Restoration efforts began at the Former Walker Air
Force Base under the Formerly Used Defense site program in 1991
when TCE was detected by NMED in private wells in the Y-O Acres
community directly east of the former base. The Corps immediately
provided bottled water and made an agreement with the City to extend
water service to affected residences. In 1992, TCE was identified
at the former base in the Roswell Industrial Air Center production
well. Again in 1994, the New Mexico Environment Department detected
groundwater contamination in residential wells immediately north
of the former base.
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The US Army Corps of Engineers (USACE) has begun a data gaps analysis for the entire Former Walker Air Force Base (WAFB) site. This report will provide cost estimates needed to justify funding for cleanup efforts, and to prioritize future actions in a strategic plan for WAFB. It will also give the regulators information they need to ensure that efforts proposed at WAFB are within their regulatory guidelines and meet the needs of the general public.
This report will be done in three phases.
The first phase includes having a contractor research all data and archives for the site, and update the site ownership/operational history report for WAFB.
This includes uses before, during and after Department of Defense (DOD) ownership of the site. The contractor will prepare a chronological summary of all use of the property, including users of the buildings or areas, number of people employed, activities conducted there and type of chemicals used.
The second phase will include identification of gaps in the available data. Phase two will include evaluating the data, identifying sites for which immediate
closure is recommended, determining sites where additional data is required for close-out and prioritizing future investigative efforts.
In the third phase the contractor will prepare a report of conclusions and recommendations. This will include a plan for future efforts at WAFB.
It is important to remember that Walker Air Force Base competes with 9800 other formerly used defense sites (FUDS) for funding. The complete histories
report will enable USACE to develop a cost effective plan for the closure of contaminated areas at WAFB.
In addition to the data gaps analysis, USACE plans to sample each of the existing monitoring wells on WAFB. This Fall Tests will be run for a broad
spectrum of contaminants, with site specific chemical analysis added at some locations.
Data from each well will be put into a GPS database. This effort will result in a baseline for groundwater conditions at a specific time within the WAFB project
area. Comparing this data to past sampling may identify areas that can be closed or confirm that new constituents need to be considered at specific
sites.
The USACE will also conduct a site investigation of the Hospital Debris Landfill, which was investigated earlier. Because testing practices of the lab conducting
the earlier study were deemed unacceptable, a new investigation is being conducted at this site. Funds are coming from a Department of Justice settlement and
not from the USACE Formerly Used Defense Sites budget. The site cannot be closed out until new data is collected.
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1991
NMED discovered TCE contamination in private wells adjacent to the
former base.
1993
The Corps began fieldwork for the Phase I Remedial Investigation
in June 1993. This effort involved the installation of monitoring
wells, soil and groundwater sampling and analysis, and geophysical
surveys to identify potential sources and to determine the extent
of contamination. No contamination source was identified but TCE
was found in the groundwater (in the alluvial aquifer).
1994
In November 1994, the Corps removed 45 fuel storage tanks at the
site.
1995
In March 1995, the Corps began site investigations at 6 sites suspected
of containing hazardous wastes, 12 Atlas Missile Silos, and ordnance
storage areas. In May 1995, the Corps began a Phase II groundwater
investigation to further define the affected groundwater and potentially
locate the source of contamination.
Click here
for a larger version of the site map
1996
The report for the Phase II effort was completed in August 1996.
A total of 32 surface soil, 82 subsurface soil and bedrock samples,
and 43 groundwater samples were collected and analyzed for Volatile
Organic Compounds (VOCs), Semi-volatile Organic Compounds, pesticides,
polychlorinated biphenyls (PCBs), total recoverable petroleum hydrocarbons,
and metals from the Resource Conservation & Recovery Act (RCRA).
TCE was detected in both the alluvial and artesian
aquifers. TCE in the artesian was detected below established health-risk
benchmarks while TCE was detected at higher levels in the alluvial
aquifer. The highest TCE concentration detected in the alluvial
aquifer was 110 µg/L.
1997
In May 1997, NMED approves abatement plan.
In August 1997, the Corps presented its Groundwater
Abatement Plan (the treatability study) to the Community. This plan
allows the Corps to pump the affected groundwater to the surface,
treat it in the City's wastewater treatment facility, and release
it into the Pecos River.
1998
In the summer of 1998, the Corps established a Restoration
Advisory Board (RAB) for the project. The first RAB meeting
was held in October 1998. RAB meetings are open to the public and
provide the community a forum to provide input to the project team
throughout the restoration effort. (See the RAB Information Page
for more information).
