PUBLIC HEALTH ASSESSMENT
OLD NAVY DUMP/MANCHESTER LABORATORY (USEPA/NOAA)
MANCHESTER, KITSAP COUNTY, WASHINGTON
Manchester Annex, also referred to as the Old Navy Dump, is located on 40 acres on the western shore of Clam Bay about 1.5 miles north of Manchester, Washington. The northern 17.5 acres is owned by the U.S. Environmental Protection Agency (EPA). The southern 22.5 acres is owned by National Oceanographic Atmospheric Administration (NOAA) and its division, National Marine Fisheries Service (NMFS). Both EPA and NOAA/NMFS operate separate offices, laboratories, and field stations at the Manchester Annex location.
Originally, Department of War owned the land and turned it over to the Department of Navy in 1919. The Navy used the property as a Net Depot to overhaul and maintain antisubmarine nets that served as underwater fences to block enemy submarines that tried to navigate the waters of Puget Sound. Additionally, military personnel used concrete structures designed to simulate ship structures for fire training exercises. Wastes from the fire training exercises, construction, and other wastes were disposed in the landfill. The Navy's long history of use of the property and disposal of hazardous materials has lead to environmental contamination. As a result of contamination of surface water and sediments along the beach and the potential for food chain contamination, Manchester Annex was listed on EPA's National Priorities List (NPL) in June 1994.
ATSDR evaluated the environmental information and site conditions at Manchester Annex to determine if people could be coming in contact with hazardous chemical contaminants at levels of health concern. We identified three situations in which people could be contacting contaminated media. These situations present no apparent public health hazard. Additionally, ATSDR evaluated groundwater contamination for possible exposures and determined that no one is exposed to contaminated groundwater. Therefore, contaminated groundwater presents no public health hazard.
NO APPARENT PUBLIC HEALTH HAZARDS
We identified three exposure situations where chemical contaminants currently present no apparent public health hazard. The exposure situations are as follows: 1) fish and shellfish contamination in Clam Bay and 2) soil gas at the landfill, and 3) soil contamination. People are coming in contact with contaminated media in two of the situations, shellfish and soil contamination situations, but the levels that people are coming in contact with are low so as not to be a health hazard. In the third situation, levels of the soil gas, methane, have not been detected in the landfill.
Shellfish adjacent to the shore in Clam Bay presents no public health hazard. Although signs posted along the pier and shoreline of Manchester Annex advise against the harvesting of shellfish, employees have reported ingesting up to 6 meals per year of shellfish from these areas. No adverse health effects are likely to result from such infrequent exposures.
Discussions about opening the area to local subsistence harvesters, mainly Suquamish tribal members, prompted ATSDR to evaluate a more frequent consumption. Current levels of lead, arsenic, polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and dioxins in intertidal shellfish would pose health hazard to subsistence harvesters. Therefore, ATSDR recommends that Clam Bay beach near Manchester Annex remain closed to shellfish harvesting until remediation of the landfill is complete and two consecutive sampling events (no closer than 3 months apart) indicate that contaminant levels in shellfish do not pose a health hazard. ATSDR is requesting to review that data when it becomes available and will make a public health determination at that time as to whether the shellfish are safe to eat.
Subtidal fish and shellfish do not contain chemical contaminants at levels of health concern for any consumer group. However, because remediation plans for the landfill are not yet final, ATSDR recommends that engineering controls be used to prevent contaminated sediments from entering the areas inhabited by subtidal seafood species.
Soil gas at the landfill has not been detected in soil borings or test pits. However, methane gas generation is possible at some landfills. The Army Corps of Engineers' remediation activities of the landfill include a design phase which will address engineering controls to prevent methane gas migration. ATSDR supports the use of engineering controls to prevent methane gas migration which could cause an explosion hazard in nearby buildings.
Soil contamination at the landfill, fire training area, and net depot poses no apparent public health hazard. Workers who accidentally ingest, inhale, or dermally contact contaminated soils stirred up during construction, environmental investigative, and remediation activities are not expected to experience adverse health effects because of the short duration and frequency of such exposures.
NO PUBLIC HEALTH HAZARD
ATSDR evaluated the public health impact of groundwater contamination to address potential concerns of nearby private well users.
Groundwater contamination does not present a public health hazard because no one is drinking contaminated water nor likely to in the future. Water in the shallow aquifer, below ground surface, is not suitable for drinking due to salt water intrusion. Levels of antimony, arsenic, beryllium, cadmium, lead, and benzene present in the shallow aquifer are roughly ten-fold higher than would be considered safe in drinking water. However, because no one is drinking this water, it does not pose a health hazard. Additionally, any mixing from the contaminated shallow aquifer to the Outwash Channel Aquifer, where drinking water wells are placed, would greatly dilute contaminant levels and would most likely be non-detectable as demonstrated by the Outwash Channel Aquifer sampling results.
Manchester Annex consists of 40 acres on the western shore of Clam Bay on the west side of Rich Passage in Puget Sound, about 1.5 miles north of Manchester, Washington in Kitsap County (Figure 1). U.S. Environmental Protection Agency (EPA) owns the northern 17.5 acres and National Oceanographic Atmospheric Administration (NOAA) and National Marine Fisheries Service (NMFS) owns the southern 22.5 acres (1). Manchester State Park borders Manchester Annex to the west and north and U.S. Naval Fuel Supply Center borders Manchester Annex to the south. EPA and NOAA/NMFS maintain offices, laboratories, and field stations at this location.
Site History: Manchester Annex originally consisted of 385 acres established as a military reservation in 1898 by the Department of War. In 1919, the property was transferred to the Department of Navy and used until the 1970s for submarine net maintenance, fire training, and waste disposal activities. In 1970, 40 acres were transferred to EPA and NOAA/NMFS and 111 acres were transferred to the State of Washington (2). The Navy maintains possession of the remaining 234 acres which now make up the Fuel Supply Center (3). The 40 acre Manchester Annex site is considered a Formerly Used Defense Site (FUDS). Manchester Annex is also referred to as the Old Navy Dump and Manchester Labs.
During the Navy's long history of use, the handling and disposal of hazardous materials led to environmental contamination at three distinct source areas at Manchester Annex. They are the landfill, fire training area, and net depot. Chemicals used, generated, or disposed at these areas, include fuels, heavy metals, asbestos, pesticides, volatile organic compounds, semi-volatile organic compounds, and polychlorinated biphenyls. Based on environmental contamination, Manchester Annex was listed on the U.S. EPA's National Priorities List in June 1994 (3). Environmental investigations have been on going since 1987 when the first preliminary assessment was performed (4). Currently, environmental investigations continue under the Formerly Used Defense Site Program.
ATSDR Involvement: ATSDR conducted a site visit of Manchester Annex on May 31, 1995. The purpose of the visit was to review available site-specific information and to visually inspect each of the contaminated sites or other areas where hazardous substances were released into the environment in order to identify any potential public health issues. Our focus is to determine if people could come in contact with site contaminants at levels that pose a health hazard and, if needed, to recommend actions to stop or prevent such exposures from occurring.
ATSDR staff met with representatives from EPA, NOAA, NMFS, and Army Corps of Engineers. We evaluated site conditions at Manchester Annex, considering the nature and extent of environmental contamination. We looked at the site's proximity to populated areas and the types of human activities that could lead to exposures (exposure pathways).