Third Five-year Review Report Lindsay Manufacturing Co. Site Lindsay Platte County Nebraska September 2008


THIRD FIVE-YEAR REVIEW REPORT

Lindsay Manufacturing Co. Site
Lindsay, Platte County, Nebraska

September 2008

by:

United States Environmental Protection Agency
Region 7
Kansas City, Kansas

with assistance from:

United States Army Corps of Engineers
Kansas City District
Kansas City, Missouri

Approved by:

Date:

CepliaTapia, Director
Superfund Division

U.S. EPA~R15gion 7



^40297842
Superfund

-------
TABLE OF CONTENTS

List of Abbreviations	iv

Executive Summary	v

Five-Year Review Summary Form.	vii

Five-Year Review Summary Form - Additional Information	 viii

I.	INTRODUCTION	1

II.	SITE CHRONOLOGY			2

III.	BACKGROUND	4

A.	Physical Characteristics	4

B.	Land and Resource Use	4

C.	History of Contamination			5

D.	Initial Response			5

E.	Basis; for Taking Action: Contaminants	;	5

IV.	REMEDIAL "ACTIONS	6

A.	Remedy Selection	6

B.	Remedy Implementation	7

C.	System Operation, Operation and Maintenance	9

V.	PROGRESS SINCE THE LAST FIVE-YEAR REVIEW	10

VI.	FIVE-YEAR REVIEW PROCESS	12

A.	Administrative Components	12

B.	Community Involvement			12

C.	Document Review	12

D.	Data Review			12

E.	Site Inspection			14

F.	Interviews	14

VII.	TECHNICAL ASSESSMENT	15

A.	Question A: Is the remedy functioning as intended by the decision documents?	15

B.	Question B: Are the exposure assumptions, toxicity data, cleanup levels, and	15

RAOs used at the time of the remedy selection still valid?	15

C.	Question C: Has any other information come to light that could call into	19

question the protectiveness of the remedy?	19

D.	Technical Assessment Summary	24

VIII.	ISSUES			;	24

IX.	RECOMMENDATION OF FOLLOW-UP ACTIONS	25

X.	PROTECTIVENESS STATEMENT	27

XI.	NEXT REVIEW	.'	27

ii

-------
Tables

Table 1 - Chronology of Site Events			2

Table 2 - Operating Costs	9

Table 3 - Summary of Pumping Volume 	12

Table 4 - Total Contaminant Mass Removal 	13

Table 5 - Groundwater Cleanup Levels 	 16 .

Table 6 - TCE/PCE Concentrations in Groundwater 	 17

Table 7 -Ecological Assessment for Domestic Cattle	21

Table 8 - Ecological Assessment for Wildlife 	21

Attachments

Attachment 1 - Site Location Map

Attachment 2 - Site Plan Showing Monitoring Wells and Other Figures
Attachment 3 - Graphs Showing Total VOCs and 1,4-dioxane vs. Time
Attachment 4 - Graphs Showing Metals vs. Time

mi

-------
List of Abbreviations

ALM

Adult Lead Methodology

AOIW

Add-on Inspector Well.

ARAR

Applicable or Relevant and Appropriate Requirement

CD

Consent Decree

CERCLA

Comprehensive Environmental Response, Compensation, and Liability Act

COCs

Contaminants of concern

COPCs

Contaminants of potential concern

DCA

Dichloroethane

DCE

Dichloroethene

EPA

United States Environmental Protection Agency

GAC

Granular Activated Carbon

HRC®

Hydrogen Release Compound

IEUBK

Integrated Exposure Uptake Biokinetic Model

MCL

Maximum Contaminant Level

MSL

Mean Sea Level

MSSL

Medium Specific Screening Level

MTBE

Methyl Tert Butyl ether

MW

Monitoring Well

NCP

National Contingency Plan

NDEC

Nebraska Department of Environmental Control

NDEQ

Nebraska Department of Environmental Quality

NOAEL

No-Observed-Adverse-Effect Level

NPDES

National Pollution Discharge Elimination System

NPL

National Priorities List

OIW

Original Interceptor Well

O&M

Operation and Maintenance

OMP

Operation and Maintenance Plan

PCE

Tetrachloroethene

PRG

Preliminary Remediation Goal

PRP

Potentially Responsible Party

QAPP

Quality Assurance Project Plans

QA/QC

Quality Assurance/Quality Control

RA

Remedial Action

RAO

Remedial Action Objective

RD

Remedial Design

RI/FS

Remedial Investigation/Feasibility Study

ROD

Record of Decision

RPM

Remedial Project Manager

SDWA

Safe Drinking Water Act

SVE

Soil Vapor Extraction

TCA

Trichloroethane

TCE

Trichloroethene

TIW

Third Interceptor Well

VOCs

Volatile Organic Compounds

WasteLan

EPA's database of Superfund Sites

iv

-------
EXECUTIVE SUMMARY

The remedy for the Lindsay Manufacturing Co. (LMC) Superfund site (Site) in Lindsay,
Nebraska, included a soil vapor extraction pilot, a full-scale soil vapor extraction system, a
groundwatei extraction and treatment system, a groundwater irrigation pilot system, a
remediation alternative pilot injection of hydrogen release compound (HRC1"'), and groundwater
monitoring. The Site achieved construction completion with the signing of the Preliminary
Closeout Report on August 2, 1995. The trigger for this Five-Year Review was the signature
date of the second Five-Year Review report on July 3, 2003.

The assessment of this Five-Year Review found that the remedy was constructed to meet the
performance standards and to implement the remedy outlined in the Record of Decision (ROD1).
The immediate threats to human health and the environment have been addressed and the remedy
remains protective. However, additional steps will continue to be implemented to address the
downgradient groundwater plume, to verify that no additional domestic water supplies are
affected, and to evaluate potential options for enhancement of the groundwater remediation
system both on and off of the facility property.

Consistent plume pumping, conducting timely activities concurrently to ensure that pumping
remains consistent (meeting substantive permit requirements, securing landowner access, and
installation and maintenance of equipment, etc. ), and adequate capture zone evaluation are issues
that have been raised in past Five-Year Reviews and site evaluations. These issues will be
reviewed to determine an appropriate approach to minimize interruptions in plume remediation.
In addition, a summary evaluation of laboratory and field Quality Assurance/Quality Control
(QA/QC) will be conducted to ensure that decisions are based on the best quality data and meet
the requirements of the Site Operation and Maintenance (O&M ) plan and Quality Assurance
Project Plans (QAPP).

LMC is performing voluntary Site activities to promote reuse of a portion of property. These
activities included soil sampling in an area of proposed building construction. The soil sampling
has shown some soil contamination exceeding U.S. Environmental Protection Agency (CPA)
Region 6 screening criteria. The results are being evaluated with EPA Region 6 soil-screening
criteria, EPA Soil Screening Level guidance, and current EPA Region 7 risk evaluation policy.
Further assessment will be conducted by LMC to refine the lateral and vertical extent. Given
that this area is in a location of ongoing remediation, protectiveness is not expected to be
affected. LMC will also evaluate the potential for Site-related vapor intrusion beginning with the
area proposed for reuse.

In areas south of the LMC, carbon tetrachloride and methyl tert butyl ether (MTBE) have been
historically detected in groundwater. The carbon tetrachloride has been historically detected in
the two wells located approximately 1,900 and 8,000 feet southeast, respectively, of the Village
of Lindsay. Its presence was identified in the second Five-Year Review for the Site. MTBE has
been historically detected in a domestic well located approximately 750 feet southeast of the
Village of L indsay. The detections of these chemicals have not exceeded federal safe drinking
water standards in the locations presented above. Based on the contaminants measured at the

-------
Site, the carbon tetrachloride and MTBE may be originating from another potential source or
sources located upgradient to, cross-gradient to, or near the current groundwater plume detection
locations. The Nebraska Department of Environmental Quality (NDEQ) and EPA site
assessment programs will be notified of these detections.

An EPA ecological technical evaluation was performed that suggested some additional surface
water sampling of Shell Creek. The current discharge is protective of acute aquatic criteria.
Acute aquatic criteria were determined appropriate given that the groundwater is mainly
discharged curing winter months and during periods of high rainfall. As part of the evaluation,
sampling of surface water was recommended to provide a greater confidence interval for chronic
aquatic criteria for metals and associated water hardness.

The 1990 ROD is silent with respect to institutional controls and their implementation.

However, it does indicate that options will be evaluated as part of implementation of the ROD to
ensure that drinking water wells are not installed in areas of the contaminant plume on- and off-
site. The site consent decree indicates that through additional response actions institutional
controls can be implemented. Therefore, the availability of institutional control mechanisms and
the opportunity to implement those at the site shall be reviewed.

In summary, the remedy at the Site is currently protective of human health and the environment.
There are no known nearby residents currently being exposed to the LMC contamination. At
present, LMC is conducting quarterly groundwater monitoring of all domestic supply wells
identified in the path of the groundwater plume or potential pathway. In addition, if any
domestic well is found to be contaminated as a result of the Site, LMC will provide alternate
water supplies.

Additional irrigation extraction wells have been installed to contain the migration of the
contaminant plume. Additional monitoring wells (MW) have been installed to define the extent
of the downgradient region of the groundwater pl ume. All other immediate threats have been
addressed by prior efforts.

Long-term protectiveness of the remedial action (RA) will be verified by continued inspections,
maintenance, and sampling of the groundwater treatment system at the Site as specified in the
O&M Plan. Current data indicate no exposure to groundwater contaminants above health-based
levels in the domestic wells at the Site. Two private domestic wells are currently being treated to
remove the contamination. Current monitoring indicates that the remedy is functioning based on
measured downgradient declining trends in contamination. Further review of plume capture will
be conducted.

