown area, the depth to groundwater
may be 60 feet or greater. The groundwater under the site is considered to be of poor quality and is not
used as a source of drinking water. The City of Omaha has an ordinance requiring a permit for the
installation of any groundwater wells.
Geology: The site lies within the Central Lowland region of the Interior Plains physiographic province.
The entire area lies within a structural feature known as the Nemaha Uplift, a north-south feature bound
on the east by the Humboldt fault zone. The topography of the Omaha area is defined by a hilly upland
in the western portion of the area and the Missouri River floodplain to the east. The elevation of the site
ranges from approximately 1,200 feet above mean sea level (AMSL) in the north to 970 feet AMSL in
the south. Geologic units in the study area include, in descending stratigraphic order: undifferentiated
Pleistocene deposits, the Kansas City Group, and undifferentiated strata of Cambrian through
Pennsylvanian age. Unconsolidated materials beneath the site consist of Pleistocene to recent alluvial
deposits and Pleistocene glacially derived loess deposits. Loess is the most common surface deposit in
the Omaha area. The loess is underlain by either glacial till, Cretaceous-aged sandstone, or
Pennsylvanian-aged sediments. The unconsolidated material has a thickness of approximately 90 feet on
the Missouri River Valley at Council Bluffs, Iowa. The Kansas City Group consists of interbedded shale
and limestone and is greater than 50 feet thick in the Omaha/Council Bluffs area. The undifferentiated
strata of Cambrian through Pennsylvanian age consist of interbedded sedimentary rock of undetermined
thickness. Cambrian rock units are present beneath the site and thicknesses generally exceed 1,000 feet
in eastern Nebraska.
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Land and Resource Use
Land use at the site consists of residential and residential-type. The site is defined to include only
residential and residential-type properties where the concentration of lead in the surface soil is
determined to be 400 ppm or greater. Residential-type properties include parks, churches, schools and
other properties used extensively by children. Other commercial properties are specifically excluded
from the definition of the site. The site is located entirely within the city limits of Omaha, Nebraska, and
local zoning ordinances control land use. The site is bordered by adjacent Omaha neighborhoods and
commercial areas to the north and west, and developed areas within the city of Bellevue, Nebraska, in
Sarpy County to the south, and the Missouri River to the east. The continued residential use of property
can be reasonably assumed for the majority of the thousands of properties that comprise the Site through
local zoning control. It is possible that, at some point in the future, interest will arise in converting some
of the current residential properties to nonresidential use.
Also located within the general area of affected residential properties are numerous nonresidential
properties, including the Omaha central business district. As noted above, commercial properties
including the Omaha central business district and industrial properties are not included in the site
definition and soil sampling is not performed at properties with this type of land use.
Groundwater is not addressed by the ROD for OU2 or any other response actions related to the Site due
to the lack of potential impact on groundwater quality and the absence of potential receptors.
Groundwater is not affected by lead-contaminated soils at the impacted residential properties that ,
comprise the Site. Potential groundwater impacts related to the former ASARCO and Aaron Ferer/Gould
facilities were mitigated through placement of a cap over remediated areas. Soil lead contamination at
the site has remained very stable, exhibitingJittle or no vertical migration or leaching during the 125
years since lead smelting/refining operations began. Because lead in surface soils at the site is not
considered readily leachable under normal circumstances, local groundwater quality is not threatened by
lead-contaminated surface soils. Shallow groundwater beneath the site discharges directly to the
Missouri River and is not useable as a potable water source due to poor quality and low productivity.
The municipal water supply is readily available and used by Omaha residents. Domestic use of local
groundwater is controlled by City Ordinance.
Surface water is also not affected by lead-contaminated soils at the site. The most prominent surface
water feature potentially affected by site contaminants is the Missouri River. Available data indicate that
public health is not threatened by potential Site impacts on surface water quality in the Missouri River.
Sampling results of water and sediment in the Missouri River immediately adjacent to the ASARCO and
Aaron Ferer/Gould facilities did not detect elevated levels of lead or other smelter-related
contamination. Public drinking water intakes which supply the cities of Omaha and Council Bluffs are
located upstream of the site.
