Region 8

Lockwood Solvent Ground Water Plume

Lockwood Solvent Superfund Site Location Map
Site Type: Final NPL
City: Billings
County: Yellowstone
Street Address: Lockwood Road
ZIP Code: 59101
EPA ID: MT0007623052
Site Aliases: Lockwood Solvent
Congressional District: At Large

What's New?

Updated October 2014

A remedy optimization has been completed for both operable units at the site. Optimization studies are a systematic site review by a team of independent technical experts, at any phase of a cleanup process, to identify opportunities to improve remedy protectiveness, effectiveness and cost efficiency, and to facilitate progress toward cleanup completion. The optimization reports are available in Site Documents.

EPA and the Montana Department of Environmental Quality (DEQ) approved an addendum to the Remedial Design Assessment Work Plan to conduct additional investigations around the Soco West Facility in Operable Unit 2 (OU2). The work plan associated with this sampling event is available in Site Documents. An investigation of the source areas located on Soco West’s facility took place in late July 2014, where soil and groundwater samples were taken. Samples were also collected from the source area for a bench-scale treatability (laboratory) studies. The treatability study will look at the types of treatment, such as chemical oxidation and ozone, that may be appropriate to inject into the soils and groundwater to treat the source areas.

Top of Page

Site Description

The Lockwood Solvent Ground Water Plume site spans 580 acres on the outskirts of Billings, Montana. Much of the groundwater at the site is contaminated with the volatile organic compounds (VOCs) tetrachloroethylene (also known as perchloroethylene or PCE), trichloroethylene (TCE), cis-1,2-dichloroethene (DCE) and vinyl chloride (VC). These chemicals are hazardous to human health. (More information is available in the Integrated Risk Information System database at The primary sources of contamination are from the former Beall Trailers of Montana and Soco West (formerly Brenntag West Inc.) facilities. The VOCs leached from the grounds of the two facilities into groundwater serving as potable water for some of Lockwood’s residents. These VOCs can also disperse as vapor and enter the indoor air of buildings.

Maps of the Superfund site boundary and Operable Units

Top of Page

Site Risk

Groundwater at the site was found to have levels of PCE, TCE, DCE, and VC above the drinking water standard (the Safe Drinking Water Act Maximum Contaminant Level), which could pose long-term risks to public health and the environment.

Media Affected Contaminants Source of Contamination
groundwater, surface water, sediment, soils chlorinated solvents bulk storage/cleaning operations

In response to the imminent and substantial threat posed by the contaminated groundwater, EPA extended the public water supply system, which allowed residents to discontinue use of the contaminated groundwater. The municipal water supply currently provided to residents is safe and is regularly sampled to ensure it is within drinking water standards.

diagram of how vapor intrusion occurs
How vapor intrusion occurs

Recently, EPA released the final health assessments for PCE and TCE to the Integrated Risk Information System (IRIS) database. IRIS is a human health assessment program that evaluates the latest science on chemicals in our environment. The final assessments characterize the chemicals as carcinogenic to humans and as a human non-cancer health hazard. These assessments allow for a better understanding of the risks posed to communities from exposure to PCE and TCE in soil, water and air. They will provide federal, state, local and other policy makers with the latest scientific information to make decisions about cleanup and other actions to protect people's health. The new assessments are currently being evaluated by the Lockwood Solvent site team because both PCE and TCE are primary contaminants of concern at the site and can disperse as vapor into the indoor air of buildings. More information is available on IRIS at

Top of Page

Cleanup Progress

The site was proposed for placement on the Superfund National Priorities List (NPL) in May 2000. The listing became final on December 1, 2000. Upon discovery of the health threat posed by the release, the Montana Department of Environmental Quality (MDEQ) supplied affected residents with bottled water until the EPA Emergency Response branch could extend the public water supply line to the area for potable water and domestic use. On August 16, 2005, following the completion of a remedial investigation and feasibility study (RI/FS), a Record of Decision (ROD) was signed by the MDEQ and EPA. The ROD identified the appropriate remedy for the site, expecting to meet all remedial action objectives and Applicable or Relevant and Appropriate Requirements within the shortest amount of time for the lowest cost. The treatment outlined in the ROD would permanently destroy the contaminants of concern to reduce risk to concentrations below proposed remediation goals in all environmental media. Because it would treat both the source materials constituting the principal threats and the groundwater, the remedy would also meet the statutory preference for the selection of a remedy that involves treatment as a principal element.

Operable Unit 1 (OU1) is the Beall Source Area and Operable Unit 2 (OU2) is the Soco West Area. Both OUs were included in the 2005 ROD.

