~ Collection
~urce Center
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United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPAIROD/R08-87/015
September,987
(3EPA
Superfund
Record of Decision:
-tE S8 - I 72. I b J
Denver Radium/11 th & Umatilla, CO
U.S. Environmenial ~r6iQethm Agency
, Region III Information Resource
Center (3PM52)
841 Chestnut Street '/, ".,;.:
Philadelphia, p~ A~Wl -<'.fi~iJ,,~i
.~~
EPA Report Collection
Information Resource Center
US EPA Region 3
Philadelphia, PA 19107
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.
1. fIIIlPOfillT NO.

~'[n /D/"\n loon o-a 7/01 C;
. TITLE AND SUITITLI
TeCHNICAL REPORT DATA
("tUt 'tad l'UlnJctlOllS 011 tltt 'tlltrtt lHfOlt com"lttlflrJ

I~' 3. RECI'IEIIIT'S ACCESSION NO.


5. ".'OfillT 0041'1

~~n~ember 29. 1987
I. PE"'ORMING ORGANIZATION CODE
-
SUPERFU~D RECORD OF DECISION
Denver Radium/11th and Umatilla, CO
Sixth Remedial Action
7.AUTHOflll.S.
8. PERFORMING ORGANIZATION REPORT "'0.
9. 'lfillflORMING ORGANIZATION NAME AND ADDRESS
JO. PROGRAM EI.EMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
401 M street, s.w.
washington, D.C. 20460'
13. TYPE OF REPORT AND PERIOD COVEREO
Final ROD Report
'4. SPONSORING AGENCY ceDe
800/00
15. SUPPLEMENTARY NOTES
US. A.STRACT
The Denver Radium site, located in Denver, Colorado, consists of more than 40
contaminated properties. These properties have been grouped into eleven operable
units. This operable unit consists of eleven Denver Radium site properties which aFe
known collectively as the 11th and Umatilla properties. The 11th and Umatilla
}roperties site consists of approximately 24 acres in an area zoned for heavy industrial
use. Two-thirds of the 11th and Umatilla properties are located within the designated
100-year flood plain. . In 1979 EPA noted a reference to the' National Radium Institute
(NRI) in a 1916 U.s. Bureau of Mines report. This reference revealed the presence of 31
radioactive sites in the Denver metropolitan area. In 1913 the NRI was established in
Denver as a domestic source of radium, which was in high demand as a wonder drug for the
treatment of cancer. subsequently, the Denver radium, vanadium and uranium industry
thrived until the ear1y 1920s, when rich deposits of ore were discovered in Africa. The
Schlesinger Radium Company and its successor, Radium Company of Colorado, produced
radium on the 11th and Umatilla properties from 1915 to 1921 and is considered to be the
source of contamination of the eleven 11th and Umatilla properties. There are
approximately 15,400. yd3 of contaminated material of which 1,000 yd3 lie under
structures and material and 11 ft2 consist of contaminated roofing from the Rocky
Mountain Research building. The primary contaminants of concern are radium, radon gas
(See Attached Sheet)
17.
~
DISCfIIIIPTOfillS
KEY WOfillOS AND DOCUMENT ANALYSIS
b.IOENTIFIEAS/OPEN eNDED TERMS
c. ceSATI Field/Croup
Record of Decision
Denver Radium/11th and Umatilla, CO
Sixth Remedial Action
Contaminated Media: soil, air, debris
Key contaminants: radium, radon gas and
associated decay products
DISTRI.UTION STATEMENT
Ig. SECURITY CLASS I TlIII Rtport/
None
~,. NO. OF PAGI!8
20. SECURITY CLASS ITltil plitt/
None
22. PRICE
I'. ,- 2220-1 (I... 4-77)
~III.VIOUI COITION .,0.,01..1'.

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EPA/ROD/R08-87/0l5
Denver Radium/11th and Umatilla, CO
Sixth Remedial Action
16.
ABSTRACT (continued)
and its decay products. Although presently no serious public health risk from radon
decay products exposure exists, a significant increase in risk would occur if any of the
contaminated material and debris were to be misused or inadvertently spread.
The selected remedial action for this site includes: excavating contaminated soil
from open areas and from under buildings and placing this material into an onsite
temporary storage" facility; decontaminating the roof in the Rocky Mountain Research
building (ap~roximately 11 ft2) and placing this material in the temporary onsite
facility; maintaining an already existing concrete cap; maintaining the temporary
storage facility until a facility suitable for the permanent disposal of site wastes
becomes available; and final offsite disposal of the contaminated material
(15,400 yd3) to a permanent disposal facility. The estimated present worth cost for
this remedial action is $4,230,300 with 5-year present worth O&M of $194,700.
,

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DECLARATION
FOR THE
RECORD OF DECISION
Site Name
11th and Umatilla Properties
Operable Unit II
Denver Radium Site
Site Location
11th Avenue and Umatilla Street
Denver, Colorado
Statement of Purpose

This decision document presents the selected remedial action
for this operable unit of the Denver Radium Site developed in
accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA),
and the National Contingency Plan (40 CFR Part .300)..
The State of Colorado has concurred on. the selected remedy.
(See attached letter.)
Statement of Basis
This. decision is based. upon the administrative record for
the 11th and Umatilla properties, Operable Unit II of the Denver
Radium Site. The attached index identifies the items which
comprise the administrative record upon which the selection of
the remedial action was based.
Des~ription of the Selected Remedy

This Record of Decision addresses the contamination present
on the 11th arid Umatilla properties, Operable Unit II of the
Denver Radium Site. This is the sixth operable unit of the
Denver Radium Site for which EPA has selected a remedy. EPA is
undertaking additional feasibility studies to evaluate remedial
action alternatives at the other Denver Radium Site operable
units and will complete a Record of Decision or an Action
Memorandum for each of the operable units for which a remedy has
not already been selected. .

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2
Radium and its associated decay products are the hazardous
substances of primary concern that have been released and
continue to be released into the environment at the 11th and
Umatilla properties. Long-term exposure to radium and its decay
products has been shown conclusively to increase the risk of
contracting lung cancer.
EPA's preferred remedial action alternative for the 11th and
Umatilla properties is Offsite Permanent Disposal. However, .
until a facility suitable for permanent disposal of the 11th and
Umatilla properties material is designated and, if necessary,
acquired and developed, this alternative cannot be implemented.
Pursuant to CERCLA Section 104(c)(3)(C)(ii), it is the
responsibility of the State of Colorado to assure the
availability of a facility for offsite disposal of the 11th and
Umatilla properties material. Although both EPA and State of
Colorado are continuing to seek a permanent disposal site, the
State estimates that this process could take up to five years.
Given the length of time which may pass before the State assures
the availability of an offsite permanent disposal facility, and
in order to prevent or minimize the threat to public health and
the environment, EPA has determined that a remedial action
alternative which includes temporary response actions should be
implemented at the 11th and Umatilla properties.
The selected remedy for the 11th and Umatilla properties is
On site Temporary Land Storage, Offsite Permanent Disposal. . This
remedial action alternative will"attain'a degree of cleanup.of
the hazardous substances which will ,assure both short-term and
long-term protection of human health and the environment. The
present-worth cost of this alternative is $4,230,300 based upon a
ten-percent interest rate, a five-year discount period, and a .
perpetual monitoring period. This alternative entails:
excavating the contaminated soil from the open areas
and from under the buildings on the 11th and Umatilla
properties and placing this mate~ial in a temporary
land-storage facility to be constructed on the 11th and
Umatilla properties;
decontaminating the 'approximately 11 square feet of
contaminated roof in the Rocky Mountain Research
building and placing this material in the temporary
land-storage facility;
maintaining the concrete cap which already covers a
portion of the contaminated material present on the
DuWald Steel property;
maintaining the temporary land-storage facility until a
facility suitable for the permanent disposal of Denver
Radium Site wastes becomes available; and
final removal of the estimated 15,400 cubic yards of
contaminated material from the temporary land-storage

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J
facility and from under the concrete cap to the
permanent disposal facility.

Remedial Design for this operable unit will include the
selected remedy described above and EPA's preferred remedial
action alternative, Off site Permanent Disposal. Should the State
of Colorado fulfill its obligatio~ to assure the availability of
a suitable disposal facility for material from the Denver Radium
Site by the time EPA has concluded Remedial Design for the 11th
and Umatilla properties, EPA may implement its preferred
alternative, Offsite Permanent Disposal.
Operation and maintenance activities will be required to
ensure the effectiveness of the temporary response actions.
These activities include site inspections, ongoing radiological
monitoring, and possible minor repairs to the concrete cap which
is already in place on the DuWald Steel property or the temporary
land-storage facility to be constructed on the 11th and Umatilla
properties. Also included as an operation and maintenance
activity for cost estimating purposes is a review of the
properties which, pursuant to SARA Section 121(c), must be
conducted no less than every five years if a remedial action is
selected that results in any hazardous substances remaining
onsite. Since EPA does not anticipate that any hazardous
substances will remain onsite longer than five years, the cost of
this review is considered a contingency. The'maximum total of
the discounted annual operation and maintenance costs of these
activities using a five-year discount period and a ten-percent
discount rate is $194,700. This operation and maintenance cost
is included'with the present-worth total alternative cost
mentioned above.
Declarations
Consistent with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA),
and the Wational Contingency Plan (40 CFR Part 300), I have
determined that the selected remedy for the 11th and Umatilla
properties, Operable Unit II of the Denver Radium Site, is
protective of. human health and the environment, attains Federal
and State public h~alth and environmental requirements that are
applicable or relevant and appropriate, and is cost-effective.

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The remedy utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable." Even though the
remedy does not satisfy the statutory preference for treatment
which reduces the toxicity, mobility, or volume of hazardous
substances as its principal element, the principal threat at the
properties will be addressed. Treatment was determined to be
impracticable based upon. effectiveness, technical feasibi~ity, .
implementability, and cost factors.


¥-;U- ~

J~ J. Scherer
Reg~onal Administrator
EPA Region VIII
. '4
+ . ~Ct
( ,
Date
I fy)

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RECORD OF DECISION
SUMMARY
Site Name
11th and Umatilla properties
Operaple Unit II
Denver Radium Site
Site History

The Denver Radium Site has its beginnings with the United
States radium, vanadium, and uranium producing industry of the
early 1900s. Radium was first discovered in the late 1800s and
was highly valued for medicinal purposes.
Prior to 1914, radium-bearing ore was shipped from the
United States to Europe where it was refined. The possibility of
war in Europe threatened to disrupt the United States'
importation of radium and prompted the development of a domestic
refinement process. The United States Bureau of Mines entered
into a cooperative agreement with a private corporation
establishing the National Radium Institute which successfully
developed and operated a radium processing plant in the United
States.' . . .
Denver was chosen as the location of the National Radium
Institute facility due to its proximity to the Colorado Plateau,
which contained rich deposits of the radium-bearing ore,
carnotite. Soon numerous radium, vanadium, and uranium
processing operations opened in Denver. In 1915, one of these
producers, the Schlesinger Radium Company, began operations on .
the property which is currently part of Operable II of the Denver
Radium Site. Schlesinger Radium Company apparently became the
Radium Company of Colorado in 1917. The Radium Company of
Colorado was one of Denver's major producers of radium,
reportedly processing between 1,000 and 1,200 tons of carnotite a
year.
The Denver radium, vanadium, and uranium industry remained
strong until the early 1920s when extremely rich deposits of ore.
were discovered in what was then the Belgian Congo. The Denver
producers were unable to remain economically competitive and the
industry in Denver collapsed. The Radium Company of Colorado
reportedly ceased operations in 1921. .