History of Contamination
The ASARCO lead smelting and processing facility was in operation from 1871 until 1997. The facility
was located at 500 Douglas Street in downtown Omaha on an approximately 23-acre site on the west
bank of the Missouri River. The land where this ASARCO facility operated was owned by Union
Pacific Railroad Company from the 1860s until it was sold to ASARCO in 1946. The ASARCO facility
processed lead bullion containing recoverable amounts of gold, silver, antimony and bismuth using the
traditional pyro-metallurgical process. This process consisted of adding metallic and nonmetallic
compounds to molten lead, separation of the lead from the otherj metals, and removing impurities. While
Page 15 of 30
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the ASARCO plant was in operation, lead and other metals were emitted to the atmosphere through
smokestacks and these contaminants were transported downwind to be deposited on the ground surface
by the combined action of turbulent diffusion and gravitational settling. The ASARCO facility was
closed in 1997 and the property is now owned by the City of Omaha and being used for commercial and
public purposes.
Aaron Ferer constructed a secondary lead smelter and a lead recycling facility in the early 1950s at 555
Farnam Street in Omaha, NE. Aaron Ferer operated this facility until 1963 when the facility was
purchased by a predecessor of Gould. Gould operated the facility until it was closed in 1982. While this
facility was in operation, lead was emitted into the atmosphere through a stack and transported
downwind to be deposited on the ground surface by the combined action of turbulent diffusion and
gravitational settling. After the Gould facility was closed, the property where the Gould facility was
located was sold to Douglas County. Douglas County performed a cleanup at the property and the
property is now a county park. Several other businesses in the Omaha area used lead in their
manufacturing processes.
Between 1972 and 1998 the Douglas County Health Department (DCHD) measured the blood lead level
in children within the county. The results of the measurements indicated a high incidence of elevated
blood lead level in children. The DCHD also performed monitoring of the ambient air quality around the
ASARCO facility beginning in 1984. This air monitoring routinely measured ambient lead
concentrations exceeding the ambient standard for lead which at that time was 1.5 micrograms per cubic
meter (|ag/m3). The highest recorded quarterly average lead concentration measured in air was 6.57
l-ig/m3- .
Initial Response
In 1998, the Omaha City Council requested assistance from the EPA in addressing the problems with
lead contamination in the area. The EPA initiated an investigation into the lead contamination under the
authority of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in
1999.
The EPA began collecting samples from residential properties and properties that were used to provide
licensed child-care services in March 1999. Response action was initiated under CERCLA removal
authority and began in August 1999 through an IA with the U.S. Army Corps of Engineers (USACE).
The initial removal response actions consisted of excavation and replacement of soil exceeding 400 ppm
at child-care centers and residences where children with elevated blood lead levels resided.
From 1999 through 2002, excavation of contaminated soil and placement of uncontaminated backfill
was completed at 257 properties by the USACE. In August 2002, a second removal action was initiated
at all other residential-type properties where the maximum non-foundation soil lead concentration
exceeded an action level of 2,500 ppm. The EPA began directly implementing the removal action in
2002. At properties determined to be eligible for response under either of the removal actions, soils
exceeding the cleanup level of 400 ppm were excavated and replaced with clean soil and excavated
areas were revegetated with sod.
The site was proposed for the EPA's National Priorities List (NPL) on February 24, 2002. The proposed
NPL listing became final on April 30, 2003. At the time of the NPL listing, the general boundaries of the
Site were estimated by establishing a perimeter surrounding the properties that had been determined to
Page 16 of 30
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exceed 1,200 ppm lead. The area enclosed by this perimeter was approximately 8,840 acres (13.8 square
miles), with a population of 65,863 (based upon 1990 U.S. Census information). Twenty public schools
were located within this area. On the basis of soil sampling performed subsequent to NPL listing, the
EPA established a focus area which included additional residential properties to be evaluated. The
original focus area boundary encompassed an area of 12,098 acres (18.9 square miles) bounded by
Ames Avenue to the north, L Street to the south, 45th Street to the west and the Missouri River to the
east.
The EPA completed excavation of contaminated soil and replacement of uncontaminated backfill at a
total of 144 properties through 2003. The EPA and the US ACE completed a combined total of 310
properties in 2004. Removal action was completed by the EPA and the USACE at 773 properties in
2005 as work was transitioning to CERCLA remedial authority.
