First Five-year Review Report for the Iowa City Former Manufactured Gas Plant Superfund Site Johnson County Iowa


FIRST FIVE-YEAR REVIEW REPORT

FOR THE

IOWA CITY FORMER MANUFACTURED GAS PLANT SUPERFUND SITE

JOHNSON COUNTY, IOWA

S7k,*c



Prepared by

U.S. Environmental Protection Agency
Region 7
Lenexa, Kansas

Robeft Whfackson, Acting Director
Superfund Division

Date

-------
2

-------
Table of Contents

List of Abbreviations 					5

Executive Summary 				7

Five-Year Review Summary Form 	10

I.	Introduction	11

A.	Site Chronology....;	12

B.	Background	12

Physical Characteristics			12

Land and Resource Use	12

History of Contamination	13

Initial Response		14

Basis for Taking Action		15

C.	Remedial Actions	16

Remedy Selection	16

Remedy Implementation	19

System Operations/Operation and Maintenance (O&M)	21

II.	Progress Since the Last Five-Year Review 		....21

III.	Five-Year Review Process		22

Administrative Components	22

Community Notification and Involvement	22

Document Review					22

Data Review	22

Site Inspection	28

IV.	Technical Assessment 	28

Question A: Is the remedy functioning as intended by the decision documents?	28

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

remedial action objectives (RAOs) used at the time of the remedy

selection still valid?	30

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

the protectiveness of the remedy?	33

Technical Assessment Summary	33

V.	Issues, Recommendations and Follow-up Actions	34

VI.	Protectiveness Statement(s)	34

VII.	Next Review		34

3

-------
Tables

Table 1 - Chronology of Site Events		

Table 2 - Action Levels for Groundwater	

Table 3 - Ralston Creek Sediment Performance Standards

Table 4 - Operation and Maintenance Costs	

Table 5 - Air Monitoring Results	

.12
.18
.19
.21
.27

Figures

1.	Current Site Layout

2.	Site Vicinity and Current Groundwater Monitoring Network

3.	Ralston Creek Sediment Sampling Location and Tile Liner Inspection Area

4.	Air Sampling Locations

Attachments

1.	List of Documents Reviewed

2.	Groundwater Monitoring Results

3.	Sediment Sampling Results

4.	Groundwater Contaminants of Concern Trend Analysis Summary

5.	Five-Year Review Inspection Form

4

-------
LIST OF ABBREVIATIONS

AOC	Administrative Order on Consent

ARAR	Applicable or Relevant and Appropriate Requirement

BTEX	Benzene, Toluene, Ethylbenzene and Xylenes

CERCLA	Comprehensive Environmental Response, Compensation and Liability Act

COC	Contaminant of Concern

DNAPL	Dense Nonaqueous Phase Liquid

EPA	United States Environmental Protection Agency

FMGP	Former Manufactured Gas Plant

FYR	Five-Year Review

IIGE	Iowa-Illinois Gas and Electric Company

IDNR	Iowa Department of Natural Resources

LLC	Limited Liability Company

LNAPL	Light Nonaqueous Phase Liquid

MCL	Maximum Contaminant Level

NPL	National Priorities List

OU	Operable Unit

O&M	Operation and Maintenance

PAHs	Polynuclear Aromatic Hydrocarbons

PECs	Probable Effects Concentrations

PQL	Practical Quantitation Limit

RAO	Remedial Action Objective

RBC	Risk Based Concentration

ROD	Record of Decision

RSL	Regional Screening Level

TBCs	To Be Considereds

TI	Technical Impracticability

UCL	Upper Confidence Limit

VOC	Volatile Organic Compound

Hg/kg	Microgram per kilogram

jig/L	Microgram per Liter

|iig/m3	Microgram per cubic meter

5

-------
6

-------
EXECUTIVE SUMMARY

This is the first Five-Year Review (FYR) for the Iowa City Former Manufactured Gas Plant (FMGP)
Superfund site located in Iowa City, Johnson County, and Iowa. The purpose of this FYR is to review
information to determine if the remedy is and will continue to be protective of human health and the
environment. The triggering action for this statutory review is the date of the start of on-site construction
of the remedial action.

The site is located east of downtown Iowa City at 505 East Burlington Street in a mixed commercial and
residential area and is approximately 1.5 acres in size. The site property is currently occupied by the
Iowa-Illinois Square (formerly known as the Iowa-Illinois Manor) apartment building, which contains
54 units, occupied by approximately 150 residents. The apartment building and paved parking areas
cover the majority of the site.

Ralston Creek runs parallel to Van Buren Street, which is located on the west side of the site, and
adjacent to the site. This reach of the creek is tile lined and heavily vegetated. The city owns the creek in
this area.

Manufactured coal gas was produced at the site beginning in approximately 1857 until approximately
1937, when natural gas became available in the area. The production of manufactured gas created waste
products that are resistant to natural decay and typically remain at FMGP sites for decades. The primary
waste is a dense, oily liquid known as "coal tar", which condensed out of the gas during various stages
of its production, leading to contamination of soil, groundwater and sediment which came into contact
with the coal tar. Coal tar is a mixture of chemicals known as polynuclear aromatic hydrocarbons
(PAHs) and volatile organic compounds (VOCs), specifically benzene, toluene, ethylbenzene and
xylenes (BTEX). Other contaminants frequently associated with the production of manufactured gas are
arsenic, cyanides and some metals.

In 1983, during the design and construction of the apartment building, an investigation was conducted
by the property owner due to the discovery of oily wastes at the site. During this investigation, it was
determined that fill material containing what was believed to be manufactured gas plant refuse was
present in the subsurface. As a result of the discovery of this material in the subsurface and vapors
encountered during the investigation, the design of the foundation of the apartment building was
modified, a liner was placed under a portion of the building and a passive venting system was installed
in the crawl space.

In March 1999, the EPA, MidAmerican Energy Company and the Iowa-Illinois Manor Partnership
entered into an Administrative Order on Consent (AOC) for site characterization activities. In December
2003, when the EPA determined that a time-critical removal action was necessary to remove
contamination associated with the FMGP along the northern edge of the site, MidAmerican and the
Manor Partnership entered into a second AOC to conduct this work. In January 2004, MidAmerican
removed the contents of the underground tank, filled it with inert material, and recovered groundwater
and light nonaqueous phase liquid (LNAPL) from two monitoring wells.

In August 2004, MidAmerican and the Manor Partnership entered into a third AOC with the EPA to
conduct a feasibility study. MidAmerican conducted some additional limited field investigations,
completed a treatability study involving the removal of LNAPL, and completed a Feasibility Study
Report dated June 2006.

-------
In September 2006 the EPA signed a Record of Decision (ROD) that selected the remedy for the site.
The major components of the selected remedy are:

• Implementation of institutional controls to prohibit the installation of water wells, maintain
conditions in Ralston Creek, and maintain conditions within the lowa-Illinois Square apartment
building.

• Implementation of a technical impracticability (TI) waiver of applicable or relevant and appropriate
requirements (ARARs) within the identified TI zone.

• Groundwater monitoring for contaminants of concern (COCs) and natural attenuation parameters.

• Evaluation of potential indoor air exposure at off-site locations from groundwater within the TI
zone.

• Sediment monitoring for COCs in Ralston Creek.

• Indoor air monitoring for COCs in the Iowa-Illinois Square apartment building.

• Recovery of LNAPL from the unconsolidated aquifer.

On November 26, 2008, MidAmerican Energy Company and Iowa-Illinois Manor, LLC, entered into a
Consent Decree to perform a remedial design and remedial actions at the site. Remedial actions include
recovery of LNAPL from monitoring wells; monitored natural attenuation of groundwater; monitoring
of air, sediment, and groundwater; and implementation of ICs, including environmental covenants. The
remedial design was started on July 10, 2008, and concluded on January 29, 2010. On-site construction
of the remedial action began on February 17, 2010.

The remedy is performing as expected, with natural attenuation processes continuing to occur in the
contaminated groundwater plume as demonstrated through evaluation of contaminant concentrations and
natural attenuation parameters. Groundwater outside of the TI zone is meeting the action levels except
for elevated levels of manganese at MW-7 and intermittent elevated levels of naphthalene at MW-35.
MW-7 is upgradient of the contamination source so it is likely that the manganese is naturally occurring
and not the result of contamination from the site.

Sediment sampling results have been quite variable, with six of the nine COCs exceeding the
performance standards in one downstream sample in 2011, compared to one COC performance standard
exceedance in 2012 and none exceeded in 2013. As additional samples are collected, the statistical
analysis of this data will become more robust. The condition of the tile lining has not degraded
significantly during the remedial action but there are areas of damage, which was discussed with
representatives of the city during the five-year review inspection.

LNAPL gauging and recovery continues consistent with the LNAPL Recovery Plan. LNAPL recovery
has been minimal since the beginning of the remedial action.

Air in the crawlspace beneath the Iowa-Illinois Square apartment building is monitored through annual
sampling for benzene and naphthalene, the COCs present at the site that are sufficiently volatile to
potentially move from groundwater into air. While low levels of benzene have been detected in air in the
crawlspace that exceeded the indoor air action level on two occasions, these wells were within the
acceptable cancer risk range and remain protective of human health for indoor air for apartment
dwellers. Naphthalene has not been detected above the analytical detection limit.

An institutional control in the form of an environmental covenant was filed with the Johnson County
Recorder on June 4, 2009, on the site property, currently occupied by the Iowa-Illinois Square

-------
apartments. The environmental covenant prohibits installation of wells on the site, other than monitoring
wells, restricts excavation deeper than six feet below grade without prior notification and approval of the
EPA except in cases of emergency, and requires notification to the EPA a minimum of 60 calendar days
prior to transfer of title of the property or change in use.

An institutional control in the form of an environmental covenant was filed with the Johnson County
Recorder on December 15, 2010, on the stretch of Ralston Creek located west of the site. The
environmental covenant prohibits installation of wells on the property, other than monitoring wells and
restricts excavation or other disturbance to the tile lining without prior notification and approval of the
EPA, except in cases of emergency.

Additional institutional controls in the form of a state rule governing installation of wells in areas of
contamination, a city code requiring connection to the public water supply and a county ordinance
requiring notification regarding setbacks from contamination for groundwater well installation remain in
force and provide additional layers of protection.

The remedy for the Iowa City FMGP site is protective of human health and the environment.

9

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

SI I !-. Ii)I \ 1 11 1( \ I l<>\

Site Name: Iowa City Former Manufactured Gas Plant Site

EPA ID: IAD 984591172

Region: 7

State: 1A

City/Countv: Iowa < 'its 'Johnson County

NPL Status: Non-NPL





Multiple Oils?
No

Has the site achieved construction completion?

Yes

Lead agency: EPA

/If "Other 1 'ederai Agency", enter Agency name/: I

Author name (Federal or State Project Manager): Diana Engeman

Author affiliation: EPA-Region 7

Review period: 1/28/2014-1/12/2015

Date of site inspection: 7/7/2014

Type of review: Statulorv

Review number: 1

Triggering action date: 2/17/2010

Due date (fiveyears after triggering action date)-. 2/17/2015

issues/Recommendations

OU(s) without IsMies/Rfcumim'ndiilifins Identified in the five Yoor Review:

OU 00. There are no issues or recommendations identified in the Five-Year Review,

Sitewide Protectiveness Statement

Protectiveness Determination;	Addendum Due Date (if applicable);

Protective

Protectiveness Statement; The remedy at the Iowa City Former Manufactured Gas Plant site is

protective of human health and the environment,

10

-------
I. INTRODUCTION

The purpose of conducting a five-year review (FYR) is to evaluate the implementation and performance
of a remedy to determine if the remedy continues to be protective of human health and the environment.
The methods, findings and conclusions of a FYR are documented in a FYR report. In addition, a FYR
report identifies any issues found during the review, and documents any recommendations to address the
issues.

The U.S. Environmental Protection Agency conducts a FYR and prepares a FYR report pursuant to the
Comprehensive Environmental Response, Compensation and Liability Act, section 121, and the
National Contingency Plan. CERCLA 121 states:

If the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site, the President shall review such remedial
action no less often than each five years after the initiation of such remedial action to
assure that human health and the environment are being protected by the remedial action
being implemented. In addition, if upon such review it is the judgment of the President
that action is appropriate at such site in accordance with section [104] or [106], the
President shall take or require such action. The President shall report to the Congress a
list of facilities for which such review is required, the results of all such reviews, and any
actions taken as a result of such reviews.

The EPA interpreted this requirement further in the National Contingency Plan, 40 Code of Federal
Regulations section 300.430(f)(4)(ii), which states:

If a remedial action is selected that results in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for unlimited use and
unrestricted exposure, the lead agency shall review such actions no less often than every
five years after the initiation of the selected remedial action.

The EPA conducted a FYR on the remedy implemented at the Iowa City Former Manufactured Gas
Plant (FMGP) Superfund site in Iowa City, Johnson County, Iowa. The EPA is the lead agency for
developing and implementing the remedy for the site. The Iowa Department of Natural Resources
(IDNR), as the support agency representing the state of Iowa, has reviewed the supporting
documentation and provided input to the EPA during the FYR process.

This is the first FYR for the Iowa City FMGP Superfund site. The triggering action for this statutory
review is the date of the start of on-site construction of the remedial action. The FYR is required because
hazardous substances, pollutants or contaminants remain at the site above levels that allow for unlimited
use and unrestricted exposure. The site is addressed as one Operable Unit (OU). This OU is the subject
of this FYR.

-------
A. SITE CHRONOLOGY

Table 1

\ \«111

i»afi'

Initial discovery of problem or contamination

12 12 1990

Preliminary Assessment complet

4 19 1991

Site Investigation completed

8 7' 1996

Expanded Site Investigation completed

9'9/1998

Administrative Order on ( on^em t V'H > lor Site t haracterization signed

3'291999

AOC for Removal Action si a

12 16 2003

Removal Action completed

6/2004

AOC for Feasibility Study signed

3 '2004

Remedial Investigation Feasibility Stud) complete and Record of Decision (ROD)
signed

9 26 2006

ROD modified by memorandum

008

Consent Decree entered

6 20081

Remedial Design start

^ 74(1,2008

Remedial Design complete

9 2

On-site Remedial Action construction start

2/17/2010

Construction completion date

8 2 7'

B. BACKGROUND

Physical Characteristics

The site is located east of downtown Iowa City at 505 F.ast Burlington Street in a mixed commercial and
residential area and is approximately 1.5 acres in si/e. The site property is currently occupied by the
Iowa-Illinois Square apartment building. Nearby commercial enterprises include the I.&NT Mighty Shop,
a convenience store and gas station, to the north: an apartment building to the south on the property
previously occupied by two auto garages. To the west, across Ralston Creek, the Burlington Commons
apartment building was constructed on property previously occupied by Hanson Auto Body Shop. The
Iowa City Recreation Center and municipal parking lot are located northwest of the site. The current site
layout is shown in Figure 1. The site \ icinity ant! current groundw ater monitoring network is depicted in
Figure 2.

Land and Resource Use

The site property is currently occupied by the Iowa-Illinois Square (formerly known as the Iowa-Illinois
Manor) apartment building, which contains 54 units, occupied by approximately 150 residents. As
shown in Figure 1, the apartment building and paved parking areas cover the majority of the site. Grass-
covered and landscaped areas arc located along the adjacent streets and along the margins of the
building with the exception of the eastern side of the building, which is covered with landscaping rock.
Ralston Creek runs parallel to Van Burcn Street, which is located on the w est side, and adjacent to the
site. This reach of the creek is tile lined and heavily \ egetated. The city owns the creek in this area.

A survey of water wells and potential groundwater usage within a one-mile radius of the site was
conducted. Eleven water wells were identified within the search radius and four of these are potentially

-------
used as a source of drinking water. None of the existing water wells are located in the contaminated
plume area or are likely to ever be impacted by the site.

The city supplies potable water to the University of Iowa, residences and businesses within the city
limits of Iowa City. The municipal water supply is drawn from intakes located on the Iowa River and a
well field located north of Iowa City, outside the one-mile search radius. Wells screened in the Silurian
and Cambro-Ordovician aquifers within the one-mile radius and owned by the University were utilized
by the city primarily for blending with the surface water supply during spring runoff. However, with the
completion of a new city water treatment plant, the city no longer uses these wells as a blending source.

The University also supplies some of its own water. The University-owned wells described in the
previous paragraph are on standby as a potential blending source for times when the University's surface
water supply is not of suitable quality. The other water wells located within the one-mile radius are not
utilized for drinking water.

The potential for new water well installations within the search radius is low. The city enforces a
municipal ordinance (City Code Section 14-3C-10) that prohibits the installation of private water wells
where a municipal water supply line is available within 300 feet. Additionally, the ordinance provides
the city authority to require owners of existing private wells to connect to the municipal water supply if
a water supply line exists within 300 feet. The Iowa City well ordinance has been approved for use as an
institutional control by the IDNR for leaking underground storage tank sites and other state-lead
projects.

Ralston Creek is a perennial stream with highly variable flow. It is managed primarily for storm water
drainage rather than for recreational use. Buried utility lines run beside and beneath Ralston Creek near
the site. In the immediate vicinity of Ralston Creek, it appears that groundwater discharges to the creek
under base-flow conditions. It is not anticipated that the use or management of the creek will change in
the future. The stretch of the creek adjacent to the site is owned by the city.

Ralston Creek ultimately discharges in the Iowa River several miles downstream of the site. The
confluence of Ralston Creek and the Iowa River is a fishery and likely a nursery for fish. The Iowa
River is used as a source of drinking water for the city of Iowa City and the University. It is not
anticipated that this usage will change in the future.

History of Contamination

Manufactured coal gas was produced at the site beginning in approximately 1857 until approximately
1937, when natural gas became available in the area. After ceasing gas production, the facilities were
used into the 1950s for distribution of natural gas. The layout of the FMGP facilities as they existed in
1926 is shown in blue in Figure 1.

The production of manufactured gas created waste products that are resistant to natural decay and
typically remain at FMGP sites for decades. The primary waste is a dense, oily liquid known as "coal
tar", which condensed out of the gas during various stages of its production. Although some of this coal
tar was sold, substantial amounts leaked from storage and processing facilities or was discharged at the
site. Soil, groundwater and sediment which came into contact with the coal tar became contaminated,
and in many cases, continues to be contaminated. Coal tar was a mixture of chemicals known as

-------
polynuclear aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs), specifically
benzene, toluene, ethylbenzene and xylenes (BTEX). Other contaminants frequently associated with the
production of manufactured gas are arsenic, cyanides and some metals.

The Iowa City FMGP operated under several names throughout its period of operation. For the majority
of the years it was operated by Tri-City Railway and Light Company, a subsidiary of United Light and
Power Company. In the early 1940s Iowa-Illinois Gas and Electric Company (IIGE) purchased Tri-City
Railway and Light Company.

Following closure of the manufactured gas plant operations, the site was utilized by IIGE as a service
facility until approximately 1971. At some point after 1971, the property was sold to Ron Shank, who
operated a bar on the property. The property was purchased from Ron Shank on December 31, 1982, by
the Iowa-Illinois Manor Partnership. The buildings on the property were demolished and the Iowa-
Illinois Manor apartments were constructed in 1983. The property is currently owned by Iowa-Illinois
Square, following its June 18, 2009, purchase from the Iowa-Illinois Manor Partnership.

Based on historical maps, Ralston Creek has been relocated twice during development of the area. The
portion of Ralston Creek located near the site has been relocated and channelized from its native
location. An 1839 map of Iowa City shows Ralston Creek meandering across the current location of the
site. Based on a review of Sanborn® maps, it appears the meander at the site was eliminated prior to
1888, and then Ralston Creek was further straightened and tile-lined at some time between 1948 and
1970 to place it in its current location. Ralston Creek is currently located approximately 40 feet west of
the site.

The EPA conducted investigations at the site and issued an Expanded Site Investigation Report in 1998
in which it was determined further investigation was warranted due to the presence of elevated levels of
BTEX, PAHs, cyanides, arsenic and lead. Contamination was found in soil and groundwater.

Initial Response

In March 1999, the EPA, MidAmerican Energy Company (a successor to IIGE) and the Manor
Partnership entered into an Administrative Order on Consent (AOC) for site characterization activities.
From October 1999 through March 2004 MidAmerican conducted this investigative work. The final Site
Characterization Report, dated August 2003, including the baseline risk assessment and all amendments
to the Report, constitute the final Remedial Investigation Report for the site.

In December 2003, the EPA determined that a time-critical removal action was necessary to remove
contamination associated with the FMGP along the northern edge of the site. This work was necessary
to minimize exposure to city and utility workers doing construction work in the area, and to address an
underground tank in the area. MidAmerican and the Manor Partnership entered into an AOC to conduct

-------
this work. In January 2004, MidAmerican removed the contents of the underground tank, filled it with
inert material, and recovered groundwater and light nonaqueous phase liquid (LNAPL) from two
monitoring wells.

In August 2004, MidAmerican and the Manor Partnership entered into a third AOC with the EPA to
conduct a feasibility study. MidAmerican conducted some additional limited field investigations,
completed a treatability study involving the removal of LNAPL, and completed a Feasibility Study
Report dated June 2006. The Site Characterization Report, the Feasibility Study Report and other
documents in the Administrative Record file may be reviewed for a more complete source of
information regarding the history of the site.

Basis for Taking Action

A baseline risk assessment was conducted as part of the site characterization. It included a human health
baseline risk assessment and a screening level ecological risk assessment. The following lists the
contaminants that were identified as contaminants of concern (COCs) for each media affected:

Soil

Arsenic

Cyanide

Iron

Manganese

Aroclor 1254

Aroclor 1260

Acenaphthylene

Benzo(a)anthracene

Benzo(b)fluoranthene

Benzo(k)fluoranthene

Benzo(a)pyrene

Chrysene

Dibenzo(a,h)anthracene

Indeno(l ,2,3-c,d)pyrene

2-Methylnaphthalene

Naphthalene

Benzene

Ethylbenzene

Indoor Air

Benzene
Naphthalene

Groundwater

Aluminum

Arsenic

Chromium

Cyanide

Iron

Lead

Manganese

Acenaphthene

Acenaphthylene

Benzo(a)anthracene

Benzo(a)pyrene

Benzo(b)fl uoranthene

Benzo(k)fluoranthene

Chrysene

Dibenzo(a,h)anthracene
Fluorene

Indeno(l,2,3-c,d)pyrene

2-Methylnaphthalene

Naphthalene

Phenanthrene

Benzene

Ethylbenzene

Toluene

Xylenes, total

Surface Water

Benzene

Sediment

Arsenic
Iron

Benzo(a)anthracene

Benzo(b)fluoranthene

Benzo(a)pyrene

15

-------
Although there were no current exposures to groundwater for residents, it was determined that potential
future exposures through consumption of contaminated groundwater or through inhalation of the vapor
from showering or cooking could present a significant carcinogenic risk as well as noncarcinogenic
health effects if exposure were to occur. The contaminants posing the greatest carcinogenic risks in
groundwater were benzo(a)pyrene, benzene and dibenzo(a,h)anthracene. The majority of the
noncarcinogenic health effects due to exposure to groundwater were posed by naphthalene and benzene.

Contaminants in soil and indoor air did not pose a significant threat provided exposure to subsurface soil
contamination did not occur in the future and site conditions preventing indoor air exposures did not
change in the future.

Exposure to contaminants in surface water did not pose an unacceptable level of risk to humans or
ecological receptors. The significant ecological resource to be protected is the fishery located at the
confluence of Ralston Creek and the Iowa River. It was determined that in the future, comparing
sediment samples from Ralston Creek in the vicinity of the site to consensus-based probable effects
concentrations of PAHs for freshwater ecosystems would serve as an indicator of possible new
contribution of contamination from the site into the creek.

C. REMEDIAL ACTIONS

Remedy Selection

The ROD for the Iowa City FMGP site was signed on September 26, 2006. Remedial action objectives
(RAOs) were developed during the Feasibility Study, utilizing data collected during the remedial
investigation, to aid in the development and screening of remedial alternatives that were considered for
the ROD. Separate RAOs were developed for soil, groundwater, indoor air and Ralston Creek. The
RAOs for the site are to:

• Prevent and/or reduce human exposure to groundwater containing COCs that exceed
applicable or relevant and appropriate requirements (ARARs) or health-based levels.

• Prevent and/or reduce future soil exposure risks to acceptable levels by maintaining the
existing land use. The future soil RAO may be reevaluated if the building is removed or
its use changed.

• Prevent and/or reduce future human exposure to indoor air containing COCs that exceed
health-based levels. ,

• Maintain the existing ecological steady state and prevent and/or reduce future
unacceptable risks to human health and the environment in Ralston Creek.

The major components of the selected remedy are:

• Implementation of institutional controls to prohibit the installation of water wells,
maintain conditions in Ralston Creek, and maintain conditions within the Iowa-Illinois
Square apartment building.

• Implementation of a technical impracticability (TI) waiver of ARARs within the
identified TI zone.

• Monitored natural attenuation of groundwater.

• Groundwater monitoring for COCs and natural attenuation parameters.

-------
•	Evaluation of potential indoor air exposure at off-site locations from groundwater within
the TI zone.

•	Sediment monitoring for COCs in Ralston Creek.

•	Indoor air monitoring for COCs in the Iowa-Illinois Square apartment building.

•	Recovery of LNAPL from the unconsolidated aquifer.

Action levels are the concentrations of the COCs in the affected media that must not be exceeded to
ensure that the RAOs will be met. These levels were initially developed for this site during the
Feasibility Study. The processes for doing so for each media are described below.

The action levels for groundwater were determined based upon the following hierarchy:

•	The maximum contaminant level (MCL) pursuant to the Safe Drinking Water Act for the
contaminant when an MCL is available.

•	For contaminants without an MCL, the action level is calculated based on an excess
lifetime cancer risk of 1 x 10"6 and/or a target hazard quotient of 1.

•	When the calculated risk-based action level is below the laboratory practical quantitation
limit (PQL), the PQL is used as the action level, provided it falls within the acceptable
risk range of lxlO"4 to lxlO"6 excess lifetime cancer risk.

The action levels for groundwater at the site, and the rationale for their selection, as described in the
ROD, are as listed in Table 2.

17

-------
Table 2

ACTION LEVELS FOR GROUNDWATER
in ng/L

Contaminant of
Potential Concern

Chemical-
Specific
ARARs
(MCLs)

Risk-Based
Concentration
(RBC)

PQL

Selected
Groundwater
Action Level
(Basis for
Selection)

2-methylnaphthalene

-

61.2

-

61.2 (RBC)

Acenaphthene

-

914

-

914 (RBC)

Acenaphthylene

-

362

-

362 (RBC)

Benzene

5

-

-

5 (MCL)

Benzo(a)anthracene

-

0.009

0.13

0.13 (PQL)

Benzo(a)pyrene

0.2

-

-

0.2 (MCL)

Benzo(b)fluoranthene

-

0.005

0.1

0.1 (PQL)

Benzo(k)fluoranthene

-

0.05

0.14

0.14 (PQL)

Chrysene

-

0.85

-

0.85 (RBC)

Cyanide

200

-

-

200 (MCL)

Dibenzo(a,h)anthracene

-

0.0003

0.033

0.033 (PQL)

Ethylbenzene

700

-

-

700 (MCL)

Fluorene

-

490

-

490 (RBC)

Indeno( 1,2,3-cd)pyrene

-

0.005

0.1

0.1 (PQL)

Naphthalene

-

6.2

-

6.2 (RBC)*

Phenanthrene

-

294

-

294 (RBC)

Toluene

1,000

-

-

1,000 (MCL)

Xylenes, total

10,000

-

-

10,000 (MCL)

Manganese

-

' 775

-

775 (RBC)

Cyanide

200

-

-

200 (MCL)

Note:

* The groundwater action level for naphthalene was 6.2 jag/L in the 2006 ROD. It was changed to
1.1 jj.g/L based on a change from health-based levels for noncancer health effects to humans to health-
based levels due to cancer risk to humans. This change was documented in a June 17, 2008,
Memorandum for Record.

Soil action levels were not established as surface soil at the site does not pose an unacceptable level of
risk. Prevention of future exposure to subsurface soil is addressed through institutional controls.

Action levels for indoor air were calculated for benzene and naphthalene based on an excess cancer risk
of 1 x 10"6 and/or a target hazard quotient of 1. The action levels for benzene and naphthalene in indoor
air, established in the ROD, were 0.8 microgram per cubic meter (jag/m3) and 1.3 |ig/m3, respectively.
The action level for naphthalene in indoor air was changed from 1.3 |J.g/m3 to 0.056 |J,g/m3 in a June 17,

18

-------
2008 Memorandum for Record. The action level was modified due to a change from health-based levels
for noncancer health effects to human beings to health-based levels due to cancer risk in humans.

Sediment samples from Ralston Creek were compared against consensus-based probable effects
concentrations (PECs) of PAHs for freshwater ecosystems (nonhuman receptors) as indicators of
possible contribution of contaminants from the site into the creek. PECs are contaminant concentrations
that have been developed for specific compounds above which the inhabitants of a body of freshwater
could be negatively affected. The PECs are listed in Table 3. These levels are significantly lower than
any concentration that would pose a threat to human health, so they are sufficiently low to be protective
of human exposure to creek sediment.

Table 3

RALSTON CREEK SEDIMENT PERFORMANCE STANDARDS
in micrograms per kilogram (jig/kg) dry weight

Contaminant of Performance

Potential Concern Standards

Anthracene

845

Benzo(a)anthracene

1,050

Benzo(a)pyrene

1,450

Chrysene

1,290

Fluoranthene

2,230

Fluorene

536

Naphthalene

561

Phenanthrene

1,170

Pyrene

1,520

Total PAHs

22,800

Remedy Implementation

On November 26, 2008, MidAmerican Energy Company and Iowa-Illinois Manor, LLC, entered into a
Consent Decree to perform a remedial design and remedial actions at the site. Remedial actions include
recovery of LNAPL from monitoring wells; monitored natural attenuation of groundwater; monitoring
of air, sediment, and groundwater; and implementation of institutional controls, including environmental
covenants. The remedial design was started on July 10, 2008, and concluded on January 29, 2010. On-
site construction of the remedial action began on February 17, 2010.

A groundwater monitoring program was designed to monitor groundwater for COCs and natural
attenuation parameters. Groundwater monitoring events have occurred semiannually, generally in April
and October, since October 2009. These data are used to evaluate compliance with groundwater action
levels, groundwater plume stability and remedial action progress via natural attenuation over time.

-------
It was noted in the ROD that the extent of groundwater contamination in bedrock downgradient of the
site had not been fully characterized during the remedial investigation but that this lack of information
would not change the decision regarding the appropriate remedy. It was further noted that determining
this extent of contamination might necessitate a change in the boundaries of the TI zone. In 2011, two
additional monitoring wells were installed to delineate the downgradient extent of contamination in
bedrock and the TI zone. Those wells are MW-56 and MW-57. Based on sampling of those wells, it was
determined that there was no need to change the boundaries of the TI zone as described in the ROD.

An LNAPL recovery plan was developed to manage the recovery of free product from the
unconsolidated aquifer in the vicinity of monitoring well MW-8 on the northern edge of the site. Per the
LNAPL Recovery Plan, LNAPL recovery and gauging will continue in the wells near MW-8 until the
recovery rate is less than or equal to 0.1 gallon per month and the LNAPL thickness remains less than
0.02 foot for 12 consecutive months. LNAPL is recovered through the placement of absorbent "socks"
in the affected wells to passively recover free product.

In October 2009, at the request of the EPA, the dense nonaqueous phase liquid (DNAPL) thickness was
measured and then the DNAPL was removed in two monitoring wells, MW-26 and MW-27, so that a
recovery rate could be determined. Since that time, the DNAPL has been gauged and removed from
those wells at least semiannually.

An indoor air monitoring program was designed to monitor benzene and naphthalene in the crawlspace
beneath the Iowa-Illinois Square apartment building. Air monitoring is conducted in the crawlspace as
this area is directly over the source of contamination and should be unaffected by sources of the
contaminants other than the site. Benzene and naphthalene can be found in many other sources routinely
found in indoor living spaces, such as cigarette smoke. Air samples are collected annually at three
locations, generally in March. The action levels were established in the ROD for indoor air in living
spaces. Since the air that is sampled is not in the actual living space, the indoor air monitoring program
assumed that there was an attenuation factor of 0.01 for samples collected in the crawlspace so
established that as long as the contaminant levels measured in the crawlspace do not exceed 80 |ig/m3
for benzene or 5.6 |ig/m3 for naphthalene it is assumed that the indoor air in the apartments does not
exceed the indoor air action levels and remains protective of human health.

In addition to air monitoring at the Iowa-Illinois Square apartment building, subslab soil gas at another
off-site building located over the contaminated groundwater plume was sampled in 2010 to determine
whether there were potential off-site impacts to indoor air. It was determined that there were no off-site
indoor air impacts due to the site.

A sediment monitoring program was designed to determine whether there are measurable changes in the
concentrations of contaminants entering Ralston Creek sediment from subsurface soil or groundwater.
Sediment samples are collected annually, generally in October, from two locations near the site. One is
at the upstream end of the site and the other is at the downstream end of the site. During the sampling
event, the tile liner of the creek is inspected to determine whether its condition is remaining relatively
the same. It is recognized that the tile liner has not been completely intact since investigations began at
the site but it has served as a barrier to movement of contamination from the site into the creek in the
condition that it was in at the time the remedy for the site was selected.

An institutional control in the form of an environmental covenant has been placed on the site property
(currently occupied by the Iowa-Illinois Square apartment building) and was filed with the Johnson

-------
County Recorder on June 4, 2009. The environmental covenant prohibits installation of wells on the site,
other than monitoring wells, restricts excavation deeper than six feet below grade without prior
notification and approval of the EPA except in cases of emergency, and requires notification to the EPA
a minimum of 60 calendar days prior to transfer of title of the property or change in use.

An institutional control in the form of an environmental covenant has been placed on the stretch of
Ralston Creek located west of the site and was filed with the Johnson County Recorder on December 15,
2010. The environmental covenant prohibits installation of wells on the site, other than monitoring wells
and restricts excavation or other disturbance to the tile lining without prior notification and approval of
the EPA, except in cases of emergency.

System Operations/Operation and Maintenance

Operation and maintenance activities at the site include semiannual groundwater monitoring, periodic
LNAPL and DNAPL gauging and recovery, annual inspection of the Ralston Creek tile liner, annual
sediment sampling, annual inspection of the liner and venting system beneath the Iowa-Illinois Square
apartment building and annual sampling of the crawlspace air beneath the building. The condition of all
monitoring wells is noted during each sampling event. The condition of the tile liner in Ralston Creek is
noted during annual sediment sampling and during the last two years representatives of the city have
been present to discuss maintenance of the creek banks. LNAPL recovery has occurred consistent with
the LNAPL Recovery Plan in the Remedial Design.

The operation and maintenance (O&M) costs are shown in the following table. The actual costs were
provided by MidAmerican Energy Company.

Table 4
O&M COSTS

Year

Approximate Cost

2010

$87,000

2011

$282,000

2012

$61,000

2013

$91,000

2014 (January-October)

$65,000

TOTAL

$586,000

These costs are consistent with the O&M costs for this remedy in the ROD, which are estimated to be
approximately $82,000 per year during this period. Not included in that estimate was the additional air
monitoring that occurred in a building over the groundwater plume in 2010 and the installation of two
deep monitoring wells in 2011. These activities account for the elevated costs in 2011.

II. PROGRESS SINCE THE LAST REVIEW

This is the first FYR for this site.

-------
III. FIVE YEAR REVIEW PROCESS

Administrative Components

MidAmerican Energy Company, the property owner, the city and the state were notified of the initiation
of the FYR. The FYR team was led by Diana Engeman, the EPA Remedial Project Manager for the site.
EPA support personnel on the FYR team included a hydrogeologist, human health and ecological risk
assessors, the site attorney and the community engagement specialist. A representative of the Iowa
Department of Natural Resources reviewed the FYR Report.

The review, which began on January 28, 2014, consisted of the following components:

• Community Involvement

• Document Review

• Data Review

• Site Inspection

• Five-Year Review Report Development and Review
Community Notification and Involvement

Activities to involve the community in the five-year review process were initiated with a notice that was
published in the local newspaper, the Iowa City Press Citizen on April 18, 2014, stating that the EPA
was conducting a review of the remedy at the site and inviting the public to submit any comments to the
EPA. The results of the review and the report will be made available at the site information repository
located at Iowa City Public Library, 123 South Linn Street, Iowa City, Iowa. The EPA did not receive
any comments from the public during the FYR.

Document Review

This FYR consisted of a review of relevant documents including annual progress reports and monitoring
data. Applicable groundwater, sediment and air cleanup standards as listed in the September 2006 ROD,
as modified by a memorandum dated June 17, 2008, were reviewed. A list of documents reviewed is in
Attachment 1.

Data Review

Groundwater

Groundwater sampling has occurred semiannually, in April and October, since the start of the remedial
action in 2010. Several of the wells have been sampled periodically since 1999. Sampling is conducted
to determine if COC concentrations in groundwater outside the TI zone comply with the action levels
and natural attenuation processes are sufficient to maintain COC compliance with action levels outside
the TI zone. During each sampling event, water levels are measured in wells so that groundwater flow
direction may be determined in each of the water-bearing units. The unconsolidated aquifer at the site is
an unconfined unit that has been divided into two units, referred to as the water table zone and the
bedrock surface zone, to facilitate evaluation. The groundwater flow at the water table is westerly at the
site with an overall southwesterly flow in this zone, toward the Ralston Creek channel. Groundwater
flow at the bedrock surface is consistently in a southwesterly direction at the site. Groundwater flow in
the Devonian and Silurian bedrock aquifers is southwesterly at the site.

-------
Compliance with action levels outside of the TI zone is evaluated by sampling seven compliance
monitoring wells: MW-7, MW-29, MW-33, MW-35 MW-41, MW-56 and MW-57, for the COCs listed
in Table 2. Well locations can be referenced in Figure 2. Compliance with the action levels is
determined by performing a statistical hypothesis test. A 95-percent upper confidence level (UCL) of the
true mean concentration for each COC is calculated using data from the site. By definition, the 95-
percent UCL of the true mean concentration of a COC at a monitoring well is a value that, when
calculated repeatedly for randomly drawn data sets, equals or exceeds the true mean concentration of the
COC 95-percent of the time.

Thirteen of the seventeen COCs have not been detected in any of the seven compliance monitoring wells
during the remedial action monitoring events. The 13 COCs that have not been detected are benzene,
toluene, ethylbenzene, xylenes, acenaphthylene, benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, debenzo(a,h)anthracene, indeno(l,2,3-cd)pyrene
and cyanide. In the unconsolidated aquifer, only manganese at MW-7 exceeded the action level.
Manganese levels have fluctuated above the risk-based level during sampling events since the
implementation of the remedial action. Because MW-7 is upgradient of the TI zone and the site, and
manganese is not present in other compliance wells in the unconsolidated aquifer, it is probable that
elevated levels of manganese in this well are naturally occurring and not site-related.

In the bedrock aquifer, the action level for naphthalene was exceeded at MW-35 in October 2010 and
April 2013. However, the April 2013 detection of naphthalene at 1.11 ng/L only exceeded the action
level of 1.1 ng/L by a very small amount and was also detected in the associated method blank, bringing
into question the validity of this value. Manganese exceeded the action level at MW-33 in April 2010.
The exceedances of naphthalene and manganese have been sporadic and do not indicate any plume
stability issues. There have been no other exceedances of an action level in the compliance monitoring
wells in the bedrock aquifer. Attachment 2 lists the groundwater monitoring results.

Containment of the contaminated groundwater plume within the TI zone through natural attenuation
processes is evaluated through analysis of COC concentrations and plume stability. Trends in
contaminant mass and plume stability provide the primary line of evidence of the natural attenuation of
COCs. Geochemical data provide a secondary line of evidence of natural attenuation by indicating
destruction of COC mass through biodegradation processes. Concentrations of COCs are measured at
wells within the Tl zone as well as at the compliance wells outside the TI zone to evaluate the COC
distribution throughout the plume. The Mann-Kendall trend test analysis is used to identify increasing
and decreasing concentration trends at the 90-percent confidence level for each COC detected in each
monitoring well. Detailed analyses of each COC at each monitoring well is included in each Remedial
Action Annual Report. Numerous field measurements and laboratory analyses were performed to
evaluate the destruction of COC mass through biodegradation processes. Detailed analyses of these data
are reported in each Remedial Action Annual Report.

Attachment 4 is a table that shows the most recent summary of this trend analysis. The contaminated
groundwater plume appears to be stable, however, 8 of 13 wells sampled within the TI zone has at least
one COC with a statistically significant increasing concentration trend. These data also indicate that 17
of 19 COCs exhibit no statistically significant trend or a statistically significant decreasing concentration
for each of the seven compliance monitoring wells which are outside of the TI zone. Naphthalene was
determined to be statistically increasing at MW-35 at the 90-percent confidence level. Manganese was
determined to be statistically increasing at MW-35 but has not exceeded the action level since October
2003. The furthest downgradient monitoring wells within the TI zone are MW-36 and MW-37, which

-------
are located approximately 75 feet from the southwest boundary of the TI zone. Benzene exceeded the
MCL in samples from these wells in 2013. In addition, six COCs have statistically significant increasing
concentration trends at these wells but have not ever exceeded the action level. Compliance wells MW-
56 and MW-57 are over 500 feet downgradient of MW-36 and MW-37 therefore it is possible for
elevated levels of benzene to exist in groundwater in the area between these monitoring points.

