PUBLIC HEALTH ASSESSMENT
NAVAL AMPHIBIOUS BASE LITTLE CREEK
VIRGINIA BEACH, VIRGINIA
The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this public health assessment (PHA) to evaluate the potential for harm to human health posed by hazardous substances at the Naval Amphibious Base (NAB) Little Creek. The NAB Little Creek, a naval support facility, encompasses 2,147 acres in Norfolk and Virginia Beach, Virginia, and to the north borders more than 2 miles of Chesapeake Bay shoreline. The U.S. government formed the base in the 1940s by combining four World War II bases: (1) the Amphibious Training Base, (2) the Construction Battalion Training Center, (3) the U.S. Naval Section Base, and (4) the Armed Guard Training Center.
Former NAB Little Creek operations, which included vehicle and boat maintenance and construction and repair of buildings and piers and abrasive blasting operations, resulted in various fuel and chemical releases or spills. Some the released materials have reached underlying groundwater and the Little Creek Harbor. On May 10, 1999, the U.S. Environmental Protection Agency (EPA) included NAB Little Creek on its National Priorities List. This was mainly because of concern about hazardous substances potentially entering surface water and endangering wildlife. The primary contaminants of concern to ATSDR of those detected at the site are metals, such as lead in surface soil, and mercury and polychlorinated biphenyls (PCBs) in fish and crab.
In 1999 and 2002, ATSDR conducted site visits and met with representatives from NAB Little Creek. At the time of the visits, ATSDR did not identify any environmental hazards posing immediate threats to public health. Following the site visits, ATSDR conducted a review of base-related information and determined that exposure to hazardous substances in groundwater, surface water, and sediment do not pose a public health hazard. Groundwater beneath portions of the base contains volatile organic compounds (VOCs) such as those found in cleaning solvents. There is, however, no public exposure to groundwater contaminants. The groundwater underlying NAB Little Creek has never been used as a source of drinking water, nor will it be used for that purpose in the foreseeable future. NAB Little Creek and the surrounding community receive drinking water from municipal water supplies that draw from surface water sources meeting federal and state drinking water standards. Although NAB Little Creek probably has contributed to the pollutant load in surface water and sediment of the harbor, none of the hazardous substances are at levels that could cause long-term health effects for people who use the harbor for boating or swimming.
ATSDR identified two main ways people might come in contact with environmental contamination associated with the base: (1) contact with hazardous substances in surface soil and (2) consumption of Little Creek Harbor fish and shellfish. ATSDR evaluated whether exposures to detected contaminant levels via these pathways are expected to affect the health of people at or in the vicinity of NAB Little Creek, and developed the following conclusions about potential exposure hazards associated with soil and fish/shellfish.
Surface Soil
On-base
ATSDR concluded that exposure to soil contaminants does not pose a public health hazard. Either contaminants in on-base soil were detected at levels below health concern, or such low-level contamination was in areas where public exposure was infrequent or unlikely. Surface soil at certain locations at NAB Little Creek was found to contain contaminants associated with former base activities. Generally, exposure has been prevented because soil contamination occurs in restricted access areas, is covered by pavement or grass, or has been removed. Occasional contact with surface soil contaminants, even at the highest levels reported, is not expected to pose a public health hazard for adults or children. Successful cleanup or removal of contamination will continue to reduce potential harmful exposures.
Off-base
Lead was detected frequently and at levels of health concern in surface soil at a former grit-blasting area and Water Tower 1553. In November and December 2000, the Navy removed surface soil contaminants from the area. Exposure to lead has the potential to cause harmful effects, particularly for young children. Under certain conditions, lead-contaminated soil or dust could have migrated from the base to a nearby off-base residential property located 100 feet from the water tower. Site-specific information does not exist to confirm whether, or to what extent, lead from the grit-blasting area/water tower settled on the nearby property. Matching the relevant data against several factors that influence a child's vulnerability to lead in soil, however, suggests that likely exposures to lead in soil were minimal, if they occurred at all. Other possible sources in the neighborhood might also contribute to a child's exposure to lead, including lead-based paint in homes built before 1978. ATSDR believes it is prudent for families who live in or near the Turner Road area to evaluate the potential for their children to be exposed to lead and follow the Centers for Disease Control and Virginia Department of Health recommendations to have potentially exposed children under age 6 screened for elevated blood-lead levels.
Little Creek Harbor Fish and Shellfish
Low levels of chemical contaminants, such as mercury, tributyltin, and PCBs, were found in a limited sampling of fish and crab from the harbor. Exposure to such low levels of these contaminants should not pose a health hazard to people who in the past ate fish or crab from the harbor. Other chemicals have not been tested. For security reasons, the base has, however, posted "No fishing or crabbing" signs along the harbor.
Shellfish in the Little Creek Harbor has been affected by bacterial contamination. In 1938, the Virginia Department of Health, Division of Shellfish Sanitation, restricted shellfish (molluscan bivalves) taking in Little Creek Harbor because of bacteriological contamination. The "restricted" status allowed shellfish taking during warm weather months, as long as the fisher had a permit (issued by marine police and VDH) and transferred the shellfish to another water body, where they would undergo a cleaning-out period. In 1990, the status was changed from "restricted" to "prohibited" to comply with the National Shellfish Sanitation Program. "Prohibited" means no shellfish taking is allowed. ATSDR corresponded with the Virginia Marine Resources Commission (VMRC) and NAB Little Creek about public notification of the harbor's shellfish prohibition. While signs warning the public about the prohibition are not currently posted in areas controlled by the Navy at the harbor, the VMRC has stated that they are available to post signs or provide signs following consultation with NAB Little Creek. Until signs are posted, people following the advisory and the security restrictions are protecting themselves against potential exposure to bacterial and chemical contaminants in shellfish as well as fish and crabs.
Should the Navy's future plans include lifting the security restrictions for fishing or crabbing or remove the "No fishing and crabbing" signs for Little Creek Harbor, ATSDR recommends that the Navy verify, through sampling conducted prior to their removal, that edible fish and crabs in the harbor are free from harmful levels of chemical contaminants and are safe to eat. At that time, the Navy in cooperation with VDH might find it prudent to determine chemical pollutant impact on the shellfish (molluscan bivalve) population near NAB Little Creek.
Site Description and Operational History
Naval Amphibious Base (NAB) Little Creek is located on 2,147 acres in the Tidewater region of Virginia, near the mouth of the Chesapeake Bay. The base straddles the communities of Norfolk to the west and Virginia Beach to the east, and borders more than 2 miles of Chesapeake Bay shoreline to the north (Figure 1).