Because of the potential that deteriorating exterior lead-based paint near the foundations of structures
was contributing to lead contamination in the soil, it was determined that the soil lead level in the drip
zone (areas near structure foundations) alone would not trigger soil removal if all mid-yard soil lead
levels at a property were less than the action level. However, if any mid-yard soil sample exceeded the
action level, soil from all areas of the property exceeding the 400 ppm cleanup level would be removed
and replaced, including drip zone soils if they exceeded 400 ppm. The action level which triggered
response for typical residential properties under the second removal action was reduced from 2,500 ppm
to 1,200 ppm in November 2003. In 2004, the two removal actions were combined into a single
response, and in 2005, following issuance of the Interim ROD, the action Level for removal response
during the transitional period was reduced from 1,200 ppm to 800 ppm for consistency with the
upcoming remedial response. It is important to note, that although the lead concentration that triggered a
response varied over time, the clean-up level remained constant at 400 ppm.
Between March 1999 and January 2004, surface soil samples were collected from 15,012 residential
properties. The EPA completed the initial Remedial Investigation (RI) at the Site in 2004 which
presented the results of previous site investigations. During data collection for the 2004 RI, the
boundaries of the focus area were expanded to include additional areas where elevated soil lead
concentrations were consistently found. The 2004 expanded focus area added portions of areas north to
Redick Avenue, west to 52nd Street, and south to Harrison Street, encompassing a total area of 16,465
acres (25.7 square miles). The 2004 RI estimated that 16,000 residential properties could exceed 400
ppm lead; 5,600 properties could exceed 800 ppm lead; and 2,800 properties could exceed 1,200 ppm
lead. The EPA completed the Final RI for the site in April 2009.
Enforcement Activities
The EPA issued a general notice letter under CERCLA authority on August 4, 1999, to ASARCO,
asking ASARCO to perform a time-critical removal action to address lead-contaminated soils at child-
care centers and residences at the site. In a response dated August 13, 1999, ASARCO declined to
perform the removal action. On August 30, 1999, the EPA issued a Unilateral Administrative Order
(UAO) (Docket Number-CERCLA-7-99-0029), ordering ASARCO to perform the necessary removal
action. ASARCO responded on September 7, 1999, stating they would not comply with the UAO. The
EPA proceeded with a fund-lead removal action to address the threat associated with the lead
contamination in the residential soils. The EPA subsequently identified four additional Potentially
Responsible Parties (PRPs): Union Pacific Railroad, Gould Electronics Inc., Aaron Ferer & Sons
Company and NL Industries.
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The EPA coordinated with the PRPs during the implementation of all response actions at the site.
General notice letters were issued on June 4, 2002, to initiate discussions on the performance of the
Remedial Investigation/Feasibility Study (RI/FS). The PRPs declined to perform the RI/FS so EPA
proceeded using Superfund Trust monies.
Following completion of the Interim ROD, special notice letters were issued to the PRPs on December
16, 2004, requesting payment of past costs and performance of the work under the Interim ROD. A good
faith offer for performance of the work was not received. On March 31, 2005, an Administrative Order
(Docket No. CERCLA-07-2005-0207) was issued with a delayed effective date to Union Pacific
requesting performance of the work required by the Interim ROD. The effective date was extended
several times to allow continued discussions with Union Pacific. The Administrative Order became
effective on December 16, 2005. Union Pacific responded on January 3, 2006, indicating that it would
not comply with all of the provisions of the Administrative Order. The EPA proceeded with a fund-lead
remedial action to address the threats posed by Site contamination.
In August 2005, ASARCO filed for bankruptcy protection under Chapter 11 of the Bankruptcy Code in
the Southern District of Texas, Corpus Christi Division. The United States filed a proof of claim in the
bankruptcy action to cover all past and future costs associated with the Site. Numerous other sites and
facilities are included in the bankruptcy case. An estimation hearing on the claim for the Site was held in
Corpus Christi, Texas in August 2007. The claim with ASARCO for the Site was resolved by the court
on July 5, 2009 (Case 05-21207). As a result of the settlement, ASARCO paid $204,000,000.00 to the
EPA.
Pursuant to Consent Decrees, Union Pacific Railroad Company paid $3.15 million to the Omaha
Healthy Kids Alliance and $21.35 million to EPA in August 2011 (8:1 l-cv-00195-LSC-FG3), Gould
Electronics Inc. paid $1.1 million to the EPA in August 2011 (8:1 l-cv-00195-LSC-FG3), NL Industries
paid $624,000 to the EPA in March 2012 (8:12-cv-00059-JMG-CRZ), Aaron Ferer & Sons Company
paid $480,000 to the EPA in February 2013 (8:12-cv-00406-RGK-CRZ).
