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The West Lake Landfill Superfund Site is located in Bridgeton and includes the Bridgeton Sanitary Landfill and other former waste disposal sites containing industrial wastes, demolition debris and municipal solid wastes. In 1990, the U.S. Environmental Protection Agency listed West Lake Landfill on the National Priorities List making it a Superfund site. In order to address issues that are unique to each site, EPA has divided the site into three operable units.

  • Operable Unit-1 (OU-1) is contaminated with radiologically impacted material and currently includes two designated radiological areas (Area 1 and Area 2) in addition to properties adjacent to Area 2 described as the Buffer Zone and Crossroads Lot 2A2.
  • Operable Unit-2 (OU-2) consists of waste disposal areas that are not known to be impacted by radiological materials.
  • Operable Unit-3 (OU-3) was recently announced by EPA to address groundwater contamination site-wide.

EPA signed a record of decision for OU-1 in May 2008, which describes the selected remedy to contain the radiological contamination using a modified solid waste landfill cover. In July 2008, EPA signed a record of decision for OU-2 selecting various remedies for three waste disposal operable units including Bridgeton Sanitary Landfill. An administrative order for OU-3 investigation was signed by all parties on Feb. 6, 2019.

Site Status for OU-1

Comprehensive, Environmental Response, Compensation, and Liability Act (CERCLA) Superfund Actions since EPA’s 2008 Record of Decision

After the record of decision was signed in 2008, the process of remedial design for the selected remedy was initiated, and later put on hold after EPA requested additional work from the potentially responsible parties to accomplish the objectives of the remedial investigation/feasibility study.

A supplemental feasibility study was developed by the potentially responsible parties and approved by EPA on Dec. 28, 2011. The study compared the selected remedy against additional alternatives. EPA Region 7 consulted with the EPA’s National Remedy Review Board on Feb. 29, 2012, on the supplemental feasibility study alternatives, and the board's feedback was made publically available June 15, 2016.

Subsequent to the approval of the supplemental feasibility study, EPA requested additional investigation to improve the resolution of the known extent of RIM, and supplement existing data to support a statistical analysis of RIM extent. The results were incorporated into a remedial investigation addendum report, and applied to an updated analysis of alternatives in the Final Feasibility Study report.EPA approved this work plan on May 18, 2016, and in a letter dated Aug. 4, 2016, EPA summarized and clarified the work remaining on the various orders and studies that were to be incorporated in the final feasibility study.

After the remedial investigation addendum and final feasibility study were finalized, EPA proposed modifications to the 2008 selected remedy on Feb. 1, 2018 and updated the administrative record. EPA closed the public comment period for the proposed plan on April 23, 2018. EPA announced the final decision on the amendment on Sept. 27, 2018, and issued a fact sheet to explain the remedy. MoDNR provided its position on the selected remedy on Sept. 25, 2018.

On May 6, 2019, EPA and the responsible parties have agreed to amend the settlement agreement adding remedial design work to the order. A consent decree for OU1 and OU2 remedial action still needs to be developed.

Site Status for OU-3

On Feb. 6, 2019 EPA and the responsible parties finalized an administrative settlement agreement and order on consent for investigation and remedial options for site-wide groundwater. The responsible parties are currently developing a workplan to perform the required work.

Site Status for OU-2

Remedial design for Operable Unit 2, inactive sanitary landfill is expected to be completed concurrent with with design of the remedy for the adjacent Operable Unit 1, Area 2 portion. Closure and post-closure of the remainder if Operable Unit 2 have been deferred to state regulatory authority. Additional information on the deferred Former Active (Bridgeton) Sanitary Landfill, and the deferred Closed Demolition Landfill is available on MoDNR’s Bridgeton Landfill page.

Interim Actions Related to OU-1

Isolation Barrier Pre-construction Actions

On May 13, 2013 Bridgeton Landfill entered into an Agreed Order with the State of Missouri, which required actions to address the subsurface smoldering event. Part of the agreed order included a phased program for Gamma Cone Penetrometer testing and subsurface soil testing in Bridgeton Landfill near Area 1 to determine potential locations for a contingent isolation barrier. EPA later took the lead role on the Gamma Cone Penetrometer investigation. EPA ordered additional work (Phase 1D) on Jan. 15, 2015 based on the results of the Phase 1 investigation. The results indicated the radiologically impacted material was located outside the previously defined boundaries of OU-1 Area 1. EPA approved the comprehensive Phase 1 Investigation report in a letter dated April 7, 2016.

In an EPA administrative order on consent dated April 16, 2014, EPA ordered the potentially responsible parties to take preparatory actions in advance of construction of an isolation barrier.

Non-Combustible Cover Time-Critical Removal Action

In a unilateral administrative order dated Dec. 9, 2015, EPA ordered the responsible parties to place non-combustible cover over portions of OU-1 where radiologically impacted material is located at or near the surface. Components of the order in addition to placement of non-combustible cover include:

  • Confirmation soil testing and surface surveys to confirm surface and near-surface radiologically impacted material has been covered;
  • Testing of vegetation to confirm the remaining trees and vegetation in OU-1 do not present a fire risk that could result in the potential for release of radiologically impacted material into the environment;
  • Maintenance of the cover; and
  • Site-wide incident management plan for responding to incidents affecting OU-1
  • Action documents and reporting requirements.

