WELDON SPRING	EPA Region 7	03/12/2010

FORMER ARMY	f if™' ^

County: St. Charles County

ORDNANCE	Other Names: Weldon Springs National

WORKS	Guard Facility,

[V,,ccnilRl	US Army Trainin" Ccntcr' Weldon

Springs-Ex Army Ordnance Plant,

EPA ID# MO5210021288	Ft. Leonard Wood

SITE DESCRIPTION

The Weldon Spring Former Army Ordnance Works site occupied more than 17,000 acres and
operated from 1941 to 1944. During its operation, the site produced explosives including
trinitrotoluene (TNT) and dinitrotoluene (DNT) for the U.S. Armed Services. A series of land
transfers left the Army with 1,655 acres, which it has operated since 1959 for the Army Reserve
as the Weldon Spring Training Area. Contaminated areas are spread throughout the 17,000 acres
of the site, with the greatest concentration in the Training Area. Some of the transferred land that
covered two small areas of the original Ordnance Works area now are owned by the U.S.
Department of Energy (DOE) and listed on the National Priorities List as Weldon Spring
Quarry/Plant/Pits site. Investigations have identified a number of potentially contaminated areas,
including seven unlined lagoons where TNT wastewater was stored, TNT production lines, two
DNT production lines, drainage ditches below TNT production lines, and eight areas where
explosive wastes were burned. Approximately 5,000 people live within 3 miles of the site, and
approximately 70,000 people obtain drinking water from St. Charles County wells located within
3 miles of the hazardous substances at the site. Surface water in the area flows either to the
Mississippi River watershed to the north or the Missouri River watershed to the south. Surface
waters located within 3 miles are used for recreational activities.

Site Responsibility:

This site is being addressed through Federal
actions.

NPL LISTING HISTORY

Proposed Date:

07/14/89


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Final Date:	02/21/90

Deleted Date:

THREATS AND CONTAMINANTS

In 1987, a Department of Defense (DoD) investigator found explosives such as
TNT and DNT in monitoring wells near the lagoons. TNT, DNT, and lead have
been identified in soil at several areas on the site, and TNT was detected in 1987 in
surface water downstream of the lagoons. The Mississippi watershed, which
supports wetlands, wildlife, and recreational activities, may be threatened by
run-off from the site. The TNT and DNT contamination on the site represent a
physical hazard with some potential for explosion. Ingestion of polluted surface
water, ground water, or contaminated soil may pose a threat to human health. DNT
is a probable human carcinogen and may be absorbed through direct contact.

CLEANUP APPROACH

Response Action Status

Initial Actions: In late 1992, the U.S. Army Corps of Engineers removed the interior wooden
boards of a storage room used by the Francis Howell School District. This storage room was a
box factory during the operation of the former Ordnance Works during World War II. Explosive
contaminants were discovered within the interior wooden boards after wipe samples from the
building were taken. The interior wooden boards were removed and replaced with sheetrock. As
part of a removal action, Burning Ground #1 was fenced to eliminate any potential exposures
while investigative actions are ongoing. Surface chunks of TNT have also been removed from
the burning grounds to eliminate any direct contact threat.

Entire Site: In 1987, the DoD identified a number of contaminated areas on the site. Under EPA
direction, DoD began a complete investigation into the nature and extent of contamination at the
site in early 1990. The study, which led to the selection of a final cleanup remedy, was divided
into two Operable Units (OUs). Operable Unit 1 (OU1) addressed surface soil, buried wooden
pipeline, and various structures, and was completed in 1996, leading to a cleanup of the various
source areas with a final report in September 2004. The primary remedy for OU1 was source
removal and destruction by incineration. Materials unsuitable for incineration were stabilized
and landfilled, in two instances some TNT was removed to a permitted facility and detonated.
Operable Unit 2 (OU2) of the study addressed ground water contamination and assessed the
impact from the source removal remedy (OU1) on the ground water contamination. As a result
of the ground water study, a monitored natural attenuation remedy with institutional controls to

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prevent future exposures was selected for the ground water contamination at the site in
September 2004. The site was placed in a construction complete category in September 2005,
indicating that all active construction to protect human health and the environment has been
accomplished. Monitoring of site ground water and implementation of institutional controls will
continue for the foreseeable future.

Site Facts: This site participated in the Installation Restoration Program (IRP), a

specially-funded program established by the DoD in 1978, to identify, investigate,
and control the migration of hazardous contaminants at military and other DoD
facilities. The site was funded by IRP in FY05


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ENVIRONMENTAL PROGRESS	

The Record of Decision (ROD) for OU1 (Source Areas) was signed September 26,
1996. Incineration of TNT-contaminated soils and wooden pipeline as the remedy was selected
and was completed in June 2004, with a final report in September 2004. Contaminated materials
unsuitable for incineration were decontaminated, stabilized, and disposed of in a containment
cell on-site or transported to a suitable RCRA-permitted facility.

The ROD for Operable Unit 2 (Ground water) was signed on September 30, 2004. Monitored
natural attenuation of contaminated ground water with institutional controls to prevent future
exposures was the selected remedy. The ground water monitoring efforts will be ongoing for the
foreseeable future.

The contaminated ground water plumes have not migrated past the site boundries. The ground
water is monitored annually and the remedy continues to be protective of human health and the
environment.

The site was considered "Construction Complete" as of September 30, 2005.

COMMUNITY INVOLVEMENT

Review and evaluate community involvement documents, as needed.
Fact sheets and other documents can be accessed at the following link -
http://www.nwk.usace.army.mil/projects/weldon/newsletters.htm


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SITE REPOSITORY

St. Charles City/County Library	Superfund Records Center

District	901 N. 5th St.

Middendorf-Kredell Branch	Kansas City, KS 66101

2750 Hwy K	Mail Stop SUPR

O'Fallon, MO 63366	(913)551-7166

REGIONAL CONTACTS

SITE MANAGER:

E-MAIL ADDRESS:

PHONE NUMBER:

COMMUNITY INVOLVEMENT
COORDINATOR:

PHONE NUMBER:

E-MAIL ADDRESS:

STATE CONTACT:
PHONE NUMBER:

Hoai Tran/R7/U SEPA/U S
tran.hoai@epa.gov
(913)551-7330

Beckie Himes

(913)551-7253
himes.beckie@epa.gov

Brandon Doster
(573)-526-2739

MISCELLANEOUS INFORMATION

STATE:	MO

07BC

CONGRESSIONAL DISTRICT:	09

EPA ORGANIZATION:	SFD- SUPR/IANE

MODIFICATIONS

Created by:	Karla	Created Date:	10/17/97 02:29 PM

Asberry/SUPRFUND/R7/US
EPA/US

Last Modified by: Dianna	Last Modified Date: 03/12/2010 09:07 AM

Whitaker/R7/U SEPA/U S


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