Simi Valley’s Sage Ranch Park Cleanup

Contaminated Soil Left by Old Recreational Shooting Range to be Removed

California’s Department of Toxic Substances Control (DTSC) has ordered the cleanup of soil polluted by lead from shot, skeet fragments and clay pigeon debris in Simi Valley’s Sage Ranch Park, the site of a former recreational shooting range for the now-defunct Rocketdyne-Atomics International Rifle and Pistol Club (Gun Club). The Gun Club used the shooting range from the 1970s through the 1990s.

The cleanup is being fast-tracked to protect some species of birds that may consume lead shot remnants and that may be eaten by other wildlife, from potential exposure to lead and to allow the reopening of the popular hiking area, the Loop Trail. The entrance to the trail is currently fenced off and closed to the public due to the lead contamination.

The land is owned by the Mountains Recreation & Conservation Authority (a joint powers agency comprised of the Conservancy, the Conejo Recreation and Park District, and the Rancho Simi Recreation and Park District), but was previously leased by a prior owner to the Gun Club, which consisted of employees of Rocketdyne and their families. Boeing acquired Rocketdyne as part of its purchase of Rockwell International in 1996.

Boeing will fund and conduct the cleanup of the former shooting range area and is currently drafting technical plans for the cleanup tentatively set to begin August 2022. DTSC, the state department charged with protecting California’s people and environment from dangerous chemicals, will supervise the planning and implementation of the cleanup.

Figure 1 shows the regional location of the former shooting range, which is the subject of the Order between Boeing and DTSC.

Former Shooting Range History and Contamination

Historic activities at the former shooting range resulted in the dispersion and deposition of lead shot in an arc of approximately 150 degrees with a radius of approximately 1000 feet from the firing platform (Figure 2). Soil sampling conducted between 1992 and 2018 indicated that areas of soil within the former shooting range location are contaminated with lead, antimony, arsenic, and polycyclic aromatic hydrocarbons (PAHs). Boeing has previously conducted several focused cleanups of the area:

• Between 1992 and 2018, Boeing conducted numerous soil, debris, and lead shot voluntary removal actions in the former shooting range area. These voluntary cleanup efforts results in the removal of approximately 410 tons of visible lead shot, soil, and debris.
• Between 2007 and 2010, Boeing excavated portions of the former shooting range area closest to the firing platform to remove any remaining clay pigeons and elevated PAH concentrations in response to Orders issued by DTSC and the Los Angeles Regional Water Quality Control Board. These excavations resulted in the removal of approximately 7,000 cubic yards of soil and debris.

The RCRA Facility Investigation sampling conducted in the former shooting range area in 2016 and 2017 utilized an incremental sampling methodology (ISM) to divide the former shooting range and overshot area into 29 decision units. Surficial soil samples within each decision unit were collected and analyzed for lead, PAHs, antimony, and arsenic. Discrete soil samples also were collected along the Loop Trail and analyzed for lead. Based on concentrations of lead detected near the hiking trail, DTSC required that the trails in the investigation area be fenced off until the impacted soil was removed.

Removal Action Goals to be Achieved

Boeing has agreed to undertake removal actions because DTSC has determined that they are necessary to mitigate the threatened release of hazardous substances at or potentially emanating from the location of the former shooting range. Based on available information, DTSC has preliminarily determined that the removal action objectives shall include:

1. Protection of public health,
2. Protection of birds and other wildlife (i.e., ecological receptors), and
3. Protection of existing and potential beneficial uses of groundwater.

In order to meet these objectives, Boeing will conduct removal actions to achieve lead levels in soil to a concentration safe for some species of birds that may consume lead shot remnants and that may be eaten by other wildlife. This lead cleanup level (36 milligrams per kilogram) is significantly more protective of human health than a cleanup based on current and future property use, since the area is a park and used for hiking and outdoor recreation. Additionally, this lead cleanup level is similar to the DTSC-approved background levels for lead, and it is protective of any existing and potential beneficial uses of groundwater. In addition to addressing lead within the former shooting range area, the removal actions also will clean up other contaminants from historic Gun Club activities, such as antimony, arsenic, and PAHs.

Figure 2 shows the Removal Action Area, which will include decision units where concentrations exceeded the lead cleanup level (1 through 18 and 28), and areas where visible lead shot and/or clay target debris was observed during the 2016-2017 ISM investigation. The Removal Action Area does not include decision unit 24 because the ISM lead concentration was consistent with lead background levels and visible lead shot and clay target debris was not observed. The target soil removal depth is 0 to 0.5 feet below ground surface or the top of bedrock, but may include deeper excavation in areas of soil accumulation with visible lead shot/clay target debris.

Removal Action Techniques and Methods

Boeing will prepare and submit a draft Removal Action Workplan to DTSC for review and approval. The Removal Action Workplan will include a Removal Action Work Implementation Plan (Implementation Plan) that describes in detail the technical and operational plans for conducting the cleanup.

