FIFTH FIVE-YEAR REVIEW REPORT FOR
MYSTERY BRIDGE RD/U.S. HIGHWAY 20 SUPERFUND SITE
NATRONA COUNTY, WYOMING

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Prepared by

U.S. Environmental Protection Agency
Region 8
Denver, Colorado

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Betsy Smidinger, Director
Superfund and Emergency Management Division

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Table of Contents

LIST 01 ABBREVIATIONS AND ACRONYMS	4

I.	INTRODUCTION	5

Site Background	5

FIVE-YEAR REVIEW SUMMARY FORM	6

II.	RESPONSE ACTION SUMMARY	8

Basis for Taking Action	8

Response Actions	8

Status of Implementation	10

Systems Operations/Operation and Maintenance (O&M)	11

III.	PROGRESS SINCE THE PREVIOUS REVIEW	13

IV.	FIVE-YEAR REVIEW PROCESS	14

Community Notification, Community Involvement and Site Interviews	14

Data Review	14

Site Inspection	15

V.	TECHNICAL ASSESSMENT	17

QUESTION A: Is the remedy functioning as intended by the decision documents?	17

QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of the

remedy selection still valid?	17

QUESTION C: Has any other information come to light that could call into question the protectiveness of the
remedy?	18

VI.	ISSUES/RECOMMENDATIONS	18

OTHER FINDINGS	18

VII.	PROTECTIVENESS STATEMENT	18

VIII.	NEXT REVIEW	19

APPENDIX A - REFERENCE LIST	A-l

APPENDIX B - SITE CHRONOLOGY	B-l

APPENDIX C - PRESS NOTICE	C-l

APPENDIX D - INTERVIEW FORMS	D-l

APPENDIX E - SITE INSPECTION CHECKLIST	E-l

APPENDIX F - SITE INSPECTION PHOTOS	F-l

APPENDIX G - DETAILED ARARS REVIEW TABLES	G-l

APPENDIX H - SCREENING-LEVEL RISK REVIEW	11-1

APPENDIX I - INSTITUTIONAL CONTROLS	1-1

Tables

Table 1: RAOs and Remedy Components	9

Table 2: Groundwater COC Cleanup Goals	9

Table 3: Summary of Institutional Controls (ICs)	11

Table 4: Protectiveness Determinations/Statements from the 2014 FYR	13

Table 5: Status of Recommendations from the 2014 FYR	13

Table B-l: Site Chronology	B-l

Table G-l: ARAR Review for Groundwater COCs	G-l

Table H-l: Summary of Screening Level Vapor Intrusion Evaluation for the Dow/DSI Property	H-l

Table H-2: Risk Evaluation of Soil Cleanup Levels	H-l

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Table H-3: Screening-Level Human Health Evaluation of 1,4-Dioxane Concentrations in Groundwater	H-2

Figures

Figure 1: Site Vicinity Map	7

Figure 2: Institutional Control Map	12

Figure 3: Detailed Site Map	16

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LIST OF ABBREVIATIONS AND ACRONYMS

AOC

Administrative Orders on Consent

ARAR

Applicable or Relevant and Appropriate Requirement

BTEX

Benzene, toluene, ethylbenzene and xylenes

CERCLA

Comprehensive Environmental Response, Compensation, and Liability Act

CFR

Code of Federal Regulations

COC

Contaminant of Concern

DCE

trans-1,2-Dichloroethylene

Dow

Dow Chemical Company

DSI

Dowell Schlumberger, Inc

EPA

United States Environmental Protection Agency

FYR

Five-Year Review

HI

Hazard Index

HQ

Hazard Quotient

IC

Institutional Control

KMI

Kinder Morgan Energy Partners, L.P.

LNAPL

Light Non-Aqueous Phase Liquid

MCL

Maximum Contaminant Level

l-ig/L

Micrograms per liter

mg/kg

Milligrams per kilogram

MNA

Monitored Natural Attenuation

NCP

National Contingency Plan

NPL

National Priorities List

O&M

Operation and Maintenance

OU

Operable Unit

PCE

T etrachloroethylene

PRP

Potentially Responsible Party

RAO

Remedial Action Objective

RI/FS

Remedial Investigation/Feasibility Study

ROD

Record of Decision

RSL

Regional Screening Levels

SVE

Soil Vapor Extraction

TBC

To-be-considered

TCA

1,1,1 -Trichloroethane

TCE

T richloroethylene

UU/UE

Unlimited Use/Unrestricted Exposure

VHO

Volatile Halogenated Organic Chemicals

WDEQ

Wyoming Department of Environmental Quality

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I. INTRODUCTION

The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy to
determine if the remedy is and will continue to be protective of human health and the environment. The methods,
findings and conclusions of reviews are documented in FYR reports such as this one. In addition, FYR reports
identify issues found during the review, if any, and document recommendations to address them.

The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National
Contingency Plan (NCP) (40 Code of Federal Regulations (CFR) Section 300.430(f)(4)(ii)), and considering EPA
policy.

This is the fifth FYR for the Mystery Bridge Rd/U.S. Highway 20 Superfund site (the Site). The triggering action
for this statutory review is the completion date of the previous FYR. The FYR has been prepared because
hazardous substances, pollutants or contaminants remain at the Site above levels that allow for unlimited use and
unrestricted exposure (UU/UE).

The Site consists of two operable units (OUs). This FYR addresses both of the OUs. OU1 addresses contaminated
groundwater plumes and OU2 addresses contaminated soil areas at the industrial facilities.

EPA is the lead agency for the Site and the Wyoming Department of Environmental Quality (WDEQ) is the
support agency. Pursuant to the 1991 Consent Decree, KN Energy, its successor Kinder Morgan Energy Partners,
L.P. (KMI) and Dow Chemical Company/Dowell Schlumberger, Inc. (Dow/DSI), now Schlumberger Technology
Corporation, the potentially responsible parties (PRPs), have jointly conducted and funded the remediation work
at the Site. EPA remedial project manager Andrew Schmidt led the FYR. Participants included WDEQ Project
Geologist Chris Brown and Treat Suomi from EPA FYR contractor Skeo. PRPs were notified of the initiation of
the FYR. The review began on December 12, 2018.

EPA has determined in the five-year review that the cleanup at the Mystery Bridge Rd/U.S. Highway 20
Superfund Site is protective. This means that the current remedy is protective of human health and the
environment and allows for residential, industrial and commercial reuse at OU1 and industrial and commercial
reuse at OU2. Although groundwater has been restored at the Site, drinking water is provided by the city of
Evansville https://www.evansvillegov.org . Restrictive covenants at the site industrial properties regulate the
handling of any soil that may be excavated in the future.

Site Background

The 410-acre Site is located in Natrona County, just east of Casper, Wyoming (Figure 1). Beginning in 1923, a
gas compressor station first operated at a portion of the Site. In the 1960s, KMI began operating a natural gas
plant in this area. Operations included gas fractionation, compression, cleaning, odorizing and transmission. In the
1950s, Dow/DSI operated a gas and oil enhancement services facility on another portion of the Site. Operations
also included repairing, maintaining and cleaning company trucks and vehicles. Improper waste disposal
practices, accidental spills and a bursting pipeline resulted in a mixture of wastewater, oils and solvents seeping
into the ground. These actions created two contaminated groundwater plumes and contaminated source area soils.

The Site includes an industrial area and a large residential area. The former KMI property is in continued
operation as a mid-stream gas processing facility owned and operated by Tallgrass Energy Partners. The
Dow/DSI property is currently used for storage. Site features include a Burlington-Northern Railroad line, which
divides the industrial area to the south from the residential area in the north, the Brookhurst residential
subdivision, and residences along Mystery Bridge Road (Figure 1). The former Sinclair/Little America Refining
Company borders the Site to the west. Mystery Bridge Road borders the Site to the east. U.S. Highway 20 borders
the Site to the south. The North Platte River borders the Site to the north. Surrounding land uses are primarily
industrial.

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An alluvial aquifer is underneath the Site and ranges in thickness from 13 to 68 feet. Groundwater flows
north/northeast, toward the North Platte River. There are a few wells in the Brookhurst subdivision, all of which
are used only for outdoor irrigation purposes. All residences and businesses in the area of the Site are connected
to municipal water. The Site's topography is generally flat, with some sloping areas near the banks of the North
Platte River. The slope of the Site is mostly less than 2 percent, but the slope reaches into steeper ranges, between
7 to 25 percent, along the river.

The KMI property portion of the Site, including OU1 and OU2 portions, was deleted from the National Priorities
List (NPL) on August 29, 2017. See Appendix A for additional site resources and Appendix B for a chronology of
site events.

FIVE-YEAR REVIEW SUMMARY FORM

SITE IDENTIFICATION

Site Name: Mystery Bridge Rd/U.S. Highway 20
EPA ID: WYD981546005

Region: 8

State: Wyoming

City/County: Evansville/Natrona

NPL Status: Final

Multiple OUs?

Yes

Has the Site achieved construction completion?

Yes

Lead agency: EPA

Author name: Andrew Schmidt with contractor support provided by Skeo

Author affiliation: EPA Region 8 and Skeo

Review period: 12/12/2018 - 6/28/2019

Date of site inspection: 3/18/2019

Type of review: Statutory

Review number: 5

Triggering action date: 9/26/2014

Due date (fiveyears after triggering action date): 9/26/2019

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Figure 1: Site Vicinity Map

Mystery Bridge/U.S
Highway 20
Superfund Site

Evansville

Sources: Esri, DigitalGlobe, GeoEye, Earthstar Geographies,
CNES/Airbus DS, USDA, USGS, AeroGrid, IGN, the GIS User
Community, DeLorme, AND, Tele Atlas, First American, UNEP-WCMC,
the Natrona Regional Geospatial Cooperative and the 2014 FYR.

Legend

^Approximate Site Boundary
V7\ DOW/DSI Property

r-7-1 Tailgrass Energy Partners, LP Property (Former
' Kinder Morgan Property)



** .; -, «¦

Sinclair/Little
America

t Refining Company

V \

¦ Burlington-Northern Railroad Line

^Skeo

Mystery Bridge Road/U.S. Highway 20 Superfund Site

Town of Evansville, Natrona County, Wyoming

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II. RESPONSE ACTION SUMMARY

Basis for Taking Action

Site investigations, initiated due to resident complaints of poor water and air quality, were completed in 1986 and
1987 and identified a benzene, toluene, ethylbenzene and xylenes (BTEX) plume originating from the former
KMI property and a volatile halogenated organic chemicals (VHOs) plume originating from the Dow/DSI
property moving northeast toward the North Platte River. Based on these findings, EPA placed the Site on the
NPL on August 30, 1990.

EPA performed a risk assessment as part of the Site's 1990 remedial investigation/feasibility study (RI/FS). The
risk assessment determined that the principal threats posed by contamination at the Site included ingestion of
contaminated groundwater, dermal contact with contaminated groundwater while bathing, showering, cooking or
swimming, and inhalation of indoor air contaminants volatized while bathing, showering or cooking. Primary
contaminants of concern (COCs) from the Dow/DSI groundwater plume were primarily VHOs, including trans-
1,2-dichloroethylene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,1-trichloroethane
(TCA). Primary COCs from the KMI groundwater plume were aromatic hydrocarbons, including BTEX, while
light non-aqueous phase liquid (LNAPL) was also present.

Response Actions

Prior to remedy selection, EPA and the PRPs performed several immediate removal actions at the Site. In January
1987, EPA installed 25 groundwater monitoring wells and provided alternative drinking water for area residents.
In January 1989, EPA extended a water transmission line from the town of Evansville and connected affected
residents to the municipal water system.

