Texas

Texas

Pantex

(Exxon) Ray Point

Falls City Site
(Conoco)
Conquista Site
(Chevron) Panna
Maria Site

Long-Term Stewardship Site Highlights
(Chevron) Panna Maria Site (page 3)
Major Activities- disposal cell monitoring;
groundwater monitoring; access restrictions; erosion
control; maintenance; inspections
Site Size- 121 hectares (300 acres)
Start/End Years- 2001/in perpetuity
Estimated Average Annual Cost FY 2000-2006$26,100
(Conoco) Conquista Site (page 7)
Major Activities - groundwater monitoring; disposal
cell monitoring; inspections; access restrictions
Estimated Average Annual Cost FY 2000-2006$38,943

(Exxon) Ray Point Site (page11)
Major Activities -disposal cell monitoring; inspections;
access restrictions
Estimated Average Annual Cost FY 2000-2006- $25,600
Falls City Site (page 15)
Major Activities- groundwater monitoring; disposal cell
monitoring and maintenance; inspections; access restrictions
Estimated Average Annual Cost FY 2000-2006- $139,300
Pantex Plant (page 21)
Major Activities- groundwater and soil cleanup; groundwater
monitoring
Site Size- 4,119 hectares (10, 177 acres)
Estimated Average Annual Cost FY 2000-2006- $1.4 million

Table of Contents

Table of Contents

(Chevron) Panna Maria Site ............................................................... 3
(Conoco) Conquista Site .................................................................. 7
(Exxon) Ray Point Site .................................................................. 11
Falls City Site .......................................................................... 15
Pantex Plant ........................................................................... 21

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National Defense Authorization Act (NDAA) Long-Term SteHtrdship Report

Texas

2

(Chevron) Panna Maria Site

(CHEVRON) PANNA MARIA SITE
1.0

SITE SUMMARY

1.1

Site Description and Mission

The (Chevron) Panna Maria Site is the location of a
former uranium milling site that operated from 1979 to
1992. The 121-hectare (300-acre) site is owned by the
Chevron Corporation and is located in Karnes County
in southern Texas. The Chevron Corporation operated
the mill to process uranium ore for commercial
purposes. Wastes from the ore processing operations
are consolidated in the onsite disposal cell, which
comprises 61 hectares (150 acres) of the site.

LONG-TERM STEWARDSHIP HIGHLIGHTS
Major Long-Term Stewardship Activities - disposal

cell monitoring; groundwater monitoring; access
restrictions; erosion control; maintenance; inspections
Total Site Area- 121 hectares (300 acres)
Estimated Volume of Residual Contaminants- disposal
cell 5.7 million cubic meters (7 .4 million cubic yards);
groundwater unknown
Long-Term Stewardship Start-End Years- 2001-in
perpetuity

The current mission of the site is to complete
Average Annual Long-Term Stewardship Cost FY
remediation. The (Chevron) Panna Maria Site is
2000-2006-$26,100
subject to Title II of the Uranium Mill Tailings
Landlord- currently Chevron Corporation; beginning
Radiation Control Act of 1978 (UMTRCA). UMTRCA
in 2001, the U.S. Department of Energy's Grand
Title II sites are privately owned and operated sites that
Junction Office
were licensed when UMTRCA was passed, or
thereafter. The majority of the mining and milling
conducted at these sites was for the private sale of uranium, but a portion of the uranium may have been sold to
the U.S. Government. None of the ore milled at the (Chevron) Panna Maria Site was sold to the U.S.
Government. As such, DOE is responsible for long-term stewardship activities but not remediation of the site.
Based on ongoing discussions with the Texas Bureau of Radiation Control, DOE anticipates that the (Chevron)
Panna Maria Site will be transferred from Chevron Corporation to DOE in 2001. Once the site is transferred to
DOE, its only mission will be long-term surveillance and maintenance of the disposal cell, and monitoring of the
groundwater.

1.2

Site Cleanup and Accomplishments

The Chevron Corporation is currently completing reclamation activities at the site. Approximately 5.7 million
cubic meters (7 .4 million cubic yards) of mill tailings from the former tailings pond, as well as contaminated soil
and construction debris, will be encapsulated onsite. The mill tailings, soil, and construction debris are
contaminated with uranium, radium, and thorium. Current plans are to consolidate all contaminated materials
in an onsite engineered disposal cell. The disposal cell will be capped when remediation activities are completed.
Soils surrounding the site will be remediated to levels that comply with standards set by the U.S. Environmental
Protection Agency (EPA).
Groundwater at the site is contaminated with uranium as a result of the former uranium processing activities.
The specific groundwater remediation strategy has not yet been determined but information from the Texas
Bureau of Radiation Control indicates that alternate concentration limits (ACLs ), cleanup standards that are based
on site-specific considerations, have been sought for, and active remediation will not continue. For ACLs to be
approved, evidence must be provided that the ACLs will not adversely impact human health or the environment.

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National Defense Authorization Act (NDAA) Long-Term Stewardshi)J Report

2.0

SITE-WIDE LONG-TERM STEWARDSHIP

2.1

Long-Term Stewardship Activities

The DOE Grand Junction Office will begin
conducting long-term stewardship activities at
the (Chevron) Panna Maria Site in 2001, when
the site is transferred to DOE. To terminate
the site's radioactive material license, Chevron
Corporation must conduct state-approved
reclamation of any onsite radioactive waste.
The Texas Bureau of Radiation Control will
then determine when the site will be
transferred to DOE for custody and long-term
care. For the site to be transferred to DOE, the
Chevron Corporation must make a one-time
payment to the U.S. Treasury fully funding
inspections and anticipated maintenance.
Access to the site will be restricted through the
use of fencing and posting warning signs, as
necessary, along the site boundary. Fences and
signs will be repaired or replaced on an asneeded basis. DOE will staff a 24-hour phone
line for reporting site concerns. Drilling and
other intrusive activities will be prevented
within site boundaries through the use of
institutional controls.


Site records will be kept in permanent storage
at the DOE Grand Junction Office in Colorado.
The types of records that will be maintained include site characterization data, remedial action design
information, the site completion report, long-term monitoring plans, annual inspection reports, and current and
historical monitoring data. A report is submitted annually to the U.S. Nuclear Regulatory Commission (NRC)
that summarizes, describes, and evaluates all surveillance and maintenance actions, as required under Title 10
of the Code of Federal Regulations, Part 40.

2.2

Specific Long-Term Stewardship Activities

Engineered Unit
The disposal cell will cover approximately 61 hectares
(150 acres) of the 121-hectare (300-acre) site area. The
cell will be designed with a low-permeability radon
barrier and a grass surface layer for erosion control.
Erosion control will be provided for all potentially
vulnerable features, and the site will be graded to
provide positive drainage. All disturbed areas will be
revegetated.

Texas

STAKEHOWER INVOLVEMENT
When licensed and transferred to DOE, copies of the
annual inspection report for the (Chevron) Panna
Maria Site will be distributed to the local library and
any stakeholders requesting them. The annual
inspection report will also be available on the DOE
Grand Junction Office website at: www.doegjpo.com.

4


DOE will conduct annual inspections to ensure the integrity of the cell cover and other engineered features, the
effectiveness of institutional controls, and the compliance of the disposal cell with applicable requirements. The
disposal cell at the (Chevron) Panna Maria Site will be designed and constructed to last for remain effective for
200 to 1,000 years, in accordance with EPA standards. However, DOE's responsibility for the safety and
integrity of the disposal cell is expected to continue in perpetuity.

Groundwater
Annual groundwater monitoring will be conducted at the (Chevron) Panna Maria Site to ensure that the site is
in compliance with ACLs, if approved, and to demonstrate the effectiveness of the engineered disposal cell in
isolating the encapsulated wastes from the local environment. Groundwater monitoring is expected to continue
in perpetuity.

2.3

Regulatory Regime

Remediation of the (Chevron) Panna Maria Site is expected to be complete by 2001. Following NRC
concurrence that cleanup has been achieved, NRC will issue a general license for the long-term care of the
residual radioactive disposal cell (contained in Title 10 of the Code of Federal Regulations, Part 40.28). The
purpose of the license is to ensure the site will be cared for in a manner that protects human health and safety and
the environment. The license also represents that NRC formally accepts the site-specific long-term surveillance
plan.
Long-term stewardship activities at the (Chevron) Panna Maria Site are governed by several requirements in the
following regulations: UMTRCA; the Atomic Energy Act of 1954, as amended; EPA Groundwater Protection
Standards, including Title 40 ofthe Code of Federal Regulations, Part 192, Subparts D and E; and the National
Environmental Policy Act of 1969, as amended.

2.4

Assumptions and Uncertainties

Long-term stewardship costs are estimated based on actual long-term stewardship costs at similar sites currently
managed by DOE. However, actual costs may vary as a result of the remediation strategies employed by the
Chevron Corporation.
DOE assumes that groundwater monitoring will only be necessary on an annual basis and that ACLs will be
applied to the groundwater contamination underlying the site.
The site is expected to be transferred to DOE in 2001.

3.0

ESTIMATED LONG-TERM STEWARDSHIP COSTS

The costs estimated for fiscal year (FY) 2000 are associated with preparing the site's long-term surveillance plan,
and preparing the site for transfer from Chevron Corporation to DOE. The costs estimated for the remaining
years are for monitoring and maintenance of the disposal cell and monitoring of the groundwater, and reflect the
assumptions listed above.

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National Defense Authorization Act (NDAA) Long-Term Stewardship Report

Site Long-Term Stewardship Costs (Constant Year 2000 Dollars)
Year(s)

Amount

Year(s)

Amount

Year(s)

Amount

FY 2000

$5,200

FY 2008

$35,100

FY 2036-2040

$170,500

FY 2001

$41,600

FY 2009

$35,000

FY 2041-2045

$170,400

FY 2002

$36,100

FY 2010

$34,300

FY 2046-2050

$170,500

FY 2003

$34,900

FY 2011-2015

$163,500

FY 2051-2055

$170,400

FY 2004

$35,300

FY 2016-2020

$159,200

FY 2056-2060

$170,500

FY 2005

$35,500

FY 2021-2025

$159,700

FY 2061-2065

$170,400

FY 2006

$34,800

FY 2026-2030

$168,700

FY 2066-2070

$170,500

FY 2007

$35,300

FY 2031-2035

$170,400

4.0

FUTURE USES

Once the site's license is transferred to DOE in 2001, activity at the site is expected to be restricted to long-term
monitoring and maintenance of the disposal cell and long-termmonitoring of the groundwater. Under UMTRCA
provisions, public access to the disposal cell will be restricted indefinitely.

