PUBLIC HEALTH ASSESSMENT
CHERRY POINT MARINE CORPS AIR STATION
CHERRY POINT, CRAVEN COUNTY, NORTH CAROLINA
A. IRP Sites - No Public Health Hazard
The 32 IRP sites do not present public health hazards because access to the sites is restricted or limited (thus exposure to contamination is not expected), migration of contaminants to areas where exposure might occur is not expected, and/or they have already been cleaned up. A summary of the IRP sites and ATSDR's evaluation of why they are not a public health hazard is in Appendix A. On-going and planned remediation at the station is designed to prevent any future exposures.
The major sources of groundwater contamination at the station are in the industrial area [Naval Aviation Depot (OU-1) - See Figure 1]. Contamination has been detected in the upper aquifers which are not used as a drinking water source. The groundwater contamination plumes radiate outward from the industrial area toward the creeks and the Neuse River. Sources of groundwater contamination are highlighted in Appendix A.
The Town of Havelock is upgradient from MCAS Cherry Point, thus its water supply should not be impacted by groundwater contamination from the station. Furthermore, in general, clay and sand layers restrict vertical contamination migration from the upper aquifers to the lower aquifer (Castle Hayne Aquifer) which supplies drinking water for the station and Havelock.(2) The U.S. Geological Survey (USGS) is currently working to identify all areas that may have thin or missing clay and sand layers.
Currently, the contamination plumes are not impacting any drinking water wells. All drinking water meets state regulations and is tested according to EPA's Safe Drinking Water Act. In addition, station personnel plan to close all drinking water wells near the industrial area to ensure that wells are not impacted by plumes in the future.(2) Since exposure to contaminated groundwater is highly unlikely, there is no public health hazard associated with the contaminated groundwater.
In 1986, the USGS detected benzene, arsenic, lead, and nickel in two station drinking water wells (wells 16 & 17) in the industrial area.(3) The concentrations were below drinking water standards. In addition, the samples were collected at the wellheads before the water from these wells was blended with 22 other station wells. Thus, the water samples were not representative of the water people actually consumed. The two wells were immediately taken off line and sealed. Initial USGS studies indicated that the clay and sand layers are thin and discontinuous in this area. Subsequent USGS studies determined that closing the wells restored the natural vertical hydraulic gradient (upward), thus eliminating downward migration of upper aquifer groundwater in the area.(4) A hole in the well casing of well 17 was discovered. Thus, contamination from the upper aquifer likely entered wells 16 and 17 through holes in the well casings.(2)
C. Fish Consumption - No Apparent Public Health Hazard
Fishing takes place in the Neuse River and Slocum and Hancock Creeks. The station may have contributed to river and creek contamination, and thus fish contamination, in the past through surface water runoff and groundwater recharging to surface water.(2) ATSDR evaluated fish tissue data and determined that no apparent public health hazard exists from consumption of those fish.
ATSDR reviewed A Biological Evaluation of Metal Contamination in Slocum Creek, North Carolina, which includes data for metal residues in fish, sediments, and water from Slocum Creek.(5) Fish data were available for 1983, 1985, and 1990. ATSDR compared maximum and average contaminant concentrations detected in edible fish with Food and Drug Administration (FDA) and EPA health guidelines. Nickel was the only contaminant detected which exceeded health guidelines. The FDA guideline of 27 parts per million (ppm) was exceeded in three samples involving two edible species - largemouth bass and summer flounder.
- Largemouth bass
Nickel concentrations were detected above the FDA guideline in two of eleven whole largemouth bass samples at maximum concentrations of 75 ppm and 30 ppm (in 1983). However, the average nickel concentration detected in largemouth bass in the same sampling round was 17 ppm, which is below the FDA guideline. Further, eight largemouth bass samples were analyzed in 1990 and all contaminants were below health guidelines.
Even though the FDA guideline for nickel was exceeded in two samples, there is no indication that consumption of largemouth bass from Slocum Creek presents a public health hazard. The FDA guideline is highly protective of public health and relates to a lifetime (70 years) of exposure. This duration of exposure is not expected in the vicinity of the station. Also, there is no subsistence fishing from Slocum Creek.(2) In addition, nickel concentrations that people would be exposed to are expected to be less than those detected during sampling because whole fish where sampled. Whole fish samples include organs and bones where nickel tends to distribute. People normally eat fillets which do not include the organs and bones. Thus, consumption of largemouth bass poses no apparent public health hazard.
- Summer flounder
Nickel was detected at 30 ppm in one of twelve whole summer flounder samples in 1983. However, the average nickel concentration detected in summer flounder was 9 ppm, three times lower than the FDA guideline. No contaminants were detected above health guidelines in subsequent summer flounder samples. Based on the concentrations detected, consumption of summer flounder from Slocum Creek presents no apparent public health hazard.
Shellfish harvesting (mussels, clams, and oysters) is prohibited in Slocum and Hancock Creeks and in the Neuse River adjacent to MCAS Cherry Point due to bacterial contamination not associated with the station. Thus, shellfish should not be consumed.
There are limited fish data available for Hancock Creek. Livers of brown bullheads from Slocum and Hancock Creeks were analyzed for metals and concentrations in fish from both creeks are considered to be low.(5) In addition, livers of brown bullheads from a control creek (Goose Creek) 10 kilometers upstream of the station and on the north shore of the Neuse River had low metal concentrations. Since contamination in brown bullheads from the creeks surrounding the station and the control creek are similar, the station apparently has not adversely impacted brown bullheads in Slocum and Hancock Creeks. In addition, ATSDR did not identify any major groundwater contamination sources discharging to Hancock Creek. Therefore, we do not expect consumption of fish from Hancock Creek to pose a public health hazard.
- Neuse River
ATSDR did not evaluate data for fish from the Neuse River. Contamination from the station has not significantly impacted fish in Slocum Creek, therefore we do not expect it to greatly impact fish in the much larger Neuse River.