KMI and Dow/DSI each entered into Administrative Orders on Consent (AOCs) for their respective removal
actions in December 1987. Beginning in late 1987 and continuing through part of 1988, Dow/DSI performed a
removal action that consisted of removals of a buried wash water disposal system, an empty and out-of-service
underground storage tank, and soil and debris from an older abandoned sump area. The excavations were
backfilled with clean sand and gravel. In addition, soil vapor extraction (SVE) systems were used to remove VHO
chemicals from the abandoned sump area and aromatic hydrocarbons (toluene, xylenes and ethylbenzene) from
the former toluene storage area. The completion of removal activities for the Dow/DSI parcel, including
confirmation sampling data and quality assurance/quality control, are documented in the Phase I Summary Report
for the DSI Property under OU2 of the Brookhurst/Mystery Bridge Superfund Site, dated February 22, 1994.

In November 1989, KMI began a removal action that consisted of groundwater pump-and-treat and SVE systems
to remove BTEX contaminants in three phases: LNAPL, groundwater and soil vapor. The removal actions on the
KMI property were also selected as part of the OU1 remedy in the Record of Decision (ROD); thus, operation of
the pump-and-treat and SVE systems continued into the remedial phase. The completion of removal activities for
the KMI parcel, including confirmation sampling data and quality assurance/quality control, are documented in
the OU2 Phase I Report, KN Energy Gas Compressor Station, dated June 27, 1995.

EPA selected the long-term cleanup plan in the 1990 OU1 ROD and the 2010 OU2 ROD. Remedial action
objectives (RAOs) and remedy components are presented in Table 1. Groundwater cleanup goals are presented in
Table 2.

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Table 1: RAOs and Remedy Components

Media

RAOs

Remedy Components

OU1 Groundwater

•	Prevent ingestion of water containing
trans-l,2-DCE, 1,1,1-TCA, TCE,
PCE or BTEX at concentrations that
either: a) exceed Maximum
Contaminant Levels (MCLs) or
proposed MCLs, or b) present a total
carcinogenic risk range greater than
lxlO"4 to lxlO 6.

•	Restore the alluvial aquifer to
concentrations that both: a) meet the
MCLs or proposed MCLs for trans-
1,2-DCE, 1,1,1-TCA, TCE, PCE or
BTEX and b) present a total
carcinogenic risk range less than
lxlO"4 to lxlO 6.

•	Groundwater monitoring.

•	Extraction and treatment of
contaminated groundwater through
air stripping.

•	Treated groundwater injection.

•	Monitored natural attenuation
(MNA) for the downgradient
portion of the Dow/DSI VHO
plume.

•	Implementation of institutional
controls (ICs) restricting
groundwater use.

OU2 Soil3

•	Restrict the use of the KMI and
Dow/DSI properties to industrial
uses.

•	Control handling of excavated soils
on the KMI and Dow/DSI properties.

• Implementation of ICs to restrict the
use of the KMI and Dow/DSI
properties to industrial uses and to
control handling of excavated soils
on these properties

Notes:

a. The 2010 ROD determined that prior removal actions cleaned up source area properties to levels safe for industrial
use.

Table 2: Groundwater COC Cleanup Goals

(iroundwiiler ( ()(

ROD Cle;inii|> (>o;ils
(iiiicro^r;ims per liter

Benzene

5

Ethylbenzene

700

Toluene

2,000

Xylenes

10,000

TCE

5

1,1,1-TCA

200

PCE

5

trans-l,2-DCE

70

Notes:



a. The OU1 cleanup levels are the final and proposed MCLs
established under the National Drinking Water
Regulations 40 CFR 141.11; proposed MCLs were used
as the cleanup levels for ethylbenzene, toluene, xylenes,
trans-l,2-DCE and PCE.

Prior to selecting the long-term remedy for soils in the OU2 ROD, EPA had developed site-specific action levels
for contaminated soil in 1988 to support the expedited removal actions. The 2010 OU2 ROD indicated that
although the site-specific action levels were not fully equivalent to the 2010 EPA industrial-based regional
screening levels for soils, EPA believes site risks to potentially exposed individuals are acceptable. Thus, EPA
selected the long-term remedy of implementing institutional controls that limit intrusive activities and require

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proper management of site soils, and limit future use to industrial activities. The 1988 site-specific action levels
were further reviewed in this FYR to confirm that the levels remain within the acceptable risk range.

Status of Implementation

QUI

In October 1991, KMI and Dow/DSI entered into a Consent Decree with EPA to conduct the selected OU1
remedy.

The KMI remediation system initiated under the 1989 removal action and continued under the 1990 ROD
operated continuously between November 1989 and August 1996, when EPA approved KMI's request to cease
active remediation. Monitoring continued until MCLs were achieved. As of January 2011, COCs in groundwater
at the KMI property (BTEX plume) met the cleanup levels and EPA determined monitoring was no longer
required.

Dow/DSI began installing extraction wells in August 1993, followed by a groundwater treatment unit and an
infiltration gallery. This system operated continuously between November 1993 and April 2001, when EPA
approved Dow/DSI's request to cease active groundwater extraction. Monitoring continued until MCLs were
achieved. Compliance with RAOs and completion of the remediation for the Dow/DSI plume was documented in
April 2019.

OU2

In September 2010, KMI and Dow/DSI filed restrictive covenants with the Natrona County Clerk as stipulated in
the 2010 ROD. The institutional control review discusses these in greater detail.

Because the KMI parcel met RAOs for the source area and in groundwater, and because the necessary
institutional controls were in place to prevent unacceptable exposure to site contaminants, the KMI property
portion of the Site, including OU1 and OU2 portions, was deleted from the NPL on August 29, 2017.

Institutional Control (IC) Review

The OU 1 and OU2 RODs required institutional controls for limiting exposure to contaminated groundwater and
soils at the small part of the Site that was in industrial use. In September 2010, KMI and Dow/DSI filed restrictive
covenants with the Natrona County Clerk on source area properties restricting use of groundwater without the
express approval of PRPs, EPA and WDEQ, restricting use of the properties to industrial uses and regulating
handling of excavated soils on the properties1. If any excavation into or through the ground surface at the KMI or
Dow/DSI properties is conducted and soil will be sent off site for any reason, the soil will not be disposed of,
applied or used at property zoned for residential use unless it is tested in accordance with an EPA or WDEQ
approved methodology and shown to be safe for residential use. Because the OU1 ROD established MCLs as the
clean-up standards for groundwater at the Site, no institutional controls were required for the non-industrial
portions of the Site in OU1. Table 3 and Figure 2 summarize the institutional controls at the Site. Copies of the
institutional controls are available in Appendix I. On March 15, 2019, research on the Natrona County website
confirmed current ownership information at the KMI and Dow/DSI properties.

1 Copies of the restrictive covenants are included in Appendix H of the 2014 FYR.

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Table 3: Summary of Institutional Controls (ICs)

Mcdi;i. r.njiinccrcd
( on(nils, iind Aiviis
1 liiil Do Noi
Support I 1 /I 1.
I$;iscd on ( urrcnl
( oiitl it ions

ICs
Needed

ICs ( idled
lor in llie
Decision
Documents

Impeded
Parcels

l(

OI).jec(i\e

Tillc of l( luslrnmeiil
Implemented :ind Dale

Groundwater and
Soil

Yesa

Yes

33780530000300
33780530000400
33780530000500
33780530000700
33780530000800

Restrict
installation of
groundwater wells
and groundwater

use without
express approval
of the PRP, EPA
and State of
Wyoming.
Restrict use of the
KMI and
Dow/DSI
properties to
industrial uses.
Regulate the
handling of any
soil that may be
excavated in the
future on the KMI
and Dow/DSI
properties.

Separate restrictive
covenants were filed on
September 2010. One for
the KMI properties and one
for the Schlumberger
Technology Corporation
(Dow) properties.

Systems Operations/Operation and Maintenance (O&M)

Routine groundwater monitoring occurred through May 20, 2015. At the request of EPA, PRPs conducted well
redevelopment and groundwater sampling activities in June 2018. No further operation or maintenance is required
for the Site; however, the effectiveness and presence of the restrictive covenants for soil will be evaluated every
five years as part of the FYR process. Once the Site is deleted from the NPL, the PRPs will work with EPA and
WDEQ to abandon remaining wells.

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Figure 2: Institutional Control Map

0 1,000 2,000	3,000

^	 ~

Sources: Esri, DigitalGlobe, GeoEye. Earthstar Geographies,

CNES/Airbus DS, USDA, AEX, Getmapping, IGP, swisstopo, AeroGRID,
IGN, the GIS User Community, DeLorme, AND, Tele Atlas, First American,
UNEP-WCMC, USGS, the 2014 FYR, Natrona Regional Geospatial
Cooperative and Figure 1 of the Revised 2018 Well Redevelopment and
Groundwater Sampling Report.

Legend

] Approximate Site Boundary

Parcels Requiring Institutional Controls

Y//\ DOW/DSI Property Restrictive Covenant

K2

Tallgrass Energy Partners, LP (Former Kinder
Morgan Property) Restrictive Covenant

Burlington-Northern Railroad Line

A Skeo O

V ~	NORTH

Mystery Bridge Road/U.S. Highway 20 Superfund Site

Town of Evansville, Natrona County, Wyoming

Disclaimer: This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational
purposes only regarding EPA's response actions at the Site.

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III. PROGRESS SINCE THE PREVIOUS REVIEW

This section includes the protectiveness determinations and statements from the previous FYR as well as the
recommendations from the previous FYR and the status of those recommendations.

Table 4: Protectiveness Determinations/Statements from the 2014 FYR

()l #

PrnleclKcness
DcliTmiiiiiliun

Pmieclheness Sliiiomonl

1

Short-term Protective

The remedy at OU1 currently protects human health and the
environment. Institutional controls are in place restricting the
use of drinking water beneath the industrial properties until

drinking water standards are met. However, to better
determine the protectiveness of the remedy in the long term,
groundwater sampling for 1,4-dioxane is needed. In order to
ensure long-term protectiveness, the EPA should also evaluate

current groundwater data and the need for additional
groundwater sampling, considering the cessation of the pump-
and-treat system in 2001.

2

Protective

The remedy at OU2 is protective of human health and the
environment. The soil has been cleaned to industrial standards
and institutional controls are in place to ensure that the KMI

and Dow/DSI properties remain in industrial use and to
regulate handling of excavated soils on the KMI and Dow/DSI
properties.

Sitewide

Short-term Protective

The remedial action at OU2 is protective. However, because
the remedial action at OU 1 currently protects human health
and the environment, the Site is currently protective of human
health and the environment in the short term.

Table 5: Status of Recommendations from the 2014 FYR

()l #

Issiio

Kccomiiicnriiilions

( II ITdl 1
Sliilus

('iirmil Impk'iiK'iiliilion Sliilus
Description

( o in plot ion

DiiUMil'
iippliciihlo)

1

1,4-Dioxane was not
tested for during the RI
but may be a COC due
to materials processed
on Site.

Conduct groundwater
sampling for 1,4-
dioxane.

Completed

PRPs sampled groundwater for 1,4-
dioxane in 2014. EPA determined
that the concentrations measured
were below WDEQ's standard and
within EPA's acceptable risk range.

5/26/2016

1

The pump-and-treat
system selected in the
OU 1 ROD was stopped

in 2001, prior to
reaching cleanup levels.

Evaluate current
groundwater data and
the need for
additional
groundwater
sampling,
considering the
cessation of the
pump-and-treat
system in 2001.

Completed

In 2018, Dow submitted a revised
statistical analysis of the groundwater
data illustrating that RAOs have been
achieved and the groundwater has
achieved MCLs.