Locations of the monitoring wells were determined based on the ability to obtain access to the property
for well installation and continue to have access for long-term monitoring. It is difficult to place
monitoring wells in technically optimal locations in an area as highly developed as the one where this
plume is located.

It has been concluded that natural attenuation of organic COCs is occurring as depth increases through
various microbial degradation processes along the groundwater flow path to the southwest.

Based on limited exceedances of COCs in compliance monitoring wells, and the evidence that
biodegradation is occurring within the TI zone, it is concluded that the plume is stable and the TI zone
established in the 2006 ROD is still appropriate.

LNAPL Gauging and Recovery

Significant quantities of LNAPL were observed in monitoring wells LMW-4, MW-2, MW-8, MW-44,
MW-47 and MW-48 during the course of investigations at the site. Prior to completion of the feasibility
study, a treatability study was conducted to assess vacuum extraction for recovery of LNAPL. During
the course of that treatability study, which took place from April through August 2005, approximately
105 gallons of LNAPL were removed from LMW-4, MW-8 and MW-48 through vacuum extraction,
with the rate decreasing significantly with each recovery event. It was determined through data gathered
during that study that the use of absorbent socks would be the most effective method to remediate
residual LNAPL.

Six monitoring wells that are within the TI zone were originally designated as LNAPL recovery wells in
the LNAPL Recovery Plan. The wells are LMW-4, MW-2, MW-8, MW-44, MW-47 and MW-48.
Monitoring wells MW-3, MW-45, MW-46, MW-49, MW-50 and MW-51 were gauged to monitor for
potential migration of LNAPL. In general, the plan was to place absorbent socks into wells that had a
measurable amount of LNAPL of greater than 0.02 foot. A sock would remain in the well until a
recovery rate is less than or equal to 0.1 gallon per month and the LNAPL thickness is less than 0.02
foot for 12 consecutive months. Gauging and recovery was to occur every two weeks to begin with and
eventually move to a quarterly basis when the rate of LNAPL recovery warranted the reduced
frequency.

LNAPL gauging and recovery began in March 2010. Biweekly events ended after one month because
the absorbent socks were not fully saturated. Gauging and recovery continued on a monthly basis for
three months and then decreased to a quarterly basis because, once again, the socks were not fully
saturated. LNAPL gauging and recovery continues on a quarterly basis except at MW-46 and LMW-4.
MW-46 was abandoned in 2013 due to an obstruction in the well. LNAPL greater than 0.02 foot in
thickness had not ever been measured in that well. In 2013, LMW-4 met the criteria for termination of
LNAPL recovery and monitoring, as stated in the LNAPL Recovery Plan. That well was re-designated
as a monitoring well.

-------
LNAPL recovery rates at all recovery wells were less than 0.1 gallon per month from March 2010
through 2014 and recovery rates have been very low. LNAPL gauging and recovery will continue as
described in the LNAPL Recovery Plan, with the addition and deletion of recovery wells occurring as
the plan describes and with the approval of the EPA.

DNAPL Gauging and Recovery

DNAPL recovery was not a component of the remedy selected in the ROD but in 2011 the EPA
requested that MidAmerican Energy add semiannual DNAPL gauging and recovery at MW-26 and
MW-27. This request was made by the EPA due to investigative work done in 2009 and 2010 to
determine the rate of DNAPL recovery that could be achieved in these two wells which had historically
been found to have significant amounts on DNAPL in them. DNAPL gauging and recovery was
conducted semiannually in 2011 and quarterly since 2012. Since 2009, 25.5 gallons of DNAPL have
been removed from MW-26 and 6.1 gallons from MW-27. While the rate of DNAPL recovery has
decreased in both wells over this time period, significant quantities of DNAPL continue to be recovered
and current plans are to continue to do so in the future.

Ralston Creek Sediment Sampling and Liner Inspection

Sediment sampling and creek liner inspection have been conducted annually since 2010 to determine
whether changes have occurred that may result in movement of contamination from the subsurface at the
site into the sediment of Ralston Creek. It was recognized at the time the ROD was written that there
were multiple off-site sources of the same contaminants found at the site making their way into the creek
but the levels of those contaminants were found at higher levels in sediment adjacent to the site.

Ensuring that the levels of those contaminants did not increase over time would ensure that the sediment
in the creek did not pose an unacceptable level of risk to ecological receptors or humans. In the ROD, it
was recognized that the liner, while not fully intact, does provide a physical barrier between
contamination at the site and the creek sediment.

Sediment is sampled at one upstream and one downstream location annually and analyzed for total
PAHs and nine COCs: anthracene, benzo(a)anthracene, benzo(a)pyrene, chrysene, fluoranthene,
fluorene, naphthalene, phenathrene and pyrene. Figure 3 shows the sediment sampling locations.
Attachment 3 lists the sediment sampling results. At the upstream sampling location, RC-4, only one
COC, naphthalene, exceeded the performance standard during one sampling event in April 2010. At the
downstream sampling location, RC-5, naphthalene has exceeded the performance standard in 2010,
2011 and 2012. In November 2011, benzo(a)anthracene, chrysene, fluoranthene, phenanthrene and
pyrene were also above their respective performance standards at RC-5. The concentrations of COCs
have been highly variable over time, likely due to the transient nature of sediment in creek channels. It
will be more valuable to evaluate trends in the data rather than relying on the assessment of individual
data points. The Mann-Kendall analysis has been used to evaluate trends but to date, no statistical trends
at the 90-percent confidence level were evident. In addition to review of trends, statistical testing using a
95-percent UCL of the true mean concentration for each COC will be conducted once the minimum of
eight samples needed have been collected. Data will continue to be collected annually and those results
will provide a more robust data set with which to conduct the statistical trend and mean analyses.

The creek liner is inspected annually when the sediment samples are collected. One of the most
significant observations during these inspections has been the amount of vegetation growing along the
steep creek banks. Small vegetation is needed to maintain the stability of the creek bank but large trees
growing along the bank, with roots pushing into the liner, are likely to damage the liner. This has been

-------
brought to the attention of the city and they have made a commitment to remove the woody growth. The
tile liner has never been in particularly good condition and it has been noted during the annual
inspections that further degradation appears to be occurring, likely due to freeze-thaw cycles. This was
also discussed with representatives of the city during the five-year review inspection and they
acknowledged that it was in the city's best interest to maintain the stability of the creek bank. They said
they were willing to look into whether there was anything they might be able to do to provide at least
minimal maintenance of the liner.

Air Monitoring and Building Inspection

Air sampling of the air in the crawlspace of the Iowa-Illinois Square apartment building has been
conducted annually since March 2010. Air samples are collected from three locations and analyzed for
naphthalene and benzene, the two contaminants in groundwater that are sufficiently volatile to move
from the subsurface soil or groundwater into the crawlspace air. The air monitoring results are shown in
Table 5. The air sampling locations are shown in Figure 4.

26

-------
Table 5

AIR MONITORING RESULTS

in Eig/m3

Sample Location

Sample Date

Parameter (jig/m3)

Benzene

Naphthalene

SP-N

March 15-16,2010

ND*

ND

SP-N

March 10-11,2011

0.65

ND

SP-N

March 15-16, 2012

0.68

ND

SP-N

March 12-13,2013

ND

ND

SP-N

March 13-14,2014

0.60

ND

SP-C

March 15-16, 2010

ND

ND

SP-C

March 10-11,2011

0.81

ND

SP-C

March 15-16,2012

0.81

ND

SP-C

March 12-13,2013

ND

ND

SP-C

March 13-14, 2014

0.81

ND

SP-S

March 15-16, 2010

ND

ND

SP-S

March 10-11,2011

0.74

ND

SP-S

March 15-16, 2012

0.79

ND

SP-S

March 12-13,2013

0.66

ND

SP-S

March 13-14, 2014

1.0

ND

DUPLICATE SP-S

March 15-16,2010

ND

ND

DUPLICATE SP-S

March 10-11,2011

0.75

ND

DUPLICATE SP-C

March 15-16,2012

0.85

ND

DUPLICATE SP-N

March 12-13,2013

ND

ND

DUPLICATE SP-N

March 13-14, 2014

0.58

ND

* ND—Non-detect

As described previously, since the air that is sampled is not in the actual living space, the Air Monitoring
Plan established that as long as the contaminant levels measured in the crawlspace do not exceed
performance standards of 80 |ig/m3 for benzene or 5.6 ng/m3 for naphthalene it could be assumed that
the indoor air in the apartments would not exceed the action levels. This was based on an assumption
that an attenuation factor of 0.01 for the crawlspace was appropriate. During the past five years
naphthalene has not been detected in crawlspace air above the detection limit of 2.6 ng/m3. Benzene has
been detected on several occasions with concentrations ranging from 0.58 to 1.0 ng/m3, well below the
performance standard of 80 |ig/m3.

Recently the EPA has revised guidance pertaining to vapor intrusion sampling that establishes an
attenuation factor of 1.0 when using crawlspace samples to predict indoor air levels, rather than an
attenuation factor of 0.01. This means that the air sampling results obtained in the crawlspace should be
compared to the indoor air action levels to determine protectiveness. The benzene levels that have been

27

-------
detected in the crawlspace air, in Table 5, exceeded the established indoor air action levels of 0.85
Hg/m3 in 2014. Although the action level was exceeded, the sampling result is still within the acceptable
cancer risk range of lxlO"4 to 1x10". Changes to the Air Monitoring Plan need to be made to reflect the
change in attenuation factor for the crawlspace air sampling. It would also be advisable to determine
whether an analytical method exists that could achieve lower detection limits for both compounds.

During each air sampling event, the condition of the passive venting system and the liner that is under a
portion of the crawlspace is observed. The venting system has always been unobstructed and the liner,
with a thick layer of gravel over the top, has been undisturbed.

Site Inspection

The inspection of the site was conducted on July 7 and 8, 2014. In attendance were Diana Engeman,
EPA project manager; Venessa Madden, EPA ecological risk assessor; Bryan Clark, property owner;
Jennifer Mclvor, Environmental Manager for MidAmerican Energy Company; Kevin Armstrong,
MWH, project manager for MidAmerican's environmental consultant; Ron Knoche, City Engineer, city
of Iowa City; and Ben Clark, Senior Civil Engineer, city of Iowa City. The purpose of the inspection
was to assess the protectiveness of the remedy. The Site Inspection Report is Attachment 5.

The building owner provided access to the crawlspace beneath the Iowa-Illinois Square apartment
building so that conditions there could be observed. There is nothing stored in the crawlspace that could
impact air sampling. The area with the liner cover with gravel was undisturbed.

The members of the city engineering office were present to discuss maintenance of the eastern bank of
Ralston Creek. The city provides maintenance of the creek bank and earlier in the summer had done
some trimming of vegetation on the eastern bank. However, the woody growth along the eastern bank
was not removed and several trees have grown up over the years in that area. While vegetation of the
creek banks helps to maintain the stability of the steep slope, tree roots will tend to have a destructive
effect on the tile liner. The EPA asked that trees and woody growth be removed and continue to be
removed periodically. The city engineer agreed that they could do that. The site inspection also included
an examination of the tile liner conditions, to the extent that it was possible to do so because the water
level was a bit higher than normal and vegetation covered a lot of the liner. The EPA requested that the
city consider more aggressive maintenance to improve or maintain the condition of the liner on the
eastern bank of the stretch of the creek adjacent to the site as it is a physical barrier that limits the
movement of site contaminants into the surface water and sediment in that area.

The city inquired whether the EPA had any grants available that might assist them in their liner
maintenance effort. At this time there are no EPA grant monies available to fund the tile liner and creek
bank maintenance efforts. The city engineer confirmed that maintaining a stable creek bank is something
that the city recognizes as important.

IV. TECHNICAL ASSESSMENT

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

Remedial Action Performance

The remedy is performing as expected, with natural attenuation processes continuing to occur in the
contaminated groundwater plume within the TI zone as demonstrated through evaluation of the

-------
contaminant concentrations and natural attenuation parameters that are sampled. Groundwater outside of
the TI zone in the unconsolidated aquifer is meeting the action levels except for sporadic exceedances of
manganese at MW-7. This well is upgradient of the site contamination source so it is likely that the
manganese is naturally occurring and not the result of contamination from the site. In the bedrock
aquifer, the action level for naphthalene was exceeded at MW-35 in October 2010 and April 2013.
However, the April 2013 detection of naphthalene at 1.11 jig/L only exceeded the action level of 1.1
(a,g/L by a very small amount and was also detected in the associated method blank, bringing into
question the validity of this value. Due to the sporadic exceedances and recent sampling results, it was
determined that these results were not indicative of a remedy issue. Manganese exceeded the action level
at MW-33 in April 2010 but has not exceeded risk-based levels since that sampling event in the bedrock
aquifer. There have no other exceedances of an action level in the compliance monitoring wells in the
bedrock aquifer.

Data for each COC in groundwater were statistically evaluated annually for concentration trends using
the Mann-Kendall test. This test is used to identify increasing and decreasing concentration trends at the
90-percent confidence level for each COC detected at each monitoring well. Based on this analysis for
COCs in each well, the contaminated groundwater plume appears to be stable.

Numerous geochemical parameters are measured to determine the presence and identity of
biodegradation processes occurring within the groundwater plume. A detailed description of these
processes are included in each Remedial Action Annual Report. In general, the data analysis supports
the conclusion that intrinsic bioremediation is occurring to some degree throughout the contaminated
groundwater plume.

Sediment sampling results have been quite variable, with six of the nine COCs exceeding the
performance standards in one downstream sample in 2011, compared to one COC exceedance in 2012
and none exceeded in 2013. As additional samples are collected, the statistical analysis of this data will
become more robust. The condition of the tile lining has not degraded significantly during the remedial
action but there are areas of damage, which was discussed with representatives of the city during the
five-year review inspection.

LNAPL gauging and recovery continues consistent with the LNAPL Recovery Plan. Six wells are
identified as recovery wells and an additional six wells were gauged. One of the wells that was gauged,
MW-46, was plugged and abandoned in 2013 due to an obstruction in the well. One recovery well,
LMW-4, was reclassified as a monitoring well in 2013 because it met the criteria for termination of
LNAPL recovery as laid out in the LNAPL Recovery Plan. LNAPL recovery continues at a very low
rate in the remaining five recovery wells Since implementation of the remedy, the PRP have been
recovering DNAPL from two additional bedrock wells where DNAPL has historically been found in
recoverable quantities. DNAPL recovery will continue from these two wells.

The vapor intrusion mitigation system components (liner and passive venting) are operating as intended
in the crawlspace. Air in the crawlspace beneath the Iowa-Illinois Square apartment building is
monitored through annual sampling for benzene and naphthalene, the COCs present at the site that are
sufficiently volatile to potentially move from groundwater into air. While benzene has been detected in
air in the crawlspace and has exceeded the indoor air action level action level in March 2014 and in a
duplicate sample in March 2012, these levels did not exceed the acceptable cancer risk range that would
indicate it could pose a health threat for indoor air for apartment dwellers. Naphthalene has not been
detected above the analytical detection limit. In the future it will be advisable to determine whether an
analytical method is available that can achieve lower detection limits for both compounds.

-------
System Operations/O&M	J

The operating procedures, as currently implemented, continue to maintain the effectiveness of the
remedy and are expected to do so in the future. Requests to modify the operating procedures will be
reviewed by the EPA when any requests are made. The process for DNAPL recovery will be added to
the LNAPL Recovery Plan. In addition, the EPA is working with the city to develop a more robust
maintenance plan for woody vegetation and tile integrity in Ralston Creek.

Implementation of ICs and Other Measures

An institutional control in the form of an environmental covenant was filed with the Johnson County
Recorder on June 4, 2009, on the site property, currently occupied by the Iowa-Illinois Square
apartments. The environmental covenant prohibits installation of wells on the site, other than monitoring
wells, restricts excavation deeper than six feet below grade without prior notification and approval of the
EPA except in cases of emergency, and requires notification to the EPA a minimum of 60 calendar days
prior to transfer of title of the property or change in use. This institutional control remains protective,
and has resulted in notification to the EPA twice in the past five years that excavation was required in
areas that were potentially contaminated, ensuring that appropriate measures were taken to protect
workers and the public from exposure and proper disposal of contaminated soil.

An institutional control in the form of an environmental covenant was filed with the Johnson County
Recorder on December 15, 2010, on the stretch of Ralston Creek located west of the site. The
environmental covenant prohibits installation of wells on the property, other than monitoring wells and
restricts excavation or other disturbance to the tile lining without prior notification and approval of the
EPA, except in cases of emergency. This institutional control continues to be protective.

Institutional controls in the form of a state rule governing installation of wells in areas of contamination,
a city code requiring connection to the public water supply and a county ordinance requiring notification
regarding setbacks from contamination for groundwater well installation remain in force and provide
additional layers of protection.

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

Changes in Standards and To-Be-Considereds (TBCs)

• Have there been changes to risk-based cleanup levels or standards identified as ARARs in the
ROD that call into question the protectiveness of the remedy?

In 2008, the ROD was modified by memorandum to change the action levels for naphthalene in
groundwater and indoor air because a significant change was made to the toxicity values for that
compound which made the previous action levels not sufficiently protective. The revised action
levels in the ROD are protective and reflect the latest science and toxicity information.

No other changes to ARARs or the ROD have been made, and the action levels remain
protective of potential current/future land and resource uses.

30

-------
Are there newly promulgated standards that call into question the protectiveness of the remedy?
No new standards have been promulgated.

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

Ecological TBCs are based on Probable Effect Levels (MacDonald et al., 2000), which have not
changed.

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 of the site remains unchanged but the use of two parcels of property adjacent to or very
near the site have changed since implementation of the remedial action. An apartment building
has been constructed to the south of the site on property previously occupied by two auto
garages. According to the owner of this building, it was constructed on a slab with the garages
occupying the ground level of the building. To the west, across Ralston Creek, the Burlington
Commons apartment building was constructed on property previously occupied by Hanson Auto
Body Shop.

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 protectiveness of the remedy?

No new contaminants, exposure pathways or receptors have been identified.

Are there newly identified contaminants or contaminant sources?

We are not aware of any new contaminants.

Are there unanticipated toxic byproducts of the retnedy not previously addressed by the decision
documents (e.g., byproducts not evaluated at the time of remedy selection)?

No toxic by-products of the remedy have been identified.

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

The tile lining of Ralston Creek is deteriorating partially due to vegetation growing through the
tiles. This lining provides a protective barrier for the creek, as it blocks migration of some of the
site-related waste. If the liner continues to deteriorate, contaminant concentrations in the
sediment may increase. Therefore, the EPA has requested that the city assist with the
maintenance of the liner by removing the woody vegetation that has become established along
the eastern bank of the creek. The city engineer said they were agreeable to this request.

-------
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?

There have been some changes to the toxicity factors which have changed the regional screening
levels (RSLs) found in the Regional Screening Levels Summary Table
(http://www.epa.gov/region9/superfund/prg/), however none of the changes rise to the level of
significance that would call into question the protectiveness of the remedy. The default exposure
factors were modified in February 2014, therefore some RSLs may have increased based on
current information, while others decreased. The overall impact of those changes may make a
particular RSL increase or decrease, however, the overall effect on the contaminants for this site
does not call into question the protectiveness of the remedy.

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

No.

Changes in Risk Assessment Methods

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

There were no changes to the human health or ecological standardized risk assessment
methodologies that would affect the protectiveness of the remedy.

Recently, vapor intrusion guidance has modified the attenuation factor to 1.0 when using
crawlspace samples to predict indoor air levels, rather than an attenuation factor of 0.01. This
means that the air sampling results obtained in the crawlspace should be compared to the indoor
air action levels to determine protectiveness. The most recent sampling events were analyzed
using the 1.0 attenuation factor and both benzene and napthalene concentrations remain within
the acceptable risk range for both contaminants. Due to this change, it is recommended that
changes to the Air Monitoring Plan be made to reflect the change in attenuation factor for the.
crawlspace air sampling. It would also be advisable to determine whether an analytical method
exists that could achieve lower detection limits for both compounds.

Expected Progress Toward Meeting RAOs

The remedy is progressing as expected toward meeting the RAOs.

The remedy is preventing human exposure to groundwater containing COCs that exceed
applicable or relevant and appropriate requirements (ARARs) or health-based levels.

The remedy is preventing soil exposure risks to acceptable levels by maintaining the existing
land use. If necessary, the future soil RAO may be reevaluated if the building is removed or its
use changed.

The remedy is preventing human exposure to indoor air containing COCs that exceed health-
based levels.

-------
• The remedy continues to maintain the existing ecological steady state and prevent and/or reduce
future unacceptable risks to human health and the environment in Ralston Creek.

Question C: Has any other information come to light that could call into question the protectiveness of
the remedy? No.

• Have newly found ecological risks been found?

No.

• Are there impacts from natural disasters (e.g., a 100-year flood)?

No.

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

There have been changes in the use of properties near the site but it is not believed that these
changes in land use impact the protectiveness of the remedy. The property directly south of the
site was originally an auto repair facility. That building and another garage to the south of that
building were demolished and a multi-unit residential building was built on the property. It is
owned by the owner of the Iowa-Illinois Square apartment building. Since they were aware of
the potential for contamination related to the site, the building was constructed on a slab with
garage space on the ground level and living spaces above. This should minimize any potential for
vapor intrusion from the site.

The other property where the land use has changed is across Ralston Creek to the west of the
site. Formerly that property was the location of an automotive body shop. That building was
demolished and a multi-unit apartment building was constructed on the property. Previous
sampling of that property did not indicate that this change in use should be of concern.

Technical Assessment Summary

Based upon a review of the analytical data, an inspection of the site and a review of the institutional
controls for the site, the remedy is performing as intended by the ROD. There is no exposure to
groundwater contamination due to the institutional controls that are in place for the plume within the TI
zone. Groundwater monitoring confirms that water outside the TI zone is not exceeding action levels.
Natural attenuation continues to occur within the contaminated groundwater plume.

The LNAPL recovery system has been effective in reducing the volume of LNAPL in the subsurface
and continues to function as designed. DNAPL recovery from two bedrock wells has been implemented.
This activity is planned to continue and will be incorporated into the LNAPL Recovery Plan.

The implementation of institutional controls for Ralston Creek and maintenance of the creek bank and
liner have been effective in maintaining the ecological steady state in the creek. Improved maintenance
of the eastern creek bank and liner by the city will aid in the future protectiveness of the element of the
remedy.

-------
The crawlspace liner and passive venting system continue to prevent exposure to indoor air containing
contaminants above health-based levels as has been demonstrated by air monitoring in the crawlspace.
In the future, levels of air contaminants measured in the crawlspace will be compared to the indoor air
action levels due to a change in the attenuation factor from 0.01 to 1.0 when comparing crawlspace air
samples to indoor air levels. The EPA will work with the PRP to determine if the analytical methods for
indoor air should be modified to allow for lower detection limits.

V. ISSUES/RECOMMENDATIONS AND FOLLOW-UP ACTIONS

There are no issues that adversely affect current or future protectiveness of the remedy.

The following recommendations are technical improvements but do not affect the protectiveness of the
remedy were identified:

• The analytical method utilized for air samples should be reviewed to determine whether a
method is available with detection limits below the indoor air action levels.

• Since the attenuation factor for comparison of crawlspace air samples to indoor air levels is now
1.0, crawlspace air samples should be compared to the air action levels rather than performance
standards that are two orders of magnitude greater than the action levels. The Air Monitoring
Plan should be modified to document this change to the data evaluation protocol and action
levels.

• DNAPL recovery has begun from two monitoring wells with significant product recovery.
DNAPL recovery from these wells will continue and the LNAPL Recovery Plan should be
modified to reflect this change.

During the site inspection, evidence of deterioration of the tile liner in Ralston Creek was identified. The
EPA will work with the city to develop plans for removal of woody vegetation and alternatives to
improve tile liner integrity.

VI. PROTECTIVENESS STATEMENT

Sitewide Protectiveness Statement

Protectiveness Determination: Addendum Due Date (if applicable):

Protective Click here to enter a date.

Protectiveness Statement:

The remedy for the Iowa City FMGP is protective of human health and the environment.

VII. NEXT REVIEW

The next FYR report for the Iowa City Former Manufactured Gas Plant Superfund site is required five
years from the completion date of this review.

-------
FIGURE 1
Current Site Layout

-------
c

c

UW-27a

LJ

LM#-3

~I

	' LMW-S

~

LMW-2 .

• LM * -6

v_

J





l



u
~

LEGEND-

lmw. WATER TABLE MONITORING WELL (L&M MIGHTY SHOP SITE)
WATER TABLE MONITORING WELL (FMGP SITE)

~ BEDROCK SURFACE MONITORING WELL

NOTES'

1.	HISTORIC STRUCTURES SHOWN IN BLUE.

2.	HISTORIC MAP SOURCE = 1926 & 1933
SANBORN FIRE INSURANCE MAPS

APPROVED >V

JAMCT IMJMflN

tOEVW AMttTftONO

KEVW MttttTKMO

SO

SCALE IN FEET

MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE
IOWA CITY, IOWA

1TOT

SITE LAYOUT

-------
FIGURE 2

Site Vicinity and Current Groundwater Monitoring Network

-------
_

-------
FIGURE 3

Ralston Creek Sediment Sampling Location & Tile Liner Inspection Area

-------
Lj u

il

L..J,

~

•LMW-6

J

L

~

BURLINGTON STREET

LEGEND:

LMW* WATER TABLE MONITORING WELL

•	BEDROCK MONITORING WELL

~	BEDROCK SURFACE MONITORING WELL
o ABANDONED WELL

RC © RALSTON CREEK SEDIMENT SAMPLING LOCATION

I TILE LINER INSPECTION AREA

APPROVED BY

PROJECT MANAGER

KEVIN ARMSTRONG

KEVW ARMSTRONG

KEVIN ARMSTRONG

KEVIN ARMSTRONG

MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE
IOWA CITY, IOWA

RALSTON CREEK
SEDIMENT SAMPLING LOCATIONS
AND TILE LINER INSPECTION AREA



MWH

2-2

-------
FIGURE 4
Air Sampling Locations

-------
Figure 4

BURLINGTON STREET

l-ECEMfr

iMWt WATER TASLt* MONTOKING WEU. (LfcM MIGHT V SHOP SITE)
W«TEH TABLE MONITORING WELL (FUBP SirE)

*¦ BEDROCK SURFACE UOMTOHWC WELL
®AIK SAMPLING LOCATION (ESI)
tl AkBIENT MR SAMPLING LOCATION 

920 tt 1S.U
' SANBORN FIRE INSURANCE MAPS

I

® MWH

On Mln«l

MtOAUERICAN ENCKGT COMPANY
FORMER MANUFACTURED
CAS PLANT SHE

iowa cny. iowa

AIR SAMPLING LOCATIONS

43

-------
ATTACHMENT 1

List of Documents Reviewed

-------
ATTACHMENT 1

DOCUMENTS REVIEWED

Record of Decision, Iowa City Former Manufactured Gas Plant Site, Iowa City, Iowa, prepared by
USEPA, September 26, 2006.

Letter regarding Further Evaluation of Metals in Groundwater, from MWH to USEPA, January 17,
2008.

Letter regarding Approval of Elimination of Some Metals from List of COCs, USEPA to MidAmerican
Energy Company, April 10, 2008.

Memorandum for Record regarding Record of Decision Modification, Change to Action Levels for
Naphthalene in Groundwater and Indoor Air, prepared by USEPA, June 17, 2008.

Consent Decree, Docket Number 3:08-cv-0133-JAJ, November 26, 2008.

Quality Assurance Project Plan for Air Monitoring, prepared by Stanley Consultants, Inc., April 2009.

Air Monitoring Program, prepared by Stanley Consultants, Inc., April 2009.

Environmental Covenant, Iowa-Illinois Manor, LLC, May 21, 2009.

Remedial Design Report, prepared by MWH, November 11, 2009.

Air Sampling Report, prepared by Stanley Consultants, Inc., May 2010.

Air Annual Progress Report, prepared by Stanley Consultants, Inc., July 2010.

Environmental Covenant, City of Iowa City, December 15, 2010.

Remedial Action Annual Report 2010, prepared by MWH, March 2011.

Air Sampling Report, prepared by Stanley Consultants, Inc., April 2011.

Air Annual Progress Report, prepared by Stanley Consultants, Inc., June 2011.

Remedial Action Annual Report 2011, prepared by MWH, February 2012.

Air Sampling Report, prepared by Stanley Consultants, Inc., April 2012.

Air Annual Progress Report, prepared by Stanley Consultants, Inc., August 2012.

Remedial Action Annual Report 2012, prepared by MWH, February 2013.

Air Annual Progress Report, prepared by Stanley Consultants, Inc., July 2013.

Remedial Action Annual Report 2013, prepared by MWH, February 2014.

-------
A'VSamP,'n« Report, prepared bvst ,

^'r Annua] Progress Re o "	^ •, May 2014

nc; Decernber 2014

-------
ATTACHMENT 2
Groundwater Monitoring Results

-------
/ \	/ Nn

1

y

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW03-GW-001 MW03-GW-002 MW03-GW-003 MW03-GW-004 MW03-GW-0410 MW03-GW-1010 MW03-GW-0411
Standard 25-Oct-1999 22-Jun-2000 11-Jul-2001 12-Dec-2001	09-Apr-2010	06-0ct-2010	13-Apr-2011

DV

VOCs

Units































Benzene

MQ/L

5

175



56



139



125



1540



134



81.8



Toluene

t-tg/L

1000

38.8



7.6



74.3



' 19.7



934



29.0



37.2-



Ethyl benzene

M9/L

700

363



113



382



355



1460

C9 J+

492



298



Xylenes, Total

(jg/L

10000

278



96.6



259



286



1280



285



206



PAHs

































Acenaphthene

Hg/L

914

25.6



8.89



23.8



26.4



209



76.5



35.3



Acenaphthylene

ug/L

362

37.5



9.43



20.4



0.19

U

177



11.8



5.75



Anthracene

ug/L

...

0.69



0.54



0.65



1.03



136



2.47



0.994



Berizo(a)anthracene

Mg/L

0.13

0.10

U

0.10

U

0.10

U

0.10

U

51.7



0.100

U

0.111

U

Benzo(a)pyrene

mq/l

0.2

0.10

U

0.10

U

0.10

U

0.10

U

35.3



0.100

U

0.111

U

Benzo(b)fluoranthene

pg/L

0.1

0.10

U

0.10

U

0.10

U

0.10

U

29.1



0.100

U

0.111

U

Benzo(ghi)perylene

|jg/L

...

0.10

U

0.10

U

0.10

U

. 0.10

U

9.36



0.100 .

U

0.111

U

Benzo(k)fluoranthene

ijg/L

0.14

0.10

U

0.10

U

0.10

U

0.10

U

7.16



0.100

U

0.111

U

Chrysene

|jg/L

0.85

0.10

U

0.10

U

0.10

U

0.10

U

40.9



0.100

U

0.111

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.10

U

0.10

U

0.10

U

0.22



2.67

MDL

0.00810

U.MDL

0.111

U

Fluoranthene

ng/L

...

0.10

U

0.23



0.10

U

0.10

U

110



0.337



0.231



Fluorene

Mg/L

490

11.5



3.22



11.7



18.4



184



28.4



10.2



lndeno(1,2,3-cd)pyrene

ng/L

0.1

0.10

U

0.10

U

0.10

U

0.10

U

8.49



0.100

U

0.111

U

Naphthalene

(jg/L

1.1

493



2.83

J

438



501



5370



309



119



Phenanthrene

ng/L

294

7.6



0.58



6.59



12



348



8.18



3.80



Pyrene

^g/L

...

0.19

U

0.19

U

0.19

U

0.19

U

97.7



0.302



0.111

U

1-Meth'ylnaphthalene

ijg/L

...

na



na



na



208



793



288



149



2-Methylnaphthalene

. pg/L

61.2

7.1



0.72



6.13



7.82



132



0.931



0.216



Inoraanics

































Cyanide, Total

mg/L

...

8.4



3.21



5.63

J

3.2



na



na







Cyanide, WAD

mg/L

0.2

na



na



na



na



0.0100

U

0.0100

U.CN5

0.0100

U,CN5

Manganese, Total

mg/L

0.775

4



2.8



2.52



2.77



2.45



2.54



1.71



Natural Attenuation Parameters

































Nitrate

mg/L

...

1.0 '

U

1.0

U

1.0

UJ

na



na



na



na



Nitrite

mg/L



na



na



na



na



na



na



na



Ammonia

mg/L

...

18



5.27



13.6



na



na



na



na



Manganese, Dissolved

mg/L

...

na



na



2.08



2.5



na



na



na



Iron, Dissolved

mg/L

...

na



na



0.20



0.14



na



na



na



Sulfate

mg/L

...

110..



440



120



na



na



na



na



Sulfide

mg/L

. ...

.7-5



0.69



5.6



na



na



na



na



Methane

Mg/L

...

na



na



na



na



na



na



na



Alkalinity, Total

mg/L

—

na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na.



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page 1 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW03-GW-1011	MW03-GW-0412	MW3-GW-1012	MW3-GW-0413	MW3-GW-1013 MW12-GW-001

Standard	25-Oct-2011	12-Apr-2012'	10-0ct-2012	11 -Apr-2013	23-Oct-2013	25-Oct-1999

DV	DV	DV	DV	DV

VOCs

Units



































Benzene

pg/L 5

82.2





77.2





91.8





20.1





86.1





10



Toluene

pg/L 100C

I 29.7





23.6





29.7





8.90





26.8





1.0

U

Ethyl be nzene

pg/L 700

344





340





435





76.2





360





1.0

U

Xylenes, Total

pg/L 10000 230





218





266





68.1





238





5.3



PAHs





































Acenaphthene

pg/L 914

41.1

RL1

J-

59.2



J-

60.4



J-

26.1



J-

54.5



J-

16.1



Acenaphthylene

pg/L 362

14.3

RL1

J-

7.47



J-

5.62



J-

5.46



J-

5.58



J-

33.8



Anthracene

pg/L

2.84

RL1

J-

1.07



J-

0.928



J-

0.900



J-

1.01

U

UJ

0.61



Benzo(a)anthracene

pg/L 0.13

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.128

U

UJ

1.01

U

UJ

0.10

U

Benzo(a)pyrene

pg/L 0.2

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.149

U

UJ

1.01

U

UJ

0.10

U

Benzo(b)fluoranthene

pg/L 0.1

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.287

u

UJ

1.01

U

UJ

0.10

U

Benzo(ghi)perylene

pg/L

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.181

u

UJ

1.01

U

UJ

0.10

U

Benzo(k)fluoranthene

pg/L 0.14

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.191

u

UJ

1.01

U

UJ

0.10

U

Chrysene

pg/L 0.85

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.117

u

UJ

1.01

u

UJ

0.10

U

Dibenzo(a,h)anthracene

pg/L 0.033 0.289

RL1.J.MDL J-

0.0170

U,MDL

UJ

0.0130

U.MDL

UJ

0.181

u

UJ

0.172

u

UJ

0.10

U

Fluoranthene

pg/L

1.00

U.RL1

UJ

0.135



J-

0.258



J-

0.521

u

UJ

1.01

u

UJ

0.10

U

Fluorene

pg/L 490

10.4

RL1

J-

20.8



J-

19.1



J-

8.57



J-

17.4



J-

8.7



lndeno( 1,2,3-cd)pyrene

pg/L 0.1

1.00

U.RL1

UJ

0.100

U

UJ

0.100

U

UJ

0.181

u

UJ

1.01

u

UJ

0.10

U

Naphthalene

pg/L 1.1

270

RL1

J-

212

B1,B

B, J'

227



J-

2.62

B

B,J-

100 .

B*

J-,J+,B

3.32

J

Phenanthrene

pg/L 294

12.2

RL1 .

J-

10.4



J-

10.9



J-

3.00



J-

9.7



J-

10.3



Pyrene

pg/L

1.00

U.RL1

UJ

0.118



J-

0.176



J-

0.585

u

UJ

1.01

U

UJ

0.19

U

1 -Methylnaphthalene

pg/L

237

RL1

J-

232



J-

234



J-

57.8



J-

177



J-

na



2-Methylnaphthale'ne

pg/L 61.2

1.32

RL1

J-

0.414



J-

0.574



J-

. 0.143



J-

1.01

U

UJ

1.8



Inoraanics





































Cyanide, Total

mg/L

na





na





na





na





na





0.0694



Cyanide, WAD

mg/L 0.2

0.0100

U



0.0264





0.0100

U



0.0730





0.0233





na



Manganese, Total

mg/L 0.775 1.70





2.40





2.00





1.010





1.2





4



Natural Attenuation Parameters





































Nitrate

mg/L

na.





na





na





na





na





1.0

U

Nitrite

mg/L

na





na





na





na





na





0.10

U

Ammonia

mg/L

na





na





na





na





na





2.5



Manganese, Dissolved

mg/L

na





na





na





na





na





na



Iron, Dissolved

mg/L

na





na





na





na





na





na



Sulfate

mg/L

na





na





na





na





na





150



Sulfide

mg/L

na





na





na





na





na





5.2



Methane

pg/L

na

-



na





na





. na





- na





59



Alkalinity, Total

mg/L

na





na





na





na





na





460



Total Kjeldahl Nitrogen

mg/L

na





'na





na





na





na





2.9



Orthophosphate

mg/L

na





na





na





na





na





0.10

U

Total Organic Carbon

mg/L

na





na





na





na





na





26.33



Chloride

mg/L ' —

na





na





na





na





na





na



icgp_gw_2013-10.xlsx

2/?'s=!=!0J 4	Way-==^\ble Wells	of 53

/ \	! \	f \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW12-GW-002 MW12-GW-003 MW12-GW-004 MW12-GW-005 MW12-GW-1002 MW12-GW-0103 MW12-GW-1003 MW12-GW-0404
Standard 21-Jun-2000 11 -Jul-2001 12-Dec-2001 16-Apr-2002 01-Nov-2002 07-Jan-2003 22-Oct-2003 06-Apr-2004

VOCs

Units

































Benzene

Mg/L

5

2.5



15.5



7



1.0

U

2.1



11.0

7.5



1.0

U

Toluene

pg/L

1000

1.0

U

1.0

U

1.0

U

1.0

U

2

U

1.0 u

1.0

U

1.0

U

Ethyl benzene

MS/L

700

1.0

U

1.8



1.0

U

1.0

U

2

U

1.0 u

1.0

U

1.0

U

Xylenes, Total

ms/l

10000

3.0

U

7.3



3.0

U

3.0

U

7

u

3.0 U

2.6



1.0

U

PAHs "



































Acenaphthene

MQ/L

914

4.80



40.4



21.9



1.48



21



52

22



2.4

U

Acenaphthylene

Mg/L

362

11.1



82.6



27.3



1.29



1

u

1.0 U

100



8.4



Anthracene

Mg/L

--

0.10

U

0.13



0.39



0.19

U

0.17



0.17

0.51



0.018

Ja

Benzo(a)anthracene

fjg/L

0.13

0.10

U

0.10

U

0.10

U

0.19

U

0.10

u

0.10 U

0.14

u

0.12

U

Benzo(a)pyrene

|jg/i-

0.2

0.10

U

0.10

U

0.10

U

0.19

U

0.10

u

0.10 . U

0.14

u

0.12

U

Benzo(b)fluoranthene

Mg/L

0.1

0.10

U

0.10

U

.0.10

U

0.10

U

0.10

u

0.10 . U

0.052

u

0.048

U

Benzo(ghi)perylene

(jg/L

...

0.10

U

0.10

U

0.10

U

0.10

U

0.10

u

0.10 u

0.21

u

0.19

U

Benzo(k)fluoranthene

ng/L

0.14

0.10

U

0.10

U

0.10

U

0.10

U

0.10

u

0.10 u

0.052

u

0.048

U

Chrysene

Mg/L .

0.85

0.10

U

0.10

U

0.10

U

0.10

U

0.10

u

0.10 u

0.14

u

0.12

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.10

U

0.10

U

0.10

U

0.10

U

0.10

u

0.10. u

0.31

u

0.29

U

Fluoranthene

Mg/L

...

0.10

U

0.10

U

0.10

U

0.19

U

0.18



0.15

1.0



0.12 .

. U

Fluorene

Mg/L

490

1.71



22.8



3.51



0.35



5



5.3

7.2



0.19

Ja

lndeno(1,2,3-cd)pyrene

ng/L

0.1

0.10

U

0.10

U

0.10

U

0.10

U

0.10



0.10 U

0.14

u

0.12

U

Naphthalene

ng/L

1.1

0.33

J

2.05



0.11



0.10

U

1



0.62

0.95

Ja

1.2

U

Phenanthrene

kig/L

294

0.47



13.6



1.1



0.26



5.4



5.1

8.3



0.16



Pyrene

MQ/L

...