Basis for Taking Action
The contaminant of concern and media of concern at the Site is lead in the soil at residential and
residential-type properties.
The human health risk assessment for lead focused on young children seven years of age and younger (0
to 84 months) who are site residents. Young children are most susceptible to lead exposure because they
have higher contact rates with soil or dust, absorb lead more readily than adults, and are more sensitive
to the adverse effects of lead than are older children and adults. The effect of greatest concern in
children is impairment of the nervous system, including learning deficits, reduced intelligence, and
adverse effects on behavior.
To evaluate risks, the Integrated Exposure Uptake Biokinetic (IEUBK.) model was run using site-
specific data to predict a lead soil level that will be protective of children and other residents. When best
estimates of the site-specific inputs were used, the resulting preliminary remediation goal (PRG) for lead
in soil at the Site was 298 ppm measured by Inductively Coupled Plasma analysis in the fine fraction of
soil or 247 ppm measured by XRF in bulk soils.
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IV. REMEDIAL ACTIONS
Remedy Selection
OU1
The EPA selected the OU1 interim remedy in 2004. The remedy selected included:
Excavation, backfilling, and revegetation of lead-contaminated residential soils at an estimated
5,600 residential-type properties exceeding 800 (ppm) and properties exceeding 400 ppm
considered high child-impact areas or with a residing child exhibiting an elevated blood lead
level;
Participation in a comprehensive remedy with other organizations and agencies to characterize
and address all identified sources of lead exposure at the Site;
Stabilization of exterior lead-based paint that threatens the long-term protectiveness achieved
through excavation and replacement of lead-contaminated surface soils;
Removal of interior dust in instances where contaminated soils contribute to interior lead dust
loadings;
Health education for the Omaha community and medical professionals to support public
awareness, exposure prevention programs, in-home assessments, blood-lead screening programs,
and diagnosis, treatment, and surveillance programs.
The Remedial Action Objective (RAO) is to reduce the risk of exposure of young children to lead such
that an individual child, or group of similarly exposed children, have no greater than a 5 percent chance
of having a blood-lead concentration exceeding 10 (ig/dl. The pre-established soil remediation level of
400 ppm was utilized during this interim remedial action.
This interim approach allows for excavation and soil replacement to continue at the most highly
contaminated properties and properties with a high potential for child exposure while additional work is
performed to generate data and information to support a final ROD for the Site. The remedy described in
the interim ROD is consistent with the final remedial action selected for the Site.
The interim ROD provided for several enhancements to the site cleanup strategy that was being
conducted under removal authority. The interim remedy allowed future response work to be performed
under remedial authority, which potentially enables the EPA to increase the rate of property remediation
beyond the current rate conducted under removal response authority.
The interim remedy also included response elements that were not included in the removal response.
The interim remedy provided the EPA with the ability to address additional exposure sources that are
related to soil remediation.
OU2
The EPA selected a final remedy for the Site in 2009. The 2009 ROD includes the following elements:
Excavation of soils that exceeds 400 ppm lead in the upper 1 foot of surface soil at residential
and residential- type properties;
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Replacing excavated soil with clean soil and revegetating the clean soil with sod;
Stabilization of deteriorating exterior lead-based paint;
Response to lead-contaminated interior dust;
Health Education;
Operation of a local lead hazard registry as a type of institutional control;
Participation in a comprehensive remedy addressing identified lead exposure sources.
The selected final remedy continues the ongoing remedial response being implemented under the
December 15, 2004, Interim ROD with the following modifications:
Under the previous interim remedy, properties were eligible for soil remediation if the maximum
non-foundation soil lead level exceeded 800 ppm. Child care centers and properties where
children with elevated blood lead levels reside (high child impact properties) were eligible for
soil remediation under the interim remedy if the maximum non-foundation soil lead level
exceeded 400 ppm. The final remedy for the Site will lower the soil lead action level, which
determines eligibility for soil remediation, to 400 ppm for all residential and residential-type
properties. By lowering the soil lead action level to 400 ppm for all residential properties, the
distinction between high child impact properties and typical residential properties is no longer
necessary to determine eligibility for response. High child impact properties will continue to be
prioritized for response.