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2
Response History

In 1979, EPA noted a reference to the National Radium
Institute in a 1916 United States Bureau of Mines repprt.
Subsequent field research revealed the presence of thirty-one
radioactive sites in the Denver metrop91itan area, two of which
are now included with the 11th and Umatilla properties, the
original location of the mill operated by the Radium Company of
Colorado (Figure 1).
Immediately after identifying these properties, the
Radiation Control Division of the Colorado Department of Health
officially notified the affected property owners of the presence
of radiological contamination on their properties. The letters
requested that no excavation or soil movement be undertaken
without first contacting the Division.
In August, 1981, the Colorado Department of Health, under a
cooperative agreement with EPA, assumed lead activities and
initiated engineering assessments of the majority of the original
31 properties. In October, 1981, shortly after the cooperative
agreement was awarded to the State, the Denver Radium Site was
placed on the Interim Priorities List. The Site was included on
the Final National Priorities List promulgated on September 8,
1983.
EPA resumed Fund-lead activities in June, 1983, because the
Colorado State Legislature failed to appropriate ~he State cost
share for remedial planning required by EPA at the time. In
December, 1983, EPA directed its contractor to conduct a Remedial
Investigation (RI) of the Denver Radium Site to determine the
nature and extent of the contamination present on those
properties which the State did not previously study plus several
contiguous properties where additional contamination was
suspected. EPA also directed its contractor to conduct a
Feasibility Study (FS) of each operable unit to evaluate proposed
remedies ~or the contamination present on all of the Denver
Radium Site properties which, with the addition of the contiguous
properties, totaled over 40 properties.
Because of the enormity and complexity of the Denver Radium
Site, EPA determined that response actions undertaken in operable
units would be cost-effective and consistent with a permanent
remedy for the entire Denver Radium Site. Thus, the original
Denver Radium Site properties plus the contiguous properties
where contamination was discovered subsequent to the initial
listing of the Site on the Interim Priorities List were divided.
into eleven operable units, the 11th and Umatilla properties
being Operable Unit II. The properties were divided based
primarily upon site conditions and proximity to other Denver
Radium Site properties.
In April, 1986, the Denver Radium Site Remedial
Investigation Report, which addresses all eleven operable units,
was released to the public. The d!aft Operable Unit II FS was

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3
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4
released for public review on August 14, 1987. Responses to .
comments received during the public comment period are contained
in the Responsiveness Summary attached to this Record of .
Decision. The final Operable Unit II FS is comprised of the
draft Operable Unit II FS incorporating the changes described in
the errata.
Pursuant to SARA Section 104(i), the draft Operable Unit II
FS was submitted for review by the Agency for Toxic Substances
and Disease Registry (ATSDR). At the signing of this Record of
Decision, ATSDR had not formally responded. However, preliminary
discussions with ATSDR indicated that ATSDR had no major
criticisms of the report.
Site Location and Description

The Denver Radium Site, located in Denver, Colorado,
(population 509,000) consists of more than 40 contaminated
properties. These properties have been grouped into operable
units. Operable Unit II is comprised of the fOllowing Denver
Radium Site properties known collectively as the 11th and
Umatilla properties:
- DuWald Steel
- Rocky Mountain Research
- G & K Services
Jenkins property
- Staab building
- Air Conditioning, Inc.
- Jerome Park Maintenance Yard
- Burlington Northern Railroad
~ Flame Spray, Inc.
- Capital Management Reality
- Alpha Omega Electronics
The 11th and Umatilla properties are bounded on the east by
the Burlington Northern Railroad, on the north by West 11th
Avenue,. on the west by Yuma Street, and on the south by West 10th
Avenue (Figures 2 and 3). Interstate-2s is located approximately
75 feet west of the western portion of the property. The Denver
Water Department Headquarter's offices and facility are adjacent
to the southeast corner of the properties. The properties cover
approximately 24 acres in an area zoned I-2 for heavy industrial
use. There are several buried municipal utilities within the
property boundaries.
Two-thirds of the 11th and Umatilla properties are located
within the designated 100-year floodplain. The entire area of
the 11th and Umatilla properties is within the sOO-year
floodplain. The properties are underlain by alluvium and the
Denver formation sandstone. The depth to ground water is greater
than 10 feet and depth to bedrock is approximately 10 to 30 feet.
There is no surface water on the properties. The climate of the

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7
area is typified by low annual precipitation, averaging about 14
inches per year.

The DuWald Steel property located on the corner of 11th
Avenue and Umatilla Street covers 10.5 acres. The property is
used as a commercial facility that buys and sells scrap metal.
Scrap metal is stacked in piles as high as 40 feet over much of
the property. A portion of the property is covered with
reinforced concrete. The topography is fairly level with a
slight westerly slope. Two major water conduits, Denver Water
Department Conduit 12 and Conduit 18, run east-west across the
center of the DuWald Steel property. Both of the conduits are
approximately five feet deep and carry treated water for water
supply. There is another conduit running north-south on the
eastern boundary of the property and a 100-foot, Denver Water
Department right-of-way located on Duwald Steel property just
south of 12th Avenue. There is approximately 0.3 mile of
railroad track on the property. There are six permanent
structures on the DuWald Steel property. These include four
buildings, an aluminum scrap smelter complex, and one permanent
scrap metal crane and shredder complex. The number of full-time
employees on the premises varies between 35 and 40.
In 1982, contaminated soil was excavated from the DuWald
Steel property during construction of an addition. Th~ material
was placed along the fence in the southwest corner and then
regraded. During remodeling of" one bf the buildings on the DuWald
Ste~l property, subfloor venting measures were taken and a vapor
barrier" was installed to prevent radon from entering the
building. The Colorado Department of Health and EPA jointly
performed oversight of this work.
The Rocky Mountain Research property is located at 1020 Yuma
Street and covers approximately 13,200 square feet. There is a
3,160 square-foot main building ~nd three storage sheds located
on the property. The majority of the open space is concrete
pavement. Four employees are present on the property for an
estimated 40 hours per week.
The G & K Services property covers approximately 1.4 acres
a"nd is located at 999 Vallejo Street. A one-story building with
two, two-story additions sits on the property.
The Jenkins property at 2177-2191 West 10th Avenue
less than one acre. A one-story office building houses
full-time employees 40 hours per week and two employees
time.
covers
four"
part-
The Staab property is located at 2121-2125 West 10th Avenue
and covers less than one acre. Approximately nine people work 40
hours per week in a one-story cinder block building. The floor
of the building is a six-inch concrete slab about four feet above
grade on the western side of the building and decreasing to about
one foot above grade on the eastern side.

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8
Located at 1001 Tejon Street is the Air Conditioning, Inc.,
property which covers less than one acre. A one-story building
is Occupied by four full-time workers.

The Jerome Park Maintenance Yard at 2300 West 11th Avenue
covers approximately three acres and is owned by the Colorado
Department of Highways. Located On the property are two.'vehicle
and equipment storage buildings and a small two-story bUilding.
On the south end of the property is a dome-shaped structure which
is used to store sand. There are several piles of sand, dirt,
and gravel situated throughout the property. An estimated 20
workers are on the property 40 hours per week, except during
storm conditions when the property is occupied around the clock.
The Burlington Northern Railroad property is 2.2 acres of
active railroad. This property is between 10th and 12th Avenues
to the east of the DuWald Steel property. A spur of the railroad
extends onto the Duwald Steel property.

The Capital Management Realty property at 1050 Yuma Street
covers less than one acre. The only structure on the property is
an office building with a finished garden level basement. The
building is presently unoccupied.
At 1010 Yuma Street is the Alpha Omega Electronics property.
This property is less than one acre in size. A one-story office
and a storage building are the only structures on the property.
Th~ office houses nine employees 40 hours per week. Most of the
ground surrounding the buildings is covered with concrete
walkways and an asphalt pavement.
Current Site Status
Radium and its associated decay products are the primary
contaminants of concern at the 11th and Umatilla properties.
Since gamma radiation readings in excess of background may
indicate the presence of radium, a gamma radiation survey was
used to outline the extent of possible radium contamination on
the 11th and Umatilla properties (Shaded areas of Figures 2
and 3). Gamma radiation readings in excess of background were
found over 170,436 square feet of the properties including in
several buildings. Average gamma radiation measurements ranged
from 0.6 microroentgen per hour (~R/hr) to 94 pR/hr above
background. The maximum gamma radiation measurement .was
611 ~R/hr above background. Elevated gamma radiation readings
were found over 11 square feet of the roof in the Rocky Mountain
Research bUilding. The average and maximum gamma radiation
measurements in this .area were 12 uR/hr and 17 ~R/hr,
respectively. (A general discussion of radiation and its
associated units of measurement is presented in Appendix A of the
Operable Unit II FS and in the Public Health and Environmental
Assessment, Appendix B of the Operable Unit II FS.)

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9
The presence of radium in 'the soil and underneath the
buildings was verified by radiochemical analysis of subsurface
soil samples. The average radium concentration in the
contaminated soils on the,11th and Umatilla properties ranged
from 3.2 picocuries per gram (pCi/g) to 931 pCi/g. The maximum
radium concentration found on the properties was 931 pCi/g. The
maximum depth of radium contamination found on the properties was
120 inches. The estimated total volume of radium contaminated
soil on the 11th and Umatilla properties is 15,400 ,cubic yards of
which 1,000 cubic yards lie under structures. Table 1 summarizes
the gamma radiation and radium concentration data collected on
the 11th and Umatilla properties.
Radon decay product coutamination on the 11th and Umatilla
properties exists in the Duwald Steel office building and the
basement of the Capital Management Realty building. During a
1985 EPA investigation, a maximum radon decay product
concentration of 0.030 working level (WL) was detected in the
southwest and northwest areas of the DuWald Steel office
building. Concentrations up to 0.304 WL were detected in the
northeast area of the basement of the Capital Management Realty
building. These levels exceed the limit of 0.02 WL allowed by
EPA standards for radon. An emergency response action was not
taken at the DuWald Steel office building because the patterns of
occupancy and the concentrations of radon decay products present
during periods of occupancy reduce the likelihood of significant
long-term exposure. No emergency response action was taken at
the Capital Management ~ealty building because the building was
and is presently unoccupied. The complete set of radon decay
product concentration data collected for the 11th and Umatilla
properties is presented in Table 2-2 in the Operable Unit II FS.
Fixed and removable alpha radioactivity sampling was
conducted in all of the buildings on the DuWald Steel property
and the Rocky Mountain Research property. No alpha radioactivity
measurements were found'which exceeded the Colorado Department of
Health guidelines for alpha radioactivity.
The radium concentration in the soils on the 11th and
Umatilla properties and the radon decay product concentrations
and gamma radiation levels found in certain buildings exceed the
"EPA Standards for Remedial Actions at Inactive Uranium
Processing Sites," 40 CFR Part 192, which EPA has determined are
relevant and appropriate Federal requirements for the 11th and,
Umatilla properties. These standards are discussed later in this
summary in the section entitled "Statutory Determinations".