NAB Little Creek was formed in 1945 by the combining of four World War II bases: (1) the Amphibious Training Base, (2) the Construction Battalion Training Center, (3) the U.S. Naval Section Base, and (4) the Armed Guard Training Center. Today, the base is homeport to about 27 naval vessels and provides on-base logistic facilities and support services to meet the amphibious training needs of the United States armed forces (NEESA 1984). Training performed at the base includes beach training, assault operations, landing craft air cushion training, and demolition and explosives training. The Navy also conducts underwater explosive detonations in Little Creek Harbor (Geo-Marine Inc. 1997). As part of its support services exercises, NAB Little Creek maintains military vehicles and boats and constructs and repairs buildings and harbor piers. The base also provides other general or miscellaneous services including routine pesticide applications, electroplating of musical instruments, and operating a laundry and dry cleaning service.
Remedial and Regulatory History
Over the years, solid waste, industrial byproducts, paints, and plating materials have been disposed of, released, or accidentally spilled onto soil at NAB Little Creek. Such chemicals include heavy metals, polychlorinated biphenyls (PCBs), and pesticides. Some of that contamination has seeped into groundwater or entered nearby waterways (EPA 1999).
In 1984 a Navy Initial Assessment Study identified 17 potentially contaminated sites (NEESA 1984). Of these sites, six were further studied in 1993 and 1994 as part of remedial investigations (RIs) (Figure 2):
Site 7: Naval Amphibious Base Landfill
Site 9: Driving Range Landfill
Site 10: Sewage Treatment Plant Landfill
Site 11: School of Music Plating Shop
Site 12: Exchange Laundry Waste Disposal Area
Site 13: PCP Dip Tank and Disposal Area
Results of the RIs included a recommendation for long-term groundwater monitoring at Sites 9 and 10, source removal and monitoring at Site 11 (A&B), and further evaluation of Sites 7, 12, and 13.
Mitigation or additional monitoring was recommended or conducted at 4, 5, 8, 15, and 16. No further action was recommended at 1, 2, 6, 14, and 17. (Site 3 is being followed under a non-CERCLA program.) More than 140 potential Solid Waste Management Units (SWMUs) were identified, but only five SWMUs of greatest concern have been scheduled for further evaluation (Navy 1999).
On May 10, 1999, the U.S. Environmental Protection Agency (EPA) placed NAB Little Creek on its National Priorities List. It did so mainly because of concern about contaminants potentially entering surface water and endangering wildlife. In September 2000, a draft Federal Facilities Agreement (FFA) was submitted for legal review. An FFA outlines the work required at NAB Little Creek and defines the responsibilities of the Navy, EPA, and the state of Virginia during investigation and cleanup. Figures 3-8 show census information or land use, other features including floodplains and locations of SWMU and Sites
Agency for Toxic Substances and Disease Registry (ATSDR) Activities
Through the public health assessment (PHA) process, ATSDR assesses site conditions at NPL
sites from a public health perspective. That is, ATSDR determines whether people can be exposed
to site-related contaminants through contact with the groundwater/drinking water, surface water,
soil, biota 
, or air. Thus ATSDR visited NAB Little Creek on July 19-23, 1999, and again on
February 11-13, 2002. ATSDR collected information necessary to rank the NAB Little Creek
according to its potential public health hazard, to identify public health issues related to
environmental contamination at the base, and to identify community health concerns. During the
visit, ATSDR staff met with Navy personnel and representatives from federal and state agencies.
After the visit and after a preliminary review of the data, ATSDR did not find any health threats at
NAB Little Creek requiring immediate attention. ATSDR did, however, identify potential
exposure pathways that needed further study. ATSDR prepared this public health assessment to
evaluate these pathways further (ATSDR 1999a).
ATSDR also gathered information about health concerns voiced by members of the community. ATSDR met with base personnel, reviewed the results of the base's survey of community concerns listed in the base's community relations plan, and generally reviewed concerns expressed by the community. In June 2000, ATSDR prepared a health consultation to address specific community concerns about exposures associated with NAB Little Creek. ATSDR concluded in the health consultation that NAB Little Creek posed little threat of imminent health hazard to the public (ATSDR 2000).
ATSDR examines demographic data (i.e., population information) to determine the number of people potentially exposed to environmental chemicals and to determine the presence of sensitive populations, such as children (age 6 and younger), women of childbearing age (see pages 15-44), and the elderly (age 65 and older). Demographic data also provide details on population mobility, which, in turn, helps ATSDR evaluate how long residents might have been exposed to environmental chemicals.
In addition to demographic information, ATSDR examines the many ways in which people near NAB Little Creek might use the land and its natural resources. ATSDR does this to determine what activities might put people at risk for exposure. This information is important because the types and frequencies of activities and land use affects exposure to contamination. In this PHA ATSDR uses this information as part of the evaluation of contamination and exposure. Both demographic and land use information used in that analysis are provided below.
NAB Little Creek is principally located in Virginia Beach, but straddles the Norfolk and Virginia Beach city lines. The base employs a workforce of about 9,200 military and 4,200 civilians. During the summer, the population increases with the influx of Navy and Marine Reservists who arrive at the base for amphibious training. About 3,600 military personnel at NAB Little Creek and family members live in on-base housing, which consists of 954 units located at one of seven housing areas. Another 1,667 military personnel live in on-base barracks. School-age children attend one of the off-base schools, but younger children may attend the on-base child-care facility. This child care facility is not near any areas of contamination. In 1990, 35,809 persons lived within a 1 mile buffer around NAB Little Creek, with 4,371 children under 6 years of age and 2370 adults age 65 and older (see Figure 3A). As of 2000, a total of 31,230 persons were living within 1 mile of the base, including 3,468 children under 7 years of age and 2,938 adults 65 and older (see Figure 3B).
The surface topography at NAB Little Creek is predominantly flat. Figure 4 shows elevation contours at the base. Land at NAB Little Creek tends to slope toward water bodies. On the western side of the base, the land surface slopes toward the Little Creek Cove and Desert Cove, while on the eastern side, the surface slopes toward Lake Bradford. Most of the 2,147 acres of the base are developed, with about 600 buildings and 400 structures (see Figure 5). Only a small portion of the property remains covered with grass or other vegetation. The Area around NAB Little Creek consists of residential, commercial, industrial, and recreational developments (EPA 1999).
Surface water runoff and drainage from most of the base's source areas empty into either Little Creek Cove or Desert Cove of the harbor area along the western portion of the base. Water from both coves flows into Little Creek Channel, which then empties into the Chesapeake Bay. Collectively Little Creek Cove, Desert Cove, and Little Creek Channel are referred to as Little Creek Harbor. The low and relatively flat areas adjacent to coastal waters fall within a 100 year and 500 year floodplain (see Figure 6). Surface water from the base flows through wetlands before actually discharging into the harbor (see Figure 7) (NEESA 1984). Lakes at the base include Lake Bradford, Chub Lake, Little Creek Reservoir, Lake Whitehurst Reservoir, and Varian Lake. Surface water runoff along the eastern portion, where most of the residential property is located, drains into Lake Bradford and Chub Lake (NEESA 1984).
