EPA/ROD/R08-87/012
1987
EPA Superfund
Record of Decision:
DENVER RADIUM SITE
EPA ID: COD980716955
OU 10
DENVER, CO
06/30/1987
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Declaration
for the
Record of Decision
Site Name
Card Corporation Property
Operable unit x
Denver Radium site
Site Location
1314 West Evans Avenue
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 BOO).
The State of Colorado has concurred on the selected remedy.
Statement of Basis
This decision is based upon the administrative record for 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.
Description of Selected Remedy
This operable unit of the Denver Radium site addresses the
contamination present on the Card Corporation property ("Card property").
The hazardous substances of primary concern that have been released and
continue to pose a significant threat of being released into the
environment are radium and its associated decay products.
epa's preferred remedial action alternative for the Card property is
Permanent Offsite Disposal. However, until a facility suitable for
permanent disposal of the Card property 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 the disposal
facilities for offsite
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2
disposal of the Card property material. Although both the epa and the
State of Colorado are continuing to seek a permanent disposal site, the
State predicts that this process could take up to five years, in order to
prevent or minimize the threat to public health, welfare, and the
environment, given the length of time until permanent offsite disposal of
the material can be implemented, the epa determined that a remedial action
alternative which includes a temporary response action should be
implemented at the Card property.
The selected remedy for the Card property is Temporary Onsite
Building Storage/Permanent Offsite Disposal. This alternative will attain
a degree of cleanup of the hazardous substances which will assure
protection of human health and the environment. This remedial action
alternative entails:
S excavation of approximately 4,000 cubic yards of radium-
contaminated soil and sediment from the Card property;
S storage of the contaminated material within reinforced
synthetic bags placed within the True Truss building and within
possible additions to the building;
S optional staging or storage of contaminated material from
selected other Denver Radium site properties on the Card
property - the total amount of material to be staged or stored
on the Card property not to exceed 13,000 cubic yards including
the contaminated material already present on the Card property;
S final removal of all contaminated material to a facility
suitable for the permanent disposal of Denver Radium site
wastes; and
S decontamination and dismantling of True Truss building and any
additions and disposal of the material in a sanitary landfill.
The present worth cost of the selected remedy is $1,148,000 assuming
a discount period of five years and a discount rate of 10%. The cost
includes excavation of all contaminated material, placement of the
material in reinforced synthetic bags, placement of the bags in the True
Truss building, and maintenance and monitoring of the bags and building
for 5 years. The cost also includes removal and transportation of the
contaminated material to an off site disposal facility, as well as
dismantling and decontaminating the building and transporting the building
material to a sanitary landfill.
Operation and maintenance activities will be required to ensure the
effectiveness of the temporary storage facility. The maximum total of
discounted annual operation and maintenance costs, using a discount period
of five years and a discount rate of 10%, is $89,500. Operation and
maintenance activities include site inspections and possible minor
structural repairs to the temporary storage facility. These activities
will be considered part of the approved remedy and will be eligible for
Trust Fund monies for the entire period that the temporary storage
facility is operational. The State of Colorado will share responsibility
for all operation and maintenance costs of the temporary facility in the
same manner as other aspects of remedial action.
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B
The 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.
Declarations
Consistent with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), the Superfund Amendments
and Reauthorization Act of 1986 (SARA), and the National Contingency Plan
(40 CFR Part BOO), I have determined that the selected remedy for the Card
property described in the preceding section is protective of human health
and the environment, attains Federal and State requirements that are
applicable or relevant and appropriate, and is cost-effective. This remedy
does not satisfy the statuatory preference for treatment which reduces the
toxicity, mobility, and volume of hazardous substances as its principal
element because treatment was determined to be impracticable based upon
technical feasibility, implementability, and cost.
Date
Regional Administrator
EPA Reqion VIII
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Summary of Remedial Alternative Selection
Site Name
Card Corporation
Operable unit x
Denver Radium site
Site History
what is known today as the Denver Radium site has its roots in the
robust U.S. radium producing industry of the early 1900's. At that time,
radium was considered to be a wonder drug, a cure-all for every ailment
from the common cold to cancer. A mere gram of the radioactive element
sold for $325,000.
Prior to 1914, there was no U.S. production of radium. Rather,
radium-bearing ore was shipped from the U.S. to Europe where it was
refined. Fearing that a European war might stymie U.S. importation of
radium, the U.S. Bureau of Mines entered into a cooperative agreement with
a private corporation, the National Radium institute to develop and
operate a radium processing plant in the united States.
Denver was the chosen location for the institute due to its proximity
to carnotite, a radium-bearing ore of the Colorado Plateau. Soon there
were at least eight other radium processing operations in Denver. One of
those radium producers was Pittsburgh Radium Company, using equipment
purchased from the institute, Pittsburgh Radium Company began operations
in 1920 in what had been the Overland Cotton Mill building.
The Denver radium industry remained strong until around 1920 when
extremely rich deposits of the radium-bearing ore, pitchblende, began to
be developed in the Belgian Congo. Most Denver radium producers were not
able to compete with their African counterparts and were forced out of
business. The Pittsburgh Radium Company was one producer which was able to
continue operations because, unlike the other radium producers who
processed carnotite for radium, Pittsburgh Radium Company processed
roscoelite for vanadium. However, Pittsburgh Radium Company, too, was
eventually forced to close. Records show that the company sold the
Overland Cotton Mill building in 1924.
Since 1924, the property has had various industrial uses including
world war II and Korean war munitions manufacturing, hardware
manufacturing, and fabrication of heavy mining equipment. The property
became known as the Card property because Card Corporation owned the
property in 1979, when the radiological contamination was discovered
there. The property will be referred to throughout the remainder of this
summary as the Card property.
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Response History
in 1979, the epa discovered a reference to the National Radium
institute in a 1916 U.S. Bureau of Mines report. Subsequent field research
revealed the presence of thirty-one radioactive sites in the Denver
metropolitan area, one of these being the Card property, the location of
the original Pittsburgh Radium Company processing facility (Figure 1).
immediately following these discoveries, the Radiation Control Division of
the Colorado Department of Health officially notified the affected
property owners of the presence of contamination on their properties. The
letters requested that no excavation or soil movement be undertaken
without first contacting the Division.
The Denver Radium site was placed on the interim Priorities List in
October, 1981, and final promulgation of the National Priorities List
occurred on September 8, 1983. The Colorado Department of Health, under a
cooperative agreement with the epa, assumed lead activities and initiated
engineering assessments of the various properties in August, 1981.
However, Mentor Corporation, owner of the Card property, denied the State
access to the site.
The epa resumed fund-lead activities in June, 1983, because the
Colorado State Legislature failed to appropriate the state cost share for
remedial planning required by epa policy at the time, in December, 1983,
the epa directed its contractor, ch2m Hill, to conduct a Remedial
investigation (ri) of the Denver Radium site to determine the nature and
extent of the threat presented by the contamination and a Feasibility
Study (FS) to evaluate proposed remedies. During the Ri, Mentor
Corporation allowed epa access to the Card property so that the extent of
the contamination present on the property could be determined.
