Region 8

Air Force Plant PJKS

Air Force Plant PJKS site location map Site Type: Federal Facility Final NPL
City: Littleton
County: Jefferson
Street Address: 12275 S. Highway 75
ZIP Code: 80127
EPA ID: CO7570090038
SSID: 08F8
Congressional District: 6

What's New?

Updated May 2014

There will be a Restoration Advisory Board (RAB) meeting on Thursday evening, May 8, 2014, from 6-8 p.m. at the Peak Community & Wellness Center, 6612 South Ward Street, Littleton, Colorado. The RAB is a forum for the Air Force and regulators to discuss environmental remediation methods, issues, and progress with interested citizens. The PJKS RAB has been meeting regularly since 1996 and is comprised of Air Force and state of Colorado and EPA representatives and community members. All members of the public are welcome to attend. The May RAB meeting agenda will include a discussion of the final site completion report and the draft operation and maintenance plan for the site. There will also be a discussion about the future of the RAB now that cleanup activities required at PJKS are complete, and the site is now in the operation and maintenance phase.

The Record of Decision for the former U.S. Air Force Plant PJKS Superfund Site was finalized in 2013. EPA, the Colorado Department of Public Health and Environment (CDPHE), and the U.S. Air Force signed the Record of Decision, which describes the final remedy selected for the site.

Both groundwater and soils were impacted by environmental contamination at the PJKS site. The contaminants of concern in the three groundwater plumes at the site are trichloroethylene (TCE) and N-nitrosodimethylamine (NDMA). The Record of Decision selects in-situ bioremediation as the preferred means for eliminating TCE in groundwater at the site. In-situ bioremediation involves injecting organisms into the groundwater on-site to treat the contaminants. For NDMA in groundwater, EPA and CDPHE granted the Air Force a Technical Impractibility Waiver. The waiver was granted because past studies did not successfully identify a technology that could degrade NDMA in groundwater. The long-term goal of the selected groundwater remedy is to, wherever practicable, achieve unlimited use/unrestricted exposure levels for NDMA and TCE in all PJKS groundwater. Until that goal is achieved, the Record of Decision selects land use controls, which prohibit the use of the groundwater on the site, as part of the remedy.

The Record of Decision also details the 53 contaminated soil areas at PJKS that have already been investigated and addressed via interim response actions. Polychlorinated biphenyls (PCBs) were the only contaminants of concern in these soil areas. For those areas where the goal of unlimited use/unrestricted exposure levels could not be achieved, the selected remedy calls for engineered covers such as concrete or asphalt, and/or the implementation of land use controls that will prohibit human access and exposure to these soil areas.

For more detailed information about the final selected remedy, view the Record of Decision in Site Documents below.

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Site Description

Air Force Plant PJKS is owned and operated by Lockheed Martin Astronautics Operation. The plant is located 25 miles southwest of Denver, near Waterton Canyon in the South Platte River Basin.

PJKS consists of 464 acres, surrounded by another 4,700 acres of Lockheed Martin land. Company operations at PJKS include testing the Titan rockets, as well as designing, developing, testing and manufacturing a variety of advanced technical systems for space and defense. In 1989 the U.S. Environmental Protection Agency (EPA) placed the PJKS site on its National Priority List (NPL).

Map of the Superfund site boundary, March 15, 2007

The Air Force is responsible for the cleanup at PJKS. CDPHE is the lead regulator of the cleanup, with EPA oversight. Many studies were done during the 1990s to determine the nature and extent of site contamination. The Air Force submitted a Supplemental Remedial Investigation report to CDPHE and EPA in 1999. The report detailed investigations into the nature and extent of soil and groundwater contamination across PJKS. Investigations identified 53 contaminated soil sites and three groundwater plumes at PJKS. The groundwater plumes are identified as East and West Fork Brush Creek and Lariat Gulch. Today, all 53 soil sites have been addressed. The groundwater at the PJKS site is being treated for contaminants. The groundwater leaving PJKS is being collected by Lockheed Martin at the Lockheed Martin property boundary and treated for TCE and NDMA.

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Site Risk

The potential risks to human health and the environment stem from contaminated soil and groundwater. The Agency for Toxic Substances and Disease Registry (ATSDR) completed a public health assessment for PJKS in March 2000. The purpose of the study was to assess whether contamination from the plant might threaten public health. ATSDR concluded that PJKS poses no apparent public health hazard to the surrounding neighborhoods.

Media Affected Contaminants
groundwater, soils, structures, surface water trichloroethylene (TCE), N-nitrosodimethylamine (NDMA) and polychlorinated biphenyls (PCBs)

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Cleanup Progress

Operable Units (OUs)

To make the cleanup more manageable, PJKS was divided into six operable units (OUs). An OU is made up of areas with certain qualities in common—for example, similar wastes or industrial processes.

OU1 consists of systems and facilities that were used for testing equipment, which used mainly hydrazine fuels and nitrogen tetroxide.

