The Santa Susana Field Laboratory (SSFL) is a roughly 2,850-acre site where rocket engine testing and nuclear research took place.

The California Department of Toxic Substances Control (DTSC) is a department within California’s Environmental Protection Agency. DTSC regulates the handling and cleanup of hazardous waste in California. At SSFL, DTSC directs and oversees the site investigation and cleanup being conducted by three Responsible Parties (RPs): The Boeing Company (Boeing), the National Aeronautics and Space Administration (NASA), and U.S. Department of Energy (DOE).

Chemicals in soil and groundwater came from testing and maintenance activities. The primary chemical contaminants include a variety of solvents (primarily trichloroethylene), metals and petroleum hydrocarbons. Radionuclides came from nuclear research activities.

As the lead regulatory agency for SSFL, DTSC has directed and overseen extensive investigations. Based on DTSC’s review of onsite and offsite environmental data and studies, the extent of contamination in soil and groundwater is defined. Small areas of contamination extend offsite (primarily soil in the Northern drainage close to the site and the limited groundwater plume along the northeast portion of the site) and are well characterized and monitored. Access to these areas is restricted to prevent exposure. The California Regional Water Quality Control Board, Los Angeles Region (LA Water Board) has jurisdiction over surface water at SSFL and it regulates stormwater runoff from the site through a National Pollutant Discharge Elimination System (NPDES) permit. DTSC and the LA Water Board require ongoing groundwater, air, and stormwater monitoring, and quarterly reports can be found on DTSC’s and the LA Water Board’s websites.

Field sampling is complete. The investigation reports for soil and groundwater are in the review and approval process with DTSC project staff. Workplans and reports for evaluating potential cleanup technologies are being reviewed simultaneously.

Groundwater sampling and monitoring are ongoing, and the Groundwater Interim Measure is operating in the initial start-up phase.

In September 2017, DTSC issued the draft Program Environmental Impact Report (PEIR) to evaluate impacts to the environment from SSFL cleanup activities and identified measures to address those impacts. DTSC is preparing responses to the comments on the draft report and the final PEIR.

SSFL is an ongoing cleanup project that will take years to complete. The site will continue to be monitored to ensure the safety of the community and the environment.

• Certification of the PEIR
• Approval of Data Summary Reports for soil investigations in DOE and NASA areas
  • Public Review of their draft Cleanup Workplans
• Approval of soil investigation reports for Boeing
  • Public Review of their draft Cleanup Workplans
• Approval of groundwater investigation reports for all three RPs
  • Public review of the groundwater draft Cleanup Workplans

Reviews of the reports that need DTSC approval are taking place simultaneously. Cleanup Workplans are also being developed and reviewed. However, some of the Cleanup documents may be ready before others. DTSC will share each of the Cleanup Workplans as soon as the drafts are ready for public review.

Several health studies and data assessments have been performed on communities surrounding SSFL. See DTSC’s  summary of the findings document. View the full report “Summary of Cancer Study and Exposure Assessment Activities related to the Santa Susana Field Laboratory (Rocketdyne) Site.”

Some sections of the 2007 Consent Order are superseded by the Settlement Agreement to expedite the regulatory process while maintaining stringent cleanup standards. For example, Boeing’s obligations under Section 3.2 of the 2007 Consent Order regarding Cleanup Schedule are replaced by the schedule presented as Exhibit 6 to the Settlement Agreement. A chart addressing the applicability of requirements of the 2007 Consent Order to the Settlement agreement is attached as Exhibit 22 to the Settlement Agreement.

The Settlement Agreement resolves prior disputes about process, cleanup and decision making under the 2007 Consent Order, facilitates the cleanup of Boeing’s areas of responsibility using streamlined processes, and establishes a mechanism for quickly resolving any potential future disputes.

Yes, once Boeing completes cleanup of soil to the final approved cleanup levels and receives DTSC approval, as the property owner, Boeing would retain responsibility for any long-term stewardship of any areas with land use restrictions. Additionally, after Boeing completes its cleanup of soil in its areas of responsibility, Boeing will retain responsibility for stormwater discharges under its National Pollutant Discharge Elimination System (NPDES) permit until it demonstrates it has met strict conditions confirming that stormwater leaving Boeing’s areas of responsibility is no longer polluted after soil cleanup.

The Los Angeles Water Board’s role in the DTSC-Boeing Settlement Agreement was to advise DTSC on the Water Boards’ laws, policies and regulations governing the protection of groundwater. In this regard, DTSC has identified the State Water Resources Control Board’s Resolution No. 92-49, Policies and Procedures for Investigation and Cleanup and Abatement of Discharges Under Water Code Section 13304, which governs soil and groundwater cleanup, an “applicable or relevant and appropriate requirement” (ARAR) for the cleanup of the site. As such, the Los Angeles Water Board will continue to advise DTSC on the application of Resolution 92-49 as DTSC oversees Boeing’s cleanup of the Boeing areas of responsibility to protect groundwater.