"0.19

U

0.19

U

0.19

U

0.19

U

0.1



0.10 U

0.26

U

0.24

U

1-Methylnaphthalene

ug'L .

...

na



na



0.19

U

0.19

U

na



na

na



na



2-Methylnaphthalene

mq/l

61.2

0.19

U

0.19

U

0.19

U

0.19

U

na



na

na



na



Inoraanics



































Cyanide, Total

mg/L

...

0.0217



0.016



0.022



0.010

U

0.009



0.0166

0.018



0.0084

B

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na

na



na



Manganese, Total

mg/L

0.775

4.2



3.04



4.39



3



3.41



3.4

2.6



2.1



Natural Attenuation Parameters



































Nitrate

mg/L

...

1.0

UJ

1.0

U

na



na



na



na

na



na



Nitrite

mg/L

...

na



na



na



na



na



na

na



na



Ammonia

mg/L



1.29



2.73



na



na



na



na

na



na



Manganese, Dissolved

mg/L

—

na



2.97



4.69



2.8



3.2



2.92

2.6



2.1



Iron, Dissolved

mg/L

...

na



3.84



4.74



4.9



6.48



6.89

6.0



4.1



Sulfate

mg/L "•

...

140



-130



na



na



na



na

na



na



Sulfide

mg/L

...

0.05

U

0.12



na



na



na



na

na



na



Methane

pg/L

...

na



na



na



na



na



na

na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na

na



na



Total'Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na

na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na

na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na

na



na



Chloride

mg/L

...

na



na



na



na



na



na

na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page 3 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW12-GW-1004 MW12-GW-0405 MW12-GW-1005 MW12-GW-0406 MW12-GW-1006 MW-12-GW-0407 MW12-GW-1007 MW12-GW-0408
Standard 20-0ct-2004 15-Apr-2005 11-0ct-2005 10-Apr-2006 10-0ct-2006 17-Apr-2007 09-0ct-2007 15-Apr-2008

VOCs

Units



































Benzene

M9'L

5

6.0



1.0

U*

3.8



1

U

2.27



1

U

5.09



1

U

Toluene

uq/l

1000

1.0

U

1.0

u-

1.0

U

1

U

1

U

1

U

1

U

1

u

Ethylbenzene

mq/l

700

1.0

U

1.0

U*

1.0

U

1

U

1

U

1

U

1

U

1

u

Xylenes, Total

mq/l

10000

1.9



2.0

U*

1.6

J

3

U

3

U

3

U

3

U

3

u

PAHs





































Acenaphthene

tjg/L

914

29



1.2

Ja

50



1.68



33.1



0.915



39.8



2.59



Acenaphthylene

|jg/L

362

110



6.7



180



1.17



49



0.6



34.9



1.87



Anthracene

ijg/L

...

0.80



0.032

Ja

1.2



0.0585



1.94



0.01

U

1.18



0.0264

J

Benzo(a)anthracene

Mg/L

0.13

0.13

u

0.12

U

0.042

Ja

0.019

U

0.00419

J

0.003

U

0.0102

J

0.003

u

Benzo(a)pyrene

Mg/L

0.2

0.13

u

0.12

U

0.034

Ja

0.019

U

0.032

U

0.032

U

0.032

U

0.032

u

Benzo(b)fluoranthene

mq/l

0.1

0.050

u

0.047

U

0.037

Ja

0.037

U

0.013

U

0.013

U

0.013

U

0.013

u

Benzo(ghi)perylene

Mg/L

...

0.20

u

0.19

U

0.20'

U

0.032

U

0.009

U

0.009

U

0.009

U

0.009

u

Benzo(k)fluoranthene

Mg/L

0.14

0.050

u

0.047

U

0.051

U

0.023

U

0.015

U

0.015

U

0.015

U

0.015

u

Chrysene

Mg/L

0.85

0.13

u

0.12

U

0.027

Ja

0.02

U

0.0281

J

0.005

U

0.005

U

0.005

u

Dibenzo(a,h)anthracene

ng/L

0.033

0.30

u

0.28

U

0.31

U

0.033

U

0.01

U

0.01

U

0.01

U

0.01

u

Fluoranthene

Mg/L

...

1.5



0.050

Ja

4.2



0.0813



1.68



0.01

U

1.42



0.01

u

Fluorene

M9/L- .

490

14



0.28



21



0.718



29



0.328



41.1



1.99



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.13

u

0.12

U

0.13

U

0.038

U

0.007

U

0.007

U

0.007

U

0.007

u

Naphthalene

Mg/L

1.1

0.58

Ja

1.2

U

1.3

U

0.104



1.02



0.054

U

14.6



0.054

u

Phenanthrene

. Mg/L

294

15



0.20 .



24



0.271



24



0.0328

J

24.2



0.007

u

Pyrene

ng/L

...

0.34



0.23

Ua

1.8



0.271



6.93



0.019

U

3.44



0.029

J

1 -Methylnaphthalene

Mg/L

...

na



na



na



na



na



na



na



na



2-Methylnaphthalene

ng/L

61.2

na



na



na



na



0.052

U

0.052

U

1.34 ,



0.052

u

Inoraarics





































Cyanide, Total

mg/L

...

0.013



0.012



0.0066

B

0.01

U

0.01

U

0.01

U

0.01

U

0.0139



Cyanide, WAD

mg/L

0.2

¦ na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

2.6



2.2



2.9



1.77



2.15



1.85



2.28



' 2.13



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



0.10

U

0.10

U

0.1

U

0.1

U

na



na



na



Nitrite

mg/L

...

na



0.020

U

0.020

U

0.1

U

0.1

U

na



na-



na



Ammonia

mg/L

...

na



0.14

B

3.4



0.84



0.84



na



na



na



Manganese, Dissolved

mg/L

...

2.6



2.2



2.7



1.68



na



na



na



na



Iron, Dissolved

mg/L

...

6.6



5.4



6.9



3.55



3.55



na



na



na



Sulfate

mg/L

...

na



53



140



87.9



87.9



na



na



na



Sulfide

mg/L

...

na



1.0

U

0.50

B

1

U

1

U

na



na



na



Methane

Mg/L



na



36

-

59



329



329



na



na



na



Alkalinity, Total

mg/L

...

na



380



350



347



347



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

¦ na



0.73



• 3.8-



1.27



1.27



na



na



na



Orthophosphate

mg/L

...

na



0.015

B

0.050

U

0.1

U

0.1

U

na



na



na



Total Organic Carbon

mg/L

...

na



3.6



3.3



3.46



3.46



na



na



na



Chloride

mg/L

...

na



na .



na



144



144



na



na



na



icgp_gw_2013-10.xlsx

14	Wat^^ble Wells	P'-^.4 of 53

! \	1 \	/ \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW12-GW-0410	MW12-GW-1010 MW12-GW-0411 MW12-GW-1011	MW12-GW-0412	MW12-GW-1012

Standard	08-Apr-2010	05-0ct-2010	13-Apr-2011	26-Oct-2011	12-Apr-2012	10-0ct-2012

DV	DV	DV

VOCs

Units































Benzene

ng/L

5

2.07





15.2



1.00

U

2.52





1.00

U

1.00

U

Toluene

pg/L

1000

1.00

U



1.00

U

1.00

U

1.00

U



1.00

U

1.00

U

Ethylbenzene

mq/l

700

1.00

U



1.00

U

1.00

u

1.00

U



1.00

'U

1.00

U

Xylenes, Total

pg/L

10000

6.00

U



7.77



3.00

u

5.15





3.00

U

3.00

U

PAHs

































Acenaphthene

Mg/L

914

20.4



J+

65.0



6.32



27.4



J-

5.73



29.8



Acenaphthylene

Mg/L

362

15.4



J+

37.5



3.43



21.6



J-

5.11



31.6



Anthracene

pg/L

...

0.409



J+

1.40



0.100

u

0.340



J-

0.100

U

0.173



Benzo(a)'anthracene

pg/L

0.13

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Benzo(a)pyrene

ijg/L

0.2

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Benzo(b)fluoranthene

ng/L

0.1

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Benzo(ghi)perylene

|jg/L

...

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Benzo(k)fluoranthene

ng/L

0.14

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Chrysene

ijg/L

0.85

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.00810

U,MDL



0.00810

U,MDL

0.100

u

0.0207

J.MDL

J-

0.0170

U,MDL

0.0130

U,MDL

Fluoranthene

ng/L

...

0.552



J+

2.78



0.155



0.927



J-

0.15



0.702



Fluorene

fjg/L

490

10.1



J+

30.3



2.00



14.5



J-

1.28



14.7



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.100

U



0.100

U

0.100

u

0.100

U

UJ

0.100

U

0.100

U

Naphthalene

fjg/L

1.1

0.569



J+

1.89



0.102



0.683



J-

0.186

B UB

0.420



Phenanthrene

Mg/L

294

7.68



J+

23.9



0.741



8.46



J-

0.452



1.46



Pyrene

ug/L

...

0.270



J+

1.56



0.100

u

0.656



J-

0.112



0.488



1-Methylnaphthalene

ng/L

...

1.46



J+

9.14



0.185



0.975



J- .

0.153



0.455



2-Methylnaphthalen'e

^g/L

61.2

0.100

U



0.125



0.100

u

0.100

U

UJ

0.100



0.171



Inoraanics

































Cyanide, Total.

mg/L

...

na





na



na



na





na



na



Cyanide, WAD

mg/L

0.2

0.0100

U



0.0100

U

0.0100

u

0.0100

U



0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

1.82





2.55



1.90



2.33





1.65



2.19



Natural Attenuation Parameters

































Nitrate

mg/L

...

na





na



na



na





na



na



Nitrite

mg/L

...

na





na



na



na





na



na



Ammonia

mg/L

...

na





na



na



na





na



na



Manganese, Dissolved

mg/L

...

na





na



na



na





na



na



Iron, Dissolved

mg/L

...

na





na



na



na





na



na



Sulfate

mg/L



na





na



na



na





na



na



Sulfide

mg/L

...

na





na



na



na





na



na



Methane ;

Mg/L

...

na

-



na



na



na





na



na



Alkalinity, Total

mg/L

...

na





na



na



na





na



na



Total Kjeldahl Nitrogen

mg/L

...

na





na



na



na





na



na



Orthophosphate

mg/L

...

na





na



na



na





na



na



Total Organic Carbon

mg/L

...

na





na



na



na





na



na



Chloride

mg/L

...

na





na



na



na





na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page 5 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW12-GW-0413	MW12-GW-1013 MW16-GW-001 MW16-GW-002 MW16-GW-003 MW16-GW-004 MW16-GW-005

Standard	11-Apr-2013	23-Oct-2013	26-Oct-1999 22-Jun-2000 11 -Jul-2001 12-Dec-2001 18-Apr-2002

DV	DV	¦0

VOCs

Units































Benzene

Mg/L

5

0.500

U



82.7



24.1



8.1



10.2



8.7

6.2



Toluene

M9'L

1000

1.00

U



5.24



56.9



10.6



3.5



2.8

1.7



Ethylbenzene

M9/I-

700

1.00

u



17.3



14.5



5.9



11.7



8.7

4



Xylenes, Total

|jg/L

10000

3.00

u



39.8



111



33.0



28.9



18.6

9.7



PAHs

































Acenaphthene

Mg/L

914

2.82



J-

78



12.7



6.36



2.57



6.37

2.3



Acenaphthylene

Mg/L

362

1.39



J-

26



41.7



13.1



3.12



17

6.88



Anthracene

ng/L

...

0.100

u

UJ

1.91



9.5



11.3



3.83



4.38

1.57



Benzo(a)anthracene

|jg/L

0.13

0.100

u

UJ

0.100

U

3.7



5.46



2.86



1.27

0.69



Benzo(a)pyrene

ijg/L

0.2

0.100

u

UJ

0.100

U

1.88



3.75



1.62



0.77

0.44



Benzo(b)fluoranthene

MQ/L

0.1

0.100

u

UJ

0.100

U

0.58



1.53



0.45



0.12

0.14



Benzo(ghi)perylene

|jg/L

...

0.100

u

UJ

0.100

U

0.79



1.81



0.65



0.33

0.18



Benzo(k)fluoranthene

Mg/L

0.14

0.100

u

UJ

0.100

U

0.14



0.10

U

0.11



0.10 U

0.10

U

Chrysene

ng/L

0.85

0.100

u

UJ

0.100

u

1.9



2.98



1.3



0.56

0.39



Dibenzo(a,h)anthracene

ng'L

0.033

0.0177

u

UJ

0.0173

u

0.14



0.11



0.21



0.1

0.10

U

Fluoranthene

ng/i-

...

0.100

u

UJ

3.04



6.5



15.8



6.44



2.64

2.62



Fluorene

. ng/L

490

0.490



J-

30.5



28.3



22.6



4.11



10.1

3.85



lndeno(1,2,3-cd)pyrene

Vg/L

0.1

0.100

u

UJ

0.100

u

0.78



1.30



0.69



0.23

0.2



Naphthalene

Hg/L

1.1

0.310

B

J-

18.2

B* J+,B

190



83.6



0.53



30.8

16.4



Phenanthrene

pg/i-

294

0.100

u

UJ

27.7



28.6



9.71



2.86



12.6

3.77



Pyrene

yg/L

...

0.100

u

UJ

1.13



2.18



7.94



2.16



0.39

' 1.35



1-Methylnaphthalene

(jg/L

...

0.100

u

UJ

89.3



na



na



na



22

na



2-Methylnaphthalene

Mg/L

61.2

0.100

u

UJ

0.192



55.1



0.19

U

0.19

U

2.58

1.1



Inoraanics

































Cyanide, Total

mg/L

...

na





na



0.3917



0.217



0.176

J

0.216

0.087



Cyanide, WAD

mg/L

0.2

0.0100

u



0.0100

U

na



na



na



na

na



Manganese, Total

mg/L

0.775

2.120





2.53



4



1.7



0.623



0.694

0.249



' Natural Attenuation Parameters

































Nitrate

mg/L

...

na





na



1.0

U

1.0

U

1.0

.UJ

na

na



Nitrite

mg/L

...

na





na



0.10

U

na



na



na

na



Ammonia

mg/L

...

na





na



1.2



0.93



0.63



na

na



Manganese, Dissolved

mg/L

...

na





na



na



na



0.231



0.225

0.181



Iron, Dissolved

mg/L

...

na





na



na



na



2.19



2.35

2



Sulfate

mg/L

...

na





na



310



370



300



na

na



Sulfide

mg/L

...

na





na



1.8



0.18



1.0

U

na

¦ na



Methane •

M9/L

...

.- - na





na



279



na



na



na

na



Alkalinity, Total

mg/L

...

na





na



350



na



na



na

na



Total Kjeldahl Nitrogen

mg/L



na





na



1.6



na



na



na

na



Orthophosphate

mg/L

...

na





na



0.10

u

na



na



na

na



Total Organic Carbon

mg/L

...

na





na



35.64



na



na



na

na



Chloride

mg/L

...

na





. na



na



na



na



na

na



icgp_gw_2013-10.xlsx

Wat^^ble Wells	of 53

\ / \ / \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW16-GW-1002 MW16-GW-0103 MW16-GW-0404 MW16-GW-0405 MW16-GW-0406 MW16-GW-1006 MW16-GW-0407 MW16-GW-1007
Standard 28-Oct-2002 08-Jan-2003 06-Apr-2004 15-Apr-2005 12-Apr-2006 11-0ct-2006 17-Apr-2007 10-0ct-2007

VOCs

Units

































Benzene

MQ/L

5

6.6



9.8

3.2



7.8

*

3.5



. 5.01



3.18



5.2



Toluene

mq/l

1000

2

U

2.0

0.66

Ja

1.6

*

1

U

1

U

1

U

1

U

Ethyl benzene

MQ/L

700

5.1



9.4

2.3



7.6

*

2.45



3.72



2.6



2.56



Xylenes, Total

Mg/L

10000

11



15

4.7



13

-

3

U

4.21



3.18



4.36



PAHs



































Acenaphthene

ug/L

914

11



6.3 J

4.1



5.7



3.07



5.15



2.27



8.23



Acenaphthylene

ug/L

362

11

U

10 U

28



78



7.83



14.4



7.51



33.1



Anthracene

(jg/L



2.6



6.0 J

2.2



4.4



2.16



4.1



1.58



3.59



Benzo(a)anthracene

^g/L

0,13

2.5



10 J

0.63



1.9



0.35



0.232



0.108

J

0.361



Benzo(a)pyrene

pg/L

0.2

1.7



6.4 J

0.53



1.2



0.271



0.032

U

0.032

U

0.058

J

Benzo(b)fluoranthene

ug/L

0.1

2.4



8.9 J

0.3



0.69



0.293



0.0529

J

0.013

U

0.013

U

Benzo(ghi)perylene

ug/L

—

0.36



2.2 J

0.19

Ja

0.43



0.0989

J

0.009

U

0.009

U

0.0577

J

Benzo(k)fluoranthene

(jg/L

0.14

0.68



2.5 J

0.17

M

0.45



0.113

J

0.015

U

0.015

U

0.0163

J

Chrysene

Mg/L

0.85

1.6



6.7 J

0.46



1.2



0.334



0.147



0.0969

J

0.204



Dibenzo(a,h)anthracene

ijg/L

0.033

1.20



3.3 J

0.29

U

0.25

J

0.033

u

0.01

U

0.01

U

0.01

U

Fluoranthene

Mg/L

...

8.8



19 J

4.8



9.8



2.78



6.2



2.34



4.72



Fluorene

MQ/L

490

8.2



13 J

7.1



12



9.31



18.5



8.87



26.4



lndeno(1,2,3-cd)pyrene

pg/L

0.1

1.1

U

1.0 U

0.16



0.46



0.132



0.007

U

0.007

U

0.007

U

Naphthalene

Mg/L

1.1

26



16 J

7.6



44



3.53



3.95



3.99



7.19



Phenanthrene

ng/t-

294

6.1



21 J

3.1



13



6.17



10.3



4.22



15.6



Pyrene

^g/L

—

5.4



15 J

1.9



4.8



8



11.3



4.54



12.3



1 -Methylnaphthalene

^g/L

...

na



na

na



na



na



na



na



na



2-Methylnaphthalene

ng/L

61.2

na



na

na



na



na



1.27



0.552



1.78



Inoraanics



































Cyanide, Total

mg/L

...

0.217



0.137

0.12



0.17



0.198 .



0.287



0.132



0.264



Cyanide, WAD

mg/L

0.2

na



na

na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.21



1.27

0.15



0.18



0.124



0.174



0.12



0.178



Natural Attenuation Parameters



































Nitrate

mg/L

...

na



na

na



0.061

B

0.1

u

na



na



na



Nitrite

mg/L

...

na



na

na



0.012

B

0.1

u

na



na



na



Ammonia

mg/L

...

na



na

na



0.2

U

0.257



na



na



na



Manganese, Dissolved

mg/L

—

0.182



0.268

0.14



0.16



0.13



na



na



na



Iron, Dissolved

mg/L



1.64



2.71

1.7



2.3



2.19



na



na



na



Sulfate

mg/L

...

na



na

na



240



241



na



na



na



Sulfide

mg/L

— .

na



na

na



1.5



1

u

na



na



na



Methane

Mg/L

...

na



na

na



48



26

u

na



na



na



Alkalinity, Total

mg/L

...

na



na

na



360



428



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na

na



0.72



1

u

na



na



na



Orthophosphate

mg/L

...

na



na

na



0.017

B

0.1

u

na



na



na



Total Organic Carbon

mg/L

—

na



na

na



3.3



4.6



na



na



na



Chloride

mg/L

...

na



na

na



na



54.3



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page 7 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW16-GW-0408 MW16-GW-0410 MW16-GW-1010 MW16-GW-0411 MW16-GW-1011	MW16-GW-0412

Standard 15-Apr-2008	08-Apr-2010	06-0ct-2010	12-Apr-2011	25-Oct-2011	11-Apr-2012

DV	DV

I'OCs

Units



























Benzene

Mg/L

5

9.14

30.2



41.4



16.8



10.9



6.62





Toluene

pg/L

1000

1.06

5.40



3.29



5.09



1.00

U

1.00

U



Ethyl benzene

ijg/L

700

6.62

21.0



33.4.



12.8



10.8



6.12





Xylenes, Total

fjg/L

10000

5.56

24.8



33.7



14.3



8.67



4.75





PAHs





























Acenaphthene

Mg/L

914

4.63

5.75



5.14



102



4.54



4.10

RL1

J-

Acenaphthylene

Mg/L

362

14.4

16.2



10.0



108



12.9



9.05

RL1

J-

Anthracene

Mg/L

...

1.44

3.19



3.06



2.51



2.31



1.72

RL1

d-

Benzo(a)anthracene

pg/L

0.13

0.34

0.588



2.55



1.96



4.46



3.39

RL1

J-

Benzo(a)pyrene

Mg/L

0.2

0.25

0.575



2.90



1.62



3.64



2.59

RL1

J-

Benzo(b)fluoranthene

ng/i-

0.1

0.218

0.501



2.62



1.51



3.17



2.31

RL1

J-

Benzo(ghi)perylene

Mg/L

...

0.148

0.157



0.923



0.623



1.34



1.00

U.RL1

UJ

Benzo(k)fluoranthene

Mg/L

0.14

0.121 J

0.2



0.920



0.559



1.52



1.14

RL1

J-

Chrysene

pg'L

0.85

0.336

0.520



2.27



1.75



3.64



2.75

RL1

J-

Dibenzo(a,h)anthracene

pg/L

0.033

0.0349 J

0.0547

J,MDL

0.326

MDL

0.207

MDL

0.461

J,MDL J

0.332

RL1.J.MDL

J-

Fluoranthene

Mg/L

...

3.98

3.03



6.94



4.80



5.84



7.85

RL1

J-

Fluorene

ng/L

490

12.5

13.6



7.96



21.5



7.85



4.99

RL1

J-

lndeno(1,2,3-cd)pyrene

pg/i-

0.1

0.138

0.155



0.999



0.612



1.36



1.00

U.RL1

UJ

Naphthalene

Mg/L

1.1

2.77

42.4



39.3



310



6.91



4.18

RL1

J-

Phenanthrene

ng/L

294

5.84

8.38



5.20



35.4



3.82



2.46

RL1

J-

Pyrene

|jg/L

...

2.55

2.30



6.23



4.00



10.7



8.36

RL1

J-

1 -Methylnaphthalene

ug/L

...

na

9.24



21.9



595



7.29



4.19

RL1

J-

2-Methylnaphthalene

|jg/L

61.2

0.855

0.194



0.326



8.82



0.349



1.00

U,RL1

UJ

tnoraanics





























Cyanide, Total

mg/L

...

0.131

na



na



na



na



na





Cyanide, WAD

mg/L

0.2

na

0.0198



0.0100

U

0.0100

U

0.0100

U

0.0100

U



Manganese, Total

mg/L

0.775

0.171

0.153



0.102



0.128



0.142



0.29





Natural Attenuation Parameters





























Nitrate

mg/L

...

na

0.10

U

0.10

U

0.10

U

0.10

U

0.100

U



Nitrite

mg/L

...

na

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



Ammonia

mg/L

...

na

0.461



0.613



0.468



0.535



0.509





Manganese, Dissolved

mg/L

...

na

0.156



0.0797

S3

0.106



0.104



0.146





Iron, Dissolved

mg/L

...

na

1.59



0.906



1.73



1.23



2.38





Sulfate

mg/L

...

na

243



385



244



206



183





Sulfide

mg/L

...

na

5.00

U

5.00

U

17



10

U

10

U



Methane

pg/L

...

na

261



274



87



120



120





Alkalinity, Total

mg/L

...

na

319



201



269



266



306





Total Kjeldahl Nitrogen

mg/L



na

1.00

U

1.19



1.00

U

1.31



1.00

U



Orthophosphate

mg/L

...

na

0.1

U

0.100

U

0.100

U

0.100

U

0.100

U



Total Organic Carbon

mg/L

...

na

2.59



1.93

ET

na



2.50



na





Chloride

mg/L

...

"na

33.6



28.8



na



na



na





icgp_gw_2013-10.xlsx

2//-^=i=
-------


Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW16-GW-1012 MW16-GW-0413 MW16-GW-1013 MW18-GW-001 MW18-GW-002 MW18-GW-003 MW18-GW-004
Standard 10-0ct-2012	10-Apr-2013	23-Oct-2013	04-Apr-2000 21-Jun-2000 10-Jul-2001 12-Dec-2001

DV

VOCs

Units































Benzene

ng/L

5

8.21



4.14



6.12



0.5

U

0.5

U

0.5

U

1.0

U

Toluene

mq/l

1000

1.24



1.00

U

1.00

U

1.0

U

1.0

U

1.0

U

1.0

U

. Ethylbenzene

Mg/L

700

8.05



3.64



5.7



1.0

U

1.0

U

1.0

u

1.0

U

Xylenes, Total

|jg/L

10000

7.74



5.25



5.31 ¦



3.0

U

3.0

U

3.0

u

3.0

U

PAHs

































Acenaphthene

ug/L

914

6.18



3.06



5.75



0.19

U

0.19

U

0.19

u

0.19

U

Acenaphthylene

pg/L

362

16.5



8.08



10.8



0.19

U

0.19

U

0.19

u

0.19

U

Anthracene

pg/L

...

1.69



1.12



0.969



0.10

u

0.10

U

0.10

u

0.10

U

Benzo(a)anthracene

|jg/L

0.13

1.38



1.57



0.449



0.10

u

0.10

U

0.10

u

0.10

U

Benzo(a)pyrene

pg/L

0.2

0.650



1.76



0.219



0.10

u

0.10

U

0.10

u

0.10

U

Berizo(b)fluoranthene

Mgfl-

0.1

0.708



1.66



0.199



0.10

u

0.10

U

0.10

u

0.10

U

Benzo(ghi)perylene

Mg/L

...

0.168



0.650



0.10

U

0.10

u

0.10

U

0.10

u

0.10

U '

Benzo(k)fluoranthene

|jg/L

0.14

0.23



0.724



0.138



0.10

u

0.10

U

0.10

u

0.10

U

Chrysene

^g/L

0.85

1.05



1.57



0.439



0.10

u

0.10 ¦

U

0.10

u

0.10

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.0666

J.MDL

0.288



0.0332



0.10

u

0.10

U

0.10

u

0.10

U

Fluoranthene

pg/L

...

5.57



4.78



4.03



0.10

u

0.10

U

0.10

u

0.10

U

Fluorene

Mg/L

490

10.6



4.92



8.48



0.19

u

0.19

U

0.19

u

0.19

U

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.170



0.629



0.10

U

0.10

u

0.10

U

0.10

u

0.10

U

Naphthalene

Mg/L

1.1

6.70



7.90



4.28

B" J+,B

0.10

u

0.14



0.14



0.10

U

Phenanthrene

Mg/L

294

4.39



2.18



3.33



0.10

u

0.10

U

0.10

u

0.10

U

Pyrene

Mg/L

...

6.21



4.63



1.61



. 0.19

u

0.19

U

0.19

u

0.19

U

1-Methylnaphthalene

mq/l

...

7.56



6.56



4.02



na



na



na



0.19

U

2-Methylnaphthalene

pg'L

61.2

0.231



0.258



0.312



0.19

u

0.19

U

0.19

u

0.19

U

Inoraanics

































Cyanide, Total

mg/L

...

na



na



na.



0.0148



0.0158

J

0.010

u

0.028



Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

0.0121



na



na



na



na



Manganese, Total

mg/L

0.775

0.234



0.0974



0.142



2.8



4



5.76



3.26



Natural Attenuation Parameters

































Nitrate

mg/L

...

0.100

U

0.471



na



1.0

u

1.0

U

1.0

u

na



Nitrite

mg/L

...

0.100

U

0.100

u

na



na



na



na



na



Ammonia

'mg/L

...

0.492



0.238



na



0.20

u

0.44



0.20

u

na



Manganese, Dissolved

mg/L

...

0.125



0.0704



na



na



na



4.72



2.91



Iron, Dissolved

mg/L



1.74



0.505



na



na



na



1.18



2.7



Sulfate

mg/L

...

169



114



na



310



300



230



na



Sulfide

mg/L



10

U

12.0



na



5.0

UJ

0.05

U

1.0

u

na



Methane

Mg/L

...

180



44.4



na



na



na



na



na



Alkalinity, Total

mg/L



316



255



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

1.00

U

1:00

u

na



na



na



na



na



Orthophosphate

mg/L.

...

0.100

U

0.100

u

na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page 9 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW18-GW-005 MW18-GW-1002 MW18-GW-0103 MW18-GW-1003 MW18-GW-0404 MW18-GW-1004 MW18-GW-0405 MW18-GW-1005
Standard 16-Apr-2002 30-0ct-2002 08-Jan-2003 22-Oct-2003 07-Apr-2004 19-0ct-2004 14-Apr-2005 12-0ct-2005

VOCs

Units



































Benzene

Pg/L

5

1.0

U

2.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

Toluene

pg/L

1000

1.0

U

2.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1-0

U

Ethylbenzene

pg/L

700

1.0

U

2.0

U

1.0

U

1.0

U

1.0

u

1..0

U

1.0

U

1.0

U

Xylenes, Total

pg/L

10000

3.0

U

7.0

•u

3.0

U

1.0

U

1.0

u

1.0

U

2.0

U

2.0

U

PAHs





































Acenaphthene

pg/L'

914

0.19

U

0.51

U

0.55

U

2.9

U

2.8

u

2.6

U

2.3

U

2.6

U

Acenaphthylene

Mg/L

362

0.19

U

1

U

1.1

U

1.5

U

1.4

u

1.3

U

1.2

U

1.3

U

Anthracene

pg/L

...

0.19

U

0.051

U

0.055

U.

0.057

U

0.056

u

0.052

U

. 0.047

U

0.052

U

Benzo(a)anthracene

MQ/L

0.13

0.19

U

0.1

U

0.11

U

0.15

U

0.14

u

0.13

U

0.12

U

0.13

U

Benzo(a)pyrene

pg/L

0.2

0.19

U

0.1

U

0.11

U

0.15

U

0.14

u

0.13

U

0.12

U

0.13

U

Benzo(b)fluoranthene

pg/L.

0.1

0.10

U

0.1

U

0.11

U

0.057

U

0.056

u

0.052

U

0.047

U

0.052

U

Benzo(ghi)perylene

pg/L

—

0.10

U

0.1

U

0.11

U

0.23

U

0.22

u

0.21

U

0.19

U

0.21

U

Benzo(k)fluoranthene

pg/L

0.14

0.10

U

0.1

U

0.11

U

0.057

U

0.056

u

0.052

U

0.047

U

0.052

U

Chrysene

pg/L

0.85 '

0.10

U

0.1

U

0.11

U

0.15

U

0.14

u

0.13

U

0.12

U

0.13

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.11



0.1

(J

0.11

U

0.34

U

0.33

u

0.31

U

0.28

U

0.31

U

Fluoranthene

pg/L

...

0.19 ,

U

0.1

U

0.11

U

0.15

U

0.14

u

0.13

U

0.12

u

0.13

U

Fluorene

pg/L

490

0.19

U

0.1

U

0.11

U .

0.29

U

0.28

u

0.26

U

0.23

u

0.26

u

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.10

U

0.1

U

0.11

U

0.15

U

0.14

u

0.13

U

0.12

u

0.13

u

Naphthalene

pg/L

1.1

0.10

U

0.51

U

0.55

U

1.5

U

1.4

u

1.3

U

1.2

u

1.3

u

Phenanthrene

pg/L

294

0.10

U

0.10

U

0.11

U

0.11

U

0.11

u

0.10

U

0.093

Ua

" 0.10

u

Pyrene

pg/L

...

0.19

U

0.1

U

0.11

U

0.29

U

0.28

u

0.26

U

0.23

u

0.26

u

1-Methylnaphthalene

pg/L

...

0.19

U

na



na



na



na



na



na



na



2-Methylnaphthalene

pg/L

61.2

0.19

u

na



na



na



na



na



na



na



Inoraanics





































Cyanide, Total

mg/L

...

0.013



0.005

U

0.00983



0.018



0.0060

B

0.013



0.010

u

0.020



Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

3.4



2.4



2.65



2.4



3.6



1.7



. 3.2



1-5



Natural Attenuation Parameters





































Nitrate

mg/L



na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

2.9



2.44



2.18



2.0



3.1



1.6



2.9



1.5



Iron, Dissolved

mg/L

...

1.3



2.89



2.53



3.1



4.1



5.4



6.0



3.1



Sulfate

mg/L

	

na



na



na



na



na



na



na



na



Sulfide

mg/L

— .

na



na



na



na



na



na.



na



na



Methane

pg/L

...

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na .



na



na



na



na



na



Chloride

mg/L

...

na



na.



na



¦na



na



na



na



na



icgp_gw_2013-10.xlsx

2A"^~\14	WaJ-^^f.ble Wells	0 of 53

: }	{ )	' 1

-------
H

\ /

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW18-GW-0406 MW18-GW-1006 MW18-GW-0407 MW18-GW-1007 MW18-GW-0408 MW18-GW-0410 MW18-GW-1010 MW18-GW-0411
Standard 12-Apr-2006 10-0ct-2006 17-Apr-2007 10-0ct-2007 15-Apr-2008 08-Apr-2010	06-0ct-2010	12-Apr-2011

VOCs

Units



































Benzene

M9/L

5

1

U

1.00

U

1

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

Toluene

mq/l

1000

1

U

1.00

U

1

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

Ethylbenzene

jjg/L

700

1

u

1.00

U

1

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

Xylenes, Total



10000

3

u

3.00

U

3

U

3.00

U

3.00

U

6.00

U

3.00

U

3.00

U

PAHs





































Acenaphthene

Mg/i-

914

0.13

u

0.0490

U

0.049

U

0.0544

U

0.049

U

0.100

U

0.124



0.100

U

Acenaphthylene

ng/L

362

0.17

u

0.0850

U

0.085

U

0.0944

U

0.085

U

0.100

U

0.139



0.100

U

Anthracene

Mg/L

...

0.0093

u

0.0100

U

0.01

U

0.0111

U

0.01

U

0.100

U

0.100

U

0.100

U

Benzo(a)anthracene

^g/L

0.13

0.019

u

0.0030

U

0.003

U

0.00333

U

0.003

U

0.100.

U

0.100

U

0.100

U

Benzo(a)pyrene

mq/l

0.2

0.019

u

0.0320

U

0.032

U

0.0356

U

0.032

U

0.100

U

0.100

U

0.100

U

Benzo(b)fluoranthene

Mg/L

0.1

0.037

u

0.0130

U

0.013

U

0.0144

U

0.013

U

0.100

U

0.100

U

0.100

U

Benzo(ghi)perylene

Mg/L

...

0.032

u

0.0090

U

0.009

U

0.01

U

0.009

U

0.100

U

0.100

U

0.100

U

Benzo(k)fluoranthene

ng/L

0.14

0.023

u

0.0150

U

0.015

U

0.0167

U

0.015

U

0.100

U

0.100

U

0.100

U

Chrysene

¦ Mg/L

0.85

0.02

u

0.0050

U

0.005

U

0.00556

U

0.005

U

0.100.

U

0.100

U

0.100

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.033

u

0.0.100

U

0.01

U

0.0111

U

0.01

U

0.00810

U,MDL

0.00973

J.MDL

0.0170

U.MDL

Fluoranthene

M9/L

—

0.032

u

0.0100

U

0.01

U

0.0111

U

0.01

U

0.100

U

0.100

U

0.100

U

Fluorene

Mg/i-

490

0.029

u

0.0100

U

0.01

U

0.0111

U

0.01

U

0.100

U

0.100

U

0.100

U

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.038

u

0.0070

U

0.007

U

0.00778

U

0.007

U

0.100

U

0.100

U

0.100

U

Naphthalene

pg/L

1.1

0.23



0.0540

U

0.054

U '

0.06

U

0.054

U

0.100

U

1.99



0.132



Phenanthrene

ug/L

294

0.015

u

0.0202'

J

0.007

U

0.00778

U

0.007

U

0.100

U

0.100

U

0.100

U

Pyrene

ug/L

...

0.036

u

0.0190

U

0.019

U

0.0211

U

0.019

U

0.100

U

0.100

U

0.100

U

1-Methylnaphthalene

ug/L

...

na



na



na



na



na



0.100

U

0.919



0.101



2-Methylnaphthalene

ng/L

61.2

na



0.0520

U

0.052

U

0.0578

U

0.052

U

0.100

U

0.123



0.100

U

Inoraanics





































Cyanide, Total

mg/L

...

0.021



0.0255



0.0208



0.0213



0.0133



na



na



na



Cyanide, WAD

mg/L

0.2

na



na



na



na



na



0.0100

U

0.0100

U

0.0113



Manganese, Total

mg/L

0.775

1.87



na



na



na



na



3.44



1.35



1.70



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

—

1.86



na



na



na



na



na



na



na



Iron, Dissolved

mg/L

...

3



na



na



na



na



na



na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L

...

• na



na



na



na



na



na



na



na



Methane

Mg/L

...

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na ¦



na



na



na



na



Chloride

mg/L

...

na



na



na



na .



¦ na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Water Table Wells	Page11of53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW18-GW-1011 MW18-GW-0412 MW18-GW-1012 MW18-GW-0413 MW18-GW-1013
Standard	25-Oct-2011	11-Apr-2012	10-0ct-2012	10-Apr-2013	23-Oct-2013

DV	DV	DV

VOCs

Units



























Benzene

pg/L

5

1.00

U



1.00

U

1.00

U



0.500

U

0.500

u

Toluene

pg/L

1000

1.00

u



1.00

U

1.00

U



1.00

U

1.00

U

Ethyl benzene

pg/L

700

1.00

u



1.00

u

1.00

U



1.00

U

1.00

U

Xylenes, Total

pg/L

10000

3.00

u



3.00

u

3.00

U



3.00

U

3.00

U

PAHs





























Acenaphthene

pg/L

914

0.100

u

UJ

0.225



0.100

U

UJ

0.455



1.09

U

Acenaphthylene

pg/L

362

0.100

u

UJ

0.100

u

0.100

U

UJ

0.450



1.09

U

Anthracene

mq/l

...

0.100

u

UJ

1.250



0.100

U

UJ

0.100

U

1.09

U

Benzo(a)anthracene

ug/L

0.13

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

U

1.09

U

Benzo(a)pyrene

pg/L

0.2

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

U

1.09

U

Benzo(b)fluoranthene

pg/L

0.1

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

U

1.09

U

Benzo(ghi)perylene

pg/L

...

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

u

1.09

U

Benzo(k)fluoranthene

pg/L

0.14

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

u '

1.09

u

Chrysene

pg/L

0.85

0.100

u

UJ

0.100

u

0.100

U

UJ

0.100

u

1.09

u

Dibenzo(a,h)anthracene

pg/L

0.033

0.0170

U.MDL

UJ

0.0170

U,MDL

0.0130

U.MDL

UJ

0.0172

u

0.185

u

Fluoranthene

pg/L

—

0.100

U

UJ

0.100

U

0.100

U

UJ

0.100

u

1.09

u

Fluorene

pg/L

490

0.100

U

UJ

0.990



0.100

U

UJ

0.106



1.09

u

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100

U

UJ

0.100

U

0.100

U

UJ

0.100

u

1.09

u

Naphthalene

jjg/L

1.1

0.157



J-

1.71



0.339



J-

1.42



3.27

B' J+,B

Phenanthrene

pg/L

294

0.100

U

UJ

0.416



0.100

U

UJ

0.172



1.09

U

Pyrene

. fjg/L

...

0.100

U

UJ

0.105



0.100

U

UJ

0.100

u

1.09

U

1-Methylnaphthalene

pg/L

...

