PUBLIC HEALTH ASSESSMENT
FORT DIX (LANDFILL SITE)
WRIGHTSTOWN, BURLINGTON COUNTY, NEW JERSEY
The U.S. Army Training Center and Fort Dix (Fort Dix) is located in Burlington and Ocean Counties, New Jersey, approximately 20 miles southeast of Trenton. Fort Dix is a permanent Class I Army installation that occupies approximately 31,110 acres.
During an installation restoration program, a preliminary assessment and site inspection were performed at Fort Dix. Several potentially contaminated sites were identified, including the Fort Dix Sanitary Landfill. The Fort Dix Sanitary Landfill was placed on the National Priorities List in 1987. Remedial investigation and feasibility studies are ongoing at several other sites at Fort Dix.
In 1960, an explosion and fire took place in a missile silo located within Fort Dix but on property leased to the Air Force. Weapons-grade plutonium was released during the fire. The site of this incident is referred to as the Boeing Michigan Aeronautical Research Center (BOMARC) site and remediation is the Air Force's responsibility.
The Agency for Toxic Substances and Disease Registry (ATSDR) visited Fort Dix in May 1991 and again in April 1998. Although no completed pathways of human exposure were identified, two potential human exposure pathways were identified. The first pathway involves ingestion of potentially contaminated groundwater by off-post residents who use private drinking water wells that draw from the aquifer downgradient of Fort Dix. The second pathway involves dermal contact with and inhalation of radiologically-contaminated soil near the BOMARC site (ATSDR, 1991).
Because the BOMARC site is leased to the Air Force and is not under the Army's jurisdiction, ATSDR will evaluate the BOMARC site in a separate document. ATSDR evaluates groundwater contamination at Fort Dix in this public health assessment. The surficial aquifer under Fort Dix is contaminated with volatile organic compounds, semi-volatile organic compounds, and metals. There are no known public water supplies that draw from this aquifer in the vicinity of Fort Dix. Two nearby off-site private drinking water wells that draw from this aquifer were identified during the remedial investigation. It does not appear that groundwater contamination at Fort Dix will affect these two wells because they are not located downgradient from the contamination. On the basis of available information, ATSDR concludes that contaminants in groundwater do not pose a public health hazard. ATSDR recommends, however, that any other potential off-site private drinking water wells be identified and, if necessary, tested and treated.
The U.S. Army Training Center and Fort Dix (Fort Dix) is located in Burlington and Ocean Counties, New Jersey, approximately 20 miles southeast of Trenton (Figure 1). Fort Dix is a permanent Class I Army installation that occupies approximately 31,110 acres. It is divided into a Cantonment Area (troop quarters, administrative areas, and industrial areas), a Training Area, and a Range and Impact Area. The Cantonment Area occupies approximately one-third of the installation. A smaller, undeveloped area southeast of the Cantonment Area is the Training Area. The undeveloped eastern two-thirds of the installation are designated the Range and Impact Area. McGuire Air Force Base borders the installation to the north and lies between the Cantonment and the Range and Impact Areas (ICF Kaiser, 1997).
Fort Dix, initially called Camp Dix, was developed from farmland and forest on July 18, 1917, as a cantonment area and training post for World War I troops. After the war, the camp served as a demobilization center, and from 1922 to 1926 it was used as a training ground for active Army, Army Reserve, and National Guard units. The camp was inactive from 1926 to 1933. From 1933 to 1939 it served as a reception, discharge, and replacement center for the Civilian Conservation Corps (ICF Kaiser, 1997).
In 1939, the camp became a permanent Army installation and the name was changed to Fort Dix. The installation again served as a reception and training center during World War II, and after the war it was used as a separation center. In 1947, Fort Dix was designated a basic training center. In 1956, the installation was officially designated the U.S. Army Training Center and Fort Dix (ICF Kaiser, 1997).