9/28/2018

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IV. FIVE-YEAR REVIEW PROCESS

Community Notification, Community Involvement and Site Interviews

A public notice was published in the Casper Star Tribune newspaper announcing the FYR process for the Site,
providing contact information for EPA remedial project manager Andrew Schmidt, EPA community involvement
coordinator Cynthia Peterson, and Chris Brown of WDEQ and inviting community participation. The press notice
is available in Appendix C. In addition, a notice was placed on the website for the Mystery Bridge Rd./U.S.
Highway 20 Superfund Site. No one contacted EPA as a result of these notices. The results of the review and the
report will be made available at the Site's information repository, Natrona County Public Library, located at 307
East 2nd Street, Casper, Wyoming 82601.

During the FYR process, interviews were conducted to document any perceived problems or successes with the
remedy implemented to date. In general, community interest in the Site is minimal. EPA reached out to a variety
of site stakeholders, local officials and community members. No local officials or community members
responded. The interviews that were completed are summarized below; completed interview forms are included in
Appendix D.

Chris Brown, WDEQ Project Geologist for the Site, was interviewed. He indicated he has an overall positive
impression of the Site's cleanup, maintenance and reuse activities and believes the remedy is performing as
intended. He noted he is not aware of any complaints or inquiries about the Site in the last five years, nor is he
aware of any changes in state laws that might affect the protectiveness of the remedy. He is also not aware of any
changes in land uses at the Site and confirmed that EPA has been very responsive and effective in communication
with WDEQ. He concluded with suggesting that EPA perform a periodic review of the status of permitted water
wells and lots connected to the town of Evansville's public water system. He also recommended that EPA suggest
to residents who actively use water wells on their property to periodically test the water quality of the well.

Representatives from Dow/DSI and KMI were interviewed. Dow/DSI and KMI both indicated that all remedial
actions have been completed at the Site and that the remedy is performing as expected. They both confirmed that
there have been no recent effects on the surrounding community or any recent complaints or inquiries from
surrounding residents. They both indicated they feel well-informed regarding activities at the Site. Dow/DSI
mentioned that PRPs should be allowed to proceed with site closure activities based on meeting remedial action
goals. KMI indicated that EPA has communicated plans, results and approvals in a timely manner.

A representative from the business operating on the KMI property, Tallgrass Energy, was also interviewed. The
representative indicated that all activities with the project were completed in a professional manner and proper
protocol was followed. The representative also noted that part of the south fence of the KMI property was cut and
electrical wire was stolen a few years ago, but no other vandalism occurred in the past five years. Finally, the
representative confirmed that EPA has kept involved parties and surrounding neighbors informed of activities at
the Site and EPA has kept the public aware of risks at the Site over the years.

Data Review

The 1990 OU1 ROD required monitoring of the two groundwater contaminant plumes at the Site: the BTEX
plume emanating from the KMI property and the VHO plume emanating from the Dow/DSI property (Figure 3).
As of January 2011, COCs in groundwater at the KMI property (BTEX plume) met the cleanup levels and EPA
determined monitoring was no longer required.

The 2014 FYR recommended sampling groundwater for 1,4-dioxane and assessing the need for additional
groundwater sampling given the shutdown of the VHO pump-and-treat system in 2001 to ensure protectiveness.
Both issues have been addressed since the 2014 FYR. Select groundwater monitoring locations were sampled and
analyzed for 1,4-dioxane. Very low detections of 1,4-dioxane were discovered in groundwater; however,
concentrations found in groundwater were determined to be within the acceptable risk range for human health as
determined by Susan Griffin, EPA toxicologist. The determination was documented in a May 17, 2016 email from

14


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Susan Griffin to Paula Schmittdiel, the Superfund remedial project manager at the time. Additional groundwater
monitoring was conducted in 2018 that demonstrated that the RAOs for site COCs had been achieved at the Site
and that no further monitoring was necessary.

Groundwater monitoring continued at the Dow/DSI property until May 2015. After this event, Dow/DSI
submitted a letter detailing achievement of RAOs for the VHO plume based on the requirements detailed in the
1993 Dow/DSI Groundwater Management Plan. Due to the age of the document and new guidance, EPA
requested that Dow/DSI evaluate groundwater data using a more stringent statistical test. In October 2017,
Dow/DSI submitted a report detailing achievement of RAOs for the VHO plume based on a more stringent 95
percent upper confidence level on the mean and using a minimum of eight data points. Dow/DSI documented
completion of the remedial action in the Completion of Remedial Action and Completion of Work Report, dated
October 18, 2017 and subsequently updated April 2019.

Dow/DSI conducted additional sampling in 2018 to confirm conclusions made in the 2017 Completion of
Remedial Action and Completion of Work Report. Sampling results confirmed that concentrations of dissolved
phase VHOs were below MCLs in the wells sampled. Results of the 2018 confirmation sampling are documented
in the Revised 2018 Well Redevelopment and Groundwater Sampling Report, dated September 28, 2018.

During a 2018 review of private wells in the area, EPA reached out to four private well owners and offered to
sample their wells. One individual accepted the offer; no response was received from the other three private well
owners. No VOCs were detected in the sample collected from the individual's well above method detection
limits.

Site Inspection

The site inspection took place on March 18, 2019. Participants included EPA remedial project manager Andrew
Schmidt, WDEQ Project Geologist Chris Brown, and Treat Suomi from EPA support contractor Skeo. The
purpose of the inspection was to assess the protectiveness of the remedy. A completed site inspection checklist
and site inspection photos are included in Appendices E and F, respectively.

Participants met at the Tallgrass Energy facility (operating on the KMI property), located at 5750 East
Yellowstone Highway, Evansville, Wyoming, to participate in the site inspection. Staff from Tallgrass Energy
Partners escorted the group around the property to observe the former areas of contamination and the remaining
well (KNABC-17) on the KMI property. The well was not locked but is located within the fenced and secured
facility. The well was subsequently plugged and abandoned on April 9, 2019. Participants then went to the fenced
and locked Dow/DSI property. Some wells were located, found to be in good condition, but not locked. Site
inspection participants were not able to locate many of the flush-mounted wells due to snow on the ground. Site
inspection participants toured the residential neighborhood; all wells were found and, with one exception, found
to be in good condition. Details are outlined in the site inspection checklist (Appendix E).

As part of the site inspection, participants visited the designated site information repository, Natrona County
Public Library. The library had a CD-ROM with the Administrative Record as of September 2010. EPA will work
with the library to update the information.

15


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Figure 3: Detailed Site Map

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AeroGRID, IGN, the GIS User Community, DeLorme, AND, Tele Atlas, First American,	Tallqrass Energy Partners, LP Property (Former Kinder

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Sampling Report, the Natrona Regional Geospatial Cooperative and the 2014 FYR.

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Disclaimer: This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational purposes only regarding EPA"s response actions at the
Site.

16


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V. TECHNICAL ASSESSMENT

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

The review of site documents, applicable or relevant and appropriate requirements (ARARs), risk assumptions,
groundwater sampling data and the site inspection indicate that the remedy is functioning as intended by the Site's
RODs. The soil has been cleaned to industrial standards and institutional controls are in place to ensure that the
KMI and Dow/DSI properties remain in industrial use and to regulate handling of excavated soils on the KMI and
Dow/DSI properties. Any soil excavated from the KMI or Dow/DSI properties will not be used on a property
zoned for residential use unless the soil is first tested and found to be safe for residential use.

The site groundwater monitoring network established that all cleanup efforts were implemented successfully and
demonstrated that groundwater meets MCLs. Once the Site is deleted from the NPL, the PRPs will work with
EPA and WDEQ to abandon remaining wells.

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

The exposure assumptions, toxicity data and cleanup levels remain valid. This FYR compared the groundwater
cleanup goals selected in the 1990 OU1 ROD against the current drinking water standards to determine whether
the cleanup goals are still valid (see Appendix G). All of the groundwater cleanup goals are still valid except for
toluene. The MCL for toluene is more stringent than the proposed MCL value selected in the OU1 ROD;
however, previous analysis of the historical data (2000 to 2013) indicated that none of the toluene concentrations
exceeded the current MCL.

Although toxicity values have changed for two of the groundwater COCs, TCE and PCE, the change in toxicity
does not affect the cleanup levels for these compounds because the cleanup levels are the MCLs, which have not
changed for these compounds.

This FYR conducted a screening-level evaluation of the potential for indoor air contamination due to vapor
intrusion at the Dow/DSI property using 2018 groundwater monitoring data to determine if previous vapor
intrusion evaluation risk conclusions remain valid. Based on historical trends, remediation history at the Site and
the results of the 2018 screening level vapor intrusion analysis, there is no indication that the vapor intrusion
exposure pathway presents an unacceptable risk at the site (Appendix H).

EPA developed site action levels for soil in 1988 to support expedited removal actions. The 2010 OU2 ROD
indicated that although these levels were not equivalent to the 2010 regional screening levels (RSLs) for soils,
EPA believes site risks to potentially-exposed individuals are acceptable based on industrial exposure. Because
toxicity values have changed since 1988, this FYR compared the 1988 action levels against EPA's current (2018)
RSLs based on industrial exposure. As demonstrated in Appendix H, the industrial risks are within EPA's risk
management range of 1 x 10~6 to 1 x 10~4 and the noncancer hazard index (HI) is below 1.0. These results indicate
that the soil action levels remain valid. Therefore, the Dow/DSI and KMI properties are protective for industrial
use.

On November 21, 2013, EPA requested that a subset of monitoring wells be sampled to determine if 1,4-dioxane
is present in site groundwater. 1,4-Dioxane has been used as a stabilizer in chlorinated solvents (primarily in
1,1,1-TCA).2 1,4-Dioxane has been identified by EPA as an emerging COC, but the risk assessment did not
evaluate this compound. Very low detections of 1,4-dioxane were discovered in groundwater in 2014. EPA

2 EPA. 2009. Fact Sheet: Emerging Contaminant- 1,4-Dioxane. Office of Solid Waste and Emergency Response. EPA 505-
F-09-006. September.

17


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determined in May 2016 that the concentrations were within the acceptable risk range for human health based on
state and federal screening levels. A screening-level risk evaluation was conducted for this FYRthat demonstrates
that the maximum detection of 1,4-dioxane is within EPA's risk management range and below the noncancer HI
of 1.0 (see Table H-3 in Appendix H).

The RAOs for OU1 remain valid. The OU1 remediation system restored groundwater to MCLs and EPA
determined monitoring was no longer required in 2011 for the BTEX plume. Dow/DSI implemented the
groundwater remedy and EPA approved Dow/DSI's request to cease active groundwater extraction in 2001. In
addition, institutional controls were implemented to prevent exposure to groundwater.

The RAOs for OU2 remain valid. In September 2010, KMI and Dow/DSI filed restrictive covenants to restrict the
use of the properties to industrial uses.

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

No. No additional information has come to light that could call into question the protectiveness of the remedy.

VI. ISSUES/RECOMMENDATIONS

Issues/Recommendations

Ol (s) without Issues/Recommendations Identified in the I YR:

OU1, OU2

Issues and Recommendations Identified in the l-'Yk:

None

OTHER FINDINGS

•	EPA will work to update documents at the local information repository. This recommendation does not
affect current or future protectiveness.

•	Once the Site is deleted from the NPL, the PRPs will work with EPA and WDEQ to abandon remaining
wells.

VII. PROTECTIVENESS STATEMENT

Protectiveness Statement

Operable Unit:	Protectiveness Determination:

1	Protective

Protectiveness Statement:

The remedy at OU1 is protective of human health and the environment.

Protectiveness Statement

^^perabl^Unit^^^^^^^^^Protectivenes^Determination^

18


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2	Protective

Protectiveness Statement:

The remedy at OU2 is protective of human health and the environment.

Sitewide Protectiveness Statement

Protectiveness Determination:

Protective

Protectiveness Statement:

The remedy at the Mystery Bridge Road/U.S. Highway 20 Superfund site is protective of human health
and the environment.

VIII. NEXT REVIEW

The next FYR Report for the Mystery Bridge Rd/U.S. Highway 20 Superfund site is required five years from the
completion date of this review.

