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.

Upon the certification of the Final Program Environmental Impact Report (PEIR), DTSC began reviewing work plans and cleanup options for SSFL. These technical concerns must be addressed to implement the cleanup to local background levels.

In 2010, DTSC entered into two legal agreements called the Administrative Orders on Consent (AOCs) with NASA and DOE for cleanup of soils under the State Superfund Authority, Chapter 6.8 of Division 20 of the California Health and Safety Code.
The AOCs establish the process to investigate and clean up soil “consistent with local background levels.” The AOCs apply to the areas of cleanup for NASA (Area II and a small portion of Area I).

Please note, effective January 1, 2024, Chapter 6.8 (commencing with Section 25300) of Division 20 of the California Health and Safety Code is repealed and replaced by Division 45 (commencing with Section 78000) to the Health and Safety Code.

An Administrative Order on Consent (AOC) is a legal agreement between a regulatory agency, like DTSC, and a person, business, or group responsible for environmental issues. In this kind of agreement, the responsible party agrees to carry out needed cleanup or corrective actions, pay any penalties, and stop activities that caused the violations. This agreement is legally binding.

The 2010 Administrative Orders on Consent (AOCs) with NASA and DOE are the legal agreements which direct soil cleanup to local background levels.

The Administrative Orders on Consent (AOCs) do not define local background levels; however, they do provide direction on how local background levels are established.

USEPA defines “Background Levels” as concentrations of substances that are not influenced by the releases from a site. Background can be naturally occurring or anthropogenic. Naturally occurring substances are present in the environment in forms that have not been influenced by human activity. Anthropogenic substances are natural and human-made substances present in the environment as a result of human activities not specifically related to the site. Per the AOCs, DTSC determined local background levels through the completion of a Chemical Background Study. The two background reference areas, Wood Ranch and China Flat, were identified with public involvement.

Yes. DTSC is committed to following the 2010 Administrative Orders on Consent (AOCs) and requiring cleanup of soils “consistent with local background levels.”

A “Look-up table” (LUT) is a list of soil cleanup levels.

As directed by the AOCs, “Upon completion of the DTSC led chemical background study, a ‘look-up’ table of the chemical cleanup levels will be prepared, which will include both local background concentrations as well as minimum detection limits for specific contaminants whose minimum detection limits exceed local background concentrations.” The AOCs require LUTs for both chemicals and radionuclides. In 2012, the USEPA provided DTSC a technical memorandum with recommendations for radionuclides LUT values after conducting the Radiological Background Study required by the AOCs.

DTSC completed a Chemical Background Study to determine local background levels and chemical method reporting limits, which resulted in the development of the provisional chemical Look-Up Table (LUT) issued in 2013. There are more than 130 chemicals included in the LUT.

USEPA completed a Radiological Background Study to determine local background levels, which resulted in the 2013 radiological LUT. There are 16 radionuclides included in the LUT.

A Method reporting limit (MRL) is the lowest concentration of a chemical that can be reliably reported by a laboratory. It can vary by laboratory and even from sample to sample due to influences of the soil.

A Background threshold value (BTV) represents the upper limit of background concentrations of a chemical and are established using statistical procedures on the data collected from a Chemical Background Reference Area.

Many of the method reporting limits (MRL) are not reliably achieved by laboratories. Non-standard methods were used to achieve the lowest possible detection limits in the DTSC Chemical Background Study. These non-standard methods were used to detect very low concentrations in the background soils to determine the look up table (LUT) values. DTSC has directed the responsible parties to perform an MRL study to report current laboratory capabilities, results are due in Winter 2025. DTSC will review the MRL report and share findings with the public. DTSC may propose draft revisions to the LUT, which would then be circulated for public comment.

The purpose of the laboratory study is to determine current reporting limit capabilities. The laboratory study involves surveying commercial laboratories regarding their ability to meet the 2013 Look-Up Table (LUT) values that are based on minimum method reporting limits (MRLs). Because the Administrative Orders on Consent (AOCs) identify any exceedance of an LUT value as contamination requiring removal, it is critical that the LUT values are routinely achievable by laboratories. In practice, the LUT values that are based on MRLs have not consistently been able to be met by laboratories. DTSC has directed the responsible parties to perform an MRL study to report current laboratory capabilities, results are due in Fall 2024. DTSC will review the MRL report and share findings with the public. DTSC may propose draft revisions to the LUT, which would then be circulated for public comment.

The purpose of the backfill evaluation is to identify suitable sources of backfill. Imported backfill materials will be needed for stabilization and restoration of areas where contaminated soil is removed at SSFL. Backfill is necessary because if left open, excavations would pose hazards to people and wildlife, adversely affect surface water drainage, flow, and erosion at the site, affect groundwater recharge, and severely limit the potential for ecological restoration of the site. The Administrative Orders on Consent (AOCs) require that all backfill soils meet the chemical and radiological Look-Up Table (LUT) values, and DTSC shall determine the best available source of backfill in consultation with the responsible parties.

Not necessarily. It’s important to remember that the “not-to-exceed” background cleanup approach and the Look-Up Table (LUT) values are not risk-based- they do not consider human health. In fact, the average LUT value is more than 300,000 times lower than residential health protective screening levels. Removing soil that is not contaminated above local background levels, is not providing a measurable benefit to human health and in fact it results in destruction of habitat for our native plants, animals, and cultural resources.

DTSC is considering approaches to the background cleanup that reduce the removal of soils misidentified as contamination while continuing to minimize risk to the community. The current approach does not consider risk so there is no consideration given to the future land use, exposure frequency, exposure duration, or the toxicity of the chemicals. Many of the look-up table values are significantly lower than residential risk-based screening levels. The proposed multiple lines of evidence approach uses risk as a line of evidence to ensure that modifications do not result in higher risk to the community.

At this point, DTSC is unable to provide an exact timeline, but plans to resolve the technical issues in a timely manner to allow NASA and DOE soil cleanups to proceed. DTSC is committed to working through these issues in a transparent manner including involving the public in identifying solutions through public engagement opportunities.

DTSC is hosting several workshops called Soil Smarts: DTSC’s Interactive Learning Series on the Background Cleanup at SSFL. The first two workshops are scheduled for November 20, 2024 and December 10, 2024. Additional workshops will be scheduled in 2025 to continue the discussion with the community and discuss the results of ongoing studies. Questions and comments can be submitted through STREAM: SSFL Tool for Response, Engagement, and Answer Management: STREAM. DTSC will provide more information on these opportunities through public notices and community updates.

A “false positive” is when soils are identified as contaminated when they are not.

No. The issues related to the frequency of misidentifying contamination are restricted to the cleanup of chemicals in soil.

Multiple Lines of Evidence (MLE) means using different types of proof to support an idea. This approach makes the argument stronger and more reliable. The MLE approach for SSFL addresses the high false positive error rate by considering the full range of detections from the DTSC Chemical Background Study, results from the ongoing MRL Study, and uses risk assessment as a backstop to ensure that any changes to the approach are health-protective. Evaluations will be on a sample-by-sample basis and the cleanup will still be based on achieving levels consistent with local background.

No, risk assessment is used as a tool in the multiple lines of evidence (MLE) approach, but the goal remains a cleanup to local background levels. Risk is used as a tool to address the high rate of misidentifying soils as contaminated when they are not (a false positive result). This will limit unnecessary soil removal and destruction of habitat while remaining protective of human health. The evaluation is still performed on a sample-by-sample basis. It does not use any area averaging or consider anticipated exposures, which are typical of a risk-based cleanup. Risk is used as a backstop to ensure the protection of human health.