RIVERBANK ARMY AMMUNITION PLANT
STANISLAUS COUNTY, CALIFORNIA
QUALITY ASSURANCE AND QUALITY CONTROL
In preparing this public health assessment (PHA), ATSDR relied on the information provided in
the referenced documents. The Agency assumes that adequate quality assurance and quality
control measures were followed with regard to chain-of-custody, laboratory procedures, and data
reporting. The availability and reliability of the referenced information determines the validity of
the analyses and the conclusions drawn in this document.
The majority of the environmental data presented in this PHA is from the Remedial Investigation
(RI) preliminary data. Generally, the methodology used in the RI activity is appropriate for
characterizing contamination at RBAAP. Additional information collection is planned during
completion of RI activities. This information will be evaluated by ATSDR. Conclusions and
recommendations of this PHA will be modified if appropriate and necessary.
COMMUNITY HEALTH CONCERNS
ATSDR identified community health concerns through meetings, correspondence, and telephone
conversations. The sources of these concerns include the facility, state and federal regulatory
agencies, and, through these agencies, individual residents. The primary concern expressed
regards the possibility of public health hazard from consumption, by residents of the Study Area,
of crops or livestock that might have been exposed to cyanide or chromium in contaminated
groundwater. This PHA discusses in detail, consumption of agricultural products is not
considered likely to be a public health hazard.
HEALTH OUTCOME DATA
We did not evaluate health outcome databases because people were not exposed to site
contaminants at levels that might cause public health hazards.
PUBLIC HEALTH ACTION PLAN
Conclusions
The primary hazardous chemical exposure issue at RBAAP is consumption of livestock and
crops from the Study Area, watered with cyanide- and chromium- contaminated groundwater.
Insufficient information on accumulation of cyanide in specific crop plants and lack of
information on the actual gardening and consumption practices (such as whether home gardens
were grown at residences with affected wells or whether contaminated wells were used to water
home gardens) lead to characterizing past consumption of home garden crops as an indeterminate
public health hazard. A toxicological evaluation determined that consumption of livestock
watered with groundwater with the contaminant levels found would not constitute a public health
hazard via normal (average) consumption of livestock. It is not likely that current or future
contaminant levels in groundwater in the Study Area constitute a public health hazard via
consumption of home garden crops. Residents of the Study Area with concerns about the
possibility of cyanide or chromium contamination of home gardens can contact the ATSDR
information "hotline" (1-800-447-1544) for further information. (Please refer to Riverbank
Army Ammunition Plant when asking for assistance.)
Another pathway for which concerns were raised is that of exposure via drinking cyanide- and
chromium-contaminated groundwater in the "Study Area". Although a limited number of
domestic wells in the vicinity of RBAAP contain low levels of these contaminants, the
toxicological evaluation concluded that past or current consumption of this well water does not
present a public health hazard. Since alternative water supplies have been provided, there is no
potential for exposure via consumption since 1993. The planned groundwater remediation is
intended to remove both cyanide and chromium for groundwater on- and off-site and halt
migration of contaminants off-site. This remediation activity, when successfully completed, will
further reduce or eliminate the potential for future exposures.
Contaminants from the E-P ponds have not migrated into sediment or water of the Stanislaus
River in amounts that would be of public health concern.
Ongoing Actions
As this PHA describes, the Army and regulators are enacting remediation activities to decrease
or eliminate migration of contaminants off-site and to decrease the levels of contaminants in off-site groundwater. These actions will further increase the likelihood that adverse public health
effects related to contaminants at RBAAP do not occur.
ATSDR, in coordination with the facility and regulators, has developed a summary sheet to
summarize the exposure evaluation process used in this PHA. The summary includes the results
of the evaluation of groundwater contamination and home garden crops exposure potentials for
the Study Area residents. The summary sheet contains information including ATSDR contacts
for community members in the event that questions arise concerning the exposure evaluations in
the public health assessment. The summary sheet is included with this public health assessment
and is available for distribution to all interested parties.
The ATSDR information "hotline" (1-800-447-1544) is available to provide further
information on the possible health effects of exposure to cyanide, chromium and other chemicals.