Water levels at some of the on-base lakes are regulated through the release of overflow into the on-base canals. These canals eventually drain into Little Creek Cove. For example, overflow from the Little Creek Reservoir and the Lake Whitehurst Reservoir is released to Little Creek Cove by canals. The 4,000 foot canal connecting Little Creek Reservoir to Little Creek Cove borders a landfill (NEESA 1984, Geo-Marine 1997).
Fishing and shellfishing are not allowed on the NAB Little Creek property at Desert Cove, Little Creek Cove, Little Creek Channel, Varian Lake, or Chub Lake. Fishing is, however, permitted at the on-base Lake Bradford and Little Creek Channel, outside the base's boundaries, and in the Chesapeake Bay, outside the harbor (NEESA 1984, Mike Tate, Manager of Little Creek Marina Harbor, personal communication regarding fishing advisory, June 2002).
NAB Little Creek has 29 stormwater outfalls which ultimately discharge into Little Creek Harbor. Most of the outfalls are within the industrial area of the base (Geo-Marine, Inc., 1997). These stormwater outfalls are subject to the Virginia Pollutant Discharge Elimination System (VPDES), a permit program that controls water pollution by regulating sources discharging into surface water. NAB Little Creek's VPDES permit contains limits on what can be ultimately discharged into the harbor and specifies acceptable levels of any pollutant in that discharge. According to provisions of the VPDES, the Navy is required to routinely sample its stormwater discharges and to notify Virginia Department of Environmental Quality (VDEQ) of its results. Collectively, these provisions ensure that the discharges entering Little Creek Harbor's are safe and that public health is protected.
At the base and in the communities of Norfolk, Virginia Beach, and Chesapeake drinking water is provided by surface water from Lake Smith, Lake Wright, Lake Whitehurst, Lake Lawson, Stumpy Lake, Little Creek Reservoir, and three lakes to the west of the city of Suffolk. Several of these drinking-water reservoirs are within a few hundred of feet of NAB Little Creek. Still, none of the potential sources of contamination at the base drains to these reservoirs or surface water bodies, and the water is treated and tested to ensure that it meets safe drinking water standards.
Quality Assurance and Quality Control
In preparing this PHA, ATSDR reviewed and evaluated information provided in the referenced documents. Documents prepared for the CERCLA program must meet standards for quality assurance and control measures for chain-of-custody, laboratory procedures, and data reporting. The environmental data presented in this PHA are from Navy site documents and remedial investigations. Based on our evaluation, ATSDR determined that the quality of environmental data available in base-related documents for NAB Little Creek was adequate for making public health decisions discussed in this document.
EVALUATION OF ENVIRONMENTAL CONTAMINATION AND POTENTIAL EXPOSURE PATHWAYS
ATSDR identified two main ways those at or near NAB Little Creek could possibly come into contact with contaminants originating from the base.
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MAIN EXPOSURE CONCERNS AT NAB LITTLE CREEK
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ATSDR analyzed environmental data for each of NAB Little Creek's installation restoration program (IRP) sites to determine if identified exposures could be past, present, or future public health hazards. Table 1 provides a description of each IRP site at NAB Little Creek and a summary of ATSDR's evaluation. Our review indicated that most IRP sites at NAB Little Creek are not associated with any known public health hazards. Many IRP sites are surrounded by perimeter fencing, covered surfaces, or both (e.g., vegetative growth, paved areas); these prevent or reduce potential exposure to contaminated soil. At other locations, harmful exposures are limited because either no site-related contaminants are present where exposure to the public could occur, or detected contaminant concentrations are too low to pose a health hazard. For some locations where levels were high enough to be a concern to regulators, cleanup efforts have successfully removed contaminated soil.
In the discussion that follows, ATSDR further evaluated environmental monitoring data and exposure information for the two main exposure scenarios to determine whether contact from either would result in harmful effects. ATSDR states the exposure concern associated with the complete or potential exposure pathway identified above, presents a brief summary of conclusions, and describes in more detail any identified exposure pathways and the basis for the conclusions. ATSDR's evaluation is also summarized by exposure situations in Table 2. In the Community Health Concern section, ATSDR discusses potential hazards associated with the subsurface soil gas near the Base Exchange and the use of the base golf driving range and baseball diamond. To acquaint the reader with terminology and methods used in this public health assessment (PHA), Appendix A provides a glossary of environmental and health terms presented in the discussion and Appendix B describes ATSDR's exposure evaluation process. Appendix C contains ATSDR's responses to comments received during the public comment period (May 27 to July 11, 2003) for this PHA.
DISCUSSION OF: Contaminated Surface Soil
Summary
Contaminants, such as lead, arsenic, and polychlorinated biphenyls (PCBs), have been detected in surface soil at various IRP sites across NAB Little Creek. ATSDR believes that harmful exposures to contaminated soil at most areas of the base are largely prevented. The land surface is either paved, covered by grass or buildings, lies in restricted land use areas, or the contamination has been removed.
In November and December 2000, the Navy removed surface soil contaminants from a former grit-blasting area and Water Tower 1553, where lead was detected frequently and at levels of health concern. Exposure to lead has the potential to cause harmful effects, particularly for young children. Children living in base housing, however, are not likely to come into contact with lead in soil at the grist blasting area/water tower, as base housing areas are located away from this source of contamination.
An off-site residential neighborhood is located 100 feet from Water Tower 1553. Site-specific information does not exist to confirm whether, or to what extent, lead from the grit-blasting area/water tower settled on nearby property. However, matching the relevant environmental data collected near the water tower against several factors that influence a child's vulnerability to lead in soil suggests that likely exposures to lead in grit-blasting material were minimal, if they occurred at all. Other possible sources in the neighborhood might also contribute to a child's overall exposure to lead, including lead-based paint in homes built before 1978. The CDC and VDH recommend that young children be assessed for lead exposure. ATSDR believes it is prudent for families who live in or near the Turner Road area to also evaluate the potential for their children to be exposed to lead and follow the CDC and VDH recommendations.
Discussion
NAB Little Creek maintains vehicles and ships and in the past, also constructed and repaired the harbor piers. Some of these activities and associated waste disposal practices inadvertently released contaminants onto the ground surface (NEESA 1984). Areas of greatest concern are:
The Navy sponsored site and remedial investigations intended to characterize the type and amount of contamination in soil at base locations where contamination was suspected. Surface soil samples collected from IRP sites at the base were found to contain metals, semivolatile organic compounds (SVOCs), PCBs, and pesticides. Figure 2 shows following areas with ABM residue contamination or grit basting materials.