As part of the Settlement Agreement, Boeing has agreed to clean up radionuclides in soil in its areas of responsibility to “background,” i.e., levels that would exist locally without industrial activity. Attachment 5 to Exhibit 5 of the Settlement Agreement provides more detail on Boeing’s commitment to clean up radionuclides in soil.

The cleanup standard for chemical constituents will be risk based and protective of humans, ecosystems, and groundwater.

Subject to the terms of the Settlement Agreement, Boeing has agreed not to contest DTSC’s selection of a remedy to a cleanup level, up to and including a “Resident with Garden” exposure scenario.

In addition to the ecological risk, Appendix K of the Final PEIR will identify the following potential human health exposure scenarios for the Boeing areas of responsibility at SSFL:

• Resident with garden
• Resident with 25% garden
• Resident with no garden
• Recreator

KEY POTENTIAL CLEANUP SCENARIOS FOR BOEING SOILS IN AREAS I AND III AT SSFL

A “resident with garden” scenario means that the cleanup meets the standard for people to live onsite and consume homegrown produce from a backyard garden.

The resident with garden scenarios assume people will reside in the location and consume homegrown produce. The higher the percentage, the more stringent the cleanup. The resident 100% garden scenario assumes that 100% of all homegrown produce a resident consumes is grown in soil cleaned up to a specific cleanup level. Conversely, the resident 25% garden scenario assumes that only 25% of all homegrown produce a resident consumes is grown in soil cleaned up to a specific cleanup level. Unless otherwise specified in these FAQs, references to the “Resident with Garden” means the “resident 100% garden” exposure scenario.

The Resident with Garden exposure scenario does assume that the resident eats a variety of fruits and vegetables from their garden. However, the current mass loading factor (MLF) for lettuce of 0.0135, which is a commonly grown vegetable, is the most conservative value for homegrown fruits and vegetables. Therefore, using the MLF for lettuce for all produce consumption provides the most conservative and protective basis for calculating risk.

The reason for the focus on the top two feet of soil for a Resident with Garden exposure scenario is because that is the typical root zone for homegrown produce.

But the Resident with Garden scenario does not focus exclusively on exposures from the top two feet of soil. It also accounts for exposures from the Resident no Garden scenario, in which potential exposures are evaluated for depths from 2 to 10 feet below the surface. As such, the Resident with Garden scenario would result in a cleanup that meets the standard for people to live onsite (Resident no Garden scenario) and consume homegrown produce from a backyard garden (Resident with Garden scenario layered on top).

No. DTSC will determine cleanup levels following the RCRA corrective action process detailed in the Settlement Agreement, which includes public review and comment. Under the Settlement Agreement, Boeing has agreed not to contest DTSC’s selection of a remedy to a cleanup level up to and including a “Resident with Garden” exposure scenario. Boeing also has agreed to clean up radionuclides in soil in its areas of responsibility to background (i.e., levels that would exist locally without industrial activity).

The standard for cleanups administered by U.S. EPA or DTSC is risk-based. Boeing is required by the 2007 Consent Order to conduct a risk-based cleanup of its areas of responsibility at SSFL. Boeing did, however, agree in both the Settlement Agreement and the Area I Burn Pit Imminent and Substantial Endangerment Consent Order to clean up radionuclides in the Boeing areas of responsibility to background (i.e., levels that would exist locally without industrial activity). (See Exhibit 5 of the Settlement Agreement.)

Yes. Although the Settlement Agreement does not make any remedy decisions, Boeing has agreed to clean up radionuclides in soil in its areas of responsibility to meet “background” levels (i.e., levels that would exist locally without industrial activity). Attachment 5 to Exhibit 5 provides more detail on Boeing’s commitment to clean up radionuclides in soil.

Although the Settlement Agreement does not make any remedy decisions, Boeing has agreed to clean up radionuclides in soil in its areas of responsibility to “background,” i.e., levels that would exist locally without industrial activity. Attachment 5 to Exhibit 5 provides more detail on Boeing’s commitment to clean up radionuclides in soil.

Contaminated soil will be removed by excavators. Excavated soil will be stored in containers on Boeing property before disposal. Boeing will conduct appropriate testing and screening for all soil to be disposed. Soil will then be characterized and disposed of under applicable laws and regulations. DTSC will oversee all of these cleanup activities.

