ENVIRONMENTAL MONITORING & ANALYSIS -...

4-1

ENVIRONMENTAL MONITORING & ANALYSIS OVERVIEW The environmental monitoring program was continued in 2009 in accordance with the requirements established by Federal and State Regulations, the Radioactive Materials License (RML), and Radiation Protection Plan Procedures (RPPP). Air Emissions Control and Liquid Management monitoring programs results are reported in sections 5 and 7 of this report respectively. Analytical results for 2009 were provided by the onsite laboratory. Results and discussion from the following programs and procedures are included in this section:

• Individual Member of the Public (IMOP) Dose: RPPP EV-010

Environmental Dose Assessment • Environmental Air Particulate: RPPP EV-020 Environmental Air

Particulate Sampling, RPPP EV-021 Calibration of Environmental Air Samplers using the Plate Orifice Method

• Environmental Radon: RPPP EV-030 Radon 222/220 Air Surveys • Environmental TLD: RPPP EV-070 Environmental TLD • Meteorological Monitoring: RPPP EV-130 Weather Monitoring • Vegetation: RPPP EV-060 Vegetation Sampling • Soils: RPPP EV-110 Soil Sampling; EV-120 Radon Flux Measurement

Public dose for 2009 was estimated by the computer code MILDOS to be slightly higher in comparison to 2008 as CCMF continued in a stand-down condition where site work was performed primarily to reduce potential hazards, maintain compliance, and maintain vital equipment. Interim cover of the Secondary Impoundment as well as excavation of ore pads commenced in 2009.

The general trend in radionuclide concentrations at Perimeter Air sampling locations since 2005, continued lower with the exception of natural uranium. This is likely attributable to increased dust control efforts in the timeframe. Average 2009 concentrations remained within historical levels and were generally lowers than 2008 with the exception of natural uranium. Environmental Radon measurements at perimeter and nearby locations in 2009 were generally higher at all locations including the three (3) background locations (Canon City, Lincoln Park and Oro Verde). Environmental TLD measurements were all generally higher for individual locations in 2009 versus 2008. Meteorological Monitoring data was quite similar for 2009 compared to 2008 with exception of precipitation which was substantially increased. The onsite rain gauge did not function correctly and was replaced in November 2009. Wind Rose data was very similar for 2009 as compared to 2008.

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Vegetation sample analytical results for 2009 indicated similar to lower levels some above historic levels. Sampling locations are selected based on predicted ground concentrations using the public dose model MILDOS. Soil sample analytical results for 2009 indicate results within historic levels. Radon Flux measurements for the Primary Impoundment were conducted in June 2009 with the resulting flux of thirteen point four (13.4) pCi/m2-s compared to the 2008 flux of nineteen point seven (19.7) pCi/m2-s versus the National Emission Standard for Hazardous Air Pollutants (NESHAPS) standard of twenty (20) pCi/m2-s. The 2009 report was filed with Environmental Protection Agency (EPA). When the 2008 Primary Impoundment preliminary results were received, Cotter initiated a program to cover the most highly elevated areas as an ALARA function. Approximately eight thousand eight hundred (8,800) cubic yards of soil cover averaging four (4) feet in depth was placed on approximately one (1) acre in the northwest corner of the exposed tailings beach encompassing tailings beach locations TB 69-72. This was completed in the latter part of 2008 and early 2009. The combination of these remedial activities and slightly more water covered area (about three (3) acres) resulted in the reduced average radon flux. For the Secondary Impoundment, the June 2008 sampling was conducted as an ALARA function and not for compliance with NESHAPS. The resulting measurements indicated a reading of fourteen (14) pCi/m2-s This result is the same (fourteen (14) pCi/m2-s)) as the readings which were taken in October 2007 after remedial ALARA actions were taken to reduce the flux of twenty-three point four (23.4) pCi/m2-s as measured in July 2007. The Secondary Impoundment was not sampled in 2009. Overall, the presented results indicate good control of airborne emissions from CCMF as evidenced by compliance with the Effluent Concentration (EC) limits in Part 4 of the Radiation Regulations, conformance to the 40 CFR 190 public dose requirements and compliance with the 40 CFR 61 National Emission Standards for Hazardous Air Pollutants (NESHAP) requirements for radon flux. INDIVIDUAL MEMBER OF THE PUBLIC (IMOP) DOSE Public Dose for 2009 was estimated using the MILDOS Computer Code and site-specific data. These are estimates for potential actual residents for 2008 which are generally higher than for 2007 estimates. Generally, the increase can be attributed to movement of Old Pond Area (OPA) soils. The 40 CFR 190 dose estimates may be compared to the Colorado Rules and Regulations Part 4.5.4 constraint level of ten (10) mrem/year (effective dose only) and the Colorado Rules and Regulations Part 4.14.4 regulatory limit of twenty-five (25) mrem/year. The Total Effective dose estimates may be compared to the Colorado Rules and Regulations Part 4.14.1.1 regulatory limit of one hundred (100) mrem/year, which includes exposure to radon. A comparison of the 2001 – 2008 estimated maximum doses to a potentially exposed individual is shown in Table 4-1.

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The maximum dose for each dose category (i.e. bone, lung, effective, and total effective) per year is shown as bold. See Appendix D Estimates of Radiation Doses to Members of the Public from Cotter 2009 Operations for additional details.

Table 4-1

Estimates of Public Dose – Maximum (mrem/yr)

Individual Year 40 CFR 190

Bone (Limit 25)40 CFR 190

Lung (Limit 25)40 CFR 190

Effective (Limit 25) Total Effective

(Limit 100) 2001 9 5 1 13 2002 10 3 1 9 2003 3 1 <1 7 2004 6 2 1 5 2005 9 5 1 18 2006 6 2 1 10 2007 5 <1 <1 9 2008 8 1 1 9

Adult

2009 15 2 1 9 2001 15 6 2 12 2002 17 4 1 9 2003 6 1 <1 7 2004 8 2 1 5 2005 13 6 1 18 2006 8 2 1 10 2007 7 1 <1 9 2008 10 1 1 9

Teen

2009 14 2 1 9 2001 6 11 2 13 2002 7 6 1 9 2003 6 2 <1 7 2004 8 4 1 5 2005 7 10 2 18 2006 5 4 1 10 2007 4 2 <1 9 2008 7 2 1 9

Child

2009 14 3 1 9 2001 Note 1 19 3 12 2002 Note 1 10 2 8 2003 Note 1 2 <1 7 2004 Note 1 6 1 6 2005 Note 1 19 3 20 2006 Note 1 7 1 12 2007 Note 1 3 1 10 2008 Note 1 2 1 9

Infant

2009 Note 1 6 1 9 Note 1: Infants do not generally consume home grown vegetables; the dose to bone was not calculated

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Figure 4-1 Estimates of Public Dose – Maximum (mrem/yr)

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2009

Adult Teen Child Infant

Individual/Year

mre

m/y

r

40 CFR 190 - Bone 40 CFR 190 - Lung 40 CFR 190 - Effective Total Effective Bone Limit - 25 Lung Limit - 25 Effective Limit - 25 Total Effective Limit - 100

ENVIRONMENTAL AIR PARTICULATE A location map of the Environmental Air Samplers is included as Figure 4-1. Radon Track Etch Measurement Devices and Environmental TLDs are co-located at these collection points. Annual Average Particulate Concentrations for the period 1979 through 2009 are presented in Figures 4-2 through 4-11. Average Annual Radon and TLD measurements are shown in figures 4-12 through 4-14 and in 4-14 and 4-15, respectively. The particulate data generally indicates radionuclide concentrations which are approximately one hundred (100) times below the regulatory EC limit with the exception of 230Th, which is generally at least ten (10) times below the limit. Please see figures 4-2A through 4-11B which show the concentrations in an exponential format (A) for trend observation and as a percent of the effluent concentration limit (B). Management of the tailings area dust control continued by soil covering, mulch application, application of soil binding agents, as well as covering as much of the tailings beach as possible with available water and use of a sprinkling system in accordance with the Air Permit Compliance Plan has provided sufficient dust control. The Primary Impoundment solution level was approximately 5,575 at the end of 2009. The sprinkler system that was initially installed on the tailings beach adjacent to the evaporation cells in May 2003 continues to be used and additional sprinklers have been added and/or moved as needed for dust control.

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AS-202, AS-209 and AS-204 Supplemental Air Samplers (AS-136), (AS-140) and (AS-143) respectively continue to show slightly elevated readings, generally in the winter periods of the last several years. AS-143 sampler was added to track air emission from Secondary Impoundment covering activities. See Section 5 and Figure 5-2 for more information. Review and comparison of the 2009 to the 2008 Environmental Air sample results generally indicate similar average radiological concentrations for the perimeter samples (AS-203, AS-204, AS-206) while AS-202 East Boundary was slightly higher and AS-209 Mill Entrance Road concentrations were markedly lower. Nearby locations designated as AS-210 Shadow Hills Estates and AS-212 Nearest Resident, which are between the Canon City Milling Facility and actual residences generally showed lower results within historical levels. The outlying locations, Canon City #2, Lincoln Park #2, and OroVerde #3 are located at residences as shown on Figure 4-1 while AS-210 and AS-212 are at locations between the site boundary and actual residences. Results from these outlying locations showed concentrations within historical levels with individual radionuclides generally lower than in 2007. All radionuclide particulate results include background, which has been determined to be represented by the Canon City #2 location.

• Natural uranium was up at all locations. This may be attributable to background being higher as other radionuclides were generally lower.