Soil sampling will continue to determine eligibility for remedial action at properties inside the
Final Focus Area where sampling has not been performed. Due to the low frequency of
properties exceeding the final EPA soil lead action level outside the boundary of the Final Focus
Area, additional soil sampling will generally be discontinued beyond the Final Focus Area
boundary following the final remedy selection and performed only if warranted based on
property-specific circumstances. Lead-based paint assessments will continue to be offered at all
properties which are eligible for soil remediation, and interior dust wipe sampling will be offered
at all properties following soil remediation.
The preferred alternative includes an institutional control involving the operation of a local lead
hazard registry which will contain information about the status of the EPA investigation and
response and other lead hazards identified at individual Omaha properties. The lead hazard
registry will provide access to property-specific lead hazard information both on-line and
through the Omaha Lead Hazard Control Program and other agencies and organizations involved
in lead hazard control efforts in Omaha. The final remedy includes establishing the lead hazard
registry with necessary hardware, software, technical assistance and personnel to provide for
operation through completion of the final remedial action. The EPA anticipates that the lead
hazard registry will continue to operate following completion of the EPA response activities
through an alternate funding mechanism.
The interim remedy included high efficiency interior cleaning at residences where elevated levels
of lead were identified in interior dust. Under the final remedy, participating residents at eligible
properties will be offered high-efficiency household vacuum equipment, training on maintenance
and the importance of proper usage, and education on mitigation of household lead hazards.
Interior dust response will be offered on a voluntary basis to residents at properties where soil
remediation is performed and interior floor wipe sampling indicates that Housing and Urban
Development (HUD) criteria are exceeded. ^
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The Remedial Action Objective specified in the ROD for OU2 is to reduce the risk of exposure of young
children to lead in (or derived from) outdoor yard soil such that, given typical exposures to lead in air,
water and food, the IEUBK. model predicts there is no greater than a 5 percent chance that an individual
child, or group of similarly exposed children, will develop a blood-lead concentration exceeding
10fj.g/dL.
The cleanup value selected for the Site for lead in soil is 400 ppm.
Remedy Implementation
Implementation of the final remedy began in 2009. The construction of the remedy is continuing. There
are 40,073 residential or residential-type properties within the focus area of the Site. (Figure 2 - Site
Status) .
As of April 30, 2014:
1. EPA collected soil samples and evaluated the lead concentration at 37,985 properties (95%) of
the properties within the focus area of the Site, as well as an additional 3,018 properties that are
outside the focus area.
2. EPA has remediated the soil at 12,198 (89%) of the 13,651 properties that qualify for soil
remediation, (based on the detection of lead in the soil in a mid-yard quadrant > 400 ppm)
3. EPA has conducted paint assessments on 11,207 (92%) of the 12,290 properties that qualified
for paint assessment.
4. EPA has completed paint stabilization at 5,991 (92%) of the 6,545 properties that are eligible
for paint stabilization.
For those residential and residential-type properties where the soil in at least one yard quadrant exhibits
a lead concentration of 400 ppm or greater, the soil is being excavated to a maximum depth of one foot.
In addition, for any properties meeting the above criteria, if the soil in the drip zone exhibits a lead
concentration of 400 ppm or greater, the drip zone around the residence is being excavated to a
maximum depth two feet. The soil in any identified garden areas is also excavated to a depth of two feet.
Excavated soil is removed and the excavated areas of the yard are backfilled with clean soil and
revegetated with sod. In the early stages of remediation a plastic mesh was placed as a way to identify
the limit of excavation. However, this practice was discontinued when the remedy was revised to
excavate all soil greater than 400 fj.g/1 rather than the previous 1200 |ig /I in the upper one foot.
/
Because the primary mechanism of contamination was deposition of airborne contaminants from lead
smelting operations, the lead concentration found in the soil generally decreases with depth. However to
date, the investigation of the Site identified 70 properties where the lead concentration is significantly
higher. As with the other residential properties, surface soil at these properties was excavated and
removed, and the excavated soil was replaced with a minimum of one foot of clean soil and revegetated.
For the present, the clean fill prevents exposure to the remaining underlying contaminated material. The
EPA anticipates reviewing the protectiveness of the remedy at these properties after the construction is
complete across the entire Site.
System Operation/Operation and Maintenance
Operation and maintenance activities include maintenance of the soil cap and revegetated areas for those
properties where lead contaminated soils are left at depth. In addition, the remedy includes
implementation and maintenance of institutional controls identifying properties where elevated lead
soils remain.
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Maintenance of the clean soil cap and revegetated areas will be evaluated during the next five-year
review, in 2019, after the construction of the remedy is complete.
