LINCOLN PARK/COTTER URANIUM MILL

CAÑON CITY, FREMONT COUNTY, COLORADO 

EPA FACILITY ID: COD042167585 

SEPTEMBER 9, 2010 

NOVEMBER 9, 2010
 
 

 

 

 

 

 

 

 

 


 


 


 


 


 

THE ATSDR PUBLIC HEALTH ASSESSMENT: A NOTE OF EXPLANATION
 

This Public Health Assessment-Public Comment Release was prepared by ATSDR pursuant to the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) section 104 (i)(6) (42 U.S.C. 9604 (i)(6), 

and in accordance with our implementing regulations (42 C.F.R. Part 90). In preparing this document, ATSDR has collected 

relevant health data, environmental data, and community health concerns from the Environmental Protection Agency (EPA), 

state and local health and environmental agencies, the community, and potentially responsible parties, where appropriate. 

This document represents the agency’s best efforts, based on currently available information, to fulfill the statutory criteria set 

out in CERCLA section 104 (i)(6) within a limited time frame. To the extent possible, it presents an assessment of potential 

risks to human health. Actions authorized by CERCLA section 104 (i)(11), or otherwise authorized by CERCLA, may be 

undertaken to prevent or mitigate human exposure or risks to human health. In addition, ATSDR will utilize this document to 

determine if follow-up health actions are appropriate at this time. 

This document has previously been provided to EPA and the affected state in an initial release, as required by CERCLA 

section 104 (i) (6) (H) for their information and review. Where necessary, it has been revised in response to comments or 

additional relevant information provided by them to ATSDR. This revised document has now been released for a 30-day 

public comment period. Subsequent to the public comment period, ATSDR will address all public comments and revise or 

append the document as appropriate. The public health assessment will then be reissued. This will conclude the public 

health assessment process for this site, unless additional information is obtained by ATSDR which, in the agency’s opinion, 

indicates a need to revise or append the conclusions previously issued. 

Agency for Toxic Substances and Disease Registry .................................... .Thomas R. Frieden, M.D., M.P.H., Administrator

 Christopher J. Portier, Ph.D., Director 

Division of Health Assessment and Consultation...............................................William Cibulas, Jr., Ph.D., Director 

Sharon Williams-Fleetwood, Ph.D., Deputy Director 

Health Promotion and Community Involvement Branch....................................Hilda Shepeard, Ph.D., M.B.A., Chief 

Exposure Investigations and Consultation Branch......................................................Susan M. Moore, M.S., Chief 

Federal Facilities Assessment Branch......................................................................Sandra G. Isaacs, B.S., Chief 

Superfund and Program Assessment Branch .......................................................................... Richard E. Gillig, M.C.P., Chief 

Use of trade names is for identification only and does not constitute endorsement by the Public Health Service or the 

U.S. Department of Health and Human Services. 

Please address comments regarding this report to:
 

Agency for Toxic Substances and Disease Registry 

Attn: Records Center 

1600 Clifton Road, N.E., MS F-09 

Atlanta, Georgia 30333 

You May Contact ATSDR Toll Free at
 

1-800-CDC-INFO or
 

Visit our Home Page at: http://www.atsdr.cdc.gov
 
 

 

 


 


 

Lincoln Park/Cotter Uranium Mill Public Comment Release 

PUBLIC HEALTH ASSESSMENT 

LINCOLN PARK/COTTER URANIUM MILL 

CAÑON CITY, FREMONT COUNTY, COLORADO 

EPA FACILITY ID: COD042167585 

Prepared by: 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
 

Agency for Toxic Substances and Disease Registry
 

Division of Health Assessment and Consultation 

Site and Radiological Assessment Branch 

This information is distributed by the Agency for Toxic Substances and Disease Registry for public 

comment under applicable information quality guidelines. It does not represent and should not be 

construed to represent final agency conclusions or recommendations. 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Foreword 

The Agency for Toxic Substances and Disease Registry, ATSDR, was established by Congress 

in 1980 under the Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA), also known as the Superfund law. This law set up a fund to identify and clean up 

hazardous waste sites. The Environmental Protection Agency (EPA) and the individual states 

regulate the investigation and clean up of the sites. 

Since 1986, ATSDR has been required by law to conduct a public health assessment at each of 

the sites on the EPA National Priorities List. The aim of these evaluations is to find out if people 

are being exposed to hazardous substances and, if so, whether that exposure is harmful and 

should be stopped or reduced. If appropriate, ATSDR also conducts public health assessments 

when petitioned by concerned individuals. Public health assessments are carried out by 

environmental and health scientists from ATSDR and from the states with which ATSDR has 

cooperative agreements. The public health assessment process allows ATSDR scientists and 

public health assessment cooperative agreement partners flexibility in document format when 

presenting findings about the public health impact of hazardous waste sites. The flexible format 

allows health assessors to convey to affected populations important public health messages in a 

clear and expeditious way. 

Exposure: As the first step in the evaluation, ATSDR scientists review environmental data to 

see how much contamination is at a site, where it is, and how people might come into contact 

with it. Generally, ATSDR does not collect its own environmental sampling data but reviews 

information provided by EPA, other government agencies, businesses, and the public. When 

there is not enough environmental information available, the report will indicate what further 

sampling data is needed. 

Health Effects: If the review of the environmental data shows that people have or could come 

into contact with hazardous substances, ATSDR scientists evaluate whether or not these contacts 

may result in harmful effects. ATSDR recognizes that children, because of their play activities 

and their growing bodies, may be more vulnerable to these effects. As a policy, unless data are 

available to suggest otherwise, ATSDR considers children to be more sensitive and vulnerable to 

hazardous substances. Thus, the health impact to the children is considered first when evaluating 

the health threat to a community. The health impacts to other high-risk groups within the 

community (such as the elderly, chronically ill, and people engaging in high risk practices) also 

receive special attention during the evaluation. 

ATSDR uses existing scientific information, which can include the results of medical, 

toxicologic and epidemiologic studies and the data collected in disease registries, to evaluate 

possible the health effects that may result from exposures. The science of environmental health is 

still developing, and sometimes scientific information on the health effects of certain substances 

is not available. 

Community: ATSDR also needs to learn what people in the area know about the site and what 

concerns they may have about its impact on their health. Consequently, throughout the 

evaluation process, ATSDR actively gathers information and comments from the people who 

live or work near a site, including residents of the area, civic leaders, health professionals, and 
 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

community groups. To ensure that the report responds to the community's health concerns, an 

early version is also distributed to the public for their comments. All the public comments that 

related to the document are addressed in the final version of the report. 

Conclusions: The report presents conclusions about the public health threat posed by a site. 

Ways to stop or reduce exposure will then be recommended in the public health action plan. 

ATSDR is primarily an advisory agency, so usually these reports identify what actions are 

appropriate to be undertaken by EPA or other responsible parties. However, if there is an urgent 

health threat, ATSDR can issue a public health advisory warning people of the danger. ATSDR 

can also recommend health education or pilot studies of health effects, full-scale epidemiology 

studies, disease registries, surveillance studies or research on specific hazardous substances. 

Comments: If, after reading this report, you have questions or comments, we encourage you to 

send them to us. 

Letters should be addressed as follows: 

Attention: Rolanda Morrison 

ATSDR Records Center (MS F-09) 

4770 Buford Hwy, NE 

Building 106, Room 2108 

Atlanta, GA 30341 
 

   

   

       

     

      

       

       

               

             

                     

           

                       

             

                     

                 

           

         

   

       

               

       

     

               

         

         

   

       

   

   

         

     

   

       

   

     

       

   

     

   

   

   

       


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 

 
 


 


 


 


 


 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table of Contents 

II. BACKGROUND........................................................................................................................................... 5
 

A. SITE DESCRIPTION AND OPERATIONAL HISTORY ...........................................................................................................5
 

B. REMEDIAL AND REGULATORY HISTORY ......................................................................................................................5
 

C. DEMOGRAPHICS.................................................................................................................................................10
 

D. LAND USE AND NATURAL RESOURCES......................................................................................................................11
 

1. Hydrogeology ...........................................................................................................................................11
 

2. Geology.....................................................................................................................................................11
 

3. Hydrology .................................................................................................................................................12
 

4. Prevailing Wind Patterns..........................................................................................................................12
 

E. PAST ATSDR INVOLVEMENT......................................................................................................................................13
 

III. EVALUATION OF EXPOSURE PATHWAYS...................................................................................................15
 

A. WHAT IS MEANT BY EXPOSURE? ............................................................................................................................15
 

B. HOW DOES ATSDR DETERMINE WHICH EXPOSURE SITUATIONS TO EVALUATE?...............................................................16
 

C. IF SOMEONE IS EXPOSED, WILL THEY GET SICK? .........................................................................................................17
 

D. WHAT EXPOSURE SITUATIONS WERE EVALUATED FOR RESIDENTS LIVING NEAR THE COTTER MILL?......................................17
 

1. Exposure to groundwater in Lincoln Park .................................................................................................18
 

2. Contact with soil adjacent to the Cotter Mill and in Lincoln Park.............................................................18
 

a) Contact with soil near the Cotter Mill .................................................................................................................. 19
 

b) Contact with soil and sediment in the community of Lincoln Park ...................................................................... 19
 

3. Contact with surface water downstream from the Cotter Mill ................................................................20
 

4. Exposure from eating locally grown produce ...........................................................................................20
 

5. Exposure from breathing windborne dust................................................................................................20
 

IV. EVALUATION OF ENVIRONMENTAL CONTAMINATION..............................................................................25
 

A. GROUNDWATER.................................................................................................................................................25
 

1. Remedial actions for controlling groundwater contamination ................................................................25
 

2. Nature and extent of groundwater contamination in Lincoln Park..........................................................26
 

a) Wells used for personal consumption.................................................................................................................. 26
 

(1) Grand Avenue Well ......................................................................................................................................... 27
 

b) Wells used to irrigate fruit and vegetable gardens .............................................................................................. 27
 

c) Wells used to water livestock............................................................................................................................... 28
 

d) Wells used to water lawns.................................................................................................................................... 29
 

(1) Well 138 .......................................................................................................................................................... 29
 

e) Groundwater trends over time ............................................................................................................................ 30
 

B. SOIL AND SEDIMENT............................................................................................................................................30
 

1. Background levels.....................................................................................................................................30
 

2. Off‐site soil contamination and remediation............................................................................................31
 

a) The nearest resident............................................................................................................................................. 32
 

b) Lincoln Park .......................................................................................................................................................... 32
 

(1) Lead in Lincoln Park......................................................................................................................................... 33
 

c) Sand Creek............................................................................................................................................................ 34
 

d) The Fremont Ditch................................................................................................................................................ 35
 

C. SURFACE WATER ................................................................................................................................................35
 

1. Nature and extent of contamination........................................................................................................35
 

a) Sand Creek............................................................................................................................................................ 36
 

b) DeWeese Dye Ditch.............................................................................................................................................. 37
 

c) Arkansas River...................................................................................................................................................... 37
 

d) Willow Lakes......................................................................................................................................................... 39
 

D. LOCALLY GROWN PRODUCE ..................................................................................................................................39
 

1. Nature and extent of contamination........................................................................................................39
 

E. AMBIENT AIR ....................................................................................................................................................40
 
 

         

         

   

   

   

           

           

       

   

       

            

     

             

       

                 

       

       

                   

     

     

    

   

       

   

         

             

                     

             

                   

                               

                               

                     

                     

                     

                     

               


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 

 
 


 


 


 


 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

1. Nature and extent of air contamination...................................................................................................41
 

a) Ambient Air Monitoring for Radioactive Substances............................................................................................ 42
 

(1) Particulate Matter........................................................................................................................................... 42
 

(2) Particle‐Bound Radionuclides ......................................................................................................................... 43
 

b) Radon Gas............................................................................................................................................................. 47
 

c) Gamma Radiation................................................................................................................................................. 48
 

d) Ambient Air Monitoring for non‐Radioactive Substances.................................................................................... 49
 

(1) Particulate Matter (TSP, PM10, and PM2.5) ...................................................................................................... 49
 

(2) Constituents of Particulate Matter ................................................................................................................. 50
 

V. PUBLIC HEALTH EVALUATION...................................................................................................................51
 

A. INTRODUCTION ..................................................................................................................................................51
 

B. HOW HEALTH EFFECTS ARE EVALUATED..................................................................................................................51
 

C. GROUNDWATER PATHWAY: PRIVATE WELLS USED FOR PERSONAL CONSUMPTION ..........................................................52
 

1. Molybdenum.............................................................................................................................................53
 

a) Health Evaluation of Molybdenum....................................................................................................................... 53
 

b) Additional Comments about Molybdenum in Drinking Water............................................................................. 55
 

2. Uranium....................................................................................................................................................55
 

a) Health Evaluation of Uranium .............................................................................................................................. 56
 

D. SOIL PATHWAY: SURFACE SOIL NEAR COTTER MILL AND LINCOLN PARK........................................................................59
 

1. Soil Near Cotter Mill..................................................................................................................................60
 

a) Arsenic.................................................................................................................................................................. 60
 

b) Cadmium .............................................................................................................................................................. 60
 

c) Lead...................................................................................................................................................................... 60
 

d) Radium‐226 .......................................................................................................................................................... 61
 

2. Soil in Lincoln Park ....................................................................................................................................62
 

a) Arsenic.................................................................................................................................................................. 62
 

E. SURFACE WATER: SAND CREEK, DEWEESE DYE DITCH, AND THE ARKANSAS RIVER .........................................................62
 

1. Manganese...............................................................................................................................................63
 

2. Molybdenum.............................................................................................................................................63
 

F. HOMEGROWN FRUITS AND VEGETABLES .................................................................................................................63
 

G. AIR PATHWAY ...................................................................................................................................................66
 

VI. COMMUNITY HEALTH CONCERNS.............................................................................................................68
 

VII. CONCLUSIONS..........................................................................................................................................74
 

VIII. RECOMMENDATIONS...............................................................................................................................75
 

IX. PUBLIC HEALTH ACTION PLAN ..................................................................................................................76
 

X. SITE TEAM................................................................................................................................................77
 

XI. REFERENCES.............................................................................................................................................78
 

APPENDIX A ‐ TABLES...................................................................................... ERROR! BOOKMARK NOT DEFINED.
 

TABLE 14. WELL USE IN LINCOLN PARK, 1989..................................................................................................................87
 

TABLE 15. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM WELLS USED FOR PERSONAL CONSUMPTION................................90
 

TABLE 16. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM BACKGROUND WELLS .............................................................92
 

TABLE 17. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM THE GRAND AVENUE WELL .....................................................94
 

TABLE 18. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM WELLS USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS ............95
 

TABLE 19. GROUNDWATER SAMPLING DATA (RADIONUCLIDES) FROM WELLS USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS ......98
 

TABLE 20. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM WELLS USED TO WATER LIVESTOCK ............................................99
 

TABLE 21. GROUNDWATER SAMPLING DATA (RADIONUCLIDES) FROM WELLS USED TO WATER LIVESTOCK....................................102
 

TABLE 22. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM WELLS USED TO WATER LAWNS ..............................................103
 

TABLE 23. GROUNDWATER SAMPLING DATA (RADIONUCLIDES) FROM WELLS USED TO WATER LAWNS ........................................106
 

TABLE 24. GROUNDWATER SAMPLING DATA (CHEMICALS) FROM WELL 138.........................................................................107
 
 

               

                                    

                     

                                  

                     

                     

                 

                     

                     

                         

                   

                       

                       

     

     

                 

                 

     

         

         

       

       

               

               

                       

                       

               

         

         

         

         

         

   

       

             

               

   

                     

                   

            

       

       

                 

               

                   

                       

                 

         


 


 


 


 


 


 


 

 
 


 


 


 


 

 
 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 

 
 


 


 


 


 


 


 


 


 


 


 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

TABLE 25. GROUNDWATER SAMPLING DATA (RADIONUCLIDES) FROM WELL 138...................................................................109
 

TABLE 26. SURFACE SOIL SAMPLING DATA (CHEMICALS) FROM EIGHT ZONES AROUND THE COTTER MILL AND FROM LINCOLN PARK.110
 

TABLE 27. SURFACE SOIL SAMPLING DATA (RADIONUCLIDES) FROM EIGHT ZONES AROUND THE COTTER MILL AND FROM LINCOLN PARK
 

..............................................................................................................................................................................112
 

TABLE 28. SURFACE SOIL SAMPLING DATA (RADIONUCLIDES) FROM THE COUNTY ROAD AND THE COTTER URANIUM MILL ACCESS ROAD
 

TABLE 29. SOIL DATA (CHEMICALS) FROM SAMPLES TAKEN BY CDPHE, JANUARY 2003..........................................................115
 

TABLE 30. SOIL DATA (RADIONUCLIDES) FROM SAMPLES TAKEN BY CDPHE, JANUARY 2003....................................................116
 

TABLE 35. SURFACE SOIL SAMPLING DATA (RADIONUCLIDES) FROM YARDS, GARDENS, AND AIR MONITORING LOCATIONS IN LINCOLN
 

..............................................................................................................................................................................114
 

TABLE 31. SURFACE SOIL SAMPLING DATA FROM 10 AIR MONITORING LOCATIONS..................................................................117
 

TABLE 32. SOIL SAMPLING DATA (CHEMICALS) FROM LOCATION AS‐212 (THE NEAREST RESIDENT)...........................................118
 

TABLE 33. SOIL SAMPLING DATA (RADIONUCLIDES) FROM LOCATION AS‐212 (THE NEAREST RESIDENT).....................................119
 

TABLE 34. SURFACE SOIL SAMPLING DATA (CHEMICALS) FROM LAWNS AND GARDENS IN LINCOLN PARK .....................................120
 

PARK .......................................................................................................................................................................121
 

TABLE 36. SURFACE SOIL DATA (CHEMICALS) FROM LAWNS AND GARDENS IN LINCOLN PARK ....................................................122
 

TABLE 37. SURFACE SOIL DATA (RADIONUCLIDES) FROM LAWNS AND GARDENS IN LINCOLN PARK..............................................123
 

TABLE 38. SEDIMENT SAMPLING DATA (CHEMICALS) FROM SAND CREEK ..............................................................................124
 

TABLE 39. SEDIMENT SAMPLING DATA (RADIONUCLIDES) FROM SAND CREEK ........................................................................125
 

TABLE 40. CHEMICAL SAMPLING FOR THE SAND CREEK CLEANUP PROJECT............................................................................126
 

TABLE 41. SURFACE WATER SAMPLING DATA (CHEMICALS) FROM SAND CREEK ......................................................................127
 

TABLE 42. SURFACE WATER SAMPLING DATA (RADIONUCLIDES) FROM SAND CREEK................................................................128
 

TABLE 43. SURFACE WATER SAMPLING DATA (CHEMICALS) FROM THE DEWEESE DYE DITCH ....................................................129
 

TABLE 44. SURFACE WATER SAMPLING DATA (RADIONUCLIDES) FROM THE DEWEESE DYE DITCH..............................................131
 

TABLE 45. SURFACE WATER SAMPLING DATA (CHEMICALS) FROM THE ARKANSAS RIVER ..........................................................132
 

TABLE 46. SURFACE WATER SAMPLING DATA (RADIONUCLIDES) FROM THE ARKANSAS RIVER....................................................133
 

TABLE 47. SAMPLING DATA (CHEMICALS) FOR LOCAL AND SUPERMARKET FOODS....................................................................135
 

TABLE 48. SAMPLING DATA (RADIONUCLIDES) FOR LOCAL AND SUPERMARKET FOODS .............................................................136
 

TABLE 49. SAMPLING DATA (CHEMICALS) FOR LOCAL PRODUCE IRRIGATED WITH CONTAMINATED WELL WATER............................137
 

TABLE 50. SAMPLING DATA (RADIONUCLIDES) FOR LOCAL PRODUCE IRRIGATED WITH CONTAMINATED WELL WATER......................139
 

TABLE 51. CHARACTERISTICS OF COTTER MILL’S AMBIENT AIR MONITORING STATIONS..........................................................139
 

TABLE 52. AVERAGE ANNUAL NATU CONCENTRATIONS 1979‐2008 (ΜCI/ML)......................................................................140
 

TABLE 53. AVERAGE ANNUAL 230TH CONCENTRATIONS 1979‐2008 (ΜCI/ML)....................................................................141
 

TABLE 54. AVERAGE ANNUAL 232TH CONCENTRATIONS 2001‐2008 (ΜCI/ML)....................................................................142
 

TABLE 55. AVERAGE ANNUAL 226RA CONCENTRATIONS 1979‐2008 (ΜCI/ML)....................................................................143
 

TABLE 56. AVERAGE ANNUAL 210PB CONCENTRATIONS 1979‐2008 (ΜCI/ML) ....................................................................144
 

TABLE 57. 220RN/

222RN CONCENTRATIONS 2002‐2008 (PCI/M3

).....................................................................................145
 

TABLE 58. ENVIRONMENTAL TLD MEASUREMENTS, 1979‐2008 (μR/HR) ..........................................................................146
 

TABLE 59. TSP AIR CONCENTRATIONS (μG/M3

) FROM 1969‐1987 ...................................................................................147
 

TABLE 60. MONITORING DATA FOR CONSTITUENTS IN TSP (1978‐1987)...........................................................................147
 

APPENDIX B ‐ SITE FIGURES .............................................................................................................................149
 

FIGURE 1. LOCATION OF THE COTTER MILL, LINCOLN PARK, AND CAÑON CITY.......................................................................150
 

FIGURE 2. DEMOGRAPHICS WITHIN 1 MILE OF THE COTTER MILL PROPERTY ..........................................................................151
 

FIGURE 3. WIND ROSE FOR COTTER MILL, 2008 ............................................................................................................152
 

FIGURE 4. MOLYBDENUM PLUME MAP .........................................................................................................................153
 

FIGURE 5. URANIUM PLUME MAP ................................................................................................................................154
 

FIGURE 6. WELLS IN LINCOLN PARK USED FOR PERSONAL CONSUMPTION..............................................................................155
 

FIGURE 7. MOLYBDENUM CONCENTRATIONS IN WELLS USED FOR PERSONAL CONSUMPTION.....................................................156
 

FIGURE 8. DISSOLVED URANIUM CONCENTRATIONS IN WELLS USED FOR PERSONAL CONSUMPTION ............................................157
 

FIGURE 9. WELLS IN LINCOLN PARK USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS ..........................................................158
 

FIGURE 10. WELLS IN LINCOLN PARK USED TO WATER LIVESTOCK........................................................................................159
 

FIGURE 11. WELLS IN LINCOLN PARK USED TO WATER LAWNS ............................................................................................160
 

FIGURE 12. MOLYBDENUM CONCENTRATIONS IN WELL 138..............................................................................................161
 
 

           

             

             

               

                 

                          

                             

                     

         

             

                 

                                   

   

   

   

                                 

               

 


 


 


 


 


 


 


 


 


 

 
 


 

 
 


 

 
 

 
 


 


 

 
 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

FIGURE 13. SELENIUM CONCENTRATIONS IN WELL 138 ....................................................................................................162
 

FIGURE 14. DISSOLVED URANIUM CONCENTRATIONS IN WELL 138 .....................................................................................163
 

FIGURE 15. MOLYBDENUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED ........................................................164
 

FIGURE 16. SELENIUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED...............................................................165
 

FIGURE 17. DISSOLVED URANIUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED................................................166
 

FIGURE 18. SAMPLING ZONES ESTABLISHED DURING THE 1998 SUPPLEMENTAL HUMAN HEALTH RISK ASSESSMENT....................167
 

FIGURE 19. LOCATIONS OF SOIL SAMPLES TAKEN ALONG THE COUNTY ROAD AND COTTER MILL’S ACCESS ROAD ...........................168
 

FIGURE 20. LOCATIONS OF SOIL SAMPLES TAKEN BY CDPHE IN JANUARY 2003.....................................................................169
 

FIGURE 21. LOCATION OF AIR SAMPLING LOCATIONS WHERE SOIL SAMPLES ARE COLLECTED......................................................170
 

FIGURE 22. SAND CREEK CLEANUP PROJECT ...................................................................................................................171
 

FIGURE 23. APPROXIMATE LOCATIONS OF COTTER MILL MONITORING STATIONS ..................................................................172
 

APPENDIX C ‐ ATSDR'S EVALUATION PROCESS AND EXPOSURE DOSE CALCULATIONS

TABLE C1. SUMMARY OF EXPOSURE FACTORS AND EXPOSURE DOSES FOR THE DRINKING WATER PATHWAY FOR CHEMICALS AT THE
 

COTTER MILL SITE......................................................................................................................................................176
 

TABLE C2. SUMMARY OF EXPOSURE FACTORS AND EXPOSURE DOSES FOR THE SOIL EXPOSURE PATHWAY FOR CHEMICALS AT THE
 

TABLE C3. SUMMARY OF EXPOSURE FACTORS AND EXPOSURE DOSES FOR THE SURFACE WATER PATHWAY FOR CHEMICALS AT THE
 

COTTER MILL SITE......................................................................................................................................................179
 

COTTER MILL SITE......................................................................................................................................................182
 

TABLE C4. SUMMARY OF EXPOSURE DOSES FOR LOCAL FRUITS AND VEGETABLES IRRIGATED WITH CONTAMINATED WELL WATER..184
 

APPENDIX D. ATSDR GLOSSARY OF ENVIRONMENTAL HEALTH TERMS.............................................................189
 
 

	 

CV 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Acronyms and Abbeviations 

CCAT	 Colorado Citizens Against Toxic Waste 

CDPHE Colorado Department of Public Health and Environment 

CREG cancer risk evaluation guide 

comparison value 

D dissolved 

EMEG environmental media evaluation guide 

EPA US Environmental Protection Agency 

LPWUS Lincoln Park Water Use Survey 

LTHA lifetime health advisory for drinking water 

MCL maximum contaminant level 

mg/L milligrams per liter 

μR/hr microroentgen per hour 

N not defined in the CDPHE database 

NA not available 

ND not detected 

NPL National Priorities List 

OU operable units 

pCi/g picocuries per gram 

pCi/L picocuries per liter 

ppm parts per million 

RAP Remedial Action Plan 

RBC risk based concentration 

RMEG reference dose media evaluation guide 

S suspended 

SCS Soil Conservation Service 

SSL soil screening level 

T total 

UMTRCA 1978 Uranium Mill Tailings Radiation Control Act 

USGS United States Geological Survey 
____________________________________________________________ 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

I. SUMMARY 

Introduction ATSDR’s top priority is to ensure that the community of Lincoln Park and 

surrounding communities have the best information possible to safeguard 

their health. 

The purpose of this public health assessment (PHA) is to evaluate 

available data and information on the release of hazardous substances 

from the Cotter Uranium Mill to determine if people could be harmed by 

coming into contact with those substances. This PHA will also list actions, 

as needed, to be taken to protect the public’s health. 

Background 

The Cotter Uranium Mill (Cotter) is located approximately two miles 

south of downtown Cañon City in Fremont County, Colorado. The 

community of Lincoln Park borders the site to the north and the housing 

developments of Dawson Ranch, Wolf Park, and Eagle Heights are 

located along Cotter’s western boundary. The nearest residence is about 

0.25 miles from the mill (Galant et al. 2007). 

The 2,500-acre site includes two inactive mills, ore stockpile areas, a 

partially reclaimed tailings pond disposal area (i.e., the old ponds area), 

and a current tailings pond disposal area (i.e., the lined “main 

impoundment area”). A large portion of the site is used to store waste 

products in the impoundment area. The former mill area is fenced and is 

known as the “restricted area”. 

The Cotter Mill began operations in 1958, extracting uranium ore using an 

alkaline leach process. In 1979, the facility switched to an acid leach 

process for extracting uranium. Cotter suspended primary operations in 

1987, and only limited and intermittent processing occurred until the 

facility resumed operations in 1999 with a modified alkaline-leaching 

capability until 2001. Cotter refabricated the mill circuits between 2002 

and 2005 to operate using an acid process when it went into stand down in 

March 2006. Cotter is currently evaluating whether to re-engineer the mill 

for future operation. 

Wastes containing metals and radionuclides were released from Cotter and 

entered the nearby environment. People could potentially be exposed to 

these wastes if they come into contact with them in drinking water, soil, 

sediment, biota (fruits and vegetables) or ambient air. 

Conclusions After evaluating the available data, ATSDR reached four important 

conclusions in this public health assessment: 

1 
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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Conclusion 1 ATSDR concludes that drinking water from contaminated private wells 

could harm people’s health. This is a public health hazard. 

Basis for Conclusion Private well sampling data collected from 1984 to 2007 revealed the 

presence of molybdenum at levels that could harm people’s health. A 

water use survey conducted in Lincoln Park in 1989 revealed that at least 

seven people used groundwater (from their private wells) for personal 

consumption. These and other residents whose private wells were affected 

by the highest molybdenum contamination may be at increased risk for 

health effects such as gout-like conditions. Individuals who do not take in 

enough dietary copper or who cannot process it correctly will be affected 

the most. 

The lack of consistent monitoring over the years and the unknown usage 

of wells before the installation of the public water supply makes these past 

exposures difficult to accurately assess. 

Most town residents are now connected to the public water supply and 

have thus eliminated their exposure to contaminated water. However, 

some residents are reported to have refused public water supply 

connections, and many may still have operational private wells. 

Additionally, no formal institutional controls exist to control groundwater 

use in Lincoln Park. Therefore, current and future uses of private wells for 

domestic purposes are still possible. 

Conclusion 2 ATSDR concludes that accidentally eating or touching soil and sediment 

near the Cotter Mill property or in Lincoln Park will not harm people’s 

health. However, ATSDR cannot make conclusions about whether lead in 

soils near Cotter Mill could harm people’s health in the future. 

Basis for Conclusion Currently, the property near the Cotter Mill property is restricted access, 

vacant or used for industrial purposes; therefore, contact with soils near 

the property should be minimal. The soil sampling conducted at the site 

does not allow ATSDR to accurately assess potential exposures if the area 

is ever developed for residential, commercial or recreational uses. 

Therefore, a conclusion regarding future exposures cannot be made 

because not enough information is available about future development of 

this area. 

ATSDR recommends that lead contamination in soil be re-evaluated if 

2 
____________________________________________________________ 

____________________________________________________________ 

____________________________________________________________ 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Next Steps the area is considered for development for residential or non-industrial 

uses. 

____________________________________________________________ 

Conclusion 3 ATSDR concludes that eating locally-grown fruits and vegetables irrigated 

with private well water will not harm most people’s health. However, a 

person eating above-average amounts of fruits and vegetables (4 times the 

average consumer) might have a low increased risk for developing cancer 

over a lifetime. As a precaution, residents should limit their use of 

contaminated well water to irrigate their crops. In all cases, the crops 

should be thoroughly cleaned prior to eating. 

____________________________________________________________ 

Basis for Conclusion Sampled locally-grown fruits and vegetables did not indicate the presence 

of contaminants at levels that would cause non-cancer health effects. The 

increased cancer risk is based on a person consuming more fruits and 

vegetables (95th percentile range) than a typical consumer. The cancer 

estimate is conservative because it assumes that a person would grow and 

eat fruits and vegetables that contain arsenic every day for 30 years. The 

amount of fruits and vegetables eaten will likely be much less than 

estimated, mainly because the growing season is not year-round. 

The amount of a contaminant ingested would depend upon the type of 

crop eaten, the likelihood of the crop bioaccumulating any of the 

contaminants, how often the crop is eaten, if contaminated well water is 

used to irrigate the crop, and if the crop is thoroughly cleaned prior to 

eating them. 

Conclusion 4 ATSDR concludes that ambient air emissions of particle bound 

radionuclides have not resulted in exposures to the public at levels that 

could cause adverse health outcomes. 

Basis for Conclusion With the exception of thorium-230 levels observed in 1981 and 1982, 

associated with excavation of contaminated tailings, every radionuclide 

monitored has been more than a factor of ten below annual dose based 

health limits to the public. The excavation releases appear to have only 

exposed on-site workers, but still below occupational limits at that time. 

ATSDR is taking the following follow-up actions at this site: 

Next Steps ATSDR’s Health Promotion and Community Involvement Branch 

(HPCIB) will conduct health-related educational activities in the 

community, as necessary. 

3 
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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

ATSDR’s HPCIB will coordinate community outreach and community 

involvement activities for the site. 

ATSDR will continue to work with appropriate state and federal agencies 

and review additional relevant environmental data (including the water use 

survey) as it becomes available. 

ATSDR will update the action plan for this site as needed. New 

environmental, toxicological, health outcome data, or implementing the 

above proposed actions may necessitate the need for additional or 

alternative actions at this site. 

For More If you have concerns about your health, you should contact you health 

Information care provider. You can also call ATSDR at 1-800-CDC-INFO for more 

information on the Lincoln Park/Cotter Uranium Mill site. 

4 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

II. BACKGROUND 

A. Site description and operational history 

The Cotter Mill is located approximately two miles south of downtown Cañon City in Fremont 

County, Colorado (see Figure 1) [Galant et al. 2007]. The community of Lincoln Park borders 

the site to the north and the housing developments of Dawson Ranch, Wolf Park, and Eagle 

Heights are located along Cotter’s western boundary. The nearest residence is about 0.25 miles 

from the mill [Galant et al. 2007]. 

The 2,500-acre site includes two inactive mills, ore stockpile areas, a partially reclaimed tailings 

pond disposal area (i.e., the old ponds area), and a current tailings pond disposal area (i.e., the 

lined “main impoundment area”). A large portion of the site is used to store waste products in the 

impoundment area. The former mill area is fenced and is known as the “restricted area” [Galant 

et al. 2007]. 

The Cotter Mill began operations in 1958, extracting uranium ore using an alkaline leach 

process. In 1979, the facility switched to an acid leach process for extracting uranium. Cotter 

suspended primary operations in 1987 [Weston 1998], and only limited and intermittent 

processing occurred until the facility resumed operations in 1999 with a modified alkalineleaching capability until 2001 [EPA 2002]. Cotter refabricated the mill circuits between 2002 

and 2005 to operate using an acid process when it went into stand down in March 2006 [Cotter 

2007]. Cotter is currently evaluating whether to re-engineer the mill for future operation 

[CDPHE 2008]. 

Additional information about the history and licensing of the Cotter Mill can be found on the 

Colorado Department of Public Health and Environment’s (CDPHE) and the US Environmental 

Protection Agency’s (EPA) Web sites at http://www.cdphe.state.co.us/hm/cotter/sitedescript.htm 

and http://www.epa.gov/region8/superfund/co/lincolnpark/. 

B. Remedial and regulatory history 

Originally, mill tailings (i.e., solid ore processing waste), raffinate (liquid waste that remains 

after extraction), and other liquids from the alkaline leach process were stored in ten on-site 

unlined ponds. In 1978, lined impoundments were built on site to store process waste products. 

The main impoundment contained two cells to segregate acid-leach tailings and liquids in the 

primary impoundment cell from alkaline-leach tailings in the secondary impoundment cell (EPA 

2002). By 1983, more than 2.5 million cubic yards of waste products from historic operations 

were transferred from the original unlined ponds to the secondary impoundment. All new process 

wastes are stored in the lined primary impoundment [Galant et al. 2007]. 

Because Cotter Mill operations released radionuclides and metals into the environment, soil 

around the mill and groundwater in the nearby Lincoln Park community became contaminated, 

primarily with molybdenum and uranium [CDPHE 

2008]. In 1984, the Lincoln Park/Cotter Mill Site was 

added to the Superfund National Priorities List (NPL) 

[EPA 2008]. EPA divided the site into two operable 

According to a signed Memorandum 

of Understanding, CDPHE is the lead 

regulatory agency overseeing 

cleanup at the Cotter Mill. 

5 
 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

units (OUs)—OU1 consists of the on-site contamination and OU2 is the neighborhood of 

Lincoln Park (i.e., the off-site impacted area) [CDPHE 2008; EPA 2007]. Together, the Lincoln 

Park/Cotter Mill Superfund Site encompasses about 7.8 square miles (5,000 acres) [EPA 2004]. 

In 1988, the Cotter Corporation and CDPHE signed a Consent Decree and Remedial Action Plan 

(RAP) [Galant et al. 2007]. The purpose of the court-ordered action was to assess and mitigate 

human and environmental impacts from the Cotter Mill. As part of the settlement, Cotter agreed 

to clean up the site at the corporation’s expense [EPA 2008]. The cleanup was estimated to take 

16 years and cost $11 million [Galant et al. 2007]. EPA and the US Department of Energy have 

also contributed to cleanup costs [DOE 2003]. Remedial activities have focused on eliminating 

the sources of contamination at the Cotter Mill and eliminating exposures to Lincoln Park 

residents [CDPHE 2008]. Many of the activities outlined in the 1988 RAP have been completed, 

including the following: 

	 Connecting Lincoln Park residents to city water; 

	 Constructing a groundwater barrier at the Soil Conservation Service (SCS) Flood Control 

Dam to minimize migration of contaminated groundwater into Lincoln Park; 

	 Moving tailings and contaminated soils into a lined impoundment to eliminate them as a 

source of contamination; and 

	 Excavating contaminated stream sediments in Sand Creek. 

The old ponds area was undergoing reclamation in late 2008 [Pat Smith, EPA Region 8, personal 

communication, August 2008]. Remaining activities include groundwater remediation and final 

site cleanup [CDPHE 2008; Galant et al. 2007]. Groundwater remediation activities have shown 

some positive results. However, the balance of the remedial activities listed in the Consent 

Decree have not been successful enough in mitigating the plume, and most have been 

discontinued (e.g., barrier wall, dam to ditch flushing, calcium-polysulfide fix/flush, and 

permeable reactive treatment wall). Table 1 below lists a timeline of process events, remedial 

activities, and government actions for the Lincoln Park/Cotter Mill Superfund Site. 

6 
 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 1. Lincoln Park/Cotter Mill Superfund Site Activity Timeline 

Date Type of 

Event1 Event2 

July 1958 Process Cotter Corporation began alkali leach process operations (licensing by the Atomic 

Energy Commission) 

June 1965 Event Flood that caused the unlined tailings ponds at the Cotter Mill to overflow into 

Lincoln Park 

1971 Remediation SCS Dam completed; dam pumps impounded surface water back to the main 

impoundment (groundwater barrier completed at a later date after 1988 RAP) 

July 1972 Remediation Pond 2 lined 

June 1976 Remediation Pond 10 lined 

1978–1979 Remediation A new lined impoundment consisting of two cells (primary and secondary) 

constructed adjacent to the old ponds area for management of wastes from the 

new mill (alkali process) 

1979 Remediation The old mill was demolished and new mill construction began 

1979– 

present 

Remediation Impounded water at the SCS Dam pumped back to the main impoundment 

1979–1998 Process Operations switched from an alkali leach process to an acid leach mill; continuing 

operations intermittently 

1980 Remediation Old upstream method tailings ponds replaced by a full-height compacted earth 

embankment 

1980 Remediation Construction of Well 333 just north of Cotter; well removes contaminated water 

flowing from the old ponds area 

June 1981 Remediation Pond 3 lined 

1981–1983 Remediation Tailings from the unlined old ponds area (~2.5 million cubic yards) removed and 

placed in the new impoundment 

December 

9, 1983 

Government 

Action 

State of Colorado files a complaint against Cotter under the Comprehensive 

Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) 

September 

21, 1984 

Government 

Action 

Cotter (OU1) and Lincoln Park (OU2) added to the NPL 

1985–1986 Investigation Remedial Investigation and Feasibility Study (GeoTrans 1986) 

April 1986 Government 

Action 

Memorandum of Agreement between EPA and the state of Colorado 

April 8, 1988 Government 

Action 

Consent decree signed, including a RAP that required cleanup activities 

1988 Remediation An additional 2 feet of soil was removed from the old ponds area and placed in the 

lined primary impoundment 

1988 Remediation Lined water distribution/surge pond constructed over Pond 7 

1988 Remediation Installation of a hydrologic clay barrier upgradient from the SCS Dam 

1989 Remediation The secondary impoundment cell was covered with liquid for dust control and to 

create evaporative capacity; additional contaminated soils were removed from the 

old ponds area and placed in the primary impoundment cell 

7 
 

 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Date Type of 

Event1 Event2 

1989–2000 Remediation Installation of two hydraulic barriers (injection/withdrawal systems) to control 

groundwater flow from the old ponds area; discontinued in 2000 because the 

system was unproductive 

1990–1996 Remediation SCS Dam to DeWeese ditch flushing project 

1990–1998 Remediation Four pilot tests to evaluate the effectiveness of active flushing of vadose zone and 

aquifer for contaminant removal in OU1 

October 29, 

1991 

Report Health Risk Assessment of the Cotter Uranium Mill Site: Phase I (HRAP 1991) 

January 7, 

1993 

Report RAP final report, Willow Lakes (Cotter) 

1993–1999 Remediation Sand Creek Soil Cleanup Action identified and removed approximately 9,000 cubic 

yards of tailings, soil, and sediment from Sand Creek (Cotter 2000) 

1995 Licensing Cotter filed a license amendment with the state for alkaline leach processing of 

uranium ore (approved 2/97) 

November 

19, 1996 

Report Supplemental Human Health Risk Assessment: Phase II Final Report (Weston 

1996) 

1996–1998 Remediation Flush/fixation process using Calcium Polysulfide in surface infiltration cells 

February 

1997 

Government 

Action 

Radioactive materials license amendment became effective 

1998 Process Mill reconverted to an alkaline leach process 

September 

29, 1998 

Report Ecological Risk Assessment, Lincoln Park Superfund Site (Stoller Corporation and 

Schafer & Associates) 

1998 Report Supplemental Human Health Risk Assessment, Phase III Final Report (Weston 

1998) 

1999 Remediation Old ponds area surface soils (~100,000 cubic yards) were removed and placed in 

the lined primary impoundment 

May 1999 Process Cotter resumed operations (which had been intermittent since 1979) with modified 

alkaline-leaching capability 

September 

30, 1999 

Investigation Final Focused Feasibility Study, Lincoln Park 

June 2000 Remediation Installation of a permeable reactive treatment wall across Sand Creek channel, 

north of SCS Dam in DeWeese Dye Ditch flush (to fulfill EPA requirement to 

address contaminated groundwater that was bypassing the SCS Dam barrier) 

2000–2005 Process Cotter proposes modifications to the circuit to process zircon ore. Process was not 

successful and discontinued by 2005. 

January 

2002 

Government 

Action 

EPA issued a Record of Decision for Lincoln Park requiring “No Further Action” for 

surface soils within Lincoln Park (EPA 2002) 

April 2002 Government 

Action 

The governor of Colorado passed an emergency bill requiring an Environmental 

Assessment be conducted before shipping out-of-state radioactive waste to Cotter 

July 9, 2002 Government 

Action 

CDPHE denied Cotter’s license amendment request, preventing receipt of 

shipments for direct disposal 

8 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Date Type of 

Event1 Event2 

September 

13, 2002 

Government 

Action 

State of Colorado allowed Cotter to receive limited amounts of waste material as a 

test of its handling/storage capability 

2002/2003 Investigation Sampling for plutonium, uranium, lead and molybdenum in the Canon City vicinity 

(CDPHE 2003) 

January 3, 

2003 

Government 

Action 

EPA issued a notice of unacceptability under the Off-Site Rule regarding the five 

Proposed Units and impoundments previously found acceptable 

2003 Remediation Permeable reactive treatment wall not functioning as designed 

September 

9, 2004 

Investigation Cotter submits Feasibility Study for Old Ponds Area with six alternatives 

December 

15, 2004 

Government 

Action 

State health officials approved a 5-year extension of Cotter’s uranium-processing 

license but denied requests to become a disposal facility for off-site radioactive 

materials 

February 1, 

2005 

Government 

Action 

Cotter filed a request for a hearing regarding the conditions of the license renewal 

October 

2005 

Investigation Survey of lead in indoor dust, soils, and blood in Lincoln Park to investigate 

potential impacts of historic smelters (ATSDR 2006a, 2006b, 2006c, 2006d) 

April 2006 Government 

Action 

A judge recommended in CDPHE’s favor and Cotter filed an exception on the direct 

disposal issue only 

2006 Remediation To replace the permeable reactive treatment wall, water building up behind barrier 

is pumped back to the impoundments 

January 

2007 

Government 

Action 

CDPHE signed a Final Agency Decision, affirming the judge’s Decision on the 

license. Cotter filed an appeal to be able to dispose of out-of-state soils in its 

primary impoundment. 

2008 Process Cotter decides not to take the case to the Court of Appeals, effectively ending the 

licensing issues from the 2004 renewal. 1

 Describes the general nature of events/actions relating to the Lincoln Park/Cotter Mill Superfund Site. 2

 Includes events/actions most pertinent to ATSDR’s evaluation of exposures and potential health effects. Not all 

site-related events and reports are included. 

9 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

C. Demographics 

ATSDR examines demographic data to identify sensitive populations, such as young children, 

the elderly, and women of childbearing age, and to determine whether these sensitive 

populations are exposed to any potential health risks. Demographics also provide details on 

population mobility and residential history in a particular area. This information helps ATSDR 

evaluate how long residents might have been exposed to contaminants. According to the 2000 

census, 1,170 people live within one mile of the Cotter Mill property—90 of whom are age 6 or 

younger, 190 are women of childbearing age (15–44 years), and 243 are age 65 or older. Figure 2 

in Appendix B shows the demographics within one mile of the mill. 

Cañon City is the largest population center in Fremont County with 15,760 residents (see Table 2 

below). The Cañon City Metro area includes Cañon City, North Cañon, Lincoln Park, Brookside, 

Prospect Heights, Four Mile Ranch, Shadow Hills, Dawson Ranch, and the Colorado State 

Correctional Facilities. Florence is the second largest community in the area with a population of 

3,816. The unincorporated portions of Fremont County represent 55% of the population and 

include Lincoln Park, Prospect Heights, and Shadow Hills [Cotter 2007]. 

Table 2. Population of communities near the Cotter Mill 

Community 2000 Census Population 2006 Population Estimate 

Brookside 219 218 

Cañon City 15,431 15,760 

Coal Creek 303 380 

Florence 3,653 3,816 

Lincoln Park 3,904 Not available 

Rockvale 426 432 

Williamsburg 714 700 

Fremont County 46,145 47,727 

Source: Cotter 2007; Galant et al. 2007 

The unincorporated community of Lincoln Park is located in the greater Cañon City area, south 

of the Arkansas River and north of the Cotter Mill (see Figure 1). The community consists of 

single and multi-family homes, trailer parks, and rural single family homes. Many of the 

residents are retired and own their homes. The Lincoln Park area is currently experiencing 

growth [Galant et al. 2007]. 

The largest employers in Fremont County are the Colorado Department of Corrections and the 

Federal Bureau of Prisons. Tourism is the second largest employer in the Cañon City area [Cotter 

2007; Galant et al. 2007]. Additional industry and manufacturing employers in Fremont County 

include Portec, Inc.; Holcim, Inc.; Thermal Ceramics; and Cañon Industrial Ceramics [Cotter 

2007]. The health care and school systems also employ a substantial number of people in the 

county [CCAT, personal communication, August 2008]. 

10 
	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

D. Land use and natural resources 

The Cotter Mill is located within an industrial zone. All abutting lands are zoned for agricultureforestry. The semi-rural community of Lincoln Park is comprised predominantly of residential 

developments, agricultural plots and orchards, and small grazing parcels. The Shadow Hills Golf 

Course is located to the north of the Cotter Mill complex. The land to the south and east of the 

site is largely undeveloped. Recently, several high end homes have been built near the golf 

course and in the Wolf Park and Dawson Ranch areas. The distance from Cotter Mill’s restricted 

area to the nearest home is about 0.25 mile [Galant et al. 2007]. 

Fremont County contains a large amount of public land managed by the US Department of the 

Interior Bureau of Land Management and the US Department of Agriculture Forest Service. 

Some of these areas are leased for livestock grazing, aggregate mining, and firewood removal. 