• Thorium-230 results were all lower • Radium-226 was mostly lower for all locations for 2009 versus 2008. • Lead-210 results were slight lower to similar for 2009 as compared to 2008. Lead-210

results at all monitoring locations are controlled by global 222Rn concentrations (The primary source of 210Pb in air is global radon 222Rn). Radon-222 emanates from the soil and is dispersed through the atmosphere. The 222Rn decay products build in as the parent decays. The short–lived decay products of 222Rn attach to dust particles and are carried long distances with the air. Pb-210 is the longest-lived of the 222Rn decay products. The 210Pb concentration in air varies with location. The average ground level concentrations in selected states are as follows (NCRP, 1992):

NCRP Report No. 94 (NCRP, 1992) cites a mean concentration for the north temperate latitude of 0.6 mBq/m3 (1.5E-14 uCi/ml). The report also states that “It appears that re-suspension of soil is not a significant contributor to air concentrations since the ratio of Pb-210 to U-238 in surface soil is only about 2 … while the ratio in air is about 1000.” The Pb-210 concentration in air in the vicinity of the Cotter mill is within the range of the average values reported for various locations. Reference: National Council on Radiation Protection and Measurements (NCRP). 1992. NCRP Report No. 94, “Exposure of the Population in the United States and Canada from Natural Background Radiation”. NCRP Bethesda, MD.

State Pb-210 concentration uBq/m3 uCi/ml

California 600 1.6 E-14 Illinois 1500 4.1 E-14 Ohio 300 8.1 E-15 Massachusetts 700 1.9 E-14

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Ten (10) air monitoring stations where environmental radon, TLD monitors, and soil sampling locations are also co-located are shown in Figure 4-1. A review of the 2009 environmental air sample data indicates that the highest annual averages for natU, 230Th, 226Ra and 232Th, are at locations as indicated below and are compared to the 2008 highest measurement. For 2009 compared to 2008 AS-202 East Boundary was highest for:

• Natural uranium – 7.32E-16 versus 4.36E-16 micro Curies/milliliter (μCi/ml) (2.70E-11 versus 1.61E-11 Becquerel/milliliter (Bq/ml) both (AS-202 East Boundary)

• Thorium-230 – 5.74E-16 versus 7.21E-16 μCi/ml (2.12E-11 versus 2.67E-11 Bq/ml) both (AS-202 East Boundary)

• Radium-226 – 2.68E-16 versus 7.92E-16 μCi/ml (9.92E-12 versus 2.93E-11 Bq/ml) both (AS-202 East Boundary)

For 2009 compared to 2008:

• Lead-210 – 1.81E-14 (AS-204 West boundary) versus 1.93E-14 uCi/ml (AS-206 North Boundary) (6.70E-10 versus 7.15E-10 Bq/ml) both (AS-202 East Boundary)

• Thorium-232 – 3.47E-17 versus 3.13E-17 μCi/ml (1.28 E-12) versus 1.16-12 Bq/ml) both at LP #2 (Lincoln Park #2)

The highest sample results in 2009 for each radionuclide, when compared to the regulatory Effluent Concentration (EC) limit, indicate the following:

Percent Radionuclide of Effluent Concentration (EC) Monitoring Location

• Natural uranium 0.8 AS-202 East Boundary • Thorium-230 2.9 AS-202 East Boundary • Radium-226 < 0.1 AS-202 East Boundary • Lead-210 3.0 AS-206 North Boundary • Thorium-232 0.6 Lincoln Park #2

This means that all samplers monitored for 2009 for the radioactive particulates including Lead-210 (210Pb), which as noted above is controlled by global radon concentrations, when combined, are less than ten percent (<10%) of the regulatory limit. Environmental radionuclide concentrations are compared to the Effluent Concentration (EC) limit in Part 4 Appendix B of the Radiation Regulations. The EC is equivalent to fifty (50) mrem/year. Therefore, one percent (1%) of EC is equivalent to a dose of five tenths (0.5) mrem/year. The regulatory dose limit for uranium mills per 40 CFR 190 to an actual resident is twenty-five (25) mrem/year excluding radon.

4-7

The analytical results include background; that is we do not subtract the naturally occurring concentration existing in the Canon City area. Accordingly, CCMF’s results (inclusive of background) are overestimates and are not just the increment above background which would be allowed by regulation. CC-2 Canon City is generally considered as background. Therefore, for example with 230Th, the 2009 average concentration at CC-2 is two tenths percent (0.2%) of the Effluent Concentration (EC) limit and if subtracted from, for example, AS-210 Shadow Hills Estates (zero point nine percent (0.9%) of EC), the observed contribution from CCMF at that location is approximately seven tenths percent (0.7%) of the Effluent Limit or a dose potential of 0.35 mrem/year. Tables 4-2 through 4-6 provide tabular data from 1979 through 2009 for each monitoring location. Figures 4-2A through 4-11B provide a graphical presentation of the data for each monitoring location from 1979 through 2009. OV-3 Relocation At the property owner’s request the air sampler at OV-3 was relocated in the fall of 2009. The relocation included electrical service and re-landscaping activities.

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Figure 4-2 Environmental Air and Vegetation

Sampling Locations

4-9

Figure 4-3A Environmental Air

Average Annual natU Concentrations 1979-2009

1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979

1980

1981

1982

1983

1984

1985

1986

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1988

1989

1990

1991

1992

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199419

9519

9619

9719

9819

9920

0020

0120

0220

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0620

0720

0820

09

uCi/m

l

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent Concentration

Figure 4-3B

Environmental Air Average Annual natU Concentrations 1979-2009

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10%

20%

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40%

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70%

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90%

100%

1979

198019

8119

8219

8319

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8619

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8919

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9119

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Years

% o

f EC

AS-202 AS-203 AS-204 AS-206 AS-209


4-10


Average Annual natU Concentrations 1979-2009

1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979198

0198

1198

2198

3198

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6198

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Years

uCi/m

l

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


Figure 4-4B

Environmental Air Average Annual natU Concentrations 1979-2009

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1979198

0198

1198

2198

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AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


4-11

Table 4-2 Environmental Air

Average Annual natU Concentrations 1979-2009 (µCi/ml)

Year AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP #1 LP #2 CC #1 CC #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 1.57E-16 1.73E-16 1.21E-16 2.60E-16

1992 6.55E-17 7.84E-17 1.12E-16 6.48E-17 9.71E-17 6.39E-17 9.40E-17 7.88E-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

2009 7.32E-16 2.62E-16 4.60E-16 2.14E-16 4.35E-16 2.45E-16 2.74E-16 2.20E-16 2.38E-16 2.16E-16

4-12


Average Annual 230Th Concentrations 1979-2009

1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979198

0198

1198

2198

3198

4198

5198

6198

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9199

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1199

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Years

uCi/m

l

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent C

oncentration

Figure 4-5B

Environmental Air Average Annual 230Th Concentrations 1979-2009

0%

50%

100%

150%

200%

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300%

350%

400%

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500%

197919

8019

8119

8219

8319

8419

8519

8619

8719

8819

8919

9019

9119

9219

9319

9419

9519

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0020

0120

0220

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Years

% o

f EC

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent C

oncentration

4-13



1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979198

0198

1198

2198

3198

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6198

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Years

uCi/m

l

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3

Effluent C

oncentration

Figure 4-6B


0%

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1979198

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f EC

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


4-14


Average Annual 230Th Concentrations 1979-2009 (µCi/ml)


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 6.93E-15 1.42E-16 8.17E-17 3.92E-16

1982 2.12E-14 1.94E-14 8.95E-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 1.08E-15 2.06E-16 1.77E-16 9.90E-17

1988 2.58E-15 3.51E-15 5.85E-15 2.05E-15 1.41E-16 1.72E-16 1.70E-16

1989 6.33E-16 3.85E-16 9.17E-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 2.83E-16 1.91E-16 1.29E-16 1.25E-16 1.01E-16 1.33E-16

1992 4.57E-16 2.20E-16 4.71E-16 9.46E-17 6.58E-17 6.39E-17 5.98E-17 6.23E-17 9.56E-17

1993 4.45E-16 3.03E-16 6.42E-16 9.32E-17 1.06E-16 9.17E-17 2.33E-16

1994 1.18E-15 2.96E-16 1.08E-15 1.24E-16 9.20E-16 1.54E-16 1.16E-16 2.83E-16

1995 1.65E-15 5.33E-16 1.24E-15 1.18E-16 8.88E-16 9.80E-17 1.12E-16 3.30E-16

1996 2.21E-15 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 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 3.76E-15 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 4.71E-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 4.15E-15 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 1.25E-15 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 1.40E-15 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 6.57E-16 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 3.41E-15 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 1.40E-15 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 1.05E-15 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

2009 5.74E-16 1.16E-16 3.38E-16 6.92E-17 3.69E-16 1.84E-16 1.45E-16 6.84E-17 4.34E-17 6.04E-17

4-15


Average Annual 226Ra Concentrations 1979-2009

1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

uCi/m

l

AS-202 AS-203 AS-204 AS-206 AS-209


Figure 4-7B Environmental Air


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1979198

0198

1198

219

8319

8419

8519

8619

8719

8819

89199

019

9119

9219

9319

9419

9519

9619

9719

9819

9920

0020

0120

0220

0320

0420

05200

6200

7200

8200

9

Years

% o

f EC

AS-202 AS-203 AS-204 AS-206 AS-209


4-16



1.00E-17

1.00E-16

1.00E-15

1.00E-14

1.00E-13

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

Years

uCi/m

l

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


Figure 4-8B

Environmental Air Average Annual 226Ra Concentrations 1979-2009

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

% o

f EC

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


4-17


Average Annual 226Ra Concentrations 1979-2009 (µCi/ml)