- SWMU 3, Pier 10 Sandblast Yard
- SWMU 5, Building 3986 Boat Painting Area
- SWMU 6, Seabee Area
- SWMU 7, Desert Cove Sandblasting Area
- SWMU 8, West Annex Sandblasting Area including Water Tower 1553 closest to the western base boundary and three other separated areas.
Some of the highest contaminant levels were concentrated in surface soil at a former grit-blasting area (SWMU 8) and at one of the base's water towers (1553) (see Figure 8). Of the contaminants detected, lead appeared frequently and in concentrations well above health concern levels (up to 1,820 ppm at the base of the tower--this exceeds EPA's residential soil screening level of 400 ppm.)
SWMU 8 is to the north of Midway Road and south of Guadalcanal Road at NAB Little Creek (OHM/IT 2001). Between 1949 and 1971, the Navy used the site for sandblasting ships and residue storage. Residue of reddish-brown abrasive blast material (ABM) and paint chips released from sandblasting operations accumulated on the ground to an average thickness of 4 inches. Periodically, the residue was removed and disposed of off base. Since 1971, the area has been a vacant lot.
The sandblasting area is located adjacent to Water Tower 1553. Constructed in the 1940s, the water tower was maintained with lead-based paint for a majority of its use. During repainting procedures, the exterior of the tower was sandblasted to remove the existing layers of paint. Some of the sandblasting residue fell onto the ground around the tower. Turner Road, a residential and commercial neighborhood, borders the base perimeter fence line near the water tower area. About 100 feet separates the nearest home from the water tower.
During a preliminary field investigation in March
2000, the Navy visually delineated the extent of
ABM in the area of SWMU 8 and the water tower
(CH2M Hill 2000). No ABM material was
observed within 50-75 feet of the fence line
separating NAB Little Creek from the adjacent
Turner Road residential property.
Since detecting elevated contaminant concentrations in surface soil at SWMU 8 and the water tower, the Navy has taken measures to reduce the contamination and any possible human exposure. Actions conducted in November and December 2000 included the removal from SWMU 8 and the nearby water tower of surface soil debris containing exposed ABM and contaminated soil. More than 4,500 tons of soil were removed to reduce lead levels to less than or equal to 400 ppm. Excavated material was shipped to an off-base disposal area. Confirmatory soil sampling following excavation within the delineated area confirmed that lead concentrations were below the EPA residential risk based concentration of 400 ppm. The confirmatory sampling also showed that no other constituents exceeding cleanup standards were left in place (NEHC 2003). Excavated areas were backfilled with certified-clean fill and covered with top soil and seeded (OHM/IT 2001). ATSDR noted during its February 2002 site visit that the grit (with the exception of sporadic occurrences of grit residue) had been removed from the property at SWMU 8 and the water tower and the area was covered with grass.
Evaluation of Public Health Hazards
Because young children are especially vulnerable to the effects of lead, ATSDR's assessment of potential health hazards focuses on whether children at or near NAB Little Creek could come in contact with harmful levels of site-related lead in surface soil. Children at potential risk of exposure include (1) children living in on-base housing and (2) children living in the Turner Road neighborhood near Water Tower 1553. ATSDR assesses potential hazards by considering how often and how long the exposure at base housing or in the Turner Road area might have occurred and what contaminant concentrations might have been present in the soil at any likely point of contact. The evaluation is described below.
NAB Little Creek Exposures–SWMU 8 and Water Tower 1553
Lead levels in surface soil at SWMU 8 and Water Tower 1553 were above levels of health concern. For several reasons ATSDR determined, however, that children living at the base should not have come in direct contact with harmful levels of lead in those soils. First, in the past the areas of contaminated surface soils were generally inaccessible to the public. A perimeter fence with gated entrances limited–and continues to limit–unauthorized access to the base. An intact metal fence topped with barbed wire separates the SWMU 8 and the water tower lead-soil contamination from base housing areas as well as from nearby residential property. Additionally, there is little chance that in the past, young children susceptible to the effects of lead would have been left unattended at SWMU 8 or the water tower. Second, even if a child gained unauthorized access to the area of lead contamination, exposures would have been intermittent and brief. Such minimal, infrequent exposure to lead in soil, if it had occurred at all, would not reasonably be expected to cause illness or make someone sick. According to the NAB Little Creek-Boone Clinic base health officials, routine blood-lead screening of children that took place between 1995 and 1999 showed no cases of elevated blood-lead levels (above 10 µg/dL) for children living on base (ATSDR 1999c).
In November and December 2000, the Navy removed lead-contaminated soil from around SWMU 8 and Water Tower 1553, eliminating future exposures. Those remedial actions were conducted with oversight from the U.S. Environmental Protection Agency (EPA) and the VDEQ. Furthermore, accessibility to the base is and will remain restricted. Given these findings, ATSDR concludes that soil contamination at SWMU 8 and Water Tower 1553 is not associated with any known public health hazard for children who live in on-base housing at NAB Little Creek.
Off-Base Exposures--Turner Road Neighborhood
Residue of reddish-brown and darker abrasive blast material and paint chips were released during sandblasting operations at SWMU 8 between 1949 and 1971. Lead-paint chips were also dislodged from the exterior of the tower during maintenance activities after the 1940s. Under certain conditions (e.g., meteorological) during water tower sandblasting or operations at SWMU 8, lead might have deposited on soils in the nearby Turner Road residential property. Information characterizing whether or to what extent lead from these operations settled on soil within the adjacent neighborhood is not available. Without this information, ATSDR does not know with certainty whether site-related lead exposure occurred at these yards. As a prudent public health measure, ATSDR evaluates possible exposure of nearby residents to lead in soil in the discussion below.
ATSDR's concerns about lead in soil
Although lead can cause adverse effects to people of all ages, ATSDR is principally
concerned about the potential for children (6 years of age and younger) to come
into
contact with lead, as they are especially vulnerable to its effects (see
text box). If airborne lead migrated to nearby residential properties,
children might have come in contact with it. The most probable form of contact
would be by handling surface soil or by inadvertently eating soil through hand-to-mouth
activity. Breathing in soil particles is not considered to be an important source
of lead exposure.
If children or adults do contact lead-contaminated soil, the symptoms of such lead exposure are not always clear. With a simple blood test, physicians can find out how much lead is circulating in a person's bloodstream. Correlations between blood-lead levels and health effects have been studied extensively to evaluate the potential for lead exposure to cause adverse health effects. Since the 1980s, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics have recommended that physicians evaluate the potential for lead exposure to children (9 months to 6 years of age) and when appropriate perform blood-lead screening (ATSDR 1999, AAP 1998). CDC recommends follow-up, treatment, or both for children with blood-lead levels equal to or greater than 10 µg/dL (ATSDR 1999b).
