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PUBLIC HEALTH ASSESSMENT

NAVAL UNDERSEA WARFARE CENTER (NUWC) DIVISION
(a/k/a NAVAL UNDERSEA WAREFARE ENGINEERING STATION)
KEYPORT, KITSAP COUNTY, WASHINGTON


SUMMARY

The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this public healthassessment to evaluate exposure pathways and to respond to community concerns about past,current, and potential future exposures to contaminants associated with the Naval UnderseaWarfare Center Division (NUWC) Keyport. ATSDR evaluated environmental information for allareas of contamination on and adjacent to the base and identified four exposure pathways wherethe potential for human exposure existed: 1) past, current, and future exposures to contaminantsin the foodchain; 2) past, current, and future exposures to contaminants in private drinking waterwells; 3) past, current, and future exposures to contaminants in on-base drinking water wells; and4) past exposure to contaminants in indoor air. On the basis of the most currently availableinformation, ATSDR has determined that exposures to contaminants in the groundwaterunderneath and adjacent to NUWC Keyport and in shellfish in marine waters surroundingNUWC Keyport do not pose a public health hazard. ATSDR also evaluated past exposures tovolatile organic compounds (VOCs) in indoor air in modular offices on Keyport Landfill and determined that past exposures did not pose a public health hazard.

NUWC Keyport is an active naval facility occupying approximately 340 acres in Kitsap County,Washington. It is located on the Kitsap Peninsula in Puget Sound near the town of Keyport. TheKeyport property, originally referred to as the Pacific Coast Torpedo Station, Keyport, wasacquired by the Navy in 1913. The facility became known as the Naval Torpedo Station,Keyport. It was first used as a still water range for torpedo testing. The base generates hazardouswastes through various activities including painting operations; the maintenance and testing oftorpedoes; and through the use of fuels for torpedoes. Past waste disposal practices resulted in thecontamination of soil, groundwater, and marine surface waters at NUWC Keyport. In addition toroutine disposal activities, several fuel spills and pipeline leaks occurred resulting incontamination of soil, marine surface water, and groundwater at NUWC Keyport.

An initial assessment study (IAS) of NUWC Keyport was released in September 1984. In May1986, the U.S. Environmental Protection Agency (EPA) recommended that NUWC Keyport beincluded on the National Priorities List, which is part of Superfund. In 1988, under the Navy'sInstallation Restoration Program, a remedial investigation and feasibility study was conducted tofurther characterize the extent of contamination at the base and determine what, if any,remediation was necessary. As a result of environmental contamination, NUWC Keyport waslisted on EPA's National Priorities List in October 1989. As a result of the IAS, six areas ofcontamination were recommended for further investigation: Area 1- Keyport Landfill, Area 2 -Van Meter Road Spill/Drum Storage Area, Area 3 - Otto Fuel Leak Area, Area 5 - Sludge Disposal Area, Area 8 - Plating Shop Waste/Oil Spill Area, and Area 9 - Liberty Bay shorelines.NUWC Keyport was organized into two operable units (OUs). OU 1 includes the KeyportLandfill (Area 1) and OU 2 contains the other five areas (Areas 2,3,5, 8, and 9).

Foodchain - shellfish
Four source areas at NUWC Keyport, Area 1 (Keyport Landfill), Area 3 (Otto Fuel Pipeline Leak), Area 8 (Plating Shop) and Area 9 (Liberty Bay - Shorelines), have released contaminants into marine waters. People who live or fish in the area around NUWC Keyport may have been exposed to very low levels of site-related contaminants if they consumed contaminated shellfish. ATSDR evaluated past, current, and potential future exposures from consuming shellfish near Areas 1, 3, 8, and 9. Most contaminants detected in shellfish samples from all four source areas were found at very low concentrations and none of the contaminants were detected at levels that are known to result in adverse health effects. Based on available sampling data collected from 1989 through 2000, ATSDR concludes that shellfish harvested from marine waters near these areas do not pose a past or current public health hazard to subsistence or recreational fishers. Shellfish sampling is currently conducted under the long-term monitoring plan. Although the June 2000 shellfish contaminant levels do not indicate levels likely to result in adverse health effects, due to inconsistences in the June 2000 analysis of metals in shellfish, ATSDR is not able to compare the June 2000 sampling results with past shellfish data. Therefore, we could not evaluate any possible trends over time in the contaminant concentration of shellfish from Areas 1 and 8. To evaluate temporal trends, ATSDR recommends that shellfish sampling continue for a minimum of three additional sampling rounds.

Private Drinking water wells - groundwater
An inventory of private wells located west, northwest, and north of Area 1 (Keyport Landfill) identified 57 active private drinking water wells, four in the town of Keyport. The Keyport Landfill has contaminated two aquifers, referred to as the upper aquifer and the intermediate aquifer. Landfill contaminants in the upper aquifer have not migrated off base. However, contaminants in the intermediate aquifer have migrated off base as far north as the Highway 308 causeway between the Tide Flats and Dogfish Bay. Groundwater in the area of NUWC Keyport flows towards the northwest, in the direction of the Tide Flats. The private wells are, therefore, upgradient and away from site related contamination. Groundwater samples collected from seven private wells did not contain any site-related contaminants. One sample contained two VOCs, chloroform (1.6 parts per billion [ppb]) and trichloroethylene (TCE) (0.42 ppb). The source of the chloroform is likely a result of the chlorine that was added to the well water. The source of the TCE is unknown, however, it is very unlikely groundwater contaminants have migrated from off base because the well is upgradient of Area 1 (Keyport Landfill). Private wells located south of NUWC Keyport are upgradient from any potential sources of contamination. Based on this information, ATSDR concludes that drinking water from private wells around NUWC Keyport does not pose a past, current, or future public health hazard.

Base Drinking water wells - groundwater
NUWC Keyport obtains its drinking water from one supply well (Base well [BW] 5). This well is screened in the deep aquifer below the Clover Park Unit aquitard at approximately 800 feet below the ground surface. The aquitard prevents contamination in the upper and intermediate aquifers from reaching the deep aquifer. The well is routinely tested for inorganics and VOCs. All monitoring tests have met state and federal drinking water standards. For these reasons, ATSDR concludes that drinking water from BW 5 does not pose a past, current, or future public health hazard.

Indoor air
People who worked in modular offices that were constructed during the mid-1980s above Keyport Landfill may have been exposed to VOCs in indoor air. These modular offices were occupied for about 8 years before being torn down or vacated. VOCs were measured during the time these offices were being used. Using conservative exposure assumptions, ATSDR evaluated exposures to VOCs in indoor air and found that detected levels of contaminants are not at levels associated with adverse health effects. Therefore, ATSDR concludes that past exposure to VOCs posed no public health hazard. Since these buildings have been removed or are no longer occupied, current and future exposures to VOCs do not pose a public health hazard.

CONCLUSION CATEGORY SITUATIONS/SITES
No Public Health Hazards
  1. Past and current exposures from consumingshellfish from the marine waters around NUWCKeyport (includes Dogfish Bay, Liberty Bay,Shallow Lagoon, and Tide Flats)

  2. Past, current, and future exposures from privatedrinking water wells

  3. Past, current, and future exposures from on-basedrinking water supply wells

  4. Past exposure from indoor air in modular officesat Keyport Landfill


BACKGROUND

Site Description and History

The Naval Undersea Warfare Center Division (NUWC), Keyport is an active naval facilityoccupying approximately 340 acres in Kitsap County, Washington. It is located on the KitsapPeninsula in Puget Sound near the town of Keyport. The facility is bounded on the north byLiberty Bay; on the east by the Port Orchard Reach (an extension of Liberty Bay); on thesoutheast by Port Orchard; on the northwest by the incorporated town of Keyport; on the west bythe Tide Flats, which are part of Dogfish Bay (an extension of Liberty Bay); and on the southwestand south by largely rural areas and some small residential communities that are part of KitsapCounty (URS 1993a) (Vicinity Map).