1979 1.55E-15 3.75E-16 7.89E-15 3.07E-16

1980 3.61E-15 7.81E-16 1.62E-15 2.78E-16 1.58E-15

1981 4.19E-15 2.35E-15 2.94E-15 2.96E-15 3.79E-16 4.59E-16 6.30E-16

1982 6.53E-15 6.92E-15 3.81E-15 3.82E-15 6.07E-16 4.02E-16 1.25E-15

1983 2.00E-15 5.08E-15 4.95E-15 2.85E-15 9.42E-17 1.76E-16 5.30E-16

1984 1.11E-15 1.84E-15 3.63E-15 2.20E-15 1.18E-16 1.67E-16 1.87E-16

1985 9.63E-15 1.11E-15 1.78E-15 1.97E-15 1.69E-16 1.88E-16 1.89E-16

1986 1.47E-15 1.98E-15 1.61E-15 2.60E-15 1.43E-16 3.45E-16 2.22E-16

1987 5.91E-16 7.52E-16 1.19E-15 4.74E-16 1.83E-16 1.15E-16 1.89E-16

1988 1.29E-15 2.05E-15 2.53E-15 3.60E-16 1.24E-16 5.09E-17 1.09E-16

1989 2.72E-16 1.81E-16 3.30E-16 4.79E-17 1.02E-16 8.89E-17 7.77E-17

1990 1.75E-16 1.68E-16 1.92E-16 4.36E-17 6.69E-17 8.36E-17 7.82E-17

1991 1.19E-16 1.25E-16 2.68E-16 6.17E-17 6.85E-17 4.33E-17 7.16E-17 6.09E-17 1.37E-16

1992 8.46E-17 7.30E-17 1.50E-15 3.71E-17 5.10E-17 4.60E-17 5.80E-17 4.73E-17 1.17E-16

1993 9.11E-17 1.14E-16 2.49E-16 5.99E-17 6.14E-17 6.72E-17 2.20E-16

1994 1.03E-16 7.57E-17 1.69E-16 4.96E-17 1.55E-16 7.80E-17 8.68E-17 2.64E-16

1995 1.21E-16 1.14E-16 2.07E-16 7.46E-17 2.06E-16 6.88E-17 1.05E-16 3.99E-16

1996 1.78E-16 1.02E-16 2.08E-16 5.33E-17 2.11E-16 5.82E-17 5.22E-17 6.67E-17 3.59E-17

1997 1.29E-16 7.55E-17 2.01E-16 5.66E-17 9.45E-16 1.06E-16 5.09E-17 5.40E-17 4.84E-17

1998 2.89E-16 8.22E-17 2.95E-16 9.43E-17 1.34E-15 1.21E-16 6.21E-17 6.71E-17 4.24E-17

1999 4.18E-16 1.29E-16 3.81E-16 1.02E-16 1.26E-15 1.46E-16 2.13E-16 8.27E-17 9.21E-17 5.90E-17

2000 3.37E-16 1.53E-16 4.64E-16 1.40E-16 2.38E-15 2.21E-16 4.60E-16 7.41E-17 4.64E-17 5.10E-17

2001 2.15E-16 2.09E-16 4.36E-16 1.38E-16 1.92E-15 1.51E-16 1.99E-16 7.01E-17 6.82E-17 5.16E-17

2002 1.55E-16 1.17E-16 2.34E-16 7.51E-17 3.83E-16 1.05E-16 1.14E-16 8.41E-17 6.07E-17 6.72E-17

2003 1.45E-16 1.10E-16 1.75E-16 8.02E-17 2.96E-16 1.23E-16 9.65E-17 9.70E-17 8.40E-17 8.93E-17

2004 7.81E-17 7.35E-17 1.41E-16 6.14E-17 3.30E-16 9.05E-17 8.14E-17 5.79E-17 6.26E-17 4.95E-17

2005 1.78E-16 1.56E-16 1.75E-16 1.97E-16 2.29E-15 2.49E-16 2.95E-16 1.08E-16 1.22E-16 9.58E-17

2006 4.10E-16 1.40E-16 2.17E-16 1.34E-16 7.52E-16 1.69E-16 1.42E-16 1.20E-16 1.03E-16 1.15E-16

2007 8.67E-16 1.11E-16 2.07E-16 1.00E-16 2.31E-16 1.16E-16 9.11E-17 1.09E-16 9.66E-17 1.11E-16

2008 7.92E-16 7.36E-17 2.00E-16 5.16E-17 1.78E-16 7.33E-17 5.71E-17 6.21E-17 5.91E-17 3.28E-17

2009 2.68E-16 8.08E-17 1.38E-16 5.48E-17 9.63E-17 6.62E-17 5.34E-17 6.05E-17 6.63E-17 3.32E-17

4-18

Figure 4-9A

Environmental Air Average Annual 210Pb Concentrations 1979-2009

1.00E-15

1.00E-14

1.00E-13

1.00E-12

197919

8019

8119

8219

8319

8419

8519

8619

8719

8819

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

9920

0020

0120

0220

0320

0420

0520

0620

0720

0820

09

Years

uCi/m

l

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent C

oncentration

Figure 4-9B


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

Years

% o

f EC

AS-202 AS-203 AS-204 AS-206 AS-209


4-19


Average Annual 210Pb Concentrations 1979-2009

1.00E-15

1.00E-14

1.00E-13

1.00E-12

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

Years

uCi/m

l

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


Figure 4-10B


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

Years

% o

f EC

AS-210 AS-212 CC #1 CC #2 LP #1 LP #2 OV-3


4-20


Average Annual 210Pb Concentrations 1979-2009 (µCi/ml)


1979 2.11E-14 1.65E-14 2.08E-14 2.30E-14

1980 1.81E-14 1.69E-14 1.25E-14 1.86E-14 1.98E-14

1981 2.01E-14 1.72E-14 4.71E-14 2.34E-14 1.57E-14 1.70E-14 2.11E-14

1982 3.87E-14 4.35E-14 9.95E-14 4.07E-14 2.50E-14 3.31E-14 4.05E-14

1983 1.70E-14 1.73E-14 1.82E-14 1.95E-14 1.29E-14 1.79E-14 1.44E-14

1984 1.44E-14 1.46E-14 1.60E-14 1.43E-14 1.26E-14 1.15E-14 1.48E-14

1985 9.12E-15 8.12E-15 8.80E-15 9.30E-15 9.97E-15 1.14E-14 9.90E-15

1986 1.26E-14 1.19E-14 1.12E-14 1.22E-14 1.07E-14 1.22E-14 8.81E-15

1987 1.95E-14 1.92E-14 2.22E-14 2.35E-14 2.17E-14 2.01E-14 1.43E-14

1988 2.15E-14 1.94E-14 2.10E-14 1.93E-14 2.04E-14 2.11E-14 1.76E-14

1989 2.28E-14 2.30E-14 1.98E-14 2.34E-14 2.43E-14 2.35E-14 2.40E-14

1990 2.05E-14 2.10E-14 2.07E-14 2.07E-14 2.24E-14 2.00E-14 1.95E-14

1991 2.40E-14 2.15E-14 2.15E-14 2.13E-14 2.23E-14 2.34E-14 2.15E-14 2.33E-14 1.07E-14

1992 2.16E-14 2.00E-14 2.20E-14 2.19E-14 1.99E-14 2.11E-14 1.61E-14 2.05E-14 2.20E-14

1993 2.38E-14 2.35E-14 2.35E-14 2.49E-14 2.22E-14 2.13E-14 2.10E-14

1994 2.21E-14 2.07E-14 2.10E-14 2.24E-14 2.18E-14 2.33E-14 2.38E-14 2.06E-14

1995 2.07E-14 2.07E-14 2.02E-14 2.01E-14 2.11E-14 1.97E-14 2.03E-14 1.74E-14

1996 2.02E-14 2.01E-14 2.16E-14 2.21E-14 2.11E-14 2.08E-14 1.96E-14 1.98E-14

1997 2.21E-14 2.07E-14 2.12E-14 2.20E-14 2.26E-14 2.05E-14 2.13E-14 2.00E-14 1.98E-14

1998 2.01E-14 2.07E-14 1.98E-14 2.11E-14 2.01E-14 1.93E-14 2.01E-14 2.01E-14 1.93E-14

1999 2.14E-14 1.94E-14 1.83E-14 1.84E-14 2.03E-14 1.94E-14 2.03E-14 2.03E-14 1.94E-14 1.78E-14

2000 2.07E-14 2.05E-14 2.01E-14 2.23E-14 2.37E-14 2.00E-14 2.07E-14 2.16E-14 2.08E-14 2.03E-14

2001 3.10E-14 3.04E-14 2.91E-14 3.11E-14 3.06E-14 2.94E-14 3.12E-14 3.06E-14 2.96E-14 2.79E-14

2002 2.36E-14 2.20E-14 2.28E-14 2.25E-14 2.30E-14 2.37E-14 2.40E-14 2.46E-14 2.33E-14 2.17E-14

2003 2.19E-14 2.11E-14 2.16E-14 2.06E-14 2.28E-14 2.12E-14 2.18E-14 2.11E-14 1.94E-14 2.27E-14

2004 1.72E-14 1.64E-14 1.58E-14 1.60E-14 1.66E-14 1.45E-14 1.79E-14 1.56E-14 1.54E-14 1.59E-14

2005 2.45E-14 2.74E-14 2.82E-14 2.54E-14 3.11E-14 2.91E-14 2.92E-14 3.11E-14 3.15E-14 2.94E-14

2006 2.11E-14 2.31E-14 2.47E-14 2.31E-14 2.09E-14 2.08E-14 1.89E-14 1.98E-14 1.89E-14 2.12E-14

2007 1.88E-14 1.64E-14 1.79E-14 1.82E-14 1.54E-14 1.58E-14 1.49E-14 1.66E-14 1.61E-14 1.72E-14

2008 1.65E-14 1.48E-14 1.64E-14 1.93E-14 1.66E-14 1.73E-14 1.57E-14 1.67E-14 1.61E-14 1.61E-14

2009 1.79E-14 1.56E-14 1.81E-14 1.86E-14 1.77E-14 1.75E-14 1.73E-14 1.77E-14 1.68E-14 1.71E-14

4-21



1.00E-18

1.00E-17

1.00E-16

1.00E-15

1.00E-14

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

uCi/m

l

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent C

oncentration

Figure 4-11B


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

% o

f EC

AS-202 AS-203 AS-204 AS-206 AS-209

Effluent C

oncentration

4-22



1.00E-18

1.00E-17

1.00E-16

1.00E-15

1.00E-14

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

uCi/m

l

AS-210 AS-212 CC #2 LP #2 OV-3

Effluent C

oncentration

Figure 4-12B


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

% o

f EC

AS-210 AS-212 CC #2 LP #2 OV-3


4-23


Average Annual 232Th Concentrations 1979-2009 (µCi/ml)