Blood-lead screening programs
Two applicable blood-lead screening programs serve families who live in or near the Turner Road neighborhood:
Data about the populations served by the Navy's PLPP program and the Lead Safe Virginia program (including the percentage of children screened and the time period over which the screening occurred) and the results of any blood-lead screening of children who lived in or near the Turner Road area would allow ATSDR to provide greater perspective about the potential for adverse health effects to have occurred as a result of exposure to lead. Without these data, we can only estimate likely exposure based on factors that influence contact with contaminated soil and a child's vulnerability to lead.
Factors that influence contact with lead contaminated soil
Exposure can only occur if an individual comes in contact with the contaminated media, such as lead in surface soil. Soil sampling data are not available to confirm whether or to what extent residential property soil contains site-related lead. Several factors, however, help ATSDR determine whether lead from SWMU 8 and the water tower might be present in areas where children play.
Factors that influence the relationship between exposure and health effects
Assessing the importance of an exposure to lead, such as possible NAB Little Creek lead in the Turner Road neighborhood, is an involved process. Health professionals typically consider several factors that influence the relationship between that exposure and blood-lead levels that could result in possible ill effects, including
Age and behavior patterns of
an exposed child. Pre-school children (6 years of age and younger) are
usually most susceptible to the effects of lead. A young child's vulnerability
to the effects of lead stems from a combination of factors, including their
tendency to play in dirt and to place their hands and other objects in their
mouths, thereby increasing the chances for soil ingestion. Children also have
the ability to absorb lead from the gastrointestinal tract more efficiently
than do adults and are more sensitive the effects of lead.In all likelihood, for several reasons people living at the Turner Road neighborhood probably have had and continue to have minimal, if any exposure, to site-related lead in soil. First, over the years most soil has been covered with top soil, grass, or pavement. These covers minimize direct contact with potential lead in soil. For some properties, potentially contaminated soil has, possibly, been removed, turned over, or otherwise disturbed during home construction, thereby moving lead that settled on the surface down to deeper, more inaccessible soil. Second, releases of lead from SWMU 8 and water tower have ceased. Operations that produced airborne lead or resuspended lead-contaminated soil/dust (active sandblasting operations at SWMU 8 or sandblasting during lead-paint removal/water tower maintenance operations) stopped after 1971. Third, the Navy delineated and then removed the entire area of soil contamination near the on-site water tower. Lastly, there are housing and recreational areas on base near other water towers and according to the NAB Little Creek-Boone Clinic base health officials, routine blood-lead screening of children that took place between 1995 and 1999 showed no cases of elevated blood-lead levels (above 10 µg/dL). Because many homes in the Turner Road area were built before 1978, many likely still contain lead-based paint. Parents, guardians, and care givers in the Turner Road area should evaluate their children's potential for lead exposure and follow the CDC and VDH recommendations to have potentially exposed children under age 6 screened for elevated blood-lead levels.
DISCUSSION OF : Contaminated Fish and Shellfish
Summary
ATSDR reviewed the limited sampling data to determine whether people could be eating contaminated fish or shellfish from Little Creek Harbor. The data available to ATSDR suggest that fish and crabs in the Little Creek Harbor have been impacted by chemical contaminants such as mercury, but at levels below those known to cause harmful health effects. No other information is available for other shellfish, including clams and oysters. There is no way, however, to determine how much of those contaminants originate from NAB Little Creek operations. Other non-base-related sources could contribute to the harbor pollution.
Shellfishing has been restricted since 1938 and prohibited since 1990 in Little Creek Harbor due to high levels of bacteriological contamination (NEESA 1984, CH2M Hill 2001a). Fishing and crabbing is not permitted at NAB Little Creek for security reasons. People following the restrictions are protecting themselves against potential exposure to biologic and chemical contaminants in fish and shellfish. Although commercial fishing is not allowed, sport fishing is common in the western, civilian half of the harbor. Should the Navy's future plans include removal of the signs for Little Creek Harbor, ATSDR recommends that the Navy verify, through sampling conducted prior to the signs' removal or lifting security restrictions, that seafood in the harbor are free from harmful levels of chemical contaminants and are safe to eat. If the harbor is dredged the sampling should be repeated.
Discussion
Little Creek Harbor and its Tributaries
Contamination has been detected in the water and sediment of Little Creek Harbor, including metals (e.g., cadmium, mercury, lead), polycyclic aromatic hydrocarbons (PAHs), and tributyltin. Some disposal areas at NAB Little Creek directly or indirectly drain into Little Creek Harbor (Old Dominion University 1992, ETS 1995). Contaminants from these areas could have been carried with groundwater and discharged into the surface water of Little Creek Harbor. Other contaminants have been released into channels that eventually discharge into Little Creek Harbor.
Several IRP sites at NAB Little Creek ultimately
drain to Little Creek Harbor. For example,
runoff from Site 7, a former landfill, drains via a
drainage ditch to Little Creek Cove. Site 7 was
once an arm of Little Creek Cove, but was filled
with dredged soil before it was used as a landfill.
The majority of the waste at the landfill likely
consisted of municipal refuse. Potentially
hazardous materials disposed of at the landfill
include paints, acids, PCBs, and pesticides
(NEESA 1984, EPA 1999). Site 12, the former
Exchange Laundry Waste Disposal Area, dumped
waste containing tetrachloroethylene (PCE), soap,
and dyes into a catch basin, which emptied into a
storm sewer. The sewer flows north form this site
into a 9-foot-deep drainage canal connecting with
Little Creek Cove. Contaminants, primarily
metals, have been found in sediment along the
drainage canal (NEESA 1984). (It is also important to note that the drainage canal stops about
3,000 feet before the Little Creek Cove and the surface water flows through wetlands before
actually discharging into the harbor.) Other IRP sites include landfills at Sites 8, 9, and 10; a
plating shop at Site 11; and a pentachlorophenol (PCP) dip tank and wash rack at Site 13.
In addition to IRP sites, activities at NAB Little Creek such as drilling at the mudflats and fueling, salvaging, and maintaining ships in the harbor affect the quality of the harbor's water and sediment. A number of non-base-related contaminant sources also contribute to contamination in the harbor.
