PUBLIC HEALTH ASSESSMENT
NAVAL AMPHIBIOUS BASE LITTLE CREEK
VIRGINIA BEACH, VIRGINIA
The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this public healthassessment (PHA) to evaluate the potential for harm to human health posed by hazardoussubstances at the Naval Amphibious Base (NAB) Little Creek. The NAB Little Creek, a navalsupport facility, encompasses 2,147 acres in Norfolk and Virginia Beach, Virginia, and to thenorth borders more than 2 miles of Chesapeake Bay shoreline. The U.S. government formed thebase 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 ArmedGuard 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 LittleCreek. At the time of the visits, ATSDR did not identify any environmental hazards posingimmediate 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 ofthe base contains volatile organic compounds (VOCs) such as those found in cleaning solvents.There is, however, no public exposure to groundwater contaminants. The groundwaterunderlying NAB Little Creek has never been used as a source of drinking water, nor will it beused for that purpose in the foreseeable future. NAB Little Creek and the surrounding communityreceive drinking water from municipal water supplies that draw from surface water sourcesmeeting federal and state drinking water standards. Although NAB Little Creek probably hascontributed to the pollutant load in surface water and sediment of the harbor, none of thehazardous substances are at levels that could cause long-term health effects for people who usethe harbor for boating or swimming.
ATSDR identified two main ways people might come in contact with environmentalcontamination 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 exposuresto detected contaminant levels via these pathways are expected to affect the health of people at orin the vicinity of NAB Little Creek, and developed the following conclusions about potentialexposure hazards associated with soil and fish/shellfish.
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.
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 removedsurface soil contaminants from the area. Exposure to lead has the potential to cause harmfuleffects, particularly for young children. Under certain conditions, lead-contaminated soil or dustcould have migrated from the base to a nearby off-base residential property located 100 feet fromthe 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 relevantdata against several factors that influence a child's vulnerability to lead in soil, however, suggeststhat likely exposures to lead in soil were minimal, if they occurred at all. Other possible sourcesin the neighborhood might also contribute to a child's exposure to lead, including lead-basedpaint in homes built before 1978. ATSDR believes it is prudent for families who live in or nearthe Turner Road area to evaluate the potential for their children to be exposed to lead and followthe Centers for Disease Control and Virginia Department of Health recommendations to havepotentially 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 alimited sampling of fish and crab from the harbor. Exposure to such low levels of thesecontaminants should not pose a health hazard to people who in the past ate fish or crab from theharbor. 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, theVirginia Department of Health, Division of Shellfish Sanitation, restricted shellfish (molluscanbivalves) 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 theywould 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 noshellfish taking is allowed. ATSDR corresponded with the Virginia Marine ResourcesCommission (VMRC) and NAB Little Creek about public notification of the harbor's shellfishprohibition. While signs warning the public about the prohibition are not currently posted in areascontrolled by the Navy at the harbor, the VMRC has stated that they are available to post signs orprovide signs following consultation with NAB Little Creek. Until signs are posted, peoplefollowing the advisory and the security restrictions are protecting themselves against potentialexposure 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 orremove the "No fishing and crabbing" signs for Little Creek Harbor, ATSDR recommends thatthe Navy verify, through sampling conducted prior to their removal, that edible fish and crabs inthe 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.
Naval Amphibious Base (NAB) Little Creek is located on 2,147 acres in the Tidewater region ofVirginia, near the mouth of the Chesapeake Bay. The base straddles the communities of Norfolkto the west and Virginia Beach to the east, and borders more than 2 miles of Chesapeake Bayshoreline to the north (Figure 1).
NAB Little Creek was formed in 1945 by the combining of four World War II bases: (1) theAmphibious Training Base, (2) the Construction Battalion Training Center, (3) the U.S. NavalSection Base, and (4) the Armed Guard Training Center. Today, the base is homeport to about 27naval vessels and provides on-base logistic facilities and support services to meet the amphibioustraining needs of the United States armed forces (NEESA 1984). Training performed at the baseincludes beach training, assault operations, landing craft air cushion training, and demolition andexplosives training. The Navy also conducts underwater explosive detonations in Little CreekHarbor (Geo-Marine Inc. 1997). As part of its support services exercises, NAB Little Creekmaintains military vehicles and boats and constructs and repairs buildings and harbor piers. Thebase also provides other general or miscellaneous services including routine pesticideapplications, electroplating of musical instruments, and operating a laundry and dry cleaning service.
Over the years, solid waste, industrial byproducts, paints, and plating materials have beendisposed of, released, or accidentally spilled onto soil at NAB Little Creek. Such chemicalsinclude heavy metals, polychlorinated biphenyls (PCBs), and pesticides. Some of thatcontamination has seeped into groundwater or entered nearby waterways (EPA 1999).
In 1984 a Navy Initial Assessment Study identified 17 potentially contaminated sites (NEESA1984). 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 9and 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. Nofurther 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) wereidentified, 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 onits National Priorities List. It did so mainly because of concern about contaminants potentiallyentering surface water and endangering wildlife. In September 2000, a draft Federal FacilitiesAgreement (FFA) was submitted for legal review. An FFA outlines the work required at NABLittle Creek and defines the responsibilities of the Navy, EPA, and the state of Virginia duringinvestigation and cleanup. Figures 3-8 show census information or land use, other featuresincluding floodplains and locations of SWMU and Sites
Through the public health assessment (PHA) process, ATSDR assesses site conditions at NPLsites from a public health perspective. That is, ATSDR determines whether people can be exposedto 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 onFebruary 11-13, 2002. ATSDR collected information necessary to rank the NAB Little Creekaccording to its potential public health hazard, to identify public health issues related toenvironmental contamination at the base, and to identify community health concerns. During thevisit, 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 atNAB Little Creek requiring immediate attention. ATSDR did, however, identify potentialexposure pathways that needed further study. ATSDR prepared this public health assessment toevaluate 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 communityconcerns listed in the base's community relations plan, and generally reviewed concernsexpressed by the community. In June 2000, ATSDR prepared a health consultation to addressspecific community concerns about exposures associated with NAB Little Creek. ATSDRconcluded in the health consultation that NAB Little Creek posed little threat of imminent healthhazard to the public (ATSDR 2000).