The Removal Action Workplan and Implementation Plan, once approved by DTSC, will constitute the approved Final Removal Action Workplan for the cleanup. Assuming Boeing receives required consent from the landowner and any approvals / permits required by other agencies by August 1, Boeing anticipates beginning the cleanup in early August 2022. The Final Removal Action Workplan and Implementation Plan will include additional descriptions of the following primary components of the removal actions:

Protection of Natural and Cultural Resources:

Prior to excavation, Boeing will conduct a biological survey to identify sensitive species and habitats and delineate identified archeological sites located within the Removal Action Area. Sensitive areas to be protected will be identified in consultation with MRCA, DTSC, the California Department of Fish and Wildlife (CDFW), the United States Fish and Wildlife Service (USFWS), the California State Historic Preservation Office, and specific Native American Tribal Councils. Biological and cultural monitoring will also be conducted during removal activities to protect natural and cultural resources.

Stormwater Protection:

Stormwater Best Management Practices will be installed along the banks of the Northern Drainage to prevent potential sediment migration from removal activities into the drainage pursuant to an approved Stormwater Pollution Prevention Plan.

Excavation:

Permitting requirements for the removal actions will be discussed with local, State, and federal agencies prior to soil disturbance, including Ventura County Public Works, CDFW, and the United States Army Corps of Engineers (USACE). Any required permits must be obtained prior to implementation of the removal actions.

Brush clearance prior to removal activities will be conducted with oversight from biologists, and may include full removal, a focused/targeted approach to minimize adverse impact to protected resources, or a mixture of the two methods.

An estimated volume of 15,000 cubic yards of contaminated soil, including lead shot and/or clay target debris, will be removed and disposed of at an appropriate landfill. Excavation techniques may include excavators and haul trucks in accessible areas (e.g., flat terrain), vacuum trucks, and hand crews on and near rocky outcrops inaccessible to larger equipment and/or where sensitive species are present.

Confirmation Sampling:

Confirmation soil sampling techniques to assess the effectiveness of the removal actions will employ ISM techniques as used during the 2016-2017 soil investigation. Soil samples will be analyzed for lead, antimony, and arsenic in all removal action decision units. PAH analysis also will be performed in decision units 01 and 04 based on previous sampling results. Additional soil excavation may be required if the results from confirmation sampling exceed cleanup levels approved in the Final Removal Action Workplan. If more excavation is required, additional rounds of confirmation sampling will be completed until cleanup goals are achieved or the excavation reaches bedrock.

Site Restoration:

The overall restoration goal is to achieve pre-excavation topographic drainage patterns and ecological habitat quality. The use of offsite backfill will be minimized to reduce the use of non-native materials during restoration.

Onsite Waste Management:

Excavated soil will not be stored on MRCA property. Boeing will use the SSFL Lower Lot area as the onsite work staging and waste storage area during implementation of the removal action (Figure 2). Onsite waste is anticipated to be stockpiled and/or stored in roll-off bins pending pickup for disposal. Stormwater best management practices will be installed around waste areas to prevent runoff.

Offsite Disposal:

Transportation and disposal of excavated materials will be conducted in accordance with all applicable federal, state, and local laws and regulations. Non-hazardous waste will be disposed of in Class 3 non-hazardous landfills, and hazardous waste will be disposed of in Class 1 hazardous landfills. A transportation plan will be included in the Implementation Plan to identify haul routes and final disposal destinations. No traffic delays are anticipated in connection with the cleanup, although increased truck traffic will be visible during clean-up hours (weekdays between 8am and 5pm). Truck traffic will be limited to a frequency of no more than one truck every 5 minutes, to minimize impacts and maintain safety to the community on Woolsey Canyon during the removal actions.

Removal Action Health and Safety

A description of controls to protect the health and safety of workers and the public during the removal actions will be described in the Removal Action Workplan, and a health and safety plan for implementation activities will be included in the Implementation Plan. Measures to address public safety will include installation of stormwater best management practices, air monitoring and dust control, trucks with covered soil, and updating perimeter fencing and signage to restrict public access to the Removal Action Area.

Schedule and Project Completion

Within sixty (60) days of completion of field activities and receipt of validated analytical data, Boeing will submit an Implementation Report documenting the implementation of the Final Removal Action Workplan (including the Implementation Plan). The removal action project will be considered complete once DTSC reviews and approves the Implementation Report.

Anticipated dates for key project milestones (pending landowner approval and any required permits) are listed below:

• Consent Order issued – March 17, 2022
• Boeing submits Draft Removal Action Workplan/Implementation Plan – May 16, 2022
• DTSC issues its decision on the Final Removal Action Workplan/Implementation Plan – July 15, 2022
• Commencement of excavation activities – August 1, 2022
• Completion of excavation activities and verification of cleanup goals – October 31, 2022
• Site restoration measures in place – November 21, 2022
• Boeing submits Implementation Report – December 1, 2022
• DTSC issues its decision on the Implementation Report – January 2023
• DTSC approves the Implementation Report and rescinds the Fence and Post Order, allowing the owner to reopen the Loop Trail – Early 2023

If the Removal Action Workplan and Implementation Plan are not approved by July 15, or if necessary third party approvals are not received by August 1, the cleanup will start in late spring 2023.

1-Year Review

Boeing will review and reevaluate the effectiveness of the restoration actions taken under the Final Removal Action Workplan and Implementation Plan after a period of 1 year from the date of the approved Implementation Report.