0.142



J-

0.71



0.114



J-

2.52



1.09

U

2-Methylnaphthalene

MQ/L

. 61.2

0.100

U

UJ

0.162



0.100

U

UJ

0.100

u

1.09

U

Inoroanics





























Cyanide, Total

mg/L

...

na





na



na





na



na



Cyanide, WAD

mg/L

0.2

0.0100

U



0.0100

U

0.0100

U



0.0100

u

0.0100

U

Manganese, Total

mg/L

0.775

1.22





1.64



1.22





1.410



1.34



Natural Attenuation Parameters





























Nitrate

mg/L

...

na





na



na





na



na



Nitrite

mg/L

...

na





na



na





na



na



Ammonia

mg/L

...

na





na



na





na



na



Manganese, Dissolved

mg/L

...

na





na



na





na



na



Iron, Dissolved

mg/L

...

na





na



na





na



na



Sulfate

mg/L

...

na





na



na





na



na



Sulfide

mg/L

...

na





na



na





na



na



¦Methane- ^

pg/L

...

na





na



na





na



na



Alkalinity, Total

mg/L

...

na





na



na





na



na



Total Kjeldahl Nitrogen

mg/L

...

na





na



na





na



na



Orthophosphate

mg/L

...

na





na



na





na



na



Total Organic Carbon

mg/L

...

na





na



na





na



na



Chloride

mg/L

...

na-





na



na





na



na



icgp_gw_2013-10.xlsx

2/'*
-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW07-GW-001 MW07-GW-002 MW07-GW-003 MW07-GW-004 MW07-GW-005 MW07-GW-1002 MW07-GW-0103 MW07-GW-0404
Standard 26-Oct-1999 21-Jun-2000 10-Jul-2001 11-Dec-2001 16-Apr-2002 28-Oct-2002 07-Jan-2003 08-Apr-2004

VOCs

Units



































Benzene

ng'L

5

0.5

U

0.5

U

0.5

U

1.0

U

1.0

U

2.0

U

1.0

U

1.0

U

Toluene

ug'L

1000

. 1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

2.0

U

¦1.0

U

1.0

U

Ethylbenzene

Mg/L

700

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

2.0

U

1.0

U

1.0

U

Xylenes, Total

fjg/L

10000

3.0

U

3.0

U

3.0

u

3.0

U

3.0

U

7.0

U

3.0

U

1.0

U

PAHs





































Acenaphthene

M9/L

914

0.19

U

0.19

U

0.19

u

0.19

U

0.19

U

0.53

U

0.51

U

2.7

U

Acenaphthylene

Mg/L

362

0.19

U

0.19

U

0.19

u

0.19

U

0.19

U

1.1

U

1.0

U

1.4

U

Anthracene

Mg/L

...

0.10

U

0.10

U

.0.10

u

0.10

U

0.19

U

0.053

U

0.051

U

0.054

U

Benzo(a)anthracene

fjg/L

0.13

0.10

U

0.10

U

0.10

u

0.10

U

0.19

U

0.11

U

0.10

U

0.14

U

Benzo(a)pyrene

ijg/L

0.2

0.10

U

0.10

U

0.10

u

0.10

U

0.19

U

0.11

U

0.10

U

0.14

U

Benzo(b)fluoranthene

Mg/L

0.1

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.054

U

Benzo(ghi)perylene

M9/L

...

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.22

U

Benzo(k)fluoranthene

MQ/L

0.14

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.054

U

Chrysene

Mg/L

0.85

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.14

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.33

U*

Fluoranthene

Mg/L

...

0.10

U

0.10

U

0.10

u

0.10

U

0.19

U

0.11

U

0.10

U

0.14

U

Fluorene

ng/L

490

0.19

U

0.19

U

0.19

u

0.19

U

0.19

U

0.11

U

0.10

U

0.27

U

lndeno(1,2,3-cd)pyrene

^g/L

0.1

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.14

U

Naphthalene

Mg/L

1.1

0.10

UJ

0.10

U

0.10

u

0.17



0.10

U

0.53

U

0.51

U

1.4

u-

Phenanthrene

Mg/L

294

0.10

U

0.10

U

0.10

u

0.10

U

0.10

U

0.11

U

0.10

U

0.11

U

Pyrene

mq/l

...

0.19

U

0.19

U

0.19

u

0.19

U

0.19

U

0.11

U

0.10

U

0.27

U

1-Methylnaphthalene

pg/L

...

na



na



na



0.19

U

0.19

U

na



na



na



2-Methylnaphthalene

pg/L

61.2

0.25

U

0.19

U

0.19

u

0.19

U

0.19

U

na



na



na



Inoraanics





































Cyanide, Total

mg/L

...

0.0085



0.0050

UJ

0.010

u

0.010

U

0.010

U

0.005

U

0.00500

U

0.010

U

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

13



10



4.37



3.96



3.6



na



9.28



9.6



Natural Attenuation Parameters





































Nitrate

mg/L

...

1.0

U

2.4



2.4



na



na



na



na



na



Nitrite

mg/L

...

0.10

U

na



na



na



na



na



ria



na



Ammonia

mg/L

...

0.20

U

0.20

U

0.20

u

na



na



na



na



na



Manganese, Dissolved

mg/L

...

na



na



2.80



3.37



0.838



2.65



1.88



1.2



Iron, Dissolved

mg/L

...

na



na



0.10

u

0.10

U

0.10

U

0.05

U

"0.05

U

0.10

U

Sulfate

mg/L

—

330



200



180



na



na



na



na



na



Sulfide

mg/L .

...

1.00

U

0.05

U

0.41



na



na



na



na •



na



Methane

ug/L

—

26



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

370



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

1.0

u

na



na



na



na



na



na



na



Orthophosphate

mg/L

...

0.10

u

na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

26.48



na



•na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Surface Wells	Page 13 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results





Performance
Standard

MW7-GW-0405
13-Apr-2005

MW7-GW-0406
12-Apr-2006

MW7-GW-0407
17-Apr-2007

MW7-GW-0408
15-Apr-2008

MW7-GW-0410
08-Apr-2010

MW7-GW-0411
12-Apr-2011

MW7-GW-0412
11-Apr-2012

DV

MW07-GW-0413
09-Apr-2013

VOCs

Units





































Benzene

ng/L

5

1.0

U

1

U

1

U

1

U

1.00

U

1.00

U

1.00

U



0.500

U

Toluene

M9'L

1000

1.0

U

1

U

1

U

1

U

1.00

U

1.00

U

1.00

U



1.00

U

Ethyl benzene

pg/L

700

1.0

U

1

U

1

u

1

U

1.00

U

1.00

U

1.00

U



1.00

U

Xylenes, Total

- ng/L

10000

2.0

U

3

U

3

u

3

U

6.00

U

3.00

U

3.00

U



3.00

U

PAHS'







































Acenaphthene

mq/l

914

2.3

U

0.13

U

0.049

u

0.049

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

Acenaphthylene

pg/L

362

1.2

U

0.17

U

0.085

u

0.085

U

0.100

u

0.100

U

0.100

U

UJ

0.10

U

Anthracene

pg/L

...

0.047

U

0.0093

U

0.01

u

0.01

U

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(a)anthraoene

pg/L

0.13

0.12

U

0.019

U

0.003

u

0.003

U

0.100

u

0.100

U

0.100

u

UJ

0.100

U

Benzo(a)pyrene

pg/L

0.2

0.12

U

0.019

U

0.032

u

0.032

U

0.100

u

0.100

u

0.100

u

UJ

0.100

U

Benzo(b)fluoranthene

pg/L

0.1

0.047

U

0.037

U

0.013

u

0.013

U

0.100

u

0.100

u

0.100

u

UJ

0.100

U

Benzo(ghi)perylene

pg/L

...

0.19

U

0.032

U

0.009

u

0.009

U

0.100

u

0.100

u

0.100

u

UJ

0.100

u

Benzo(k)fluoranthene

pg/L

0.14

0.047

U

0.023

U

0.015

u

0.015

U

0.100

u

0.100

u

0.100

u

UJ

0.100

u

Chrysene

pg/L

0.85

0.12

U

0.02

U

0.005

u

0.005

U

0.100

u

0.100

u

0.100

u

UJ

0.100

u

Dibe'nzo(a,h)anthracene

pg/L

0.033

0.28

" U

0.033

U

0.01

u

0.01

U

0.0081

U.MDL

0.017

U.MDL

0.017

U.MDL

UJ

0.0175

u

Fluoranthene

pg/L

...

0.12

U

0.032

U

0.01

u

0.01

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

Fl uorene

pg/L

490

0.23

U

0.029

U

0.01

u

0.01

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.12

¦ U

0.038

U

0.007

u

0.007

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

Naphthalene

pg/L

1.1

1.2

U

0.1

U

0.054

u

0.054

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

Phenanthrene

pg/L

294

0.093

U

0.015

U

0.007

u

0.007

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

Pyrene ¦

pg/L

...

0.23

u

0.036

U

0.019

u

0.019

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

1-Methylnaphthalene

Mg/L

...

na



na



na



na



0.100

U

0.100

U

0.100

U

UJ

0.100

u

2-Methylnaphthalene

pg/L

61.2

na



na



0.052

u

0.052

U

0.100

U

0.100

U

0.100

U

UJ

0.100

u

Inoraanics







































Cyanide, Total

mg/L

...

0.010

u

0.01

U

0.01

u

0.01

U

na



na



na





na



Cyanide, WAD

mg/L

0.2

na



na



na



na



0.01

u

0.01

U

0.01

u



0.0100

u

Manganese, Total

mg/L

0.775

2.3



16



na



na



2.42



6.15



1.67





1.350



Natural Attenuation Parameters







































Nitrate

mg/L

1.8



3.69



na

na

0.95

P2

0.93

P2

1.37

P2

3.28



Nitrite

mg/L

0.020

U

0.1

U

na

na

0.100

U

0.100

-u

0.100

U

0.100

U

Ammonia

mg/L

0.20

U

0.2

U

na

na

0.200

U

0.200

U

0.200

U

0.200

U

Manganese, Dissolved

mg/L

2.0



1.19



na

na

2.11



1.77



1.45



1.18



Iron, Dissolved

mg/L

0.10

U

0.1

U

na

na

0.100

U

0.100

U

0.100

U

0.100

U

Sulfate

mg/L

180



139



na

na

156



146



139



118



Sulfide

mg/L

1.0

U

1

U

na

na

5.00

U

19.00



10

U

12.8



Methane

pg/L

na



26

-U

na

na

26.0

U

0.58

U

0.58

U

0.580

u

Alkalinity, Total

mg/L

370



399



na

na

400



372



375



432



Total Kjeldahl Nitrogen

mg/L

0.34

B

1

U

na

na

1.00

U

0.10

U

1.00

U

1.39



Orthophosphate

mg/L

0.099



0.1

U

na

na

0.100

u

0.100

U

0.100

U

0.100

u

Total Organic Carbon

mg/L

2.0



2.19



na

¦ na

1.13



na



na



na



Chloride

mg/L

na



138



na

na .

227



na



na



na



icgp_gw_2013-10.xlsx

2//^-S!n.14	Bedro^'-^'.irface Wells	Pr'--J4 of 53

-------
,o
\ /

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW13-GW-001 MW13-GW-002 MW13-GW-003 MW13-GW-004 MW13-GW-0410 MW13-GW-1010 MW13-GW-0411
Standard 25-Oct-1999 ,21-Jun-2000 11 -Jul-2001 12-Dec-2001	09-Apr-2010	05-0ct-2010 13-Apr-2011
	 ¦ DV

VOCs

Units

































Benzene

mq/l

5

62.8



18.5



97.2



68.9



5.65





5.85



4.07



Toluene

Mg/L

1000

122



1.5



3.0



5.0

U

1.00

U



1.00

U

1.00

U

Ethyl benzene

Mg/L

700

261



16.4



68.9



41.6



2.55





2.58



1.57



Xylenes, Total

fjg/L

10000

374



19.1



60.3



25



6.00

U



3.90



3.29



PAHs



































Acenaphthene

pg/L

914

43.6



54.9



63.0



35.8



17.0



J+

19.1



14.3



Acenaphthylene

ng/L

362

246



177



223



12.6



70.1



J+

67.0



56.3



Anthracene

Mg/L

...

13.5



18.9



19.7



13.7



5.01



J+

8.72



1.66



Benzo(a)anthracene

Mg/L

0.13

5.1



5.0

U

8.5



6.78



1.27



J+

3.85



0.544



Benzo(a)pyrene

Mg/L

0.2

2.27



2.36



3.9



3.77



1.00

U



2.61



0.199



Benzo(b)fluoranthene

ijg/L

0.1

0.58



0.86



1.0

U

1.0

U

1.00

U



1.96



0.173



Benzo(ghi)perylene

Mg/L

—

1.08



0.10

U

1.0

U

1.88



1.00

U



0.895



0.100

U

Benzo(k)fluoranthene

Mg/L

0.14

0.43



0.16



1.0

U

1.0

U

1.00

U



0.922



0.100

"U

Chrysene

fjg/L

0.85

2.04



5.0

U

2.8



2.95



1.16



J+

3.64



0.475



Dibenzo(a,h)anthracene

ug/L

0.033

0.2



0.20



1.0

U

1.0

u-

0.0810

U.MDL



0.280

MDL

0.100

U

Fluoranthene

Mg/L

...

0.10

U

11.8



12.6



10.7



4.97



J+

8.25



2.21



Fluorene

ng/L

490

77.2



121



129



47.2



26.7



J+

25.0



21.8



lndeno(1,2,3-cd)pyrene

fjg/L

0.1

0.9



0.79



1.9



1.0

U

1.00

U



0.814



0.100

U

Naphthalene

Mg/L

1.1

943



8.19

J

175



13.9



1.44



J+

1.49



0.474



Phenanthrene

Mg/L

294

46.9



70.4



87.3



39.1



36.8



J+

34.7



31.8



Pyrene

Mg/L

—

0.19

U

0.19

U

1.9

U

1.9

U

4.23



J+

11.0



2.87



1 -Methylnaphthalene

(jg/L

...

na



na



na



81.5



12.1



J+

12.4



5.31



2-Methylnaphthalene

ug/L

61.2

346



70.9



53.9



7.66



1.00

U



0.431



0.100

U

Inoraanics



































Cyanide, Total

mg/L

...

0.0143



0.0099



0.010

UJ

0.010

U

na





na



na



Cyanide, WAD

mg/L

0.2

na



na



na



na



0.0100

U



0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

15



6.3



5.35



2.99



2.26





2.21



2.33



Natural Attenuation Parameters



































Nitrate

mg/L

...

1.0

U

1

UJ

1.0

U

na



na





na



na



Nitrite

' mg/L

...

na



na



na



na



na





na



na



Ammonia

mg/L

...

0.91



1.49



1.14



na



na





na



na



Manganese, Dissolved

mg/L

...

na



na



2.87



3.03



na





na



na



Iron, Dissolved

mg/L

...

na



na



9.60



10.2



na





na



na



Sulfate

mg/L

...

190



170



140



na



na





na



na



Sulfide

mg/L

...

1.00

U

1

U

1.0

U

na



na





na



na



Methane

Mg/L

...

na



na



na



na



na





na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na





na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na





na



na



Orthophosphate

mg/L

...

na



na



na



na



na





na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na





na



na



Chloride

mg/L

...

na



na



na



na



na





na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Surface Wells	Page 15 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW13-GW-1011 MW13-GW-0412 MW13-GW-1012 MW13-GW-0413 MW13-GW-1013 MW19-GW-001 MW19-GW-002
Standard 26-Oct-2011 12-Apr-2012 10-0ct-2012 11 -Apr-2013 23-Oct-2013 04-Apr-2000 21-Jun-2000
DV	DV	DV	DV 	DV	

VOCs

Units



































Benzene

pg/L

5

3.84

3.17





3.68





3.29





4.59



915



1070



Toluene

Mg/L

1000

1.00

U 1.00

U



1.00

U



1.00

U



1.00

U

91.5



110



Ethylbenzene

Hg/L

700

1.28

1.08





1.00

U



1.00

U



1.00

U

225



241



Xylenes, Total

ug/L

10000

3.00

U 3.00

U



3.00

U



3.00

u



3.00

u

457



511



PAHs





































Acenaphthene

pg/L

914

7.08

7.37



J-

10.6



J-

11.3



J-

13.8



71.7



29.0



Acenaphthylene

Mg/L

362

48.7

29.9



J-

44.9



J-

41.4



J-

47.8



272



52.3



Anthracene

pg/i-

...

1.92

1.04



J-

0.900



J-

1.08



J-

1.29



8.2



3.54



Benzo(a)anthracene

M9/I-

0.13

0.908

0.294



J-

0.363



J-

0.347



J-

0.709



5.0

u

0.69

J

Benzo(a)pyrene

Mg/L

0.2

0.526

0.100

U

UJ

0.100

U

UJ

0.141

U

UJ

0.314



5.0

u

0.39



Benzo(b)fluoranthene

ng/i

0.1

0.489

0.100

U

UJ

0.100

U

UJ

0.273

U

UJ

0.288



5.0

U

0.14



Benzo(ghi)perylene

Mg/L

...

0.194

0.100

U

UJ

0.100

U

UJ

0.172

U

UJ

0.123



5.0

u

0.15



Benzo(k)fluoranthene

Mg/i-

0.14

0.112

0.100

U

UJ

0.100

U

UJ

0.182

u

UJ

0.112



5.0

U

0.10

U

Chrysene

Mg/L

0.85

0.743

0.250



J-

0.265



J-

0.245



J-

0.715



5.0

U

0.10

U

Dibenzo(a,h)anthracene

(jg/L

0.033

0.0695

J,MDL UB 0.0170

U.MDL

UJ

0.0130

U,MDL

UJ

0.172

u

UJ

0.0425



5.0

U

0.10

U

Fluoranthene

Mg'L

...

2.59

2.52



J-

2.55



J-

2.91



J-

4.47



5.0

U

3.84



Fluorene

Mg/L

490

15.4

12



J-

16.8



J-

16.5



J-

20.1



77.0



20.3



lndeno( 1,2,3-cd)pyrene

Mg/L

0.1

0.150

0.100

U

UJ

0.100

U

UJ

0.172

u

UJ

0.1

u

5.0

U

0.10



Naphthalene

Mg/L

1.1

0.579

0.362

B

UB,J-

0.572



UB,J-

1.43

B

UB,J-

0.724

B' J+,B

1680



924



Phenanthrene

pg/L

294

16.1

17.8



J-

19.0



J-

14.8



J-

22.9



38.4



14.9



Pyrene

mq/l

...

3.83

2.73



J-

3.66



J-

3.74



J-

2.14



9.5

U

0.19

U

1-Methylnaphthalene

pg/L

...

4.59

2.47



J-

3.55



J-

3.17



J-

3.13



na



na



2-Methylnaphthalene

pg/L

61.2

0:100

U 0.100

U

UJ

0.122



J-

0.237



J-

0.106



39.6



21.6



Inoraanics¦





































Cyanide? Total

mg/L

...

na

na





na





na





na



0.0100



0.0113

J

Cyanide, WAD

mg/L

0.2

0.0100

U 0.0100

U



0.0100

U



0.0100

U



0.0100

u

na



na



Manganese, Total

mg/L

0.775

2.13

2.16





2.28





2.260





2.34



10



9.4



Natural Attenuation Parameters





































Nitrate

mg/L

...

na

na





na





na





na



1.0

U

1.0

U

Nitrite

mg/L

...

na

na





na





na





na



na



na



Ammonia

mg/L

...

na

na





na





na





na



2.03



2.34



Manganese, Dissolved

mg/L

...

na

na





na





na





na



na



na



Iron, Dissolved

mg/L

...

na

. na





na





na





na



na



na



Sulfate

mg/L

...

na

na





na





na





na



53



48



Sulfide

mg/L

...

na

na





na





na





na



5.0

UJ

0.05

U

Methane

Mg/L

...

na

na





na





na





na



na



na



Alkalinity, Total

mg/L

...

na

na





na





na





na



na



na



Total Kjeldahl Nitrogen

mg/L



na

na





na





na





na



na



na



Orthophosphate

mg/L

...

na

na





na





na





na



na



na



Total Organic Carbon

mg/L

...

na

na





na





na





na



na



na



Chloride

mg/L

...

na

na





na





na





na



na



na



icgp_gw_2013-10.xlsx

2/^^^qj4	Bedro^^^^irface Wells	Pf ^^^6 of 53

/

^ ^	'r™	V \'

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW19-GW-003 MW19-GW-004 MW19-GW-005 MW19-GW-1002 MW19-GW-0103 MW19-GW-1003 MW19-GW-0404 MW19-GW-1004
Standard 10-Jul-2001 12-Dec-2001 17-Apr-2002 30-0ct-2002 08-Jan-2003 22-Oct-2003 07-Apr-2004 19-0ct-2004

VOCs

Units



































Benzene

ng/L

5

867



868



829



760

J

34

J

960



1100



1400



Toluene

ng/L

1000

108



122



94



89

J

4.4

J

110



150



110



Ethyl benzene

ng/L

700

258



250



196



190

J

12

J

270



270



270



Xylenes, Total

kig/L

10000

528



450



419



410

J

25

J

540



500



490



PAHs





































Acenaphthene

ng/L

914

3.8

U

58.1



79.4



140

J

280

J

120



120



140



Acenaphthylene

ijg/L

362

9.3



206



122



10

U

10

U

1900



1600



2200



Anthracene

iig/L

...

2.0

U

3.68



9.5

U

7



6.6

J

7.3



7.1



7.8



Benzo(a)anthracene

ijg/L

0.13

0.10



0.11



0.19

U

1

U

1.0

U

1.3

U

0.12

Ja

1.4

U

Benzo(a)pyrene

ng/L

0.2

0.10

u

0.10

U

0.19

U

1

U

1.0

U

1.3

U

0.052

Ja

1.4

U

Benzo(b)fluoranthene

mq/l

0.1

0.10

u

0.10

U

0.10

U

1

U

1.0

U

0.51

U

0.052

Ua

0.54

U

Benzo(ghi)perylene

|jg/L

...

0.10

u

0.10

U

0.10

U

1

U

1.0

U

2.0

U

0.21

U

2.2

U

Benzo(k)tluoranthene

MQ/L

0.14

0.10

u

0.10

U

0.10

U

1

U

1.0

U

0.51

U

0.052

U

0.54

U

Chrysene

ijg/L

0.85

0.10

u

0.10

U

0.10

U

0.16



1.0

U

1.3

U

0.10

Ja

1.4

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.10

u

0.10

U

0.11



1

U

1.0

U

3.0

U

0.31

U

3.2

U

Fluoranthene

ijg/L

...

0.10

u

0.81



1.78



4.9



4.6

J

5.6



5.1



5.4



Fluorene

M9/L

490

3.8

u

28.5



50.8



27



30

J

28



25



25



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.10

u

0.10

U

0.10

U

1.00

U

1.0

U

1.3

U

0.14

U

1.4

U

Naphthalene

Mg/L

1.1

998



1,160



1,530



1,900



1,600

J

2200



1800



2100



Phenanthrene

ijg/L

294

2.0

u

22.3



29.6



39



43

J

45



45



46



Pyrene

Mg/L

...

0.19

u

0.19

U

1.61



2.6



2.3

J

2.5

Ua

0.84



2.7

Ua

1-Methylnaphthalene

Mg/L

...

na



388



510



na



na



na



na



na



2-Methyl naphthalene

Mg/L

61.2

3.8

u

31



35.6



na



na



na



na



na



Inoraanics





































Cyanide, Total

mg/L

...

0.011



0.010

U

0.010

U

0.005

U

0.006



0.012



0.010

U

0.010

U

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

6.63



5.52



5.3



5.09



5.08



5.7



5.3



5.1



Natural Attenuation Parameters





































Nitrate

mg/L

...

1.0

u

na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

—

2.07



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

5.45



5.52



4.9



5.06



5.21



5.0



5.1



4.8



Iron, Dissolved

mg/L

...

5.14



5.59



5.0



6.87



7.42



5.6



5.4



5.6



Sulfate

mg/L

...

80



na



na



na



na



na



na



na



Sulfide

mg/L

...

1.0

u

na



na ¦



na



na



na



na



na



Methane

ijg/L

...

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

—

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp gw 2013-10.xlsx
2/11/2014

Bedrock Surface Wells

Page 17 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW19-GW-0405 MW19-GW-1005 MW19-GW-0406 MW19-GW-1006 MW19-GW-0407 MW19-GW-1007 MW19-GW-0408 MW19-GW-0410
Standard 14-Apr-2005 12-0ct-2005 12-Apr.-2006 10-0ct-2006 17-Apr-2007 10-0ct-2007 15-Apr-2008	08-Apr-2010

VOCs

Units



































Benzene

^g/L

5

2000

-

1000



1130



1290



1180



538



870



1100



Toluene

^g/L

1000

150

•

120



48.4



82.2



112



179



87.3



158



Ethylbenzene

ng/L

700

300

*

220



173



211



184



112



151



187



Xylenes, Total

Mg/L

10000

550

*

380



312



368



331



293



261



440



PAHs





































Acenaphthene.'

pg/L

914

160



170



135



147



155



158



146



152

RL1

Acenaphthylene

ng/L

362

2200



2200



125



148



120



201



156



152

RL1

Anthracene

ug/L

...

7.7



9.1



7.32



7.88



7.19



7.88



6.86



13.8

RL1

Benzo(a)anthracene

ng/L

0.13

0.12



0.36

Ja

0.704



0.167



0.0784

J

0.148



0.214



1.00

U,RL1

Benzo(a)pyrene

ijg/L

0.2

0.12

U

0.16

Ja

0.019

U

0.0909

J

0.0356

U

0.032

U

0.186

J

1.00

U.RL1

Benzo(b)fluoranthene

Mg/L

0.1

0.047

U

0.23

U

0.037

U

0.0702

J

0.0144

U

0.013

U

0.117



1.00

U.RL1

Benzo(ghi)perylene

pg/L



0.19

u

0.93

U

0.032

u

0.009

(J

0.01

U

0.009

U

0.113



1.00

U,RL1

Benzo(k)fluoranthene

Mg'L

0.14

0.047

u

0.23

U

0.023

u

0.0381

J

0.0167

U

0.015

U

0.015

U

1.00

U.RL1

Chrysene

Mg/L

0.85

0.067

Ja

0.24

Ja

0.02

u

0.0972

J

0.0409

J

0.0839

J

0.005

U

1.00

U.RL1

Dibenzo(a,h)anfhracene

pg/L

0.033

0.28

U

1.4

U

0.033

u

0.01

U

0.0111

U

0.01

U

0.0287

J

0.0810

U.RL1.MDL

Fluoranthene

ng/i-

...

5.9



6.1



0.032

u

3.95



3.11



2.89



4.79



2.65

RL1

Fluorene

pg/L

490

27



25



69.2



86.5



81.6



162



106



34.8

RL1

lndeno(1,2,3-cd)pyrene'

pg/L

0.1

0.12

U

0.60

U

0.038

u

0.007

U

0.00778

U

0:007

u

0.0833

J

1.00

U,RL1

Naphthalene

ng/L

1.1

1700



1300



1030



1060



967



871



737



620

RL1

Phenanthrene

pg/L

294

48



49



45.8



48.6



47.1



60.3



62.1



45.4

RL1

Pyrene

pg/L

...

0.57



1.4

M

23.8



16.8



16



14.3



0.019

U

1.92

RL1

1-Methylnaphthalene

MQ/L

...

na



na



na



na



na



na



na



900

RL1

2-Methylnaphthalene

pg/i-

61.2

na



na



na



46.5



43.1



29.9



40



13.6

RL1

Inoraanics





































Cyanide, Total

mg/L

...

0.010

U

0.0058

B

0.01

u

0.01

U

0.01

U

0.01

u

0.01

U

na



Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



0.0100

U

Manganese, Total

mg/L

0.775

4.9



4.8



7.63



na



na



na



na



3.84



Natural Attenuation Parameters





































Nitrate

mg/L

— .

na



na



na



na



na



na



na



0.10

U

Nitrite

mg/L

...

na



na



na



na



na



na



na



0.100



Ammonia

mg/L

...

na



na



na



na



na



na



na



2.31



Manganese, Dissolved

mg/L

...

4.9



4.3



4.3



na



na



na



na



3.70



Iron, Dissolved

mg/L

¦

6.3



6.0



4.77 ¦



na



na



na



na



"5.31



Sulfate

mg/L

...

na



na



na



na



na



na



na



34.4



Sulfide

mg/L

...

na



na



na



na



na



na



na



5.00

U

Methane

pg/L

...

na.



na



na



na



na



na



na



• 68.0



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



389



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



2.61



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



0.100

U

Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



3.01



Chloride

mg/L



na



na



na



na



na



na



na



182



icgp_gw_2013-10.xlsx

Bedro^'^Mrface Wells	Pp-~tJ8 of 53

i )	: )	¦ ^

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW19-GW-1010 MW19-GW-0411 MW19-GW-1011 MW19-GW-0412	DP02-GW-0412	MW19-GW-1012

Standard 06-0ct-2010 12-Apr-2011	25-Oct-2011	11-Apr-2012	11-Apr-2012	10-0ct-2012
	 DV DV DV

VOCs

Units

































Benzene

M9/L

5

1060



864



964





968



984





870





Toluene

M9/L

1000

161



170



152





173



176





139





Ethylbenzene

Mg/L

700

256



217



208





212



212





229





Xylenes, Total

pg/L

10000

406



347



328





319



315





355





PAHs



































Acenaphthene

pg/L

914

126



99.5



56.5



J-

89.2



97.6

RL1

J-

91.0



J-

Acenaphthylene

pg/L

' 362

127



99.9



129



J-

98.3



103

RL1

J-

73.8



J-

Anthracene

pg/L

...

13.3



10.3



6.50



J-.J-

8.05



8.21

RL1

J-

8.30



J-

Benz'o(a)anthracene

pg/L

0.13

0.144



0.120



0.147



J-,J-

0.145



1.00

U.RL1

UJ

0.161



J-

Benzo(a)pyrene

pg/L

0.2

0.100

U

0.100

U

0.100

U

UJ

0.100

U

1.00

U.RL1

UJ

0.100

U

UJ

Benzo(b)fluoranthene

ug/L

0.1

0.100

U

0.100

U

0.100

U

UJ

0.100

U

1.00

U.RL1

UJ

0.100

U

UJ

Benzo(ghi)perylene

|jg/i-

...

0.100

U

0.100

U

0.100

U

uj-

0.100

U

1.00

U.RL1

UJ

0.100

u

UJ

Benzo(k)fluoranthene

mq/l

0.14

0.100

U

0.100

U

0.100

U

UJ

0.100

U

1.00

U.RL1

UJ

0.100

u

UJ

Chrysene

pg/i-

0.85

0.122



0.106



0.127



J-.J-

0.125



1.00

U.RL1

UJ

0.101



J-

Dibenzo(a,h)anthracene

pg/L

0.033

0.00810

U,MDL

0.017

U.MDL

0.0170

U,MDL

UJ

0.0170

U.MDL

0.170

U.RL1.MDL

UJ

0.0130

U.MDL

UJ

Fluoranthene

pg/L

...

1.66



1.46



2.62



J-.J-

1.93



2.11

RL1

J-

2.13



J-

Fluorene

pg/L

490

28.8



24.8



8.07



J-

20.5



23.6

RL1

J-

27.7



J-

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100

U

0.100

U

0.100

U

UJ

0.100

U

1.00

U.RL1

UJ

0.100

U

UJ

Naphthalene

pg/L

1.1

488



384



416



J-

292



372

RL1

J-

292



J-

Phenanthrene

pg/L

294

53.5



37.7



29.8



J-

37.1



44.8

RL1

J-

31.1



J-

Pyrene

Mg/L

...

1.03



1.47



5.55



J-,J-

1.85



2.21

RL1

J-

2.12



J-

1 -Methylnaphthalene

pg/L



733



619



652



J-

483



595

RL1

J-

504



J-

2-Methylnaphthalene

pg/L

61.2

10.8



5.84



9.71



J-,J-

8.85



11.3

RL1

J-

11.8



J-

tnoraanics



































Cyanide, Total

mg/L

—

na



na



na





na



na





na





Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

0.0100

U



0.0100

U

0.0100

U



0.0100

U



Manganese, Total

mg/L

0.775

3.63



4.11



3.59





3.89



3.67





3.92





Natural Attenuation Parameters



































Nitrate

mg/L

...

0.10

U,M1

0.10

U

0.10

U



0.100

U

na





0.100

u



Nitrite

mg/L

...

0.100

U

0.100

U

0.100

(J



0.100

U

na





0.100

u



Ammonia

mg/L

...

2.23



2.26



2.14





2.22



na





2.14





Manganese, Dissolved

mg/L

...

3.64



3.51



3.76





3.99



na





4.10





Iron, Dissolved

mg/L

...

5.46



4.37



5.21





5.56



na





5.76





Sulfate

mg/L

...

31.4



34.4



36.5





36.8



na





38.0





Sulfide

mg/L

...

5.00

U

10.00

U

10

U



10

U

na





10

u



Methane

Mg/L

...

74.6

-

21



28





31



na





43





Alkalinity, Total

mg/L

...

376



351



345





311



na





345





Total Kjeldahl Nitrogen

mg/L

...

2.90



2.85



2.85





2.4



na





2.57





Orthophosphate

mg/L

...

0.100

U

0.100

U

0.100

U



0.100

U

na





0.100

u



Total Organic Carbon

mg/L

...

2.65



na



2.32

ET



na



na





na





Chloride

mg/L

—

193



na



na





na



na





na





icgp_gw_2013-10.xlsx

2/11 /2014	Bedrock Surface Wells	Page 19 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW19-GW-0413 MW19-GW-1013 MW20-GW-0D1 MW20-GW-003 MW20-GW-004 MW20-GW-005 MW20-GW-1002 MW20-GW-0103
Standard	10-Apr-2013	23-Oct-2013	02-Apr-2001 10-Jul-2001 12-Dec-2001 18-Apr-2002 30-0ct-2002 09-Jan-2003

DV	DV

VOCs

Units



































Benzene

^g/L

5

977

J-

840



2300



2800



3000



3140



1.7



2000

J

Toluene

t-ig/L

1000

134



99.9



906



1130



1430



1270



0.79



1300

J

Ethyl benzene

pg/L

700

186



179



969



987



1220



1050



0.67



1300



Xylenes, Total

|jg/L

10000

316



296



997



1010



1220



1170



0.78



450



PAHs





































Acenaphthene

ng/L

914

134



112



71.9



65.5



95.7



54.6



0.041



420

J

Acenaphthylene

Ug/L

362

134



111



198



250



- 443



240



11

U

10

U

Anthracene



—

9.27



5.31



10

U

5.91



10

U

5.0

U

7.8



6.4

J

Benzo(a)anthracene

Mg/L

0.13

0.147



1.02

U

0.39



0.13



0.4



0.56



0.71



0.45

J

Benzo(a)pyrene

pg/L

0.2

0.100

U

1.02

U

0.22



0.10

U

0.17



0.22



0.34



0.18

J

Benzo(b)fluoranthene

ug/L

0.1

0.100

U

1.02

U

0.10

U

0.10

U

0.10

U

0.10

U

0.45



0.24

J

Benzo(ghi)perylene

tjg/L

—

0.100

U

1.02

U

0.10

U

0.10

U

0.10

U

0.10

u

1.1

U

1.0

u

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

1.02

U

0.10

U

0.10

U

0.10

U

0.10

u

1.1

U

1.0

u

Chrysene

|jg/L

0.85

0.137



1.02

U

0.26



0.10

U

0.10

U

0.21



0.34



0.24

J

Dibenzo(a,h)anthracene

ug'L

0.033

0.0173

U

0.173

U

0.10

U

0.10

U

0.10

U

0.10

u

1.1

U

1.0

u

Fluoranthene

ng/L

...

1.55



1.29



1.5



2.07



0.10

U

0.10

u

6.4



3.8

J

Fl uorene

M9/L

490

31.7



25.8



56.9



58.3



74.3



64.7



29



41

J

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.100

U

1.02

U

0.10

U

0.1

U

0.10

U

0.10

u

1.1

U

1.0

u

Naphthalene

ng/L

1.1

400



352

B* J+,B

1880



1940



3220



1830



2700



2700

J

Phenanthrene

kig/L

294

38.2



60.1



29.4



26.3



40.1



27.8



43



43

J

Pyrene

ug/L

...

1.59



1.83



0.19

U

0.19

U

0.19

U

1.52



3.8



2.1

J

1-Methylnaphthalene

pg'L

...

770



665



na



na



662



na



na



na



2-Methylnaphthalene

Mg/L

61.2

13.4



11.1



353



303



485



277



na



na



Inoraanics





































Cyanide, Total

mg/L

...

na



na



0.021



0.17



0.02



0.015



0.005

U

0.00574



Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

na



na



na



na



na



na



Manganese, Total

mg/L

0.775

4.05



3.61



1.07



0.918



0.94



0.986



0.897



0.953



Natural Attenuation Parameters





































Nitrate

mg/L

... .

0.100

U

na



1.0

U

1.0

U

na



na



na



na



Nitrite

mg/L

...

0.100

U

na

*

na



na



na



na



na



na



Ammonia

mg/L

...

2.25



na



0.20

UJ

0.20

U

na



na



na



na



Manganese, Dissolved

mg/L

...

4.11



na



na



0.884



0.94



0.926



0.824



0.906



Iron, Dissolved

mg/L

...

5.56



na



na



14.9



15.5



16



14.6



15.8



Sulfate

mg/L

...

34.9



na



120



130



na



na



na



na



Sulfide

mg/L

...

10.0

U

na



2.0

U

0.10

U

na



na



na



na



Methane

ug'L

...

28.8



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

365



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

2.83



na



¦ na



na



na



na



na



na



Orthophosphate

mg/L

...

0.100

U

na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp_gw_2013-1O.xlsx

2//^'^14	Bedro^^'.irface Wells	of 53

¦' \ /' \

-------
>/

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW20-GW-1003 MW20-GW-0404 MW20-GW-1004 MW20-GW-0405 MW20-GW-1005 MW20-GW-0406 MW20-GW-1006 MW20-GW-0407
Standard 22-Oct-2003 08-Apr-2004 20-0ct-2004 14-Apr-2005 11-0ct-2005 12-Apr-2006 10-0ct-2006 17-Apr-2007

VOCs

Units

































Benzene

ng/L

5

2800



2800



1700



4700



2700



2830



2140

2360



Toluene

ug/L

¦ 1000

1500



1400



920



3500



1500



1860



1180

1510



Ethylbenzene

UQ/L

700

1300



1300



830



1900



1200



1540



1170

1290



Xylenes, Total

pg/L

10000

1400



1400



900



2500



1800



1730



1260

1380



PAHs



































Acenaphthene

Mg/L

914

96



140



100



120



160



205



141

121



Acenaphthylene

ug/L

362

2000



1900



1400



1900



1900



168



119

85.6



Anthracene

ng/L

...

7.0



5.6



5.4



6.7



17



38



7.16

5.75



Benzo(a)anthracene

Hg/L

0.13

0.62

Ja

0.54

Ja

0.50

Ja

0.16



6.6



17



0.609

0.131

J

Benzo(a)pyrene

ng/L

¦ 0.2

1.4

Ua

0.37

Ja

1.3

U

0.018

Ja

3.9



16.5



0.542

0.0759

J

Benzo(b)fluoranthene

Mg/L

0.1

0.53

U

0.53

U

0.50

U

0.047

U

1.6



10.9



0.37

0.0144

U

Benzo(ghi)perylene

pg/i-

...

2.1

U

2.1

U

2.0

U

0.19

U

1.0

Ja

5.74



0.168

0.01

U

Benzo(k)fluoranthene

ijg/L

0.14

0.53

U

0.53

U

0.50

U

0.047

U

0.90



7.01



0.21

0.0167

U

Chrysene

Mg/L

0.85

0.33

Ja

0.43

Ja

0.32

Ja

0.090

Ja

4.6



11.5



0.44

0.0589

J

Dibenzo(a,h)anthracene

ng/t-

0.033

3.2

U

3.2

U

3.0

U

0.28

u ¦

3.0

U

1.81



0.0322 J

0.0111

U

Fluoranthene

pg/L

...

7.2



7.0



5.5



6.3



23



42.6



4.42

5.32



Fluorene

Mg/L

490

34



40



29



37



44



140



88.6

79.1



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

1.4

U

1.4

U

1.3

U

0.12

U

1.2

Ja

6.19



0.129

0.00778

u

Naphthalene

Mg/L

1.1

3800



3700



2400



3400



3400



3340



2640

2470



Phenanthrene

ng'L

294

41



48



33



43



64



120



40.8

32



Pyrene

ug/L

...

2.6

Ua

2.3

Ja

2.5

Ua

0.72



13



234



22.4

13.7



1 -Methylnaphthalene

Mg/L

...

na



na



na



na



na



na



na

na



2-Methylnaphthalene

ng/L

61.2

na



na



na



na



na



na



428

388



Inoroanics



































Cyanide, Total

mg/L

...

0.011



0.0079

B

0.010



0.0099

B

0.0085

B

0.1

U

0.01 U

0.0108



Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na

na



Manganese, Total

mg/L

0.775

1.2



0.88



0.79



0.78



0.89



1.18



na

na



Natural Attenuation Parameters



































Nitrate

mg/L

...

na



na



na



0.10

U

0.020

U

0.1

U

na

na



Nitrite

mg/L

...

na



na



na



0.020

U

0.020

U

0.1

u ¦

na

na



Ammonia

mg/L

...

na



na



na



0.20

u

0.22



0.2

u

na

na



Manganese, Dissolved

mg/L

...

0.85



0.81



0.79



0.80



0.74



0.698



na

na



Iron, Dissolved

mg/L

...