For more information about the (Chevron) Panna Maria Site, please contact:
Art Kleinrath, Long-Term Surveillance and Maintenance Program Manager
U.S. Department of Energy, Grand Junction Office
2597 B3/4 Road, Grand Junction, CO 81503
Phone: 970-248-6037
or visit the Internet website at http://www.doegjpo.com

Texas

6

(Conoco) Conquista Site

(CONOCO) CONQUISTA SITE
1.0

SITE SUMMARY

1.1


The (Conoco) Conquista Site is located in Karnes
County, Texas, southwest of Falls City. The (Conoco)
Conquista Site is a uranium milling site site owned and
operated by the Continental Oil Company (CONOCO).
The (Conoco) Conquista Site encompasses 243 hectares
(600 acres) and has an onsite, 101-hectare (250-acre)
mill tailings disposal cell.
CONOCO's current site llliSSlon is to complete
remediation activities. Once remediation is complete
and the site is transferred to the U.S. Department of
Energy's (DOE) Grand Junction Office in 2002, DOE's
sole mission at the site will be to conduct long-term
stewardship activities.


Major Long-Term Stewardship Activities-

groundwater monitoring; disposal cell monitoring;
inspections; access restrictions
cell5.9 million cubic meters (6.5 million cubic yards);
groundwater unknown
perpetuity
2000-2006- $38,943
Landlord- Continental Oil Company; U.S.

Department of Energy, Grand Junction Office
(beginning in 2002)

In the early 1970s, CONOCO, in cooperation with
Pioneer Nuclear Corporation, began a venture known as
the Conquista Project to mine uranium and build and operate a 1,750-ton-per-day processing mill southwest of
Falls City in Karnes County. The project called for mining ore by open pit methods within a 56-kilometer (35mile radius) of the plant and hauling it back to the mill by truck. Mining began in 1971, followed by milling
operation between 1972 and 1982.
The (Conoco) Conquista Site is subject to Title II of the Uranium Mill Tailings Radiation Control Act of 1978
(UMTRCA). UMTRCA Title II sites are privately owned and operated sites that were licensed when the Act
was passed or thereafter. The majority of the uranium produced at these sites was for private sale, but a portion
was sold to the U.S. Government. Under UMTRCA Title ll, DOE is responsible for long-term stewardship
activities, by the site's owner, CONOCO, is responsible for remediation.

1.2


Remedial actions at the site of the former uranium milling site were carried out by CONOCO under provisions
of UMTRCA. The cost of the (Conoco) Conquista Site's reclamation and closure is borne by CONOCO, the
commercial owner of the processing facility. CONOCO began decommissioning the site in 1982, and finished
in 1984. The site's closure plan was submitted in 1987 and was approved in 1988, at which time the site was
reclaimed to comply with applicable standards. Mill tailings, contaminated soils, and construction debris were
remediated to EPA standards, and then disposed of in an unlined disposal cell. The cell was then capped with
grass and soil. The cell encompasses approximately 101 hectares (250 acres), and is designed and located to
achieve maximum protection from erosion and other geologic or environmental hazards, as well as provide the
required protection of human health and safety and the environment. The volume of the residual contamination
in the disposal cell is approximately 5.9 million cubic meters (6.5 million cubic yards). The strip mines have
been converted into fish-stocked ponds, and the mill's remediated tailings pond was converted into a sustainable
hay-growing business.
The groundwater at the site is believed to be contaminated by radionuclides, including radium and uranium. No
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National Defense Authorization Act (NDAA) Long-Term Stewm·dship Report

groundwater remediation has occurred, and supplemental standards, as defined in Title 40 of the Code ofFederal
Regulations Part 192.22, will likely be applied. Groundwater monitoring will be required to ensure compliance
with the supplemental standards and the effectiveness of the disposal cell. A request has not yet been made for
the application of supplemental standards to the contaminated groundwater. CONOCO is working with the State
of Texas (an Agreement State) to determine if supplemental standards can be used, and will be submitting a
request to the State of Texas in the near future.
2.0


2.1


The (Conoco) Conquista Site will be
transferred to DOE's Grand Junction Office in
2002 for custody and long-term care. Upon
transfer, DOE will be responsible for
conducting long-term stewardship activities,
including groundwater and disposal cell
monitoring. DOE will be responsible for
ongoing regulatory compliance at the site.
DOE will inspect the site and report site
conditions to the NRC annually. Inspection
parameters will be developed as part of the
site's long-term surveillance plan.
The site inspections will identify conditions
that might affect site integrity. The
recommended changes will be evaluated, and
DOE will conduct any needed maintenance or
monitoring. Maintenance activities could
include repairs to fences and site access
controls; adjustments to drainage and
construction of drainage structures to correct
erosion problems; and vegetation control,
including periodic mowing.
Specific
environmental monitoring activities will be
specified in the long-term surveillance plan.
Monitoring will likely include an annual
inspection to ensure the integrity of the cell cover and other engineered features, and to ensure that institutional
controls are effective and the site complies with applicable requirements.
Access to the site will be restricted through the use of fencing and posting warning signs, as necessary, along the
site boundary. DOE will staff a 24-hour phone line for reporting site concerns. Drilling and other intrusive
activities will be prevented within site boundaries through institutional control.
Site records will be kept in permanent storage at the DOE Grand Junction Office in Grand Junction, Colorado.
The types of records to be kept include characterization data, the remedial action design, the completion report,
the long-term monitoring plan, annual inspection reports, and monitoring data.

Texas

8


2.2


Groundwater

STAKEHOWER INTERACTION
When licensed and transferred to DOE, the annual
inspection report for the (Conoco) Conquista Site will
be distributed to the local libraries and any stakeholder
requesting one. The report will also be published on
the GJO website at www.doegjpo.com.

This site has residually contaminated groundwater
underlying the area around the cell. It is likely the
groundwater is contaminated by radionuclides,
including radium and uranium. Specific monitoring
requirements will be prescribed in the site's long-term
surveillance plan. However, it is likely that the groundwater will require annual monitoring for an unspecified
period of time to ensure the effectiveness of the selected cleanup remedy and compliance with supplemental
standards, as defined in Title 40 of the Code ofFederal Regulations Part 192.22.

Engineered Units
DOE will conduct annual inspections of the disposal cell to ensure the integrity of the cap and other engineered
features. Maintenance and repairs will be conducted on an as-needed basis. Long-term stewardship activities
will continue for the disposal cell in perpetuity. The disposal cell will have access controls that include warning
signs and a fence with locked gates.

2.3

Regulatory Regime

Long-term stewardship activities at the (Conoco) Conquista Site will be governed by several requirements in the
following regulations: UMTRCA; the Atomic Energy Act of 1954, as amended; Title 10 of the Code of Federal
Regulations Part 40; and the National Environmental Policy Act of 1969.

2.4


DOE assumes that it will be responsible for long-term stewardship activities at the site starting in 2002.
DOE assumes the frequency of groundwater monitoring will be comparable to the groundwater monitoring
frequency at similar sites.
The approval and application of supplemental standards, as defined in Title 40 of the Code of Federal
Regulations Part 192.22, to the site's contaminated groundwater is also anticipated.
The disposal cell cap is not expected to be replaced for a least 200 years.

3.0

ESTIMATED LONG· TERM STEWARDSHIP COSTS

The cost estimate for the (Conoco) Conquista Site is based on the known long-term stewardship activity costs
at other sites managed by DOE's Grand Junction Office that are similar to the (Conoco) Conquista Site.

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National Defense Authorization Act (NDAA) Long-Term Steardship Report

Site Long-Term Stewardship Costs (Constont Year2000Dollars)
Year(s)

Amount

Year(s)

Amount

Year(s)

Amount

FY 2000

$4,700

FY 2008

$52,700

FY 2036-2040

$255,700

FY 2001

$3,100

FY 2009

$52,600

FY 2041-2045

$255,700

FY 2002

$54,200

FY 2010

$51,500

FY 2046-2050

$255,800

FY 2003

$52,300

FY 2011-2015

$245,300

FY 2051-2055

$255,700

FY 2004

$52,900

FY 2016-2020

$238,700

FY 2056-2060

$255,700

FY 2005

$53,200

FY 2021-2025

$239,500

FY 2061-2065

$255,800

FY 2006

$52,200

FY 2026-2030

$253,100

FY 2066-2070

$255,700

FY 2007

$53,000

FY 2031-2035

$255,700

4.0

FUTURE USES

The site will be a permanent uranium mill tailings repository and will continue to be used for hay production.
Once NRC includes the site within DOE's general license for custody and long-term care in 2002, the disposal
site will be owned by the Federal Government, which will control land use within site boundaries. DOE will
perform long-term stewardship activities, as required under the NRC general license, to maintain protectiveness
and regulatory compliance.

For more information about the (Conoco) Conquista Site, contact:
Phone: 970-248-6037

Texas

10

(Exxon) Ray Point Site

(EXXON) RAY POINT SITE
1.0

SITE SUMMARY

1.1


The (Exxon) Ray Point Site is a privately owned and
operated site that was formerly used for the milling of
uranium ore. The site is located near the southern
Texas town of Ray Point, approximately 113 kilometers
(70 miles) southeast of San Antonio. The site covers
approximately 24 hectares (60 acres) and has a 16hectare (39-acre) onsite disposal cell for wastes that
were generated during uranium mining operations.

Major Long-Term Stewardship Activities - disposal

cell monitoring; inspections; access restrictions
cell275,400 cubic meters (360,000 cubic yards)
perpetuity

The current mission of the site is to complete
2000-2006- $25,600
remediation of onsite radioactive mill tailings and
Landlord- U.S. Department of Energy, Grand
waste. The (Exxon) Ray Point Site is subject to Title II
Junction Office (beginning in 2001)
of the Uranium Mill Tailings Radiation Control Act of
1978 (UMTRCA). UMTRCA Title II sites are privately
owned and operated sites that were licensed when UMTRCA was passed, or thereafter. The majority of the
mining and milling conducted at these sites was for the private sale of uranium, but a portion of the uranium was
sold to the U.S. Government. As such, the U.S. Department of Energy (DOE) is responsible for long-term
stewardship activities but not remediation of the site. Based on ongoing discussions with the Texas Bureau of
Radiation Control, DOE expects that the (Exxon) Ray Point Site will be transferred from Exxon Corporation
(now called Exxon Mobil Corporation) to DOE's Grand Junction Office in 2001 for long-term stewardship. At
that time, the only mission for the site will be the ongoing monitoring and maintenance of the disposal cell.

The historic mission of the site was the processing of uranium ore with an alkaline-leach process. The uranium
milled at the site was for private sale, but a portion was sold to the U.S. Government. The (Exxon) Ray Point
Site was originally owned by Susquehanna-Western, Inc., who acquired the property in 1969 and constructed a
uranium mill tailings impoundment. Susquehanna-Western, Inc. operated the mill from 1970 through 1973,
processing approximately 490,000 tons of ore during this period. In 1973, Exxon Corporation purchased the Ray
Point tract, including the mill and tailings impoundment. No further uranium was processed at the site. In 1979,
Exxon began decommissioning the mill and completed reclamation activities in 1987.
To terminate the Texas Bureau of Radiation Control license, Exxon Mobil Corporation must conduct stateapproved reclamation ofthe site's radioactive waste. The U. S. Nuclear Regulatory Commission (NRC) will
concur with the state concerning when the site will be transferred to DOE for custody and long-term care. In
order for the site to be transferred to DOE, Exxon Mobil Corporation must make a one-time payment to the U.S.
Treasury fully funding inspections and ongoing maintenance.