Visiting the many scenic attractions in Colorado’s High Country (e.g., the Royal Gorge Bridge) 

and rafting in the Arkansas River are popular recreational activities [Cotter 2007]. 

1.	 Hydrogeology 

In the vicinity of the Cotter Mill, contaminated groundwater primarily migrates along the near 

surface alluvium and fractured, weathered bedrock immediately underlying the alluvium (<100 

feet deep) [USGS 1999a]. Groundwater migration is generally in northerly directions from the 

mill area, along the Sand Creek drainage area, through a gap in Raton Ridge, and into Lincoln 

Park. However, groundwater contamination has also been found in the vicinity of the Shadow 

Hills Golf Course, which is west of the Sand Creek drainage [EPA 2007]. The hydrogeology of 

the Lincoln Park/Cotter Mill Superfund Site can be conceptually divided into two areas: the 

upgradient area near the mill and the downgradient area to the north-northeast in Lincoln Park 

[USGS 1999a]. 

	 In the upgradient area near the mill, the rate of groundwater flow is limited by small 

hydraulic conductivities [USGS 1999a]. However, cracks in the bedrock, fractures, and 

weathering enhance water transmission and allow groundwater to travel at considerable 

rates. Monitoring wells in the upgradient area, specifically in the Poison Canyon 

Formation, yield small amounts of water. 

	 The downgradient area in Lincoln Park is characterized by an “alluvial aquifer” 

comprised of alluvium and terrace alluvium, to a depth of 0–60 feet, and the underlying 

weathered and/or fractured bedrock below the alluvium. In this area, groundwater can be 

transmitted at substantial rates. The mix of gravel, sand, silt, and clay in this aquifer 

yields 10 to 400 gallons per minute to wells in Lincoln Park. The aquifer discharges to 

Sand Creek, as well as to multiple springs and seeps as far downgradient as the Arkansas 

River, approximately 2.5 miles downgradient from the Cotter site. 

2.	 Geology 

The Cotter Mill is located in a topographic depression resulting from an underlying structure 

called the Chandler syncline. The core of the syncline is the Poison Canyon formation, which is 

the uppermost bedrock unit beneath the site. Soils near the mill are shallow and well drained. 

11 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The top layer consists of brown loam. The subsoil is a pale brown loam, grading into a yellowish 

brown sandy loam. Areas north of the mill are covered with Quaternary alluvium consisting of 

gravel, cobble, boulders, and sand [EPA 2002]. 

3. Hydrology 

The Cotter Mill lies within the Sand Creek watershed [HRAP 1991]. The main hydrologic 

feature of the Lincoln Park/Cotter Mill Superfund 

Site is Sand Creek, a primarily ephemeral creek [EPA 

2007]. The creek originates at Dawson Mountain 

An ephemeral creek has flowing water 

only during, and for a short duration 

after, precipitation. A perennial creek 

(south of the Cotter Mill), travels north through the has flowing water year-round. 

Cotter Mill, intersects the DeWeese Dye Ditch, and 

runs north-northeast through Lincoln Park. It becomes perennial for the last 0.25–0.5 mile before 

its confluence with the Arkansas River. The DeWeese Dye Ditch is one irrigation ditch that 

flows between the Cotter Mill and Lincoln Park. 

Alluvial material (sediment deposited by flowing water) associated with Sand Creek is the 

predominant migration pathway for mill-derived contaminants in groundwater. Sand Creek 

carved a channel into the Vermejo formation at the Raton outcrop in the vicinity of the SCS 

Dam, which filled with permeable sediments, creating a preferential pathway for alluvial 

groundwater into Lincoln Park. The alluvial aquifer in Lincoln Park receives recharge from the 

DeWeese Dye Ditch, Crooked Ditch, Pump Ditch, ditch laterals, and ponds filled by the 

DeWeese Dye Ditch [EPA 2007]. 

4. Prevailing Wind Patterns 

Cotter’s monitoring network includes an on-site meteorological station that continuously 

measures a standard set of meteorological parameters (e.g., wind speed, wind direction, 

temperature, and relative humidity). The wind rose in Figure 3 in Appendix B depicts the 

statistical distribution of measured wind speeds and wind directions. During 2008, wind patterns 

at the station were principally westerly (i.e., winds out of the southwest to northwest) and 

accounted for 55% of the total winds [Cotter 2008b]. Easterly winds (i.e., winds out of the 

southeast to northeast) accounted for a smaller, but still significant, portion (26%) of the 

observed wind directions. Southerly and northerly winds were much less common. A nearly 

identical profile was observed in 2007. Other average parameters measured in 2008 follow: air 

temperature of 53.4 °F; relative humidity of 41%; and rainfall of 5.18 inches. 

The prevailing westerly and easterly wind patterns are reasonably consistent with trends in the 

observed concentrations. Ambient air concentrations of selected site-related pollutants were 

highest at the perimeter monitoring stations directly east and west of the primary operations. 

There is a hilly ridge that straddles the western border of the site, blocking much east/west wind 

flow. However, it should be noted that prevailing wind patterns measured at Cotter Mill may not 

be representative of surface winds throughout the area, especially considering the proximity of 

nearby terrain features. 

12 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

E. Past ATSDR involvement 

ATSDR has been involved with the Lincoln Park site in the past. In October 1983, ATSDR 

completed a Public Health Assessment for the site. After reviewing available groundwater data, 

ATSDR concluded that the potential long term health effects from consumption of the 

contaminated water were: 

 cancer and kidney damage, from uranium; 

 gout-like symptoms, from molybdenum; and 

 possibly a group of physiological and psychological symptoms, from selenium. 

None of the potential health effects were definitive. 

Numerous questions and concerns have been voiced by residents of Lincoln Park regarding the 

historical sites of numerous milling and smelting facilities in the Cañon City area. Among the 

various concerns were specific concerns about residual lead contamination from these milling 

and smelting operations. In response to these concerns, and after a specific request by the EPA, 

ATSDR evaluated the health risks associated with lead contamination in the area. ATSDR 

focused on two primary issues: 1) the blood lead level of children living in the area and 2) lead 

contaminated dust in homes in the Lincoln Park area. 

In September and October 2005, ATSDR conducted an Exposure Investigation (EI) to answer 

the questions presented by the community and EPA. Previously, ATSDR concluded that lead 

levels in house dust and lead exposures to children represented an indeterminate health hazard 

because of a lack of available data. ATSDR conducted the EI to gather data on blood lead levels 

in the children, and soil and indoor dust level from homes. 

The activities of the EI included: 

 Collecting 44 indoor dust samples from 21 homes in Lincoln Park 

 Collecting 80 composite soil samples from 22 properties (sampling conducted by EPA) 

 Obtaining 45 blood samples from 21 households (42 blood samples were analyzed) 

After evaluating the data obtained during the EI, ATSDR concluded that blood lead levels in 

adults and children, lead levels in dust in homes, and lead levels in soil did not represent a public 

health harard. ATSDR recommended no further actions related to lead in dust in homes, but did 

recommend routine monitoring of children’s blood lead levels in the Lincoln Park area. 

In September 2005, ATSDR conducted a blood lead testing program as a service to the 

community of Lincoln Park. A total of 115 children from a local school were tested for blood 

lead. None of the children tested had elevated blood lead levels. Therefore, ATSDR concluded 

that the children tested did not have unusual exposures to lead at the time of testing. ATSDR 

recommended that local and state agencies continue routine monitoring of lead levels in area 

children. 

13 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Full reports discussed above may be obtained by contacting any of the contacts listed at the end 

of this report, by visiting our website at www.atsdr.cdc.gov or by calling our toll-free hotline at 

800-232-4636. 

14 
	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

III. EVALUATION OF EXPOSURE PATHWAYS 

A. What is meant by exposure? 

ATSDR’s public health assessments are driven 

by exposure to, or contact with, environmental 

contaminants. Contaminants released into the 

environment have the potential to cause 

harmful health effects. Nevertheless, a release 

does not always result in exposure. People can 

only be exposed to a contaminant if they come 

in contact with that contaminant—if they 

breathe, eat, drink, or come into skin contact 

with a substance containing the contaminant. If 

no one comes in contact with a contaminant, 

then no exposure occurs, and thus no health 

effects could occur. Often the general public 

does not have access to the source area of 

An exposure pathway has five elements: (1) a 

source of contamination, (2) an environmental 

media, (3) a point of exposure, (4) a route of 

human exposure, and (5) a receptor 

population. The source is the place where the 

chemical or radioactive material was released. 

The environmental media (such as 

groundwater, soil, surface water, or air) 

transport the contaminants. The point of 

exposure is the place where people come into 

contact with the contaminated media. The 

route of exposure (for example, ingestion, 

inhalation, or dermal contact) is the way the 

contaminant enters the body. The people 

actually exposed are the receptor population. 

contamination or areas where contaminants are moving through the environment. This lack of 

access to these areas becomes important in determining whether people could come in contact 

with the contaminants. 

The route of a contaminant’s movement is the pathway. ATSDR identifies and evaluates 

exposure pathways by considering how people might come in contact with a contaminant. An 

exposure pathway could involve air, surface water, groundwater, soil, dust, or even plants and 

animals. Exposure can occur by breathing, eating, drinking, or by skin contact with a substance 

containing the chemical contaminant. ATSDR identifies an exposure pathway as completed or 

potential, or eliminates the pathway from further evaluation. 

	 Completed exposure pathways exist for a past, current, or future exposure if contaminant 

sources can be linked to a receptor population. All five elements of the exposure pathway 

must be present. In other words, people have or are likely to come in contact with siterelated contamination at a particular exposure point via an identified exposure route. As 

stated above, a release of a chemical or radioactive material into the environment does 

not always result in human exposure. For an exposure to occur, a completed exposure 

pathway must exist. 

	 Potential exposure pathways indicate that exposure to a contaminant could have occurred 

in the past, could be occurring currently, or could occur in the future. It exists when one 

or more of the elements are missing but available information indicates possible human 

exposure. A potential exposure pathway is one which ATSDR cannot rule out, even 

though not all of the five elements are identifiable. 

	 An eliminated exposure pathway exists when one or more of the elements are missing. 

Exposure pathways can be ruled out if the site characteristics make past, current, and 

future human exposures extremely unlikely. If people do not have access to contaminated 

15 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

areas, the pathway is eliminated from further evaluation. Also, an exposure pathway is 

eliminated if site monitoring reveals that media in accessible areas are not contaminated. 

Contact with contamination at the Cotter Mill is an eliminated exposure pathway. 

Because the mill site itself is fenced and access is restricted, exposure to on-site contamination by the 

public at the Cotter Mill is limited. Further, remediation efforts have removed some of the on-site soil 

contamination, including moving millions of cubic yards of tailings and contaminated soils from unlined 

ponds to lined impoundments (EPA 2002). In some areas, contaminated soil was removed down to 

bedrock. In addition, various process changes reduced the release of contaminated materials (EPA 

2002). Any potential exposure by the occasional trespasser to remaining impacted soils at the Cotter 

Mill would be too infrequent to present a health hazard. 

B. How does ATSDR determine which exposure situations to evaluate? 

ATSDR scientists evaluate site conditions to determine if people could have been, are, or could 

be exposed (i.e., exposed in a past scenario, a current scenario, or a future scenario) to siterelated contaminants. When evaluating exposure pathways, ATSDR identifies whether exposure 

to contaminated media (soil, sediment, water, air, or biota) has occurred, is occurring, or will 

occur through ingestion, dermal (skin) contact, or inhalation. 

If exposure was, is, or could be possible, ATSDR scientists consider whether contamination is 

present at levels that might affect public health. ATSDR scientists select contaminants for further 

evaluation by comparing them to health-based comparison values. These are developed by 

ATSDR from available scientific literature related to exposure and health effects. Comparison 

values are derived for each of the different media and reflect an estimated contaminant 

concentration that is not likely to cause adverse health effects for a given chemical, assuming a 

standard daily contact rate (e.g., an amount of water or soil consumed or an amount of air 

breathed) and body weight. 

Comparison values are not thresholds for adverse health effects. ATSDR comparison values 

establish contaminant concentrations many times lower than levels at which no effects were 

observed in experimental animals or human epidemiologic studies. If contaminant concentrations 

are above comparison values, ATSDR further analyzes exposure variables (for example, duration 

and frequency of exposure), the toxicology of the contaminant, other epidemiology studies, and 

the weight of evidence for health effects. 

Some of the comparison values used by ATSDR scientists include ATSDR’s environmental 

media evaluation guides (EMEGs), reference dose media evaluation guides (RMEGs), and 

cancer risk evaluation guides (CREGs) and EPA’s maximum contaminant levels (MCLs). 

EMEGs, RMEGs, and CREGs are non-enforceable, health-based comparison values developed 

by ATSDR for screening environmental contamination for further evaluation. MCLs are 

enforceable drinking water regulations developed to protect public health. Effective May 2008, 

Colorado established state groundwater standards for uranium and molybdenum. 

You can find out more about the ATSDR evaluation process by calling ATSDR’s toll-free 

telephone number, 1-800-CDC-INFO (1-800-232-4636) or reading ATSDR’s Public Health 

Assessment Guidance Manual at http://www.atsdr.cdc.gov/HAC/PHAManual/. 

16 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

C. If someone is exposed, will they get sick? 

Exposure does not always result in harmful health effects. The type and severity of health effects 

a person can experience because of contact with a contaminant depend on the exposure 

concentration (how much), the frequency (how often) and/or duration of exposure (how long), 

the route or pathway of exposure (breathing, eating, drinking, or skin contact), and the 

multiplicity of exposure (combination of contaminants). Once exposure occurs, characteristics 

such as age, sex, nutritional status, genetics, lifestyle, and health status of the exposed individual 

influence how the individual absorbs, distributes, metabolizes, and excretes the contaminant. 

Together, these factors and characteristics determine the health effects that may occur. 

In almost any situation, there is considerable uncertainty about the true level of exposure to 

environmental contamination. To account for this uncertainty and to be protective of public 

health, ATSDR scientists typically use worst-case exposure level estimates as the basis for 

determining whether adverse health effects are possible. These estimated exposure levels usually 

are much higher than the levels that people are really exposed to. If the exposure levels indicate 

that adverse health effects are possible, ATSDR performs more detailed reviews of exposure and 

consults the toxicologic and epidemiologic literature for scientific information about the health 

effects from exposure to hazardous substances. 

D. What exposure situations were evaluated for residents living near the Cotter 

Mill? 

ATSDR obtained information to support the exposure pathway analysis for the Lincoln 

Park/Cotter Mill Superfund Site from multiple site investigation reports; state, local, and facility 

documentation; and communication with local and state officials. The analysis also draws from 

available environmental and exposure data for groundwater, soil, surface water and sediment, 

and biota. Throughout this process, ATSDR examined concerns expressed by the community to 

ensure exposures of special concern are adequately addressed. ATSDR identified the following 

exposure pathways for further evaluation: 

1. Exposure to site-related contaminants in groundwater in Lincoln Park. 

2. Contact with site-related contaminants in soil adjacent to the Cotter Mill and in Lincoln Park. 

3. Contact with site-related contaminants in surface water downstream from the Cotter Mill. 

4. Exposure from eating produce locally grown in Lincoln Park. 

5. Exposure from site-related soil contaminants in windborne dust. 

6. Exposure from air emission sources (stacks and uncontrolled fugitive dust) 

This exposure pathway analysis focuses on past, current, and future exposures for residents 

living near the Cotter Mill, with a focus on the community of Lincoln Park. Some attention is 

also paid to exposures at the Shadow Hills Golf Course and along the county road. Table 3 below 

provides a summary of exposure pathways evaluated in this public health assessment. 

17 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

1. Exposure to groundwater in Lincoln Park 

In the past, a number of residences used wells1 on their property (GeoTrans 1986; IMS 1989). 

Based on a 1989 water use survey in Lincoln Park, 60 out of 104 wells, springs, and cisterns 

were used to obtain water for domestic purposes, including consumption and irrigation (IMS 

1989). See Table 14 in Appendix A for the reported groundwater uses in the Lincoln Park area. 

Seven survey respondents indicated that they used groundwater for domestic consumption, 

accounting for 5 to 100% of their total water consumption. Based on the survey, five residents 

had private wells that were affected by contaminated groundwater; these residents were 

connected to the municipal water supply between 1989 and 1993 [EPA 2002]. The 1988 RAP 

requires Cotter to connect eligible affected users with legal water rights for a well to the town 

water supply [CDPHE 2005]. Cotter checks the State of Colorado’s Engineer’s Office database 

for new water permits and reports their findings in their annual ALARA reports [Pat Smith, EPA 

Region 8, personal communication, August 2008]. 

While the majority of town residents are now 

connected to the public water supply [Galant et al. The use of private groundwater wells in 

2007], several residences also have operational 

private wells. A 2005 summary of the RAP status 

reports that some residents have refused public water 

the past was a completed exposure 

pathway. Most residences are now 

connected to the public water supply. 

The current and future use of these 

supply connections [CDPHE 2005]. Additionally, no wells is a potential exposure pathway 

formal institutional controls exist to control because the extent to which these wells 

groundwater use in Lincoln Park [EPA 2007]. The are used is not well documented. 

United States Geological Survey (USGS) reports that 

existing private wells are used primarily for stock watering and irrigation [USGS 1999a]. 

However, a newspaper article reports that at least one residence, located on Grand Avenue in 

Lincoln Park, used private well water for consumption as recently as 2002 [Plasket 2002]. Based 

on a 2007 review of Colorado State well permits for residences in the plume configuration, at 

least one well is permitted for irrigation and domestic use, but no details of actual use are 

documented [EA 2007]. On properties that continue to use private wells, new purchasers are 

offered connection to the town’s municipal water system [Galant et al. 2007]. In late 2008, EPA 

conducted another water use survey to verify whether groundwater is being utilized by 

residences in Lincoln Park. Well water samples were also collected and analyzed. Once 

available, ATSDR will review the information and will revise the public health assessment, if 

needed. 

2. Contact with soil adjacent to the Cotter Mill and in Lincoln Park 

People (especially children) might accidentally ingest soil or exposed sediment, and dust 

generated from these materials, during normal activities. Everyone ingests some soil or dust 

every day. Small children (especially those of preschool age) tend to swallow more soil or dust 

than any other age group because children of this age tend to have more contact with soil through 

play activities and have a tendency for more hand-to-mouth activity. Children in elementary 

school, teenagers, and adults swallow much smaller amounts of soil or dust. The amount of grass 

1

 The term “well” is used to represent all groundwater sources, and includes both wells and springs. 

18 
	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

cover in an area, the amount of time spent outdoors, and weather conditions also influence how 

much contact people have with soil. 

a) Contact with soil near the Cotter Mill 

Soils adjacent to the Cotter Mill have been contaminated by wind-blown particulates [CDPHE 

2005]. Elevated levels are primarily detected in soils directly east and west of the facility 

[Weston 1998]. This distribution of contaminated soils 

is consistent with wind patterns in the area, which blow 

mainly from west to east with occasional flows from 

east to west. The primarily vacant areas directly east 

and west of the facility are referred to as a “buffer 

zone” between the Cotter Mill and residential 

developments [EPA 2002]. Therefore, limited opportunities for exposure to impacted siteadjacent soils exist—people are not expected to be in this area on a daily basis and for an 

extended period of time. One exception may be at the Shadow Hills Golf Course, located 

immediately north of the Cotter mill complex. Exposure to potentially impacted soil at this 

public golf course is unlikely due to grass cover. 

Contact with contaminated soil near 

the Cotter Mill (i.e., in the buffer zone) 

is a past, current, and future potential 

exposure pathway. 

For nearly 50 years, Cotter has intermittently hauled materials by truck, possibly losing some 

materials along the county road leading to the facility and along the access road entering the mill 

site [MFG 2005]. The public could be exposed to potentially impacted soils along the county 

road. However, there is limited potential for exposure to contaminants along the access road, 

since access to the Cotter Mill is restricted and Cotter remediated soil adjacent to the access road 

in 2007 and 2008. 

b) Contact with soil and sediment in the community of Lincoln Park 

The community of Lincoln Park is located approximately 1.5 miles north-northeast of the 

restricted area of the Cotter Mill. Contaminated materials from the Cotter Mill may have 

contributed to soil contamination in Lincoln Park in two ways: 

1.	 Dust from soil or tailings associated with site operations could be transported by wind to 

Lincoln Park. However, wind patterns in the area suggest that wind-blown contamination 

is not likely a considerable source of soil contamination in Lincoln Park (Weston 1998). 

Additionally, on-site remediation at the Cotter Mill substantially reduced the sources of 

soil contamination. 

2.	 Potentially impacted groundwater used for irrigation could lead to the accumulation of 

chemicals in town soils [Weston 1998]. 

Further, in the past, contaminated surface water runoff Contact with contaminated 

sediment in Sand Creek was a past from the Cotter Mill entered Sand Creek, where it was 

potential exposure pathway. Due to transported downstream toward Lincoln Park [EPA the remediation of Sand Creek, 2002]. However, Sand Creek is not believed to be used current and future contact is an 

for recreational activities—the creek is ephemeral and on eliminated exposure pathway. 

private land until it goes under the river walk and enters 

the Arkansas River [Phil Stoffey, CDPHE, personal communication, June 2007]. 

19 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Contact with contaminated soil in Lincoln Park was a past completed exposure pathway. Cotter has 

performed all required off-site soil cleanup activities, as outlined in the RAP [EPA 2002]. CDPHE 

reports that the Cotter Mill poses no risk to the residents of Lincoln Park by exposure to soil [Weston 

1998], and EPA and CDPHE have advised “No Further Action” in regards to Lincoln Park soils [EPA 

2002]. EPA’s Record of Decision states that surface-soil cleanup activities have eliminated or reduced 

risks to “acceptable” levels [EPA 2002, 2007]. Therefore, current and future contact with soil and 

sediment is an eliminated exposure pathway. 

3. Contact with surface water downstream from the Cotter Mill 

In the past, people could have come in contact with contamination in surface water during 

recreational activities. The Arkansas River is used primarily for fishing and boating or rafting, as 

well as some swimming [Phil Stoffey, CDPHE, 

personal communication, June 2007]. Sand Creek is on Contact with contaminated surface 

private land until it goes under th water near the Cotter Mill was a past e river walk and enters 

potential exposure pathway. Due to the Arkansas River, and is generally not used for the construction of the SCS Dam and recreational activities [Phil Stoffey, CDPHE, personal the remediation of Sand Creek, communication, June 2007]. Many Lincoln Park current and future contact is an 

residents use water from the DeWeese Dye Ditch to eliminated exposure pathway. 

irrigate their orchards and gardens [Galant et al. 2007]. 

4. Exposure from eating locally grown produce 

Many Lincoln Park residents have orchards and gardens. Water from the DeWeese Dye Ditch is 

primarily used to irrigate the orchards and gardens, however, some residents use water from their 

groundwater wells [Galant 2007; IMS 1989]. If fruits and vegetables are grown in contaminated 

soil and/or irrigated with contaminated water, the people who eat this produce could be exposed 

to contamination. 

5. Exposure from breathing windborne dust 

Many Lincoln Park residents are concerned about the arid environment and the risks of breathing 

in contaminated dust from the site. The profile of air emission sources at Cotter Mill has changed 

considerably over the years. These sources include both releases through stacks and uncontrolled 

(or fugitive) dust emissions. Stack emissions occurred during times of active processing at Cotter 

Mill; however, the magnitude of these stack emissions has varied, depending on production rates 

and effectiveness of air pollution controls. The sources of fugitive dust emissions have also 

changed. In the past, the site had many uncontrolled sources of wind-blown dust, which would 

cause particulate matter (along with any chemical and radiological constituents) to be emitted 

into the air. Examples of these sources include ore handling operations, stockpiles, and the 

previous unlined holding ponds. Many of these sources of wind-blown dust have since been 

controlled or eliminated, causing facility-wide fugitive dust emissions to decrease considerably 

over the years, though some fugitive dust emissions (e.g., from unpaved roads) continue to 

occur. 

20 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 3. Exposure pathways for residents living near the Cotter Mill 

Exposure 

Pathway 

Exposure Pathway Elements Time 

Frame Sources of 

Contamination 

Fate and 

Transport 

Point of 

Exposure Exposed Population Route of Exposure 

Groundwater 

Completed Exposure Pathway Private Tailings and other Migration of Residential tap Residents, including Ingestion, Past Past 

groundwater wastes from the groundwater water drawn children, who are not Dermal privawells Cotter Mill (heavy 

metals and radionuclides) 

into the Lincoln Park area 

from private wells 

connected to the public water supply and rely on private wells 

contact and w

expo

Potential Exposure Pathway Private Tailings and other Migration of Residential tap Residents, including Ingestion, Current The groundwater wastes from the groundwater water drawn children, who are not Dermal Future currewells Cotter Mill (heavy 

metals and radionuclides) 

into the Lincoln Park area 

from private wells 

connected to the public water supply and rely on private wells 

contact unce

suppindicdrinkas 20wells purpwateirrigapurpfuturis a p

21 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Exposure 

Pathway 

Exposure Pathway Elements Time 

Frame Sources of 

Contamination 

Fate and 

Transport 

Point of 

Exposure Exposed Population Route of Exposure 

Soil and Sediment Completed Exposure Pathway Surface soil and Tailings, dusts, and Windblown Residences and Residents, including Dermal Past Prior 

dust in Lincoln other wastes from dust; soil public areas children contact, were Park the Cotter Mill irrigated by 

contaminated groundwater 

Incidental ingestion, Inhalation 

lawnwith was pathw

Potential Exposure Pathways Surface soil near Tailings, dusts, and Windblown The Shadow Golfers at the public golf Dermal Past Soils 

the Cotter Mill other wastes from 

the Cotter Mill 

dust Hills Golf 

Course west of the Cotter Mill; along the county road leading to the Cotter Mill 

course; people on the county road 

contact, Incidental ingestion, Inhalation 

Current Future 

been partisoil nthe pcounfutur

Sediment in Tailings, dusts, and Tailings carried Along Sand Recreational users; Dermal Past Ther

Sand Creek other wastes from 

the Cotter Mill 

in surface water runoff 

Creek children playing along 

Sand Creek 

contact, Incidental ingestion 

expoused Therto thwas pathw

Eliminated Exposure Pathways Surface soil at Tailings, dusts, and Windblown Unauthorized None None Past Becathe Cotter Mill other wastes from 

the Cotter Mill 

dust; surface water runoff 

access is not allowed 

Current Future 

and on-sexporemesome 

22 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Exposure 

Pathway 

Exposure Pathway Elements Time 

Frame Sources of 

Contamination 

Fate and 

Transport 

Point of 

Exposure Exposed Population Route of Exposure 

Surface soil and Tailings, dusts, and Windblown Cleanup None None Current Due 

dust in Lincoln other wastes from dust; soil activities Future in Lin

Park the Cotter Mill irrigated with 

contaminated groundwater 

have eliminated or reduced risks to acceptable levels 

contaelimi

Sediment in Sand Creek 

Tailings, dusts, and other wastes from the Cotter Mill 

Tailings carried in surface water runoff 

Contaminated sediment was removed from Sand Creek 

None None Current 

Future 

Sedi

hazaSand Therwith elimi

Surface Water Potential Exposure Pathway Surface water 

near the Cotter 

Mill 

Tailings and other 

waste from the Cotter Mill 

Surface water 

runoff; transport from Sand Creek to the Arkansas River 

Along Sand 

Creek between the Cotter Mill and the Arkansas River; the DeWeese Dye Ditch; the Arkansas River 

Recreational users 

(mostly in the Arkansas River, limited recreational use in Sand Creek); people irrigating with water from the DeWeese Dye Ditch 

Incidental 

ingestion, Dermal contact 

Past In th

CreelevelThercontaCottepathw

Eliminated Exposure Pathway Surface water near the Cotter 

Mill 

Tailings and other waste from the 

Cotter Mill 

Surface-water runoff; 

transport from Sand Creek to the Arkansas River 

Contamination was removed 

from Sand Creek 

None None Current 

Future 

Due 

Dam Creecontaelimi

23 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Exposure 

Pathway 

Exposure Pathway Elements Time 

Frame Sources of 

Contamination 

Fate and 

Transport 

Point of 

Exposure Exposed Population Route of Exposure 

Locally Grown Produce 

Potential Exposure Pathway Produce grown Tailings, dusts, and Produce grown Orchards and People who eat locally Ingestion Past Beca

in Lincoln Park other wastes from 

the Cotter Mill 

in contaminated soil or irrigated with contaminated water 

gardens in Lincoln Park 

grown produce Current 

Future 

have localcurrepathw

Air Emissions Completed Exposure Pathway Ambient air near Ground-level Windblown Off-site or down- People who live in the Inhalation Past Cotte

the Cotter Mill fugitive emissions dust; stack wind locations vicinity of Cotter Mill or Future monfacility (e.g., wind-blown 

dust) and elevated point sources (e.g., stacks) 

emissions into the air and transport to offsite locations 

downwind of the stacks Present locat

“stanare nqualcharstatio

24 
	 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

IV. EVALUATION OF ENVIRONMENTAL CONTAMINATION 

A. Groundwater 

Prior to 1980, Cotter disposed of waste in unlined ponds, which allowed contaminated liquids to 

leach into the groundwater [EPA 2002]. Groundwater was shown to be contaminated as far away 

as the Arkansas River, which is approximately 2.5 miles downgradient from the mill [EPA 

2002]. Results from the 1984–1985 Remedial Investigation found that despite attempts at 

remediation, the new, lined impoundments were leaking and the old ponds area was a continuing 

source of groundwater contamination [GeoTrans 1986]. This study also found that a gap in the 

ridge at the SCS Dam, built in 1971 across Sand Creek on the Cotter property, was allowing 

shallow groundwater to move downgradient towards Lincoln Park, resulting in concentrations of 

molybdenum and uranium that were 2,000 times above background levels at that time. 

Groundwater concentrations of molybdenum and uranium have decreased in recent years, but 

concentrations have not yet returned to background levels in some wells [Weston 1998]. Figures 

4 and 5 show the extent of the molybdenum and uranium concentrations, respectively, above 

water quality standards (0.035 milligrams per liter [mg/L] for molybdenum and 0.03 mg/L for 

uranium). The highest levels in Lincoln Park were detected nearest to the Cotter property in the 

vicinity of the DeWeese Dye Ditch [Weston 1998]. Additionally, despite remediation efforts, the 

physical and chemical groundwater data suggest minor leakage from the primary impoundment 

at the Cotter site [CDPHE 2007a; EPA 2002; USGS 1999b]. 

1. Remedial actions for controlling groundwater contamination 

Since the early- to mid-1980s, remedial actions aimed at controlling groundwater contamination 

and the spread of the resulting plume have taken place. Remediation has targeted the area along 

the primary surface groundwater migration pathway, which runs parallel to Sand Creek [USGS 

1999a]. Remediation has included the following: 

	 In the early 1980s, contaminated materials were moved into lined impoundments [EPA 

2002]. 

	 In 1988, a hydrologic clay barrier was installed on the Cotter property to help contain the 

contaminated groundwater plume associated with the Cotter Mill. 

	 In 1989, a network of injection and withdrawal wells were constructed downgradient of 

the lined impoundment to reverse the hydraulic gradient and prevent the northward 

migration of contaminated groundwater. This system was discontinued in 2000, because 

the system had little or no discernable effect on groundwater conditions [CDPHE 2005]. 

	 Dam to ditch flushing began in 1990. However, this effort was discontinued in 1996 due 

to citizens’ concerns about contaminant concentrations rising in groundwater wells as the 

plume was being flushed [CDPHE 2005]. 

	 In 2000, a permeable reactive treatment wall was constructed across Sand Creek channel 

in the DeWeese Dye Ditch flush, downstream of the SCS Dam [EPA 2002]. Although the 

25 
 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

permeable reactive treatment wall has not performed as anticipated, it is acting as a 

barrier to additional groundwater flowing into Lincoln Park [Phil Egidi, CDPHE, 

personal communication, July 2008]. 

These efforts have reduced groundwater contamination downgradient of the Cotter Mill [CDPHE 

2008; EPA 2002; USGS 1999a], although the rate at which groundwater quality is being restored 

is slower than anticipated [EPA 2007]. Cotter and CDPHE continue to explore options for 

cleaning the groundwater. Until a solution is reached, contaminated groundwater is captured at 

the SCS Dam and pumped back to the on-site lined impoundments [CDPHE 2008]. 

2. Nature and extent of groundwater contamination in Lincoln Park 

CDPHE maintains a database containing environmental sampling data from various sources 

dating back to 1961. The most recent data entered into the database are from September 2007. To 

evaluate exposures to residents of Lincoln Park, ATSDR identified data within the CDPHE 

database for the wells reported to be in use during the 1989 water use survey (see Table 14 in 

Appendix A). After discussions with a CDPHE representative, the following assumptions were 

made while summarizing the data within the database. 

	 For chemicals, samples that were designated “Y” in the detect flag column and contained 

a zero in the result value column, but no value in the reporting detection limit column 

were excluded from the summary statistics. For radionuclides, however, these samples 

were included in the summary statistics since zero is considered a valid result. 

	 Samples that were designated “N” in the detect flag column and had the same value in the 

result value column as the reporting detection limit column were included in the 

summary statistics as 1⁄2 the reporting detection limit. 

	 Negative result values for manganese and iron were assumed to be not detected and were 

included in the summary statistics as 1⁄2 the reporting detection limit. 

	 Negative values2

 for radionuclides were included in the summary statistics. 

a) Wells used for personal consumption 

The 1989 Lincoln Park Water Use Survey identified seven When this document was written, wells used for personal consumption (IMS 1989). Data for data from EPA’s 2008 water use 

six of the wells are available in the CDPHE database (see survey were not yet available. 

Table 14). The seventh well had a broken pump at the time ATSDR will update well use 

information when the data are of the survey [IMS 1989]; no data for this well appear to be available. in the database. The data for wells reportedly used for 

personal consumption in 1989 are summarized in Table 15. 

Samples were collected intermittently from 1984 to 2007. The locations of these wells are shown 

in Figure 6. With the exception of molybdenum and uranium, the data are limited (e.g., only two 

wells were sampled for the majority of the chemicals and none were sampled for radionuclides). 

2

 Negative values for radionuclides occur when samples are not much different from background, since standard 

protocol is to subtract background radioactivity from the sample count. 

26 
 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

However, all six wells were repeatedly tested for molybdenum and uranium, which were the only 

chemicals detected above comparison values (see Table 15). Of the personal consumption wells, 

Well 189 contains the highest molybdenum and uranium concentrations. Well 189 is the only 

well with levels of uranium consistently detected above the comparison value (see Figure 6). 

It is difficult to evaluate the molybdenum and uranium data over time, because of the limited 

sampling data for these wells and the inconsistency of sampling the same wells over time. The 

molybdenum and uranium concentrations in the personal consumption wells over time are 

graphically shown in Figure 7 and Figure 8 in Appendix B, respectively. Well 168 (house well 

on Grand Avenue)3

 and Well 189 (house well on Hickory)4 were sampled the most frequently. 

No clear pattern of decreasing concentrations from 1984 to 2007 exists. 

The USGS identified Well 10 (So. 12th St.) and Well 114 (Pine) as representative of background 

for the Lincoln Park area [Weston 1998]. The data available in the CDPHE database for these 

two wells are summarized in Table 16.5

 The average concentration of molybdenum in the wells 

used for personal consumption (0.082 mg/L; see Table 15) is higher than the average 

concentration found in the background wells (0.023 mg/L; see Table 16). The average uranium 

concentration in the wells used for personal consumption (0.028 mg/L; see Table 15) is only 

slightly higher than the average concentration in the background wells (0.021 mg/L; see Table 

16). 

(1) Grand Avenue Well 

In a 2002 newspaper article, a resident on Grand Avenue reported drinking water from their well 

[Plasket 2002]. Limited data (1 to 20 samples) are available in the CDPHE database for this 

location (see Figure 6). Samples were collected and analyzed for most chemicals in 1984, and 

then from either 2004 or 2005 to 2007. Samples from this well were also tested for molybdenum 

and uranium from 1988 to1991. The water from this well was tested for several chemicals, but 

not for radionuclides. None of the samples detected chemicals above comparison values (see 

Table 17). 

b) Wells used to irrigate fruit and vegetable gardens 

The 1989 Lincoln Park Water Use Survey identified 22 When this document was written, 

wells used to irrigate fruit and 21 wells used to irrigate data from EPA’s 2008 water use 

vegetable gardens [IMS 1989].6

 Data for 28 of these wells survey were not yet available. 

ATSDR will update well use are available in the CDPHE database (see Table 14). information when the data are Samples were sporadically collected from these wells and available. 

analyzed for various chemicals between 1962 and 2007. 

Samples were collected and analyzed for radionuclides from 

3

 There are five non-detected molybdenum values for Well 168. Four of them are most likely due to the detection 

limit being too high for the level of molybdenum in that well. The detection limits were 0.01 mg/L for three of the 

samples and 0.05 mg/L for one of the samples. The concentrations in that well hover around 0.01 mg/L. 

4

 One of the non-detected molybdenum concentrations in Well 189 is unexplainable. The detection limit (0.01 mg/L) 

is low enough to have detected the level of molybdenum typically found in the well. The detection limit (0.5 mg/L) 

for the other non-detected concentration is too high for the level of molybdenum typically found in the well. 

5

 Groundwater samples from the background wells were not tested for radionuclides. 

6

 Some wells were used for both purposes. 

27 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

1995 to 2000. The data for wells reportedly used to irrigate fruit and vegetable gardens in 1989 

are summarized in Table 18 (chemicals) and Table 19 (radionuclides). The locations of these 

wells are shown in Figure 9. The data for these wells are much more robust than the data 

available for the wells used for personal consumption, in part due to the increased number of 

wells. Molybdenum and uranium were sampled in all 28 wells used for irrigation. Five wells 

were tested for radionuclides. 

The maximum concentrations in the wells used to irrigate fruit and vegetable gardens exceeded 

the comparison values for molybdenum, selenium, sulfate, total dissolved solids, and uranium. 

The average concentrations exceeded comparison values only for molybdenum, total dissolved 

solids, and uranium. Looking at data from 2000 to 2007, only the average molybdenum 

concentration (0.1 mg/L) continued to exceed the comparison value. 

The average concentration of molybdenum in the wells used to irrigate fruit and vegetable 

gardens (0.99 mg/L; see Table 18) is higher than the average concentration found in the wells 

that USGS identified as background for Lincoln Park (0.023 mg/L; see Table 16). Similarly, the 

average uranium concentration in the wells used to irrigate fruit and vegetable gardens (0.13 

mg/L; see Table 13) is higher than the average concentration in the background wells (0.021 

mg/L; see Table 16). The average concentration for total dissolved solids in the wells used to 

irrigate fruit and vegetable gardens (550 mg/L; see Table 18) is also higher than the average 

concentration found in the background wells (429 mg/L; see Table 16). 

c) Wells used to water livestock 

The 1989 Lincoln Park Water Use Survey identified 22 When this document was written, 

wells used to water livestock [IMS 1989]. Data for 19 of data from EPA’s 2008 water use 

survey were not yet available. these wells are available in the CDPHE database (see Table ATSDR will update well use 14). Samples were sporadically collected from these wells information when the data are and analyzed for various chemicals between 1962 and available 

2007. Samples were collected and analyzed for 

radionuclides from 1995 and 1996. The data for wells 

reportedly used to water livestock in 1989 are summarized in Table 20 (chemicals) and Table 21 

(radionuclides). The locations of these wells are shown in Figure 10. Only one to four wells were 

sampled for the majority of the chemicals, however, molybdenum and uranium were sampled in 

all 19 wells used to water livestock. Two wells were tested for radionuclides. 

The maximum concentrations exceeded the comparison values for molybdenum, sulfate, total 

dissolved solids, and uranium. The average concentrations only exceeded comparison values for 

molybdenum and uranium. Looking at data from 2000 to 2007, only the average molybdenum 

concentration (0.08 mg/L) continued to exceed the comparison value. 

The average concentration of molybdenum in the wells used to water livestock (0.212 mg/L; see 

Table 20) is an order of magnitude higher than the average concentration found in the wells that 

USGS identified as background for Lincoln Park (0.023 mg/L; see Table 16). The average 

uranium concentration in the wells used to water livestock (0.034 mg/L; see Table 20) is higher 

than the average concentration in the background wells (0.021 mg/L; see Table 16). 

28 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

d) Wells used to water lawns 

The 1989 Lincoln Park Water Use Survey identified 42 When this document was written, 

wells used to water lawns [IMS 1989]. Data for all 42 data from EPA’s 2008 water use 

wells are available in the CDPHE database (see Table 14). survey were not yet available.

ATSDR will update well use Samples were sporadically collected from these wells and information when the data are analyzed for various chemicals between 1962 and 2007. available. 

Samples were collected and analyzed for radionuclides 

from 1995 to 2000. The data for wells reportedly used to 

water lawns in 1989 are summarized in Table 22 (chemicals) and Table 23 (radionuclides). The 

locations of these wells are shown in Figure 11. Several wells were sampled for each chemical, 

and molybdenum and uranium were tested in all 42 wells used to water lawns. Seven wells were 

sampled for radionuclides. 

The maximum concentrations exceeded the comparison values for chloride, molybdenum, 

selenium, sulfate, total dissolved solids, and uranium. The average concentrations exceeded 

comparison values for molybdenum, sulfate, total dissolved solids, and uranium. Looking at data 

from 2000 to 2007, only the average molybdenum concentration (0.1 mg/L) continued to exceed 

the comparison value from 2000 to 2007, while the average uranium concentration (0.03 mg/L) 

was at the comparison value. 

The average concentration of molybdenum in wells used to water lawns (2.2 mg/L; see Table 22) 

is two orders of magnitude higher than the average concentration found in the wells that USGS 

identified as background for Lincoln Park (0.023 mg/L; see Table 16). The average sulfate 

concentration in wells used to water lawns (351 mg/L; see Table 22) is almost six times higher 

than the average concentration in the background wells (61 mg/L; see Table 16). The average 

concentration for total dissolved solids in wells used to water lawns (746 mg/L; see Table 22) is 

higher than the average concentration found in the background wells (429 mg/L; see Table 16). 

The average dissolved uranium concentration in wells used to water lawns (0.233 mg/L; see 

Table 22) is an order of magnitude higher than the average concentration in the background 

wells (0.021 mg/L; see Table 16). 

(1) Well 138 

Well 138 (field well on Cedar Street; see Figure 11) was identified during the 1998 Supplemental 

Human Health Risk Assessment as the maximally impacted off-site well [Weston 1998]. In 1989, 

Well 138 was used only to water the lawn [IMS 1989]. Adequate data for this well are available 

in the CDPHE database. Samples were collected from Well 138 and analyzed for various 

chemicals between 1968 and 2000. Samples were collected and analyzed for radionuclides from 

1995 to 2000. The data for Well 138 are summarized in Table 24 (chemicals) and Table 25 

(radionuclides). 

The maximum concentrations exceeded the comparison values for chloride, molybdenum, 

selenium, sulfate, total dissolved solids, and uranium. The average concentrations also exceeded 

comparison values for molybdenum, sulfate, total dissolved solids, and uranium. A clear 

29 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

decrease in concentrations occurred over time for molybdenum (see Figure 12), selenium (see 

Figure 13), and uranium (see Figure 14). 

Well 138 has higher levels of contamination than the wells that USGS identified as background 

for Lincoln Park. The average concentration of molybdenum in Well 138 (8.0 mg/L; see Table 

244) is hundreds of times higher than the average concentration found in the background wells 

(0.023 mg/L; see Table 16). The average sulfate concentration in Well 138 (1,059 mg/L; see 

Table 24) is considerably higher than the average concentration in the background wells (61 

mg/L; see Table 16). The average concentration for total dissolved solids in Well 138 (1,530 

mg/L; see Table 24) is three times higher than the average concentration found in the 

background wells (429 mg/L; see Table 16). The average dissolved uranium concentration in 

Well 138 (0.73 mg/L; see Table 24) is more than an order of magnitude higher than the average 

concentration in the background wells (0.021 mg/L; see Table 16). 

e) Groundwater trends over time 

To evaluate the levels of molybdenum, selenium, and uranium in groundwater over time, 

ATSDR combined and graphed all the groundwater data for the wells used for personal 

consumption, irrigating fruit and vegetables, watering livestock, and watering lawns (Figures 15 

through 17 in Appendix B). Figure 15 shows a pattern of decreasing concentrations of 

molybdenum in groundwater over time. The concentrations of selenium seem to hold steady, but 

do decrease slightly over time (see Figure 16). The concentrations of uranium also clearly 

decrease over time (see Figure 17). 

B. Soil and sediment 

1. Background levels 

Cotter was required by the 1988 RAP to establish background levels of certain elements in soils 

and sediments. Twenty soil samples were collected from five sub-basins considered free from 

mill-related contamination to represent natural background typical of the area near the mill 

[HRAP 1991]. Table 4 below presents the results of that study, which were further supported by 

additional sampling [CDPHE 2005]. 

Table 4. Background soil and sediment levels 

Soil Sediment 

Average 

Upper 

Confidence 

Limit 

Average 

Upper 

Confidence 

Limit 

Molybdenum 2.4 ppm 4.6 ppm 2.3 ppm 4.7 ppm 

Uranium 2.1 ppm 2.9 ppm 2.0 ppm 3.4 ppm 

Radium-226 1.3 pCi/g 1.9 pCi/g 1.1 pCi/g 1.7 pCi/g 

Thorium-230 1.8 pCi/g 3.2 pCi/g 1.5 pCi/g 3.1 pCi/g 

Gamma Exposure Rates 9.4 μR/hr -­ -­ -­

Source: CDPHE 2005; HRAP 1991 

pCi/g – picocuries per gram 

ppm – parts per million 

μR/hr – microroentgen per hour 

30 
 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

2. Off-site soil contamination and remediation 

As part of the 1988 RAP, Cotter was required to survey soils outside the restricted area (the 

fenced active mill site) and to remediate contaminated soils with levels of radium and 

molybdenum that are above the established background [CDPHE 2005]. 

As part of the 1998 Supplemental Human Health Risk Assessment [Weston 1998], Weston (a 

contractor for Cotter) collected surface soil samples (0-2 inches) from eight zones around the 

mill property (see Figure 18 in Appendix B). Each zone was divided into 8 to 12 grids. Four 

samples were collected near the center of each grid and were composited (i.e., combined and 

homogenized) to form a single representative sample [Weston 1998]. The results of this 

sampling are shown in Table 26 (chemicals) and Table 27 (radionuclides). The maximum 

concentrations exceeded the comparison values for arsenic7

 in all eight zones, for cadmium in all 

zones except one (D), for lead in three zones (F, G, and H), and for radium-226 in four zones (A, 

B, C, and E). The average concentrations also exceeded comparison values for arsenic7

 in all 

eight zones, for cadmium in one zone (F), for lead in one zone (H), and for radium-226 in two 

zones (A and B). The average radium-226 and thorium-230 concentrations were higher than the 

established average background levels in all eight zones (see 4 for background). 

Cotter has occasionally hauled ore and other materials by truck to the site for processing at their 

facility. To assess the potential that material has been lost alongside the county road leading to 

the mill and the access road entering the mill site, MFG (a contractor to Cotter) scanned the 

county road (assuming CR 143) from the road leading to the Shadow Hills Golf Course to the 

Cotter Mill access road for gamma radiation (see 

Figure 19). They also collected soil samples to There is limited potential for exposure to 

contaminants along the access road establish a correlation between the gamma exposure since access to the Cotter Mill is rate and the concentration of gamma emitters in the restricted and soils along the access road soil. A total of 16 locations were sampled—five were remediated in 2007 and 2008. 

along the county road, five along the mill’s access 

road, and six from background locations. The locations were not chosen to estimate an average 

concentration, but rather to provide data for a range of gamma exposure rates. Each sample was a 

composite of 10 aliquots within a 100 x 100 meter area [MFG 2005]. The results of this sampling 

are shown in Table 28. The maximum and average radium-226 and natural uranium 

concentrations exceeded the comparison values for samples taken along the mill’s access road. 