15



15



14



15



14



13.4



na

na



Sulfate

mg/L

...

na



na



na



88



130



112



na

na



Sulfide

mg/L

...

na



na



na



1.0

u

0.90

B

1

u

na

na



Methane

fjg/L

...

na



na



na



26



63



151



na '

na



Alkalinity, Total

mg/L

...

na



na



na



430



380



456



na

na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



0.26

B

0.50



1

u

na

na



Orthophosphate

mg/L

...

na



na



na



0.019

B

0.050

U

0.1

u

na

na



Total Organic Carbon

mg/L

...

na



na



na



6.7



9.5



6.66



na

na



Chloride

mg/L

...

na



na



na



na



na



134



na

na



icgp_gw_2013-1O.xlsx
2/11/2014

Bedrock Surface Wells

Page 21 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW20-GW-1007 MW20-GW-0408 MW20-GW-0410 MW20-GW-1010 MW20-GW-0411 MW20-GW-1011 MW20-GW-0412
Standard 09-0ct-2007 15-Apr-2008	08-Apr-2010	06-0ct-2010 12-Apr-2011 25-Oct-2011	11-Apr-2012

DV	DV	DV

VOCs

Units



































Benzene

pg/L

5

1800



1920



549



637



919



1250





2490





Toluene

pg/L

1000

1120



1070



272



247



353



361





846





Ethylbenzene

ng/L

700

1100



1100



978

C9 J+

947



865



974





1180





Xylenes, Total

pg/L

10000

1170



1240



929



1010



1160



1090





1190





PAHs





































Acenaphthene

pg'L

914

149



123



79.5

RL1

92.9



94.0



39.3



J-

78.6

RL1

J-

Acenaphthylene

pg/L

362

301



77.1



82.5

RL1

133



96.9



91.9



J-

48.3

RL1

J-

Anthracene

pg/L



5.67



6.07



10.0

U,RL1

8.98



7.13



6.51



J-

2.37

RL1

J-

Benzo(a)anthracene

pg/L

0.13

0.22



.0.348



10.0

U.RL1

0.161



0.100

U

1.00

U

UJ

1.00

U.RL1

UJ

Benzo(a)pyrene

pg/L

0.2

0.156

J

0.304



10.0

U,RL1

0.100

U

0.100

U

1.00.

U

UJ

1.00

U.RL1

UJ

Benzo(b)fluoranthene

pg/L

0.1

0.013'

U

0.203



10.0

U.RL1

0.100

U

0.100

U

1.00

U

UJ

1.00

U.RL1

UJ

Benzo(ghi)perylene

pg/L

...

1.18



0.137



10.0

U.RL1

0.100

u

0.100

U

1.00

U

UJ

1.00

U,RL1

UJ

Benzo(k)fluoranthene

pg/L

0.14

0.015

u

0.015

U

.10.0

U,RL1

0.100

u

0.100

U

1.00

U

UJ

1.00

U,RL1

UJ

Chrysene

pg/L

0.85

0.18



0.0649

J

10.0

U.RL1

0.140



0.100

U

1.00

U

UJ

1.00

U.RL1

UJ

Dibenzo(a,h)anthracene

pg/L

0.033

0.01

u

0.01

U

0.81

U,RL1,MDL

0.00810

U.MDL

0.0170

U,MDL

0.276

J.MDL

J-

0.170

U,MDL

UJ

Fluoranthene

pg/L

...

2.14



3.87



10

U,RL1

3.25



1.37



2.23



J-

1.14

RL1

J-

Fluorene

pg/L

490

152



88.2



41.1

RL1

49.8



48.5



19.6



J-

30.6

RL1

J-

lndeno( 1,2,3-cd)pyrene

pg/L

0.1

0.007

u.

0.14



10.0

U,RL1

0.100

U

0.100

U

1.00

U

UJ

1.00

U.RL1

UJ

Naphthalene

pg/L

1.1

3210



2180



1940

RL1

2100



1890



1690



J-

1510

B1 B

J-

Phenanthrene

pg/L

294

42.7



44.4



42.4

RL1

42.2



37.4



22.9



J-

28.4

RL1

J-

Pyrene

pg/L

...

13



0.019

U

10.0

U,RL1

2.52



1.48



3.77



J-

1.23

RL1

J-

1-Methylnaphthalene

pg/L

...

na



na



457

RL1

637



497



430



J-

328

RL1

J-

2-Methyinaphthalene

pg/L

61.2

482



362



154

RL1

164



146



158



J-

176

RL1

J-

Inoraanics





































Cyanide, Total

mg/L

...

0.0109



0.01

U

na



na



na



na





na





Cyanide, WAD 1

mg/L

0.2

na



na



0.0100

U

0.0100

U

0.0100

U

0.0100

U



0.0100

U



Manganese, Total

mg/L

0.775

na



na



0.592



0.557



0.616



0.581





0.584





Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na





na





Nitrite

mg/L

...

na



na



na



na



na



na





na





Ammonia

mg/L

...

na



na



na



na



na



na





na





Manganese, Dissolved

mg/L

...

na



na



na



na



na



na





na





Iron, Dissolved-

mg/L

...

na



na



'na



na



na



na





na





Sulfate

mg/L

...

na



na



na



na



na



na





na





Sulfide

mg/L

...

na



na



na



na



na



na





na





Methane

pg/L

...

na



na



na



na



na



na





na





Alkalinity, Total

mg/L

...

na



na



na



na



na



na





na





Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na





na





Orthophosphate

mg/L

...

na



na



na



na



na



na





na





Total Organic Carbon .

mg/L

...

na



na



na



na



na



na





na





Chloride

mg/L

...

na



na



na



na



na



na





na





icgp_gw_2013-10.xlsx

2/^^014	Bedrcr-'-S'.jrface Wells	of 53

/ \ \

-------
I

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW20-GW-1012 MW20-GW-0413 MW20-GW-1013 MW23-GW-005 MW23-GW-1002 MW23-GW-0103 MW23-GW-1003 MW23-GW-0404
Standard 10-0ct-2012 10-Apr-2013 23-Oct-2013 17-Apr-2002 31-0ct-2002 08-Jan-2003 21-0ct-2003 Q6-Apr-2004
DV	DV	DV		 . 	 	

VOCs

Units









































Benzene

MQ/L

5

3640





3310





2770





14.1



10



16



22



13



Toluene

MQ/L

1000

1360





1440





1320





1.0

U

2.0

U

1.0

U

1

U

1

U

Ethylbenzene

Mg/L

700

1600





1510





1460





1.0

U

2.0

U

4.1



0.79

J

0.73

Ja

Xylenes, Total ¦

ng/L

10000

1620





1610





1530





6.9



7.9



11



8.8



7.6



PAHs











































Acenaphthene

ng/L

914

75.0



J-

143



J+

88.3



J-

0.19

U

110



45

J

24



28



Acenaphthylene

pg/L

362

40.2



J-

50.5



J+

40.4



J-

52.6



1.0

U

1.0

U

240



200



Anthracene

MQ/L



1.77



J-

29.6

U



2.38



J-

0.26



0.22



0.42

J

0.34



0.47



Benzo(a)anthracene

ijg/L

0.13

0.111



J-

12.2

U



1.02

U

UJ

0.19

U

0.1

U

0.10

U

0.14

U

0.12

U

Benzo(a)pyrene

ng/L

0.2

0.100

U

UJ

14.3

U



1.02

U

UJ

0.19

U

0.1

U

0.10

U

0.14

U

0.12

U

Benzo(b)fluoranthene

Mg/L

0.1

0.100

U

UJ

27.6

U



1.02

u

UJ

0.10

U

0.10

U

0.10

U

0.054

U

0.048

U

Benzo(ghi)perylene

Mg/L

...

0.100

U

UJ

17.3

U



1.02

u

UJ

0.10

U

0.10

U

0.10

U

0.22

U

0.19

U

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

UJ

18.4

U



1.02

u

UJ

0.10

U

0.10

U

0.10

U

0.054

U

0.048

U

Chrysene

^g/L

0.85

0.100

U

UJ

11.2

U



1.02

u

UJ

0.10

U

0.10

U

0.10

U

0.14

U

0.12

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.0130

U.MDL

UJ

17.3

U



0.173

U

UJ

0.10

U

0.10

U

0.10

U

0.33

U

0.29

U

Fluoranthene

ng/L

...

1.14



J-

50

U



1.02

u

UJ

0.19

U

0.1



0.22

J

0.37



0.82



Fluorene

Mg/L

490

26.1



J-

47.7



J+

29.3



J-

7.38

J

15



9.6

J

9.0



9.4



lndeno(1,2,3-cd)pyrene

ijg/L

0.1

0.100

U

UJ

17.3

U



1.02

u

UJ

0.10

U

0.10

U

0.10

U

0.14

U

0.12

U

Naphthalene

pg/L

1.1

2380



J-

3870

B

B,J+

2290

B"

J-,J+,B

1.32



0.9



3.7

J

10.

Ja

1.3



Phenanthrene

Mg/L

294

19.3



J-

43.5



J+

32.1



J-

2.88



4

J

5.9

J

5.0



6.8



Pyrene

pg/L

...

1.23 '



J-

56.1

U



1.09



J-

0.19

U

0.1

U

0.10

U

0.27

U

0.24

U

1 -Methylnaphthalene

pg/L

...

371



J-

604



J+

412



J-

14.4



14.4



na



na



na



2-Methylnaphthalene

^g/L

61.2

262



J-

505



J+

307



J-

0.19

u

na



na



na



na



Inoraanics











































Cyanide, Total

mg/L

...

na





na





na





0.010

u

0.005

U

0.005

U

0.01

U

0.01

U

Cyanide, WAD

mg/L

0.2

0.0100

U



0.189





0.0100

u



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.607





0.587





0.603





0.302



0.299



0.309



3.9



0.63



Natural Attenuation Parameters











































Nitrate

mg/L

...

na





na





na





na



na



na



na



na



Nitrite

mg/L

...

na





na





na





na



na



na



na



na



Ammonia

mg'/L

...

na





na





na





na



na



na



na



na



Manganese, Dissolved

mg/L

...

na





na





na





0.295



0.272



0.296



0.28



0.28



Iron, Dissolved

mg/L

... ¦

na





na





na





4



3.63



4.61"



' 3.4



3.5



Sulfate

mg/L

...

na.





na





na





na



na



na



na



na



Sulfide

mg/L

...

na





na





na





na



na



na



na



na



Methane

Mg/L

...

na





na





na ¦





na



na



na



na



na



Alkalinity, Total

mg/L

...

na





na





na





na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na





na





na





na



na



na



na



na



Orthophosphate

mg/L

...

na





na





na





na



na



na



na



na



Total Organic Carbon

mg/L

...

na





na





na





na



na



na



na



na



Chloride

mg/L

...

na





na





na





na



na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Surface Wells	Page 23 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW23-GW-1004 MW23-GW-0405 MW23-GW-1005 MW23-GW-0406 MW23-GW-1006 MW23-GW-0407 MW23-GW-1007 MW23-GW-0408
Standard 20-0ct-2004 15-Apr-2005 11-0ct-2005 11-Apr-2006 11-0ct-2006 18-Apr-2007 10-0ct-2007 16-Apr-2008

VOCs

Units



































Benzene

ug/L

5

21



22

¦

21



8.7



5.91



9.25



13.3



12.7



Toluene

Mg/L

1000

^ 1

U

1.0

U*

1.0

U

1

U

1

U

1

U

1

U

1

U

Ethyl benzene

|jg/L

700

1

U

1.0

U*

1.0

U

1

U

1

U

1

U

1

U

1

U

Xylenes, Total

i^g/i-

10000

7.4



8.2

*

5.9



7.12



6.08



5.84



6.15



5.56



PAHs





































Acenaphthene

pg/i-

914

25



36



32



27.3



24.7



21.3



28.2



20



Acenaphthylene

MQ/L

362

240



340



270



48.1



41.6



38.9



35.8



37.2



Anthracene

fjg/L

...

0.47



0.72



0.40



0.0106

U

0.706



0.592



0.664



0.291



Benzo(a)anthracene

(ig/L

0.13

0.13

u

0.12

u

0.12

U

0.0216

U

0.003

u

0.004

U

0.003

U

0.003

u

Benzo(a)pyrene

|jg/i-

0.2

0.13

u

0.12

u

0.12

U

0.0216

U

0.032

u

0.0427

U

0.032

U

0.032

u

Benzo(b)fluoranthene

Mg/L

0.1

0.050

u

0.047

u

0.046

U

0.0216

U

0.013

u

0.0173

U

0.013

U

0.013

u

Benzo(ghi)perylene

fjg/L

—

0.20

u

0.19

u

0.19

U

0.0364

U

0.009

u

0.012

U

0.009

U

0.009

u

Benzo(k)fluoranthene

ng/L

0.14

0.050

u

0.047

u

0.046

U

0.0261

U

0.015

u

0.02

U

0.015

U

0.015

u

Chrysene

ng/L

0.85

0.13

u

0.12

u

0.12

U

0.0227

U

0.005

u

0.00667

U

0.005

U

0.005

u

Dibenzo(a,h)anthracene

fjg/L

0.033

0.30

u

0.28

u

0.28

U

0.0375

U

0.01

u

0.0133

U

0.01

U

0.01

u

Fluoranthene

Mg/L



0.73



1.1



0.63



0.0364

U

0.603



0.466



0.447



0.272



Fluorene

Mg/L

490

9.6



14



10



24.8



24



19.7



37.3



24.5



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.13

u

0.12

u

0.12

U

0.0432

U

0.007

u

0.00933

U

0.007

U

0.007

u

Naphthalene

ng/L

1.1

1.3

u

1.2

u

1.2

U

1.04



1.34



1.6



1.13



0.663



Phenanthrene

Mg/L

294

6.6



10



' 5.9



8.74



7.94



6.8



8.41



7.16



Pyrene

ng/L

...

0.25

u

0.23

u

0.23

U

3.44



2.62



2.21



2.64



0.019

u

1 -Methylnaphthalene

ug/L

...

na



na



na



na



na



na



na



na



2-Methylnaphthalene

Mg/L

61.2

na



na



na:



na



0.513



0.378



0.052

U

0.052

u

Iroraanics





































Cyanide, Total

mg/L

...

0.01

u

0.0027

B

0.0027

B

0.01

U

0.01

u

0.01

U

0.01

U

0.01

u

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.35



0.29



0.54



0.257



na



na



na



na



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.29



0.30



0.28



0.294



na



na



na



na



Iron, Dissolved

mg/L

...

3.7



3.8



0.17



4.29



na



na



na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L

. —

na



na



na



na



na



na



na



na



Methane

Mg/L



na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



¦ na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

Bedro^-^'-irface Wells	Prp~--'>4 of 53

-------


Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW23-GW-0410 DUP2-GW-0410 MW23-GW-1010 MW23-GW-0411 MW23-GW-1011 MW23-GW-0412 MW23-GW-1012
Standard 08-Apr-2010 08-Apr-2010 05-0ct-2010 12-Apr-2011	24-Oct-2011	11-Apr-2012	09-0ct-2012

DV	DV

VOCs

Units



































Benzene

M9/L

5

11.4



13.2



13.2



15.3



16.8





10.8





9.99



Toluene

fjg/L

1000

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U



1.00

U



1.00

U

Ethylbenzene

ug/L

700

1.00

U,C9

1.00

U,C9

1.00

U

1.00

U

1.00

U



1.00

U



1.00

U

•Xylenes, Total

ug/L

10000

6.00

U

6.00

U

4.11



5.22



4.44





4.43





4.57



PAHs





































Acenaphthene

Mg/L

914

19.3



21.4



17.7



22.5



9.14



J-

16.5



J-

21.1



Acenaphthylene

Mg/L

362

39.2



45.0



34.1



41.0



31.6



J-

30.5



J-

33.8



Anthracene

Mg/L

...

0.778



0.705



0.479



0.485



0.252



J-

0.225



J-

0.279



Benzo(a)anthracene

Mg/L

0.13

0.100

U

0.100

U

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

U

Benzo(a)pyrene

Mg/L

0.2

0.100

U

0.100

U

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

U

Benzo(b)fluoranthene

MQ/L

0.1

0.100

U

0.100

U

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

u

Benzo(ghi)perylene

ijg/L

...

0.100

U

0.100

U

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

u

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

0.100

u

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

u

Chrysene

Mg/L

"0.85

0.100

U

0.100

u

0.100

u

0.100

U

0.100

u

UJ

0.100

U

UJ

0.100

u

Dibenzo(a,h)anthracene

Mg/L

0.033

0.00810

U.MDL

0.00810

U.MDL

0.00810

U,MDL

0.0170

U.MDL

0.0170

U.MDL

UJ

0.0170

U.MDL

UJ

0.0130

U.MDL

Fluoranthene

pg/L

...

0.425



0.430



0.299



0.400



0.247



J-

0.208



J-

0.245



Fluorene

ng/L

490

13.1



15.4



11.5



14.2



5.43



J-

9.75



J-

13.8



lndeno(1,2,3-cd)pyrene

ug/L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

Naphthalene

(jg/L

1.1

0.701



0.614



0.407



0.449



0.514



J-

0.491

B

UB,J-

0.816



Phenanthrene

fjg/L

294

8.66



11.6



8.18



8.68



7.37



J-

5.55



J-

8.00



Pyrene



...

0.311



0.299



0.327



0.428



0.253



J-

0.229



J-

0.235



1-Methylnaphthalene

Ug/L

...

1.86



1.56



1.25



1.34



0.934



J-

0.933



J-

1.22



2-Methylnaphthalene

M9'L

61.2

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

0.126



Inoraanics





































Cyanide, Total

mg/L

...

na



na



na



na



na





na





na



Cyanide, WAD

mg/L

0.2

0.0100

U

0.01

U

0.0100

U

0.0100

U

0.0100

U

UJ

0.0100

U



0.0100

U

Manganese, Total

mg/L

0.775

0.323



0.325



0.464



0.397



0.316





0.339





0.362



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na





na





na



Nitrite

mg/L

...

na



na



na



na



na





na





na



Ammonia

mg/L

...

na



na



na



na



na





na





na



Manganese, Dissolved

mg/L

...

na



na



na



na



na





na





na



Iron, Dissolved

mg/L

...

na



na



na



na



na





na





na



Sulfate

mg/L

...

na



na.



na



na



na





na





na



Sulfide

mg/L

...

na



na



na



• na



na





- na





na



Methane

Mg/L

...

na



na



na



na



na





na





na



Alkalinity, Total

mg/L

...

na



na



na



na



na





na





na



Total Kjeldahl Nitrogen

mg/L

...

na



na>



na



na



na





na





na



Orthophosphate

mg/L

...

na



na



na



na



na





na





na



Total Organic Carbon

mg/L

...

na



na



na



na



na





na





na



Chloride

mg/L

...

na



na



na



na



na





na





na



icgp_gw_2013-10.xlsx
2/11/2014

Bedrock Surface Wells

Page 25 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW23-GW-0413 MW23-GW-1013 MW25-GW-005 MW25-GW-1002 MW25-GW-0103 MW25-GW-1003 MW25-GW-0404 MW25-GW-1004
Standard	10-Apr-2013	22-Oct-2013 17-Apr-2002 29-Oct-2002 08-Jan-2003 21-0ct-2003 06-Apr-2004 20-0ct-2004

DV	DV

VOCs

Units





































Benzene

ng/L

5

5.35





8.41



39.9



19



31



5.9



2.2



5.3



Toluene

mq/l

1000

1.00

U



1.00

U

1.0

U

2.0

U

1.0

U

1.0

U

1.0

U

1.0

U

. Elhylbenzene

ug'L

700

1.00

U



1.00

U

1.0

U

2.0

U

1.0

U

1.0

U

1.0

U

1.0

u

Xylenes, Total

pg/L

10000

4.11





3.72



6.4

J

7

U

3.0

U

1.8



1.1



1.6



PAHs







































Acenaphthene

ug'L

914

24.1





17



3.81

J

6.4



9.0



4.4



5-°,



4.3



Acenaphthylene

pg/L

362

39.9





24.6



7.4

J

1

U

1.0

U

53



40 '



41



Anthracene

ug/L

...

0.336





0.206



0.19

U

0.051

U

0.051

U

0.049

Ua

0.0073

Ja

0.0073

Ja

Benzo(a)anthracene

pg/L

0.13

0.121

U



0.100

U

0.19

U

0.1

U

0.10

U

0.13

U

0.13

U

0.13

U

Benzo(a)pyrene

ng/L

0.2

0.141

U



0.100

U

0.19

U

0.1

U

0.10

U

0.13

U

0.13

U

0.13

U

Benzo(b)fluoranthene

"¦ ijg/L

0.1

0.273

U



0.100

U

0.10

U

0.1

U

0.10

U

0.049

U

0.049

U

0.050

U

Benzo(ghi)perylene

Mg/i-

...

0.172

U



0.100

U

0.10

U

0.1

U

0.10

U

0.19

U

0.19

u

0.20

U

Benzo(k)fluoranthene

ug/L

0.14

0.182

U



0.100

U

0.10

U

0.1

U

0.10

U

0.049

U

0.049

u

0.050

U

Chrysene

pg/L

0.85

0.111

U



0.100

U

0.10

U

0.1

u

0.10

U

0.13

U

0.13

u

0.13

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.172

U



0.0173

U

0.10

U

0.1

u

0.10

U

0.29

U

0.29

u

0.30

U

Fluoranthene

pg/L

...

0.495

U



0.223



0.19

U

0.1

u

0.10

U

0.13

U

0.13

u

0.13

U

Fluorene

Mg/L

490

15.4





9.47



0.19

U

"0.1

u

0.25



0.28



0.35



0.26



lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.172

U



0.100

U

0.10

U

0.1

u

0.10

U

0.13

U

0.13

u

0.13

U

Naphthalene

pg/L

1.1

¦ 0.923

B

UB

0.451



0.10

U

1.5



0.8



1.3

U

1.3

u

1.3

U

Phenanthrene

Mg/L

294

10.2





4.02



0.10

U

0.10

u

0.10

U

0.014

Ja

0.097

u

0.099

U

Pyrene

ng/L

...

0.556

U



0.236



0.19

U

0.1

u

0.10

U

0.24

U

0.24

u

0.25

U

1 -Methylnaphthalene

[jg/L

...

1.33





0.841



0.19

U

na



na



na



na



na



2-Methylnaphthalene

Mg/L

61.2

0.118





0.100

U

0.19

U

na



na



na



na



na



Inoraanics







































Cyanide, Total

mg/L

...

na





na



0.010

U

0.005

u

0.009



0.010

U

0.010

u

0.010

U

Cyanide, WAD

mg/L

0.2

0.0100

U



0.0100

U

na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.318



J-

0.303



0.406



0.41



0.42



0.74



0.49



0.46



Natural Attenuation Parameters







































Nitrate

mg/L



na





na



na



na



na



na



na



na



Nitrite

mg/L

...

na





na



na



na



na



na



na



na



Ammonia

mg/L



na





na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

na





na



0.382



0.488



0.41



0.38



0.38



0.34



Iron, Dissolved

mg/L

...

na





na



3.7



3.84



3.92"



3.3



3.2



2.8



Sulfate

mg/L

...

na





na



na



na



na



na



na



na



Sulfide

mg/L

...

na





na



na '



na



na



na



na



na



Methane

Mg/L

...

na





na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na





na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

. mg/L

...

na





na



na



na '



na



na



na



na



Orthophosphate

mg/L

...

na





na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na





na



na



na



na



na



na



na



Chloride

mg/L

...

na





na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

Bedro^^^'.irface Wells	of 53

N	! \	' \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW25-GW-0405 MW25-GW-1005 MW25-GW-0406 MW25-GW-1006 MW25-GW-0407 MW25-GW-1007 MW25-GW-0408
Standard 14-Apr-2005 11-0ct-2005 13-Apr-2006 11-0ct-2006 18-Apr-2007 10-0ct-2007	15-Apr-2008

VOCs

Units































Benzene

t-ig/L

5

11



' 1.8



25.8



10.7



27



14.4



27.2



Toluene

[jg/L

1000

1.0

U

1.0

U

1

U

1

U

1

U

1

U

1

U

Ethylbenzene

fjg/L

700

1.0

U

1.0

U

1

U

1

U

1

U

1

U

1

U

Xylenes, Total

ug/L

10000

2.3



1.1

J

7.81



5.15



4.39



3.8



6.14



PAHs

































Acenaphthene

ng/L

914

6.2



5.2



7.58



8.71



7.32



12.5



11.2



Acenaphthylene

pg/L

362

57



48



13.5



16.5



12.2



0.085

u

19.4



Anthracene

ug/L

...

0.047

Ua

0.051

U

0.0395

J

0.0472

J

0.0287

J

0.0235

J

0.0299

J

Benzo(a)anthracene

ug/L

0.13

0.12

U

0.13

U

0.019

U

0.003

U

0.003

u

0.00908

J

0.003

U

Benzo(a)pyrene

pg/L

0.2

0.12

U

0.13

U

0.019

U

0.032

U

0.032

u

0.032

u

0.032

U

Benzo(b)fluoranthene

ng/L

0.1

0.047

U

0.051

U

0.037

U

0.013

U

0.013

-u

0.013

u

0.013

U

Benzo(ghi)perylene

ng/L

...

0.19

U

0.20

U

0.032

U

0.009

U

0.009

u

0.009

u

0.009

U

Benzo(k)fluoranthene

pg/L

0.14

0.047

U

0.051

U

0.023

U

0.015

U

0.015

u

0.015

u

0.015

U

Chrysene

|ig/L

0.85

0.12

U

0.13

U

0.02

U

0.094

J

0.005

u

0.0221

J

0.005

U

Dibenzo(a,h)anthracene

ijg/L

0.033

0.28

U

0.30

U

0.033

U

0.01

U

0.01

u

0.01

u

0.01

U

Fluoranthene

ng/L

...

0.12

U

0.13

U

0.032

U

0.0149

J

0.01

u

0.01

u

0.01

U

Fluorene

Mg/L

490

0.37



0.29



2.77



3.31



2.79



10.6



8.81



lndeno(1,2,3-cd)pyrene

i-ig/L

0.1

0.12

U

0.13

U

0.038

U

0.007

U

0.007

u

0.007

u

0.007

U

Naphthalene

Mg/L

1.1

1.2

U

¦ 1-3

U

0.401



0.534



1.16



0.632



0.62



Phenanthrene

Mg/L

294

0.093

U

0.10

U

0.161



0.214



0.164



0.22



0.007

U

Pyrene

ms/l

...

0.23

Ua

0.25

U

0.036

u

0.019

U

0.019

u

0.019

u

0.019

U

1-Methylnaphthalene

ng/L

...

na



na



na



na



na



na



na



2-Methylnaphthalene

ijg/L

61.2

na



na



' na



0.171

J

0.17

J

0.0793

J

0.052

U

Inorganics

































Cyanide, Total

mg/L

...

0.010

U

0.010

U

0.01

u

0.01

U

0.01

u

0.01

u

0.01

U

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.42



0.40



0.305



na1



na



na



na



Natural Attenuation Parameters

































Nitrate

mg/L

...

0.10

U

0.10

U

0.1

u

na



na



na



na



Nitrite

mg/L

...

0.020

U

0.020

U

0.1

u

na



na



na



na



Ammonia

mg/L

...

0.15

B

0.20

U

0.2

u

na



na



na



na



Manganese, Dissolved

mg/L

...

0.39



0.37



0.336



na



na



na



na



Iron, Dissolved

mg/L

...

2.7



3.0



2.89



na



na



na



na



Sulfate

mg/L

...

120



120



112

M1

na



na



na ¦



na



Sulfide

mg/L

...

1.0

U

1.0

u

1

U

na



na .



na



na



Methane

na/L .

...

4



4.2



26

U

na



na



na



na



Alkalinity, Total

mg/L

...

360



330



385



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

0.18

B

0.17

B

1

u

na



na



na



na



Orthophosphate

mg/L

...

0.008

B

0.050

U

0.1

u

na



na



na



na



Total Organic Carbon

mg/L

...

1.4



.1.5



1:42



na



na



na



na



Chloride

mg/L

...

na



na



99.4

M1

na.



na



na



na



icgp gw 2013-10.xlsx
2/11/2014

Bedrock Surface Wells

Page 27 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance
Standard

MW25-GW-0410
08-Apr-2010

MW25-GW-1010
05-0ct-2010

MW25-GW-0411
12-Apr-2011

MW25-GW-1011
25-Oct-2011

DV

DP02-GW-1011
25-Oct-2011

DV

MW25-GW-0412
10-Apr-2012

DV

DP01-GW-0412
10-Apr-2012

DV

VOCs

Units







































Benzene



5

139



131



46.4



88.6





88.4





82.2





76.8





Toluene

M9/1-

1000

1.76



1.00

U

1.00

U

1.00

U



1.00

U



1.00

U



1.00

U



Ethylbenzene



700

1.72



1.00

U

1.00

U

1.00

U



1.00

U



1.00

U



1.00

U



Xylenes, Total

m/l

10000

19.2



13.2



4.32



3.41





3.01





3.00

U



3.00

U



PAHs









































Acenaphthene

pg/L

914

18.5



16.6



10.1



8.95



J-

8.94



J-

6.19



J-

7.56



J-

Acenaphthylene

M9/I-

362

. 22.1



18.3



9.94



9.21



J-

9.50



J-

6.56



J-

9.43



J-

Anthracene

w/l

...

0.359



0.322



0.118



0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Benzo(a)anthracene

Mg/L

0.13

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Benzo(a)pyrene

Mg/L

0.2

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Benzo(b)fluoranthene

M9'L

0.1

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Benzo(ghi)perylene

Mg/L

...

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Benzo(k)fluoranthene

^g/L

0.14

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Chrysene

ng/L

0.85

0.100

U

0.100

U

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Dibenzo(a,h)anthracene

Mg/L

0.033

0.00810

U,MDL

0.00810

U.MDL

0.0170

U,MI 0.0170

U.MDL

UJ

0.0170

U,MDL

UJ

0.0170

U,MDL

UJ

0.0170

U.MDL

UJ

Fluoranthene

Mg/L

...

0.150



0.163



0.123



0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Fluorene

Mg/L

490

4.64



5.09



2.35



1.56



J-

1.60



J-

0.804



J-

1.00



J-

lndeno(1,2,3-cd)pyrene

pg'L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

Naphthalene

Mg/L

1.1

1.87



0.738



0.789



0.240



J-

0.162



J-

0.12



J-

0.135



J-

Phenanthrene

Mg/L

294

2.70



2.59



1.74



1.19



J-

1.25



J-

0.381



J-

0.545



J-

Pyrene

fjg/L

...

0.112



0.183



0.145



0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

1-Methylnaphthalene

Mg/L

...

26.3



18.0



2.2



0.938



J-

0.863



J-

0.332



J-

0.426



J-

2-Methylnaphthalene

^g/L

61.2

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

u

UJ

0.100

U

UJ

Inoraanics









































Cyanide, Total

mg/L

...

na



na



na



na





na





na





na





Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

u

0.0100

U

0.0100

U



0.0100

U



0.0100

u



0.0100

U



Manganese, Total

mg/L

0.775

0.354



0.336



0.373



0.315





0.312





0.325'

R



0.295





Natural Attenuation Parameters









































Nitrate

mg/L

...

0.10

U

0.10

u

0.10

U

0.10

U



0.100

u



0.100

U



0.100

U



Nitrite

mg/L

...

0.100

U

0.100

u

0.100

U

0.100

U



'0.100

u



0.100

U



0.100

U,H



Ammonia

mg/L

...

0.200

U

0.200

u

0.200

U

0.200

U



0.200

u



0.200

U



0.200

U



Manganese, Dissolved

mg/L

...

0.343



0.324



0.317



0.333





0.328





0.311





0.316





Iron, Dissolved

mg/L

...

2.76



2.78



2.54



2.81

"



2.82





2.68





2.81





Sulfate

mg/L

...

81.4



81.4



103



91.6





36.8





86.8





84.8





Sulfide

mg/L

...

5.00

U

5.00

u

10.00

U

10

u



10

u



10

u



10

U



Methane

Mg/L

...

43.0



39.8



10



16





14





31





31





Alkalinity, Total

mg/L

...

394



371



341



340





336





321





321





Total Kjeldahl Nitrogen

mg/L

...

1.00

U

1.00

u

1.00

u

¦ 1.00

u



1.00

u



1.00

u



1.00

U



Orthophosphate

mg/L

...

0.100

U

0.100

u

0.100

u

0.100

u



0.100

u



0.100

u



0.100

U



Total Organic Carbon

mg/L

...

1.00

U

1.00

u

na



1.00

U.ET



1.00

U,ET



na





na





Chloride

mg/L

...

83.5



89.1



na



na





na





na





na





icgp_gw_20l3-10.xlsx
2/;^\14

Bedros-
/

^'jrface Wells

Pp.-_^?8 of 53

/ \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW25-GW-1012 DP02-GW-1012 MW25-GW-0413 DP02-GW-0413 MW25-GW-1013 DP02-GW-1013

Standard 10-0ct-2012 10-0ct-2012 10-Apr-2013 10-Apr-2013 23-Oct-2013 23-Oct-2013
		DV	.	DV

VOCs

Units



























Benzene

pg/L

5

120



126



1140

J-

10.3



43.5



44.3



Toluene

pg/L

1000

1.00

U

1.00

U

161



1.00

U

1.00

U

1.00

U

Ethylbenzene

pg/L

700

1.00

U

1.00

U

22.4



1.00

U

1.85



1.69



Xylenes, Total

MQ/L

10000

4.65



4.95



317



3.00

U

5.24



5.21



PAHs





























Acenaphthene

pg/L

914

8.33



8.64



10.1



10.8



15.1



14.6



Acenaphthylene

pg/L

362

11.2



11.6



8.56



11



13.9



13.4



Anthracene

pg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)anthracene

pg/L

0.13

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)pyrene

pg/L

0.2

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(b)fluoranthene

pg/L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(ghi)perylene

pg/L

...

0.100

U

0.100-

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(k)fluoranthene

pg/L

0.14

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Chrysene

pg/L

0.85

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.0130

U.MDL

0.0130

U,MDL

0.0173

U

0.0179

U

0.0183

U

0.0179

U

Fluoranthene

pg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Fluorene

pg/L

490

0.795



0.882



0.807



0.77



.1.5



1.48



lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

Naphthalene

pg/L

1.1

0.185



0.220



0.989



0.218



1.66



1.57



Phenanthrene

pg/L

294

0.331



0.400



0.158



0.107



0.464



0.433



Pyrene

pg/L

...

0.100

U

0.100

u

0.100

U

0.100

U

0.100

U

0.100

U

1-Methylnaphthalene

pg/L



0.479



0.542



1.60



0.756



2.27



2.19



2-Methylnaphthalene

pg/L

61.2

0.100

U

0.225



0.100

U

0.100

U

0.100

U

0.100

U

Inoraanics





























Cyanide, Total

mg/L

...

na



na



na



na



na



na



Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

u

0.0100

U

0.0100

U

0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

0.343



0.332



0.343



0.342



0.355



0.427



Natural Attenuation Parameters





























Nitrate

mg/L

...

0.100

U

0.100

u

0.100

U

0.100

U

na



na



Nitrite

mg/L

...

0.100

U

0.100

u

0.100

U

0.100

U

na



na



Ammonia

mg/L

...

0.200

U

0.200

u

0.200

U

0.200

U

na



na



Manganese, Dissolved

mg/L

...

0.318



0.326



0.353



0.36



na



na



Iron; Dissolved

mg/L

...

2.81



2.85



3.030



2.980



na



na



Sulfate

mg/L

...

80.7



82.6



92.2



92.7



na



na



Sulfide

mg/L

...

10

U

10-

u

16.9



20.9



na



na



Methane

pg/L

...

28..



28



.5.65



8.01



na



na



Alkalinity, Total

mg/L

...

355



350



365



365



na



na



Total Kjeldahl Nitrogen

mg/L

...

1.00

U

1.00

u

1.00

U

1.00

U

na



na



Orthophosphate

mg/L

...

0.100

U

0.100

u

0.100

U

0.100

U

na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



icgp gw 2013-10.xls*
2/11/2014

Bedrock Surface Wells

Page 29 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW29-GW-1002 MW29-GW-0103 MW29-GW-1003 MW29-GW-0404 MW29-GW-1004 MW29-GW-0405 MW29-GW-1005 MW29-GW-0406
Standard 28-Oct-2002 07-Jan-2003 20-0ct-2003 07-Apr-2004 18-0ct-2004 14-Apr-2005 11-0ct-2005 12-Apr-2006

l/QCs	Unrfs

Benzene	pg/L

Toluene	pg/L

Ethylbenzene	pg/L

Xylenes, Total	pg/L
RAHs

Acenaphthene	'	pg/L

Acenaphthylene	pg/L

Anthracene	pg/L

Benzo(a)anthracene	pg/L

Benzo(a)pyrene	pg/L

Benzo(b)fluoranthene	pg/L

Benzo(ghi)perylene	pg/L

Benzo(k)fluoranthene	pg/L

Chrysene	pg/L

Dibenzo(a,h)anthracene	pg/L

Fluoranthene	pg/L

Fluorene	pg/L

lndeno(1,2,3-cd)pyrene	pg/L

Naphthalene	pg/L

Phenanthrene	pg/L

Pyrene	pg/L

1-Methylnaphthalene.	pg/L

2-Methylnaphthalene	pg/L
Inorganics

Cyanide, Total	mg/L

Cyanide, WAD	mg/L

Manganese, Total	mg/L
Natural Attenuation Parameters

Nitrate	mg/L

Nitrite	mg/L

Ammonia	mg/L

Manganese, Dissolved	mg/L

Iron, Dissolved	mg/L

Sulfate	mg/L

Sulfide	mg/L

Methane	pg/L

Alkalinity, Total -	mg/L

Total Kjeldahl Nitrogen	mg/L

Orthophosphate	mg/L

Total Organic Carbon	mg/L

Chloride	mg/L

5

2

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1

U

1000

2

U

1.0

U

1.0

U

1.0

U

1.0 "

U

1.0

U

1.0

U

1

U

700

2

U

1.0

U

1.0

U

1.0

u

1.0

U

1.0

U

1.0

u

1

U

10000

7

U

3.0

U

1.0

U

1.0

u

1.0

U

2.0

U

2.0

u

3

U

914

0.52

U

0.54

U

2.6

U

. 2.4

u

2.4

U

2.5

U

2.4

u

0.13

u'

362

1

U

1.1

U

1.3

U

1.2

u

1.2

U

1.3

U

1.2

u

0.17

U

...

0.052

U

0.054

U

0.051

U*

0.047

u

0.048

U

0.050

U

0.047

u

0.0093

U

0.13

0.1

U

0.11

U

0.13

U

0.12

u

0.12

U

0.13

U

0.12

u

0.019

U

0.2

0.1

U

0.11

U

0.13

U

0.12

u

0.12

U

0.13

U

0.12

u

0.019

U

0.1

0.1

U

0.11

U

0.051

U

0.047

u

0.048

U

0.050

U

0.047

u

0.037

U

...

0.1

U

0.11

U

0.20

U

0.19

u

0.19

U

0.20

U

0.19

u

0.032

U

0.14

0.1

U

0.11

U

0.051

U

0.047

u

0.048

U

0.050

U

0.047

u

0.023

U

0.85

0.1

U

0.11

U

0.13

U

0.12

u

0.12

U

0.13

U

0.12

u

0.02

U

0.033

0.1

U

0.11

U

0.31

U

0.28

u

0.29

U

0.30

U

0.28

u

0.033

U

...

0.1

U

0.11

U

0.13

U

0.12

u

0.12

U

0.13

U

0.12

u

0.032

U

490

0.1

U

0.11

U

0.26

U

0.24

u

0.24

U

0.25

U

0.24

u

0.029

U

0.1

0.1

U

0.11

U

0.13

U

0.12

u

0.12

U

0.13

U

0.12

u

0:038

u

1.1

0.52

U

0.54

U

1.3

U

1.2

u

1.2

U

1.3

U

1.2

u

0.1

u

294

0.1

U

0.11

U

0.10

U

0.094

u

0.096

U

0.10

U

0.094

u

0.015

u

—

0.1

u ¦

0.11

U

0.26

U

0.24

u

0.24

U

0.25

U

0.24

u

0.036

u

...

na



na



na



na



na



na



na



na



61.2

na



na



na



na



na



na



na



na



...

0.005

U

0.00500

U

0.010

U

0.010

u

0.010

U

0.010

U

0.010

u

0.01

u

0.2

na



na



na



na



na



na



na



na



0.775

0.19



0.0871



0.17



0.065



0.10



0.050



0.053



0.0579



—

na



na



na



na



na



0.10

U

0.027

B

0.1

u

...

na



na



na



na



na



0.020

U

0.020

u

0.1

u

...

na



na



na



na



na



0.45



0.27



0.377



...

0.0541



0.0445



0.043



0.044



0.040



0.041



0.039



0.0432



...