1.2


Exxon Corporation was responsible for conducting all remediation activities at this site. Contamination resulting
from the uranium milling operations was consolidated into an onsite disposal cell. The 16-hectare (39-acre) cell
contains approximately 27 5,400 cubic meters (360,000 cubic yards) of uranium mill tailings. The disposal cell
has a 1-meter thick, low-permeability radon barrier cover and a grass surface layer for erosion control. Erosion
control has been provided for all potentially vulnerable features, and the site was graded to provide positive
drainage. All disturbed areas were revegetated.
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National Defense Autho.-ization Act (NDAA) Long-Term Stewardship Report

Groundwater remediation is not necessary at the (Exxon) Ray Point Site, and no groundwater monitoring is
expected. Groundwater beneath the site is limited to perched zones of water with no alluvial groundwater table.
This situation eliminates the potential for groundwater yield and reduces the likelihood of contaminant migration.

2.0


2.1


When Exxon completed remedial action on the
tailings pond, a 2-meter (6-foot) high fence
was installed around the perimeter of the
property to protect the public from
unauthorized intrusion onto the property.
Anticipated site-wide long-term stewardship
activities include restricting access through the
use of the existing fence and warning signs
posted along the site boundary. DOE will
repair the fence and replace signs as necessary.
DOE will staff a 24-hour phone line for
reporting site concerns. Drilling and other
intrusive activities will be prevented within
site boundaries through institutional controls.
DOE's Grand Junction Office will be
responsible for performing long-term
stewardship activities for the disposal cell at
the (Exxon) Ray Point Site upon transfer to
DOE.
Site records will be stored at DOE's Grand
Junction Office in Colorado. The types of
records that will be maintained include site
characterization data, remedial action design
information, the site completion report,
long-term monitoring plans, annual inspection
reports, and current and historic monitoring
data.

2.2


Engineered Units
The site has one disposal cell containing approximately 275,400 cubic meters (360,000 cubic yards) of residual
contamination. The mill tailings, soils, and construction debris within the cell are contaminated with uranium,
radium, and thorium. DOE will conduct annual inspections of the 16-hectare (39-acre) disposal cell to ensure
the integrity of the cap and other engineered features. Maintenance and repairs will be conducted on an asneeded basis.

Texas

12

(Exxon) Ray Point Site

2.3

Regulatory Regime

STAKEHOLDER INVOLVEMENT

Long-term stewardship activities at the (Exxon) Ray
Point Site will be governed by several requirements in
the following regulations: UMTRCA; the Atomic
Energy Act of 1954, as amended; Title 10 of the Code
of Federal Regulations Part 40, and the National
Environmental Policy Act of 1969.

2.4

Community interaction is expected to be minimal once
the site is transferred. Copies of the annual inspection
report for the (Exxon) Ray Point Site and other sites
will be distributed to the local library and to any
stakeholder requesting one. The site's annual
inspection reports will also be published on the DOE
Grand Junction Office website at www.doegjpo.com.


Cost estimates are based on the actual costs oflong-term stewardship activities at similar disposal cells currently
managed by DOE's Grand Junction Office.
No groundwater monitoring is anticipated at the site based on ongoing conversations with the Texas Department
of Health, as well as experience with similar sites.

3.0


Long-term stewardship costs for the (Exxon) Ray Point Site are estimated to include an initial start-up cost of
$25,000 in 2001, when the site is transferred to the Grand Junction Office. Costs incurred before that time are
associated with developing the initial site long-term surveillance plan and conducting activities necessary for the
site's transfer to DOE. Following initial start-up, costs are associated with the ongoing monitoring and
maintenance of the disposal cell. Costs are expected to remain relatively constant over the cost estimate's
lifespan.
Site Long-Term Stewardship Costs (Constant Year 2000 Dollars)
Year(s)

Amount

Year(s)

Amount

Year(s)

Amount

FY 2000

$15,200

FY 2008

$26,300

FY 2036-2040

$127,900

FY 2001

$31,200

FY 2009

$26,300

FY 2041-2045

$127,800

FY 2002

$27,100

FY 2010

$25,700

FY 2046-2050

$127,900

FY 2003

$26,100

FY 2011-2015

$122,700

FY 2051-2055

$127,800

FY 2004

$26,400

FY 2016-2020

$119,400

FY 2056-2060

$127,900

FY 2005

$26,600

FY 2021-2025

$119,800

FY 2061-2065

$127,800

FY 2006

$26,100

FY 2026-2030

$126,600

FY 2066-2070

$127,900

FY 2007

$26,500

FY 2031-2035

$127,800

4.0

FUTURE USES

The future use of the site will be limited to monitoring and maintaining the disposal cell. Under UMTRCA
provisions, access to the site will be restricted indefinitely.

Texas

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National Defense Authol"ization Act (NDAA) Long-Term Stewardship Report

For more information about the (Exxon) Ray Point Site, please contact:
Phone: 970-248-6037

Texas

14

Falls City Site

FALLS CITY SITE
1.0

SITE SUMMARY

1.1


The Falls City Site is the location of a former uranium
milling site that operated from 1961 until 1973. The
site contains a disposal cell for the uranium mill tailings
and process-related wastes resulting from mill
operations. The site is located in Kames County,
Texas, approximately 74 kilometers (46 miles)
southeast of San Antonio, and approximately 13
kilometers (8 miles) southwest of Falls City. The site
covers 96 hectares (232 acres) and contains a 51hectare ( 125-acre) disposal cell.

Major Long-Term Stewardship Activitiesgroundwater monitoring, disposal cell monitoring and
maintenance; inspections; access restrictions
Estimated Volume of Residual Contaminantsgroundwater 4.5 million cubic meters (1.2 billion
gallons); disposal cell4.4 million cubic meters (5.8
million cubic yards)
perpetuity
2000-2006-$139,300
Landlord- U.S. Department of Energy, Grand
Junction Office

The mill used a sulfuric acid leach extraction process to
produce uranium oxide from approximately 2.3 metric
tons (2.5 million tons) of ore. As a result of these
operations, more than 2.8 metric tons (3.1 million tons)
of tailings (a sand-like, radioactive waste product) were
discharged to tailings ponds, four of which were open
pit mines excavated into the ore-bearing sandstone. The tailings ponds were nine to 11 meters (30 to 35 feet)
deep and unlined, except for the naturally clayey foundation soils and sediments.
The processing site consisted of two parcels, approximately 1.6 kilometers (one mile) apart. Parcel A was fenced
and encompassed 191 hectares (473 acres), including the former mill site, the mill building, five tailings piles,
and a tailings pond. Parcel B encompassed 49 hectares (120 acres) and included a sixth tailings pile in the
northeast area of the parcel. Windblown contamination from the tailings piles were deposited on both parcels:
121 hectares (298 acres) at Parcel A and 32 hectares (80 acres) at Parcel B. An estimated 4.4 million cubic
meters (5.8 million cubic yards) of residual radioactive materials were contained within both parcels. The
disposal cell is located on Parcel A.
The current mission at the Falls City Site is conducting long-term stewardship activities, including disposal cell
and groundwater monitoring. The Falls City Site is subject to Title I of the Uranium Mill Tailings Radiation
Control Act of 1978 (UMTRCA). As such, the U.S. Department of Energy's (DOE) Albuquerque Office
remediated the site and the Grand Junction Office is responsible for conducting long-term stewardship activities.
DOE began conducting long-term stewardship activities at the site in 1997.
The historic mission of the Falls City Site was to process uranium for sale to the U.S. Government for its national
defense program. The original mill was built, owned, and operated from 1961 to 1973 by Susquehanna-Western,
Inc., of San Antonio, Texas. Uranium extracted from sandstone ore was subjected to a sulfuric acid leaching
process, which created approximately 2.8 metric tons (3.1 million tons) of tailings. These tailings were deposited
in unlined ponds on the site. Solution Engineering, Inc., purchased the site in 1975, and conducted secondary
solution mining from four tailings piles between 1978 and 1982. In 1982, the liquid in the ponds was evaporated,
and the tailings were covered with soil and revegetated.

Texas

15


@ Groundwater Monitoring Well
~ Groundwater Contamination

0

0.5

Miles

Falls City Site

1.2


DOE conducted an environmental assessment of the Falls City Site and selected the remedial action alternative
of consolidating the tailings onsite in a disposal cell. DOE began remedial action at the Falls City Site in 1992
and completed site remediation in 1994. The cleanup involved consolidation of seven tailings piles and
additional contaminated material from 13 vicinity properties, totaling approximately 4.4 million cubic meters (5 .8
million cubic yards) of residual radioactive material, into a stabilized, 51-hectare (125-acre) disposal cell. The
affected area was remediated to U.S. Environmental Protection Agency (EPA) standards. The lined disposal cell
has a radon barrier cover, rock side slopes, and a grass-covered top surface layer to control erosion. The Nuclear
Regulatory Commission (NRC) concurred in the DOE certification that the site was remediated to NRC-accepted
design. In 1997, the site's disposal cell came under NRC's general license for the custody and long-term care
of residual radioactive material disposal cells.
Groundwater beneath the Falls City Site is contaminated by past uranium ore processing activities, open pit
mining, and in situ solution leaching of tailings. Open pit mining occurred on Parcels A and B of the site before
milling activities began in 1961. Also, the shallow groundwater in the mined areas is of naturally poor quality
because of ore bodies in the aquifer matrix. As a result, approximately 4.5 million cubic meters (1.2 billion
gallons) of groundwater are contaminated. The groundwater is classified as limited use because of the naturally
occurring contamination. Consequently, supplemental standards, as defined in Title 40 of the Code ofFederal
Regulations Part 192.22, have been applied and no groundwater remediation is expected.

Texas

16

Falls City Site

2.0


2.1


The Grand Junction Office is responsible for long-term monitoring and maintenance at the Falls City Site. DOE
manages the site according to an NRC-approved long-term surveillance plan prepared specifically for the Falls
City Site. The site is owned by the Federal Government, which controls land use within site boundaries.
DOE is responsible for conducting long-term stewardship activities, and maintaining access restrictions and
institutional controls. Access is restricted by a locked gate, a wire fence, and warning signs posted every 152
meters (500 feet) along the site boundary. DOE staffs a 24-hour phone line for reporting site concerns. Drilling
and other intrusive activities are prevented within site boundaries through institutional controls. DOE conducts
an annual inspection to assess the integrity of the cell cover and other engineered features, and to ensure that
institutional controls are effective and the site complies with applicable requirements. DOE also performs site
maintenance, as necessary, including removal of woody vegetation from the rock armor and annual hay
harvesting from the grass-covered areas. Groundwater is sampled and analyzed periodically, and water levels
are monitored in selected wells.
The site records for the Falls City Site are kept in permanent storage at the DOE Grand Junction Office in
Colorado. The types of records kept include characterization data, the remedial action design, completion report,
the long-term monitoring plan, annual inspection reports, and monitoring data. Real property records are
maintained at the DOE Albuquerque Operations Office.