Year AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP #2 CC #2 OV-3

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 5.68E-17

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 4.68E-17

2003 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 3.96E-17

2004 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 2.39E-17

2005 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 3.45E-17

2006 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 3.65E-17

2007 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 3.92E-17

2008 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 2.03E-17

2009 1.46E-17 1.44E-17 2.20E-17 2.35E-17 2.54E-17 2.42E-17 2.85E-17 3.47E-17 2.66E-17 1.25E-17

ENVIRONMENTAL RADON Beginning in the second (2nd) quarter of 2002 combined 220Rn (from natural thorium) and 222Rn (from natural uranium) measurements were conducted at all locations. Radon-220/222 levels measured for 2009 are all higher than for 2008 with the exception of AS-210 Shadow Hills Estates and LP#2 Lincoln Park #2 and indicate a low range of concentrations for all monitors. Figures 4-12 through 4-14 and Table 4-7 show the concentrations for 220Rn/222Rn for 1979-2008 and indicate a similar pattern over time at all locations. This is indicative of natural fluctuations (i.e. background) in the release of 220Rn/222Rn (see discussion above relative to 210Pb monitoring under Environmental Air Particulate). Note that AS-206 is grouped with AS-210 and AS-212 because they use the same equilibrium fraction. As expected, 1979 through 2009 data (tables and figures RN-2 and RN-3) demonstrate slightly elevated readings at boundary locations with readings in residential areas at background levels. Comparison to the CDPHE required equilibrium factors and effluent concentration limits per the CDPHE letter of June 24, 2004 is shown in Table RN-3. Background mean is calculated for 2008 and 2009 as specified in CDPHE letter of June 24, 2004. The Background Mean plus two (2) standard deviations of the Background Mean is added to the Alternate Effluent Limit and compared to the semiannual average results. All locations, showed compliance at less than the Effective Effluent Limit (EEL) for the 2009 reporting period. Note that this is an annual limit. First (1st) quarter data was particularly skewed high for boundary locations as compared to nearby and offsite locations. However, for all locations in the second (2nd) quarter and third (3rd) quarter the data shown are similar. Fourth (4th) quarter data shows a reversal to lower boundary readings versus nearby and background locations. No reason is known for this difference between quarterly data. However, the Quality Control data show differences of at least twenty-five percent (25%). When this uncertainty is taken into account, all readings are in a very narrow band.

4-24

Due to concerns raised by CDPHE in early July when the Secondary Impoundment was allowed to dry in anticipation of starting the initial cover, five (5) additional radon monitors were deployed starting in August and co-located at AS-202, AS-203 and AS-204 as well as new monitors located between AS-202 and AS-203 as well as between AS-203 and AS-204. These results are reported in Table RN-3. Measurements for the third (3rd) quarter were generally similar, while fourth (4th) quarter results were more varied. The semiannual averages for these newly deployed monitors when compared to the existing monitors are all within the QC variability noted above.

Figure 4-13 Environmental Air

Average Annual 222Rn Concentration

0200400600800

10001200140016001800200022002400

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

pCi/m

3 (a

vg)

AS-202 AS-203 AS-204 AS-209

4-25


Average Annual 222Rn Concentration

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

pCi/m

3 (a

vg)

CC LP OV-3

Figure 4-15

Environmental Air Average Annual 222Rn Concentration

0200400600800

10001200140016001800200022002400

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Years

pCi/m

3 (a

vg)

AS-206 AS-210 AS-212

4-26

Table 4-7 222Rn (pCi/m3)

1979-2009 Year AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 CC LP OV-3 1979 420 460 785 707

1980 330 250 240 310 293

1981 380 378 520 970 260 260 395

1982 470 579 1360 923 657 1040 576

1983 916 705 875 1190 419 492 648

1984 610 720 650 850 414 544 895

1985 660 690 820 830 560 470 572

1986 1940 1510 1440 1090 1250 1370 1050

1987 775 675 800 875 775 400 475

1988 525 900 975 775 833 550 450

1989 725 1030 950 525 850 500 500

1990 500 375 500 325 325 375 158

1991 400 450 475 475 475 325 293

1992 725 750 650 500 500 575 475

1993 375 325 375 350 275 250 120

1994 590 580 650 690 980 560 500 540

1995 500 450 580 500 680 450 450 380

1996 680 650 900 780 1030 880 660 700 700

1997 820 720 750 600 800 720 690 720 560

1998 560 500 520 550 920 600 450 430 520

1999 750 725 700 550 1025 850 733 975 725 450

2000 1050 1000 1233 825 1533 1267 1250 1050 900 750

2001 192 375 325 160 350 218 192 192 268 267

2002 543 975 1125 693 1475 700 698 875 673 625

2003 700 825 775 900 625 675 700 375 800 567

2004 1500 850 1025 950 1100 850 925 825 875 825

2005 925 1025 850 700 1025 675 775 700 900 800

2006 1250 1275 1275 1450 1400 1125 1275 1075 1375 1200

2007 1000 1100 1175 1100 1250 975 825 925 1175 975

2008 850 900 925 950 1075 950 850 800 925 825

2009 1050 1075 1175 1025 1275 875 850 900 900 933

4-27

Table 4-8 Alternate Effluent Limit Comparison for 222Rn

2008 – 2009 Background Concentrations (pCi/ m3)

CC LP OV3 Background (BKG)

MEAN

Standard Deviation of

MEAN

BKG + 2 Standard

Deviations of MEAN

2009 Q1 700 600 700 Q2 1000 1100 1100 Q3 1000 1000 1000 Q4 900 1100 900 925 49 1024

2008 Q1 1300 1300 1100 Q2 100 300 200 Q3 900 1100 900 Q4 900 1000 1100 850 120 1091

Assumed Equilibrium

Fraction

Alternate Effluent

Limit

Effective Effluent Limit = Alternate Effluent Limit + BKG + 2

Standard Deviations of MEAN

Average Radon

(including BKG)

Year Sampler Location (pCi/m3) (pCi/m3) (pCi/m3) (pCi/m3) > Effluent Limit? AS 202 0.2 500 1524 1050 no AS 203 0.2 500 1524 1075 no AS 204 0.2 500 1524 1025 no AS 206 0.4 250 1274 1025 no AS 209 0.2 500 1524 1275 no AS 210 0.4 250 1274 875 no

2009

AS 212 0.4 250 1274 850 no AS 202 0.2 500 1591 800 no AS 203 0.2 500 1591 900 no AS 204 0.2 500 1591 1100 no AS 206 0.4 250 1341 1000 no AS 209 0.2 500 1591 1100 no AS 210 0.4 250 1341 900 no

2008

AS 212 0.4 250 1341 900 no

4-28

ENVIRONMENTAL TLD Environmental Thermoluminescent Dosimeters (TLDs) were used in 2009 at the environmental air sampler locations and 1979-2008 readings are displayed in Figures 4-15, 4-16, and Table 4-9. The range of exposure rates is from ten point five (10.5) µR/hr to nineteen point five (19.5) µR/hr. All locations were slightly higher than for 2008. All readings are within range of historical levels. Cañon City (CC-2) has been designated as the local background with a reading of ten point five (10.5) µR/hr which is equivalent to eighty-nine (92) mrem/year (0.92 mSv/y), dose from background external sources. The highest measured gamma level was nineteen point five (19.5) μR/hr (0.2 μGray/hour (μGy/h)) at AS-209, along the mill entrance road. This is a slightly higher than 2008 but generally lower than previous years. The elevated exposure rate may be attributable to past spillage of ore and other materials along the entrance road over time. CCMF commissioned a study by MFG, Inc. entitled Assessment of Potential Dose to Members of the Public from Materials Along Roads Near the Cotter Corporation Canon City Milling Facility for the entrance road and the county road north past the Shadow Hills Golf Club. This report was to CDPHE and the community and demonstrated that the risk to nearby golfers and community residents was well within acceptable regulatory criteria. However, at the request of the Fremont County Independent Outreach Committee (FCIOC) an “As Low As Reasonably Achievable” (ALARA) based soil removal work plan for the entrance road was prepared by MFG, Inc. and was approved by CDPHE. Initial characterization and soil removal along part of the entry road was accomplished in the fall of 2006. Cleanup was completed in 2007. .