A number of buildings and industrial areas are situated all around the base; the base itself is notdivided into designated land use areas. The topography of the base rises gently from the shorelineto an average of 25 to 30 feet above sea level. At the southeast corner of NUWC Keyport, a morerapid rise in elevation occurs to a maximum 185 feet above sea level in the southern most portionof the base (SCS and Landau Associates 1984).

The NUWC Keyport property, originally referred to as the Naval Torpedo Station, Keyport, wasacquired by the Navy in 1913 and first used as a still water range for torpedo testing. DuringWorld War II (between 1942 and 1943), the base acquired 62 acres of land and added 25facilities and 200 housing units. The new facilities were used to test and overhaul torpedoes, andincrease the overall capacity to design and test new torpedoes (SCS Engineers 1987).

In 1978, the facility changed its name to the Naval Undersea Warfare Engineering Station in recognition of its expanded functions, including the testing of various undersea warfare weapons as well as systems engineering and development activities. In 1992, the name of the facility was changed again to its present name, the Naval Undersea Warfare Center Division (URS 1993a). Many of the NUWC Keyport facilities are used for multiple purposes, often combining office, industrial, research, and support functions under one roof (SCS Engineers 1987). The base generates hazardous wastes through various activities, including painting operations; the manufacture, maintenance, and testing of torpedoes; and the use of fuels for torpedoes (SCS and Landau Associates 1984).

Past waste disposal practices resulted in the contamination of soil, groundwater, and marinesurface waters at NUWC Keyport. In addition to routine disposal activities, several fuel spillsand pipeline leaks occurred resulting in contamination of soil, marine surface water, andgroundwater at NUWC Keyport. Most of the spills involved small quantities, up to 700 gallons,of torpedo fuel (Otto Fuel), 5000 gallons of plating solution, and as much as 30 gallons ofchromate. A description of each of the areas of contamination at NUWC Keyport are described in Appendix A.

Remedial and Regulatory History

The first environmental assessment at NUWC Keyport dates back to October 1976 when a waterquality monitoring study consisting of marine water and sediment sampling was conducted. Aninitial assessment study (IAS) of NUWC Keyport was released in September 1984. During theIAS, a total of 10 sites were identified at NUWC Keyport as potential sources of contaminationbased on historical records, aerial photos, surface and aerial surveys, and personnel interviews(SCS and Landau Associates 1984)

In May 1986, the U.S. Environmental Protection Agency (EPA) recommended that NUWCKeyport be placed on the National Priorities List (NPL), which is part of Superfund. A CurrentSituation Report, released in December 1987, was used to help prioritize specific areas forfurther investigation (SCS Engineers 1987). In 1988, under the Navy's Installation RestorationProgram, a remedial investigation (RI) and feasibility study were conducted to furthercharacterize the extent of contamination at the base and determine what, if any, remediation wasnecessary. As a result of the IAS and the Current Situation Report, six areas of contamination were recommended for further investigation:

Area 1 -- Keyport Landfill. The former Keyport landfill comprises about 9 acres in thewest-central part of NUWC Keyport. Most of the landfill area was formerly marshlandthat extended from the tidal flats to the shallow lagoon . It was the base's primary disposalarea for both domestic and industrial wastes from the 1930s to 1973. Wastes disposed ofat the landfill included paints, thinners, strippers, solvents, heavy metals from platingshops, cutting oils, pesticide rinsate from pest control shops, and wastewater treatment plant sludges (URS 1997b; URS 1997c).

Area 2 -- Van Meter Road Spill/Drum Storage Area. This area covers approximately 1.3acres on both sides of Van Meter Road near where it crosses a stream that empties to theshallow lagoon. There are three distinct waste disposal or spill areas: 1) Van Meter Roadspill area, 2) former Building 957 drum storage area, and 3) former Building 734 drumstorage area. Contaminants at these areas include heavy metals from plating shop wastes,methyl ethyl ketone, trichloroethylene (TCE), carbon tetrachloride, pesticides, Otto fuel(a liquid torpedo fuel), paints, strippers, and thinners (URS 1997b; 1997c).

Area 3 -- Otto Fuel Leak Area. This area, located near the shallow lagoon and Buildings106 and 499, covers approximately 800 square feet. Building 106 is used to test torpedomotors. Prior to 1984, wastewater containing Otto fuel from testing, washdown, and tankflushing from Building 106 was piped into a 1,000-gallon underground sump southeast ofBuilding 499 which has been removed under the underground storage tank program (URS1997b; 1997c).

Area 5 -- Sludge Disposal Area. This area is a former wastewater treatment sludge disposalarea covering approximately 0.4 acre near Building 94 in the northeastern part of the base. Contaminants include metals and some organic compounds (URS 1997b; 1997c).

Area 8 -- Plating Shop Waste/Oil Spill Area. This area occupies about 1 acre on the easternportion of the base near the plating shop. A number of releases have taken place at this areaincluding a chromate spill during the 1970s, an oil release in 1987, and a plating waste spill in 1988 (URS 1997b; 1997c).

Area 9 -- Liberty Bay-shoreline. This area includes approximately 5,000 feet of shorelinearound the NUWC Keyport peninsula, including near shore areas around piers 1 and 2. Avariety of substances were discharged to Liberty Bay through drainage pipes and stormsewers from 1915 to about 1980, including metal and cyanide wastes, strippers, thinners,solvents, paints, and Otto fuel (URS 1997b; 1997c).

NUWC Keyport was officially placed on the NPL in October 1989 as a result of contaminationidentified in these six areas. The final RI report was released in October 1993 and the finalfeasibility study report was released in November 1993 (URS and SAIC 1998). During the summerof 1994, following the public comment period on the proposed cleanup plan for the six areas,NUWC Keyport was organized into two operable units (OUs). OU 1 includes the Keyport Landfill(Area 1) and OU 2 contains the other five areas (Areas 2, 3, 5, 8, and 9) (Vicinity Map).

A record of decision (ROD) for OU 2 was released in September 1994. The proposed remedialaction for Area 2 (Van Meter Road Spill/Drum Storage Area) consists of institutional controls,which will prevent residential use of the site and construction of domestic drinking water wells,preclude the use of groundwater except for remediation purposes, and groundwater monitoring,which will be used to monitor groundwater contaminant concentrations. The proposed remedy forArea 8 (Plating Shop Waste/Oil Spill Area) includes continued groundwater monitoring, sedimentand biological (marine tissue) monitoring, institutional controls to restrict residential use of thesite, and removal and off-site disposal of highly contaminated soils in the saturated zones, justabove the water table.

No remedial actions were recommended for Area 3 (Otto Fuel Leak Area), Area 5 (SludgeDisposal Area), and Area 9 (Liberty Bay) because levels of site-related contaminants were deemedtoo low to pose human health risks. Confirmatory sampling was conducted in Area 5 and Area 9 inorder to ensure that these two areas do not pose dangers to human health. Again the results showedcontaminant levels too low to pose a health hazard.

A ROD for OU 1 was released in September 1998. The selected remedial actions for OU 1 include:1) planting poplar trees to filter contaminants; 2) removing PCB-contaminated sediment; 3)upgrading the tide gate; 4) upgrading and maintaining the landfill cover; 5) long-term monitoring;6) contingent actions for off-base domestic wells (if long-term monitoring shows that off-basedomestic wells could become contaminated in the future); and 7) institutional controls (URS and SAIC 1998).