Major components of the ROD are as follows:

Site-Wide Elements
  • Long-term groundwater monitoring.
  • Five-year CERCLA reviews.
  • Institutional controls.
    • Controlled groundwater area.
    • Deed notices/deed restrictions.
    • Community awareness/education.
  • Risk mitigation measures.
  • Continued potable well(s) groundwater monitoring and mitigation measures.
  • Indoor air monitoring and mitigation measures.
Beall Source Area Groundwater and Plume Leading Edge
  • Treat with enhanced bioremediation.
Beall Source Area Soil
  • Treat vadose soil with soil vapor extraction.
Brenntag Source Area Groundwater
  • Contain and treat with a permeable reactive barrier (or other treatment/containment barrier technology determined by MDEQ and EPA during remedial design to be equally effective in achieving performance criteria as set forth in this Record of Decision).
  • Treat with enhanced bioremediation.
Brenntag Source Area Soil
  • Excavate accessible vadose-zone soil and accessible fine-grain saturated-zone soil and thermally treat on-site.
  • Treat inaccessible vadose soil with soil vapor extraction.
  • Treat inaccessible saturated zone soil with chemical oxidation.
Site-Wide Groundwater
  • Treat with enhanced bioremediation followed by monitored natural attenuation.

On October 3, 2011, the consent decree for the remedial design/remedial action (RD/RA) was entered in Federal District Court for the District of Montana. The court approved the settlement reached by the United States, the State of Montana and Soco West, Inc. for the cleanup of Operable Unit 2 (OU2).

HydraSleeve well sampling
Team using HydraSleeve groundwater sampling to capture
a core of water from a discrete interval in the screened
portion of the well.

In April 2012, additional chemical and geotechnical data were collected at the Beall Source Area in order to design the remedial action components for OU1. The chemical and geotechnical data are currently being evaluated to determine the best approach for remediating the source of contamination at the Beall property. In October 2012, an aquifer test was performed to better define the characteristics of the groundwater for remediation of the contaminated groundwater plume. The Remedial Design Supplemental Sampling Program Quality Assurance Project Plan and the Aquifer Test work plan for Beall Operable Unit 1 are available in Site Documents below. These documents detail the investigation activities in and around the Beall Trailers property.

EPA approved Soco's Remedial Design Assessment Work Plan and Quality Assurance Project Plan. Both of these documents can be found in the Site Documents section below. Soco’s contractor collected additional soil and groundwater data in the summer of 2014 to support the development of the remedial design components of the remedy for OU2.

Two rounds of indoor air sampling of homes and business around the Lomond Lane area have been completed. Sampling was conducted to determine if vapors emanating from the volatilization of contaminants in the groundwater is occurring. The results indicate that the indoor air in all structures sampled are below recommended cleanup levels for indoor air. A report is currently undergoing review by EPA and DEQ and will be available in the site repository once it has been completed. EPA performed a similar investigation near the Beall property.

Semiannual groundwater sampling will continue on both the Beall and Soco Operable Units, with the next round scheduled for October 2014.

Top of Page

Community Involvement

Community involvement plays an important role in the Superfund process. EPA uses a number of different tools and resources to promote effective, ongoing, meaningful community involvement. The goals of the Superfund community involvement program are to:

  • Keep communities affected by sites informed throughout the cleanup process.
  • Provide opportunities for communities to comment and offer their input about site cleanup plans.
  • Facilitate the resolution of community issues tied to a site.

Top of Page


EPA places a high priority on land reuse as part of its Superfund response program mission. The agency tries to select cleanup options that encourage and support future use of a site. EPA uses two fundamental methods to facilitate reuse of Superfund sites:

  • Exploring future uses before the cleanup remedy is implemented, an approach that gives the Agency the best chance of designing cleanup remedies to support the likely future use of a site.
  • Working with landowners and communities to remove barriers not considered necessary for the protection of human health or the environment at those sites where remedies are already in place.

One option for reuse is the siting of clean and renewable energy projects on contaminated (or formerly contaminated) lands. As part of this effort, EPA is evaluating the potential for energy projects on these properties and working with landowners and communities to identify ways to remove barriers to such projects.

An important part of the Superfund cleanup process is working with communities to promote site reuse after cleanup.

In addition to making the cleanup protective of human health and the environment, EPA is working with the Lockwood community to plan for appropriate future land reuse options within the Lockwood cleanup process. It is possible that all or parts of the Lockwood sites, including the source areas where contamination started, may be sold to new owners during or after the cleanup process. A change of ownership will not affect the Superfund cleanup plan or its quality.

EPA provides guidance to make sure that the cleanup standards are maintained throughout all Superfund property ownership changes. EPA also continues to partner with the community and new property owners to promote safe and productive use planning for Superfund areas.