4-29


Average Annual Environmental TLD Concentrations 1979-2009

0

5

10

15

20

25

30

35

40

45

50

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

YearsAS-202 AS-203 AS-204 AS-206 AS-209

uR/h

r (a

vg)


Average Annual Environmental TLD Concentrations 1979-2009

0

5

10

15

20

25

30

35

40

45

50

1979198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

AS-210 AS-212 CC#2 LP#2 OV#3

uR/h

r (a

vg)

4-30

Table 4-9 Environmental TLD (µR/hr)

2009 Year AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 CC LP OV3 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 12.3

1982 13.7 12.6 14.7 20.4 9.9 11.2 12.7

1983 13.6 12.6 14.2 15.6 10.6 11.6 12.0

1984 14.5 14.3 14.6 14.8 12.3 11.2 13.2

1985 14.3 13.5 14.5 14.8 10.5 11.2 12.3

1986 13.9 13.7 14.5 14.2 11.0 10.7 11.8

1987 12.9 12.5 12.6 12.6 9.6 9.7 10.4

1988 15.0 13.6 12.8 13.4 9.3 11.6 10.2

1989 14.7 14.9 15.3 15.9 10.6 13.7 11.9

1990 13.2 13.1 14.8 15.2 9.6 11.5 11.7

1991 14.1 13.2 15.7 17.5 10.0 12.9 12.4

1992 13.7 13.2 16.0 18.3 9.6 12.1 11.3

1993 12.5 12.6 14.4 15.6 8.6 10.7 10.9

1994 14.3 13.8 15.9 16.2 27.8 10.8 12.1 12.3

1995 12.5 13.7 14.0 15.4 23.0 9.2 10.3 11.3

1996 13.1 13.2 14.5 16.2 27.2 13.0 9.7 10.9 11.4

1997 12.6 13.1 13.8 15.7 29.1 12.3 9.1 10.2 11.1

1998 12.3 12.0 13.4 15.9 28.0 12.0 9.0 10.3 11.5

1999 12.7 12.0 13.8 16.0 29.6 12.2 9.1 9.3 10.6 10.9

2000 12.7 12.6 14.7 16.6 27.7 12.5 9.3 9.5 10.7 11.4

2001 13.7 14.3 15.4 18.6 26.2 13.9 9.7 10.4 12.0 12.2

2002 14.0 14.4 15.9 17.7 30.3 14.3 10.5 10.5 12.3 12.6

2003 12.8 13.3 14.8 15.5 27.7 13.3 10.0 10.0 11.7 11.8

2004 13.6 14.1 15.5 14.7 25.5 14.2 10.9 10.5 12.2 12.5

2005 12.8 13.5 14.8 13.8 22.9 12.9 9.9 10.1 11.5 11.5

2006 12.7 13.4 14.6 14.2 21.5 12.6 9.5 10.1 11.5 11.7

2007 12.9 13.2 14.6 14.1 17.8 12.7 9.5 10.1 11.5 11.6

2008 13.9 13.5 15.5 14.9 18.7 13.3 10.2 10.8 12.2 12.6

2009 14.2 14.3 16.1 15.9 19.5 13.7 10.5 11.1 12.7 13.2

4-31

METEOROLOGICAL MONITORING The meteorological monitoring station performance was good in 2009. Overall data recovery during 2009 was ninety-eight point ninety-three percent (98.93%), compared to ninety-nine point twenty-five percent (99.25%) in 2008 however as noted below the precipitation data was not accurate. Data for the 2008 and 2009 monitoring periods are shown in Table 4-10 and 4-11. The evaporation system operated from May 5th to October 9th, 2009. Total evaporation during the 2009 monitoring period was forty-three point ninety-nine inches (43.99”), which averages approximately zero point twenty-eight inches (0.28”) per day (one hundred fifty-seven (157) days measured). The average evaporation rate of zero point twenty-eight inches (0.28”) per day is about ten percent (10%) lower than the rate for 2008, but still remained ten percent (10%) higher than years prior to 2008. In 2008, the total precipitation recorded by the meteorological station was five point eighteen inches (5.18”), thus prompting a study to be performed as to the reason for such a low value. Due to a defective rain gauge, the precipitation for 2009 is inaccurate. A new rain gauge was installed in November of 2009. Two (2) Canon City monitoring stations, one (1) the KRLN radio station and another monitor utilized by the “Weather Underground” website had annual precipitation of fifteen point sixty-one (15.61) inches and sixteen (16) inches respectively. Onsite observations using a manual precipitation gauge show approximately twenty-six (26) inches for 2009 with over seven (7) inches recorded in July 2009. Based on site erosion and water retained at the SCS Dam and pumped back to the Primary Impoundment (approximately twenty-five (25) acre feet – ten (10) million gallons) this seems quite possible. The 2009 annual Wind Rose was generated based on eight thousand seven hundred sixty (8,760) hours of wind data. The 2009 Wind Rose (Figure 4-18) indicates that the winds were predominantly westerly with a smaller easterly component and can be compared to the 2008 Wind Rose (Figure 4-17). The westerly (SW to NW) winds comprised fifty-three percent (53%) of the total winds whereas the easterly (NE to SE) winds comprised approximately twenty-six percent (26%) with the remaining twenty-one percent (21%) of the winds distributed over the southerly and northerly directions. The calm winds less than four miles per hour (<4.0 mph) comprised twenty point eight percent (20.8%) of the hourly readings. Wind speed averages reaching as high as a Class 6 rating greater than twenty-four point seven miles per hour (>24.7 mph) ) occurred only zero point zero one percent (0.01%) of the time. The wind speed averages ranged from zero point zero (0.0) to twenty-four point nine miles per hour (24.9 mph). The winds occurred at approximately the same speeds and frequency as in previous years. Winds in the Class 2 (4.0-7.5 mph) and the Class 3 (7.5-12.1 mph) ranges accounted for approximately sixty-six percent (66%) of the winds in 2009. The Wind Rose data for 2009 is very similar to 2008.

4-32

Table 4-10

2008 Meteorological Summary

WS mph

WD Deg

AT Deg-F

RH %

RN inch

BP inHg

Average 7.70 53.4 40.7% 24.43 Total 5.18 Max 24.6 94.9 96.8% 24.96 Min 0.0 -0.7 2.4% 23.76

% recovery 100% 100% 100% 100% 100% % recovery total 99.25%

East winds 25.80% west winds 54.6%

Evaporation Total inches 62.60 (April 8th to October 24th)

Table 4-11 2009 Meteorological Summary

WS mph

WD Deg

AT Deg-F

RH %

RN inch

BP inHg

Average 7.49 52.8 43.2% 24.44 Total * Max 24.9 93.6 95.9% 24.82 Min 0.0 -5.2 2.4% 23.83

% recovery 99% 99% 99% 99% 99% % recovery total 98.93%

East winds 26.04% west winds 53.4%

Evaporation Total inches 43.99 (May 5th to October 9th)

KEY: WS = Wind Speed WD = Wind Direction AT = Air Temperature RH = Relative Humidity RN = Rainfall BP = Barometric Pressure

4-33

Figure 4-18 Wind Rose Plot 2008

4-34

Figure 4-19 Wind Rose Plot 2009

4-35

VEGETATION Vegetation samples were collected three (3) times during the growing season in 2009. Vegetation samples were predominantly comprised of natural browse grass and were collected at the locations shown in Section 4 of this report (Figure 4-1). Sampling protocol and location selection criteria was modified in 2005 to comply with changes in the vegetation sampling procedure. Sample locations since 2005 were chosen based on the highest predicted levels of deposition as determined by MILDOS computer modeling. Samples for 2009 were analyzed for natU, 230Th, 226Ra, 210Pb, 232Th and Molybdenum. (Table 4-12 thru 4-17and Figures 4-19 and 4-24) Note that comparisons are made to historical results from the sampled locations as well as other locations. Please check the footnotes for clarity. CDPHE, in reviewing the 2008 report, requested an evaluation of the data variability and of the sampling procedure. Cotter provided a response in a December correspondence to CDPHE which was subsequently accepted by CDPHE. No change in sample procedure was deemed necessary. Vegetation samples are not washed prior to analysis; therefore, results may reflect the presence of dust on the plant material. Variability in sample concentrations can generally be attributed to plant growth, plant species variability, and precipitation. The analytical results for 2009 are generally lower than 2008 and when compared to the range of historical sample results at these and other comparable locations.

• The highest 2008 natU concentration was sixty-one (61) pCi/kg (2.3 Bq/kg) at AS-209 (Mill Entrance Road). The lowest 2008 natU concentration was three (3.0) pCi/kg (0.11 Bq/kg) and was measured at AS-212 (Nearest Resident). Sample results are within the historical range of samples collected at these and nearby locations.

• The highest 230Th concentration was one hundred fifty-four (154) pCi/kg (5.7 Bq/kg) at the AS-209 (Mill Entrance Road). The lowest concentration was eighteen (18) pCi/kg (0.7 Bq/kg) at AS-212 (Nearest Resident).

• The highest 226Ra concentration was one hundred thirty-four (134) pCi/kg (5.0 Bq/kg); at the AS-209 (Mill Entrance Road). The lowest concentration was twenty-five (25) pCi/kg (0.9 Bq/kg); at the AS-212 (Nearest Resident).

• The highest 210Pb concentration was three hundred ninety (390) pCi/kg (14.4 Bq/kg); at the AS-212 (Nearest Resident). The lowest 210Pb concentration was one hundred fifty (150) pCi/kg (5.6 Bq/kg); at the AS-209 (Mill Entrance Road).

• The highest 232Th concentration measured in 2009 was eight (8) pCi/kg (0.3Bq/kg); at the AS-204 (West Boundary). The lowest concentration measured was one (1) pCi/kg (0.04 Bq/kg) at the AS-212 (Nearest Resident).

• The highest Molybdenum concentration measured in 2009 was twenty-seven (27) mg/kg at the AS-209 (Mill Entrance Road). The lowest molybdenum concentration measured was two point one (2.1) mg/kg at the AS-202 (East Boundary) and AS-212 (Nearest Resident). The 2009 results are near the historical range of samples collected at these and nearby locations.