The maximum and average radium-226 concentrations also exceeded the comparison value for 

samples taken along the county road. Average concentrations of all radionuclides sampled were 

higher along the county road and the mill’s access road than from those areas designated as 

background (see Table 28). 

To address public concerns about the impact of the Cotter Mill on the health of Cañon City 

residents, CDPHE collected 21 soil samples in January 2003 [CDPHE 2003]. Each sample was a 

composite of 30–40 scrape samples8

 from each location. Seven samples from Lincoln Park were 

7 The 1998 Supplemental Human Health Risk Assessment found no discernible spatial pattern for arsenic around the 

Cotter Mill, indicating that arsenic levels have not been measurably altered by airborne releases from the mill 

(Weston 1998). 

8

 Surface soil samples were collected using a method developed specifically to look for airborne contamination that 

settled to the ground (CDPHE 2003). 

31 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

collected, including one sample of suspected flood sediment (Pine Street near Elm Avenue), two 

samples of dust (one from a barn loft and one from a residential attic), and four samples of 

surface soil (one from the McKinley Elementary School playground). Seven samples were 

collected from areas east of the mill, including the Brookside Head Start School. Six samples 

were collected from areas west of the mill, including a private residence. One sample was 

collected from the extreme northern part of Cañon City to represent the regional background 

(corner of Orchard Avenue and High Street). The sampling event was intentionally biased 

toward finding the highest amounts of contamination possible [CDPHE 2003]. Sample locations 

are shown in Figure 20. The data from this sampling event are summarized in Table 29 

(chemicals) and Table 30 (radionuclides). The maximum concentrations for lead and radium-226 

exceeded the comparison values. The average concentration for lead also exceeded the 

comparison value. The average concentration for radium-226 did not exceed the comparison 

value. 

Since 1994, Cotter has been annually collecting surface soil samples (0–6 inches) at 10 

environmental air monitoring stations that are located along the facility’s boundary and in 

residential areas (see Figure 21). From 1979 to 1993, soils were collected every 9 months. The 

data from this effort are summarized in Table 31. The maximum concentration for radium-226 

exceeded the comparison value; however, the average concentration of samples over the 

timeframe did not. 

a) The nearest resident 

The nearest resident is located 0.25 mile from the restricted area [Galant et al. 2007]. One of the 

air monitoring stations annually monitored by Cotter was established as “the nearest resident” 

(AS-212). This location is between the Cotter Mill and an actual residence [Cotter 2007]. The 

limited data for this location are shown in Table 32 (chemicals) and Table 33 (radionuclides). 

The maximum concentration for radium-226 exceeded the comparison value; however, the 

average concentration did not. 

b) Lincoln Park 

As part of the 1988 RAP, Cotter was required to EPA determined that sediment and soil in 

conduct a gamma scintillometer survey in Lincoln Lincoln Park are no longer an issue since 

Park to evaluate whether soils had been the completion of the Sand Creek Cleanup 

project in 1998 [EPA 2002, 2007]. contaminated by windblown and waterborne 

contaminants from the facility. In December 1988, 

127 scintillometer readings were taken near intersections in Lincoln Park. The average external 

gamma radiation for Lincoln Park was 9.8 microroentgen per hour (μR/hr), which is considered 

to show “no elevated gamma in Lincoln Park” [CDPHE 2005; HRAP 1991]. 

As part of the 1996 Supplemental Human Health Risk Assessment [Weston 1996], Weston 

compiled data from several past soil studies, including the following: 

 Samples collected at the air monitoring location in Lincoln Park in 1987 and 1988 

32 
 

 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

	 Samples collected from yards of 10 participants in the Lincoln Park water use survey in 

1989 

	 Samples collected from residential gardens in Lincoln Park in 1990 

	 Samples collected from lawns and gardens in Lincoln Park in 1996 

The data from these studies are collectively summarized in Table 34 (chemicals) and Table 35 

(radionuclides). Only the maximum and average concentrations for arsenic exceeded the 

comparison value. 

The soil samples collected from yards of the participants in the 1989 Lincoln Park water use 

survey were also analyzed for molybdenum and uranium. The average molybdenum 

concentration was 2.0 ppm and the average uranium concentration was 2.8 ppm [HRAP 1991]. 

The samples collected as part of the 1990 residential garden soil survey were also analyzed for 

molybdenum. The average concentration was 0.13 ppm [HRAP 1991]. These concentrations are 

well below the comparison values for molybdenum (300 ppm) and uranium (100 ppm).9 

As part of the 1998 Supplemental Human Health Risk Assessment [Weston 1998], 73 surface soil 

samples were collected from lawns (0–2 inches) and gardens (0–6 inches) in Lincoln Park. For 

sampling purposes, Lincoln Park was divided into seven areas and 6–16 samples were taken 

from each area [Weston 1998]. The results of this sampling are shown in Table 26 (chemicals) 

and Table 27 (radionuclides). Only the maximum and average arsenic concentrations exceeded 

the comparison value. 

The effect of irrigation with contaminated well water on the levels in the soil was also examined 

during the 1998 Supplemental Human Health Risk Assessment [Weston 1998]. The soil samples 

from Lincoln Park were divided into two categories—those irrigated with well water that had 

been impacted by mill releases and those not believed to have been irrigated with contaminated 

well water. These data are shown in Table 36 (chemicals) and Table 37 (radionuclides). The 

concentrations of arsenic, molybdenum, and uranium were statistically higher in soil samples 

irrigated with impacted well water [Weston 1998]. 

(1) Lead in Lincoln Park 

Residents of Lincoln Park expressed concerns about lead contamination in soil and dust due to 

historical and current mining and milling operations in the area. Six potential sources of lead are 

located near the community of Lincoln Park—the Cotter Mill, the Empire Zinc Smelter (also 

known as New Jersey Zinc and the College of the Cañons), the US Smelter Facility, the Cañon 

City Copper Smelter, the Ohio Zinc Company, and the Royal Gorge Smelter [EPA 2004]. The 

Lincoln Park neighborhood is located generally east-southeast of these facilities and the general 

wind direction is west to east. 

To address the residents’ concerns, EPA requested that ATSDR assess the health risk associated 

with lead contamination in Lincoln Park. After a site visit and discussions with the community, 

9

 The data for molybdenum and uranium are not summarized in Table because the raw data for these two chemicals 

are not presented in the 1996 Supplemental Human Health Risk Assessment (Weston 1996). 

33 
	 

	 

	 

EPA’s report documenting the residential soils 

sampling project can be accessed at the following site: 

http://www.epa.gov/region8/superfund/co/lincolnpark/. 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

ATSDR focused assessments on two primary issues—1) blood lead levels in children living in 

Lincoln Park and 2) lead contaminated dust in homes in Lincoln Park. 

ATSDR reviewed the available data on blood lead levels in children and concluded that the rate 

of elevated blood lead levels for Fremont County is below the state average. However, it was not 

possible to evaluate whether area children, including “high risk” children, were being adequately 

screened for blood lead levels [ATSDR 2006a]. To further assess blood lead levels, ATSDR 

tested the blood level of 115 “at risk” school children in 2005. None of the children had elevated 

blood lead levels [ATSDR 2006b]. 

ATSDR reviewed the available data on lead levels in household dust and found the data to be 

sparse and/or lacking. ATSDR 

conducted a screening level evaluation 

of the available dust samples and 

concluded that the data were not 

sufficient to determine the magnitude or extent of the potential hazard associated with levels of 

lead in household dust [ATSDR 2006c]. To further assess the health impacts in Lincoln Park, 

ATSDR, in collaboration with the Colorado Citizens Against Toxic Waste (CCAT) and EPA, 

collected and analyzed 44 indoor dust samples, 80 surface soil samples (0–2 inches or 0–6 

inches) from 22 properties, and 45 blood samples. The results of this exposure investigation did 

not indicate the presence of unusual levels of lead in residential indoor dust samples, the soil at 

those homes, or in the blood of occupants of those homes [ATSDR 2006d]. 

c) Sand Creek 

Sand Creek is primarily an ephemeral creek that passes through the Cotter Mill and runs northnortheast through Lincoln Park. It becomes perennial for the last 0.25–0.5 mile before its 

confluence with the Arkansas River. Prior to the construction of the SCS Dam north of the Cotter 

Mill in 1971, surface water and sediment from the facility flowed down the Sand Creek drainage 

into Lincoln Park [CDPHE 2005; GeoTrans 1986]. Mill tailings in the Old Tailings Pond Area 

are the source of the mill-derived contaminants (primarily radium-226 and thorium-230) in Sand 

Creek [Cotter 2000]. 

During the 1986 Remedial Investigation [GeoTrans 1986], sediment samples were collected from 

the following locations in Sand Creek to evaluate present (i.e., 1985) and historical loadings 

from the Cotter Mill. 

	 SD01 – mouth near the Arkansas River 

	 SD02 – near spring where flow begins (reflects migration of contaminants in the 

groundwater) 

	 SD04 – below the SCS Dam in 

(1) an abandoned stock watering pond (formed by diversion of runoff water into a 

depression adjacent to Sand Creek) 

(2) in drainage (reflects historical picture of uncontrolled emissions) 

(3) in drainage above #2 (reflects historical picture of uncontrolled emissions) 

34 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

 SD05 – above the SCS Dam adjacent to the west property edge 

The results of this sampling are presented in Table 38 and Table 39. Only the concentrations for 

arsenic and radium-226 exceeded ATSDR’s comparison values. 

As part of the 1988 RAP, Cotter was required to evaluate the mill’s potential impacts to Sand 

Creek and remove sediments that exceeded the radium-226 cleanup goal of 4.0 picocuries per 

gram (pCi/g), which allows unrestricted use of the creek [Cotter 2000]. A total of 721 samples 

were systematically collected along the 1.25 mile stretch from just north of the Cotter Mill to 

where Sand Creek becomes perennial (see Figure 22). Surveying and cleanup began in the spring 

of 1993 and continued until remediation was completed in December 1998. Approximately 9,000 

cubic yards of soil were removed from Sand Creek and disposed of on Cotter property [Cotter 

2000]. The excavated areas were backfilled with clean soil [CDPHE 2005]. Thirty confirmatory 

samples established that the average site-wide radium-226 concentration was 1.5 pCi/g (below 

the cleanup goal of 4.0 pCi/g) and the average site-wide thorium-230 concentration was 3.9 

pCi/g after remediation [Cotter 2000]. In addition to the sampling and remediation for radium226, seven of the confirmation samples were analyzed for 10 chemicals in 1998 [Cotter 2000]. 

These results are presented in Table 40. Only the maximum and average concentrations for 

arsenic exceeded ATSDR’s comparison value. 

At the time of mill closure, Cotter was required by the 1988 RAP to survey molybdenum and radium

226 in sediments in the perennial stream segments of Sand Creek and Willow (Plum) Creek to 

determine whether these areas have been impacted by the mill. If necessary, sediments above 

background will be removed and properly disposed of (CDPHE 2005). 

­

d) The Fremont Ditch 

The Fremont Ditch system is downstream of Sand Creek. It diverts water from near the 

confluence of Sand Creek and the Arkansas River downgradient toward Florence. The ditch 

receives substantial amounts of water from Sand Creek during low flows in the Arkansas River. 

During these periods, any contaminants moving down Sand Creek would likely be transported to 

Fremont Ditch [GeoTrans 1986]. 

As part of the 1988 RAP, Cotter was also required to conduct a gamma survey of the dry beds of 

the Fremont Ditch. Cotter sampled sediment in Fremont Ditch from its head gate near Sand 

Creek to about a quarter mile downstream. The average radium-226 level was 1.86 pCi/g, which 

was below the cleanup standard of 4 pCi/g. The state agreed with Cotter that the Fremont Ditch 

did not require remediation because the concentrations of gross alpha (3.8 pCi/g), uranium (6.6 

ppm), and molybdenum (2.2 ppm) were also low [CDPHE 2005]. 

C. Surface water 

1. Nature and extent of contamination 

The Cotter Mill is a non-discharge facility, meaning that Cotter does not release wastewater to 

the surface water system. All remediation water is pumped to on-site impoundments for 

35 
 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

evaporation or recycling. However, prior to construction of the SCS Dam in 1971, storm events 

carried contaminated surface water and sediments from the facility down the Sand Creek 

drainage [CDPHE 2005]. One event in particular, a flood in June 1965, caused the unlined 

tailings ponds at the Cotter Mill to overflow into Lincoln Park. Sediment in the Lincoln Park 

portion of Sand Creek was contaminated with tailings that were carried in surface water runoff 

from the mill [EPA 2007]. 

CDPHE maintains a database containing surface The SCS Dam was built to prevent 

water monitoring data dating back to 1962. The surface water and sediment from flowing 

most recent data entered into the database are from into Lincoln Park during storm-generated 

floods. Since the construction of the dam, September 2007. To evaluate exposures to people Lincoln Park no longer receives runoff living near the Cotter Mill, ATSDR extracted from the Cotter Mill. Additionally, since surface water data collected from Sand Creek, the 1979, impounded water collected at the 

DeWeese Dye Ditch, and the Arkansas River. After dam has been pumped back to the lined 

discussions with a CDPHE representative, the impoundment on site [EPA 2002; 

GeoTrans 1986; HRAP 1991]. following assumptions were made while 

summarizing data within the database. 

	 Samples that were designated “N” in the detect flag column and had the same value in the 

result value column as the reporting detection limit column were included in the 

summary statistics as 1⁄2 the reporting detection limit. 

	 Negative result values for manganese and iron were assumed to be not detected and were 

included in the summary statistics as 1⁄2 the reporting detection limit. 

	 Negative values10 for radionuclides were included in the summary statistics. 

a) Sand Creek 

From 1993 to 1998, Cotter conducted the Sand Creek Cleanup project to identify and remove 

mill tailings that had moved into the creek bed as the result of surface water runoff from the 

Cotter Mill prior to the construction of the SCS Dam. Sediments above the radium-226 cleanup 

goal of 4.0 pCi/g were removed, which allows unrestricted use of the creek [Cotter 2000; EPA 

2002]. 

Two locations in Sand Creek—one at Ash Street (008) and one at the confluence with the 

Arkansas River (506)—are sampled as part of the surface water monitoring program (Cotter 

2007). The CDPHE database contains surface water monitoring data from these two locations, 

which are summarized in Table 41 (chemicals) and Table 42 (radionuclides). The maximum 

concentrations for manganese, molybdenum, sulfate, and total dissolved solids exceeded the 

comparison values. However, for all four of these chemicals, only the maximum concentrations 

exceeded comparison values—the second highest detected concentrations were below 

comparison values. None of the average concentrations exceeded comparison values. 

10 Negative values for radionuclides occur when samples are not much different from background, since standard 

protocol is to subtract background radioactivity from the sample count. 

36 
 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

As part of the 1991 Health Risk Assessment of the Cotter Uranium Mill Site [HRAP 1991], the 

Health Risk Assessment Panel (HRAP) reviewed over 18,000 samples collected from 1976– 

1989, from 55 different surface water locations. More than 95% of the surface water data were 

collected from 10 main locations. The location in Sand Creek at Ash Street (008, formerly 

known as 555) was one of these locations. The average molybdenum (0.009 mg/L) and uranium 

(0.016 mg/L) concentrations from this location were well below the comparison values 

(molybdenum: 0.035 mg/L; uranium: 0.03 mg/L).11 

b) DeWeese Dye Ditch 

The DeWeese Dye Ditch is an irrigation ditch that flows between the Cotter Mill and Lincoln 

Park. The ditch diverts water from Grape Creek to irrigate about 1,200 acres during the summer 

growing period [GeoTrans 1986]. The ditch crosses Sand Creek downstream from the SCS Dam, 

but does not join it. Seepage from the ditch recharges groundwater within the Sand Creek 

drainage. This process dilutes and flushes the contaminated groundwater under Lincoln Park 

[EPA 2002]. 

The CDPHE database contains surface water monitoring data from two locations in the DeWeese 

Dye Ditch—one upstream of the confluence with Forked Gulch (520) and one at Cedar Avenue 

(526). The location at Cedar Avenue is sampled as part of the surface water monitoring program 

[Cotter 2007]. The data for both locations are summarized in Table 43 (chemicals) and Table 44 

(radionuclides). The maximum concentrations exceeded the comparison values for iron, 

manganese, total dissolved solids, and dissolved uranium. However, for iron and manganese, 

only the maximum concentrations exceeded comparison values—the second highest detected 

concentrations were below comparison values. Only three of the total dissolved solids samples 

and three of the dissolved uranium samples were detected above comparison values. None of the 

average concentrations exceeded comparison values. 

Molybdenum and uranium data from 1984 to 1989, from the same two locations in the DeWeese 

Dye Ditch (520 and 526), are summarized in the 1991 Health Risk Assessment of the Cotter 

Uranium Mill Site (HRAP 1991). The average molybdenum and uranium concentrations were 

well below the comparison values (see Table 5 below). 

Table 5. Average molybdenum and uranium concentrations in the DeWeese Dye Ditch 

Chemical Average concentration at 

Location 520 (mg/L) 

Average concentration at 

Location 526 (mg/L) 

Comparison Value 

(mg/L) 

Molybdenum 0.003 0.003 0.035 

Uranium 0.002 0.0019 0.03 

Source: HRAP 1991 

Molybdenum data that were several orders of magnitude greater than any other observed sample (i.e., outliers) were 

not used to calculate the average concentrations (HRAP 1991). 

It was not possible to determine whether these data are included in the CDPHE database. 

c) Arkansas River 

11 It was not possible to determine whether these data are included in the CDPHE database. 

37 
	 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The Arkansas River sampling plan was 

approved by the CDPHE Water Quality 

Control Division [CDPHE 2005]. 

From April 1989 to June 1990, Cotter and their 

consultant, Western Environmental Analysts, 

conducted bi-weekly sampling in the Arkansas River 

at the following five locations: 

1.	 Parkdale (background) 

2.	 Grape Creek 

3.	 1st Street (upstream of where Sand Creek enters the Arkansas River) 

4.	 Mackenzie Avenue Bridge (downstream from where Sand Creek enters the Arkansas 

River) 

5.	 Where Highway 67 to Florence crosses the river 

Water, sediment, autotrophs (algae), primary consumers/detrivores (tadpoles, 

macroinvertebrates), and carnivores (fish) were collected and tested for molybdenum, uranium, 

radium-226, and thorium-230. Extremely low concentrations were detected, which indicated no 

statistical evidence of an increase in contamination downstream on the Arkansas River [CDPHE 

2005]. 

In addition, four synoptic sampling events (i.e., sampling of water in-flows) were conducted 

between Canyon Mouth and Highway 67. The purpose of the synoptic sampling was to 

determine whether tributary flows reflect unusual sources of uranium or molybdenum. The 

sampling showed that other sources such as Fourmile Creek, as well as Sand Creek and Plum 

Creek, contribute to increases in the Arkansas River [CDPHE 2005]. 

Two locations in the Arkansas River—one upstream of Sand Creek at 1st Street (907) and one 

downstream of Sand Creek at Mackenzie Avenue (904)—are sampled as part of the surface 

water monitoring program [Cotter 2007]. The CDPHE database contains surface water 

monitoring data from these two locations, which are summarized in Table 45 (chemicals) and 

Table 46 (radionuclides). At both locations, the maximum concentrations exceeded the 

comparison value for sulfate. The maximum concentration for total dissolved solids exceeded the 

comparison value for the upstream location, but not the downstream location. In all three 

instances, these maximum concentrations appear to be outliers and are the only concentrations 

that exceeded comparison values—the second highest detected concentrations were below 

comparison values. The maximum concentration for molybdenum also exceeded the Colorado 

state groundwater standard for the upstream location, but not the downstream location. None of 

the average concentrations exceeded comparison values. 

Data from 1984 to 1989, from two locations in the Arkansas River—one upstream of Sand Creek 

near Grape Creek (502) and one downstream of Sand Creek near Fourmile Bridge (504)—are 

summarized in the 1991 Health Risk Assessment of the Cotter Uranium Mill Site [HRAP 1991]. 

The average molybdenum and uranium concentrations were well below the comparison values 

(see Table 6 below). 

38 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 6. Average molybdenum and uranium concentrations in the Arkansas River 

Chemical 

Average concentration 

upstream of 

Sand Creek near Grape 

Creek (502) (mg/L) 

Average concentration 

downstream of 

Sand Creek near Fourmile 

Bridge (504) (mg/L) 

Comparison 

Value (mg/L) 

Molybdenum 0.00391 0.0056 0.035 

Uranium 0.00532 0.00574 0.03 

Source: HRAP 1991 

Molybdenum data that were several orders of magnitude greater than any other observed sample (i.e., outliers) were 

not used to calculate the average concentrations (HRAP 1991). 

d) Willow Lakes 

The Willow Lakes are comprised of several small ponds near the Arkansas River in the Willow 

Creek watershed, which lies directly to the east of the Sand Creek watershed. The Willow Lakes 

receive water from shallow groundwater and surface runoff [HRAP 1991]. 

Cotter was required by the 1988 RAP to evaluate whether the Willow Lakes had been 

contaminated by the mill. Water, sediment, autotrophs (algae), primary consumers/detrivores 

(tadpoles, macroinvertebrates), and carnivores (fish) from the Willow Lakes and three 

comparison lakes were collected and tested for molybdenum, uranium, and radium. The 

information showed that the Willow Lakes had not been contaminated by the Cotter Mill 

[CDPHE 2005]. 

D. Locally grown produce 

1. Nature and extent of contamination 

As part of the 1996 Supplemental Human Health Risk Assessment (Weston 1996), Weston 

compiled available food data from several past studies. Samples included chicken meat, fruit 

(apples, cherries, grapes), and vegetables (asparagus, carrots, lettuce, tomatoes, turnips). The 

local samples were compared to food collected from supermarkets. The data are presented in 

Table 47 and Table 48 in Appendix A. The limited sample data suggest that the chemicals and 

radionuclides found in the foods are probably natural in origin, however, it was not possible to 

exclude the possibility that some food types may be influenced by mill-related contaminants 

[Weston 1996]. 

To further evaluate exposures to residents who eat locally grown fruits and vegetables, a 

sampling program was initiated in Lincoln Park during the 1998 Supplemental Human Health 

Risk Assessment [Weston 1998]. People were asked to donate locally grown produce samples for 

analysis. The fruits and vegetables sampled are presented in the table below. The samples were 

tested for heavy metals and radionuclides. The analytical results of the sampling program are 

summarized in Table 49 and Table 50 in Appendix A. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Fruits Sampled Vegetables Sampled 

Apples Acorn squash Green Beans Rhubarb 

Cantaloupe Beets Green Onions Squash 

Grapes Carrots Kohlrabi Tomatoes 

Honey dew melon Celery Patty pan squash Turnip Greens 

Plums Corn Peppers Turnips 

Watermelon Cucumbers Pumpkin Winter squash 

The samples were divided into two categories—(1) produce that was grown in soil known to 

have been irrigated with contaminated well water (fruits n = 16; vegetables n = 43) and (2) 

produce that was grown in soil not believed to have been irrigated with contaminated well water 

(fruits n = 1; vegetables n = 6). A statistical comparison of the data for the two categories of 

vegetables indicated that irrigation with contaminated well water did not cause a significant 

increase in contaminant levels (Weston 1998). The following trends were also noted: 

	 The concentrations of most metals were higher in root vegetables than other types of 

vegetables and fruit. 

	 Concentrations were much lower in peeled turnips than in whole turnips, suggesting that 

most of the contamination was on or in the surface layer. 

	 There was high variability both within and between the different types of produce. 

	 Concentration values were below the limit of detection for many of the samples. 

E. Ambient Air 

ATSDR reviewed ambient air monitoring data and air sampling data collected from the 

following two sources: 

	 Cotter Mill has operated an ambient air monitoring program to characterize air quality 

impacts of radioactive particulates and radon for more than 20 years. ATSDR accessed 

summaries of the monitoring data from Cotter Mill’s annual Environmental and 

Occupational Performance Reports, which are posted to the CDPHE’s web site; and 

	 The state of Colorado operated three particulate monitoring stations in Fremont County, 

one each in Lincoln Park, Cañon City, and Florence. The station in Cañon City continues 

to operate today. ATSDR downloaded measured concentrations of particulate matter, and 

some chemical constituents of particulate matter, from EPA’s Air Quality System (AQS) 

database—a publicly accessible online clearinghouse of ambient air monitoring data. 

Some of the measurements collected by these monitors date back 40 years. 

Historically, Cotter Mill had two general types of air emission sources: ground-level fugitive 

emissions (e.g., wind-blown dust) that would be expected to have greatest air quality impacts 

nearest the source; and elevated point sources (e.g., stacks) that have the potential for having 

peak ground-level impacts at downwind locations. With the facility currently in “stand down” 

40 
 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

status, facility emissions are now predominantly fugitive and their air quality impacts should be 

adequately characterized by the perimeter monitoring stations. 

1.	 Nature and extent of air contamination 

ATSDR compiled and evaluated ambient air monitoring data to assess potential air quality 

impacts from Cotter Mill’s past and ongoing operations. As will be discussed later, ambient air 

concentrations of some substances changed considerably from one year to the next—in some 

cases, annual average concentrations vary by more than a factor of 250 over the period of record. 

These substantial changes in measured air contamination levels can sometimes be traced back to 

site-specific activities. 

To provide background information and context for the air quality trends documented later in 

this report, the following list identifies key milestones over the history of Cotter Mill’s 

operations. The timeline is not intended to be a comprehensive listing of site-specific events, but 

rather focuses on events and activities expected to be associated with notable changes in the 

facility’s air emissions. 

 1958: Cotter Corporation begins its uranium milling operations at the Cotter Mill site 

 1979: Continuous operations cease, but intermittent operations continue 

 1981-1983: Cotter excavates 2,500,000 cubic yards of contaminated tailings from unlined 

holding ponds and places the material in a newly constructed, lined surface impoundment 

 1987: Cotter suspends its primary milling operations and only limited and intermittent ore 

processing occurs for the next 12 years 

 1993-1999: Cotter excavates 9,000 cubic yards of contaminated tailings, soil, and 

sediment from 1.25 miles of Sand Creek near the facility 

 1999: Cotter excavates 100,000 cubic yards of contaminated soil in “near surface soils” 

from the on-site Old Pond Area and places this material into the lined, surface 

impoundment 

 1999: Milling operations using a different production process begin 

 2005: Cotter ceases its routine operations and enters “stand down” status; site 

remediation activities continue; stack emissions from most sources continue into 2006, 

after which the main operational stack is for the laboratory baghouse 

 2009: Cotter submits letter to CDPHE announcing its intent to refurbish the mill, rather 

than decommission it 

The following sections summarize the data and air quality trends for particulate matter, selected 

particle-bound radionuclides, radon gas and gamma radiation. 

41 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

a) Ambient Air Monitoring for Radioactive Substances 

The Cotter Mill monitoring network is operated by Cotter Mill in accordance with guidelines and 

requirements set forth by the U.S. Nuclear Regulatory Commission (USNRC 1980) and the 

Radioactive Materials License established between Cotter Mill and the state of Colorado 

[CDPHE 2009]. The purpose of the network is to characterize the extent to which Cotter Mill’s 

operations affect off-site air quality. 

Cotter Mill’s ambient air monitoring network has been operating from 1979 to the present, but 

the number of monitoring stations included in the network has changed over time. In 1979, four 

stations were fully operational; this increased to seven by 1981 and to ten by 1999. These ten 

monitoring stations continue to operate today. Each station is equipped with the same monitoring 

equipment: an environmental air sampler used to collect particulates for analysis of particlebound radionuclides; a radon track etch measurement device; and an environmental 

thermoluminescent dosimeter (TLD) for measuring gamma exposure. The height of the sampling 

inlet probes was not specified in the reports that ATSDR reviewed to prepare this health 

assessment. Table 51 in Appendix A identifies the monitoring stations and their periods of 

operation. Figure 23 in Appendix B shows the approximate locations of the monitoring stations. 

For purposes of this evaluation, ATSDR has classified the ten monitoring stations as being either 

“perimeter” or “off-site.” The five “perimeter” monitoring stations are located along or just 

within Cotter Mill’s property line; and the five “off-site” monitoring stations are located off-site, 

anywhere from 0.5 mile to 4 miles from the Cotter Mill property line. 

(1) Particulate Matter 

At each of the 10 monitoring stations described above, Cotter Mill operates a high-volume total 

suspended particulate (TSP) sampling device. For each sampling period, the devices are loaded 

with glass fiber filters that collect airborne particulates as ambient air passes through the 

sampling apparatus. The TSP sampling devices collect 1-week integrated samples; when the 

sampling period ends, field personnel remove filters, record observations on chain-of-custody 

forms, and store filters for subsequent laboratory analysis. 

Cotter prepares annual summary reports for its environmental monitoring network, and those 

reports document monthly average TSP concentrations measured at each station. ATSDR had 

access to the summary reports for 2006, 2007, and 2008. TSP data from earlier years can be 

accessed through data reports that CDPHE has on compact disk. Over the last three years, annual 

average TSP concentrations were consistently higher in the more populated areas (Lincoln Park 

and Cañon City) than at the perimeter monitoring stations. In 2008, for instance, the annual 

average TSP levels at Lincoln Park and Cañon City were 29.9 μg/m3

 and 26.5 μg/m3, 

respectively; in contrast, annual average concentrations at the five perimeter monitoring stations 

ranged from 15.5 μg/m3

 to 21.4 μg/m3. 

Although quantitative quality control information was not available when summarizing Cotter’s 

TSP data, these measurements can be compared to CDPHE’s PM10 monitoring results in Cañon 

City during the same time frame. From 2006 to 2008, the annual average TSP levels measured 

by Cotter Mill in Cañon City were 26.6 μg/m3, 26.3 μg/m3, and 26.5 μg/m3, respectively; the 

annual average PM10 levels measured by CDPHE in Cañon City during these same years were 

42 
	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

16.5 μg/m3, 16.4 μg/m3, and 15.0 μg/m3. The difference between the TSP and PM10 annual 

average concentrations in Cañon City are within the expected range and direction (i.e., TSP 

levels exceeding PM10 levels), which gives some assurance in the quality of the underlying data 

sets. 

(2) Particle-Bound Radionuclides 

Weekly particulate filters collected at the 10 stations mentioned in the previous section are not 

only weighed for mass loading but are also analyzed at Cotter Mill’s analytical laboratory for 

concentrations of five radionuclides, identified below. All laboratory analyses are conducted 

according to methodologies approved by CDPHE. 

Field sampling and laboratory analyses for particle-bound radionuclides are conducted according 

to specifications outlined in Cotter Mill’s Quality Assurance Program Plan (QAPP). This 

document is revised periodically and submitted to CDPHE for review. The QAPP outlines many 

quality control and quality assurance procedures implemented to ensure that the network’s 

measurements are of a known and high quality. Examples of specific procedures followed 

include: routine collection and analysis of blank samples to ensure sampling media and 

laboratory equipment are not contaminated; quarterly calibration of flow rates for the “high 

volume” samplers; audit of sampler flow rates using special equipment; collection of duplicate 

samples that are analyzed in replicate to quantify measurement precision; and participation in a 

“laboratory exchange program” through which a subset of environmental samples (mostly water 

samples, by all appearances) are split and sent to Cotter Mill’s laboratory and two commercial 

laboratories for analyses. While these and other quality control procedures give some assurance 

that samples are collected and analyzed with fine attention to data quality, the reports available to 

ATSDR during this review generally did not present the actual data quality metrics (e.g., the 

relative percent difference in duplicate samples or for inter-laboratory audits, contamination 

levels found in blanks) for the particle-bound radionuclides. 

The key findings from the monitoring program for the five radionuclides measured are below. 

For each substance, a section compares the measured concentrations to regulatory limits or 

health-based comparison values, comments on temporal and spatial variations, and then presents 

a brief summary. 

 Natural uranium (natU). Table 52 in Appendix A presents the history of annual average 

natU concentrations measured in Cotter Mill’s monitoring network. The shaded cells in 

the table are the highest annual average concentration for the year. 

o	 Screening. Cotter Mill compares measured concentrations of natU to an “effluent 

concentration” (9.0 x 10-14 μCi/ml), which is defined (10 CFR 20, Appendix B) as 

the radionuclide concentration which, if inhaled continuously over the course of a 

year, would produce a total effective dose equivalent of 50 mrem. None of the 

annual average concentrations in Table 52 exceed this derived concentration 

guide. The highest annual average concentration over the period of record (2.5 x 

10-14 μCi/ml at a perimeter monitoring station in 1982) is 3.6 times below this 

screening value. The highest annual average in 2008 (4.4 x 10-16 μCi/ml at a 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

perimeter monitoring station) was approximately 200 times below the screening 

value, and larger margins are observed for the off-site monitoring stations. 

o	 Spatial and temporal variations. Generally, the highest annual average 

concentrations of natU were observed at perimeter monitoring stations, with lower 

levels observed at the off-site stations. During most years, the annual average 

values did not vary considerably (by more than an order of magnitude) across all 

of the stations. As an exception, the 1982 annual average natU concentration 

observed at the west boundary monitoring station was roughly 50 times greater 

than the annual averages observed at the other monitoring stations during the 

same year; this “spike” at one station during one year was most likely caused by 

air emissions associated with an on-site tailings excavation project. As another 

exception, in several years between 1998 and 2006, annual average natU 

concentrations at the mill entrance road monitoring station were more than an 

order of magnitude higher than those recorded at all other stations, which most 

likely reflects contributions from clean-up of the site entry road and delivery of 

ores (which mostly ended in 2006). As noted above, the highest annual average 

concentration of natU was observed in 1982, and more recent (2004-2008) annual 

average levels are considerably lower. 

o	 Summary. Every annual average concentration of natU recorded to date has been 

lower than Cotter Mill’s health-based regulatory limit. In the last five years, the 

annual average concentrations at every station have been at least 20 times below 

this limit. It seems unlikely that air emissions from the mill would lead to an offsite “hot spot” of natU concentrations that could be considerably higher than the 

levels measured by the monitoring network. 

 Thorium-230 (230Th). Table 53 in Appendix A presents the history of annual average 

230Th concentrations measured in Cotter Mill’s monitoring network. The shaded cells in 

the table are the highest annual average concentration for the year. 

o	 Screening. Cotter Mill compares measured concentrations of 230Th to an “effluent 

concentration” (2.0 x 10-14 μCi/ml), which is defined (10 CFR 20, Appendix B) as 

the radionuclide concentration which, if inhaled continuously over the course of a 

year, would produce a total effective dose equivalent of 50 mrem. The annual 

average concentration at the west boundary monitoring station exceeded this 

value in 1981 and 1982, as did the annual average concentration in 1981 at the 

east boundary monitoring station. The highest annual average concentration 

recorded by this network (9.0 x 10-14 μCi/ml at the west boundary in 1982) was 

4.5 times higher than the derived concentration guide. Concentrations decreased 

over the years, and the highest annual average in 2008 (7.2 x 10-16 μCi/ml at a 

perimeter monitoring station) was a factor of 28 times lower than the screening 

value, and larger margins are observed for the off-site monitoring stations. 

o	 Spatial and temporal variations. Without exception, the highest annual average 

concentrations of 230Th were observed at perimeter monitoring stations, with 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

considerably lower levels observed at the off-site stations—a spatial trend 

suggesting that Cotter Mill’s emissions very likely account for a considerable 

portion of the measured levels. As with natural uranium, the 230Th concentrations 

exhibited a notable “spike” in 1981-1982, when 2.5 million cubic yards of on-site 

tailings were excavated from the unlined ponds. As an illustration of this effect, 

the highest annual average concentration in 1981 (3.0 x 10-14 μCi/ml at a 

perimeter monitoring station) was nearly 370 times higher than the annual 

average concentration measured in Cañon City. Moreover, the highest 

concentrations were observed at the monitoring station closest to, and downwind 

from, the excavation activity. Average concentrations of 230Th decreased 

markedly after the 1981-1982 peak: the most recent (2004-2008) annual average 

concentrations at perimeter stations are all at least 20 times lower than the highest 

levels from 1981-1982. 

o	 Summary. In 1981 and 1982, annual average concentrations of 230Th at two 

perimeter monitoring stations exceeded Cotter Mill’s health-based regulatory 

limit; however, for every other calendar year, every station’s annual average 

concentration was lower than this limit. In the last five years, the annual average 

concentrations at every station were between six and 30 times below this limit. 

For the off-site monitoring stations, however, all annual average concentrations 

during this 5-year time frame were at least a factor of 40 below Cotter Mill’s 

health-based regulatory limit. 

 Thorium-232 (232Th). Table 54 in Appendix A presents the history of annual average 

232Th concentrations measured in Cotter Mill’s monitoring network. Laboratory analyses 

for this radionuclide first began in 2001. The shaded cells in the table are the highest 

annual average concentration for the year. 

o	 Screening. Cotter Mill compares measured concentrations of 232Th to an “effluent 

concentration” (4.0 x 10-15 μCi/ml), which is defined (10 CFR 20, Appendix B) as 

the radionuclide concentration which, if inhaled continuously over the course of a 

year, would produce a total effective dose equivalent of 50 mrem. None of the 

annual average concentrations in Table 54 exceed this derived concentration 

guide. In 2008, the highest annual average concentration (3.1 x 10-17 μCi/ml in 

Lincoln Park) was a factor of 128 lower than the screening value. 

o	 Spatial and temporal variations. Unlike natU and 230Th, for which measured 

concentrations were consistently (if not always) highest at perimeter monitoring 

stations, the highest annual average concentrations of 232Th have always been 

observed at off-site monitoring stations, most commonly at the Lincoln Park 

monitoring station. Moreover, of all the radionuclides measured, annual average 

concentrations of 232Th exhibited the least variability from station to station. For 

any given year between 2001 and 2008, annual average concentrations at the ten 

monitoring stations fell within a factor of three of each other. The annual average 

concentrations did not exhibit considerable variability from one year to the next. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

o	 Summary. Over the last five years, annual average concentrations of 232Th at 

every monitoring station were more than 60 times lower than Cotter Mill’s healthbased regulatory limit. The spatial variations in 232Th concentrations have been 

limited, suggesting that air emissions from Cotter Mill may be relatively 

insignificant for this radionuclide. 

 Radium-226 (226Ra). Table 55 in Appendix A presents the history of annual average 

226Ra concentrations measured in Cotter Mill’s monitoring network. The shaded cells in 

the table are the highest annual average concentration for the year. 

o	 Screening. Cotter Mill compares measured concentrations of 226Ra to an “effluent 

concentration” (9.0 x 10-13 μCi/ml), which is defined (10 CFR 20, Appendix B) as 

the radionuclide concentration which, if inhaled continuously over the course of a 

year, would produce a total effective dose equivalent of 50 mrem. None of the 

annual average concentrations in Table 55 exceed this derived concentration 

guide. In 2008, the highest annual average concentration (7.9 x 10-16 μCi/ml at a 

perimeter monitoring station) was three orders of magnitude lower than the 

screening value. 

o	 Spatial and temporal variations. In almost every year between 1979 and 2008, the 

highest annual average concentrations of 226Ra were measured at perimeter 

monitoring stations, and primarily at the west boundary and mill entrance road 

locations. For most years, the highest annual average value at the facility’s 

perimeter was usually between one and two orders of magnitude greater than the 

lowest annual average concentration at off-site locations—a pattern that points to 

facility emissions as a likely source for contributing to at least part of the 

measured concentrations. At the four perimeter stations with the longest period of 

record, the highest annual average concentrations occurred prior to 1985, and the 

current (2008) levels at these stations are between 10 and 100 times lower than 

those peaks. 

o	 Summary. The spatial variations in 226Ra concentrations suggest that Cotter Mill’s 

emissions contribute to the measured levels. However, over the last five years, 

annual average concentrations of 226Ra at every monitoring station were more 

than 390 times lower than Cotter Mill’s health-based regulatory limit. 

 Lead-210 (210Pb). Table 56 in Appendix A presents the history of annual average 210Pb 

concentrations measured in Cotter Mill’s monitoring network. The shaded cells in the 

table are the highest annual average concentration for the year. 

o	 Screening. Cotter Mill compares measured concentrations of 210Pb to an “effluent 

concentration” (6.0 x 10-13 μCi/ml), which is defined (10 CFR 20, Appendix B) as 

the radionuclide concentration which, if inhaled continuously over the course of a 

year, would produce a total effective dose equivalent of 50 mrem. None of the 

annual average concentrations in Table 56 exceed this derived concentration 

guide. In 2008, the highest annual average concentration (1.9 x 10-14 μCi/ml at a 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

perimeter monitoring station) was more than a factor of 30 lower than the 

screening value. 

o	 Spatial and temporal variations. The main distinguishing feature of the 210Pb 

monitoring data (when compared to data for the other radionuclides) is the low 

variability, both spatially and temporally. Since 1983, annual average 

concentrations across the ten monitoring stations tended to fall within a factor of 

two; and year-to-year variability was of a comparable magnitude. This lack of 

variability points to a “background effect” (i.e., the measured concentrations 

likely are not the result of Cotter Mill’s emissions, but reflect typical atmospheric 

levels for this part of the country). In 1981-1982, annual average concentrations at 

a perimeter monitoring station were slightly higher than what was routinely 

measured at all other locations and years; and these slightly elevated levels likely 

reflected air quality impacts from the excavation of the unlined holding ponds. 

o	 Summary. Of all the radionuclides considered, 210Pb showed the least variability 

in annual average concentrations, suggesting that the monitoring data characterize 

background levels and not a site-specific contribution. From 1983 to the present, 

annual average concentrations during every year and at every station were 

generally at least 20 times below Cotter Mill’s health-based regulatory limit. 

With one exception, the five radioactive substances measured by Cotter Mill’s network were 

below their corresponding health-based regulatory limits at all 10 monitoring stations and for the 

entire 30 years of record. As the exception, annual average 230Th concentrations exceeded healthbased regulatory limits during a tailing pond excavation project, but this was limited to a short 

time frame (1981-1982) and the immediate proximity of the facility (two fenceline monitoring 

locations). The spike in measured concentrations during this time frame was far less pronounced 

(if not completely imperceptible) at monitoring stations in Lincoln Park or Cañon City. Another 

spatial variation linked to site activities is the relatively elevated readings (e.g., for natU) observed 

at the “mill entrance road” monitoring station between roughly 1997 and 2006. 

Over the last five years, annual average concentrations of every radionuclide were at least 20 

times lower than health-based screening limits at the five off-site monitoring stations. This large 

margin provides some assurance that the monitoring network has adequate coverage in terms of 

monitors—it is quite possible that annual average ambient air concentrations of radionuclides at 

some un-monitored off-site locations exceed what has been measured to date, but it is far less 

likely that the network is failing to capture a “hot spot” with concentrations more than 20 times 

higher than the levels that are currently measured. 

b) Radon Gas 

Cotter measures radon gas concentrations at the same ten monitoring stations where particlebound radionuclides are sampled. The annual environmental monitoring reports provide very 

limited information on the sampling methodology, other than noting that the detectors are 

apparently exposed to ambient air for a calendar quarter and then retrieved for laboratory 

analysis. Recent data summary reports suggest that a new sampling and analytical method was 

implemented in the second quarter of 2002. This new method outputs combined 220Rn (from 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

natural thorium) and 222Rn (from natural uranium). However, the report does not describe what 

the previous sampling and analytical method measured. 

According to Cotter’s radon sampling procedures (Cotter 2004b), the sampling devices are 

“Landauer Type DRNF Radon Detectors.” The reports provided to ATSDR suggest that various 

quality control measures have been implemented for this sampling (e.g., collection and analysis 

of duplicate samples to characterize precision), but they do not document quantitative data 

quality metrics. The method detection limit for the combined 220Rn/222Rn measurement is 70 

pCi/m3

 (Cotter 2004b). This appears to offer adequate measurement sensitivity, because most 

quarterly average concentrations measured since this method was implemented are at least an 

order of magnitude greater than the detection limit. 

Table 57 presents the annual average 220Rn/222Rn concentrations that Cotter has measured from 

2002 to the present. Data are not presented for earlier years (1979 to 2001), as they may not be 

directly comparable due to the use of different measurement technologies. Cotter has recently 

concluded that its radon monitoring data “demonstrate slightly elevated readings at boundary 

locations [when compared to] readings in residential areas at background levels” (Cotter 2008b). 

This statement seems to be supported, in a general sense, by the monitoring results, though the 

difference between the perimeter and the off-site concentrations is much lower in certain years, 

particularly in 2008. 

The approach used for screening the 220Rn/222Rn concentrations differs from that used for other 

radionuclides. Cotter screens the 220Rn/222Rn using an approach approved by CDPHE. In this 

approach, Cotter derives an “effective effluent limit” based on a baseline regulatory limit, an 

equilibration factor for the measurements, and average background concentrations that are 

calculated semi-annually. The details of this derivation are documented in a letter that CDPHE 

sent to Cotter in June, 2004. The net effect of this calculation approach is that the “effective 

effluent limit” (i.e., the concentration used for screening purposes) can vary across the 

monitoring stations and years. To illustrate this point, between 2006 and 2008, the “effective 

effluent limit” of 220Rn/222Rn concentrations ranged from 1,290 to 1,981 pCi/m3, depending on 

the magnitude of the background concentrations at the time. During this time frame, measured 

concentrations at perimeter monitoring stations reached as high as 85% of the “effective effluent 

limit.” 

c) Gamma Radiation 

Cotter measures gamma radiation levels at the same ten monitoring stations where particlebound radionuclides are sampled. Measurements are made using thermoluminescent dosimeters 

(TLDs) that are exposed for 3-month periods before being sent off-site for analysis. Every 

calendar quarter, an additional duplicate TLD is deployed to at least one monitoring station to 

assess measurement precision, and a control TLD is placed in a lead-shielded box at another 

location to serve as a “blank” sample. However, the site reports provided to ATSDR did not 

contain any quantitative metrics of data quality (e.g., relative percent difference in co-located 

samples). 

Table 58 presents annual average gamma radiation exposure rates between 1979 and 2008, by 

monitoring station; these annual averages were calculated from the quarterly TLD measurements 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

from each calendar year. For every year on record, the highest annual average exposure rate was 

observed at one of the perimeter monitoring stations. Since Cotter installed the monitoring 

station at the mill’s entrance road in 1994, this station has recorded the highest annual average 

exposure rates every year through the present. The relatively high readings at this location are 

believed to result primarily from past spillage or incoming materials entering the facility (Cotter 

2008b). Under oversight from CDPHE, Cotter removed contamination alongside the entrance 

road in 2006 and 2007, with exposure rates decreasing thereafter. 

Cotter’s monitoring reports do not include health-based screening evaluations for these 

measurements, but they do acknowledge that the exposure rates near the facility perimeter (and 

particularly along the entrance road) exceed background levels. Specifically, the reports assume 

that the Cañon City station’s measurements reflect “background” contributions from all external 

sources. The report indicates that the reported background level at this station (10.2 μR/hr) is 

equivalent to a dose of 89 mrem/year. 

d) Ambient Air Monitoring for non-Radioactive Substances 

To prepare this summary, ATSDR accessed all ambient air monitoring data that the state of 

Colorado collected in Fremont County and reported to EPA’s Air Quality System (AQS), an 

online clearinghouse of monitoring data that states collect to assess compliance with federal air 

quality standards. The AQS database included monitoring results for three locations in Fremont 

County: one in Cañon City, one in Lincoln Park, and one in Florence. This section summarizes 

only those data collected in Cañon City and in Lincoln Park given their closer proximity to 

Cotter Mill. However, the monitoring summarized in this section was not conducted to 

characterize air quality impacts associated with Cotter Mill’s emissions; the measured 

concentrations at these locations likely reflect contributions from many different local emission 

sources (e.g., mobile sources, wind-blown dust, wood-burning stoves). The AQS database does 

not specify quality control parameters for the monitoring results; however, state agencies that 

submit data to AQS are supposed to thoroughly validate measured concentrations before entering 

them into the database. 