OU2 covers the engineering propulsion laboratory facilities, where engines were tested. It is also where rocket propellant gas and fluorine gas were generated. The investigation includes soils, building structures and groundwater. In October 2001, the Air Force completed a soil removal action at two high priority sites at OU2—the Upper and Lower Volcanoes. About 6000 tons of PCB-contaminated soil were removed.

OU2 also contains the T8-A containment pond, which was cleaned by removing and treating the pond water, removing the sediment, and shutting off the sources of water to the pond. Today, the cleanup and closure of the T8-A pond is complete.

OU3 is made up of the test stands and deluge system where rocket engines were test fired. In 1986 two half-full drums of scrap metal alloy containing low levels of radioactive waste were removed from the D-1 landfill, part of OU3. In fall 2005, the site investigation was completed at the D-1 landfill, including utility abandonment, well abandonment, and soil excavation. Cleanup of the D-1 landfill is complete.

OU4 involves the Lariat Gulch groundwater plume that affects groundwater, surface water and sediment along an unnamed Lariat Gulch tributary. The plume consists mainly of solvents. It extends north of the PJKS property boundary onto Lockheed Martin property. The remedial investigation for Lariat Gulch was completed in 2002.

OU5 covers the Brush Creek groundwater plume which flows beneath the West Fork of Brush Creek and one of its tributaries, also beneath the East Fork of Brush Creek. Groundwater beneath the East Fork of Brush Creek on PJKS property is monitored regularly. A geotechnical investigation was conducted there to help guide remedial work. Groundwater plumes are being addressed using in-situ bioremediation, as described in the 2013 Record of Decision. The Air Force expects environmental remediation at Air Force Plant PJKS to continue into 2014. Long-term treatment of groundwater source areas and groundwater pump and treatment systems will be ongoing.

OU6 is the ordnance-testing laboratory once used for detonation of waste detonators and ordnance. Suspected contaminants include propellants, explosives, pyrotechnics, pesticides, greases and oil solvents. It was recently confirmed that the Open Burning/Open Detonation Unit in OU6 requires no further cleanup.


To treat TCE, a bedrock pilot study began in fall 2003 at three source locations known to have high contaminant concentrations in the bedrock aquifer groundwater. The three source locations include the engineering propulsion lab, the systems and components area and the D-1 landfill. The pilot study used a process called in-situ bioremediation, whereby carbon and naturally occurring bacteria are injected directly into the groundwater plume. Results indicated that the process reduced TCE concentrations by two-thirds at the D-1 Landfill Bedrock Pilot Study monitoring well. However, this same treatment was less successful at treating TCE at the Engineering Propulsion Lab and the systems and components area. After conducting supplemental activities at those locations and performing additional sampling, the study demonstrated that in-situ bioremediation works at all three source areas.

In September 2005, the Air Force prepared and provided for public comment a focused Engineering Evaluation/Cost Analysis (EE/CA) to evaluate cleanup options for TCE in groundwater at PJKS. The preferred alternative described in the EE/CA was in-situ bioremediation, as demonstrated in the above pilot study.

The Air Force attempts to find an acceptable technology to reduce levels of NDMA in groundwater at PJKS proved unsuccessful. Meanwhile, Lockheed Martin has instituted an interim measure by which all groundwater leaving Lockheed Martin property is collected for TCE and NDMA treatment. This includes groundwater from PJKS.

Annual Groundwater Monitoring

The Air Force monitors for NDMA and VOCs, including TCE, in the groundwater at PJKS every spring and fall. The most recent groundwater monitoring report shows no significant data changes. The trend indicates that the groundwater plumes are stable and the levels of TCE are decreasing.


There are 53 identified soil contamination areas at PJKS. In October 2005, the Air Force completed numerous interim measures, including excavating soils in 16 locations, known as the combined soils, which had high levels of PCBS. One of these locations requires an environmental covenant, which ensures restricted use, because some PCBs remain capped in place in that area. Currently, remediation is complete at all 53 identified contaminated soil areas at PJKS. The last two soil areas of concern were addressed during the D-1 landfill excavation in 2008/2009.

Overall Site Cleanup

In January 2011, the Air Force, with EPA and state approval, finalized a Focused Feasibility Study for overall site groundwater contamination. The Superfund process requires a feasibility study be completed at every site to assess the various methods available to remediate site contamination. This feasibility study primarily evaluated the method of using in-situ bioremediation to address TCE and NDMA in groundwater. The method was already being implemented at the site and had shown success in degrading TCE in the groundwater. The study also recommended a Technical Impracticability Waiver for NDMA, as previous research and investigations revealed no feasible means for treating NDMA in bedrock groundwater.