Institutional Controls
The EPA is working with the City of Omaha to develop institutional controls (ICs) for the Site. One of
the ICs is a database referred to as the Omaha Lead Registry that identifies the status of each property.
The database is available to the public via the internet at http://www.omahalead.org/. As the EPA
remediates properties, the status of the property is changed in an internal EPA database referred to as the
Omaha Lead database. The City retrieves selected data from EPA's database for use in the Omaha Lead
Registry. The Omaha Lead Registry identifies the properties where the soil has been remediated, and
any lead based paint has been stabilized.
Partial Deletion Process
As properties are cleaned up pursuant to the ROD for the Site and it is determined that no further
response action under CERCLA is appropriate, the properties are eligible for deletion from the NPL.
The partial deletion process is conducted in accordance with 40 CFR 300.425(e) and is consistent with
the Notice of Policy Change: Partial Deletion of Sites Listed on the National Priorities List 60 FR
55466 (Nov. 1, 1995). On December 6, 2013, EPA deleted 1,154 properties from the Site. All of the
deleted properties were remediated to levels that allow for unrestricted use and do not require operation
or maintenance activities (i.e. there is no contamination left behind at depth that exceeds the cleanup
standards specified in the ROD).
V. PROGRESS SINCE THE LAST REVIEW
Not applicable. This is the first five-year review for the Omaha Lead site.
VI. FIVE-YEAR REVIEW PROCESS
Administrative Components
According to information in the Comprehensive Environmental Response, Compensation, and Liability
Information System (CERCLIS), the five-year review for the Site was initiated on June 11, 2013.
However, due to a number of issues including the retirement of several key personnel in March 2014,
the FYR was delayed. NDEQ was notified of the initiation of the five-year review on June 16, 2014. The
FYR was led by Steve Kemp, Remedial Project Manager, SUPR/SPEB; Todd Phillips and Venessa
Madden, ENSV/EAMB did the technical review. Steve Sanders provided the legal review. Stacey
Strieker, of NDEQ, assisted in the review as the representative for the support agency.
The review consisted of the following components:
Community Involvement
Document Review
Five-Year Review Report Development and Review
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Community Notification and Involvement
A notice was published in the local newspaper, Omaha World Herald, in August 2014, stating there was
a five-year review of the Site and inviting the public to submit any comments to the EPA. The results of
the review and the report will be made available at the Site information repositories located at the
following locations:
' EPA Public Information Center
(north)
3040 Lake St.
Omaha, Nebraska 68111
EPA Public Information Center
(south)
4911 S. 25th St.
Omaha, Nebraska 68107
W. Dale Clark Library
215 South 15th Street Omaha, Nebraska
68102
Washington Branch Library
2868 Ames Ave.
Omaha, Nebraska 68111
South Omaha Branch Library
2302 M St.
Omaha, Nebraska 68107
EPA Records Center
11201 Renner Blvd.
Lenexa, Kansas 66219
Document Review
This five-year review consisted of a review of relevant documents including decision documents, court
documents and financial documents as well as remedial investigation and confirmatory sampling data
for each property addressed. Applicable soil cleanup standards, as listed and finalized in the May 2009
Record of Decision, were also reviewed.
Data Review
As properties are identified as having surface soils contamination above the ROD cleanup levels, they
are remediated by removing up to the first foot of contaminated soils. As necessary, exterior lead based
paints and indoor dust issues are also evaluated and addressed. Upon completion of the soil excavation
work, samples are collected from the bottom of the excavation. The results of these sampling events are
documented for each property and indicate if and what types of operation and maintenance activities, if
any, are needed at each of the properties. These results are put in the site file and the lead registry for the
site is updated.
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Other than property specific data collected during the RI/FS and RA, there is no additional sampling that
was conducted.
Site Inspection
A Site Inspection was riot conducted as part of this five-year review since remedial activities are-
ongoing. The EPA is heavily involved in day-to-day activities at the Site.
Interviews
Interviews were not conducted as part of this five-year review.
VII. TECHNICAL ASSESSMENT
Question A: Is the remedy functioning as intended by the decision documents?
Remedial Action Performance
The remedy is under construction and has not been implemented site-wide. However, for those
residential properties that have been remediated, the remedy is working as intended. All properties
requiring remediation had the surface soils removed from the property and clean back fill placed. The
lead registry for the Site is updated as cleanup progresses to document the status of cleanups for each
property.