Prior to October 1992, Fort Dix was a government-owned installation under the jurisdiction of the U.S. Army Training and Doctrine Command. Its mission was to conduct basic combat training and advanced individual training, and to provide combat support and support to Reserve and National Guard Units (ICF Kaiser, 1997). In October 1992, the major command was shifted to Forces Command (FORSCOM). The primary mission of Fort Dix under FORSCOM was to provide command, administration, and support of the U.S. Army Garrison, Fort Dix; the New York Area Command (Fort Hamilton, Fort Totten, and the Bellmore Logistics Activity); active U.S. Army units stationed, assigned, or attached to the installation; and all tenant and satellite units (Army, 1997a and b). In October 1997, the major command was shifted to U.S. Army Reserve Command (USARC). The current mission is to provide training for reserve and national guard troops.
Fort Dix began the process of site characterization and remediation in the 1980s under the Army's installation restoration program (IRP). Through the preparation of a preliminary assessment, Fort Dix identified the following sites as potentially contaminated: the Fort Dix Sanitary Landfill, storage areas, underground storage tanks, other landfills, lagoons, impact areas, and an incinerator. Heavy metals, petroleum/oil/lubricants, and chlorinated solvents associated with these sites were detected in soil and groundwater (EPA, 1997).
At the conclusion of the preliminary assessment/site inspection process, the U.S. Environmental Protection Agency (EPA) assigns a score to the site using its Hazard Ranking System. If a site receives a score of 28.5 or higher (on a scale of 100), it is placed on the National Priorities List (NPL). The Fort Dix Sanitary Landfill received a score of 37.4; it was proposed for the NPL in September 1984 and listed in July 1987 (EPA, 1997). In addition to the investigation of the Fort Dix Sanitary Landfill, remedial investigation and feasibility studies are ongoing at several other sites at Fort Dix.
An explosion and fire took place in a missile silo located on Fort Dix property in 1960. This land was and is leased to McGuire Air Force Base and is referred to as the Boeing Michigan Aeronautical Research Center (BOMARC) site. Weapons-grade plutonium was released during the fire, and contamination occurred within a 218-acre portion of the Range and Training Area of Fort Dix. In 1976, the Army Surgeon General considered the BOMARC site unsafe for Army use (ATSDR, 1991). The BOMARC site is not an NPL site.
As part of the Superfund process, the Agency for Toxic Substances and Disease Registry (ATSDR) visited Fort Dix and met with the Army and county health department personnel in May 1991. In April 1998, ATSDR toured the site again and spoke with Restoration Advisory Board (RAB) members. No completed pathways of human exposure were identified during either visit.
During the 1991 site visit, ATSDR identified two potential human exposure pathways. The first pathway involves ingestion of potentially contaminated groundwater by off-post residents who use private drinking water wells that draw from the aquifer downgradient of Fort Dix. The second pathway involves dermal contact with and inhalation of radiologically-contaminated soil by Fort Dix personnel conducting training in contaminated areas near the BOMARC site (ATSDR, 1991).
Portions of Fort Dix have been designated for Base Realignment and Closure (BRAC). Under this program, several acres, predominantly in the Cantonment Area, are subject to transfer or lease under the Community Environmental Response Facilitation Act (CERFA). CERFA directs federal agencies to evaluate all BRAC property to identify uncontaminated parcels, and allows the transfer or lease of remediated parcels when the success of an approved remediation has been demonstrated. The BRAC environmental restoration program includes non-Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) substances that are not normally addressed under the IRP, including asbestos-containing material, lead-based paint, radon, unexploded ordnance (UXO) and/or ordnance fragments, and radionuclides (Woodward-Clyde, 1997a and b).
The climate in the Fort Dix region is characterized by moderate temperatures, precipitation, and wind, with an average annual temperature of 54 degrees Fahrenheit. The average annual precipitation is 44 inches, and is fairly well distributed throughout the year (ICF Kaiser, 1997).
Fort Dix is located in the Atlantic Coastal Plain Physiographic Province, approximately 15 miles east of the Fall Line that separates that region from the Piedmont Physiographic Province. The Coastal Plain is comprised of a wedge-shaped mass of sedimentary strata. Fort Dix is underlain primarily by sand, gravel, and clay formations that appeared after glacial melt waters deposited these materials in stream valleys more than 20,000 years ago. The Cohansey Formation and the underlying Kirkwood Formation form eastward-thickening wedge-shaped units under Fort Dix (ICF Kaiser, 1997).