2.2


Groundwater
Contaminated groundwater has been identified in three
plumes in the shallow bedrock aquifers. Approximately
4.5 million cubic meters (1.2 billion gallons) of
groundwater are contaminated with arsenic, cadmium,
chromium, lead, mercury, molybdenum, net gross alpha,
nitrate, radium, selenium, and uranium, which have
exceeded maximum concentration limits at least twice
since 1990.

STAKEHOWER INTERACTION

Community interaction has been minimal since the
remedial action was completed. Copies of the annual
inspection report for the Falls City Site are distributed
to the local library and any stakeholders requesting
them. The report is also published on the DOE Grand
Junction Office website at www.doegjpo.com.

No groundwater remediation is expected because
supplemental standards, as defined in Title 40 of the Code of Federal Regulations Part 192.22, have been
approved. However, groundwater must be monitored for at least five years. The groundwater protection strategy
is to apply supplemental standards, as the groundwater in the uppermost aquifer is classified as 'limited use'
because of its poor ambient quality and because it is not a current or potential source of drinking water.
Groundwater from the uppermost aquifer contains widespread ambient contamination resulting from naturally
occurring conditions and from the effects of human activity unrelated to uranium milling operations. The
groundwater cannot be effectively cleaned up for drinking purposes with the treatment methods currently and
reasonably employed by public water supply systems. NRC and the State of Texas concurred with the
groundwater protection strategy for the disposal site in September 1992, and NRC approved the site's
groundwater compliance action plan in September 1998. Monitoring will continue until2003. At that time, the
need to continue monitoring will be evaluated.

Texas

17


Engineered Units
Remedial action at the site was completed in July 1994, when all radioactive materials and tailings were
consolidated into an EPA-compliant, onsite disposal cell and all remediated areas were regraded and reseeded.
The disposal cell contains 7,143,000 dry tons of radioactive material with a total activity of 1,277 curies of
radium-226. The cell, which measures 792 meters by 671 meters (2,600 feet by 2,200 feet) at the base and rises
19 meters (62 feet) above the surrounding land, is sited at grade on a drainage divide. It occupies 51 hectares
(127 acres) and is enclosed by a posted security fence. A clayey soil layer serves as a low-permeability radon
barrier. A vegetated layer of top soil over a compacted soil layer covers the top of the cell. The cell was
designed to promote rapid runoff of precipitation to minimize leachate. Riprap with a median diameter of 18
centimeters (seven inches) overlays a granular bedding layer on the side slopes of the cell. This 20-percent sideslope grade allows water to run off the cell sides into the surrounding six meter (20 foot) wide rock apron. The
riprap protects the side slopes from erosion.
The surface conditions of the disposal cell will be monitored during annual inspections to determine whether the
disposal cell and erosion protection components of the cell are performing as intended. The disposal cell at the
Falls City Site was designed and constructed to last for 200 to 1,000 years. DOE's responsibility for the safety
and integrity of the Falls City Site will continue in perpetuity.

2.3

Regulatory Regime

In 1997, the Falls City Site came under a general license issued by NRC for custody and long-term care of
residual radioactive material disposal sites (contained at Title 10 of the Code of Federal Regulations, Section
40.27). The purpose of the general license is to ensure that such sites will be cared for in a manner that protects
human health and safety and the environment. The general license went into effect when NRC concurred that
the site conformed to cleanup standards and formally accepted the site-specific long-term surveillance plan.
Long-term stewardship activities at the Falls City Site are governed by several other requirements in the
following regulations: the Uranium Mill Tailings Radiation Control Act of 1978; the Atomic Energy Act of 1954,
as amended; EPA groundwater protection standards, including Subparts B and C of Title 40 of the Code of
Federal Regulations, Part 192; a cooperative agreement between DOE and the State of Texas; and the National
Environmental Policy Act of 1969, as amended.

2.4


Because the site is already performing long-term stewardship activities, long-term stewardship activities are well
known and are not expected to change dramatically. DOE assumes the annual groundwater monitoring frequency
will be reduced to once every three years after 2003. DOE also assumes that monitoring will continue
indefinitely until the disposal cell demonstrates infiltration control. It is expected that the cap will not be
replaced for a minimum of 200 years.

3.0


The following table shows the estimated costs of the long-term stewardship activities at the Falls City Site. The
estimated costs are based on actual costs of long-term stewardship activities at this and other sites. Contingency
costs, such as cap replacement, have not been incorporated into the cost estimates.
DOE will monitor groundwater at the site annually through 2003, and then, after an evaluation of the need, will
monitor likely once every three years thereafter. Fiscal Years (FY) 2001-2006 include costs for well
decommissioning.
Texas

18

Falls City Site

Site U,ng•Term Stewardship Costs (Constant Year 2000 Dollars)
Year(s)

Amout#

Year(s)

Amount

Year(s)

Amount

FY 2000

$82,100

FY 2008

$39,700

FY 2036-2040

$225,400

FY 2001

$173,400

FY 2009

$55,400

FY 2041-2045

$242,200

FY 2002

$181,700

FY 2010

$39,700

FY 2046-2050

$225,500

FY 2003

$165,400

FY 2011-2015

$220,800

FY 2051-2055

$242,200

FY 2004

$153,500

FY 2016-2020

$204,900

FY 2056-2060

$225,400

FY 2005

$101,100

FY 2021-2025

$225,300

FY 2061-2065

$242,200

FY 2006

$117,600

FY 2026-2030

$223,300

FY 2066-2070

$225,500

FY 2007

$39,900

FY 2031-2035

$242,200

4.0

FUTURE USES

Public access to the disposal cell will be restricted indefinitely. The site is owned by the Federal government
and the future land use is not anticipated to change.

For more information about the Falls City Site, please contact:
Phone: 970-248-6037

Texas

19

National Defense Authol"ization Act (NOAA) Long-Tenn Stewardship Report

Texas

20

Pantex Plant

PANTEX PLANT

1.0

SITE SUMMARY

1.1


The Pantex Plant was built by the United States Army
in 1942 as a conventional bomb plant. At the end of
World War II, the Plant was deactivated and the
property eventually reverted to the War Assets
Administration. In 1949, the entire installation was sold
to Texas Tech University to be used for experimental
farming, subject to recall, if necessary. Following an
extensive survey of World War II ordnance plants, the
Atomic Energy Commission (which later became the
Department of Energy) in 1951 chose the Pantex site
for expansion of its nuclear weapons assembly
facilities. The Army Ordnance Corps reclaimed the site
for the Atomic Energy Commission and contracted with
the Silas Mason Company to rehabilitate it. From 1956
to the present, the Pantex Plant has been operated by the
Mason & Hanger Corporation (MHC).

Major Long-Term Stewardship Activities-

groundwater and soil cleanup; groundwater monitoring
Total Site Area- 4,119 hectares (10,177 acres)
Estimated Volume of Residual Contaminants-

groundwater 5.7 billion liters (1.5 billion gallons);
playa/ditch sediment 100 hectares (250 acres); soil 250
hectares (610 acres); engineered units 16 hectares (40
acres)
Portions Requiring Long-Term Stewardship as of
2006-2
2000-2006- $1.4 million
Landlord- U.S. Department of Energy, Office of

Defense Programs

Located in the Texas Panhandle in Carson County north of U.S. 60, the Plant lies 27 kilometers (17 miles)
northeast of downtown Amarillo. The Pantex Plant site consists of land owned and leased by the U.S. Department
of Energy (DOE). DOE owns 4,119 hectares (10,177 acres), including 3,683 hectares (9,100 acres) in the main
Plant area and 436 hectares (1,077 acres) at Pantex Lake, which lies approximately 4 kilometers (2.5 miles)
northeast of the main Plant area. Currently, no government industrial operations are conducted at the Pantex Lake
property. In addition, 2,347 hectares (5,800 acres) of land south of the main Plant area are leased from Texas
Tech University for a safety and security buffer zone. The Plant is composed of several functional areas,
commonly referred to as numbered zones. These include a weapons assembly/disassembly area (Zone 12), a
weapons staging area (Zone 4), an area for experimental explosive development (Zone 11), a drinking water
treatment plant, a sanitary wastewater treatment facility, and vehicle maintenance and administrative areas. Other
functional areas include a utilities area for steam and compressed air, explosive test-firing facilities, a burning
ground for thermally treating (i.e., burning) explosive materials, landfills, and Zone 10, which is currently used
only for storage. Overall, there are more than 400 buildings at the Plant.
DOE's Office of Defense Programs (nuclear weapons mission) and Office of Environmental Management
(environmental restoration) are jointly responsible for activities at the site. The nuclear weapons mission of the
Pantex Plant, which is under the Office of Defense Programs, involves the assembling and disassembling,
evaluating, repairing, and retrofitting nuclear weapons in the nations stockpile; sanitizing components from
dismantled nuclear weapons; providing interim storage for plutonium pits from dismantled weapons; and
developing, fabricating, and testing of chemical explosives and explosive components for nuclear weapons in
support of DOE initiatives. These activities involve handling (but not processing) highly enriched uranium,
plutonium, and tritium. Other activities include managing classified components that result from dismantling
nuclear explosives, as well as a variety of non-radioactive toxic chemicals. Although government-owned, the
Plant is a contractor-operated and managed facility since 1956.

Texas

21

National Defense Authorization Act (NDAA) Long-Te1·m Stewa1·dship Report

--116'9
74
To Lake Pantex
(-2.5 miles)

68

Texas Tech Research Farm

Groundwater Contamination

0

1

2

Miles
Pantex Plant

Texas

22

Pantex Plant

1.2


During more than 50 years of operation of the Pantex
Plant to support defense missions, contaminants were
released to the surface environment. Key contaminants
include volatile and semi-volatile organic compounds,
high explosives, and heavy metals. Contamination was
found in the perched groundwater beneath the Zone 12
operations area, in the soil near operations areas, in
previously operated landfills, and in the ditches and
playas that form the Plant's drainage system.
Contaminants were also found in the perched aquifer on
properties neighboring the Plant to the south and
southeast. A large-scale pump-and-treat system
continues to operate to remove explosives, organic
compounds, and chromium from the perched aquifer
onsite and to reduce migration of contaminated
groundwater offsite. More than 295 million liters (78
million gallons) of contaminated water has been treated,
removing over 500 kilograms (1,100 lbs.) of high
explosives. Interim corrective measures conducted at
various areas of the Plant include:
•

removal of depleted uranium contamination,
which included radiation surveys,
identification, and excavation of over 1,400
cubic meters (1,830 cubic yards) of
contaminated soil.