The' elevated concentration of radium and the uncontrolled
state of the soils at the 11th and Umatilla properties pose a
health hazard due to three principal potential exposure pathways.
In order of decreasing significance, they are: (1) inhalation of
radon gas, the immediate decay product of radium, and radon's own
short-lived decay products, (2) direct gamma radiation exposure
from the decay of radium and its progeny, and (3) ingestion or
inhalation of radium-contaminated materials. Since radium is in

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Location
Area A
Area B
Area C
Area D
Area E1
Area E.,
Area ~
Area :;:
Area F~
Area G1
Area G2
Area G3
Area H
Area 11
Area 12
Area J1
Area 'J
Area K2
Area L
Area M

AreaN
Area 0
Area P
Area Q
Area R
Area s
Area T
Area tr
Area V
Total
10
Tab Ie 1
SURFAC~ AND SUBSURFACE CONTAMINATION
OPERABLE UNIT II, DENVER. RADIUM SITE
Vol~e
(yd )
3.7
1.1
13
129
3,481
124
209
10
3,010
2,S71
259
908
232
. 3,646
661b
39
6
i?
14b
11
5:~
7.S
4.2
22
4.4
0.2
4.1

15,398
(15,397
so11;
<1
detlr1s)c
Arza
ill..l

100
30
350
2,610
27,S10
1,344
1,S36
72
14,778
S3,392
1,SOO
13 ,373
690
43,680
S,100
1,040
,300
300
7S0
7S0
300
75
50
163
, 75
409
118
11
--1.2

170,436
(170,425
so11;
11
detlr1s)
Gamma (UR/hr)
Averace Max~um
9
4
9
14
22
5
19
18
47
79
1S
S9
S
28
7
1S
6
:2
S
6
33
7
- 3
6
7
S
5
2
9
7
90
7
S
2
22
8
611
94
12
0.6
174
17
0.6
&cepth indicates the estimated de~th of contamination.
variation in the depth of contamination.

bVolume does not include clean overburden.

~ebr1s is material from RMR buildinq.
Notes:
Maxi:llum qamma 1s maximum qr:.d scan qamma.
readinqs above ba~~qround.
Gamma readinqs are net corrected
Deptha
Cin.)
9
5
13
19
73
8
29
19
197
191
10
Maximum
De~th: 120
Radium Concentration
(pCi/a)
Averaae Max~u=
9
NA
4.6
NA
64
17
NA
NA
6S
79.7
NA
.931
156.0
71.1
125.8
27.3
. 6.S
40~7
16.1
22.4
1S.3
3.2
8.7
51
156.8
. NA
NA
NA
44
A ranqe indicates a
NA = Data not available or not recorded for this area.
12
12
12
16
Range frolll
22 to 68
Avq: 41
30
44
44
66
Range frolll
6 to 56
Avq: 15.6
51 56
191 . Range frolll
14 to S2
Avg: 22
8 109
471 Range from
14 to 84
Avq: 27
24 and 30
at
78 - 120
12
. 6
12
6 at
42 to 48
6 at
84 to 90
9
6
6 at 36
15
18
Range of
12 to 22
Avq: 17
, 12
6
44
15.0
NA
S.7
NA
111
17
NA
NA
65
- 690
NA
931
409.5
311.7
.- -.. "
176.S
105
8.S
354
16.1
. 22.4
98.9
3.7
54.7
21S.9
,. - 660
NA
NA
NA
44

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1 1
a form that is relatively insoluble, and since migration of
radiological contaminants into the ground water has not been
found, ingestion or contact with contaminated ground water is not
among the principal potential exposure pathways. Since there is
no surface water onsite,' ingestion or contact with contaminated
surface water is also not among the principal potential exposure
pathways., Each of the three principal exposure routes resulting
from the radium contamination on the 11th and Umatilla properties
will be discussed briefly in terms of the potential health risks
associated with that exposure route.
Inhalation of Radon Decay Products:
Radon gas and its decay products present the greatest health
risk from long-term exposure. Radon gas decays to a series of
short-lived particulates which are typically electrostatically.
charged at their formation and often attach themselves to
airborne particles. If these contaminated particles are inhaled,
then the lungs and other internal organs are exposed to the
highly ionizing sub~atomic particles which the radon decay
products emit. Prolonged inhalation of air with a high
concentration of radon decay products has been conclusively shown
to increase the risk of contracting lung cancer in uranium
miners.
Dispersion quickly dilutes radon emanating from radium-
contaminated ground. This mechanism will minimize the radon
concentration in the air above the open areas of the 11th and
. Umatilla properties to such an extent that no one working on or
living near the properties is presently at risk from exposure to
radon and its associated decay products from this source. Radon
decay products can concentrate to unacceptable levels in
buildings built over contaminated ground if those buildings are
energy efficient and well-sealed, that is, have little exchange
of indoor air with outdoor air. The DuWald Steel qffice building
and the basement of the Capital Management Realty building
exhibit concentrations of radon decay products exceeding the
relevant and appropriate EPA standard. The current risks
associated with the elevated radon decay product concentrations
in the DuWald Steel office building are believed to be small
compared with possible future risks for the following reasons.
First, the buildings are forced-air ventilated. Second, the
duration of exposure is limited due to the fact that people work
there rather than live there. Finally, during the times that
people are working there, radon levels, and consequently
exposures to radon, are reduced because the air exchange rate
with the outdoors increases when people are entering and leaving
the building. No current risk associated with the elevated radon
decay product concentration exists in the basement of the Capital
Management Realty building because the area is presently
unoccupied.
Although the present public health risk from radon decay
product exposure at the 11th and Umatilla properties is
comparatively minor for the reasons stated above, EPA has

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12
determined that a significant increase in public health risk
would occur if (1) any of the contaminated material on the
properties is spread closer to potential receptors, especially if
it is used as fill or construction material, or (2) if any of the
buildings on the 11th and Umatilla properties are sealed to make
them more airtight, or (3) if changes in existing occupancy or
use occur, or (4) if the properties are ever redeveloped'for any
use that involves occupancy in enclosed, energy-efficient
structures. The Public Health and Environmental Assessment for
the 11th and Umatilla properties, summarized below and contained
in Appendix B of the Operable Unit II FS, presents projected
cancer risks if EPA were to take no action at the properties and
the properties were redeveloped in any of these ways.

If a building were constructed over Area G, the largest
contaminated area on the 11th and Umatilla properties,
representing about 17% of the estimated total volume of
contamination on the properties, and several conservative
assumptions are made (such as lifetime exposure), the estimated
radon decay product concentration in the building would average
0.35 WL with an estimat~d maximum concentration of 4.14 WL. The
radon decay product concentration in a typical United States home
is 0.005 WL and the relevant and appropriate EPA standard, 40 CFR
Part 192, is 0.02 WL. The average projected cancer risk
(excluding background) to individuals working in such a building
ranges from 380 to 1,400 cancer deaths per 10,000 persons.
exposed. The average projected cancer risk to individuals living
. in such a building ranges from 1,900 to 5,000 cancer death$ per
10,000 persons exposed. .
These risk values can be compared to the average projected
cancer risk if the radon decay product concentration in the
building was 0.02 WL, the EPA standard. In this case, the
average projected cancer risk to individuals working in such a
building ranges from 23 to 91 cancer deaths. per 10,000 persons
exposed. The average projected cancer risk to individuals living
in such a building ranges from 130 to 500 cancer deaths per
10,000 persons exposed. If the radon decay product concentration
in the building was that of a typical United States home,
0.005 WL, then the average projected cancer risk to individuals
living in the bUilding would range from 33 to 130 cancer deaths
per 10,000 persons exposed. It should be noted that these
average projected cancer risk numbers do not include the EPA-
estimated spontaneous risk of lung cancer, that is, the risk not
attributable to either smoking or radon. Table 2 presents the
information stated above. .
Gamma Radiation Exposure:

The radioactive decay of radium and its decay products
results in the emission of highly penetrating gamma radiation.
Gamma radiation is of concern because it can easily penetrate a
few centimeters of soil to give anyone standing over a
contaminated area a reasonably uniform irradiation over the whole
body. The greater the duration or intensitY,of this exposure,

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Scenario
Radon Decay Products:
Building ~onstructed
over Area G
EPA Standard*
Typical U.S. Home
Gamma Radiation:
Building ~onstructed
over Area G
EPA Standard*
Background
13
Table 2
PROJECTED CANCER RISKS
OPERABLE UNIT II
DENVER RADIUM SITE
Average
Exposure
Average Cancer Deaths
Per 10,000 Persons Exposed
0.35 WL Workplace 380 to 1400
 Residential 1900 to 5000
0.02 WL Workplace 23 to 91
 Res i dent i a 1 1 30 to 500
0.005 WL Res i dent; a 1 33 to 130
159 pR/hr Workplace 40**
 Res; dent; a.1 1 30 **
20 ,uR/hr Workplace 31**
 Res i dent; a 1 53**
15 .uR/hr Res i dent; a 1 27
* 40 CFR Part 192
** In addition to risk from exposure to background gaml11a radiation levels.

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14
the larger the dose, and hence the greater the risk of adverse
health effects. In the case of the 11th and Umatilla properties,
the gamma radiation emission is limited to the area immediately
above the contamination.
As discussed previously, EPA has determined that a
significant increase in public health risk would result If any of
the contaminated material on the 11th and Umatilla' properties was
disturbed and misused or if the area was redeveloped. If a
building was constructed over Area G, the largest area of
contamination on the 11th and Umatilla properties, the estimated
annual dose to a person working in the building would average
159 millirem per year (mrem/yr) with an estimated maximum annual
dose of 384 mrem/yr. The estimated annual dose to a person
living in a building built over Area G would average 519 mrem/yr
with an estimated maximum annual dose of 1,255 mrem/yr. These
doses are in addition to the background dose of 130 mrem/yr
incurred by those living in the Denver area and resulting from
cosmic, terrestrial, and internal sources. The National Council
on Radiation Protection and Measurements (NCRP) and the
International Commission on Radiological Protection (ICRP)
recommend a maximum allowable whole-body gamma radiation dose of
100 mrem/yr for members of the public in addition to natural
background radiation and medical exposures they receive.

The projected cancer risk from gamma radiation (including
background) to individuals working in a building built over
Area G wpuld average 44 cancer.deaths per 10,000 persons exposed.
-The projected cancer ~isk to individuals living in the building
would average 130 cancer deaths per 10,000 persons exposed. If
individuals in any building were to receive a lifetime gamma
radiation dose equivalent to that of the relevant and appropriate
EPA standard, 40 CFR Part 192, then the project~d cancer risk to
those "working in the building would average 31 cancer deaths per
10,000 persons exposed and the projected cancer risk to those
living in the building would average 53 cancer deaths per 10,000
persons exposed. The average projected cancer risk to
individuals receiving a lifetime dose resulting from the Denver
area background would be 27 cancer deaths per 10,000 persons
exposed. It should be noted that cancer risks resulting from
gamma radiation exposure are in addition to those resulting from
inhalation of radon decay products. Table 2 presents the
information stated above.
Inhalation or Ingestion of Radiologically Contaminated Material:
Inhalation of the long-lived radionuclides like uranium,
thorium, and radium is possible for persons living or working on
or near the 11th and Umatilla properties. Airborne part~culate
matter may contain small concentrations of these radionuclides
resulting in a potential human exposure pathway. Inhalation or
direct ingestion of long-lived radionuclides can result in
significant doses to various internal organs of the body.
However, studies by the United States- Department of Energy have
shown that the projected radiation doses from this source are

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15
many times smaller than those estimated for either radon decay
product inhalation or direct gamma radiation exposure using even
the most conservative assumptions. Also, it is unlikely that a
person would ingest large amounts of the radium-cont~minated
material on the 11th and Umatilla properties and dust control
measures ordinarily employed during excavation have been shown to
provide sufficient control of exposure from this source." For
these reasons, EPA acknowledges the human exposure pathway
resulting from inhalation and ingestion of radionuclides, but no
quantitative risk numbers were developed in the Public Health and
Environmental Assessment for the 11th and Umatilla properties.
It is clear that a release or substantial threat of release
of a hazardous substance or pollutant or contaminant into the
environment has occurred at the 11th and Umatilla properties and
the release or threat of release may present an imminent and
substantial endangerment to public health. It is also clear from
the calculated risks that remedial action at the 11th and
Umatilla properties is justified.
Enforcement
A detailed responsible party search for the entire Denver
Radium Site has been initiated. Initial investigations regarding
the 11th and Umatilla properties indicate that the Schlesinger
Radium Company and its successor, Radium Company of Colorado,
operated a processing facility at this location from
approximately 1915 to 1921, the time of apparent disposal of ore
processing wastes containing, among other contaminants, radium,
the hazardous substance of concern. The responsible party search
has yet to trace either of these companies or any associated
companies to a viable, present-day entity. At this time, the
responsible party search has not revealed that the present owners
of the 1fth and Umatilla properties have any record of having
been connected with the activities that caused the site to be
contaminated with radioactivity.