In consultation with DTSC, Boeing will identify disposal locations for any soil contaminated with radionuclides based the levels of radioactivity determined by the waste characterization sampling and in compliance with applicable laws and regulations.

No materials will be recycled as part of Boeing’s soil cleanup.

Boeing anticipates demolishing its remaining buildings in Area IV when the Physicians for Social Responsibility litigation is resolved.

DTSC (and co-Respondent Department of Public Health) won in the Physicians for Social Responsibility (PSR) litigation on all claims. The Court of Appeal affirmed the trial court in a ruling issued in May 2023, finding that the Boeing Area IV demolition was not a project under CEQA. The Supreme Court of California denied a petition from PSR for review of the case, and the decision on the merits is now final. In December 2023, the trial court also denied a motion from PSR for attorney’s fees, which Petitioners had sought under a “catalyst” theory after losing twice on the legal merits.

The Standardized Risk Assessment Methodology (SRAM) is a workplan required under the 2007 Consent Order between Boeing, NASA, DOE, and DTSC that provides the risk assessment methodology for human health and ecological receptors for a risk-based cleanup at SSFL. The data in the risk assessment reports prepared pursuant to the SRAM will be used in the Boeing Corrective Measures Study (CMS) to evaluate cleanup alternatives at the Site. DTSC will evaluate the alternatives presented in the CMS in making a final remedy decision for cleanup of soil in Boeing’s areas of responsibility at SSFL.

CalEPA and DTSC are committed to scientific integrity. DTSC is directing Boeing to prepare an amendment to the 2014 SRAM document to incorporate the most current and best available science, including updating exposure factors and toxicity criteria. The U.S. EPA and DTSC have made important updates to input parameters used in the risk assessment calculations since the SSFL SRAM, Revision 2 Addendum (2014 SRAM) (MWH, 2014) was prepared. Exhibit 5 to the Settlement Agreement provides details about how the 2014 SRAM will be updated.

No. DTSC has provided clear direction on how to revise the 2014 SRAM, and Boeing and DTSC have both agreed to an expedited process for preparing, reviewing, and approving the revised SRAM so that all risk assessments can be completed and approved in accordance with the schedule in Exhibit 6 to the Settlement Agreement. This agreement avoids costly disputes and litigation that would delay the cleanup.

The revised SRAM will require Boeing to evaluate human health exposures for recreational users, onsite workers, and residents (with and without a home garden), as well as ecological receptors. Exhibit 5 to the Settlement Agreement provides details about how the SRAM will be updated.

The two agreements are related. The DTSC-Boeing Agreement sets forth a streamlined set of processes for the soil remediation of Boeing’s areas of responsibility at the site. The Draft MOU establishes the conditions that must be satisfied before the Board will consider relieving Boeing from future NPDES permit obligations. The processes in the Draft MOU would only be triggered after Boeing completes soil cleanup in its areas of responsibility under DTSC’s oversight. The DTSC-Boeing Agreement will become effective only if the Los Angeles Water Board-Boeing MOU becomes effective.

If the Los Angeles Water Board fails to approve the draft MOU, then the settlement agreement that Boeing has reached with DTSC will not go into effect. If that happens, then it is possible that DTSC and Boeing would rekindle their dispute and the accelerated timeline for cleanup of the Boeing areas of responsibility at the SSFL, and the streamlined processes therein, would not occur. Cleanup of the Boeing areas of responsibility would take longer, and the efficient, streamlined processes for cleanup in that agreement would not take place. Perhaps most importantly, however, the path established in the DTSC/Boeing settlement agreement for a stringent soil cleanup and the potential for a cleanup standard that allows people to live on site and consume produce from a backyard garden would likely be contested by Boeing in court, causing both delay in the cleanup and uncertainty as to whether the same range of cleanup standards, including a potential residential with backyard garden cleanup standard, would be achieved.

The failure to approve the draft MOU would have no impact on Boeing’s current NPDES permit. However, it is very likely that, once Boeing cleans up to the standard DTSC requires, it would petition the Los Angeles Water Board to remove its NPDES permit. Without the modeling and confirmation sampling required in the draft MOU, it would be harder to ensure that stormwater runoff will be safe for human health and the environment. Although nothing prohibits the Los Angeles Water Board from imposing these requirements on Boeing anyway, this could lead to litigation between Boeing and the Board. If approved, the MOU would ensure that the appropriate modeling and confirmation sampling will occur.

The RCRA Facilities Investigation Remedy Selection Track (RCRA FIRST) program is a tool developed by the U.S EPA to streamline and accelerate cleanup of contaminated sites.