4-36

Table 4-12

natU Vegetation (pCi/kg)

Sample Date Historical

Range

Location 6/9/2008 7/21/2008 8/8/2008 06/12/09 07/06/09 08/25/09 1995 - 2007

Alkali Gap SW of Mill -------- -------- -------- -------- -------- -------- ------ -------

AS-202 East Boundary 74.47 66.4 216.6 19 45.5 16.5 4.1 284

AS-210 Golf Course -------- -------- -------- -------- -------- -------- 5.4 108.3

AS-209 Mill Entrance Rd 61.1 45 94.8 24.3 61.1 40.8 4.1 406.2

AS-212 Nearest Resident 54.4 13.9 17.5 9.7 21.9 3 1 237

AS-204 West Boundary -------- -------- -------- -------- -------- -------- 13 21

Figure 4-20 natU Vegetation Sample

(pCi/kg)

0

100

200

300

400

500

600

700

800

900

1000

6/9/2008

7/21/2008

8/8/2008

6/12/2009

7/6/2009

8/25/2009

pCi/k

g

Alkali Gap SW of Mill AS-202 East Boundary AS-204 West Boundary AS-209 Mill Entrance Rd AS-210 Golf Course AS-212 Nearest Resident

4-37

Table 4-13 230Th Vegetation

(pCi/kg)


Range Location 6/9/2008 7/21/2008 8/8/2008 6/12/09 7/6/09 8/25/09 1988 - 2007

AS-210 Golf Course -------- -------- -------- -------- -------- -------- 2.7 134

AS-209 Mill Entrance Rd 127 127 262 62 154 144 25 322

AS-202 East Boundary 119 97 395 36 94 36 12.8 395

AS 204 West Boundary -------- -------- -------- -------- -------- -------- 17 54


AS-212 Nearest Resident 94 26 35 32 73 18 1 131

Figure 4-21

230Th Vegetation Samples (pCi/kg)

0

100

200

300

400

500

600

700

800

900

1000

6/9/087/21/0

88/8/08

6/12/2009

7/6/2009

8/25/2009

pCi/k

g

Alkali Gap SW of Mill AS-202 East Boundary AS 204 West Boundary AS-209 Mill Entrance Rd AS-210 Golf Course AS-212 Nearest Resident

4-38

Table 4-14

226Ra Vegetation (pCi/kg)


Range

Location 6/9/2008 7/21/2008 8/8/2008 6/12/2009 7/6/2009 8/25/2009 1995 - 2007

AS-210 Golf Course -------- -------- -------- -------- -------- -------- 3 112


AS-202 East Boundary 103 87 371 47 51 49 2 371

AS 204 West Boundary -------- -------- -------- -------- -------- -------- 24 37



Figure 4-22 226Ra Vegetation Sample

(pCi/kg)

0

100

200

300

400

500

600

700

800

900

1000

6/9 /087 /21/0

88 /8 /08

6 /12/2009

7 /6 /2009

8/25/2009

pCi/k

g

Alkali Gap SW of Mill AS-202 East Boundary AS 204 West Boundary AS-209 Mill Entrance Rd AS-210 Golf Course AS-212 Nearest Resident

4-39

Table 4-15 210PbVegetation

(pCi/kg)


Range

Location 6/9/2008 7/21/2008 8/8/2008 6/12/2009 7/6/2009 8/25/2009 1988 - 2007


AS-202 East Boundary 997 378 1566 160 260 160 28 997

AS 204 West Boundary -------- -------- -------- -------- -------- -------- 58 79


AS-210 Golf Course -------- -------- -------- -------- -------- -------- 41 831


Figure 4-23 210Pb Vegetation Sample

(pCi/kg)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

6/9/08

7/21/08

8/8/08

6/12/2009

7/6/2009

8/25/2009

pCi/k

g

Alkali Gap SW of Mill AS-202 East Boundary AS 204 West Boundary AS-209 Mill Entrance Rd

AS-210 Golf Course AS-212 Nearest Resident

4-40

Table 4-16 232Th Vegetation

(pCi/kg)


Range

Location 6/9/2008 7/21/2008 8/8/2008 6/12/09 7/6/09 8/25/09 1988 - 2007

AS-210 Golf Course -------- -------- -------- -------- -------- -------- 0 1.3


AS-202 East Boundary 8 6 16 2 8 2 0 16

AS 204 West Boundary -------- -------- -------- -------- -------- -------- 1 1

Alkali Gap SW of Mill -------- -------- -------- -------- -------- -------- 0 1.7


Figure 4-24 232Th Vegetation Sample

(pCi/kg)

0

100

200

300

400

500

600

700

800

900

1000

6/9/08

7/21/08

8/8/08

6/12/2009

7/6/2009

8/25/2009

pCi/k

g



4-41

Table 4-17 Molybdenum Vegetation

(mg/kg)


Range Location 6/9/2008 7/21/2008 8/8/2008 06/12/09 07/06/09 08/25/09 1979-2006


AS-202 East Boundary 4.8 2.1 4.3 11 1.5 2.6 0.54 879

AS 204 West Boundary -------- -------- -------- -------- -------- -------- 23 26

AS-209 Mill Entrance Rd 30 15 28 10.2 14 27 0.6 62

AS-210 Golf Course -------- -------- -------- -------- -------- -------- 0.5 41

AS-212 Nearest Resident 4.9 1.8 1.8 4.4 2.6 5.9 0.3 6

Figure 4-25 Molybdenum Vegetation

(mg/kg)

0

100

200

300

400

500

600

700

800

900

1000

6/9/2008

7/21/2008

8/8/2008

6/12/2009

7/6/2009

8/25/2009

mg/

kg



4-42

SOILS Soils collected in 2009 continue to show variability as expected based on historical levels. All of the samples showed levels within the historical range of concentrations although several are at historical highs. Samples have been historically analyzed for natU, 230Th, 226Ra, and Molybdenum. Thorium-228 and 224Ra are being reported for the fourth (4th) time. (Tables 4-18 thru 4-25 and Figures 4-25 thru 4-32)

• Natural uranium concentrations ranged from one point nine (1.9) pCi/g (0.07 Bq/g) AS-206 (North Boundary) to seven point four (7.4) pCi/g (0.3 Bq/g) AS-204 (West Boundary).

• Thorium-230 concentrations ranged from one point nine (1.9) pCi/g (0.07 Bq/g) at LP-2 (Lincoln Park #2) to 29.5 pCi/g (1.1 Bq/g) AS-210 (Shadow Hills Estates).

• Radium-226 concentrations ranged from one (1.0) pCi/g (0.04 Bq/g) at AS-206 (North Boundary) to seven point eight (7.8) pCi/g (0.29 Bq/g) at AS-202 (East Boundary). These sample results are within the range of historical sample results. Note: 2005 Radium data was not reported based on QA analysis.

• Thorium-232 concentrations ranged from seven tenth (0.7) pCi/g (0.03 Bq/g) AS-202 (East Boundary) one point five (1.5) pCi/g (0.06 Bq/g) at LP-2 (Lincoln Park #2). These sample results are within the range of historical sample results. There appears to be no difference between on-site, nearby, and off-site concentrations which suggests that these are all background values.

• Thorium-228 concentrations ranged from eight tenths (0.8) pCi/g (0.03 Bq/g) at AS-202 (East Boundary) to one point five (1.5) pCi/g (0.06 Bq/g) at LP-2 (Lincoln Park) and AS-203 (South Boundary). All other sampler locations were between nine tenths (0.9) pCi/g (0.03 Bq/g) to one point two (1.2) pCi/g (0.04 Bq/g). This appears to be background range.

• Radium-224 concentrations ranged from (nine tenths) 0.9 pCi/g (0.03 Bq/g) at AS-202 (East Boundary) and Canon City (CC-2) to one point four (1.4) pCi/g (0.5 Bq/g) at AS-210 Shadow Hills Estates and OV-3 OroVerde #3. This appears to be background range.

• Molybdenum results ranged from less than two tenths (<0.2) µg/g at OV-3 Oro Verde #3 to six point one (6.1) µg/g at AS-204 (West Boundary) has historically shown the highest level.

4-43

Table 4-18 Uranium Soil

(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate

AS-212 Nearest Resident

OroVerde #3

Lincoln Park #2

Canon City #2

1979 6.4 3.4 3.2

1980 1.7 1.4 3.5 3.5 3.1

1980 7.3 4.3 14.5 4.3 7.8

1981 4.9 2.7 5.3 1.6 2.6

1982 1.1 0.2 1.1 <0.001 <0.001 <0.001 <0.001

1983 1.2 2 2.1 2.2 27 2.4 2

1983 3.6 2.1 3 9.8(21)* 1.8 1.9 6.6(4.2)*

1984 4.1 2.9 2.6 2.8 2.3 1.7 2.5

1985 2.3 2.3 3.2 4 2.3 2.3 2.3

1986 5.7 3.2 5 6.3 3.3 5.6 3.7

1986 0.9 1.3 2.2 3.2 0.9 3 1.4

1987 1.5 1.9 1 5.9 1.4 0.7 4.3

1988 3 3.2 3.2 5 2.6 3.7 3.2

1989 1.3 1.5 7.4 1.3 1.1 1.3 1.1

1989 0.5 1.6 3.7 0.7 0.9 2 0.6

1990 2.2 2.9 2.6 2 2.6 2.7 3.3

1991 3.7 1.8 4.1 5.1 7.7 1.7 1.7

1992 2.2 2.4 23.8 2.4 2.8 2.6 3.2

1992 1.9 1.8 5 0.8 1.4 1 0.9

1993 3.2 1.9 7.3 2.8 1.4 1 1.6

1994 3.1 2.7 4.9 1.8 14.9 2.3 2.3 2.2

1995 9.5 2.7 3.5 1.6 4.1 2 2 1.2

1996 2.6 2.8 4.9 1.6 4.9 7.4 2.2 2 2.2

1997 2.4 1.3 3.9 0.8 19.6 6.3 2.2 1.4 2.6

1998 5.5 2.7 3.2 1.4 6 6.4 2.4 2 3

1999 2 1.8 2.4 2 13.5 7.4 3.1 3 2 3.9

2000 7.4 3.9 6 1.7 67.7 8.1 5.3 1.2 2.6 1.8

2001 6 2.8 2.4 1.6 28.4 4.2 2.7 1.8 2.4 1.7

2002 3.2 3.3 20 2.4 73.6 6.4 5.8 2.8 2.6 2.4

2003 5.5 3.5 8.1 3.6 19.6 7.4 2 1.8 2.2 2.4

2004 12 4.8 8.2 1.6 56 10 13 2.1 2.7 1.9

2005 1.2 2 15.4 0.8 28.8 6.8 4.7 0.9 0.9 0.5

2006 3.9 2.0 3.3 1.4 12.2 7.4 3.2 1.9 1.4 0.4

2007 4.5 4.0 5.6 2.2 39.9 8.8 3.6 2.2 1.8 1.6

2008 7.1 3.7 9.4 3.9 7 10 5.5 2.9 3 3.2 2009 6.4 2.7 7.4 1.9 3.7 6.8 3.7 2.2 2.3 2.4

