More than 400 underwater sites have been identified as potentially contaminated with munitions. A majority of these areas are located in relatively shallow water (0 – 35 meter depth) where they pose a threat to human health and the environment. SERDP and ESTCP are supporting the development of underwater standardized unexploded ordnance (UXO) demonstration sites (“test beds”) for assessing the performance of technologies that can detect, classify, and ultimately remediate underwater UXO. The Pacific Northwest National Laboratory’s Marine and Coastal Research Laboratory is implementing the operational phase of a standardized underwater test bed in Sequim Bay, a coastal embayment in Washington State. Earlier stages were completed under MR-2735. which included preliminary design and site location studies, and environmental characterization.  

Formalized operation and maintenance of the test bed will include:

  • Hosting multiple technology remediation developers through the full range of technology readiness levels
  • Executing field protocols and operations that support a variety of remediation system demonstrations
  • Developing a programmatic permitting pathway to support wide scale test bed operations
  • Collection of ground truth data to support formal scoring of technology demonstrations
  • Ongoing collection of environmental data to support long term programmatic needs and specific system developer’s requirements
  • Modification and updating of operational protocols as test bed and programmatic requirements change

Technology Description

The Sequim Bay underwater test bed is located in a water depth of 5 to 30 meters with a variety of mud, sand and gravel substrate. The protected non-urban embayment and temperate climate allows for testing during multiple seasons in optimal conditions. Maintenance and operation of the test bed include the following tasks: 1) securing the necessary environmental permits and authorizations in a timely manner to conduct demonstrations, 2) handling all aspects of target and clutter items including obtaining, inventorying, collection of metadata, diver emplacement and recovery, geolocation with submeter accuracy, and secure storage, 3) designing target layouts in the test bed, and collection of environmental ground-truth and metadata for independent scoring of technology demonstrations, and 4) providing operational, logistical and facilities support to remediation system developers during deployment of their technologies.


Developing technologies and equipment for detection and classification of UXO requires standardized test sites where performance can be evaluated in a realistic environment under controlled conditions using inert and surrogate munitions. Several land-based test sites have been established in the United States, however underwater munitions sites are more difficult to access and to assess. Underwater test sites such as Sequim Bay are critical for controlled performance evaluation of underwater munition detection technologies, and progressing future technologies toward operational status.