0.807



1.16



1.1



1.2



1.1



1.0



1.4



1.4



...

na



na



na



na



na



110



120



111



...

na



na



na



na



na



1.0

U

1.0

u

1

u

...

na



na



na



na



na



2

U

2

u

26

u

...

na



na



na



na



na



330



320



366





na



na



na



na



na



0.43



0.71



1

u

...

na



na



na



na



na



0.011

B

0.050

u

0.1

u

...

na



na



na



na



na



1.3



1.4



1.77



...

na



na



na



na



na



na



na



24.8



icgp_gw_2013-10.xlsx
2/s-^.14

Wells

/ \

Pp-^-30 of 53

¦ N

-------
/ \

Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW29-GW-1006 MW29-GW-0407 MW29-GW-1007 MW29-GW-0408 MW29-GW-0410 MW29-GW-0411 MW29-GW-0412 MW29-GW-0413
Standard 11-0ct-2006 17-Apr-2007 09-0ct-2007 14-Apr-2008 08-Apr-2010	12-Apr-2011	11 -Apr-2012	09-Apr-2013

VOCs	Units

Benzene

Mg/L

5

1

U

1

U

1 U

1

U

1.00

U

1.00

U

1.00

U

0.500

U

Toluene

M9/L

1000

1

U

1

U

- 1 U

1

U

1.00

U

1.00

U

1.00

u

1.00

U

Ethyl benzene

Mg/L

700

1

U

1

U

1 U

1

U

1.00

U

1.00

U

1.00

u

1.00

U

Xylenes, Total

ng/L

10000

3

U

3

U

3 U

3

U

6.00

U

3.00

u

3.00

u

3.00

u

PAHs

Acenaphthene

pg/L

914

0.049

U

0.049

U

0.049

U

0.049

U

0.100

U

0.100

U

0.100

U

0.100

U

Acenaphthylene

Mg/i-

362

0.085

U

0.085

U

0.085

U

0.085

U

0.100

.U

0.100

U

0.100

U

0.100

U

Anthracene

ng/L

...

0.01

U

0.01

U

0.01

U

0.01

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)anthracene

pg/L

0.13

0.003

U

0.003

U

0.003

U

0.003

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)pyrene



0.2

0.032

U

0.032

U

0.032

U

0.032

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(b)fluoranthene

ijg/L

0.1

0.013

U

0.013

U

0.013

U

0.013

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(ghi)perylene

ng/L

...

0.009

U

0.009

U

0.009

U

0.009

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(k)fluoranthene

ng/L

0.14

0.015

U

0.015

U

0.015

U

0.015

U

0.100

U

0.100

U

0.100

U

0.100

U

Chrysene

fjg/L

0.85

0.005

U

0.005

U

0.005

U

0.005

U

0.100

U

0.100

U

0.100

U

0.100

U

Dibenzo(a,h)anthracene

|jg/L

0.033

0.01

U

0.01

u

0.01

U

0.01

U

0.0081

U.MDL

0.0170

U,MDL

0.0170

U.MDL

0.0183

U

Fluoranthene

Mg/L

...

0.01

U

0.01

u

0.01

U

0.01

U

0.100

U

0.100

U

0.100

U

0.100

U

Fluorene

ng/L

490

0.01

U

0.01

u

0.01

U

0.01

U

0.100

U

0.100

U

0.100

U

0.100

U

lndeno(1,2,3-cd)pyrene

fjg/L

0.1

0.007

U

0.007

u

0.007

U

0.007

U

0.100.

U

0.100

U

0.100

U

0.100

U

Naphthalene

pg/L

1.1

1.37



0.054

u

0.054

U

0.054

U

0.100

U

0.100

U

0.100

U

0.100

U

Phenanthrene

Mg/L

294

0.007

U

0.007

u

0.007

U

0.007

U

0.100

U

0.100

U

0.100

U

0.100

U

Pyrene

ng/L

...

0.019

U

0.019

u

0.11

J

0.019

U

0.100

U

0.100

U

0.100

U

0.100

U

1-Methylnaphthalene

Mg/i-

...

na



na



na



na



0.100

U

0.100

U

0.100

U

0.100

U

2-Methylnaphthalene

pg/L

61.2

0.129

J

0.052

u

0.052

U

0.052

U

0.100

U

0.100

U

0.100

U

0.100

U

Inoraanics





































Cyanide, Total

mg/L

...

0.01

U

0.01

u

0.01

U

0.01

U.

na



na



na



na



Cyanide, WAD

mg/L

0.2

na



na



na



na



0.0100

U

0.0100

U

0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

na



na



na



na



0.0444



0.0427



0.0942



0.241



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



0.10

U,R

0.100

U

0.100

U

0.100

U

Nitrite

mg/L

...

na



na



na



na



0.100

U

0.100

U

0.100

U

0.100

U

Ammonia

mg/L

...

na



na



na



na



0.322



0.35



0.338



0.371



Manganese, Dissolved

mg/L

...

na



na



na



na



0.0381



0.0392



0.0397



0.0403



Iron, Dissolved

mg/L

...

na



na



na



na



1.43



1.35



1.57



1.690



Sulfate

mg/L



na



na



na



na



94.5



94.1



96:5



94.2



Sulfide

mg/L

...

na



na



na



na



5.00

U

10.0

U

10.0

U

26.6



Methane

pg/L

...

na



na



na



na



26.0

U

0.61



0.76



1.45



Alkalinity, Total

mg/L

...

na



na



na



na



389



351



316



365



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



1.00

U

1.00

U

1.00

U

1.00

U

Orthophosphate

mg/L

...

na



na



na



na



0.100

U

0.100

U

0.100

U

0.100

U

Total Organic Carbon

mg/L

...

na



na



na



na



1.00

U

na



na



na



Chloride

mg/L

—

na



na



na



na



28.3



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	BedrockWells	Page31of53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW31-GW-1002 MW31-GW-0103 MW31-GW-1003 MW31-GW-0404 MW31-GW-1004 MW31-GW-0405 MW31-GW-1005 MW31-GW-0406
Standard 01-Nov-2002 07-Jan-2003 21-0ct-2003 06-Apr-2004 18-0ct-2004 13-Apr-2005 11-0ct-2005 11-Apr-2006

VOCs

Units

































Benzene

Mg/L

5

370



190

380



300



180



350



360



370



Toluene

yg/L

1000

7.5



8.7

9.0



7.1

Ja

4.7

Ja

8.6



8.1



8.27



Ethyl benzene

ra'L

700

420



180

370



320



200



380



350



385



Xylenes, Total

Mg/L

10000

220



250

250



210



130



250



240



243



PAHs



































Acenaphthene

Mg/L

914

140



180 J

79



71



73



83



78



64.1



Acenaphthylene

|jg/L

362

1

U

1.1 U

730



560



670



790



750



0.17

U

Anthracene

pg/L

...

1.4

J

1.6 J

1.8

•

1.7



1.9



2.1



2.4



1.88



Benzo(a)anthracene

pg/L

0.13

0.1

U

3 J

0.027

Ja

0.020

Ja

0.023

Ja

0.025

Ja

0.038

Ja

0.0608



Benzo(a)pyrene

pg/L

0.2

0.1

U

0.11 U

0.13

U

0.13

U

0.13

U

0.13

U

0.12

U

0.0261



Benzo(b)fluoranthene

ug/L

0.1

0.1

U

0.11 U

0.051

U

0.051

U

0.049

U

0.049

U

0.047

U

0.124



Benzo(ghi)perylene

ug/L

...

0.1

U

0.11 U

0.20

U

0.20

U

0.19

U

0.19

U

0.19

U

0.0861



Benzo(k)fluoranthene

ug/L

0.14

0.1

U

0.11 U

0.051

U

0.051

U

0.049

U

0.049

U

0.047

U

0.0515



Chrysene

pg/L

0.85

0.1

u

0.11 U

0.13

U

0.13

U

0.13

U

0.13

U

0.12

U

0.0808



Dibenzo(a,h)anthracene

Mg/L

0.033

0.1

u

0.11 U

0.31

U

0.31

U

0.29

U

0.29

U

0.28

U

0.033

U

Fluoranthene

pg/L

—

0.88



0.82 J

1.5



1.7



1.4



1.6



1.7



0.032

U

Fluorene

pg/L

490

16



20 J

16



15



15



17



16



30.8



lndeno( 1,2,3-cd)pyrene

pg/L

0.1

0.1

u

0.11 U

0.13

U

0.13

U

0.13

U

0.13

U

0.12

U

0.111



Naphthalene

pg/L

1.1

280



260 J

360



230



280



300



310



209



Phenanthrene

ug/t-

294 ¦

11



11 J

14



14



12



14



14



12.3



Pyrene

Hg/L

...

0.38



0.34 J

0.26

U

0.62



0.28



0.30

M

0.30

M

6.04



1 -Methylnaphthalene

tig/L

...

na



na

na



na



na



na



na



na



2-Methylnaphthalene

pg/i-

61.2

na



na

na



na



na



na



na



na



Inoraanics



































Cyanide, Total

mg/L

...

0.005

u

0.00500 U

0.010

U

0.010

U

0.010

U

0.010

U

0.010

U

0.01

U

Cyanide, WAD

mg/L

0.2

na



na

na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.146



0.158

0.16



0.15



0.15



0.16



0.16



0.157



Natural Attenuation Parameters



































Nitrate

mg/L

...

na



na

na



na



na



0.10

U

0.043

B

0.1

U

Nitrite

mg/L

...

na



na

na



na



na



0.020

U

0.020

U

0.1

U

Ammonia

mg/L

...

na



na

na



na



na



0.17

B

0.20

U

0.2

U

Manganese, Dissolved

mg/L

...

0.144

u

0.165

0.15



0.15



0.15



0.15



0.17



0.151



Iron, Dissolved

mg/L

...

0.552

u

0.625

0.57



0.45



0.52



0.47



0.76



0.516



Sulfate

mg/L

...

na



na

na



na



na



24



31



26.3



Sulfide

mg/L

...

na



na

na



na



na



1.5



1.2



1

U

Methane

pg/i-

...

na



na

na



na



na



16



27



54



Alkalinity, Total

mg/L

...

na



na

na



na



na



460



430



499



Total Kjeldahl Nitrogen

mg/L

...

na



na

na



na



na



0.22

B

0.26

B

1

U

Orthophosphate

mg/L

...

na



na

na



na



na



0.13



0.016

B

0.1

U

Total Organic Carbon

mg/L

...

na



na

na



na



na



2.5



2.6



2.9



Chloride

mg/L

...

na



na

na



na



na



na



na



69.9



icgp_gw_2013-10.xlsx

2/.'^=-°-ai4	Wells	Pjs2»32 of 53

N	/ \	\

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW31-GW-1006 MW31-GW-0407 MW31-GW-1007 MW31-GW-0408 MW31-GW-0409 MW31-GW-1009 MW31-GW-0110
Standard 10-0ct-2006 18-Apr-2007 09-0ct-2007 15-Apr-2008 22-Apr-2009 14-0ct-2009 14-Jan-2010

VOCs

Units





























Benzene

|jg/L

5

360



326



304



334



157



150



251

Toluene

|jg/L

1000

9.46



8.37



7.47



8.82



4.27



3.96



5.82

Ethyl benzene

fig/L

700

376



369



321



319



17.9



164



248

Xylenes, Total

MQ/L

10000

237



241



201



219



117



105



167

PAHs































Acenaphthene

mq/l

914

81.2



71.9



63.6



78.5



27.2



29.6

M1

37.7

Acenaphthylene

|ig/L

362

0.085

U

53.4



0.085

U

0.085

U

8.73



12.5



16.6

Anthracene

Mg/L

...

2.25



2.01



1.24



2.21



0.903



2.32



1.95

Benzo(a)anthracene

Mg/L

0.13

0.0336

J

.0.0198

J

0.0167



0.0303

J

0.0907

J

0.0682

J

0.101

Benzo(a)pyrene

ng/L

0.2

0.032

U

0.032

U

0.032

U

0.032

U

0.123



0.0616

J

0.133

Benzo(b)fluoranthene

ng/L

0.1

0.0542

J

0.0538

J

0.013

u

0.013

u

0.261



0.131



0.229

Benzo(ghi)perylene

Mg/L

...

0.009

U

0.0203

J

0.009

u

0.009

u

0.148



0.0652

J

0.158

Benzo(k)fluoranthene

w/L

0.14

0.015

U

0.0366

J

0.015

u

0.015

u

0.0732

J

0.0372

J

0.105

Chrysene

ng/L

0.85

0.0407

J

0.0376

J

0.0265



0.0418

J

0.149



0.0855

J

0.161

Dibenzo(a,h)anthracene

MQ/L

0.033

0.01

U

0.01

U

0.01

u

0.01

u

0.0214

J

0.0122

J

0.0286

Fluoranthene

fig/L

...

1.34



1.13



0.549



1.72



0.407



0.618.



0.633

Fluorene

Mg/L

490

36.2



35.4



61.2



49.2



6.40



9.87

M1

11.0

lndeno(1,2,3-cd)pyrene

ng/L

0.1

0.007

U

0.0448

J

0.007

u

0.007

u

0.129



0.0518

J

0.135

Naphthalene

Mg/i-

1.1

270



202



238



274



93.0



121

M1

161

Phenanthrene

pg/L

294

13.5



13.1



13.7



17.8



5.41



6.98

M1

9.80

Pyrene

ug/L

...

5.35



5.05



2.97



0.019

u

0.434



0.618



0.989

1-Methyl naphthalene

Mg/L

...

na



na



na



na



na



na





2-Methylnaphthalene

fg/L

61.2

15.7



11.1



11.2



15.7



2.69



5.41

M1

5.48

Inoraanics































Cyanide, Total

mg/L

...

0.01

U

0.01

U

0.01

u

0.01

u

na



na



na

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



0.0100

Manganese, Total

mg/L

0.775

na



na



na



na



na



na



0.159

Natural Attenuation Parameters































Nitrate

mg/L

...

na



na



na



na



na



na



na

Nitrite

mg/L

...

na



na



na



na



na



na



na

Ammonia

mg/L

...

na



na



na



na



na



na



na

Manganese, Dissolved

mg/L

...

na



na



na



na



na



na



na

Iron, Dissolved

mg/L

...

na



na



na



na



na .



na



na

Sulfate

mg/L

...

na



na



na



na



na



na



na

Sulfide

mg/L

...

na



na



na



na



na



na



na

Methane

Mg/L

...

na



na



na



na



na



na



na

Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na

Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na

Orthophosphate

mg/L

...

na



na



na



na



na



na



na

Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na

Chloride

mg/L

...

na



na



na



na



na



na



na

icgp_gw_2013-10.xlsx
2/11/2014

Bedrock Wells

Page 33 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results





Performance

MW31-GW-0410



Dup1-GW-0410



MW31

-GW-0710

DP01

-GW-0710



MW31

-GW-1010

MW31(DP)-GW-1010





Standard

07-Apr-2010



07-Apr-2010



07-Jul-2010

07-Jul-2010



05-0ct-2010

05-0ct-2010











DV





DV



DV





DV



DV





VOCs

Units

































Benzene

M9/I-

5

206

M1



198

M1



237



220





299



293



Toluene

pg/L

1000

7.35





6.6





5.73



5.45





8.17



7.86



Ethyl benzene

pg/L

700

340

C9



316

C9



288



263





357



341



Xylenes, Total

pg/L

10000

241

M1



224

M1



174



162





202



194



PAHs



































Acenaphthene

pg/L

914

68.9



J+

68.5 -



J+

35.6

H2 J-

37

H2

J-

24.9

RL1

27.8



Acenaphthylene

fig/L

362

26.6



J+

25.0



J+

10.2



9.93





9.41

RL1

10.8



Anthracene

pg/L

...

2.69

M1

J+

2.35



J+

1.36



1.2





1.60

RL1

1.20



Benzo(a)anthracene

pg/L

0.13

0.151



J+

0.113



J+

0.100

U

0.100

U



1.00

U.RL1

0.100

U

Benzo(a)pyrene

fig/L

0.2

0.230



J+

0.160



J+

0.100

U

0.100

U



1.00

U.RL1

0.122



Benzo(b)fluoranthene

M9/L

0.1

0.410



J+

0.288



J+

0.104



0.114





1.00

U.RL1

0.241



Benzo(ghi)perylene

fig/L

...

0.250



J+

0.175



J+

0.100

U

0.100

U



1.00

U.RL1

0.166



Benzo(k)fluoranthene

pg/L

0.14

0.162



J+

0.130



J+

0.100

U

0.100

U



1.00

U,RL1

0.110



Chrysene

pg/L

0.85

0.234



J+

0.175



J+

0.100

U

0.100

U



1.00

U,RL1

0.183



Dibenzo(a,h)anthracene

pg/L

0.033

0.0414

J, MDL

J+

0.0142

J,MDL

J+

0.00994

J,MDL

0.0103

J, MDL



0.0810

U,RL1, MDL

0.0194

J, MDL

Fluoranthene

pg/L

...

0.832



J+

0.764



J+

0.406



0.397





1.00

U,RL1

0.517



Fluorene

pg/L

490

19.4



J+

18.8



J+

7.69



7.24





6.80

RL1

7.83



lndeno( 1,2,3-cd)pyrene

pg/L

0.1

0.208



J+

0.147



J+

0.100

U

0.100

U



1.00

U,RL1

0.129



Naphthalene

pg/L

1.1

217



J+

223



J+

120

H2 J-

130

H2

J-

92.0

RL1

106



Phenanthrene

mq/l

294

9.03

M1

J+

9.06



J+

6.09



5.43





5.30

RL1

5.15



Pyrene

pg/L

—

0.767



J+

0.647



J+

0.464



0.448





1.00

U,RL1

0.541



1-Methylnaphthalene

pg/L

—

267



J+

273



J+

135

H2 J-

145

H2

J-

93.5

RL1

109



2-Methylnaphthalene

pg/L

61.2

4.61

M1

J+

4.38



J+

3.09



3.14





3.44

RL1

3.89



Inoraanics



































Cyanide, Total

mg/L

...

na





na





na



na





na



na



Cyanide, WAD

mg/L

0.2

0.0100

U,M1, R



0.0100

U



0.0100

U

0.0100

U



0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

0.149





0.145





0.152



0.154





0.148



0.140



Natural Attenuation Parameters



































Nitrate

mg/L

...

0.10

U



0.10

U



na



na





0.10

U

0.10

U

Nitrite

mg/L

...

0.100

U,M1



0.100

U



na



na





0.100

U

0.100

U

Ammonia

mg/L

...

0.200

U



0.200

U



na



na





0.200

U.

0.200

U

Manganese, Dissolved

mg/L

...

0.134





0.144





na



na





0.141



0.141



Iron, Dissolved

mg/L

...

0.860





0.934





na



na





1.11



1.11



Sulfate

mg/L

...

37.5





40.7





na



na





51.4



50.6



Sulfide

mg/L

...

5.00

U



5.00

U



na



na





5.00

U

5.00

U

Methane

pg/L

...

87





101





na



na





109 '



103



Alkalinity, Total

mg/L

...

497





497





na



na





453



458



Total Kjeldahl Nitrogen

mg/L

...

1.00

U,M1



1.00

U



na



na





1.00

U

1.00

U

Orthophosphate

mg/L

...

0.100

U



0.100

U



na



na





0.100

U

0.100

U

Total Organic Carbon

mg/L

...

1.23





1.27





na



na





1.21 .



1.21



Chloride

mg/L

...

56.4





54.2





na



na





50.0



50.6



icgp_gw_2013-10.xlsx

B's-^pk Wells	of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW31-GW-0411	MW31-GW-1011	MW31-GW-0412 MW31-GW-1012 MW31-GW-0413 MW31-GW-1013 MW33-GW-1002

Standard	12-Apr-2011	25-Oct-2011	10-Apr-2012	09-0ct-2012 10-Apr-2013 22-Oct-2013	29-Oct-2002

DV	DV			DV

VOCs

Units



































Benzene

ug/L

5

264

MHA



213





229



218



255



289



2

u

Toluene

|jg/L

1000

6.06





5.97





7.62



6.49



345



10.1



2

U

Ethylbenzene

pg/L

700

284

MHA



262





313



296



7.19



367



2

U

Xylenes, Total

Hg/L

10000

175

MHA

J-

162





180



172



206



236



7

U

PAHs





































Acenaphthene

pg/L

914

28.2

M1



16.6



J-

37.9



31.5



52.4



34.1



0.52

u

Acenaphthylene

pg/L

362

8.63

M1



14.0



J-

14.4



15.0



18.8



12.9



1

U

Anthracene

pg/L



1.26





1.46



J-

1.49



1.24



1.74



1.69



0.052

U

Benzo(a)anthracene

pg/L

0.13

0.100

U



0.100

U

UJ

0.100

U

0.100

U

0.100

U

0.100

U

0.1

u

Benzo(a)pyrene

pg/L

0.2

0.100

U



0.100

U

UJ

0.100

U

0.100

u

0.100

U

0.100

U

0.1

U

Benzo(b)fluoranthene

pg/L

0.1

0.106





0.100

u

UJ

0.100

U

0.100

u

0.100

U

0.100

U

0.1

U

Benzo(ghi)perylene

pg/L

—

0.100

U



0.100

u

UJ

0.100

U

0.100

u

0.100

U

0.100

U

0.1

U

Benzo(k)fluoranthene

pg/L

0.14

0.100

U



0.100

u

UJ

0.100

U

0.100

u

0.100

U

0.100

u

0.1

U

Chrysene

pg/L

0.85

0.100

U



0.100

u

UJ

0.100

U

0.100

u

0.100

U

0.100

U

0.1

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.0170

U.MDL



0.0170

U.MDL

UJ

0.0170

U,MDL

0.013

U.MDL

0.0191

U

0.0179

U

0.1

U

Fluoranthene

pg/L

...

0.387





0.420



J-

0.515



0.389



0.59



0.654



0.1

U

Fluorene

pg/L .

490

7.06

M1

J-

9.90



J-

9.60



10.3



15.6



9.91



0.1

U

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100





0.100

U

UJ

0.100

U

0.100

U

0.100-

U

0.100

u

0.1

U

Naphthalene

pg/L

1.1

88.5

M1



128



J-

154



122



180



166

J-

0.52

U

Phenanthrene

pg/L

294

5.67

M1

J-

8.07



J-

9.32



7.14



8.27



6.09



0.1

U

Pyrene

pg/L

...

0.413





0.416



J-

0.516



0.395



0.643



0.846



0.1

U

1-Methylnaphthalene

pg/L

...

108

M1



117



J-

164



121



198



145

J-

na



2-Methylnaphthalene

pg/L

61.2

2.96

M1

J-

4.89



J-

5.21



5.99



9.15



7.5



na



Inoraanics





































Cyanide, Total

mg/L

...

na





na





na



na



na



na



0.00637



Cyanide,-WAD

mg/L

0.2

0.0100

U,M1

UJ

0.0100

U



0.0100

U

0.0100

U

0.0100

U

0.0100

u

na



Manganese, Total

mg/L

0.775

0.152





0.145





0.151



0.150



0.108



0.143



0.295



Natural Attenuation Parameters





































Nitrate

mg/L

...

0.10

U



0.100

U



0.100

U

0.100

U

0.100

U

na



na



Nitrite

mg/L

...

0.100

U



0.100

U



0.100

U

0.100

U

0.100

U

na



na



Ammonia

mg/L

...

0.200

U



0.200

U



0.200

U

0.200

U

0.200

U

na



na



Manganese, Dissolved

mg/L

...

0.136





0.152





0.145



0.152



0.148



na



0.23



Iron, Dissolved

mg/L

...

0.949





1.23





1.15



1.32



0.951



na



.1.79



Sulfate

mg/L

...

50.7





18.3





44.2



55.8



26.8



na



na



Sulfide

mg/L

...

43





10

U



10

U

10

U

21.7



¦' na



na



Methane

mq/l

...

32





26





71



71



49



na



na



Alkalinity, Total

mg/L



444





444





434



429



487



na



na



Total Kjeldahl Nitrogen

mg/L

...

1.00

U,M1



1.00

U



1.00

U

1.00

U

1.00

U

na



na



Orthophosphate

mg/L



0.100

U



0.100

Li



O'.IOO

U

0.100

U

0.100

U

na



na



Total Organic Carbon

mg/L

—

na





1.29





na



na



na



na



na



Chloride

mg/L

...

na





na





na



na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Wells	Page 35 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW33-GW-0103 MW33-GW-0103 MW33-GW-1003 MW33-GW-0404 MW33-GW-1004 MW33-GW-0405 MW33-GW1005
Standard 06-Jan-2003	09-Jan-2003	21-0ct-2003	05-Apr-2004	19-0ct-2004	12-Apr-2005	10-0ct-2005

VOCs

Units































Benzene



5

1.0

U

ns



1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

Toluene

m/l

1000

1.0

U

ns



1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

Ethyl benzene

ng/L

700

1.0

u

ns



1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

Xylenes, Total

ng/L

10000

3.0

u

ns



1.0

U

1.0

U

1.0

U

2.0

U

2.0

U

PAHs

































Acenaphthene

Mg/L

914

0.51

u

0.52

U

2.6

u

2.5

LI-

2.5

U

2.5

U

2.5

U

Acenaphthylene

kig/L

362

1.0

u

1

U

1.4

u

1.3

LI*

1.3

U

1.3

U

1.3

U

Anthracene

Mg/L

...

0.051

u

0.052

U

0.052

u*

0.050

U

0.050

U

0.050

U

0.050

U

Benzo(a)anthracene

Mg/L

0.13

0.10

u

0.1

U

0.14

u

0.13

U

0.13

U

0.13

U

0.13

U

Benzo(a)pyrene



0.2

0.10

u

0.1

U

0.14

u

0.13

U

0.13

U

0.13

U

0.13

U

Benzo(b)fluoranthene

mq/l

0.1

0.10

u

0.1

u

0.052

u

0.050

U

0.050

U

0.050

U

0.050

U

Benzo(ghi)perylene

MQ/L

...

0.10

u

0.1

u

0.21

u

0.20

U

0.20

U

0.20

U

0.20

U

Benzo(k)fluoranthene

Mg/L

0.14

0.10

u

0.1

u

0.052

u

0.050

U

0.050

U

0.050

U

0.050

U

Chrysene

Mg/L

0.85

0.10

u

0.1

u

0.14

u

0.13

U

0.13

U

0.13

U

0.13

U

Dibenzo(a,h)anthracene

Mg/i-

0.033

0.10

u

0.1

u

0.31

u

0.30

U

0.30

U "

0.30

U

0.30

U

Fluoranthene

pg/L

...

0.10

u

0.1

u

0.14

u

0.13

U

0.13

U

0.13

U

0.13

U

Fluorene

Mg/L

490

0.10

u

0.1

u

0.26

u

0.25

U"

0.25

U

0.25

U

0.25

U

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.10

u

0.1

u

0.14

u

0.13

U

0.13

U

0.13

U

0.13

U

Naphthalene

ng/L

1.1

0.51

u

0.52

u

1.4

u

1.3

U*

1.3

U

1.3

U

1.3

U

Phenanthrene

Mg/L

294

0.10

u

0.1

u

0.10

u

0.099

U*

0.10

U

0.099

U

0.10

U

Pyrene

tjg/L

...

0.10

u

0.1

u

0.26

u

0.25

U

0.25

U

0.25

U

0.25

U

1 -Methylnaphthalene

ng/L

...

na



na



na



na



na



na



na



2-Methylnaphthalene

|jg/L

61.2

na



na



na



na



na



na



na



Inoraanics

































Cyanide, Total

mg/L

...

0.00595



ns



0.0086

B

0.0087

B

0.010

U

0.010

U

0.010

U

Cyanide, WAD

mg/L

0.2

na



ns



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.247



ns



0.24



0.21



0.25



0.23



0.26



Natural Attenuation Parameters

































Nitrate

mg/L

...

na



ns



na



na



na



na



na



Nitrite

mg/L



na



ns



na



na



na



na



na



Ammonia

mg/L

...

na



ns



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.233



ns



0.22



0.21



0.21



0.22



0.31



Iron, Dissolved

mg/L

...

2.09



ns



2.1



2.0



1.9



1.8



2.4



Sulfate

mg/L

...

na



ns



na



na



na



na



na



Sulfide

mg/L

...

na



ns



na



na



na



na



na



Methane

ng/L

...

na



ns



na



na



na



na



na



Alkalinity, Total

mg/L

—

na



ns



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



ns



na



na



na



na



na



Orthophosphate

mg/L

...

na



ns



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



ns



na



na



na



na



na



Chloride

mg/L

...

na



ns



na



na



na



na



na



icgp_gw_2013-10.xlsx

4	B'-'-^pk Wells	£s-==-36 of 53

i \	! "\	\

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW33-GW-0406 MW33-GW-0410 MW33-GW-0411 MW33-GW-0412 MW33-GW-0413 MW35-GW-1002 MW35-GW-0103 MW35-GW-1003
Standard 10-Apr-2006	07-Apr-2010	11 -Apr-2011	10-Apr-2012 09-Apr-2013 28-Oct-2002 07-Jan-2003 22-Oct-2003

VOCs

Units



































Benzene

Mg/L

5

1

U

1.00

U

1.00

U

1.0

U

0.50

U

2

U

1.0

U

1.0

U

Toluene

mq/l

1000

1

U

1.00

U

1.00

U

1.0

U

1.00

U

2

U

1.0

U

1.0

U

Ethylbenzene

hq/l

700

1

U

1.00

U

1.00.

U

1.0

U

1.00

U

2

U

1.0

U

1.0

U

Xylenes, Total

mq/l

10000

3

U

6.00

U

3.00

U

1.0

U

3.00

U

7

u

3.0

U

1.0

U

PAHs





































Acenaphthene

Mg/L

914

0.13

U

0.100

U

0.100

U

0.100

U

0.100

U

0.52

u

0.54

U

2.6

U

Acenaphthylene

MQ/L

362

0.17

U

0.100

U

0.100

u

0.100

U

0.100

U

1

u

1.1

U

1.4

U

Anthracene

Mg/L

...

0.0093

U

0.100

U

0.100

u

0.100

U

0.100

U

0.052

u

0.054

U

0.052

U

Benzo(a)anthracene

Mg/L

0.13

0.019

U

0.100

U

0.100.

u

0.100

U

0.100

U

0.1

u

0.11

U

0.14

U

Benzo(a)pyrene

Mg/L

0.2

0.019

U

0.100

U

0.100

u

0.100

U

0.100

U

0.1

u

0.11

u

0.14

U

Benzo(b)fluoranthene

Mg/L

0.1

0.037

U '

0.100

U

0.100

u

0.100

U

0.100

U

0.1

u

0.11

u

0.052

U

Benzo(ghi)perylene

Mg/L

...

0.032

U

0.100

U

0.100

u

0.100

U

0.100

U

0.1

u

0.11

u

0.21

U

Benzo(k)fluoranthene

Mg/L

0.14

0.023

U

0.100

U

0.100

u

0.100

U

0.100

U

0.1

u

0.11

u

0.052

U

Chrysene

Mg/L

0.85

0.02

U

0.100

U

0.100

u

0.100

U

0.100

U

0.1

u

0.11

u

0.14

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.033

U

0.00810

U,J,MDL

0.0170

U,MDL

0.0170

U,MDL

0.0172

U

0.1

u

0.11

u

0.31

U

Fluoranthene

ms/l

...

0.032

U

0.100

U

0.100

U

0.100

U

0.100

U

0.1

u

0.11

u

0.14

U

Fluorene

Mg/L

490

0.029

U

0.100

U

0.100

U

0.100

U

0.100

U

0.1

u

0.11

u

0.26

U

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.038

U

0.100

U

0.100

U

0.100

U

0.100

U

0.1

u

0.11

u

0.14

U

Naphthalene

m9/l

1.1

0.1

U

0.100

U

0.100

U

0.100

U

0.100

U

0.52

u

0.54

u

1.4

U

Phenanthrene

Mg/L

294

0.015

U

0.100

U

0.100

U

0.100

U

0.100

u

0.1

u

0.11

u

0.10

U

Pyrene

Mg/L

...

0.036

U

0.100

U'

0.100

U

0.100

U

0.100

(J

0.1

u

0.11

u

0.26

U

1-Methylnaphthaiene

Mg/L

...

na



0.100

U

0.100

U

0.100

U

0.100

u

na



na



na



2-Methylnaphthalene

Mg/L

61.2

na



0.100

U

0.100

U

0.100

U

0.100

u

na



na



na



Inoraanics





































Cyanide, Total

mg/L

...

0.01

U

na



na



na



na



0.005

u

0.00500

u

0.010

U

Cyanide, WAD

mg/L

0.2

na



0.0100

U

0.0100

U

0.0100

U

0.0100

u

na



na



na



Manganese, Total

mg/L

0.775

0.208



1.06



0.218



0.188



0.205



0.0251



0.0158



0.98



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.204



na



na



na



na



0.0137



0.00744



0.0094

B

Iron, Dissolved

mg/L

...

2.26



na



na



na



na



0.198

u

0.123



0.050

U

Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L

...

. na



na



na



na1.



na



na



na



na



Methane

Mg/L

. —

na



na



na



na



na



na



na



na



Alkalinity, Total ¦

mg/L

...

na



na



na



na ""



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Wells	Page 37 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW35-GW-0404 MW35-GW-1004 MW35-GW-0405 MW35-GW1005 MW35-GW-0406 MW35-GW-1006 MW35-GW-0407
Standard 07-Apr-2004 - 20-0ct-2004 13-Apr-2005 12-0ct-2005 11-Apr-2006	10-0ct-2006	16-Apr-2007

VOCs	Units

Benzene

|jg/L

5

1.0

u

1.0

u

1.0

u

1.0

u

1 u

1

U

1.00

u

Toluene

M9/L

1000

1.0

u

1.0

u

1.0

u

1.0

u

1 u

1

u

1.00

u

Ethylbenzene

Hg/L

700

1.0

u

1.0

u

1.0

u

1.0

u

1 u

1

u

1.00

u

Xylenes, Total

Mg/L

10000

1.0

u

1.0

u

2.0

u

2.0

u

3 U

3

u

3.00

u

PAHs

Acenaphthene

ra/L

914

2.4

U

2.7

U

2.5

U

2.3

U

0.13

U

0.049

U

0.0490

U

Acenaphthylene

M9/I-

362

1.2

U

1.4

U

1.3

U

1.2

U

0.17

U

0.085

U

0.0850

U

Anthracene

M9/L

...

0.048

u

0.0089

Ja

0.050

u

0.047

u

0.0093

U

0.01

U

0.0100

U

Benzo(a)anthracene

ng/i

0.13

0.12

u

0.14

U

0.13

u

0.12

u

0.019

U

0.003

U

0.0030

U

Benzo(a)pyrene

ug/L

0.2

0.12

u

0.14

U

0.13

u

0.12

u

0.019

U

0.032

U

0.0320

U

Benzo(b)fluoranthene

Mg/L

0.1

0.048

u .

0.055

U

0.050

u

0.047

u

0.037

U

0.013

U

0.0130

U

Benzo(ghi)perylene

^g/L

...

0.19

u

0.22

U

0.20

• u

0.19

u

0.032

U

0.009

U

0.00900

U

Benzo(k)fluoranthene

Mg/i-

0.14

0.048

u

0.055

U

0.050

u

0.047

u

0.023

U

0.015

U

0.0150

U

Chrysene

Mg/L

0.85

0.12

u

0.14

U

0.13

u

0.12

u

0.02

U

0.005

U

0.00500

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.29

u

0.33

U

0.30

u

0.28

u

0.033

U

0.01

U

0.0100

U

Fluoranthene

pg/L

...

0.12

u

0.14

U

0.13

u

0.12

u

0.032

U

0.01

U

0.0100

U

Fluorene

Mg/L

490

0.24

u

0.27

U

0.25

u

0.23

u

0.029

U

0.01

U

0.0100

U

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.12

u

0.14

U

0.13

u

0.12

u

0.038

U

0.007

U

0.00700

U

Naphthalene

Mg/L

1.1

1.2

u

1.4

U

1.3

u

1.2

u

0.1

U

0.054

U

0.0540

U

Phenanthrene

pg/L

294

0.095

u

0.048

Ja

• 0.10

u

0.093

u

0.015

U

0.007

U

0.00700

U

Pyrene

pg/L

...

0.24

u

0.27

U

0.25

u

0.23

u

0.036

U

0.019

U

0.0190

U

1-Methylnaphthalene

pg/L

...

na



na



na



na



na



na



na



2-Methylnaphthalene

Mg/L

61.2

na



na



na



na



na



0.052

U

0.0520

U

Inoraanics

































Cyanide, Total

mg/L

...

0.0061

B

0.010

U

0.010

u

0.0019

B

0.01

U

0.01

U

0.0100

U

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.040



0.14



0.22



0.23



0.264



na



na



Natural Attenuation Parameters

































Nitrate

mg/L

...

na



na



na



na



na



na



na



Nitrite

mg/L-

...

na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.0084

B

0.044



0.19



0.25



0.249



na



na



Iron, Dissolved

mg/L

...

0.050

U

0.050

U

0.10

u

0.10

u

. 0.1

U

na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



Sulfide

mg/L

...

na



na '



na



na



na



na



na



Methane

pg/L

...

na



na



na



na



na



na •



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



Chloride

mg/L

...

na



na--'



na



na



na



na



na



icgp_gw_2013-10.xlsx

4	B-r^-ck Wells	P,=~
-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW35-GW-1007 MW35-GW-0408 MW35-GW-0410 MW35-GW-1010 MW35-GW-0411 MW35-GW-1011	MW35-GW-0412

Standard 09-0ct-2007	15-Apr-2008	08-Apr-2010	06-0ct-2010	11 -Apr-2011	24-Oct-2011	11-Apr-2012

						DV

VOCs

Units

































Benzene

ug/L

5

1.00

U

1.00

U.L1

1.00

U

1.00

U

1.00

U

1.00

U



1.00

U

Toluene

ng/L

1000

1.00

U

1.00

U.L1

1.00

U

1.00

U

1.00

U

1.00

U



1.00

U

Ethylbenzene

Hg/L

700

1.00

U

1.00

U,L1

1.00

u

1.00

(J

1.00

U

1.00

U



1.00

U

Xylenes, Total

pg/t-

10000

3.00

U

3.00

U.L1

6.00

u

3.00

u

3.00

U

3.0

U



3.0

U

PAHs



































Acenaphthene

ng/L

914

0.057

U

0.0995

J

0.100

u

0.383



0.100

U

0.100

U

UJ

0.100

U

Acenaphthylene

ug/L

362

0.0988

U

0.0850

U

0.100

u

0.273



0.100

U

0.100

U

UJ

0.100

U

Anthracene

ug/L

...

0.0116

U

0.0351

J

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(a)anthracene

Hg/L.

0.13

0.00349

U

0.0030

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(a)pyrene

Mg/L

0.2

0.0372

U

0.0320

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(b)fluoranthene

pg/L

0.1

0.0151

U

0.0130

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(ghi)perylene

pg/L

...

0.0105

U

0.00900

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Benzo(k)fluoranthene

M9/L

0.14

0.0174

U

0.0150

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Chrysene

Mg/L

0.85

0.00581

U

0.00500

U

0.100

u

0.100

u

0.100

U

0.100

U

UJ

0.100

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.0116

u

0.0100

U

0.0081

U,MDL

0.00810

U.MDL

0.0170

U,MDL

0.0170

U.MDL

UJ

0.0170

U.MDL

Fluoranthene

Mg/L

...

0.0116

u

0.0100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

Fluorene

Mg/L

490

0.0116

u

0.249



0.100

U

0.180



0.100

U

0.100

U

UJ

0.100

U

lndeno(1,2,3-cd)pyrene

i^g/L

0.1

0.00814

u

0.00700

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

Naphthalene

ijg/L

1.1

0.0628

u

0.312



0.100

U

2.18



0.100

U

0.100

U

UJ

0.104



Phenanthrene

pg/L

294

0.00814

u

0.175



0.100

U

0.145



0.100

U

0.100

U

UJ

0.100

U

Pyrene

Mg/L

...

0.0221

u

0.0190

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

1-Methylnaphthalene

Mg/L

...

na



na



0.100

U

0.632



0.100

U

0.100

U

UJ

0.125



2-Methylnaphthalene

Mg/L

61.2

0.0605

u

0.0520

U

0.100

U

0.152



0.100

U

0.100

U

UJ

0.100

U

Inoraanics



































Cyanide, Total

mg/L

...

0.0100

u

0.0100

U

na



na



na



na





na



Cyanide, WAD

mg/L

0.2

na



na



0.0100

U

0.0100

U

0.0100

U

0.0100

U

UJ

0.0100

U

"Manganese, Total

mg/L

0.775

na



na



0.354



0.355



0.326



0.358





0.325



Natural Attenuation Parameters



































Nitrate

mg/L

...

na



na



na



na



na



na





na



Nitrite

mg/L

...

na



na



na



na



na



na





na



Ammonia

mg/L

...

na



na



na



na



na



na





na



Manganese, Dissolved

mg/L

...

na



na



na



na



na



na





na



Iron,. Dissolved

mg/L

...

na



na



na



na



na



na





na



Sulfate

mg/L

...

na



na



na



na



na



na





na



Sulfide

mg/L

...

na



na



na



na



na



na





na



Methane

ng/L

...

na



na



na



na



na



na





na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na





na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na





na



Orthophosphate

mg/L

...

na



na



na



na



na



na





na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na





na



Chloride

mg/L

...

na



na



na



na



na



na





na



icgp_gvv_2013-10.xlsx
2/11/2014

Bedrock Wells

Page 39 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW35-GW-1012	MW35-GW-0413 MW35-GW-1013 MW36-GW-1002 MW36-GW-0103 MW36-GW-1003 MW36-GW-0404

Standard	09-0ct-2012	11-Apr-2013	22-Oct-2013	29-Oct-2002 06-Jan-2003 21-0ct-2003 06-Apr-2004

DV	DV	DV

VOCs

Units

































Benzene

Hg/L

5

1.00

U



0.500

U

0.500

u

110



120



150



120



Toluene

ng/L

1000

1.00

U



1.00

U

1.00

u

2.5



3.1



1.1



1.4



Ethylbenzene

mq/l

700

1.00

U



1.00

U

1.00

u

100



140



140



140



Xylenes, Total

ng/L

10000

3.00

U



3.00

U

3.00

U

58



87



38



54



PAHs



































Acenaphthene

pg/L

914

0.100

U

UJ

0.100

u

0.100

U

60



0.5

U

35



44

¦

Acenaphthylene

ng/L

362

0.100

U

UJ

0.100

u

0.100

U

1.1

U

1.0

U

310



370

*

Anthracene

pg/L

...