4-44

Figure 4-26

Uranium Soil

0

100

200

300

400

500

1979198

0198

0198

1198

2198

3198

3198

4198

5198

6198

6198

7198

8198

9198

9199

0199

1199

2199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

pCi/G

AS-202 East Boundary AS-203 South Boundary AS-204 West Boundary AS-206 North BoundaryAS-209 Mill Entrance Road AS-210 Shadow Hills Estate AS-212 Nearest Resident Canon City #2Lincoln Park #2 OroVerde #3

4-45

Table 4-19 230Th Soil

(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1996 8.3 13 18.6 1.2 14.3 26.5 1.6 1.2 2.1 1997 22.6 5.9 23.4 1.9 125.3 48.3 2.1 1.7 1.8 1998 19.5 11.9 7 2 26 78 2.6 1.9 2.7 1999 21.2 6 22.1 1 40 38.4 3.3 2.6 1.9 4.1 2000 23.3 15.9 6.4 3 134 30.6 9.8 2 2.7 2.4 2001 21.7 11.5 3.5 2.5 88.7 17.8 5.6 1.4 2.7 3.5 2002 9 11.5 53.8 4.2 354 30.8 9.8 3.2 2.6 2.9 2003 14.5 7.4 13.9 2.2 85.5 35.2 3.4 1.1 1.8 1.2 2004 25 10 14 1.2 177 10 20 0.4 1.2 0.7 2005 4.7 14.4 61.2 2.0 123.0 52.7 18.3 1.3 1.5 1.6 2006 26.2 9.1 9.3 2.4 41 79.6 10.7 2.9 2.8 2.4 2007 10.8 14.6 12.6 2.7 159 58.8 6.1 1.7 1.7 1.9 2008 17.3 6 22.8 2.4 11.9 53.2 6.3 1.7 2.1 2 2009 19.7 9.9 28.2 2.3 6.9 29.5 6.9 1.8 1.9 3.3

Figure 4-27

230Th Soil

0

50

100

150

200

250

300

350

400

450

500

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

pCi/G

AS-202 East Boundary AS-203 South Boundary AS-204 West BoundaryAS-206 North Boundary AS-209 Mill Entrance Road AS-210 Shadow Hills EstateAS-212 Nearest Resident Canon City #2 Lincoln Park #2OroVerde #3

4-46


(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1996 1997 1998 1999 2000 2001 1.3 1.4 1 1.3 1.9 1.9 1.1 1.4 1.8 1.3 2002 1.2 1.6 1.6 1.9 7.9 1.8 1.1 1.4 1.8 1.6 2003 0.7 1.5 1.3 1.4 2.4 1.4 1 0.9 1.4 1.4 2004 0.7 1 1.2 1.1 1.7 1.1 0.7 0.9 1.1 0.5 2005 0.5 1.4 1.1 1.1 1.3 1.2 1.0 1.2 1.5 1.0 2006 0.9 1.3 1 1.1 1.2 1.3 0.9 1.4 1.9 1.3 2007 0.8 1.2 0.8 1.2 1.2 1.2 0.8 1.1 1.6 0.9 2008 0.8 1.4 1 1.1 1.1 1.1 1 1.2 1.4 1.2 2009 0.7 1.4 1.1 1.0 1.2 1.3 0.8 1.1 1.5 1.2

Figure 4-28

232Th Soil

0102030405060708090

100

19961997

19981999

20002001

20022003

20042005

20062007

20082009

pCi/G


4-47


(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 0.6 1.1 1.0 1.3 0.9 1.3 1.1 1.3 1.9 1.2 2007 0.7 1.4 0.7 1.1 1.2 1.3 0.9 1.1 1.6 1.4 2008 0.8 1.4 1.2 1.4 1.2 0.9 1.0 1.1 1.5 0.9 2009 0.8 1.5 1.2 1.0 1.2 1.1 0.9 1.3 1.5 1.3

Figure 4-29

228Th Soil

0102030405060708090

100

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

pCi/G

AS-202 East Boundary AS-203 South Boundary AS-204 West BoundaryAS-206 North Boundary AS-209 Mill Entrance Road AS-210 Shadow Hills EstateAS-212 Nearest Resident Canon City #2 Lincoln Park #2

4-48

Table 4-22 226Ra Soil

(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2 Canon City #2

1979 13.3 1.9 2.4 1980 3.2 1.6 5.1 2.4 4.4 1980 6.9 2.4 4.1 1.4 1981 5.2 2.6 3.7 1.1 1.6 1982 3.5 <0.5 <0.5 <0.5 <0.5 <0.5 0.5 1983 2.2 2.5 2.1 4.7 0.8 1.6 1 1983 4 4.8 2.8 12(5.2)*(2.6)+ 1 1.2 9.8(10)*(1.1)+ 1984 7.3 2.2 2 3.2 1.6 2 1 1985 3 1.9 2.4 4.4 1.2 1.5 1.2 1986 3.3 1.2 4.6 6.8 1.4 1.7 1.8 1986 0.7 2.8 4 8.5 1 4.5 1.4 1987 0.5 0.5 1.1 2.2 0.8 0.8 2.3 1988 1.3 1.2 0.9 3.1 0.7 0.8 0.6 1989 2 2.7 7.7 1.4 1.3 1.6 1.2 1989 2.2 5.6 5.9 1.3 1.4 2 1.3 1990 2 4.9 2.1 0.9 1.5 1.7 1.5 1991 5.4 4.2 6.3 1.5 1.6 1.9 1.7 1992 1.5 3.7 18.1 1.6 1.4 1.4 2.4 1992 3.9 4.1 11.7 1 1.3 1.3 1.1 1993 10 1.9 9.1 1 1.3 0.4 1 1994 4.7 3.5 4.2 2.6 10.8 1.3 1.8 1.2 1995 15.3 4.2 4.3 1.1 3.2 1.2 1.6 1.3 1996 3.9 8.5 6.1 1.2 3.6 3.3 1.3 1.2 1.3 1997 12.3 3.4 8.3 1.6 21.9 6.6 1.8 1.4 1.5 1998 10.8 5.6 3.1 1.3 7.3 7.2 1.2 1.5 1.8 1999 10 3.1 9.3 1.4 11 3.8 1.4 1.4 0.7 1.4 2000 12.3 9.5 2 1.5 24 5.1 3 1.3 1.7 1.3 2001 10.5 6.3 1.5 1.5 18.7 2.9 2.1 1.5 2.3 1.4 2002 4.2 4.1 11.5 1.2 53.5 3.5 3 1.3 1.5 1.3 2003 7.6 4.1 3.8 1.4 17.9 4.1 1.4 1 1.2 1 2004 13 6.8 5 1.5 36 4.1 7.5 1.5 1.8 1.5 2005 ** ** ** ** ** ** ** ** ** ** 2006 11.0 4.6 3.3 1.6 9.1 5.8 3.0 1.5 1.8 1.3 2007 4.6 7.3 3.6 1.3 26.5 5.2 2 1.3 1.1 1.2 2008 8.6 3.7 5.8 1.6 3.9 3.8 2.5 1.2 1.2 1.1 2009 7.8 4.5 7.2 1.0 2.2 4.0 2.3 1.2 1.4 1.4

*Reanalysis January 24, 1984 +Resampled January 24, 1984 ** Sample results not reported based on QA analysis

4-49

Figure 4-30 226Ra Soil

0

50

100

150

200

250

300

350

400

450

500

1979198

0198

0198

1198

2198

3198

3198

4198

5198

6198

6198

7198

8198

9198

9199

0199

1199

2199

2199

3199

4199

5199

6199

7199

8199

9200

0200

1200

2200

3200

4200

5200

6200

7200

8200

9

pCi/G


4-50

Table 4-23 224Ra Soil

(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 -4.3 -1.5 -3.4 -5.7 -4.1 -2.6 -3.6 -0.9 0.3 -3.0 2007 -2.1 -1.6 -5.4 -3.6 -3.2 1.4 -0.4 -2.1 -1.4 2.6 2008 0.6 1.2 1.3 1.2 0.8 1.0 0.7 0.9 1.2 1.0 2009 0.9 1.1 1.1 1.3 1.1 1.4 1.2 1.4 1.3 0.9