19


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APPENDIX A - REFERENCE LIST

Action Memorandum: Removal Request for the Brookhurst Subdivision, Natrona County, Wyoming. Prepared by
EPA Region 8. January 7, 1987.

Action Information: Partial deletion of the Kinder Morgan, Inc. (KMI) parcel of the Mystery Bridge Road/U.S.
Hwy 20 Superfund Site from the National Priorities List (NPL). Prepared by EPA Region 8.

Completion of Remedial Action and Completion of Work Report. Prepared by Schlumberger. April 5, 2019

Consent Decree. United States of America, Plaintiff v. The Dow Chemical Company, Dowell Schlumberger, Inc.,
and Knenergy, Inc., Defendants. October 3, 1991.

Federal Registry Deletion Notice, Vol 85, No. 125. U.S. Federal Register. June 30, 2017.

Final Close Out Report for Mystery Bridge Rd./U.S. HWY 20 Superfund Site. Prepared by EPA. April 25, 2019.

First Five-Year Review Report for Mystery Bridge Road/U.S. Highway 20 Superfund Site. Prepared by EPA
Region 8. February 4, 1999.

First Quarter Progress Report - 2014. Prepared by Schlumberger. May 20, 2015.

Fourth Five-Year Report, Mystery Bridge Road/U.S. Highway 20 Superfund Site, Natrona County, Wyoming.
EPA Region 8. September 26, 2014.

Fourth Quarter Progress Report - 2014. Prepared by Schlumberger. January 21, 2015.

1,4-Dioxane VRP Fact Sheets. Prepared by EPA Region 8. June 24, 2016.

Isoconcentration Map of PCE and Benzene, Brookhurst Site, Casper, Wyoming. Prepared by Deuell
Environmental, LLC. 1993.

Isoconcentration Map of PCE and Benzene, Brookhurst Site, Casper, Wyoming. Prepared by Deuell
Environmental, LLC. 2010.

Mystery Bridge Rd/U.S. Highway 20 Superfund Site, Highlights since the 2009 Five-Year Review. January 2011.

Mystery Bridge Rd./U.S. Highway 20 NPL Site Map, Natrona County, Wyoming. Prepared by EPA Region 8.
August 9, 2010.

Operable Units and Institutional Controls Map of Mystery Bridge, Natrona County, Wyoming. Prepared by EPA
Region 8. January 30, 2014.

Proposed Plan for Mystery Bridge Superfund Site, Operable Unit 2 Informational Release. Prepared by EPA
Region 8. August 2010.

Follow-up to Issues from May 12, 2016 Meeting on Mystery Bridge Superfund Site, Casper, Wyoming. Prepared
by EPA Region 8. May 25, 2016.

A-l


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Record of Decision, Mystery Bridge Road/U.S. Highway 20, OU1. Prepared by EPA Region 8. September 24,
1990.

Record of Decision, Mystery Bridge Road/U.S. Highway 20, OU2. Prepared by EPA Region 8. September 30,
2010.

Response to Agency Comments on 2018 Well Redevelopment and Groundwater Sampling Report, dated July 31,
2018. Prepared by Schlumberger. September 28, 2018.

Second Five-Year Review Report for Mystery Bridge Road/U.S. Highway 20 Superfund Site. Prepared by EPA
Region 8. September 27, 2004.

Second Quarter Progress Report - 2014. Prepared by Schlumberger. September 10, 2014.

Second Quarter Progress Report - 2015. Prepared by Schlumberger. July 16, 2015.

Technical Memorandum Evaluating Vapor Intrusion (Revision 2), RE: Dow/Dowell Brookhurst/Mystery Bridge
Site. Prepared by Deuell Environmental, LLC for EPA Region 8. August 3, 2010.

Technical Memorandum RE: Revised Summary of Vapor Intrusion Modeling for the Kinder Morgan Portion of
the Mystery Bridge Superfund Site. Prepared by Golder Associates, Inc. for EPA Region 8. August 5, 2010.

Technical Memorandum RE: Summary of Remediation Actions Related to Operable Unit 2 (OU2) at the Casper
Compressor Station. Prepared by Golder Associates, Inc. for EPA Region 8. June 22, 2010.

Third Five-Year Review Report for Mystery Bridge Road/U.S. Highway 20 Superfund Site. Prepared by EPA
Region 8. September 30, 2009.

Third Quarter Progress Report - 2014. Prepared by Schlumberger. December 3, 2014.

A-2


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APPENDIX B - SITE CHRONOLOGY

Table B-l: Site Chronology

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Diilo

A gas compressor station began operating on the present-day KMI
property

1923

Dow/DSI began gas and oil enhancement operations on the Site

1950s

Dow/DSI released chlorinated solvents into the ground at the Site

1950s-1970s

KMI began operating a natural gas plant on the Site and an underground
pipeline burst

1960s

Residents complained of poor air and water quality

August 1986

EPA and WDEQ began initial site investigations

October 1, 1986

EPA filed an Action Memorandum for Removal Request to address
immediate threats to the Brookhurst subdivision

January 7, 1987

KMI and Dow/DSI entered into separate AOCs with EPA to perform the
RI/FS

December 15, 1987

Dow/DSI initiated immediate removal actions on the Dow/DSI property

January 4, 1988

KMI and Dow/DSI began the RI/FS

February 15, 1988

Dow/DSI completed removal actions on the Dow/DSI property

February 22, 1988

EPA proposed the Site for listing on the NPL

June 24, 1988

EPA connected affected residents to the Evansville municipal water
system

January 1989

KMI began immediate removal actions on the KMI property

November 1989

EPA finalized the Site on the NPL

August 30, 1990

KMI and Dow/DSI completed the RI/FS and EPA signed the OU1 ROD

September 24, 1990

KMI and Dow/DSI entered into a Consent Decree with EPA to conduct
the remedial design/remedial action for OU 1

October 1991

KMI and Dow/DSI completed the OU 1 remedial design and began OU 1
remedial actions

September 14, 1993

KMI and Dow/DSI completed OU 1 remedial actions and EPA issued the
OU1 Preliminary Close-Out Report

December 16, 1993

Dow/DSI completed removal actions for their portion of OU2

July 7, 1994

KMI completed removal actions for their portion of OU2

April 24, 1998

EPA signed the Site's first FYR report

February 4, 1999

EPA approved Dow/DSI shutting down the groundwater extraction and
treatment system

April 2001

EPA signed the Site's second FYR report

September 27, 2004

EPA signed the Site's third FYR report

September 30, 2009

KMI and Dow/DSI implemented restrictive covenants for their properties

September 29, 2010

EPA signed the OU2 ROD

September 30, 2010

EPA signed the Site's fourth FYR report

September 26, 2014

Dow/DSI completed final O&M groundwater sampling event

May 20, 2015

EPA approved Dow/DSI removal of pump-and-treat system and three
recovery wells

May 16, 2016

EPA issued letter detailing no further action is required for possible 1,4-
dioxane

May 25, 2016

EPA deleted KMI portion of OU 1 and OU2 from NPL

August 29, 2017

EPA issued the remedial action completion report for OU 1

October 18, 2017

Dow/DSI conducted well redevelopment activities and sampling

June 2018

Schlumberger completed the updated Remedial Action and Completion
of Work Report.

April 5, 2019

EPA completed the Final Close Out Report.

April 25,2019.

B-l


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APPENDIX C - PRESS NOTICE

EPA Five-Year Review Planned for the
Mystery Bridge Road/U.S. Highway 20 Superfucid Site

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C-l


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APPENDIX D - INTERVIEW FORMS

Mystery Bridge Rd/U.S. Highway 20
Superfund Site	

Five-Year Review Interview Form

Site Name: Mystery Bridge Rd/U.S. Highway EPA ID No.: WYD981546005
20

Interviewer Name:
Subject Name:

Andrew Schmidt
Chris Brown

Affiliation:
Affiliation:

EPA

Subject Contact Information:

Time: 08:30 a.m.

Interview Location: 200 W. 17th Street,

Chevenne. WY 82001

Interview Format (circle one):

Date:

WDEO
04/04/2019

Interview Category: State Agency

1.	What is your overall impression of the project, including cleanup, maintenance and reuse activities (as
appropriate)?

My overall impression of the project, including cleanup, maintenance and reuse activities, is positive.

2.	What is your assessment of the current performance of the remedy in place at the Site?

Based on a review of institutional controls in place at the site and the results of the most recent
groundwater monitoring activities conducted by the responsible parties and United States Environmental
Protection Agency at the Site, the remedy appears to be performing as intended for the protection of human
health and the environment.

3.	Are you aware of any complaints or inquiries regarding site-related environmental issues or remedial
activities from residents in the past five years?

The Wyoming Department of Environmental Quality (WDEQ) is not aware of any complaints or inquiries
regarding site-related environmental issues or remedial activities from residents in the past five years.

4.	Has your office conducted any site-related activities or communications in the past five years? If so, please
describe the purpose and results of these activities.

The WDEQ has visited the site to witness site-related activities.

•	The WDEQ participated in the 5-year review Site inspection with the USEPA and its consultant
on March 18, 2019.

•	The WDEQ witnessed a portion of the well redevelopment activities of select wells conducted
by Dow/Schlumberger (D/DSI) the week of June 18, 2018.

•	The WDEQ witnessed the plugging and abandonment of monitor wells on the Kinder- Morgan Inc.
(KMI) portion of the Site on October 5, 2017.

5. Are you aware of any changes to state laws that might affect the protectiveness of the Site's remedy?

The WDEQ is not aware of any changes to state laws that might affect the protectiveness of the Site's

D-l


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remedy.

6.	Are you comfortable with the status of the institutional controls at the Site? If not, what are the associated
outstanding issues?

The WDEQ is comfortable with the status of the institutional controls at the Site at this time.

7.	Are you aware of any changes in projected land use(s) at the Site?

The WDEQ is not aware of any changes in project land use(s) at the Site.

8.	How effective has EPA been at communicating risks associated with the site? How could the agency improve
its risk communication?

The EPA has been very responsive and effective in its communications with the WDEQ regarding the Site.

9.	Do you have any comments, suggestions or recommendations regarding the management or operation of the
Site's remedy?

The WDEQ suggests that periodic review of the status of permitted water wells and lots connected to the
Town of Evansville's public water system in the Brookhurst Subdivision be performed by the USEPA and
that the USEPA recommend that any residents actively using a water well on their property periodically test
the water quality of the well.

10.	Do you consent to have your name included along with your responses to this questionnaire in the FYR
report?

I do.

D-2


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Mystery Bridge Rd/U.S. Highway 20 Five-Year Review Interview Form
Superfund Site	

Site Name: Mystery Bridge Rd/U.S. Highway EPA ID No.: WYD981546005
20

Interviewer Name: Andrew Schmidt
Subject Name:	Virgilio Cocianni

Affiliation: EPA

Affiliation: Schlumberger Technology
Corporation

Subject Contact Information:
Time: 12:00 p.m.

Interview Location: By email

Date: 03/15/2019

Interview Format (circle one):

Interview Category: Potentially Responsible Parties (PRPs)

1.	What is your overall impression of the remedial activities at the Site?

Remedial activities included quarterly monitoring at 27 on-site and off-site wells. Remedial action goals have
been met at all of the wells since at least the second quarter of 2015, many of the wells met cleanup criteria
prior to this date. Confirmation sampling was completed at two wells in mid-2018 and confirmed that
groundwater concentrations are below cleanup goals.

2.	What have been the effects of this Site on the surrounding community, if any?

None to my knowledge.

3.	What is your assessment of the current performance of the remedy in place at the Site?

The current performance of the remedy is successful by demonstrating that natural attenuation has
consistently reduced concentrations of COCs to below MCLs in all site monitoring wells.

