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Military Ocean Terminal Concord, California

Military Munitions Response Program

Common-User Ammunition Terminal

Military Ocean Terminal Concord (MOTCO), CA, is the U.S. military’s primary West Coast common-user ammunition terminal. Under the direction of the U.S. Army’s Surface Deployment and Distribution Command, MOTCO operates two ocean terminal piers and an Army-owned rail system that connects with two major public rail lines. MOTCO’s mission is to safely and efficiently process, ship, and receive military cargo, including ordnance, to support the Pacific Command area of operation.

Located in the East San Francisco Bay region, the 6,641-acre installation encompasses a 115-acre inland area and a 6,526-acre tidal area, which includes 2,045 acres of offshore islands. The installation is the site of a 1944 explosion of two ships that were being loaded with 5,000 tons of munitions. The explosion scattered munitions and debris up to 12,000 feet away, impacting 5,000 acres on the land and in the water.

Under the Military Munitions Response Program (MMRP), Parsons is conducting environmental restoration services in a remedial investigation and feasibility study (RI/FS) at MOTCO to determine and evaluate cleanup options for military munitions and explosive debris at three previously identified munitions response sites (MRSs) resulting from the 1944 explosion and from other munitions handling and demilitarization activities.

Tugboat (on left) to intercept any approaching boats outside the blast radius

Remedial Investigation Methods

The MRSs in this project cover diverse topographies, including dry land, marshes, and under water. Parsons is integrating standard investigation approaches with cutting-edge technologies on this project:

  • Historic records review
  • High-resolution aerial photography
  • Digital geophysical mapping
    • Underwater
    • Airborne
    • Ground based
  • Intrusive investigations and munitions constituents (MC) sampling
  • Underwater anomaly investigation using an electromagnet
  • Munitions and explosives of concern (MEC) disposal/demolition
  • Munitions debris (MD) disposal/disposition
  • MEC/MD accountability
  • MEC hazard assessment
  • Assessment of risks from MC
  • Site restoration

First Use of Electromagnet Recovery Technique

Two methods were employed to survey land and water for MEC and MD. Over dry land, marshes, and shallow water, a helicopter outfitted with a geophysical magnetometer mapped anomaly densities. Where the water was deeper, a boat-towed magnetometer and sidescan sonar were used.

To recover underwater metallic debris and potential MEC, the standard approach would be to use diving-certified unexploded ordnance (UXO) technicians. However, due to visibility of less than 1 foot and tidal currents up to 6 knots, Parsons uses a barge with a crane-mounted electromagnet. The crane sweeps the electromagnet over the bottom of the bay in areas identified during the survey. Recovered debris and MEC are placed on a separate barge and evaluated by UXO technicians. This is the first time an underwater electromagnet has been used in an MMRP RI/FS, and the technique has proven to be safer and more efficient than traditional approaches. The electromagnet has recovered both MEC and MD, including 3‑in, 5‑in, and 40‑mm projectiles.

Typical MEC and MD recovered.

Protecting Endangered Species

The marsh areas at MOTCO remain relatively untouched and are home to several special status plant, fish, bird, and rodent species. Breeding and nesting periods for the endangered California clapper rail, black rail, and other birds limit the times when Parsons may work in the marsh areas to a few months during the fall. Similarly, migrating salmon restrict times when the barge and electromagnet may be used to the late summer and fall. During the water work, sidescan sonar helps our team avoid underwater vegetation that is home to the endangered delta smelt. Parsons has worked with the U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, and National Marine Fisheries Services to ensure that all appropriate precautions are taken to protect and preserve the wildlife and vegetation at MOTCO.

The environmental restoration resulting from this program creates a safer place for the U.S. Army to conduct operations and paves the way for future activities at the installation.

Parsons has a proven track record in munitions response and environmental remediation. We have worked at hundreds of Department of Defense (DoD) facilities worldwide, and we are highly experienced in supporting the Army, Air Force, Navy, Marine Corps, National Park Service, Customs and Border Protection, and other federal agencies in munitions cleanup as well as other environmental mitigation missions.