(1) Particulate Matter (TSP, PM10, and PM2.5) 

The state-operated Cañon City and Lincoln Park monitoring stations measured three different 

size fractions of particulate matter between 1969 and the present. Following standard practice, all 

three size fractions were measured in 24-hour average integrated samples that were typically 

collected once every 6 days, though more frequent monitoring occurred during some years. 

Measurements were collected using either standard technologies (e.g., high-volume samplers for 

TSP and PM10) or EPA-approved Federal Reference Method devices. A brief summary of the 

measurements follows: 

 TSP measurements. From 1969 through 1987, high-volume sampling devices were used 

to measure TSP. Table 59 in Appendix A presents the maximum and annual average TSP 

concentrations measured by the two monitoring stations over the period of record. 

Annual average TSP in Cañon City did not change considerably from 1969-1987. In 

Lincoln Park, only two calendar years have complete data sets; the annual average 

concentration in 1982 was below the range of annual averages observed at Cañon City. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The fact that TSP levels were lower in Lincoln Park than in Cañon City suggests that 

Cotter Mill’s emissions are not the primary contribution to TSP levels in the area. 

 PM10 measurements. The state of Colorado began monitoring PM10 in Cañon City in 

1987 and continues this monitoring today. The monitoring station was originally located 

at the courthouse in Cañon City, but the state moved the monitoring equipment in 1987 to 

a less obstructed site at city hall. Annual average PM10 concentrations throughout the 

period of record range from 15 to 23 μg/m3, well below EPA’s former National Ambient 

Air Quality Standard for annual average levels (50 μg/m3

). Between 1987 and 2009, only 

one measured 24-hour average concentration exceeded EPA’s current health-based 

standard; that occurred in 1988 and likely reflected contributions from many different 

local sources and should not be attributed solely to Cotter Mill’s emissions. 

 PM2.5 measurements. In 1991 and 1992, the state conducted PM2.5 monitoring at its 

Cañon City station. All measured 24-hour average concentrations and both annual 

average concentrations were lower than the health-based standards that EPA would 

develop later in the 1990s. This monitoring occurred before EPA designated Federal 

Reference Methods for PM2.5 measurement devices. 

(2) Constituents of Particulate Matter 

Between 1978 and 1987, the state of Colorado analyzed some of the TSP filters collected in 

Cañon City and Lincoln Park for chemical constituents. This included analyses for metals (iron, 

lead, manganese, and zinc) and ions (nitrate and sulfate). Table 60 summarizes these 

measurements by presenting the highest 24-hour average concentration and the highest annual 

average concentration for the period of record. 

50 
 

 

 

	 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

V. PUBLIC HEALTH EVALUATION 

A. Introduction 

This section of the public health assessment evaluates the health effects that could possibly result 

from exposures to site-related contaminants at or near the Cotter Mill site. For a public health 

hazard to exist, people must contact contamination at levels high enough and for long enough 

time to affect their health. The environmental data and conditions at the site revealed five 

completed exposure pathways: 

1.	 Exposure to site-related contaminants in groundwater in Lincoln Park. 

2.	 Contact with site-related contaminants in soil adjacent to the Cotter Mill and in Lincoln 

Park. 

3.	 Contact with site-related contaminants in surface water downstream from the Cotter Mill. 

4.	 Exposure from eating produce locally grown in Lincoln Park 

5.	 Exposure to ambient air near the Cotter Mill facility 

B. How Health Effects are Evaluated 

The potential health effects associated with completed exposure pathways (listed above) will be 

evaluated in this section. For chemicals found to exceed comparison values, ATSDR calculated 

exposure doses and estimated non-cancer and cancer risks, where applicable. The calculations 

estimate the amount of the chemical to which a person may have been exposed. Calculated 

exposure doses are then compared to the available health guidelines to determine whether the 

potential exists for adverse non-cancer health effects. In the event that calculated exposure doses 

exceed established health guidelines (e.g., ATSDR’s Minimal Risk Levels or EPA’s Reference 

Doses), an in-depth toxicological evaluation is necessary to determine the likelihood of harmful 

health effects. ATSDR also may compare the 

estimated amount of exposure directly to 

human and animal studies, which are reported 

 in ATSDR's chemical-specific toxicological 

profiles. Not only do the toxicological 

profiles provide health information, 

they also provide information about 

environmental transport, human exposure, 

and regulatory status. 

A detailed explanation of ATSDR’s evaluation 

process for determining cancer and non-cancer 

health effects is contained in Appendix C of 

this document. The equations to calculate 

exposure doses, the exposure scenarios, 

and the exposure assumptions used to 

estimate exposures at this site are also 

in Appendix C. 

ATSDR’s Minimal Risk Level (MRL), which is 

derived from human and animal studies, is an 

estimate of daily exposure to a contaminant 

below which non-cancer health effects are 

unlikely to occur. 

EPA's Reference Dose An estimate (with 

uncertainty spanning perhaps an order of 

magnitude) of a daily oral exposure to the 

human population (including sensitive 

subgroups) that is likely to be without an 

appreciable risk of deleterious effects during a 

lifetime. It can be derived from a NOAEL, 

LOAEL, or benchmark dose, with uncertainty 

factors generally applied to reflect limitations of 

the data used. Generally used in EPA's 

noncancer health assessments. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

C. Groundwater Pathway: Private wells used for personal consumption 

As discussed above, the data from the 1989 Lincoln Park Water Use Survey survey indicated 

approximately 7 wells are used for personal consumption; sampling data for 6 of the 7 wells 

were available to ATSDR for evaluation. Samples were collected intermittently from 1984 to 

2007. 

Although most residents in Lincoln Park currently use municipal water for drinking purposes, the 

survey reveals that residents at 7 locations still use their private wells for drinking purposes. It is 

not verified whether residents who reported using their well water for personal consumption also 

use their well water for other household purposes, such as bathing and showering. Some 

residents report that they and others used their private wells for personal consumption and other 

household uses in the past (before the installation of the municipal water line). Therefore, it is 

reasonable to assume that many more people obtained their drinking water from private wells in 

the past, and that some people are continuing to use their private wells for drinking, and possibly, 

household purposes. 

Very little quantitative information is known about what levels of contamination residents may 

have been exposed to in the past. However, ATSDR attempted to address this issue by assuming 

that the average resident would have been exposed to the average chemical concentration (i.e., 

temporal average per well) detected in the 6 private wells for which we have sampling data. 

There is some uncertainty in using this estimate because some people may have been exposed to 

more, and some to less, than the estimated amount. To capture the resident who may have been 

more highly exposed (or a worst case scenario), ATSDR used the average chemical 

concentration from the single private well that consistently contained the highest chemical 

concentrations (Well 189). ATSDR assumed that adults and children drank the water from this 

well for 350 days per year for 30 years (adults) and 6 years (children), respectively. 

Molybdenum was the only chemical in private wells that had an average detected level (0.082 

mg/L) that exceeded its comparison value (0.05 mg/L). The average level of molybdenum in 

Well 189 (0.16 mg/L) also exceeded the comparison value for molybdenum in drinking water. 

Therefore, molybdenum was retained as a chemical of concern and evaluated for possible 

adverse health effects. The maximum detected level of uranium (0.067 mg/L), but not the 

average detected level (0.028 mg/L), also exceeded the comparison value of 0.03 mg/L for 

uranium. Additionally, the average detected level of uranium in Well 189 (0.048 mg/L) exceeded 

the comparison value for uranium. Therefore, ATSDR evaluated uranium more closely for 

potential adverse health effects. Table 7 below summarizes the estimated child and adult doses 

for molybdenum and uranium that guide the health discussion below. (See Table C1 in Appendix 

C for a detailed discussion of how these values were derived.) 

52 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 7. Estimated Child and Adult Doses for Molybdenum and Uranium 

in Drinking Water 

Chemical Exposure 

Group 

Adult 

Estimated Dose 

(mg/kg/day) 

Child 

Estimated Dose 

(mg/kg/day) 

Health 

Guideline 

(mg/kg/day) 

Molybdenum 

Well 189 

(high 

exposures) 

0.004 0.010 

0.005 

Chronic Oral 

RfD All wells 

(average 

exposures) 

0.002 0.005 

Uranium 

Well 189 

(high 

exposures) 

0.001 0.003 

0.002 

Intermediate 

Oral MRL All Wells 

(average 

exposures) 

0.0008 0.002 

1. Molybdenum 

Molybdenum is a naturally occurring element found in various ores. Molybdenum is also 

considered an essential dietary nutrient in humans and animals. Foods such as legumes, leafy 

vegetables, nuts and cereals tend to be higher in molybdenum than meats, fruits, and root and 

stem vegetables [WHO 2003]. The Food and Nutrition Board (FNB) of the Institute of Medicine 

has determined the Tolerable Upper Intake Level12 (UL) for molybdenum in children and adults 

[FNB 2001] as follows: 

 children 1 to 3 years of age - 0.3 mg/kg/day; 

 children 4 to 8 years of age - 0.6 mg/kg/day; 

 children 9 to 13 years of age - 1.1 mg/kg/day; 

 adolescents 14 to 18 years of age - 1.7 mg/kg/day; and 

 adults - 2.0 mg/kg/day. 

a) Health Evaluation of Molybdenum 

Drinking water from a private well contaminated with molybdenum would result in an estimated 

dose of 0.002 mg/kg/day for an average adult and 0.005 mg/kg/day for an average child. The 

adult dose is lower than the oral RfD of 0.005 mg/kg/day for molybdenum. The estimated child 

dose is equal to the oral RfD (0.005 mg/kg/day) for molybdenum. Therefore, adverse health 

12 UL = maximum level of daily nutrient intake that is likely to pose no risk of adverse health effects in all 

individuals. The UL represents the total intake from food, water, and supplements. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

effects are not expected for the average adult or child who drank from a private well 

contaminated with molybdenum. 

Adults who may have had high exposures, such as those similar to Well 189, have an estimated 

dose of 0.004 mg/kg/day, and children who may have had high exposures have an estimated dose 

of 0.010 mg/kg/day. The adult high dose is less than the oral RfD for molybdenum. However, the 

estimated child high exposure dose is 2 times greater than the oral RfD of 0.005 mg/kg/day for 

molybdenum. Because the estimated exposure dose for children exceeds the long-term health 

guidelines for molybdenum, the possibility of health consequences from this exposure was 

evaluated further. 

To further evaluate the possibility of adverse health effects, ATSDR divides the lowest observed 

adverse effect level (LOAEL) and/or the no observed adverse effect level (NOAEL) by the sitespecific exposure doses. Interpretation of the resulting value is subjective and depends on a host 

of toxicological factors. Further evaluation consists of a careful comparison of site-specific 

exposure doses and circumstances with the epidemiologic and experimental data on the 

chemical. The purpose of the comparison is to evaluate how close the estimated exposure doses 

are to doses that cause health effects in humans or animals. 

The oral RfD for molybdenum is based on a human epidemiological study that found a LOAEL 

of 0.14 mg/kg/day for increased serum uric acid levels and prevalence of gout-like condition in 

Armenian villagers [Koval’skiy 1961]. A higher incidence (18-31%) of a gout-like disease was 

associated with high intake of molybdenum (10-15 mg/day) from soil and plants. The gout-like 

condition was characterized by pain, swelling, inflammation and deformities of the joints, and, in 

all cases, an increase in the uric acid content of the blood. In a number of cases, illnesses of the 

GI tract, liver, and kidneys accompanied the condition [EPA IRIS]. In deriving the oral RfD, an 

uncertainty factor of 3 was used for protection of sensitive human populations and a factor of 10 

was used for the use of a LOAEL instead of a NOAEL for a long-term study in a human 

population. The estimated child high dose (0.010 mg/kg/day) for molybdenum at the Cotter 

Mill/Lincoln Park site is 14 times lower than the LOAEL from this study. There was no NOAEL 

determination for molybdenum from this study. 

Molybdenum is known to interfere with copper metabolism in ruminant animals (grazing 

animals that “chew their cud,” such as sheep or cows); the resulting copper deficiency is reported 

to cause the animal’s hair/wool to turn white [FNB 2001]. This is a problem with ruminant 

animals in particular because high dietary molybdenum reacts with moderate to high dietary 

sulfur in the rumen (the first stomach) to form thiomolybdates. These compounds greatly reduce 

copper absorption, and certain thiomolybdate species can be absorbed and interfere systemically 

with copper metabolism [Spear 2003]. This interaction between thiomolybdates and copper is 

not expected to occur to a significant degree in humans [Turnlund 2002]. Although the exact 

effect of molybdenum intake on copper status in humans remains to be clearly established, 

individuals who do not take in enough dietary copper or cannot process it correctly could be at 

increased risk of molybdenum toxicity [FNB 2001]. 

In conclusion, children who drink water containing high concentrations of molybdenum could be 

at increased risk of adverse health effects such as gout-like symptoms. However, molybdenum is 

not stored at high levels in the body, so it is unlikely that children will suffer long-term health 

54 
	 

	 

	 

	 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

effects once the exposure is stopped [FNB 2001]. In healthy people, excess molybdenum is not 

associated with adverse health outcomes. However, individuals who do not take in enough 

dietary copper or cannot process it correctly could be at increased risk for adverse health effects. 

The actual risk of adverse health effects occurring depends on the concentration of molybdenum 

in the water and how much water is drunk. Therefore, private wells known to be contaminated 

with molybdenum should not be used for drinking purposes. 

b) Additional Comments about Molybdenum in Drinking Water 

	 ATSDR did not evaluate potential exposures to molybdenum that could occur if well 

water is used for other household purposes such as showering or bathing. If it is 

confirmed that residents are using their wells for other potable purposes, then exposure 

levels would increase, as well as the likelihood of adverse health effects. However, 

exposure to airborne and/or dermal molybdenum is not likely to be a major exposure 

pathway because of the physicochemical properties of molybdenum. 

	 The estimated dose for children and adults at this site did not exceed the Tolerable Upper 

Intake Level (UL) for molybdenum established by the Institute of Medicine. However, 

ATSDR’s evaluation did not consider molybdenum intake from other sources, including 

food and supplements, which would increase total intake. 

	 Molybdenum is often found naturally in the geology of this region. The wells identified 

and sampled as background for the Lincoln Park area contained an average molybdenum 

concentration of 0.023 mg/L. This concentration is lower than the average of 0.082 mg/L 

found in private wells used for personal consumption. The maximum concentration of 

molybdenum in a background well (0.3 mg/L) was about the same as that in a private 

well (0.28 mg/L) used for personal consumption. 

	 Overall molybdenum levels in groundwater decreased over time. Molybdenum levels 

measured from 1968 to 2000 show a clear pattern of decrease in molybdenum 

concentrations. Therefore, exposures to molybdenum in groundwater were likely higher 

in the past, and may continue to decrease in the future. 

People who currently own private wells are not prevented from using their private wells for any 

purpose. New residents who move to the area may install new wells in the contaminated zone 

and use their well for any purpose. Therefore, this exposure pathway will continue to exist as a 

potential exposure pathway in the future. 

2.	 Uranium 

Throughout the world uranium is a natural and common radioactive element. Uranium is a 

silver-white, extremely dense, and weakly radioactive metal. It is typically extracted from ores 

containing less than 1% natural uranium. Natural uranium is a mixture of three isotopes: 238U 

(99.2739%), 235U (0.7204%), and 234U (0.0057%). It usually occurs as an inorganic compound 

with oxygen, chlorine, or other elements [NHANES 2005]. Rocks, soil, surface and ground 

water, air, plants, and animals all contain varying amounts of uranium. Colorado ranks third, 

55 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

behind Wyoming and New Mexico, tied with Arizona and Utah, as the state with the most 

uranium reserves in the United States [EIA 2001]. 

a) Health Evaluation of Uranium 

Natural uranium is radioactive but poses little radioactive danger—it releases only small amounts 

of radiation that cannot travel far from its source. Moreover, unlike other types of radiation, 

alpha radiation released by natural uranium cannot pass through solid objects, such as paper or 

human skin. You have to eat, drink, or breathe natural uranium in order to be exposed to the 

alpha radiation; however, no adverse effects from natural uranium’s radiation properties have 

been observed in humans. The National Academy of Sciences determined that bone sarcoma is 

the most likely cancer from oral exposure to uranium; its report noted, however, that this cancer 

has not been observed in exposed humans and concluded that exposure to natural uranium may 

have no measurable effect [BEIR IV]. 

Scientists have seen chemical effects in people who have ingested large amounts of uranium. 

Kidney disease has been reported in both humans and animals that were exposed to large 

amounts of uranium; however, the available data on soluble (more bioavailable) and insoluble 

uranium compounds are sufficient to conclude that uranium has a low order of metallotoxicity in 

humans [Eisenbud and Quigley 1955]. 

When uranium is ingested most of it leaves the body through the feces and a small portion 

(approximately 2% for an adult) will be absorbed into the blood stream through the 

gastrointestinal (GI) tract. Most of the uranium in the blood is excreted from the body through 

urine excretion within a few days; however, a small amount will be retained in the kidneys, bone, 

and soft tissue for as long as several years. The percentage of the uranium retained in the kidneys 

over time is different for acute and chronic ingestion of uranium (as long as the individual 

continues to drink the water). When an individual discontinues drinking the uranium 

contaminated water, the percentage of retention in the kidney decreases similar to an acute 

exposure. In the case of chronic ingestion of drinking water containing uranium, the kidney 

retention (or kidney burden) increases rapidly in the first two weeks. After approximately 100 

days, the amount present in the kidney is approximately 5% of the daily intake for an infant and 

approximately 3% for all other ages. After 25 years of chronic ingestion, the uranium kidney 

burden reaches equilibrium for all age groups at approximately 6.6% of the daily intake [Chen et 

al 2004]. 

Nephrotoxicity (kidney toxicity) occurs when the body is exposed to a drug or toxin such as 

uranium that causes temporary or permanent damage to the kidneys. When kidney damage 

occurs, blood electrolytes (such as potassium and magnesium) and chemical wastes in the blood 

(such as creatinine) become elevated indicating either a temporary condition or the development 

of kidney failure. Creatinine is a chemical waste molecule that is generated from muscle 

metabolism. The kidneys maintain the blood creatinine in the normal range. Creatinine is a fairly 

reliable indicator of kidney function. As the kidneys are impaired, the creatinine level in the 

blood will rise because of the poor clearance by the kidney. If detected early, permanent kidney 

problems may be avoided. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Several mechanisms for uranium-induced kidney toxicity have been proposed. In one of these, 

uranium accumulates in specialized (epithelial) cells that enclose the renal tubule, where it reacts 

chemically with ion groups on the inner surface of the tubule. This interferes with ion and 

chemical transport across the tubular cells, causing cell damage or cell death. Cell division and 

regeneration occur in response to cell damage and death, resulting in enlargement and decreased 

kidney function. Heavy metal ions, such as uranyl ions, may also delay or block the cell division 

process, thereby magnifying the effects of cell damage [Leggett 1989, 1994; ATSDR 1999]. 

Animal and human studies conducted in 1940s and 1950s provide evidence that humans can 

tolerate certain levels of uranium, suffering only minor effects on the kidney [Leggett 1989]. 

Most of these studies involved inhalation exposures to uranium; however, the kidney is the target 

organ for inhaled as well as ingested uranium. On the basis of this tolerance, the International 

Council on Radiologic Protection (ICRP) adopted a maximal permissible concentration of 3 μg 

of uranium per gram of kidney tissue for occupational exposure in 1959 [Spoor and Hursh 1973]. 

This level has often been interpreted as a threshold for chemical toxicity. 

More recent papers have been published on effects of uranium at levels below 3 μg/g, and those 

papers have discussed possible mechanisms of uranium toxicity [Diamond 1989; Leggett 1989, 

1994; Zhao and Zhao 1990; Morris and Meinhold 1995]. It is thought that the kidney may 

develop an acquired tolerance to uranium after repeated doses; however, this tolerance involves 

detectable histological (structural) and biochemical changes in the kidney that may result in 

chronic damage. Cells of the inner surface of the tubule that are regenerated in response to 

uranium damage are flattened, with fewer energy-producing organelles (mitochondria). 

Transport of ions and chemicals across the tubule is also altered in the tubule cells [Leggett 

1989, 1994; McDonald-Taylor et al. 1997]. These effects may account for the decreased rate of 

filtration through the kidney and loss of concentrating capacity by the kidney following uranium 

exposure. Biochemical changes include diminished activity of important enzymes (such as 

alkaline phosphatase), which can persist for several months after exposure has ended. Therefore, 

acquired tolerance to uranium may not prevent chronic damage, because the kidney that has 

developed tolerance is not normal [Leggett 1989]. Acting on the basis of this recent information 

for uranium, researchers have suggested that exposure limits be reduced to protect against these 

chronic effects on the kidney. 

Renal damage appears to be definite at concentrations of uranium per gram of kidney tissue 

above 3 μg/g for a number of different animal species, but mild kidney injury can occur at 

uranium concentrations as low as 0.1 to 0.4 μg/g in dogs, rabbits, guinea pigs, and rats after they 

inhale uranium hexafluoride or uranium tetrachloride over several months [Maynard and Hodge 

1949; Hodge 1953; Stokinger et al. 1953; Diamond 1989]. Zhao and Zhao proposed a limit of 

uranium to the kidney of 0.26 μg/g based on renal effects in a man who was exposed to high 

concentrations of uranyl tetrafluoride dust for 5 minutes in a closed room [Zhao and Zhao 1990]. 

The man showed signs of kidney toxicity, including increased protein content in the urine 

(proteinuria) and nonprotein nitrogen. These signs persisted for 4.6 years, gradually returning to 

normal values. The kidney content 1 day after the accident was estimated to be 2.6 μg/g. 

A study conducted in Finland and published in 2002 observed 325 people that had used their 

drilled wells for drinking water over a period of 13 years on average (range 1 – 34 years) 

[Kurttio et. al 2002]. The median uranium concentration in the water was 28 ppb (range 0.001 – 

57 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

1,920 ppb). The study showed an association between increased uranium exposure through 

drinking water and tubular function, but not between uranium exposure and indicators of 

glomerular injury. The primary target is the proximal convoluted tubule of the kidney which is 

where most of the sodium, water, glucose, and other filtered substances are reabsorbed and 

returned to the blood. The authors of the study indicated that tubular dysfunction may merely 

represent a manifestation of subclinical toxicity, and it is unclear if it carries a risk of 

development into kidney failure or overt illness. This study concluded that “The public health 

implications of these findings remain uncertain, but suggest that the safe concentration of 

uranium in drinking water may be close to the guideline values proposed by the WHO and the 

U.S.EPA.” However, this study found that altered tubular function was statistically significant at 

water uranium concentrations exceeding 300 μg/L [Kurttio et. al 2002], or 0.3 mg/L, which is an 

order of magnitude higher than EPA’s guideline (0.035 mg/l) and the highest average 

concentration at the Lincoln Park site (0.048 mg/L). At 300 μg/L and assuming ingestion of two 

liters of water per day, the kidney burden after 25 years of chronic ingestion would be 39.6 μg of 

uranium with a uranium concentration per gram of kidney tissue of 0.13 μg/g. 

A review of studies of uranium effects on the kidney [Morris and Meinhold 1995] suggests a 

probability distribution of threshold values for kidney toxicity ranging from 0.1 to 1 μg/g, with a 

peak at about 0.7 μg/g. The researchers proposed that the severity of effects increases with 

increasing dose to the kidney with probably no effects below 0.1 to 0.2 μg/g, possible effects on 

the kidney at 0.5 μg/g, more probable effects at 1 μg/g, and more severe effects at 3 μg/g and 

above [Morris and Meinhold 1995; Killough et al. 1998b]. 

If an adult in Lincoln Park drank 2 liters (L) of uranium-contaminated water per day (at the 

highest average exposure concentration of 0.048 mg/L, or 48 μg/L) for 25 years or longer, then 

the maximum daily ingestion would be 96 μg of uranium, resulting in a uranium kidney burden 

of 6.3 μg (96 μg × 0.066). The weight of both kidneys in adults is about 300 g [Madsden et al 

2007]. Thus, the uranium concentration per gram of kidney tissue for an adult would be 0.02 

μg/g. If a child drank 1 L of uranium-contaminated water per day (at the highest average 

exposure concentration of 0.048 mg/L, or 48 μg/L) for 100 days to 25 years, then the maximum 

daily ingestion would be 48 μg of uranium, resulting in a uranium kidney burden of 1.4 μg (48 

μg x 0.03). The weight of both kidneys in a child is about 100 g; therefore, the uranium 

concentration per gram of kidney tissue to be 0.01 μg/g. The calculated kidney uranium 

concentration for adults and children is below the level found to cause harm in published studies. 

ATSDR’s health-based guidelines for ingested (and inhaled) uranium are lower than the lower 

limit threshold for kidney toxicity proposed by Morris and Meinhold (1995). ATSDR’s 

guidelines are derived by use of levels of toxicity observed in animal studies, and those 

guidelines incorporate safety factors to account for uncertainty in extrapolating from animals to 

humans and to protect the most sensitive human individuals [ATSDR 1999]. 

Note that urinalysis has limitations as a test for kidney toxicity. First, the presence of substances 

in urine may indicate that kidney damage has occurred, but it cannot be used to determine 

whether the damage was caused by uranium. Second, most uranium leaves the body within a few 

days of exposure, so that urine tests can be used only to determine whether exposure has 

occurred in the past week or two. Finally, the tests may be used to detect mild effects on the 

kidney, but such effects are generally transient in nature and may not result in permanent 

58 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

damage. More severe effects involve greater damage to the kidney that is likely to be clinically 

manifest and longer lasting. The kidney has incredible reserve capacity and can recover even 

after showing pronounced clinical symptoms of damage; however, biochemical and functional 

changes can persist in a kidney that appears to have recovered structurally [Leggett 1989, 1994; 

CDC 1998]. 

The maximum average uranium concentration detected in a private well was 0.048 mg/L, or 48 

μg/L. The residence where this concentration was detected is not connected to the municipal 

water supply and is noted to use a private well for personal consumption. Drinking water from 

this private well containing uranium would result in an estimated dose of 0.001 mg/kg/day for an 

adult and 0.003 mg/kg/day for a child. The adult dose is lower than the intermediate oral MRL. 

The estimated child dose slightly exceeds the MRL of 0.002 mg/kg/day for an intermediateduration oral exposure. The MRL level for intermediate-duration oral exposure is also protective 

for chronic-duration oral exposure because the renal toxicity of uranium exposure is more 

dependent on the dose than on the duration of the exposure. The MRL is based on a LOAEL of 

0.05 mg U/kg/day for renal effects in rabbits. The estimated child dose is an order of magnitude 

lower than the LOAEL; therefore, adverse health effects are not likely. 

Although older evaluations suggested carcinogenicity of uranium among smokers, the U.S. EPA 

has withdrawn its classification for carcinogenicity for uranium; the International Agency for 

Research on Cancer (IARC) and the National Toxicology Program (NTP) have no ratings 

[NHANES 2005]. 

D. Soil Pathway: Surface Soil near Cotter Mill and Lincoln Park 

As discussed above, surface soil samples were collected from areas around the Cotter Mill 

property, from property access roads and in the Lincoln Park area. Surface soil sampling data 

were available from eight designated zoned areas around Cotter Mill and in Lincoln Park. People 

who live or recreate in these areas could accidentally ingest some contaminated soil or get it on 

their skin. ATSDR evaluated these potential exposure scenarios to determine if concentrations of 

chemicals and radionuclides in soil are high enough to cause adverse health effects. 

ATSDR assumed that the average adult would accidentally ingest 100 milligrams of soil per day 

and would also contact the contaminated soil with their skin (dermal). Small children were not 

assumed to access the soil around Cotter Mill because these areas are primarily industrial or 

vacant. The vacant area has been designated as a “buffer zone” between the Cotter Mill property 

and the residential areas. Therefore, it is unlikely that small children would access the area. A 

residential exposure scenario was used to evaluate potential exposures in Lincoln Park. For 

Lincoln Park, we assumed that a small child would ingest 200 mg of soil per day, and an adult 

would ingest 100 mg/day, for 350 days per year. 

Concentrations of arsenic, cadmium and lead exceeded their comparison values in soil taken 

from the area surrounding Cotter Mill. The concentration of radium-226 was the only 

radionuclide to exceed its comparison value in soil near Cotter Mill. Arsenic was the only 

chemical to exceed its comparison value in soil in Lincoln Park. The highest zonal average 

concentration of arsenic, cadmium, lead and radium-226 was used to estimate exposure doses. If 

59 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

the highest zonal average concentration of a chemical would not result in adverse health effects, 

it follows that lower concentrations of the chemical would not as well. 

1. Soil Near Cotter Mill 

a) Arsenic 

Arsenic is a naturally occurring element that is widely distributed throughout the earth’s crust 

and may be found in air, water, and soil [ATSDR 2000]. Arsenic in soil exists as inorganic and 

organic arsenic. Generally, organic arsenic is less toxic than inorganic arsenic, with some forms 

of organic arsenic being virtually non-toxic. Inorganic arsenic occurs naturally in soil, and 

children may be exposed to arsenic by eating soil or by direct skin contact with soil containing 

arsenic [ATSDR 2007]. 

The estimated dose of arsenic for adolescents and adults at this site is 0.00002 mg/kg/day. This 

dose is lower than the Minimal Risk Level (MRL) of 0.0003 mg/kg/day for arsenic; therefore, 

non-cancer health effects are not likely from being exposed to arsenic in surface soil near Cotter 

Mill (Zones A through H). The chronic oral MRL of 0.0003 mg/kg/day for inorganic arsenic was 

derived by dividing the identified chronic No Observable Adverse Effect Levels (NOAEL) of 

0.0008 mg/kg/day (obtained from human epidemiologic studies) by an uncertainty factor of three 

to account for the lack of data on reproductive toxicity and to account for some uncertainty as to 

whether the NOAEL accounts for all sensitive individuals [ATSDR 2007]. The Lowest Observed 

Adverse Effect Level (LOAEL) associated with these epidemiologic studies was 0.014 

mg/kg/day, where exposure to arsenic above this level resulted in hyperpigmentation of the skin, 

keratosis (patches of hardened skin), and possible vascular complications [ATSDR 2007]. 

The U.S. Environmental Protection Agency (EPA), the International Agency for Research on 

Cancer (IARC), and the National Toxicology Program (NTP) classify arsenic as a human 

carcinogen. The EPA has developed an oral cancer slope factor to estimate the excess lifetime 

risk for developing cancer. Using EPA’s cancer slope factor for arsenic, and based on a 30 year 

exposure scenario, ATSDR calculated a lifetime estimated cancer risk level of 1 x 10-5 for 

exposure to arsenic in soil near Cotter Mill. Qualitatively, we interpret this as a very low 

increased lifetime risk of developing cancer. 

b) Cadmium 

The estimated dose for adolescents and adults for cadmium is 0.00002 mg/kg/day, which is 

lower than the MRL of 0.0001 mg/kg/day for cadmium; therefore, non-cancer adverse health 

effects are not likely. The U.S. Department of Health and Human Services (DHHS), IARC, and 

EPA have determined that cadmium is carcinogenic to humans. Although cadmium can be 

carcinogenic when inhaled, human or animal studies have not provided sufficient evidence to 

show that cadmium is a carcinogen by oral routes of exposure (ATSDR 1999b). Therefore, a 

cancer evaluation for cadmium was not done as part of this assessment. 

c) Lead 

The highest average concentration of lead detected in any of the zones (Zone H) is 445 ppm, 

which is only slightly higher than the soil screening value of 400 ppm for lead. A value of 400 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

ppm is commonly used to evaluate lead in soil in residential properties. The property near the 

Cotter Mill site is currently restricted, vacant or used for industrial purposes; therefore contact 

with these soils should be minimal. Adverse health effects are not expected to occur from these 

limited exposures to soils near the site. Exposures to lead, however, should be re-evaluated 

should the area ever be considered for residential or other non-industrial use. 

Maximum lead concentrations in zones F, G and H are 800 ppm, 450 ppm, and 1,400 ppm, 

respectively. To protect children from exposure to lead, it is important to know the average lead 

level in a yard or other frequent play area. The 1998 Supplemental Human Health Risk 

Assessment provides the only characterization of surface soils adjacent to the Cotter Mill 

property (See Figure 17, Zones A through H). The soil sample results in this report were 

generated by collecting four samples from the center of a grid and compositing the samples to 

form a single representative sample. The size of each sampled grids, however, appears to be 

larger than 100 x 100 feet, which is the size that triggers additional sampling for lead (EPA 

1995). Although the sampling in the 1998 Supplemental Human Health Risk Assessment 

measured contamination in soils at several properties near Cotter Mill, it does not allow ATSDR 

to evaluate contamination in individual exposure units (yards, playgrounds, etc), as would be 

required to accurately assess exposures in a residential setting, commercial or recreational 

setting. The sample design is sufficient for making general public health decisions about 

exposure to lead in soil based on current use patterns. However, any future public health decision 

regarding the soil near the Cotter Mill property must be made with the limitations of the current 

sampling design in mind. 

The Centers for Disease Control and Prevention (CDC) has established a level of concern for 

case management of 10 micrograms lead per deciliter of blood (μg/dL). This means that when 

blood lead levels in children exceed 10 μg/dL, CDC recommends that steps be taken to lower 

their blood lead levels. However, some agencies and public health officials have mistakenly used 

this level in blood as a safe level of exposure or as a no effect level. Recent scientific research 

has shown that blood lead levels below 10 μg/dL cause serious harmful effects in young 

children, including neurological, behavioral, immunological, and development effects. 

Specifically, lead causes or is associated with decreases in intelligent quotient (IQ), attention 

deficit hyperactivity disorder (ADHD), deficits in reaction time, visual-motor integration, fine 

motor skills, withdrawn behavior, lack of concentration, sociability, deceased height, and delays 

in puberty, such as breast and pubic hair development, and delays in menarche [CDC]. 

d) Radium-226 

The average concentrations of radium-226 detected in Zones A and B are higher than allowed by 

the Uranium Mill Tailing Act (UMTRA). That standard does not apply in this case, since the 

Cotter Mill is still considered active. 

The highest average soil concentration of 9.2 pCi/g in surface soil would result in a dose from 

radium’s decay gammas of 58 mrem per year above background, assuming that residents spend 

12 hours per day 365 days per year sitting or lying on the highest measured radium concentration 

of 9.2 pCi/g on the haul road. Since Zones A and B are buffer areas (actually haul roads), the 

time spent in these areas would be much lower (less than 2 hours per day) and the resulting dose 

would be roughly 10 mrem per year above background, to a maximally exposed individual. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

2.	 Soil in Lincoln Park 

a) Arsenic 

The estimated arsenic dose for an adult in Lincoln Park is 0.00003 mg/kg/day, which is an order 

of magnitude lower than the MRL of 0.0003 mg/kg/day for arsenic. The estimated arsenic dose 

for a child in Lincoln Park is 0.0003 mg/kg/day, which is equal to the MRL of 0.0003 mg/kg/day 

for arsenic. Children are estimated to have higher arsenic doses than adults because they tend to 

engage in activities that increase their soil ingestion exposure, and because they weigh less than 

adults. Neither children nor adults should experience adverse health effects from exposure to 

arsenic in soil in Lincoln Park. 

Arsenic is a naturally occurring element in soil. Arsenic has also historically been used in a 

variety of industrial applications, including bronze plating, electronics manufacturing, preserving 

animal hides, purifying industrial gases, and mining, milling and smelting activities. Studies of 

background levels of arsenic in soils have revealed that background concentrations range from 1 

ppm to 40 ppm, with average values around 5 ppm [ATSDR 2007]. The average arsenic 

concentration detected in Lincoln Park was 31 ppm, a concentration within the observed 

background range but higher than the average background concentration. The maximum 

concentration of arsenic detected in Lincoln Park was 50 ppm. 

Although the maximum arsenic concentration is higher than the observed background 

concentration, this fact alone does not definitely point to an anthropogenic source for the arsenic 

found in soil in Lincoln Park. Uncertainty exists regarding whether the arsenic levels detected 

are a natural occurrence or from past milling operations in the area. 

Several factors contribute to whether people have contact with contaminated soil, including: 

	 grass cover, which is likely to reduce contact with contaminated soil when grass cover is 

thick but increase contact with soil when grass cover is sparse or bare ground is present, 

	 weather conditions, which is likely to reduce contact with outside soil during cold months 

because people tend to stay indoors more often, 

	 the amount of time someone spends outside playing or gardening, and 

	 people's personal habits when outside, for instance, children whose play activities involve 

playing in the dirt are likely to have greater exposure than other children 

Using EPA’s cancer slope factor for arsenic, and based on a 30 year exposure scenario, ATSDR 

calculated a lifetime estimated cancer risk level of 5 x 10-5 for exposure to arsenic in Lincoln 

Park. Qualitatively, we interpret this as no apparent increased lifetime risk of developing cancer. 

E. Surface Water: Sand Creek, DeWeese Dye Ditch, and the Arkansas River 

People who swim or wade in the surface waters of Sand Creek, the DeWeese Dye Ditch, or the 

Arkansas River will get surface water on their skin and they might also accidentally ingest some 

of the surface water. To estimate exposures to adults and children who may have come into 

62 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

contact with contaminated surface water, ATSDR assumed that adults and children will swallow 

50 mL of water per hour while swimming or wading, for 104 days per year for 30 and 6 years, 

respectively. Molybdenum exceeded its comparison value in Sand Creek and the Arkansas River. 

Manganese exceeded its comparison value in Sand Creek and the DeWeese Dye Ditch. ATSDR 

conservatively selected the maximum concentration for each chemical to estimate exposures. 

1. Manganese 

The estimated exposure dose for manganese is 0.0007 mg/kg/day for adults and 0.0006 

mg/kg/day for children. Both adult and child doses are considerably lower than the reference 

dose of 0.05 mg/kg/day for manganese. Therefore, no adverse health effects are expected to 

occur as a result of exposure to manganese in surface waters. 

2. Molybdenum 

The estimated exposure dose for molybdenum is 0.00002 mg/kg/day for adults and 0.00006 

mg/kg/day for children. Both adult and child doses are below the chronic oral reference dose 

(RfD) of 0.005 mg/kg/day for molybdenum. Therefore, no adverse health effects are expected to 

occur as a result of exposure to molybdenum in surface waters. 

F. Homegrown Fruits and Vegetables 

Ingestion of contaminated foods is a potential exposure pathway for this site. Residents may 

have been exposed to contaminants when they ate homegrown fruits and vegetables after using 

contaminated groundwater (either surface water or private well water) to irrigate their crops, or 

after growing their crops in contaminated soil. The soil may become contaminated from 

contaminated water or from tailings, dusts and other wastes deposited in the soil in the past. 

Eating fruits, vegetables, herbs, or other produce grown in gardens with contaminated soil can 

cause exposure. This type of exposure occurs because some plants slowly absorb small amounts 

of the chemicals found in soil into their plant tissue or because contaminated soil can adhere to 

the exterior surface of produce, particularly low-growing leafy produce or produce where the 

underground portion is eaten. Some of these absorbed chemicals are essential nutrients and are 

actually good for humans to eat, but other chemicals can present health hazards if they are found 

at high enough levels and are consumed on a regular basis. 

Generally, there is not a strong relationship between levels of heavy metals in soils and plants 

[Vousta 1996]. The uptake of heavy metal concentration depends on speciation of metal, soil 

characteristics, the type of plant species and other characteristics [Laizu 2007]. Table 8 below 

developed by Sauerbeck (1988) provides a qualitative guide for assessing heavy metal uptake 

into a number of plants. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 8. Plant Uptake of Heavy Metals 

High Moderate Low Very Low 

Lettuce Onion Corn Beans 

Spinach Mustard Cauliflower Peas 

Carrot Potato Asparagus Melons 

Endive Radish Celery Tomatoes 

Crest Berries Fruit 

Beet 

Beet leaves 

Source: USEPA (1991), Human Health Evaluation Manual, Supplemental Guidance: “Standard 

Default Exposure Factors.” 

To address the concern regarding contaminated crops, residents contributed locally grown 

produce for sampling analysis. ATSDR used the sampling results to estimate an exposure dose 

for each contaminant using typical consumption rates for the average and above-average (95th 

percentile) consumer in the Western United States. Child and infant consumption rates were also 

used to assess exposures to these vulnerable populations. Table 9 below provides the 

consumption rates used by ATSDR for homegrown fruits and vegetables. 

Table 9. Homegrown Fruit and Vegetable Consumption Rates for the Western United States 

Food Consumer Type† Intake Rate 

(g/kg/day) Standard Error 

Homegrown fruits 

Average consumer 2.62 

Above-average 0.3

consumer 

10.9 

Child 4.1 

NA Infant (1 to 2 years) 8.7 

Homegrown 

vegetables 

Average consumer 1.81 

Above-average 0.1

consumer 

6.21 

Child 2.5 

NA Infant (1 to 2 years) 5.2 

Sources: EPA Exposure Factors Handbook, Volume II, 1997; Child-Specific Exposure Factors Handbook, 2008 

g/kg/day: grams per kilogram per day 

NA = not applicable 

†An average consumer is represented here as a person who eats fruits and vegetables in the typical range 

(mean intake). An above average consumer is a person who eats more fruits and vegetables than is typical, 

represented here by the 95th percentile intake. 

All of the estimated fruit and vegetable doses were below health guideline values except for 

those for arsenic (See Table C4 in Appendix C). The estimated doses for fruits for the aboveaverage consumer (95th percentile intake rate) and for infants exceed the chronic health guideline 

64 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

for arsenic. The above-average consumer and infant doses for fruit are 0.0006 mg/kg/day and 

0.0004 mg/kg/day, respectively. Also, the estimated doses for vegetables for the above-average 

consumer (95th percentile intake rate) and for infants exceed the chronic health guideline for 

arsenic. The vegetable doses are 0.0005 mg/kg/day for an above-average consumer and 0.0004 

mg/kg/day for an infant. These doses exceed the chronic oral MRL of 0.0003 mg/kg/day for 

arsenic. 

 Next, ATSDR assumed that a person will eat both fruits and vegetables daily. To do this, we 

added the calculated doses for fruits and vegetables to derive a single dose. The estimated fruit 

and vegetable doses for the above-average consumer, child and infant exceed the health 

guideline of 0.0003 mg/kg/day for arsenic. The above-average consumer dose is 0.001 

mg/kg/day; the child dose is 0.0004 mg/kg/day; and the infant dose is 0.0008 mg/day/day. 

The chronic oral MRL of 0.0003 mg/kg/day for inorganic arsenic was derived by dividing the 

chronic No Observable Adverse Effect Level (NOAEL) of 0.0008 mg/kg/day (obtained from 

human epidemiologic studies) by an uncertainty factor of 3 to account for the lack of data on 

reproductive toxicity and to account for some uncertainty as to whether the NOAEL accounts for 

all sensitive individuals [ATSDR 2007]. The Lowest Observed Adverse Effect Level (LOAEL) 

associated with these epidemiologic studies was 0.014 mg/kg/day, where exposure to arsenic 

above this level resulted in hyperpigmentation of the skin, keratosis (patches of hardened skin), 

and possible vascular complications [ATSDR 2007]. The child and infant doses are below or 

equal to the NOAEL, and the above-average consumer dose is 14 times lower than the dose that 

caused adverse health effects in epidemiologic studies. Therefore, adverse health effects are not 

expected in infants, children or the above-average consumer. 

Using EPA’s cancer slope factor for arsenic and the above consumer exposure dose, and based 

on a 30 year exposure scenario, ATSDR calculated a lifetime estimated cancer risk level of 6 x 

10-4 for exposure to arsenic in fruits and vegetables. Qualitatively, we interpret this as a low to 

moderate increased risk of developing cancer over a lifetime. 

ATSDR conservatively assumed that every consumer ate homegrown fruits and vegetables every 

day for 30 years. In reality, it is likely that most people only eat homegrown fruits and vegetables 

during a defined season, usually a 3 to 4 month period during the summer/fall growing season. 

Therefore, the true risk to consumers is likely overestimated. 

ATSDR also noted that the highest arsenic level detected in lawns and gardens in Lincoln Park 

was 50 ppm. This level is near what is typically observed as background arsenic levels (1 ppm to 

40 ppm) in soil. This suggests that the contaminated well water used to irrigate crops is not 

contributing significantly to arsenic soil levels, or other soil additives may have been added that 

dilute soil contamination [ODEQ 2003]. The highest arsenic level detected in soil at the site was 

86 ppm. There were no sampling data for arsenic in drinking or irrigation water. ATSDR is 

unsure if the arsenic found in soil at this site is a natural occurrence or from an anthropogenic 

(man-made) source. 

Plants vary in the amount of arsenic they absorb from the soil and where they store arsenic. 

Some plants move arsenic from the roots to the leaves, while others absorb and store it in the 

roots only [Peryea 1999]. The best method of reducing exposure to external arsenic from home65 
 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

grown vegetables is to soak and wash residual soil from produce before bringing it into the home 

and washing the produce again thoroughly indoors before eating [ATSDR 2007]. It is always a 

good health practice to wash all fruits and vegetables thoroughly before eating, whether they are 

bought or homegrown. 

Molybdenum was the only other contaminant to approach a health guideline when calculating a 

single dose for fruits and vegetables. The above-average consumer and infant doses are 

0.005mg/kg/day, which is equal to the chronic health guideline of 0.005mg/kg/day for 

molybdenum. 

G. Air Pathway 

ATSDR looked at all the air data collected from 1979 to present. Concentrations of radionuclides 

in air from direct release or re-suspension of radioactive contaminants in soil were less than a 

tenth of ATSDR’s health based comparison value (100 millirem per year) at all off-site sampling 

locations (CC-1/2, LP-2, AS-210, AS-212, OV-3). ATSDR evaluated doses to all age groups and 

found that adults would have received the highest doses, because of their higher breathing rate. 

Infants only received one quarter the dose of an adult. 

Table 10 below breaks down the dose estimates by age group and by the highest annual 

concentration measured for each radionuclide and by the highest location. The two highest doses 

were both in 1982, during the excavation of the unlined settling ponds and were measured at the 

on-site sampling location AS-204, that was directly adjacent to the dewatered ponds. Neither of 

those doses would have been to the public. The combined dose to a worker near AS-204 would 

have been less than a third of the sum in the table since the worker was there less than 8 hours 

per day for 5 days a week, or 70 mrem of inhalation dose for the year 1982, while the numbers in 

Table 10 reflect 24/7 exposure through the year. Doses listed in Table 10 did not result in any 

elevated exposures to the public. 

Table 10. Annual Effective Doses by Highest Concentration, Location and Age Group 

Radionuclide 

Highest 

Year 

Highest 

Location 

Concentration 

(μCi/ml) 

Dose to 

Infant 

(mrem/yr) 

Annual 

Dose to 

Adult Notes 

Natural Uranium 

(μCi/ml) 1979 AS-204 2.48E-14 2.72 5.97 

Thorium-230 

(μCi/ml) 1982 AS-204 8.95E-14 71.57 272.68 

Thorium-232 

(μCi/ml) 2001 CC#2 8.33E-17 0.07 0.27 

Radium-226 

(μCi/ml) 1985 AS-202 9.63E-15 1.25 2.75 

Lead-210 

(μCi/ml) 1982 AS-204 9.95E-14 7.01 16.77 

Dose from 

Radon Progeny 

Radon-220/222 

(pCi/l) 2004 AS-202 1.50E+00 NA NA 

No dose from 

Radon 

Most of the calculated inhalation dose was from the isotope Thorium-230 (Th-230). Table 11 

below lists just the dose from Th-230 for the highest annual average concentration at each 

66 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

sampling station. Again it can be seen that the on-site concentrations are consistently orders of 

magnitude higher than at off-site locations in Cañon City, Lincoln Park and west of the site 

boundary. 