ATSDR examines demographic data (i.e., population information) to determine the number ofpeople potentially exposed to environmental chemicals and to determine the presence of sensitivepopulations, 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 toenvironmental chemicals.
In addition to demographic information, ATSDR examines the many ways in which people nearNAB Little Creek might use the land and its natural resources. ATSDR does this to determinewhat activities might put people at risk for exposure. This information is important because thetypes and frequencies of activities and land use affects exposure to contamination. In this PHAATSDR uses this information as part of the evaluation of contamination and exposure. Bothdemographic 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 VirginiaBeach 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 whoarrive at the base for amphibious training. About 3,600 military personnel at NAB Little Creekand family members live in on-base housing, which consists of 954 units located at one of sevenhousing areas. Another 1,667 military personnel live in on-base barracks. School-age childrenattend 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 livedwithin a 1 mile buffer around NAB Little Creek, with 4,371 children under 6 years of age and2370 adults age 65 and older (see Figure 3A). As of 2000, a total of 31,230 persons were livingwithin 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 elevationcontours at the base. Land at NAB Little Creek tends to slope toward water bodies. On thewestern 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 thebase are developed, with about 600 buildings and 400 structures (see Figure 5). Only a smallportion of the property remains covered with grass or other vegetation. The Area around NABLittle 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 LittleCreek Cove or Desert Cove of the harbor area along the western portion of the base. Water fromboth 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 LittleCreek Harbor. The low and relatively flat areas adjacent to coastal waters fall within a 100 yearand 500 year floodplain (see Figure 6). Surface water from the base flows through wetlands beforeactually discharging into the harbor (see Figure 7) (NEESA 1984). Lakes at the base include LakeBradford, 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 theon-base canals. These canals eventually drain into Little Creek Cove. For example, overflow fromthe Little Creek Reservoir and the Lake Whitehurst Reservoir is released to Little Creek Cove bycanals. The 4,000 foot canal connecting Little Creek Reservoir to Little Creek Cove borders alandfill (NEESA 1984, Geo-Marine 1997).
Fishing and shellfishing are not allowed on the NAB Little Creek property at Desert Cove, LittleCreek Cove, Little Creek Channel, Varian Lake, or Chub Lake. Fishing is, however, permitted atthe on-base Lake Bradford and Little Creek Channel, outside the base's boundaries, and in theChesapeake Bay, outside the harbor (NEESA 1984, Mike Tate, Manager of Little Creek MarinaHarbor, 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). Thesestormwater outfalls are subject to the Virginia Pollutant Discharge Elimination System (VPDES),a permit program that controls water pollution by regulating sources discharging into surfacewater. NAB Little Creek's VPDES permit contains limits on what can be ultimately dischargedinto the harbor and specifies acceptable levels of any pollutant in that discharge. According toprovisions of the VPDES, the Navy is required to routinely sample its stormwater discharges andto notify Virginia Department of Environmental Quality (VDEQ) of its results. Collectively, theseprovisions ensure that the discharges entering Little Creek Harbor's are safe and that public healthis protected.
At the base and in the communities of Norfolk, Virginia Beach, and Chesapeake drinking water isprovided 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 ofthese drinking-water reservoirs are within a few hundred of feet of NAB Little Creek. Still, noneof the potential sources of contamination at the base drains to these reservoirs or surface waterbodies, and the water is treated and tested to ensure that it meets safe drinking water standards.
In preparing this PHA, ATSDR reviewed and evaluated information provided in the referenceddocuments. Documents prepared for the CERCLA program must meet standards for qualityassurance 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 remedialinvestigations. Based on our evaluation, ATSDR determined that the quality of environmentaldata available in base-related documents for NAB Little Creek was adequate for making public health decisions discussed in this document.
ATSDR identified two main ways those at or near NAB Little Creek could possibly come into contact with contaminants originating from the base.
MAIN EXPOSURE CONCERNS AT NAB LITTLE CREEK
ATSDR analyzed environmental data for each of NAB Little Creek's installation restorationprogram (IRP) sites to determine if identified exposures could be past, present, or future publichealth hazards. Table 1 provides a description of each IRP site at NAB Little Creek and asummary of ATSDR's evaluation. Our review indicated that most IRP sites at NAB Little Creekare not associated with any known public health hazards. Many IRP sites are surrounded byperimeter fencing, covered surfaces, or both (e.g., vegetative growth, paved areas); these preventor reduce potential exposure to contaminated soil. At other locations, harmful exposures arelimited because either no site-related contaminants are present where exposure to the public couldoccur, or detected contaminant concentrations are too low to pose a health hazard. For somelocations where levels were high enough to be a concern to regulators, cleanup efforts havesuccessfully removed contaminated soil.