EPA does not feel that response actions should be delayed
pending finalization of the responsible party search. If, upon
finalization of the search, responsible parties are clearly
identified, EPA will formally notify them of the selected remedy
for the 11th and Umatilla properties and initiate negotiations.
for the implementation of the remedy. If the responsible parties.
do not formally commit to performing the remedy in a timely
manner, EPA will proceed with a Fund-financed remedial design and
remedial action and will attempt to recover EPA's response costs
from the responsible parties.

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16
Community Relations History

On August 13, 1987, the Proposed Plan for the 11th and
Umatilla properties was published in the Denver Post. On August
14, 1987, the Proposed Plan was published in-the Rocky Mountain
News. The display ads announced the August 14 through
September 4, 1987, public comment period and the August ~6 public
meeting, gave a brief description of the remedial action
alternatives, and stated the rationale for the Proposed Plan.
In addition to publishing the Proposed Plan, EPA issued a
press release announcing the public comment period. The press
release, along with the Executive Summary of the Operable Unit II
FS, was mailed to the approximately 300 names on the EPA-compiled
Denver Radium Site mailing list.
On August 7,1987, EPA scheduled a meeting with the owners
and tenants of the 11th and Umatilla properties to describe and
discuss the cleanup alternatives being considered for the 11th
and Umatilla properties. No owners or tenants attended the
meeting.

On August 26, 1987, EPA held a public meeting concerning the
11th and Umatilla properties. Major concerns raised by those who
attended the meeting were how the remedial action at the
properties would affect the business operations of the owners and
tenants and if the owners or tenants would be compensated for any
loss of bus~ness. A second major concern raised,at the public
meeting was the liability Ot owners of contaminated properties.
Another major concern raised during the public meeting was a
question of why remedial action at the Site would be so costly.
In general, the public supports the complete excavation and
permanent offsite disposal of all Denver Radium Site material
including the contaminated material present on the 11th and
Umatilla properties. The community has reservations about any
temporary response action which EPA may take at the 11th and
Umatilla properties because of concerns that the State of
Colorado will not make available a permanent disposal site for
this material and therefore, no permanent measures will ever be
implemented at the 11th and Umatilla properties. The portion of
the community in the vicinity of the Card Corporation property
(See Figure 1) strongly opposes the alternative which envisions
temporary storage at the Card Corporation property, Operable
Unit X of the Denver Radium Site, again because of concerns,that
the State of Colorado will not make available a permanent
disposal site and that the temporary storage facility on the Card
Corporation property will become permanent, resulting in a
decrease in property values in the area.
, The Responsiveness Summary attached to the Record of
Decision contains the official transcript of the public meeting,
describes in more detail the nature and level of the community's
concern, and includes EPA's responses to all comments received
during the public review of the Operable Unit II FS.

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17
Alternatives Evaluation

EPA evaluated potential remedial action alternatives for the
11th and Umatilla properties primarily by progressing through the
series of analyses which are outlined in the National Contingency
Plan (NCP), in particular, 40 CFR Section 300.68; the Interim
Guidance on Superfund Selection of Remedy, December 24, 1986,
(OSWER Directive No. 9355.-0-19); and the Additional Interim
Guidance for FY '87 Records of Decision, July 24, 1987, (OSWER
Directive No. 9355.0-21). This process, in part, enables EPA to
address the SARA Section 121 requirements of selecting a remedial
action that is protective of human health and the environment,
that is cost-effective, that attains Federal and State public
health and environmental requirements that are applicable or
relevant and appropriate, and that utilizes permanent solutions
and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. Additionally,
SARA Section 121 and the guidance documents referenced above
require EPA to give preference to remedies which employ treatment
which permanently and significantly reduces the toxicity,
mobility, or volume of hazardous substances as their principal
element. -
The selection of remedy process begins by identifying
certain site-specific information to be assessed in determining
the types of response actions that will be considered for the
properties. A general ~ist of site-spedific information to be
considered in the process is contained in Section 300.68(e)(2) of
the NCP. This 'list was used to identify specific site and waste
characteristics of the 11th and Umatilla properties. (See Table
5-1 of the Operable Unit II FS.) Based upon these site and waste
characteristics, EPA was able to scope, from the universe of all
possible response actions, a set of response actions and
associated technologies to be considered for the 11th and
Umatilla properties. An example of this scoping process was the
elimination of onsite biological treatment from further
consideration because biological processes capable of detoxifying
radioactive contaminants do not exist. Appendix D of the
Operable Unit II FS summarizes the scoping process and Table 5-2
of the Operable Unit II FS details the results.

Section 121(b)(1) of SARA requires that an assessment of
permanent solutions and alternative treatment technologies or
resource recovery technologies that, in whole or in part, will
result in a permanent and significant decrease in the toxicity,
mobility, or volume of the hazardous substance, pollutant, or
contaminant be conducted. As part of this process, EPA evaluated
permanent solutions to the problems associated with the speci~ic
hazardous substances present on the 11th and Umatilla properties.
The alternative treatment and resource recovery technologies
considered included, among others, reprocessing.
Before the technologies were assembled into remedial action
alternatives, they were categorized as either source control or
management-of-migration measures and then prescreened based on

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18
. their suitability to abate the threat at the 11th and Umatilla
properties. Source control ~easures are intended to contain the
hazardous substances onsite or eliminate the potential for
contamination altogether by transporting the hazardous substances
to a safer location. Management-of-migration actions are taken
to minimize and mitigate the migration of hazardous substances.
The result of the prescreening of both source control and.
management-of-migration measures based on their suitability to
abate the threat at the 11th and Umatilla properties is presented
in Table 5-3 of the Operable Unit II FS.
The next step of the selection of remedy process is
assembling the remaining technologies and/or disposal options
into remedial action alternatives. Pursuant to OSWER Directive
No. 9355.0-19, "Interim Guidance on Superfund Selection of
Remedy", remedial action alternatives are to be developed ranging
from those that would eliminate the need for long-term management
(including monitoring) at the site to alternatives involving
treatment that would reduce toxicity, mobility, or volume as
their principal element. Remedial action alternatives developed
in this way will vary mainly in the degree to which they rely on
long-term management of. treatment residuals or low-concentration
wastes. Further, a containment option involving little or no
treatment and a no action alternative are to be developed.
Remedial action alternatives developed in the Operable Unit II FS
for the 11th and Umatilla properties were:
1 .
No Action
2.
Deferred Removal, Offsite Permanent Disposal
3. Onsite Reprocessing/Treatment, Offsite
Permanent Disposal
4.
5.
Onsite Permanent Disposal
Offsite Permanent Disposal
6.
Onsite Temporary Land Storage, Offsite
Permanent Disposal
7.
Onsite Temporary Building Storage, Offsite
Permanent Disposal
8.
Onsite Temporary Containment (Capping),
Offsite Permanent Disposal
9.
Temporary Building Storage at the Card
Corporation Property (OU X), Offsite
Permanent Disposal
Alternatives 2, 3, 5, 6, 7, 8, and 9, since they require the
permanent offsite disposal of contaminated material, would
eliminate the need for long-term management (including
monitoring) at the 11th and Umatilla properties. Alternative 3

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19
involves treatment as its principal element, but does not
necessarily reduce the mobility, toxicity, or volume of the
waste. Alternative 4 requires a permanent onsite remedy, and
hence, long-term management and monitoring at the 11th and
Umatilla properties. . Alternatives 4, 6, 7, and 8 are containment
options - Alternative 4 requiring permanent onsite containment
and Alternatives 6, 7, and 8 requiring temporary onsite .,
containment. Finally, No Action was included as Alternative 1.
Alternative 5, Offsite Permanent Disposal, is not
immediately implementable because the State of Colorado has not
at this time designated a facility for the disposal of the Denver
Radium Site wastes. Pursuant to CERCLA Section 104(c)(3)(C)(ii),
it is the responsibility of the State to assure the availability
of a disposal site. Also, in order to comply with SARA Section
104(k), and in order to assure that remedial actions within
Colorado continue, the State must provide adequate assurance of
the availability of a hazardous waste treatment or disposal
facility within three years from the effective date of SARA,
October 17, 1986. Although progress is being made to this end,
the State does not expect to have a fully operational disposal
facility prior to implementation of any remedial action and
possibly for up to five years.. In the meantime, in its presently
uncontrolled state, the radium-contaminated material at the 11th
and Umatilla properties could be misused or inadvertently spread,
possibly increasing the risk to present or future public health
or .the environment. In addition, the cost of final.remedial
action is expected to increase due.to inflation; the 11th and'
Umatilla property owners and tenants face economic losses
associated with restricted use of their properties; and EPA may
incur further cost by updating site .studies in. face of changing
site conditions. For these reasons, EPA determined that, in
order to effectively mitigate or minimize short-term threats. to
and provide adequate protection of public health and the
environment at the 11th and Umatilla properties, developing
remedial action alternatives which include temporary response
actions was appropriate. Thus, Alternatives 6, 7, 8, and 9 were
developed to reduce existing risks by including temporary
response measures followed by permanent offsite disposal of the
contaminated material when a facility for such disposal becomes
available.
Initial screening, which is the next step in the selection
of remedy process, narrows the list of potential remedial action
alternatives. Consistent with Section 300.68(g) of the NCP and
the OSWER Directive No. 9355.0-19, the remedial action
alternatives developed for the 11th and Umatilla properties were
initially screened using the criteria of cost, implementability
(acceptable engineering practices), and effectiveness. Table 7-1
in the Operable Unit II FS summarizes the initial screening
process. Alternatives 1, 2, 6, 7, and 9 passed the initial
screening and were carried forward for detailed analysis while
Alternatives 3, 4, 5, and 8 were screened out primarily for the
reasons set forth below.