4.	Are you aware of any complaints or inquiries regarding environmental issues or the remedial action from
residents since implementation of the cleanup?

None to my knowledge.

5.	Do you feel well-informed regarding the Site's post-construction and long-term maintenance activities? If not,
how might EPA convey site-related information in the future?

6. Do you have any comments, suggestions or recommendations regarding the management or operation of the
Site's remedy?

The PRPs should be allowed to proceed with site closure activities as allowed in the ROD based on meeting
remedial action goals for the site.

Yes.

D-3


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7.	Do you consent to have your name included along with your responses to this questionnaire in the FYR
report?

Yes.

8.	How effective has EPA been at communicating risks associated with the site? How could the agency improve
its risk communication?

There has been no risk communication provided by EPA to my knowledge.

D-4


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Mystery Bridge Rd/U.S. Highway 20 Five-Year Review Interview
Superfund Site	Form	

Site Name:	Mystery Bridge Rd/U.S.	EPA ID No.: WYD981546005

Highway 20

Interviewer Name:	Andrew Schmidt	Affiliation: EPA

Subject Name:	David White	Affiliation: Kinder Morgan

Subject Contact Information: david_white@kindermorgan.com - 713-369-9556
Time:	08:00 AM	Date: 03/21/2019

Interview Location:	Houston, TX

Interview Format (circle one):	(^EmaiT^	

Interview Category:	Potentially Responsible Parties (PRPs)

1.	What is your overall impression of the remedial activities at the Site?

All site remedial activities complete.

2.	What have been the effects of this Site on the surrounding community, if any?

Nothing for 5 plus years.

3.	What is your assessment of the current performance of the remedy in place at the Site?

Remedy is performing as expected.

4.	Are you aware of any complaints or inquiries regarding environmental issues or the remedial action from
residents since implementation of the cleanup?

None that I am aware of.

5.	Do you feel well-informed regarding the Site's post-construction and long-term maintenance activities? If not,
how might EPA convey site-related information in the future?

Yes.

6.	Do you have any comments, suggestions or recommendations regarding the management or operation of the
Site's remedy?

No.

7.	Do you consent to have your name included along with your responses to this questionnaire in the FYR
report?

Yes.

8.	How effective has EPA been at communicating risks associated with the site? How could the agency improve
its risk communication?

EPA has communicated timely with plans, results, and approvals.

D-5


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Mystery Bridge Rd/U.S. Highway 20 Five-Year Review Interview Form
Superfund Site	

Site Name: Mystery Bridge Rd/U.S. Highway EPA ID No.: WYD981546005
20

Interviewer Name: Andrew Schmidt
Subject Name:	Cary Zimmerman

Affiliation: EPA

Affiliation: Tallgrass Energy

Time: 08:06 a.m.

Date: 03/19/2019

Interview Location: 5750 East Yellowstone Hwv. Casper WY. 82609

Interview Format (circle one):

Interview Category: Residents and Local Businesses

1.	Are you aware of the former environmental issues at the Site and the cleanup activities that have taken place
to date?

Yes, I am.

2.	What is your overall impression of the project, including cleanup, maintenance and reuse activities (as
appropriate)?

All completed in a professional manner.

3.	What have been the effects of this Site on the surrounding community, if any?

Clean up activity was performed in the late 1980's and early 1990's with proper protocol followed and the
testing of monitor wells over numerous years.

4.	Have there been any problems with unusual or unexpected activities at the Site, such as emergency response,
vandalism or trespassing?

We did have the south fence cut and some electrical wire that was taken a few years ago. The fence was
repaired and added additional cameras to monitor around the facility.

5.	Has EPA kept involved parties and surrounding neighbors informed of post-construction and long-term
maintenance activities at the Site? How can EPA best provide site-related information in the future?

Yes, they have. This is coming to a close so there may not be much information on this matter in the future.

6.	Do you own a private well in addition to or instead of accessing city/municipal water supplies? If so, for what
purpose(s) is your private well used?

No active private well as all water supplied by the town of Evansville, WY.

7.	Do you have any comments, suggestions or recommendations regarding any aspects of the project?

No, I do not.

D-6


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8. How effective has EPA been at communicating risks associated with the site? How could the agency improve
its risk communication?

I feel that they have kept the public and our company informed of the risks over the years during the
Superfund cleanup and sampling.

D-7


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APPENDIX E - SITE INSPECTION CHECKLIST

FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST

L SITE INFORMATION

Site Name: Mystery Bridge Rd/U.S. Highway 20

Date of Inspection: 03/18/2019

Location and Region: Evansville, Wyoming; Region
8

EPA ID: WYD981546005

Agency, Office or Company Leading the Five-Year
Review: EPA Region 8	

Weather/Temperature: 44 degrees Fahrenheit and
sunny	

Monitored natural attenuation

~	Groundwater containment

~	Vertical barrier walls

Remedy Includes: (Check all that apply)

~	Landfill cover/containment

~	Access controls
^ Institutional controls

Groundwater pump and treatment

~	Surface water collection and treatment

~	Other: Water lines were extended to the area, soil vapor extraction was conducted, and early in the
	removal and remediation process groundwater pump and Ircal was performed. 	

Attachments:

Inspection team roster attached

I I Site map attached

H. INTERVIEWS (check all that apply)

1. O&M Site Manager

Name

Interviewed ~ at site ~ at office ~ by phone
Problems, suggestions ~ Report attached:

Title

Date

2. O&M Staff

Name

Interviewed ~ at site ~ at office ~ by phone
Problems/suggestions ~ Report attached:

Title
Phone:

Date

3.

Local Regulatory Authorities and Response Agencies (i.e., state and tribal offices, emergency
response office, police department, office of public health or environmental health, zoning office,
recorder of deeds, or other city and county offices). Fill in all that apply.

Agency WDEO

Contact Chris Brown Project Geologist

Name	Title

Problems/suggestions ^ Report attached:

04/04/2019
Date

Phone No.

4.

Other Interviews (optional) Report attached:

David White - KMI (PRP), 03/21/2019

Virgilio Cocianni - Dow/DSI (PRP), 03/15/2019

Cary Zimmerman - Tallgrass Energy, 03/19/2019

III. ON-SITE DOCUMENTS AND RECORDS VERIFIED (check all that apply)

1. O&M Documents

~	O&M manual

~	As-built drawings

~	Maintenance logs

~	Readily available

~	Readily available

~	Readily available

~	Up to date

~	Up to date

~	Up to date

I N/A
|N/A
I N/A

E-l


-------
Remarks:

2.

Site-Specific Health and Safety Plan

~ Contingency plan/emergency response plan

Remarks:

~	Readily available

~	Readily available

~	Up to date

~	Up to date

[El N/A
IXI N/A

3.

O&M and OSHA Training Records

Remarks:

~ Readily available

~ Up to date

XI N/A

4.

Permits and Service Agreements

~	Air discharge permit

~	Effluent discharge

~	Waste disposal, POTW
I-! Other Dcrmits:

Remarks:

~	Readily available

~	Readily available

~	Readily available

~	Readily available

~	Up to date

~	Up to date

~	Up to date

~	Up to date

[XI N/A

XI n/a
XI n/a
[XI N/A

5.

Gas Generation Records

Remarks:

~ Readily available

~ Up to date

XI n/a

6.

Settlement Monument Records

Remarks:

~ Readily available

~ Up to date

IXI N/A

7.

Groundwater Monitoring Records

Remarks:

^ Readily available

1X1 Up to date

~ n/a

8.

Leachate Extraction Records

Remarks:

~ Readily available

~ Up to date

IXI N/A

9.

Discharge Compliance Records

~	Air ~ Readily available ~ Up to date

~	Water (effluent) ~ Readily available ~ Up to date
Remarks:

M

N/A
N/A

10.

Daily Access/Security Logs ~ Readily available ~ Up to date ^ N/A
Remarks: Both the KMI and Dow Droocrtics are fenced and secured. The active olant at KMI keens



access loss associated with their current operations and not related to the Site.



IV. O&M COSTS

1.

O&M Organization

1 1 State in-house
I~1 PRP in-house
1 1 Federal facility in-house

n

1 1 Contractor for state
1^1 Contractor for PRP
1 1 Contractor for Federal facility



2.

O&M Cost Records

1 1 Readily available

1 1 Up to date





E-2


-------
~ Funding mechanism/agreement in place ^ Unavailable

Original O&M cost estimate:	 Q Breakdown attached

Total annual cost by year for review period if available
From:		To:			

Date

Date

Total cost

From:

To:

Date

Date

Total cost

From:

To:

Date

Date

Total cost

From:

To:

Date

Date

Total cost

From:

To:

~	Breakdown attached

~	Breakdown attached

~	Breakdown attached

~	Breakdown attached

~	Breakdown attached

Date

Date

Total cost

3. Unanticipated or Unusually High O&M Costs during Review Period

Describe costs and reasons: Not applicable

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

A. Fencing

1. Fencing Damaged

Remarks:	

~ Location shown on site map

Gates secured ~ N/A

B. Other Access Restrictions

1. Signs and Other Security Measures

Remarks:	

~ Location shown on site map

N/A

C. Institutional Controls (ICs)

1. Implementation and Enforcement

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

Site conditions imply ICs not being fully enforced	~ Yes ^ No [] N/A

Type of monitoring (e.g., self-reporting, drive by): Observation during site inspection
Frequency: Every five years
Responsible party/agency: EPA

Contact 							

Title

Name
Reporting is up to date
Reports are verified by the lead agency

Specific requirements in deed or decision documents have been met

Violations have been reported

Other problems or suggestions: ~ Report attached

Date



Phone no.

I~1 Yes

~

No

KIn/a

I~1 Yes

~

No

M N/A

1^1 Yes

~

No

~ n/a

I~1 Yes



No

~ n/a

E-3


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

Remarks:	

D. General

1.	Vandalism/Trespassing ~ Location shown on site map ^ No vandalism evident
Remarks:	

2.	Land Use Changes On Site	^ N/A

Remarks:	

3. Land Use Changes Off Site	^ N/A

Remarks:	

VI. GENERAL SITE CONDITIONS

A. Roads ~ Applicable ^ N/A

B. Other Site Conditions

Remarks:

VII. LANDFILL COVERS	~ Applicable [XI N/A

VIII.	VERTICAL BARRIER WALLS	~ Applicable N/A

IX.	GROUNDWATER/SURF ACE WATER REMEDIES ^Applicable ~ N/A

A.	Groundwater Extraction Wells, Pumps and Pipelines	~ Applicable ^ N/A

B.	Surface Water Collection Structures, Pumps and Pipelines ~ Applicable ^ N/A

C.	Treatment System	~ Applicable ^ N/A

D.	Monitoring Data

1.	Monitoring Data

Is routinely submitted on time	^ Is of acceptable quality

2.	Monitoring Data Suggests:

Groundwater plume is effectively contained ^ Contaminant concentrations are declining

E.	Monitored Natural Attenuation	

1. Monitoring Wells (natural attenuation remedy)

Properly secured/locked	Functioning ~ Routinely sampled ^ Good condition

~ All required wells located	~ Needs maintenance	~ N/A

Remarks: Some wells were not able to be located due to snow and access issues. Wells within the locked
and fenced areas of the Site did not all have locks. Wells within the Brookhurst subdivision were found
to be locked with the exception of EPA 1-1 and EPA 2-1. After the site inspection. EPA replaced the
lock on EPA 2-1. EPA 1-1 was damaged during recent well redevelopment activities. As a result of
getting the rod and brush mechanism lodged in the well, the top of the well was cut and covered with
duct tape to secure it. It does not appear possible to lock the well in its current state, but it is also not
very feasible that someone would be able to access the well.

X. OTHER REMEDIES

If there are remedies applied at the site and not covered above, attach an inspection sheet describing the physical

nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.