Due to the enormity and complexity of the Denver Radium site, the epa
determined that response actions could be undertaken as operable units in
a cost-effective manner, consistent with a permanent remedy for the entire
Denver Radium site, and would decrease the release, threat of release, and
pathways of exposure. Thus, the original Denver Radium site properties
plus several 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 Card property being
Operable unit x.
in April, 1986, the Denver Radium site Remedial investigation Report,
which addresses all eleven operable units, was released to the public. A
draft Card Corporation Operable unit x Feasibility Study was released for
public review on October 1, 1986. A second draft Card Corporation Operable
unit x Feasibility Study was released for public comment on April 24,
1987. The second draft report reflected public comments received on the
first draft report and incorporated new requirements mandated by the
passage of the Superfund Amendments and Reauthorization Act (SARA) in
October, 1986. The final Card Corporation Operable unit x Feasibility
Study which incorporates responses to comments received during the both
public comment periods will be released along with the Record of Decision
(ROD) for the Card property.
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B
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Site Location and Description
The Card property is a 17.2-acre site located at 1314 west Evans
Avenue. The site is in an area of Denver zoned 1-2 for industrial use. its
ownership is currently divided between Mentor Corporation, which owns 13.7
acres, and Consolidated Freightways, which owns the rest. Mentor rents its
portion of the site to various light manufacturing and warehousing
companies. Consolidated Freightways operates a trucking terminal on the
southern end of the property. There are currently five buildings on the
Card property - the Brick Commercial building, the Office building, the
upl building, the True Truss building, and the Consolidated Freightways
facility. There is a small oil and waste water pond on the eastern side of
the property. The property is crossed by several currently unused rail
spurs.
The site is bounded on the north and east by commercial offices and
some light manufacturing and storage buildings. To the west is the
Colorado and Southern Railroad property, and to the south is west Wesley
Avenue and the Arapahoe generating station of the Public Service Company
of Colorado. The nearest residences are two blocks east of the site.
The Card property is located within the Platte River valley but is
not within the designated 100-year flood plain. The site is underlain by
fill material, alluvium, and the Denver formation sandstone. Depth to
bedrock is approximately 10 feet and depth to ground water is
approximately 20 feet. The topography of the site is predominantly flat
although surface runoff tends eastward toward a storm sewer near the
intersection of west iliff Avenue and South Navajo Street. There is no
surface water on the site other than the small oil and waste water pond
mentioned earlier.
Current Site Status
Radium is the primary contaminant of concern at the Card property.
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 Card property (Figure 2).
Gamma radiation readings in excess of background were found over 67,000
square feet of the site including in the Brick Commercial and upl
buildings. The presence of radium in the soil and underneath the buildings
was verified by radiochemical analysis of subsurface soil samples. Average
radium concentrations ranged from 4.4 to 472 picocuries per gram. The
maximum radium concentration, 960 picocuries per gram, was found in area
m2. The radium contamination extended to a maximum depth of 108 inches in
Areas f2 and G. The estimated total volume of radium contaminated soil is
3,900 cubic yards of which 475 cubic yards lie underneath buildings. There
is an additional estimated 200 cubic yards of radioactively contaminated
sediment around and on the bottom of the oil and waste water pond. Table 1
summarizes the data presented above. (A general discussion of radiation
and its associated units of measurement is presented in Appendix A of the
FS and in the Public Health Assessment, Appendix B of the FS.)
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Table 1
OPERABLE UNIT X
DENVER RADIUM SITE
SURFACE and SUBSURFACE CONTAMINATION
Radium
Concentration
Volume Area Gamma (uR/hr) Deptha (pCi/ q)
Location (yd3) (ft2) iAvera^e_ ^aximurr^ (in.) ^vera^e_ ^Max^murn
Area
A
30
1,100
4
5
6 at
12-18
10.4
31
Area
B
1
25
15
15
12
NA
NA
Area
C
4
100
8
8
12
NA
NA
Area
D
4 1
1,100
6
9
12
15 . 6
30
Area
E
10
550
5
6
6
5 . 8
5
Area
F1
300
8,100
7
21
12
8
34
Area
F2
183
550
54
8 9
108
9 6.9
287
Area
G
200
600
12
2 6
108
99
99
Area
H
5
125
6
11
12
NA
NA
Area
I
11
580
7
17
6
6 . 4
6
Area
J
67
1,815
7
34
12
119.2
224
Area
K
3
7 9
1
1
12
18
18
Area
L
2
7 9
5
5
6
7 . 8
7
Area
Ml
2,500
33,720
13
95
Range
from
99.8
660
0-30
Avg: 18
Area
M2
33
180
12
12
60
23 6.9
960
Area
N
5
130
5
5
12
8 . 4
8
Area
0
18
110
8
8
5 4 at
12-66
47.5
182
Area
P
6
150
6
34
12
202
685
Area
Q
8
420
7
8
6
NA
NA
Area
R
1
4 0
4
4
6
NA
NA
Area
S
1
30
8
8
6
NA
NA
Area
T
3
180
7
7
6
10
10
Area
U
7
80
1
1
12 and
2 6.2
4 1
18 at
54-72
24.9
37
Area
V
9
230
12
24
12
53 . 7
8 9
Area
W
1
60
7
13
6
19
19
Area
X
6
300
5
10
6
7 . 9
12
Area
Y
2
110
7
14
6
5 . 6
5
Area
Z
2
95
3
5
6
4 . 4
6
Area
AAb
(32)
1,733
2
3
6
7 . 1
11
Area
BBb
(2)
65
2
5
12
14.9
34
Area
CC
145
7,800
4
6
6
NA
NA
Area
DD
62
480
38
69
42
56.2
27 0
Area
EE
53
1,430
5(11)
11(12)
12
12 . 1
28
Area
FF
21
57 0
8
23
12
5 . 5
6
Area
GG
15
800
9
16
6 at
12-18
60.5
282
Area
HH
99
2,660
9
54
12
120
288
Area
II
4
240
10
17
6
18
18
Area
JJ
24
430
8
16
18
7 . 4
16
Area
KK
4
110
NA
NA
12
472
900
Area
LL (ffa11)
NA
10
10
14
NA
6
6
Area
MM
3
7 0
7
7
12
12
12
TOTAL
3,889
67,03 6
Maximum
Depth: 108
a Depth indicates the estimated depth of contamination. A range from x to y indicates a
variation in the depth of contamination. X at y to z indicates a lens of contamination of
thickness x under y inches of clean overburden.
b These contaminated locations are no longer identifiable after construction of the
Consolidated Freightways facility.
c Areas AA and BB are not included in this total.
NOTE: Maximum gamma exposure rate is maximum surface grid scan gamma exposure rate. Gamma
radiation readings are net readings above background, which in Denver is 15 ^iR/hr.
NA: Data not available or not recorded for this area.
DE/TEN/053
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7
The radium concentrations found on the Card property and the gamma
radiation levels in places within the Brick Commercial and upl buildings
exceed the "epa Standards for Remedial Actions at inactive uranium
Processing Sites," 40 cfr Part 192, which the epa has determined are
relevant and appropriate Federal public health requirements for the Card
property. These standards are discussed in detail later in this summary in
the section entitled "Degree of Cleanup".
Radon decay product contamination resulting from the radium
contamination on the site is not a concern on the Card property under
present use of the property and existing site conditions. Slightly
elevated radon decay product concentrations were detected in the Brick
Commercial, upl, and Office buildings; however, all measurements with one
exception were well below the relevant and appropriate 40 CFR Part 192
standard of 0.02 working levels. The one measurement which exceeded the
epa standard was taken in a relatively small, unventilated location of the
upl building (a storage closet) and is not considered representative of
the entire building.
Alpha particle radioactivity also resulting from the radium
contamination on the site was not found in any significant degree in the
Brick Commercial, Office, and upl buildings. Of the 108 samples taken,
only 14 had measurable levels of removeable alpha activity and all of the
levels were well below the release limits specified by the Colorado
Department of Health standards.