-------
Five-Year Review Summary Form

TIFICATION

Site name (front WasteLAN): Lindsay Manufacturing Co.

¦n

EPA ID (from WasteLAN)-. NED068645696

SITE STAT

NPL statu*;: V Final Deleted ~ Other (specify)

Remediation status (choose all that apply): ~ Under Construction V Operating ~ Complete

Site Wide FYR V YES ~ NO

Construction completion date: 08 / 03 /1995

Has site been put into reuse? V YES NO

EPA ~ State ~ Tribe ~ Other Federal Agency

Author name: Robert J. Weber with support from U.S. Army Corps of Engineers, Kansas
City District (M. Saqib Khan, Project Manager)	

Author title: Remedial Project Manager Author affiliation: U.S. EPA, Region 7

Review period: 07 / 03 / 2003 to 07 / 03 / 2008

Date(s) of site inspection: 11/26/ 2007

Type of review:

V Statutory
Policy

V Post-SARA ~ Pre-SARA

~	Non-NPL Remedial Action Site

~	Regional Discretion

~ NPL-Removal only
~ NPL State/Tribe-lead

Review number: ~ 1 (first) ~ 2 (second) V 3 (third) ~ Other (specify)

Triggering action:

~ Other (specify)

~	Actual RA Onsile Construction at OU #_

~	Actual RA Start

~	Construction Completion

V Previous Five-Year Review Report

Triggering action date (from WasteLAN): 07 / 03 / 2003

Due date (fiveyears after triggering action date): 07 / 03 / 2008

vii

-------
Five-Ycar Review Summary Form - Additional Information

Issues

(1) LMC is performing voluntary site activities to promote reuse of a portion of their
property. These activities included soil sampling in an area of proposed building
construction on their facility. The soil sampling has detected chemicals in soil exceeding
EPA Region 6 screening criteria. The results are being evaluated with EPA Region 6 s:oil
screening criteria, EPA Soil Screening Level guidance, and current EPA Region 7 risk
evaluation policy. LMC has also expressed interest in further enhancing their
groundwater extraction and treatment system. LMC provided a streamlined evaluation, of
potential supplemental groundwater remediation alternatives.

(2) Groundwater contaminant migration has been delineated through a series of MWs and
exist ing irrigation wells. The groundwater plume has migrated approximately 14,000
feet (2.65 miles) from the LMC facility.

(3) Surface water discharges were approved by NDEQ to promote year-round pumping in
extraction well G127000 and EXT07-02. Both discharges are into Shell Creek.

(4) Vapor intrusion has not been assessed for occupied structures (offices, residences, etc.)
abov£ the contaminant plume. Volatile organic compounds (VOCs) including
chlorinated solvents comprise the soil and groundwater contamination on the facility and
in of)-site groundwater.

(5 ) In areas south of the LMC facility, carbon tetrachloride and MTBE have been historically
detected in groundwater. The carbon tetrachloride has been historically detected in two
wells located approximately 1,900 and 8,000 leet southeast, respectively, of the Village
of Li ndsay. Its presence was identified in the second Five-Year Review for the Site.
MTBE has been historically detected in a domestic well located approximately 750 feet
southeast of the Village of Lindsay. The detection levels of these chemicals have not
exceeded federal safe drinking water standards in the locations presented above. Based
on the contaminants measured at the Site, the carbon tetrachloride and MTBE may be
originating from another potential source or sources located upgradient to, cross-gradient
to, or near the current groundwater plume detection locations.

(6) Consistent plume pumping, conducting timely activities concurrently to ensure that
pumping remains consistent (meeting substantive permit requirements, securing
landowner access, and installation and maintenance of equipment, etc. ), and adequate
capture zone evaluation are issues that have been raised in past Five-Year Reviews and
evaluations. An evaluation of the sample shipments over the past five years has shown
that approximately half of the shipments received by the laboratory have had some errors
in consistency. These errors, while not severe enough to disqualify the data, do create
concerns regarding consistency in collection and handling of the samples.

(7) The 1990 ROD is silent with respect to institutional controls and their implementation.
However, it does indicate that options will be evaluated as part of implementation of the

Vlll

-------
ROD to ensure that drinking water wells are not installed in areas of the contaminant
pluir.e on- and off- site.

Recommendations and Follow-Up Actions

(1) Further assessment in the area of proposed construction activities will be conducted by
LMC to determine the lateral and vertical extent, current and future risks, and whether
any further action is warranted. Based on these facility data and LMC's interest in
enhancing groundwater treatment, LMC may also consider supplemental remediation in
other areas on the LMC facility property and other portions of the groundwater plume as
part of their assessment for enhancing groundwater treatment.

(2) Extraction well and discharge authorizations for G127000 and EXT07-02 were
completed by LMC to capture and treat the distal portion of the groundwater contaminant
plume. Both extraction wells are currently pumping continuously. If needed, additional
MWs may be required to assess plume capture and treatment. As identified above. LMC
may consider additional groundwater remedial alternatives.

(3) An ecological technical assessment was performed to evaluate the discharge from the
permitted location. Acute aquatic criteria are considered appropriate given that the
groundwater is mainly discharged during the winter months or during periods of high
rainfall. Groundwater in well G127000 does not exceed acute aquatic criteria for metals
and is well below conservative screening criteria for VOCs. However, additional
samples for metals and hardness data from surface water in Shell Creek shall be collected
and compared to surface water quality criteria. The additional data will provide a greater
confidence interval for chronic aquatic criteria.

(4) LMC shall identify occupied structures (office areas, residences, etc.) located above the
chlorinated solvent plume. LMC shall determine if vapor intrusion is likely in these
structures, based on EPA guidance, and, if so, shall conduct vapor intrusion sampling to
determine risk. If an increased risk is identified that threatens human health, LMC shall
take actions to reduce the risk which may also require a revision to the Site decision
documents. The evaluation of the potential for Site-related vapor intrusion will be
initiated in the area proposed for reuse.

(5 ) The locations of detections for carbon tetrachloride and MTBE will be referred to NDEQ
and EPA site assessment programs for further evaluation and/or assessment if determined
necessary.

(6) Consistent plume pumping, conducting timely activities concurrently to ensure that
pumping remains consistent (obtaining substantive permit requirements, securing
landowner access, and installation and maintenance of equipment, etc.), and adequate
capture zone evaluation are issues that have been raised in past Five-Year Reviews and
evaluations. These issues will be reviewed to determine an appropriate approach to
minimize interruptions in plume remediation. In addition, a summary evaluation of
laboratory and field QA/QC will be conducted to ensure that decisions are based on the
best quality data and meet the requirements of the Site O&M plan and QAPP.

-------
(7) The site consent decree indicates that through additional response actions institutional
controls can be implemented. Therefore, the availability of institutional control
mechanisms and the opportunity to implement those at the site shall be reviewed.

Protectiveness Statcnient(s)

The remedy at LMC in its present state is protective of human health and the environment. LMC
has taken several steps toward plume containment and stopping downgradient plume migration.
However, due to numerous technical and logistical difficulties, a downgradient extraction well
(G127000) could not be pumped continuously as planned, thus allowing the plume to migrate
further downgradient. Those difficulties have been addressed through a surface water discharge
point and associated authorization to discharge to Shell Creek during periods where irrigation
discharge is not possible. An additional extraction well, EXT07-02, was installed in October
2007 to prevent further plume migration. Also at that time, two additional MWs were installed
to evaluate plume migration. Permission to discharge extracted groundwater to Shell Creek at
the second location near the newly installed extraction well was obtained from NDEQ.

The contamination present at the Site (source area) has been addressed to date through the use of
soil vapor extraction and groundwater extraction and treatment. The extent of groundwater
contamination migrating from the facility has been generally determined and LMC has presented
potential alternatives to enhance the remediation of the groundwater plume.

LMC is providing drinking water and whole-house treatment for the owners of two domestic
supply wells that are contaminated. Monitoring of the groundwater and domestic water supplies
continue. Concentrations in the groundwater plume have been reducing over time based on site
monitoring.

Long-Term Protectiveness

Long-term protectiveness of the RA will be verified by continuing inspections, maintenance, and
sampling of groundwater at the Site as specified in the O&M Plan. Whole-house treatment
systems provided to the private homeowners with impacted wells have been monitored on a
quarterly basis to ensure the remedy is working as implemented. Future work will include
continued monitoring to evaluate the extent of the off-site contamination and possible
supplemental RAs. The potential for site-related vapor intrusion will be evaluated. Consistent
pumping of extraction wells, plume capture, and sample handling will be reviewed. The
opportunity for implementation of institutional controls at the Site shall be reviewed.

Other Comments

LMC will identify any remaining areas affected by Site contamination and present further
alternatives to address this contamination. EPA and NDEQ will work with LMC to ensure that
the migration of the plume is halted.

-------
LINDSAY MANUFACTURING CO. SUPERFUND SITE
LINDSAY, PLATTE COUNTY, NEBRASKA
THIRD FIVE-YEAR REVIEW REPORT

I. INTRODUCTION

The purpose of the Five-Year Review is to determine whether the remedy at a site is protective
of human health and the environment. The methods, findings, and conclusions of reviews are
documented in the Five-Year Review report. In addition, the Five-Year Review report identifies
issues found during the review, if any, and identifies recommendations to address them.

The Agency is preparing this Five-Year Review report pursuant to section 121 of (he
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 as amended
by the Superfund Amendments Reauthorization Act of 1986 (CERCLA) and the National
Contingency Plan (NCP). CERCLA section 121 (c) states:

If the President selects a remedial action that results in any hazardous
subsiances, pollutants, or contaminants remaining at the site, the President
shall review such remedial action no less often than each 5 years after the
initia tion 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 Agency interpreted this requirement further in the NCP. Specifically, 40 CFR section
300.430(t)(4)(ii) 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
action no less often than every five years after the initiation of the selected
remedial action.

