Boeing Everett

Last updated: May, 2024

Boeing Everett is "pilot testing" their groundwater remedy. Boeing is implementing their Cleanup Action Plan. Current work includes installing roads up a steep hillside so treatment wells can be installed at the edge of the plume. Clean water will be put into wells at the edge of the plume while contaminated water is removed from a central point. After contaminated water is withdrawn, it will be treated. This is called "dynamic groundwater circulation", and Boeing is testing this treatment on part of the plume (called a pilot test) to make sure this treatment works before installing wells to treat the entire plume. 

In addition, treatment of the source area of the TCE plume began in August and September 2023 as part of Boeing’s implementation of their Cleanup Action Plan. These treatments were Enhanced In Situ Bioremediation (EISB) injections. The injections provide nutrients to the naturally occurring bacteria in the groundwater to help them break down the TCE to non-hazardous products. Treating the source area reduces TCE concentrations throughout the Powder Mill Gulch plume.

What's Next?

The Cleanup Action Plan for soil contamination under buildings is for the contamination to remain in place until it can be removed without disrupting facility operations. We require regular sampling of groundwater and indoor air to ensure the contamination does not impact human health or the environment. Contaminated groundwater will be pumped and treated to remove TCE and VC (vinyl chloride).

The Boeing Company owns and operates the Boeing Everett Plant. The plant produces models 747, 767, 777, and 787 commercial aircraft.  Dangerous wastes are generated during aircraft assembly, and accumulated on site for less than 90 days.
 
Boeing used to store dangerous waste under a U.S. Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) interim status permit. Boeing no longer stores dangerous waste on-site for more than 90 days. However, Ecology will not withdraw Boeing’s interim status until all site wide cleanup is completed.

Boeing submitted the draft Feasibility Study (FS) in late 2015. After review, the FS was completed in 2016.

Boeing submitted a draft Supplemental Feasibility Study (SFS) in late 2018 for the Trichloroethylene (TCE) Plume at Powder Mill Gulch (PMG). After review, the SFS was completed in 2020.

Based on the evaluations presented in the FS and SFS, a draft Cleanup Action Plan (dCAP) was developed and completed by Ecology in late 2020.

The FS, SFS, and dCAP went out for public comment in early 2021. Ecology decided the final cleanup alternatives for the site based on the information provided in the FS and SFS reports and compliance with Washington State cleanup regulations.

Ecology is using an Enforcement Order to implement the cleanup. Boeing refused to sign the Agreed Order because the groundwater cleanup levels are set to a level that is equal to surface water quality standards instead of state drinking water standards.

Ecology issued an Enforcement Order to implement the Cleanup Action Plan at the site. However, the portion of the site called the Bomarc property will be cleaned up under an Agreed Order; this allowed Boeing to sell the property. 

We held a public comment period in 2021 on the CAP. Ecology responded to all comments received. These responses can be read in our Responsiveness Summary posted in the "Electronic Documents" section of this site. Boeing has been implementing their cleanup action plan since it was approved. 

Over time, the facility released hazardous substances to soils, groundwater, surface water, and/or sediments. These hazardous substances include, but are not limited to: 

• Chlorinated solvents (like TCE and PCE) 
• Non-chlorinated solvents 
• Fuels 
• Oils 
• Polychlorinated biphenyls (PCBs) 
• Heavy metals

The 2012 RI identified TCE groundwater contamination on Boeing Everett property and migrating off Boeing Everett property. This contamination flowed north into Powder Mill Gulch).
 
TCE concentrations in groundwater are well above drinking water standards. Although residents in the area receive drinking water from piped in off-site drinking water sources (and not the TCE contaminated Esperance Sand Aquifer), Ecology advises that no groundwater within or near the contaminated portion of the Esperance Sand Aquifer is withdrawn for any reason. 

As a safety precaution, Ecology advises that people and animals should stay on the walking trails adjacent to Powder Mill Creek and not enter or go near the creek. There is TCE contaminated groundwater seeping from the creek banks that drains along the surface of the creek shore and eventually flows into the creek. There are signs posted at visible trail entry points advising walkers to stay on the trails during the TCE groundwater remediation. 

• The Remedial Investigation (RI) studies the site conditions and contamination so the Feasibility Study (FS) and Supplemental Feasibility Study (SFS) can compare cleanup actions. The RI is in two volumes. RI Vol. 1A and RI Vol. 1B. The FS and SFS compare cleanup methods for the site. The SFS report was modified by four letters: Aug. 2016; July 2017; May 2019; Sept 2019.
• Cleanup Action Plan (CAP): Ecology prepared this CAP that describes the cleanup actions and sets the cleanup standards.
• Enforcement Order: Ecology is using an Enforcement Order to implement the Cleanup Action Plan.
• Agreed Order (AO): We and Boeing decided to use an Agreed Order to implement the Cleanup Action Plan for the portion of the site called the Bomarc property so it can be sold.
• Permit: A Permit Lite is a “Dangerous Waste Corrective Action Permit,” that allows environmental cleanup at the site to continue.
• State Environmental Policy Act (SEPA) Checklist: We use SEPA during site cleanups to find and evaluate large, negative environmental impacts that could result from a proposed action. Ecology's evaluation of this SEPA checklist resulted in an Associated Determination of Non-Significance.
• Public Participation Plan (PPP): The PPP encourages comment and involvement in cleanup decisions from the community.

Ecology approved the Boeing Everett Remedial Investigation (RI) in 2012.

The RI is an in-depth study to:-Determine site features such as groundwater flow, sediment type, and other factors.-Define the type and extent of contamination.-Assess potential effects on human health and the environment.-Determine if interim cleanup actions are needed. -Determine which contaminated areas need evaluation in the Feasibility Study (FS).Ecology received the Boeing Everett Feasibility Study (FS) in 2016.

The FS:

-Evaluates and selects cleanup alternatives for the entire site.
-Evaluates cost estimates of the selected cleanup alternatives for the entire site.

Ecology approved the Boeing Everett Supplemental Feasibility Study (SFS) in 2019.

The SFS:

-Evaluates and selects cleanup alternatives for Powder Mill Gulch.
-Evaluates cost estimates of the selected cleanup alternatives for Powder Mill Gulch.

Ecology completed the Boeing Everett draft Cleanup Action Plan (dCAP) in 2020. The dCAP became final in April 2021 following a public comment period.

The CAP describes:

-The cleanup standards for the entire site.
-The cleanup methods that will be used to achieve these cleanup standards.
-The requirements the cleanup must comply with for the entire site.

Boeing is required to cleanup contamination at their Everett plant and all contamination that has migrated off the Everett plant. Ecology uses both RCRA and the Model Toxics Control Act (MTCA) regulations when overseeing cleanup of hazardous waste sites. These cleanup measures protect human health and the environment from releases of dangerous wastes and chemicals at and from the facility.

Powder Mill Gulch Trichloroethylene (TCE) Groundwater Contamination:

Ecology required Boeing to install a groundwater pump-and-treat system to minimize contaminated groundwater flowing off of the Boeing property and into Powder Mill Creek. In addition, interim actions to cleanup the source of contamination were conducted to reduce groundwater contamination. These interim actions were done prior to developing a final cleanup plan for the entire Boeing Everett facility (including Powder Mill Gulch). The cleanup of Powder Mill Gulch is still on-going. The dCAP is intended to present the cleanup remedy for the entire Boeing Everett facility (including Powder Mill Gulch).