Minor amounts of non-radiological contamination, mainly polyaromatic
hydrocarbons, were detected in the soils and in the pond sediments at the
Card property. There is nothing to suggest that either dispersion or
migration of these substances has occurred. No known sources of these
compounds are present on the property at this time, and thus, there is no
reason to suspect any additional releases. The Public Health Assessment of
the Card property indicated that the non-radiological contamination
represents a minimal concern relative to the radiological contamination
present at the site, in addition, any remedy that reduces or eliminates
the radiological hazard at the Card property will eliminate the known
non-radiological hazards as well.
The elevated concentration of radium at the Card property poses 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 a form that is relatively insoluble, and
since migration of contaminants into the ground water or from the pond
sediments into the pond water has not been noted, ingestion or contact
with contaminated surface water or ground water is not one of the
principal potential exposure pathways. Each of the three principal
exposure routes will be discussed briefly in order to describe the
potential health risks.
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8
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 which has a high
concentration of radon decay products has been conclusively shown to cause
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 Card property to such an extent that no one
working on or living near the site is presently at risk from exposure to
radon and its associated decay products. 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. However, this is not
presently the case for the buildings on the contaminated portions of the
Card property because the buildings have enough ventilation to keep the
radon decay product concentration at low levels.
The analysis summarized above shows that there is no serious public
health risk at present from the radon gas exposure pathway at the Card
property. However, the epa has determined that a significant increase in
public health risk would occur if any of the contaminated material at the
site is spread closer to potential receptors, especially if it is used as
fill or construction material, or if any of the buildings on the site are
sealed to make them more airtight, or if the site is ever redeveloped for
any use that involves occupancy in enclosed, well-sealed structures. The
Public Health Assessment summarized below presents projected cancer risks
if the epa were to take no action at the site and the Card property were
redeveloped in any of these ways.
if a building were constructed over Area Ml, the largest contaminated
area on the Card property, and several conservative assumptions are made
such as lifetime exposure, the estimated radon decay product concentration
in the building would average 0.18 working level (wl) with an estimated
maximum concentration of 1.2 WL. The radon decay product concentration in
a typical U.S. home is 0.005 wl and the relevant and appropriate epa
standard, 40 CFR Part 192, is 0.02 WL. The projected cancer risk
(excluding background to individuals working in the building ranges from
190 to 790 cancer deaths per 10,000 persons exposed with a maximum
projected cancer risk of 1,200 to 3,700 cancer deaths per 10,000 persons
exposed. The projected cancer risk to individuals living in the building
ranges from 1,100 to 5,600 cancer deaths per 10,000 persons exposed with a
maximum projected cancer risk of 4,400 to 7,900 cancer deaths per 10,000
persons exposed.
These risk values can be compared to the projected cancer risk if the
radon decay product concentration in the building was 0.02 wl, the epa
standard, in this case, the projected cancer risk to individuals working
i n
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9
the building ranges from 23 to 91 cancer deaths per 10,000 persons
exposed. The projected cancer risk to individuals living in the 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
U.S. home, 0.005 wl, then the projected cancer risk to individuals living
in the building would range from 33 to 130 cancer deaths per 10,000
persons exposed. Areas Ml and m2 combined represent about 65% of the
estimated total volume of contamination present at the site, it should be
noted that these 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 above stated
i nformation.
Gamma Radiation Exposure:
The radioactive decay of radium and its decay products results in the
emission of highly penetrating gamma rays. Gamma rays are of concern
because they 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,
the larger the dose, and hence the greater the risk of adverse health
effects. The gamma radiation emission is limited to the area immediately
above the contamination.
As discussed previously, the epa has determined that a significant
increase in public health risk would result if any of the contaminated
material on the Card property was disturbed and misused or if the area was
redeveloped, if a building was constructed over the area with the highest
gamma radiation readings, Area f2, the estimated annual dose to a person
working in the building would average 109 millirem per year with an
estimated maximum annual dose of 179 mi 11irem per year. These doses are in
addition to the background dose of 130 millirem per year incurred by those
living in the Denver area and resulting from cosmic, terrestrial, and
internal sources. The maximum allowable whole-body gamma radiation dose
derived from the relevant and appropriate epa standard, 40 CFR Part 192,
and the National Council on Radiation Protection and Measurements (ncrp)
and international Commission on Radiological Protection (icrp)
recommendation for a person in the workplace are 180 and 100 millirem per
year, respectively, in addition to natural background and medical
exposure. The estimated annual dose to a person living in a building built
over Area f2 would average 355 millirem per year with an estimated maximum
annual dose of 585 millirem per year. The whole-body gamma radiation dose
derived from the relevant and appropriate epa standard, 40 CFR Part 192,
and the ncrp and icrp recommendation for a residential occupant are 130
and 100 millirem per year, respectively, in addition to natural background
and medical exposure.
The projected cancer risk from gamma radiation (including background)
to individuals working in a building built over Area f2 would average 40
cancer deaths per 10,000 persons exposed with a maximum projected cancer
risk of 47 cancer deaths per 10,000 persons exposed. The projected cancer
risk to individuals living in the building would average 98 cancer deaths
per 10,000 persons exposed with a maximum projected cancer risk of 1,200
cancer deaths per 100 persons exposed. Area f2 represents about 5% of the
estimated volume of contamination on the site.
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10
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 projected 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 projected cancer
risk to individuals receiving a lifetime dose of 9.5 rem 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 above state information.
inhalation or ingestion of Radium-Contaminated Material:
inhalation of the long-lived radionuclides like uranium, thorium, and
radium is possible for persons living or working on or near the Card
property. Surface material suspended by the wind may contain small
concentrations of these elements and the resulting airborne contamination
is a potential human exposure pathway. Direct ingestion of long-lived
radionuclides can result in significant doses to various internal organs
of the body. However, studies by the U.S. Department of Energy have shown
that the projected radiation dose from this source are 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-contaminated material on the Card property and dust control
measures ordinarily employed during excavation have been shown to provide
sufficient control of exposure from this source. For these reasons, the
epa acknowledges this human exposure pathway, but no quantitative risk
numbers were developed in the Public Health Assessment.
Low-levels of certain non-radiological carcinogenic contaminants were
found in discrete locations on the Card property. The Public Health
Assessment quantifies risks to human health from ingesting soil containing
these contaminants. The projected cancer risks from this type of exposure
range from .038 cancer deaths per 10,000 persons exposed to 1.2 cancer
deaths per 10,000 persons exposed. These risk estimates are several orders
of magnitude lower than the estimated risks resulting from exposure to the
radiological contamination on the property. Nonetheless, the presence of
non-radiological contaminants on the site will be explicitly considered in
all health and safety provisions of the cleanup.
The foregoing discussion demonstrates that a release or substantial
threat of release of a hazardous substance or pollutant or contaminant
into the environment has occurred at the Card property and that the
release or threat of release may present an imminent and substantial
endangerment to public health or welfare, it is also clear from the
calculated risks that remedial action at the Card property is justified.
The short- and long-term potential for adverse health effects from human
exposure associated with the various remedial action alternatives
evaluated for the Card property are discussed later in this summary.
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Table 2
PROJECTED CANCER RISKS
OPERABLE UNIT X
DENVER RADIUM SITE
Scenario
Radon Decay Products:
Building constructed over
Area Ml
epa standard
Typical U.S. Home
Exposure
0.18 WL
0.02 WL
0.005 WL
Average Cancer Deaths
Per 10.000 Persons Exposed
workplace
Residential
workplace
Residential
190 to 790
1100 to 5600
23 to 91
130 to 500
Maximum Cancer Deaths
Per 10.000 Persons Exposed
workplace
Residential
1200 to 3700
4400 to 7900
Residential 33 to 130
Gamma Radiation:
Building constructed
over Area F2
epa standard
Background
54 |jR/hr
20 |jR/hr
15 |jR/hr
Workplace 40-
Residential 98-
workplace 31-
Residential 53-
Residential 27
workplace
Residential
47*
1,200-
* in addition to risk from exposure to background gamma radiation levels.
