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The Naval Computer and Telecommunications Area Master Station, Pacific site (NCTAMS PAC) is an active military installation located on the island of Oahu in the state of Hawaii. The mission of NCTAMS PAC is to operate and maintain communications facilities and equipment for naval shore installations and fleet units in the eastern Pacific area. The main station and receiver site, NCTAMS PAC Wahiawa, is located in central Oahu; the Naval Radio Transmitter Facility Lualualei (NRTF Lualualei) is located in a large coastal valley near the southwestern shoreline of Oahu.

As the first phase of the Department of Defense's Installation Restoration Program in 1986, the Naval Energy and Environmental Support Activity conducted an initial assessment study at NCTAMS PAC and identified 14 potentially contaminated sites. NCTAMS PAC was placed on the U.S. Environmental Protection Agency's National Priorities List in May 1994. The potentially contaminated sites identified in the initial assessment study included various disposal areas throughout NCTAMS PAC and multiple transformer locations.

The Agency for Toxic Substances and Disease Registry (ATSDR) performed a site visit at NCTAMS PAC in January 1995. No completed human exposure pathways were identified. During that visit and in the subsequent review of environmental data collected at the site, however, ATSDR identified three potential exposure pathways.

Two of these exposure pathways involve the potential for contaminated soil at various sites at NCTAMS PAC Wahiawa to migrate via surface water runoff during rain storms and affect the downgradient aquatic ecosystem and fish. On the basis of available data, ATSDR determined that soil contaminants at NCTAMS PAC Wahiawa are unlikely to be transported by surface water runoff to perennial streams at detectable levels and are therefore unlikely to accumulate in fish. Because no pathway for exposure exists, ATSDR concludes that soil contaminants at NCTAMS PAC Wahiawa do not pose any public health hazards.

In the third potential exposure pathway, ATSDR identified three former polychlorinated biphenyl (PCB)-contaminated transformer sites located in residential areas, one of which is also located adjacent to a playground. PCB contamination did migrate to the playground, but detected levels were generally low and sporadic. ATSDR believes that past exposures to contaminated soil were infrequent and of short duration. Moreover, the PCB transformers at NCTAMS PAC have been removed or replaced and soil at the sites has been remediated. On the basis of available data, ATSDR concludes that no apparent public health hazards exist from past exposure to PCB-contaminated soil.

The community has expressed health concerns regarding a possible association between childhood leukemia and electromagnetic fields (EMFs) from the radio transmission towers at NRTF Lualualei. The radio towers emit low frequency EMFs, which are within established guidelines. The Hawaii Department of Health investigated an increased incidence of childhood leukemia in the area surrounding NRTF Lualualei. This study did not show a clear association between the incidence of childhood leukemia and emissions from the radio towers. On the basis of available data, ATSDR concludes that childhood leukemia in the area surrounding NRTF Lualualei cannot be attributed with any certainty to the EMFs from the radio transmission towers. No public health hazards appear to exist from exposure to the radio transmission towers.


Site Description and History

The Naval Computer and Telecommunications Area Master Station, Pacific site (NCTAMS PAC) consists of several facilities located on the Island of Oahu. NCTAMS PAC is an active military installation with a mission to operate and maintain communications facilities and equipment for naval shore installations and fleet units in the eastern Pacific area. During the Navy's initial assessment study (IAS), 14 potential hazardous waste sources were identified at NCTAMS PAC, all located in either the NCTAMS PAC Wahiawa or the Naval Radio Transmitter Facility Lualualei (NRTF Lualualei) areas of the site (NEESA, 1986). NCTAMS PAC Wahiawa is the main station and receiver site and NRTF Lualualei is the transmitting site for NCTAMS PAC (Figure 1).

Navy communications facilities were first installed on the Hawaiian Islands in 1916 at Hospital Point. Construction of the transmitting station at Lualualei, intended to support a receiver station installed in 1920 at Wailupe, commenced in 1933. The main antennas were completed in 1935 and the facility was activated in 1936. NCTAMS PAC Wahiawa was originally established in 1940 as a temporary Naval Radio Station and Naval Radio Direction Finder Station, but the need to expand receiving facilities and to separate transmitting and receiving facilities forced expansion at NCTAMS PAC Wahiawa. The expansion schedule was accelerated after the attack on Pearl Harbor and receiver functions at Wailupe and Lualualei were consolidated at Wahiawa by the end of 1941. Military activities at NCTAMS PAC decreased after World War II, but were increased in the early 1950s during the Korean War and in the early 1960s during the Vietnam War (HLA, 1989).