ATSDR Involvement

As part of the public health assessment (PHA) process, the Agency for Toxic Substances andDisease Registry (ATSDR) conducted an initial site visit on May 22 - 24, 1991. The purpose ofthis trip was to meet with NUWC Keyport representatives and other federal, state, and localofficials and obtain information to assist in preparing the PHA. Other site visits were conducted onSeptember 13, 1994, May 27, 1995, and June 12, 1997. ATSDR also attended a public availabilitysession on May 27, 1995 and restoration advisory board meetings in June and September 1997.

ATSDR prepared two health consultations for NUWC Keyport to evaluate the safety of consumingshellfish taken from waters bordering the facility. The first health consultation was released August21, 1995 (Appendix B), and a follow-up health consultation was released February 5, 1997(Appendix C). ATSDR concluded in the August 1995 health consultation that the chemicalconcentrations detected in shellfish sampled in Liberty Bay and the Shallow Lagoon are not likelyto cause adverse health effects and are safe for consumption by subsistence, commercial,ceremonial, and recreational harvesters. ATSDR was unable to make a public health determinationabout shellfish taken from Dogfish Bay because the tests did not include polychlorinated biphenyls(PCBs) and because discrepancies in sampling results for lead did not allow for a public healthdetermination. In the February 1997 follow-up health consultation, ATSDR evaluated newsampling data that included PCB analyses. ATSDR determined that PCB and lead concentrationsdo not pose a public health hazard to individuals who consume native littleneck clams collected from Dogfish Bay.

Additional shellfish data was collected in June 2000 and evaluated in this public health assessment.

Demographics

ATSDR examines demographic information or population information to identify the presence ofsensitive populations, such as young children and the elderly, in the vicinity of a site. Demographicinformation also provides details on residential history in a particular area, information that helpsATSDR assess time frames of potential human exposure to contaminants. Demographicinformation for the base and residential areas surrounding NUWC Keyport is presented in thissection.

As of December 1999, over 1,800 civilian and military personnel were employed at NUWCKeyport. This total includes 27 military personnel, 1,268 civil service personnel, andapproximately 600 contractors (D. Jennings, NUWC Keyport, personal communication, November1999). On-base residential areas are located in the north-central portion and south-east portions ofNUWC Keyport (URS and SAIC 1997a). Approximately 80 individuals, including 21 children,live in this residential area. About half of the residents live in officers quarters located just north ofthe center of the base and the other on-site residents live in enlisted quarters located on Radio Hill,which is the southeast portion of NUWC Keyport (D. Jennings, NUWC Keyport, personalcommunication, April 2000). There are no schools or daycare facilities on base. Several areas onthe base are used for recreation, including a park area near the shallow lagoon on the south side ofthe base, which is used for picnics. The main recreational area, however, is the Shallow LagoonPicnic Area.

Nearby off-base residential areas include the town of Keyport (population 350), which is immediately adjacent to the base; the city of Poulsbo (population 4,850), which is about 2 miles northwest of NUWC Keyport across Liberty Bay; the town of Silverdale (population 7,660), which is about 6 miles southwest of the base; and the Port Madison Indian Reservation (population 4,834), which is located about one-half mile northeast of the base across Liberty Bay. The reservation is home to the Suquamish people, a fishing tribe whose leader was Chief Sealth, after whom the city took its name.

Port Madison Indian Reservation and the Suquamish Tribe
The original inhabitants of the Port Madison Reservation were primarily of the Suquamish Tribe and a few from other tribes represented in the Point Elliott Treaty. The Tribe's 1996 membership roll lists over 780 enrolled members. However, the Reservation accommodates tribal members, other Native Americans, Alaskan Natives, and non-Indians.

The Reservation consists of over 7,486 acres that contain tribal trust lands, individually andcollectively owned trust lands, historic allotments held in trust, and fee lands owned by Indians and non-Indians.

Land Use and Natural Resources

NUWC Keyport is entirely fenced and access to the base is restricted. A security policeman isposted at the gate for additional security. Land uses at NUWC Keyport include industrial facilities,operation support areas, on-base residential areas, forest lands (approximately 60 acres), wetlands,tidal flats, and a shallow lagoon used for row and paddle boating, sailing, and picnicking.

Most land use in the vicinity of NUWC Keyport is rural/agricultural, residential, or light industrial.Directly south of the base is a very rural residential and agricultural area which has not beenincorporated as a city or town and is part of Kitsap County. More than half of NUWC Keyportborders marine water, either Liberty Bay, the Shallow Lagoon, or Dogfish Bay and Tide Flats.There is little or no commercial fin fishing in Liberty Bay. However, a small number of people fishfor recreation. Commercial and private clam and oyster (shellfish) beds are abundant in the LibertyBay/Port Orchard area (URS 1994). In 1987, NUWC Keyport closed its own beaches on LibertyBay to shellfish harvesting because the Bremerton-Kitsap County Health District issued a PublicHealth Advisory for harvesting shellfish in Liberty Bay due to inconsistent water quality frombiological contamination (i.e., fecal coliforms) caused by septic and sewer discharges (ATSDR1995; URS 1994).

Dogfish Bay, located northwest of the base, is used for recreational fin fishing and for commercialoyster harvesting. Commercial oyster beds in Dogfish Bay are owned by the Coast OysterCompany (URS 1994). Recreational shellfish harvesting has historically taken place in the TideFlats, which are an extension of Dogfish Bay. Members of the Suquamish Indian Tribe harvest finfish and shellfish for ceremonial, subsistence, and economic purposes in Dogfish Bay and LibertyBay (URS 1994). The Tribe raise chum and chinook salmon as part of a fisheries enhancementprogram, in and near Liberty Bay (URS and SAIC 1993b).

The Suquamish people have lived, gathered food, ceremonial, and spiritual items, and hunted andfished for thousands of years in western Washington. The Tribe used lands and waters north intoCanada, Whidbey, Blake and Bainbridge islands, and most of Kitsap County. The usual andaccustomed (U and A) fishing places of the Suquamish Tribe extends well beyond Reservationboundaries and includes marine waters of Puget Sound from the northern tip of Vashon Island tothe Fraser River in Canada, including Haro and Rosario Straits, the streams draining into thewestern side of Puget Sound and also Hood Canal. The U and A of the Suquamish Tribe extendswest into Jefferson County, south into Mason County, and includes most of Kitsap County(Suquamish 1999).

Hydrogeology

NUWC Keyport is characterized by multiple water-bearing zones separated by aquitards(impermeable layers). The Clover Park Unit constitutes a thick aquitard comprised of silt/clay non-glacial deposits and is present throughout NUWC Keyport (URS 1993a). The Clover Park Unitvaries in thickness, but generally ranges between 100 to 200 feet thick in the region, except in theeastern part of NUWC Keyport, near Area 8, where most of it is only about 16 feet thick. TheClover Park Unit is generally considered impermeable and is found between 25 and 75 feet belowground surface (bgs) in most areas of NUWC Keyport (URS and SAIC 1993).

Above and below the Clover Park Unit are multiple water bearing zones separated by otheraquitards. Water bearing zones above the Clover Park Unit are referred to as the shallow aquifersand those below are called the deep aquifers (EA Engineering 1999). The shallow aquifers abovethe Clover Park aquifer generally are less than 50 feet below ground surface, except in outwashareas where they extend as much as 100 feet below ground surface.