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12
Enforcement
A detailed responsible party search for the entire Denver Radium site
has been initiated. Thus far, the search has not identified any parties
responsible for the contamination on the Card property. Records show that
Pittsburgh Radium Company owned and operated the radium processing
facility at the time of disposal (circa 1920-1924) of radium, the
hazardous substance of concern. Although extensive investigation has been
conducted, the responsible party search has yet to trace the corporate
history of Pittsburgh Radium Company to a viable, present-day company.
Mentor Corporation is a current owner of a large portion of the site.
The responsible party search indicates that Mentor Corporation acquired
the property in 1977 without knowledge of the contamination on the site.
Further, it does not appear that (1) Mentor Corporation conducted or
permitted the generation, transportation, storage, treatment, or disposal
of any hazardous substance at the Card property or that (2) Mentor
Corporation, since becoming aware of the contamination on its property,
contributed to the release or threat of release of a hazardous substance
at the facility through any action or omission.
Based upon these initial findings, epa has begun negotiations with
Mentor Corporation concerning a covenant not to sue for potential
liability to the united States, including future liability, resulting from
the release or threatened release of the hazardous substance to be
addressed by remedial action at the Card property. The terms of this
covenant not to sue are embodied in a draft administrative order on
consent which is attached to the ROD. upon selection of the remedy and
finalization of the responsible party search for the Card property, epa
will revise the draft administrative order to comport with the ROD and
current laws, in exchange for this covenant not to sue, Mentor Corporation
would agree to provide access to its property to enable epa to undertake
remedial action at the Card property and, at epa's discretion, permit epa
to deliver for storage at the Mentor property radium-contaminated
materials from other properties included in the Denver Radium site.
Consolidated Freightways is a current owner of a portion of the Card
property. Consolidated Freightways bought its portion of the property in
March, 1985, nearly two years after the formal listing of the Denver
Radium site on the National Priorities List. During the summer of 1985,
the company proceeded to construct a trucking terminal on the property and
as a result two areas of contamination on the site can no longer be
i denti fi ed.
The epa does not feel that remedial action should be delayed pending
finalization of the responsible party search, epa anticipates discussions
and negotiations with both Mentor Corporation and Consolidated
Freightways.
Further, if upon finalization of the search, the epa identifies
additional responsible parties, the epa will formally notify them of the
remedy selected in the ROD and initiate negotiations for the
implementation of the remedy. Negotiations will not exceed sixty days.
Thereafter, if the
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IB
responsible parties do not formally commit to performing the remedy in a
timely manner, the 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.
Degree of Cleanup
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, the epa requested that the State of Colorado
identify potentially applicable or relevant and appropriate state
requirements for the Card property. On January 21, 1987, the State
responded to this request and provided a list of Colorado requirements
which the State believed pertained to the Denver Radium site. Concurrently
with this State activity, the epa developed potentially applicable or
relevant and appropriate Federal requirements. The epa classified all
applicable or relevant and appropriate requirements identified into four
categories: contaminant-specific arars, action-specific arars,
location-specific arars, and other Federal and State criteria, advisories,
and guidance to be considered. A description of each of these categories
is provided in both chapter 4 and Appendix c of the FS. Tables C-l through
C-4 in Appendix c of the FS contain a brief description of each potential
Federal and State requirement identified and epa's analysis of each
requirement's applicability or relevance and appropriateness to the Card
property. The result of this analysis is summarized below.
Contaminant-specific arars:
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 Card property. 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 applicable to the Card property since the
standards apply only to certain specifically designated sites where
uranium was processed, the standards are relevant and appropriate to the
Card property because (1) it is the radium content of the uranium 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.
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The portion of the standard relevant and appropriate to the
contaminated soil on the Card property 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) 5 pCi/g, averaged over the first 15 cm of soil below
the surface, and
(2) 15 pCi/g, averaged over 15 cm thick layers of soil
more than 15 cm below the surface."
(40 CFR Section 192.12.)
The portion of the standard relevant and appropriate to the buildings
on the Card property is 40 CFR Section 192.12(b) which states:
(b) in any occupied or habitable building -
(1) 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
0.0B wl, and
(2) The level of gamma radiation shall not exceed the
background level by more than 20 microroentgens per
hour.
(40 CFR Section 192.12(b).)
Even though the radon decay product concentration in the buildings is
well below the 0.02 working level standard, some gamma radiation
measurements in the Brick Commercial building exceed 20 microroentgens per
hour.
The second contaminant-specific arar identified for the Card property
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
Card property. However, epa has determined that portions of the
regulations are relevant and appropriate to individuals who would be
conducting the remedial action on the Card property, in particular,
Appendix B of 10 CFR Part 20 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
3.
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Table 3
POTENTIAL CONTAMINANT-SPECIFIC ARAR'S
OPERABLE UNIT X, DENVER RADIUM SITE
Regulatory Agency
FEDERAL
U.S. E PA-4 0 CFR Part
192, Subpart B-
Standards
Type of Contaminant
Radium-22 6
Concentration
Nuclear Regulatory
Commission (NRC)
10 CFR Part 20
Gamma radiation3
Radon Decay Product
Concentration
Uranium-natural
Ai rborne
Thorium-2 30
Ai rborne
Radium-226 Airborne
Gamma radiation3
Standard, Requirement,
Criteria, or Limitation
5 pCi/g above background
within 15 cm of the
surface measured over a
10 0-m2 area
15 pCi/g above
background within
subsequent 15 cm layers
measured over a 100-m2
area
20 ^iR/hr above
background
0.02 WL annual average
0.03 WL maximum
5 pCi/m3, Unrestricted
area
100 pCi/m3, Restricted
area
3 pCi/m3, Unrestricted
area
30 pCi/m3, Restricted
area
3 pCi/m3, Unrestricted
area
30 pCi/m3, Restricted
area
5 rem/yr, (5,000
mrem/yr) Restricted area
500 mrem/yr,
Unrestricted area
Comments
Standards for cleanup of open lands or buildings;
concentration of radium-226 in land, averaged over
any area of 100 square meters. Point of compliance
is at any contaminated area greater than 100 m2.
However, during cleanup all contaminated areas would
be remediated.
Relevant and appropriate to indoor gamma radiation.
Point of compliance is inside any site building.
Relevant and appropriate to indoor radon. Point of
compliance is inside any site building.
Point of compliance is any location within site.
Point of compliance is any location within site.
Point of compliance is any location within site.
Point of compliance is any location within site;
site would be unrestricted for remediation workers.
Relevant and appropriate standard but not as protective as Other Guidance; see Table 4-3.
bAn unrestricted area is regarded as any place around a waste consolidation/storage area facility where access is not controlled.
CA restricted area is regarded as any place around a waste consolidation/storage area where access is controlled.
DE/TEN2/017
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Location-specific arars:
The Colorado Historical Society has made a preliminary determination
that the Card property is eligible for inclusion in the National Register
of Historic Places. This finding was based on the property's earlier
industrial importance as a radium processing facility. The epa has
determined that both the National Historic Preservation Act and the
Archeological and Historic Preservation Act are location-specific arars.