As the first phase of the Department of Defense's Installation Restoration Program (IRP) in 1986, the Naval Energy and Environmental Support Activity conducted an IAS at NCTAMS PAC to identify potentially contaminated sites. The 14 potentially contaminated sites identified during the IAS included the Old Wahiawa Landfill, the Building 6 Disposal Area, various other disposal areas throughout NCTAMS PAC, and multiple transformer locations (NEESA, 1986). In 1989, as Phase II of the IRP, a site inspection was performed to confirm findings of the IAS. During the site inspection, soil and groundwater sampling was performed at the sites that were recommended for further study in the IAS (HLA, 1989).

NCTAMS PAC was proposed for the U.S. Environmental Protection Agency's (EPA's) National Priorities List in January 1994 and was listed in May 1994. Phase III of the IRP is the remedial investigation/feasibility study (RI/FS). This phase is currently ongoing, and corrective measures are being implemented to mitigate the hazards from contaminated sites that were identified during Phases I and II.

The Old Wahiawa Landfill was used for general disposal of all wastes generated at NCTAMS PAC from the 1940s until 1973. Although the majority of wastes included municipal solid wastes, waste lubricant oils, chlorinated and nonchlorinated solvents, transformer oil, hydraulic fluid, paint thinners, creosote, and mercury were disposed of in the landfill. The landfill was closed in 1973, and was graded and covered with an additional layer of soil in 1978. The draft RI for Old Wahiawa Landfill was completed in 1997, and the findings do not suggest the need for further remedial activity (Earth Tech, 1997b).

The Building 6 Disposal Area was used for disposal of inert wastes as well as waste oils and solvents. The gulch in which it is located also contains a drum disposal area and a concrete burn area. During the RI, localized areas of soil contamination were identified. The results of the draft RI indicate that portions of the site need remediation (Earth Tech, 1997b).

Polychlorinated biphenyls (PCBs) were detected in soil surrounding electrical transformers throughout NCTAMS PAC, some of which were located near on-base residences. The PCB contamination is a result of practices that were in effect from approximately 1942 until 1977 (EPA, 1993). In order to evaluate the insulating properties of the transformers, a 6-ounce sample of fluid from each transformer was drawn and tested quarterly. The sample fluid was then disposed of on the ground next to the transformer. An estimated 2 gallons of dielectric fluid were disposed of at each transformer site over the course of this testing (EPA, 1994; NEESA, 1986). The Navy excavated PCB-contaminated soil at eight transformer sites in 1990 and 1991 to meet a cleanup goal of 10 parts per million (ppm) (PRC, 1992). Soil excavation at several remaining contaminated transformer sites is scheduled to be completed in 1998 (Earth Tech, 1997a).

Natural Resources and Land Use

Oahu ranges in elevation from sea level to more than 4,000 feet above mean sea level. The coastal plains and valleys are level or gently sloping. The Schofield Plateau, in the center of the island, ranges from an elevation of nearly sea level to more than 1,000 feet and is bounded on the west by the Waianae Mountain Range and on the east by the Koolau Mountain Range. Rainfall on the island ranges from 20 inches a year along the leeward coast to more than 300 inches along the Koolau Mountain Range crest (Ogden, 1995).

NCTAMS PAC Wahiawa is located on approximately 700 acres of land in central Oahu on the eastern side of the highest part of the Schofield Plateau, at an elevation ranging from 1,050 to 1,300 feet above mean sea level. The deep soils of the surface are dissected by narrow, steep-sided ravines; these ravines divide the station into a northern area used for receiver facilities, and a southern area containing communications and support facilities. Land adjacent to NCTAMS PAC Wahiawa consists of conservation land and pineapple fields. The town of Whitmore Village lies ½ mile to the southwest. The city of Wahiawa lies 1 mile to the south and is separated from NCTAMS PAC Wahiawa by a deep gulch. Helemano Military Reservation, a 282-acre Army sub-installation, is located north of NCTAMS PAC Wahiawa (Earth Tech, 1997c).

Rainfall averages nearly 50 inches per year at NCTAMS PAC Wahiawa. NCTAMS PAC Wahiawa is drained westward by Poamoho Stream on the north and by the North Fork of the Kaukonahua Stream on the south. The North Fork of the Kaukonahua Stream enters the Wahiawa Reservoir about 3 miles downstream from NCTAMS PAC Wahiawa. Approximately 7 miles west of NCTAMS PAC Wahiawa, the North Fork of the Kaukonahua Stream and the Poamoho Stream join approximately 1 mile before emptying into Kanaka Bay and the Pacific Ocean. Other than intermittent streams, no other surface water bodies exist at NCTAMS PAC Wahiawa (Ogden, 1995).

