Paducah Background

Background concentrations for naturally occurring inorganic chemicals and selected radionuclides in surface and subsurface soil

These tables were originally obtained from Methods for Conducting Risk Assessments and Risk Evaluations at the Paducah Gaseous Diffusion Plant. Volume 1. Human Health, DOE/OR/07-1506&D2. 2000. A more recent DRAFT Methods document is Methods for Conducting Risk Assessments and Risk Evaluations at the Paducah Gaseous Diffusion Plant. Volume 1. Human Health, DOE/LX/07-0107&D1/V1. 2009. This document should be final in 2010. In the meantime, the 2000 report is recommended. The background values presented below are form the more recent release and the values in these tables were developed considering agreements reached between the United States Department of Energy and the regulatory agencies during comment resolution meetings, in the Federal Facility Agreement, and at technical meetings. The human health document appendices contain a series of Action and No Action Risk-based screening values for the various receptors and the provisional background values for groundwater and soil. Finally, the Commonwealth has released a state-wide background table. Because surface water and sediment are transient media in which concentrations and activities can change rapidly, PGDP does not plan to develop surface water and sediment background. Only draft background values for groundwater drawn from the Regional Gravel Aquifer (RGA) and McNairy Formation are currently available. This description will be updated to indicate when these values have been approved.

Further information about the use of background in Ecological Assessments may be found here Methods for Conducting Risk Assessments and Risk Evaluations at the Paducah Gaseous Diffusion Plant. Volume 2. Ecological, DOE/LX/07-0107&D2/V2. 2009.

Analyte Background Valueb
Surface Subsurface
Inorganic Chemicals (mg/kg)a
Aluminum 16,045 9,732
Antimony 0.21 0.21
Arsenic 11 4.0
Barium 182 78
Beryllium 0.90 0.92
Cadmium 0.21 0.21
Calcium 8,376 1,926
Chromium (III) 25 22
Chromium (VI)d --- ---
Cobalt 13 8.8
Copper 24 12
Cyanide (CN-)c --- ---
Iron 28,657 23,698
Lead 35 14
Magnesium 2,652 1,168
Manganese 701 250
Mercury 0.20 0.20
Nickel 28 15
Potassium 1,005 499
Selenium 0.6 0.6
Silver 3.0 1.9
Sodium 142 331
Sulfided --- ---
Thallium 0.21 0.45
Tind --- ---
Uranium 7.6 7.2
Vanadium 44 34
Zinc 82 38
Radionuclide (pCi/g)
Cesium-137 0.50 0.074
Neptunium-237e 0.028 ---
Plutonium-238e 0.004 ---
Plutonium-239e 0.018 ---
Potassium-40 27 27
Radium-226 2.2 2.3
Strontium-90e 0 ---
Technetium-99 0.3 0.79
Thorium-228 2.3 2.3
Thorium-230 2.2 2.2
Thorium-232 2.2 2.2
Uranium-234 1.9 1.8
Uranium-235 0.11 0.11
Uranium-238 1.9 1.8

Notes: Cells with dashes (---) indicate data are not available or not applicable.

aIncludes inorganic chemicals found on Target Analyte List as defined by EPA in 1988 CLP Statement of Work and RCRA Appendix IX list of constituents.

bValue for use in screening to determine if inorganic chemical or radionuclide detected at naturally occurring concentration in surface or subsurface soil. Details on the derivation of the background concentrations for antimony, beryllium, cadmium, thallium, uranium, and all radionuclides are in DOE 1997a . Details on the derivation of the background concentration for all other inorganic chemicals are in DOE 1996a.

cCyanide is not expected to be naturally occurring in soil at PGDP; background values were not derived.

dData are not adequate to calculate a background concentration in soil for this analyte.

eConcentrations for these radionuclides in subsurface soil were not derived.




Provisional background concentrations for naturally occurring inorganic chemicals and selected radionuclides in filtered and unfiltered groundwater drawn from the RGA and McNairy Formation