Remedial action at the Card property will not adversely affect the
historic character of the site. Nonetheless, the epa will continue to
cooperate with the Colorado Historical Society by providing documentation
lending historical significance to the property and will adhere to the
requirements of the aformentioned Acts.
Action-specific arars:
The epa has identified several action-specific arars. Since these
arars are technology-based restrictions triggered by specific types of
remedial measures under consideration they were considered along with the
development of remedial action alternatives and will be discussed in the
next section entitled "Alternatives Evaluation".
Other Criteria to be Considered:
in the category of other Federal and State criteria, advisories, and
guidances the epa determined that when selecting the remedy it would
consider the National Committee on Radiation Protection and Measurements
(ncrp) and international Commission on Radiological Protection (icrp)
guidelines. The ncrp and icrp recommend a maximum gamma radiation dose to
the whole body of 100 mi Hi rem per year for all sources except medical and
natural background for chronic exposure situations.
Pursuant to the ncp, 40 CFR Section 300.68(a)(3) and SARA Section
121, Federal, State, and local permits are not required for on-site
fund-financed remedial actions. However, the epa expects that non-
environmental and construction permits will be required in carrying out
CERCLA Sections 104 and 106 onsite response actions. The epa will also
take steps to ensure that offsite disposal of any contaminated material
removed from Card property is consistent with the epa's offsite disposal
policy, that is, final disposal will be at a facility suitable for the
disposal of the Denver Radium site wastes.
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Alternatives Evaluation
The epa evaluated potential remedial action alternatives for the Card
property by progressing through the series of analyses which are outlined
in the National Contingency Plan (ncp), in particular, 40 CFR Section
300.68, and the interim Guidance on Superfund Selection of Remedy,
December 24, 1986, (OSWER Directive No. 9355.0-19). This process in part
enables the 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, and that utilizes permanent solutions and
alternative treatment technologies or resource recovery technologies to
the maximum extent practicable.
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 site. A general list of
site-specific information is contained in Section 300.68(e)(2) of the ncp.
This list was used to identify specific site and waste characteristics of
the Card property. (See Table 5-1 of the FS.) Based upon these site and
waste characteristics, the 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 Card property. An example of this
scoping process was the elimination of ground water barriers from further
consideration because ground water contamination is not a characteristic
of the Card property. Appendix D of the FS illustrates the scoping process
and Table 5-2 of the FS details the results.
Section 121(b)(1) of SARA states that, "The President shall conduct
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." As part of this process, the epa evaluated permanent
solutions to the problems associated with the specific hazardous
substances present on the Card property. The necessity to find a treatment
technology which successfully reduces the mobility, toxicity, and volume
of a hazardous substance presents a problem since the hazardous substance
associated with the Card property is a radioactive element. 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
significantly reducing volume or mobility. These treatment and resource
recovery technologies often also leave a waste product which is still
radioactive. Nonetheless, epa considered several treatment and resource
recovery technologies along with more conventional response actions such
as capping or excavation. These alternative treatment technologies include
sand sifting, in situ vitrification, and reprocessing.
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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 their suitability to
abate the threat at the card property. Source control measures 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. Management
of migration measures have particular importance at the Card property
since radon gas, alpha particles, and gamma rays are continuously being
released from the source, radium. The results of the prescreening of both
source control and management of migration measures based on their
suitability to abate the threat at the Card property are presented in
Table 5-3 of the FS.
The next step of the selection of remedy process is assembling the
remaining technologies and/or disposal options into remedial action
alternatives. Section 300.68(f)(2) of the ncp requires epa to develop
remedial action alternatives in a range of categories which are based in
part upon ARAR attainment. The OSWER Directive No. 9355.0-19, "interim
Guidance on Superfund Selection Remedy" requires epa to develop remedial
action alternatives 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. Alternatives developed in this way will vary
mainly in the degree to which they rely on long-term management of
treatment residuals or low-concentrated wastes. The OSWER Directive also
instructs EPA to develop a containment option involving little or no
treatment and a no action alternative.
Alternatives developed in the FS for the Card property were:
1. No Action
2. Deferred Removal, Offsite Permanent Disposal
3. Onsite Reprocessing/Treatment, Offsite Permanent Disposal
4. in Situ vitrification
5. Onsite Permanent Disposal
6. Offsite Permanent Disposal
7. Onsite Temporary Land Storage, Offsite Permanent Disposal
8. Onsite Temporary Building storage, Offsite Permanent Disposal
9. Onsite Temporary Containment (Capping), offsite Permanent Disposal
Table 4 provides a comparison of each of the alternatives listed above
with the alternative categories specified in Section 300.68(f)(2) of the
NCP.
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Table 4
NCP ALTERNATIVE CATEGORIES
OPERABLE UNIT X
DENVER RADIUM SITE
NCP Category
Common
Elements
Alternative Number
7
Comments
1. Complete removal and subse-
quent treatment or disposal
at an offsite facility.
Complete removal of oily layer and
decontamination of wall material;
complete removal of soils and
sediments.
2. Attain applicable or rel-
evant and appropriate
Federal and State public
health and environmental
requirements
Vitrification and capping might attain
ARAR's.
3. Exceed applicable or rel-
evant and appropriate
Federal and State public
health and environmental
requirements
Onsite and offsite disposal could be
designed and implemented to exceed
ARAR's.
Does not attain Federal and
State requirements but
reduces present or future
threat and provides signi-
ficant protection to pub-
lic health and the
environment
Reprocessing may not provide a non-
radioactive soil after treatment;
significant reduction could occur.
Temporary measures will probably not
meet ARAR's until the contaminated
materials are removed from the site
and placed in an offsite disposal
facility. Alternatives 7 and 8 could
temporarily reduce exposure to radio-
active materials. Alternative 9 could
reduce exposures, depending upon
thickness of the cap.
5. No action
Also serves as a baseline for
comparison.
DE/TEN2/030
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20
Alternatives 2, 3, 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 Card property.
Alternatives 3 and 4 involve treatment as their principal element, but do
not necessarily reduce the mobility, toxicity, or volume of the waste.
Alternative 3 necessarily includes a provision for the permanent disposal
of the treatment residues. Alternatives 4 and 5 require permanent onsite
remedies, and hence, long-term management and monitoring at the Card
property. Finally, No Action was included as Alternative 1.
Alternatives 7, 8, and 9 were developed to include temporary response
measures followed by permanent offsite disposal of the contaminated
material when a facility for such a disposal becomes available.
Alternative 6, 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 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 for up to five years, in the meantime,
in its presently uncontrolled state, the radium-contaminated material at
the Card property could be misused or inadvertantly spread, possibly
increasing the risk to present or future public health, welfare, or the
environment, in addition, the cost of final remedial action is liable to
increase due to inflation; the Card property owners and tenants face
economic losses associated with restricted use of their properties; and
the epa may incur further costs by updating site studies in the face of
changing site conditions. The epa determined that developing alternatives
which include temporary response actions was not only justified, but
necessary in order to effectively mitigate or minimize threats to and
provide adequate protection of public health, welfare, or the environment
at the Card property.
Once the remedial action alternatives were developed, it was possible
to identify action-specific arars. These arars are distinct from the
contaminant-specific and location-specific arars identified earlier in
this summary in that action-specific arars are technology-based
restrictions triggered by specific action elements associated with the
remedial action alternatives under consideration. The following action
elements are part of at least one or more remedial action alternative
developed for the Card property:
- removal of the oily layer of the oil and waste water pond
- removal of soils and sediments
- removal of wall material
- permanent onsite disposal
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- permanent offsite disposal
- temporary onsite storage or containment
- treatment or reprocessing
Potential action-specific arars for the action elements listed above
were considered in Appendix c of the FS and are presented in Table 6-3 of
the FS.
initial screening, which is the next step in the selection of remedy
process, narrows the list of potential remedial action alternatives
requiring detailed analysis. Consistent with 40 CFR Section 300.68(g) and
the OSWER Directive 9355.0-19, the remedial action alternatives developed
for the Card property were initially screened using the criteria of cost,
implementability (acceptable engineering practices), and effectiveness.