Implementation of Institutional Controls and Other Measures
The EPA is working with the City of Omaha and Douglas County to develop and implement
institutional controls. The city has a database that identifies the properties within the Site boundary that
have been remediated, http://www.omahalead.org/
Question B: Are the exposure assumptions, toxicity data, cleanup levels, and RAOs used at the
time of the remedy section still valid?
Changes in Standards and To Be Considered
Have there been changes to risk-based cleanup levels or standards identified as Applicable or Relevant and
Appropriate Requirements (ARARs) in the Record of Decision (ROD) that call into question the
protectiveness of the remedy?
At this site, there are no risk-based cleanup levels that were identified as ARARs in the ROD.
i
Are there newly promulgated standards that call into question the protectiveness of the remedy?
EPA Region 7 is not aware of any newly promulgated standards that call into question the protectiveness
of the remedy.
/ '
Have TBCs been used in selecting cleanup level at the site changed in a way that could affect the
protectiveness of the remedy? . ¦
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At this Site, the soil lead cleanup goal of 400 ppm was established to meet the EPA's health protection
goal of no more than a 5% probability of exceeding a blood lead level of 10 ng/dL in a child or group of
similarly exposed children. Part of the basis for this goal was that the Centers for Disease Control and
Prevention (CDC) had determined that adverse health effects occur at or below a blood lead level of
10 (a.g/dl. In 2012, the CDC followed the advice of its Advisory Committee on Childhood Lead
Poisoning Prevention and adopted a new reference value of 5 fig/dL, based on the 97.5th percentile
blood lead level in children ages one to five. The CDC plans to update this reference value every four
years. Currently, the EPA's health protection goal is still valid, and the remedy for the Site remains
protective. However, the EPA is currently re-evaluating the goal. In the event that the health protection
goal is revised, the EPA will evaluate the modified goal in future FYRs.
Changes in Exposure Pathways
Has land use or expected land use on or near the site changed (e.g., industrial to residential,
commercial to residential)?
We are not aware of any land use changes or any potential future land use changes at the Site. In
addition, because the remedy was based on residential assumptions, it remains protective if individual
properties covered by the ROD switch to industrial or commercial use or become vacant.
Have any human or ecological routes of exposure or receptors changed or been newly identified
(e.g., dermal contact where none previously existed, new populations or species identified on site or
near the site) that could affect the protectiveness of the remedy?
The Assessing Protectiveness at Sites for Vapor Intrusion Supplement to the "Comprehensive Five Year
Review Guidance" (U.S. EPA, 2012) recommends evaluation of the vapor intrusion pathway during the
Five-Year Review. For the Omaha Lead Site, the contaminants of concern are not sufficiently volatile to
pose an inhalation risk via the vapor intrusion pathway. No other new routes of exposure or receptors for
the Site were identified.
Are there newly identified contaminants or contaminant sources?
The available data do not indicate any new contaminants or contaminant sources.
Are there unanticipated toxic byproducts of the remedy not previously addressed by the decision documents
(e.g., byproducts not evaluated at the time of remedy selection)?
We are not aware of any unanticipated toxic byproducts. '
Have physical site conditions (e.g., changes in anticipated direction or rate of groundwater flow) or the
understanding of these conditions (e.g., changes in anticipated direction or rate of groundwater flow)
changed in a way that could affect the protectiveness of the remedy?
We have no information to indicate that Site conditions or the understanding of these conditions has
changed.
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Changes in Toxicity and Other Contaminant Characteristics
Have toxicity factors for contaminants of concern at the site changed in a way that could affect the
protectiveness of the remedy?
Several non-carcinogenic and carcinogenic toxicity values have been revised since the ROD was signed
in 2009. However, the changes in toxicity values do not significantly change the results of the human
health risk assessment and thus, do not impact the protectiveness of the remedy. Also, because the risk
assessment preceded Risk Assessment Guidance Superfund Part F (U.S. EPA, 2009b), inhalation
exposures were assessed on a body weight basis, instead of on a concentration basis. Although the
method to assess inhalation exposures has changed, the screening level calculations provided in the site
human health risk assessment indicate that exposure to particulates suspended in outdoor air is very
small compared to oral exposure. Therefore, because the inhalation pathway is a minor contributor to
risk compared to ingestion at this Site, these changes are unlikely to affect the protectiveness of the
remedy.