In November 1998, the Corps began a 5-year pump and
treat pilot study of the shallow groundwater aquifer to determine
a sustainable pump rate. The Corps also began quarterly sampling.
1999
In July 1999, the Corps expanded the water use agreement with 14
affected landowners. This agreement increased each landowner's compensation
for water usage based on current and future land use plans.
In November 1999, analytical results from the first
year of quarterly sampling showed a steady reduction in TCE levels
in groundwater wells at the Roswell Industrial Air Center and in
the Y-O acres community. However, long term groundwater chemical
data is needed to make a definitive conclusion as to TCE reduction
in groundwater.
2000
In April 2000, the Corps begins evaluating appropriate innovative
technologies to accelerate the cleanup rate at the site.
In October 2000, the Corps initiated a second pump
test near the eastern boundary to determine if an accelerated pump
and treat effort is feasible.
2001
In 2001, the well with the highest TCE level was at 80 ppb. Overall
TCE levels have not changed in the wells that have been sampled.
Some of the wells show a slight increase in TCE concentrations and
some show a slight decrease. The safe drinking water standard for
TCE is 5 ppb. During the April 2001 RAB meeting, several community
members provided the project team some new leads that may help in
finding the contamination source.
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Geoprobe used for soil gas surveys
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In the summer of 2001, the Corps followed up on the
lead by investigating an old drain in front of one of the hangars.
The Corps used a geoprobe
rig down to 30 feet and found the highest level of TCE at the
site thus far at about 1,000 ppb. The Corps anticipates installing
several monitoring wells in the area to investigate further.
In July 2001, the Corps initiated additional Underground
Storage Tank (UST) investigations. It will involve quarterly sampling
and analysis from 19 wells. The Corps will be analyzing for total
petroleum hydrocarbons. During the month of August 2001, the Corps
collected groundwater samples for the UST investigation. During
the sampling event, two monitoring wells were identified as having
free petroleum product. Since free petroleum product is less dense
than water, it will separate from the water and float on top the
groundwater. Approximately one foot of free petroleum product was
detected in two monitoring wells. The Corps in cooperation with
the New Mexico Environment Department, Underground Storage Tank
Bureau is evaluating this UST site. The Corps plans to install a
new well at the site to recover the petroleum that has impacted
the groundwater.
December 2001 - A new monitoring well (PH7-W20) was re-drilled to replace a vandalized monitoring well near Pump House #7.
2002
During 2002, responsibility for environmental project support for the Walker AFB site transferred from the Tulsa District to Sacramento District of the Corps of Engineers, due to a re-alignment of division boundaries.
Two new monitoring wells were installed adjacent to Pump House #7. Non-aqueous phased petroleum (NAPL) levels fluctuate with the seasons. It is detected during the summer (irrigation) months and is not detected in the monitor wells after the irrigation season ends.
A field investigation at the Waste Oil Disposal Site (WODA) was begun. Fifteen borings were drilled to a depth of approximately 25 feet, with 3 soil samples
taken from each. Two monitoring wells were also installed, with all results submitted to NMED for review.
Two new monitoring wells were drilled near Hanger #58, indicating TCE contamination in both the upper and lower granular zones.
A data gaps analysis was proposed and begun for the former Walker AFB site. This will consist of gathering all data from WAFB and consolidating it in a
report. From that report, it could be determined what areas have sufficient information and where further information is required. The data gaps analysis will consist
of three phases.
The first phase includes hiring a contractor and going through all data and archives and doing a site ownership operational history report for WAFB, including uses
before, during, and after DOD uses. The contractor will prepare a chronological summary of all use of the property, including users of the building or areas, number of
people employed, activities conducted there and types of chemical used.
The second phase will identify any gaps in the available data. Phase two will include evaluating the data and determining where the clean up efforts need to
focus. Because of limited funding, efforts need to be prioritized to maximize the payback for dollars spent.
The third phase will be to have the contractor prepare a report of conclusions and recommendations. This will include a plan of where to focus for future efforts,
and estimated costs to complete those activities.
2003
To establish a consistent baseline of contaminants and concentrations in groundwater, the Corps contractor sampled every (61) monitoring well on the WAFB
sites. Each sample was tested for a wide range of contaminants.
A site investigation of the Hospital Debris Landfill was started. This site was investigated earlier, but testing practices of the laboratory conducting that
investigation were deemed unacceptable. Funds for this re-investigation are coming from a Justice Department settlement.
Investigation of the Waste Oil Disposal Site was completed and the final report forwarded to NMED.
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Note: Click on the image to view a large
version of the Restoration History timeline Exhibit Display.
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