The U.S. Environmental Protection Agency (EPA) Region 7 conducted the third Five-Year
Review of the remedy implemented at the Lindsay Manufacturing Co. (LMC) Superfund site
(Site) in Lindsay, Nebraska. This review was conducted by the Remedial Project Manager
(RPM) for the entire site by reviewing data collected from July 2003 through June 2008. This
report documents the results of the review.

This is the third Five-Year Review for the Site. The triggering action for this statutory review is
the signature date of the second Five-Year Review which was July 3, 2003. The third Five-Year
Review 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.

-------
II. SITE CHRONOLOGY

The following table presents the site chronology. More details on the remediation events shown
on the table are presented in Section III.

Tabic 1: Chronology of Site Events

Event

Date

Paul Zimmerer starts a sprinkler irrigation business that would later become
LMC.

1958

Plant constructed and LMC begins.

1961 - 1969

Incorporated and expanded.

1971 - 1972

DeKalb Agrasearch Inc., acquires LMC.

1974 •

LMC drills 4 test holes and a deep test hole. Proposed water treatment
facility, acidic groundwater and elevated temperatures. New public water
supply installed.

1983

Original Interceptor Well (OIW) installed. LMC proposed for National
Priorities List (NPL)

1984

Add-on Inspector Well (AOIW) installed.

1988

LMC begins Remedial Investigation/Feasibility Study (RI/FS).

1988

NPL Final.

1989

Proposed Plan to Public.

1990

Record of Decision (ROD).

1990

Consent Decree Signed, Remedial Design approved for Third Interceptor
Well (TIW).

1992

TIW installed date that triggered the first Five-Year Review.

1992

Design for soil vapor extraction (SVE) system approved. Remedial Action
(RA) Work Plan Approved.

1994

Inspection of SVE System.

1995

Established SVE clean up criteria. Incorporated irrigation as part of the
groundwater treatment system. New risk assessment by state.

1996

Determined that both Area 1 and Area 2 for SVE were approaching cleanup

1997

Decommissioned SVE in Area 2. Abandoned selected groundwater
monitoring wells (MW). Changed groundwater pumping schedule.

1998

Completed first Five-Year Review.

1998

Turned over TIW to land owner. Investigated additional areas where plume
could migrate. Identified additional domestic water supply wells where
plume migrated.

1999

Hydrogen Release Compound (HRC®) study approved and conducted on
plant site near treatment lagoon.

2001

Extraction system hit by ice storm. LMC requested that EPA and the
Nebraska Department of Environmental Quality (NDEQ) consider using
water for crop irrigation. Approval given.

2003

Initiated second Five-Year Review process.

2003

Conducted Five-Year Review Inspection. Held public availability session.

o
o

-------
Event

Date

Sampled 3 domestic water supply wells. Provided results to owners.

Quarterly groundwater sampling initiated. Samples collected during
February, May, August, and November of each year.

2003

Subsurface Investigation and Groundwater Monitoring Report Prepared.

2003

Whole-house treatment systems installed at two private residences and a new
domestic well also installed.

2004

Installation of one irrigation well (G127000) between two residences to
remove Volatile Organic Compounds (VOCs) in this portion of the lower
Sand and Gravel Aquifer. Pumping initiated in May 2004.

2004

Additional 9 MWs installed to delineate southern extent of plume

2006

LMC received discharge authorization from NDEQ for Extraction well
G127000.

2006

LMC began periodic discharging of water to Shell Creek.

2007

The 75l" quarterly groundwater sampling event occurred in August 2007.

2007

Initiated third Five-Year Review process.

2007

A second extraction well EXT07-02 installed in the south terminus of the
plume along with two MWs.

2007

LMC conducted sampling in support of an area of reuse on the facility
property and. presented plans for the intended reuse activity.

2007

LMC provided a voluntary evaluation of potential supplemental remedial
alternatives for enhanced groundwater remediation.

2007

LMC received approval from NDEQ for periodic surface water discharge to
Shell Creek from EXT07-02.

2008

LMC conducted additional sampling in support of reuse on the facility
property.

2008

EPA Certification of Completion of the Remedy.

Not Yet
Certified

-------
III.

BACKGROUND

A. Physical Characteristics

LMC operates a manufacturing facility on 42 acres and manufactures galvanized irrigation
systems. LMC is located in the Village of Lindsay, Platte County, Nebraska. The Village of
Lindsay lies on the east boundary of the Nebraska Sandhills and the local region is characterized
by rolling and dissected loess plains. The Site is surrounded on the north and east by farmland
and on the south and west by the Village of Lindsay. The Site is surrounded by farmland with an
approximate population of 3,000 within a 3-mile radius of the Site including the Village of
Lindsay. Wastes from the galvanizing process were discharged into an unlined earthen lagoori
for 11 years between 1971 and 1982. Prior to the RAs. contaminants of concern (COCs) at the
Site included zinc. iron, cadmium, sulfate, chromium, lead and VOCs including dichloroethene
(DCE), dich.loroethane (DCA). tetrachloroethene (PCE), trichloroethane (TCA), and
trichloroethene (TCE). People could have been exposed to contaminants by drinking water from
contaminated domestic wells, by direct conlact with contaminated water, by inhaling
contaminants released during water use. or by eating food in which contaminants had
bioaccumula.ted.

B. Land and Resource Use

The site is bounded on the north by farmland, on the east by Lindsay Village limits and
farmland, on the south by state highway 91. and a residential area of Lindsay, and on the west by
a tributary to Shell Creek, its greenbelt, and a residential area of Lindsay. In 1980, the total
population of Lindsay was 383 people. In 2000, the population of Lindsay was 276. Three
schools serve the Lindsay area. Land use within the city limits is primarily residential with the
exception of the Site and a community business and general commerce area located southwest of
the site. A public recreational and utility area is located approximately 0.2 miles southwest of
the Site. The utility area consists of the town public sewage treatment plant and ponds. The area
within a 2 mile radius of the Lindsay Village limits is primarily agricultural with an average of
three farmsteads per square mile. Groundwater elevation ranges from approximately 1.649 feet
Mean Sea Level (MSL) at MW 89-14 on-site near the northern portion of the LMC to
approximately 1,621 feet MSL at MW06-04, the furthest measured elevation point downgradient
based on 2007 data. The site is in the upland drainage area of Shell Creek. The western
boundary of the site is a tributary (Dry Creek) draining to Shell Creek which historically
received nearly continuous discharge from an interim groundwater remediation operation which
started in 1987. The treated waters were discharged under the facility's National Pollution
Discharge Elimination System (NPDES) permit. Groundwater under the current remedy is
extracted from wells MW89-12 and AOIW and the water is discharged through center pivot
irrigation systems rather than to Dry Creek. The interim groundwater remediation is no longer in
operation. Groundwater flow in the vicinity of Lindsay is generally to the south-southeast. The
aquifer saturated thickness ranges from approximately 35 to 60 feet. The groundwater flow
velocity is approximately 520 feet per year. Groundwater flow direction at the site is complex
because of the influence of several high-capacity wells.

-------
C. Histoi"y of Contamination

The site was. originally a gasoline station until the late 1950's. In 1958. Paul Zimmerer began
manufacturi ng irrigation systems. In 1961, the plant was constructed and in 1965, LMC began.
Disposal of materials from plant operations historically included discharge ofspent acid from the
galvanizing process. From the early 1970s to 1982, a spent acid stream was piped to an earthen
disposal pit located north of LMC/s galvanizing building. In 1982. Lindsay replaced the pit with
a new wastewater treatment facility designed to neutralize the spent acid. During the installation
of the wastewater treatment facility, four wells and a deep test hole were drilled and sampled in
January 1983. The samples revealed the groundwater had abnormal acidity and temperatures.
Lindsay reported these findings to NDBQ and began an investigation of the soils and
groundwater.

D. Initial Response

In 1984, Lindsay began operating a groundwater extraction and treatment system, whereby the
groundwater is treated by neutralizing and removing contaminants OIW. A second extraction
well AOIW was installed in 1989 to control off-site migration of contaminants and increase the
radius of influence. Lindsay began a study of the nature and extent of contamination remaining
at the Site and completed its study in 1990. The Site was proposed to the NPL on October 15,
1984. On October 4, 1989, the Site was placed on the final NPL listing. In response to a release
or a substantial threat of a release of hazardous substance(s) at or from the Site, Lindsay initialed
an RI/FS on January 5, 1988. The RI report was completed on June 20, 1990, and an FS Report
was completed on August 27, 1990. On July 10, 1990, the Proposed Plan identifying the
preferred remedy was presented to the public for their review and comment along with the final
Rl and draft FS reports.

E. Basis for Taking Action: Contaminants

Hazardous substances that have been released at the site include sulfate, zinc, iron, cadmium,
chromium, lead, and volatile organics from former process waste. Off-site groundwater contains
heavy metals including cadmium and zinc, and VOCs including 1,1-DCA; 1,2-DCA; 1,1-DCEi;
1,2-DCE; PCE; 1,1,1-TCA and TCE. These VOCs have been identified in the perched sand
channel in the northern half of the site, in clay soils in the area around the northern quarter of the
main plant, and between the main plant and the southern end of the galvanizing building. People
could be exposed to contaminants by drinking water from contaminated domestic wells, by direct
contact with contaminated water, by inhaling contaminants released during water use, or by
eating food in which contaminants have bioaccumulated.

-------
IV. REMEDIAL ACTIONS

A. Remedy Selection

EPA selected a remedy that included a pilot study to evaluate the feasibility of vacuum
extraction of on-site soils; installation of such a system, if it is deemed practical; enhancement
and utilization of the existing groundwater extraction and treatment systems; installation of
additional groundwater MWs; installation of an additional extraction well; and continued
monitoring of the groundwater collection/treatment system during cleanup activities. The ROD
for the Site was signed on September 28, 1990. The following Remedial Action Objectives
(RAOs) were developed from data collected during the remedial investigation to aid in the
developmeni: and screening of remedial alternatives to be considered for the ROD.