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20
Alternative 3, Onsite Reprocessing, was eliminated from
further consideration based on its lack of effectiveness. The
residuals from this process, both the reprocessed soil and the
concentrated precipitate resulting from the reprocessing of the
soil, would require disposal in a facility that meets or exceeds
the requirements of 40 CFR Part 192. These residuals would
retain many of the toxicity and mobility characteristics.'of the
untreated material and, in addition, the volume would not be
significantly affected. This remedial action alternative would
provide no additional benefit to public health or the environment
over other remedial action alternatives to be considered. With
the elimination of this remedial action alternative, no remedial
a~tion alternative which involves treatment as a principal
element survives the initial screening. However, EPA has no
reasonable belief that this remedial action alternative is
equally protective as other remedial action alternatives, or
offers the potential for better treatment performance or
implementability, lesser adverse impacts, or lower costs than
demonstrated remedial action alternatives.
Alternative 4, Onsite Permanent Disposal, was eliminated
from further consideration because of implementability and
effectiveness factors. The property would have to be permanently
dedicated as a disposal site and measures would have to be taken
to isolate the contaminated material from man and the environment
for a thousand years without ongoing active maintenance. This
objective would be difficult to attain in an urban area where
there is a high potential .for human disturbance and in an. area
where the ground water is close to the surface as it is on the
11th and Umatilla properties. This remedial action alternative
would require long-term government ownership, licensing, and
management and monitoring to protect the integrity of the
f.acility. In addition, the implementation of this alternative
would cause severe disruption of the business operations of the
11th and Umatilla properties, and place permanent restrictions on
future land use. These requisites would conflict with current.
and proposed land uses for the area, as well as State policies on
siting permanent disposal facilities (6 CCR 1007-1, Part III,
Schedule E, Criterion 1). The State siting objectives specify,
among other things, that permanent disposal facilities must be
located away from populated areas and that hydrogeologic and
other environmental conditions be conducive to continued
immobilization and isolation of contaminants from usable ground
water sources. These criteria are clearly not met at the 11th
and Umatilla properties which are located within a metropolitan
area, and where the depth to ground water is only 10 to 15 feet.
Alternative 5, Offsite Permanent Disposal, is not
implementable at this time because the State of Colorado has yet
to designate a facility for the disposal of Denver Radium Site
wastes. This alternative was therefore eliminated during initial
screening.
Alternative 8, Onsite Temporary Containment (Capping),
Offsite. Permanent Disposal, was eliminated from further

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21
consideration because it would not be as protective of public
health as other remedial action alternatives being considered and
would require severe access restrictions on a large portion of
the 11th and Umatilla properties to maintain the integrity of the
cap. These access restrictions would be difficult to implement
without forcing business operations on the properties and use of
the area to cease.
The following is a description of the remedial action
alternatives surviving the initial screening: .
1 .
No Action
If this remedial action alternative were selected, no
action would be taken at the contaminated 11th and
Umatilla properties. This alternative serves as a
baseline and was retained for further analysis and
consideration as required by Section 300.68(f)(1 )(v) of
the NCP.
2.
Deferred Removal, Offsite Permanent Disposal
If this remedial action alternative were selected,
removal of the contaminated material at the 11th and
Umatilla properties would be deferred until an approved
offsite permanent disposal facility. is identified and
. made available by the State of Colorado. Once this
facility becomes available, the entire estimated 15,400
cubic yards of contaminated material on the 11th and
Umatilla properties including the estimated 1,000 cubic
yards of contaminated material lying beneath the DuWald
Steel east storage shed, the Duwald Steel office
building and attached warehouse, the DuWald Steel
southeast warehouse, and the Staab building would be
excavated. Special precautions would be required
. during the excavation of material from around the water
supply conduits that are present on the properties.
Excavation at the 11th and Umatilla properties would
also involve the moving of metal scrap piles which are
present on the DuWald Steel property. There is a
concrete cap on the DuWald Steel property which rests
on contaminated soil. This cap would have to be
removed in order to excavate the underlying material.
The contaminated material from the 11th and Umat111a .
properties would be transported by either truck or rail
for final disposal at a permanent disposal facility.
The 11th and Umatilla properties would then be
available for unrestricted use.
6.
Onsite Temporary Land Storage, Offsite Permanent
Disposal
If this remedial action alternative were selected, all
contaminated material on the 11th and Umatilla
properties, with the exception of the material lying

-------
22
under the concrete cap, would be excavated as described
above and temporarily stored op the site. An asphalt
pad would be constructed on an open area of the
properties. Contaminated material would be placed on
the pad and covered with a suitable material. Security
precautions, inspections, and radiation monitoring of
the storage facility and concrete cap that is already
present on the DuWald Steel property would be
instituted. Once a suitable Qffsite permanent disposal
facility becomes available, the entire estimated 15,400
cubic yards of contaminated material would be
transported by either rail or truck to the facility.
The 11th and Umatilla properties would then be
available for unrestricted use.
7.
Onsite Temporary Building Storage, Offsite Permanent
Disposal
If this remedial action alternative were selected,
contaminated material on the 11th and Umatilla
properties, with the exception of the material lying
under the concrete cap, would be excavated as described
above and placed in containers. The containers would
be temporarily stored in an existing or newly
constructed building on the properties. Security
precautions, inspections, and radiation monitoring of
the storage facility and concrete cap would be
instituted. Once a suitable offsite permanent disposal
facility becomes available, the entire estimated 15,400
cubic yards of contaminated material would be
transported by either rail or truck to the facility.
Upon- removal of the containers, the building would be
decontaminated and either dismantled or left in place.
The 11th and Umatilla properties would then be
available for unrestricted use.
9.
Temporary Building Storage at the Card Corporation
Property (OU X), Offsite Permanent Disposal
If this remedial action alternative were selected, a
portion of the contamination on the 11th and Umatilla
properties would be excavated, placed in containers,
and the containers transported to the Card Corporation
Property (OU X) for temporary storage. The remaining
material on the 11th and Umatilla properties would be
temporarily stored onsite in either a land storage or
building storage facility. Security precautions,
inspections, and radiation monitoring of the storage
facilities on both operable units would be instituted.
Once a suitable offsite permanent disposal facility
becomes available, the contaminated material from both
operable units would be transported by either rail or
truck to the facility. The- 11th and Umatilla
properties, as well as the Card Corporation property,- .
would then be available for unrestricted use.

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23
The response action for the 11 square feet of contaminated
roof in the Rocky Mountain Research building is common to each of
the previously discussed remedial action alternatives except for
the No Action Alternative. The contaminated portion of the
building's roof would be decontaminated or, if necessary,
replaced. Radioactive material from the decontamination would be
handled with the contaminated soils from the 11th and Umatilla
properties.

Consistent with Section 300.68(h) of the NCP, the OSWER
Directive No. 9355.0-19, and the OSWER Directive No. 9355.0-21,
the remedial action alternatives remaining after initial
screening were further refined and then subjected to detailed
analysis. Detailed analysis of each remedial action alternative
entailed evaluation based on the three broad criteria of
implementability, effectiveness, and cost. For each of these
broad criteria, EPA identified appropriate and more specific
"component measures" so that the remedial action alternatives
could be compared to each other using a full array of evaluation
factors. The component measures derived for implementability,
effectiveness, and cost were based upon specific requirements and
criteria contained in Section 300.68(h)(2) of the NCP, SARA
Sections 121(b)(1 )(A through G), SARA Section 121(c), the
discussion on detailed analysis contained in the OSWER Directive
No. 9355.0-19, and the OSWER Directive No. 9355.0-21.
The component measures of implemen~ability are: technical
feasibility, constructabilit~, reliability, administrative
concerns, availability of the technology, and operation and
maintenance. The component measures of effectiveness are
att~inment of applicable or relevant and appropriate requirements
(ARARs); effectiveness in significantly and permanently reducing
mobility, toxicity, and vol~me; persistence, toxicity, mobility,
and propensity to bioaccumulate of the hazardous substances and
their constituents; protectiveness/health effects; environmental
protectiveness/potential for adverse environmental impacts; and
compliance with the Solid Waste Disposal Act. The component
measures of cost are: capital cost, operation and maintenance
costs, and potential future remediation costs if the alternative
fails. Section 8 of the Operable Unit II FS provides a
comparative review of the remedial action alternatives based upon
each of the component measures listed above.
Implementability Analysis:
. All of the alternatives which were analyzed in detail are
technically feasible and constructable as they rely on common
earth moving and construction technologies - technologies-which
are both operationally reliable and readily available. Removal
of materials from around the water supply conduits on the DuWald
Steel property will require special precautions. Removal of
material from under structures and scrap metal storage areas will
be more difficult than removing material from the open areas on
the properties. The necessary equipment and specialists for
implemen~ation of any' of the remedial action alternatives are

-------
24
readily available. Remedial action work similar to that
envisioned in any of the.remedial action alternatives is already
being safely conducted in Grand Junction, Colorado, under the
auspices of the Uranium Mill Tailings Remedial Action Project.
Alternative 7, Onsite Temporary Building Storage, Offsite
Permanent Disposal, and Alternative 9, Temporary Building Storage
on the Card Corporation Property, Offsite Permanent Disposal, are
the most dif.ficult remedial action alternatives to implement
because of the limited space on the 11th and Umatilla properties
where a building could be constructed and because of the limited
capacity of existing bUildings on the properties.'
.
No Action and Alternative 2, Deferred Removal, Offsite
Permanent Disposal, are administratively the easiest alternatives
to implement. The need to coordinate and obtain access
agreements with the 11th and Umatilla property owners and the
need to obtain necessary approvals and non-environmental
construction permits from other offices and agencies are
administrative implementation constraints common to all of the
remedial action alternatives with the exception of No Action.
,Alternative 9 has an additional administrative implementation
constraint, that is, an agreement with the Mentor Corporation,
current owner of the Card Corporation property, to allow for
storage of other Denver Radium Site wastes on the property must
be finalized.
All remedial action alternatives except No Action and
Alternative 2 require 'a limited degree of maintenance activities.
The final response action associated with the remedial action
alternatives, permanent offsite disposal, cannot be implemented
until the State of Colorado provides a facility suitable for the
disposal of this material. This implementation constraint is
common to all of the-remedial action alternatives except No
Action. '
Effectiveness Analysis:
Alternatives 6, 7, and 9 are protective remedial action
alternatives which will meet contaminant-specific ARARs for
radium levels in site soils and gamma radiation levels and radon
decay product concentration in the DuWald Steel office building
and Capital Management Realty basement once the temporary
response actions are completed. In addition, these three
remedial action alternatives will meet all identified action-
specific and location-specific ARARs and other guidance to be
considered. Alternative 2 will provide no short-term protection
of public health and the environment and will meet the
contaminant-specific ARARs only after the contaminated material
is removed to the permanent disposal facility. No Action will
provide neither short-term nor long-term protection of public
health and the environment and will not meet the cont~minant-
specific ARARs and the possible resulting exposure would result
in unacceptable risks to public health.

-------
25
No Action and, in the interim, Alternative 2 will not reduce
the mobility, tQxicity, or volume of the contaminated material on
the properties. Although Alternatives 6, 7, and 9 will not
reduce the toxicity or volume of the radioactive waste, they
transfer the contaminants from the uncontrolled status to a
controlled facility, thereby reducing mobility. In addition, an
increase in volume is often the result of the contaminated
material being disturbed. Thus, Alternatives 6, 7, and 9, since
they reduce the chances of the material being disturbed, also may
prevent the volum~ of contamination from increasing.
EPA conducted a Public Health Evaluation of Remedial
Alternatives to determine the short-term potential for adverse
health effects from human exposure associated with the various
remedial action alternatives. This analysis, summarized in
Appendix F of the Operable Unit II FS, revealed that all of the
alternatives considered except No Action would result in nearly
equivalent exposures during implementation of the remedy. All
estimated exposures are well below target levels established in
ARARs. EPA also conducted a Public Health and Environmental
Assessment to determine the long-term potential for adverse
health effects associated with the contaminant levels present on
the 11th and Umatilla properties. This analysis, summarized
earlier in this summary and contained in Appendix C of the
Operable Unit II FS, showed that there would be a significant
increase in public health risk if the No Action alternative was
implemented at the 1000 West, Louisiana properties.
The potential for adverse environmental impacts at the 11th
and Umatilla properties is low. However, leaving the material
onsite in an uncontrolled state provides an opportunity for
potential environmental impacts during a catastrophic event, such
as a flood or a water main break, resulting in a substantial
dispersal of the contaminants.
Cost Analysis:
No Action is the least costly alternative followed by
Alternative 2. ' Alternative 9 is the most expensive alternative
followed by Alternative 7. Alternative 6 has a mid-range cost.
Table 3 presents a breakdown of each alternative's cost based
upon the component measures of cost described above. An even
more detailed breakdown of each alternative's cost is provided in
Appendix H of the Operable Unit II FS. Section 8 of the Operable
Unit II FS contains a sensitivity analysis of these costs.
In summary, the selected remedy for the 11th and Umatilla
properties was chosen from the detailed analysis of remedial
action alternatives. The analysis was based upon component
measures of implementability, effectiveness, and cost. Table 4
outlines the detailed analysis of remedial action alternatives.'
(See also Se~tion 9 of the Operable Unit II FS.)