Outdoor concentrations of radon contributed zero dose to the public, because it is a noble gas and 

does not stay in the lungs long enough to radioactively decay. On the other hand, the dose from 

radon decay products (e.g., lead-210) attached to respirable dust held constant year over year and 

accounted for an annual inhalation dose of four to seven millirem annually. Radon decay product 

concentration off-site did not appear to be related to releases from the site. Radon and its decay 

products appear to be from natural background and do not represent any health threat at the 

reported concentrations. 

Table 11. Annual Doses from Thorium-230 by Location and Year 

Year 

Highest 

Location 

Concentration 

(μCi/ml) 

Annual Dose to Infant 

(mrem/yr) 

Annual Dose to 

Adult(mrem/yr) 

1982 AS-204 8.95E-14 71.57 272.68 

1982 AS-202 2.12E-14 16.95 64.59 

1983 AS-203 9.79E-15 7.83 29.83 

1982 AS-206 1.26E-14 10.08 38.39 

2000 AS-209 4.16E-15 3.33 12.67 

2005 AS-210 4.85E-16 0.39 1.48 

2000 AS-212 6.69E-16 0.53 2.04 

1982 LP-1/2 7.49E-16 0.60 2.28 

1982 CC-1/2 9.18E-16 0.73 2.80 

1982 OV-3 3.15E-15 2.52 9.60 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

VI. COMMUNITY HEALTH CONCERNS 

Responding to community health concerns is an essential part of ATSDR’s overall mission and 

commitment to public health. The community associated with a site is both an important 

resource for and a key audience in the public health assessment process. Community members 

can often provide information that will contribute to the quality of the health assessment. 

Therefore, during site visits and telephone conversations with community members, ATSDR 

obtained information from the community regarding their specific health concerns related to the 

site. 

In some cases, ATSDR was unable to address a community health concern because 1) adequate 

scientific information on the particular health effect is not available or is limited or 2) the 

available scientific data are insufficient to assess whether the specific health effect is related to 

exposure to a particular chemical. Where feasible, ATSDR addressed the health concerns 

identified by the community. Below is a summary of the community concerns and ATSDR’s 

response to those concerns. 

1. How did the 1965 flood event affect my health? 

In June 1965, prior to the construction of the SCS Dam in 1971, a flood caused the unlined 

tailings ponds at the Cotter Mill to overflow into Lincoln Park. According to the residents, the 

waters flowed north through the gap in the ridge, 

down Pine Street, and ultimately down 12th Street 

(Sharyn Cunningham, CCAT, personal 

communication, February 2008). There is concern 

that this flood event contaminated groundwater 

wells and that dust from soil or tailings may have 

been resuspended by wind and distributed in 

Lincoln Park. Community members are very 

concerned that current illnesses may be a result of 

this tailings pond flood event. 

ATSDR tried to locate data to evaluate the 

potential health effects resulting from this flood 

event. No data from 1965 or 1966 exist in the 

CDPHE database. The 1986 Remedial 

There is documentation that ponds at the 

Cotter Mill historically overflowed, which led 

to the construction of the SCS Dam. Aerial 

photography from October 1970 indicates 

that one of the evaporation ponds 

overflowed into an alluvial channel tributary 

to Sand Creek (Wilder et al. 1983). A 

chronology compiled by CDPHE states that 

in October 1970 and January 1971, an 

evaporation pond overflowed with high 

levels of total dissolved solids, sodium, 

molybdenum, sulfate, and high radiation 

(CDPHE 1975).However, since the 

construction of the SCS Dam, there are no 

recorded surface water discharges past the 

dam (GeoTrans 1986). 

Investigation (GeoTrans 1986) states that off-site groundwater contamination in the Lincoln Park 

areas was first identified in 1968; therefore, any data prior to 1968 are unlikely to exist. The only 

data ATSDR found related to this flood event were from a sediment sample collected in January 

2003 (CDPHE 2003). To address community concerns, CDPHE collected a sample of suspected 

flood sediment from Pine Street near Elm Avenue. This area was identified by a property owner 

who was present during the flood. The sample was collected from two locations. About 250 

grams of soil were collected from each location to a depth of approximately 18 inches. No 

obvious soil horizons were identified, and no significant differences in gamma radiation were 

noted between shallow and deep soils. The results are presented in Table 12 below. All 

concentrations from this one sample are below comparison values. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The results of the sediment sample from the flood did not exceed any comparison values. If this 

sample was representative of the material moved by the floodwaters, it would not cause any 

adverse health effects. 

Table 12. Concentrations found in a suspected flood sediment sample, January 2003 

Chemical Concentration (ppm) Comparison Value (ppm) 

Lead 87 400 

Molybdenum Not detected 300 

Uranium 1.6 100 

Radionuclide Concentration (pCi/g) Comparison Value (pCi/g) 

Cesium-137 0.12 Not available 

Lead-210 2.2 Not available 

Plutonium-239, 240 Not detected Not available 

Potassium-40 22.5 Not available 

Radium-226 2.2 15 

Radium-228 1.3 15 

Source: CDPHE 2003 

2.	 Were an adequate number of soil samples collected during the 1998 Supplemental 

Human Health Risk Assessment? 

The community expressed concern that not enough samples were collected during the 1998 

Supplemental Human Health Risk Assessment. Weston, a contractor for Cotter, collected surface 

soil samples (0-2 inches) from eight zones around the mill property (see Figure ). Each zone was 

divided into 8 to 12 grids. Four samples were collected near the center of each grid and were 

composited (i.e., combined and homogenized) to form a single representative sample (Weston 

1998). The dates the samples were collected were not specified in the report; however, it is 

assumed to be in the 1994–1996 timeframe. In 1995, EPA released guidance for obtaining 

representative soil samples at Superfund sites (EPA 1995). The systematic grid sampling 

approach used by Weston conforms with EPA’s guidance for delineating the extent of 

contamination. The number of samples taken from each grid for compositing, however, is not 

entirely consistent with EPA’s guidance. For grids larger than 100 x 100 feet, which it appears 

that the grids established by Weston are, EPA recommends collecting nine aliquots from each 

grid. Compositing four aliquots from each grid is recommended for grids smaller than 100 x 100 

feet (EPA 1995). Because the timeframe of the sampling is unclear, it is not known whether 

EPA’s 1995 guidance was available during Weston’s sampling effort. 

3.	 Are there high levels of thorium near the Black Bridge? 

The community expressed concern that high thorium levels were detected in surface water near 

the Black Bridge. This bridge is located where a railroad spur crosses the Arkansas River 

between the 4th Street and 9th Street bridges. The closest sampling location in the Arkansas River 

is upstream at 1st Street (907). Thorium-230 was sampled at this location as part of the surface 

water monitoring program between 1995 and 2007. These data are summarized below in Table 

13. The highest thorium-230 concentration detected was 2.5 picocuries per liter (pCi/L) 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

(suspended sample) in August 2007. This concentration is below levels known to cause adverse 

health effects. It should also be noted that the Black Bridge is located upstream of the confluence 

with Sand Creek. 

Table 13. Thorium-230 data upstream of the Black Bridge 

Chemical Frequency of 

Detection 

Minimum 

(pCi/L) 

Average 

(pCi/L) 

Maximum 

(pCi/L) 

Thorium-230 (D) 121/127 -0.1 0.1 1 

Thorium-230 (S) 115/120 0 0.2 2.5 

Thorium-230 (T) 7/7 0.1 0.3 0.7 

Source: CDPHE 2007b 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Negative and zero result values were included in the summary statistics. 

Thorium-230 “D” and “S” samples were collected between 1995 and 2007. Thorium-230 “T” samples were only
 

collected in 1995. 

D – dissolved S – suspended 

pCi/L – picocuries per liter T – total 

4.	 I grew up near the Cotter plant. Does this increase my risk of getting cancer? 

Soil sampling data from the nearest residence to the Cotter plant did not indicate the presence of 

chemicals at levels above established guidelines. Soil sampling data from the Lincoln Park 

community did not reveal the presence of contaminants at levels associated with adverse health 

effects, including cancer. Air data do not indicate the presence of chemicals at levels associated 

with adverse health effects, including cancer. If you drank water from a contaminated private 

well, you might be at increased risk for gout-like conditions, such as pain, swelling, 

inflammation and deformities of the joints. However, once exposure is stopped, the risk of 

adverse health effects goes down. 

5.	 I used water from my private well or surface water to irrigate my crops and garden 

vegetables. Am I going to get sick? 

According to our evaluation, people who ate fruits or vegetables irrigated with contaminated well 

water are not at increased risk for non-cancer health effects. However, people who eat more than 

the average amount of fruits and vegetables (95th percentile consumers) might be at increased 

risk for developing cancer over a lifetime. This conclusion is based on a person eating 

approximately 4 times more fruits and vegetables than the average person every day for 30 years. 

People who grew fruits and vegetables at their home and used their well water to irrigate their 

crops submitted crop samples for analysis. The analysis revealed that vegetables irrigated with 

well water did not cause a significant increase in contaminant levels (Weston 1998). As a 

precaution, however, we recommend washing all homegrown fruits and vegetables before eating 

them. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

6.	 I have lived in Lincoln Park since the 1960s. I know of many neighbors and family 

members who are sick. Is uranium from the mill making us sick? 

Uranium primarily acts as a heavy metal toxin. Renal toxicity is the hallmark effect of uranium 

exposure, specifically to the proximal tubules of the kidney. We looked at CDC’s Compressed 

Mortality Database “WONDER” looking specifically at specific modes of kidney failure that 

could be associated with uranium toxicity. Fremont County in Colorado had an age adjusted rate 

for renal failure as the cause of death of 7.1 per 100,000, for the years 1999-2006. The state 

average during that same period was 12.1 per 100,00013. From the available health outcome data, 

it does not appear that residents in the area have elevated rates of kidney disease, which could be 

associated with uranium exposure. 

7.	 My husband worked at the plant. Was I possibly exposed when he brought his dirty 

work clothes home? 

Workers in industrial settings have the potential to expose their household members to workrelated chemicals if residues attach to the worker’s clothing, skin, shoes, or in their vehicles and 

is inadvertently brought into the home. Whether and to what magnitude these take-home 

exposures actually occur depends on a number of factors, including the nature of the job held by 

the worker, the occupational practices of the industrial facility (e.g., providing workers with 

disposable gowns and gloves), and the precautions/practices of the worker and other family 

members. ATSDR did not evaluate potential exposures to workers’ families because the data 

needed to quantitatively or qualitatively make a determination on potential health effects were 

not available. 

8.	 I used contaminated water from my private well water for many years as a potable 

source of water for my family. Are we now at risk for adverse health effects? 

The levels of molybdenum were high enough in some wells to cause adverse health effects in 

individuals who were exposed for many years. Once exposure is stopped, the risk of adverse 

health effects goes down. Residents, particularly individuals who do not take in enough dietary 

copper or cannot process copper correctly, might be at increased risk for gout-like conditions. 

The levels of other contaminants are too low to cause adverse health effects. 

9.	 CCAT conducted a health survey and submitted it to ATSDR. Why didn’t ATSDR 

use the results of this survey to determine if people are experiencing adverse health 

effects in the community? 

The community organization CCAT conducted a health survey in 2004–2005. The survey 

included responses from 239 individuals in the Lincoln Park area. Volunteers went door-to-door 

in Lincoln Park and the surrounding areas to administer the health surveys. Each person filled 

out a survey and submitted it to a volunteer. A tabulation of self-reported illnesses reported by 

respondents included occurrences of cancer; lung, health, skin, central nervous system, kidney, 

and thyroid problems; reproductive issues, including chromosomal and congenital defects; 

13 Centers for Disease Control and Prevention, National Center for Health Statistics. Compressed Mortality File 

1999-2006. CDC WONDER On-line Database, compiled from Compressed Mortality File 1999-2006 Series 20 

No. 2L, 2009. Accessed at http://wonder.cdc.gov/cmf-icd10.html on Sep 30, 2009 10:42:05 AM 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

autoimmune disease, psychological disorders, and gout. Although ATSDR could not use the 

survey to make conclusions about disease associations, we did use the survey results to focus our 

attention and pursue a more in-depth scientific analysis of the health conditions identified by the 

community. 

While the CCAT health survey was a good effort by the community to examine the frequency of 

their various health concerns, there are many issues that make it of limited use in determining the 

prevalence of adverse health effects present in the entire community and their potential 

associations with exposure to environmental contaminants. Some of these issues include the use 

of a relatively small convenience sample, the lack of medical verification of self-reported health 

outcomes, and the need for individual-level exposure data. Convenient samples are typically not 

representative of the entire population, so results cannot be extrapolated to the community. 

People who participate in nonrandomized surveys such as this may provide biased information 

because of perceived relationships between environmental contamination or other risk factors 

and their health. Many of the self-reported health outcomes measured in the survey are present 

in most populations and are related to several different potential causes beyond environmental 

exposures, such as lifestyle or genetics. Therefore, without any assessment of exposure, it is not 

possible to link the occurrence of disease to environmental concerns. 

10. CDPHE previously ordered Cotter to have all environmental samples analyzed by 

an external laboratory until Cotter could demonstrate that its laboratory had 

addressed various deficiencies. Why was this done and how did it affect the data 

used by ATSDR? 

Cotter’s license requires the company to collect and report a wide range of environmental 

measurements. Cotter’s own analytical laboratory conducted most of the measurements between 

the late 1970s and the present. The main exception is that an external analytical laboratory 

measured contamination levels in most of the samples collected in 2005 and 2006. 

For many years, Cotter has participated in so-called “round robin” inter-laboratory performance 

evaluations. As part of these evaluations, selected environmental samples are split every calendar 

quarter and simultaneously sent to Cotter’s laboratory and to three external analytical 

laboratories for analysis. The measurement results are then compared to assess the performance 

of Cotter’s laboratory. CDPHE’s website presents data from these inter-laboratory comparisons 

from 2007 to the present. Earlier comparisons are not readily available, mostly because Cotter’s 

laboratory was not analyzing samples throughout much of 2005 and 2006 and data from earlier 

years have since been archived from CDPHE’s website. 

In September 2008, Cotter submitted a letter to CDPHE documenting five quarters of interlaboratory comparisons for groundwater samples [Cotter 2008]. These comparisons presented 

“round robin” data for more than two dozen substances or indicators, including uranium, 

molybdenum, selenium, nitrate, and selected radionuclides. In some cases, Cotter’s laboratory 

tended to measure higher concentrations than the other participating laboratories; but in other 

cases, the opposite was observed. With one exception, the differences between the measurements 

made by the various laboratories fell within the range typically observed or expected. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The exception is for molybdenum, for which Cotter’s laboratory did not meet pre-established 

comparability limits for the “round robin” sampling. Specifically, in two out of the five quarters 

of samples that were collected, Cotter’s laboratory did not meet the acceptable limits.14 In 

contrast, the three external laboratories’ molybdenum measurements met the pre-established 

comparability limits for all five quarters considered in this report. The table below presents the 

specific concentration measurements for the two quarters of interest, and these measurements 

show that (in these two instances) the molybdenum levels measured by Cotter were less than 50 

percent of the average concentrations calculated from the three external laboratories’ 

measurements. 

After CDPHE requested that Cotter investigate the issue further, Cotter prepared a written 

response to the issue [Cotter 2009]. The response suggests that the poor performance on these 

samples resulted from the analytical method used. Cotter uses atomic adsorption to measure 

molybdenum levels in groundwater samples, and the external laboratories used a different 

method (inductively coupled plasma with mass spectrometry). When molybdenum 

concentrations are below roughly 0.5 mg/L, Cotter measures molybdenum by atomic adsorption 

graphite furnace analysis; but at higher concentrations, analysis is by atomic adsorption flame 

analysis. The two quarters with the poor comparisons both had concentration levels below 0.5 

mg/L, leading Cotter to infer that the underreporting was associated with the graphite furnace 

analyses. In January 2009, Cotter proposed several measures that were believed to cause the 

graphite furnace analyses to perform better, and CDPHE approved of the proposed remedy. 

Overall, the “round robin” studies have demonstrated that Cotter’s analytical laboratory met prespecified performance criteria for almost every one of the substances considered. Only for 

molybdenum was a performance issue noted, and it appears that Cotter’s laboratory previously 

used a method that would understate molybdenum concentrations, but typically only when those 

concentrations were less than approximately 0.5 mg/L. This issue was observed for samples 

collected between January 2007 and March 2008, but it likely also affected earlier samples that 

Cotter’s laboratory analyzed; and this negative bias should be considered in any uses of these 

data. Measurements collected since this timeframe likely do not exhibit the same negative bias, 

given the changes that Cotter proposed to its analytical methods. 

Inter-Laboratory Comparison Results for Molybdenum: First Quarter 2007 & First Quarter 2008 

Parameter Analytical Laboratory 

Cotter Laboratory #1 Laboratory #2 Laboratory #3 

Inter-Laboratory Comparison for First Quarter 2007 

Measurement 1 (mg/L) 0.012 0.0263 0.027 0.024 

Measurement 2 (mg/L) 0.012 0.025 0.027 0.0232 

Average (mg/L) 0.012 0.0257 0.027 0.0236 

Avg across three comparison laboratories (mg/L) 0.025 

Inter-Laboratory Comparison for First Quarter 2008 

Measurement 1 (mg/L) 0.01 0.0281 0.029 0.0267 

Measurement 2 (mg/L) 0.011 0.0274 0.029 0.0274 

Average (mg/L) 0.011 0.0278 0.029 0.0271 

Avg across three comparison laboratories (mg/L) 0.028 

Note: Every laboratory was supposed to analyze each sample twice, thus providing data allowing for intra-laboratory and inter-laboratory comparisons. 

14 CDPHE actually voiced concern about three quarters of Cotter’s molybdenum data, even though only two of these 

three quarters did not meet the pre-established comparability limits. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

VII. CONCLUSIONS 

ATSDR reached four important conclusions in this public health assessment: 

1.	 ATSDR concludes that drinking water for many years from contaminated private wells 

could harm people’s health. This is a public health hazard. 

Private well sampling data collected from 1984 to 2007 revealed the presence of 

molybdenum at levels that could harm people’s health. A water use survey conducted in 

Lincoln Park in 1989 revealed that at least seven people used groundwater (from their 

private wells) for personal consumption. These and other residents whose private wells 

were affected by the highest molybdenum contamination may be at increased risk for 

health effects such as gout-like conditions, particularly individuals who do not take in 

enough dietary copper or cannot process copper correctly. 

The lack of consistent monitoring over the years and the unknown usage of wells before 

the installation of the public water supply make these past exposures difficult to 

accurately assess. 

Most town residents are now connected to the public water supply and have eliminated 

their exposure to the contaminated well water. However, some residents are reported to 

have refused public water supply connections, and many may still have operational 

private wells. Additionally, no formal institutional controls exist to control groundwater 

use in Lincoln Park. Therefore, current and future uses of private wells for domestic 

purposes are still possible. 

2.	 ATSDR concludes that accidentally eating or touching soil and sediment near the Cotter 

Mill property or in Lincoln Park will not harm people’s health. However, ATSDR cannot 

make conclusions about soils near Cotter Mill if the properties closest to the facility are 

developed for residential or other non-industrial uses in the future. 

3.	 ATSDR concludes that eating locally-grown fruits and vegetables irrigated with private 

well water will not harm most people’s health. However, a person eating above-average 

amounts of fruits and vegetables (4 times the average consumer) might have a low 

increased risk for developing cancer over a lifetime. As a precaution, residents should 

limit their use of contaminated well water to irrigate their crops. In all cases, the crops 

should be thoroughly cleaned prior to eating. 

4.	 ATSDR concludes that ambient air emissions of particle bound radionuclides have not 

resulted in completed exposures to the public at levels that could cause adverse health 

outcomes. With the exception of thorium-230 levels observed in 1981 and 1982, 

associated with excavation of contaminated tailings, every radionuclide monitored has 

been more than a factor of ten below annual dose based health limits to the public. The 

excavation releases appear to have only exposed on-site workers, but still below 

occupational limits at that time. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

VIII. RECOMMENDATIONS 

Based upon ATSDR’s review of the environmental data and the concerns expressed by 

community members, the following recommendations are appropriate and protective of the 

health of residents in and around the Lincoln Park area. 

	 Residents should be informed about the health risks associated with contaminated private 

wells and advised to connect to the public water supply if possible. Local officials should 

advise new residents who move to the area of the groundwater contamination and that 

they should have their water supply tested before using groundwater for household 

purposes. 

	 Residents should discontinue of use of any impacted private wells for household 

purposes, including watering livestock and crops. 

	 CDPHE should continue to monitor the groundwater contaminant plume to assess 

whether additional wells may be impacted in the future. 

 CDPHE should conduct a water use survey in the affected area to determine how 

groundwater is being utilized by residents in Lincoln Park. 

	 CDPHE should evaluate the need for further analysis of lead in soil should the areas 

adjacent to the Cotter Mill property change current use patterns. 

	 ATSDR in the short-term, and CDPHE in the long-term, should advise residents who 

have fruit and vegetable gardens to wash the crops thoroughly before eating them. This 

measure is just a precaution to remove soil adhering to the surface of the crop. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

IX. PUBLIC HEALTH ACTION PLAN 

The public health action plan for the site contains a description of actions that have been taken or 

will be taken by ATSDR or other government agencies at the site. The purpose of the public 

health action plan is to ensure that this document both identifies public health hazards and 

provides a plan of action designed to mitigate and prevent harmful human health effects resulting 

from exposure to the hazardous substances at this site. 

Public health actions COMPLETED: 

	 ATSDR conducted site visits to gather community health concerns, to communicate to 

identified stakeholders, and to gather relevant site-related data; 

	 ATSDR’s Exposure Investigations and Site Assessment Branch (EISB) performed two 

Exposure Investigations to 1) evaluate blood lead levels in children living in the Lincoln 

Park area and 2) evaluate lead in dust in homes in the Lincoln Park area. (These 

documents are available on our website at www.atsdr.cdc.gov.) 

 Public health actions PLANNED: 

	 ATSDR’s Health Promotion and Community Involvement Branch (HPCIB) will conduct 

health-related educational activities in the community, as necessary. 

	 ATSDR’s HPCIB will coordinate community outreach and community involvement 

activities for the site. 

	 ATSDR will continue to work with appropriate state and federal agencies and review, if 

requested, additional relevant environmental data (including the water use survey) as it 

becomes available. 

	 ATSDR will re-evaluate and revise the public health action plan if needed. New 

environmental, toxicological, health outcome data, or implementing the above proposed 

actions may necessitate the need for additional or alternative actions at this site. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

X. SITE TEAM 

Teresa Foster, MPH 

Environmental Health Scientist 

Division of Health Assessment and Consultation 

Site and Radiological Assessment Branch 

Michael Brooks, CHP 

Health Physicist 

Division of Health Assessment and Consultation 

Site and Radiological Assessment Branch 

Debra Joseph, MHA 

Community Involvement Specialist 

Division of Health Assessment and Consultation 

Health Promotion and Community Involvement Branch 

Carla Galindo,* MPH 

Health Education Specialist 

Division of Health Assessment and Consultation 

Health Promotion and Community Involvement Branch 

Dawn Arlotta, MPH, CHES 

Health Education Specialist 

Division of Health Assessment and Consultation 

Health Promotion and Community Involvement Branch 

ATSDR Regional Representatives: 

Chris Poulet 

Environmental Health Scientist 

Division of Regional Operations 

David Dorian 

Environmental Health Scientist 

Division of Regional Operations 

Epidemiological Review: 

Candis Mayweather Hunter, MSPH 

Epidemiologist 

Division of Health Studies 

*Carla Galindo provided health education input until 2009. Carla is no longer employed at ATSDR. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

XI. REFERENCES 

[ATSDR] Agency for Toxic Substances and Disease Registry. 2006a. Health Consultation, 

Blood Lead Levels in Children in the Lincoln Park Neighborhood, Cañon City, Fremont County, 

Colorado. November 16, 2006. Available at: 

http://www.atsdr.cdc.gov/HAC/pha/LincolnParkBloodLeadLevels/LincolnParkBloodLeadLevelsChildrenHC11.16.06.pdf. 

[ATSDR] Agency for Toxic Substances and Disease Registry. 2006b. Health Consultation, 

Blood Levels in the Cañon City Vicinity, Fremont County, Colorado. November 16, 2006. 

Available at: http://www.atsdr.cdc.gov/HAC/pha/CanonCityBloodLevels/BloodLevelsCanonCityEI11.16.06.pdf. 

[ATSDR] Agency for Toxic Substances and Disease Registry. 2006c. Health Consultation, Lead 

in Dust in Homes in the Lincoln Park Neighborhood, Cañon City, Fremont County, Colorado. 

November 16, 2006. Available at: 

http://www.atsdr.cdc.gov/HAC/pha/LincolnParkDustinLeadinHomes/LincolnParkLeadinDustHC11.16.06.pdf. 

[ATSDR] Agency for Toxic Substances and Disease Registry. 2006d. Health Consultation, 

Exposure Investigation Report: Lead in Indoor Dust, Outdoor Soil, and Blood of Lincoln Park 

Neighborhood Residents. November 16, 2006. Available at: 

http://www.atsdr.cdc.gov/HAC/pha/LincolnParkLeadinIndoo%20Dust/LincolnParkLeadEI11.16.06.pdf. 

[ATSDR] Agency for Toxic Substances and Disease Registry, 2007. Toxicological profile for 

arsenic (update). Atlanta: US Department of Health and Human Services. 2007. 

[ATSDR] Agency for Toxic Substances and Disease Registry, 1999. Toxicological profile for 

uranium (update). Atlanta: US Department of Health and Human Services. September 1999. 

[ATSDR] Agency for Toxic Substances and Disease Registry, 2006e. ToxFACTS Chemical 

Agent Briefing Sheet - Arsenic. Atlanta: US Department of Health and Human Services. January 

2006. 

[ATSDR] Agency for Toxic Substances and Disease Registry, 2004. Interaction Profile for: 

arsenic, cadmium, chromium, and lead. Atlanta: US Department of Health and Human Services. 

May 2004. 

[BEIR IV]. Committee on the Biological Effects of Ionizing Radiations, National Research 

Council. 1988. Health risks of radon and other internally deposited alpha-emitters. Washington 

DC: National Academy Press. 

[CCAT] Colorado Citizens Against Toxic Waste. 2004-2005 Lincoln Park Health Survey, Cañon 

City, Colorado 81212. 

[CDC] Centers for Disease Control and Prevention. 1998. Estimation of the impact of the former 

Feed Materials Production Center (FMPC) on lung cancer mortality in the surrounding 

78 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

community. Atlanta: US Department of Health and Human Services Public Health Service; 1998 

Dec. 

[CDPHE 1975] Colorado Department of Public Health and Environment. 1975. Letter to Fred 

Matter, Cotter Corporation, from Joe Virgona, CDPHE, concerning the chronological report on 

Cotter Corporation. July 1975. 

[CDPHE 2003] Colorado Department of Public Health and Environment, Laboratory Services 

Division. 2003. Results of Sampling for Plutonium, Uranium, Lead and Molybdenum in the 

Cañon City Vicinity. July 2003. 

[CDPHE 2005] Colorado Department of Public Health and Environment. 2005. Cotter Cañon 

City Uranium Mill 1988 Remedial Action Plan, Summary and Status – August 2005. Available 

at: http://www.cdphe.state.co.us/hm/cotter/rapsummary050826.pdf. 

[CDPHE 2007a] Colorado Department of Public Health and Environment. 2007a. Letter to Mr. 

John Hamrick, Cotter Corporation, from Steve Tarlton, CDPHE, concerning the Cotter 

Corporation Cañon City Mill Impoundments evaluation. June 14, 2007. 

[CDPHE 2007b] Colorado Department of Public Health and Environment. 2007b. Cotter Mill 

Site Monitoring Database: data through September 25, 2007. 

[CDPHE 2008] Colorado Department of Public Health and Environment. 2008. Cotter 

Corporation Uranium Mill Site Description. Available at: 

http://www.cdphe.state.co.us/hm/cotter/sitedescript.htm. 

[CDPHE 2001] Colorado Department of Public Health and the Environment. 2001. 6 CCR 1007

1, Part 18, State Board of Health Licensing Requirements for Uranium and Thorium Processing. 

Hazardous Materials and Waste Management Division, Radiation Control, November 2001. 

[CDPHE 2005b] Colorado Department of Public Health and the Environment. 2005. Cotter 

Cañon City Uranium Mill 1988 Remedial Action Plan Summary and Status – August 2005b. 

[CDPHE 2005c] Colorado Department of Public Health and the Environment. 2005. 6 CCR 

1007-1, Part 3, Licensing of Radioactive Material. Hazardous Materials and Waste Management 

Division, State Board of Health Rules and Regulations Pertaining to Radiation Control, July 

2005. 

[CDPHE 2009] Colorado Department of Public Health and the Environment. 2009. Radioactive 

Materials License 369-01, Amendment 50, February 2009. 

Chen J, Meyerhof DP, Tracy BL. 2004. Model results of kidney burdens from uranium intakes. 

Health Phys 86(1):3-11 (2004). 

Cotter. 2000. Sand Creek Project Cleanup Report. June 2000. 

­

79 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

[Cotter 2007] Environmental and occupational performance report, ALARA review and annual 

report on remedial action plan activities. Calendar year 2006. Cañon City Milling Facility. June 

29, 2007. Available at: http://www.cdphe.state.co.us/hm/cotter/LetterFromCotter/2006perfrpt/. 

Cotter. 2008. Operational unit 2 (OU2) Lincoln Park water use survey. April 7, 2008. Available 

at: http://www.cdphe.state.co.us/hm/cotter/08cotterdocs.htm. 

[Cotter 2004a] Cotter Corporation, Cañon City Milling Facility. 2004. Procedure: Environmental 

Air Particulate Sampling, #EV-020, Revision 5. July 2004. 

[Cotter 2004b] Cotter Corporation, Cañon City Milling Facility. 2004. Procedure: Radon222/220 Air Surveys, #EV-030, Revision 2. July 2004. 

[Cotter 2008b] Cotter Corporation, Cañon City Milling Facility. 2008. Environmental and 

Occupational Performance Report, ALARA Review, and Annual Report on Remedial Action 

Plan Activities for Calendar Year 2008. 

[Cotter 2009b] Cotter Corporation, Cañon City Milling Facility. 2009. Quality Assurance 

Program Plan for Environmental and Occupational Sampling and Monitoring Studies for the 

Cotter Corporation, Cañon City Milling Facility and Lincoln Park, Colorado Superfund Site. 

Prepared by Environmental Alternatives, Inc., May 2009. 

Diamond GL. 1989. Biological consequences of exposure to soluble forms of natural uranium. 

Rad Protect Dosim 26: 23-33. 

[DOE] United States Department of Energy. 2003. Fiscal year 2003 status report, 

Reimbursements to licensees of active uranium and thorium processing sites. Title X of the 

Energy Policy Act of 1992. September 2003. 

[DOE 1993] U.S. Department of Energy. 1993. Order 5400.5 Change 2. Radiation Protection of 

the Public and the Environment. Office of Environment, Safety, and Health, January, 1993. 

[EA] Environmental Alternatives, Inc. 2007. Report on Semi-Annual Review of Well Permits. 

March 20, 2007. Available at: 

http://www.cdphe.state.co.us/hm/cotter/LetterFromCotter/wellpermitreview070329.pdf. 

[EIA] Energy Information Administration, 2001, Web site: U.S. Department of Energy, 

http://www.eia.doe.gov/. 

Eisenbud M, Quigley JA. 1955. Industrial hygiene of uranium processing. AMA Archives of 

Industrial Health. p. 12–22. 

[EPA] Environmental Protection Agency, Environmental Response Team. 1995. Superfund 

Program, Representative Sampling Guidance, Volume 1: Soil. Interim Final. Available at: 

http://www.clu-in.org/download/char/SF_Rep_Samp_Guid_soil.pdf. 

80 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

[EPA] Environmental Protection Agency. 2002. Record of Decision: Lincoln Park Study Area 

Surface Soils, Lincoln Park Superfund Site, Cañon City, Colorado. Available at: 

http://www.epa.gov/region08/superfund/co/lincolnpark/LincolnPkROD.pdf. 

[EPA] Environmental Protection Agency, Superfund Technical Assessment and Response Team 

2 - Region 8. 2004. Cañon City Lead Data Compilation Report, Cañon City, Fremont County, 

Colorado. March 24, 2004. Available at: http://www.epa.gov/region8/superfund/co/lincolnpark/. 

[EPA] Environmental Protection Agency, Region 8. 2007. Final First 5-year review report for 

Lincoln Park Superfund site, Operable Unit 2. September 2007. Available at: 

http://www.epa.gov/region08/superfund/co/lincolnpark/LincolnPark5YrRvw07.pdf. 

[EPA] Environmental Protection Agency, Region 8. 2008. Superfund Program: Lincoln Park. 

Available at: http://www.epa.gov/region8/superfund/co/lincolnpark/. 

[EPA] Environmental Protection Agency, Integrated Risk Information System (IRIS). 

Cincinnati, OH: Office of Health and Environmental Assessment, Environmental Criteria and 

Assessment. Accessed June 16, 2009 at http://www.epa.gov/ncea/iris/subst/0425.htm. 

[FNB] Food and Nutrition Board, Institute of Medicine. 2001. Molybdenum. In: Dietary 

reference intakes for vitamin A, vitamin K, boron, chromium, copper, iodine, iron, manganese, 

molybdenum, nickel, silicon, vanadium, and zinc. Washington, D.C.: National Academy Press. 

p. 420–41. 

[FDA] US Food and Drug Administration. 2008. Total Diet Study - Summary of Toxic and 

Nutritional Elements Found in TDS Foods. Accessed August 4, 2009 at . 

http://www.fda.gov/downloads/Food/FoodSafety/FoodContaminantsAdulteration/TotalDietStud 

y/UCM184301.pdf. 

Galant, M.M., Linnert, T., and J. Dalton. 2007. Community involvement plan: Lincoln Park 

Superfund site and associated activities at the Cotter Corporation uranium mill. March 2007. 

Available at: http://www.cdphe.state.co.us/hm/cotter/lincolnparkcottercip.pdf. 

[GeoTrans] GeoTrans, Inc. 1986. Remedial Investigation: Cotter Corporation Uranium Mill Site. 

February 1986. 

[HRAP] Health Risk Assessment Panel, Cotter Uranium Mill Site. 1991. Health Risk 

Assessment of the Cotter Uranium Mill Site, Cañon City, Colorado. Prepared with the assistance 

of ENVIRON Corporation, Radiation Surveillance Associates, Radiant Energy Management, and 

Western Radiation Consultants. October 29, 1991. 

Hodge HC. 1953. Resume of chapters 18 to 28. In: Voegtlin C and Hodge HC, eds. 

Pharmacology and toxicology of uranium compounds. National Nuclear Energy Series, Division 

VI, Vol 1, Part IV. New York: McGraw-Hill. 

[IMS] IMS Inc. 1989. Lincoln Park Water Use Survey. Submitted to Cotter Corporation, 

Lakewood, Colorado. June 28, 1989. 

81 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

[IPCS] International Programme on Chemical Safety. 2001.Environmental Health Criteria for 

Arsenic and Arsenic compounds. EHC 224, Chapter 1: Summary, section 4. 

Juhasz, Albert L., Euan Smith, John Weber, Matthew Rees, Allan Rofe, Tim Kuchel, Lloyd 

Sansom, Ravi Naidu, Application of an In Vivo Swine Model for the Determination of Arsenic 

Bioavailability in Contaminated Vegetables. Chemosphere. Feb 7, 2008. 

Killough GG, Case MJ, Meyer KR, et al. 1998. Fernald Dosimetry Reconstruction Project, Task 

6radiation doses and risk to residents from FMPC Operations from 1951-1988. Vol I and II 

(final report). Radiological Assessments Corporation Report No. CDC-1. Neeses, SC: 1998 Sep 

[Koval’skiy] Koval’skiy, V.V., G.A. Yarovaya and D.M. Shmavonyan. 1961. Changes of purine 

metabolism in man and animals under conditions of molybdenum biogeochemical provinces. Zh. 

Obshch. Biol. 22: 179-191. 

[Kurttio et al] Päivi Kurttio, Anssi Auvinen, Laina Salonen, Heikki Saha, Juha Pekkanen, Ilona 

Mäkeläinen, Sari B. Väisänen, Ilkka M. Penttilä, and Hannu Komulainen. Renal Effects of 

Uranium in Drinking Water. Environmental Health Perspectives Volume 110, Number 4, April 

2002. 

Laizu Jahanara. 2007. Speciation of arsenic in vegetables and their correlation with inorganic 

phosphate level. Bangladesh J Pharmacol 2007; 2:88-94. 

Leggett RW. 1989. The behavior and chemical toxicity of U in the kidney: a reassessment. 

Health Phys 57(3): 365-383. 

Leggett RW. 1994. Basis for ICRP’s age-specific biokinetic model for uranium. Health Phys 67: 

589-601. 

[MFG] MFG, Inc. 2005. Assessment of potential dose to members of the public from materials 

along roads near the Cotter Corporation, Cañon City Milling Facility. May 2005. Available at: 

http://www.cdphe.state.co.us/hm/cotter/potentialdoseassessment.pdf. 

Madsden KM, Nielsen S, Tisher CC. 2007. Chapter 2 – Anatomy of the Kidney from Brenner: 

Brenner and Rector’s The Kidney, 8th ed. Oxford: Elsevier Science Ltd. 

Maynard EA, Hodge HC. 1949. Studies of the toxicity of various uranium compounds when fed 

to experimental animals. In: Voegtlin IC, Hodge HC, eds. Pharmacology and toxicology of 

uranium compounds. National Nuclear Energy Series (VI). New York: McGraw-Hill; 309-376. 

McDonald-Taylor CK, Singh A, Gilman A. 1997. Uranyl nitrate-induced tubule alterations in 

rabbits: a quantitative analysis. Toxicol Pathol 25(4): 381-389. 

Morris SC, Meinhold AF. 1995. Probabilistic risk assessment of nephrotoxic effect of uranium in 

drinking water. Health Phys 69: 897-908. 

82 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

[ODEQ] State of Oregon Department of Environmental Quality. 2003. Memorandum, Red Rock 

Road Project File, Evaluation Potential for Arsenic and Mercury Uptake into Garden Vegetables. 

September 22, 2003. 

[NHANES] National Health and Nutrition Examination Survey. Third National Report on 

Human Exposure to Environmental Chemicals, Dept of Health and Human Services, Centers for 

Disease Control and Prevention. Atlanta, GA. July 2005. 

Plasket, BJ. 2002. Cotter at the Crossroads: On the Hot Seat. The Daily Record News Group. 

Available at: http://www.timescall.com/cotter/cotter24.htm. 

Spear JW. Trace mineral bioavailability in ruminants. J. Nutr. 2003; 133: 1506S—1509S. 

Spoor NL, Hursh JB. 1973. Protection criteria. In: Hodge HC, Stannard JN, Hursh JB, eds. 

Handbook of experimental pharmacology. Berlin: Springer-Verlag; 241-270. 

Stokinger HE, Baxter RC, Dygent HP, et al. 1953. In: Voegtlin C, Hodge HC, eds. Toxicity 

following inhalation for 1 and 2 years. National Nuclear Energy Series: Manhattan Project 

Technical Section, Div VI, Vol 1. New York: McGraw-Hill. 

Turnlund JR. Molybdenum metabolism and requirements in humans. Met. Ions Bio. Syst. 2002; 

39:727—739. 

[USGS] United States Geological Survey. 1999a. Migration and Geochemical Evolution of 

Ground Water Affected by Uranium-Mill Effluent near Cañon City, Colorado. Water-Resources 

Investigations Report 98-4228. DT Chafin and ER Banta. 

[USGS] United States Geological Survey. 1999b. Ground-Water Hydrology and Simulation of 

Five Remediation Alternatives for an Area Affected by Uranium-Mill Effluent near Cañon City, 

Colorado. ER Banta and DT Chafin. 

[USNRC 1980] U.S. Nuclear Regulatory Commission. 1980. Regulatory Guide 4.14 

Radiological Effluent and Environmental Monitoring at Uranium Mills, Revision 1. Office of 

Standards Development, April 1980. 

[USNRC 1996] U.S. Nuclear Regulatory Commission. 1996. Regulatory Guide 4.20 Constraint 

on Releases of Airborne Radioactive Materials to the Environment for Licensees other than 

Power Reactors. Office of Nuclear Regulatory Research, December 1996. 

Vousta D, Grimanis A, Samara C. 1996. Trace elements in vegetables grown in an industrial area 

in relation to soil and air particulate matter. Environ Pollution 94(3):325–35. 

[Weston] Roy F. Weston, Inc. 1996. Supplemental Human Health Risk Assessment. Lincoln 

Park Superfund Site. Cañon City, Colorado. Phase II Evaluation. Baseline Human Health Risks 

in 1988. Final Report. Prepared for CDPHE. November 19, 1996. 

83 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

[Weston] Roy F. Weston, Inc. 1998. Supplemental Human Health Risk Assessment, Lincoln 

Park Superfund Site, Cañon City, Colorado: Phase III Evaluation, Baseline Human Health Risks 

in 1994-1996. January 1998. 

Wilder, RJ, DJ Goode, P Huidobro, MO Kozik, DR Cogley, NH Krusell, ME Connolly, EJ 

Limberakis, and AW Levin. 1983. Assessment of data concerning ground water contamination in 

the Lincoln Park section of Cañon City, Colorado. Final report prepared for EPA by GCA 

Corporation. May 1983. 

[WHO] World Health Organization. 2003. Molydbenum in Drinking water: Background 

document for development of WHO Guidelines for Drinking-water Quality. 

Zhao LS, Zhao SF. 1990. Nephrotoxic limit and annual limit on intake for natural U. Health Phys 

58: 619-623. 

84 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Appendix A - Tables 

85 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 14. Well Use in Lincoln Park, 1989 

Well 

Number Description 

Reported Well Use 

Personal 

Consumption 

Irrigating 

Fruit 

Irrigating Vegetable 

Gardens 

W

Li

117 Logan (LPWUS) 



119 Birch (LPWUS) 



122 Elm (LPWUS) 123 Cedar (LPWUS) 

124 Elm (LPWUS) 



129 Elm (LPWUS) 





130 Poplar (LPWUS) 



138 Field well, Cedar (LPWUS) 139 House well, Cedar (LPWUS) 

140 C. R. Ransom house well, Cedar (LPWUS) 





144 Cedar (LPWUS) 





165 Spring, Elm (LPWUS) 





166 Willow (LPWUS) 

168 Grand (house well) (LPWUS) 



173 Beulah (LPWUS) 



174 Chestnut (LPWUS) 



189 Hickory (LPWUS) 



198 Grand (LPWUS) 







206 Grand (field well) (LPWUS) 

212 Cedar (LPWUS) 





219 Locust (LPWUS) 



221 Elm (LPWUS) 

222 Elm (LPWUS) 

87 
Well 

Number Description 

Reported Well Use 

Personal 

Consumption 

Irrigating 

Fruit 

Irrigating Vegetable 

Gardens 

W

Li

223 Elm (LPWUS) 224 Elm (LPWUS)  226 Chestnut (LPWUS) 229 Grand (LPWUS) 230 Birch (LPWUS)  231 Birch (LPWUS)  235 Elm (LPWUS) 237 Elm (LPWUS) 239 Grand (LPWUS)   241 Grand (LPWUS) 243 Chestnut (LPWUS) 245 Elm (LPWUS) 246 Elm (LPWUS)  252 Poplar (cistern* in barn) (LPWUS) 255 Riley Dr. (LPWUS)   261 Elm (LPWUS)   262 Cedar (LPWUS)   263 Willow (LPWUS) 264 Chestnut (LPWUS)   266 Willow (LPWUS)   267 Willow (spring) (LPWUS)   269 Birch  273 Willow (cistern #1) (LPWUS)  274 Grand (LPWUS)   278 Cedar (LPWUS) 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

88 
Well 

Number Description 

Reported Well Use 

Personal 

Consumption 

Irrigating 

Fruit 

Irrigating Vegetable 

Gardens 

W

Li

280 Grand (LPWUS) 

284 Spring - Grand St. (LPWUS) 285 Grand (LPWUS) 286 Willow (cistern #2) (LPWUS) 287 Willow (LPWUS)  

288 Poplar (cistern* on porch) 

293 Cedar (LPWUS)   

 Totals 6 22 20 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Source: IMS 1989 *Modified from the original spelling: “cystern”Street numbers have been excluded for privacy reasons.LPWUS – Lincoln Park Water Use Survey

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 15. Groundwater sampling data (chemicals) from wells used for personal consumption 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum CV (mg/

Chloride N/T* 11/11 4.5 8.8 14 Spring, Elm [165] 13-Mar-84 

250 

(Seconda

MCL) 

Iron D 2/12 0.04 0.06 0.1 Grand (house well) [168] 19-Aug-05 26 (RBC

Manganese D 2/12 0.002 0.008 0.01 Grand (house well) [168] 13-Dec-04 0.5 (RME

child) 

Molybdenum D 52/59 0.007 0.082 0.28 Hickory [189] 19-Jan-89 

0.035 (SS

0.05 (RME

child) 

Nitrate T 8/8 0.5 2.9 7.7 Grand (house well) [168] 19-Mar-07 10 (MCL

Selenium D 0/2 ND ND ND -­ -­

0.05 

(c-EMEG

child) 

Sulfate N/T* 11/11 15 62 214 Grand (house well) [168] 19-Aug-05 

250 

(Seconda

MCL) 

Total Dissolved Solids 

N/T* 11/11 240 330 410 Spring, Elm [165] 13-Mar-84 

500 

(Seconda

MCL) 

Uranium D 56/57 0.001 0.028 0.067 Hickory [189] 15-Dec-06 0.03 (MC

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. The source of water used for personal consumption at 1935 Elm [165] was a spring.

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

* For chloride, sulfate, and total dissolved solids, 1984 data were designated “N” and 2005–2007 data were designated “T”. c-EMEG – chronic environmental media evaluation guide N – not defined in the CDPHE database CV – comparison value ND – not detected D – dissolved RBC – risk based concentration for drinking wateLTHA – lifetime health advisory for drinking water RMEG – reference dose media evaluation guide MCL – maximum contaminant level SS – Colorado state groundwater standard mg/L – milligrams per liter T – total 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 16. Groundwater sampling data (chemicals) from background wells 

Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV 

Aluminum D 0/25 ND ND ND -­ 

(c-EM

Ammonia N 3/45 0.02 0.4 4.2 26-Jan-90 30 

Ammonium T 0/3 ND ND ND -­ Chloride N/T* 168/168 3 12 110.3 07-Jan-80 

(Seco

Iron D 24/79 0.02 0.03 0.3 16-May-89 26 

Manganese D 13/79 0.005 0.007 0.05 16-Mar-99 

(RM

Molybdenum D 116/193 0.005 0.023 0.3 09-Nov-82, 09-Jun-76 0.0

0.05 (R

Nitrate N/T* 70/79 0.4 2.5 50.4** 10-Feb-89 10 

Selenium D 10/103 0.001 0.003 0.015 15-Apr-80 

(c-EM

Sulfate N/T* 171/171 10 61 434§ 18-Aug-80 

(Seco

Total Dissolved Solids N/T* 171/171 286 429 1,580† 18-Aug-80 

(Seco

Uranium D 155/193 0.004 0.021 0.29 07-Aug-79 0.0

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. The USGS identified Well 10 (1220 So. 12th St.) and Well 114 (1408 Pine) as representative of background for the Lincoln Park area (Weston 1

* For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. 