The purpose of the selected remedy in this ROD is to prevent current or future exposure to the
contaminated groundwater, to determine the practicability of reducing contaminant migration
from the soil into the groundwater, to implement soil vapor extraction if practicable, and to
restore the groundwater aquifer to MCL quality.

T he major components of the selected remedy for the affected
groundwater and soil include the following:

• A pilot study to evaluate the practicability of vacuum extraction of organic
compounds from contaminated soil;

• If determined to be practicable by EPA and/or NDEC, design and
implementation of full scale soil vapor extraction system based on pilot study
data;

• Enhancement of the existing groundwater extraction and treatment system by
e ither increasing the volume of on-site pumping from the existing extraction
wells or by the installation of an additional interceptor (extraction) well;

• Utilization of the existing groundwater treatment facility to remove
contaminants from the collected ground water;

• Installation of additional groundwater monitoring wells near irrigation well
#54278 to further delineate the groundwater contaminant plume;

• The monitoring of the groundwater collection/treatment system and the
groundwater contaminant plume during groundwater remediation activities;
and

• If appropriate to protect human health, EPA and NDEC will evaluate options,
as part of implementation of the ROD, to ensure that drinking water wells are
not installed in areas of the contaminant plume on- and off- site.

-------
B. Remedy Implementation

In a Conseir: Decree (CD) signed with EPA on April 9. 1992, the responsible party agreed to
perform the remedial design/remedial action (RD/RA) and pay past costs for cleaning up the site.
The RD was completed in conformance with the ROD. The RD was approved by EPA in 1992.
In early 1993, a third extraction well became operational to assist in pumping and treating the
groundwater. The SVE pilot study was concluded in 1993. Design of the full-scale SVE system
was completed in mid 1994, construction began shortly thereafter, and the SVE system became
operational in early 1995. In 1996. EPA evaluated the SVE system and determined site-specific
remediation levels had been attained and verified. Once verified, the SVE system equipment
was decommissioned and the site restored. EPA also evaluated the use of irrigation as a means
for disposal of the removed groundwater. The Nebraska Department of Health performed a risk
assessment and the results of this assessment determined that no unacceptable risks were
associated with using irrigation as a disposal option. EPA modified the groundwater pumping
and is allowing the pumped water to be beneficially reused for irrigation. This reduced the -
operating costs by approximately $100,000 annually. EPA completed the first Five-Year Review
of the site activities in 1998, which served to document the modifications to the extraction and
treatment system and also determined that the remedy remained protective of human health and
the environment.

LMC and EPA have sampled downgradient domestic water wells since 1990. The wells that
have been sampled are shown in Attachment 2, the Site Plan. In 1994, chlorinated solvents were
detected in a. domestic well. In 1995, this well was reported as nondetect for chlorinated
solvents. In 1998. the Preister domestic well showed the presence of tetrachloroethene above the
MCL. The other domestic wells remained free of site-related contamination.

In May 1998, LMC proposed conducting a three-month treatability study utilizing MW89-12 as
the extraction well. Lindsay determined that water could be extracted from this well at a rate of
60 gallons per minute. The extracted groundwater would be piped into the settling pond for air
stripping through a modified irrigation system. As the residual contamination is in the top of the
aquifer, pumping only the upper zone would be more efficient than pumping the entire aquifer.
In October 1998, EPA notified LMC that EPA and NDEQ supported the modification to use
MW89-12 as the extraction well provided all remediation wells (OIW, AOIW, and TIW) remain
in place until remediation levels are attained. In addition, EPA and NDEQ support the use of the
low level contaminated groundwater as irrigation water during the summer months. In the fall of
1998, MW89-12 removed 6.2 million gallons of contaminated groundwater from the aqui fer. In
March 1999, OIW removed 30.5 million gallons of water from the aquifer. In the next six
months, MW89-I2 removed 12.8 million gallons of contaminated groundwater. In August 1999,
several nearby domestic residents' water supplies were tested to determine if they contained
contamination from the Site. No new domestic supplies were found to contain contamination
from Lindsay above the MCLs.

In November 2000, EPA held discussions with LMC in order to explain the levels of
contamination present in selected MWs. MW89-14 is located in the sandy channel area of LMC
and the water in this well is from infiltration. MW89-15 is a deeper well and is screened in the
upper portion of the sand and gravel aquifer. Water levels in the sand and gravel aquifer

-------
fluctuate each summer based on seasonal irrigation demand. As the water levels drop,
groundwater in the perched sand channel and in the silty clays between the sand channel and the
aquifer drain in part to the aquifer. The silty clays between the sand channel and the aquifer
contain chlorinated solvent residuum that continues to release to the aquifer. In 2000, drought
conditions resulted in wider seasonal fluctuations in water levels in the aquifer. MW89-12 is in
an area with mixed penneability. The upper portion has very low permeability. The lower
portion of the screened interval is in the upper portion of the groundwater, therefore the levels of
the VOCs removed from the pumping of this well reflect the contamination as it drains into the
aquifer. See the letter report to EPA dated January 30, 2003, for further details. Remediation
efforts are focused on the capture of the VOCs present to protect the aquifer and to enhance the
degradation of the contamination present. In 2000, approximately 23,000,000 gallons of
contaminated groundwater were removed from MW89-12. Irrigation wells removed
contaminated groundwater, but the amount used for irrigation was not recorded. In 2001,
approximately 19.000,000 gallons of contaminated groundwater were removed from M'W
MW89-12. Irrigation wells were used to remove the contamination migrating from the plant site.

In 2001, Lindsay proposed additional work using an innovative technology, hydrogen release
compound or HRC™ to address the residual aquifer contamination. The HRC'"' was injected into
the aquifer at 22 locations. One hundred and fifty pounds of HRC "' was injected at each
location. This work was completed in September 2001. Quarterly groundwater monitoring was
modified to include the inorganic parameters used to assess the effectiveness of the HRC'81. The
groundwater monitoring program was modified to test for the inorganic parameters (dissolved
oxygen, oxygen release, potential sulfate, sulfide, dissolved iron, total iron) at MWs close to the
injection locations. Based on data collected through February 2003, the Held parameters
monitored did not clearly indicate a change in the subsurface chemistry. This was thought to be
due to the soils at the site or the drought conditions which would have accelerated the movement
of the HRCK from the treatment zones into the aerobic aquifer. EPA completed the second Five-
Year Review of the site activities in 2003, which served to document the modifications to the
extraction and treatment system and also determined that the remedy remained protective of
human health and the environment.

The analytical results from the 58th to the 75th quarters are presented in Attachment 3 of this
document. The results indicated that contaminants of concern (COCs) are being removed via
pump and treat system from the source area and downgradient irrigation/pumping wells. During
the past five years, the plume has migrated farther downgradient. LMC installed two extraction
wells to contain the plume. The first well, G127000, was not initially pumped as planned and
thus was not able to contain the plume. However, the performance of the first well has shown
improvement since 2007. LMC installed one additional extraction well, EXT07-02, in October
2007 and the results are pending.

This Five-Year Review, the third Five-Year Review, of the Site activities completed from 2003
to the signing of this document in 2008, serves to document the modifications to the extraction
and treatment system and other activities at the Site. This document also determines that the
remedy remains protective of human health and the environment.

-------
C. System Operation, Operation and Maintenance

LMC is conducting groundwater monitoring and maintenance activities pursuant to the
Operation and Maintenance Plan (OMP) that was approved by EPA in the 1992 CD. The
primary activities associated with the OMP include the following:

• Inspect and maintain the condition of the MW network, the extraction system, and the
iirigation system used for disposal of the extracted water;

• Conduct quarterly groundwater monitoring until the MCLs are reached;

• Prepare reports of the groundwater monitoring information and send to EPA on a
biannual basis.

Table 2 below provides a yearly summary of the Operation and Maintenance (O&M) costs.

These include monitoring and sampling efforts, installation of extraction wells, MWs,
maintenance of monitoring and extraction wells, and costs of preparing reports.

Table 2: Operating Costs

Year

2003

2004

2005

2006

2007

Consultants Fees
& Expenses

$114,885

$91,622

$91,580

$121,583

$152,037

Lab Fees

25.178

17,616

39.766

35,945

128.497

Construction &
Operational Fees

36,590

202,004

122,067

196,927

95,497

Grand Tota ls

$176,653

$311,241

$253,413

$353,455

$375,711

Table 2 reflects costs associated with specific tasks. The O&M costs in.the ROD were estimated
at $636,600 per year. The time frame for this estimate was greater than five years of O&M.
Although the costs have not exceeded this estimate, they have gradually increased during the
past five years. This is primarily due to increase in extraction and monitoring network,
additional consulting charges, engineering time, and laboratory costs.

-------
V.

PROGRESS SINCE THE LAST FIVE-YEAR REVIEW

During the last five years, LMC continued to perform all the tasks including pumping of selected
wells, installation of additional extraction wells, MWs, installation of Granular Activated Carbon
(GAC) units on private drinking water wells, and other tasks requested and mutually agreed-
upon by EPA and LMC. The following is a summary of all additional work completed at this
Site:

• February 2004: Installation of one irrigation well (G127000) between two residences to
remove VOCs in this portion of the lower Sand and Gravel Aquifer. Pumping initiated in
May 2004;

• August 2004: 1,4-Dioxane sampling was initiated in selected wells. 1,4-Dioxane was
detected in several of the extraction and MWs;

• November 2004: An additional three MWs were installed. The purpose was to delineate
the eastern edge and southern extent of VOCs in groundwater;

• March 2006: Nine additional wells (MW06-01 through MW06-09) were installed;

• March 2006: LMC received discharge authorization from NDEQ to discharge extracted
water from G127000 into Shell Creek;

• March 2006: MWs MW89-14 and MW89-15 were plugged and abandoned and replaced
with M Ws MW06-10 and MW06-11;

• 2007: LMC began discharging groundwater from G127000 to Shell Creek per Discharge
Authorization. Since August 2007, this well has been pumping continuously at 400gpm;
Lindsay is in the process of increasing the extraction rate in this well;

• October 2007: A second extraction well EXT07-02 and two additional MWs were
installed in the south terminus of the plume.