In January 2012, the Air Force, with EPA and state approval, issued a proposed cleanup plan for final soil and groundwater remediation at PJKS. All 53 identified contaminated soil areas have already been investigated and addressed through interim corrective measure actions, each with its own associated public review process. Therefore, the proposed sitewide cleanup plan focused only on remaining groundwater contamination at the site. The contaminants of concern in the three groundwater plumes at PJKS are trichloroethylene (TCE) and N-nitrosodimethylamine (NDMA). For TCE, the preferred alternative in the proposed plan is in-situ bioremediation, a process described in detail in the 2011 Feasibility Study and already successfully implemented at the site. For NDMA, EPA and the state of Colorado granted the Air Force a Technical Impracticability Waiver in 2011, indicating that past studies at the site did not successfully identify a feasible means of remediating NDMA in the bedrock groundwater.

The Air Force solicited public comment for 45 days, from January 12 through February 25, 2012, on its proposed plan for final groundwater and soil remediation at Air Force Plant PJKS. The Air Force, EPA and CDPHE considered all public comments received and issued a final cleanup decision in a Record of Decision, in 2013. The Record of Decision includes written responses to all significant public comment received. The final cleanup decision was the alternative preferred by the agencies in the proposed plan: In-situ bioremediation with restrictive notice for groundwater and engineering and land use controls. Long-term treatment of groundwater source areas and groundwater pump and treatment systems will be ongoing.

As at all CERCLA sites where contamination is controlled and managed in place, the Air Force will conduct, with EPA and state oversight, a review of the remedy at least every five years to ensure its effectiveness.

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Community Involvement

Community involvement plays an important role in the Superfund process. EPA uses a number of different tools and resources to promote effective, on-going, 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.

The PJKS Community Restoration Advisory Board (RAB) has been involved in this cleanup effort since 1995. The RAB members are dedicated and important to the PJKS restoration effort. RAB meetings are held regularly and are open to the public.

Site-specific updates are mailed as fact sheets to the community mailing list.

Community interviews have been conducted at least every three years to help identify potential community concerns.

At certain decision-making points in the environmental cleanup process, EPA requires that the Air Force publish in local papers a notice announcing any proposed action, where relevant information can be reviewed, and details of public meetings and comment periods.

An updated Community Involvement Plan was published in September 2010.

An information repository is maintained for public viewing at the Columbine Library. The Administrative Record is also available from the Air Force online—see Links below.

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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.

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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.

At PJKS, the 2013 Record of Decision selects land use controls, which prohibit the use of groundwater until the long-term goal for groundwater is met. The long-term goal for groundwater is to achieve unlimited use/unrestricted exposure levels for NDMA and TCE in all PJKS groundwater. The Record of Decision also selects land use controls in the form of engineered covers, such as concrete over soil areas, where unlimited use/unrestricted exposure levels could not be achieved.

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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.

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Site Documents

Remedial Action Completion Report and Preliminary Close-Out Report, February 2014

Record of Decision, May 2013

Focused Feasibility Study, November 2010

Proposed Plan for Final Groundwater and Soil Remediation at Former USAF Plant PJKS, Waterton Canyon, Colorado, December 2011

Community Involvement Plan, September 2010

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David Rathke
EPA Project Manager
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop Street (8EPR-F)
Denver, CO 80202-1129
303-312-6016 or
800-227-8917 ext. 312-6016 (toll free Region 8 only)


Corey Lam
PJKS Remedial Program Manager
1801 10th Street, Suite 2
Wright-Patterson AFB, OH 45433
800-982-7248 ext, 52970

Judy Charles
Public Affairs Specialist
1801 10th Street, Suite 2
Wright-Patterson AFB, OH 45433
800-982-7248 ext. 53593


David Walker
State Project Manager
Colorado Department of Public Health and Environment
4300 Cherry Creek Drive South
Denver, CO 80246-1530
888-569-1831 ext. 3354 (toll-free)

Jeannine Natterman
State Community Involvement Coordinator
Colorado Department of Public Health and Environment
4300 Cherry Creek Drive South
Denver, CO 80246-1530
888-569-1831 ext. 3303 (toll-free)

Site Information Repositories:

Columbine Library
7706 West Bowles Avenue
Littleton, CO 80123

Colorado Department of Public Health and Environment
HMWMD Records Center
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
888-569-1831 ext. 3331 (toll free)
303-759-5355 FAX
By appointment only

EPA Superfund Records Center
1595 Wynkoop Street
Denver, CO 80202-1129
To request copies of administrative record documents call:
800-227-8917 ext. 312-7273 (toll free Region 8 only)

U.S. Air Force, ASC/ENVR Building B8
ATTN: Judy Charles
1801 10th Street, Suite 2
Wright-Patterson AFB, OH 45433-7626

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Photo/Video Gallery

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The following links exit the site Exit

Columbine Library branch of the Jefferson County Public Library

Air Force Civil Engineer Center CERCLA Administrative Record Search

Air Force Plant PJKS site at the Colorado Department of Public Health and Environment

ATSDR Public Health Assessment for Air Force Plant PJKS, March 29, 2000

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