In the discussion that follows, ATSDR further evaluated environmental monitoring data andexposure information for the two main exposure scenarios to determine whether contact fromeither would result in harmful effects. ATSDR states the exposure concern associated with thecomplete or potential exposure pathway identified above, presents a brief summary ofconclusions, and describes in more detail any identified exposure pathways and the basis for theconclusions. ATSDR's evaluation is also summarized by exposure situations in Table 2. In theCommunity Health Concern section, ATSDR discusses potential hazards associated with thesubsurface soil gas near the Base Exchange and the use of the base golf driving range and baseballdiamond. To acquaint the reader with terminology and methods used in this public healthassessment (PHA), Appendix A provides a glossary of environmental and health terms presentedin 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.
Contaminants, such as lead, arsenic, and polychlorinated biphenyls (PCBs), have been detectedin surface soil at various IRP sites across NAB Little Creek. ATSDR believes that harmfulexposures to contaminated soil at most areas of the base are largely prevented. The land surfaceis either paved, covered by grass or buildings, lies in restricted land use areas, or thecontamination has been removed.
In November and December 2000, the Navy removed surface soil contaminants from a formergrit-blasting area and Water Tower 1553, where lead was detected frequently and at levels ofhealth concern. Exposure to lead has the potential to cause harmful effects, particularly for youngchildren. Children living in base housing, however, are not likely to come into contact with leadin soil at the grist blasting area/water tower, as base housing areas are located away from thissource of contamination.
An off-site residential neighborhood is located 100 feet from Water Tower 1553. Site-specificinformation does not exist to confirm whether, or to what extent, lead from the grit-blastingarea/water tower settled on nearby property. However, matching the relevant environmental datacollected near the water tower against several factors that influence a child's vulnerability to leadin soil suggests that likely exposures to lead in grit-blasting material were minimal, if theyoccurred at all. Other possible sources in the neighborhood might also contribute to a child'soverall exposure to lead, including lead-based paint in homes built before 1978. The CDC andVDH recommend that young children be assessed for lead exposure. ATSDR believes it is prudentfor families who live in or near the Turner Road area to also evaluate the potential for theirchildren to be exposed to lead and follow the CDC and VDH recommendations.
NAB Little Creek maintains vehicles and ships and in the past, also constructed and repaired theharbor piers. Some of these activities and associated waste disposal practices inadvertentlyreleased contaminants onto the ground surface (NEESA 1984). Areas of greatest concern are:
- Abrasive Blasting Grit or Sandblasting Areas: Several SWMUs are the sites of formership maintenance activities, which included sandblasting and metal grinding. Many of theareas lacked release controls and, prior to removal, stored spent sandblasting grit onunpaved surfaces.
- Water Towers: Three base water towers constructed in the 1940s were maintained withlead-based paint. During repainting procedures, including those in the 1940s, 1950s, and1960s, the exteriors of the towers were sandblasted to remove the paint layers. Some of thepaint scrapings fell onto the ground around the towers. It is possible that duringsandblasting activities some of the scrapings became airborne and traveled from the towersto nearby recreational and residential property.
- Landfills and Operational Areas: Materials disposed of at base landfills or released frombase operations have contaminated on-base soil. Contaminated soil from base landfillscould have migrated with overland surface water flow. The landfills have been coveredwith soil and closed, and some landfills also have future land use restrictions in place.
The Navy sponsored site and remedial investigations intended to characterize the type and amountof contamination in soil at base locations where contamination was suspected. Surface soilsamples collected from IRP sites at the base were found to contain metals, semivolatile organiccompounds (SVOCs), PCBs, and pesticides. Figure 2 shows following areas with ABM residuecontamination 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-blastingarea (SWMU 8) and at one of the base's water towers (1553) (see Figure 8). Of the contaminantsdetected, lead appeared frequently and in concentrations well above health concern levels (up to1,820 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 andresidue storage. Residue of reddish-brown abrasive blast material (ABM) and paint chips releasedfrom 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 avacant lot.
The sandblasting area is located adjacent to Water Tower 1553. Constructed in the 1940s, thewater tower was maintained with lead-based paint for a majority of its use. During repaintingprocedures, the exterior of the tower was sandblasted to remove the existing layers of paint. Someof the sandblasting residue fell onto the ground around the tower. Turner Road, a residential andcommercial neighborhood, borders the base perimeter fence line near the water tower area. About100 feet separates the nearest home from the water tower.
During a preliminary field investigation in March2000, the Navy visually delineated the extent ofABM in the area of SWMU 8 and the water tower(CH2M Hill 2000). No ABM material wasobserved within 50-75 feet of the fence lineseparating NAB Little Creek from the adjacentTurner Road residential property.
Since detecting elevated contaminantconcentrations in surface soil at SWMU 8 and thewater tower, the Navy has taken measures to reducethe contamination and any possible humanexposure. Actions conducted in November andDecember 2000 included the removal from SWMU8 and the nearby water tower of surface soil debriscontaining exposed ABM and contaminated soil.More than 4,500 tons of soil were removed toreduce lead levels to less than or equal to 400 ppm. Excavated material was shipped to an off-basedisposal area. Confirmatory soil sampling following excavation within the delineated areaconfirmed that lead concentrations were below the EPA residential risk based concentration of400 ppm. The confirmatory sampling also showed that no other constituents exceeding cleanupstandards were left in place (NEHC 2003). Excavated areas were backfilled with certified-cleanfill and covered with top soil and seeded (OHM/IT 2001). ATSDR noted during its February 2002site visit that the grit (with the exception of sporadic occurrences of grit residue) had beenremoved 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 ofpotential health hazards focuses on whether children at or near NAB Little Creek could come incontact with harmful levels of site-related lead in surface soil. Children at potential risk ofexposure include (1) children living in on-base housing and (2) children living in the Turner Roadneighborhood near Water Tower 1553. ATSDR assesses potential hazards by considering howoften and how long the exposure at base housing or in the Turner Road area might have occurredand what contaminant concentrations might have been present in the soil at any likely point ofcontact. The evaluation is described below.