PREPARERS OF REPORT
Jeff Kellam, M.S.
Environmental Health Scientist
Federal Facilities Assessment Section
Division of Health Assessment and Consultation
David Fowler, Ph.D.
Environmental Health Scientist
Federal Facilities Assessment Section
Division of Health Assessment and Consultation
ATSDR Regional Representatives
William Nelson
ATSDR EPA Region IX
San Francisco, California
William Deviny
ATSDR EPA Region IX
San Francisco, California
ATSDR Reviewers
Diane Jackson
Chief, Defense Section A
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
ATSDR
Carole Hossom
Defense Section A
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
ATSDR
Julie Corkran, Ph.D.
Environmental Health Scientist
Federal Facilities Assessment Section
Division of Health Assessment and Consultation
REFERENCES
Bechtel, Environmental, Inc, 1989, Engineering Evaluation/Cost Assessment Report for the Interim Ground-Water Treatment System Removal Action Selection at the Riverbank Army
Ammunition Plant, prepared for USATHAMA, November, 1989.
USATHAMA, 1987, Riverbank Army Ammunition Plant Remedial Investigation/Feasibility Study Offsite Monitoring Program Groundwater Sampling Plan, May 1987.
US EPA, 1987, Hazard Ranking System Ranking Package.
USATHAMA, 1991, Riverbank Army Ammunition Plant Remedial Investigation (RI) Report, Volume 1, July 1991.
USAEC, 1994, Riverbank Army Ammunition Plant (RBAAP) Record of Decision, March
1994.
USATHAMA, 1980, Installation Assessment of Riverbank Army Ammunition Plant, Report 144.
ATSDR, 1997, Record of Communication, Luther Stover, RBAAP Environmental Program, March 12, 1997.
ATSDR, 1997, Record of Communication, Luther Stover, RBAAP Environmental Program,
April 1, 1997.
Riverbank Army Ammunition Plant, 1993, Riverbank Army Ammunition Plant Proposed Plan Fact Sheet, August 1993.
Riverbank Army Ammunition Plant, 1995, Quarterly Groundwater Monitoring Report
RBAAP Groundwater Program, 1995 - Third Quarter, October, 1995.
Roy F. Weston, Inc., 1990, Remedial Investigation/Feasibility Study, Phase II, Task 5, Riverbank Army Ammunition Plant, May 1990.
Riverbank Army Ammunition Plant, 1996, Quarterly Groundwater Monitoring Report,
RBAAP Groundwater Program, 1995 - Fourth Quarter, March 25, 1996.
RATSS-Riverbank Army Ammunition Plant Remedial Investigation/Feasibility Study
Groundwater Model Calibration Report, March 1987.
Riverbank Army Ammunition Plant, 1996, Quarterly Groundwater Monitoring Report,
Riverbank Army Ammunition Plant Groundwater Program, 1996 - Fourth Quarter.
Riverbank Army Ammunition Plant, 1989, Riverbank Army Ammunition Plant Public
Involvement and Response Plan.
Roy F. Weston, Inc., 1991, Riverbank Army Ammunition Plant, Engineering Evaluation/Cost Analysis (EE/CA) for the E-P Ponds, April, 10, 1991.
California Regional Water Quality Control Board, 1994, Order No 94-088, NPDES No. CA 0083330, Waste Discharge Requirements for United States Department of the Army, NI
Industries, Inc., Riverbank Army Ammunition Plant, Stanislaus County.
City of Riverbank, 1995, City of Riverbank Industrial Wastewater Discharge Permit Number 95-001 for the United States Department of the Army, NI Industries, Inc. 5300 Claus Road,
Stanislaus County
Roy F. Weston, Inc., 1991, Engineering Evaluation/Cost Analysis (EE/CA) for the Permanent Potable Water Supply (PPWS).
Radian, Inc., 1990, Air Toxics Inventory Report, Riverbank Army Ammunition Plant, March 1994.
ATSDR, 1993, Toxicological Profile for Chromium - Update, TP-92/08, April 1993.
ATSDR, 1993, Toxicological Profile for Cyanide - Update, TP-92/09, April 1993.
