ENVVEST Program Addresses Nonpoint Source Pollution
in Watersheds

The Sinclair and Dyes Inlet watershed in Kitsap County, Washington, forms a subestuary of Puget Sound in the Pacific Northwest. The creeks and streams that drain the 62,348 acres transport water, sediment, and chemicals from forests, farms, industrial, suburban, and urban land-use areas. About 35% of the watershed is classified as developed, centered along the shoreline and located in the urban centers of Bremerton, Silverdale, and Port Orchard, an area that includes roads, parking lots, and other urban infrastructure, as well as the Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS & IMF) industrial area.

The stream networks drain about 80% of the watershed, but about 30% of the developed areas (11% of the watershed) drain directly to the nearshore. A little over 100 years ago, Sinclair Inlet and the Kitsap Peninsula were relatively undeveloped. However, since the establishment of the Navy base in Sinclair Inlet in 1891, the creation of the town of Bremerton in 1901, and the major expansions at PSNS & IMF during World Wars I and II, the area has seen a significant increase in contaminants from military installations, industrial activities, municipal outfalls, and other nonpoint sources. At the height of WW II, with a Bremerton population that peaked at over 80,000, industrial operations poured out goods for the war effort with little regard for the environmental safeguards that exist today. Although work at PSNS was reduced after the war, with the 1975 establishment of the Submarine Base at Bangor, Kitsap County has continued to experience rapid growth in population, infrastructure, and development of open space, particularly along the coastal fringe. Currently, about a quarter of a million people live in Kitsap County.

In 1998 the Washington Department of Ecology (WDOE) listed some of the sediments in both Sinclair and Dyes Inlets under Section 303(d) of the Clean Water Act (CWA), because concentrations of mercury, copper, other metals, and organic chemicals (e.g., polychlorinated biphenyls, or PCBs) exceeded sediment quality standards.

For the past two years, chemists and biologists from the Pacific Northwest National Laboratory, Marine Sciences Laboratory (MSL) in Sequim, Washington, a Battelle-managed Department of Energy Laboratory, have collaborated with scientists and others at the Navy, the Space and Naval Warfare Systems Command (SPAWAR), San Diego, California, and the U.S. Army Corps of Engineers Engineering Research and Development Center, Vicksburg, Mississippi, to understand the sources, pathways, and sinks of the contaminants entering the inlets. The resulting PSNS & IMF environmental investment (ENVVEST) program incorporates advisory and technical committees comprised of members from the U.S. Environmental Protection Agency, WDOE, and several county, municipal, and tribal stakeholders.

Battelle’s contributions have included the following:

• Developing a sediment contamination mass-balance for copper
• Evaluating sources of bacterial pollution for development of a total maximum daily load (TMDL)
• Collecting and analyzing surface and cored sediments for metals and organic contamination
• Surveying and evaluating PSNS railroad culverts for fish passage
• Monitoring of freshwater streams for biological integrity
• Assessing salmon habitat
• Helping develop a watershed-based restoration plan

Sediment cores collected in the inlets by MSL divers and analyzed at the MSL show that contamination levels of mercury and PCBs were higher 40 years ago than they are today. The Navy’s cleanup efforts, as well as source control by the Navy and others, have resulted in an improvement in sediment and water quality that has recently allowed the reopening of shellfish beds in Dyes Inlet. Additional measurements, numerical modeling, and monitoring will allow the science team to determine the most effective management steps to continue the improvement of water and sediment in the inlets.

For additional information, contact Dr. Martin C. Miller at (360) 681-3668, martin.miller@pnl.gov.