0.100

U

UJ

0.100

u

0.100

U

0.24



0.31

J

0.61



0.76



Benzo(a)anthracene

^g/L

0.13

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.13

U

0.12

U

Benzo(a)pyrene

Mg/L

0.2

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.13

U

0.12

u

Benzo(b)fluoranthene

ijg/L

0.1

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.050

U

0.048

u

Benzo(ghi)perylene

Mg/L

...

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.20

U

0.19

u

Benzo(k)fluoranthene

M9/L

0.14

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.050

U

0.048

u

Chrysene

pg/L

0.85

0.100

U

UJ

0.100

u

0.100

U

0.11

U

0.10

U

0.13

U

0.12

u

Dibenzo(a,h)anthracene

Mg/L

0.033

0.0130

U.MDL

UJ

0.0185

u

0.0173

U

0.11

u

0.10

U

0.30

U

0.29

u

Fluoranthene

MQ/L

...

0.100

U

UJ

0.100

u

0.100

U

0.14



0.15

J

0.48



0.79



Fluorene

Mg/L

490

0.100

U

UJ

0.100

u

0.100

U

7



0.22

J

7.2



9.3

•

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.100

U

UJ

0.100

u

0.100

U

0.11

u

0.10

U

0.13

U

0.12

u

Naphthalene

Mg/L

1.1

0.100

U

UJ

1.11

B

0.12



54

u

26

J

14



30

'

Phenanthrene

ijg/L

294

0.100

U

UJ

0.100

u

0.100

U

1.7



2.1

J

4.4



6.8

*

Pyrene

Mg/L

...

0.100

U

UJ

0.100

u

0.100

U

0.11

u

0.10

U

0.25

Ua

0.24

u

1-Methylnaphlhalene

Mg/L

...

0.100

U

UJ

0.154



0.100

U

na



na



na



na



2-Methylnaphthalene

Mg/L

61.2

0.100

U

UJ

0.135



0.100

U

na



na



na



na



Inoraanics



































Cyanide, Total

mg/L

...

na





na



na



0.005



0.00500

U

0.010

U

0.010

u

Cyanide, WAD

mg/L

0.2

0.0100

U



0.0100

u

0.0100

U

na



na



na



na



Manganese, Total

mg/L

0.775

0.361





0.371



0.313



0.146



0.166



0.18



0.17



Natural Attenuation Parameters



































Nitrate

mg/L

...

na





na



na



na



na



na



na



Nitrite

mg/L

...

na





na



na



na



na



na



na



Ammonia

mg/L

...

na





na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

na





na



na



0.151



0.158



0.16



0.16



Iron, Dissolved

mg/L

...

na





na



na



1.47



1.39



1.4



1.2



Sulfate

mg/L

...

na





na



na



na



na



na



na



Sulfide

mg/L

...

na





na



na



na



na



na



na



Methane

W/L

...

na





na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na





na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na





na



na



na



na



na



na



Orthophosphate

mg/L

...

na





na



na



na



na



na



na



Total Organic Carbon

mg/L

¦ ...

na





na



na



na



na



na



na



Chloride

mg/L

...

na





na



na



na



na



na



na



icgp_gw_2013-10.xlsx

E^^pk Wells

ppji-v40 of 53

\

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW36-GW-1004 MW36-GW-0405 MW36-GW-1005 MW36-GW-0406 MW36-GW-1006 MW36-GW-0407 MW36-GW-1007 MW36-GW-0408
Standard 20-0ct-2004 13-Apr-2005 12-0ct-2005 12-Apr-2006 09-0ct-2006 18-Apr-2007 10-0ct-2007 16-Apr-2008

VOCs	Units

Benzene

M9/L

5

140



120



120



91.6



60.7



30.8



82.9



1

U

Toluene

ng/L

1000

1.1



0.78

Ja

1.0

U

1

U

1.16



1

U

4.19



1

U

Ethylbenzene

ug/L

700

160



130



120



92.6



36



15.7



84



1

u

Xylenes, Total

ug/L

10000

51



39



19



10.2



11.6



3

U

7.06



3

u

PAHs





































Acenaphthene

Mg/L

914

37



41



42



28.9



28.8



24.9



37.8



7.64



Acenaphthylene

ra'L

362

320



380



¦ 350



0.17

U

0.085

U

0.085

U

0.085

U

0.085

u

Anthracene

Mg/L

—

0.87



1.1



1.1



0.815



0.792



0.447



0.567



0.0809

J

Benzo(a)anthracene

Mg/L

0.13

0.13

U

0.12

U

0.12

U

0.019

U

0.003

U

0.003

U

0.003

U

0.003

u

Benzo(a)pyrene

pg/L

0.2

0.13

U

0.12

U

0.12

u

0.019

U

0.032

U

0.032

U

0.032

U

0.032

u

Benzo(b)fluoranthene

Mg/L

0.1

0.052

u

0.047

U

0.048

u

0.037

U

0.013

U

0.013

U

0.013

U

0.013

u

Benzo(ghi)perylene

Mg/L

...

0.21

u

0.19

U

0.19

u

0.032

U

0.009

U

0.009

U

0.009

U

0.009

u

Benzo(k)fluoranthene

pg/L

0.14

0.052

u

0.047

U

0.048

u

0.023

U

0.015

U

0.015

U

0.015

U

0.015

u

Chrysene

Mg/L

0.85

0.13

u

0.12

U

0.12

u

0.02

U

0.005

U

0.005

U

0.005

U

0.005

u

Dibenzo(a,h)anthracene

Mg/L

0.033

0.31

u

0.28

U

0.29

u

0.033

U

0.01

U

0.01

U

0.01

U

0.01

u

Fluoranthene

ijg/L

...

0.78



0:82



0.54



0.651



0.424



0.237



0.382



0.0648

J

Fluorene

pg/L

490

7.7



9.1



8.6



10.4



13.8



11



33.3



3.99



lndeno(1,2,3-cd)pyrene

Hg/L

0.1

0.13

u

0.12

U

0.12

u

0.038

U

0.007

U

0.007

U

0.007

U

0.007

u

Naphthalene

|jg/L

1.1

19



7.9



5.2



2.77



3.78



1.93



4.89



0.493



Phenanthrene

ng/L

294

5.7



6.6



5.9



6.2



4.67



3.05



5.61



0.706



Pyrene

ijg/L

...

0.29



0.099

Ja

0.28



2.69



1.7



0.964



1.21



0.0411

J

1-Methyl naphthalene

Mg/i-

—

na



na



na



na



na



na



na



na



2-Methylnaphthalene

ijg/L

61.2

na



na



na



na



0.052

U

0.29



0.052

U

0.0707

J

tnoraanics





































Cyanide, Total

mg/L

...

0.010

u

0.010

U

0.0027

B

0.01

U

0.01

U

0.01

U

0.01

U

0.01

u

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.18



0.18



0.25



0.154



na



na



na



na



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na.



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.17



0.17



0.17



0.161



na



na



na



na



Iron, Dissolved

mg/L

...

1.2



1.3



1.6



1.44



na



na



na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L



na



na



na



na



na



na



na



na



Methane

pg/L

¦ —

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na'



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



• na



na



na



na



na



icgp_gw_2013-10.xlsx
2/11/2014

Bedrock Wells

Page 41 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW36-GW-0409 MW36-GW-1009 MW36-GW-0110 DP01-GW-0110 MW36-GW-0410	MW36-GW-0710	MW36-GW-1010

Standard 22-Apr-2009 14-0ct-2009 14-Jan-2010 14-Jan-2010	07-Apr-2010	07-Jul-2010	05-0ct-2010

DV

VOCs

Units

































Benzene

mq/l

5

1

U

25.6



1.00

U

1.00

U

2.92



23.2





40.2



Toluene

Mg/L

1000

1

U

1

U

1.00

U

1.00

U

1.00

' U

1.00

U



1.00

U

Ethyl benzene

mq/l

700

1

U

7.13



1.00

U

1.00

U

1.00

U

4.68





20.8



Xylenes, Total

Mg/L

10000

3

U

3

U

3.00

U

3.00

U

6.00

u

4.35





4.48



PAHs



































Acenaphthene

Mg/L

914

7.75



15.5



10.5



10.3



16.0



18.6

H2

J-

14.9



Acenaphthylene

M9/L

362

1.85



4.6



2.01



2.04



3.28



3.78

H2

J-

3.21



Anthracene

pg/L

...

0.0551

J

0.143



0.0487

J

0.0488

J

0.120



0.131

H2

J-

0.100

U

Benzo(a)anthracene

|jg/L

0.13

0.0250

J

0.0216

J

0.0125

J

0.0119

J

0.100

u

0.100

U,H2

UJ

0.100

U

Benzo(a)pyrene



0.2

.0.0186

J

0.016

U

0.0160

U

0.0160

U

0.100

u

0.100

U.H2

UJ

0.100

U

Benzo(b)fluoranthene

ng/L

0.1

0.0211

J

0.0158

J

0.00760

U

0.00760

U

0.100

u

0.100

U,H2

UJ

0.100

U

Benzo(ghi)peryiene

Mg/L

...

0.0121

J

0.00887

J

0.00810

U

0.00810

U

0.100

u

0.100

U,H2

UJ

0.100

U

Benzo(k)fluoranthene

fjg/L

0.14

0.00790

U

0.0077

U

0.00770

U

0.00770

U

0.100

u

0.100

U,H2

UJ

0.100

U

Chrysene

Mg/L

0.85

0.0136

J

0.0101

J

0.00700

U

0.00700

U

.0.100

u

0.100

U,H2

UJ

0.100

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.00760

U

0.0081

U

0.00810

U

0.00810

U

0.0081

U.MDL

0.00810

U,H2,MDL

UJ

0.00810

U,MDL

Fluoranthene

ijg/L

...

0.0727

J

0.107



0.0386

J

0.0434

J

0.100

U

0.100

U.H2

UJ

0.100

U

Fluorene

Mg/L

490

1.95



4.34



2.25



2.33



3.55



3.99

H2

J-

2.97



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.0101

J

0.011

U

0.0110

U

0.0110

u

0.100

U

0.100

U,H2

UJ

0.100

U

Naphthalene

ug/L

1.1

0.00590

u

0.488



0.0290

U

0.0290

u

0.184



0.889

H2

J-

1.32



Phenanthrene

ng/L

294

0.555



0.858



0.170



0.144



0.357



0.377

H2

J-

0.295



Pyrene

ng/L

...

0.068

J

0.111



0.0808

J

0.0831

J

0.100

U

0.100

U,H2

UJ

0.100

u

1-Methylnaphthalene

Mg/L



na



na



na



na



0.54



2.40

H2

J-

7.04



2-Methylnaphthalene

Mg/L

61.2

0.0195

J

0.0531

J

0.0310

U

0.0310

u

0.1

U

0.100

U,H2

UJ

0.100

u

Inoraanics



































Cyanide, Total

mg/L

...

na



na



na



na



na



na





na



Cyanide, WAD

mg/L

0.2

na



na



0.0100

U

0.0100

u

0.0100

U

0.0100

U



0.0100

u

Manganese, Total

mg/L

0.775

na



na



0.120



0.120



0.125



0.144





0.123



Natural Attenuation Parameters



































Nitrate

mg/L

...

na



na



na



na



na



na





na



Nitrite

mg/L

...

na



na



na



na



na



na





na



Ammonia

mg/L

...

na



na



na



na



na



na





na



Manganese, Dissolved

mg/L

...

na



na



na



na



na



na





na



Iron, Dissolved

mg/L

...

na



na



na



na



na



na





na



Sulfate

mg/L

...

na



na



na



na



na



. na





na



Sulfide

mg/L

...

na



na



na



na



na



na





na



Methane

pg/L

...

na



na



na



na



na



na





na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na





na



Total Kjeldahl Nitrogen

mg/L

—

na



na



na



na



na



na





na



Orthophosphate

mg/L

...

na



na



na



na



na



na





na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na





na



Chloride

mg/L

...

na



na



na



na



na



na





na



icgp_gw_2013-10.xlsx

4	Brs^sk Wells	P?.^42 0f 53

^ ' \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW36-GW-0411 MW36-GW-1011 MW36-GW-1011-DUP-01 MW36-GW-0412 MW36-GW-1012	DP01-GW-1012

Standard	11 -Apr-2011	25-Oct-2011	25-Oct-2011	10-Apr-2012	09-0ct-2012	09-0ct-2012

¦	 	DV	DV	DV	DV

VOCs

Units































Benzene

W/L

5

4.24



21.4



20.9



8.76



21.8





22.8





Toluene

MQ/L

1000

1.00

U

1.00

U

1.00

U

1.0

U

1.00

U



1.00

U



Ethyl benzene

hq/l

700

1.00

U

4.95



4.72



1.0

U

2.53





2.75





Xylenes, Total

w/L

10000

3.00

U

4.09



4.22



3.0

U

3.00

U



3.00

U



PAHs

































Acenaphthene

hq/l

914

10.6



8.33

J-

7.57

J-

14.3



16.2



J-

15.7



J-

Aceriaphthylene

MQ/L

362

2.66



3.39



3.40



2.71



3.34



J-

3.48



J-

Anthracene

M9/L

...

0.100

U

0.100

U

0.100

U

0.100

U "

0.100

U

UJ

0.100

U

UJ

Benzo(a)anthracene

mq/l

0.13

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

Benzo(a)pyrene

|jg/L

0.2

0.100

U

0.100

U

0.100

u

0.100

U

0.100

U

UJ

0.100

U

UJ

Benzo(b)fluoranthene

mq/l

0.1

0.100

U

0.100

U

0.100

u

0.100

U

0.100

U

UJ

0.100

U

UJ

Benzo(ghi)perylene

W/L

...

0.100

U

0.100

U

0.100

u

0.100

U

0.100

U

UJ

0.100

U

UJ

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

0.100

U

0.100

u

0.100

U

0.100

U

UJ

0.100

U

UJ

Clirysene

Mg/L

0.85

0.100

U

0.100

U

0.100

u

0.100

U

0.100

U

UJ .

0.100

U

UJ

Dibenzo(a,h)anthracene

MQ/L

0.033

0.0170

U.MDL

0.0170

U.MDL

0.0170

U,MDL

0.0170

U,MDL

0.0130

U,MDL

UJ

0.0130

U.MDL

UJ

Fluoranthene

Mg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

Fluorene

Mg/L

490

2.88



3.49



3.53



2.63



3.28



J-

3.38



J-

lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

Naphthalene

ijg/L

1.1

0.745



0.741



0.427



0.158



0.287



J-

0.246



J-

Phenanthrene

M9/L

294

0.162



0.178



0.167



0.132



0.164



J-

0.160



J-

Pyrene

ug'L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

1-Methylnaphthalene

fjg/L

...

1.33



6.47



6.25



0.435



1.58



J-

1.46



J-

2-Methylnaphthalene

w/l

61.2

0.100

U

0.100

u

0.100

U

0.100

U

0.100

U

UJ

0.100

U

UJ

Inoraanics

































Cyanide, Total

mg/L

...

na











na



na





na





Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

u

0.0100

U

0.0100

U

0.0100

U



0.0100

U



Manganese, Total

mg/L

0.775

0.127



0.159



0.147



0.12



0.141





0.144





Natural Attenuation Parameters

































Nitrate

mg/L

...

na



na .



na



na



na





na





Nitrite

mg/L

...

na



na



na



na



na





na





Ammonia

mg/L

...

na



na



na



na



na





na





Manganese, Dissolved

mg/L

...

na



na



na



na



na





na





Iron, Dissolved

mg/L

...

na



na



na



na



na





na





Sulfate

mg/L

...

na



na



na



na



na





na





Sulfide

mg/L

...

na



na



na



na



na





na





Methane

ug/L

...

na



na



na



na



na





na





¦Alkalinity, Total

mg/L

...

na



na



na



na



na





na





Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na





na





Orthophosphate

mg/L

...

na



na



na



na



na





na





Total Organic Carbon

mg/L

—

na



na



na



na



na





na





Chloride

mg/L

...

na



na



na



na



na





na





icgp_gw_20l3-10.xlsx
2/11/2014

Bedrock Wells

Page 43 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW36-GW-0413 DP01-GW-0413 MW36-GW-1013 DP01-GW-1013 MW37-GW-1002 MW37-GW-0103 MW37-GW-1003 MW37-GW-0404
Standard 09-Apr-2013 09-Apr-2013 22-Oct-2013 22-Oct-2013 29-Oct-2002 06-Jan-2003 21-0ct-2003 06-Apr-2004
DV	DV	DV	DV 	

VOCs

Units





































Benzene



5

5.18





5.16



45.8



43.9



6.7



52



87



73



Toluene

IJg/L

1000

1.00

U



1.00

U

1.00

U

1.00

U

2

U

1.3



1.0

U

1.0

U

Ethylbenzene

mq/l

700

1.00

U



1.00

U

21.3



20.7



4.9



56



8.1



6.2



Xylenes, Total

Mg/L

10000

3.00

u



3.00

u

5.19



5.09



7

U

26



6.4



5.8



PAHs







































Acenaphthene

|jg/L

914

22.4





21



22.6



24.6



3.4



17



15



19

*

Acenaphthylene

M9/L

362

3.51



J+

3.41



5.19



5.34



1.1

U

1.0

U

150



200

¦

Anthracene



—

0.100

u



0.100

u

0.16



0.149



0.053

U

0.051

U

0.14



0.17



Benzo(a)anthracene

|jg/L

0.13

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.13

U

0.13

U

Benzo(a)pyrene

(jg/L

0.2

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.13

U

0.13

U

Benzo(b)fluoranthene

mq/l

0.1

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.050

U

0.050

u

Benzo(ghi)perylene

M9"-



0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.20

U

0.20

u

Benzo(k)fluoranthene

ms/l

0.14

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.050

U

0.050

u

Chrysene

ng/L

0.85

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u.

0.13

U

0.13

u

Dibenzo(a,h)anthracene

Mg/L

0.033

0.0173

u



0.0173

u

0.0173

U

0.0175

U

0.11

U

0.10

u

0.30

U

0.30

u

Fluoranthene

ng/L

...

0.12



J+

0.113 ¦



0.125



0.118



0.11

U

0.10

u

0.074

Ja

0.12

Ja

Fluorene

|jg/L

490

4.13



J+

3.95



5.88



5.88



0.36



1.6



2.5



3.4

-

lndeno( 1,2,3-cd)pyrene

Mg/L

0.1

0.100

u



0.100

u

0.100

U

0.100

U

0.11

U

0.10

u

0.13

U

0.13

u

Naphthalene

Mg/L

1.1

0.136



J+

0.142



0.653



0.739



1.4



9.7



1.6



1.0

Ja*

Phenanthrene

i-ig/L

294

0.100

u



0.100

u

0.739



0.73



0.11

U

0.23



1.0



1.5

•

Pyrene

i^g/L

...

0.126



. J+

0.12



0.145



0.133



0.11

. U.

0.10

u

0.25

U

0.25

U

1-Methylnaphthalene

pg/L

...

0.305



J+

0.311



13.9



15.4



na



na



na



na



2-Methylnaphthalene

i-tg/L

61.2

0.100

u



0.100

u

0.100

U

0.100

U

na



na



na



na



Inoraanics







































Cyanide, Total

mg/L

...

na





na



na



na



0.005

U

0.00500

u

0.010

U

0.010

u

Cyanide, WAD

mg/L

0.2

0.0100

u



0.0100

u

0.0100

U

0.0100

U

na



na



na



na



Manganese, Total

mg/L

0.775

0.129





0.131



0.145



0.141



0.0435



0.0476



0.058



0.062



Natural Attenuation Parameters







































Nitrate

mg/L

—

na





na



na



na



na



na



na



na



Nitrite

mg/L

...

na





na



na



na



na



na



na



na



Ammonia

mg/L

...

na





na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

na





na



na



na



0.0381



0.0419



0.050



0.058



Iron, Dissolved

mg/L

...

na





na



na



na



1.89



2.03



2.3



2.3



Sulfate

mg/L

...

na





na



na



na



na



na



na



na



Sulfide

mg/L

...

na





na



na



na



na



na



na



na



Methane

ug/L

...

na





na



na



na



na



na



na



na



Alkalinity, Total

mg/L



na





na



na



na



'na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na





na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na





na



na



na



na



na



na



na



Total Organic Carbon

mg/L

—

na





na



na



na



na



na



na



na



Chloride

mg/L

...

na





na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

2Wr'-iYoi4	Wells	F^»«v44 of 53

( \ ( \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW37-GW-1004 MW37-GW-0405 MW37-GW-1005 MW37-GW-0406 MW37-GW-1006 MW37-GW-0407 MW37-GW-1007 MW37-GW-0408
Standard 19-0ct-2004 13-Apr-2005 12-0ct-2005 12-Apr-2006 09-0ct-2006 18-Apr-2007 09-0ct-2007 16-Apr-2008

VOCs

Units



































Benzene

Mg/L

5

70



40



19



8.83



2.07



1

U

7.89



1

U

Toluene

mq/l

1000

1.0

U

1.0

U

1.0

U

1

U

1.00

U

1

U

1.11



1

U

Ethylbenzene

MQ/L

700

4.3



1.8



1.0

U

1

U

1.00

U

1

U

1

U

1

U

Xylenes, Total

ng/L

10000

4.3



2.0

J

2.0

U

3

U

3.00

U

3

U

3

U

3

U

PAHs





































Acenaphthene

ng/L

914

18



23



24



20.6



19.6



16.8



25.3 ¦



13.8



Acenaphthylene

Mg/L

362

190



210



230



0.17

U

0.085

U

0.0944

U

0.085

U

0.085

U

Anthracene

Mg/L

...

0.24



0.31



0.32



0.24



0.205



0.133

J

0.486



0.0716

J

Benzo(a)anthracene

ng/L

0.13

0.12

U

0.054

Ja

0.12

u

0.019

U

0.003

U

0.00333

U

0.003

U

0.003

U

Benzo(a)pyrene

pg/L

0.2

0.12

U

0.044

Ja

0.12

u

0.019

U

0.032

U

0.0356

U

0.032

U

0.032

U

Benzo(b)fluoranlhene

pg/L

0.1

0.048

U

0.097



0.046

u

0.037

U

0.013

U

0.0144

U

0.013

U

0.013

U

Benzo(ghi)perylene

mq/l

—

0.19

U

0.079 "

Ja

0.19

u

0.032

U

0.009

U

0.01

U

0.009

U

0.009

U

Benzo(k)fluoranthene

pq/l

0.14

0.048

U

0.092



0.046

u

0.023

U

0.015

U

0.0167

U

0.015

U

0.015

U

Chrysene

mq/l

0.85

0.12

U

0.090

Ja

0.12

u

0.02

U

0.005

U

0.00556

U

0.005

U

0.005

U

Dibenzo(a,h)anthracene

ng/L

0.033

0.29

U

0.090

Ja

0.28

u

0.033

U

0.01

U

0.0111

U

0.01

U

0.01

U

Fluoranthene

Mg/L

...

0.15



0.22



0.18



0.182

J

0.133

J

0.0703

J

0.0418

J

0.01

U

Fluorene

Mg/L

490

3.2



4.1



3.9



6.11



7.43



5.88



16.7



6.28



lndeno(1,2,3-cd)pyrene

Mg/L

0.1

0.12

U

0.085

Ja

0.12

u

0.038

U

0.007

U

0.00778

U

0.007

U

0.007

U

Naphthalene

pg/L

1.1

1.2

U

0.45

Ja

1.2

u

0.438



0.385



0.44



0.534



0.297



Phenanthrene

Mg/L

294

1.4



1.6



1.5



1.62



1.27



0.741



1.93



0.442



Pyrene

Mg/L

...

0.24

U

0.24

U

0.23

u

0.036

U

0.339



0.202

J

0.457



0.019

U

1-Methylnaphthalene

pg/L

...

. na



na



na



na



na



na



na



na



2-Methylnaphthalene

pg/L

61.2

na



na



na



na



0.0715

J

0.103

J

0.052

U

0.052

U

Inoraanics





































Cyanide, Total

mg/L

...

0.010

U

0.010

U

0.0032

B

0.01

U

0.01

U

0.01

U

0.01

U

0.01

U

Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.074



0.073



0.070



0.07



na



na



na



na



Natural Attenuation Parameters





































Nitrate-

mg/L

...

na



0.10

U

0.10 .

u

0.1

U

na



na



na



na



Nitrite

mg/L

...

na



0.020

U

0.0096

B

0.025

U

na



na



na



na



Ammonia

mg/L

...

na



0.67



0.50



0.622

U

na



na



na



na



Manganese, Dissolved

mg/L

...

0.062



0.069



0.068



0.0635



na



na



na



na



Iron, Dissolved

mg/L

...

2.4



2.3



2.6



.2.55



na



na



na



. na



Sulfate

mg/L

...

na



69



75



52.8



na



na



na



na



Sulfide

mg/L

...

na



1.0

U

1.0

U

1

u

na



na



na'



na



Methane

Mg/L

...

na



9.6



9.1



26

u

na



na



na



na



Alkalinity, Total

mg/L

...

na



410



400



480



na



na



na"



na



Total Kjeldahl Nitrogen

mg/L

...

na



0.56



0.80



1

u

na



na



na



na



Orthophosphate

mg/L

...

na



0.012

B

' '0.0090

B

0.1

U,M1

na



na



na



na



Total Organic Carbon

mg/L

...

na



1.8



1.9



1.67



na



na



na



na



Chloride

mg/L

...

na



na



na



61.7

M1

na



na



na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Wells	Page 45 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW37-GW-0409 MW37-GW-1009 MW37-GW-0110 MW37-GW-0410 MW37-GW-0710 MW37-GW-1010 MW37-GW-0411
Standard 22-Apr-2009 14-0ct-2009 14-Jan-2010	07-Apr-2010	07-Jul-2010	05-0ct-2010	11 -Apr-2011

VOCs

Units































Benzene

Mg/L

5

1

U

1

U

1.00

U

1.00

U

1.00

U

3.37



1.00

U

Toluene

pg/L

1000

1

U

1

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

Ethyl benzene

Hg/L

700

1

U

1

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

Xylenes, Total

Hg/L

10000

3

U

3

U

3.00

U

6.00

U

3.00

U

3.00

U

3.00

U

PAHs

































Acenaphthene



914

4.41



9.39



9.49



10.4



8.52



10.3



10.1



Acenaphthylene

Mg/L

362

0.313



0.709



0.834



0.843



0.577



0.867



0.591



Anthracene

Mg/L

...

0.00826

J

0.0364

J

0.0259

J

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)anthracene

MQ/L

0.13

0.00944

J

0.0134

J

0.0104

J

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(a)pyrene

pg/L

0.2

0.00850

U

0.016

U

0.0160

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(b)fluoranthene

ug/L

0.1

0.00990

U

0.0076

U

0.00760

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(ghi)perylene

ug/L



0.00550

U

0.0081

U

0.00810

U

0.100

U

0.100

U

0.100

U

0.100

U

Benzo(k)fluoranthene

ng/L

0.14

0.00790

U

0.0077

U

0.00770

U

0.100

U

0.100

U

0.100

U

0.100

U

Chrysene

pg/i-

0.85

0.00530

U

0.007

U

0.00700

U

0.100

U

0.100

U

0.100

U

0.100

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.00760

U

0.0081

U

0.00810

U

0.00810

U,MDL

0.00810

U.MDL

0.00810

U.MDL

0.0170

U,MDL

Fluoranthene

ijg/L

...

0.0129

J

0.0285

J

0.0283

J

0.100

U

0.100

U

0.100

U

0.100

U

Fluorene

Mg/L

490

0.876



1.9



1.82



2.09



1.53



1.87



1.81



lndeno(1,2,3-cd)pyrene

ng/L

0.1

0.00690

U

0.011

U

0.0110

U

0.100

U

0.100

U

0.100

U

0.100

U

Naphthalene

Mg/L

1.1

0.00590

U

0.029

U

0.0290

U

0.100

U

0.100

U

0.100

U

0.112



Phenanthrene

ng/L

294

0.0337

J

0.113



0.0554

J

0.100

U

0.100

U

0.100

U

0.100

U

Pyrene

ijg/L

...

0.0134

J

0.0347

J

0.0546

J

0.100

U

0.100

U

0.100

U

0.100

U

1-Methylnaphthalene

tjg/L

...

na



na







0.223



0.239



0.734



0.234



2-Methylnaphthalene

Mg/L

61.2

0.00708

J

0.031

U

0.0310

U

0.100

U

0.100

U

0.100

U

0.100

U

Inoraanics

































Cyanide, Total

mg/L

...

na



na



na



na



na



na



. na



Cyanide, WAD

mg/L

0.2

na



na



0.0100

U

.0.0100

U

0.0100

U

0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

na



na



0.0619



0.0639



0.0718



0.0685



0.0696



Natural Attenuation Parameters

































Nitrate

mg/L



na



na



na



0.10

U

na



0.10

U

0.10

U

Nitrite

mg/L

...

na



na



na



0.100

U

na



0.100

U

0.100

U

Ammonia

mg/L

...

na



na



na



0.627



na



0.560



0.698



Manganese, Dissolved

mg/L

...

na



na



na



0.065



na



0.0621



0.0546



Iron, Dissolved

mg/L

...

na



na



na



2.6



na



2.80



2.29



Sulfate

mg/L

...

na



na



na



41.8



na



44.3



43.5



Sulfide

mg/L

...

na



na



na







na



5.00

U

10

U

Methane

ng/L

...

na



na



na



48



na



46.3



15



Alkalinity, Total

mg/L

...

na



na



na



470



na



"433



424



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



1.00

U

na



1.00

U,M1

1.13



Orthophosphate

mg/L

...

na



na1



na



0.100

u

na



0.100

U

0.100

U

Total Organic Carbon

mg/L

...

na



na



na



1.00

u

na



1.00

U

na



Chloride

mg/L

...

na



na



na



30.7



na



38.8



na



icgp_gw_2013-10.xlsx

2/^-—4	Bp.—°ck Wells	of 53

i	' ^

-------


Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW37-GW-1011 MW37-GW-0412 MW37-GW-1012 MW37-GW-0413 MW37-GW-1013 MW41-GW-1002 MW41-GW-0103
Standard 25-Oct-2011 10-Apr-2012 09-0ct-2012 09-Apr-2013	22-Oct-2013	31-0ct-2002 07-Jan-2003

DV	DV		DV	DV	DV

VOCs

Units





































Benzene



5

1.03



1.00

U

1.48





0.500

U



9.11





2

U

1.0

U

Toluene

Mg/L

1000

1.00

U

1.00

U

1.00

U



1.00

U



.1.00

U



2

U

1.0

U

Ethylbenzene

US/L

700

1.00

U

1.00

U

1.00

U



1.00

U



1.00

U



2

U

1.0

u

Xylenes, Total

pg/L

10000

3.00

U

3.00

U

3.00

u



3.00

U



3.00

U



7

U

3.0

u

PAHs







































Acenaphthene

^g/L

914

5.22

J-

12.4

J-

11.3

M1

J-

15.3





14.8





0.55

U

0.51

u

Acenaphthylene

Mg/L

362

0.696



0.823



1.07





1.22





2.02





1.1

U

1.0

u

Anthracene

[jg/i-

...

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.055

U

0.051

u

Benzo(a)anthracene

Mg/L

0.13

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Benzo(a)pyrene

pg/L

0.2

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Benzo(b)fluoranthene

ijg/L

.0.1

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Benzo(ghi)perylene

W/L

...

0.100

U

0.100

U

0.100

U,M1

UJ

0.100

U

UJ

0J00

U

UJ

0.11

U

0.10

u

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Chrysene

ng/L

0.85

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Dibenzo(a,h)anthracene

Mg/L

0.033

0.0170

U,MDL

0.0170

U,MDL

0.0267

J, M1

J-

0.0173

U

UJ

0.0173

U

UJ

0.11

U

0.10

u.

Fluoranthene

MQ/L

...

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Fluorene

ng/L

490

1.77



2.13



2.00





2.91





3.27





0.11

U

0.10

u

lndeno(1,2,3-cd)pyrene

Hg/L

0.1

0.100

U

0.100

U

0.100

U,M1

UJ

0.100

U

UJ

0.100

U

UJ

0.11

U

0.10

u

Naphthalene

ug/L

1.1

0.100.

U

0.100

U

0.119





0.100

U



0.244





0.55

U

0.51

u

Phenanthrene

ijg/L

294

0.100

U

0.-100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

Pyrene

^g/L

...

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



0.11

U

0.10

u

1-Methyl naphthalene

ug/L

...

0.623



0.126



0.345





0.164





2.48





na



na



2-Methyl naphthalene

t-tg/L

61.2

0.100

U

0.100

U

0.100

U



0.100

U



0.100

U



na



na



Inornanins







































Cyanide, Total

mg/L

...

na



na



na





na





na





0.00592



0.00500

u

Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

0.0100

U



0.0100

U



0.0100

U



na



na



Manganese, Total

mg/L

0.775

0.0654



0.0606



0.0715





0.0685





0.0716





0.229



0.0488



Natural Attenuation Parameters







































Nitrate

mg/L

...

0.10

U

0.10

U

0.100

U



0.100

U



na





na



na



Nitrite

mg/L

...

0.100

U

0.10

U

0.100

U



0.100

U



na





na



na



Ammonia

mg/L

...

0.647



0.623



0.579

M1



0.655





na





na



na



Manganese, Dissolved

mg/L

...

0.0649



0.0709



0.0715





0.0656





na





0.0372



0.0323



Iron, Dissolved

mg/L

...

2.88



3.08



3.16





3.130





na





0.985



1.4



Sulfate

mg/L

...

42.1



44.4



45.1





40.3





na





na



na



Sulfide

mg/L

...¦

10

U'-

10

U

10

U



11.1





na





na



na



Methane

Mg/L

...

17



42



41





29.7





na





na



na



Alkalinity, Total

mg/L

...

444



414



444





459





na





na



na



Total Kjeldahl Nitrogen

mg/L

...

1.00

U

1.00

U

1.00

U



1.00

U



na





na



na



Orthophosphate

mg/L

...

0.100

U

0.100

U

0.100

U,M1



0.100

U



na





na



na



Total Organic Carbon

mg/L

...

1.00



na



na





na





na





na



na



Chloride

mg/L



na



na



na





na





na





na



na



icgp_gw_2013-10.xlsx

2/11/2014	Bedrock Wells	Page 47 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW41-GW-1003 MW41-GW-0404 MW41-GW-1004 MW41-GW-0405 MW41-GW-1005 MW41-GW-0406 MW41-GW-0410 MW41-GW-0411
Standard 20-0cl-2003 06-Apr-2004 19-0ct-2004 14-Apr-2005 13-0ct-2005 10-Apr-2006 07-Apr-2010	11-Apr-2011

VOCs

Units



































Benzene

Mg/L

5

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.00

U

1.00

U

Toluene

.pg/L

1000

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.0

U

1.00

U

1.00

U

Ethyibenzene

Mg/L

700

1.0

U

1.0

U

1.0

U

1.0

U

0.53

J

1.0

U

1.00

u

1.00

u

Xylenes, Total

M9/L

10000

1.0

U

1.0

U

1.0

U

2.0

U

2.0

U

3.0

U

6.00

u

3.00

u

PAHs





































Acenaphthene

Pg/L

914

2.5

U

2.4

ir

2.6

,U

2.3

U

2.5

U

0.13

U

0.100

u

0.100

u

Acenaphthylene

pg/L

362

1.3

U

1.2

U*

1.3

U

1.2

U

1.3

U

0.17

U

• 0.100

u

0.100

u

Anthracene

pg/L

...

0.050

LI-

0.048

U

0.051

U

0.047

U

0.049

u

0.0093

U

0.100

u

0.100

u

Benzo(a)anthracene

ng/L

0.13

0.13

LI

0.12

U

0.13

U

0.12

U

0.13

u

0.019

U

0.100

u

0.100

u

Benzo(a)pyrene

pg/L

0.2

.0.13

U

0.12

U

0.13

U

0.12

U

0.13

u

0.019

U

0.100

u

0.100

u

Benzo(b)fluoranthene

pg/L

0.1

0.050

U

0.048

U

0.051

U

0.047

U

0.049

u

0.037

U

0.100

u

0.100

u

Benzo(ghi)perylene

ug/L

...

0.20

U

0.19.

U

0.20

U

0.19

U

0.20

u

0.032

U

0.100

u

0.100

u

Benzo(k)fluoranthene

pg/L

0.14

0.050

U

0.048

U

0.051

U

0.047

U

0.049

u

0.023

U

0.100

u

0.100

u

Chrysene

pg/L

0.85

0.13

U

0.12

U

0.13

U

0.12

U

0.13

u

0.02

U

0.100

u

0.100

u

Dibenzo(a,h)anthracene

pg/L

0.033

0.30

U

0.29

U

0.31

U

0.28

U

0.29

u

0.033

U

0.0081

U,MDL

0.0170

U.MDL

Fluoranthene

pg/L

...

0.13

U

0.12

U

0.13

U

0.12

U

0.13

u

0.032

U

0.100

U

0.100

U

Fluorene

pg/L

490

0.25

U

0.24

U*

0.26

U

0.23

U

0.25

u

0.029

U

0.100

U

0.100

U

lndeno(1,2,3-cd)pyrene

s-tg/L

0.1

0.13

U

0.12

U

0.13

U

0.12

U

0.13

u

0.038

U

0.100

U

0.100

U

Naphthalene

M9/L

1.1

1.3

U

1.2

u*

1.3

U

1.2

u

1.3

u

0.1

U

0.100

U

0.100

U

Phenanthrene

ng/L

294

0.099

U

0.095

u*

0.10

U

0.093

u

0.098

u

0.015

U •

0.100

U

0.100

U

Pyrene

MQ/L

...

0.25

U

0.24

u

0.26

u

0.23

u

0.25

u

0.036

U

0.100

U

0.100

U

1 -Methylnaphthalene

MQ/L

...

na



na



na



na



na



na



0.100

U

0.100

U

2-Methylnaphthalene

pg/L

61.2

na



na



na



na



na



na



0.100

U

0.100

U

Inoraanics





































Cyanide, Total

mg/L

...

0.010

U

0.010

u

0.010

u

0.010

u

0.010

u

0.01

U

na



na



Cyanide, WAD

mg/L

0.2

na



na



na



na



na



na



0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

0.045



0.027



0.053



0.032



0.046



0.08



0.0316



0.0428



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

...

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

ria



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

0.028



0.027



0.027



0.027



0.026



0.0266



na



na



. Iron, Dissolved

mg/L

...

1.3



1.2



1.2



1.0



1.3



1.43



na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L

...

na-



na



na



na



na



na



na



na



Methane

pg/L

...

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

—

na



na



na



na



na



na



na"



na



Total Kjeldahl Nitrogen

mg/L

—

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp_gw_2013-10.xlsx

2/-"™,,14	>sk Wells	of 53

f ¦ )	]

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW41-GW-0412 MW41-GW-0413 MW55-GW-1005 MW55-GW-0406 MW55-GW-1006 MW55-GW-0407 MW55-GW-1007 MW55-GW-0408
Standard	10-Apr-2012 09-Apr-2013 13-0ct-2005 11-Apr-2006 11-0ct-2006 17-Apr-2007 10-0ct-2007 15-Apr-2008

VOCs

Units



































Benzene

M9/L

5

1.00

U

0.500

U

1.0

U

1

U

1

U

1

U

1

U

1

U.L1

Toluene

mq/l

1000

1.00

U

1.00

U

1.0

U

1

U

1

U

1

U

1

U

1

U,L1

Ethylbenzene

ng/L

700

1.00

U

1.00

U

1.0

U

1

U

1

U

1

u

1

U

1

U,L1

Xylenes, Total

Mg/L

10000

3.00

U

3.00

U

2.0

U

3

U

3

U

3

u

3

U

3

U,L1

PAHs





































Acenaphthene

"E

r2

914

0.100

U

0.100

U

2.4

U

0.13

U

0.049

U

0.049

u

0.0557

U

0.049

U

Acenaphthylene

Mg/L

362

0.100

U

0.100

U

1.2

U

0.17

U

0.085

U

0.085

u

0.0966

U

0.085

u

Anthracene



...