In addition, construction of more than 2.8 hectares
(seven acres) of administrative landfill covers at four
sites has been completed.
There are 249 identified release sites within 144 solid
waste management units and areas of concern at
Pantex. These sites are managed as 14 release site
groupings for investigation and remediation purposes.
DOE anticipates that, with the exception of perched
groundwater and three-to-five soil/sediment solid waste
management units, interim corrective measure cleanup
Texas

• 42 of 43 release sites are now in steady-state and
the Resource Conservation and Recovery Act
(RCRA) Facility Investigation for the 43 rd site (95
th Terrace Site) is under Environmental Protection
Agency (EPA) review
• Completed the Corrective Measures Study to
determine which cleanup method to use for the
95th Terrace Site
PLANNED ACCOMPLISHMENTS

• Complete the Corrective Measures Implementation
Design which specifies construction details for
cleanup of the 95 th Terrace Site
• Continue groundwater treatment and monitoring
activities, including well monitoring and
maintenance, preparing regulatory reports, and
groundwater interceptor well design

innovative in-situ biologic treatment and exsitu composting of high-explosivescontaminated soil;
excavation and disposal of more than 11,469
cubic meters (15,000 cubic yards) of soil
contaminated with high explosives, volatile
and semi-volatile organic compounds, and
heavy metals; and

•

PAST ACCOMPLISHMENTS

STAKEHOLDER INTERACTION

Public participation associated with the Pantex
Environmental Restoration Program includes monthly
meetings with the Pantex Plant Citizen's Advisory
Board; quarterly public meetings that are open to the
community; and various presentations provided to
local special interest groups, such as the League of
Women Voters, the Pantex Plant Environmental Task
Force, and owners of land adjacent to the Pantex Plant.
An electronic reading room has been established at a
local community college, in addition to the
Administrative Record file located at Pantex, which
allows the public access to technical documents that
provide investigation and assessment results that
support decisions regarding corrective actions at
Pantex. Public notice and comment periods are
required for review of corrective measures and
preferred alternative selection; public notice is also
required once a final preferred corrective action design
is approved. In addition, press releases, public tours,
and videos are provided to update the public on the
status.
23

National Defense Authorization Act (NDAA) Long· Term Stewardship Report

results will meet regulatory closure requirements. For those solid waste management units not closed by interim
corrective measures, final corrective action design and construction activities to implement preferred remediation
alternatives will be conducted. Interim corrective measures for the perched aquifer will continue through 2004,
when completion of construction activities for the final preferred remediation alternative is scheduled to occur.
Completion of final preferred alternative construction activities for soil/sediment sites that require corrective
action is also scheduled to be completed by 2004.

2.0

SITE-WIDE LONG-TERM STEWARDSHIP DISCUSSION

2.1

Site-Wide Long-Term Activities

As the site landlord, DOE Defense Programs has
LONG-TERM STEWARDSHIP GOALS
stewardship responsibilities for all Pantex facilities and
will determine their future use after the current cleanup
Long-term stewardship goals at Pantex include
end-states are achieved. All release sites at Pantex will
restoring impacted groundwater to beneficial use
be remediated to achieve closure designation in
quality and ensuring soil/sediment sites requiring post
closure care are managed in a manner that prevents
accordance with the cleanup levels specified by the
adverse effects to human health and the environment.
Texas Risk Reduction Standards regulations and
associated site-specific guidance for soils and
groundwater cleanup. It is anticipated that groundwater
pump-and-treat operations will continue through 2055 to effectively treat groundwater contamination; however,
the long-term efficiency and capability of the groundwater extraction and treatment system is uncertain, and
additional time could be required to fully achieve groundwater remediation objectives. The assumed date for the
project end-state will be evaluated periodically, as additional operational effectiveness information becomes
available. Further, regulatory requirements for landfill/soil/sediment cover maintenance, and groundwater
monitoring and treatment operations will be negotiated with the regulatory agency periodically.

2.1.1

Institutional and Engineered Controls

Institutional and engineered controls for the Pantex Plant will vary depending on the level of residual
contamination remaining at the release site. These controls may include, as appropriate, deed recordation and
land use restrictions according to residual contaminant levels remaining and cleanup levels achieved; in-situ
containment by use of landfill covers/caps and ditch liners; fencing; and administrative controls, such as
operating procedures that limit exposure to environmental media with residual contamination.

2.1.2

Record-Keeping Activities

Record-keeping activities for the Pantex Plant Environmental Restoration Program are directed under Title 42
United States Code (42 U.S.C.) 9613, Section 113(k) Administrative Record and Public Participation; Title 40
Code of Federal Regulations (40 CFR) Part 300, Subpart I - Administrative Record for Selection of Response
Action; 36 CPR Chapter XII, National Archives and Records Administration Requirements (Subchapter B), and
record-keeping requirements stipulated in the Pantex Plant's Resource Conservation and Recovery Act (RCRA)
Hazardous Waste Operating Permit. Governing documents include DOE Orders 1324.2A, Records Disposition;
5500.7 A, Vital Records Protection Program; 1325.5A, Records Management Program; and various Pantex Plant
records manuals, directives, standards and internal operating procedures. These regulatory drivers and governing
documents, along with guidance documents, provide for what records must be maintained, where they must be
maintained, the duration of document maintenance, and final disposition requirements. In general, operating
records, investigation, assessment, remediation, monitoring, interaction documentation between Pantex and
regulatory agencies, and public participation records will be kept onsite at the Pantex Plant as part of an
Administrative Records file.
Texas

24

Pantex Plant

The Pantex Plant is on the National Priorities List and, therefore, the Administrative Records file at Pantex will
maintain official records that relate to response/remedial action decisions for environmental corrective action
for a period of time identified as the Statute of Limitations time period specified for sites on the National
Priorities List. General DOE record-keeping requirements stipulate that unscheduled records, such as
environmental records, must be maintained for 75 years. Records are microfilmed for long-term retrieval
purposes. DOE maintains a public reading room for the Pantex Plant at Amarillo College, located in Amarillo,
Texas. Documents that are generated and placed in the Pantex Administrative Records file are provided in hard
copy or electronic form to Amarillo College for public access purposes.

2.2


The possibility exists that additional investigations may be necessary to resolve regulatory comments on
documents previously provided due to the fact that not all investigation and cleanup reports have been reviewed
and approved by the applicable regulatory agencies. In addition, corrective measures studies/designs approval
and subsequent final corrective action construction activities are dependent on final approval of the
investigations. Additional investigations have the potential to identify conditions requiring revision of previous
recommendations or future corrective actions planned. Input received from regulatory authorities and/or the
public on proposed final corrective actions may result in final corrective action alternative selections differing
from those currently anticipated.

2.3

Regulatory Regime

Site-wide assessments and environmental monitoring programs have been and are being conducted. The first
environmental characterization began in 1981 in order to prepare an Environmental Impact Statement. This
activity was followed by a multi-phased Comprehensive Environmental Restoration Program assessment from
1985 through 1986. A 1986 environmental survey found soil contamination in various locations at the Pantex
Plant. A RCRA Facility Assessment, completed in 1989, identified solid waste management units that required
characterization to ensure potential threats to human health and the environment were identified and minimized.
There are currently 14 groupings of solid waste management units based on suspected types of contaminants and
potential source areas.
Restoration activities at the Pantex Plant are regulated jointly by the Texas Natural Resources Conservation
Commission (TNRCC) and the U.S. Environmental Protection Agency (EPA), and the agencies have signed a
memorandum of understanding for activities at Federal facilities. As a permitted hazardous waste facility, the
Pantex Plant is regulated under RCRA, and the TNRCC has been granted authority to administer the RCRA
Program in Texas. An Administrative Order on Consent was signed by EPA and DOE in 1990, outlining the
remedial response actions under RCRA for the Pantex Plant. In May 1994, the Pantex Plant was added to the
National Priorities List, thereby subjecting Pantex to Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA) requirements. EPA and TNRCC have allowed an integration of RCRA and
CERCLA processes to continue closure of contaminated sites. The Pantex Plant is still on theN ational Priorities
List.
Closure of release sites with residual contamination is classified in the State of Texas by contaminant levels that
correspond to one of three Risk Reduction Standards. Risk Reduction Standard 1 closures represent release sites
with no residual contamination remaining above established background levels. Risk Reduction Standard 2
closures represent release sites with residual contamination that is protective of human health and the
environment without implementation of post-closure care. Risk Reduction Standard 3 closures represent release
sites with residual contamination at levels that require post-closure care in the form of administrative, and/or
institutional, and/or engineering controls.

Texas

25

' National Defense Authorization Act (NDAA) Long-Term Stewardship Report

2.4

Estimated Site-Wide Long-Term Stewardship Costs

Costs for long-term stewardship at Pantex consist primarily of groundwater corrective actions and monitoring.
Groundwater corrective actions may consist of both pump-and-treat and in-situ treatment methodologies. Costs
associated with long-term groundwater treatment, in addition to actual equipment maintenance, system
augmentation, technical oversight, utility costs, and infrastructure costs, include both regulatory-required
corrective action and compliance monitoring. Corrective action and compliance monitoring costs include
personnel costs to maintain equipment and collect samples, system operation costs, and analytical costs to
evaluate contaminant reduction. It is estimated that groundwater treatment and corrective action monitoring will
continue at Pantex through Fiscal Year 2055. The time period for conducting groundwater compliance monitoring
will be negotiated between DOE and the TNRCC but is anticipated to continue indefinitely (for purposes of this
report, through Fiscal Year (FY) 2070). Long-term stewardship costs for Risk Reduction Standard 3 closures of
soil/sediment sites include engineered unit maintenance and, as needed, replacement. Also included are the
technical oversight costs necessary to evaluate the effectiveness of the implemented corrective action and costs
necessary to maintain administrative controls. It is estimated that approximately 5 percent of the total long-term
stewardship costs at Pantex will be a result of maintaining administrative controls for release sites closed under
Risk Reduction Standard 2. The remaining costs are attributable to meeting cleanup objectives, maintaining, and
monitoring the cleanup of sites closed under Risk Reduction Standard 3.
Site Long-Term Stewardship Costs (Constant Year ZOIJ,() Dollars)
Year(s)

Year(s)

Amount

Amount

Year(s)