In Area 1, an unconfined (water table) aquifer with a maximum depth of approximately 15 feetbelow ground surface and a confined aquifer with a maximum depth between 40 and 60 feet belowground surface have been identified above the uppermost clay of the Clover Park Unit. These waterbearing zones are referred to as the "shallow aquifer" and "intermediate aquifer." In Area 2, oneunconfined (water table) aquifer was identified above the Clover Park Unit. The depth of theaquifer ranges from just below ground surface to approximately 40 feet below ground surface. InArea 3, an unconfined (water table) aquifer ranging from just below ground surface toapproximately 6 feet below ground surface and a partially confined aquifer between 10 and 20 feetbelow ground surface have been identified above the Clover Park Unit. Area 5 has a very thick till(sand and silt) layer which confines the uppermost aquifer. Besides a very shallow moist zone justbelow ground surface, the uppermost aquifer at Area 5 is found approximately 50 feet belowground surface. In Area 8, one unconfined aquifer and one confined aquifer were identified. Theunconfined aquifer is a thick shallow aquifer near Area 8. This unconfined aquifer may extendnearly 200 feet below ground surface. The confined aquifer begins between 125 and 150 feet below ground surface (URS and SAIC 1993).

Groundwater flow direction in the shallow aquifer at NUWC Keyport generally follows surfacewater topography. In Area 1, groundwater flow converges from the southwest and the northeasttowards the low-lying marsh and Tide Flats area (URS 1993a). Groundwater in Area 2 flowsnortheasterly and discharges into the shallow lagoon. Groundwater near Area 3 generally flowssouthward and discharges into the shallow lagoon and an adjacent marsh. In Area 5 and Area 8,groundwater flow is strongly influenced by tidal fluctuations in Liberty Bay, however, the overallflow direction is towards Liberty Bay (URS 1993a;1994). Groundwater flow direction in the deep aquifers beneath NUWC Keyport has not been determined.

Groundwater Use

On-Base Groundwater Use

One supply well (Base well [BW] 5) supplies NUWC Keyport with drinking water (R. Beynum,NUWC Keyport, personal communication, December 1999). BW 5 is located about 500 feetnortheast of Area 3. This well is screened in the deep aquifer below the Clover Park Unit aquitardat approximately 800 feet below ground surface.

The water is chlorinated prior to being released into two 50,000 gallon tanks. The tanks areprimarily used as a mixing and detention basin. There is no other treatment for the system. Thewater from both tanks is then pumped into a 500,000 gallon underground holding reservoir whereit is ready to be distributed throughout the base. The system serves approximately 1,800 employeesand approximately 100 residents of NUWC Keyport. There are no backup wells on base, however,there is a metered connection with the Kitsap County Public Utility District that can supply up to500,000 gallons of water per day (R. Beynum, NUWC Keyport, personal communication, January2000). The NUWC Keyport drinking water is routinely sampled in accordance with the SafeDrinking Water Act and meets all applicable drinking water standards.

Off-Base Groundwater Use

An inventory and sampling of private water wells in the area around NUWC Keyport wasconducted by the U.S. Navy between March 1996 and May 1997. The private well inventory area,which focused on regions west, northwest, and north of Area 1, the former landfill, identified atotal of 57 private active drinking water wells, four in the town of Keyport. Most of the upperaquifer wells were located between 500 and 1,500 feet west-northwest of Area 1. In addition to thewells identified during the inventory, a small number of private shallow wells are located south ofNUWC Keyport (URS 1997b).

Two Kitsap public utility district (PUD) water wells that supply much of the town of Keyport andthe surrounding area are screened in the deep aquifers (at depths of 700 to 800 feet below groundsurface) below the Clover Park Unit aquitard (URS 1994). One of these PUD wells is a backupdrinking water well for the Keyport area and is located just outside the NUWC Keyport main gatenear Dogfish Bay. This well is screened in the deep aquifer at about 780 feet below ground surface.The other PUD well is located about 2,000 feet southwest of NUWC Keyport (URS 1993a).

Quality Assurance and Quality Control

In preparing this public health assessment, ATSDR relied on the information provided in thereferenced documents. Documents prepared for the CERCLA and RCRA programs must meetspecific standards for adequate quality assurance and quality control measures for chain-of-custodyprocedures, laboratory procedures, and data reporting. The validity of the analyses and conclusionsdrawn in this document are dependent upon the availability and reliability of the referencedinformation. The environmental data presented in this public health assessment are from the Navy and NUWC Keyport contractor's reports.


EVALUATION OF EXPOSURE PATHWAYS

In this section, ATSDR evaluates whether community members have been (past), are (current), orcould be (future) exposed to harmful levels of chemicals. ATSDR considers how people mightcome into contact with, or be exposed to, contaminated media. Specifically, ATSDR determineswhether an exposure could occur through ingestion, dermal (skin) contact with contaminatedmedia, or inhalation (breathing) of vapors, and also considers the likely length (duration) andfrequency of the exposure.

If exposure was or is possible, ATSDR then considers whether chemicals were or are present atlevels that might be harmful to people. ATSDR does this by screening the concentrations ofcontaminants in an environmental medium against health-based comparison values (Appendix D).Health based comparison values are the amount of chemical per body weight that health scientistshave determined are not likely to cause adverse effects, even when assuming very conservativeexposure scenarios that over-estimate exposure. ATSDR emphasizes that regardless of the level ofcontamination, a public health hazard exists only if people come in contact with, or are otherwiseexposed to, harmful levels of contaminated media.

Following the strategy outlined above, ATSDR examined whether human exposure to harmfullevels of contaminants via these pathways existed in the past, exists now, or could potentially existin the future. ATSDR summarizes its evaluation of these exposure pathways in Table 1 anddescribes it in more detail in the discussion that follows. Past exposures are evaluated based on theperiod of time prior to 2000 when sampling data is available. For the purposes of this pubic healthassessment ATSDR has used the term "past" as pertaining to the time at which environmentalsampling was first collected - the late 1980s. However, true past exposures prior to the late 1980scannot be accurately assessed without sampling data. Exposures were most likely greater before the1980s when less stringent environmental waste regulations were in place and hazardous materialuse was increased due to greater on-base activities.

ATSDR has reviewed the environmental data generated from preliminary site evaluations and RIsof the 10 source areas identified at NUWC Keyport to determine if there are any associated past,current, or future public health hazards. ATSDR also evaluated other environmental data such asdrinking water monitoring data. From this review, ATSDR identified the following four completed or potential exposure pathways of concern.

  1. Past, current, and future exposures to base-related contaminants in shellfish and other marine biota.

  2. Past, current, and future exposures to groundwater contaminants in upper (shallow) aquifer and intermediate aquifer private wells located west and northwest of the Keyport Landfill.

  3. Past, current, and future exposures to contaminants in on-base drinking water supply wells.

  4. Past exposure to volatile organic compounds (VOCs) from indoor air in modular offices at the Keyport Landfill.

Exposure via the Foodchain

Summary

Four source areas at NUWC Keyport, Area 1 (Keyport Landfill), Area 3 (Otto Fuel Leak Area),Area 8 (Plating Shop Waste/Oil Spill Area) and Area 9 (Liberty Bay - Shoreline), have releasedcontaminants, either through groundwater or storm sewer and sanitary sewer system discharge, intomarine waters. The marine waters adjacent to these areas were sampled in 1991, 1994 and 1996. In2000, marine waters adjacent to Area 8 (Plating Shop Waste/Oil Spill Area) and Area 1 weresampled.

The Keyport facility has been in existence since 1931, but clam tissue samples were not collecteduntil 1989. The majority of chemical releases from the site likely occurred before 1989. Suquamishconsumption of these resources was also likely higher prior to 1989 because potential health riskswere not recognized. Without tissue data from this period (1931-1989) it is difficult to make anyinferences regarding public health hazards at the site before 1989.