0.100

U

0.100

U

0.047

U

0.0093

U

0.01

U

0.01

u

0.0114

u

0.01

u

Benzo(a)anthracene

Mg/L

0.13

0.100

U

0.100

U

0.12

U

0.019

U

0.003

U

0.003

U

0.00341

u

0.003

u

Benzo(a)pyrene

Mg/L

0.2

0.100

U

0.100

U

0.12

U

0.019

U

0.032

U

0.032

u

0.0364

u

0.032

u

Benzo(b)fluoranthene

pg/L

0.1

0.100

U

0.100

U

0.047

U

0.037

U

0.013

U

0.013

u

0.0148

u

0.013

u

Benzo(ghi)perylene

Mg/L

—

0.100

U

0.100

U

0.19

U

0.032

U

0.009

U

0.009

u

0.0102

u

0.009

u

Benzo(k)fluoranthene

(jg/L

0.14

0.100

U

0.100

U

0.047

U

0.023

U

0.015

u

0.015

u

0.017

u

0.015

u

Chrysene



0.85

0.100

U

0.100

U

0.12

U

0.02

U

0.005

u

0.005

u

0.00568

u

0.005

u

Dibenzo(a,h)anthracene

M9/L

0.033

0.0170

U,MDL

0.0172

U

0.28

U

0.033

U

0.01

u

0.01

u

0.0114

u

0.01

u

Fluoranthene

ng/L

...

0.100

U

0.100

U

0.12

U

0.032

U

0.01

u

0.01

u

0.0114

u

0.01

u

Fluorene

Mg/L

490

0.100

U

0.100

U

0.24

U

0.029

U

0.01

u

0.01

u

0.0114

u

0.01

u

lndeno(1,2,3-cd)pyrene

MQ/L

0.1

0.100

U

0.100

U

0.12

U

0.038

U

0.007

u

0.007

u

0.00795

u

0.007

u

Naphthalene

MQ/L

1.1

0.100

U

0.100

U

1.2

U

0.1

U

0.248



0.837



0.538



0.054

u

Phenanthrene

Mg/L

294

0.100

U

0.100

U

0.094

U

0.015

U

0.0262

J

0.007

u

0.0757

J

0.007

u

Pyrene

MQ/L

...

0.100

U

0.100

U

0.24

U

0.036

U

0.019

u

0.019

u

0.0504

J

0.019

u

1 -Methylnaphthalene

Mg/L

...

0.100

U

0.100

U

na



na



na



na



na



na



2-Methyl naphthalene

^g/L

61.2

0.100

U

0.100

U

na



na



0.052

(J

0.1

J

0.0591

u

0.052

u

Inoraanics





































Cyanide, Total

mg/L

...

na



na



0.011



0.01

U

0.01

u

0.01

u

0.01

u

0.01

u

Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

na



na



na



na



na



na



Manganese, Total

mg/L

0.775

0.193



0.204



0.046



0.0249



na



na



na



na



Natural Attenuation Parameters





































Nitrate

mg/L

...

na



na



na



na



na



na



na



na



Nitrite

mg/L

—

na



na



na



na



na



na



na



na



Ammonia

mg/L

...

na



na



na



na



na



na



na



na



Manganese, Dissolved

mg/L

...

na



na



0.045



0.017



na



na



na



na



Iron, Dissolved

mg/L

—

na



na



0.042

B

0.1

U

na



na



¦ na



na



Sulfate

mg/L

...

na



na



na



na



na



na



na



na



Sulfide

mg/L

...

na



na



na



na



na



na



na



na



Methane

pg/L

...

na



na



na



na



na



na



na



na



Alkalinity, Total

mg/L

...

na



na



na



na



na



na



na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na



na



na



na



na



na



na



Orthophosphate

mg/L

...

na



na



na



na



na



na



na



na



Total Organic Carbon

mg/L

...

na



na



na



na



na



na



na



na



Chloride

mg/L

...

na



na



na



na



na



na



na



na



icgp gw 2013-10.xlsx
2/11/2014

Bedrock Wells

Page 49 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results





Performance
Standard

MW55-GW-0410
08-Apr-2010

MW55-GW-1010
05-0ct-2010

MW55-GW-0411
12-Apr-2011

MW55-GW-1011
25-Oct-2011

MW55-GW-0412
11-Apr-2012

MW55-GW-1012
09-0ct-2012

MW55-GW-0413
10-Apr-2013

DV

MW55-GW-
22-Oct-2C

VOCs

Units





































Benzene

[jg/L

5

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

0.500

U

UJ

0.500

U

Toluene

pg/L

1000

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U



1.00

U

Ethyl benzene

Mg/L

700

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U

1.00

U



1.00

U

Xylenes, Total

pg/L

10000

6.00

U

3.00

U

3.00

U

3.00

U

3.00

U

3.00

U

3.00

U



3.00

U

PAHs

Acenaphthene

|ig/L

914

0.100

U

0.202



0.422



0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Acenaphthylene

Mg/L

362

0.100

U

0.100

U

0.608



0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Anthracene

|jg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Benzo(a)anthracene

Mg/L

0.13

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Benzo(a)pyrene

pg/L

0.2

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Benzo(b)fluoranthene

ng/L

0.1

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Benzo(ghi)perylene

ng/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Benzo(k)fluoranthene

Mg/L

0.14

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100.

U

Chrysene

pg/L

0.85

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Dibenzo(a,h)anthracene

pg/L

0.033

0.100

U

0.00810

U,MDL

0.170

U.MDL

0.0170

U.MDL

0.0170

U,MDL

0.0130

U,MDL

0.0173

U



0.0173

U

Fluoranthene

pg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Fluorene

ug/L

490

0.0380

J,MDL

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

lndeno(1,2,3-cd)pyrene

M9/t-

0.1

¦ 0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Naphthalene

ug/L

1.1

0.100

U

0.672



1.20



0.100

U

0.172



0.100

U

0.113



J+

0.100

U

Phenanthrene

i-tg/t-

294

0.100

U

0.100

U

0.195



0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Pyrene

pg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

1 -Methylnaphthalene

ug/L

...

0.100

U

0.704



2.91

U

0.100

U

0.100

U

0.100

U

0.131



J+

0.100

U

2-Methylnaphthalene

ug/L

61.2

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U



0.100

U

Inoraanics







































Cyanide, Total

mg/L

...

na



na



na



na



na



na



na





na



Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

0.0100

U

0.0100

U

0.0100

U

0.0100

U

0.0100

U



0.0100

U

Manganese, Total

mg/L

0.775

0.0187



0.0100

U

0.0135



0.0103



0.0214



0.0128



0.0107





0.0100

U

Natural Attenuation Parameters







































Nitrate

mg/L

...

0.10

U

0.10

U

0.10

U

0.10

U

0.100

U

0.100

u

0.100

U



na



Nitrite

mg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

u

0.100

U



na



Ammonia

mg/L

...

1.43



1.41



1.49



1.44



1.48



1.41



1.54





na



Manganese, Dissolved

mg/L

...

0.0184



0.0100

U

0.0129



0.0100

U

0.0130

R

0.0112



0.0100

U



na



Iron, Dissolved

mg/L

...

0.380



0.234



0.127



0.100

U

0.103



0.108



0.100

U



na



Sulfate

mg/L

...

89.5



36.2



89.6



86.7



90.3



94.8



87.2





na



Sulfide

mg/L

...

5.00

U

5.00

U

16



10

U

10

U

10

u

10.0

U



na



Methane

pg/L

...

26.0

U

26.0

U

1-.5



2.1



1.9



3.1



2.58





na



Alkalinity, Total

mg/L

...

432



402



393



390



385



375



410





na



Total Kjeldahl Nitrogen

mg/L

...

1.77



1.54



1.83



1.92



1.58



1.70



1.79





na



Orthophosphate

mg/L

...

0.100

U

0.100

U

0.100

U

0.100

U

0.100

U

0.100

u

0.100

U



na



Total Organic Carbon

mg/L

...

1.00

U

1.00

U

na



1.00

U

na



na



na





na



Chloride

mg/L

...

2.00

U,RL1

2.00

U,RL1 '

- na



na



na



na



na





na



icgp_gw_2013-10.xlsx

2h~»wv|4	Bp^ck Wells	Pp~~-50 of 53

/ > < \ ,

I

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW56-GW-1011 MW56-GW-1011 MW56-GW-0412 MW56-GW-1012 MW56-GW-0413 MW56-GW-1013 MW57-GW-1011
Standard	27-Jul-2011	24-Oct-2011	10-Apr-2012	09-0ct-2012 09-Apr-2013 22-Oct-2013 27-Jul-2011

DV	DV	DV	DV	DV

VOCs

Units







































Benzene

Pg/L

5

1.00

U

1.00

U



1.00

U



1.00

U



0.500

U

UJ

0.500

U

1.00

u

Toluene

pg/L

1000

1.00

U

1.00

U



1.00

U



1.00

U



1.00

U

UJ

1.00

U

1.00

u

Ethylbenzene

Pg/L

700

1.00

u

1.00

U



1.00

U



1.00

U



1.00

U

UJ

1.00

U

1.00

u

Xylenes, Total

pg/L

10000

3.00

u

3.00

U



3.00

U



3.00

U



3.00

U

UJ

3.00

U

3.00

u

PAHs









































Acenaphthene

ng/L

914

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Acena.phthylene

ug/L

362

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Anthracene

ug/L

...

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Benzo(a)anthracene

pg/L

0.13

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Benzo(a)pyrene

pg/L

0.2

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Benzo(b)fluoranthene

pg/L

0.1

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

u

UJ

0.100

U



0.100

U

0.100

u

Benzo(ghi)perylene

pg/L

...

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Benzo(k)fluoranthene

pg/L

0.14

0.100

u

. 0.100

U

UJ

0.100

U

UJ

0.100

u

UJ

0.100

U



0.100

U

0.100

u

Chrysene

pg/L

0.85

0.100

u

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Diben^o(a,h)anthracene

pg/L

0.033

0.0170

U.MDL

0.0170

U,MDL

UJ

0.0170

U,MDL

UJ

0.0130

U.MDL

UJ

0.0172

U



0.0173

U

0.0170

U.MDL

Fluoranthene

ng/L

...

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

u

Fluorene

pg/L

490

0.100

U

0.100

U-

UJ

. 0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

U

0.100

U

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.100

U

Naphthalene

pg/L

1.1

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.287



Phenanthrene

pg/L

294

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.100

U

Pyrene

pg/L

...

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.100

U

1 -Methylnaphthalene

pg/L

...

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.105



2-Methylnaphthalene

pg/L

61.2

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

UJ

0.100

U



0.100

u

0.112



Inoraanics









































Cyanide, Total

mg/L

...

na



na





na





na





na





na



na



Cyanide, WAD

mg/L

0.2

0.0100

U

0.0100

U

UJ

0.0100

U



0.0100

U



0.0100

U



0.0100

u

0.0100

U

Manganese, Total

mg/L

0.775

0.130



0.123





0.0673



J+

0.0875





0.0792





0.0713



0.605



Natural Attenuation Parameters









































Nitrate

mg/L

...

na



na





0.100

U



0.100

U



0.100

U



na



na



Nitrite

mg/L

...

na



na





0.100

U



0.100

U



0.100

U



na



na



Ammonia

mg/L

...

na



na





1.1





1.04-





1.13





na



na



Manganese, Dissolved

mg/L

...

na



na





0.0821





0.0840





0.0764





na



na



Iron, Dissolved

mg/L

...

na



na





1.4





1.70





1.670





na



na



Sulfate

mg/L

...

na



na





66.9





67.4





60.5





na



na



Sulfide

mg/L

...

na



na





10

U



10

U



10.0

U



na



na



Methane

pg/L

...

na



na





11





10





9.84





na



na



Alkalinity, Total

mg/L

...

na



na





370





370





410





na



na



Total Kjeldahl Nitrogen

mg/L

...

na



na





1.33





1.22





1.11





na



na



Orthophosphate

mg/L

...

na



na





0.100

U



0.100 .

U



0.100

U



na



na



Total Organic Carbon

mg/L

...

na



na





na





na





na





na



na



Chloride

mg/L

...

na



na





na





na





na





na



na



icgp_gw_2013-10.xlsx
2/11/2014

Bedrock Wells

Page 51 of 53

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Performance MW57-GW-1011 MW57-GW-0412 MW57-GW-1012 MW57-GW-0413 MW57-GW-1013
Standard 24-Oct-2011	10-Apr-2012	09-0ct-2012 09-Apr-2013 22-Oct-2013

DV	DV	DV

VOCs

Units



























Benzene

pg/L

5

1.00

U

1.00

U



1.00

U



0.500

U

0.500

U

Toluene

pg/L

1000

1.00

U

1.00

U



1.00

U



1.00

U

1.00

U

Ethylbenzene

ng/L

700

1.00

u

1.00

u



1.00

U



1.00

U

1.00

U

Xylenes, Total

Mg/L

10000

3.00

u

3.00

u



3.00

U



3.00

U

3.00

U

PAHs





























Acenaphthene

pg/L

914

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Acenaphthylene

pg/L

362

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Anthracene

pg/L

...

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Benzo(a)anthracene

pg/L

0.13

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Benzo(a)pyrene

|jg/L

0.2

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Benzo(b)fluoranthene

pg/L

0.1

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Benzo(ghi)perylene

pg/L

...

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Benzo(k)fluoranthene

pg/L

0.14

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Chrysene

fjg/L

0.85

0.100

u

0.100

u

UJ

0.100

U

UJ

0.100

U

0.100

U

Dibenzo(a,h)anthracene

Mg/L

0.033

0.0170

U.MDL

0.0170

U,MDL

UJ

0.0130

U.MDL

UJ

0.0173

U

0.0173

U

Fluoranthene

pg/L

...

0.100

U

0.100-

U

UJ

0.100

U

UJ

0.100

U

0.100

U

Fluorene

pg/L

490

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

lndeno(1,2,3-cd)pyrene

pg/L

0.1

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

Naphthalene

pg/L

1.1

0.126



0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

Phenanthrene

ng/L

294

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

Pyrene

Hg/L

...

¦ 0.100

U

0.100

U

UJ

0.100

U

UJ ¦

0.100

U

0.100

U

1-Methylnaphthalene

pg/L

...

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

2-Methylnaphthalene

pg/L

61.2

0.100

U

0.100

U

UJ

0.100

U

UJ

0.100

U

0.100

U

Inoraanics





























Cyanide, Total.

mg/L

...

na



na





na





na



na



Cyanide, WAD

mg/L

0.2

0.0100

U UJ.

0.0100

U



0.0100

U



0.0100

U

0.0100

U

Manganese, Total

mg/L

0.775

0.317



0.18





0.246





0.216



0.225



Natural Attenuation Parameters





























Nitrate

mg/L

...

na



0.1

u



0.100

U



0.100

U

na



Nitrite

mg/L

...

na



0.1

u



0.100

U



0.100

U

na



Ammonia

mg/L



na



1.5





1.40





1.55



na



Manganese, Dissolved

mg/L

...

na



0.228





0.198





0.195



na



Iron, Dissolved

mg/L

...

na



1.28





1.37





1.520



na



Sulfate

mg/L

...

na



120





132





120



na



Sulfide

mg/L

...

na



10 ¦

u



10

U



28.3



na '



Methane

Mg/L

...

na



10





11





12.8



na



Alkalinity, Total

mg/L

...

na



355





360





376



na



Total Kjeldahl Nitrogen

mg/L

...

na



1.78





1.79





1.72



na



Orthophosphate

mg/L

...

na



0.1

U-



0.100

U



0.100

U

na



Total Organic Carbon

mg/L

...

na



na





na





na



na



Chloride

mg/L

...

na



•' na





na





na



na



icgp_gw_2013-10.xlsx

Bf—'k Wells	P,~ "~»52 of 53

^ ( ') '' \

-------
Iowa City, Iowa Former Manufactured Gas Plant Site
MidAmerican Energy Company

Groundwater Analytical Results

Notes:

na = not analyzed.

ns = not sampled, insufficient water.

nc = RPD not calculated.

RPD = Relative Percent Difference.

mg/L = milligrams per liter.

|jg/L = microgram per liter.

Laboratory Qualifiers

* = Batch QC exceeds upper or lower control limits.

8 = Analyte was detected in the associated Method Blank.

B1 = Analyte was detected in the associated Method Blank. Analyte concentration in the sample is greater than 10x the concentration found in the Method Blank.

C9 = Calibration Verification recovery was outside the method control limits for this analyte. The LCS for this analyte met CCV acceptance criteria, and was used to validate the batch.

CN5 = Sample found to contain Sulfide. The sulfide was treated and removed prior to distillation.

ET = Matrix interference in sample is causing an endpoint timeout.

H = Sample analysis performed past method-specified holding time.

H2 = Initial analysis within holding time. Reanalysis verification was past holding time.

J = Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

Ja = Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

L1 = Laboratory Control Sample and/or Laboratory Control Sample Duplicate recovery was outside control limits.

M1 = The MS and/or MSD were outside control limits.

MDL = Results calculated/entered to the method detection limit (MDL).

MHA = Due to high levels of analyte in the sample, the MS/MSD calculation does not provide useful spike recovery information.

P2 = Sample adjusted to method prescribed pH range prior to analysis.

R = Sample duplicate RPD exceeded the laboratory control limit.

RL1 = Reporting limit raised due to sample matrix effects.

S3 = Post digestion spike is out of acceptance limits for this analyte.

U = Indicates the analyte was analyzed for but not detected.

U* = Indicates the analyte was analyzed for but not detected. Batch QC exceeds the upper or lower control limits.

Ua = Analyte was not detected at or above the stated limit. Concentration is below the method reporting limit.

Z6 = Surrogate recovery was outside control limits.

ZX = Due to sample matrix effects, the surrogate recovery was outside the control limits.

Data Validation (DV) Qualifiers

B = The analyte was found in an associated blank, as well as in the sample at a concentration greater than 5 times (or 10 times for common laboratory contaminants) that detected in an associated blank.
J = The analyte was positively identified; the quantitation is an estimation.

J+ = The analyte was positively identified; the quantitation is an estimation with a potential high bias.

J- = The analyte was positively identified; the quantitation is an estimation with a potential low bias.

UB = The analyte is considered not detected; the concentration in the sample was less than 5 times (or 10 times for common laboratory contaminants) that detected in an associated blank.

UJ = The analyte was analyzed for, but not detected. Due to a QC deficiency identified during data validation, the value reported may not accurately reflect the sample quantitation limit.

Data collected as part of the Remedial Action qualified in accordance with the January 2009 Quality Assurance Project Plan.

icgp_gw_2013-10.xlsx
2/11/2014

Notes

Page 53 of 53

-------
ATTACHMENT 3
Sediment Sampling Results

-------
/*—\

TABLE 4-1

RALSTON CREEK - SEDIMENT ANALYTICAL RESULTS
MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE - IOWA CITY, IOWA





RC04

RC04

RC04

RC04

RC04

RC04







RC04-RS

RC-04-RS DUP

RC04-SD-0410

RC04-SD-1010

DP01-SD-1010

RC04-SD-1111





Performance

9/17/2002

9/17/2002

4/8/2010

10/5/2010

10/5/2010

11/11/2011



Units

Standard

0-0.5 feet

0-0.5 feet

0-0.5 feet

0-0.5 feet

0-0.5 feet

0-0.5 feet

DV

Polynuclear Aromatic Hydrocarbons (PAHs)

Acenaphthene

mg/kg

—

0.021



<0.2

U

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1



Acenaphthylene

mg/kg

...

<0.04

U

<0.39

U

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Anthracene

mg/kg

0.845

0.0071



<0.04

U

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U,RL1,M1

UJ

Benzo(a)anthracene

mg/kg

1.050

0.013

J

0.052

J

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Benzo(a)pyrene

mg/kg

1.450

. 0.059

J

0.08



<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Benzo(b)fluoranthene

mg/kg

...

0.068



0.087



<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

0.179

RL1.M1

J+.J-.J

Benzo(ghi)perylene

mg/kg

_

0.029



0.037

J

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Benzo(k)fluoranthene

mg/kg

...

0.011

J

0.029

J

<0.353

U.RL1

<0.117

U,RL1

<0.117

U.RL1

<0.171

U.RL1

UJ

Chrysene

mg/kg

1.290

<0.0041

U

0.066



<0.353

U.RL1

<0.117

U,RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Dibenzo(a,h)anthracene

mg/kg

...

0.017



<0.12

U

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1

UJ

Fluoranthene

mg/kg

2.230

0.041

J

0.21



<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

0.291

RL1.M1

J+.J-.J

Fluorene

mg/kg

0.536

<0.018

U

<0.180

U

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1 ,M1



lndeno(1,2,3-cd)pyrene

mg/kg

...

0.015



0.014

J

<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Naphthalene

mg/kg

0.561

0.20



<0.59

U

11.3

RL1

0.259

RL1

0.161

RL1

<0.171

U.RL1



Phenathrene

mg/kg

1.170

0.056



0.14



<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

<0.171

U.RL1.M1

UJ

Pyrene

mg/kg

1.520

0.059



0.14



<0.353

U.RL1

<0.117

U.RL1

<0.117

U.RL1

0.227

RL1.M1

J+.J-.J

2-Methylnaphthalene

mg/kg



na



na



0.363

RL1

0.363

RL1

0.363

RL1

<0.171

U.RL1



Total PAHs

mg/kg

22.8

0.435



0.687



11.300



0.259



0.161



0.518





Page 1 of 4

-------
TABLE 4-1

RALSTON CREEK - SEDIMENT ANALYTICAL RESULTS
MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE - IOWA CITY, IOWA

RC04	RC04	RC04	RC05	RC05	RC05

DP01-SD-1111	RC04-SD-1112	RC04-SD-1013	RC05-RS	RC05-SD-0410	DP01-SD-0410

Performance 11/11/2011	11/8/2012	10/24/2013	9/17/2002	4/8/2010	4/8/2010

Units Standard 0-0.5 feet	0-0.5 feet	0-0.5 feet DV	0-0.5 feet	0-0.5 feet	DV 0-0.5 feet

Polynuclear Aromatic Hydrocarbons (PAHs)

Acenaphthene

mg/kg

—

<0.586

U.RL1

<0.516

U.RL1

<0.130

U

0.93



<0.128

U.RL1.M1

<0.135

U.RL1

Acenaphthylene

mg/kg

...

<0.586

U,RL1

<0.516

U.RL1

<0.130

U

<0.43

U

<0.128

U.RL1

<0.135

U.RL1

Anthracene

mg/kg

0.845

<0.586

U.RL1 ,M1

<0.516

U.RL1

<0.130

U

0.10



<0.128

U.RL1

<0.135

U.RL1

Benzo(a)anthracene

mg/kg

1.050

<0.586

U,RL1

<0.516

U.RL1

<0.130

U

0.18



<0.128

U.RL1

0.221

RL1

Benzo(a)pyrene

mg/kg

1.450

<0.586

U,RL1

<0.516

U.RL1

<0.130

U

0.19



<0.128

U.RL1

0.222

RL1

Benzo(b)fluoranthene

mg/kg

—

<0.58.6

U.RL1 ,M1

<0.516

U.RL1

<0.130

U

0.25



<0.128

U.RL1

0.271

RL1

Benzo(ghi)perylene

mg/kg

...

<0.586

U,RL1

<0.516

U.RL1

<0.130

U

0.055

J

<0.128

U.RL1

0.152

RL1

Benzo(k)fluoranthene

mg/kg

...

<0.586

U.RL1

<0.516

U.RL1

<0.130

U

0.088



<0.128

U.RL1

<0.135

U.RL1

Chrysene

mg/kg

1.290

<0.586

U.RL1

<0.516

U.RL1

<0.130

U

0.11



<0.128

U.RL1

0.196

RL1

Dibenzo(a,h)anthracene

mg/kg

...

<0.586

U.RL1

<0.516

U.RL1

<0.130

U

<0.13

U

<0.128

U.RL1

<0.135

U.RL1

Fluoranthene

mg/kg

2.230

<0.586

U.RL1.M1

<0.516

U.RL1

<0.130

U

0.35



0.176

RL1.M1 J+

0.544

RL1

Fluorene

mg/kg

0.536

<0.586

U.RL1

<0.516

U,RL1

<0.130

U

0.20



<0.128

U.RL1

<0.135

U,RL1

lndeno(1,2,3-cd)pyrene

mg/kg

...

<0.586

U.RL1

<0.516

U.RL1

<0.130

U

0.10



<0.128

U.RL1

<0.135

U.RL1

Naphthalene

mg/kg

0.561

<0.586

U.RL1

<0.516

U.RL1

0.421

J,J+

0.74



0.403

RL1.L1.M1 J-

0.233

RL1.L1

Phenathrene

mg/kg

1.170

<0.586

U,RL1

<0.516

U,RL1

<0.130

U

0.40



<0.128

U.RL1

0.236

RL1

Pyrene

mg/kg

1.520

<0.586

U.RL1.M1

<0.516

U.RL1

<0.130

U

0.38



0.136

RL1

0.407

RL1

2-Methylnaphthalene

mg/kg

...

<0.586

U.RL1

<0.516

U,RL1

<0.130

U

na



<0.128

U.RL1

<0.135

U,RL1

Total PAHs

mg/kg

22.8

0.000



0.000



0.421



2.650



0.715



2.059



-------
TABLE 4-1

RALSTON CREEK - SEDIMENT ANALYTICAL RESULTS
MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE - IOWA CITY, IOWA

RC05	RC05	RC05	RC05	RC05	RC05

RC05-SD-1010	RC05-SD-1111	RC05-SD-1112	DP01-SD-1112	RC05-SD-1013	DP01-SD-1013

Performance 10/5/2010	11/11/2011	11/8/2012	11/8/2012	10/24/2013	10/24/2013

Units Standard 0-0.5 feet	0-0.5 feet	DV 0-0.5 feet	0-0.5 feet	0-0.5 feet	0-0.5 feet

Polynuclear Aromatic Hydrocarbons (PAHs)

Acenaphthene

mg/kg

—

0.199

RL1.M1

<0.552

U.RL1



<0.580

U.RL1

0.663

RL1

<0.116

U

<0.116

U

Acenaphthylene

mg/kg

...

<0.117

U.RL1

<0.552

U.RL1



<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Anthracene

mg/kg

0.845

0.118

RL1.M1

0.593

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Benzo(a)anthracene

mg/kg

1.050

<0.117

U.RL1.M1

1.60

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Benzo(a)pyrene

mg/kg

1.450

<0.117

U.RL1.M1

1.20

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Benzo(b)fluoranthene

mg/kg



<0.117

U.RL1 ,M1

1.70

RL1

J+

<0.580

U;RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Benzo(ghi)perylene

mg/kg

—

<0.117

U.RL1 ,M1

0.653

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Benzo(k)fluoranthene

mg/kg

...

<0.117

U.RL1

<0.552

U.RL1



<0.580

U,RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Chrysene

mg/kg

1.290

<0.117

U.RL1

1.38

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Dibenzo(a,h)anthracene

mg/kg

...

<0.117

U.RL1

<0.552

U.RL1



<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Fluoranthene

mg/kg .

2.230

0.125

RL1.M1

3.14

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Fluorene

mg/kg

0.536

<0.117

U.RL1.M1

<0.552

U.RL1



<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

lndeno(1,2,3-cd)pyrene

mg/kg

...

<0.117

U.RL1.M1

0.572

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Naphthalene

mg/kg

0.561

0.894

RL1.M1

1.57

RL1:

J+

3.94

RL1

4.47

RL1

0.204



0.277



Phenathrene

mg/kg

1.170

0.39

RL1.M1

2.37

RL1

J+

<0.580

U.RL1

<0.560 ¦

U.RL1

<0.116

u

<0.116

U

Pyrene

mg/kg

1.520

<0.117

U.RL1

2.26

RL1

J+

<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

2-Methylnaphthalene

mg/kg

...

<0.117

U.RL1.M1

<0.552

U.RL1



<0.580

U.RL1

<0.560

U.RL1

<0.116

u

<0.116

U

Total PAHs

mg/kg

22.8

1.527



14.113





3.94



4.47



0.204



0.277



Page 3 of 4

-------
TABLE 4-1

RALSTON CREEK - SEDIMENT ANALYTICAL RESULTS
MIDAMERICAN ENERGY COMPANY
FORMER MANUFACTURED GAS PLANT SITE - IOWA CITY, IOWA

Notes:

< = Less than.

mg/kg = Milligram(s) per kilogram,
na = Constituent not analyzed.

Concentrations above Performance Standard in bold font.

PAH = Polynuclear aromatic hydrocarbon.

Laboratory Qualifiers

U = Compound not detected above reporting limit.

J = Estimated value below reporting limit.

L1 = Laboratory Control Sample and/or Laboratory Control Sample Duplicate recovery was outside control limits.

M1 = The matrix spike (MS) and/or matrix spike duplicate (MSD) were outside control limits.

RL1 = Reporting limit raised due to sample matrix effects.

Data Validation (DV) Qualifiers

J = The analyte was positively identified; the quantitation is an estimation.

J+ = The analyte was positively identified; the quantitation is an estimation with a potential high bias.

J- = The analyte was positively identified; the quantitation is an estimation with a potential low bias.

UJ = The analyte was analyzed for, but not detected. Due to a quality control (QC) deficiency identified during data validation, the value reported may not accurately reflect the sample quantitation

-------
Attachment 4

Groundwater Contaminants of Concern Trend Analysis Summary

-------
TABLE 3-2

STATISTICAL SUMMARY
MIDAMERICAN ENERGY COMPANY]

FORMER MANUFACTURED GAS PLANT SITE - IOWA CITY, IOWA

Performance Standard 5 1000 700 10000

914 362 0.13

0.14 0.85 0.033 490 0.1 1.1 294.0 61.2

775 0.200

Compliance Wells
MW-7	UCL <1

Trend NT

MW-29

MW-33

MW-35

MW-41

MW-56

MW-57

UCL <1
Trend NT

UCL <1
Trend NT

UCL <1
Trend NT

UCL <1
T rend NT

UCL <1
Trend NT

UCL

MW-12
MW-13
MW-16
MW-18
MW-19
MW-20
MW-23
MW-25
MW-31
MW-36
MW-37
MW-55

<1

Trend NT

7/ Zone Wells
MW-3	Trend D90

Trend	NT

Trend	D90

Trend	NT

Trend	NT

Trend	D90

Trend	190

Trend	NT

T rend	190

Trend	190

Trend	190

Trend	190

Trend	NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

NT

NT
D90
NT
NT
NT
NT
NT
NT
190
NT
NT
NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

<1
NT

190

NT
D90
NT
NT
NT
NT
NT
NT
190
NT
NT
NT

<3
NT

<3
NT

<3
NT

<3
NT

<3
NT

<3
NT

<3
NT

NT
NT
D90
NT
NT
NT
NT
D90
NT
190
NT
NT
NT

<0.1 <0.1
NT NT

<0.1
NT

<0.1
NT

<0.1 <0.1
NT NT

0.149 <0.1
NT NT

<0.1 <0.1
NT NT

<0.1 <0.1
NT NT

<0.1 <0.1
NT NT

D90	190

NT	NT

D90	D90

NT	NT

NT	NT

D90	D90

D90	D90

D90	D90

NT	NT

NT	NT

190	190

190	190

NT	NT

<0.1
NT

<0.1
NT

<0.1

m

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

NT
NT
D90
NT
NT
NT
D90
NT
NT
NT
D90
190
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1 <0.017
NT NT

<0.1
NT

<0.1 <0.1 <0.017 <0.1
NT NT . NT NT

<0.1 <0.1 <0.017 <0.1
NT NT NT NT

NT	NT

NT	NT

D90	NT

190	190

NT	NT

NT	NT

NT	NT

NT	NT

NT	NT

D90	D90

NT	D90

NT	NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1 <0.1
NT NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1 <0.1 <0.017 0.077 <0.1 0.495 0.055 0.092
NT NT NT NT NT 190 NT NT

<0.1
NT

<0.1
NT

<0.1
NT

<0.1 <0.017 <0.1
NT NT NT

<0.1 <0.017
NT NT

<0.1
NT

<0.1 <0.017 <0.1
NT NT NT

<0.1
NT

<0.1
NT

<0.1
NT

NT	NT

NT	NT

NT	D90

190	190

NT	NT

NT	NT

NT	NT

NT	NT

NT	NT

D90	D90

NT	D90

NT	NT

NT NT NT NT

NT
NT
NT
190

NT
NT
NT
NT
NT
D90
NT
NT
NT

NT	NT

NT	NT

D90	D90

D90	190

NT	NT

D90	NT

D90	NT

D90	NT

D90	NT

NT	D90

NT	NT

190	NY

NT	NT

<0.1
NT

<0.1
NT

0.215
D90

D90
| NT
D90
NT
190
D90
NT
D90
NT
NT
NT
190
NT

<0.1
NT

<0.1
NT

<0.1
NT

NT

NT
D90
D90
190
D90
NT
NT
NT
NT
D90
NT
NT

<0.1
NT

<0.1
NT

<0.1
NT

D90
NT
D90
D90
NT
D90
NT
NT
D90
190
NT
NT
NT

8764

D90

134 <0.01
D90 NT

426
D90

535 <0.01
190 NT

181
NT

115
D90

427
NT

D90
NT
D90
NT
D90
D90
D90
NT
D90
D90
NT
NT
D90

Notes:

NT = No statistically significant trend at greater than or equal to 90-percent confidence level.

D90 ss Decreasing trend at greater than or equal to 90-percent confidence level.

I90 - Increasing trend at greater than or equal to 90-percent confidence level.

All concentration units in micrograms per liter except for cyanide, which is in milligrams per liter.

Statistical summary based on samples collected through October 2013.

UCL = 95 Percent Upper Confidence Limit.

Calculated UCLs that exceed the respective Performance Standard and increasing trends are shown in red text.
PAHs - Polynuclear aromatic hydrocarbons.

Tl = Technical Impractibility.

VOCs = Volatile orga lie compounds.

Page 1 of 1

-------
ATTACHMENT 5
Five-Year Review Inspection Form

-------
Attachment 5
FIVE-YEAR REVIEW INSPECTION FORM

I. SITE INFORMATION

Site name: Iowa City FMGP

Date of inspection: July 7, 2014

Location: Iowa City, Iowa

EPA ID: IAD984591172

Agency, office, or company leading the five-year
review: EPA-Region 7

Weather/temperature: Sunny and mid-80s

Remedy Includes: (Check all that apply)

~	Landfill cover/containment

~	Access controls
IHI Institutional controls

~	Groundwater pump and treatment

~	Surface water collection and treatment

IE Other LNAPL recovery and air monitoring

IE! Monitored natural attenuation

~	Groundwater containment

~	Vertical barrier walls

Attachments: ~ Inspection team roster attached

~ Site map attached

II. INTERVIEWS (Check all that apply)

1. O&M site manager Kevin Armstrong

Name

Project Manager. MWH
Title

7-7-14

Date

Interviewed IE at site ~ at office ~ by phone Phone no. 515-251-1023
Problems, suggestions; ~ Report attached	

Other interviews (optional) ~ Report attached.



Bryan Clark, Owner, Iowa-Illinois Square apartments-granter access to building crawlspace and discussed on-
going air monitoring in the building

Jennifer Mclvor, Environmental Manager, MidAmerican Energy Company-manages remedial action activities for
all actions except air monitoring in Iowa-Illinois Square

Ron Knoche, City Engineer, City of Iowa City-Engineering office oversees maintenance of Ralston Creek and
directs Public Works to conduct needed maintenance.

Ben Clark, Senior Civil Engineer, City of Iowa City

III. DOCUMENTS & RECORDS VERIFIED (Check all that apply)

1. O&M Documents

IE O&M manual

~	As-built drawings

~	Maintenance logs
Remarks

~	Readily available

~	Readily available

~	Readily available

IE Up to date ~ N/A

~	Up to date IS N/A

~	Up to date IE N/A

-------
2.

Site-Specific Health and Safety Plan IE] Readily available IEI Up to date
~ Contingency plan/emergency response plan ~ Readily available ~ Up to date
Remarks

~	N/A

~	N/A







3.

O&M and OSHA Training Records IEI Readily available Kl Up to date
Remarks

~ N/A







4.

Permits and Service Agreements

~	Air discharge permit ~ Readily available ~ Up to date

~	Effluent discharge ~ Readily available ~ Up to date

~	Waste disposal, POTW ~ Readily available ~ Up to date

~	Other permits ~ Readily available ~ Up to date
Remarks

IE N/A
IE N/A
IE N/A
IE N/A







5.

Groundwater Monitoring Records IEI Readily available IEI Up to date
Remarks

~ N/A







IV. O&M COSTS

1.

O&M Organization

~	State in-house ~ Contractor for State

~	PRP in-house IE Contractor for PRP

~	Federal Facility in-house ~ Contractor for Federal Facility

~	Other MidAmerican contracts with MWH for O&M work. Buildine owner contracts with Stanley



Consultants for O&M work.









2.

O&M Cost Records

IE Readily available IE Up to date



3.

Unanticipated or Unusually High O&M Costs During Review Period

Describe costs and reasons: See description in FYR Report.

































V. ACCESS AND INSTITUTIONAL CONTROLS IE Applicable ~ N/A

A.

Fencing



1.

Fencing damaged ~ Location shown on site map ~ Gates secured IE N/A
Remarks









B.

Other Access Restrictions



1.

Signs and other security measures ~ Location shown on site map IE N/A
Remarks









-------
C. Institutional Controls (ICs)

1. Implementation and Enforcement

Site conditions imply ICs not properly implemented	~ Yes 13 No ~ N/A

Site conditions imply ICs not being fully enforced	~ Yes 13 No ~ N/A

Type of monitoring (e.g., self-reporting, drive by) self-reported	

Frequency annually	

Responsible party/agency City and owner of Iowa-Illinois Square	

Reporting is up-to-date IE Yes ~ No ~ N/A
Reports are verified by the lead agency IE Yes ~ No ~ N/A
Specific requirements in deed or decision documents have been met IE Yes ~ No ~ N/A
	Violations have been reported	~ Yes ~ No IE N/A

2. Adequacy	IE ICs are adequate ~ ICs are inadequate . ~ N/A

Remarks

D. General

1. Vandalism/trespassing ~ Location shown on site map IE No vandalism evident
Remarks

2. Land use changes on site IE N/A

Remarks

3. Land use changes off site ~ N/A

Remarks One adjacent property and one near-bv property have changed from commercial uses to multi-
family dwellings.	

VI. GENERAL SITE CONDITIONS

A. Roads	~ Applicable IE N/A

B. Other Site Conditions

Remarks _Apartment building and surroundings in good condition. Creek liner exhibiting some missing
tiles and creek banks have significant woody growth that the city has agreed to remove.	

VII. LANDFILL COVERS ~ Applicable IE N/A

VIII. VERTICAL BARRIER WALLS

~ Applicable IE N/A



IX. GROUNDWATER/SURFACE WATER REMEDIES IE Applicable

~ N/A

A. Groundwater Extraction Wells, Pumps, and Pipelines

~ Applicable IE

N/A

B. Surface Water Collection Structures, Pumps, and Pipelines

~ Applicable IE

N/A

C. Treatment System ~ Applicable IE N/A

D. Monitored Natural Attenuation

1. Monitoring Wells (natural attenuation remedy)

IE Properly secured/locked	IE Functioning IE Routinely sampled IE Good condition

IE All required wells located ~ Needs Maintenance	~ N/A

Remarks

<

-------
	X. OTHER REMEDIES	

A.	LNAPL Recovery-Recovery occurs in designated monitoring wells and removal and replacement of absorbent

socks has been observed in the past but was not observed during this inspection. Monitoring wells were
observed to be in good condition.

B.	Air Monitoring and Crawlspace Barrier and Passive Vent Inspection-Air monitoring occurs in the

apartment crawlspace. Crawlspace liner and gravel cover were observed to be in good condition. Vents were
not obstructed.

C.	Creek Liner Inspection-Creek liner condition was reviewed with City Engineering staff and MidAmerican

Energy manager and consultant. City was requested to remove woody growth from eastern bank of creek
adjacent to site and consider more aggressive maintenance of the tile liner. Liner is missing in some areas,
most notably along freeze-thaw line.	

XI. OVERALL OBSERVATIONS

A. Implementation of the Remedy

Describe issues and observations relating to whether the remedy is effective and functioning as designed.
Begin with a brief statement of what the remedy is to accomplish (i.e., to contain contaminant plume,
minimize infiltration and gas emission, etc.).

All aspects of the remedy appear to be functioning as intended and designed.	

B. Adequacy of O&M

Describe issues and observations related to the implementation and scope of O&M procedures. In
particular, discuss their relationship to the current and long-term protectiveness of the remedy.
O&M appears to be effective except for maintenance of vegetation removal on the banks of Ralston
Creek. The city engineering office has committed to improving control of vegetation on the creek bank
near the site. Thev committed to investigating improved maintenance of the tile liner in the creek near
the site.

C. Early Indicators of Potential Remedy Problems

Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high
frequency of unscheduled repairs that suggest that the protectiveness of the remedy may be compromised
in the future.

None

-------