There are five major aquifers in the Coastal Plain. Starting with the most shallow aquifer, they are: the Kirkwood-Cohansey Aquifer, the low 800-foot sand aquifer of the Kirkwood Formation, the Mt. Laurel-Wenonah Aquifer, the Englishtown Aquifer, and the Potomac-Raritan-Magothy Aquifer (Figure 2). The aquifers are separated by relatively impermeable units that vary in thickness and in their ability to function as confining layers, ranging from largely semi-confined to confined (ICF Kaiser, 1997). The aquifers, and their use as potable water supplies, are more fully described in the Evaluation of Environmental Contamination and Potential Exposure Pathways section below.
The Fort Dix installation is drained by several perennial and intermittent tributaries of Crosswick Creek and the North Branch of Rancocas Creek. The North Branch of Rancocas Creek is located immediately south of Fort Dix and flows westward into the Delaware River. Crosswick Creek, also a tributary of the Delaware River, flows 6 miles north and west before joining it. The total length of stream channels within the installation is estimated to be 54 miles. Fort Dix has several ponds and lakes. The largest, Brindle Lake, has a surface area of about 40 acres (ICF Kaiser, 1997).
Fort Dix occupies an area of diverse natural habitats. It is located in the northernmost portion of a region known as the Pinelands, which is the largest tract of open land on the Mid-Atlantic Coast that contains forests of pine, oak, and cedar. Groundwater in the shallow aquifers feeds area hardwood swamps, bogs, and marshes. The Pinelands is characterized by more than 850 species of plants and more than 350 species of birds, mammals, reptiles, and amphibians, some of which are rare, threatened, or endangered (ABB, 1997b).
The average daily resident population at Fort Dix in August 1996, including employees, guests, and inmates, was 15,238; of these, 4,978 were military and 10,260 were civilians. There are an additional 12,281 installation retirees living in the surrounding communities who visit the Fort Dix facilities for various reasons (ICF Kaiser, 1997). In September 1993, 21,855 military trainees were reportedly assigned to Fort Dix as part of the Reserve Component (Woodward-Clyde, 1997a).
The populations of Burlington County and Ocean County are 395,066 and 433,203, respectively. The communities surrounding Fort Dix include the townships of New Hanover (population 9,546), Pemberton (population 31,342), Plumstead (population 5,138), and Manchester (population 35,976) and the boroughs of Wrightstown (population 3,843), New Egypt (population 2,327), Pemberton (population 1,367), Brown Mills (population 11,429), and Mount Holly (population 10,639) (census data cited in ICF Kaiser, 1997).
The demographics of the population residing within a 1-mile radius of Fort Dix are presented in Figure 3.
In preparing this public health assessment, ATSDR relied on the information provided in the referenced documents. The environmental data presented in this public health assessment are from the proposed response (Camp Dresser, 1986) and the proposed response, addendum 1 (Camp Dresser, 1987), for the Fort Dix Sanitary Landfill; the final 1997 sampling and analysis report for ground water, surface water, and sediment for the Fort Dix Sanitary Landfill (EA Engineering, Science, and Technology, Inc., 1997); the draft 1997 annual summary of the air monitoring report for the landfill gas venting system (EA Engineering, Science, and Technology, Inc., 1998); the final environmental investigation report for 19 sites (ICF Kaiser, 1997); the final remedial investigation report for the golf course sites (Pacific Western Technologies, Ltd., 1997); the final remedial investigation report for the MAG-1 Area (ABB, 1997a); the draft remedial investigation report for the ARDC Test Facility (ABB, 1997b); the draft remedial investigation report for the ANC-9 Landfill (KEMRON, 1997a); the draft remedial investigation report for the Boiler Blowdown Area (KEMRON, 1997b); and the draft remedial investigation report for the Fire Training Tanks Area (KEMRON, 1997c). ATSDR assumes that the parties gathering the data followed adequate quality assurance and quality control measures with regard to chain-of-custody, laboratory procedures, and data reporting. Thus, the validity of the conclusions in this document depends on the completeness and reliability of the referenced information.