Shellfish gather food by filtering nutrients from the water. Contaminants from the land and watermay be taken up through this filtration mechanism and concentrated in shellfish tissue. People whoharvest and consume shellfish from the Tide Flats or Dogfish Bay, the Shallow Lagoon, and/orLiberty Bay may be exposed to contaminants that have migrated off base into the shallow marinewaters surrounding NUWC Keyport.

Area 1: Wastes disposed of at the Keyport Landfill included paints, thinners, solvents, heavymetals from plating shops, cutting oils, pesticide rinsate, and wastewater treatment plant sludges.Contaminants have been detected in the upper and intermediate aquifer below the landfill.Groundwater beneath Area 1 flows toward and discharges into adjacent surface water bodies,primarily the Tide Flats, which in turn empty into Dogfish Bay. Several species of clams have beenidentified in these marine habitats, including native littleneck clams, bent-nosed clams, mud clams,and manila clams.

Area 3: The Shallow Lagoon adjacent to Area 3 may have received site-related contaminantsthrough groundwater migration. The primary source of contamination was wastewater containingOtto fuel. Shellfish are limited to a small population of mussels which are not readily consumed bypeople because it is not a popular fishing area. This is due to the limited edible fish/shellfish and tothe limited access to people off site. Some species of fish and crabs are found in the ShallowLagoon, but they are generally too small to consume.

Area 8: Plating Shop Waste/Oil Spill Area occupies about 1 acre on the eastern portion of the basenear the plating shop. A number of releases have taken place at this area including a chromate spillduring the 1970s, an oil release in 1987, and a plating waste spill in 1988 (URS 1997b; 1997c).Additionally, a variety of substances, including metal and cyanide wastes, solvents, paints andpaint residues, and Otto fuel, were discharged into Liberty Bay from 1915 until approximately1980. Area 8 is included in NUWC Keyport's long-term monitoring program. Commonlyconsumed biota found in the portion of Liberty Bay closest to NUWC Keyport include clams,crabs, mussels, rough piddocks, herring, sole, flounder, and salmon. Repeated sampling

Area 9: The Liberty Bay area comprises approximately 5,000 feet of shoreline. Originally, Area 9was the entire shoreline area of NUWC Keyport. The area was included in the Operable Unit 2along with Area 8. Divisions were made to focus environmental investigations more on Area 8 atdischarge points. Repeated sampling of the entire shoreline found the locations near Area 8 toshow contamination while the shoreline further away did not show contamination. Area 9 wassubsequently considered for No Further Action.

People who live or fish in the area around NUWC Keyport may have been exposed to very lowlevels of site-related contaminants if they consumed shellfish obtained near these source areasbecause shellfish and other marine biota may concentrate some of the contaminants in edibletissues. ATSDR evaluated past, current, and future exposures from consuming shellfish in Areas 1,3, 8, and 9. Concentrations of chemical contaminants detected in shellfish samples from all foursource areas were found to be below levels that are known to result in any adverse health effects.

Nature and Extent of Contamination in Shellfish

Area 1: Shellfish tissue samples were collected in June 2000. Native littleneck clams (Protothacastaminea), a prevalent and widely consumed species of clams, were collected for the June 2000long-term monitoring effort. Many clams from three Dogfish Bay locations and from three Tidalflats locations were analyzed as part of Area I. Chemical analyses of the clam tissue wereperformed using dry weight methodology for volatile organic compounds (VOCs) and inorganicchemicals (metals) in Area 1 and wet weight methodology for semi-volatile organic compounds(SVOCs) and pesticides/polychlorinated biphenyls (PCBs).

One VOC (naphthalene) and three pesticides were detected at low concentrations in the shellfishtissue samples. Several SVOCs were detected at low concentrations in the tissue samples,including phenol, benzyl alcohol, and benzoic acid in all six tissue samples.PCBs were detected at23 g/kg, wet weight. Six of the seven prescribed metals were detected in all six tissue samples.

In 1989, native littleneck clams were collected from nine locations in the Tide Flats and eightlocations in Dogfish Bay close to the Tide Flats area. Contaminants were generally detected at verylow concentrations. Bis (2-ethyl- hexyl) phthalate (BEHP) (32 parts per million [ppm]) -a semi-volatile organic compound- and arsenic (4.5 ppm) were among the contaminants detected inshellfish (See Appendix B).

In April 1996, one additional clam tissue sample was collected from each of three locations in theTide Flats, three locations in Dogfish Bay, and two samples were collected from a reference stationat Agate Pass, an approved area for harvesting shellfish which is approximately 3 miles northeastof NUWC Keyport. These samples were analyzed for PCBs, lead, and cadmium. Arochlor 1254was detected slightly above its detection limit in only one sample in the Tide Flats (0.013 ppm) andone sample in Dogfish Bay (0.005 ppm). The one sample containing detectable concentrations ofArochlor 1254 in the Tide Flats was closest to the landfill. Lead was detected in all six samplescollected near the landfill at levels ranging from 0.109 to 0.189 ppm. These concentrations wereslightly above the background/reference samples (0.085 to 0.094 ppm) collected from Agate Pass.Cadmium was also detected in all six samples collected (0.230 to 0.280 ppm), however, the levelswere very similar to the background/reference samples (0.202 ppm to 0.233 ppm) collected fromAgate Pass.

Area 3: Shellfish tissue samples were collected in 1989. Pacific staghorn sculpin (Leptocottusarmatus) and bay blue mussels (Mytilus edulis) were collected from the northern shore of the on-base shallow lagoon. Arsenic (0.97 ppm), was detected in shellfish tissue samples as well as a fewother metals at very low concentrations. Propylene glycol dinitrite, a primary component of liquidtorpedo fuel, was also detected at very low concentrations (0.00041 ppm) in one Pacific staghornsculpin tissue sample.

Area 8 and 9: For the Liberty Bay shoreline referred to as Area 8 for the June 2000 samplinground, native littleneck clams were collected from nine locations along NUWC Keyport shorelinebetween Piers 1 and 2. Chemical analyses of the clam tissue were performed using dry weightmethodology for metals and cyanide. Chemical analyses of the clam tissue were performed usingwet weight methodology for SVOCs. No pesticide/PCB or VOC analysis was performed for thisarea as was conducted at Area 1. Levels of total polyaromatic hydrocarbons (PAHs) were belowlevels likely to result in adverse health effects. Concentrations of metals such as cadmium,chromium, lead, nickel, silver, and lead were detected at low levels. However, dry weightmethodology requires conversion to a wet weight prior to comparison with health guidelines.Conversions at levels near detection limits is likely to introduce unreliability to the values.

Shellfish tissue samples were collected in 1989 and 1992. In 1989, samples, primarily littleneckclams (Protothaca staminea), were collected from 19 stations in or near Liberty Bay. Areas 8 and 9combined. In 1992, the native littleneck clam (Protothaca staminea) and rough piddocks (Zirfaeapilsbryi) were collected from two stations in Liberty bay. Some metals and semivolatile organiccompounds were detected at very low concentrations. Pentachlorophenol (4.3 ppm), was detectedin one of 17 marine shellfish tissue samples (Protothaca staminea). The source ofpentachlorophenol, a common wood preservative, may be from the wooden pilings used for piersor other treated wood (URS and SAIC 1993).