Amount

FY 2000

$0

FY 2008

$1,381,000

FY 2036-2040

$6,374,000

FY 2001

$0

FY 2009

$1,411,000

FY 2041-2045

$6,945,000

FY 2002

$0

FY 2010

$1,624,000

FY 2046-2050

$7,566,000

FY 2003

$1,496,000

FY 2011-2015

$8,240,000

FY 2051-2055

$8,547,000

FY 2004

$1,418,000

FY 2016-2020

$9,351,000

FY 2056-2060

$4,195,000

FY 2005

$1,317,000

FY 2021-2025

$10,463,000

FY 2061-2065

$4,843,000

FY 2006

$1,374,000

FY 2026-2030

$11,337,000

FY 2066-2070

$5,060,000

FY 2007

$1,471,000

FY 2031-2035

$12,745,000

3.0

PORTION OVERVIEW

The regulatory regime in Texas identifies three closure standards (Risk Reduction Standards) for release sites
depending on residual contamination remaining in environmental media, subsequent risk to human health and
the environment resulting from the residual contamination, and the controls required to maintain acceptable risk
levels. Therefore, for the purpose of this document, long-term stewardship activities are discussed in terms of
"portions," which correspond to Risk Reduction Standard closures that have long-term stewardship requirements.
Portions have been further subdivided into the type of environmental media or units (i.e. soil, groundwater,
surface water/sediment, engineered units) that are subject to closure under the Risk Reduction Standards.
Release sites approved for closure under Risk Reduction Standard 1 do not require administrative, institutional,
engineered controls, or monitoring. Release sites approved for closure under Risk Reduction Standard 2 require
long-term stewardship in the form of deed recordation that restricts use of the property to activities that
correspond to the cleanup levels achieved (residential vs. non-residential). Release sites at Pantex closed under
Texas

26

Pantex Plant

Risk Reduction Standard 2 will primarily be cleaned up to levels that restrict, by implementation of deed
restrictions, the future use of the site to activities that are allowed for property zoned for industrial use (nonresidential). It is currently planned that contaminated perched groundwater within the Pantex Plant property
boundaries will be cleaned up to approved Risk Reduction Standard 3 residual concentration levels (alternate
concentration levels) that result in contaminant concentrations that meet Risk Reduction Standard 2 residential
cleanup levels at the property boundary. It is currently planned that cleanup levels for offsite perched
groundwater will achieve Risk Reduction Standard 2 levels for residential use; however, final cleanup levels
achieved will depend on technical limitations for remediating the groundwater and negotiations with offsite
landowners. Release sites at Pantex recommended for closure under Risk Reduction Standard 2 include certain
soils, sediments, and surface water solid waste management units.
Release sites approved for closure under Risk Reduction Standard 3 require post-closure care in the form of
continued remedial actions until approved cleanup levels are met and/or it can be demonstrated that residual
contamination does not represent risk to human health and the environment above approved cleanup levels in
the absence of post-closure care. Release sites closed under Risk Reduction Standard 3 also require corrective
action monitoring and maintenance until the post-closure care period is complete. Release sites closed under
Risk Reduction Standard 3 will have institutional and/or engineered controls that limit the future use of the
release site on a site-specific basis. Generally, when closed under Risk Reduction Standard 3, the future use of
the release site will be restricted to activities allowed in areas zoned for industrial activities. However, in some
Risk Reduction Standard 3 closures, post-closure care requirements and residual contamination will limit future
use of the release site to activities associated with monitoring and maintenance of the engineered control or
activities allowed by institutionalized access control. Release sites that are anticipated to require the complete
RCRA corrective action process (Baseline Risk Assessment, Corrective Measure Study, Corrective Measure
Design, and Corrective Measure Construction) to achieve closure under Risk Reduction Standard 3 include
several inactive landfill solid waste management units, several solid waste management units that consist of
ditches previously used for waste water transport, perched groundwater, and one solid waste management unit
associated with previous discharges of high explosives waste water.
The primary contaminants at both Risk Reduction Standard 2 and Risk Reduction Standard 3 sites include the
metals chromium, lead, and barium; the high explosives RDX, HMX, and TNT; and volatile and semi-volatile
organic compounds, including trichloroethylene, chrysene, acetone, benzo(a)pyrene and benzo(a)anthracene.
Current estimates indicate that 5. 7 billion liters ( 1.5 billion gallons) of contaminated perched groundwater require
treatment and approximately 364 hectares (900 acres) of soil/sediments/surface water sites will be closed under
Risk Reduction Standard 2 and Risk Reduction Standard 3. Planned engineered units include ditch liners,
engineered soil coverings, and a groundwater treatment and processing system and facility. All final preferred
alternative corrective measures construction activities are scheduled to be completed by 2004.
The tables on the following pages provide a correlation of the proposed Risk Reduction Standard closure to each
solid waste management unit and area of concern that comprise the operable unit groupings at Pantex.

Portion

Long-Term Stewardship End-Year

Risk Reduction 2

2003

in perpetuity

Risk Reduction 3

Texas

Long-Term Stewardship Start-Year
2003

in perpetuity

27


AL- PX- 01 Burning Ground

AL- PX- 02 High Priority
Potential Release Sites

AL- PX- 03 Former Cooling
Tower

SWMUs 14 to 27- Explosive Bum Pads
SWMUs 37 to 44- Landfills
SWMU 47- Chemical Bum/ Evaporation Pits
SWMU - Demonstration Facilities
SWMU 11 - Building FS- 16 -Surface Impondment in Zone 5
SWMU 13 - Former Solar Evaporation Pond (Building 11- 51)
SWMU 109- Concrete Sump (Building 12- 68)
SWMU 136- Subsurface Leaching Beds (Building 12- 59)
SWMU 139- Photo Processing Leaching Bed (Building FS- 10)
AOC 12 Building 12- 5D Paint Shop Area
Unassigned - Firing Site 1 (FS- 1) - Unlined Landfill
Firing Site 20 (FS- 20) - Equipment
Site 24
-Concrete
AOC 13- Former Cooling Tower in Zone 12

X
X
X
X
X
X
X
X
X
X
X

SWMU 140- Old Sewage Treatment Plant Sludge Beds

X

AOC 11 - Fire Training Area Burn Pits

X

Site-Wide Groundwater
Groundwater
AL- PX- 07 Landfills

AL- PX- 08 Ditches and Playas

Texas

Construction Debris Landfills:
SWMU 54 - Landfill 3
SWMU 55- Landfill4
SWMU 61 -Landfill 10
SWMU 62 - Landfill II
SWMU 63- Landfill12
SWMU 66- Landfill 15
General Purpose General Sanitary Landfills:
SWMU 68a - Original Landfill
SWMU 68b - Landfill 1
SWMU 68c - Landfill 2
SWMU68dLandfill
SWMU 1 - Building 12- 17 - Drainage Ditch
SWMU 2- Building 12-43- Drainage Ditch
SWMU 3- Building 11-44- Drainage Ditch
SWMU 4 - Building 11- 50 - Drainage Ditch
SWMU 5-01- Buildings 12-5 and 12- 5B Ditches
SWMU 5-02- Buildings 12-51, 12-67, and 12- 110 Ditches
SWMU 5-03- Buildings 12-9, 12- 10, 12- 18, and 12-68 Ditches
SWMU 5-04- Buildings 12- 19 and 12-73 Ditches
SWMU 5-05- Buildings 12-21 and 12-24 Ditches
SWMU 5-06- Buildings 12- 44E and 12- 81 Ditches
SWMU 5-07- Building 12-41 Ditches
SWMU 5- 08 -Building 11- 36 Ditches
SWMU 5- 09 - Buildings 11- 17, 11- 20, and Pond 11- 51 Ditches
SWMU 5- 10 - Ditches Near the Old Sewage Treatment Plant
SWMU 5- II - Zone 11 Main Perimeter Ditch
SWMU 5- 12- Zone 12 Main Perimeter Ditch
SWMU 5- 13 - Three Main Ditches to Playa I
SWMU 5- 14- Main Ditches to Playa 2
SWMU 5- 15 - Main Ditches to Playa 4
SWMU 6 - Playa 1
SWMU 7 - Playa 2
SWMU 8 - Playa 3
SWMU 9 - Playa 4
SWMU 10 - Pantex Lake

X

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

28

Pantex Plant

. : . ' ()peril/Jle Unit
.

···,

.

AL- PX- 09 Firing Sites

AL-PX-10 Leaking USTs at
Buildings 12-35 and 16-1
AL- PX- 11 Miscellaneous High
Explosives/ Rad Sites

AL- PX- 12 Miscellaneous
Chemical Spills/ Release Sites

Texas

. i ·Solid W4$te Managemellt Units (~~M(lsMrem: pfConcem (AOCs), and
·'
Other PQtential Release Sites •. .··· ....
SWMU 70 - Firing Site 5
SWMU 71 - Firing Site 6
SWMU 73- Firing Site 15
SWMU 69- Firing Site 4 (Active)
SWMU 75 -Firing Site 22 (Active)
AOC 6- Gasoline Leaks at Buildings 12-35 and 16-1
SWMU 53 - Temporary HE Burning Grounds
SWMU 82- Nuclear Weapon Accident Residue Storage
SWMU 135- Leaching Bed Building 12- 44E
Zone 10 TNT Settling Pits:
SWMU 144 Building 10- 13
SWMU 146 Building 10-26
Zone 11 TNT Settling Pits:
Building 11- 44- Wastewater Treatment Unit:
SWMU 117 HE Settling Tank
SWMU 118 Equalization Basin
SWMU 119a HE Filters
SWMU 120a Carbon Filters
Building 12- 43 -Wastewater Treatment Unit:
SWMU 119b HE Filters
SWMU 120b Carbon Filters
SWMU 121 HE Settling Tank
SWMU 122 Equalization Basin
SWMU !22b Building 12- 24N & Building 12-43 Upland Soils
SWMU 123 Concrete Sump
SWMU 84- Building 10- 9, Scrap Salvage & Storage Yard
SWMU 103- Former Battery Storage Area, Building 12- 81
SWMU 143- Former Waste Drum Storage Areas, Buildings 10-9&10-7
AOC 1 -Transformer Leak, Building 11- 14A
AOC 3 - Former Boiler House Areas
Zone 10- AOC 3a
Zone 11- AOC 3b
AOC S- Electrical Equipment Bone Yard
AOC 7 - Sulfuric Acid Spills:
Building 11- 36- AOC 7a
Building 12- 4- AOC 7b
Building 12- 64- AOC 7c
AOC 8 - Solvent Leaks:
Pad 11- 2 - AOC Sa
Pad 11-13-AOCSb
Building 11- 17 - AOC 8c
Building 11- 22 -AOC 8d
Building 11- 36- AOC 8e
AOC 10- Pesticide Rinse Areas:
Building 12- 43A- AOC lOa
Building 12-51- AOC lOb
AOC 14- Battery Storage Area, Building 12- 18
AOC 15- DDT Release at Building 12- 35
Unassigned - Capacitor Bank Rupture
Unassigned- Evaporation Pit East of Bay 3, Building 11-20
Unassigned- Evap. Pit South of Bay 11 & West of Bay 6, Bldg 11- 20
Unassigned-Form. Leaching Bed N. of Bldg 11-50 & W. of Bldg 11-36
SWMU 113 -Overflow From 11-36 Collection System/Sump
AOC 2 - Main Electrical SYstem Subsystem