RCRA FIRST generally speeds up the regulatory process by focusing cleanup assessment documents on known contamination and cleanup technologies. This allows for a streamlined process for evaluating cleanup options in the Corrective Measures Study. Boeing and DTSC agreed to use several elements of the RCRA FIRST program to streamline the process at SSFL in order to meet the schedule set forth in Exhibit 6 to the Settlement Agreement.

RCRA FIRST will apply to most aspects of Boeing’s cleanup at SSFL. Exhibit 4 to the Settlement Agreement identifies the RCRA FIRST tools that will apply at SSFL. For example, DTSC and Boeing agree that Boeing will submit a focused CMS for its soil remedy and for certain elements of the groundwater remedy. The process and details in the identified RCRA FIRST tools will be used to accelerate the preparation, review, and approval of the remedy decision-making documents. Public participation requirements remain the same under the RCRA FIRST process.

DTSC and Boeing were in a dispute that may have led to years of litigation and cleanup delay. In order to avoid further delay and expedite Boeing’s cleanup, the parties agreed to enter into confidential mediation. The Los Angeles Water Board joined the mediation at the request of CalEPA, DTSC and Boeing, given its jurisdiction over surface water quality at the site under the NPDES permitting program and its role in advising DTSC on the Water Boards’ laws, policies and regulations regarding groundwater protection. All mediation participants, including the Los Angeles Water Board, were subject to a confidentiality agreement that covered everything negotiated and discussed in the mediation, including the MOU.

As the courts have explained, confidentiality is considered essential to effective mediation and is routinely used because it allows for frank and candid discussions by the parties. One of the Legislature’s fundamental means of encouraging mediation has been the enactment of mediation confidentiality provisions. To ensure confidentiality, the statutory scheme bars disclosure of specified communications and writings associated with a mediation absent an express statutory exception. See Evidence Code sections 1115-1129.

The comprehensive framework consists of two separate but inter-dependent agreements, a Settlement Agreement between DTSC and Boeing and a proposed MOU between the Los Angeles Water Board and Boeing. Both DTSC and the Los Angeles Water Board will be providing opportunities for public participation.

DTSC will host a public meeting on June 2 to discuss the highlights of the Settlement Agreement and what it means for the Boeing cleanup. The public will have the opportunity to ask questions. As will be explained in more detail at the public meeting, the Settlement Agreement creates a more efficient and streamlined process for Boeing’s cleanup. The public will continue to be involved in the decision-making processes for Boeing’s cleanup and Boeing’s Post-Closure Permit. Critically, DTSC will seek public input on the proposed remedy before adopting the final cleanup remedy.

The Los Angeles Water Board will also host a public meeting on June 9 to discuss the draft MOU and explain the process it creates for ensuring that no stormwater runoff from the Boeing areas of responsibility will impact human health or the environment following Boeing’s soil cleanup. The public will have the opportunity to comment on the draft MOU and ask questions at the meeting. The Los Angeles Water Board will consider a resolution at that meeting approving the draft MOU and authorizing the Executive Officer to execute the MOU. After Boeing completes its soil cleanup and the conditions in the MOU have been satisfied, the Los Angeles Water Board will seek public input prior to considering whether to relieve Boeing of its NPDES permit obligations using the Board’s standard public process. This public process will include opportunities for the public to comment prior to and during a future public hearing.

DTSC will hold an informational meeting on June 2 where the public can learn more and ask questions about the executed Settlement Agreement. Information, including a full copy of the Settlement Agreement and Frequently Asked Questions and our Community Update, are provided on the DTSC website. The public will continue to be involved in the decision-making process for Boeing’s cleanup and Boeing’s Post-Closure Permit. Critically, DTSC will seek public input on the proposed remedy before adopting the final cleanup remedy.

The following steps are necessary before DTSC can arrive at a cleanup decision: The PEIR must be certified. Boeing must complete the risk assessment documents and prepare the Corrective Measures Study (CMS). DTSC will select a remedy based on the CMS and place that proposed remedy out for public review and comment. DTSC will make a cleanup decision following review and consideration of public comment.

The DTSC-Boeing Settlement Agreement (Exhibit 6) creates a schedule for these processes.

After DTSC makes a cleanup decision, Boeing must prepare implementation plans. Cleanup can commence once DTSC reviews and approves the plans.

The DTSC-Boeing Settlement Agreement anticipates the site-wide cleanup for Boeing soil and groundwater areas of responsibility to start in 2025.

The Area I Burn Pit cleanup is anticipated to start as early as Spring 2023.

More detail on the schedule is provided in Exhibit 6 to the Settlement Agreement.