Evaluation of Potential Public Health Hazards

From the August 2000 Fish Consumption Survey of the Suquamish Indian Tribe of the PortMadison Indian Reservation, Puget Sound Region, ATSDR obtained the ingestion rates of adultsand children who eat shellfish. ATSDR used consumption values of shellfish between 142 and 292grams per day for a 79 kilogram adult and 24 grams per day for a 30 kilogram child. We evaluatedthe likelihood of this subsistence population to experience adverse health effects from theconsumption of native littleneck clams collected solely from Areas 1, 3, 8 and 9 adjacent to theshores of NUWC Keyport even though the usual and accustomed (U and A) fishing places of theSuquamish Tribe extends well beyond Reservation boundaries including marine waters of PugetSound from the northern tip of Vashon Island to the Fraser River in Canada (Suquamish 2000).Although the U and A areas for clamming may include many miles of shoreline, ATSDR overestimated the exposures to be protective of even the greatest seafood consumers by assuming that100 percent consumption of the clams from the shoreline adjacent to NUWC Keyport.

Based on these over-estimations of exposures, ATSDR determined that chemical contaminantspresent in native littleneck clams along the shoreline of NUWC Keyport do not present a publichealth hazard to subsistence seafood consumers (adults and children).

ATSDR was not able to evaluate the trends of chemical contaminant concentrations in nativelittleneck clams over time because of the inconsistency in the data analyses and reporting of theJune 2000 clams tissue analyses data. That data reported some chemical contaminantconcentrations using dry weight methodology instead of the more desirable wet weightmethodology. Contaminant levels using dry weight methodology need to be converted to wetweight values in order to be compared with health guidelines as well as compared with past data.Because much of the data was below, at, or only marginally above the detection limits, conversionto wet weight concentrations at those low levels would inherently introduce significant error.

Conversion of the contaminant values does allow for public health evaluation. However, becausemost of the contaminant concentration values are so low and so close to detection limits, reliabilityof those low values as to whether the chemical contaminants are actually present or not comes intoquestion after converting from dry to wet weight at these low levels. If larger amounts ofcontaminants were present, conversion to wet weight would not introduce noticeable error. So,from a pubic health standpoint, low detection values are good and indicate the safety of theshellfish. ATSDR has not included a data table with the sampling results, conversions, and comparisons of the June 2000 data because of the inherent errors associated with the conversionprocess of chemical quantitation at such low or barely detectable levels. Instead, we recommendthat future shellfish sampling for all chemical constituents be consistent with those prior to June2000 sampling and report results in a wet weight format.

Area 1 (Keyport Landfill)

Past exposure

Based on sampling information from 1989 and supplemental sampling conducted in 1996, it isvery unlikely that shellfish harvested and consumed from Dogfish Bay or the Tide Flats containedharmful levels of contaminants at that time. BEHP (32 ppm) was detected in two shellfish samples,but not at levels likely to result in adverse health effects (ATSDR 1993). ATSDR evaluated thepotential health effects of ingesting BEHP detected in shellfish by estimating the maximumexposure dose using very conservative exposure scenarios (See Appendix D). The maximumpotential dose slightly exceeded EPAs non-carcinogenic health guideline value for subsistencefishers and exceeded the carcinogenic risk guideline for subsistence and recreational fishers.However, these health guidelines are very conservative and the estimated maximum potential doseis well below levels that are known to cause health effects in humans (ATSDR 1993).Additionally, BEHP was only detected in the samples collected in 1989 and not in any of thesamples collected in 1996. Arochlor 1254, lead, and cadmium were not detected in clam tissuesamples from Dogfish Bay or the Tide Flats at levels of expected to result in adverse health effects(ATSDR 1997c) (Appendix A) and, therefore, did not pose a past public health hazard.

Arsenic was detected in most of the shellfish tissue samples collected. The maximumconcentration of total arsenic (inorganic plus organic concentrations) was 4.5 ppm. While organicforms of arsenic are relatively nontoxic, the inorganic form can produce a variety of adverse healtheffects (ATSDR 1998a). For evaluating potential health effects, ATSDR assumed that 10% of thetotal arsenic concentration detected (0.45 ppm) was in the inorganic form. This assumption isbased on the U.S. Food and Drug Administration's findings that the inorganic component of totalarsenic in shellfish comprises approximately 10 percent of total arsenic (FDA 1993). Based onATSDR's evaluation, the estimated maximum exposure dose of inorganic arsenic was slightlyhigher than the non-carcinogenic health guideline for subsistence fishers and exceeded thecarcinogenic health guideline for subsistence and recreational fishers (See Appendix D). However,it is very unlikely that even heavy consumers of shellfish (i.e., subsistence fishers) would haveexperienced any adverse health effects from ingesting shellfish in the past from Dogfish Bay or theTide Flats. ATSDR reviewed the toxicologic and epidemiologic literature and found that theestimated ingestion exposure dose using the maximum concentration detected and the ingestionrates equivalent to a subsistence fisher are generally two orders of magnitude lower than the levelsthat are known to cause adverse health effects in humans (ATSDR 1998a). Therefore, consumptionof contaminated shellfish from Dogfish Bay or the Tide Flats in the past did not pose a publichealth hazard.

In 1997, ATSDR evaluated additional shellfish samples collected in 1996 from Dogfish Bay andthe Tide Flats. This supplemental sampling effort was in response to ATSDR's initial healthconsultation concluding that there was insufficient sampling information to determine the safety ofconsuming shellfish from Dogfish Bay (ATSDR 1995). ATSDR recommended that additionalshellfish samples be collected and analyzed for PCBs and lead. This evaluation was completed andATSDR determined that shellfish collected in Dogfish Bay and in the adjacent Tide Flats area donot contain contaminants at levels likely to cause adverse health effects. As long as the source ofcontamination, Keyport Landfill, is contained, concentrations of PCBs and lead, as well as otherchemicals that were present as a result of past use or disposal at NUWC Keyport, do not pose acurrent or future health hazard to people who consume shellfish collected from Dogfish Bay andthe Tide Flats (ATSDR 1997). Dogfish Bay and the Tide Flats have been restricted tofishing/shellfishing in the past because of biological contamination. ATSDR considers the shellfishfrom Dogfish Bay and the Tide Flats to be safe to consume, as long as the shellfish in these areasmeet all state and federal health guidelines regarding biological contaminants.

Current and future exposures

Based on the June 2000 sampling event of Area 1, chemical contaminant levels in native littleneckclams are at low levels not likely to result in adverse health effect in those adults or children whoingest even the highest amounts of clams on a subsistence basis. Therefore, chemical contaminantspresent in native littleneck clams do not present a public health hazard.

Although contaminant levels were barely detected, inconsistencies in laboratory methodologymakes comparison with previous sampling events difficult and unreliable. Typically, laboratoriesuse wet weight methodology to determine chemical contaminant levels in seafood species. Becausesome analytes were determined using wet weight and some dry weight methodology, conversion ofall analytes to wet weight values would need to be done. When converting contaminant levels ofthose contaminants barely above laboratory method detection limits, significant uncertainty aboutthe true value of the chemical analytes present are introduced making comparability unreliable.Therefore, trends of whether contaminant levels are increasing or decreasing over time cannot beevaluated. For that reason, ATSDR recommends that the Navy provide set methodologyparameters to the laboratory similar to previous sampling events and that wet weight methodologybe used in the future to determine chemical analyte levels in seafood. Additionally, the Navyshould conduct a minimum of three consecutive sampling events.

Area 3 (Otto Fuel Leak Area)

Past exposure

The Shallow Lagoon has not been a source of edible fish/shellfish in the past because of the limitednumber of edible species that are found in this lagoon. Even if mussels were harvested andconsumed from the Shallow Lagoon, contaminants were not detected in tissue samples at levels that would have posed a past public health hazard.

