Boeing Auburn Cleanup Site

Read about the groundwater cleanup standard dispute

In Washington, there are two clean water standards:

• Surface water standards (most strict).
• Drinking water standards (less strict).

Our position

We proposed Boeing clean up contaminated groundwater to the stricter standard, which is the surface water cleanup standard. It is roughly ten times more strict than the drinking water standard. The reason for this is that contaminated groundwater at Boeing Auburn goes into surface water.

Boeing’s position

After informal dispute resolution, Boeing has decided to accept our decision to use the surface water cleanup standard. They originally disagreed with setting strict cleanup levels and wanted to use the drinking water standard instead.

There are two stages of dispute resolution: informal, then formal.

• Read our comments on Boeing's feasibility studies (PDF).
• Read Boeing's response to our comments (PDF).
• Read our decision (PDF).

1966 - 1990s: TCE in use

Boeing uses trichloroethylene (TCE), a chemical, to clean metal parts.

1990s: Early investigation and TCE releases reported

• Boeing begins looking for contamination in soil and groundwater.
• They tell us about the releases of TCE at the facility.

2002: Agreed order and bioremediation testing

• We and Boeing sign an agreed order to investigate releases at the facility. 
• Boeing tests bioremediation to clean up an area under a building with high levels of TCE.

2003: Remedial investigation begins

Boeing begins to study the contamination further.

2005: Interim action using bioremediation

• High TCE contamination levels lead us to require Boeing to conduct an interim cleanup.
• Boeing conducts interim cleanup using a bioremediation pilot project to treat an area with highly contaminated levels of TCE and related chemicals.
• Interim action brings area to within federal drinking water standards.

2006: Agreed order amendment

We and Boeing amend the agreed order to include property ownership transitions.

2009: Investigation off site

We require Boeing to check for contaminated groundwater outside of their property.

2011: Contamination found off site

• Boeing finds groundwater contamination outside of their property. 
• We inform water districts and the cities of Algona, Auburn, and Pacific.

2012: Tests show drinking water is safe

Department of Health confirms that the public drinking water is safe.

2013: Public meetings

We hold public meetings in Algona to discuss the investigation and air quality testing.

2015: Cleanup method trial (bioremediation) 

• Boeing tests enhanced bioremediation on low level TCE contamination in commercial Algona. 
• All bioremediation applications are successful.

2017: Draft remedial investigation report & comment period

We approve the revised remedial investigation in September 2017. 

2019 - 2021: Boeing submits feasibility studies

• We received Boeing's feasibility and supplemental feasibility studies (studies that compares possible cleanup methods) in October 2019 and December 2020.
• Public comment on these documents ended June 18, 2021.
• These documents are now final.

2021: Cleanup action plan

We will propose a cleanup action plan.

2022 - beyond: Cleanup implemented and monitored

• We will approve a cleanup action plan after public comment.
• Boeing will follow this cleanup action plan to continue cleaning up the site.
• We will continue to monitor contamination levels to make sure the cleanup is working.

Boeing’s cleanup must follow Washington's cleanup process. The process requires a thorough investigation of the contamination and possible cleanup options. The large area of contaminated groundwater (1 mile by 1.5 miles) at depths of 30-100 feet underground, increases the work and time for the investigation. Boeing regularly tests both groundwater and surface water at the site under our supervision.   

The use of microbes — such as bacteria that live naturally in the environment — to clean up contaminated soil or groundwater. Bioremediation stimulates the growth of certain microbes that use contaminants as a source of food and energy.

At the Boeing Auburn site, bioremediation has been used successfully to break down chemicals in contaminated groundwater.

For more information, read:

• Blog post about the bioremediation pilot study at Boeing Auburn.
• Focus sheet: Current bioremediation at Boeing Auburn.

Monitored natural attenuation (MNA) means to oversee how effective the natural environment breaks down chemicals at a contaminated site.

Natural processes in the environment that are monitored include:

• Dispersion and dilution: Chemicals spread out (dispersion) and are watered down (dilution) as they flow with groundwater away from the contamination source over time.
• Chemical reactions: Chemicals break down through chemical reactions in the soil and groundwater.
• Biodegradation: Living bacteria naturally found in soil and water consume contaminants over time.
• Sorption: Chemicals in groundwater stick to carbon in the soil it comes in contact with. This removes them from the groundwater.
• Evaporation: Chemicals become vapor and move into small air pockets around soil particles. These gases eventually reach the surface, reducing the amount of chemicals in the groundwater.

How effective is this cleanup method?

Computer modeling and groundwater sampling indicate that MNA, when paired with bioremediation, effectively reduces contaminants in soil and groundwater.

For more information, read our:

• Focus sheet: Monitored natural attenuation

Yes. Water in homes and businesses comes from public water systems that are monitored by the Department of Health.

• Contamination does not affect drinking water wells
• Groundwater flows away from existing wells.
• Testing by the Department of Health has not found any chemicals of concern.

Private wells are not monitored by the Department of Health.

No. The rainbow-colored sheen sometimes seen in ditches is likely from bacteria commonly found in wetlands. TCE and its breakdown products are colorless and odorless at low concentrations.