Significant progress has been made towards delineating the downgradient end of the plume.
During this review period, additional attempts were made to understand the nature and extent of
the groundwater plume. Steps were taken to control further downgradient migration of the
groundwater plume. Impacted private wells were connected to treatment systems and where
applicable, new wells were installed. Other domestic water supply wells were tested in the areas.
No contamination was detected in those wells.

LMC is performing voluntary site activities to promote reuse of a portion of property. These
activities included soil sampling in an area of proposed building construction. The soil sampling
has shown some soil contamination exceeding EPA Region 6 screening criteria. The results are
being evaluated with EPA Region 6 soil screening criteria, EPA Soil Screening Level guidance,
and current EPA Region 7 risk evaluation policy.

-------
Further assessment will be conducted by LMC to determine the lateral and vertical extent, any
current and future risks, and if any further action is warranted. LMC will also evaluate the
potential for vapor intrusion at the Site, beginning with the area proposed for reuse.

LMC has also expressed interest in further enhancing their groundwater extraction and treatment
system. LMC provided a streamlined evaluation of potential supplemental groundwater
remediation alternatives for future evaluation.

-------
VI. FIVE-YEAR REVIEW PROCESS

A. Administrative Components

The third Five-Year Review Team was led by Robert Weber, the EPA remedial project manager
(RPM) for this site. The review was conducted between September 11, 2007, and the signature
date of this report. The review included document review, data review, site inspection,
community involvement, local interviews, and report development and review.

B. Community Involvement

A newspaper advertisement was placed in the Columbus Telegram on November 27, 2007,
notifying the public of the start of the Five-Year Review process. Upon completion of this
report, a notice will be placed in the local newspapers announcing the completion of the Five-
Year Review and its availability at the local library (or other appropriate location) and EPA
Region 7 Records Center. The EPA will hold a public availability session to discuss the Five-
Year Review Report and findings.

C. Document Review

The Five-Year Review included a review of all relevant documents including decision
documents, site investigation documents. O&M records, and monitoring data.

D. Data Review

Groundwater monitoring was originally initiated at this site in 1982 and continues to date. This
section discusses the groundwater monitoring results from April 1, 2003, to September 30, 2007.
Quarterly sampling events are conducted in February, May, August, and November of each year.
The data review includes the biannual report received by EPA on October 19, 2007. Any
biannual reports received after this dale will be included in the next Five-Year Review. Table 3
shows amount of contaminated water (gallons) that was pumped during the last five years.

Table 3: Suimmary of Pumping Volume (gallons):

Well
No./Year

2003

2004

2005

2006

2007

Pumping
Months

April -
December

April -
August

MW89-12

7,748,652

7,737048

16,714,685

20,959,476

10,426,999

AOIW

45,245,400

99,634,396

101,254,700

52,475,400

G127000

68,896171

63,683,765

49,063,341

35,191,774

TOTAL

7,748,652

121,878,619

180,032,846

171,277,517

98,094,173

-------
Table 4 provides the tolal VOCs/1,4-dioxane removed from April 2005 through August 2007
from the three extraction wells: MW89-12, AOIW. and G127000. Mass removal data from April
2003 to March 2005 is not available.

Tabic 4: Total Contaminant Mass Removal (lbs):

Well No./Ycar

Contaminant

2005

2006

2007

MW89-12

Total VOCs (lbs)

57.800

63.600

22.700

1,4-dioxane (lbs)

4.900

6.300

2.200

AOIW

Total VOCs (lbs)

83.200

53.500

39.300

1,4-dioxane (lbs)

7.500

5.300

3.600

C. 127000

Total VOCs (lbs)

55.500

37.800

14.600

1,4-dioxane (lbs)

0.393

0.735

0.313

Table 4 shows total VOCs, as well as 1,4-dioxane, removed from the groundwater during the
past three years. During this time over 320 lbs of total VOCs have been removed from the
source area groundwater. Approximately 107.9 lbs of VOCs were also removed from the
downgradient extraction well.

Volatile Organic Compounds Results

Total VOCs concentration over time in extraction and MWs was plotted for each monitoring and
extraction well and is illustrated graphically in Attachment 3. Figure 3.1 presents total VOC
concentration detected in the MWs in the upper shallow perched sand channel. Figures 3.2
through 3.5 illustrate VOC concentrations in on-site extraction and MWs. Although
contamination still exists in the groundwater, it appears to be decreasing in these wells. Figures
3.6, 3.7 and 3.8 show VOCs concentrations in off-site extraction and MWs. The overall VOCs
levels exhibit a declining trend for most wells. Figures 3.9 and 3.10 show levels of 1, 4-dioxane
detected in the source area wells; however, contamination is declining. Figure 3.1 1 illustrates
low levels of 1,4-dioxane observed in the downgradient MWs.

In areas south of LMC, carbon tetrachloride and methyl tert butyl ether (MTBE) have been
historically detected in groundwater. The carbon tetrachloride has been historically detected i:n
two wells located approximately 1.900 and 8,000 feet southeast, respectively, of the Village of
Lindsay. Its presence was identified in the second Five-Year Review for the site. MTBE has
been historically detected in a domestic well located approximately 750 feet southeast of the
Village of Lindsay. The detections of these chemicals have not exceeded federal safe drinking
water standards in the locations presented above. Based on the contaminants measured at the
Site, the carbon tetrachloride and MTBE may be originating from another potential source or
sources located upgradient to, cross-gradient to, or near the current groundwater plume detection
locations.

-------
Metals Results:

Metal results are illustrated graphically in Figures 4.1 through 4.9 (Attachment 4)

The data analysis reveals that cadmium, chromium, lead, iron, and zinc are among the major
contaminants present at the site. Data evaluation indicates that with the exception of iron and
zinc (Graph 15). the concentration of metals in the north area wells remains significantly low.
The iron and zinc levels are higher in MW06-11 and MW89-15. Chromium, in wells installed
along highway 91 (including MW06-05, MW06-06, MW06-07, MW06-08, and MW06-09), '
although present in low levels, shows increasing trends.

E. Site Inspection

An inspection was conducted at the Site by EPA and NDEQ on November 27, 2007. The
purpose of the inspection was to assess the protectiveness of the remedy, evaluate current site
property conditions and areas within and near the downgradient groundwater plume, locate
extraction wells and MWs, locate discharge areas including pivot irrigation locations and Shell
Creek, and view the whole-house treatment systems installed in residences on-site.

The Site includes the LMC where public access is limited, the downgradient off-facility-property
areas of the groundwater contamination plume, and any areas used to implement the remedy.
There are no institutional controls for the Site including the facility property.

The inspection of the Site revealed no major O&M problems. The facility is a manufacturing
site with limited access. Groundwater information is being presented to EPA and NDEQ on a
biannual basis, so no documents were reviewed by EPA or NDEQ during the Site inspection.
Extraction wells, including center-pivot irrigation systems and MWs, were found to be in good
condition. A whole-house treatment system on a residential property was inspected and found to
be operating as designed. A surface water discharge point was inspected and found to be
operating as designed. A new extraction well, EXT07-02. being constructed and at the time of
the inspection was not operational. Evidence of water transmission piping trenching and power
poles for electric utility service was observed lor this well.

In addition to the Site inspection and on the day of the inspection, EPA collected a groundwater
sample from an existing irrigation well within the groundwater plume at the request of the
private property owner to verify past results. The results from this sampling event were
submitted to the private property owner and provided to LMC to incorporate into the site data
set. The results show a decrease in contamination at this location since the last sampling event.

F. Interviews

During the Site inspection, EPA conducted in-person interviews with three LMC personnel. The
responses were positive and indicated that progress was being made at the Site with the
installation of an additional extraction well. It was mentioned that overall, contaminant
concentrat ions were shown to be decreasing. It was noted that the scope of sampling had
increased including more households to the south. System optimization was mentioned in the
form of groundwater How rate adjustment and that the groundwater plume has been delineated.
No major issues were cited other than the usual weather-related concerns (e.g. temperature and
precipitation, etc.).

-------
VII. TEC HNICAL ASSESSMENT

A. Question A: Is the remedy functioning as intended by the decision documents?

The review of biannual reports, applicable or relevant and appropriate requirements (ARARs),
risk'assumpi.ions, and the results of the Site inspection indicate that the remedy is functioning as
intended by the ROD. This report consists of the third Five-Year Review. The first and second
Five-Year Reviews present information that documents the remediation of source area soils with
SVE technology. However, the groundwater remained contaminated at the LMC. The VOC
plume migrated further downgradient. Lindsay has taken additional steps toward preventing the
further migration of the groundwater contaminant plume. Since these additional steps for the
distal portion of the plume were taken at the end of this Five-Year Review period, the full impact
of these efforts were not apparent at the time of this report. Quarterly monitoring of existing
MWs and domestic supply wells will continue until remediation levels are attained.

Optimizatio n of the existing pump and treat system was observed in the form of pumping rate
ad justment during this review. Direct discharge of the extracted groundwater from the
downgradient well provides longer pumping duration which in turn will assist with plume
capture. Although the downgradient extraction well G127000 did not operate for the period
intended, it was able to remove a significant quantity of VOCs from the groundwater (see Table
4). With the installation of additional downgradient MWs. the existing MW network provides
sufficient data to evaluate the effectiveness of the remedy on plant property and the
downgradient end of the plume. Additional characterization may be required as data are
collected.