Figure 4-31

224Ra Soil

-6

94

194

294

394

494

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

pCi/G


4-51

Table 4-24 Molybdenum Soil

(µg/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1992 4.3 5.7 3.4 3.2 5.2 3.6 <1.25 1992 6.3 5.9 54.0 <2.50 3.1 <2.50 <2.50 1993 11.6 5.2 220.0 <1.05 <2.05 <2.50 <2.50 1994 6.9 2.5 22.0 <1.14 18.0 <1.30 <1.34 <1.00 1995 20.0 5.9 76.0 2.1 6.2 3.1 2.2 3.9 1996 3.9 2.3 55.0 2.4 3.8 <1.25 <1.25 <1.25 <1.25 1997 <1.25 <1.25 48.0 2.0 30.0 10.0 <1.25 <1.25 <1.25 1998 15.0 8.0 35.0 <1.25 13.0 5.6 2.7 4.6 1.6 1999 3.5 3.6 85.0 <1.2 10.8 2.4 2.3 <1.2 <1.2 1.5 2000 2.5 1.3 20.0 <1.25 13.0 1.4 1.6 <1.25 <1.25 1.7 2001 3.6 2.7 2.9 1.9 3.3 2.4 2.7 2.0 1.9 1.8 2002 3.0 4.4 251.3 2.6 138.5 4.4 9.5 1.8 2.1 1.8 2003 5.8 5.2 120.0 3.3 26.0 4.7 3.7 2.5 2.5 2.7 2004 11.0 3.2 95.0 0.8 43.0 2.9 16.0 1.1 1.2 1.4 2005 2.4 2.9 217.0 1.2 42.2 4.5 42.4 0.6 1.1 0.9 2006 5.6 <5 6.7 <5 13.0 12.0 9.3 <5 <5 <5 2007 <2.4 <2.4 12.0 <2.4 14.0 <2.4 <2.4 <2.4 <2.4 <2.4 2008 9.8 4.3 32.2 3.6 5.9 6.2 8.0 <2.2 3.5 3.2 2009 2.0 2.0 6.1 1.9 0.3 1.5 2.2 <0.02 2.0 <0.3

Figure 4-32

Molybdenum

0

50

100

150

200

250

300

350

400

450

500

1992

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

ug/g


4-52

Table 4-25 210Pb Soil

(pCi/g)

Year

AS-202 East

Boundary

AS-203 South

Boundary

AS-204 West

Boundary

AS-206 North

Boundary

AS-209 Mill

Entrance Road

AS-210 Shadow

Hills Estate


OroVerde #3

Lincoln Park #2

Canon City #2

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 9.0 4.8 3.8 2.5 8.7 6.8 4.2 3.0 3.7 3.5 2007 3.6 6.1 3.7 1.6 19.9 4.5 1.9 1.2 1.5 1.3 2008 6.2 3.3 6.2 1.7 3.1 4.6 2.6 1.9 2.2 1.5 2009 6.7 4.6 7.7 1.5 2.6 4.4 3.3 2.9 1.5 1.8

Figure 4-33

210Pb

0

50

100

150

200

250

300

350

400

450

500

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

pCi/G


4-53

NEW ANALYTICAL AND TECHNICAL CAPABILITIES In the fourth (4th) quarter of 2009, Cotter gained a number of additional analytical capabilities to further support the company’s environmental and occupational health physics programs. To date, these new capabilities have proved beneficial for guiding, assessing, and documenting soil cleanup progress in nearly real time. In the future, these capabilities are expected to be highly advantageous for planning important aspects of decommissioning projects including determination of criteria required to meet regulatory standards, design and implementation of MARSSIM surveys, and performing ALARA assessments to plan remedial projects in a manner that maximizes radiological protection for workers, the public, and the environment. These new capabilities include the following:

• A measurement system for direct and rapid estimation of 226Ra concentrations in soil samples. The system includes a lead-shielded gamma counting well and conventional gross gamma counting instrumentation (Ludlum 2350 rate meter and 44-10 NaI detector). The method is a modification of a published gamma spectroscopy approach (Whicker et al. 2006) that relies on a calibration developed from gross gamma measurements versus known 226Ra concentrations in secondary soil reference material standards. This gross gamma based screening technique has demonstrated generally reliable results when compared to analytical results from a commercial laboratory using state-of-the-art HPGe-based gamma spectroscopy systems.

• A GPS-based gamma scanning system and field mapping software to provide high-density characterizations of existing gamma fields across areas both small (e.g. less than one acre) and large (e.g. up to thousands of acres) which are automatically recorded for real-time documentation and assessment. This system has been leased from Tetra Tech Incorporated (Fort Collins, CO) and can be mounted on backpacks for walking surveys or on all terrain vehicles for surveying larger areas. The system has been described in several scientific publications (Johnson et al., 2006; Meyer et al., 2005a and 2005b), and can be used alone or in conjunction with gamma/soil 226Ra correlations (Whicker et al., 2008) to meet various project objectives.

• Randy Whicker was hired by Cotter in September, 2009 to provide additional environmental and occupational Health Physics support at the Canon City Mill. He was also assigned as Radiation Safety Officer and Environmental Coordinator for Cotter’s Schwartzwalder Mine in Jefferson County, Colorado. Mr. Whicker has a Master’s Degree in Radiological Health Sciences from Colorado State University, and is qualified by training and experience to perform RESRAD assessments, MARSSIM surveys, and other types of radiological characterizations and analyses. His RESRAD capabilities include dose assessment and contaminant transport modeling using RESRAD, RESRAD OFFSITE, and RESRAD BUILD. He has also designed and performed MARSSIM surveys or other types of environmental assessments at several conventional uranium mills as well as numerous in-situ recovery sites. Bringing these capabilities in house is expected to help Cotter with future decommissioning and operational activities.

4-54

References Whicker, R.; Whicker, M.; Johnson, J.; Meyer, B. 2006. Mobile soils lab: on-site radiological analysis supporting remedial activities. 2006. Health Physics (Operational Radiation Safety supplement), Vol. 91, No. 2. August 2006. Whicker, R.; Cartier, P.; Cain, J.; Milmine, K.; Griffin, M. 2008. Radiological Site Characterizations: Gamma Surveys, Gamma/Ra-226 Correlations and Related Spatial Analysis Techniques. Operational Radiation Safety, Health Physics, Vol. 95 (Supplement 5): S180-S189; November, 2008. Johnson, J.A. Meyer, H.R., and Vidyasagar, M. 2006. Characterization of Surface Soils at a Former Uranium Mill. Operational Radiation Safety. Supplement to Health Physics, Vol. 90, February, 2006. Meyer, R.; Shields, M.; Green, S. 2005a. A GPS-based system for preliminary or remedial action gamma scanning. American Nuclear Society Topical Meeting on Decommissioning, Decontamination, & Reutilization. Denver, Colorado, August 7-11, 2005.

Meyer, R.; Shields, M.; Green, S.; Johnson, J. 2005b. A GPS-based system for radium/uranium contamination gamma scanning. Uranium Mining and Hydrogeology IV. Broder J. Merkel, Andrea Hasche-Berger (Editors). Uranium in the Environment, conference proceedings, Freiberg, September 2005. RADON FLUX - TAILINGS IMPOUNDMENTS Radon Flux measurements for the Primary Impoundment were conducted in June 2009 with the resulting flux of thirteen point four (13.4) pCi/m2-s compared to the 2008 flux of nineteen point seven (19.7) pCi/m2-s versus the National Emission Standard for Hazardous Air Pollutants (NESHAPS) standard of twenty (20) pCi/m2-s. The 2009 report was filed with the Environmental Protection Agency (EPA). When the 2008 Primary Impoundment preliminary results were received, Cotter initiated a program to cover the most highly elevated areas as an ALARA function. Approximately eight thousand eight hundred (8,800) cubic yards of soil cover averaging four (4) feet in depth was placed on approximately one (1) acre in the northwest corner of the exposed tailings beach encompassing tailings beach locations TB 69-72. This was completed in the latter part of 2008 and early 2009. The combination of these remedial activities and slightly more water covered area (about three (3) acres) resulted in the reduced average radon flux. For the Secondary Impoundment, the June 2008 sampling was conducted as an ALARA function and not for compliance with NESHAPS. The resulting measurements indicated a reading of fourteen (14) pCi/m2-s This result is the same (fourteen (14) pCi/m2-s) as the readings which were taken in October 2007 after remedial ALARA actions were taken to reduce the flux of twenty-three point four (23.4) pCi/m2-s as measured in July 2007. The Secondary Impoundment was not sampled in 2009.

4-55

Figure 4-34 Average Calculated Mean Radon Flux

for the Primary and Secondary Impoundment 1999-2009

0

5

10

15

20

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

pCi/m

2 -s

Primary Impoundment Secondary Impoundment NESHAPS Standard

ALARA

ALARA

LAND USE (LC 28.8) Land use changes within a five (5) mile radius of the Cotter mill, southwest of Cañon City, Colorado, were investigated. The complete report is provided in Appendix A. Economic and developmental growth in the area is most directly impacted by availability of water, employment opportunity and fuel costs. Whereas the area water shed and cost of fuel seems to be within normal ranges for calendar year 2009, the local economic picture remains bleak. Local unemployment rates continue to rise, while average weekly wages are unstable with periodic decreases. Local sales tax collections, both Cañon City and Fremont County continue the decline that began in 2006. Even with the record Royal Gorge Bridge tourism attendance for 2009, taxes, tourism dollars and tourism employment opportunity were not able to make up for the decline in primary jobs and wages. Employment opportunities in the correctional industry were steady in 2009 but show promise for 2010 with state employment freeze over and opening of new state correctional facility. The construction industry continued the decline that began in 2006 with no indication of leveling off. Overall demographics indicate a net growth in Fremont County of two hundred seventy-three (273) individuals. Bearing in mind that the intent of LC 28.1.1.10 is to “address changes in land use, local demographic trends, possible factors contributing to land use trends and efforts by Cotter Corporation to mitigate the impact of the mill’s operation on local governments and socioeconomic conditions”; personnel and ongoing facility activities make a positive contribution to the local and area economy.

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