The Settlement Agreement establishes a more efficient and streamlined process for cleanup. By using the RCRA FIRST model outlined by the U.S. EPA, Boeing can develop cleanup documents with clear, specific cleanup objectives from the start. RCRA FIRST means all parties have a clear understanding of the objectives. DTSC and Boeing’s agreement to this process will result in templates for future documents and more efficient review periods. This agreement also prevents delays from litigation between Boeing and DTSC. Since both parties have agreed and committed to this process, they were able to agree upon a schedule as well, facilitating faster decision-making and cleanup.

Boeing’s cleanup can begin upon completion of the required environmental review process, and DTSC makes the required findings, conducts a public process, and makes the remedy decision.

While final cleanup has not yet begun, many interim actions have already been completed:

• 15 critical soil cleanups completed
• Groundwater pump and treat system removes contamination and stops groundwater migration (Active)
• Stormwater treatment system helps prevent off-site releases (Active)
• Surface water permit requires use of Best Management Practices to prevent runoff and compliance monitoring. (Active)

The Area I Burn Pit cleanup is exempt from CEQA because it qualifies as an emergency project. Given predicted changes to regional weather patterns due to climate change, including the potential for more severe precipitation events and storms, wildfires, and high wind events that may potentially damage or destroy the geotextile fabric covering part of the Area I Burn Pit area, DTSC identified that there is a clear and imminent threat to wildlife and other ecological receptors and an immediate need to conduct soil remediation, in order to prevent the potential for harmful run-off and migration of hazardous substances from the Site.

Site-wide cleanup cannot legally begin until after the SSFL PEIR is certified, and the subsequent final cleanup decision documents (Statements of Basis) are approved and published.

DTSC will post the schedule attached as Exhibit 6 to the Settlement Agreement on the SSFL website. DTSC will update each element of the schedule affected by an extension or a delay. The version of the schedule posted on the website will be updated within one week of Boeing or DTSC providing notice of an extension or a delay.

Yes. The Settlement Agreement contains robust penalty provisions to ensure compliance. DTSC may seek penalties of up to $70,000 per day per violation of the Settlement Agreement. DTSC also retains full authority to assess penalties for any violations of law not covered by the Settlement Agreement.

Dispute resolution under the Settlement Agreement involves an accelerated three-step process: (i) an informal process between the parties to try to resolve any dispute, (ii) a non-binding mediation process if the parties’ informal discussions are unsuccessful, and if mediation is unsuccessful, (iii) final resolution will be determined by a panel of three (3) Judicial Referees. The Settlement Agreement provides for judicial review in only limited circumstances. In all other respects, decisions by the panel of three Judicial Referees will be final and not subject to judicial review.

Excavated soil will be stored in containers on Boeing property before disposal. Boeing will conduct appropriate testing and screening for all soil to be disposed. Soil will then be characterized and disposed of under applicable laws and regulations. DTSC will oversee all of these cleanup activities.

The framework involves separate but inter-dependent agreements between Boeing and two CalEPA agencies, the Department of Toxic Substances Control (DTSC) and the Los Angeles Regional Water Quality Control Board (Los Angeles Water Board). Together, they establish a path toward comprehensive cleanup and ensure that no stormwater runoff will impact human health or the environment following cleanup.

Benefits of the DTSC-Boeing Settlement Agreement include:

• expediting the cleanup process using a tool called RCRA FIRST developed by the United States Environmental Protection Agency to streamline and accelerate cleanup of contaminated sites.
• cleaning up radionuclides in soil in Boeing’s areas of responsibility to “background,” i.e., levels that would exist locally without industrial activity.
• establishing a range of stringent health protective cleanup standards that will be evaluated during environmental analysis and will not be contested if chosen. The range includes a “Resident with Garden” standard.
• starting cleanup of the Area I Burn Pit as soon as Spring 2023. Prior soil sampling identified radionuclides, heavy metals, PCBs, and dioxins at levels that exceed screening levels in the area. Cleaning it up first protects wildlife and prevents potentially harmful runoff and migration of hazardous substances.

Benefits of the Los Angeles Water Board-Boeing Draft MOU include:

• Providing a comprehensive framework and incentive to Boeing to agree to a stringent cleanup that addresses not only soil and groundwater concerns (overseen by DTSC), but also cleans up industrial pollution from all stormwater discharges (overseen by Los Angeles Water Board) in the Boeing areas of responsibility, to facilitate long term compliance with surface water quality standards after completion of its soil cleanup.
• Providing agreement regarding the substantive requirements that Boeing must satisfy before a future board will consider whether to relieve Boeing of its National Pollutant Discharge Elimination System (NPDES) permit requirements so there will not be disputes later.

The comprehensive framework of the MOU and the DTSC Settlement Agreement establishes an accelerated, streamlined path for a stringent soil cleanup that is protective of groundwater, stormwater runoff, human health, and the environment.

