Five-Year Review Addendum
John Deere Ottumwa Works Site
City of Ottumwa
Wapello County, Iowa
Region 7
United States Environmental Protection Agency
Lenexa, Kansas
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Addendum to John Deere Ottumwa Works Site
Fourth Five-Year Review Report, dated April 3, 2013
A Five-Year Review (FYR) addendum is generally completed for remedies where the protectiveness
determination is deferred until further information is obtained. When deferring protectiveness in the
FYR report, the U.S. Environmental Protection Agency typically provides a timeframe for when the
information will be obtained and a protectiveness statement can be made. This document provides
progress since the FYR and a protectiveness determination for the remedy where the statement was
deferred in the April 3, 2013 Fourth FYR.
The FYR report for the John Deere Ottumwa Works Site in Ottumwa, Iowa, was signed by Cecilia
Tapia, Superfund Division Director, on April 3, 2013. The protectiveness statement(s) outlined in the
FYR were as follows:
"A protectiveness determination of the remedy at OU 1 cannot be made at this time until further
information is obtained. Further information will be obtained by collecting surface water samples from
Black Lake. It is expected these actions will take approximately one year to complete, at which time a
protectiveness determination will be made."
The protectiveness determination was deferred based on the following issue and recommendation.
The April 3, 2013 Fourth FYR stated, "A potential ecological exposure pathway may exist in Black
Lake. Black Lake needs to be more fully characterized by collecting surface water samples. Results of
the sampling will provide data needed to evaluate if John Deere Ottumwa Works should conduct other
elements of a screening level ecological risk assessment to more fully characterize the site in the area of
Black Lake. Surface water samples have not been collected from Black Lake since 1995. Cadmium and
lead concentrations detected in Black Lake in 1994 exceeded National Ambient Water Quality Criteria
(NAWQC)." The recommendation to address this issue was, "Collect surface water samples from Black
Lake to evaluate if concentrations of metals (arsenic, barium, cadmium, chromium and lead) exceed
ecological water quality standards and evaluate if any ecological exposure pathways exist."
Progress Since the Five-Year Review Completion Date
Black Lake (also known as the Black Lake Quarry) is located northeast of the John Deere Ottumwa
Works facility, between State Highway 34 and the Des Moines River. The lake is a man-made water
body, constructed by mining unconsolidated materials and limestone bedrock below the water table. It is
located approximately 200 feet northeast of the John Deere Ottumwa Works facility, on the north side of
State Highway 34. The present teardrop-shaped lake is approximately 500 feet wide at its widest point,
near the southern end of the lake, and approximately 1,500 feet long at its longest point. It is estimated
to encompass approximately 11 acres. No published information was identified that described the lake
depth.
The ecological exposure pathway was adequately evaluated by collecting two rounds of surface water
samples from Black Lake. The sampling was conducted in July 2013 and November 2013. During each
sampling event, five surface water samples and a duplicate surface water sample were collected to
further characterize any potential impacts to Black Lake (Attachment 1). Based on the surface water
sampling results from monitoring events performed in July 2013 and November 2013, there are no
contaminants (metals) of potential ecological concern in surface water collected from Black Lake that
would present an adverse ecological risk to flora and/or fauna at the site, demonstrating that the surface
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water at Black Lake has not been adversely affected by the John Deere Ottumwa Works Superfund Site.
The analytical data from the sampling events are provided in the tables below. The reporting limit of
0.500 for cadmium is greater than the NAWQC Chronic value of 0.41.
Table 1 - Black Lake Surface Water Sample Results - July 2013
Concentrations are in (.ig/L - micrograms per liter
Contaminants of
NAWQC
Concern
SW-1
SW-2
SW-3
SW-4
SW-5
(EPA, 2009B)
Acute
Chronic
Arsenic
4.13
4.52
3.95
4.20
4.30
340a
<
o
lo
Barium
68.9
68.9
61.2
62.7
64.0
NS
NS
Cadmium
<0.500
<0.500
<0.500
<0.500
<0.500
4.2e
0.41e
Chromium (Total)
<5.00
<5.00
<5.00
<5.00
<5.00
NS
NS
Chromium (III)
<5.00
<5.00
<5.00
<5.00
<5.00
O
L/i
m
137e
Chromium (VI)
<0.0200
<0.0200
<0.0200
<0.0200
<0.0200
16
11
Lead
<0.500
<0.500
<0.500
<0.500
<0.500
145e
5.6E
NS: No standard
A: Derived from arsenic (II) but applies to total arsenic
E: Hardness dependent, adjusted based on average hardness of 212 mg/L
Chromium (III) concentration calculated: [(Chromium total) - Chromium (VI)]
Criteria for metals are expressed in terms of the dissolved metal in the water column.
Table 2 - Black Lake Surface Water Sample Results - November 2013
Concentrations are in [ig/L - micrograms per liter
Contaminants of
NAWQC
Concern
SW-1
SW-2
SW-3
SW-4
SW-5
(EPA, 2009B)
Acute
Chronic
Arsenic
2.84
2.87
2.82
3.22
2.85
340a
<
o
Barium
111
118
110
126
120
NS
NS
Cadmium
<0.500
<0.500
<0.500
<0.500
<0.500
6.6e
0.57e
Chromium (Total)
<5.00
<5.00
<5.00
<5.00
<5.00
NS
NS
Chromium (III)
<5.00
<5.00
<5.00
<5.00
<5.00
1549e
201e
Chromium (VI)
<0.0200
<0.0200
<0.0200
<0.0200
<0.0200
16
11
Lead
<0.500
<0.500
<0.500
<0.500
<0.500
237E
9 2e
NS: No standard
A: Derived from arsenic (II) but applies to total arsenic
E: Hardness dependent, adjusted based on average hardness of 339 mg/L
Chromium (III) concentration calculated: [(Chromium total) - Chromium (VI)]
Criteria for metals are expressed in terms of the dissolved metal in the water column.
Issues and Recommendations
There were no additional issues and recommendations identified since the completion of the April 3,
2013 FYR.
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Protectiveness Statements
Based on new information and/or actions taken since the FYR completion date, the protectiveness
statement for OU 1 is being revised as follows:
The remedy at OU 1 is protective of human health and the environment.
The site wide protectiveness determination is revised as follows:
The remedy at the site is protective of human health and the environment.
Next Five-Year Review
The next FYR will be completed by April 3, 2018, five years after the signature of the last FYR report.
2
Date
Acting Superfund Division Director
U.S. EPA, Region 7
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Attachment 1
Black Lake
Surface Water Sampling Locations
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Attachment 2
Black Lake Aerial Photo
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HE
Hyde Environmental, Inc.
FIGURE 3
BLACK LAKE SURFACE WATER
SAMPLING LOCATIONS
John Deere Ottumwa Works
Ottumwa. IA
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