During the course of placing non-combustible cover over remaining radiologically impacted materials on steep slopes in Area 2, a total of 167 tires were found lining one of the slopes. A cleaning, screening, and disposal plan was developed by the PRPs and approved by EPA prior to removal of the tires from the site. The vegetation sampling work plan is not yet finalized. A final report is required to be submitted within 30 days of completion of the remaining action items.

North Quarry Time-Critical Removal Action

In an administrative settlement agreement and order on consent dated April 28, 2016, EPA ordered the potentially responsible parties to implement and install engineering controls within portions of the Bridgeton Landfill to mitigate potential impacts to OU-1 Area 1 of subsurface exothermic events originating in Bridgeton Landfill. Action items in the order include:

  • Inert gas injection plan, and triggers for implementing inert gas injection;
  • Installation of ethylene vinyl alcohol cover over the North Quarry
  • Installation of a heat extraction system in the neck area of Bridgeton Landfill based on the document that was conditionally approved by MoDNR on Dec. 4, 2015;
  • Two sulfur dioxide ambient air monitors and monitoring for one year;
  • Installation of a system of temperature monitoring probes in the north quarry area of Bridgeton Landfill; and
  • Action documents and reporting requirements.

Remaining action items include completion of the phased ethylene vinyl alcohol installation plan and continued operation and monitoring of the installed systems.

MoDNR Involvement

EPA is the lead regulatory authority over the Superfund site; therefore the department’s Federal Facilities Section provides a support and assistance role for activities and actions.

The section provides technical review on major decision documents, work plans, pre-design investigation reports, remedial designs and post remedial action reports. Depending on the nature of the activity and content of the documents, the section may coordinate with other programs and state entities to respond appropriately.

Periodically, field personnel conduct site visits to observe and document the status of remedial actions, environmental monitoring, contaminant migration prevention and pre-design investigations.

Occasionally, staff also perform independent investigations and sampling in the vicinity of West Lake Landfill. Results of these investigations are available below.

Recent MoDNR correspondence to EPA on CERCLA related documents

MoDNR letters responding to EPA’s proposed Record of Decision Amendment

  • April 10, 2018, MoDNR’s technical Comment Letter to EPA regarding EPA’s proposed Record of Decision Amendment.
  • Aug. 31, 2018 MoDNR’s position letter on EPA’s proposed Record of Decision Amendment.

MoDNR letters responding to open draft remedial investigation addendum related documents submitted to EPA by the responsible parties.

  • Oct. 5, 2017, MoDNR's Comment Letter to EPA regarding respondents' fifth draft Stormwater Monitoring Plan (posted 01/19/18)
  • Aug. 3, 2017, MoDNR’s Comment Letter to EPA regarding respondents’ fourth draft Stormwater Monitoring Plan

MoDNR letters responding to open time-critical removal action related documents submitted to EPA by the potentially responsible parties.

Non-Combustible Cover Time-Critical Removal Action

West Lake Landfill Vicinity Radiological Surveys

May 16, 2013 -- Staff visited the West Lake Landfill and Bridgeton Sanitary Landfill sites to conduct a radiological survey at locations upwind and downwind of the site using odor as a wind direction indicator. The upwind and downwind readings were compared for differences in radiological readings. Ambient radiation readings were collected to the south, southwest, east, and northeast of the sites using several types of equipment. In addition, deposition dust samples were collected to measure radiological activity in the predominant wind direction and in the downwind location at the time of sampling. All readings and sample results were consistent with background levels.

Jan. 25, 2016 -- The department released the West Lake Interim Vicinity Report - Radiological Survey and Sampling - Nov. 4-6, 2015. Also, the Department of Health and Senior Services released a Bridgeton/West Lake Interim Report for radiological sampling conducted during the same period. See the interim reports below.

April 1, 2016 -- The department released the West Lake Landfill Final Vicinity Report - Radiological Survey and Sampling - Nov. 4-6, 2015. This final report supplements the department's West Lake Landfill Interim Vicinity Report that was released Jan. 25, 2016. See the final report below.

Bridgeton Sanitary Landfill – Learn more about the department's Solid Waste Management Program’s work at the Bridgeton Landfill (OU-2)

  • Air – MoDNR Air Pollution Control Program’s Permit for Bridgeton Landfill and renewal status
  • Water – MoDNR Water Protection Program’s Stormwater Permit for Bridgeton Landfill

Community Support

Health Information

Community Groups

Miscellaneous Related Public Documents

Administrative Record

EPA maintains electronic files for the administrative record and hard copies at the address provided below. The administrative record includes site work plans, sampling results, technical reports, fact sheets and other site updates. It also includes the community involvement plan and general information about the Superfund program. The record includes all documents and data used and produced during the site investigation phase to develop cleanup alternatives for the site.

The administrative record is available at:

Bridgeton Trails Branch of the St. Louis County Library
3455 McKelvey Road
Bridgeton, MO 63044
Hours: Monday through Thursday 9 a.m. to 9 p.m., Friday and Saturday 9 a.m. to 5 p.m. and Sunday from 1 to 5 p.m.

Additional Site Information:
EPA Region 7 West Lake Landfill Website