** Only two of 79 samples were above the CV. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

§ Only one of 171 samples was above the CV. † The maximum concentration appears to be an outlier. The next highest concentration is 590 mg/L. 

c-EMEG – chronic environmental media evaluation guide NA – not available 

CV – comparison value ND – not detected D – dissolved RBC – risk based concentration for drinking wateLTHA – lifetime health advisory for drinking water RMEG – reference dose media evaluation guide MCL – maximum contaminant level SS – Colorado state groundwater standard mg/L – milligrams per liter T – total N – not defined in the CDPHE database 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 17. Groundwater sampling data (chemicals) from the Grand Avenue Well 

Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV 

Chloride N/T* 10/10 4.5 8.250 11 20-Jun-84, 20-Jun-05 

(Secon

Iron D 2/11 0.04 0.06 0.1 19-Aug-05 26 

Manganese D 2/11 0.002 0.009 0.01 13-Dec-04 

(RM

Molybdenum D 15/20 0.008 0.01 0.015 21-Jun-04 

0.0

(RM

Nitrate T 8/8 0.5 2.9 7.7 19-Mar-07 10 

Selenium D 0/1 ND ND ND -­ 

(c-EM

Sulfate N/T* 10/10 15 58 214 19-Aug-05 

(Secon

Total Dissolved Solids N/T* 10/10 240 322 402 19-Mar-07 

(Secon

Uranium D 20/20 0.001 0.013 0.0218 28-Mar-05 0.0

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * For chloride, sulfate, and total dissolved solids, 1984 data were designated “N” and 2005–2007 data were designated “T”. c-EMEG – chronic environmental media evaluation guide ND – not detected CV – comparison value RBC – risk based concentration for drinking wateD – dissolved RMEG – reference dose media evaluation guide MCL – maximum contaminant level SS – Colorado state groundwater standard mg/L – milligrams per liter T – total N – not defined in the CDPHE database 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

 Table 18. Groundwater sampling data (chemicals) from wells used to irrigate fruit and vegetable g

Chemical Type 

Frequency 

of 

Detection 

Minimu 

m (mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum CV (mg/L) 

Aluminum D 3/120 0.01 0.186* 0.02 Elm [124 ] & Elm [129] 15-Mar-95 10 (c-EMEG, child) 

Ammonia N 10/53 0.01 0.3 0.6 house well, Cedar [140] 23-Aug-88 30 (LTHA) 

Ammonium T 0/3 ND ND ND -­ -­ NA Cadmium D 0/3 ND ND ND -­ -­

0.002 

(c-EMEG, 

child) 

Chloride N/T** 784/793 2.5 19.6 232 house well, Cedar [140] 05-Apr-79 250 (Secondary MCL) 

Copper D 0/3 ND ND ND -­ -­ 0.1 (i-EMEG, child) 

Iron D 114/398 0.011 0.029 0.31 Elm [129] 21-Apr-03 26 (RBC) 

Manganese D 69/397 0.0007 0.008 0.13 house well, Cedar [140] 09-Sep-94 0.5 (RMEG, child) 

Molybdenum D 1,052/1,077 0.004 0.99 42 house well, Cedar [140] 12-May-73 

0.035 (SS); 

0.05 

(RMEG, 

child) 

Nickel D 0/3 ND ND ND -­ -­ 0.2 (RMEG, child) 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical Type 

Frequency 

of 

Detection 

Minimu 

m (mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum CV (mg/L) 

Nitrate N/T** 159/185 0.1 1.7 9.8 Cedar [144] 14-May-70 10 (MCL) 

Selenium D 115/626 0.001 0.003 0.082† house well, Cedar [140] 21-Apr-78 0.05 (c-EMEG, child) 

Sulfate N/T** 798/800 8 214 25,460‡ house well, Cedar [140] 07-May-79 250 (Secondary MCL) 

Total Dissolved Solids 

N/T** 767/767 31 550 3,438 house well, Cedar [140] 20-Apr-81 500 (Secondary MCL) 

Uranium 

D 1,048/1,088 0.0003 0.13 2.54 house well, Cedar [140] 

house well, Cedar 

[140] 

05-Jan-79 

0.03 (MCL) 

S 1/20 0.081 0.005§ 0.081 27-May-97 

Vanadium D 0/3 ND ND ND -­ -­

0.03 

(i-EMEG, 

child) 

Zinc D 2/3 0.005 0.01 0.022 Birch [119] 25-Aug-95 3 (c-EMEG, child) 

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. The source of water used to water fruits and vegetable gardens at 1935 Elm [165] was a spring.

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

* The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation. ** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. † Only two of 626 samples were above the CV. ‡ The maximum concentration appears to be an outlier. The next highest concentration is 1,948 mg/L from the same well [140] in 1981. § The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. 

c-EMEG – chronic environmental media evaluation guide NA – not available CV – comparison value ND – not detected 

D – dissolved RBC – risk based concentration for drinking wate

i-EMEG – intermediate environmental media evaluation guide RMEG – reference dose media evaluation guide LTHA – lifetime health advisory for drinking water S – suspended MCL – maximum contaminant level SS – Colorado state groundwater standard mg/L – milligrams per liter T – total N – not defined in the CDPHE database 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 19. Groundwater sampling data (radionuclides) from wells used to irrigate fruit and vegetable 

Radionuclide Type 

Frequency 

of 

Detection 

Minimu 

m (pCi/L) 

Average 

(pCi/L) 

Maximum 

(pCi/L) 

Location of 

Maximum 

Date of 

Maximum 

CV 

(pCi/L) 

Lead-210 

D 29/29 -0.2 0.22 1.5 Birch [119] 

house well, Cedar 

[140] 

 21-Jun-95 

NA 

S 20/20 -0.1 0.15 0.6 22-Feb-96, 05-May-99 

Polonium-210 

D 29/29 -0.1 0.13 0.6 Cedar [144] 

house well, Cedar 

[140] 

08-Mar-95, 

21-Jun-95, NA 

S 20/20 0 0.12 0.6 22-Feb-96, 05-Dec-96 

Radium-226 

D 29/29 0 0.12 0.5 house well, Cedar [140] 

-­

12-May-95 5 (MCL radium226/228) 

S 19/19* 0 0 0 -­ 

Thorium-230 

D 28/28 -0.1 0.08 0.3 

Birch [119] 

house well, Cedar 

[140] 

house well, Cedar 

[140] 

25-Aug-95 

21-Feb-95 NA 

S 17/17 0 0.08 0.3 05-May-99 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. *The detect flag is “Y” for all 19 samples, however, the result value is zero for all 19 samples.CV – comparison value NA – not available D – dissolved pCi/L – picocuries per liter MCL – maximum contaminant level S – suspended 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 20. Groundwater sampling data (chemicals) from wells used to water livestock 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum CV (mg/L) 

Aluminum D 0/19 ND ND ND -­ -­ 10 (c-EMEG, child) Ammonia N 0/10 ND ND ND -­ -­ 30 (LTHA) 

Ammonium T 0/1 ND ND ND -­ -­ NA 

Cadmium D 0/1 ND ND ND -­ -­ 0.002 (c-EMEG, child) 

Chloride N/T* 160/160 2.5 14 185 Cedar [144] 24-Aug-83 250 (Secondary MCL) 

Copper D 0/1 ND ND ND -­ -­ 0.1 (i-EMEG, child) Iron D 27/97 0.03 0.04 0.19 Cedar [144] 18-Oct-01 26 (RBC) 

Manganese D 14/96 0.0007 0.007 0.02 Cedar [144] 

13-Jul-81, 

 13-Sep-83, 

17-May-01, 

06-Jun-02, 

23-Oct-03 

0.5 (RMEG, 

child) 

Molybdenum D 271/286 0.006 0.212 1 Cedar [144] 12-May-71 

0.035 (SS); 

0.05 (RMEG, 

child) 

Nickel D 0/1 ND ND ND -­ -­ 0.2 (RMEG, child) 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum CV (mg/L) 

Nitrate N/T* 55/58 0.1 1.8 9.8 Cedar [144] 14-May-70 10 (MCL) 

Selenium D 10/119 0.001 0.003 0.011 Cedar [144] 19-Mar-80 0.05 (c-EMEG, child) Sulfate N/T* 162/162 10 95 1,650** Cedar [144] 18-Aug-80 250 (Secondary MCL) 

Total Dissolved Solids 

N/T* 162/162 195 465 860 Cedar [144] 18-Aug-80 500 (Secondary MCL) 

Uranium 

D 283/302 0.001 0.034 0.46 Cedar [144] 28-Jun-68 

0.03 (MCL) 

S 0/1 ND ND ND -­ -­ 

Vanadium D 0/1 ND ND ND -­ -­ 0.03 (i-EMEG, child) Zinc D 0/1 ND ND ND -­ -­ 3 (c-EMEG, child) 

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. ** The maximum concentration appears to be an outlier. The next highest concentration is 340 mg/L from the same well [144] in 1984. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

c-EMEG – chronic environmental media evaluation guide CV – comparison value D – dissolved i-EMEG – intermediate environmental media evaluation guide LTHA – lifetime health advisory for drinking water MCL – maximum contaminant level mg/L – milligrams per liter 

N – not defined in the CDPHE database ND – not detected RBC – risk based concentration for drinking wateRMEG – reference dose media evaluation guide S – suspended SS – Colorado state groundwater standard T – total 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 21. Groundwater sampling data (radionuclides) from wells used to water livestock 

Radionuclide Type 

Frequency 

of 

Detection 

Minimum 

(pCi/L) 

Average 

(pCi/L) 

Maximum 

(pCi/L) 

Location of 

Maximum 

Date of 

Maximum CV (pCi/

Lead-210 

D 4/4 -0.1 0.1 0.3 Cedar [144] 

Chestnut [174] 

08-Mar-95 

NA 

S 1/1 0.2 0.2 0.2 19-Sep-96 

Polonium-210 

D 4/4 -0.1 0.3 0.6 Cedar [144] 

Chestnut [174] 

08-Mar-95, 

21-Jun-95 

NA 

S 1/1* 0 0 0 19-Sep-96 

Radium-226 

D 4/4 0.1 0.1 0.1 --** 

Chestnut [174] 

--** 5 (MCL 

radium226/228) 

S 1/1* 0 0 0 19-Sep-96 

Thorium-230 

D 4/4 0 0.05 0.1 Cedar [144] Chestnut [174] 

Chestnut [174] 

20-Sep-95 

19-Sep-96 NA 

S 1/1* 0 0 0 19-Sep-96 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. * The detect flag is “Y” for the one sample, however, the result value is zero. ** All four result values were 0.1 pCi/L. CV – comparison value D – dissolved MCL – maximum contaminant level 

NA – not available pCi/L – picocuries per liter S – suspended 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 22. Groundwater sampling data (chemicals) from wells used to water lawns 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum 

CV 

(mg/L) 

Aluminum D 11/239 0.01 0.19* 0.13 Field well, Cedar [138] 18-Dec-90 

10 

(c-EMEG, 

child) 

Ammonia N 21/112 0.01 0.3 0.9 Field well, Cedar [138] 23-Aug-88 30 (LTHA) Ammonium T 0/5 ND ND ND -­ -­ NA 

Cadmium D 0/5 ND ND ND -­ -­

0.002 

(c-EMEG, 

child) 

Chloride N/T** 1,362/1,372 2.5 30 450 Field well, Cedar [138] 12-Aug-80 

250 

(Secondary 

MCL) 

Copper D 0/5 ND ND ND -­ -­

0.1 

(i-EMEG, 

child) 

Iron D 205/683 0.005 0.031 0.31 

Field well, Cedar [138] 

Elm [129] 

09-Mar-95 

21-Apr-03 

26 (RBC) 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum 

CV 

(mg/L) 

Manganese D 134/683 0.0005 0.008 0.13 house well, Cedar [140] 09-Sep-94 

0.5 

(RMEG, 

child) 

Molybdenum D 1,755/1,790 0.004 2.2 56.7 Field well, Cedar [138] 11-Aug-72 

0.035 (SS); 

0.05 

(RMEG, 

child) 

Nickel D 0/5 ND ND ND -­ -­ 0.2 (RMEG, child) 

Nitrate N/T** 277/314 0.1 1.8 9.8 Cedar [144] 14-May-70 10 (MCL) Selenium D 320/1,105 0.001 0.005 0.134 Field well, Cedar [138] 13-Jul-81 

0.05 

(c-EMEG, 

child) 

Sulfate N/T** 1,382/1,384 8 351 25,460† house well, Cedar [140] 07-May-79 

250 

(Secondary 

MCL) 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical Type 

Frequency 

of 

Detection 

Minimum 

(mg/L) 

Average 

(mg/L) 

Maximum 

(mg/L) 

Location of 

Maximum 

Date of 

Maximum 

CV 

(mg/L) 

Total Dissolved Solids 

N/T** 1,311/1,311 31 746 4,373 Field well, Cedar [138] 06-Mar-81 

500 

(Secondary 

MCL) 

Uranium 

D 1,733/1,789 0.0003 0.233 5.161 Field well, Cedar [138] 01-Aug-68 

0.03 (MCL) 

S 4/38 0.0067 0.010 0.26 Field well, Cedar [138] 27-May-97 

Vanadium D 0/5 ND ND ND -­ -­

0.03 

(i-EMEG, 

child) 

Zinc D 3/5 0.005 0.007 0.022 Birch [119] 25-Aug-95 3 (c-EMEG, child) 

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation. ** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. † The maximum concentration and the second highest concentration (23,200 mg/L from Well 138 in 1978) appear to be outliers. The third highe

from Well 138 in 1979. 

c-EMEG – chronic environmental media evaluation guide MCL – maximum contaminant level RMEG – reference 

CV – comparison value mg/L – milligrams per liter S – suspended D – dissolved N – not defined in the CDPHE database SS – Colorado stai-EMEG – intermediate environmental media evaluation guide ND – not detected T – total LTHA – lifetime health advisory for drinking water RBC – risk based concentration for drinking water 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 23. Groundwater sampling data (radionuclides) from wells used to water lawns 

Radionuclide Type 

Frequency 

of 

Detection 

Minimum 

(pCi/L) 

Average 

(pCi/L) 

Maximum 

(pCi/L) 

Location of 

Maximum 

Date of 

Maximum 

CV 

(pCi/L) 

Lead-210 

D 53/53 -0.2 0.2 1.5 Birch [119] 

house well, Cedar [140] 

Field well, Cedar [138] 

21-Jun-95 

NA 

1

S 38/38 -0.1 0.1 0.6 22-Feb-96, 05-May-99 1

T 1/1* 0 0 0 06-Sep-96 

Polonium-210 

D 53/53 -0.1 0.2 0.9 Field well, Cedar [138] 

house well, Cedar [140] 

Field well, Cedar [138] 

04-May-99 

NA 

1

S 38/38 0 0.1 0.6 22-Feb-96, 05-Dec-96 1

T 1/1 0.5 0.5 0.5 06-Sep-96 

Radium-226 

D 51/51 0 0.1 0.5 house well, Cedar [140] 

Field well, Cedar [138] 

Field well, Cedar [138] 

12-May-95 5 (MCL 

radium226/228) 

1

S 37/37** 0 0.003 0.1 30-Oct-95 1

T 2/2 0 0.05 0.1 06-Sep-96 

Thorium-230 

D 51/51 -0.1 0.08 0.4 Field well, Cedar [138] 

house well, Cedar [140] 

Field well, Cedar [138] 

06-Aug-98 

NA 

1

S 34/34 0 0.06 0.3 05-May-99 1

T 1/1 0.1 0.1 0.1 06-Sep-96 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. * The detect flag is “Y” for the one sample, however, the result value is zero. ** For all but one sample, the result value is zero. CV – comparison value pCi/L – picocuries per liter D – dissolved S – suspended MCL – maximum contaminant level T – total NA – not available 

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Table 24. Groundwater sampling data (chemicals) from Well 138 

Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV 

Aluminum D 8/57 0.05 0.23* 0.13 18-Dec-90 

(c-EM

Ammonia N 10/42 0.02 0.29 0.9 23-Aug-88 30 

Ammonium T 0/1 ND ND ND -­ 

Cadmium D 0/1 ND ND ND -­ 

(c-EM

Chloride N/T** 199/199 5.5 70 450 12-Aug-80 

(Secon

Copper D 0/1 ND ND ND -­ 

(i-EM

Iron D 21/106 0.01 0.025 0.31 09-Mar-95 26 

Manganese D 21/107 0.01 0.008§ 0.06 11-Jun-91 

(RM

Molybdenum D 253/253 1.1 8.0 56.7 11-Aug-72 

0.0

(RM

Nickel D 0/1 ND ND ND -­ 

(RM

Nitrate N/T** 59/62 0.7 2.3 4.1 11-Jun-91 10 

Selenium D 102/151 0.001 0.011 0.134† 13-Jul-81 

(c-EM

Sulfate N/T** 200/200 71 1,059 23,200‡ 01-Nov-78 

(Secon

Total Dissolved Solids N/T** 202/202 290 1,530 4,373 06-Mar-81 

(Secon

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Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV Uranium 

D 253/253 0.0005 0.73 5.161 01-Aug-68 0.0

S 3/18 0.007 0.016 0.26 27-May-97 

Vanadium D 0/1 ND ND ND -­ 

(i-EM

Zinc D 0/1 ND ND ND -­ 3 (c-E

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation. ** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. § The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. † Only three of 151 samples were above the CV. 

‡ The maximum concentration appears to be an outlier. The next highest concentration is 3,360 mg/L in 1979. 

c-EMEG – chronic environmental media evaluation guide NA – not available 

CV – comparison value ND – not detected D – dissolved RBC – risk based concentration for drinking watei-EMEG – intermediate environmental media evaluation guide RMEG – reference dose media evaluation guide LTHA – lifetime health advisory for drinking water S – suspended MCL – maximum contaminant level SS – Colorado state groundwater standard mg/L – milligrams per liter T – total N – not defined in the CDPHE database 

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Table 25. Groundwater sampling data (radionuclides) from Well 138 

Radionuclide Type Frequency of Detection Minimum (pCi/L) Average (pCi/L) Maximum (pCi/L) Date of Maximum CV 

Lead-210 

D 21/21 -0.2 0.22 1.1 03-Aug-95 

27-May-97, 06-Feb-98, 

29-Jul-99, 19-Oct-99 

06-Sep-96 

S 18/18 0 0.08 0.2 

T 1/1* 

0 0 0 

Polonium-210 

D 21/21 0 0.28 0.9 04-May-99 

28-Aug-00 

06-Sep-96 

S 18/18 0 0.11 0.4 

T 1/1 0.5 0.5 0.5 

Radium-226 

D 19/19 0 0.13 0.4 21-Mar-96 

30-Oct-95 

06-Sep-96 

5 (MC

2

S 18/18 0 0.006 0.1 

T 2/2 0 0.05 0.1 

Thorium-230 

D 20/20 0 0.07 0.4 06-Aug-98 

04-May-99, 29-Jul-99 

06-Sep-96 

S 17/17 0 0.04 0.2 

T 1/1 0.1 0.1 0.1 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. *The detect flag is “Y” even though the result value is zero. CV – comparison valueD – dissolvedMCL – maximum contaminant levelNA – not available pCi/L – picocuries per liter S – suspended T – total 

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Table 26. Surface soil sampling data (chemicals) from eight zones around the Cotter Mill and from Lin

Chemical Zone A Zone B Zone C Zone D Zone E Zone F Zone G Zone 

Arsenic 

Range (ppm) 33–69 19–39 14–42 10–40 16–38 17–60 17–33 19–8

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (ppm) 45 30 25 26 28 35 26 42 

Beryllium 

Range (ppm) 0.5–1.6 0.5–0.9 0.6–1 0.5–1.2 0.6–1.7 0.5–0.7 0.6–0.7 0.5–0

Frequency of Detection 9/10 11/12 9/12 10/10 6/8 8/8 4/4 7/8 

Average (ppm) 0.8 0.7 0.7 0.6 0.7 0.6 0.7 0.6 

Cadmium 

Range (ppm) 1.2–15 2.1–13 2.2–16 2.5–6.8 5.3–18 8.9–110 1.6–20 4.4–

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (ppm) 6.9 6.4 6.4 4.1 9.8 36.5 7.9 21.

Lead 

Range (ppm) 43–270 45–240 46–260 47–130 100–280 68–800 37–450 61–1,

Frequency of Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (ppm) 132 104 113 74 173 380 201 445 

Manganese 

Range (ppm) 180–480 320–630 200–500 110–750 150–420 140–400 200–370 210–7

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (ppm) 336 422 356 391 298 268 290 439 

Selenium 

Range (ppm) 5–7 39 7–16 5 ND ND ND 7 

Frequency of Detection 5/10 1/12 2/12 1/10 0/8 0/8 0/4 1/8 

Average (ppm) 4.2* 5.5* 4* 2.8* ND ND ND 3.1

Source: Weston 1998 Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

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Each sample is a composite of four subsamples collected from the corners of a 10x10 square established near the center of the grid.

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.See Figure for a map of the sampling zones. * The calculated averages are lower than the minimum detected concentrations due to including 1⁄2 the detection limit in the calculation. 

c-EMEG – chronic environmental media evaluation guide CREG – cancer risk evaluation guide CV – comparison value ND – not detected ppm – parts per million RMEG – reference dose media evaluation guide SSL – EPA’s soil screening level for residential areas 

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Table 27. Surface soil sampling data (radionuclides) from eight zones around the Cotter Mill and from L

Radionuclide Zone A Zone B Zone C Zone D Zone E Zone F Zone G Zone 

Lead-210 

Range (pCi/g) 1.6–9.7 3.0–14.4 2.5–6.0 2.3–4.5 2.6–6.1 2.7–4.9 1.2–4.4 1.5–4

Frequency of Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 6.3 8.2 4.1 3.4 4.4 3.9 2.9 2.6 

Radium-226 

Range (pCi/g) 2.4–10.7 3.6–16.5 1.3–5.7 1.4–2.3 2.5–5.6 1.9–3.0 1.4–1.9 1.2–2

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 6.6 9.2 2.6 1.8 3.9 2.5 1.7 1.5 

Thorium-230 

Range (pCi/g) 3.6–35.3 5.8–40.1 1.6–21.7 1.8–4.4 4.3–12.1 3.6–8.3 1.7–2.8 1.6–1

Frequency of Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 17.7 20.9 5.9 2.5 7.7 5.2 2.4 3.3 

Uranium, natural 

Range (pCi/g) 0.871– 4.288 1.541– 5.427 0.737– 5.628 0.737–1.64 1.005– 2.412 0.6432– 1.943 0.5561– 1.005 0.53

1.20

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 2.45 3.29 1.98 1.17 1.52 1.21 0.83 0.7

Uranium-234 

Range (pCi/g) 0.436–2.14 0.771–2.71 0.369–2.81 0.369–0.82 0.503–1.21 0.322– 0.972 0.278– 0.503 0.26

0.60

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 1.23 1.65 0.991 0.584 0.758 0.606 0.413 0.36

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Radionuclide Zone A Zone B Zone C Zone D Zone E Zone F Zone G Zone 

Uranium-238 

Range (pCi/g) 0.436–2.14 0.771–2.71 0.369–2.81 0.369–0.82 0.503–1.21 0.322– 0.972 0.278– 0.503 0.26

0.60

Frequency of 

Detection 10/10 12/12 12/12 10/10 8/8 8/8 4/4 8/8 

Average (pCi/g) 1.23 1.65 0.991 0.584 0.758 0.606 0.413 0.36

Source: Weston 1998 Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide.The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.Each sample is a composite of four subsamples collected from the corners of a 10x10 square established near the center of the grid.

See Figure for a map of the sampling zones. CV – comparison valueNA – not available pCi/g – picocuries per gramUMTRCA – 1978 Uranium Mill Tailings Radiation Control Act

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 28. Surface soil sampling data (radionuclides) from the county road and 

the Cotter Uranium Mill access road 

Radionuclide Samples from 

background areas 

Samples along the 

county road 

Samples along the 

access road* CV 

Radium-226 

Range (pCi/g) 0.8–2.1 3.8–14 2.7–351 5 pCi/g 

(UMTRCA, 

surface) 

Frequency of Detection 5/5 5/5 6/6 

Average (pCi/g) 1.42 7.7 65 

Thorium-230 

Range (pCi/g) 0.2–2.4 9.7–25 10–395 

Frequency of Detection 3/5 5/5 6/6 NA

Average (pCi/g) 1.53 20 87 

Uranium, 

natural 

Range (ppm) 1.18–3.05 5.28–29.2 4.31–922 100 ppm 

(i-EMEG, child 

for highly 

soluble salts) 

Frequency of Detection 5/5 5/5 6/6 

Average (ppm) 1.87 13.6 161 

Uranium-238** 

Range (pCi/g) 0.39–1.01 1.74–9.64 1.42–304 

Frequency of Detection 5/5 5/5 6/6 NA

Average (pCi/g) 0.62 4.5 53 

Gamma 

Exposure 

Rates 

Range (μR/hr) NA 13.8–55.3 18.6–893 

Frequency of Detection NA NA NA NA

Average (μR/hr) 15.7 25.8 73.7 

Source: MFG 2005 

Bolded text indicates that the average and/or maximum concentration exceeded the comparison value.
 

Each sample consists of 10 aliquots taken from 0–6 inches within a 100 m2

 area. 

See Figure for a map of the sampling locations. 

*There is limited potential for exposure to contaminants along the access road since access to the Cotter Mill is restricted and soils 

along the access road were remediated in 2007 and 2008. 

**Uranium-238 concentrations were calculated by multiplying the natural uranium concentrations by 0.33. 

CV – comparison value 

i-EMEG – intermediate environmental media evaluation guide 

μR/hr – microroentgen per hour 

NA – not available 

pCi/g – picocuries per gram 

ppm – parts per million 

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 29. Soil data (chemicals) from samples taken by CDPHE, January 2003 

Chemical Frequency of Detection Minimum (ppm) Average (ppm) Maximum (ppm) Location of Maximum 

Lead 20/20 23 410 3,651* Private barn in Lincoln Park 

sample) 

Molybdenum 0/20 ND** ND** ND** -­ Uranium 20/20 1.2 6.0 31 Mill Entrance Road 

Source: CDPHE 2003, 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. See Figure for a map of the sampling locations. The sampling event was intentionally biased toward finding the highest amounts of contamination possible (CDPHE 2003).*The second highest lead concentration is 908 ppm from a location northwest of the Cotter Mill. **The molybdenum detection limit was 25 ppm.

§ Concentrations from the background location on the corner of Orchard Avenue and High Street were not included in the table.

CV – comparison valuei-EMEG – intermediate environmental media evaluation guide ND – not detected ppm – parts per million RMEG – reference dose media evaluation guideSSL – EPA’s soil screening level for residential areas 

LeMoUra

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 30. Soil data (radionuclides) from samples taken by CDPHE, January 2003 

Radionuclide Frequency of Detection Minimum (pCi/g) Average (pCi/g) Maximum (pCi/g) Location of Maximum 

Cesium-137 20/20 0 0.64 1.33 Private residence in Lincol

Park (dust sample) 

Lead-210 20/20 1.9 9.7 22.8 East of the Cotter Mill 

Plutonium-239, 240 9/20 0.03 0.03* 0.06 

East of the Cotter Mill & 

a private residence in Linco

Park (dust sample) 

Potassium-40 20/20 17.6 22.6 31.9 East of the Cotter Mill 

Radium-226 20/20 1.4 7.8 21.2 East of the Cotter Mill Radium-228 20/20 0.6 1.0 1.3 

Private barn in Lincoln Par

(dust sample), private residen

in Lincoln Park (dust sample

Pine St near Elm Ave in Linc

Park (sediment sample), 

Northwest of the Cotter Mi

Source: CDPHE 2003, 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide.Averages were calculated using 1⁄2 the reporting detection limit for non-detects. See Figure for a map of the sampling locations. The sampling event was intentionally biased toward finding the highest amounts of contamination possible (CDPHE 2003).* The calculated average is the same as the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. 

** Concentrations from the background location on the corner of Orchard Avenue and High Street were not included in the table. CV – comparison value NA – not available pCi/g – picocuries per gram UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

C

B

CesiuLeadPlutoPotasRadiuRadiu

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 31. Surface soil sampling data from 10 air monitoring locations 

Chemical Frequency of Detection Minimum (ppm) Average (ppm) Maximum (ppm) Location of Maximum Date of Maximum Ye

Sam

Molybdenum 106/134 0.6 15.1 251.3 AS-204 (West Boundary) 2002 1992–

Radionuclide Frequency of Detection Minimum (pCi/g) Average (pCi/g) Maximum (pCi/g) Location of Maximum Date of Maximum Ye

Sam

Radium-224** 10/10 -5.7 -2.9 0.3 Lincoln Park 2006 20

Radium-226 246/251 <0.5 3.9 53.5 AS-209 (Mill Entrance Road) 2002 1979–

Thorium-230 107/107 0.4 22.2 354 AS-209 (Mill Entrance Road) 2002 1996–

Thorium-232 60/60 0.5 1.4 7.9 AS-209 (Mill Entrance Road) 2002 2001–

Uranium 258/262 <0.001 4.6 73.6 AS-209 (Mill Entrance Road) 2002 1979–

Source: Cotter 2007; GeoTrans 1986 Bolded text indicates that the average and/or maximum concentration exceeded the comparison value.

Uranium and radium-226 were also tested in soil from two additional off-site locations (Oro Verde #1 and Oro Verde #2) in 1983 and 1984.

See Figure for a map of the air monitoring locations. *Data from 2006 are unavailable.**Data are blank corrected. †Results from 2005 were not reported based on quality assurance analysis (Cotter 2007). 

CV – comparison value NA – not available pCi/g – picocuries per gram ppm – parts per million RMEG – reference dose media evaluation guide UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

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Table 32. Soil sampling data (chemicals) from location AS-212 (the Nearest Resident) 

Chemical Frequency of Detection Minimum (ppm) Average (ppm) Maximum (ppm) Date of Maximum Years Sample

Lead 1/1 199 199 199 15-Jan-03 2003 

Molybdenum 7/8 1.6 11.3 42.4 2005 1999–2005 Uranium 1/1 4.9 4.9 4.9 15-Jan-03 2003 

Source: CDPHE 2007b, Cotter 2007 Averages were calculated using 1⁄2 the reporting detection limit for non-detects. See Figure for the location of AS-212, the nearest resident. CV – comparison value i-EMEG – intermediate environmental media evaluation guide ppm – parts per million RMEG – reference dose media evaluation guide SSL – EPA’s soil screening level for residential areas 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 33. Soil sampling data (radionuclides) from location AS-212 (the Nearest Resident) 

Radionuclide Frequency of Detection Minimum (pCi/g) Average (pCi/g) Maximum (pCi/g) Date of Maximum Years Sample

Cesium-137 1/1 0.61 0.61 0.61 15-Jan-03 2003 

Lead-210 1/1 

8 8 8 15-Jan-03 2003 

Plutonium-239, 240 1/1 0.03 0.03 0.03 15-Jan-03 2003 

Potassium-40 1/1 17.7 17.7 17.7 15-Jan-03 2003 

Radium-224* 1/1 -3.6 -3.6 -3.6 2006 2006 

Radium-226 8/8 1.4 3.3 7.5 2004 1999–2004, 200Radium-228 1/1 0.9 0.9 0.9 15-Jan-03 2003 

Thorium-230 8/8 3.3 10.1 20 2004 1999–2006 

Thorium-232 6/6 0.7 1.0 1.1 2001, 2002 2001–2006 Uranium 8/8 2.0 5.2 13 2004 1999–2006 

Source: CDPHE 2007b, Cotter 2007 Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide. See Figure for the location of AS-212, the nearest resident. *Data are blank corrected. CV – comparison value NA – not available pCi/g – picocuries per gram UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

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Table 34. Surface soil sampling data (chemicals) from lawns and gardens in Lincoln Park 

Chemical Frequency of Detection Minimum (ppm) Average (ppm) Maximum (ppm) Location of Maximum Years Samp

Arsenic 15/15 31 44 50 garden soil 1996 Beryllium 14/15 0.5 0.7 1.1 lawn soil 1996 

Cadmium 14/15 0.5 1.2 1.9 lawn soil 1996 

Manganese 15/15 290 428 640 lawn soil 1996 

Selenium 1/32 18 1.7* 18 garden soil 1990, 199

Source: Weston 1996 (some or all of these data may also be included in Table) Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. 

c-EMEG – chronic environmental media evaluation guide CV – comparison value ppm – parts per million RMEG – reference dose media evaluation guide 

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Table 35. Surface soil sampling data (radionuclides) from yards, gardens, and air monitoring locations in 

Radionuclide Frequency of Detection Minimum (pCi/g) Average (pCi/g) Maximum (pCi/g) Source of Maximum Years S

Lead-210 17/17 0.4 1.6 2.5 0–2” garden sample 19

Polonium-210 17/17 1.1 1.7 2.6 0–2” garden sample 19

Radium-226 19/19 0.8 1.5 2.0 0–2” garden sample 1987, 19

Thorium-228 17/17 1.0 1.4 1.8 0–2” garden sample 19

Thorium-230 17/17 1.0 1.5 2.3 0–2” garden sample 19

Uranium-234 29/29 0.355 1.23 1.95 Soil from the yard of a participant in the LPWUS 1987–

Uranium-235 0/17 ND* ND* ND* -­ 19

Uranium-238 29/29 0.355 1.21 1.95 Soil from the yard of a participant in the LPWUS 1987–

Source: Weston 1996 *The uranium-235 detection limit was 0.2 pCi/g. CV – comparison value LPWUS – Lincoln Park Water Use Survey NA – not available ND – not detected pCi/g – picocuries per gram UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

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Table 36. Surface soil data (chemicals) from lawns and gardens in Lincoln Park 

Chemical 

Samples from locations 

irrigated with 

contaminated well water 

Samples from locations 

not irrigated with 

contaminated well water 

CV (ppm) 

Arsenic 

Range (ppm) 14–50 13–38 

0.5 (CREG), 

20 (c-EMEG, child) Frequency of Detection 26/26 47/47 

Average (ppm) 36* 28* 

Beryllium 

Range (ppm) 0.5–1.1 0.6–1.7 

Frequency of Detection 25/26 47/47 100 (c-EMEG, child)

Average (ppm) 0.7 0.8 

Cadmium 

Range (ppm) 0.6–1.9 0.5–5 

Frequency of Detection 23/26 45/47 10 (c-EMEG, child) 

Average (ppm) 1.2 1.5** 

Lead 

Range (ppm) 17–270† 

Frequency of Detection 73/73 400 (SSL) † 

Average (ppm) 122 121 

Manganese 

Range (ppm) 290–640 320–580 

3,000 

(RMEG , child) Frequency of Detection 26/26 47/47 

Average (ppm) 430 421** 

Molybdenum 

Range (ppm) Data not available§ Data not available§ 

Frequency of Detection Data not available 300 (RMEG , child) § Data not available§ 

Average (ppm) 1.7* 0.5* 

Selenium 

Range (ppm) 18 5–44 

Frequency of Detection 1/26 6/47 300 (c-EMEG, child)

Average (ppm) 3.1 3.8 

Uranium 

Range (ppm) Data not available§ Data not available§ 100 (i-EMEG, child 

for highly soluble 

salts) 

Frequency of Detection Data not available§ Data not available§ 

Average (ppm) 2.3* 1.6* 

Source: Weston 1998 

Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.
 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.
 

*The concentrations were statistically higher in irrigated soil samples. 

**The calculated averages for cadmium and manganese differ slightly from the reported mean concentrations in Table 3-3.
 †The raw data for lead are not presented by whether the samples were taken from locations irrigated with contaminated well water. 

However, Table 3-3 presents the mean concentrations by manner of irrigation. 

§

The raw data for molybdenum and uranium are not presented in the report. Therefore, the range and frequency of detection could not 

be determined. Table 3-3 presents the mean concentrations. 

c-EMEG – chronic environmental media evaluation guide ppm – parts per million 

CREG – cancer risk evaluation guide RMEG – reference dose media evaluation guide 

CV – comparison value SSL – EPA’s soil screening level for residential areas 

i-EMEG – intermediate environmental media evaluation guide 

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Table 37. Surface soil data (radionuclides) from lawns and gardens in Lincoln Park 

Radionuclide 

Samples from locations 

irrigated with 

contaminated well water 

Samples from locations 

not irrigated with 

contaminated well water 

CV (pCi/g) 

Lead-210 

Range (pCi/g) 0.8–3.0 0.7–4.2 

Frequency of Detection 11/11 47/47 NA

Average (pCi/g) 2.2 2.1* 

Radium-226 

Range (pCi/g) 1.3–1.7 1.1–2.2 

5 (UMTRCA, 

surface) Frequency of Detection 11/11 47/47 

Average (pCi/g) 1.4 1.5 

Thorium-230 

Range (pCi/g) 1.1–2.2 1.0–4.2 

Frequency of Detection 11/11 47/47 NA

Average (pCi/g) 1.6* 1.7 

Uranium, natural 

Range (pCi/g) 0.871–3.417 0.6566–2.077 

Frequency of Detection 26/26 47/47 NA

Average (pCi/g) 1.514 1.05 

Uranium-234 

Range (pCi/g) 0.436–1.709 0.328–1.039 

Frequency of Detection 26/26 47/47 NA

Average (pCi/g) 0.755 0.525 

Uranium-238 

Range (pCi/g) 0.436–1.709 0.328–1.039 

Frequency of Detection 26/26 47/47 NA

Average (pCi/g) 0.755 0.525 

Source: Weston 1998 

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe. 

*The calculated averages for lead-210 and thorium-230 differ slightly from the reported mean concentrations in Table 3-3. 

CV – comparison value 

NA – not available 

pCi/g – picocuries per gram 

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

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Table 38. Sediment sampling data (chemicals) from Sand Creek 

Chemical 

Location Concentration (ppm) 

CV (ppm) SD01 SD02* SD04 

SD05

1 2 3 

Arsenic NA 13.7 13 NA 17 <5 20 (c-EMEG, child) 

Cadmium NA 3.9 7.2 NA 7.6 1.5 10 (c-EMEG, child) 

Cobalt NA 11.3 43 NA 21 10 500 (i-EMEG, child) 

Copper 19 52.3 46 NA 38 19 500 (i-EMEG, child) 

Lead 27 106 93 NA 130 22 400 (SSL) 

Molybdenum 4.4 2.6 8 NA 7.9 9.4 300 (RMEG , child) 

Nickel NA 17 63 NA 28 18 1,000 (RMEG, child) 

Zinc NA 343 540 NA 580 106 20,000 (c-EMEG, child) 

Source: GeoTrans 1986 

SD01 – mouth near the Arkansas River 

SD02 – near spring where flow begins (reflects migration of contaminants in the groundwater) 

SD04 – below the SCS Dam in 

(1) an abandoned stock watering pond (formed by diversion of runoff water into a depression adjacent to Sand Creek) 

(2) in drainage (reflects historical picture of uncontrolled emissions) 

(3) in drainage above #2 (reflects historical picture of uncontrolled emissions) 

SD05 – above the SCS Dam adjacent to the west property edge 

Bolded text indicates that the concentration exceeded the comparison value for that chemical. 

Samples were collected July 10–20, 1985. 

*Values are the mean of three field replicates. 

c-EMEG – chronic environmental media evaluation guide 

CREG – cancer risk evaluation guide 

CV – comparison value 

i-EMEG – intermediate environmental media evaluation guide 

ppm – parts per million 

RMEG – reference dose media evaluation guide 

SSL – EPA’s soil screening level for residential areas 

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Table 39. Sediment sampling data (radionuclides) from Sand Creek 

Radionuclide 

Location Average (pCi/g) 

CV

SD01 SD02 

SD04 

SD05

1 2 3 

Gross Alpha 22±3 47±9 240±40 74±9 39±7 22±5 NA 

Gross Beta 29±6 43±8 90±20 34±7 32±7 32±6 NA 

Radium-226 1.21±0.06 1.7±1 12.8±0.6 3.5±0.2 3.4±0.2 2.3±1 5 (UMTRCA, 

surface) 

Throium-230 4.6±0.3 34±2 82±4 32±2 15.5±0.8 5.2±0.3 NA 

Total Uranium 2.4 4.3 11.7 3.4 3.4 3.9 NA 

Source: GeoTrans 1986 

SD01 – mouth near the Arkansas River 

SD02 – near spring where flow begins (reflects migration of contaminants in the groundwater) 

SD04 – below the SCS Dam in 

(1) an abandoned stock watering pond (formed by diversion of runoff water into a depression adjacent to Sand Creek) 

(2) in drainage (reflects historical picture of uncontrolled emissions) 

(3) in drainage above #2 (reflects historical picture of uncontrolled emissions) 

SD05 – above the SCS Dam adjacent to the west property edge 

Bolded text indicates that the concentration exceeded the comparison value for that radionuclide. 

Samples were collected July 10–20, 1985. 

CV – comparison value 

NA – not available 

pCi/g – picocuries per gram 

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act 

125 
 

 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 40. Chemical sampling for the Sand Creek Cleanup Project 

Chemical Frequency of 

Detection 

Minimum 

(ppm) 

Average 

(ppm) 

Maximum 

(ppm) CV (ppm) 

Arsenic 7/7 2.7 3.9 6.9 20 (c-EMEG, child) 

Barium 7/7 69 106 160 10,000 (c-EMEG, child) 

Beryllium 7/7 0.2 0.3 0.6 100 (c-EMEG, child) 

Chromium 7/7 7.4 9.5 12.8 200 (RMEG, child for 

hexavalent chromium) 

Lead 7/7 17 35 75 400 (SSL) 

Manganese 7/7 258 343 502 3,000 (RMEG , child) 

Molybdenum 7/7 2.1 2.8 3.5 300 (RMEG , child) 

Nickel 7/7 8 10.9 16 1,000 (RMEG , child) 

Selenium 0/7 ND* ND* ND* 300 (c-EMEG, child) 

Vanadium 7/7 16.1 20.3 26.1 200 (i-EMEG, child) 

Source: Cotter 2000 

Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Samples were collected in April and May 1998. 

*The selenium detection limit was 5 ppm. 

c-EMEG – chronic environmental media evaluation guide 

CREG – cancer risk evaluation guide 

CV – comparison value 

i-EMEG – intermediate environmental media evaluation guide 

ND – not detected 

ppm – parts per million 

RMEG – reference dose media evaluation guide 

SSL – EPA’s soil screening level for residential areas 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 41. Surface water sampling data (chemicals) from Sand Creek 

Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV 

Aluminum D 0/2 ND ND ND -­ 10 (c-E

Ammonia N 2/35 0.5 0.43* 0.8 10-Nov-88 30 

Ammonium T 0/3 ND ND ND -­ Chloride N/T** 92/92 3 8 14 13-May-04 250 (Sec

Iron D 21/55 0.03 0.04 0.26 07-Nov-02 26 

Manganese D 36/55 0.0084 0.04 1.3† 19-Nov-01 0.5 (R

Molybdenum D 98/104 0.005 0.02 0.051† 01-Dec-87 0.0

0.05 (R

Nitrate N/T** 75/87 0.5 1.1 4.7 03-May-06 10 

Selenium D 0/8 ND ND ND -­ 0.05 (c-

Sulfate N/T** 94/94 12 65 310† 11-Oct-96 250 (Sec

Total Dissolved Solids N/T** 99/99 10.7 369 1,372‡ 22-Aug-91 500 (Sec

Uranium 

D 101/101 0.006 0.012 0.0267 01-Aug-95 0.0

S 8/48 0.000098 0.001 0.0031 10-Jan-00 

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. 

** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. † Only the maximum concentration was above the CV. 

‡ This appears to be an outlier. The next highest concentration is 460 mg/L. Only the maximum concentration was above the CV. 

c-EMEG – chronic environmental media evaluation guide mg/L – milligrams per liter RBC – risk based 

CV – comparison value N – not defined in the CDPHE database RMEG – reference 

D – dissolved NA – not available S – suspended 

LTHA – lifetime health advisory for drinking water ND – not detected SS – Colorado sta

MCL – maximum contaminant level T – total 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 42. Surface water sampling data (radionuclides) from Sand Creek 

Radionuclide Type Frequency of Detection Minimum (pCi/L) Average (pCi/L) Maximum (pCi/L) Date of Maximum CV (pCi/

Lead-210 

D 40/49 -0.2 0.39 3.7 06-Aug-07 

06-Aug-07 

NA 

S 40/49 -0.1 0.40 4.6 

Polonium-210 

D 41/49 -0.1 0.15 0.6 28-Nov-06 

09-Nov-99 

NA 

S 40/49 0 0.13 1.6 

Radium-226 

D 45/49 0 0.12 0.6 03-May-06 

09-Nov-99, 

28-Nov-06 

5 (MCL rad

226/228

S 42/47 0 0.06 0.4 

Thorium-230 

D 44/49 -0.1 0.13 0.8 28-Nov-06 

06-Aug-07 

NA 

S 41/46 0 0.16 0.9 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. CV – comparison value D – dissolved MCL – maximum contaminant level NA – not available pCi/L – picocuries per liter S – suspended 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 43. Surface water sampling data (chemicals) from the DeWeese Dye Ditch 

Chemical Type Frequency of Detection Minimum (mg/L) Average (mg/L) Maximum (mg/L) Date of Maximum CV 

Aluminum D 1/4 0.02 0.06* 0.02 14-Jun-95 10 (c-E

Ammonia N 0/2 ND ND ND -­ 30 

Chloride N/T** 95/102 2 7 18 08-May-01 250 (Sec

Iron D 22/50 0.029 0.9 43† 09-Jun-99 26 

Manganese D 28/50 0.004 0.05 1.9‡ 09-Jun-99 0.5 (R

Molybdenum D 10/120 0.001 0.013§ 0.013 06-Aug-03 0.0

0.05 (R

Nitrate N/T** 7/26 0.1 0.3 0.8 10-May-00, 02-Aug-06 10 

Selenium D 4/76 0.005 0.003†† 0.011 22-Jun-87, 25-Apr-88 0.05 (c-

Sulfate N/T** 102/102 6 31 95 28-Apr-82 250 (Sec

Total Dissolved Solids N/T** 119/119 12.9 231 1,647‡‡ 10-Sep-90 500 (Sec

Uranium 

D 86/116 0.0004 0.01 0.11§§ 05-May-83 0.0

S 0/8 ND ND ND -­ 

Source: CDPHE 2007b Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical. 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. * The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”. † This appears to be an outlier. The next highest concentration is 0.24 mg/L from the same location in 2003. Only the maximum concentration w

‡ Only the maximum concentration was above the CV.§ The calculated average is the same as the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

†† The calculated average is the lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. ‡‡ This appears to be an outlier. The next highest concentration is 870 mg/L. Only three of the 119 samples were above the CV. §§ Only three of the samples were above the CV. 

c-EMEG – chronic environmental media evaluation guide CV – comparison value D – dissolved LTHA – lifetime health advisory for drinking water MCL – maximum contaminant level mg/L – milligrams per liter N – not defined in the CDPHE database ND – not detected RBC – risk based concentration for drinking water RMEG – reference dose media evaluation guide S – suspended SS – Colorado state groundwater standard T – total 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 44. Surface water sampling data (radionuclides) from the DeWeese Dye Ditch 

Radionuclide Type Frequency of Detection Minimum (pCi/L) Average (pCi/L) Maximum (pCi/L) Date of Maximum CV (pCi/

Lead-210 

D 8/8 0 0.3 1.2 09-May-96 

12-May-97 

NA 

S 8/8 0 0.09 0.2 

Polonium-210 

D 8/8 0 0.1 0.2 09-Jun-99, 02-Sep­ 99 

09-Jun-99 

NA 

S 8/8 0 0.05 0.2 

Radium-226 

D 8/8 0 0.04 0.1 09-May-96, 16-Jul-96, 02-Sep-99 

02-Sep-99 

5 (MCL rad

226/228

S 7/7 0 0.01 0.1 

Thorium-230 

D 8/8 0 0.025 0.2 12-May-97 

09-Sep-98 

NA 

S 7/7 0 0.07 0.2 

Source: CDPHE 2007b Averages were calculated using 1⁄2 the reporting detection limit for non-detects. Negative and zero result values were included in the summary statistics. CV – comparison value D – dissolved MCL – maximum contaminant level NA – not available pCi/L – picocuries per liter S – suspended 

131 
 

 


 

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Table 45. Surface water sampling data (chemicals) from the Arkansas River 

Chemical Type 

Upstream of 

Sand Creek at 

1st Street (907) 

Downstream of 

Sand Creek at 

Mackenzie Ave (904) 

CV (mg/L) 

Chloride T 

Range (mg/L) 3–60 3–14 

Frequency of Detection 127/130 127/130 250 (Secondary MCL) 

Average (mg/L) 8 8 

Molybdenum D 

Range (mg/L) 0.0029–0.046 0.003–0.029 

0.035 (SS); 

0.05 (RMEG, child) Frequency of Detection 32/142 46/142 

Average (mg/L) 0.025 0.025 

Molybdenum S 

Range (mg/L) 0.0019–0.022 0.0017–0.016 

0.035 (SS); 

0.05 (RMEG, child) Frequency of Detection 8/135 6/135 

Average (mg/L) 0.025 0.025 

Molybdenum T 

Range (mg/L) 0.006 0.005 

0.035 (SS); 

0.05 (RMEG, child) Frequency of Detection 1/7 1/7 

Average (mg/L) 0.003* 0.003* 

Sulfate T 

Range (mg/L) 10–1,300** 5–4,200** 

Frequency of Detection 130/130 130/130 250 (Secondary MCL) 

Average (mg/L) 41 84 

Total 

Dissolved 

Solids 

T 

Range (mg/L) 45–2,880† 62–337 

Frequency of Detection 130/130 130/130 500 (Secondary MCL) 

Average (mg/L) 172 192 

Uranium D 

Range (mg/L) 0.0003– 0.0135 0.0002–0.0155 

Frequency of Detection 129/130 130/130 0.03 (MCL) 

Average (mg/L) 0.004 0.005 

Uranium S 

Range (mg/L) 0.0002– 0.014 0.0002–0.0043 

Frequency of Detection 16/121 14/121 0.03 (MCL) 

Average (mg/L) 0.001 0.001 

Uranium T 

Range (mg/L) 0.0033–0.0056 0.0029–0.0054 

Frequency of Detection 7/7 7/7 0.03 (MCL) 

Average (mg/L) 0.004 0.004 

Source: CDPHE 2007b 

Bolded text indicates that the average and/or maximum concentration exceeded the comparison value for that chemical.
 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

All samples were collected between 1995 and 2007. The “T” samples for uranium were only collected in 1995. 