	XL OVERALL OBSERVATIONS	

A. Implementation of the Remedy	

E-4


-------
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 designed to accomplish (e.g., to contain contaminant
plume, minimize infiltration and gas emissions).

Routine sampling at the KMI portion of the Site ended in 2010. and routine sampling at the Dowl/DSI
portion of the Site ended in 2015. Additional groundwater monitoring conducted in 2018 did not change
any conclusions made during previous certifications of completion and statistical anavlsis made by the
PRPs. The site remedy has achieved RAOs and groundwater meets MCLs.

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 activites have been adequate and satisfactory. Because the site remedy has achieved RAOs. no
	Further routine O&M is required. 	

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	

D.	Opportunities for Optimization	

Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.

None

E-5


-------
APPENDIX F - SITE INSPECTION PHOTOS

Sign and entryway to the Tallgrass Energy partners facility on the KMI property

Former contaminated area on the KMI property

F-l


-------
IN CASE OF AN
EMERGENCY

1-800-894-3251

Locked entrance to Dow/DSI property

Monitoring well KNABC - 17 on KMI property

F-2


-------
BROOKHURST SUBDIVISION

A sign for the Brookhurst subdivision

Dow/DSI property

F-3


-------
Monitoring well EPA 1-1 after well rehabilitation resulting in inoperable well

F-4


-------
Monitoring well EPA 2-2
F-5


-------
Monitoring well EPA 2-3

F-6


-------
APPENDIX G - DETAILED ARARS REVIEW TABLES

Groundwater

The 0U1 ROD identified the MCLs established by the Safe Drinking Water Act as the groundwater ARARs for
the Site. In the absence of an established MCL, proposed MCLs were selected for the remaining COCs and are to-
be-considered (TBC) criteria according to the OU1 ROD. Table G-l details the OU1 groundwater ARARs at the
time of remedy selection and their current standards. As shown in Table G-l, the five COCs with TBC criteria
now have established MCLs; the MCL for toluene is more stringent than the proposed MCL, while the MCLs for
PCE and trans-l,2-DCE were the same or less stringent than the proposed MCL, respectively.

Table G-l: ARAR Review for Groundwater COCs

(>miiii(lw;ilcr ( ()(

()l 1
(.rnuii(l\\;ik'r
ARARs

(iili/l.l

( iirivnl
Siiindiird

AKAK (h initio



(fiji/I.C



Benzene

5

5

No change

Ethylbenzene

700b

700

No change

Toluene

2,000b

1,000

More stringent

Xylenes

10,000b

10,000

No change

trans-l,2-DCE

70b

100

Less stringent

PCE

5b

5

No change

TCE

5

5

No change

1,1,1-TCA

200

200

No change

Notes:







a)Based on EPA's federal drinking water MCLs as of 2019 (40 CFR 141.11),
available at httos://www.era.eov/eround-water-and-drinkine-water/national-

Drimarv-drinkinu-watcr-rcmilations (accessed on 4/2/2019).
b)The OU1 ROD established the proposed MCL for these compounds as TBC criteria.

G-l


-------
APPENDIX H - SCREENING-LEVEL RISK REVIEW

Table H-l: Summary of Screening Level Vapor Intrusion Evaluation for the Dow/DSI Property



Miixiiniiin A Mil \ iiil

Risk for llisloric;il

Risk lor ('iiitciiI



(>miiiulw;iicr

(>roiimlw;iiiT

(>rouii(lw;iicr

(¦(>(¦

( oncciilriilion lug/1.)

( OIICCIII

r;il ions'

Coiicciilr;ilions''



Ilislork'iir

( iirrcnl1'

('.nicer

\onc;inccr

( .nicer

\onc;inccr



Risk

III

Risk

III

Trans-1,2-DCE


-------


Soil Action

Composite Worker RSI.1'







1 .e\ el

(mg/kg)



ny1

(llii/iird
(Jiioiienl)

(¦<>(¦

Bused on
Indiislriiil
Hxposure'1
(mg/kg)

( iineer-
IJsised RSI.
(10'' Risk)

Non-Csi liter

RSI.
(110= 1.0)

Risk'

Lie ii/ci ic

u .us:

5.1

420

l.o \ lo'

0.0002

Ethylbenzene

325

25

20,000

1.3 x 10"5

0.02

Toluene

107

--

47,000

NA

0.002

Xylenes

176

--

2,500

NA

0.07

Notes:

a.	The highest removal action cleanup level reported in the OU2 ROD.

b.	EPA RSLs, dated November 2018, available at https://semspub.epa. eov/work/HO/197422.pdf
(accessed 4/2/2019).

c.	Cancer risk calculated using the following equation, based on the fact that RSLs are derived
based on 1 x 10~6 risk: cancer risk = (soil action level cancer-based RSL) x 10~6.

d.	Noncancer HQ calculated using the following equation, based on the fact that the RSLs are
derived based on a HQ of 1: HQ = (soil action level noncancer RSL).

NA = not applicable

-- = EPA has not finalized a carcinogenic or noncarcinogenic toxicity value for this compound.

mg/kg = milligrams per kilogram	

Table H-3: Screening-Level Human Health Evaluation of 1,4-Dioxane Concentrations in Groundwater

Chemiciil

Miiximiim
(irouiulwiiier
l.4-l)io\iine
Deleclioir1
(fig/1.)

Tap Wilier Residenlhil RSI.1'
(ug/l.)

Risk'

None;ineer

ny

Risk-hiised

Nonciineer-hiised

1,4-Dioxane

0.69J

0.46

57

1.5 x 10"6

0.01

Notes:

a.	1,4-Dioxane concentrations were obtained from page 4 of the Completion of Remedial Action
and Completion of Work Report. Dated October 18, 2017.

b.	Current EPA RSLs. dated November 2018. are available at httos://www.era.eov/risk/reeional-
screenins-levels-rsls-seneric-tables (accessed 4/3/2019).

c.	The cancer risk was calculated using the following equation, based on the fact that RSLs are
derived based on 1 x 10~6 risk: cancer risk = (maximum detection cancer-based RSL) x 10~6.

d.	The noncancer HQ was calculated using the following equation, based on the fact that the RSLs
are derived based on a HQ of 1: HQ = maximum detection noncancer-based RSL.

|ig/L = micrograms per liter

J = estimated value

H-2


-------
APPENDIX I - INSTITUTIONAL CONTROLS

1-1


-------
1162491 -R8 SDMS

NOTICE OF USE RESTRICTIONS
AND RESTRICTIVE COVENANT

THIS NOTICE OF USE RESTRICTIONS AND RESTRICTIVE COVENANT is made
effective this Z@ day of	2010, by and between SCHLUMBERGER

TECHNOLOGY CORPORATION, as successor in merger to Dowel] Schlumberger
Incorporated hereinafter referred to as "SIC", the UNITED STATES OF AMERICA,
hereinafter referred to as "the United States", and the STATE OF WYOMING, hereinafter
referred to as the "State".

WITNESSETH:

WHEREAS, STC is the owner of real property (two parcels) ("the Property") as
described on Exhibit "A" attached hereto and by this reference incorporated herein; and

WHEREAS, STC, as successor to Dowell Schlumberger Incorporated., is a party to the
Consent Decree filed in the United States District Court for the District of Wyoming, Civil
Action Number 91 CV I042B; and

WHEREAS, STC, the United States, ami State have determined that the use of the
Property shall be restricted to the current uses which are industrial in nature to prevent future
exposures to environmental conditions and contaminants on or under the Property; and

WHEREAS, the United States and the State, as parties to this Notice of Use Restrictions
and Restrictive Covenants, are granted full rights of enforcement as to the provisions contained
herein.

Therefore. STC as owner in fee title of the Property, does hereby impose restrictions on
the use of the Property as follows;	mntowt county clerk, uy

R«nea Vitto	Recorded: $R

Sap 29, 2ti8 01:08:49 PH
AftFAAA Pat«s: M Fe«! $47.00
o959wv dcucll bwiswcnt*.

1

1-2


-------
1,	The Properly is presently zoned heavy industrial pursuant to the 2000 Natrona
County Zoning Resolution. STC does hereby agree and sets forth that said Property shall not be
used for any other purpose than heavy industrial as set forth in the Natrona County Zoning
Resolution. A copy of the Heavy Industrial classification for the Natrona County Zoning
Resolution is attached hereto and marked as Exhibit "B".

2,	The groundwater under or on the Property shall not be used for any use or
purpose, except for monitoring of groundwater elevations and periodic sample collection,
without the express approval of STC, the United States and the State.

3.	If any excavation into or through the ground surface at the Property is conducted
and soil is going to be sent off site for any reason, the soil will not be disposed of, applied or
used at property zoned for residential use unless it is tested in accordance with an EPA or
Wyoming DEQ approved methodology and shown to be safe for residential use.

4.	The Property shall not be used for any purpose that may cause or result in a
violation of any federal, state, or local laws, ordinances, or regulations related to environmental
conditions and contaminants on or under the Property.

5.	The Property shall not be used for any purpose that is determined to create, cause,
or result in risk to human health or the environment related to environmental conditions and
contaminants on or under the Property as determined by the United States, State, or any other
governmental agency having jurisdiction over the Property.

6,	The Property shall not be used for any purpose inconsistent with any existing
remedy agreement, decision document or other applicable agreement or document or decree or
order, or for any purpose that interferes with the implementation or completion of any response
actions required thereby.

2

1-3


-------
7.	The restrictions which are imposed upon this Property shall ran with the land and
be binding upon STC and its successors, assigns, future owners, future lessees, sub lessees and
occupants of the Property, including persons who take title to the Property as heirs, and their
invitees, guests, agents, employees or persons acting under their control or direction. The
restrictions are imposed for the purpose of protecting the public health and the environment and
to prevent interference with the performance and maintenance of any response actions required
by the United States, State and any other governmental agencies having jurisdiction over the
Property.

8.	STC, on behalf of itself and its successors, transferees and assigns, does hereby
agree that the United States and the State, their successors and assigns, as parties to this
instrument, shall have tlte right to enforce any and all terms contained herein.

9.	The restrictions on the use of the Property may not be modified, amended or
terminated by STC, its successors, transferees and assigns without written approval of the
United States or the State. In the event that STC conveys, transfers or assigns all or any part of
its right, title and interest in and to the Property, STC, the United States, and the State shall have
the retained and reversionary right to enforce the terms and conditions hereof.

10.	S'fC agrees that in the event of STC's default or non-compliance with the terms
of this Notice of Use Restrictions and Restrictive Covenant, the United States ami the State shall
have the right of specific performance of this instrument and the right to obtain from any court of
competent jurisdiction a temporary restraining order, preliminary injunction and permanent
injunction to obtain such performance.

3

1-4


-------
11.	It is STC's intent that this Property be encumbered by this Notice of Use
Restrictions and Restrictive Covenant and that such restrictions run with the land and are
enforceable by the United Slates and the State for the benefit of the public.

12.	Notice upon Conveyance. STC shall notify the United States and State promptly
after each conveyance of an interest in any portion of the Property. STC's notice shall include
the name, address, and telephone number of the Transferee or its representative, a copy of the
deed, or other documentation evidencing the conveyance, and an uniurveyed plat that shows the
boundaries of the property being transferred.

Each instrument hereafter conveying any interest in the Property or any portion of the
Property shall contain a notice of the activity and use limitations set forth in this Notice Of Use
Restrictions And Restrictive Covenant and provide the recorded location of this Notice Of Use
Restrictions And Restrictive Covenant. The notice shall be substantially in the following form:

THE INTEREST CONVEYED I1ERE13Y IS SUBJECT TO A NOTICE OF USE

RESTRICTIONS AND RESTRICTIVE COVENANT, DA TED 	, 2010,

RECORDED IN THE DEED OR OIITCIAI. RECORDS OF THE NATRONA COUNTY

RECORDER ON „	, 2010, IN I DOCUMENT	. OR BOOK PAGE	

THE NOTICE OF USE RESTRICTIONS AND RESTRICTIVE COVENANT CONTAINS
THE ACTIVITY AND USE LIMITATIONS PRESENTED IN EXHIBIT C.