B. Question B: Are the exposure assumptions, toxicity data, cleanup levels, and
RAOs used at the time of the remedy selection still valid?

EPA Region. 7 Risk Assessors conducted a technical assessment in support of the five-year
review of the Site. The following responses were prepared based on data submitted.

Have there been changes to risk-based cleanup levels or standards identified as Applicable or
Relevant and Appropriate Requirements (A RA Rs) in the Record of Decision (ROD) thai call into
question the protectiveness of the remedy?

-------
Table 5: Groundwater Cleanup Levels for Lindsay Manufacturing Site:

COPC identified in
ROD

Cleanup Level in
ROD (jig/L)

Current IV1CL or
Secondary
Standard
(Hg/L)

Maximum
Concentration
(Hg/L)

1,2-dichloroethane
(DCA)

0.6

1, 1-dichlooethene
(DCEi)

930

17,v-1, 2-
dichloroethene

72 (total 1,2-DCE)

trans-1,2-
dichloroethene

100

72 (total 1.2-DCE)

1,U-

trichloroe thane
(TCA)

200

300

6.5-8.5

4.96 (minimum)

Zinc:

5000

95,200

SulfaLe

250,000

250.000

1.100,000

Cadmium

Chromium (total)

100

279

Lead

Only groundwater cleanup levels were established for the Site. All of the risk-based cleanup
levels for groundwater are based on human health exposures. The groundwater ARARS are
based on maximum contaminant levels (MCLs) and Secondary Drinking Water Regulations
established under the Safe Drinking Water Act (SDWA). For three of the contaminants of
potential concern (COPCs) - cadmium, chromium, and lead - the health based standards have
changed since the completion of the ROD. The groundwater cleanup levels established in the
ROD (Table 5) are the current regulatory standards (EPA, 2006a) and the highest contaminant
concentrations identified in the biannual report (URS, 2007c). Note that Secondary MCLs are
not health based, but instead reflect nuisance levels based upon taste, odor, color, etc. Secondary
MCLs constitute nonenforced standards or guidelines. It should be noted that cleanup levels do
not appear to have been established in the 1990 ROD for several contaminants for which
regulatory values exist (Table 6).

Table 6: TCE/PCE Concentration in Groundwater:

Contaminant

Maximum Concentration
(*ig/L)

Regulatory' Standard or
Screening Value (ng/L)

TCE

PCE

1.100

Iron

101.000

1,4-dioxane

140

6.1

-------
Are there newly promulgated standards that call into question the protect iveness of the remedy?

Please see T able 5 for groundwater standards that have changed since the development of the
ROD.

Have TBCs used in selecting cleanup levels at the site changed in way that could affect the
protect iveness of the remedy?

TBCs were not considered in selecting cleanup levels for this site. Whole-house treatment
systems were installed at two residences whose drinking water wells were impacted by the
groundwater contamination plume. Therefore, even though Tables 5 and 6 show elevated levels
of contamination, the health of nearby residents is protected by the current remedy.

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)?

Land use has not changed at the site nor is any future land use change apparent.

Have any human health 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 protect iveness of the remedy?

Groundwater in the area is relatively shallow. Table 4 of the biannual report (URS, 2007c)
shows that elevated concentrations of VOCs continue to be present in the groundwater. EPA's
subsurface vapor intrusion guidance (EPA, 2002) contains generic screening values against
which site contaminant concentrations can be compared to see if a potential exists for the
intrusion of VOCs into above ground structures at levels of possible concern. A comparison of
the VOC co ncentrations (identified in Table 4 of the biannual report) with the screening values
in EPA's vapor intrusion guidance indicates that the potential for subsurface vapor intrusion may
exist. The vapor intrusion pathway was not evaluated in the original baseline risk assessment for
the site.

LMC received a discharge authorization from NDEQ in March 2006 to pump groundwater from
G127000 to Shell Creek. Therefore, aquatic receptors in Shell Creek may now come in contact
with the trea ted groundwater. To address this new route of exposure, analytical results from
discharges to Shell Creek were compared to risk-based ecological benchmarks (see Question C).

Are there newly identified contaminants or contaminant sources?

Table 4 of the biannual report (URS 2007c) shows elevated concentrations of both TCE and
PCE. These two contaminants were identified as COPCs in the original risk assessment.
However, it appears that cleanup levels were not established for either of these contaminants in
the 1990 ROD. Similarly, a secondary drinking water regulation for iron exists, yet iron does not

-------
appear to be included in the ROD. Finally, page 10 of the biannual report states that 1,4-dioxane
has been identified in groundwater at concentrations which exceed the preliminary remediation
goal (PRG) established in the EPA Region 6 screening levels (EPA, 2006b). Table 6 shows the
maximum concentration of each of these contaminants presented in Table 4 of the biannual
report, as well as the current MCLs for the TCE and PCE. the current secondary drinking water
standard for iron, and the current EPA Region 6 screening level for 1,4-dioxane (EPA, 2008).

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)?

No unanticipated toxic by-products have been identified.

Have physical site conditions or the understanding of these conditions changed in a way that
could affect the protect iveness of the remedy?

A comparison of Figure V-5 in the ROD with Figure 1 1 in the biannual report (URS, 2007c)
indicates that the groundwater contamination plume has migrated approximately 9000 feet
downgradient since the ROD was finalized. Several additional MWs have been installed in and
near the plume since the ROD, and the installation of another extraction well at the south
terminus of :he groundwater plume is planned (URS, 2007b). This effort will further delineate
the extent of the groundwater contamination, halt the downgradient migration of the plume, and
prevent additional water supply wells from being impacted.

Other than discharges of groundwater to Shell Creek, no other changes in the physical site
conditions exist.

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?

Many of the noncarcinogic and carcinogenic toxicity factors identified in the ROD have been
updated in the past 17 years. However, these changed toxicity values for VOCs do not impact
the protectiveness of the remedy. The toxicity value for lead has also changed, and an action
level for lead in drinking water supplies has been developed. As shown in Table 5 above, the
current action level for lead in drinking water is 15 (ig/L.

Have other contaminant characteristics changed in a way that could affect protectiveness of the
remedy?

Other changes to contaminant characteristics have not been identified that could impact the
protectiveness of the remedy.

-------
Changes in Risk Assessment Methods

Have standardized risk assessment methodologies changed in a way that could effect the
protectiveness of the remedy?

EPA has significantly revised its dermal risk assessment guidance since the completion of the
original risk assessment. Region 7 also uses a different approach when estimating the health
risks from inhalation of VOCs during household use of contaminated groundwater ( i.e., bathing,
showering, cooking, etc.). Several exposure assessment input parameters in the original risk
assessment are slightly different than values currently used. EPA also now uses the Integrated
Exposure Uptake Biokinetic Model (IEUBK) and the Adult Lead Methodology (ALM) to
evaluate potential health risks from lead and to help establish cleanup levels. Finally, EPA has
developed and implemented risk assessment guidance which evaluates the vapor intrusion
pathway. These changes in methodology do not adversely affect the protectiveness of the
remedy.

C. Question C: Has any other information come to light that could call into
question the protectiveness of the remedy?

Have newly found ecological risks been found?

Additional ecological pathways of concern that were not addressed in the original ecological risk
assessment include direct exposure to aquatic life via groundwater discharge to Shell Creek,
exposure to wildlife consuming water from Shell Creek, and exposure to livestock via ingestion
of groundwa ter in stock wells. Tables 7 and 8 document that these potential ecological exposure
pathways have been addressed. First, the maximum concentrations of contaminants in stock
wells were compared to No-Observed-Adverse-ElTect Level (NOAEL) benchmarks for cattle.
Three scenarios are presented. First, NOAEL water concentrations were calculated for a calf
weighing an average of 50 kg that drinks a portion of its water from stock wells per day. The
next scenario is a pregnant cow weighing an average of 600 kg drinking a portion of her water
from the stock well a day. Finally, the highest exposure scenario is for a dairy cow weighing 600
kg and drinking 100 liters per day from the stock well. All three scenarios assume the food was
not contaminated and the only source of exposure is through drinking water. A NOAEL water
concentration was not calculated for iron, but the maximum level of iron from the site is far
above levels that may cause taste or appearance issues. Also, a NOAEL was not available for
1,1-DCA, so a NOAEL water concentration was not calculated. However, based on the
NOAELs for other PCE/TCE break-down products, it is unlikely that 1,1 -DCA would present a
potential risk to cattle.

Next, the average groundwater concentrations of contaminants discharged to Shell Creek were
compared to screening benchmarks for aquatic life as well as to NOAELs for wildlife that may
be drinking I'rom the creek. This comparison shows that concentrations of VOCs are well below
conservative aquatic screening benchmarks and wildlife NOAELs. To determine if metal
concentrations are meeting water quality criteria, the concentrations from G127000 were
evaluated. Cadmium concentrations were all nondetect. The detection limit used for cadmium is
above chron ic criteria but below acute criteria.

-------
Average lead and zinc concentrations detected at G127000 were above chronic criteria but well
below acute criteria. At the highest hardness values of 400 ppm CaCCh, lead and zinc
concentrations fall below chronic criteria.

It may be appropriate to use acute criteria given that the groundwater is mainly discharged
during the winter months or during periods of high rainfall. Groundwater in well G127000 does
not exceed acute criteria for metals and is well below conservative screening criteria for VOCs.
Metals and hardness data from surface water in Shell Creek compared to the water quality data
and data from a suitable reference location upstream is recommended. This comparison would
allow a more confident determination of the level of ecological risk posed by discharging
groundwater into the creek.