* The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation. 

** This appears to be an outlier. The next highest concentration is 200 mg/L. Only the maximum concentration was above the CV. 

† This appears to be an outlier. The next highest concentration is 405 mg/L. Only the maximum concentration was above the CV. 

CV – comparison value mg/L – milligrams per liter SS – Colorado state 

D – dissolved RMEG – reference dose media evaluation guide groundwater standard 

MCL – maximum contaminant level S – suspended T – total 

132 
 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 46. Surface water sampling data (radionuclides) from the Arkansas River 

Radionuclide Type 

Upstream of 

Sand Creek at 

1st Street (907) 

Downstream of 

Sand Creek at 

Mackenzie Ave (904) 

CV (pCi/L) 

Lead-210 D 

Range (pCi/L) ND 3.7 

Frequency of Detection 0/1 1/1 NA

Average (pCi/L) ND 3.7 

Lead-210 S 

Range (pCi/L) ND 0 

Frequency of Detection 0/1 1/2 NA

Average (pCi/L) ND 0.25* 

Polonium-210 D 

Range (pCi/L) ND ND 

Frequency of Detection 0/1 0/1 NA

Average (pCi/L) ND ND 

Polonium-210 S 

Range (pCi/L) ND 0.26–3.3 

Frequency of Detection 0/1 2/2 NA

Average (pCi/L) ND 1.8 

Radium-226 D 

Range (pCi/L) 0–0.6 0–0.4 

5 (MCL radium226/228) Frequency of Detection 119/128 116/127 

Average (pCi/L) 0.13 0.07 

Radium-226 S 

Range (pCi/L) 0–0.8 0–2.3 

5 (MCL radium226/228) Frequency of Detection 114/120 112/119 

Average (pCi/L) 0.08 0.09 

Radium-226 T 

Range (pCi/L) 0.1–0.7 0.1–0.7 

5 (MCL radium226/228) Frequency of Detection 7/7 7/7 

Average (pCi/L) 0.3 0.3 

Thorium-230 D 

Range (pCi/L) -0.1–1 -0.1–1.2 

Frequency of Detection 121/127 116/127 NA

Average (pCi/L) 0.1 0.1 

Thorium-230 S 

Range (pCi/L) 0–2.5 0–2.4 

Frequency of Detection 115/120 113/119 NA

Average (pCi/L) 0.2 0.2 

Thorium-230 T 

Range (pCi/L) 0.1–0.7 0–0.6 

Frequency of Detection 7/7 7/7 NA

Average (pCi/L) 0.3 0.2 

Source: CDPHE 2007b 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Negative and zero result values were included in the summary statistics. 

Radium-226 and thorium-230 “D” and “S” samples were collected between 1995 and 2007. The radium-226 and thorium-230 “T” 

samples were only collected in 1995. Lead-210 and polonium-210 were sampled upstream (907) in 2005 (“D” and “S”) and 

downstream (904) in 2005 (“D”) and 2006 (“D” and “S”). 

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* The calculated average is higher than the detected concentration due to including 1⁄2 the detection limit in the calculation. 

CV – comparison value 

D – dissolved 

MCL – maximum contaminant level 

NA – not available 

ND – not detected 

pCi/L – picocuries per liter 

S – suspended 

T – total 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 47. Sampling data (chemicals) for local and supermarket foods 

Chemical Food Type Average (mg/kg) 

Local Supermarket 

Barium* Vegetables 4.75 NA 

Cadmium* Vegetables 0.215 NA 

Chromium* Vegetables 0.095 NA 

Manganese* Vegetables 11.25 NA 

Molybdenum 

Chicken 0.19 0.72 

Fruits 0.079 0.017 

Vegetables 0.667 0.023 

Selenium 

Chicken 0.31 0.18 

Fruits 0.024 0.017 

Vegetables 0.061 0.020 

Strontium* Vegetables 22 NA 

Uranium 

Chicken 0.061 0.001 

Fruits 0.0056 0.0013 

Vegetables 0.0043 0.0013 

Vanadium* Vegetables 0.105 NA 

Zinc* Vegetables 7.5 NA 

Source: Weston 1996 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Concentrations are reported on a wet weight basis. 

Vegetables were also tested for arsenic, beryllium, cobalt, lead, mercury, nickel, and silver, but none of these chemicals were detected. 

*Chicken and fruits were not analyzed for these chemicals. 

NA – not available 

mg/kg – milligrams per kilogram
 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 48. Sampling data (radionuclides) for local and supermarket foods 

Radionuclide Food Type Average (pCi/kg) 

Local Supermarket 

Lead-210 

Chicken 1.26 1.70 

Fruits 1.48 1.18 

Vegetables 0.58 0.60 

Polonium-210 

Chicken 3.79 21.75 

Fruits 2.26 1.30 

Vegetables 1.13 1.56 

Radium-226 

Chicken 0.64 2.60 

Fruits 1.34 0.05 

Vegetables 1.37 0.07 

Thorium-228 

Chicken 0.39 ND 

Fruits 0.33 ND 

Vegetables 0.41 1.42 

Thorium-230 

Chicken 1.01 0.53 

Fruits 1.85 ND 

Vegetables 0.27 0.29 

Uranium-234 

Chicken 1.10 1.05 

Fruits 1.53 0.34 

Vegetables 0.55 0.76 

Uranium-235 

Chicken ND 0.36 

Fruits 0.13 0.13 

Vegetables 0.13 0.14 

Uranium-238 

Chicken 1.59 0.53 

Fruits 1.41 0.23 

Vegetables 0.44 0.25 

Source: Weston 1996 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Concentrations are reported on a wet weight basis. 

ND – not detected 

pCi/kg – picocuries per kilogram 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 49. Sampling data (chemicals) for local produce irrigated with contaminated well water 

Chemical Fruits Vegetables 

Arsenic 

Frequency of Detection 2/16 14/43 

Average (mg/kg) 0.051 0.077 

Maximum (mg/kg) 0.2 0.4 

Barium 

Frequency of Detection 7/16 33/43 

Average (mg/kg) 0.44 1.6 

Maximum (mg/kg) 0.9 15 

Cadmium 

Frequency of Detection 2/16 18/43 

Average (mg/kg) 0.041 0.034 

Maximum (mg/kg) 0.23 0.14 

Chromium 

Frequency of Detection 12/16 39/43 

Average (mg/kg) 0.052 0.056 

Maximum (mg/kg) 0.1 0.19 

Cobalt 

Frequency of Detection 0/16 6/43 

Average (mg/kg) ND 0.02 

Maximum (mg/kg) ND 0.07 

Lead 

Frequency of Detection 3/16 26/43 

Average (mg/kg) 0.13 0.2 

Maximum (mg/kg) 1.2 1.9 

Manganese 

Frequency of Detection 16/16 43/43 

Average (mg/kg) 0.87 2.4 

Maximum (mg/kg) 1.8 11 

Molybdenum 

Frequency of Detection 6/16 41/43 

Average (mg/kg) 0.11 0.68 

Maximum (mg/kg) 0.3 9.8 

Nickel 

Frequency of Detection 0/16 2/43 

Average (mg/kg) ND 0.075 

Maximum (mg/kg) ND 0.2 

Strontium 

Frequency of Detection 16/16 43/43 

Average (mg/kg) 1.6 4.9 

Maximum (mg/kg) 8.5 33 

Uranium 

Frequency of Detection 3/16 14/43 

Average (mg/kg) 0.0074 0.0071 

Maximum (mg/kg) 0.035 0.041 

Vanadium 

Frequency of Detection 0/16 16/43 

Average (mg/kg) ND 0.046 

Maximum (mg/kg) ND 0.21 

137 
 
 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical Fruits Vegetables 

Frequency of Detection 16/16 43/43 

Zinc Average (mg/kg) 1.4 3.1 

Maximum (mg/kg) 4.0 10 

Source: Weston 1998 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Concentrations are reported on a wet weight basis. 

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.
 

ND – not detected 

mg/kg – milligrams per kilogram
 

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Table 50. Sampling data (radionuclides) for local produce irrigated with contaminated well water 

Radionuclide Fruits Vegetables 

Lead-210 

Frequency of Detection 3/16 8/43 

Average (pCi/kg) 12 21 

Maximum (pCi/kg) 21 51 

Radium-226 

Frequency of Detection 1/16 15/43 

Average (pCi/kg) 5.7 6.2 

Maximum (pCi/kg) 18 41 

Thorium-230 

Frequency of Detection 1/16 8/43 

Average (pCi/kg) 3.9 5.1 

Maximum (pCi/kg) 10 20 

Uranium (natural) 

Frequency of Detection 3/16 14/43 

Average (pCi/kg) 5.0 4.8 

Maximum (pCi/kg) 23 27 

Source: Weston 1998 

Averages were calculated using 1⁄2 the reporting detection limit for non-detects. 

Concentrations are reported on a wet weight basis. 

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.
 

pCi/kg – picocuries per kilogram
 

Table 51. Characteristics of Cotter Mill’s Ambient Air Monitoring Stations 

Monitor 

Code 

Monitor Location Years of 

Operation 

Monitor 

Type 

Area Description 

AS-202 East Boundary 1979 – present Perimeter Eastern perimeter of Cotter Mill facility 

AS-203 South Boundary 1979 – present Perimeter Southern perimeter of Cotter Mill facility 

AS-204 West Boundary 1979 – present Perimeter Western perimeter of Cotter Mill facility 

AS-206 North Boundary 1981 – present Perimeter Northern perimeter of Cotter Mill facility 

AS-209 Mill entrance road 1994 – present Perimeter Entrance road to Cotter Mill 

AS-210 Shadow Hills Estates 1997 – present Off-site Near Shadow Hills Golf Club 

AS-212 Nearest resident 1999 – present Off-site Residential 

LP-1/LP-2 Lincoln Park 1980 – present Off-site Residential 

CC-1/CC-2 Cañon City 1979 – present Off-site Residential 

OV-3 Oro Verde 1981 – present Off-site Remote (1 mile west of AS-204) 

Notes:	 Both the Lincoln Park and Cañon City monitoring stations moved locations in the 1991-1992 time frame. The 

original station in Lincoln Park (LP-1) operated from 1980 to 1992, and the new station (LP-2) operated from 1991 

to the present. The original station in Cañon City (CC-1) operated from 1979 to 1992, and the new station (CC-2) 

operated from 1991 to the present. 

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Table 52. Average Annual natU Concentrations 1979-2008 (μCi/ml) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stations 

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 CC-1/2 OV-3 

1979 6.19E-15 1.50E-15 2.26E-15 -­ -­ -­ -­ -­ 1.00E-15 -­

1980 3.71E-15 1.55E-15 2.82E-15 -­ -­ -­ -­ 8.36E-16 1.40E-15 -­

1981 4.07E-15 1.54E-15 5.28E-15 8.30E-15 -­ -­ -­ 1.03E-15 1.02E-15 1.37E-15 

1982 2.31E-15 1.26E-15 2.48E-14 2.79E-15 -­ -­ -­ 5.28E-16 4.79E-16 5.96E-16 

1983 1.26E-15 1.43E-15 1.32E-15 1.63E-15 -­ -­ -­ 4.77E-16 6.86E-16 5.03E-16 

1984 5.50E-16 7.64E-16 8.36E-16 1.52E-15 -­ -­ -­ 2.78E-16 3.27E-16 4.01E-16 

1985 1.42E-15 1.22E-15 8.96E-16 1.92E-15 -­ -­ -­ 4.56E-16 5.77E-16 6.66E-16 

1986 6.71E-16 6.56E-16 4.05E-16 9.36E-16 -­ -­ -­ 2.95E-16 2.93E-16 4.84E-16 

1987 8.08E-16 1.03E-15 1.09E-15 1.05E-15 -­ -­ -­ 4.66E-16 5.12E-16 4.60E-16 

1988 6.73E-16 6.96E-16 9.03E-16 5.51E-16 -­ -­ -­ 1.85E-16 1.95E-16 1.89E-16 

1989 9.58E-17 9.95E-17 2.86E-16 3.62E-17 -­ -­ -­ 8.37E-17 9.38E-17 6.38E-17 

1990 5.59E-17 3.14E-17 1.06E-16 3.10E-17 -­ -­ -­ 6.18E-17 1.26E-16 9.09E-17 

1991 1.12E-16 9.18E-17 2.65E-16 1.24E-16 -­ -­ -­ 1.70E-16 1.73E-16 2.60E-16 

1992 6.55E-17 7.84E-17 1.12E-16 6.48E-17 -­ -­ -­ 9.71E-17 9.40E-17 8.23E-17 

1993 7.13E-17 9.08E-17 1.61E-16 6.30E-17 -­ -­ -­ 8.26E-17 1.20E-16 2.55E-16 

1994 1.25E-16 4.68E-17 1.00E-16 3.68E-17 1.55E-16 -­ -­ 9.68E-17 8.12E-17 2.54E-16 

1995 2.99E-16 5.86E-17 1.53E-16 5.23E-17 2.11E-16 -­ -­ 9.34E-17 1.26E-16 4.83E-16 

1996 2.25E-16 1.43E-16 2.26E-16 8.62E-17 2.44E-16 7.89E-17 -­ 9.73E-17 1.25E-16 5.93E-17 

1997 1.23E-16 1.18E-16 2.20E-16 1.19E-16 1.51E-16 1.75E-16 -­ 1.27E-16 2.00E-16 9.48E-17 

1998 1.32E-16 1.02E-16 3.29E-16 1.06E-16 2.27E-15 2.32E-16 -­ 8.13E-17 7.50E-17 2.43E-16 

1999 4.06E-16 1.49E-16 2.91E-16 3.23E-16 1.46E-15 2.82E-16 4.59E-16 1.16E-16 9.41E-17 7.97E-17 

2000 4.33E-16 2.04E-16 2.61E-16 1.63E-16 1.49E-15 1.89E-16 4.82E-16 5.39E-17 5.33E-17 5.39E-17 

2001 4.96E-16 6.19E-16 4.96E-16 5.29E-16 1.32E-15 2.06E-16 2.88E-16 4.96E-17 3.80E-17 5.18E-17 

2002 6.50E-16 4.93E-16 6.21E-16 3.24E-16 9.91E-16 3.69E-16 4.05E-16 2.46E-16 1.59E-16 2.05E-16 

2003 3.55E-16 2.19E-16 2.55E-16 2.01E-16 4.91E-16 2.21E-16 2.20E-16 2.11E-16 2.07E-16 2.62E-16 

2004 2.51E-16 1.95E-16 2.40E-16 1.99E-16 6.27E-16 1.40E-16 2.30E-16 9.69E-17 9.68E-17 8.61E-17 

2005 4.54E-16 2.77E-16 2.87E-16 1.58E-16 3.97E-15 4.85E-16 5.25E-16 1.68E-16 1.29E-16 1.23E-16 

2006 5.14E-16 2.68E-16 3.24E-16 2.12E-16 1.72E-15 6.62E-16 3.40E-16 2.20E-16 1.75E-16 1.87E-16 

2007 3.56E-16 1.51E-16 2.03E-16 1.39E-16 3.13E-16 1.46E-16 1.33E-16 1.41E-16 1.43E-16 1.27E-16 

2008 4.36E-16 8.61E-17 1.72E-16 8.44E-17 2.17E-16 9.77E-17 9.78E-17 9.02E-17 8.97E-17 6.43E-17 

Notes: For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. 

For station CC-1/2, data from 1979-1992 were collected at CC-1, and data from 1993-2008 were collected 

at CC-2. 

Shaded cells are the highest annual averages for the calendar year; “--” indicates that no data are available because 

the station was not yet operating. 

140 
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Table 53. Average Annual 230Th Concentrations 1979-2008 (μCi/ml) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stations 

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 CC-1/2 OV-3 

1979 2.33E-15 1.05E-15 8.08E-15 -­ -­ -­ -­ -­ 3.07E-16 -­

1980 2.50E-16 8.76E-16 2.81E-16 -­ -­ -­ -­ 8.17E-17 1.30E-16 -­

1981 2.60E-15 3.50E-15 3.00E-14 

8.95E-14 

6.93E-15 -­ -­ -­ 1.42E-16 8.17E-17 3.92E-16 

1982 2.12E-14 1.94E-14 1.26E-14 -­ -­ -­ 7.49E-16 9.18E-16 3.15E-15 

1983 5.86E-15 9.79E-15 5.64E-15 8.26E-15 -­ -­ -­ 3.74E-16 3.12E-16 1.07E-15 

1984 1.64E-15 2.98E-15 3.82E-15 6.35E-15 -­ -­ -­ 2.69E-16 2.00E-16 2.89E-16 

1985 1.84E-15 2.15E-15 4.86E-15 3.73E-15 -­ -­ -­ 2.60E-16 2.64E-16 2.84E-16 

1986 3.70E-15 5.55E-15 3.13E-15 4.68E-15 -­ -­ -­ 3.70E-16 3.08E-16 2.41E-16 

1987 1.21E-15 1.29E-15 2.28E-15 

5.85E-15 

9.17E-16 

1.08E-15 -­ -­ -­ 2.06E-16 1.77E-16 9.90E-17 

1988 2.58E-15 3.51E-15 2.05E-15 -­ -­ -­ 1.41E-16 1.72E-16 1.70E-16 

1989 6.33E-16 3.85E-16 1.08E-16 -­ -­ -­ 8.93E-17 9.03E-17 9.24E-17 

1990 7.63E-16 4.00E-16 5.86E-16 1.09E-16 -­ -­ -­ 7.40E-17 7.04E-17 7.20E-17 

1991 7.25E-16 4.59E-16 8.75E-16 

4.71E-16 

6.42E-16 

2.83E-16 -­ -­ -­ 1.91E-16 1.25E-16 1.33E-16 

1992 4.57E-16 2.20E-16 9.46E-17 -­ -­ -­ 6.58E-17 5.98E-17 9.56E-17 

1993 4.45E-16 3.03E-16 9.32E-17 -­ -­ -­ 1.06E-16 9.17E-17 2.33E-16 

1994 1.18E-15 

1.65E-15 

2.21E-15 

2.96E-16 1.08E-15 1.24E-16 9.20E-16 -­ -­ 1.54E-16 1.16E-16 2.83E-16 

1995 5.33E-16 1.24E-15 1.18E-16 8.88E-16 -­ -­ 9.80E-17 1.12E-16 3.30E-16 

1996 2.95E-16 8.13E-16 8.85E-17 7.67E-16 2.33E-16 -­ 7.11E-17 5.08E-17 6.39E-17 

1997 7.64E-16 1.31E-16 6.17E-16 6.49E-17 1.99E-15 3.82E-16 -­ 8.37E-17 7.86E-17 3.24E-17 

1998 2.88E-15 

3.76E-15 

2.02E-16 9.34E-16 1.15E-16 2.17E-15 3.32E-16 -­ 7.70E-17 7.99E-17 7.82E-17 

1999 3.24E-16 1.09E-15 1.84E-16 2.19E-15 4.15E-16 3.02E-16 7.37E-17 9.51E-17 1.11E-16 

2000 1.22E-15 2.48E-16 1.01E-15 2.02E-16 4.16E-15 

4.15E-15 

1.25E-15 

1.40E-15 

6.57E-16 

3.41E-15 

1.40E-15 

1.05E-15 

4.71E-16 6.69E-16 1.47E-16 1.57E-16 1.27E-16 

2001 8.20E-16 5.19E-16 9.67E-16 2.61E-16 4.04E-16 4.61E-16 1.56E-16 9.95E-17 1.13E-16 

2002 5.84E-16 2.76E-16 5.95E-16 2.57E-16 2.38E-16 3.13E-16 8.15E-17 8.54E-17 8.55E-17 

2003 5.19E-16 2.62E-16 4.90E-16 9.73E-17 4.11E-16 1.77E-16 8.27E-17 8.91E-17 5.30E-17 

2004 2.17E-16 8.26E-17 3.87E-16 8.33E-17 2.26E-16 1.08E-16 5.36E-17 5.62E-17 6.07E-17 

2005 3.17E-16 1.97E-16 3.51E-16 2.64E-16 4.85E-16 4.81E-16 1.04E-16 1.05E-16 1.08E-16 

2006 5.17E-16 2.91E-16 4.74E-16 1.77E-16 4.73E-16 3.27E-16 2.73E-16 2.04E-16 2.85E-16 

2007 6.62E-16 1.90E-16 4.32E-16 1.48E-16 2.77E-16 2.23E-16 1.68E-16 1.57E-16 1.53E-16 

2008 7.21E-16 1.87E-16 5.12E-16 1.32E-16 6.21E-16 2.88E-16 2.05E-16 1.11E-16 1.08E-16 1.16E-16 

Notes: For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. 

For station CC-1/2, data from 1979-1992 were collected at CC-1, and data from 1993-2008 were collected 

at CC-2. 

Shaded cells are the highest annual averages for the calendar year; “--” indicates that no data are available because 

the station was not yet operating; bold cells are concentrations above Cotter Mill’s regulatory limit 

141 
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Table 54. Average Annual 232Th Concentrations 2001-2008 (

μCi/ml) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stations AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP #2 CC #2 O

2001 5.78E-17 7.62E-17 6.97E-17 6.37E-17 8.32E-17 4.58E-17 6.67E-17 6.85E-17 8.33E-17 5.6

2002 4.67E-17 3.81E-17 3.09E-17 4.55E-17 4.34E-17 3.17E-17 3.35E-17 5.36E-17 3.51E-17 4.62003 4.57E-17 4.14E-17 4.84E-17 2.06E-17 5.72E-17 4.61E-17 3.71E-17 6.21E-17 4.61E-17 3.92004 1.39E-17 2.53E-17 2.53E-17 1.40E-17 1.57E-17 1.99E-17 1.65E-17 3.24E-17 2.28E-17 2.32005 2.83E-17 2.40E-17 2.86E-17 3.09E-17 3.36E-17 2.53E-17 3.42E-17 3.99E-17 3.57E-17 3.42006 4.11E-17 5.18E-17 4.82E-17 4.29E-17 5.54E-17 4.33E-17 4.79E-17 6.25E-17 4.98E-17 3.62007 4.07E-17 3.47E-17 4.60E-17 4.14E-17 4.12E-17 3.99E-17 3.51E-17 5.43E-17 4.48E-17 3.92008 1.08E-17 1.63E-17 1.15E-17 9.89E-18 1.57E-17 2.30E-17 1.26E-17 3.13E-17 2.25E-17 2.0

Note: Shaded cells are the highest annual averages for the calendar year; “--” indicates that no data are available because the station w

142 
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Table 55. Average Annual 226Ra Concentrations 1979-2008 (

μCi/ml) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stat

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 C

1979 1.55E-15 3.75E-16 7.89E-15 -­ -­ -­ -­ -­ 3.0

1980 3.61E-15 

4.19E-15 

7.81E-16 1.62E-15 -­ -­ -­ -­ 2.78E-16 1.5

1981 2.35E-15 2.94E-15 2.96E-15 -­ -­ -­ 3.79E-16 4.51982 6.53E-15 6.92E-15 

5.08E-15 

3.81E-15 3.82E-15 -­ -­ -­ 6.07E-16 4.0

1983 2.00E-15 4.95E-15 2.85E-15 -­ -­ -­ 9.42E-17 1.71984 1.11E-15 1.84E-15 3.63E-15 2.20E-15 -­ -­ -­ 1.18E-16 1.61985 9.63E-15 1.11E-15 1.78E-15 1.97E-15 -­ -­ -­ 1.69E-16 1.81986 1.47E-15 1.98E-15 1.61E-15 2.60E-15 -­ -­ -­ 1.43E-16 3.41987 5.91E-16 7.52E-16 1.19E-15 

2.53E-15 3.30E-16 1.92E-16 2.68E-16 1.50E-15 2.49E-16 

4.74E-16 -­ -­ -­ 1.83E-16 1.1

1988 1.29E-15 2.05E-15 3.60E-16 -­ -­ -­ 1.24E-16 5.01989 2.72E-16 1.81E-16 4.79E-17 -­ -­ -­ 1.02E-16 8.81990 1.75E-16 1.68E-16 4.36E-17 -­ -­ -­ 6.69E-17 8.31991 1.19E-16 1.25E-16 6.17E-17 -­ -­ -­ 6.85E-17 7.11992 8.46E-17 7.30E-17 3.71E-17 -­ -­ -­ 5.10E-17 5.81993 9.11E-17 1.14E-16 5.99E-17 -­ -­ -­ 6.14E-17 6.71994 1.03E-16 7.57E-17 1.69E-16 4.96E-17 1.55E-16 -­ -­ 7.80E-17 8.61995 1.21E-16 1.14E-16 2.07E-16 7.46E-17 2.06E-16 -­ -­ 6.88E-17 1.01996 1.78E-16 1.02E-16 2.08E-16 5.33E-17 2.11E-16 5.82E-17 -­ 5.22E-17 6.61997 1.29E-16 7.55E-17 2.01E-16 5.66E-17 9.45E-16 1.06E-16 -­ 5.09E-17 5.41998 2.89E-16 8.22E-17 2.95E-16 9.43E-17 1.34E-15 1.21E-16 -­ 6.21E-17 6.71999 4.18E-16 1.29E-16 3.81E-16 1.02E-16 1.26E-15 1.46E-16 2.13E-16 8.27E-17 9.22000 3.37E-16 1.53E-16 4.64E-16 1.40E-16 2.38E-15 2.21E-16 4.60E-16 7.41E-17 4.62001 2.15E-16 2.09E-16 4.36E-16 1.38E-16 1.92E-15 1.51E-16 1.99E-16 7.01E-17 6.82002 1.55E-16 1.17E-16 2.34E-16 7.51E-17 3.83E-16 1.05E-16 1.14E-16 8.41E-17 6.02003 1.45E-16 1.10E-16 1.75E-16 8.02E-17 2.96E-16 1.23E-16 9.65E-17 9.70E-17 8.42004 7.81E-17 7.35E-17 1.41E-16 6.14E-17 3.30E-16 9.05E-17 8.14E-17 5.79E-17 6.22005 1.78E-16 1.56E-16 1.75E-16 1.97E-16 2.29E-15 2.49E-16 2.95E-16 1.08E-16 1.22006 4.10E-16 1.40E-16 2.17E-16 1.34E-16 7.52E-16 1.69E-16 1.42E-16 1.20E-16 1.02007 8.67E-16 1.11E-16 2.07E-16 1.00E-16 2.31E-16 1.16E-16 9.11E-17 1.09E-16 9.62008 7.92E-16 7.36E-17 2.00E-16 5.16E-17 1.78E-16 7.33E-17 5.71E-17 6.21E-17 5.9

Notes: For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. For station CC-1/2, data f

collected at CC-1, and data from 1993-2008 were collected at CC-2. Shaded cells are the highest annual averages for the calendar 

data are available because the station was not yet operating. 

143 
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Table 56. Average Annual 210Pb Concentrations 1979-2008 (

μCi/ml) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stat

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 C

1979 2.11E-14 1.65E-14 2.08E-14 -­ -­ -­ -­ -­ 2.3

1980 1.81E-14 1.69E-14 1.25E-14 -­ -­ -­ -­ 1.86E-14 1.91981 2.01E-14 1.72E-14 4.71E-14 2.34E-14 -­ -­ -­ 1.57E-14 1.71982 3.87E-14 4.35E-14 9.95E-14 4.07E-14 -­ -­ -­ 2.50E-14 3.31983 1.70E-14 1.73E-14 1.82E-14 1.95E-14 -­ -­ -­ 1.29E-14 1.71984 1.44E-14 1.46E-14 1.60E-14 1.43E-14 -­ -­ -­ 1.26E-14 1.11985 9.12E-15 8.12E-15 8.80E-15 9.30E-15 -­ -­ -­ 9.97E-15 1.11986 1.26E-14 1.19E-14 1.12E-14 1.22E-14 -­ -­ -­ 1.07E-14 1.21987 1.95E-14 1.92E-14 2.22E-14 2.35E-14 -­ -­ -­ 2.17E-14 2.01988 2.15E-14 1.94E-14 2.10E-14 1.93E-14 -­ -­ -­ 2.04E-14 2.11989 2.28E-14 2.30E-14 1.98E-14 2.34E-14 -­ -­ -­ 2.43E-14 2.31990 2.05E-14 2.10E-14 2.07E-14 2.07E-14 -­ -­ -­ 2.24E-14 2.01991 2.40E-14 2.15E-14 2.15E-14 2.13E-14 -­ -­ -­ 2.23E-14 2.11992 2.16E-14 2.00E-14 2.20E-14 2.19E-14 -­ -­ -­ 1.99E-14 1.61993 2.38E-14 2.35E-14 2.35E-14 2.49E-14 -­ -­ -­ 2.22E-14 2.11994 2.21E-14 2.07E-14 2.10E-14 2.24E-14 2.18E-14 -­ -­ 2.33E-14 2.31995 2.07E-14 2.07E-14 2.02E-14 2.01E-14 2.11E-14 -­ -­ 1.97E-14 2.01996 2.02E-14 2.01E-14 2.16E-14 2.21E-14 2.11E-14 -­ -­ 2.08E-14 1.91997 2.21E-14 2.07E-14 2.12E-14 2.20E-14 2.26E-14 2.05E-14 -­ 2.13E-14 2.01998 2.01E-14 2.07E-14 1.98E-14 2.11E-14 2.01E-14 1.93E-14 -­ 2.01E-14 2.01999 2.14E-14 1.94E-14 1.83E-14 1.84E-14 2.03E-14 1.94E-14 2.03E-14 2.03E-14 1.92000 2.07E-14 2.05E-14 2.01E-14 2.23E-14 2.37E-14 2.00E-14 2.07E-14 2.16E-14 2.02001 3.10E-14 3.04E-14 2.91E-14 3.11E-14 3.06E-14 2.94E-14 3.12E-14 3.06E-14 2.92002 2.36E-14 2.20E-14 2.28E-14 2.25E-14 2.30E-14 2.37E-14 2.40E-14 2.46E-14 2.32003 2.19E-14 2.11E-14 2.16E-14 2.06E-14 2.28E-14 2.12E-14 2.18E-14 2.11E-14 1.92004 1.72E-14 1.64E-14 1.58E-14 1.60E-14 1.66E-14 1.45E-14 1.79E-14 1.56E-14 1.52005 2.45E-14 2.74E-14 2.82E-14 2.54E-14 3.11E-14 2.91E-14 2.92E-14 3.11E-14 3.12006 2.11E-14 2.31E-14 2.47E-14 2.31E-14 2.09E-14 2.08E-14 1.89E-14 1.98E-14 1.82007 1.88E-14 1.64E-14 1.79E-14 1.82E-14 1.54E-14 1.58E-14 1.49E-14 1.66E-14 1.62008 1.65E-14 1.48E-14 1.64E-14 1.93E-14 1.66E-14 1.73E-14 1.57E-14 1.67E-14 1.6

Notes: For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. For station 

1992 were collected at CC-1, and data from 1993-2008 were collected at CC-2. 

Shaded cells are the highest annual averages for the calendar year; “--” indicates that no data are available because the station w

144 
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Table 57. 220Rn/222Rn Concentrations 2002-2008 (pCi/m3) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stat

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 CC-1 L

2002 543 975 1125 693 1475 700 698 875 

2003 700 825 775 900 625 675 700 375 2004 1500 850 1025 950 1100 850 925 825 2005 925 1025 850 700 1025 675 775 700 2006 1250 1275 1275 1450 1400 1125 1275 1075 2007 1000 1100 1175 1100 1250 975 825 925 2008 850 900 925 950 1075 950 850 800 

Notes: Data are presented for only those years when measurements quantified combined levels of the two isotopes. 

Shaded cells are the highest annual averages for the calendar year. 

145 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 58. Environmental TLD Measurements, 1979-2008 (μR/hr) 

Year Perimeter Monitoring Stations Off-Site Monitoring Stations AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 CC-1 LP-1 

1979 14.0 12.6 12.7 -­ -­ -­ -­ 11.8 11.4 

1980 13.4 11.7 12.9 -­ -­ -­ -­ 10.4 11.4 1981 14.3 12.8 12.7 -­ -­ -­ -­ 10.6 12.3 1982 13.7 12.6 14.7 20.4 -­ -­ -­ 9.9 11.2 1983 13.6 12.6 14.2 15.6 -­ -­ -­ 10.6 11.6 1984 14.5 14.3 14.6 14.8 -­ -­ -­ 12.3 11.2 1985 14.3 13.5 14.5 14.8 -­ -­ -­ 10.5 11.2 1986 13.9 13.7 14.5 14.2 -­ -­ -­ 11.0 10.7 1987 12.9 12.5 12.6 12.6 -­ -­ -­ 9.6 9.7 1988 15.0 13.6 12.8 13.4 -­ -­ -­ 9.3 11.6 1989 14.7 14.9 15.3 15.9 -­ -­ -­ 10.6 13.7 1990 13.2 13.1 14.8 15.2 -­ -­ -­ 9.6 11.5 1991 14.1 13.2 15.7 17.5 -­ -­ -­ 10.0 12.9 1992 13.7 13.2 16.0 18.3 -­ -­ -­ 9.6 12.1 1993 12.5 12.6 14.4 15.6 -­ -­ -­ 8.6 10.7 1994 14.3 13.8 15.9 16.2 27.8 -­ -­ 10.8 12.1 1995 12.5 13.7 14.0 15.4 23.0 -­ -­ 9.2 10.3 1996 13.1 13.2 14.5 16.2 27.2 13.0 -­ 9.7 10.9 1997 12.6 13.1 13.8 15.7 29.1 12.3 -­ 9.1 10.2 1998 12.3 12.0 13.4 15.9 28.0 12.0 -­ 9.0 10.3 1999 12.7 12.0 13.8 16.0 29.6 12.2 9.1 9.3 10.6 2000 12.7 12.6 14.7 16.6 27.7 12.5 9.3 9.5 10.7 2001 13.7 14.3 15.4 18.6 26.2 13.9 9.7 10.4 12.0 2002 14.0 14.4 15.9 17.7 30.3 14.3 10.5 10.5 12.3 2003 12.8 13.3 14.8 15.5 27.7 13.3 10.0 10.0 11.7 2004 13.6 14.1 15.5 14.7 25.5 14.2 10.9 10.5 12.2 2005 12.8 13.5 14.8 13.8 22.9 12.9 9.9 10.1 11.5 2006 12.7 13.4 14.6 14.2 21.5 12.6 9.5 10.1 11.5 2007 12.9 13.2 14.6 14.1 17.8 12.7 9.5 10.1 11.5 2008 13.9 13.5 15.5 14.9 18.7 13.3 10.2 10.8 12.2 

Notes: Shaded cells are the highest annual averages for the calendar year; “--” indicates that no data are available because the station w

146 
 

 

 

 

 

	 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table 59. TSP Air Concentrations (μg/m3) from 1969-1987 

Year Cañon City Lincoln Park 

Maximum Average Maximum Average 

1969 172 64.2 -­ -­

1970 200 55.9 -­ -­

1971 148 58.7 -­ -­

1972 240 69.9 -­ -­

1973 229 66.1 -­ -­

1974 187 58 -­ -­

1975 419 73.7 -­ -­

1976 174 56.8 -­ -­

1977 227 62.7 -­ -­

1978 313 84.7 -­ -­

1979 286 72.6 -­ -­

1980 304 70.4 -­ -­

1981 180 56.8 61* 8.2* 

1982 525 84 228 51.7 

1983 187 65.2 106 77.6 

1984 571 70.9 -­ -­

1985 334 64.8 -­ -­

1986 402 66.3 -­ -­

1987 385 65.2 -­ -­

Notes:	 Data downloaded from EPA’s Air Quality System database. 

EPA’s former annual average National Ambient Air Quality Standard for TSP was 75 μg/m3

. 

* The TSP monitoring station in Lincoln Park started operating late in 1981; therefore, the statistics reported are not 

representative of the entire calendar year. 

Table 60. Monitoring Data for Constituents in TSP (1978-1987) 

Constituent Location Years of Data 

Concentrations (μg/m3

) 

Highest 24-Hour 

Average 

Highest Annual 

Average 

Iron Lincoln Park 1981-1982 1.2 0.8 

Lead Lincoln Park 1981-1982 0.1 0.034 

Manganese Lincoln Park 1981-1982 0.03 0.0185 

Nitrate Cañon City 1978-1987 14.3 2.35 

Lincoln Park 1981-1982 4.7 1.81 

Sulfate Cañon City 1978-1987 18.4 5.99 

Lincoln Park 1981-1982 13 6.48 

Zinc Lincoln Park 1981-1982 0.04 0.0283 

Notes Data downloaded from EPA’s Air Quality System database. 

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Appendix B - Site Figures 

149 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 1. Location of the Cotter Mill, Lincoln Park, and Cañon City 

Source: Galant et al. 2007 

150 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 2. Demographics within 1 mile of the Cotter Mill property 

151 
 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 3. Wind Rose for Cotter Mill, 2008 

152 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 4. Molybdenum Plume Map 

Source: Cotter 2008 

153 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 5. Uranium Plume Map 

Source: Cotter 2008 

154 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 6. Wells in Lincoln Park used for personal consumption 

Source: CDPHE 2007b (coordinates) 

155 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 7. Molybdenum concentrations in wells used for personal consumption 

Molybdenum in Personal Consumption Wells 

0.00 0.05 0.10 0.15 0.20 0.25 0.30 

Mar-84

Mar-85

Mar-86

Mar-87

Mar-88

Mar-89

Mar-90

Mar-91

Mar-92

Mar-93

Mar-94

Mar-95

Mar-96

Mar-97

Mar-98

Mar-99

Mar-00

Mar-01

Mar-02

Mar-03

Mar-04

Mar-05

Mar-06

Date Sampled 

Molybdenum Concentration (mg/L) 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

156 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 8. Dissolved uranium concentrations in wells used for personal consumption 

Dissolved Uranium in Personal Consumption Wells 

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 

Mar-84

Mar-85

Mar-86

Mar-87

Mar-88

Mar-89

Mar-90

Mar-91

Mar-92

Mar-93

Mar-94

Mar-95

Mar-96

Mar-97

Mar-98

Mar-99

Mar-00

Mar-01

Mar-02

Mar-03

Mar-04

Mar-05

Date Sampled 

Dissolved Uranium Concentration (mg/L) 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

157 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 9. Wells in Lincoln Park used to irrigate fruit and vegetable gardens 

Source: CDPHE 2007b (coordinates) 

158 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 10. Wells in Lincoln Park used to water livestock 

Source: CDPHE 2007b (coordinates) 

159 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 11. Wells in Lincoln Park used to water lawns 

Source: CDPHE 2007b (coordinates) 

160 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 12. Molybdenum concentrations in Well 138 

Molybdenum in Well 138 

0 

10 20 30 40 50 60 

Jun-68

Jun-69

Jun-70

Jun-71

Jun-72

Jun-73

Jun-74

Jun-75

Jun-76

Jun-77

Jun-78

Jun-79

Jun-80

Jun-81

Jun-82

Jun-83

Jun-84

Jun-85

Jun-86

Jun-87

Jun-88

Jun-89

Jun-90

Jun-91

Jun-92

Jun-93

Jun-94

Date Sampled 

Molybdenum Concentration (mg/L) 

Source: CDPHE 2007b 

161 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 13. Selenium concentrations in Well 138 

Selenium in Well 138 

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 

Jan-74

Jan-75

Jan-76

Jan-77

Jan-78

Jan-79

Jan-80

Jan-81

Jan-82

Jan-83

Jan-84

Jan-85

Jan-86

Jan-87

Jan-88

Jan-89

Jan-90

Jan-91

Jan-92

Jan-93

Jan-94

Jan-95

Date Sampled 

Selenium Concentration (mg/L) 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

162 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 14. Dissolved uranium concentrations in Well 138 

Dissolved Uranium in Well 138 

0 1 2 3 4 5 6 

Jun-68

Jun-69

Jun-70

Jun-71

Jun-72

Jun-73

Jun-74

Jun-75

Jun-76

Jun-77

Jun-78

Jun-79

Jun-80

Jun-81

Jun-82

Jun-83

Jun-84

Jun-85

Jun-86

Jun-87

Jun-88

Jun-89

Jun-90

Jun-91

Jun-92

Jun-93

Jun-94

Date Sampled 

Dissolved Uranium Concentration (mg/L) 

Source: CDPHE 2007b 

163 
50 

Molybdenum Concentration (mg/L) 40 30 20 10 

0 

-10 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 15. Molybdenum concentrations in all groundwater wells evaluated 

Molybdenum 

60 

May-68

May-70

May-72

May-74

May-76

May-78

May-80

May-82

May-84

May-86

May-88

May-90

May-92

May-94

May-96

May-98

Date Sampled 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

164 
Selenium Concentration (mg/L) 0.10 0.08 0.06 0.04 

0.02 0.00 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 16. Selenium concentrations in all groundwater wells evaluated 

Selenium 

0.14 0.12 

Jan-74

Jan-75

Jan-76

Jan-77

Jan-78

Jan-79

Jan-80

Jan-81

Jan-82

Jan-83

Jan-84

Jan-85

Jan-86

Jan-87

Jan-88

Jan-89

Jan-90

Jan-91

Jan-92

Jan-93

Jan-94

Jan-95

Date Sampled 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

165 
5 

6 

Dissolved Uranium Concentration (mg/L) 4 3 2 1 

0 

-1 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 17. Dissolved uranium concentrations in all groundwater wells evaluated 

Dissolved Uranium 

Apr-62

Apr-64

Apr-66

Apr-68

Apr-70

Apr-72

Apr-74

Apr-76

Apr-78

Apr-80

Apr-82

Apr-84

Apr-86

Apr-88

Apr-90

Apr-92

Apr-94

Apr-96

Apr-98

Date Sampled 

Source: CDPHE 2007b Non-detected concentrations were plotted as 1⁄2 the reporting detection limit. 

166 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 18. Sampling zones established during the 

1998 Supplemental Human Health Risk Assessment 

Source: Weston 1998 

167 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 19. Locations of soil samples taken along the county road and Cotter Mill’s access road 

Source: MFG 2005 

168 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 20. Locations of soil samples taken by CDPHE in January 2003 

Source: CDPHE 2007b (coordinates) 

169 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 21. Location of air sampling locations where soil samples are collected 

Source: Cotter 2007 

Note: An additional air sampling station is located in Cañon City (not depicted on the figure).
 

170 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 22. Sand Creek Cleanup Project 

Source: Cotter 2000 

171 
 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Figure 23. Approximate Locations of Cotter Mill Monitoring Stations 

Notes: Figure reproduced from: Cotter 2008 

172 
 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

APPENDIX C: 

ATSDR’s Evaluation Process 

And 

Exposure Dose Calculations
 

173 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

ATSDR’s Evaluation Process 

Step 1 – Comparison Values and the Screening Process 

To evaluate the available data, ATSDR used comparison values (CVs) to determine which 

chemicals to examine more closely. CVs are the contaminant concentrations found in a specific 

media (for example: air, soil, or water) and are used to select contaminants for further evaluation. 

CVs incorporate assumptions of daily exposure to the chemical and a standard amount of air, 

water, or soil that someone may inhale or ingest each day. CVs are generated to be conservative 

and non-site specific. These values are used only to screen out chemicals that do not need further 

evaluation; CVs are not intended as environmental clean-up levels or to indicate that health 

effects occur at concentrations that exceed these values. 

CVs can be based on either carcinogenic (cancer-causing) or non-carcinogenic effects. Cancerbased comparison values are calculated from the U.S. Environmental Protection Agency’s (EPA) 

oral cancer slope factor (CSF) or inhalation risk unit. CVs based on cancerous effects account for 

a lifetime exposure (70 years) with an unacceptable theoretical excess lifetime cancer risk of 1 

new case per 1 million exposed people. Non-cancer values are calculated from ATSDR’s 

Minimal Risk Levels (MRLs), EPA’s Reference Doses (RfDs), or EPA’s Reference 

Concentrations (RfCs). When a cancer and non-cancer CV exists for the same chemical, the 

lower of these values is used in the comparison for conservatism. 

Step 2 – Evaluation of Public Health Implications 

The next step in the evaluation process is to take those contaminants that are above their 

respective CVs and further identify which chemicals and exposure situations are likely to be a 

health hazard. Separate child and adult exposure doses (or the amount of a contaminant that gets 

into a person’s body) are calculated for site-specific exposure scenarios, using assumptions 

regarding an individual’s likelihood of accessing the site and contacting contamination. A brief 

explanation of the calculation of estimated exposure doses is presented below. Calculated doses 

are reported in units of milligrams per kilograms per day (mg/kg/day). Separate calculations have 

been performed to account for non-cancer and cancer health effects, if applicable, for each 

chemical based on the health impacts reported for each chemical. Some chemicals are associated 

with non-cancer effects while the scientific literature many indicate that cancer-related health 

impacts are not expected from exposure. 

174 
 

 

 

 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Exposure Dose Factors and Calculations 

When chemical concentrations at the site exceed the established CVs, it is necessary for a more 

thorough evaluation of the chemical to be conducted. In order to evaluate the potential for human 

exposure to contaminants present at the site and potential health effects from site-specific 

activities, ATSDR estimates human exposure to the site contaminant from different 

environmental media by calculating exposure doses. 

A discussion of the calculations and assumptions used in this assessment is presented below. The 

equations are based on the EPA Risk Assessment Guidance for Superfund, Part A (1989), or 

ATSDR’s Public Health Guidance Manual (2005), unless otherwise specified. Assumptions used 

were based on default values, EPA’s Exposure Assessment Handbook (1997) or Child-Specific 

Exposure Factors Handbook (2008), or professional (site-specific) judgment. When available, 

site-specific information is used to estimate exposures. 