RRS
J

N/A
N/A
N/A
N/A
N/A

RRS

RRS3

2
X
X
X
N/A
N/A
N/A
N/A
N/A

N/A
N/A
N/A
N/A
N/A

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

29

National Defense Authorization Act (NDAA) Long-Term Stewardship Repot·t

Operable Unit
I

AL- PX- 13 Supplemental
Verification Sites

AL-PX-14 USTs at Other
Locations

3.1

Solid Waste Managemmt U11its (SWMUs),Are,as.of:'Jonce,rn(AOCs), ~
Other Potential Release Sit:es .· ..·· · '· ·
·. ·.•
SVS I - Denuded Area near Playa I
SVS 2 -Parallel Depressions Near Building I I- 26
SVS 3 (SWMU 67) -Carbon Black Burial Area near Building 10- 7
SVS 4- Old Pistol Range (Active)
SVS 5- Zone 11 Landfill East of Pad 11- 13
SVS 6 (SWMU 65)- Unnumbered Zone 7 Landfills
SVS 7 - Igloo Demolition Debris Landfills, Zone 4 & Zone 5
UST #9- Building 12-!7E
UST #7- Building 12-5B
UST #38- Building 12-84A
SWMU 133- Waste Oil Tank at Building 16-1

RRS
1

N/A

N/A
N/A
N/A
N/A

RRS
2
X
X
X
N/A
X
X
X
N/A
N/A
N/A
N/A

RRS3

N/A

N/A
N/A
N/A
N/A

Risk Reduction Standard 2 Sites Portion

Risk Reduction Standard 2 Sites portion at Pantex
RISK REDUCTION STANDARD 2 SITES
comprises a total of approximately 280 hectares (700
PORTION HIGHLIGHTS
acres). The Portion size does not include surface area
covering Risk Reduction Standard 2 areas of the
Major Long-Term Stewardship Activities- deed
perched aquifer (estimated at 320 hectares, 800 acres).
recordation that restricts use of the property/media to
Of the 249 identified release sites at Pantex that
activities that correspond to the cleanup levels
correspond to solid waste management units and areas
achieved (residential vs. non-residential)
of concern, approximately 150 of the sites, including
Portion Size- 280 hectares (700 acres)
Estimated Volume of Residual Contamination- soil
soils, sediments, offsite impacted perched groundwater,
200 surface hectares (500 acres); groundwater 1,890
and surface water sites, have been or will be
million liters (500 million gallons); sediment 81
recommended for closure under Risk Reduction
surface hectares (200 acres)
Standard 2. Release sites approved for closure under
Long-Term Stewardship Start-End Years- 2003Risk Reduction Standard 2 are sites with residual
indefinitely
contaminant levels that are protective of human health
Average Annual Long-Term Stewardship Costs FY
and the environment and that allow for continued use
2003-2006of the site, consistent with deed restrictions imposed.
Pantex has a site-specific Risk Reduction Standard
closure guidance document that has been approved by the TNRCC. This document is used to establish cleanup
levels for individual contaminants and provides the statistical and confirmation framework to ensure cleanup
levels are met.
For the general purpose of release site closure under Risk Reduction Standard 2, cleanup levels for individual
contaminants are represented by Texas or federal promulgated heath-based standards, or, when these are not
available or do not provide appropriate protection for human health or the environment, cleanup levels (identified
as medium specific concentrations) must be developed. The medium specific concentrations address a single
contaminant in a medium and consider one or more exposure pathways-- specifically, water ingestion and soil
ingestion with inhalation of volatiles and particulates. Where a contaminant in one medium has the potential to
contaminate another medium, additional numeric criteria are developed as cleanup levels. The cleanup levels
must correspond to contaminant concentrations that represent: 1) upper bound lifetime cancer risk of 0.000001
for class A and B carcinogens and 0.00001 for class C carcinogens; and 2) for systemic toxicants, exposure
cannot result in any deleterious effect.
Additional medium-specific requirements for soil/sediments include the following:
1) Residual contamination must not exhibit the hazardous waste characteristic of ignitability, reactivity
or corrosivity;

Texas

30

Pantex Plant

----~9
Lake
(~2.5

P~ntex

miles)

Playa 3

Texas Tech Research Farm

Active Site Locations
- - • Risk Reduction Standard 2 Sites
~ Soil Contamination

0.=-~--~2,~00~0~~~~-000

Feet
Risk Reduction Standard 2 Portion

Texas

31


2) The sum of volatile organic compounds in vapor phase must not exceed 1,000 parts per million by
weight or volume;
3) For closure to residential use criteria, residual contaminant concentrations throughout the soil column
shall not exceed the lower of the soil medium-specific concentration, based upon residential human
ingestion of soil and inhalation of particulates and volatiles and the residential soil-to-groundwater crossmedia protection concentration. The residential soil-to-groundwater cross-media protection concentration
is equivalent to one hundred times the residential groundwater cleanup level or a concentration in soil
that does not produce a leachate in excess of maximum contaminant levels or medium specific
concentrations;
4) For closure to non-residential use criteria, contaminant concentrations shall not exceed one hundred
times the non-residential groundwater cleanup level or a concentration in soil that does not produce a
leachate in excess of the non-residential groundwater cleanup level.
Additional medium-specific concentration cleanup levels for groundwater include the following:
1) For residential exposure, promulgated Safe Drinking Water Act maximum contaminant levels. If
maximum contaminant levels do not exist, cleanup levels are calculated medium-specific concentrations
for human ingestion with no resulting adverse affect ;
2) For non-residential exposure, maximum contaminant levels, or if maximum contaminant levels do not
exist, calculated medium specific concentration levels that have been multiplied by 3.36 for carcinogens
and 2.8 for systemic toxicants.
Pantex has a site-specific Risk Reduction Standard closure guidance document that has been approved by the
TNRCC. This document is used to establish cleanup levels for individual contaminants and provides the
statistical and confirmation framework to ensure cleanup levels are met. However, due to the fact that not all
investigation and cleanup reports have been reviewed and approved by the TNRCC, the possibility exists that
additional investigations may be necessary to resolve regulatory comments on documents previously provided.
Additional investigations have the potential to identify conditions requiring revision of previous
recommendations. In addition, ultimate cleanup goals for offsite property that is not owned by the DOE are
subject to negotiation with offsite landowners.

Deed recordation, which limits the use of the land that is closed under Risk Reduction Standard 2, is the
applicable institutional control. Implementing mechanisms to ensure that deed restrictions are adhered to include
management controls provided in Plant Standards, Directives, and Operating Procedures for activities conducted
on land owned by the DOE. The placement of deed restrictions on property not owned by DOE will require
negotiation with the landowners. It is anticipated that, in some cases, fencing, signs, and access restriction will
accompany deed restriction of Risk Reduction Standard 2 sites to ensure land use is consistent with covenant
restrictions.

3.1.1

Soil

Releases affecting soil at Pantex have resulted from past production operations associated with fabrication of
chemical explosive components for nuclear weapons, nuclear weapon assembly/disassembly, weapon
modification and repair, surveillance testing of weapon components, and treatment/disposal of chemical
explosives and non-radioactive components. Media contamination from these operations occurred by discharging
Texas

32

Pantex Plant

wastewater to unlined ditches, onsite treatment/disposal of high explosives contaminated solvents, spills and
leaks of raw and produced materials, onsite landfilling of solid wastes, and onsite discharge of wastewater to
playa lakes. The primary contaminants at Risk Reduction Standard 2 soil sites include the metals chromium, lead,
and barium; the high explosives RDX, HMX, and TNT; and volatile and semi-volatile organic compounds,
including trichloroethylene, chrysene, acetone, benzo(a)pyrene and benzo(a)anthracene. It is estimated that
approximately 200 surface hectares (500 acres) of soil media will be closed under Risk Reduction Standard 2.
Soil sites closed under Risk Reduction Standard 2 include soils less than 0.6 meter (two feet) below surface
elevation (surface soils) and greater than 0.6 meter (two feet) below surface elevation (subsurface soils). Risk
Reduction Standard 2 sites are determined to be protective of human health and the environment as long as land
use and activity restrictions match deed restrictions.
Long-term stewardship goals for soil sites closed under Risk Reduction Standard 2 are to ensure land use is
consistent with restrictions imposed by deed recordations and to ensure controls are maintained that comply with
closure requirements. In general, Risk Reduction Standard 2 closures of sites will be conducted to meet nonresidential cleanup requirements. Activities conducted to meet these goals may include implementation of
procedural limitations for site use, construction and maintenance of signs, fencing, etc., and administrative
limitations of site operations.
3.1.2

Groundwater

The estimated volume of offsite groundwater that requires treatment to meet Risk Reduction Standard 2 cleanup
levels is approximately 1,890 million liters (500 million gallons). Approximately 320 hectares (800 acres) is the
estimated total offsite surface area below which perched groundwater requires cleanup. Releases affecting
perched groundwater at Pantex have resulted from past production operations associated with fabrication of
chemical explosive components for nuclear weapons, nuclear weapon assembly/disassembly, weapon
modification and repair, surveillance testing of weapon components, and treatment/disposal of chemical
explosives and non-radioactive components. Perched groundwater contamination from these operations is
believed to have occurred primarily by discharging wastewater to unlined ditches, on-site treatment/disposal of
high explosives contaminated solvents, and spills and leaks of raw and produced materials. The primary
contaminants in offsite perched groundwater are the high explosives RDX and HMX. The primary contaminants
in onsite perched groundwater are high explosives (primarily RDX, TNT, and HMX), heavy metals (primarily
chromium), and volatile organic compounds (primarily trichloroethylene). It is anticipated that onsite perched
groundwater will be closed under Risk Reduction Standard 3 while offsite perched groundwater will be closed
under Risk Reduction Standard 2.
The two principal aquifers beneath the Pantex Plant and adjacent areas are the Ogallala aquifer and the
underlying Dockum Group aquifer. Approximately 140 meters (450 feet) of unsaturated vadose zone is present
between the ground surface and the Ogallala aquifer. A perched water zone (perched aquifer) is present in the
middle of the Ogallala formation at a depth of approximately 82 meters (270 feet) below ground surface and is
generally continuous beneath the main facilities of the Pantex Plant and some adjacent areas. The saturated
thickness in this perched aquifer ranges from a few feet at the southern margin to greater than 15 meters (50 feet).
The main Ogallala aquifer is unconfined and lies beneath the perched aquifer. The main Ogallala aquifer, the
saturated portion of the Ogallala formation, is the principal water supply of the Southern High Plains. The
regional groundwater flow in the main Ogallala aquifer beneath most of the Southern High Plains is to the
southeast. Groundwater flow in the Ogallala aquifer beneath the Pantex Plant and adjacent area is toward the
north-northeast. The north-north-east flow is controlled by the east-northeast slope of the Southern High Plains
and the Canadian River Valley to the north and also by a large cone of depression surrounding the City of
Texas