Current and future exposures

In 1995, ATSDR evaluated contaminant exposure from the potential consumption of two speciesin the Shallow Lagoon, bay blue mussels and Pacific staghorn sculpin, by subsistence, recreational,and commercial harvesters. ATSDR determined that chemicals most likely to be released in Area 3(e.g., Otto fuel and heavy metals) are present below levels likely to cause adverse health effects.Therefore, based on chemical contaminants, the shellfish are safe for all consumers (ATSDR1995). In addition, the Shallow Lagoon is not currently and is not expected in the future to be asignificant source of edible shellfish because few edible fish, crabs, or other organisms wereidentified during a biological survey of the lagoon conducted in June 1991 (URS 1993a). Thispotential exposure pathway does not pose a current or future public health hazard.

Area 8 (Plating Shop Waste/ Oil Spill Area) and Area 9 (Liberty Bay - Shoreline)

Past exposure

Pentachlorophenol was detected in one shellfish tissue from Liberty Bay. Pentachlorophenol is acommon preservative in wood and the numerous piers around Liberty Bay are the likely source.Since this chemical was only detected in 1 of 17 shellfish samples, however, it is not likely thatpast consumption of shellfish from Liberty Bay posed a public health hazard. In addition, ATSDRhas not identified any studies that suggest adverse health effects would occur at the estimated doseassuming the maximum concentration detected, even for subsistence fishers (ATSDR 1999).

In 1995, ATSDR evaluated potential exposures from the consumption of native littleneck clamsand rough piddock clams by subsistence, commercial, and recreational harvesters. ATSDRdetermined that the list of chemicals for which the Liberty Bay shellfish were analyzed wascomplete, the sampling location and number of samples collected were adequate to evaluatepotential health effects, and that these shellfish are safe for all consumers (ATSDR 1995).Contaminant levels were not found to be at levels expected to cause adverse health effects and donot pose a current or future health hazard to people who consume the most commonly harvestedshellfish, native littleneck and rough piddock clams, from Liberty Bay.

Current and future exposures

Based on the June 2000 sampling event of Area 8 in the Liberty Bay shoreline area, chemicalcontaminant levels in native littleneck clams are at low levels not likely to result in adverse healtheffect in those adults or children who ingest even the highest amounts of clams on a subsistencebasis. Therefore, chemical contaminants present in native littleneck clams do not present a publichealth hazard.

Although contaminant levels were barely detected, inconsistencies in laboratory methodologymakes comparison with previous sampling events unreliable. Therefore, trends of whethercontaminant levels are increasing or decreasing over time cannot be evaluated. For that reason,ATSDR recommends that the Navy provide set methodology parameters to the laboratory similarto previous sampling events and that wet weight methodology be used in the future to determinechemical analyte levels in seafood. Additionally, the Navy should conduct a minimum of threeconsecutive sampling events.

Exposure to Groundwater

Private wells located west, northwest, and north of the former Keyport Landfill

Summary

The Keyport Landfill (OU 1) has contaminated two aquifers, referred to as the upper aquifer andthe intermediate aquifer. Landfill contaminants in the upper aquifer have not migrated off base.However, the intermediate aquifer is contaminated as far north as the Highway 308 causewaybetween the Tide Flats and Dogfish Bay. People who drank water in the past or who currentlydrink water from private wells screened in the intermediate aquifer may have been or may currentlybe exposed to site-related contaminants. An inventory and sampling of private wells to the west,northwest, and north of OU 1 was conducted by the Navy between March 1996 and May 1997(URS 1997b). According to the Keyport Area and Private Well Sampling Report, there are noknown private wells in the upper or intermediate aquifers located in a downgradient pathway fromKeyport Landfill (URS 1997b). Since groundwater samples collected from private wells did notshow any site-related contaminants and groundwater flow data show that groundwater reaching theprivate wells in the inventory area does not originate from the Keyport Landfill (URS 1997b),drinking water from private wells in the inventory area does not pose a past, current, or futurepublic health hazard.

Nature and Extent of Groundwater Contamination

The inventory of private wells was comprehensive and identified 10 private wells withinapproximately 1,500 feet west of Keyport Landfill. A total of 73 private wells were identified inthe inventory area. The Navy sampled seven private water wells during 1997, five in February andtwo in May. Three upper aquifer wells close to NUWC Keyport were sampled, the nearestintermediate aquifer well was sampled, and three more-distant deep aquifer wells were alsosampled. All samples were analyzed for VOCs.

None of the wells contained VOCs above EPA's maximum contaminant levels. Only one well,which is screened in the upper aquifer, contained detectable levels of chloroform (1.6 parts perbillion [ppb]) and TCE (0.42 ppb). The chloroform may be from bleach that the owner used in thewell to disinfect the well water. The source of TCE is not known, however, groundwater flowpatterns in the upper aquifer would make it very unlikely that these chemicals originated fromNUWC Keyport (URS 1997b). The groundwater flowing beneath the landfill discharges intoDogfish Bay rather than migrating to onshore areas where drinking water wells are located (URS1997b). Based on groundwater flow data, groundwater reaching all the private wells directly north(Keyport) and south of Dogfish Bay does not originate from the Keyport Landfill and according tothe United States Geologic Survey, groundwater from the landfill flows under the center ofDogfish Bay and does not reach any land areas (URS 1997b).

Evaluation of Potential Public Health Hazards

Past exposure

Groundwater contamination did not pose a past public health hazard for residents using privatedrinking water wells. The private wells to the west, northwest, and north of Keyport Landfill havenot been impacted by landfill contaminants and groundwater flow models indicate thatgroundwater flowing under the Keyport Landfill would not reach private wells in the inventory area.

Current and future exposures

Groundwater does not pose a current or future public health hazard for residents living to the west,northwest, and north of Keyport Landfill using private drinking water wells because private wellsaround the inventory area are not downgradient of Keyport Landfill and associated contaminantplumes.

On-base drinking water supply well

Summary

There is one active base supply well (BW 5) that provides NUWC Keyport with potable water.People who work and reside on base and who obtain drinking water from this well could bepotentially exposed to site-related contaminants if the shallow groundwater were impacting BW 5.The well is tested routinely for inorganics and VOCs. All monitoring results have met state andfederal drinking water standards. The drinking water well is screened in the deep aquifer below theClover Park Unit and is not very susceptible to contamination from source areas on base.Therefore, drinking water from this well does not pose a past, current, or future public healthhazard.

Nature and Extent of Groundwater Contamination

The NUWC Keyport supply well is tested annually for inorganic compounds and every 3 years forVOCs. Drinking water from the base supply well was tested for synthetic organics (e.g., pesticides)in 1993, but a waiver was issued by the Washington Department of Health and monitoring forsynthetic organics is no longer required (R. Beynum, NUWC Keyport, personal communication,January 2000). All recent monitoring results have met state and federal safe drinking waterstandards.

As part of site investigations, two groundwater samples were collected from BW 5 (June 1991 andJune 1992). One sample contained lead at a concentration of 15.2 ppb, which is slightly aboveEPA's action level of 15 ppb for lead. The May 1997 sampling reported lead levels at 1.0 ppb.Lead is not currently detected in the drinking water at or close to the level identified during the siteinvestigations. It is possible that the earlier sample was contaminated, however, this can not beconfirmed. The two samples did not contain any other contaminants above state and federal safedrinking water standards (URS 1993a; SAIC 1993b).