NAB Little Creek ExposuresSWMU 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 limitedand continues to limitunauthorized 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 SWMU8 and Water Tower 1553, eliminating future exposures. Those remedial actions were conductedwith 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 notassociated with any known public health hazard for children who live in on-base housing atNAB Little Creek.
Off-Base Exposures--Turner Road Neighborhood
Residue of reddish-brown and darker abrasive blast material and paint chips were released duringsandblasting operations at SWMU 8 between 1949 and 1971. Lead-paint chips were alsodislodged from the exterior of the tower during maintenance activities after the 1940s. Undercertain conditions (e.g., meteorological) during water tower sandblasting or operations at SWMU8, lead might have deposited on soils in the nearby Turner Road residential property. Informationcharacterizing whether or to what extent lead from these operations settled on soil within theadjacent neighborhood is not available. Without this information, ATSDR does not know withcertainty whether site-related lead exposure occurred at these yards. As a prudent public healthmeasure, ATSDR evaluates possible exposure of nearby residents to lead in soil in the discussionbelow.
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 Roadneighborhood:
- The Navy's Pediatric Lead Poisoning Prevention (PLPP) program. Since approximately1992, the Navy has operated a PLPP program that calls for physicians to administer annualquestionnaires to guardians of children 6 years of age and younger, starting at their age-1check-up. It also calls for blood-lead testing of all children at age 1, and of older childrencategorized as high risk on the basis of the questionnaire responses (NAVOSH n.d.,Nielsen 2002b). Routine blood-lead testing by NAB Little Creek health officials at BooneClinic between 1995 and 1999 disclosed no elevated blood-lead levels among children.
- The Lead Safe Virginia program. VDH's childhood lead-poisoning prevention program isknown as Lead-Safe Virginia. Currently, the program recommends that physiciansevaluate the risk for exposure to lead in all children at 1 year of age and again at 2 years ofage, as well as any children 3 to 5 years of age who have not previously been evaluated. Ablood-lead screening test is recommended for all at-risk children, including children whoseadult parent or guardian's job or hobby involves exposure to lead, children living in ahome built before 1978 that is undergoing renovation or has deteriorating paint, andchildren living in selected "high-risk" ZIP codes (VDH 1999). The Lead Safe Virginiaprogram has the potential to serve non-Navy families living near the Turner Roadneighborhood. Because, however, the program does not call for universal screening, itwould not necessarily reach all potentially affected families.
Data about the populations served by the Navy's PLPP program and the Lead Safe Virginiaprogram (including the percentage of children screened and the time period over which thescreening occurred) and the results of any blood-lead screening of children who lived in or nearthe Turner Road area would allow ATSDR to provide greater perspective about the potential foradverse health effects to have occurred as a result of exposure to lead. Without these data, we canonly estimate likely exposure based on factors that influence contact with contaminated soil and achild'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 aslead in surface soil. Soil sampling data are not available to confirm whether or to what extentresidential property soil contains site-related lead. Several factors, however, help ATSDRdetermine whether lead from SWMU 8 and the water tower might be present in areas wherechildren play.
- Age/location of home. Homes along Turner Road constructed before or during the time ofactive sandblasting operations at SWMU 8, the water tower or both (roughly 1940-1971)and in close proximity to the fence line near SWMU 8 and Water Tower 1553 could havebeen impacted by lead releases. Over time, lead released to the air could build up in soil.Lead deposited from the air is generally retained in the top 1 inch of soil. (Opportunitiesfor exposure are therefore much greater for surface soil than for subsurface soil.) Homesbuilt after sandblasting operations ceased (roughly after 1971) probably have less, if any,exposed site-related soil-lead contamination. Moreover, any contamination that migratedto off-base properties would likely have been turned over during construction, therebymoving lead residue down to deeper, more inaccessible subsurface soil layers.
- Presence of soil cover. Grass and other soil covers (e.g., asphalt, pavement) in a child's play area greatly minimize or eliminate direct contact with soil that could contain lead.
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 theTurner Road neighborhood, is an involved process. Health professionals typically consider severalfactors that influence the relationship between that exposure and blood-lead levels that couldresult 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.
- Concurrent exposure to other sources of lead. Lead from other sources can also contribute to a child's increase in blood-lead level and the risk of developing health effects. For example, lead can be deposited in soil from flaking lead paint around the home, can be released to air from motor vehicles that used leaded gasoline, or can leach into drinking water from lead pipes.
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.
ATSDR reviewed the limited sampling data to determine whether people could be eatingcontaminated fish or shellfish from Little Creek Harbor. The data available to ATSDR suggestthat fish and crabs in the Little Creek Harbor have been impacted by chemical contaminants suchas mercury, but at levels below those known to cause harmful health effects. No other informationis available for other shellfish, including clams and oysters. There is no way, however, todetermine how much of those contaminants originate from NAB Little Creek operations. Othernon-base-related sources could contribute to the harbor pollution.
