Table 1 - Maximum Site-Related Surface Water Contamination Found at the FMC or J.R. Simplot Facilities, Eastern Michaud Flats Contamination National Priorities List Site, Pocatello, Bannock County, Idaho

Contaminant

Maximum Concentration at the FMC Facility

Maximum Concentration at the J.R. Simplot Facility

Comparison Value for Ingestion and Source*

Metals, Nutrients, and Fluoride (milligrams per liter)

Arsenic (Total)

6.0

0.04

0.01 EMEG

Boron (Total)

6.8

0.51

0.4 Intermediate EMEG

Cadmium (Total)

5,268

0.54

0.007 EMEG

Chromium (Total)

3.0

0.42

0.1 LTHA

Fluoride

1,250

26.6

4 MCLG

Nitrate as Nitrogen

18.4

4.2

10 MCL

Selenium (Total)

6.3

0.12

0.02 EMEG

Sulfate

19,800

2,590

500 MCLG

Radiological Parameters (picocuries per liter)

Gross Alpha

232

360

15 MCL

Gross Beta

9,720

272

50 MCL

* - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days).

Note: The concentrations reported for the FMC facility have been adjusted (increased 150%) because the facility now uses a richer ore than previously.

Table 2 - Maximum Site-Related Sediment Contamination Found at the FMC or J.R. Simplot Facilities, Eastern Michaud Flats Contamination National Priorities List Site, Pocatello, Bannock County, Idaho

Contaminant

Maximum Concentration at FMC Facility

Maximum Concentration at J.R. Simplot Facility

Comparison Value for Ingestion and Source*

Metals, Nutrients, and Fluoride (milligrams per kilogram)

Arsenic

256

13.0

0.5 CREG

Boron

2,640

193

7,000 Adult Intermediate EMEG

Cadmium

2,410

108

500 Adult EMEG

Chromium

677

2,350

4,000 Adult EMEG

Fluoride

191,000

25,900

35,000 Adult EMEG

Selenium

49.6

61.2

1,000 Adult EMEG

Radiological Parameters (picocuries per gram)

Gross Alpha

299

131

15

Gross Beta

783

64

50

* = A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days).

Table 3 - Maximum Surface Water Contamination Found in the Portneuf River Beyond the FMC or J.R. Simplot Facility Fence Lines, Eastern Michaud Flats National Priorities List Site, Pocatello, Bannock County, Idaho

Contaminant

Maximum Concentration in the Portneuf River near the Facilities

Maximum Concentration in the Portneuf River Up-Stream from the Facilities

Comparison Value for Ingestion and Source*

Metals, Nutrients, and Fluoride (milligrams per liter)

Arsenic (Total)

0.006

0.014

0.01 EMEG

Boron (Total)

0.38

0.33

0.4 Intermediate EMEG

Cadmium (Total)

0.0003

0.001

0.007 EMEG

Chromium (Total)

0.002

0.001

0.1 LTHA

Fluoride

0.65

0.39

4 MCLG

Nitrate as Nitrogen

1.3

1.2

10 MCL

Selenium (Total)

0.005

0.013

0.02 EMEG

Sulfate

65

50

500 MCLG

Radiological Parameters (picocuries per liter)

Gross Alpha

5.8

4.9

15 MCL

Gross Beta

4.9

9.8

50 MCL

* - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days).

Table 4 - Maximum Sediment Contamination Found in the Portneuf River Beyond the FMC or J.R. Simplot Facility Fence Lines, Eastern Michaud Flats National Priorities List Site, Pocatello, Bannock County, Idaho

Contaminant

Maximum Concentration in the Portneuf River near the Facilities

Maximum Concentration in the Portneuf River Up-Stream from the Facilities

Comparison Value for Ingestion and Source*

Metals, Nutrients, and Fluoride (milligrams per kilogram)

Arsenic

3.7

9.9

0.5 CREG

Boron

10.3

13.2

7,000 Adult Intermediate EMEG

Cadmium

22.2

0.82

500 Adult EMEG

Chromium

10.6

5.1

4,000 Adult EMEG

Fluoride

3,080

550

35,000 Adult EMEG

Selenium

0.88

0.72

1,000 Adult EMEG

Radiological Parameters (picocuries per gram)

Gross Alpha

29.2

13.6

15

Gross Beta

30

25.3

50

* - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days).