33

National Defense Authorization Act (NDAA) Long-Tenn Stewardship Report

Amarillo-Carson County Well Field, located immediately north of the Pantex Plant.
Groundwater contamination at Pantex is primarily restricted to the perched aquifer. Detection of contaminants
above drinking water standards have recently been identified in samples collected from Ogallala aquifer
monitoring wells near the northwest boundary of the Pantex Plant and in an Ogallala well southeast of the Plant.
Investigation of the nature and extent of the contamination in the Ogallala aquifer is currently being conducted
at Pantex. The Dockum Group aquifer lies under the Ogallala aquifer beneath the Pantex Plant and to the south.
No detailed information is available on the potentiometric surface of the Dockum Group aquifer for the Pantex
Plant area.
Specific Risk Reduction Standard 2 residential remedial action objectives for the primary contaminants in
perched groundwater at Pantex are 0.00774 milligrams per liter for RDX; 0.018 milligrams per liter for TNT;
1.825 milligrams per liter for HMX; and 0.005 milligrams per liter for trichloroethylene. Current fate and
transport modeling does not indicate that chromium contamination in the perched aquifer will migrate off-site;
therefore, a Risk Reduction Standard 3 alternate concentration level will be developed for this contaminant.
Ultimate cleanup goals for offsite property that is not owned by DOE are subject to negotiation with offsite
landowners. Therefore, the overall level of confidence for cleanup of offsite perched groundwater to Risk
Reduction Standard 2 residential levels is low due to the fact that ultimate cleanup requirements are subject to
negotiation and technical feasibility.
Long~ Term

Stewardship Activities

Long-term stewardship goals for closure of perched groundwater under Risk Reduction Standard 2 are to protect
the Ogallala aquifer and restore perched groundwater to beneficial use. Activities necessary to obtain these goals
include implementation of corrective actions, which consist of both pump-and-treat and in-situ treatment
methodologies to reduce contaminant concentration levels to those that allow for offsite unrestricted perched
groundwater residential use, groundwater monitoring, and deed recordation.

3.1.3

Surface Water/Sediment

DOE estimates that approximately 81 surface hectares (200 acres) of sediment will be closed under Risk
Reduction Standard 2. A volume estimation of surface water/sediment with residual contamination that will be
closed under Risk Reduction Standard 2 does not provide a useful tool because use restrictions of residually
contaminated environmental media are identified and implemented by surface surveys. The primary contaminants
at Risk Reduction Standard 2 surface water/sediment sites include the metals chromium, lead, and barium; the
high explosives RDX, HMX, and TNT; and volatile and semi-volatile organic compounds including
trichloroethylene, chrysene, acetone, benzo(a)pyrene and benzo(a)anthracene. The primary reason for residual
contamination of surface water/sediments is the historical practice of discharging untreated wastewater.
Untreated wastewater is no longer discharged to ditches or surface water bodies (playas).
Surface water/sediment sites recommended for closure under Risk Reduction Standard 2 include several surface
water sites (playas) and primarily ditch sediments that are less than 0.6 meter (two feet) below surface elevation
(surface sediments). Sediments greater than 0.6 meter (two feet) below surface elevation are categorized as
subsurface soils. Although the playas at Pantex are ephemeral water bodies often containing water only
seasonally, many playas meet the soils, hydrology, and vegetation criteria for classification as jurisdictional
wetlands. Sediments at Pantex are associated primarily with a network of constructed ditches, including some
that direct surface water flow away from buildings within interior zones of the Pantex Plant.
For release sites associated with surface water/sediments at Pantex that have been recommended for closure
under Risk Reduction Standard 2, the level of confidence for attaining regulatory approval is medium. Pantex
Texas

34

Pantex Plant

has a site-specific Risk Reduction Standard closure guidance document that has been approved by the TNRCC.
This document is used to establish cleanup levels for individual contaminants and provides the statistical and
confirmation framework to ensure cleanup levels are met. Because of the fact that not all investigation and
cleanup reports have been reviewed and approved by the TNRCC, the possibility exists that additional
investigations may be necessary to resolve regulatory comments on documents previously provided. Additional
investigations have the potential to identify conditions requiring revision of previous recommendations.

Long-term stewardship goals for surface water/sediment sites closed under Risk Reduction Standard 2 are to
ensure land use is consistent with restrictions imposed by deed recordations and to ensure controls are maintained
that comply with closure requirements. In general, Risk Reduction Standard 2 closures of sites will be conducted
to meet non-residential cleanup requirements. Activities conducted to meet these goals may include
implementation of procedural limitations for site use, construction and maintenance of signs, fencing, etc., and
administrative oversight of site operations.

3.1.4

Estimated Long-Term Stewardship Costs for Risk Reduction Standard 2 Sites Portion

The table below identifies the estimated costs for performing long-term stewardship activities at the Risk
Reduction Standard 2 Sites portion. Costs to implement and maintain Risk Reduction Standard 2 closures
represent about five percent of the total long-term stewardship costs for release site closures at Pantex.

Long-Term Stewardship Costs (Constant Year 2000 Dollars)
FY 2000FY 2020
$576,000

3.2

FY 2011FY 2020···

PY 2021·
FY 2030

FY 2031FY 2040

FY 2041·
FY 2050

FY 2051FY 2060

FY 2061FY 2070

$880,000

$1,090,000

$956,000

$726,000

$637,000

$495,000

Risk Reduction Standard 3 Sites Portion

Estimated
Total
$5,360,000

RISK REDUCTION STANDARD 3 SITES
PORTION HIGHLIGHTS

The Risk Reduction Standard 3 Sites portion comprises
a total of 81 hectares (200 acres). This size represents
Major Long-Term Stewardship Activities- deed
recordation; maintaining administrative; institutional
the estimated total area of all sites recommended for
and/or engineered controls
closure under Risk Reduction Standard 3 but does not
Portion Size- approximately 81 hectares (200 acres) of
include the estimated total onsite surface area below
soil/sediment solid waste management units, of which
which perched groundwater requires cleanup (557
approximately 16 hectares (40 acres) will be
hectares, 1,376 acres). The volume of perched
comprised of engineered corrective action units such
groundwater that is anticipated to be closed under Risk
as landfill caps/soil covers and ditch liners
Reduction Standard 3 is approximately 3.8 billion liters
Estimated Volume of Residual Contaminants- soil45
(one billion gallons). Of the 249 identified release sites
surface hectares (110 acres); onsite perched
at Pantex that correspond to solid waste management
groundwater 3.8 billion liters (one billion gallons);
units and areas of concern, approximately 50 of the
sediment 20 surface hectares (50 acres); engineered
sites, including soils (landfills, historical
units 16 surface hectares (40 acres)
Long-Term Stewardship Start-End Years - 2003spill/discharge, historical waste processing sites),
indefinitely
sediments (ditches), and onsite perched groundwater,
Average Annual Long-Term Stewardship Costs FY
will be recommended for closure under Risk Reduction
2003-2006- $5,324,000
Standard 3. It is currently anticipated that
approximately 16 hectares (40 acres) of the total 81
hectares (200 acres) that will be recommended for
closure under Risk Reduction Standard 3 will require engineered controls (caps/covers, liners, etc.).
Texas

35

National Defense Authol"ization Act (NDAA) Long-Term Stewardship Report

Firing
Sites

-

Active Site Locations
-

Risk Reduction Standard 3 Sites

~ Soil Contamination

0

1,500

3,000

Feet

Risk Reduction Standard 3 Portion

Texas

36

Pantex Plant

For release sites at Pantex recommended for closure under Risk Reduction Standard 3, the level of confidence
for attaining regulatory approval is medium. A Baseline Risk Assessment is required for Risk Reduction Standard
3 sites. Pantex has submitted a draft Baseline Risk Assessment to the TNRCC. The majority of issues concerning
contaminants of concern selection and exposure modeling have been resolved. The objective of the Baseline Risk
Assessment is to analyze Pantex Plant site conditions in the absence of remedial action and to provide human
health and environmental baseline data to be used in evaluating remedial action alternatives. Human health
impacts are quantified through a process that estimates average daily doses (i.e., intake) for likely exposure
scenarios that could place humans in contact with contaminated environmental media. Exposure to contaminated
media can occur through a number of exposure routes such as ingestion, dermal contact, and inhalation. Health
impacts are expressed differently depending on the type of health impact caused by the contaminant. The health
impact end-point for carcinogenic chemical contaminants is expressed as the lifetime risk of cancer incidence
(i.e., the probability of contracting cancer from exposure to the contaminant over a lifetime). Health impacts for
exposure to non-carcinogenic chemicals are expressed as a hazard quotient, which is the ratio of the estimated
average daily dose to the reference dose for the chemical.
General target cleanup levels for media closed under Risk Reduction Standard 3 are concentrations that: 1)
represent upper-bound lifetime cancer risk of individual carcinogenic contaminants ofO.OOOOO 1 and a cumulative
excess cancer risk from all carcinogens combined not to exceed 0.0001, each in consideration of all applicable
exposure pathways and standard exposure scenarios; 2) comply with National Ambient Air Quality Standards;
and 3) for systemic toxicants, do not exceed a hazard index or hazard quotient of one.
For groundwater that is a current or potential source of drinking water and is closed under Risk Reduction
Standard 3, specific cleanup levels must not exceed maximum contaminant levels promulgated under the Safe
Drinking Water Act. If maximum contaminant levels do not exist, calculated medium-specific concentrations
apply, using standard exposure factors consistent with current, historical, and/or probable future land use. If
future land use other than residential is appropriate for the site/release area, and demonstration can be made that
institutional or legal controls will effectively prevent use of contaminated groundwater, the extent of plume
remediation may be revised to allow cleanup to alternate concentration levels.
Specific media cleanup levels for soil/sediment closed under Risk Reduction Standard 3 include medium-specific
contaminant concentrations that are protective of air, surface water, and groundwater based on sound scientific
principles, including fate and transport modeling. Contaminant concentrations determined protective of other
media must be maintained over time, taking into account any implemented engineering controls.

Deed recordation, which limits the use of media closed under Risk Reduction Standard 3, is required. In addition
to deed recordation, post-closure care is required, which may be in the form of engineered controls and/or
access/activity restrictions that limit exposure to contaminants to durations that result in excess risk levels below
Risk Reduction Standard 3 cleanup levels. Exposure limitations can include construction of engineered controls,
procedural restrictions that limit access to specified duration and frequency, and/or procedural implementation
of protective equipment protocols that decrease or eliminate exposure to contaminant concentrations.
Implementing mechanisms to ensure that deed restrictions are adhered to include management controls provided
in Plant Standards, Directives, and Operating Procedures for activities conducted on land owned by the DOE.
Deed restrictions and other institutional controls placed on property not owned by the DOE will require
negotiation and agreement with the applicable landowners.
It is anticipated that, in some cases, fencing to provide access restriction will accompany deed restriction of Risk
Reduction Standard 3 sites to ensure land use is consistent with covenant restrictions. Other engineered controls
currently planned are containment technologies, including soil/sediment liners (for certain ditches) and
Texas

37

Texas

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