The former Tulalip Ammuntion storage depot is located in Marysville, Washington.
In 1942, the Government activated the Tulalip Backup Ammuntion Storage Depot (BASD) for the temporary storage of large quantities of different munitions including chemical warfare agents.
The Army Corp of Engineers (USACOE) tasked their subcontractor to conduct a site investigation which included a geophysical survey and an investigation of all geophysical anomalies.
Based on the geophysical survey, three locations – PW-02, PW-03, and PW-03 were identified as locations requiring removal using an excavator.
On June 14, 2006, at approximately 0800 hours the field team uncovered a rusted-through 55 gallon drum with reinforced ribs. Subsequent soil samples analysis detected mustard agent and mustard agent breakdown product present in the samples.
The USACOE subcontractors stop field activities to update their site work plans and health and safety plans.
The USEPA was contacted by the Tulalip Indian Tribe about site activities.
Site Activities to Date:
• On August 14, 2006 site removal excavation restarted at location PW-04.
• On August 15, 2006 during the removal, several unidentified glass containers were discovered. Due to possibility that these containers may contain Chemical Warfare Agents the site was shut down to update site work plans and health and safety plans.
• Based on the Maximum Credible Event the new work plans included the installation of a negative-pressured temporary building (tent) placed over the excavations.
• On December 11, 2006 site removal excavation restarted inside the negative-pressured temporary building at location PW-02.
• On January 25, 2007 the excavation at PW-02 was completed. Confirmation samples for Mustard Agent and derivatives were collected and analyzed offsite.
• On January 30, 2007 after receiving the Mustard Agent samples results, the confirmation samples for HTRW were collected. All confirmation samples for Mustard Agent and HTRW were split and received by the USEPA subcontractor.
• On February 1, 2007 the negative-pressured temporary building was repositioned.
Future Site Activities:
• The excavation will continue at location PW-04 next week (February 6, 2007).
• The USACOE subcontractor anticipates a late-February completion date for the site.