-------
Table 7: Ecological Assessment for Domestic Cattle

Contaminant

Maximum
Concentrations
in Stock Wells
(HS/L)

Calf NOAEL
(Hg/L)

Cow NOAEL
(Hg/L)

Dairy Cow
NOAEL (jiig/L)
100 L/day

1,2-DCA

1.0

1,2e+5

6.5e+4

2.5e+4

1,1 -DCE

1.3e+5

7.2e+4

2.8e+4

1,1, DCA

1,2-DCE

2.5

l.le+5

5.9e+4

2.3 e+4

1,1,1-TCA

2.5e+6

2.3e+6

5.0e+6

Zinc

0.032

7.1e+5

3.8e+5

1.5e+5

Cadmium

0.002

4.5e+3

2.4e+3

932

Chromium

0.005

1,5e+4

7.8e+3

3.1 e+4

Lead

0.002

3.6e+4

1,9e+4

7.5e+3

TCE

1.5

1.7e+3

905.6

353

PCE

130

3.5e+3

1.8e+3

710

Iron

0.05

1,4-dioxa;:ie

2.2e+3

1,2e+3

466.1

Table 8: Ecological Assessment for Wildlife

Contaminant

*Maximum
Concentrations
in stock wells
(Hg/L)

Aquatic
Screening
Benchmark
(HS/L)

Whitetail Deer
NOAEL
(Hg/L)

Wild Turkey
NOAEL (|u.g/L)

1,2-DCA

0.2 .1

910

1,2e+5

5.3e+5

1.1-DCE

7.5 J

1.3e+5

1,1, DCA

0.6 J

1.2-DCE

2.9

970

1.0e+5

1.1,1-TCA

9.8 J

2.4e+6

Zinc

120

80.Oh

6.9e+5

4.4e+5

Cadmium

2.0 U

0.27h

4e+3

4.4e+4

Chromium

5.0 U

1,4e+4

3.1 e+4

Lead

23.0

3.0h

3.4e+4

1,2e+5

TCE

0.2 UJ

350

1,6e+3

PCE

7.5 J

120

3.3e+3

Iron

48400

1000

1,4-dioxane

5.0 U

2.2e+4

2.1e+3

h - Criteria calculated based on hardness
U - Nondetect

* Metal data taken from G127000 samples, VOC Data taken from Shell Creek.

-------
Are (here impacts from natural disasters (e.g.. a I OO-year flood)'

No natural disasters have been recorded on this site.

Has any other information come to light which could affect the protectiveness of the remedy?

LMC has submitted documents (URS, 2007d) indicating their intention to reclaim the land near
the northern boundary of the facility for future expansion of facility operations. This area
formerly contained an earthen disposal pit which received waste from the galvanizing process
and portions of a burn pit which was also used to dispose of facility waste materials. The extent
of soil contamination resulting from the previous waste disposal operations is being evaluated..
At this time, the surface soil and shallow subsurface sampling results are not available to
evaluate the residential and commercial/industrial pathways. The evaluation of residential and
some industrial scenarios require near-surface soil samples; the evaluation of exposure to utility
or construction workers requires samples from the top ten feet of soil. Figures 4.2-1. 4.2-2 and
4.2-3 of the RI report present isopleths maps of VOC contamination in soil borings but Table B
shows that those results are from deep, rather than shallow, soil borings. Similarly, the results of
limited sampling in the areas of Cell 1 and Cell 2 show the presence of contamination,
particularly TCE and PCE (URS, 2007d), but no samples were taken at the surface or from
depths greater than six feet. Lindsay will submit plans for additional sampling in the area of
proposed reuse/reclamation which includes the former bum and disposal pits. The results of the
additional sampling will be screened against EPA Region 6 MSSLs to determine if further on-
site activities are warranted.

Lindsay's submitted a voluntary evaluation of potential supplemental groundwater remediation
alternatives. Lindsay may wish to evaluate additional areas of the groundwater plume and
source area as part of these supplemental alternatives to determine whether any residual
materials ex ist and whether treatment of those materials would enhance the groundwater
extraction system effectiveness. Areas where residual materials may be present include a former
TCA tank site maintenance area and an area near the back door of the main plant where solvents
and other degreasing compounds may have been discarded.

Consistent plume pumping, conducting timely activities concurrently to ensure that pumping
remains consistent (meeting substantive permit requirements, securing landowner access, and
installation and maintenance of equipment, etc.), and adequate capture zone evaluation are issues
that have been raised in past Five-Year Reviews and site evaluations. These issues will be
reviewed to determine an appropriate approach to minimize interruptions in plume capture. In
addition, a summary evaluation of laboratory and field Quality Assistance/Quality Control
(QA/QC) will be conducted to ensure that decisions continue to be made based on the best
quality data and meet the requirements of the site O&M plan and QAPP. An evaluation of
sample shipments over the past five years has shown that approximately half of the shipments
received by the labs had some errors in consistency when received by the laboratory. These
errors, while not severe enough to disqualify the data, do create concerns regarding consistency
in collection and handling of the samples.

-------
The 1990 ROD is silent with respect to institutional controls and their implementation.

However, it does indicate that options will be evaluated as part of implementation of the ROD to
ensure that drinking water wells are not installed in areas of the contaminant plume on- and off-
site. The Site consent decree indicates that through additional response actions institutional
controls can be implemented. Therefore, the availability of institutional control mechanisms and
the opportunity to implement those at the Site shall be reviewed.

-------
D. Technical Assessment Summary

VIII. ISSUES

Issue

Currently Affects
Protectivencss
(Y/N)

Affects Future
Protectiveuess
(Y/N)

LMC is perforning voluntary site activities. These activities included
soil sampling in an area on their facility to promote reuse. The proposed
reuse activity includes construction of a new building. The soil sampling
has detected chemicals in the soil exceeding EPA Region 6 Medium
Specific Screening Level (MSSL) screening criteria. The results are
being evaluated with EPA Region 6 soil screening criteria. EPA Soil
Screening Level guidance, and current EPA Region 7 risk evaluation
policy. LMC has also expressed interest in further enhancing their
groundwater extraction and treatment system. LMC provided a
streamlined evaluation of potential supplemental groundwater
remediation alternatives.

Groundwater contaminant migration has been delineated through a series
of MWs and existing irrigation wells. The groundwater plume has
migrated approximately 14.000 feet (2.65 miles) from LMC.

Surface water discharges were approved bv NDEQ to promote year-round
pumping in extraction wells G 127000 and EXT07-02. Both discharges
are into Shell Creek.

Vapor intrusion has not been assessed for occupied structures above the
contaminant plume. VOCs including chlorinated solvents comprise the
soil and groundwater contamination on the facility and in the groundwater
off the facility.

In areas south of LMC, carbon tetrachloride and MTBE have been
historically detected in groundwater. The carbon tetrachloride has been
historically detected in two private wells located approximately 1.900 and
8,000 feel southeast, respectively, of the Village of Lindsay. Its presence
was identified in the second Five-Year Review for the site. MTBE has
been historically detected in a domestic well located approximately 750
feet southeast of the Village of Lindsay. The detections of these
chemicals have not exceeded federal safe drinking water standards in the
locations presented above. Based on the contaminants measured at the
Site, the enrbon tetrachloride and MTBE may be originating from another
potential source or sources located upgradient to, cross-gradient to, or
near the current groundwater plume detection locations.

Consistent plume pumping, conducting timely activities concurrently to
ensure that pun ping remains consistent (obtaining substantive permit
requirements, securing landowner access, and installation and
maintenance of equipment, etc.), and adequate capture zone evaluation
are issues that have been raised in past Five-Year Reviews and
evaluations. Ail evaluation of the sample shipments over the past live
years has shown that approximately half have had some errors in
consistency vvh.-n received by the laboratory. The errors have not been
severe enough to disqualify portions of the data sets, but have been
identified as concerns regarding consistency in collection and handling of
the samples.

The 1990 ROD is silent with respect to institutional control s and their
implementation. However, it does indicate that options will be evaluated
as part of implementation of the ROD to ensure that drinking water wells
are not installed in areas of the contaminant plume on and off site.
Institutional controls have not been implemented at the Site due to a
historical absence of possible implementing mechanisms.

-------
IX. RECOMMENDATION OF FOLLOW-UP ACTIONS

Issue

Recommendations/ Follow up Actions

Party

Responsible

Oversight
Agency

!\ ,1: i ~ * r* _ * ~

IT 1 UV. 3 lull t; L/dlC

Affects
Protectiveness?
(Y/N)

Current

Future

LMC voluntary site source
area reuse activities and
voluntary potential
supplemental groundwater
activities

Further assessment of the area of proposed construction activities will be
conducted by Lindsay to determine the lateral and vertical extent, any
current and future risks, and if any further action is warranted. Based on
these facility data and Lindsay's interest in enhancing groundwater
treatment, Lindsay may also consider supplemental remediation in other
areas on the Lindsay facility property and other portions of the
groundwater plume as part of their assessment for enhancing
groundwater treatment.

LMC

EPA/NDEQ

December 31, 2009

Groundwater contaminant
plume migration and
delineation

Extraction well and discharge authorizations for G127000 and EXT07-02
were completed by LMC to capture and treat the distal portion of the
groundwater contaminant plume. Both extraction wells are currently
pumping continuously. If needed, additional MWs may be required to
assess plume capture and treatment. As identified above, LMC may
consider additional groundwater remedial alternatives.

LMC

EPA/NDEQ

December 31, 2008

Surface water discharge and
ecological surface water
quality criteria

A ecological technical assessment was performed to evaluate the
discharge from the permitted location. Acute surface water ecological
criteria is considered appropriate given that the groundwater is mainly
discharged during the winter months or during periods of high rainfall.
Groundwater in well G127000 does not exceed acute criteria for metals
and is well below conservative screening criteria for VOCs. However,
additional samples for metals and hardness data from surface water in
Shell Creek shall be collected and compared to surface water quality
criteria. The additional data will provide a greater confidence interval for
chronic surface water ecoloaical criteria.

