ATSDR Releases Hill AFB PHA for public comment

ATSDR MEDIA ANNOUNCEMENT
ATSDR releases Hill AFB public health assessment for public comment;
PHA finds residents' exposure to contaminants does not pose a health hazard

For Immediate Release: March 10, 2003

ATLANTA - The Agency for Toxic Substances and Disease Registry (ATSDR), a public health agency of the U.S. Department of Health and Human Services, today announced the release for public review and comment of its public health assessment (PHA) of the Hill Air Force Base (AFB) site near Ogden, Utah. The site is listed on the Environmental Protection Agency's National Priorities List (NPL). The public comment period starts March 10 and ends April 28, 2003.

After conducting a thorough evaluation of available environmental monitoring data and potential exposure situations, ATSDR concluded that exposure to contaminated groundwater, soil, indoor air, surface water, and fruits and vegetables does not pose a health hazard to residents and workers of Hill AFB or the surrounding communities.

A public meeting will be held at 6:30 p.m. on Wednesday, March 12, at the Courtyard by Marriott, 1803 Woodland Park Drive, Layton, Utah, to discuss the public health assessment and its findings.

As a result of former base operations and waste disposal practices at Hill AFB, various fuels and chemicals have spilled or have been released to the ground, some of which have reached underlying groundwater and storm-water ponds. The U.S. Environmental Protection Agency (EPA) listed Hill AFB on its National Priorities List in July 1987 on the basis of indications that contamination in multiple areas had spread to communities surrounding the base. The primary contaminants of concern are volatile organic compounds, such as those used in cleaning solvents. These contaminants, as well as others, have been detected in groundwater and soil.

ATSDR evaluated whether exposures to environmental contaminants are expected to affect the health of residents of Hill AFB or surrounding communities. To accomplish this, ATSDR identified ways in which people living at or near the base or in surrounding communities might come in contact with environmental contamination associated with Hill AFB, including contact with contaminants in groundwater, surface soil, surface water and/or sediment, indoor air and locally grown foods.

Conclusions regarding potential past, current and future exposure situations for communities near Hill AFB are based on a thorough evaluation of base investigation data and observations made during base visits. Although exposure occurred in indoor air, surface water, crops, groundwater and soil, the levels of exposure are too low to present a public health hazard. ATSDR developed the following conclusions about potential exposure hazards to indoor air and surface water contamination.

* Some of the contamination found in the indoor air in sampled homes was not found in the groundwater contamination plumes located near these homes. For a majority of the communities studied, background samples (sampling performed in homes that are not above groundwater plumes that were used to identify typical levels of contaminants in the indoor environment) found the same level of contamination as in homes directly above the groundwater plumes. From this information, it appears that groundwater off-gassing in most of the communities is not a significant source of indoor air contamination. ATSDR evaluated the indoor air contaminant levels (from all sources) in this assessment.

* Contaminants, primarily volatile organic compounds (VOC), were detected in indoor air at certain residential units in the Hill AFB Patriot Hills Housing Area. However, the VOC levels are low and below those associated with adverse health effects. In this area, Pond 3 is the only surface body of water on Hill AFB where exposure to contaminants (via dermal contact) is possible. The contamination detected is low and far below levels associated with adverse health effects.

* A school in Sunset, Utah, and several hundred residential homes in the cities of Sunset, Clinton, Roy, Layton, Riverdale (Craigdale subdivision), and South Weber sit above groundwater plumes that have migrated from Hill AFB source areas. Indoor air monitoring of potentially affected buildings showed VOC contaminants were present in the air inside certain homes, but at levels below those known to be associated with adverse health effects. ATSDR also confirmed these findings with air modeling techniques because of the limited air sampling in the housing area. Air modeling uses known groundwater contamination values to determine a likely indoor air concentration.

Past indoor air exposure was most likely higher in some of the communities when the groundwater contamination was higher. Exposure possibly began sometime in the 1960s. ATSDR used indoor air modeling techniques to determine how high indoor air concentrations could have been in the past from groundwater off-gassing. The results of the modeling indicate that past indoor air levels were several times higher than they are today, but at levels far below those shown to cause adverse health effects.

Future indoor air concentrations are not expected to be higher due to the remediation efforts that have been initiated or soon will be initiated at Hill AFB and in the communities surrounding Hill AFB. In communities that have had indoor air sampled, both before and after remediation efforts were implemented, the indoor air concentrations are declining, indicating that remediation efforts are working. Additionally, the waste disposal practices on Hill AFB that led to this groundwater contamination have stopped and remedial actions have been put in place at most source area locations that have either cleaned up or controlled contamination from leaving the base.

* Several surface water bodies, in the form of springs, field drains, creeks and ponds, are contaminated with low levels of VOCs. Adults and children who come into contact with the contaminated surface water, through either accidental ingestion or touch, are not exposed to harmful levels of contaminants. The VOC levels are low and below those associated with adverse health effects.

* Contamination is present in water that some community members might use for irrigation. It is believed that adults and children who eat crops grown with contaminated water are not exposed to harmful levels of contaminants from Hill AFB. Preliminary research has found that uptake of contaminants from the contaminated groundwater by crops grown in the area is low and below levels that are known to cause illness. The U.S. Air Force continues to study the issue.

The draft public health assessment will be available for public review and comment on or about March 10, 2003, at the following records repository:

The public comment period begins March 10 and ends April 28, 2003. ATSDR welcomes comments from the public. Mail written comments to the following address:

Chief, Program Evaluation, Records and Information Services Branch
ATSDR
1600 Clifton Rd., NE (MS E-32)
Atlanta, GA 30333

Comments received, without the names of individuals who submitted them, and ATSDR's responses to the comments will appear in an appendix to the final public health assessment. Names of those who submit comments, however, will be subject to release for requests made under the U.S. Freedom of Information Act.

Community members seeking information on the procedures or the content of the public health assessment may contact Environmental Health Scientist Carole Hossom or Community Involvement Specialist Debra Joseph, toll free, at 1-888-422-8737. Regional Representative Susan Muza also may be contacted at 303-312-7011. Callers should refer to the Hill Air Force Base site in Utah.

Members of the news media may request an interview with ATSDR staff by calling Elaine McEachern or John Florence in the ATSDR Office of Policy and External Affairs at 770-488-0700.

This page updated March 10, 2003
For more information, contact ATSDR at:
770-488-0700 or e-mail (news media)

ATSDR MEDIA ANNOUNCEMENT ATSDR releases Hill AFB public health assessment for public comment; PHA finds residents' exposure to contaminants does not pose a health hazard

ATSDR MEDIA ANNOUNCEMENT
ATSDR releases Hill AFB public health assessment for public comment;
PHA finds residents' exposure to contaminants does not pose a health hazard