Along Chesapeake Bay and Little Creek Channel one commonly encounters striped bass, spot, bluefish, croaker, sea trout, and blue crabs (NEESA 1984, CH2M Hill 2001a). Limited information is available on contaminant concentrations in fish and crabs inhabiting the harbor. In 1994 and 1995 NAB Little Creek collected fish (croaker and spot) and crab samples from the harbor. The samples were analyzed for mercury and tributyltin (see Table 3). Those contaminants were selected because of their presence in harbor sediment and, particularly for mercury, their ability to accumulate at high levels in fish and shellfish over time. The study found mercury in fish (0.132-0.148 ppm) and crab (0.097-0.225 ppm) in the samples obtained from the harbor (Baker Environmental, Inc., 1996). Tributyltin was only detected in fish (0.006 ppm) and crab (0.028 ppm) samples collected in 1995. Additional limited information is provided through the VDEQ 1998 fish sampling program along the Chesapeake Bay. As part of that sampling event, VDEQ collected and analyzed for PCBs two Little Creek Channel fish samples (mummichog and spot). PCB concentrations in the samples were 0.062 ppm and 0.127 ppm (VDEQ 1998).
ATSDR has reviewed the scientific literature
to gain a better understanding of the extent to
which fish can accumulate mercury, tributyltin, and PCBs. EPA has compiled data on average
mercury concentrations in fish commonly consumed by the U.S. population. A review of these
data suggests that the average concentration of mercury in flat fish (such as spot or flounder) and
blue crabs is 0.092 ppm and 0.117 ppm, respectively (ATSDR 1999d). A 1980-1981 survey by
the U.S. Fish and Wildlife Service found the average concentration of PCBs in fish at 102
nationwide locations was 0.53 ppm. Another study by the EPA, conducted between 1986 and
1989, reported chemical residues in fish at 362 sites nationwide, including industrial and
hazardous waste sites. In the study, PCBs were detected at an average concentration of 1.9 ppm in
bottom feeding and game fish (ATSDR 2000b). By comparison, PCB concentrations in Little
Creek Harbor fish appear to fall within the range observed nationwide in the 1990s. But mercury
concentrations in fish from the harbor appear to be slightly higher than levels typical in fish of
like species.
Shellfishing has been restricted since 1938 and prohibited since 1990 in Little Creek Harbor due to high levels of bacteriological contamination (NEESA 1984, CH2M Hill 2001a). The Navy has prohibited fishing and shellfishing at Little Creek Cove, Desert Cove, and Little Creek Channel on NAB Little Creek property for security reasons. Fishing is, however, allowed at sections of Little Creek Channel lying outside NAB Little Creek property and in the Chesapeake Bay, outside the harbor.
On July 19-23, 1999, and again on February 11-13, 2002, ATSDR toured NAB Little Creek, surveying base water bodies and areas of public access. It was unclear during the site visit whether fish or shellfish including crab were ever harvested at NAB Little Creek or whether any recreational fishing or shellfishing takes place now in the freshwater, brackish, and saltwater bodies.
Evaluation of Potential Public Health Hazards
In 1994, 1995, and 1998 mercury, tributyltin, and
PCBs were detected in fish and crab samples
collected from Little Creek Harbor. Some of the
chemical contamination in fish possibly originated
from base-related activities. Still, additional sources
of chemical pollutants include other naval activities
(i.e., dredging, fueling operations, ship salvage and
maintenance) and non-naval activities (i.e., railroad
ferry, barge loading/unloading, private boat
refurbishing).
Shellfishing has been restricted since 1938 and prohibited since 1990 in Little Creek Harbor due to high levels of bacteriological contamination (NEESA 1984, CH2M Hill 2001a). The "restricted" status allowed shellfish taking during warm weather months, as long as the fisher had a permit (issued by marine police and VDH) and transferred the shellfish to another water body, where they would undergo a cleaning-out period. In 1990, the status was changed from "restricted" to "prohibited" to comply with the National Shellfish Sanitation Program. "Prohibited" means no shellfish taking is allowed.
To determine if the consumption of fish or shellfish containing the detected levels of chemical contaminants was or is detrimental to human health, ATSDR estimated doses for individuals who ate fish from the harbor in the past, or who continue to do so against restrictions in place at the harbor. Because uncertainty exists regarding how often people ate fish from the harbor and how large a portion was eaten, ATSDR conservatively assumed that each month an adult ate seven 8-ounce meals of Little Creek Harbor fish and shellfish. ATSDR assumed a child ate half the amount of an adult, or seven 4-ounce meals per month. This is likely a conservative assumption: individuals tend to get their fish from varied sources. ATSDR also assumed that fish consumed contained the highest probable level of contamination. Collectively, those health-protective assumptions allow ATSDR to evaluate safely the likelihood, if any, that eating harbor fish and shellfish could cause harm to area consumers.
ATSDR then compared the estimated exposure doses to health-based guidance levels, such as ATSDR minimal risk levels (MRLs) and EPA's oral reference doses (RfDs). We also compared the doses to information on the detected contaminants in the toxicologic literature. The health guidance level is an amount of contaminant taken into the body per unit weight per day that is not likely to cause adverse health effects. This value is derived from the available scientific literature on exposure and health effects. At doses less than the guidance levels, no adverse health effects have been observed. Comparison of the estimated dose to the health guidance level allows ATSDR to evaluate the likelihood–if any–that mercury, tributyltin, or PCBs in fish and shellfish could be associated with adverse health effects. Appendix B describes in greater detail ATSDR's methods, assumptions, and health guidance levels.
For both an adult and a child the exposure doses estimated for mercury, tributyltin, and PCBs are lower than their respective screening values (ATSDR MRLs or EPA RfDs), and below levels associated with adverse health effects. This finding suggests that people who ate fish, shellfish, or crabs containing the detected levels of contaminant in the past are not at risk of developing adverse health effects. Contaminants such as mercury are persistent in the environment. Since the initial sampling in 1994-1995, the levels in fish may have increased or decreased. Thus as a prudent public health measure, ATSDR recommends that people minimize current and potential future exposure to chemical contaminants by following the restrictions for the NAB Little Creek Harbor.
Should the Navy's future plans include removal of the "No fishing and crabbing" signs for Little Creek Harbor, ATSDR recommends that the Navy verify, through sampling conducted prior to their removal, that edible fish and crabs in the harbor are free from harmful levels of chemical contaminants and are safe to eat. At that time, the Navy in cooperation with VDH might find it prudent to determine chemical pollutant impact on the shellfish population near NAB Little Creek. If the harbor is dredged the sampling should be repeated.
A shellfish prohibition due to bacterial contamination has been in place along Little Creek Harbor. Signs warning people of the shellfish prohibition are not currently posted along the harbor shoreline. ATSDR has talked with the Navy and the Virginia Marine Resources Commission (VMRC) about providing sufficient notification to the public about the harbor's shellfish prohibition. The VMRC has offered to provide or place signs relative to shellfish bacterial contamination along the harbor if, after further evaluation, the Navy judges it necessary to do so (VMRC 2003).