Recent monitoring of the base drinking water supply did not identify any site-related VOCs. Threetrihalomethanes-chloroform (9.7 ppb), bromodichloromethane (4.0 ppb), andchlorodibromomethane (1.4 ppb)-were detected in the drinking water, however, these are commonbyproducts of chlorination and are not related to environmental contamination on base. In May1997 and September 1998, all inorganic compounds analyzed met state and federal safe drinkingwater standards (R. Beynum, NUWC Keyport, Personal communication, January 2000). The back-up drinking water system for NUWC Keyport is the Kitsap County Public Utility District waterwell (PUD # 1). This well is screened in the deep aquifers below the Clover Park Aquitard,approximately 980 feet below ground surface. The results of October 1996 water quality testing forPUD # 1 did not identify any contaminants that exceeded state or federal drinking water standards(Kitsap PUD 1996).

Evaluation of Potential Public Health Hazards

Past exposure

The drinking water well for the base is screened in the deep aquifers below the Clover ParkAquitard. Because of the Clover Park aquitard's low permeability, it is very unlikely thatcontaminants on base could have penetrated the aquitard and contaminated the deeper aquifers. Inaddition, groundwater flow from the Keyport Landfill, which is located to the east of BW 5, istowards the west away from BW 5, further minimizing any potential contamination of the drinkingwater source. Therefore, drinking water from BW 5 at NUWC Keyport did not pose a past public health hazard.

Current and future exposures

Drinking water from BW 5 at NUWC Keyport does not pose a current or future public healthhazard. Recent monitoring results for VOCs and inorganics have met all state and federal safedrinking water standards and contamination of the groundwater is very unlikely since BW 5 is drawn from deep aquifers below the Clover Park Aquitard.

Exposure to Air Contaminants

Summary

People who worked in modular offices that were constructed during the mid-1980s above KeyportLandfill may have been exposed to VOCs in indoor air. These modular offices were occupied forabout 8 years before being torn down or vacated. Sampling of VOCs at OU 1 was initiated becausethe landfill was known to have released methane and solvent gases and there was some concernabout potential exposure to these gases (D. Jennings, NUWC Keyport, personal communication,April 2000).

VOCs were measured during the time these offices were being used. Soil vapor measurementswere also taken at OU 1. It is possible that occupants of these modular offices were exposed, in thepast, to VOCs in indoor air, however they were not at harmful levels and did not pose a publichealth hazard. Since these buildings have been removed or are no longer occupied, current andfuture exposures to VOCs do not pose a public health hazard.

Nature and Extent of Air Contamination

Indoor air samples were collected in September 1991 to assess potential exposures to VOCs inmodular office units that were used from 1986 until 1994 at Area 1- Keyport Landfill (OU 1). Themodular units sampled represented different workplace environments. Modular Units 1 and 2reflected more typical office workplaces; Modular Unit 4 was an electronic maintenance and repairfacility, where computer equipment was refurbished; and Building 884 was the office trailer for thehazardous waste storage facility.

Indoor samples were collected at each sampling location on three consecutive workdays inSeptember 1991 (URS 1993a). A total of 18 air samples (3 replicate samples) were collected fromfive sampling locations (4 indoor and 1 outdoor) and analyzed for VOCs. These samples wereanalyzed for organic compounds, primarily VOCs and methane. Twenty-six VOCs were detectedin ambient and indoor air samples at OU 1. Air samples collected inside the modular officescontained many VOCs including chloromethane (1,800 ug/m3), 1,4-dichlorobenzene (1,923 ug/m3),1,1-dichloroethylene (6 ug/m3), methylene chloride (521 ug/m3), tetrachloroethylene (12 ug/m3),1,1,1-trichloroethane (2,457 ug/m3), and TCE (156 ug/m3) (URS 1993a; URS and SAIC 1993b).

The landfill is a potential source of some of the VOCs detected indoors since some contaminantswere detected in both the ambient air and soil vapor samples. However, some of the mostfrequently detected compounds in soil vapor samples collected at the landfill (such as vinylchloride and methane) were either not detected or were detected infrequently in indoor air samples.It is possible that some of the VOCs detected in the modular offices were from activities conductedin the offices and unrelated to the landfill (e.g., use of common office equipment and cleaningcompounds) (URS 1993a). Indoor air samples also showed very high day-to-day variability incontaminant concentrations (URS 1993a).

Evaluation of Potential Public Health Hazards

Past exposure

ATSDR looked at the most conservative exposure scenario for exposure to VOCs in the indoor airof modular offices. Individuals who worked in the modular offices on Keyport Landfill could havebeen exposed to VOCs in indoor air for a maximum of 8 years. Even assuming individuals wereexposed to the highest concentrations of VOCs detected in indoor air, it is very unlikely that suchexposures would have resulted in any adverse health effects. ATSDR reviewed the VOCs presentin ambient and indoor air samples: maximum exposure dose estimates of VOCs in indoor air wereseveral orders of magnitude lower than concentrations that are known to cause health effects inhumans (ATSDR 1992; 1994a; 1994b; 1997a; 1997b; 1998b; 1998c; 1998d). Therefore, pastexposure to VOCs poses no public health hazard.

Current and future exposures

The modular buildings and trailers that were present on the landfill at the time the RI wasconducted have since been removed or are no longer occupied. Therefore, current and future exposures to VOCs do not pose a public health hazard.


COMMUNITY HEALTH CONCERNS

In April 1996, NUWC Keyport conducted 26 community interviews to help the base develop aplan responsive to community concerns. General concerns included clean water in Liberty Bay,shellfish contamination, clean air, general pollution and hazardous waste, clean drinking water, andtorpedo fuel pollution.

ATSDR has evaluated the past releases of hazardous materials at NUWC Keyport and addressed these community concerns in the body of this document.


ATSDR CHILD HEALTH INITIATIVE

ATSDR recognizes that infants and children may be more sensitive than adults to environmentalexposures in communities faced with contamination of their water, soil, air, or food. Thissensitivity is a result of the following factors: (1) children are more likely to be exposed to certainmedia like soil when they play outdoors; (2) children are shorter and therefore may be more likelyto breathe dust, soil, and vapors close to the ground; and (3) children are smaller than adults andtherefore may receive a higher dose of chemical exposure relative to their body weight. Childrenalso can sustain permanent damage if exposed to toxic substances during critical growth stages.ATSDR is committed to evaluating children's special interests at sites such as NUWC Keyport aspart of its Child Health Initiative. ATSDR evaluated the likelihood of children to experienceadverse health effects from eating shellfish caught at the shoreline areas of NUWC Keyport.ATSDR identified no situations in which children are likely to be exposed to harmful levelsof contaminants associated with NUWC Keyport.

ATSDR evaluated the likelihood that children living at or near NUWC Keyport, may have been(past) or are currently being exposed to contaminants at levels of health concern. There arecurrently two children under the age of five years and 23 children of school age living at NUWCKeyport. ATSDR determined that children living on base have not been and are not currently beingexposed to contamination that would be harmful because access to areas that contain hazardouscontaminants, including Keyport Landfill, are restricted and not accessible to children (D.Jennings, NUWC Keyport, personal communication, May 2000). There are no schools or day carecenters on base and the picnic area and playgrounds are not located near any sources ofcontamination. The water supply on base is from a deep well that has not been impacted by anysite-related contaminants. ATSDR did not identify any situations where children residing on basehave been, are being, or could be exposed to contaminants that could pose a public health hazard.

ATSDR also did not identify any situations where children living off site near NUWC Keyport,would have been, are currently, or could be exposed to site-related contaminants, either throughsoil, drinking water, or surface water. Based on data from 1989 through 2000, children who eat fishor shellfish from waters near NUWC Keyport are not expected to experience adverse health effects from that activity.



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