13.	This Notice of Use Restrictions and Restrictive Covenant shall be interpreted in
all respects in accordance with the laws of the State of Wyoming, resolving any ambiguities and
questions of the validity of specific provisions so as to favor restricting use of the Property to
uses that are protective of human health and the environment and that will not interfere with the
performance and maintenance of any response actions required by the United States, State, or
any other governmental agencies having jurisdiction over the Property.

4

1-5


-------
14. If any provision of this Notice of Use Restrictions and Restrictive Covenant, or
the application thereof to any person or circumstance, is found to be invalid, the remainder of the
provisions of this Notice of Use Restrictions and Restrictive Covenant, or the application of such
provision to persons or circumstances other than those as to which it is found to be invalid, as the
case may be, shall not be affected thereby.

DATED this	day of	2010.

SCHLUMBERGER TECHNOLOGY
CORPORATION , , k

i U-i JJ

V\

0y;-

\ ; rt

'	I ->€k.3

' :> !L-<



Date

hi

Printed Name

\ / $ ) f

f. c

t J- (, f

Title (Printed)

STATE OF
COUNTY OFW

rrTolVllINU

)ss.

mx~ )

AzouJ

lorized represetftative of Scl

being first duly sworn, did say that he/she is the duty
authorized represerifative of Schlumbcrger Technology Corporation; and that he/she is authorized
by aid Corporation to execute the foregoing instrument on behalf of said Corporation and he/she
acknowledges the execution of said instrument to be the free act and deed of said Corporation,



Name

Title

I and sworn to before trie by
, 2010.

Witness my hand and official seal



this^f'day of.

My Commission Expires:



Notary Public

1-6


-------
UNITED STATES ENVIRONMENTAL
PROTECTION AGENCY

By:,



CWigs k

hlln

Dale



Pelted Name

> p

TitleVPrinted)



SL

Caniw

Qvi efT

^oUtfiAtb i?k
STATE OF WYOMING t ^

0fe«W S"a\ of ^c1' <* d. 2010.

Witness my hand and official seal.

My Commission Expires;

6

1-7


-------
EXHIBIT A

1-8


-------
1-9


-------
WARRANTY DEED

CHARLES V. TUNXSON and ALICE J. WNISON, Hu^aiKl and Wife

Cn«*r..l, at	—	_!5K52!!£.	—			 ......					€

„ *VS*5iG		&r sod tm ctuwidtrfttiti* *t. M9.*<>9- ^nd_oj^hgr.%q$d jjm		

	valuf&ie^pnsijiSL^^Ji—

In Hand {Mud, {*e*ipt wbwwf i* h&xhr »ckn<-^l«d«ed. CONVEY AND WARRANT TO				

thf_ noy	Compaq , a		

^Highiyan										

KlOLAXD 	_ _ _ _____ County, smt State of			_».	MICHIGAN

th« Mowing (tncribMi real estate, situate ia 						..... Cotmty *e£ State

«rf Wyoming, Hereby releasing and wsdvinc *lt riehts bb4#t art fey irbtae ©f the homestead exemption is«a oi the State,
to.witr

\ tract of land situated in the SfASVrtt, Section 5, Township 33 North, Range
?a Seat of the 6th ?.K., Natrona County, Wyoming, nsore particularly described
as follows.-

ComBsncing at the one-quarter corner canoon to Sections S and 6 of said
Township and Range; Thence S. 0°iS' w., 151.0 feet to a point; Thence S.
36°33* £., 543.7 feet to a poi.n&; Thence 5. 86°19» s., 1068.26 feet te the
point of beg liming; said point being located on the southerly right-of-way
line of th6 Chicago Burlington and Quincy Railroad Co, and being the north-
westerly comer of the tract heroin described; Thence S. S§°19* E., 261.7
feet Along said right-of-way to the northeasterly comer of the tract;

Ttience S. 0°15' ©27-3 foet to the southeasterly corner of the tract
arid a point on the northerly right-of-way line of the U. S, Highway No. 20;
Thence s. Siw., 269.9 feet along said right-of-way to the southwesterly
corner of the tract; thence N. 0°1S* E., 604.7 feet to the point of beginning.

EXCEPTING TKERE?T*0M a stri? of land beir.g a portion of the above described
tract, more particularly described as follows?

3eq;inning at the southwest corner of the above described tract of land;

Thence N. 0°15" E, for a distance of 36.4 f«et along the wast boundary
thereof; Thence S. Si°33* E. for a distance of 269.9 feet along a line
parallel to the north right of way boundary of State Highway U- s. 20 and
36.0 feet northerly thereof when uninsured at right angles thereto, to a
point on the east boundary of said tract of land; Thence S. 0°15" W. 36.4
feet to a point on the north right o£ way boundary of present State Highway
U.S. 20; Thence N, 31°33* W, 269.9 feet along said State Highway right of
way boundary to the point of beginning.

Together with all improvements thereon situate J J'-ECortU-irsOct 6 i$Sl aT3 :41oclg-~£; PM

1 iL-.v>v.t w 320270	 '

Subject to reservations and easements of racor>

S-OH^v l TC3JN	CCUN .'Y CLEKK.

U

WITNESS... SWZ...	 h»nd-.§	thb.-VLrrC	day	0K5J°**" CI..'...*'.	

lN-i«.Sui .» I,* »- i»;:

Wnison}'^^

STATE OF ., WV01£Sg.	i

COUNTY OF 		...HATRCMJA	_ J*"

Ttw tor.CT».C MnMR »M		

th\&	day	i-.9.L._—J__	t jf A "^T"

w. . ta-	Wtrf /?* <3^

\%\ X	- jfV/	Tit!* of Officer

*j	My ComnuMicJS Expires:

1-10


-------
EXHIBIT B

1-11


-------
Section 10, Heavy Industrial {HI}

a.	The intern and purpose of the HI district is to create and preserve an area for industrial
uses of liiat require isolation from many other land uses.

For each permitted or conditional use, check the definitions. Appendix A, and Design Criteria,
Chapter VII, to determine requirements for that specific use.

b,	The following are permitted uses in this district:

(1)	Accessory buildings ami uses.

(2)	Auto and truck wash.

(3)	Auto wrecker service.

(4)	Automobile, truck and trailer sales.

(5)	Business, retail; with or without outdoor storage.

(6)	Business, wholesale; with or without outdoor storage.

(7)	Chemical plant, processing and storage.

(8)	Concrete batch plant.

m	Construction yard and shop.

(10)	Creosote manufacturing and treating.

(11)	Gas and l-PG processing plant,

(12)	Heavy equipment sales and service.

(13)	Hot mix plain,

(14)	Mineral manufacturing, refining and processing.

(15)	Oil field or mining equipment.

(16)	Pipe yards, drill rig assembly.

(17)	Pipeline terminal and pump station.

(18)	Pre cast concrete manufacturing.

(1
-------
(1)	Mining: aggregate extraction (See Chapter VII, Design Criteria and Procedures),

(2)	Auto rcductionfrccyclir.g center.

(3)	Communication tower.

(2)	Manufacturing, and storage of explosives.

(3)	Public facility.

( Salvage yard.

(5)	Security quarters, subject to the following conditions;

(i)	The only employee accommodations allowed in the District be

exclusively for a caretaker or watchman employed specifically for the purpose of
providing full-time security and/or maintenance.

(ti)	The employee accommodations shall be contained within a

building containing a permitted use or. if outside the building, the employee
accommodations shall be a mobile home or travel trailer. No permanent security
structures shall be permitted on site.

(iii)	The employee accommodations must be on the sane property and
under the saute ownership as the use for which the occupants are providing
security or maintenance.

(iv)	All applicable covenants, bulk regulations, building codes, and
health department regulations shall be coaiplied with.

(6)	Sign, billboard advertising over 480 square feet, (See Chapter VII, Design Criteria
and Procedures. Section 4. Sign*)

(7)	Storage of flammable and combustible liquids in excess of 12,000 gallons.

(8)	Toxic and hazardous waste storage.

(9)	Utility installation.

(10)	Other similar and compatible uses as determined by the Board.

d.	Minimum district size is 10 acres.

e.	Minimum lot size is 2 acres.

f.	Minimum setbacks for principal end accessory buildings are as follows:

(1)	60 feet adjacent to all Federal, State and County roads.;

(2)	40 feet adjacent to ail other roads;

(3)	10 feet from all property lines not abutting a road; ISO feet adjacent to a business
or residential district.

g.	No Maximum Might.

h.	No minimum open space.

32

2000 Natrona County Zoning Resolution

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EXHIBIT C

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Notte® of Use Restrictions and Restrictive Covenant*

1.	The Property is presently zoned heavy Industrial pursuant So the 2000 Natrona County
Zoning Resolution. Grantee does hereby agree and sets forth mat said Property shall not be used (or any
other purpose than heavy industrial as set forth in the Natrona County Zoning Resolution,

2.	The groundwater under or on the Property shall not be used for any use or purpose,
except tor monitoring of groundwater elevations and periodic sample collection, without the express
approval of Grantee, tie United States and the State.

3.	If any excavation into or through the ground surface at the Property is conducted and soil
is going to tie sent off site for any reason, the soil will not be disposed of, applied or used at properly
zoned for residential use unless it is tested in accordance with an EPA or Wyoming DEQ approved
methodology and shown to be safe for residential use.

4.	The Property shall not be used for any purpose that may cause or result in a violation of
any federal, state, or local laws, ordinances, or regulations related to environmental conditions and
contaminants on or under the Property.

5.	The Property shall not be used for any purpose that is determined to create, cause, or
result in risk to human health or the environment related to environmental conditions and contaminants on
or under the Property as determined by the United States, State, or any other governmental agency
having jurisdiction over the Property.

6.	The Property shall not be used for any purpose inconsistent with any existing remedy
agreement, decision document or other applicable agreement or document or decree or order, or for any
purpose that interferes with the implementation or completion of any response actions required thereby.

7.	The restrictions which are imposed upon this Property shall run with the land and be
binding upon Grantee and its successors, assigns, future owners, future lessees, sub lessees and
occupants of the Property, including persons who take title to the Property as heirs, and their invitees,
guests, agents, employees or persons acting under their control or direction. The restrictions are
imposed for the purpose of protecting Ihe public health and the environment and to prevent interference
with the performance and maintenance of any response actions required by the United States, State and
any other governmental agencies having jurisdiction over the Property.

8.	Grantee, on behalf of itself and its successors, transferees and assigns, does hereby
agree that Hie United States and the State, their successors and assigns shall have the right to enforce
any and all terms contained herein.

9 The restrictions on the use of the Property may not be modified, amended or terminated
by Grantee, its successors, transferees and assigns, without written approval of the United States or the
State. In the evenl that Grantee conveys, transfers or assigns all or any part of its right, title and interest
in and to the Property. Grantee, the United States, and the State shall have the retained and reversionary
right to enforce the terms and conditions hereof.

10. Grantee agrees that in the event of Grantee's default or non-compliance with the terms of
this Notice of Use Restrictions and Restrictive Covenants, the United States and the State shall have the
right of specific performance of this instrument and the right to obtain from any court of competent
jurisdiction a temporary restraining order, preliminary injunction and pennanent injunction to obtain such
performance.

11 It is Grantee's intent that mis Property be encumbered by this Notice of Use Restrictions
and Restrictive Covenants and that such restrictions run with the land and are enforceable by the United
States and the State for the benefit of ihe public.

