PUBLIC HEALTH ASSESSMENT
MARINE CORPS AIR STATION YUMA
YUMA, ARIZONA
TABLE 1
POPULATION DATA TABLE
|
CITY OF YUMA (1990) | |
| Total persons | 54,923 |
| Total area (square miles) | 21.86 |
| Persons per square mile | 2,512 |
| % Male | 49.4 |
| % Female | 50.6 |
| % White | 73.0 |
| % Black | 3.8 |
| % American Indian, Eskimo, or Aleut | 1.1 |
| % Asian or Pacific Islander | 1.7 |
| % Other races | 20.4 |
| % Hispanic origin | 35.6 |
| % Under age 10 | 18.7 |
| % Age 65 and older | 12.0 |
TABLE 2
HOUSING DATA TABLE
|
CITY OF YUMA (1990) | |
| Households(1) | 19,282 |
| Persons per household | 2.80 |
| % Households owner-occupied | 58.5 |
| % Households renter-occupied | 41.5 |
| % Households mobile homes | 12.7 |
| % Persons in group quarters | 1.6 |
| Median value, owner-occupied households (dollars) | 65,400 |
| Median rent paid, renter-occupied households (dollars) | 375 |
Figure 1. Location Map of MCAS Yuma and Surrounding Area
Figure 2. Station Map of MCAS Yuma
Figure 3. ATSDR's Exposure Evaluation Process
Figure 4. Marine Corps Air Station Yuma Impacted Groundwater Plumes and Downgradient Drinking Wells
Figure 5. Location of ACM at Radar Hill Disposal Area
Appendix A: Evaluation of Potential Public Health Hazards Associated With Marine Corps Air Station Yuma
The following section was not available in electronic format for conversion to HTML at the time of preparation of this document. To obtain a hard copy of the document, please contact:
Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
Attn: Chief, Program Evaluation, Records, and Information Services Branch
E-56
1600 Clifton Road NE, Atlanta, Georgia 30333
Appendix B: Comparison Values
The conclusion that a contaminant exceeds the comparison value does not mean that it will cause adverse health effects. Comparison values represent media-specific contaminant concentrations that are used to select contaminants for further evaluation to determine the possibility of adverse public health effects.
Cancer Risk Evaluation Guides (CREGs)
Environmental Media Evaluation Guides (EMEGs)
Maximum Contaminant Level (MCL)
Reference Media Evaluation Guides (RMEGs)
Appendix D: Responses to Public Comments
ATSDR distributed copies of the public comment release of the Marine Corps Air Station Yuma Public Health Assessment (PHA). The comment period lasted between June 8, 1998 and July 19, 1998. The following are the comments received by ATSDR and ATSDR's responses.
Currently in the State of Arizona, MTBE in the groundwater is not a concern. There are no remedial alternatives being considered to remediate MTBE.
Response: MTBE levels in groundwater at MCAS Yuma do not pose a public health hazard and no one has been, is currently, or likely will be in the future exposed to the MTBE plumes in the groundwater at MCAS Yuma. Therefore, ATSDR has removed references to MTBE contamination in the groundwater at MCAS Yuma.
I do not agree with Conclusion #4.
During the OU2 Remedial Investigation, this area was sampled and did not suggest that there were any tear gas crystals buried in that area. In addition to the sampling, that area is highly disturbed due to the building of the CALA. The comment that tear gas crystals were buried in the area is questionable and if tear gas crystals were to be buried, it would have been done by an individual, who would have used his shovel and dug to a depth of only a few feet below ground surface.
Response: ATSDR has further clarified statements in the PHA on the issue of the reported tear gas disposal. Although the reports of tear gas disposal could not be verified, ATSDR still feels that some precautionary measures should be taken for future excavations at this site.
The area in which high levels of organic lead were found are currently used as contractor storage yards. These yards mainly contain construction materials and some vehicles. Personnel do not work in these areas 8 hours per day, 5 days per week. Any exposure to organic lead should not be considered as chronic exposure. This area has been used as contractor storage yards for at least the last 10 years. Prior to that, this area was used as shops area. The area in question has not been used as a barracks area. Military personnel who worked in that area would not have been assigned to MCAS Yuma for more than three years. Considering that the areas of contamination are outdoors and the personnel who worked in the area were not assigned to the base for a significant period of time, I would assume that any exposure to tetraethyl lead would have been minimal and would not affect their health.