-------
[Vllultlon Crlterl.
C.pltll Co.n
o Inlt III
o De ferred
Operltlon Ind Helntenlnc.
o Short-t.~ fup to 5 ,r)
o 5",r .Ic. r.vlew
'r.lent-Yorth Alt.rnltlv. Calc
~!~!!r. IIUocd18!!~
COltl If Alternltlv. rlill
AIUrn.th. 1
No Action
lIot Ippllcabl.
Hot Ippllcabl.
lIot .ppll",l>I.
Not appllcabl.
Not ',pllca!!l.
Hot 'pp II cab I.
Alteraatlv. 2
De'arred 'e...,,,.
O".lt. 'Ir.~nenc DI,po.II
S 50.)00
2,285.JOO
105,000
U,O!,O
2,1012,000
Ha.loua co.t equel.
Inltlel clplt.1 coet
Table 3
COST nALIIATlat or ALTUNATlftS
O'EIlAILI! UNit II. DfWEI kADlUH sin
Alternlth. ,

On.It. le.pourT 1.8001 Store.e.
Offllt. 'enol"lIIt D18po..1
'1,900,700
2,1)S,1000
16),700
)1,000
10,130, )00
Hello... co.t equel. loltlel
clpltal co.t
Alteroecl.,. J

Oo.lt. 'e.por." 'uI1410. Stor',I,
O"llte ,.,.IOlot Dllpo.11
$1,125,500
2,OtS,900
'61,"00
U,OOO
5, "10,800
Healo... co.t equ.11 101tl.1 clplc..
co.t
<arnlth'. t
II..porer,
lulldlo. Storl" on OU 1/
OI(llt. 'enolr-ent DI'pol.'
$),195,'00
2.)SS.)00
nJ,)OO
n,ooo
'.'53.'00
Healo... calC .qu.11
IDltl.1 clplt.1 COlt
Co- U...aU
I JI:R Iloo f)
Colt 0' c-
"e.enU la-
elud.d In COIU
'or loll IItU-
OIC Iv...
Hot .ppllcable

-------
[vllultlon Crlterll
Table 4
SIItIHAIY OF AltERNATIVE [VAUIATION
OPERABLE UKlr II.' DENVER IADIUH SirE
Altemltlve 1
Ho Actloo
Fe"lbl.
lDple..nteblllt,
E((ect Ivene..
CoUI
40 CrR 192 condltlonl fo~ ~ldlu.-226 In '011.
would oot b. Itt.lned. Prot.ctlven... level.
for rldon .nd Ilmml redl.tlon would not b.
.ttllne4. ~".e e.po.ur.. could be Inc~el'ed If
uncontrolled lend U'I chlns.e occur.
Ho Action dOle not rlduc. .oblllt" to.lclt,.
Ind volu.. of OU II rldlolctlv. .Iterllil.
"diu. I. not v.r, .oblle Ind Ilvel off rldon
decI, producu to the It.o.pherl. ""U. not
very lolubl. .fte~ reproc.lllnl, rldlu. I. .ub-
'Ject to dl.p.r'll vi. hU'ln Ictlvlty. aldon
decI, product. c.n ,ccu.ulltl In hueln luna' Ind
er. clrclnolenlc. e.m.. ~Idl.tloo could CIU..
cencI~ or len.tlc dlfect..
Hot 'ppllcable.
AltemlUve 2
Def.rred RellOval/Per88neot
Off.lte OI,po'll

Additional bulldlnl' could b. built O"er coo-
t..lnltld .rlll. Contl.lnlt.d .lterl.l. could be
dllper.ed o~ dllutld .uch thlt th., would no
lonle~ b. Idlntlfllbl..
Eaclv.tlon clnnot proc'ld untl' '0 off.lte dl.- ,
po..1 fecillt, I. IVllllbl.. A..ur.nce of Iv.II-'
.bliity requlrld by SARA 104(k). Flcillt, I.
.11U8ed not to be IVllllble untl' 1992.
IA.II. rellOval h deflrred, "dl_-226 '.ve" In
loll would not b. ..t. Actlon-Ipeclflc ARAR'I
wIll b. .et durlnl rI8Ov.l. Durlna d.l.rrld
r'~ovII. lit. worker. would b. '.pOlcd to
Ippro.I..t.l, 11 .re.',~,

Durlnl e.clvetlon. r.88dl.1 Ictlon worterl would
b. e.poled to Ippro.I'ltel, J5 .r..,,~ (whole bOd,
001. [qllivalent). which" below th. 10 CrR 20
.tendlrd of 500 .r..l,r for workerl. On.lt.
workerl vho er. not ..Ioclet.d with clelnup would
b. ..po..d to Ipproxl'ltel, 2 .re.',~. which I.
b.low thl HCRP IICRP luldlnce of 100 .rl./yr for
chronic I.polure to the lenlral public. rran.-
portltlon of 350 .11.1 to off.ltl dllpo'll f.clllt,
would Involv. driver e.polur. of 6.4 .re./trlp.
"Inl.el e.po.ur. would occur to lenerll public
durlnl trlnlportltlon. unle.. In .ccldentll 'plll
occurred, which would re.ult 10 . 'Inor Incre..e
10 ..po.ur...
C.p&tll Pw8--S2,336.000
O&H '1I--$J6,OOO
AhemlUve 6
On.lt. re8porlr, Lend Stor"el
Peralneot Olf.lte Ol,po'l

r"porlry .tore.. cln he"e technlcII prob-
Ie... .uch .. rlpplnl of the .,nthltlc
Cover or crlcke 10 the ..phllt pld.
re8po~lry Itorll' woul' b. ulld uotll off-
lite dl,po'll Ilclllt, II IVllllbll.' .'
AVllllblllt, required b, SARA 104(k).
',clllt, II l'l~d not to b. eVllleble
until 1992.
Site .ccel. ~eltrlctlon. Ind 'pprovll.
would be needed to conltruct the IIphllt
pld .torl,1 unit. StOrl.1 Ilclllt, would
.evlrel, reltrlct ullie 01 over.11 .It.
fo~ 5 ,e.rl. Iince It would occup, I Ilr.e
percent'.e of opeo 'p'c, .t one of the .
prop.rtl...

lb. flcillt, Ihould be protective of the
envlron.ent If Ipproprl.t. Iinerl Ind
t'PI .re uled. 'otentlll I'PICtl could
occu~ durlnl r180vII (both for pllce8ent
In thl telporlrr flcillt, .nd the pe"l-
nlnt of I. It I f.clllt,) If uncontroillbl.
dllplr..1 OCcur. to the Invlron8l0t.'
N
'-J
Durlnl te.porlry Itorlil. 'Ite work.r.
would b. e'poled to 'ppro.l.lt.l,
. 11 .re.l,r.
. Durlnl .xuvetloo, reaedhl ecUon
worker. VDuld b. '.po.ed to 81 'r..',~
(whole bod, dOle equlvllent). which I.
below the 10 CfR 20 .tende~d. Onllte '
worken nut ,"ocleted with cleanup would
b. e.pol.d to 3 .re.l,r. whIch I. b.low
thl "CRP/ICR, luI4elln.. rrln'portetloo
e.po.ur. would be Identicil to
AI,terneUvl 2.
I
CIP&t.1 Pw8~-$4,O)5,600
O&H '"--$194,100'

-------
[v.lu.tlon Crlt.rl.
AlternaUv. 7
ea.lt. T"porn, BuUdlo. Stor...
P,r..n.nt OII.lt. DI.po..1

Caat.laar. could rip and .plll ..t.rl.1 la
th. bulldln.. Hovev.~. tha bulldln. .hould
coat.lo .ny 'pill.d .,t,rl.I..
1apl.~ t.blllt,
&"por.rp .tor... vould ba u..d until 01,. It.
dl.p~..1 '.cllltr I. .vall.ble. A..ur.nca 01
.v.ll.blllty r.qulr.d b, SARA 10'(k). f.cll-
It, I. al.~d Dot to b. avall.bla uotll 1992.
Sita acca.. r..trlctlon, .nd .pprov.l, vould
b, needed to con.truct the ..ph.lt p.d .tor-
... uolt. Stor..e ',clllt, would ..v.r.I,
rutrlct .uu.. 01 ovar.11 alt. lor 5 yun,
.Inci It would occupr . I.r,. p.rc.ot... 01
op.o .p.ca .t on. 01 the prop.rtla..
EII.cth.n...
,.dlu.-226 .t.nd.rd. ID .011. would ba ~t
upon Inltl.1 r.~ov.l. C.... r.dl.tloo .nd
r.doo dec.y product .tand.rda ',y .1.0 b. ..t
.Iter re,ov.l. Ourln. te'por.ry .tor..., .
.It. w~r~.rl would b. 8.pOI.4 10 appro....t.l,
10 'r88/,r.

Durin. a.c.v.tlon, r...41.1 .ctlon varkar.
\lould be upol.d to 'Pl'ro&l..t"y 87 .r../,~
(whol. body 00'1 [qulvaleot vhlch I. balow
the 10 CfR 10 .t.ndlrd~ Onl't. varkar. who
.r. aat 'I,oc'ated vlth cle.nup vauld ba
"POled to 1 .u./yr, "'Ilch II b.low tha
"CRt/ICiP auldelln.. Tr.nlpart.tlan a.pa-
aur.a vould ba Id.ntlcal to Altarnat'v, 2.
Caat.
"IOV.I .nd te'porl" cont.laer .to~'.a viII
not It a 10 perc.nt dl.count factor. nl,
~blllt, of tha ..t.rl.1 vould b. decr....d
ua"" the container b~ok'i however. .tha u..
01 I Lulldln. for Itor'na the conta'n.r.
vould coot.ln .n, .plll.... .