12.	This Notice of Use Restrictions and Restrictive Covenants shall be interpreted in all
respects in accordance with the laws of the State of Wyoming, resolving any ambiguities and questions of
the validity of specific provisions so as to favor restricting use of the Property to uses that are protective of
human health and the environment and that will not interfere with the performance and maintenance of
any response actions required by the United States, State, or any other governmental agencies having
jurisdiction over the Property.

13.	If any provision of this Note of Use Restrictions and Restrictive Covenants, or the
application thereof to any person or circumstance, is found to be invalid, the remainder of the provisions
of this Notice of Use Restrictions and Restrictive Covenants, or the application of such provision to
persons or circumstances other than those as to which it is found to be invalid, as the case may be, shall
not be affected thereby.

Page 1 of 1

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1162490-R8SDMS

NBTHONft COUNTY CLERK, UY

Remsa Vltto	R«cord«l: SR

Sap 29, 2010 01:01:91 PH
mm	Paf*s: 3	F««: $20,08

895899 «»»nose*

SPECIAL WARRANTY DEED

KINDER MORGAN, INC., a Kansas corporation with an address of 370 Van Gordon, P. O. Box 281304,
Lakewood, Colorado 80228 - 8304 (formerly known as K N Energy, Inc., Kansas Nebraska Natural Gas Company. Inc..
Kansas Pipeline & Gas Co and successor in interest to Northern Gas Company, by merger), successor in interest to
North Central Gas Company, successor in interest to Northern Utilities, Inc., ("GRANTOR"). County of Jefferson and
State of Colorado, for and in consideration of Five Dollars ($5 00) and other good and valuable consideration, in hand
paid, hereby sells and conveys to KM UPSTREAM LLC,, a Delaware limited liability company ("GRANTEE"), whose legal
address is 370 Van Gordon, P.O. Box 281304-8304, Lakewood, Colorado 80228-8304 of the County of Jefferson and
State of Colorado, the parcels of real estate situated in Natrona County, Wyoming (the "Property"), together with all of
Grantor's right, title and interest, if any, in and to (i) all improvements located on the Property, and (ii) all and singular, the
rights and appurtenances pertaining to the Property as more particularly described on Exhibit "A" and subject to certain
use restrictions and restrictive covenants as more particularly described on Exhibit "B", both attached hereto and made a
part hereof.	.

This conveyance is subject to all matters recorded in the real property records of Natrona County, Wyoming and all
matters that would be revealed by a current, on the ground survey of the Property.

Grantor warrants the title against alt persons claiming by, through or under the Grantor but not otherwise.

Signed this &4... day of		2010.

GRANTOR(S):

KINDER MORGAN, INC.

STATE OF TEXAS	)

) ss.

COUNTY OF HARRIS	)

The foregoing instrument was acknowledged before me this <4^dav
je&eM usrtMMr. ac. Vic-*

Witness my hand and official seal.

My commission expires: /JQ/Jio/3		

.2010, by

£Mc..

¦MwtwyOHhlln 
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EXHIBIT "A"

Attached to and made a part of that certain Special Warranty Deed dated Jj'Jth. . 2010 by and
between Kinder Morgan, Inc., as Grantor, and KM Upstream lie, as Grantee.

Parcel 1 -

A portion of the Northwest Quarter of the Southwest Quarter (NW/4SW/4) of Section 5,

Township 33 North, Range 78 West of the P.M., described, as follows;

Beginning at a point which is the intersection of the west boundary of Section 5, T33N, R78W, 6W
P.M., and the south boundary of the Chicago, Burlington & Quincy Railroad Company right of way
and bears South 0" 15' West 151 feet from the west quarter comer of said section, township and
range, thence running South 86° 21' East 5511 feet, along the south boundary of the C. B. & Q
right of way, thence South 0° 15' West 815.5 feet to the north boundary of the Chicago & North
Western Railway Company right of way, thence North 81° 29' West 555.9 feet along said north
boundary of the C. & N. W. right of way to the west boundary of Section 5, T33N, R78W. 6* P.M.,
thence North 0° 15' East 768.3 feet along said west boundary of said Section 5 to the point of
beginning, containing 10 acres, more or less.

SAVE AND EXCEPT:

A strip of land 136.0 feet wide along the south boundary of a ten acre tract of land in the
NW/4SW/4 of Section 5, T33N - R78W of the 6th P .M . described as follows:

The strip of land hereby conveyed and quit claimed being ail that portion of the above
described ten acre tract as follows:

Beginning at a point which is the intersection of the west boundary of Section 5 and the north
boundary of the Chicago, Burlington & Quincy Railroad Company right of way, which point bears
S 0° 15' W a distance of 919 3 feet, more or less, from the west quarter corner of said Section 5,
thence running N 0° 15' E along the west boundary of said Section 5 for a distance of .137.4 feet;
thence running S 81° 29' E for a distance of 555.9 feet parallel to the north boundary of the
Chicago & North Western Railway Company right of way and 136 0 feet northerly thereof when
measured at right angles thereto, to a point on the east boundary of said ten acre tract; thence
running S 15° W for a distance of 137.4 feet to appoint on the north boundary of said railway
company right of way; thence running N 81° 29' W, along the north boundary of said railway
company right of way for a distance of 555.9 feet to the point of beginning.

Said strip of land containing 1.74 acres, more or less of which approximately 1.28 acres are
contained in the right of way of the present highway.

Parcel 2 -

A tract of land in the Northwest Corner of said N/2SW/4 of Section 5, Township 33 North, Range
78 West of the 6th P.M., said tract being more particularly described, as follows:

Beginning at the Northwest Corner of said N/2SW/4 of Section 5, running thence S 0° 15' W ,
151 feet along the west boundary of Section 5 to a point on the south boundary of the right of way
for C. B & Q. RR., which point is the Northwest Corner of the North Central Gas Co.'s tract,
thence S 86° 33' E., 549.7 feet along said railroad right of way boundary to an iron pin marking
the northeast corner of said Gas Co.'s tract, thence S 0° 15' W., 314.0 feet aiong the east
boundary of said Gas Co. 's tract to a Vz steel reinforcing rod marking the Northwest Corner of the
tract being described, thence S 81° 33' E., 800 0 feet along a line parallel to the north boundary of

Exhibit "A" Page 1 of 2

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the State Highway U S 20, to a'/«" reinforcing rod marking the Northeast Corner of said tract
being described, thence S 0° 15' W„ 400,0 feet to a V4" reinforcing rod on the north boundary of
the 100 feet wide right of way for State Highway U S 20, marking the Southeast Corner of the
tract being described, thence N 81" 33' W., 800.0 feet along said highway right of way to an iron
pin on the east boundary of the Gas Co.'s tract, marking the Southwest Comer of the tract being
described, thence N 0° 15' E., 400.0 feet along the east boundary of the Gas Co.'s tract to the
above described Northwest Corner of the tract being described, situated in the County of
Natrona. State of Wyoming.

Parcel 3 -

Commencing at the West Quarter Corner of Section 5, Township 33 North. Range 78 West of the
6* P.M., Natrona County, Wyoming, thence South 0° 15' West, 151.0 feet to a point, thence
South 86° 33' East, 549.7 feet to the point of beginning, said point being situated at the
Northeasterly Corner of the North Central Gas Company's tract and also a point of the southerly
right of way line of the Chicago Burlington and Quincy Railroad, thence South 86° 19" East,
793,7 feet along the southerly right of way line of said railroad to a point, thence South 0° 15'
West, 381.5 feet to a point, thence North 81° 33' West, 800 feet to a point, situated on the
easterly boundary of the North Central Gas Company's tract, thence North 0° 15' East, 314.7 feet
along said boundary to the point of beginning, containing 6.36 acres.

Parcels 1,2 and 3 comprise the "Property* and contain 21.97 acres, more or less.

Exhibit "A" Page 2 of 2

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EXHIBIT "B"

NOTICE OF USE RESTRICTIONS AND RESTRICTIVE COVENANTS

Attached to arid made a part of that certain Special Warranty Deed dated AtJil. ¦ 2010 by and
between Kinder Morgan, Inc., as Grantor, and KM Upstream LLC, as Grantee

1.	The Property is presently zoned heavy industrial pursuant to the 2000 Natrona County
Zoning Resolution. KM Upstream LLC does hereby agree and sets forth that said Property shall not be
used for any other purpose than heavy industrial as set forth in the Natrona County Zoning Resolution.

2.	The groundwater under or on the Property shall not be used for any use or purpose,
except for monitoring of groundwater elevations and periodic sample collection, without the express
approval of KM Upstream LLC. the United States and the State.

3.	If any excavation into or through the ground surface at the Property is conducted and soil
is going to be sent off site for any reason, the soil will not be disposed of, applied or used at property
zoned for residential use unless it is tested in accordance with an EPA or Wyoming DEQ approved
methodology and shown to be safe for residential use.

4.	The Property shall not be used for any purpose that may cause or result in a violation of
any federal, state, or local laws, ordinances, or regulations related to environmental conditions and
contaminants on or under the Property.

5.	The Property shall not be used for any purpose that is determined to create, cause, or
result in risk to human health or the environment related to environmental conditions and contaminants on
or under the Property as determined by the United States, State, or any other governmental agency
having jurisdiction over the Property

6.	The Property shall not be used for any purpose inconsistent with any existing remedy
agreement, decision document or other applicable agreement or document or decree or order, or for any
purpose that interferes with the implementation or completion of any response actions required thereby.

7.	The restrictions which are imposed upon this Property shall run with the land and be
binding upon KM Upstream LLC and its successors, assigns, future owners, future lessees, sub lessees
and occupants of the Property, including persons who take title to the Property as heirs, and their
invitees, guests, agents, employees or persons acting under their control or direction. The restrictions are
imposed for the purpose of protecting the public health and the environment and to prevent interference
with the performance and maintenance of any response actions required by the United States, State and
any other governmental agencies having jurisdiction over the Property

8.	KM Upstream LLC, on behalf of itself and its successors, transferees and assigns, does
hereby agree that the United States and the State, their successors and assigns shall have the right to
enforce any and ail terms contained herein.

9.	The restrictions on the use of the Property may not be modified, amended or terminated
by KM Upstream LLC, its successors, transferees and assigns, without written approval of the United
States or the State. In the event that KM Upstream LLC conveys, transfers or assigns all or any part of its
right, title and interest in and to the Property, KM Upstream LLC, the United States, and the State shall
have the retained and reversionary right to enforce the terms and conditions hereof.

10 KM Upstream LLC agrees that in the event of KM Upstream LLC's default or non-
compliance with the terms of this Notice of Use Restrictions and Restrictive Covenants, the United States
and the State shall have the right of specific performance of this instrument and the right to obtain from
any court of competent jurisdiction a temporary restraining order, preliminary injunction and permanent
injunction to obtain such performance.

11.	It is KM Upstream LLC's intent that this Property be encumbered by this Notice of Use
Restrictions and Restrictive Covenants and that such restrictions run with the land and are enforceable by
the United States and the State for the benefit of the public.

12.	This Notice of Use Restrictions and Restrictive Covenants shall be interpreted in all
respects in accordance with the laws of the State of Wyoming, resolving any ambiguities and questions of
the validity of specific provisions so as to favor restricting use of the Property to uses that are protective of
human health and the environment and that will not interfere with the performance and maintenance of

Exhibit •B* Page 1 of 2

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any response actions required by the United States, State, or any other governmental agencies having
jurisdiction over the Property,

13. If any provision of this Notice of Use Restrictions and Restrictive Covenants, or the
application thereof to any person or circumstance, is found to be invalid, the remainder of the provisions
of this Notice of Use Restrictions and Restrictive Covenants, or the application of such provision to
persons or circumstances other than those as to which it is found to be invalid, as the case may be, shall
not be affected thereby.

Exhibit "B" Page 2 of 2

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