LMC

EPA/NDEQ

December 31, 2008

-------

Affects
Protectiveness?
(Y/N)

Vapor intrusion evaluation

Lindsay shall identify occupied structures located above the chlorinated
solvent plume. Lindsay shall determine if vapor intrusion is likely in
these structures based on EPA guidance and if so, shall conduct vapor
intrusion sampling to determine risk. If an increased risk is identified
that threatens human health, Lindsay shall install vapor mitigation
systems to reduce the risk. Lindsay shall begin its evaluation in the
source area near the area proposed for reuse activities.

LMC

EPA/NDEQ

December 3 1, 2008

Carbon tetrachloride and
MTBE detections in
groundwater below safe
drinking water act levels that
are not thought to be related
to LMC

The locations of detections for carbon tetrachloride and MTBE will be
referred to the NDEQ and EPA site assessment programs for further
evaluation and/or assessment, if determined to be necessary.

EPA/NDEQ

September 30,
2008

Plume pumping, capture zone
analysis, and sample handling

Lindsay shall ensure the extraction wells pump continuously at designed
rates, evaluate the capture zone in detail, and recommend any further
assessment which may include soil and or groundwater samples, and
evaluate the current sample collection and handling procedures in
accordance with the O&M plan and QAPP and take corrective actions as
needed.

LMC

EPA/NDEQ

December 3 1, 2008

Institutional controls

The site consent decree indicates that through additional response actions
institutional controls can be implemented. Therefore, the availability of
institutional control mechanisms and the opportunity to implement those
at the site shall be reviewed.

LMC/

EPA/NDEQ

July 3, 2013

-------
X. PROTECTIVENESS STATEMENT

The remedy at the site is currently protective of human health and the environment. There are no
known nearby residents currently being exposed to the Lindsay contamination. At present,
Lindsay is conducting quarterly groundwater monitoring of all domestic supply wells identified
in the path of the groundwater plume or potential pathway. In addition, if any domestic or stock
well is found to be contaminated, Lindsay will provide alternate water supplies.

Additional i rrigation extraction wells have been installed to contain the migration of the
contaminant plume. Additional MWs were installed to define the extent of the downgradient
region of the groundwater plume. All other threats have been addressed by prior efforts.

Long-term protectiveness of the RA will be verified by continued inspections, maintenance, and
groundwater sampling at the Site as specified in the O&M Plan. Current data indicate no
exposure to groundwater contaminants in the wells in the surrounding area other than identified
during the second Five-Year Review. Two domestic wells are currently being treated to remove
the contamination. Current monitoring indicates that the remedy is functioning based on
declining trends measured downgradient in contamination. Further review of plume capture and
sample handling will be conducted. The potential for site-related vapor intrusion will be
evaluated. The opportunity for implementation of institutional controls at the Site shall be
reviewed.

XI. NEXT REVIEW

The next Five-Year Review for the Site is required five years from the date this review is signed.
EPA and NDEQ may consider conducting another review of the effectiveness of the systems ait
Lindsay earlier if conditions change or otherwise warrant such evaluation.

-------
ATTACHMENTS

-------
ATTACHMENT 1
SITE LOCATION MAP

-------
¦ -4-. I-W.'A h i *TF&s /^mrrw-

SOURCE: USGS 7.5-mtnJ<* topogrtphtc map, LMSty, Ntbns**, rsvfstd 1985

O 2,000 4,000

Scale In Feet

£)

Job NO. £1769811

Figure 1

Vicinity Map

URS

Lindsay Manufacturing LLC
Lindsay, Nebrasica

-------
ATTACHMENT 2
Site Plan Showing Monitoring Well Locations

-------
WEI.

.IDEtflOT&HTQN

6w> Pfcritar (D)

P%.fer (D)

® BW« imoaoon (#67638)

Old Motbvbc (0)

® VMytanNMl (Oai796)(f)

66(1*-' Dffn«ttc

e«n.- Sim* M«i SE Irrtgetton (1)

Hog Cortwianl

Total VOC concentration ' %

-Appfcwdmale plume

boundary (WD) Not Delected

(91*100) Tot* VOC concentration
range for wtteat proflisng
J3u*C!t VMS '.e-fflwuv hvmreeMe mm. LMm* -wAm*

/at Mo. SJTWn

UBS

Figure It

Total VOC Concentrations {Februaiy 2008)

Untlay MwiufccUrlrlfl LLC
UndMty. Nebraska

-------
ATTACHMENT 3

Graphs showing total VOCs and 1,4-dioxanc vs. time in extraction and monitoring

wells

-------
Figure 3.1: Total VOCs, Lindsay facility wells - perched sand channel

-------
2000

1800

1600

1400

1200

1000

800

600

400

200

-------
Figure 3.3: Total VOCs, Lindsay north area wells

sampling date

—MW89-15
MW06-11
Ol Well

-------
Figure 3.4: Total VOCs - Lindsay main area wells

2000

1800

1600

1 1000

C
©

1 800

0 4—

% \ \ \ \ \ \ \ \ \ X \ \ \ % \ % \ \ \

'<%> °j> -£V Or ^ °s ° °> °>

sampling date

-~-well 89-12
-• well 87-3
AOI Well

-------
Figure 3.5: Total VOCs. hwy 91 monitoring wells

MW06-05
MW06-06
MW 06-07
•-MW06-08
—MW06-09

-------
Figure 3.6: Total VOCs, Lindsay downgradient wells - sand & gravel aquifer

-o 4,
%

'"J"

-G A,
\ % ^

<(?

% \ \ \ \ \ \ ^
^ ^ %-

I . - %. \ \ %

'% <%• % 3*

^ %

\ \ \
°> Q>

sampling date

—92-3A
92-3B
G12700
-~—POD
—MW04-02
—MW04-03

-------
Figure 3.7: Total VOCs, Beller farm vicinity wells

sampling date

—MW89-11B
• Beller New Stock 2003
Beller Domestic
92-3A
92-3B

Beller Irngation

-------
Figure 3.8: Total VOCs, Priester Farm vicinity wells

350

—*—012700

-• New Domestic (2003)
Old Domestic
MW04-02(98)
-• MW04-03( 120)

°6 % ^

As Xs

* o6 To,

\ X \ % \ "V *

x \

% \ X

Or Q? Qp Qy Op Op Of Of % Cfo Og, Oq o^ o^

sampling date

-------
Figure 3.9: 1,4-dioxane ¦ Lindsay north area wells

-------
Figure 3.10: 1,4-dioxane - Lindsay main area wells

160

140

120

100

®<5 \ \

3? '
*0. ®A

<%> ^ ^ '<&> % *<&

sampling date

\ x \ w ¦«

4. 4,

<%> "4> * ^

^ % \

-well 89-12
well 87-3
AOI Well

-------
Figure 3. 11: 1,4-dioxane - Lindsay downgradient wells

-Beller new stock 2003
G12700
MW04-03

% \ \ \ \ \ X \ \ \ X \ % \ X \ \ \ X %

Q °\? Of °e

sampling date

-------
-------
Figure 4.1: Cadmium, chromium, & lead in Lindsay north area wells

0 14

¦o
E

Q
C

0.06

002

sampling date

-~-Cd, MW89-15
-•-Cd. MW06-10
Cd, Ol Well
— Cf, MW89-15
Cr. MW06-11
-•-Cr, Ol Well
—f-Pb. MW89-15

Pb. MW06-10

— Pb. Ol Well

-------
Figure 4.2: Iron & zinc in Lindsay north area wells

160

-•-Fe. MW89-15
-»-Fe. MWQ6-11
Fe. Ol Well
Zn, MW89-15
¦=» Zn. MW06-11
-•-Zn. Ol Well

% %

°9 ' °?

°S

%- X \ % \ ^

¦os°os os % *

*<5

% •?/

% % <%¦ 3> 0"

sampling date

-------
Figure 4.3: Cadmium, chromium, & lead in Lindsay main area wells

sampling date

-#-Cd. MW89-12
-*-Cd, MW87-3
Cd. AOI Well
Cr, MW89-12
-»-Cf. MW87-3
-•-Cr. AOI Well
-t-Pb. MW89-12

Pb. MW87-3

— Pb. AOI Well

-------
Figure 4,4: Iron & zinc in Lindsay main area welts

"fe \ "t-, \

% % \

%. X- %. %. %. %. % %,

-Fe. MW89-12
Fe, MW87-3
Fe. AOI Well
Zn. MW89-12
Zn MW87-3
-Zn. AOI Well

?<5 %. \ °t- ® oe oe o& o> a> Oj. oj>

sampling date

-------
Figure 4.5: Cadmium in hwy 91 wells

¦Cd, MW06-05
Cd. MW06-06
Cd, MW06-07
Cd, MW06-08
Cd. MW06-09

°e

sampling date

-------
Figure 4.6: Chromium in hwy 91 wells

018

°e

x>
«6

°> Oj,

sampling date

-Cr, MW06-05
Cr. MW06-06
Cr, MW06-07
Cr. MW06-08
-Cr. MW06-09

-------
Figure 4.7: Lead in hwy 91 wells

Pb, MW06-05
Pb. MW06-06
Pb. MW06-07
Pb. MW06-08
Pb MW06-05

sampling date

•u

-------
Figure 4.8: Iron in hwy 91 wells

160

140

120

100

en
S

c
o

m 80

tt)
U
C

i~Fe, MW06-05
»- Fe. MW06-06
Fe. MW06-07
Fe. MW06-08
- Fe MW06-09

°e

sampling date

-------