Analyte Over All Observations Over Wells
RGA McNairy RGA McNairy
Inorganic Chemicals (mg/L)
Aluminum 2.189 0.687 1.64 0.75
Aluminum, Dissolved 0.311 0.579 0.201 0.587
Antimony 0.060 a 0.060 a 0.060 a 0.060 a
Antimony, Dissolved 0.060 a 0.060 a 0.060 a 0.060 a
Arsenic 0.005 a 0.005 a 0.005 a 0.005 a
Arsenic, Dissolved 0.005 a 0.005 a 0.005 a 0.005 a
Barium 0.235 0.296 0.202 0.265
Barium, Dissolved 0.200 0.268 0.179 0.266
Beryllium 0.004 a 0.017 a 0.004 a 0.017 a
Beryllium, Dissolved 0.004 a 0.004 a 0.004 a 0.004 a
Cadmium 0.010 a 0.010 a 0.010 a 0.010 a
Cadmium, Dissolved 0.010 a 0.010 a 0.010 a 0.010 a
Calcium 41.238 38.858 40.0 39.47
Calcium, Dissolved 38.166 38.829 35.8 40.27
Chloride 91.021 19.708 89.2 20.23
Chromium 0.144 0.060 a 0.134 0.060 a
Chromium, Dissolved 0.050 a 0.050 a 0.050 a 0.050 a
Cobalt 0.045 a 0.096 0.045 a 0.072
Cobalt, Dissolved 0.045 a 0.045 a 0.045 a 0.045 a
Copper 0.036 0.057 0.034 0.033
Copper, Dissolved 0.020 0.013 a 0.018 0.013 a
Fluoride 0.270 0.330 0.245 0.298
Iron 5.030 18.360 3.72 15.83
Iron, Dissolved 0.267 12.372 0.164 9.446
Lead 0.129 0.050 a 0.250 0.050 a
Lead, Dissolved 0.098 0.050 a 0.250 0.050 a
Magnesium 16.262 13.418 15.7 16.457
Magnesium, Dissolved 16.215 14.171 15.4 16.533
Manganese 0.119 0.941 0.082 0.729
Manganese, Dissolved 0.068 0.894 0.048 0.682
Mercury 0.0002 a 0.0002 a 0.0002 a 0.0002 a
Mercury, Dissolved 0.0002 a 0.0002 a 0.0002 a 0.0002 a
Molybdenum 0.050 a 0.050 a 0.050 a 0.050 a
Molybdenum, Dissolved 0.050 a 0.050 a 0.050 a 0.050 a
Nickel 0.682 0.109 a 0.682 0.109 a
Nickel, Dissolved 0.305 0.050 a 0.305 0.050 a
Nitrate as Nitrogen 15.561 1.474 13.5 1.43
Potassium 5.195 55.752 4.47 64.080
Potassium, Dissolved 4.096 51.205 3.70 58.750
Selenium 0.005 a 0.005 a 0.005 a 0.005 a
Selenium, Dissolved 0.005 a 0.005 a 0.005 a 0.005 a
Silica 26.401 36.0 21.1 29.4
Silver 0.011 a 0.050 a 0.011 a 0.050 a
Silver, Dissolved 0.060 a 0.050 a 0.060 a 0.050 a
Sodium 59.450 29.2 63.5 24.92
Sodium, Dissolved 60.433 27.98 65.7 25.90
Sulfate 19.947 28.9 19.1 27.27
Thallium 0.056 a 0.644 0.056 a 0.255
Thallium, Dissolved 0.056 a 0.056 a 0.056 a 0.056 a
Uranium 0.002 a 0.001 a 0.002 a 0.001 a
Uranium, Dissolved 0.002 a 0.001 0.002 a 0.001
Vanadium 0.134 0.126 0.139 0.119
Vanadium, Dissolved 0.134 0.126 0.131 0.107
Zinc 0.054 0.142 0.025 0.104
Zinc, Dissolved 0.049 0.116 0.026 0.080
Radionuclides (pCi/L)
Gross Alpha 5.8 11.9 2.36 5.3
Gross Beta 13.8 144.5 7.3 125.4
Neptunium-237 0.8 0.5 0.21 0.13
Plutonium-239 0.1 0.2 0.03 0.04
Radium-226 0.6 1.2 0.10 0.29
Radon-222 626 295 555.3 228.3
Technetium-99 22.3 20.6 10.8 7.8
Thorium-230 1.1 1.5 0.54 0.40
Total Radium 1.3 0.7 0.46 0.36
Uranium-234 b 0.7 0.3 0.7 0.3
Uranium-235 b 0.3 0.2 0.3 0.2
Uranium-238 b 0.7 0.3 0.7 0.3

Notes: Values taken from the draft Background Concentrations of Naturally Occurring Inorganic Chemicals and Selected Radionuclides in the Regional Gravel Aquifer and McNairy Formation at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (Unnumbered).

Values for filtered water samples are also available in the aforementioned report.

For all projects where averages within wells over time are considered, the values derived over wells should be used. For all other projects, the values derived over all observations should be used

aBackground value was derived qualitatively over all observations because analyte was never detected or was detected infrequently at a concentration near the analyte's detection limit.

bUranium isotopic concentrations were derived from the mass concentration of uranium.