Shellfishing has been restricted since 1938 and prohibited since 1990 in Little Creek Harbor dueto high levels of bacteriological contamination (NEESA 1984, CH2M Hill 2001a). Fishing andcrabbing is not permitted at NAB Little Creek for security reasons. People following therestrictions are protecting themselves against potential exposure to biologic and chemicalcontaminants in fish and shellfish. Although commercial fishing is not allowed, sport fishing iscommon in the western, civilian half of the harbor. Should the Navy's future plans includeremoval of the signs for Little Creek Harbor, ATSDR recommends that the Navy verify, throughsampling conducted prior to the signs' removal or lifting security restrictions, that seafood in theharbor are free from harmful levels of chemical contaminants and are safe to eat. If the harbor isdredged the sampling should be repeated.
Little Creek Harbor and its Tributaries
Contamination has been detected in the water and sediment of Little Creek Harbor, includingmetals (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 (OldDominion University 1992, ETS 1995). Contaminants from these areas could have been carriedwith groundwater and discharged into the surface water of Little Creek Harbor. Othercontaminants have been released into channels that eventually discharge into Little Creek Harbor.
Several IRP sites at NAB Little Creek ultimatelydrain to Little Creek Harbor. For example,runoff from Site 7, a former landfill, drains via adrainage ditch to Little Creek Cove. Site 7 wasonce an arm of Little Creek Cove, but was filledwith dredged soil before it was used as a landfill.The majority of the waste at the landfill likelyconsisted of municipal refuse. Potentiallyhazardous materials disposed of at the landfillinclude paints, acids, PCBs, and pesticides(NEESA 1984, EPA 1999). Site 12, the former Exchange Laundry Waste Disposal Area, dumpedwaste containing tetrachloroethylene (PCE), soap,and dyes into a catch basin, which emptied into astorm sewer. The sewer flows north form this siteinto a 9-foot-deep drainage canal connecting withLittle Creek Cove. Contaminants, primarilymetals, have been found in sediment along thedrainage canal (NEESA 1984). (It is also important to note that the drainage canal stops about3,000 feet before the Little Creek Cove and the surface water flows through wetlands beforeactually discharging into the harbor.) Other IRP sites include landfills at Sites 8, 9, and 10; aplating 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 andsediment. A number of non-base-related contaminant sources also contribute to contamination inthe 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). Limitedinformation is available on contaminant concentrations in fish and crabs inhabiting the harbor. In1994 and 1995 NAB Little Creek collected fish (croaker and spot) and crab samples from theharbor. The samples were analyzed for mercury and tributyltin (see Table 3). Those contaminantswere selected because of their presence in harbor sediment and, particularly for mercury, theirability to accumulate at high levels in fish and shellfish over time. The study found mercury infish (0.132-0.148 ppm) and crab (0.097-0.225ppm) in the samples obtained from the harbor(Baker Environmental, Inc., 1996). Tributyltinwas only detected in fish (0.006 ppm) andcrab (0.028 ppm) samples collected in 1995.Additional limited information is providedthrough the VDEQ 1998 fish samplingprogram along the Chesapeake Bay. As partof that sampling event, VDEQ collected andanalyzed for PCBs two Little Creek Channelfish samples (mummichog and spot). PCBconcentrations in the samples were 0.062 ppmand 0.127 ppm (VDEQ 1998).
ATSDR has reviewed the scientific literatureto gain a better understanding of the extent towhich fish can accumulate mercury, tributyltin, and PCBs. EPA has compiled data on averagemercury concentrations in fish commonly consumed by the U.S. population. A review of thesedata suggests that the average concentration of mercury in flat fish (such as spot or flounder) andblue crabs is 0.092 ppm and 0.117 ppm, respectively (ATSDR 1999d). A 1980-1981 survey bythe U.S. Fish and Wildlife Service found the average concentration of PCBs in fish at 102nationwide locations was 0.53 ppm. Another study by the EPA, conducted between 1986 and1989, reported chemical residues in fish at 362 sites nationwide, including industrial andhazardous waste sites. In the study, PCBs were detected at an average concentration of 1.9 ppm inbottom feeding and game fish (ATSDR 2000b). By comparison, PCB concentrations in LittleCreek Harbor fish appear to fall within the range observed nationwide in the 1990s. But mercuryconcentrations in fish from the harbor appear to be slightly higher than levels typical in fish oflike species.
Shellfishing has been restricted since 1938 and prohibited since 1990 in Little Creek Harbor dueto high levels of bacteriological contamination (NEESA 1984, CH2M Hill 2001a). The Navy hasprohibited fishing and shellfishing at Little Creek Cove, Desert Cove, and Little Creek Channel onNAB Little Creek property for security reasons. Fishing is, however, allowed at sections of LittleCreek Channel lying outside NAB Little Creek property and in the Chesapeake Bay, outside theharbor.
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 whetherfish or shellfish including crab were ever harvested at NAB Little Creek or whether anyrecreational fishing or shellfishing takes place now in the freshwater, brackish, and saltwaterbodies.
Evaluation of Potential Public Health Hazards
In 1994, 1995, and 1998 mercury, tributyltin, andPCBs were detected in fish and crab samplescollected from Little Creek Harbor. Some of thechemical contamination in fish possibly originatedfrom base-related activities. Still, additional sourcesof chemical pollutants include other naval activities(i.e., dredging, fueling operations, ship salvage andmaintenance) and non-naval activities (i.e., railroadferry, barge loading/unloading, private boatrefurbishing).
Shellfishing has been restricted since 1938 andprohibited since 1990 in Little Creek Harbor due tohigh 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 theywould 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 noshellfish taking is allowed.