Have other contaminant characteristics changed in a way that could affect protectiveness of the
remedy?
We are not aware of any other changes to contaminant characteristics that could impact the
protectiveness of the remedy.
Changes in Risk Assessment Methods
Have standardized risk assessment methodologies changed in a way that could affect the
protectiveness of the remedy?
Overall, the human health risk assessment was conducted in a similar manner as compared to current
risk assessments. It is worth noting that concurrently with review of the EPA's health protection goal for
lead, the agency is also re-examining several default input values for the IEUBK model. In the event that
the default input values are modified, the EPA will evaluate how the change may impact work done at
the site in a future FYR.
As mentioned previously, current methodology used to assess exposure and risks via the inhalation
pathway differ from the methods used in the site risk assessment. However, because the inhalation
pathway is a minor contributor to risk compared to ingestion at this site, these changes are unlikely to
affect the protectiveness of the remedy.
The site is located entirely within an urban area in eastern Omaha and includes only residential
properties. Therefore, ecological risk is generally not relevant to this site. However, the human health
based soil cleanup level for lead, which is 400 mg/kg, is likely protective of ecological receptors that
would utilize urban environments. This conclusion is based on ecological preliminary remediation goals
(PRG) that have been developed for southern Missouri lead sites. These PRGs include sensitive
ecological receptors, such the American Robin. Robins are common migratory songbirds in the urban
landscape that tend to be highly exposed to contaminated soil due to ingestion of soil invertebrates. The
PRG range for the robin is between 340 mg/kg in the southern portion of their range, to 670 mg/kg in
the northern portion of their range. Finally, because robins are a sensitive ecological receptor, urban
wildlife species that are less sensitive, should also be protected within this range of lead concentrations.
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Expected Progress Towards Meeting RAOs
Upon completion of construction the remedy is expected to meet the RAOs specified in the ROD.
Question C: Has any other information come to light that could call into question the
protectiveness of the remedy?
Are there impacts from natural disasters (e.g., a 100-vear flood)?
Although tornados are a common occurrence in the Midwest, tornados are not expected to result in
exposure to contamination because lead contaminated soil is being removed from the properties. For
those properties where soil contaminated with lead at concentrations that could potentially pose a risk to
human health remain at depth, the remaining contamination is covered with a minimum of one foot of
clean soil and the soil has been revegetated.
Although flooding does occur along the Missouri River, Omaha is protected by a levy constructed by the
US ACE and relatively few of the residential properties would be exposed to any flooding. At many of
the properties, all of the soil that exhibited lead concentrations greater than 400 ppm was removed from
the property. These properties would not present a risk even if flooding were to occur and erode the
clean backfill.
For those properties where lead concentrations in the soil exceed 400 ppm at depths greater than one
foot, damage from tornadoes due to uprooted trees or flooding and any associated erosion could
potentially expose lead contaminated soil. These issues will be evaluated as part of the protectiveness
determination during future five-year reviews.
Has any other information come to light which could affect the protectiveness of the remedy?
At this time, we are not aware of any other information which could affect the protectiveness of the
remedy.
Technical Assessment Summary
For properties remediated to date, the selected remedy has effectively addressed exposure of vulnerable
populations to lead contaminated soils. Upon completion of construction the remedy is expected to meet
the RAOs specified in the ROD.
VIII. ISSUES/RECOMMENDATIONS AND FOLLOW-UP ACTIONS
Not applicable.
IX. PROTECTIVENESS STATEMENT
OU1
The remedy at OU1 is expected to be protective of human health and the environment upon completion.
In the interim, remedial activities completed to date have adequately addressed all exposure pathways
that could result in unacceptable risks in these areas. I
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OU2
The remedy at 0U2 is expected to be protective of human health and the environment upon completion.
In the interim, remedial activities completed to date have adequately addressed all exposure pathways
that could result in unacceptable risks in these areas.
X. NEXT REVIEW
The next five-year review report for the Omaha Lead Superfund Site is required five years from the
completion date of this review.
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NOTE: The Environmental Protection
Agency does not guarantee the
accuracy, completeness, or fe
timeliness of the information
shown, and shall not be liable J/
for any injury or loss resulting from
reliance upon the information shown.
Date Saved: 8/25/2014
Casey J. McLaughlin
Omaha Lead Superfund Site
Omaha, Nebraska
Figure 1
Site Locator
April 15, 2014
Legend
[ = ] Omaha Focus Area
Central Business District
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