NCTAMS PAC Wahiawa overlies the Schofield groundwater body. At the site, the water table is roughly 660 to 900 feet below ground surface (Ogden, 1995). Groundwater is the primary source of drinking water on Oahu. The Schofield groundwater body supplies water to several military installations, municipal drinking water wells, and irrigation wells throughout the Schofield Plateau. NCTAMS PAC Wahiawa's drinking water has been supplied in the past from supply wells at nearby Schofield Army Barracks and from the Wahiawa municipal wells.1 Since April 1997, a well located on site has been supplying drinking water to the facility (Earth Tech, 1997b). Water supplied from all three of these well sites is monitored.

NRTF Lualualei occupies approximately 1,700 acres and lies in a large coastal valley near the southwestern shoreline of Oahu. NRTF Lualualei is located approximately 10 miles to the southwest of NCTAMS PAC Wahiawa. The topography is generally level and the elevation ranges from 10 to 100 feet above mean sea level. NRTF Lualualei is located on land that consists of a thin layer of alluvial and coastal sediments and reef deposits overlying consolidated limestone. Civilian land use surrounding this facility is largely rural and the site is surrounded by agricultural and small areas of Urban and Conservation Land Use districts. NRTF Lualualei is contiguous to the Naval Magazine Lualualei, which occupies an additional 8,105 acres of the valley (Earth Tech, 1997c). The nearest urban area is the town of Maili, which lies approximately 1 mile west of the station (Ogden, 1995). The towns of Waianae and Nanakuli are also located nearby.

Rainfall at Lualualei averages 20 inches per year, and potential evaporation exceeds this amount. The surface of NRTF Lualualei is drained by the Maili Stream, an intermittent stream that flows westward along the northern boundary of the facility to the Pacific Ocean. The semiarid conditions, flat to gently rolling topography, and permeable surface soils restrict runoff from the station (ANL, 1992). Groundwater at Lualualei is unconfined at elevations ranging from 2 to 4 feet above mean sea level. Groundwater is brackish and there are no drinking water wells downgradient of the facility. Most of the approximately 100 wells drilled into this aquifer have been abandoned due to salinity (Ogden, 1995). Potable drinking water for NRTF Lualualei is purchased from Naval Magazine Lualualei (NEESA, 1986).



NCTAMS PAC Wahiawa is home to 650 residents, including dependents, who are housed in family housing and barracks. The station employs 754 people, 109 of whom are civilians (Figure 2; cited in Ogden, 1995).

NRTF Lualualei has a residential population of approximately 25 people housed in 11 units. The station employs 35 Navy personnel, 15 civilians, 5 to 10 coast guard personnel, and a contractor (Figure 3; cited in Ogden, 1995). Residents of the Naval Magazine Lualualei use the facility as an exercise area (Earth Tech, 1997c).

Surrounding Communities

Whitmore Village is a predominantly Filipino residential community which lies ½ mile southwest of NCTAMS PAC Wahiawa. The population of approximately 3,373 residents includes transient immigrant field workers (cited in Ogden, 1995). Wahiawa is a residential community 1 mile south of NCTAMS PAC Wahiawa. The population of 17,386 people includes a large sector of military retirees and older citizens (cited in Ogden, 1995). Residential development in Wahiawa is ongoing. Helemano Military Reservation contains bachelor and family housing for 1,876 residents, community services, and maintenance facilities. Development of family housing for 1,043 soldiers and their dependents is planned for Helemano (Earth Tech, 1997c).

Nanakuli, Maili, and Waianae are surrounding communities of NRTF Lualualei with populations of 8,758, 9,575, and 6,059, respectively (cited in Ogden, 1995). These three communities comprise the District of Waianae, which is a relatively isolated rural community. All three towns are proposing further residential development (cited in Ogden, 1995). Naval Magazine Lualualei is contiguous to NRTF Lualualei.

Quality Assurance and Quality Control

In preparing this public health assessment (PHA), the Agency for Toxic Substances and Disease Registry (ATSDR) relied on the information provided in the referenced documents. The environmental data presented in the PHA are from the 1989 site inspection (HLA, 1989), the draft RI/FS for the Old Wahiawa Landfill, Building 6 Disposal Area, and Dump Site Near Building 293 (Earth Tech, 1997b), the final site inspection for Buildings 236 and 262 (Ogden, 1992), and the final removal action field report (PRC, 1992) and engineering evaluation/cost analysis for removal action (Earth Tech, 1997c) for various transformer locations. The limits of these data have been identified in the associated reports. The data associated with the removal action field report (PRC, 1992) are not considered valid by the EPA after discovery that the associated laboratory was engaged in fraudulent practices (Earth Tech, 1997c). The data from that report were used for screening purposes only.

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