To determine if the consumption of fish or shellfish containing the detected levels of chemicalcontaminants was or is detrimental to human health, ATSDR estimated doses for individuals whoate fish from the harbor in the past, or who continue to do so against restrictions in place at theharbor. Because uncertainty exists regarding how often people ate fish from the harbor and howlarge 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 theamount 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 consumedcontained the highest probable level of contamination. Collectively, those health-protectiveassumptions allow ATSDR to evaluate safely the likelihood, if any, that eating harbor fish andshellfish 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 likelihoodif anythat 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 arelower than their respective screening values (ATSDR MRLs or EPA RfDs), and below levelsassociated with adverse health effects. This finding suggests that people who ate fish, shellfish, orcrabs containing the detected levels of contaminant in the past are not at risk of developingadverse health effects. Contaminants such as mercury are persistent in the environment. Since theinitial sampling in 1994-1995, the levels in fish may have increased or decreased. Thus as aprudent public health measure, ATSDR recommends that people minimize current and potentialfuture exposure to chemical contaminants by following the restrictions for the NAB Little CreekHarbor.
Should the Navy's future plans include removal of the "No fishing and crabbing" signs for LittleCreek Harbor, ATSDR recommends that the Navy verify, through sampling conducted prior totheir removal, that edible fish and crabs in the harbor are free from harmful levels of chemicalcontaminants and are safe to eat. At that time, the Navy in cooperation with VDH might find itprudent to determine chemical pollutant impact on the shellfish population near NAB LittleCreek. 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 harborshoreline. ATSDR has talked with the Navy and the Virginia Marine Resources Commission(VMRC) about providing sufficient notification to the public about the harbor's shellfishprohibition. The VMRC has offered to provide or place signs relative to shellfish bacterialcontamination 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 personneland a review of base documents. A Restoration Advisory Board was formed in 1994. Thefollowing concerns have been identified:
- Concern about harmful levels of indoor air contaminants entering the BaseExchange/Commissary from underlying groundwater plumes.
- Concern about exposure to contaminants when using the base golf driving range or the baseball diamond.
- Age of the landfill. Gases are usually emitted within 20 years after the waste is disposed of, peaking within 5-7 years after disposal. Only small volumes of gases would be expected after 50 or more years. Given this information, older landfills, such as those beneath the driving range and the baseball diamondwhich accepted refuse almost 50 years agoare beyond the age at which they should still generate substantial volumes of gases (ATSDR 2002a). However, this has not been verified.
- Waste composition. The more organic waste present in the landfill, the morelandfill gases (e.g., methane and carbon dioxide) produced by bacterialdecomposition. The contents of the landfills are reported to include organiccompounds found in solid waste, household waste, and industrial waste.Nevertheless, groundwater monitoring indicates that VOCs are not present in thelandfills. Therefore, these landfills are not likely to emit landfill gases that arecreated when VOCs change from liquids into vapors (ATSDR 2002a).
- Presence of an impervious cap. Protective impervious landfill caps tend to inhibit upward movement of certain gases. When upward movement is inhibited, these gases, such as methane, can move laterally out from beneath the landfill and build up in surrounding areas with lower gas concentrations. Build up of high levels of methane can pose an explosive hazard. The landfills at NAB Little Creek are not covered with an impervious cap, but rather with a 2-foot layer of soil. This soil layer should not inhibit the upward movement and diffusion of any remaining small volumes of landfill gases (NAB Little Creek 2001, ATSDR 2002a).
- Proximity of buildings. Finally, and perhaps most importantly, there are no nearby buildings within the immediate area of either former landfill that would be at risk of accumulating landfill gases.
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 nearbysurface water channel. Surface water and groundwater sampling has shown that the waterin and beneath the channel is free of VOCs. VOCs in groundwater near the BaseExchange/Commissary also move toward a leaky sanitary sewer line. At the exit briefingfor ATSDR's 1999 site visit, ATSDR recommended that the Navy conduct periodicsampling 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 formertrench-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 aspesticides, PCBs, and motor oil, could have also been disposed of in the landfills. Afterclosure each landfill was covered with 2 feet of vegetative soil cover. The soil coverprevents 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 thelandfill cover and pose unacceptable harm to the public. The land use limits would restrictany: (1) digging into the cover or contents of the landfill, (2) use of groundwater beneaththe sites, and (3) development of the site for residential use. As long as the cover on eachlandfill is undisturbed, ATSDR does not anticipate any public exposure to the materialscontained within the landfill in the future. Leachate seeps have not been identified at theground 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-methaneorganic 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 smalleramounts of non-methane organic vapors (e.g., VOCs) (ATSDR 2002a). Sometimes thesegases can pose hazards when they travel through the soils and then upward into the indoorair of nearby buildings. Residents living in these buildings could then incur exposure whenbreathing air containing the contaminants. On occasion, these gases can also pose anexplosive hazard. Several factors greatly influence how much gas a landfill currentlyreleases and whether any gas releases might pose a public health hazard. A review of thesefactors 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, ATSDRexpects that people using either the golf range or the baseball field today will not reasonably comein 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 gasesbefore constructing any future buildings near the former landfills.
ATSDR's Child Health Considerations recognizes that the unique vulnerabilities of infants andchildren 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 tohazardous substances emitted from waste sites and from emergency events. In general, childrenare more likely to be exposed because they play outdoors and they often bring food intocontaminated areas. They are shorter than adults, which means they breathe dust, soil, and heavyvapors close to the ground. Children are also smaller, so they receive higher doses of chemicalexposure proportional to their body weight. The developing body systems of children can sustainpermanent damage if toxic exposures occur during critical growth stages. Most importantly, mostchildren depend completely on adults for risk identification and management decisions, housingdecisions, and access to medical care.