Page 13 Conclusions
I do not agree with ATSDR with Conclusion #6.
ATSDR identified the presence of organic lead at three sites, CAOCs 1, 2, and 7, as a concern. They go on to say that since these areas are isolated and paved (or covered with sealant), or have restricted access, they do not pose a current or future public health hazard. [The commentor] agrees.
ATSDR goes on to say they do not have sufficient information to evaluate the past exposures to organic lead, so they classify these sites as an indeterminate public health hazard and recommend further investigation regarding the organic lead. [The commentor] does not agree with this assessment.
Based on [the commentor's] review of historical aerial photographs and station records, the portion of CAOC 1 where the organic lead was found has always been associated with flight operations and appears to have been always paved. Thus, past exposure to organic lead in soil at this location is minimal. Any increased exposure to organic lead, or other contaminants, in this area were likely due to the daily maintenance operations that occurred.
At CAOC 7, the organic lead hits were found at former Fire Training Pit (FTP) 15 located to the north of the CALA. This FTP was apparently used during the 1970s for fire and crash training. The FTP is currently covered with a sealant for dust control, and appears to have been covered since the early 1980s. This FTP appears to have been in use for a limited period of time, and has been covered with the sealant since the early 1980s. Thus, exposure to organic lead at this location since use of this FTP was terminated is minimal. During operations, exposure to the burning of flammables during fire training exercises was likely to be more significant than the presence of organic lead in the soil.
At CAOC 2, this site has been used for vehicle maintenance and public works from the 1940s to the early 1980s. The OU2 RI investigated areas of reported spills and ground disposal of chemicals, which reportedly occurred until the early 1980s. Of the areas investigated, only one hit of organic lead was detected. If this hit of organic lead was related to past spills and/or disposal activities, the impacted area appears small so exposure to the contaminated soil was likely minimal. In addition, this area was used for industrial activities, so it is unlikely that any station personnel would be in this area for more than a normal work schedule. Also, the nearby base dormitories and Enlisted Dining Facilities were constructed after the early 1980s so occupants of these buildings would have minimal exposure to past spills or disposals. Since the area where the organic lead hit was found has been used as a vehicle parking area for at least the past 5 years, it is likely that the presence of organic lead came from parked vehicles and does not represent a significant past exposure pathway.
Response: ATSDR has further clarified statements in the PHA on the issue of past exposure to organic lead.
The very high levels of organic lead found at some locations, while not a current or future concern, do raise questions about potential exposures in the past. The current high levels of tetraethyl lead degradation products suggest the possibility that high levels of tetraethyl lead may have been present in the past. Past exposure at the Flight Line CAOC 1 (the Flight Line) was quite limited. Although, as the commentor states, past exposures at the Fire School Area CAOC 7 (the Fire School Area) and CAOC 2 (the Shops Area) may have also been quite limited, ATSDR does not have sufficient information to evaluate potential past exposures to organic lead at these areas.
ATSDR agrees with the commentor that exposure to organic lead in the past at CAOC 1 is not a public health hazard. ATSDR still believes, however, that past exposures at CAOC 7 and CAOC 2 pose an indeterminate public health hazard.
I do not agree with the ATSDR recommendation that the Navy further investigate the soil contaminated with organic lead.
As the Public Health Assessment states, it does not present a present or future health risk. Any exposure in the past would have been incidental and would not pose a health risk. The Navy has spent several millions of dollars in investigating soil contamination at MCAS Yuma. The area in question was included in CERCLA Area of Concern #2. This area was recommended for no further action because the threat of exposure to chemicals which would cause cancer was less than one in one million and the non-cancer threat was less than one. The recommendation was agreed upon by the State of Arizona, the Environmental Protection Agency, and the U.S. Navy. It does not seem practical to spend more money to verify what the Public Health Assessment and the OU2 Record of Decision state.
Response: ATSDR's recommendations have been modified as suggested by the commentor. However, if the restricted access and use of this area changes in the future, ATSDR still recommends further characterization of soil contaminated by organic lead.
1. A household is an occupied housing unit, but does not include group quarters such as military barracks, prisons, and college dormitories.