Table 7-1 in the FS summarizes the initial screening process. Alternatives
1, 2, 5, 7, and 8 passed the initial screening and were carried forward
for detailed analysis while Alternatives 3, 4, 6, and 9 were screened
primarily for the reasons set forth below.
Alternative 3, Onsite Reprocessing, was eliminated from further
consideration based on its lack of effectiveness. Since both the
reprocessed soil and the concentrated precipitate resulting from the
reprocessing of the soil would require disposal in a facility that meets
the requirements of 40 CFR Part 192, this alternative would provide no
additional benefit to public health or the environment over other
alternatives to be considered. Alternative 4, in situ vitrification, was
eliminated during the initial screening because its implementability for
this particular application is unproven. in situ vitrification has not
been demonstrated on a large scale or utilized in a highly-populated urban
area like that of the Card property. The extreme temperature requirements
of this process could cause unknown damage to onsite structures and any
buried utilities or pipelines. Once vitrified, a cap over the area might
be necessary to limit the escape of radon gas and associated radon decay
products. Furthermore, the property would have to be permanently dedicated
as a disposal site and measures would have to be taken to prevent human
contact with or disturbance of the vitrified material. Finally, this
alternative would require long-term government ownership, licensing,
management, and monitoring to protect the integrity of the vitrified mass.
These requisites would conflict with current and proposed land uses for
the area, as well as State policies on siting disposal facilities.
with the elimination of these two alternatives, no alternatives which
involve treatment as a principal element survive the initial screening.
However, epa has no reasonable belief that either of these alternatives
offers the potential for better treatment performance or imp!ementabi"lily,
lesser adverse impacts, or lower costs than demonstrated alternatives.
Alternative 6, Permanent Offsite Disposal, was eliminated during
initial screening because it is not implementable at this time. As
discussed earlier, the State of Colorado has not at this time designated a
facility for the
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22
disposal of the Denver Radium site wastes. Alternative 9, Temporary Onsite
Capping, Permanent Offsite Disposal, was eliminated during initial
screening because it is neither as effective nor as implementable as
similar alternatives, Alternatives 7 and 8, and would cost almost as much
as other alternatives that achieve the same objectives.
Following is a description of the remedial action alternatives
surviving the initial screening.
1. No Action
if this alternative were selected, no action would be taken at
the contaminated Card property. This alternative was retained
for further analysis and consideration as required by the ncp
(40 CFR Section 300.68(f)(1)(v)).
2. Deferred Removal, Permanent Offsite Disposal
This alternative would defer removal of the contaminated
material at the Card property until an approved permanent
offsite disposal facility is identified and made available by
the State of Colorado. Once this facility becomes available,
the entire estimated 4,000 cubic yards of contaminated soils
and sediments on the Card property, which includes the
estimated 475 cubic yards of contaminated soils lying under the
Brick Commercial and upl buildings, would be excavated. The
material would then be transported by either truck or rail for
final disposal at this facility. The Card property would then
be available for unrestricted use.
5. Permanent Onsite Disposal
This alternative entails the excavation of the approximately
4,000 cubic yards of contaminated material on the property and
disposal onsite in a facility constructed in accordance with 40
CFR Part 192 Subparts A and B. The disposal area would require
permanent access restrictions and long-term monitoring. A
buffer zone would be created between the disposal facility and
the surrounding businesses, in accordance with SARA Section
121(c), a review of the permanent onsite disposal facility
would be required no less than every five years.
7. Temporary Onsite Land Storage, Permanent Offsite Disposal
This alternative would provide temporary storage of the
estimated 4,000 cubic yards of contaminated material until a
permanent offsite disposal facility becomes available. There
are several options for the land-based storage facility
including an asphalt pad with a suitable cover. The storage
facility would require security precautions, radiation
monitoring, and regular inspections. An option associated with
this alternative is the use of the temporary
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facility for storage and staging of material from certain other
Denver Radium site properties. Once a permanent offsite
disposal facility becomes available, then the contaminated
material would be sent by truck or rail to the facility. The
Card property would then be available for unrestricted use.
8. Onsite Temporary Building storage, Offsite Permanent Disposal
This alternative consists of excavating the approximately 4,000
cubic yards of contaminated material, placing the material in
reinforced synthetic bags, and storing the bags in the True
Truss Building until a permanent offsite disposal facility
becomes available. As with Alternative 7, an option associated
with this alternative is to bring material from certain other
Denver Radium site properties for staging and storage in the
True Truss building. Once a permanent offsite disposal facility
becomes available, the contaminated material would be
transported by either truck or rail to the facility. The True
Truss building would be decontaminated, then demolished and the
material sent to a sanitary landfill. The Card property would
then be available for unrestricted use.
Common to all of the remedial action alternatives briefly described
above with the exception of Alternative 1, No Action, is the response
actions that would be taken for the decontamination of the contaminated
portion of wall within the Brick Commercial building and the removal of
the water and the oily layer from the oil and waste water pond. The
contaminated portion of wall within the Brick Commercial building would be
decontaminated by surface scrubbing or by possible removal of the brick
wall surface. Any wall material requiring removal would be disposed of
along with the contaminated soils and sediments which are present on the
Card property.
The oily layer of the oil and waste water pond would be tested for
radioactive and nonradioactive contamination, if only radioactively
contaminated, the oil would be handled with the contaminated site soils
and sediments, if contaminated only with hazardous substances, depending
on the amount and type of nonradiological contaminants, the waste would be
transported to a hazardous waste disposal or treatment facility or an
industrial boiler or furnace for energy recovery.
if testing reveals both radiological and nonradiological
contaminants, the oily layer could be a mixed waste as defined in the
OSWER Directive No. 9440.00-1, "Guidance on the Definition and
identification of Radioactive Mixed wastes" (epa, 1987) and would have to
be handled in accordance with restrictions on such waste.
The standing water in the oil and waste water pond would also be
tested, if uncontaminated, the water would be either evaporated or used
for onsite dust control if removal or excavation measures are implemented,
if contaminated, the water would be evaporated and the remaining sludge
would be handled with contaminated site soils and sediments or, if
necessary, as a mixed waste.
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Consistent with Section 300.68(h) of the ncp and the OSWER Directive
No. 9355.0-19, the remedial action alternatives remaining after initial
screening were further refined and then subject to detailed analysis.
Detailed analysis of each alternative entailed evaluation based on the
three broad criteria of implementability, effectiveness, and cost. For
each of these broad criteria, the 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), and the OSWER Directive No. 9355.0-19 discussion on
detailed analysis.
The component measures of implementability are: technical
feasibility, constructability, reliability, administrative concerns,
availability of technology, and operation and maintenance. The component
measures of effectiveness are: arar attainment; effectiveness in
significantly and permanently reducing mobility, toxicity, and volume;
persistance, toxicity, mobility, and propensity to bioaccumulate of the
hazardous substances and their constituents; protectiveness/hea~l th
effects; environmental protectiveness/potential for adverse environmental
impacts; and compliance with the Solid waste Disposal Act. The component
measures of cost are: capital costs, operation and maintenance costs, and
potential future remediation costs if the alternative fails. Chapter 8 of
the FS provides a comparative review of each remedial action alternative
based upon each of the component measures listed above. Table 5 summarizes
the detailed analysis of alternatives. The selected remedy was chosen
after the detailed analysis of alternatives and is discussed in the next
section.