This Settlement Agreement is separate and apart from the 2010 AOCs. Boeing is not a party to the 2010 AOCs; only the 2007 Consent Order and the Settlement Agreement apply to the Boeing areas of responsibility.

DOE and NASA’s cleanup responsibilities remain unchanged and are governed by the 2007 Consent Order (for groundwater only) and the 2010 AOCs (for soil).

The Area I Burn Pit was operated by Rocketdyne personnel from about 1958 until 1971 and was used for the destruction of chemicals by combustion and detonation. Since the early 1980s, multiple remedial investigations and removal actions have been conducted in the Area I Burn Pit. Additional cleanup below and around the geotextile fabric covers is needed to remove the covers and safeguard against changing environmental conditions.

The work to be performed includes removal of: (1) between six inches and two feet of soil underneath all areas covered by geotextile fabric; (2) soil within Corrective Measures Study (CMS) areas as necessary to address Chemicals of Ecological Concern that present potential risk to ecological receptors that will be identified in an ecological risk assessment report; and (3) soil that has radionuclide concentrations in excess of the Look Up Table Values (LUTVs) to a depth of one foot greater than each exceedance. The ISE consent order for the Area I Burn Pit is posted on DTSC’s website.

There is an imminent threat to wildlife and other ecological receptors in the area of the Area I Burn Pit. The threat results from the predicted changes to regional weather patterns due to climate change, including the potential for far more severe precipitation events and storms, wildfires, and high wind events that may potentially damage or destroy the geotextile fabric covering part of the Area I Burn Pit area. Damage to or destruction of the geotextile fabric would expose wildlife and other ecological receptors to the covered soils and render the fabric ineffective to protect against the potential run-off and migration of hazardous substances.

Cadmium, polychlorinated biphenyls (PCBs), and dioxins are present in soil at levels that pose risks to wildlife and other ecological receptors in this area. Radionuclides also exceed local background in certain areas of the Area I Burn Pit. There is more possibility for exposure in the future due to expected severe storms, wind, rain and wildfire events. This cleanup will address the threat to wildlife and other ecological receptors and prevent the potential for harmful run-off and migration of hazardous substances from the Area I Burn Pit.

For this interim project, DTSC is requiring that Boeing clean up chemicals to ecological risk-based screening levels. This cleanup complies with California’s rigorous standards of protection of ecological habitat. Boeing also is cleaning up radionuclides to a level at or below the Look Up Table Values (LUTVs), which means that radionuclides will be cleaned up to background. Boeing will complete soil cleanup at the Area I Burn Pit during the sitewide cleanup, consistent with the final remedy decision.

This cleanup is exempt from CEQA because it qualifies as an emergency project.

The interim cleanup of the Area I Burn Pit is scheduled to begin in spring 2023 and is estimated to take several months.

Yes. Boeing will prepare a workplan for the cleanup, and DTSC will make it publicly available.

Contaminated soil will be removed by excavators. Excavated soil will be stored in containers on Boeing property before disposal. Boeing will conduct appropriate testing and screening for all soil to be disposed. Soil will then be characterized and disposed of under applicable laws and regulations. DTSC will oversee all of these cleanup activities.

The cleanup implementation plan will include industry best practices to protect on-site workers and nearby residents.

The two potential exposure pathways would be dust and stormwater. With respect to dust, DTSC will require the use of dust controls and provide updates to the public on monitoring results. This will include spraying water and covering soil stockpiles; upwind and downwind air monitoring; remediation Best Management Practices; and soil that is being hauled offsite in trucks will be covered. With respect to stormwater, the Regional Water Board will require a Stormwater Pollution Prevention Plan to ensure best management controls are in place. In addition, the excavation work will be conducted primarily in the dry season.

An archaeologist will screen the work area prior to start of work. In addition, Native American monitors will be onsite during cleanup activities to protect any cultural resources.

Onsite excavation work will occur during standard working hours, 7 AM to 4 PM, Monday through Friday. Transportation of material offsite will be limited to 8 AM to 5 PM Monday through Friday.

Boeing will conduct appropriate testing and screening for all soil to be disposed. Soil will then be characterized and disposed of under applicable laws and regulations. DTSC will oversee all of these activities.

This Order allows Boeing to fast-track an interim cleanup of the Area I Burn Pit because of the potential risk to the geotextile fabric and movement of soils, given the State’s recent report on Climate Change¹. The final cleanup will take place in accordance with DTSC’s regulatory process, which includes public review and input.

Groundwater is already being cleaned up at several locations at the Site under DTSC direction (Groundwater Interim Measure). The groundwater interim measure will continue and may be a portion of the final groundwater cleanup.