ATSDR has attempted to identify populations of children in the vicinity of NAB Little Creek andany completed exposure pathways to these children. The community surrounding NAB LittleCreek contains residential neighborhoods with children and schools. Demographic data for 2000indicate that 3,468 children under 6 years of age live in communities within a 1-mile radius of theNAB Little Creek. Children in these communities cannot easily trespass onto NAB Little Creekproperty due to perimeter fencing and military security measures.
Following a careful evaluation of these pathways as they relate to children, ATSDR determinedthat no harmful exposures have occurred at NAB Little Creek in the past, nor are they expected tooccur–either now or in the future. Although contaminants have been detected at NAB LittleCreek, 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, childrenmight eat fish and seafood taken from Little Creek Harbor. If children do eat locally caughtfish/shellfish/crabs, they could be exposed to low levels of chemicals present in that fish andseafood. ATSDR recommends that children and parents observe the restrictions and advisory forLittle Creek Harbor.
Lead-contaminated soil or dust might have migrated from the former grit-blasting area and fromthe 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 toconfirm whether or to what extent exposure has occurred. ATSDR believes, however, that mostchildren playing in the neighborhood have not come in contact with harmful levels of lead fromNAB Little Creek. Depending on factors influencing exposure (e.g., age of home, age of child atexposure, play habits, concurrent lead exposures), certain children could be at greater risk ofdeveloping lead-related effects. ATSDR recommends blood-lead screening for all children age 6and younger as recommended by CDC and VDH. These exposure pathways are discussed in theEvaluation of Environmental Contamination and Potential Exposure Pathways section of this PHA.
Conclusions regarding potential past, current, and future exposure situations on and in thecommunities near NAB Little Creek are based on an evaluation of site investigation data andobservations made during site visits. Conclusions about exposures are described below. (Adescription of the public health hazard conclusion categories is included in the glossary.)
- Surface soil at certain locations at NAB Little Creek was found to contain contaminantsassociated with former base activities. Most often, exposure has been prevented becausesoil contamination occurs in restricted access areas, is covered by pavement or grass, orhas been removed. Occasional contact with surface soil contaminants, even at the highestlevels 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 harmfulfuture exposures. Exposure to contaminants in surface soil at NAB Little Creek poses no apparent public health hazard.
- SWMU 8 and Water Tower 1553 are located about 100 feet from the Turner Roadneighborhood. Airborne lead or resuspended lead-contaminated soil/dust (activesandblasting operations at SWMU 8 or sandblasting during lead-paint removal or otherwater tower maintenance operations) could have migrated off site. Data are not availableto confirm whether site-related lead settled in nearby residential yards in the past. ATSDRevaluated available on-site data and possible exposure situations to assess possible healthhazards associated with lead. Based on this assessment, ATSDR concluded that peopleliving in the Turner Road neighborhood probably incurred minimal, if any, exposure tosite-related lead in soil or lead dust for several reasons. Foremost, soil has been covered atneighboring properties over the years with top soil, grass, or pavement. For some off-baseproperties, potentially contaminated soil has possibly been removed. For others, the soilwas turned over or otherwise disturbed during home construction, which has had the effectof moving lead that settled on the surface down to the deeper, inaccessible subsurface soil.No exposure is occurring now. Operations that produced airborne lead or resuspendedlead-contaminated soil/dust stopped after 1971. Exposure to contaminants possibly insurface soil from base operations at Turner Road neighborhood near NAB Little Creekposes no apparent public health hazard.
- Homes built before 1978 probably have lead-base paint. ATSDR believes it is prudent forfamilies who live in or near the Turner Road neighborhood area to evaluate the potentialfor they and their children to be exposed to lead. Families should also follow the CDCand VHD guidelines and have potentially exposed children under the age of 6 screened forelevated blood-lead levels.
- Low levels of mercury, tributyltin, and PCBs have been found in a limited sampling of fishand crabs from the harbor. Exposure to the low levels of those contaminants should notpose a health hazard to those who in the past ate fish or crabs from the harbor. Otherchemicals have not been tested. Shellfishing (molluscan bivalves) has been restricted since1938 and prohibited since 1990 in Little Creek Harbor due to high levels of bacterialcontamination. Fishing and crabbing are not permitted at NAB Little Creek for securityreasons. Still, people can best protect themselves from exposure to chemical and bacterialcontaminants in fish and shellfish by adhering to the existing restrictions for the harbor.Consumption of fish, crabs, and shellfish from Little Creek Harbor is expected to pose noapparent public health hazard for the chemical contaminants sampled.
- Based on previous studies which indicate that older landfills, such as those beneath the driving range and base ball diamondwhich accepted refuse almost 50 years agoare beyond the age at which they should still generate substantial volumes of gases. ATSDR concluded that the landfills at NAB Little Creek pose no apparent health hazards.
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).
- If additional soil sampling is to be conducted, ATSDR recommends that the Navy consider sampling surface soil at residential property near SWMU 8 and Water Tower 1553.
- Because some homes in the Turner Road neighborhood were constructed when lead-basedpaint was commonly used, ATSDR believes that it is prudent for families who live in theneighborhood to evaluate the potential for they and their children to be exposed to lead.Families and individuals should follow the CDC and VDH recommendations to havepotentially exposed children under 6 screened for elevated blood-lead levels.
- ATSDR also recommends that NAB Little Creek, in cooperation with the Virginia MarineResource Commission, and Virginia Department of Health provide public notificationabout the shellfish (molluscan bivalves) prohibition at 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 Virginia Department of Health might find it prudent to determine chemical pollutant impact on the shellfish (molluscan bivalve) population near NAB Little Creek if shellfish prohibition is lifted. If the harbor is dredged the sampling should be repeated.