Selected Remedy
epa's preferred remedial action alternative for the Card property is
Alternative 6, Permanent Offsite Disposal. This alternative, however, was
eliminated during the initial screening of alternatives because until the
State of Colorado identifies a permanent disposal site for material from
the Card property, this alternative cannot be implemented, epa has
therefore determined that the appropriate extent of remedy at the Card
property is Temporary Onsite Building Storage/Permanent Offsite Disposal,
Alternative 8. in the event that a permanent disposal facility becomes
available before Alternative 8 is implemented at the Card property, epa
may immediately implement Alternative 6, Permanent Offsite Disposal.
Temporary Onsite Building Storage/Permanent Offsite Disposal,
Alternative 8, is protective of human health and the environment and
attains or exceeds the relevant and appropriate Federal and State public
health and environmental requirements that have been identified for the
Card property. As determined during the detailed analysis, this
alternative is a cost effective remedy that effectively mitigates and
minimizes threats to and provides adequate protection of public health,
welfare, and the environment.
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Evaluation Criteria
Implementabi1i ty
Alternative 1
No Action
Feasible
Table 5
SUMMARY OF ALTERNATIVE EVALUATION
OPERABLE UNIT X, DENVER RADIUM SITE
Alternative 2
Deferred Removal/
Permanent Offsite Disposal
Site could undergo additional
development (i.e., Consolidated
Freightways) in contaminated
area. Contaminated materials
could be dispersed or diluted
such that they would no longer
be identifiable.
Alternative 5
Onsite Disposal
Land disposal facilities can have
technical problems, such as
seepage; moderate potential for
component failure exists. During
construction of disposal facility,
clean materials could be dispersed
onsite resulting in dilution of
contaminated soils.
Effectiveness
40 CFR 192 conditions for
radium-226 in soils would not
be attained. If the property
is redeveloped,
protectiveness levels for
radon would not be attained.
NCRP/ICRP guidance for gamma
radiation may not be met if
the property is developed.
No Action does not reduce
mobility, toxicity, and
volume of site radioactive
materials.
Excavation cannot proceed until
an offsite disposal facility is
available. Availability required
by SARA 104 (k). Facility is
assumed not to be available
until 1992.
While removal is deferred, 40
CFR 192 radon and 10 CFR 20
airborne concentration ARAR's
may not be met unless use
restrictions and controls are
implemented. Radium-226 levels
in soil would not be met until
removal.
Condemning site for a 1,000-year
storage facility plus the
historical aspects of the site
could create problems that may
delay implementation. Site access
restrictions are mandatory; the
site would be dedicated for use as
a storage facility for low-level
radio-active wastes for the
indefinite future.
40 CFR 192 and 10 CFR 20 standards
would be met by a properly
designed, constructed, and
implemented facility. Site cleanup
would result in gamma radiation and
radon levels that are below
standards.
6 CCR 1007-1 (Colorado Rules and
Regulations Pertaining to Radiation
Control) siting objectives would
not be met because the disposal
facility would be in a populated
Radioactive materials are
extremely persistent; radium
is not very mobile and gives
off radon decay products to
the atmosphere. While not
very soluble after
reprocessing, radon is
subject to dispersal via
human activity. Radon decay
products can accumulate in
human lungs and are
carcinogenic. Gamma radiation
could cause cancer or genetic
defects.
25
Alternative 7
Temporary Onsite Land Storage/
Permanent Offsite Disposal
Temporary storage can have technical
problems, such as ripping of the
synthetic liner or cracks in the
asphalt pad.
Temporary storage would be used until
offsite disposal facility is
available. Availability required by
SARA 104(k). Facility is assumed not
to be available until 1992.
Site access restrictions and
approvals would be needed to
construct the asphalt pad storage
unit. Storage facility would severely
restrict usage of overall site for 5
years, since it would occupy a large
percentage of open space at the site.
DE/TEN2/047.1
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Table 5
(continued)
Evaluation Criteria
Effectiveness
(continued)
Alternative 1
No Action
Alternative 2
Deferred Removal/ Permanent Offsite
Di sposal
During excavation, remedial action
workers would be exposed to
approximately 162 mrem/yr (whole
body Dose Equivalent) which is
below the 10 CFR 20 standard of 500
mrem/yr for workers. Onsite workers
that are not associated with
cleanup would be exposed to
approximately 7.4 mrem/yr, which is
below NCRP/IRCP guidance of 100
mrem/yr for chronic exposure to the
general public. Transportation of
350 miles to offsite disposal
facility would involve driver
exposure of 6.4 mrem/per trip.
Minimal exposure would occur to
general public during
transportation, unless an
accidental spill occurred, which
would result in a minor increase in
exposures.
Not Applicable
Capital Pwa—$731,500
O&M PW--$22,700
PW = present worth at a 10 percent discount factor.
O&M = Operations and Maintenance.
DE/TEN2/047.2
26
Alternative 5
Onsite Disposal
During excavation, remedial action
workers would be exposed to 171
mrem/yr (whole body Dose
Equivalent) which is below the 10
CFR 20 standard of 500 mrem/yr.
Onsite workers who are not
associated with cleanup would be
exposed to approximately 7.6
mrem/yr which is below the
NCRP/ICRP standard of 100 mrem/yr.
Alternative 7
Temporary Onsite Land Storage/
Permanent Offsite Disposal
The facility should be protective of
the environment if appropriate
liners and caps are used. Potential
impacts could occur during removal
(both for placement in the temporary
facility and the permanent offsite
facility) if uncontrollable
dispersal occurs to the environment.
During excavation, remedial action
workers would be exposed to
approximately 162 mrem/yr (whole
body Dose Equivalent), which is
below the 10 CFR 20 standard of 500
mrem/yr. Onsite workers who are not
associated with cleanup would be
exposed to 7.4 mrem/yr, which is
below the NCRP/ICRP guideline of 100
mrem/yr and the 40 CFR 190 standard
of 25 mrem/yr at the facility
boundary. Transportation exposures
would be identical to Alternative 2.
If other Denver Radium property
wastes are temporarily stored
onsite, remedial action workers
would be exposed to approximately
214 mrem/yr. Exposure to workers not
associated with cleanup would
increase to approximately 10.6
mrem/yr. In-town truck drivers would
be exposed to approximately 200
mrem/yr, which is below the 10 CFR
20 standard of 500 mrem/yr.
Consolidating uncontrolled wastes
from other Denver Radium properties
at this site would probably provide
increased overall protection of the
environment. Dispersal risk at these
other properties would be reduced.
Capital PW—$1,354,000
08M PW—$1,333,400
Capital PW—$1,501,400
O&M PW--$244,500
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Table 5
(Conti nued)
Evaluation Criteria
o Implementability
o Effectiveness
Temporary Onsite Containment/
Permanent Offsite Disposal
Alternative 8
Synthetic bags could rip and
spill material in the building.
However, the building should
contain any spilled materials.
Temporary storage would be used
until offsite disposal facility
is available. Availability
requi red by SARA 104(k)¦
Facility is assumed not to be
available until 1992.
Approvals for using True Truss
Building for radioactive
material storage have been
tentatively obtained.
Temporary storage facility would
not meet 40 CFR 192 and 10 CFR
20 standards for gamma radiation
and radon unless ventilation is
used. However, radium standards
in soils would be met upon
initial removal.