The Settlement Agreement provides a streamlined process under RCRA FIRST program for further remediation of groundwater. According to the schedule included in the Settlement Agreement, implementation of the final groundwater remedy will begin in mid-2025.

Exhibit 17 of the Settlement Agreement provides additional detail on the groundwater cleanup process.

Groundwater in certain areas beneath the SSFL site is not safe for human consumption at this time. DTSC and Boeing will execute and record an enforceable LUC to prohibit human consumption or domestic uses of groundwater.

Yes. The Settlement Agreement is consistent with CEQA because it does not result in selection of any particular course of action or substantive decisions – it describes the processes the parties have agreed to for arriving at those decisions. DTSC has not agreed to any remedy in the Settlement Agreement. DTSC reserves all of its rights on making a final remedy decision, including whether or not to approve a particular remedy, whether or not to adopt an alternative, and adoption of mitigation measures. After public review and comment on the Draft Statement of Basis, DTSC will select the final remedy and approve the Boeing project under CEQA.

No. The Settlement Agreement does not result in selection of any particular course of action or substantive decisions – it describes the processes the parties have agreed to for arriving at those decisions. DTSC has not agreed to any remedy in the Settlement Agreement. DTSC reserves all of its rights on making a final remedy decision, including whether or not to approve a particular remedy, whether or not to adopt an alternative, and adoption of mitigation measures. After public review and comment on the Draft Statement of Basis, DTSC will select the final remedy and approve the Boeing project under CEQA.

Ventura County Air Pollution Control District (VCAPCD) Rule 55 requires work to be suspended at a wind speed threshold of 25 mph sustained for at least 5 minutes in a one-hour period. Regardless of wind speed, work is to be stopped if visible dust is observed or if particulate matter levels exceed specified thresholds.

Pursuant to the Removal Action Work Plan (RAW), required dust monitoring and dust mitigation measures in place are protective of workers and the public. DTSC personnel conduct routine onsite inspections to ensure compliance with the RAW. If DTSC finds Boeing or its contractors out of compliance, or AIBP impacts on human health, safety, or the environment change, DTSC will issue a stop work order, institute additional controls and measures, and issue updated requirements.

• Stockpiles are protected from wind erosion with a temporary perimeter sediment barrier, covered with plastic sheeting, and secured daily at the end of the work shift, or earlier if necessary, based on conditions at the AIBP site.
• Best Management Practices (BMPs) for the Stockpiles comply with Storm Water Pollution Prevention Plan (SWPPP) requirements. The AIBP SWPPP is also subject to the Construction General Permit (CGP) monitored under the California Regional Water Quality Control Board, Los Angeles Region (LA Water Board).
• BMPs are used to properly manage stockpiles, such as placing waste containers and stockpiles away from concentrated flows of stormwater, drainage courses, and inlets.
• Waste storage areas are protected from stormwater run-on by using a temporary perimeter sediment barrier such as k-rails, berms, dikes, fiber rolls, silt fences, sandbags, gravel bags, or straw bale barriers.

During the interim soil cleanup at the AIBP site, fugitive dust control measures are implemented, and air quality monitoring is performed to comply with federal, state, and local air quality laws and regulations, including Ventura County Air Pollution Control District (VCAPCD) Rule 55. The current air quality monitoring program for the AIBP and the SSFL sitewide air monitoring program effectively covers both PM2.5 and PM10 (fine inhalable particles with diameters of 2.5 and 10 micrometers or smaller, respectively).\

• Real-time PM10 air monitoring stations are located upwind and downwind of the AIBP interim cleanup area. Air monitoring occurs during working hours. The difference between upwind and downwind PM10 concentrations is used to determine the amount of dust generated (if any) during AIBP interim cleanup activities. If the difference exceeds 50 micrograms per cubic meter (µg/m³), or if visible dust is observed, the RAW requires that earth-moving activities stop, and additional dust control measures be used. Earth moving activities will not restart until the PM10 concentrations drop below 50 µg/m³ and no visible dust is observed.
• PM2.5 is monitored by three monitoring stations as part of the SSFL sitewide program. These measurements are conducted using MetOne Environmental Beta Attenuation Monitors (EBAM).

Yes, integrated personal air samples for metals, radionuclides and volatile organic compounds (VOCs) are being analyzed by an American Industrial Hygiene Association (AIHA) accredited laboratory as described in the RAW.

Real-time PM10 air monitoring stations are located upwind and downwind of the AIBP interim cleanup area. Air monitoring data is validated and posted routinely in DTSC’s SSFL AIBP Air Monitoring page.