ATSDR identified community health concerns through meetings with NAB Little Creek personnel and a review of base documents. A Restoration Advisory Board was formed in 1994. The following concerns have been identified:
Volatile organic compounds (VOCs), including trichloroethylene (TCE) and tetrachloroethylene (PCE), have been detected in groundwater beneath Site 12, the former Exchange Laundry Disposal Area, and the site of the new Base Exchange/Commissary. Soil gases can seep into buildings located above groundwater contaminant plumes. In 1992 the Navy conducted a soil gas survey to characterize any releases beneath the former laundry facility (Target 1992). High levels of PCE (up to 198 µg/L [ppb]) were found in the southeastern portion of Site 12, and away from the proposed building location and other buildings. Other VOCs were found in scattered locations, but generally at low levels. As a precautionary measure, however, as part of the new construction the Navy installed a passive gas removal system. With the new system, gases collect in the coarse gravel/rock under the building and move through a series of pipes in the gravel to pipes that passively release the gas from the top of the building. This minimizes or can even eliminate adverse impacts on air quality inside the Base Exchange/Commissary.
Groundwater near the Base Exchange/Commissary flows away from and toward a nearby surface water channel. Surface water and groundwater sampling has shown that the water in and beneath the channel is free of VOCs. VOCs in groundwater near the Base Exchange/Commissary also move toward a leaky sanitary sewer line. At the exit briefing for ATSDR's 1999 site visit, ATSDR recommended that the Navy conduct periodic sampling of gases in confined spaces (e.g., sewers), in the indoor air of nearby buildings, in structures in the migration path of the groundwater, and along the sewer line.
A 2001 investigation along the north end of the sewer line found relatively low levels of PCE at 9 ppb, TCE at 1.4 ppb, and cis-1,2-dichloroethylene (DCE) at 1.7 ppb in the groundwater. The findings indicate that the VOCs are seeping through a crack in the sewer line where, during supplemental remedial investigation activities, PCE had been measured up to 72 µg/L. PCE is expected to dilute as it seeps out through the crack in the pipe and mixes with groundwater. A sample taken 20 feet north of the crack had PCE at only 1.7 µg/L. All 12 other samples were free of VOCs. The Navy, EPA, and VDEQ are in the process of evaluating remedial action alternatives; no remedy has been selected. Water in the sanitary sewer line is routed to a water treatment plant. If, however, findings from future groundwater, soil gas, or sewer line monitoring suggest that contaminants move toward the Base Exchange/Commissary, ATSDR recommends additional studies to determine potential impacts to indoor air quality (CH2M Hill 2001b).
ATSDR does not expect that the public will come in contact with waste in the former trench-style landfills beneath the base driving range and portions of the baseball diamond. Waste buried at these sites during their operation in the 1950s included incinerator ash, unburned solid waste, and scrap metal. Small amounts of hazardous material, such as pesticides, PCBs, and motor oil, could have also been disposed of in the landfills. After closure each landfill was covered with 2 feet of vegetative soil cover. The soil cover prevents exposure of the public to materials or contaminants within the landfill.
Land use restrictions are proposed to limit activities that could threaten the integrity of the landfill cover and pose unacceptable harm to the public. The land use limits would restrict any: (1) digging into the cover or contents of the landfill, (2) use of groundwater beneath the sites, and (3) development of the site for residential use. As long as the cover on each landfill is undisturbed, ATSDR does not anticipate any public exposure to the materials contained within the landfill in the future. Leachate seeps have not been identified at the ground surface of the landfill, nor do leachate collection systems exist at either landfill.
Landfills can emit gases created from decomposing waste or from other non-methane organic compounds created when liquid or solid waste changes into vapors. By volume, landfill gas typically contains 45-60% methane and 40-60% carbon dioxide, with smaller amounts of non-methane organic vapors (e.g., VOCs) (ATSDR 2002a). Sometimes these gases can pose hazards when they travel through the soils and then upward into the indoor air of nearby buildings. Residents living in these buildings could then incur exposure when breathing air containing the contaminants. On occasion, these gases can also pose an explosive hazard. Several factors greatly influence how much gas a landfill currently releases and whether any gas releases might pose a public health hazard. A review of these factors suggests that the former landfills at the driving range and baseball diamond are not likely to release harmful amounts of gases at this time. These factors include
Given the information about the former landfills and the current status of the area, ATSDR expects that people using either the golf range or the baseball field today will not reasonably come in contact with either landfill waste material or landfill gases. As a prudent public health measure, however, ATSDR recommends that the Navy consider potential movement of landfill gases before constructing any future buildings near the former landfills.
ATSDR CHILD HEALTH CONSIDERATIONS
ATSDR's Child Health Considerations recognizes that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than are adults from certain kinds of exposures to hazardous substances emitted from waste sites and from emergency events. In general, children are more likely to be exposed because they play outdoors and they often bring food into contaminated areas. They are shorter than adults, which means they breathe dust, soil, and heavy vapors close to the ground. Children are also smaller, so they receive higher doses of chemical exposure proportional to their body weight. The developing body systems of children can sustain permanent damage if toxic exposures occur during critical growth stages. Most importantly, most children depend completely on adults for risk identification and management decisions, housing decisions, and access to medical care.
ATSDR has attempted to identify populations of children in the vicinity of NAB Little Creek and any completed exposure pathways to these children. The community surrounding NAB Little Creek contains residential neighborhoods with children and schools. Demographic data for 2000 indicate that 3,468 children under 6 years of age live in communities within a 1-mile radius of the NAB Little Creek. Children in these communities cannot easily trespass onto NAB Little Creek property due to perimeter fencing and military security measures.
Following a careful evaluation of these pathways as they relate to children, ATSDR determined that no harmful exposures have occurred at NAB Little Creek in the past, nor are they expected to occur–either now or in the future. Although contaminants have been detected at NAB Little Creek, children cannot access the site or contaminated areas on the base.
If parents choose not follow the fish or shellfish restrictions for the Little Creek Harbor, children might eat fish and seafood taken from Little Creek Harbor. If children do eat locally caught fish/shellfish/crabs, they could be exposed to low levels of chemicals present in that fish and seafood. ATSDR recommends that children and parents observe the restrictions and advisory for Little Creek Harbor.
Lead-contaminated soil or dust might have migrated from the former grit-blasting area and from the Water Tower 1553 area to a nearby residential property about 100 feet from the tower. Children are especially vulnerable to the effects of lead. Site-specific information does not exist to confirm whether or to what extent exposure has occurred. ATSDR believes, however, that most children playing in the neighborhood have not come in contact with harmful levels of lead from NAB Little Creek. Depending on factors influencing exposure (e.g., age of home, age of child at exposure, play habits, concurrent lead exposures), certain children could be at greater risk of developing lead-related effects. ATSDR recommends blood-lead screening for all children age 6 and younger as recommended by CDC and VDH. These exposure pathways are discussed in the Evaluation of Environmental Contamination and Potential Exposure Pathways section of this PHA.