C.plt.1 rw.-S5,221.'00 O&H rw--$69J,'OO
:rw - pr..ent worth .t . 10 percent dlacouat f.ctor.
. 0f.H - Operetlon. .nd "1Intenlnc..
Table 4
(cootlauad)
AI t.na.Un ,
Te'par.r, Bulldla. Storl.. at
OU I/Olfllt. Per'la.at Dllpo..1

l'ple8ent.blllt, coalld.r.tloa. .. d..crlb..
la~ Alt.rnltlve. 6 .nd J .ppl, .t OU I lor
thl. .It.rnltlv..
Te.par." .tor,.. would b. u..d uatll oll.lt.
dl'po..1 Ilclllt, .. .vall.bl.. Av.ll.b,I't,
requlr.d b, SARA 10'(k). F.cll't, I. ...u...
nOl 10 b. Iv.lllbl. uatll 1992. Volu.. 01
v..t. would b. trlnll.rr.' Ir08 the OU 11 pro-
p.re'e. to the OU I propert,.
EI'.ctlven... canll'.r.tlonl I' dllc~'bed lo~
Aiternativi. 6 .nd J .ppl, It OU I lor thll
.hernltlv..
&on.olld.tlon 01 .0.. OU II prop.rt, WI.t..
vlth OU I prapert, V.lt.. voul' provld.
'ncr....d ov.r.11 protection 01 the .avlron-
..at.
Durin. I'C.v.tlan, r...d..1 .ct'oa vork.r.
vould b. "pol.d.ta 'ppro.I'lt.l, 101 .re./,~
01 vlool. bod, Do.. Equlv.l.nt. wh'cb II b.low
tll' 10 C." 20 'Underd 01 500..r../yr. eallt.
vark.rl ~o .r. not Illocl.ted w'th CI.lnur
would bl expalld to , .r../,r, wlllcb .. be ow
th. NCRP/ICap .uldel'ne 01 100 .re'/yr. trla.-
Fartlelon 01 150 .11.. to olf.lt. dllpal.l
f.c.llt, would Involv. drlv.r "palur. of
6.4 .r../tr'p. H'nl..1 "polurl would occur
to ,en.r.1 public durin. trlnlporeltlao.
unl'.1 .n .ccld.ae.l .p'll occurred.
rv--S5,414.100 O&H rv--SJI9,JOO
Co-a EII..ot
IIHR Roof
"101..1 pot.ntl.1 lor poo~ d.coatl.lolt'oo
perfora.nc., line. roof could Ilw',1 b.
co'pl.t.l, r'8Dved. IJ.k of "Ilur. dur'n.
r18ov.1 I. "nl..l.
"80v.1 01 rldlo.ctlv. ..t.r'll. '0 th. roo I
will not reduce 'tl to,'clty. ~blilty, lad
volue., the ..t.rl.1 viii be tr.o.I,rred froa
the bulldln. to .Ieh.~ I tl"por." Itor...
flClllt, or '0 olilit. d'lpol.1 f,cliity.
Includ.d 'a Alt.rn.t'v, rltl.lt...

-------
29
Selected Remedy
This Record of Decision addresses the contamination present
on the 11th and Umatilla properties, Operable Unit II of the
Denver Radium Site. This is the sixth operable unit of the
Denver Radium Site for which EPA has selected a remedy. EPA is
undertaking additional feasibility studies to evaluate remedial
action alternatives at the other Denver Radium Site operable
units and will complete a Record of Decision or an Action
Memorandum for each of the operable units for which a remedy has
not already been selected. EPA's preferred remedial action
alternative .for the 11th and Umatilla properties is
Alternative 5, Offsite Permanent Disposal. This alternative,
however, was eliminated during the initial screening of remedial
action alternatives because, until the State of Colorado provides
a permanent disposal site for material from the 11th and Umatilla
properties, this alternative cannot be implemented. EPA has
therefore determined that the appropriate extent of remedy at the
11th and Umatilla properties is Alternative 6, Onsite Temporary
Land Storage, Offsite Permanent Disposal. The State of Colorado
has been consulted and concurs with the selected remedy.
Remedial Design for Operable Unit II will include the
selected remedy, Alternative 6, and EPA's preferred remedial
action alternative, Alternative 5, Offsite Permanent Disposal.
Should the State of Colorado fulfill its obligation to assure the
availability of a suitable disposal facility for material from
the Denver Radium Site by the time EPA has concluded Remedial
Design for the 11t~ and Umatilla properties, EPA may implement
its preferred alternative, Offsite Permanent Disposal.
Description of the Selected Remedy:
The selected remedy consists of (1) implementing two
temporary source control response actions, (2) maintaining one
temporary management-of-migration response action which is
already in place, and (3) implementing one final and permanent
source control response action when possible.
The temporary source control response actions consist of
decontaminating the 11 square feet of roof in the Rocky Mountain
Research building and excavating the majority of the estimated
15,400 cubic yards of conta~inated material on the properties and
placing the material in a temporary land-storage facility. The
implementation of these response actions will entail the
construction of a large asphalt pad on the 11th and Umatilla
properties. Contaminated material will be placed on this pad to
a height of 10 to 15 feet and covered with a suitable liner. The
temporary land-storage facility will limit the spread of
contaminated material by wind and water erosion and human
activity. The facility will also provide temporary protection of
human health by reducing direct exposure to gamma radiation and
by reducing the risk of inhalation or ingestion of contaminated
soil." In addition, with the removal of contaminated material
from under the buildings, radon decay product levels in those

-------
30
buildings should decrease. Excavation of the contaminated
material and its placement in the temporary land-storage facility
could take four to eight months. Once in place, the land-storage
facility will be routinely inspected and access restrictions will
be instituted to maintain the integrity of the facility. The
contaminated material will remain in the temporary land-storage
facility until a permanent offsite disposal facility becomes
available. .
The temporary management-of-migration response action
consists of maintaining a six-inch thick, reinforced concrete cap
that already covers contaminated material on the northern portion
of the DuWald Steel property. This cap, which was constructed by
the property owner, will continue to limit the spread of
contamination, and also provides temporary protection of human
health by reducing the direct exposure to gamma radiation and the
risk of inhalation or ingestion of radionuclides. The concrete
cap will remain in place until a permanent offsite disposal
facility becomes available.

The final and permanent source control response action will
occur once a permanent offsite disposal facility becomes
available and consists of removing the material in the temporary
land-storage facility as well as the contamination beneath the
concrete cap. This material and any portion of the cap or
asphalt pad which is contaminated would then be transported by .
either truck or rail to the permanent offsite disposal facility.
Removal of contaminated material from the land-storage facility
and from under the concrete cap and transportation of this
material to the permanent offsite disposal facility could take
three to six months. A more detailed implementation schedule for
this response action and the ones described above will be
developed during Remedial Design.
'~ -_./
The present-worth cost of the selected remedy is $4,230,300
based upon a ten-percent interest rate, a five-year discount
period, and a perpetuai monitoring period. The cost of this
alternative includes construction of a temporary land-storage
facility for the contaminated material, excavation of the
material from the open areas and from under the buildings,
decontaminating the roof of the Rocky Mountain Research building,
placement of the contaminated material into the temporary storage
facility, and maintenance and monitoring of the temporary land-
storage facility and concrete cap for a period of five years.
The cost of this alternative also includes removal and transport
of all contaminated material, including the ~aterial beneath the
concrete cap, to the offsite permanent disposal facility,
decontaminating and, if necessary, dismantling the temporary
land-storage facility and transporting the uncontaminated
material (asphalt and liner) to a solid waste landfill.
Operation and maintenance activities will be required to
ensure the effectiveness of the temporary response actions.
.These activities include site inspections, ongoing radiological
. monitoring, and' possible minor re'pairs to the concrete cap

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already in place on the DuWald Steel property or the temporary
land-storaga facility to be constructed on the 11th and Umatilla
properties. Also included as an operation and maintenance
activity for cost estimating purposes is a review of .the
properties which, pursuant to SARA Section 121(c), must be
conducted no less than every five years if a remedial action is
selected that results in any hazardous substances remaining
onsite. Since EPA does not anticipate that any hazardous
substances will remain onsite longer than five years, the cost of
this review i~ considered a contingency. The maximum total of
the discounted annual operation and maintenance costs of these
activities using a five-year discount period and a ten-percent
discount rate is $194,700. This operation and maintenance cost
is included with the present-worth total alternative cost
mentioned above.
Statutory Determinations:
Protectiveness: The Public Health and Environmental
Assessment for the 11th and Umatilla properties summarized
earlier in this document clearly shows that there would be a
significant increase in the risk of contracting lung and other
cancers if Alternative 1, No Action, was selected for this
operable unit of the Denver Radium Site and the properties were
ever developed. in a way which might reasonably be expected. The
only effective way to reduce this risk is excavation to achieve
target residual levels established in contaminant-specific ARARs
and removal of the contaminated material from the 11th and
Umatilla properties to an offsite permanent disposal facility.
Further, because the offsite permanent disposal facility would be
designed to isolate the contaminated material from man and the
environment for a thousand years, the selected remedy would
provide long-term protectiveness. The temporary measures
envisioned in the selected remedy will provide the necessary
short-term protectiveness.
In addition to preparing the Public Health and Environmental
Assessment mentioned above, EPA conducted a Public Health
Evaluation of Remedial Alternatives, summarized in Appendix F of
the Operable Unit II FS. For this evaluation, exposures to gamma
radiation, inhalation of contaminated soils, and inhalation of
radon decay products were estimated for persons who might be
exposed to hazards during implementation of each alternative
undergoing detailed analysis. These persons include onsite
remedial action workers, individuals not associated with remedial
activities but working in an onsite office, residents of a home
located outside of the property boundary, a transportation
worker, and an onlooker present during truck transportation of
the contaminated materials. Exposures were calculated for each
remedial action alternative undergoing detailed analysis. The
evaluation revealed that none of the estimated exposures for any
scenario of any remedial action alternative, including the'
selected. remedy, exceeded exposure limits set by the relevant and
appropriate standards or guidelines. Also, for any given .
scenario, there was no appreciabl~ difference amorig the estimated

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32
exposures for the remedial action alternatives. The risks
ass9ciated with this type of remedial action work lie not with'
possible radiological exposure, but with the inherent dangers
associated with general construction work. Based upon statistics
from the construction industry, EPA estimates that the number of
non-fatal injuries to cleanup workers would range from 0.239 to
0.473 for the type of work to be conducted during remedial action
at the 11th and Umatilla properties; the number of fatalities
wo~ld range from 0.025 to 0.050. (See report entitled Operable
Unit IIr Public Health and Environmental Assessment, Dose
Commitments.) These numbers can be significantly reduced by
hiring competent and properly trained construction contractors
and by st~ict adherence to the site safety plan.

The OSWER Directive No. 9355.0-19 states, "Remedies must be
protective of human health and the environment. This means that
the remedy meets or exceeds ARARs..." EPA has determined that
the selected remedy will meet all ARARs identified for the 11th
and Umatilla properties. In addition, from the analyses
conducted in the Public Health and Environmental Assessment and
the Public Health Evaluation of Remedial Alternatives and because
of the permanence associated with the design of the offsite
disposal facility, EPA has concluded that the selected remedy
would be protective of public health and the environment.
. Consistency With Other Laws: Pursuant to SARA Section
121(d), remedial actions shall attain a degree of cleanup of
hazardous substances, pollutants, and contaminants released into
the environment and control of further release which at a minimum
assures protection of human health and the environment. In
addition, remedial actions shall, upon their completion, reach a
level or standard of control for such hazardous substances,
pollutants, or contaminants which at least attains legally
applicable or relevant and appropriate Federal standards,
requirements, criteria, or limitations, or any promulgated
standards, requirements, criteria, or limitations under a State
environmental or facility siting law that is more' stringent than
any Federal standard (ARARs).