Common Elements
(Contaminated Wall and
Oily Layer)
Minimal potential for poor
decontamination
performance, since wall
could always be completely
removed. Oily layer, as a
liquid, could present
handling problems; risk of
failure during removal is
minimal.
Cleanup of the wall
material would be
remediated as part of the
cleanup for the site.
Access restrictions during the
storage period would limit
public appreciation of historic
value of the site.
Colorado Department of
Health regulates alpha
particle emissions; these
standards would be met
during decontamination.
Pond water would be
evaporated.
The mobility of the material
would be decreased unless the
container broke; however, the
use of a building for storing
the containers would contain any
spillage. The mobility of radon
gas could be decreased, but
could still present a problem
within the container building
used for storage.
If other Denver Radium property
wastes are consolidated and
stored at the Card Corporation
site, the volume of material
will significantly increase.
DE/TEN2/047.3
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Table 5
(Conti nued)
Evaluation Criteria
Effectiveness
(continued)
Costs
Temporary Onsite Containment/
Permanent Offsite Disposal
Alternative 8
During excavation, remedial
action workers would be exposed
to approximately 162 mrem/yr
(whole body Dose Equivalent),
which is below the 10 CFR 20
guideline of 500 mrem/yr and the
40 CFR 190 standard of 25
mrem/yr at the facility
boundary. Onsite workers that
are not associated with cleanup
would be exposed to
approximately 7.4 mrem/yr, which
is below the NCRP/ICRP standard
of 100 mrem/yr. Transportation
risks would be identical to
Alternative 2.
Capital PW--$1,028,100
O&M PQ--$89,500
Common Elements
(Contaminated Wall and Oily
Layer)
Included in Alternative
Estimates
DE/TEN2/047.4
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The selected remedy does not satisfy the statuatory preference for
treatment which reduces toxicity, mobility, and volume of the hazardous
substances as a principal element, epa evaluated several treatment
technologies, including sand sifting, reprocessing, and in situ vitrification.
None were found to be suitable to the site conditions or the type of
contamination present on the Card property.
As described earlier, Temporary Onsite Building Storage/Permanent Offsite
Disposal would provide safe, temporary storage of the approximately 4,000 cubic
yards of radium-contaminated soil from the Card property until a permanent
offsite disposal facility is made available by the State of Colorado. The
material would be excavated from the property, placed in reinforced synthetic
bags, and the bags placed in the True Truss building located near the southern
end of the Card property, if extra capacity is necessary to store the entire
volume of material, an addition to the True Truss building could be
constructed, upon the availability of a permanent disposal facility, all
material would be removed from the property and transported by either rail or
truck to the permanent offsite disposal site. The True Truss building and any
additions would be dismantled, decontaminated, and the material disposed of in
a sanitary landfill.
This alternative includes the option of consolidating and storing
radium-contaminated material from a select few other Denver Radium site
properties, epa initially considered bringing up to 40,000 cubic yards of
material from other Denver Radium site properties, but because of concerns
raised by elected officials and the neighboring community, epa decided to limit
the maximum amount of material that could be stored at the Card property to
13,000 cubic yards. Factors that will be considered in determining whether
material from the other properties will be brought to the storage facility
include capacity of the storage facility, timing, and the comparative health
and environmental threats posed by the other Denver Radium site properties
whose cleanup would be facilitated by temporary offsite storage. No material
would be brought from any Denver Radium site property where epa determines
during the selection of remedy process for that property that an onsite remedy
could be implemented, e.g., there is sufficient space for an onsite action, and
where there is direct access at the property to a rail line for transportation
to a permanent offsite disposal facility.
in further response to public concerns about temporary storage on the
property, epa also decided to limit the duration of the temporary storage, epa
initially considered a duration of storage extending for as much as three years
additional time beyond the initial five year period if no disposal facility had
been made available by the State. But in response to comments, epa has decided
to limit the maximum amount of time for temporary storage at the Card property
to five years.
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The present worth cost of this alternative is $1,148,000. This includes
excavation of all contaminated material, placement of the material in the bags,
placement of the bags in the True Truss building, and maintenance and
monitoring of the bags and building for 5 years. The cost also includes removal
and transportation of the contaminated material to the offsite disposal
facility, as well as dismantling and decontaminating the building, and
transporting the material to a sanitary landfill.
Operation and Maintenance
Operation and maintenance activities will be required to ensure the
effectiveness of the temporary storage facility. The total of discounted annual
operation and maintenance costs, using a time period of five years and a
discount rate of 10%, is $89,500. This figure could vary depending upon the
State's progress towards identifying a permanent disposal site. Operation and
maintenance activities include site inspections and possible minor structural
repairs, epa will have lead responsibility for all operation and maintenance
activities during temporary storage. The costs of operation and maintenance
during temporary storage will be shared between epa and the State of Colorado
in the same manner as other aspects of remedial action.
Community Relations
The Denver Radium site Community Relations Plan establishes a means for
communicating information and eliciting comments concerning the site from State
and local officials, potentially interested neighborhood associations and
individuals, and the local media. The epa issued a press release announcing the
October 6 through November 15, 1986 public comment period on the first draft
Card Corporation Operable unit x Feasibility Study. The Denver Post, the Rockv
Mountain News, and the Washington Park Profile provide a news coverage. A great
deal of public interest resulted. The epa received numerous letters and several
petitions, most of which opposed the use of the Card property as a storage
facility. The Denver city Council passed a resolution against the storage of
any radioactive waste anywhere in the Denver metro area.
So great was the public concern, that the epa extended the public comment
period to November 30 and held a public meeting on November 19, 1986. Major
concerns raised by those who attended the meeting were: impacts of cleanup and
storage on property values; justification for temporary storage; health risks
from the cleanup; risks from transporting material to the site; and concerns
that the temporary storage facility would become permanent if the State fails
to assure the availability of a permanent disposal site.
The comment period on the second draft Card Corporation Operable unit x
Feasibility Study was from April 27 through May 15, 1987. During this comment
period, the epa held several availability sessions where concerned citizens
could speak one-on-one with epa representatives. A second public meeting was
held on May 7, 1987. issues raised during this meeting and the availability
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31
sessions were similar to those expressed during the first public meeting. The
Community Relations Responsiveness Summary attached to the ROD describes in
more detail the nature and level of the community's concern and includes epa's
response to all comments received during the public review of both the first
and second draft Card Corporation Operable unit x Feasibility Study.
Future Actions
The future remedial activities that are required to complete remedial
action at the Card property are:
(1) Negotiate final administrative order with Mentor Corporation.
(2) Design remedial action and temporary storage facility.
(3) Enter into State Superfund Contract with state of Colorado.
(4) Conduct remedial action for contamination present on Card property.
(5) Determine via rods on remaining Denver Radium site Operable units if
material from certain other Denver Radium site properties will be
temporarily stored and staged at the Card property.
(6) Select and, if necessary, design and construct permanent disposal
facility. (This activity is to be conducted by State of Colorado.)
(7) Remove contaminated material from Card property to permanent disposal
faci1i ty.
(8) Decontaminate and demolish temporary storage facility and dispose of
material in a sanitary landfill.
Schedule
Dates for completing key milestones leading to remedial action at the Card
property are highlighted below.
(1) Complete design of remedial action and temporary storage facility by April
1, 1988
(2) Complete negotiations on administrative order with Mentor Corporation by
August 1, 1987
(3) Finalize State Superfund Contract with state of Colorado by April 1, 1988
(4) initiate remedial action no later than during third quarter fiscal year
1988
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