• The cleanup protocols and mitigation measures implemented at the AIBP prevent water runoff from leaving SSFL. Water on-site is primarily used for dust mitigation, and it is applied in a controlled manner. As part of the conditional approval of the RAW, Boeing implemented a stormwater control plan in the western portion of the excavation area to redirect runoff to the Perimeter Pond, adjacent to AIBP.
• Water runoff collected in the Perimeter Pond is pumped to R-1 Pond, where it is then treated at the stormwater treatment plant located next to the R-1 Pond.

Boeing monitors groundwater quality around the Perimeter Pond in wells RS-07, RD-03, and PZ-077. These wells are located downgradient (RS-07 and RD-03) and upgradient (PZ-077) of the Perimeter Pond. This groundwater monitoring would show any variation in contaminant infiltration. Groundwater contaminant concentrations have decreased since site operations ceased, and recent data shows no changes or increase in concentrations, indicating water temporarily stored in the Perimeter Pond is not impacting groundwater.

All samples are submitted to a laboratory accredited under the National Environmental Laboratory Accreditation Conference and National Voluntary Laboratory Accreditation for analysis in accordance with chain-of-custody procedures.

DTSC, in coordination with the California Department of Public Health (CDPH), oversees cleanup activities routinely to ensure they are performed in accordance with the RAW.

All personnel onsite attend a daily health and safety meeting before entering the work exclusion zone. These meetings address site specific hazards, safety precautions, procedures, and any health and safety issues from the previous shift. Late arrivals receive an ad-hoc safety briefing to ensure they are informed of any critical updates.

In addition to Boeing confirmation sampling, CDPH will analyze some split confirmation samples for radionuclides using CDPH’s analytical laboratory, which is independent of the laboratories used by Boeing.

A deed restriction is not required at this time, as this interim cleanup is not the final cleanup. Further cleanup will be conducted under the 2007 Consent Order and the 2022 Boeing Settlement Agreement. The necessity for a Land Use Covenant (LUC) will be evaluated as part of the sitewide cleanup process.

Once waste haul trucks leave the SSFL, the primary route to the various disposal facilities is based on reaching State Route (SR) 118, the Ronald Reagan Freeway. From the SSFL gate, vehicles turn right (east) onto Woolsey Canyon Road, right (south) onto Valley Circle Boulevard, left (east) onto Roscoe Boulevard, and left (north) onto Topanga Canyon Boulevard. The entrance to SR 118 is on Topanga Canyon Boulevard.

• Boeing and their contractors must adhere to specific regulations in California Code of Regulation, Title 22; the U.S. Department of Transportation (DOT) requirements, and Federal Regulations Title 49, section 271 for transporting all Resource Conservation and Recovery Act (RCRA) and non-RCRA hazardous wastes as indicated in the RAW.
• All trucks are covered with a suitable retractable cover before leaving SSFL.
• Trucks carrying hazardous material are completely contained with heavy gauge plastic and tape in addition to having a retractable cover. Packaging radioactive materials is conducted in accordance with U.S. DOT requirements.

Four soil samples are collected from each 150-cubic yard portion of a stockpile and analyzed by an analytical laboratory. All waste soil stockpiles are sampled for radiological waste, regardless of the history, screening, and sorting. Based on the results of the waste profile and classification, the generated waste will be transported to a proper offsite disposal facility. The final determination of the facility selected for disposal is based on waste profiling and approval from the disposal facility. Material characterized with radioactivity greater than the look up table values (LUTVs) will be transported to a facility licensed to accept radioactive materials at the concentrations identified.

So far, all soil excavated from the AIBP as part of this interim action has been disposed of at US Ecology in Grandview, ID.

Cleanup to LUT values is representative of a soil cleanup to background and is consistent with United States Environmental Protection Agency (USEPA) recommendations. The radiological LUT values were developed by DTSC pursuant to the USEPA recommendations. As stated in the USEPA Final Technical Memorandum for SSFL, USEPA recommends the use of the Background Threshold Values (BTV) as the basis for development of LUT values for radiological contamination; for the reasons described herein, BTVs alone are neither appropriate nor recommended for use as the LUT values.

Gamma scanning is a screening tool used to ensure worker safety, segregate waste, and assess whether cleanup goals are likely being met before collecting post-excavation confirmation samples for laboratory analysis. While gamma scanning is not used as the sole basis for final cleanup decisions or waste classification, gamma scanning data will contribute to creating an electronic map for further evaluation and remedial activities. It plays an important role in the overall cleanup process, complementing other methods and data.

The current interim cleanup targets soil contamination up to a depth of 10 feet or bedrock. Per the Settlement Agreement between DTSC and Boeing, Boeing will evaluate soil radiological data above LUTVs at depths greater than 10 feet in the final sitewide cleanup.