On November 20, 1986, EPA requested that the State of
Colorado identify potentially applicable or relevant and
appropriate State public health and environmental requirements
for the Card Corporation property, (OU X). The State responded
to this request on January 21, 1987, with a list of Colorado
requirements which pertained to the entire Denver Radium Site.
EPA classified all Federal and State public health and
environmental requirements applicable or relevant and appropriate
to the 11th and Umatilla properties into three categories:
contaminant-specific ARARs, action-specific ARARs, and location-
specific ARARs. A description of each of these categories is
provided in both Section 4 and Appendix C of the Operable Unit II
FS. Other Federal and State criteria, advisories, and guidance
were also considered. Tables C-1 through C-4 in Appendix C of
the Operable Unit II FS contain a brief description of each'

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33
potential Federal and S~ate requirement identified and EPA's
analysis of ,each requirement's applicability or relevance and
appropriateness to the 11th and Umatilla properties. EPA has
determined that the selected remedy will meet all applicable or
relevant and appropriate public health and environmental
requirements of Federal and State laws and, therefore, no SARA
Section 121(d)(4) waivers need be invoked. A brief discussion of
ARARs for the 11th and Umatilla properties is provided below.
The EPA Standards for Remedial Action at Inactive Uranium
Processing Sites, 40 CFR Part 192, 'are one of two contaminant-
specific ARARs identified for the 11th and Umatilla properties.
For properties contaminated with uranium processing residues,
these standards establish limits for the gamma radiation level
and annual average radon decay product concentration in any.
occupied or habitable bUilding and for the radium concentration
in soil on open lands. Although not necessarily applicable to
the 11th and Umatilla properties since the standards apply only
to certain specifically designated sites where uranium was
processed, the standards are relevant and appropriate to the 11th
and Umatilla properties because (1) it is the radium content of
the uran~um mill tailings which is regulated; (2) the waste
products resulting from uranium ore processing are very similar
to those from both radium and vanadium ore processing; (3) the
residues from both processes enter the environment through the
same exposure pathways; and (4) the adverse health concerns
resulting from-exposure to the residues from both processes are
the same.
The portion of the standards relevant and appropriate to the
contaminated soil on the 11th and Umatilla properties and the
portion which serves as EPA's target residual level for cleanup
is 40 CFR Section 192.12 which states:
"Remedial actions shall be conducted so as to provide
reasonable assurance that, as a result of residual radioactive
, materials from any designated processing site:
(a)
the concentration of radium-226 in land averaged over
any area of 100 square meters shall not exceed the
background level by more than -
( 1 )
( 2 )
5 pCi/g, averaged over the first 15 centimeters of
soil below the surface, and
15 pCi/g, averaged over 15 centimeter-thick layers
of soil more than 15 centimeters below the
surface."
(40 CFR Section 192.12)
The portion of the standard relevant and appropriate to the
buildings on the 11th and Umatilla properties is 40 CFR
Section 192.12(b) which states:
(b) .In any oc~up~ed or habitable building

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34
.( 1 )
( 2 )
The objective of remedial action shall be, and
reasonable effort shall be made to achieve, an
annual average (or equivalent) radon decay product
concentration (including background) not to exceed
0.02 WL. In any case, the radon decay product
concentration (including background) shall not
exceed 0.03 WL, and
The level of gamma radiation shall not exceed the
background level by more than 20 microroentgens
per hour.
o
(40 CFR Section 192.12(b).)
The second contaminant-specific ARAR identified for the 11th
and Umatilla properties is the Nuclear Regulatory Commission
Standards for Protection Against Radiation, 10 CFR Part 20.
These regulations establish standards for protection against
radiation hazards arising out of activities under licenses issued
by the Nuclear Regulatory Commission (NRC). Because these
.standards apply to licensed NRC facilities, they are not
applicable to the 11th and Umatilla properties. However, EPA has
determined that portions of the regulations are relevant and
.appropriate to individuals who would be conducting the remedial
action on the 11th and Umatillaproperty. In addition, these
regulations are incorporated by reference in the Occupational
Safety and Health Administration Standards, 29 CFR Parts 1910 and
1926, which, due to the mandate contained in SARA Section 126,
now apply to employees involved in responses covered by CERCLA.

Of particular importance is Appendix B of 10 CFR Part 20.
which provides limits for airborne concentrations of natural
uranium, thorium-230, and radium-226. Gamma radiation dose
standards for individuals in restricted and unrestricted areas
are cited in 10 CFR Sections 20.101 and 20.105, respectively.
These 10 CFR Part 20 standards along with the 40 CFR Part 192
standards are summarized in Table 5.
EPA has identified one potential location-specific ARAR. for
the 11th and Umatilla properties, the Executive Order on Flood
Plain Management, 40 CFR Section 6.302(b), which requires Federal
agencies to evaluate the potential effects of actions they may
take in a flood plain to avoid, to the maximum extent possible, .
the adverse impacts associated with the direct and indirect
development of a flood plain. Remediation of the contamination
of the 11th and Umatilla properties is not likely to have an
adverse effect in the event of a flood especially since having
the contaminated material in a properly engineered and designed
land-storage facility will reduce the chance that contaminated
material would be spread during a flood. Currently there are no
identified State location-specific ARARs for the 11th and
Umatilla properties.

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ReguloLory Agency
~pe of COntamInant
FEDERAL

U.5. EPA-40 CFR 192,
Subpart B-Stonduda
Rad1Ull-226
Concentration
Gamma radiationS
Radon Dccay Product
Concent ration
Nuclear Regulatory
COIOlllla&1on WRC)
10 Clo'R ~O
UranIum-natural
Airborne Concentra-
tions
1110rlull-230
Allhorne Concentra-
tions
Radlum-226 Airborne
Concentrations
GaDlma radlaUcma
c
. Table 5
POTENTIAL CONTAtIINANT-SI'F.CJFIC ARAR'S
OPEltABLE liNn: 11, DJ::NVER RADIUM SIn:
Standard, Requirement,
Crlterl... or LlwltoLlon
5 pCI/S above background
wltMn 15 CII of the aur- .
face ,caaured over a
]00-11 area
15 pCI/g above background
within aubsequent ]5 CII
layer! measured over a
100-11 area
20 IJR/hr above background
COmmenta
Stondards for cleanup of open land. or buildIng.; concen-
traUOIl of ndlull-226 In land, averaged over any ana of
]00 square IIden. Point of c2mpJJance h at any contam-
inated area greater tha.. 100 II. lIowever, during cleanup
all contaminated ares would be remedlated.
Relevant and approprIate to Indoor gamma radIation.
Point of compliance Is Inside any alte building.

0.02 WI. annuol average Relevant and appropriate to Indoor radon. Point of
0.03 WI. IISXIaIUil compl1once 18 InsIde any site LuUdlng.

3 b
5 pCI/. '3Unrestrlcted arese Point of cOllpllance 18 any 10caUon wHhln "te.
100 pCI/m , Restricted area
3 b
3 pCI/. 3 Unrestricted neB .Polnt of compliance Is any location withIn alte.
30 pCI/m , Restricted area
w
VI .
3 b
3 pCI/. 3 Unrestricted are~ Point of cOllpllsnce 1& any location within alte.
30 pCI/.. , Restricted arca
5 rell/yr, (5tOog .rem/yr)
Restricted area b
500 rarcm/yr, Ullrea trleted
. area
Point of compliance Is any location within site; site
would be unrestrlcLed for remediation workers.
akelcvant and appropriate IILandard but not a. protective aa Other Guidance; aee Table 4-3.
bAn unrestricted area la regarded as any place around a wuste consolidation/storage area facility wher~ access la
cA resLrlcted area Ia regarded as any place around a waste consolldstlon/storGge area where access is controlled.
. "
not cont rolled.

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36
Action-specific ARARs are technology-based restrictions
triggered by specific types of remedial measures under
consideration. Once the remedial action alternatives were
developed in the Operable Unit II FS, EPA identified specific
action elements which were part of at least one or more of the
alternatives. These action elements are listed in Section 6 of
the Operable Unit II FS. EPA then identified numerous a~tion-
specific ARARs for each of the action elements. These action-
specific ARARs were evaluated in Appendix C of the Operable
Unit II FS and are presented in Table 6-2 of the Operable Unit II
FS. .'..
In addition to the ARARs mentioned above, EPA also
considered other Federal and State criteria, advisories, and
guidance in determining the appropriate degree of cleanup for the
11th and Umatilla properties. In particular, EPA considered the
National Council on Radiation Protection and Measurements (NCRP)
and the International Commission on Radiological Protection
(ICRP) recommendation for maximum gamma radiation dose to the
whole body. This dose, 100 mrem/yr, is for chronic exposure to
the general public, excluding natural background and medical
radiation. This recommended level is more protective than the
level established by the NRC in its regulations (10 CFR Part 20),
and will be used in evaluating exposures to those working on the
site but who are not associated with the cleanup of the 11th and
Umatilla properties.

SARA Section 121(d)(3) codifies EPA's offsite disposal
policy; which requires that offsite disposal of any hazardous
substances, pollutants, or contaminants from a Superfund site
take place only at a facility that is in compliance with
applicable Federal law and all applicable State requirements.
Furthermore, the' unit to which these wastes are transported must
not be releasing any hazardous waste or constituent to ground
water, surface water, or soil, and any such releases from other
units at the facility must be controlled by an approved
corrective action 'program. It is incumbent upon the State of
Colorado, as part of its CERCLA Section 104(c)(3) obligations, to
assure the availability of a disposal facility which is in
compliance with EPA's offsite disposal policy.
Cost-effectiveness and Utilization of Permanent Solutions
and Alternative Treatment Technologies or Resource Recovery
Technologies to the Maximum Extent Practicable: Alternative 6,
Onsite Temporary Land Storage, Offsite Permanent Disposal, is a
cost-effective remedial action alternative which effectively
mitigates and minimizes threats to and provides adequate
protection of public health and the environment. The results of
this alternative cannot be achieved by the methods envisioned in
the two alternatives which were less costly, Alternatives 1 and
2~ Alternative 7 and Alternative 9 would be equally effective
but much more expensive to implement than Alternative 6.

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37
The selected remedy will address the principal threat at the
11th and Umatilla properties. However, the selected remedy does
not satisfy the statutory preference for treatment as a principal
element. As part of the selection of remedy process, EPA
evaluated permanent solutions to the hazards associated with the
specific substances present on the 11th and Umatilla properties.
However, since the hazardous substance associated with the 11th
and Umatilla properties is a radioactive element, the number of
treatment technologies which may successfully reduce the
mobility, toxicity, and volume of the hazardous substance is
'extremely limited. The characteristic of spontaneously emitting
energy and subatomic particles is a property inherent to each
atom of a radioactive element and which cannot be altered or
destroyed by any chemical or physical treatment known today.
Most treatment and resource recovery technologies concentrate the
radioactive elements present in 'the waste, increasing toxicity
without sufficiently reducing volume or mobility. These'
treatment and resource recovery technologies will leave a waste
product which is still radioactive. Nonetheless, EPA considered
several treatment and resource recovery technologies in the
technology scoping. and screening phase and even the initial
alternative screening stage of the Operable Unit II FS. However,
no technology was found which would result in a permanent and
significant decrease in the toxicity, mobility, and volume of the
hazardous substance, radium, which is present on the 11th and
Umatilla properties.
u
Future Actions'
The future remedial activities that are required to complete
remedial action at the 11th and Umatilla properties are:
( 1 )
( 2 )
( 3 )
(4 )
( 5 )
( 6 )
Design remedial action.
Enter in to State Superfund Contract with State of Colorado.
Conduct temporary remedial actions for contamination present
on 11th and Umatilla properties.
Select and, if necessary, design and construct permanent
disposal facility. (This activity is to be conducted by
State of Colorado.)
Remove contaminated material from the 11th and Umatilla
properties and transport it to the permanent disposal
facility.
Confirm that the 11th and Umatilla properties have been
decontaminated to conform with the requirements of ARARs and
can be made available for unrestricted use.

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38 "... HozardouS W~
\nformot\on . R{
Schedule . US EPA Re9'~
~h"ade\Ph'a, ;
Dates for completing key milestones leading to remedi -- ~
action at the 11th and Umatilla properties are highlighted elow:
( 1 )
(2 )
Complete design of remedial action by September 30, 1988.

Finalize State Superfund Contract with State of Colorado by
September 30, 1988.
( 3 )
Initiate remedial action no later than during first quarter
fiscal year 1989.

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