Ingestion of Chemicals in Well Water: 

The exposure dose formula used for the ingestion of chemicals in well water is: 

Exposure Dose (ED) = C x IR x EF x ED

 BW x AT 

Where: 

ED = exposure dose in milligrams per kilogram per day (mg/kg/day) 

C = concentration of contaminant in water in milligrams per liter (mg/L) 

IR = ingestion rate in liters per day (L/day) 

EF = exposure frequency (days/year) 

ED = exposure duration (years) 

BW = body weight (kg) 

AT = averaging time, days (equal to ED for non-carcinogens and 70 year lifetime for 

carcinogens, i.e., 70 years x 365 days/year) 

Note: In the intake equation, averaging time (AT) for exposure to non-carcinogenic compounds 

is always equal to ED; whereas, for carcinogens a 70 year AT is still used in order to compare to 

EPA’s cancer slope factors typically based on that value. 

This pathway assumes that an adult resident drinks 2 liters (L) of water per day for 350 days per 

year. In terms of exposure duration (ED), the adult resident is assumed to live in the same home 

and drink the same well water for 30 years. The drinking water ingestion rate for children was 

assumed to be 1 L per day for 350 days per year for 6 years. For average body weight, 70 kg and 

16 kg were used for adults and children, respectively. 

ATSDR used the average chemical concentration in Well 186 to represent a high exposure 

scenario from a single well. Well 186 was selected because it consistently contained the highest 

chemical concentrations over time. The average concentration for all private wells was used to 

represent exposures to a typical well user. 

175 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table C1. Summary of Exposure Factors and Exposure Doses for the Drinking Water Pathway for Chemicals at 

Chemical 

Chemical 

Concentration 

(mg/L) 

Daily 

Ingestion 

Rate 

(L/day) 

Exposure 

Frequency 

(days/yr) 

Exposure 

Duration 

(yrs) 

Body 

Weight 

(kg) 

Averaging 

Time 

(days) 

Exposure Dos

(mg/kg/day) 

Drinking Water Pathway: Ingestion – ADULT and CHILD Molybdenum ADULT 0.16 

WELL 189* 

HIGH EXPOSURE 

2 350 30 70 10950 0.004 

Molybdenum CHILD 1 350 6 16 2190 0.010 Molybdenum ADULT 

0.082 

All wells 

TYPICAL 

EXPOSURE 

2 350 30 70 10950 0.002 

Molybdenum CHILD 1 350 6 16 2190 0.005 Uranium ADULT 0.048 

Well 189* 

HIGH EXPOSURE 

2 350 30 70 10950 0.001 

Uranium CHILD 1 350 6 16 2190 0.003 Uranium ADULT 

0.028 

All wells 

TYPICAL 

EXPOSURE 

2 350 30 70 10950 0.0008 

Uranium CHILD 1 350 6 16 2190 0.002 

Bolded type exceeds a comparison value. * “Well 189” represents a high exposure scenario. This well contained the highest level of chemicals in the sampled group. 

“All wells” is used to represent an average exposure scenario for the average private well drinker. 

176 
 

 

 

 

 

 

 

 

 

 


 


 


 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Accidental Ingestion of Chemicals in Soil 

The exposure dose formula for incidental ingestion of chemicals soil and/or sediment is: 

Exposure Dose (ED) = C × IR× EF × ED × CF

 BW × AT 

Where: 

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)
 

C = concentration of contaminant in soil in milligrams per kilogram (mg/kg or ppm)
 

IR = ingestion rate in milligrams per day (mg/day)
 

EF = exposure frequency (days/year) 

ED = exposure duration (years) 

CF = conversion factor (10-6 kg/mg) 

BW = body weight (kg)
 

AT = averaging time, days (equal to ED for non-carcinogens and 70 year lifetime for 

carcinogens, i.e., 70 years x 365 days/year) 

This pathway assumes that the average adolescent (11 to 16 years of age) or adult resident 

accidentally ingests 100 milligrams of soil per day. Because the area is in a primarily vacant 

“buffer zone” between the Cotter Mill and residential homes, ATSDR assumed that very young 

children would not access the area. Adolescent and adults would access the site infrequently. 

Therefore, exposure duration (ED) for an adolescent and adult resident was assumed to be 2 days 

per week (or 104 days/year) for 30 years. For average body weight, 57 kg was used for an 

adolescent and70 kg was used for an adult. 

In this evaluation, the bioavailability from incidental ingestion of arsenic in soil was assumed to 

be 80% because it is protective of health. Cadmium was assumed to be 100% bioavailable, 

which is also conservative but protective of health. 

Direct Skin (Dermal) Contact with Chemicals in Soil 

Dermal absorption of chemicals from soil depends on the area of contact with exposed skin, the 

duration of contact, the chemical and physical attraction between the contaminant and soil, the 

ability of the chemical to penetrate the skin, and other factors. 

The exposure dose formula for dermal absorption of chemicals soil and/or sediment is: 

Exposure Dose (ED) = C × SA× AF × ABS × EF × ED × CF 

BW × AT 

Where: 

ED = exposure dose in milligrams per kilogram per day (mg/kg/day) 

C = chemical concentration (mg/kg) 

SA = surface area exposed (square centimeters/day or cm2

/day) 

177 
 

 

 

 

 

 

 


 


 


 


 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

AF = soil to skin adherence factor (milligrams per square centimeters or mg/cm2) 

ABS = Absorption factor (unitless)
 

EF = exposure frequency (days/year) 

ED = exposure duration (years)
 

CF = conversion factor (10-6 kg/mg)
 

BW = body weight (kg)
 

AT = averaging time (days)
 

Note: Absorption factors (ABS) are used to reflect the desorption of the chemical from soil and 

the absorption of the chemical across the skin and into the bloodstream. 

For the dermal contact pathway, ATSDR assumed that the surface area available in an adolescent 

for direct skin contact is 4,300 cubic centimeters per day (cm2

/day); the surface area available in 

an adult is 5,000 cm2

/day. An adherence factor of 0.07 milligrams per cubic centimeter (mg/cm3) 

was used. An absorption factor of 0.03 was used for arsenic and 0.01 was used for cadmium. 

Individuals were assumed to weigh 57 kg as an adolescent and 70 kg as an adult, and to be 

exposed for 6 and 30 years, respectively. 

The total soil oral and dermal non-carcinogenic dose was estimated as follows: 

Total Dose (TD) = ID + DD 

Where: 

TD = total soil ingestion and dermal non-carcinogenic dose 

ID = Soil ingestion non-carcinogenic dose (mg/kg/day) 

DD= Soil dermal non-carcinogenic dose (mg/kg/day) 

Cancer Risk Estimates 

EPA classifies arsenic as a Class A known human carcinogen by the oral and inhalation routes. 

Cadmium is classified by EPA as a probable human carcinogen, but only via the inhalation route 

of exposure. Therefore, only arsenic is evaluated for its carcinogenic risk. 

The Lifetime Estimated Cancer Risk for arsenic is estimated as follows: 

LECR = TDs x CSF x EF 

Where: 

LECR = lifetime estimated cancer risk 

TDs = total soil oral and dermal non-carcinogenic dose (mg/kg/day) 

CSF = cancer slope factor ((mg/kg-day)-1) 

EF = Exposure factor (unitless) = exposure duration / lifetime = (30 years) / (70 years) = 0.4 

The cancer slope factor for arsenic is 1.5 mg/kg-day. Therefore, the LECR is 1.2 x 10-5. 

178 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table C2. Summary of Exposure Factors and Exposure Doses for the Soil Exposure Pathway for Chemicals at t

Chemical 

Chemical 

Concentration 

(mg/kg) 

Daily 

Intake 

Rate 

(mg/day) 

Exposure 

Frequency 

(days/yr) 

Exposure 

Duration 

(years) 

Body 

Weight 

(kg) 

Averaging 

Time 

(days) 

Exposure D

(mg/kg/day

Soil Exposure Pathway: Accidental Ingestion and Direct Skin Contact - ADULT and ADOLESCENT Arsenic (ingestion) 

45 

100 104 30 70 10950 0.00002 

Arsenic (dermal) NA 104 30 70 10950 0.000002

 TOTAL DOSE ARSENIC - Adult 0.00002 

Cadmium (ingestion) 

37 

100 104 30 70 10950 0.00002 

Cadmium (dermal) NA 104 30 70 10950 0.0000005 

TOTAL DOSE CADMIUM -Adult 0.00002 

Arsenic (ingestion) 

45 

100 104 6 54 2190 0.00002 

Arsenic (dermal) NA 104 6 54 2190 0.000002

 TOTAL DOSE ARSENIC - Adolescent 0.00002 

Cadmium (ingestion) 

37 

100 104 6 54 2190 0.00002 

Cadmium (dermal) NA 104 6 54 2190 0.0000006

 TOTAL DOSE CADMIUM - Adolescent 0.00002 

179 
 

 

 

 

 

 

 

 

 

 

 

 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Incidental Ingestion of Chemicals in Surface Water 

The ATSDR exposure dose formula used for the ingestion of chemicals in surface water while 

wading or swimming is: 

Exposure Dose (ED) = C x IR x ET x EF x ED

 BW x AT 

Where: 

ED = exposure dose in milligrams per kilogram per day (mg/kg/day) 

C = concentration of contaminant in water in milligrams per liter (mg/L) 

IR = ingestion rate in liters per day (L/day); based on contact rate of 50 ml/hr 

ET = exposure time (hours/event) 

EF = exposure frequency (events/year) 

ED = exposure duration (years) 

BW = body weight (kg) 

AT = averaging time, days (equal to ED for non-carcinogens and 70 year lifetime for 

carcinogens, i.e., 70 years x 365 days/year) 

This pathway assumes that adult and children residents would accidentally swallow 50 milliliters 

of water per hour while swimming, wading or recreating in Sand Creek or the DeWeese Dye 

Ditch. In terms of exposure time and frequency, ATSDR conservatively assumed an adult and 

child resident would recreate in these waters for 2 hours per day, 2 days per week (or 104 

days/year) for 30 years and 6 years, respectively. For average body weight, 70 kg and 16 kg were 

used for adults and children, respectively. 

Direct Skin (Dermal) Contact with Chemicals in Surface Water 

ATSDR’s exposure dose formula for dermal absorption of chemicals soil and/or sediment is: 

Exposure Dose (ED) = C × SA × PC × ET x EF × ED × CF 

BW × AT 

Where: 

ED = exposure dose in milligrams per kilogram per day (mg/kg/day) 

C = chemical concentration (mg/L) 

SA = surface area exposed (cm2

) 

PC = chemical-specific dermal permeability constant (cm/hr) 

ET = exposure time (hours/day) 

EF = exposure frequency (days/year) 

ED = exposure duration (years) 

CF = volumetric conversion factor for water (1L/1000 cm3) 

BW = body weight (kg) 

AT = averaging time (days) 

180 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

The dermal contact pathway assumes that the total body surface area available for contact with 

water is 20,000 cm2

 for adults and 9,300 cm2 for children. Adults were assumed to weigh 70 kg 

and to be exposed for 30 years. Children were assumed to weigh 16 kg and to be exposed for 6 

years. Adults and children were conservatively assumed to swim in the contaminated water 2 

days per week (104 days per year) for 2 hours per recreating event. A dermal permeability 

constant of 0.001 cm/hr was used for both manganese and molybdenum. 

181 
Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table C3. Summary of Exposure Factors and Exposure Doses for the Surface Water Pathway for Chemicals at 

Chemical 

Chemical 

Concentration 

(mg/L) 

Daily 

Ingestion 

Rate 

(L/day) 

Exposure 

Frequency 

(days/yr) 

Exposure 

Duration 

(yrs) 

Body 

Weight 

(kg) 

Averaging 

Time 

(days) 

Exposu

(mg/k

Surface Water Exposure Pathway: Accidental Ingestion and Direct Skin Contact while Wading or Swimming – ADULT and CHILD Manganese* Adult Ingestion 

1.9 

0.1 104 30 70 10950 3.9 

Manganese Adult Dermal NA 104 30 70 10950 3.1 

TOTAL DOSE MANGANESE – Adult 7 x 

Manganese Child Ingestion 0.1 104 6 16 2190 1.7 

Manganese Child Dermal NA 104 6 16 2190 6.3 

TOTAL DOSE MANGANESE - Child 2.3 

Molybdenum† Adult Ingestion 

0.051 

0.1 104 30 70 10950 1.0 

Molybdenum Adult Dermal NA 104 30 70 10950 8.3 

TOTAL DOSE MOLYBDENUM - Adult 1.8 

Molybdenum Child Ingestion 0.1 104 6 16 2190 4.5 

Molybdenum Child Dermal NA 104 6 16 2190 1.7 

TOTAL DOSE MOLYBDENUM - Child 6.2 

*Maximum concentration of manganese in surface water detected in DeWeese Dye Ditch †Maximum concentration of molybdenum in surface water detected in Sand Creek 

182 
 

 


 

Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Consumption of Homegrown Fruits and Vegetables 

The following formula presents the method for calculating an exposure dose for a typical 

consumer of homegrown fruits and vegetables: 

 Exposure Dose (mg/kg/day) = C x IR x CF 

Where: 

C = contaminant concentration (mg/kg) 

IR = intake rate of fruit or vegetable (g/kg/day) 

CF = conversion factor (1 x 10-3 kg/mg)
 

Exposure doses for ingestion of garden vegetables were calculated using the average detected 

concentration of each contaminant measured in fruit and vegetable samples, in mg/kg, multiplied 

by average consumption rates of homegrown fruits or vegetables in grams per kilogram of body 

weight per day (g/kg/day). Intake rates were taken from EPA’s Exposure Factors Handbook for 

adults, and EPA’s Child-Specific Exposure Factors Handbook for children, for the Western 

United States. The average consumption rate was used to represent a “typical” fruit and 

vegetable consumer. The 95 percentile consumption rate was used to represent an “above 

average” consumer of fruits and vegetables. The calculated value was multiplied by a conversion 

factor of 0.001 kilograms per gram. 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Table C4. Summary of Exposure Doses for Local Fruits and Vegetables Irrigated with 

Contaminated Well Water 

Chemical 

Chemical 

Concentration/ 

Exposure 

Group 

Exposure Dose 

Fruits 

(mg/kg/day) 

Exposure Dose 

Vegetables 

(mg/kg/day) 

Health 

Guideline 

(mg/kg/day) 

Arsenic 

Average consumer 0.0001 0.0001 

0.0003, Chronic 

Oral MRL 

Above Average 

Consumer 0.0006 0.0005 

Child 0.0002 0.0002 

Infant 0.0004 0.0004 

Barium 

Average consumer 0.001 0.003 

0.2 Chronic Oral 

MRL 

Above Average 

Consumer 0.005 0.010 

Child 0.002 0.004 

Infant 0.004 0.008 

Cadmium 

Average consumer 0.0001 0.0001 

0.001, RfD 

Above Average 

Consumer 0.0005 0.0002 

Child 0.0002 0.0001 

Infant 0.0004 0.0002 

Chromium 

Average consumer 0.0001 0.0001 

1.5 RfD 

Above Average 

Consumer 0.0006 0.0003 

Child 0.0002 0.0001 

Infant 0.0005 0.0003 

Cobalt 

Average consumer ND 0.00004 

0.01 Intermediate 

MRL 

Above Average 

Consumer ND 0.00012 

Child ND 0.00005 

Infant ND 0.0001 

Lead 

Average consumer 0.0003 0.0004 

NA 

Above Average 

Consumer 0.001 0.001 

Child 0.0005 0.0005 

Infant 0.001 0.001 

Manganese 

Average consumer 0.002 0.004 

0.14 RfD 

Above Average 

Consumer 0.01 0.02 

Child 0.004 0.006 

Infant 0.008 0.01 

Molybdenum 

Average consumer 0.0003 0.001 

Above Average 0.005 RfD

Consumer 0.001 0.004 

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Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment 

Chemical 

Chemical 

Concentration/ 

Exposure 

Group 

Exposure Dose 

Fruits 

(mg/kg/day) 

Exposure Dose 

Vegetables 

(mg/kg/day) 

Health 

Guideline 

(mg/kg/day) 

Child 0.0005 0.002 

Infant 0.001 0.004 

Nickel 

Average consumer ND 0.0001 

0.02 RfD 

Above Average 

Consumer ND 0.0005 

Child ND 0.0002 

Infant ND 0.0004 

Strontium 

Average consumer 0.004 0.009 

0.6 RfD 

Above Average 

Consumer 0.02 0.03 

Child 0.007 0.01 

Infant 0.01 0.03 

Uranium 

Average consumer 0.00002 0.00001 

0.002 Intermediate 

MRL 

Above Average 

Consumer 0.00008 0.00004 

Child 0.00003 0.00002 

Infant 0.00006 0.00004 

Vanadium 

Average consumer ND 0.00008 

0.003 Intermediate 

MRL 

Above Average 

Consumer ND 0.0003 

Child ND 0.0001 

Infant ND 0.0002 

Zinc 

Average consumer 0.004 0.006 

0.3 Chronic Oral 

MRL 

Above Average 

Consumer 0.02 0.02 

Child 0.006 0.008 

Infant 0.01 0.02 

Bolded text exceeds a health guideline. 

ND = not detected 

NA = not available 

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ATSDR’s Evaluation of Cancer and Non-Cancer Health Effects 

Non-Cancer Health Effects 

The doses calculated for exposure to each individual chemical are compared to an established 

health guideline, such as a MRL or RfD, in order to assess whether adverse health impacts from 

exposure are expected. These health guidelines, developed by ATSDR and EPA, are chemicalspecific values that are based on the available scientific literature and are considered protective 

of human health. Non-carcinogenic effects, unlike carcinogenic effects, are believed to have a 

threshold, that is, a dose below which adverse health effects will not occur. As a result, the 

current practice for deriving health guidelines is to identify, usually from animal toxicology 

experiments, a No Observed Adverse Effect Level (or NOAEL), which indicates that no effects 

are observed at a particular exposure level. This is the experimental exposure level in animals 

(and sometimes humans) at which no adverse toxic effect is observed. The NOAEL is then 

modified with an uncertainty (or safety) factor, which reflects the degree of uncertainty that 

exists when experimental animal data are extrapolated to the general human population. The 

magnitude of the uncertainty factor considers various factors such as sensitive subpopulations 

(for example; children, pregnant women, and the elderly), extrapolation from animals to humans, 

and the completeness of available data. Thus, exposure doses at or below the established health 

guideline are not expected to result in adverse health effects because these values are much lower 

(and more human health protective) than doses, which do not cause adverse health effects in 

laboratory animal studies. For non-cancer health effects, the following health guidelines are 

described below in more detail. It is important to consider that the methodology used to develop 

these health guidelines does not provide any information on the presence, absence, or level of 

cancer risk. Therefore, a separate cancer evaluation is necessary for potentially cancer-causing 

chemicals detected in samples at this site. A more detailed discussion of the evaluation of cancer 

risks is presented in the following section. 

Minimal Risk Levels (MRLs) – developed by ATSDR 

ATSDR has developed MRLs for contaminants commonly found at hazardous waste sites. The 

MRL is an estimate of daily exposure to a contaminant below which non-cancer, adverse health 

effects are unlikely to occur. MRLs are developed for different routes of exposure, such as 

inhalation and ingestion, and for lengths of exposure, such as acute (less than 14 days), 

intermediate (15-364 days), and chronic (365 days or greater). At this time, ATSDR has not 

developed MRLs for dermal exposure. A complete list of the available MRLs can be found at 

http://www.atsdr.cdc.gov/mrls.html. 

References Doses (RfDs) – developed by EPA 

An estimate of the daily, lifetime exposure of human populations to a possible hazard that is not 

likely to cause non-cancerous health effects. RfDs consider exposures to sensitive subpopulations, such as the elderly, children, and the developing fetus. EPA RfDs have been 

developed using information from the available scientific literature and have been calculated for 

oral and inhalation exposures. A complete list of the available RfDs can be found at 

http://www.epa.gov/iris. 

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If the estimated exposure dose for a chemical is less than the health guideline value, the exposure 

is unlikely to result in non-cancer health effects. Non-cancer health effects from dermal exposure 

were evaluated slightly differently that ingestion and inhalation exposure. Since health guidelines 

are not available for dermal exposure, the calculated dermal dose was compared with the oral 

health guideline value (RfD or MRL). 

If the calculated exposure dose is greater than the health guideline, the exposure dose is 

compared to known toxicological values for the particular chemical and is discussed in more 

detail in the text of the PHA. The known toxicological values are doses derived from human and 

animal studies that are presented in the ATSDR Toxicological Profiles and EPA’s Integrated 

Information System (IRIS). A direct comparison of site-specific exposure doses to study-derived 

exposures and doses found to cause adverse health effects is the basis for deciding whether 

health effects are likely to occur. This in-depth evaluation is performed by comparing calculated 

exposure doses with known toxicological values, such as the no-observed adverse-effect-level 

(NOAEL) and the lowest-observed-adverse-effect-level (LOAEL) from studies used to derive 

the MRL or RfD for a chemical. 

Cancer Risks 

Exposure to a cancer-causing compound, even at low concentrations, is assumed to be associated 

with some increased risk for evaluation purposes. The estimated excess risk of developing cancer 

from exposure to contaminants associated with the site was calculated by multiplying the sitespecific adult exposure doses, with a slight modification, by EPA’s chemical-specific Cancer 

Slope Factors (CSFs or cancer potency estimates), which are available at 

http://www.epa.gov/iris. Calculated dermal doses were compared with the oral CSFs. 

An increased excess lifetime cancer risk is not a specific estimate of expected cancers. Rather, it 

is an estimate of the increase in the probability that a person may develop cancer sometime 

during his or her lifetime following exposure to a particular contaminant. Therefore, the cancer 

risk calculation incorporates the equations and parameters (including the exposure duration and 

frequency) used to calculate the dose estimates, but the estimated value is divided by 25,550 

days (or the averaging time), which is equal to a lifetime of exposure (70 years) for 365 

days/year. 

There are varying suggestions among the scientific community regarding an acceptable excess 

lifetime cancer risk, due to the uncertainties regarding the mechanism of cancer. The 

recommendations of many scientists and EPA have been in the risk range of 1 in 1 million to 1 in 

-6 -4 

10,000 (as referred to as 1 x 10 to 1 x 10 ) excess cancer cases. An increased lifetime cancer 

risk of one in one million or less is generally considered an insignificant increase in cancer risk. 

-5 

Cancer risk less than 1 in 10,000 (or 1 x 10 ) are not typically considered a health concern. An 

important consideration when determining cancer risk estimates is that the risk calculations 

incorporate several very conservative assumptions that are expected to overestimate actual 

exposure scenarios. For example, the method used to calculate EPA’s CSFs assumes that highdose animal data can be used to estimate the risk for low dose exposures in humans. As 

previously stated, the method also assumes that there is no safe level for exposure. Lastly, the 

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method computes the 95% upper bound for the risk, rather than the average risk, suggesting that 

the cancer risk is actually lower, perhaps by several orders of magnitude. 

Because of the uncertainties involved with estimating carcinogenic risk, ATSDR employs a 

weight-of-evidence approach in evaluating all relevant data. Therefore, the carcinogenic risk is 

also described in words (qualitatively) rather than giving a numerical risk estimate only. The 

numerical risk estimate must be considered in the context of the variables and assumptions 

involved in their derivation and in the broader context of biomedical opinion, host factors, and 

actual exposure conditions. The actual parameters of environmental exposures have been given 

careful and thorough consideration in evaluating the assumptions and variables relating to both 

toxicity and exposure. A complete review of the toxicological data regarding the doses 

associated with the production of cancer and the site-specific doses for the site is an important 

element in determining the likelihood of exposed individuals being at a greater risk for cancer. 

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Appendix D. ATSDR Glossary of Environmental Health Terms 

The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health 

agency with headquarters in Atlanta, Georgia, and 10 regional offices in the United States. 

ATSDR’s mission is to serve the public by using the best science, taking responsive public 

health actions, and providing trusted health information to prevent harmful exposures and 

diseases related to toxic substances. ATSDR is not a regulatory agency, unlike the U.S. 

Environmental Protection Agency (EPA), which is the federal agency that develops and enforces 

environmental laws to protect the environment and human health. 

This glossary defines words used by ATSDR in communications with the public. It is not a 

complete dictionary of environmental health terms. If you have questions or comments, call 

ATSDR’s toll-free telephone number, 1-800-CDC-INFO (1-800-232-4636). 

Absorption 

The process of taking in. For a person or an animal, absorption is the process of a substance 

getting into the body through the eyes, skin, stomach, intestines, or lungs. 

Acute 

Occurring over a short time [compare with chronic]. 

Acute exposure 

Contact with a substance that occurs once or for only a short time (up to 14 days) [compare with 

intermediate duration exposure and chronic exposure]. 

Additive effect 

A biologic response to exposure to multiple substances that equals the sum of responses of all the 

individual substances added together [compare with antagonistic effect and synergistic effect]. 

Adverse health effect 

A change in body function or cell structure that might lead to disease or health problems 

Aerobic 

Requiring oxygen [compare with anaerobic]. 

Ambient 

Surrounding (for example, ambient air). 

Anaerobic 

Requiring the absence of oxygen [compare with aerobic]. 

Analyte 

A substance measured in the laboratory. A chemical for which a sample (such as water, air, or 

blood) is tested in a laboratory. For example, if the analyte is mercury, the laboratory test will 

determine the amount of mercury in the sample. 

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Analytic epidemiologic study 

A study that evaluates the association between exposure to hazardous substances and disease by 

testing scientific hypotheses. 

Antagonistic effect 

A biologic response to exposure to multiple substances that is less than would be expected if the 

known effects of the individual substances were added together [compare with additive effect 

and synergistic effect]. 

Background level 

An average or expected amount of a substance or radioactive material in a specific environment, 

or typical amounts of substances that occur naturally in an environment. 

Biodegradation 

Decomposition or breakdown of a substance through the action of microorganisms (such as 

bacteria or fungi) or other natural physical processes (such as sunlight). 

Biologic indicators of exposure study 

A study that uses (a) biomedical testing or (b) the measurement of a substance [an analyte], its 

metabolite, or another marker of exposure in human body fluids or tissues to confirm human 

exposure to a hazardous substance [also see exposure investigation]. 

Biologic monitoring 

Measuring hazardous substances in biologic materials (such as blood, hair, urine, or breath) to 

determine whether exposure has occurred. A blood test for lead is an example of biologic 

monitoring. 

Biologic uptake 

The transfer of substances from the environment to plants, animals, and humans. 

Biomedical testing 

Testing of persons to find out whether a change in a body function might have occurred because 

of exposure to a hazardous substance. 

Biota 

Plants and animals in an environment. Some of these plants and animals might be sources of 

food, clothing, or medicines for people. 

Body burden 

The total amount of a substance in the body. Some substances build up in the body because they 

are stored in fat or bone or because they leave the body very slowly. 

CAP [see Community Assistance Panel.] 

Cancer 

Any one of a group of diseases that occur when cells in the body become abnormal and grow or 

multiply out of control. 

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Cancer risk 

A theoretical risk for getting cancer if exposed to a substance every day for 70 years (a lifetime 

exposure). The true risk might be lower. 

Carcinogen 

A substance that causes cancer. 

Case study 

A medical or epidemiologic evaluation of one person or a small group of people to gather 

information about specific health conditions and past exposures. 

Case-control study 

A study that compares exposures of people who have a disease or condition (cases) with people 

who do not have the disease or condition (controls). Exposures that are more common among the 

cases may be considered as possible risk factors for the disease. 

CAS registry number 

A unique number assigned to a substance or mixture by the American Chemical Society 

Abstracts Service. 

Central nervous system 

The part of the nervous system that consists of the brain and the spinal cord. 

CERCLA [see Comprehensive Environmental Response, Compensation, and Liability Act of 

1980] 

Chronic 

Occurring over a long time [compare with acute]. 

Chronic exposure 

Contact with a substance that occurs over a long time (more than 1 year) [compare with acute 

exposure and intermediate duration exposure] 

Cluster investigation 

A review of an unusual number, real or perceived, of health events (for example, reports of 

cancer) grouped together in time and location. Cluster investigations are designed to confirm 

case reports; determine whether they represent an unusual disease occurrence; and, if possible, 

explore possible causes and contributing environmental factors. 

Community Assistance Panel (CAP) 

A group of people from a community and from health and environmental agencies who work 

with ATSDR to resolve issues and problems related to hazardous substances in the community. 

CAP members work with ATSDR to gather and review community health concerns, provide 

information on how people might have been or might now be exposed to hazardous substances, 

and inform ATSDR on ways to involve the community in its activities. 

Comparison value (CV) 

Calculated concentration of a substance in air, water, food, or soil that is unlikely to cause 

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harmful (adverse) health effects in exposed people. The CV is used as a screening level during 

the public health assessment process. Substances found in amounts greater than their CVs might 

be selected for further evaluation in the public health assessment process. 

Completed exposure pathway [see exposure pathway]. 

Comprehensive Environmental Response, Compensation, and Liability Act of 1980 

(CERCLA) 

CERCLA, also known as Superfund, is the federal law that concerns the removal or cleanup of 

hazardous substances in the environment and at hazardous waste sites. ATSDR, which was 

created by CERCLA, is responsible for assessing health issues and supporting public health 

activities related to hazardous waste sites or other environmental releases of hazardous 

substances. This law was later amended by the Superfund Amendments and Reauthorization Act 

(SARA). 

Concentration 

The amount of a substance present in a certain amount of soil, water, air, food, blood, hair, urine, 

breath, or any other media. 

Contaminant 

A substance that is either present in an environment where it does not belong or is present at 

levels that might cause harmful (adverse) health effects. 

Delayed health effect 

A disease or an injury that happens as a result of exposures that might have occurred in the past. 

Dermal 

Referring to the skin. For example, dermal absorption means passing through the skin. 

Dermal contact 

Contact with (touching) the skin [see route of exposure]. 

Descriptive epidemiology 

The study of the amount and distribution of a disease in a specified population by person, place, 

and time. 

Detection limit 

The lowest concentration of a chemical that can reliably be distinguished from a zero 

concentration. 

Disease prevention 

Measures used to prevent a disease or reduce its severity. 

Disease registry 

A system of ongoing registration of all cases of a particular disease or health condition in a 

defined population. 

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DOD 

United States Department of Defense. 

DOE 

United States Department of Energy. 

Dose (for chemicals that are not radioactive) 

The amount of a substance to which a person is exposed over some time period. Dose is a 

measurement of exposure. Dose is often expressed as milligram (amount) per kilogram (a 

measure of body weight) per day (a measure of time) when people eat or drink contaminated 

water, food, or soil. In general, the greater the dose, the greater the likelihood of an effect. An 

“exposure dose” is how much of a substance is encountered in the environment. An “absorbed 

dose” is the amount of a substance that actually got into the body through the eyes, skin, 

stomach, intestines, or lungs. 

Dose (for radioactive chemicals) 

The radiation dose is the amount of energy from radiation that is actually absorbed by the body. 

This is not the same as measurements of the amount of radiation in the environment. 

Dose-response relationship 

The relationship between the amount of exposure [dose] to a substance and the resulting changes 

in body function or health (response). 

Environmental media 

Soil, water, air, biota (plants and animals), or any other parts of the environment that can contain 

contaminants. 

Environmental media and transport mechanism 

Environmental media include water, air, soil, and biota (plants and animals). Transport 

mechanisms move contaminants from the source to points where human exposure can occur. The 

environmental media and transport mechanism is the second part of an exposure pathway. 

EPA 

United States Environmental Protection Agency. 

Epidemiologic surveillance [see Public health surveillance]. 

Epidemiology 

The study of the distribution and determinants of disease or health status in a population; the 

study of the occurrence and causes of health effects in humans. 

Exposure 

Contact with a substance by swallowing, breathing, or touching the skin or eyes. Exposure may 

be short-term [acute exposure], of intermediate duration, or long-term [chronic exposure]. 

Exposure assessment 

The process of finding out how people come into contact with a hazardous substance, how often 

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and for how long they are in contact with the substance, and how much of the substance they are 

in contact with. 

Exposure-dose reconstruction 

A method of estimating the amount of people’s past exposure to hazardous substances. Computer 

and approximation methods are used when past information is limited, not available, or missing. 

Exposure investigation 

The collection and analysis of site-specific information and biologic tests (when appropriate) to 

determine whether people have been exposed to hazardous substances. 

Exposure pathway 

The route a substance takes from its source (where it began) to its end point (where it ends), and 

how people can come into contact with (or get exposed to) it. An exposure pathway has five 

parts: a source of contamination (such as an abandoned business); an environmental media and 

transport mechanism (such as movement through groundwater); a point of exposure (such as a 

private well); a route of exposure (eating, drinking, breathing, or touching), and a receptor 

population (people potentially or actually exposed). When all five parts are present, the exposure 

pathway is termed a completed exposure pathway. 

Exposure registry 

A system of ongoing followup of people who have had documented environmental exposures. 

Feasibility study 

A study by EPA to determine the best way to clean up environmental contamination. A number 

of factors are considered, including health risk, costs, and what methods will work well. 

Geographic information system (GIS) 

A mapping system that uses computers to collect, store, manipulate, analyze, and display data. 

For example, GIS can show the concentration of a contaminant within a community in relation to 

points of reference such as streets and homes. 

Grand rounds 

Training sessions for physicians and other health care providers about health topics. 

Groundwater 

Water beneath the earth’s surface in the spaces between soil particles and between rock surfaces 

[compare with surface water]. 

Half-life (t1⁄2) 

The time it takes for half the original amount of a substance to disappear. In the environment, the 

half-life is the time it takes for half the original amount of a substance to disappear when it is 

changed to another chemical by bacteria, fungi, sunlight, or other chemical processes. In the 

human body, the half-life is the time it takes for half the original amount of the substance to 

disappear, either by being changed to another substance or by leaving the body. In the case of 

radioactive material, the half life is the amount of time necessary for one half the initial number 

of radioactive atoms to change or transform into another atom (that is normally not radioactive). 

After two half lives, 25% of the original number of radioactive atoms remain. 

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Hazard 

A source of potential harm from past, current, or future exposures. 

Hazardous Substance Release and Health Effects Database (HazDat) 

The scientific and administrative database system developed by ATSDR to manage data 

collection, retrieval, and analysis of site-specific information on hazardous substances, 

community health concerns, and public health activities. 

Hazardous waste 

Potentially harmful substances that have been released or discarded into the environment. 

Health consultation 

A review of available information or collection of new data to respond to a specific health 

question or request for information about a potential environmental hazard. Health consultations 

are focused on a specific exposure issue. Health consultations are therefore more limited than a 

public health assessment, which reviews the exposure potential of each pathway and chemical 

[compare with public health assessment]. 

Health education 

Programs designed with a community to help it know about health risks and how to reduce these 

risks. 

Health investigation 

The collection and evaluation of information about the health of community residents. This 

information is used to describe or count the occurrence of a disease, symptom, or clinical 

measure and to evaluate the possible association between the occurrence and exposure to 

hazardous substances. 

Health promotion 

The process of enabling people to increase control over, and to improve, their health. 

Health statistics review 

The analysis of existing health information (i.e., from death certificates, birth defects registries, 

and cancer registries) to determine if there is excess disease in a specific population, geographic 

area, and time period. A health statistics review is a descriptive epidemiologic study. 

Indeterminate public health hazard 

The category used in ATSDR’s public health assessment documents when a professional 

judgment about the level of health hazard cannot be made because information critical to such a 

decision is lacking. 

Incidence 

The number of new cases of disease in a defined population over a specific time period [contrast 

with prevalence]. 

Ingestion 

The act of swallowing something through eating, drinking, or mouthing objects. A hazardous 

substance can enter the body this way [see route of exposure]. 

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Inhalation 

The act of breathing. A hazardous substance can enter the body this way [see route of exposure]. 

Intermediate duration exposure 

Contact with a substance that occurs for more than 14 days and less than a year [compare with 

acute exposure and chronic exposure]. 

In vitro 

In an artificial environment outside a living organism or body. For example, some toxicity 

testing is done on cell cultures or slices of tissue grown in the laboratory, rather than on a living 

animal [compare with in vivo]. 

In vivo 

Within a living organism or body. For example, some toxicity testing is done on whole animals, 

such as rats or mice [compare with in vitro]. 

Lowest-observed-adverse-effect level (LOAEL) 

The lowest tested dose of a substance that has been reported to cause harmful (adverse) health 

effects in people or animals. 

Medical monitoring 

A set of medical tests and physical exams specifically designed to evaluate whether an 

individual’s exposure could negatively affect that person’s health. 

Metabolism 

The conversion or breakdown of a substance from one form to another by a living organism. 

Metabolite 

Any product of metabolism. 

mg/kg 

Milligram per kilogram. 

mg/cm2 

Milligram per square centimeter (of a surface). 

mg/m3 

Milligram per cubic meter; a measure of the concentration of a chemical in a known volume (a 

cubic meter) of air, soil, or water. 

Migration 

Moving from one location to another. 

Minimal risk level (MRL) 

An ATSDR estimate of daily human exposure to a hazardous substance at or below which that 

substance is unlikely to pose a measurable risk of harmful (adverse), noncancerous effects. 

MRLs are calculated for a route of exposure (inhalation or oral) over a specified time period 

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(acute, intermediate, or chronic). MRLs should not be used as predictors of harmful (adverse) 

health effects [see reference dose]. 

Morbidity 

State of being ill or diseased. Morbidity is the occurrence of a disease or condition that alters 

health and quality of life. 

Mortality 

Death. Usually the cause (a specific disease, a condition, or an injury) is stated. 

Mutagen 

A substance that causes mutations (genetic damage). 

Mutation 

A change (damage) to the DNA, genes, or chromosomes of living organisms. 

National Priorities List for Uncontrolled Hazardous Waste Sites (National Priorities List or 

NPL) 

EPA’s list of the most serious uncontrolled or abandoned hazardous waste sites in the United 

States. The NPL is updated on a regular basis. 

National Toxicology Program (NTP) 

Part of the Department of Health and Human Services. NTP develops and carries out tests to 

predict whether a chemical will cause harm to humans. 

No apparent public health hazard 

A category used in ATSDR’s public health assessments for sites where human exposure to 

contaminated media might be occurring, might have occurred in the past, or might occur in the 

future, but where the exposure is not expected to cause any harmful health effects. 

No-observed-adverse-effect level (NOAEL) 

The highest tested dose of a substance that has been reported to have no harmful (adverse) health 

effects on people or animals. 

No public health hazard 

A category used in ATSDR’s public health assessment documents for sites where people have 

never and will never come into contact with harmful amounts of site-related substances. 

NPL [see National Priorities List for Uncontrolled Hazardous Waste Sites] 

Physiologically based pharmacokinetic model (PBPK model) 

A computer model that describes what happens to a chemical in the body. This model describes 

how the chemical gets into the body, where it goes in the body, how it is changed by the body, 

and how it leaves the body. 

Pica 

A craving to eat nonfood items, such as dirt, paint chips, and clay. Some children exhibit picarelated behavior. 

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Plume 

A volume of a substance that moves from its source to places farther away from the source. 

Plumes can be described by the volume of air or water they occupy and the direction they move. 

For example, a plume can be a column of smoke from a chimney or a substance moving with 

groundwater. 

Point of exposure 

The place where someone can come into contact with a substance present in the environment 

[see exposure pathway]. 

Population 

A group or number of people living within a specified area or sharing similar characteristics 

(such as occupation or age). 

Potentially responsible party (PRP) 

A company, government, or person legally responsible for cleaning up the pollution at a 

hazardous waste site under Superfund. There may be more than one PRP for a particular site. 

ppb 

Parts per billion. 

ppm 

Parts per million. 

Prevalence 

The number of existing disease cases in a defined population during a specific time period 

[contrast with incidence]. 

Prevalence survey 

The measure of the current level of disease(s) or symptoms and exposures through a 

questionnaire that collects self-reported information from a defined population. 

Prevention 

Actions that reduce exposure or other risks, keep people from getting sick, or keep disease from 

getting worse. 

Public availability session 

An informal, drop-by meeting at which community members can meet one-on-one with ATSDR 

staff members to discuss health and site-related concerns. 

Public comment period 

An opportunity for the public to comment on agency findings or proposed activities contained in 

draft reports or documents. The public comment period is a limited time period during which 

comments will be accepted. 

Public health action 

A list of steps to protect public health. 

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Public health advisory 

A statement made by ATSDR to EPA or a state regulatory agency that a release of hazardous 

substances poses an immediate threat to human health. The advisory includes recommended 

measures to reduce exposure and reduce the threat to human health. 

Public health assessment (PHA) 

An ATSDR document that examines hazardous substances, health outcomes, and community 

concerns at a hazardous waste site to determine whether people could be harmed from coming 

into contact with those substances. The PHA also lists actions that need to be taken to protect 

public health [compare with health consultation]. 

Public health hazard 

A category used in ATSDR’s public health assessments for sites that pose a public health hazard 

because of long-term exposures (greater than 1 year) to sufficiently high levels of hazardous 

substances or radionuclides that could result in harmful health effects. 

Public health hazard categories 

Public health hazard categories are statements about whether people could be harmed by 

conditions present at the site in the past, present, or future. One or more hazard categories might 

be appropriate for each site. The five public health hazard categories are no public health hazard, 

no apparent public health hazard, indeterminate public health hazard, public health hazard, and 

urgent public health hazard. 

Public health statement 

The first chapter of an ATSDR toxicological profile. The public health statement is a summary 

written in words that are easy to understand. The public health statement explains how people 

might be exposed to a specific substance and describes the known health effects of that 

substance. 

Public health surveillance 

The ongoing, systematic collection, analysis, and interpretation of health data. This activity also 

involves timely dissemination of the data and use for public health programs. 

Public meeting 

A public forum with community members for communication about a site. 

Radioisotope 

An unstable or radioactive isotope (form) of an element that can change into another element by 

giving off radiation. 

Radionuclide 

Any radioactive isotope (form) of any element. 

RCRA [see Resource Conservation and Recovery Act (1976, 1984)] 

Receptor population 

People who could come into contact with hazardous substances [see exposure pathway]. 

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Reference dose (RfD) 

An EPA estimate, with uncertainty or safety factors built in, of the daily lifetime dose of a 

substance that is unlikely to cause harm in humans. 

Registry 

A systematic collection of information on persons exposed to a specific substance or having 

specific diseases [see exposure registry and disease registry]. 

Remedial investigation 

The CERCLA process of determining the type and extent of hazardous material contamination at 

a site. 

Resource Conservation and Recovery Act (1976, 1984) (RCRA) 

This Act regulates management and disposal of hazardous wastes currently generated, treated, 

stored, disposed of, or distributed. 

RFA 

RCRA Facility Assessment. An assessment required by RCRA to identify potential and actual 

releases of hazardous chemicals. 

RfD [see reference dose] 

Risk 

The probability that something will cause injury or harm. 

Risk reduction 

Actions that can decrease the likelihood that individuals, groups, or communities will experience 

disease or other health conditions. 

Risk communication 

The exchange of information to increase understanding of health risks. 

Route of exposure 

The way people come into contact with a hazardous substance. Three routes of exposure are 

breathing [inhalation], eating or drinking [ingestion], or contact with the skin [dermal contact]. 

Safety factor [see uncertainty factor] 

SARA [see Superfund Amendments and Reauthorization Act] 

Sample 

A portion or piece of a whole. A selected subset of a population or subset of whatever is being 

studied. For example, in a study of people the sample is a number of people chosen from a larger 

population [see population]. An environmental sample (for example, a small amount of soil or 

water) might be collected to measure contamination in the environment at a specific location. 

Sample size 

The number of units chosen from a population or an environment. 

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Solvent 

A liquid capable of dissolving or dispersing another substance (for example, acetone or mineral 

spirits). 

Source of contamination 

The place where a hazardous substance comes from, such as a landfill, waste pond, incinerator, 

storage tank, or drum. A source of contamination is the first part of an exposure pathway. 

Special populations 

People who might be more sensitive or susceptible to exposure to hazardous substances because 

of factors such as age, occupation, sex, or behaviors (for example, cigarette smoking). Children, 

pregnant women, and older people are often considered special populations. 

Stakeholder 

A person, group, or community who has an interest in activities at a hazardous waste site. 

Statistics 

A branch of mathematics that deals with collecting, reviewing, summarizing, and interpreting 

data or information. Statistics are used to determine whether differences between study groups 

are meaningful. 

Substance 

A chemical. 

Substance-specific applied research 

A program of research designed to fill important data needs for specific hazardous substances 

identified in ATSDR’s toxicological profiles. Filling these data needs would allow more accurate 

assessment of human risks from specific substances contaminating the environment. This 

research might include human studies or laboratory experiments to determine health effects 

resulting from exposure to a given hazardous substance. 

Superfund [see Comprehensive Environmental Response, Compensation, and Liability Act of 

1980 (CERCLA) and Superfund Amendments and Reauthorization Act (SARA)] 

Superfund Amendments and Reauthorization Act (SARA) 

In 1986, SARA amended the Comprehensive Environmental Response, Compensation, and 

Liability Act of 1980 (CERCLA) and expanded the health-related responsibilities of ATSDR. 

CERCLA and SARA direct ATSDR to look into the health effects from substance exposures at 

hazardous waste sites and to perform activities including health education, health studies, 

surveillance, health consultations, and toxicological profiles. 

Surface water 

Water on the surface of the earth, such as in lakes, rivers, streams, ponds, and springs [compare 

with groundwater]. 

Surveillance [see public health surveillance] 

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Survey 

A systematic collection of information or data. A survey can be conducted to collect information 

from a group of people or from the environment. Surveys of a group of people can be conducted 

by telephone, by mail, or in person. Some surveys are done by interviewing a group of people 

[see prevalence survey]. 

Synergistic effect 

A biologic response to multiple substances where one substance worsens the effect of another 

substance. The combined effect of the substances acting together is greater than the sum of the 

effects of the substances acting by themselves [see additive effect and antagonistic effect]. 

Teratogen 

A substance that causes defects in development between conception and birth. A teratogen is a 

substance that causes a structural or functional birth defect. 

Toxic agent 

Chemical or physical (for example, radiation, heat, cold, microwaves) agents that, under certain 

circumstances of exposure, can cause harmful effects to living organisms. 

Toxicological profile 

An ATSDR document that examines, summarizes, and interprets information about a hazardous 

substance to determine harmful levels of exposure and associated health effects. A toxicological 

profile also identifies significant gaps in knowledge on the substance and describes areas where 

further research is needed. 

Toxicology 

The study of the harmful effects of substances on humans or animals. 

Tumor 

An abnormal mass of tissue that results from excessive cell division that is uncontrolled and 

progressive. Tumors perform no useful body function. Tumors can be either benign (not cancer) 

or malignant (cancer). 

Uncertainty factor 

Mathematical adjustments for reasons of safety when knowledge is incomplete. For example, 

factors used in the calculation of doses that are not harmful (adverse) to people. These factors are 

applied to the lowest-observed-adverse-effect-level (LOAEL) or the no-observed-adverse-effectlevel (NOAEL) to derive a minimal risk level (MRL). Uncertainty factors are used to account for 

variations in people’s sensitivity, for differences between animals and humans, and for 

differences between a LOAEL and a NOAEL. Scientists use uncertainty factors when they have 

some, but not all, the information from animal or human studies to decide whether an exposure 

will cause harm to people [also sometimes called a safety factor]. 

Urgent public health hazard 

A category used in ATSDR’s public health assessments for sites where short-term exposures 

(less than 1 year) to hazardous substances or conditions could result in harmful health effects that 

require rapid intervention. 

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Volatile organic compounds (VOCs) 

Organic compounds that evaporate readily into the air. VOCs include substances such as 

benzene, toluene, methylene chloride, and methyl chloroform. 

Other glossaries and dictionaries: 

Environmental Protection Agency (http://www.epa.gov/OCEPAterms/) 

National Library of Medicine (NIH) 

(http://www.nlm.nih.gov/medlineplus/mplusdictionary.html) 

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