- As prudent public health measure ATSDR recommends that the Navy consider potentialmovement of landfill gases before constructing any future buildings near the formerlandfills.
The Public Health Action Plan (PHAP) for NAB Little Creek contains a description of actionstaken and those to be taken by ATSDR, the Navy, the EPA, and Virginia Department ofEnvironmental Quality at and in the vicinity of the site after the completion of this public healthassessment. The purpose of the PHAP is to ensure that this public health assessment not onlyidentifies public health hazards, but also provides a plan of action designed to mitigate andprevent adverse human health effects resulting from exposure to hazardous substances in theenvironment. The public health actions completed, being implemented, or planned are as follows:
- Under the Installation Restoration Program, the Navy has identified and conducted, orplans to conduct, environmental investigations at 17 base locations.
- Additional monitoring or mitigation was recommended or conducted at site 8. No furtheraction was recommended at Sites 1, 2, 4, 5, 6, 14, 15, and 16. (Sites 3 and 17 are under anon-Comprehensive Environmental Response, Compensation, and Liability Act[CERCLA] program.)
- The Navy has identified more than 140 potential Solid Waste Management Units(SWMUs), and has recommended further investigations at 5 SWMUs of greatest concern.
- Long-term groundwater monitoring is underway at Sites 7, 9, and 10.
- The Navy has removed contaminated soil, covered and revegetated the area, or both atformer landfill Sites 7, 9, and 10.
- In 1987 Navy Building 3323 at Site 12 was demolished and the catch basin and a portionof the storm sewer were removed. Eventually the rest of the storm sewer was removed andthe area was regraded to prepare for the construction of the Base Exchange/Commissary.A 1992 soil gas survey found that soil gas concentrations were not elevated near the newCommissary. Still, the Navy installed a passive gas removal system beneath the newbuilding that was constructed in 1993.
- The Navy removed the surface soil debris containing visible abrasive blast material andcontaminated soil from SWMU 8 and nearby Water Tower 1553. More than 4,500 tons ofsoil was removed to levels less than or equal to 400 ppm. Excavated areas were backfilledwith certified clean fill and covered with top soil and seed.
- In 1996 and 2002, the Navy prepared a community relations plan (CRP) providingguidance for community involvement in the remediation process. Subsequent to the CRP,the Navy sponsored community interviews to gain a better understanding of communityawareness of environmental issues at NAB Little Creek. Restoration Advisory Boardmeetings are scheduled quarterly to semi-annually to inform the community ofenvironmental restoration activities. NAB Little Creek also maintains an active Web siteto provide information.
Ongoing and Planned Actions
- The Navy will continue monitoring groundwater at Sites 7, 9 and 10.
- The Navy will continue to monitor groundwater near Site 11, 11A, 12, and 13 and evaluate multiple options for groundwater remediation in the Feasibility Study.
- The municipal water suppliers regularly monitor their water supply to ensure that the waterdelivered to their customers, including NAB Little Creek, is free from contamination atlevels of health concern. Regular monitoring includes collecting samples fromgroundwater supply wells and analyzing the samples for volatile organic compounds.
- Members of the community and the NAB Little Creek participate in regularly scheduledRestoration Advisory Board meetings. These meetings serve as a forum forcommunication of ongoing and planned activities at NAB Little Creek to the communityand for communication of community concerns to NAB Little Creek personnel.
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
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.
Regional Representative, Region III
Agency for Toxic Substances and Disease Registry
GIS mapping assistance in the preparation of this report was provided by:
Paul Calame, B.S.
ATSDR, OAA, Spatial Analysis Activities Group.
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
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 andHuman Services.
[ATSDR] Agency for Toxic Substances and Disease Registry. 1999e. Toxicological profile formercury(update).
[ATSDR] Agency for Toxic Substances and Disease Registry. 2000a. ATSDR Health consultationregarding 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 forpolychlorinated biphenyls (PCBs) (update). Atlanta: US Department of Health and HumanServices.
[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 LittleCreek. 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 AnnexSandblast Area. NAB Little Creek. Herndon, VA
CH2M Hill. 2001a. Final baseline (step 3) ecological risk assessment IR sites 9 and 10. NABLittle Creek. Herndon, VA.
CH2M Hill. 2001b. Final remedial investigation/human health risk assessment/focused feasibilitystudy for sites 9 and 10. NAB Little Creek. Herndon, VA.
[EPA] Environmental Protection Agency. 1999. Support document for the revised National PrioritiesList–final rule. Washington, DC.
[EPA] Environmental Protection Agency 2000. Guidance for assessing chemical contaminant datafor use in fish advisories. Washington, DC: Office of Water; EPA23-B-00-008.
[EPA] Environmental Protection Agency. 2001a. Residential lead hazard standards - TSCA section403. 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 FacilitiesEngineering 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 PoisoningPrevention (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 NavalEnergy and Environmental Support Activity. Philadelphia, PA.
Nielsen J. 2002. Written communication from Janice Nielsen, Installation Restoration ProgramManager, Norfolk Naval Shipyard, regarding ATSDR questions.
[OHM/IT] OHM Remediation Services Corp. 2001. Project close-out reportremoval 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 constructionproject. Naval Amphibious Base, Little Creek, VA. Columbia, MD.
[VDEQ] Virginia Department of Environmental Quality. 1998. Results of 1998 fish tissuesampling 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.