Conclusions regarding potential past, current, and future exposure situations on and in the communities near NAB Little Creek are based on an evaluation of site investigation data and observations made during site visits. Conclusions about exposures are described below. (A description of the public health hazard conclusion categories is included in the glossary.)
There are housing and recreational areas on base near other water towers and according to the NAB Little Creek-Boone Clinic base health officials, routine blood-lead screening of children that took place between 1995 and 1999 showed no cases of elevated blood-lead levels (above 10 µg/dL).
The Public Health Action Plan (PHAP) for NAB Little Creek contains a description of actions taken and those to be taken by ATSDR, the Navy, the EPA, and Virginia Department of Environmental Quality at and in the vicinity of the site after the completion of this public health assessment. The purpose of the PHAP is to ensure that this public health assessment not only identifies public health hazards, but also provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. The public health actions completed, being implemented, or planned are as follows:
Completed Actions
Ongoing and Planned Actions
This report was prepared under the direction and supervision of the following individuals:
Charles Grosse, M.S., REM
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
Diane Jackson
Environmental Engineer
Chief, Defense Facilities Assessment Section B
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
Assistance in site visits and the preparation of this report was provided by:
Jessica Graham, M.S.
Environmental Health Scientist
Eastern Research Group, Inc.
Tom Stukas
Regional Representative, Region III
Agency for Toxic Substances and Disease Registry
Philadelphia, PA
GIS mapping assistance in the preparation of this report was provided by:
Paul Calame, B.S.
ATSDR, OAA, Spatial Analysis Activities Group.
Jerri Anderson.
ATSDR, OAA, Spatial Analysis Activities Group (Demographic Map)
Review of this report was provided by:
Gary Campbell, Ph.D.
Chief, Department of Defense Section
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
Sandra Isaacs
Chief, Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
[ATSDR]. Agency for Toxic Substances and Disease Registry. 1999a. Site scoping visit report. Atlanta: US Department of Health and Human Services.
[ATSDR] Agency for Toxic Substances and Disease Registry. 1999b. ToxFAQs for lead. Atlanta: US Department of Health and Human Services. Available at: www.atsdr.cdc.gov. Last accessed June, 1999.
[ATSDR] 1999c. Toxicological profile for lead (update). Atlanta: US Department of Health and Human Services.
[ATSDR] Agency for Toxic Substances and Disease Registry. 1999e. Toxicological profile for mercury(update).
[ATSDR] Agency for Toxic Substances and Disease Registry. 2000a. ATSDR Health consultation regarding various exposure issues from initial July 1999 site visit to Naval Amphibious Base, Little Creek. Atlanta: US Department of Health and Human Services.
[ATSDR] Agency for Toxic Substances and Disease Registry. 2000b. Toxicological profile for polychlorinated biphenyls (PCBs) (update). Atlanta: US Department of Health and Human Services.
[ATSDR] 2002a. Agency for Toxic Substances and Disease Registry. Landfill gas primer–an overview for environmental health professionals. Atlanta: US Department of Health and Human Services. Available at: www.atsdr.cdc.gov/HAC/landfill. Last accessed July 28, 2002.
Baker Environmental, Inc. 1996. Draft final supplemental ecological assessment, NAB Little Creek. Norfolk, VA. Prepared for Department of the Navy. May 9, 1996. Coraopolis, PA
CH2M Hill. 2000. Final engineering evaluation/cost analysis (EE/CA) for SWMU 8, West Annex Sandblast Area. NAB Little Creek. Herndon, VA
CH2M Hill. 2001a. Final baseline (step 3) ecological risk assessment IR sites 9 and 10. NAB Little Creek. Herndon, VA.
CH2M Hill. 2001b. Final remedial investigation/human health risk assessment/focused feasibility study for sites 9 and 10. NAB Little Creek. Herndon, VA.
[EPA] Environmental Protection Agency. 1999. Support document for the revised National Priorities List–final rule. Washington, DC.
[EPA] Environmental Protection Agency 2000. Guidance for assessing chemical contaminant data for use in fish advisories. Washington, DC: Office of Water; EPA23-B-00-008.
[EPA] Environmental Protection Agency. 2001a. Residential lead hazard standards - TSCA section
403. Available at: http://www.epa.gov/lead/leadhaz.htm Last updated June 19, 2002.
Environmental Testing Services. 1995. A study of sediment and water quality in Little Creek Harbor. Naval Amphibious Base, Little Creek, VA. Norfolk, VA.
Foster Wheeler Environmental Services. 1994. Draft final remedial investigation feasibility study. Naval Amphibious Base Little Creek. Livingston, NJ.
Geo-Marine, Inc. 1997. Integrated natural resources management. Prepared for the Naval Facilities Engineering Command, Naval Amphibious Base, Little Creek, VA. Newport News, VA.
US Navy. 1999. Naval Amphibious Base Little Creek. Fact Sheet.
US Navy. 2001. Proposed plan for site 9 and site 10.
US Navy. (undated). Occupational Safety and Health (NAVOSH). Navy Pediatric Lead Poisoning
Prevention (PLPP) Program. Available at: http://www.navosh.net/docs/public/22/plppnms2.pdf .
Last accessed December 20, 2002.
[NEESA] Naval Energy and Environmental Support Activity. 1984. Initial assessment study. Naval Amphibious Base, Norfolk, VA. Prepared by Rogers, Golden & Halpern for the Naval Energy and Environmental Support Activity. Philadelphia, PA.
Nielsen J. 2002. Written communication from Janice Nielsen, Installation Restoration Program Manager, Norfolk Naval Shipyard, regarding ATSDR questions.
[OHM/IT] OHM Remediation Services Corp. 2001. Project close-out report–removal of abrasive blast material solid waste management, Unit 8, Naval Amphibious Base Little Creek, Virginia Beach, Virginia.
Old Dominion University. 1992. Water quality and living resources assessments of five sites in Little Creek Harbor. Norfolk, VA: Old Dominion University; Applied Marine Research laboratory and Department of Biological Sciences.
[Target] Target Environmental Services, Inc. 1992. Soil gas survey commissary construction project. Naval Amphibious Base, Little Creek, VA. Columbia, MD.
[VDEQ] Virginia Department of Environmental Quality. 1998. Results of 1998 fish tissue
sampling of the Chesapeake Bay. http://www.state.va.us Last accessed June 21, 2002.
[VMRC] Virginia Marine Commission. 2003. Personal communication between Charles Grosse, ATSDR, and Lt. Col. Lewis Jones, Virginia Marine Resources Commission. September 16, 2003.
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