Lockwood Ground Water Plume site area residents, as well as both source and non-source commercial property owners, are able to refinance and/or sell their properties during and after cleanup. EPA provides assistance, when needed, to facilitate these land transactions. There are several EPA programs in place to help "innocent landowners," those who purchase contaminated property with no prior knowledge of contamination; "contiguous landowners," property owners who have owned land that became contaminated during their period of ownership; and those who inherit contaminated property in refinance and sales transactions.

Top of Page

Land Use Controls and Other Institutional Controls

Land use controls are the most common type of institutional control (IC). ICs are administrative or legal controls that help reduce the likelihood for human exposure to contamination. ICs can also help protect the integrity of the remedy. Examples of ICs are:

  • Zoning ordinances.
  • Environmental covenants.
  • Deed notices.
  • Well-drilling restrictions.
  • Building permits.
  • Informational advisories.

The 2005 Record of Decision documented the selection of groundwater use restrictions, deed notices/restrictions, and community awareness and education programs as the institutional controls for the site. Soco West is currently working with EPA to file a deed notice with the Clerk and Recorder's Office of Yellowstone County, Montana, on the property it owns in OU2. In 2015, Soco West will also provide the supporting information needed to allow RiverStone Health to prepare a petition to the Department of Natural Resources and Conservation to establish a controlled groundwater area under Title 85, Chapter 2, Part 5 Montana Code Annotated.

Top of Page

Five-Year Reviews

EPA or the lead agency conducts five-year reviews following the start of a Superfund cleanup when contamination is left on the site. These reviews are repeated every five years. We use these reviews to determine:

  • How the remedy is working.
  • If the remedy remains protective of human health and the environment.

Five-year reviews are not yet required at this site.

Top of Page

Site Documents

You will need Adobe Reader to view some of the files on this page. See  EPA's PDF page to learn more.

Optimization Review Reports for OU1 and OU2, September 22, 2014

Addendum 01 to the Remedial Design Assessment Work Plan for Soco West Area (OU2), July 9, 2014

Open House Presentation, January 24, 2013

Site Update Fact Sheet, December 2012

Remedial Design Assessment Quality Assurance Project Plan for Soco West Area (OU2), Revised December 14, 2012

Data Trend Evaluation Technical Memorandum for the Remedial Design Supplemental Sampling Program, Beall Source Area (OU1), October 23, 2012

Dewatering Monitoring Plan for the Lockwood Water and Sewer District Sewer Installation, June 2012

Remedial Design Aquifer Testing Program for Beall Source Area (OU1), July 11, 2012

Open House Presentation, April 24, 2012

Site Update Fact Sheet, April 2012

Supplemental Sampling Program Quality Assurance Project Plan, Beall Source Area Operable Unit 1, March 15, 2012

Community Involvement Plan, November 2011

Remedial Design/Remedial Action Consent Decree, October 3, 2011

Record of Decision (PDF), August 16, 2005(241 pp, 3.6 MB)

Feasibility Study Report, July 6, 2004

Remedial Investigation Report, June 2003

Top of Page



Tillman McAdams
Remedial Project Manager (for OU1)
U.S. Environmental Protection Agency
Region 8, Montana Office
Federal Building
10 West 15th Street, Suite 3200
Helena, MT 59626
866-457-2690 (toll free)

Roger Hoogerheide
Remedial Project Manager (for OU2)
U.S Environmental Protection Agency
Region 8, Montana Office
Federal Building
10 West 15th Street, Suite 3200
Helena, MT 59626
866-457-2690 (toll free in Montana)

Montana DEQ

Richard Sloan
Remedial Project Officer
Montana Department of Environmental Quality
1100 North Last Chance Gulch
P.O. Box 200901
Helena, MT 59620-0901
800-246-8198 (toll free in Montana)

Site Information Repositories:

Montana State University – Billings
Library – Reference Section
1500 University Drive
Billings, MT 59101

EPA Superfund Records Center
Montana Office
10 West 15th Street, Suite 3200
Helena, MT 59626
866-457-2690 (toll free)
Hours: M-F, 8:00 a.m.-4:30 p.m.

Top of Page

Photo/Video Gallery

Click on a thumbnail below to view the full size image.

Former acid tank farm looking west
Former acid tank farm looking east
Former acid tank farm looking northeast
Looking north
Looking north at rail spur
Looking northeast
Looking northwest at soil vapor extraction system
Looking south at rail spur
Looking west
Soil vapor extraction shed

Top of Page


ATSDR Public Health Assessment, July 7, 2003

Montana Department of Environmental Quality, Remediation Division Exit

Montana State University Billings Library Exit

Top of Page