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 Value^b
Analyte	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
Sulfide^d	---	---
Thallium	0.21	0.45
Tin^d	---	---
Uranium	7.6	7.2
Vanadium	44	34
Zinc	82	38
Radionuclide (pCi/g)
Cesium-137	0.50	0.074
Neptunium-237^e	0.028	---
Plutonium-238^e	0.004	---
Plutonium-239^e	0.018	---
Potassium-40	27	27
Radium-226	2.2	2.3
Strontium-90^e	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
Analyte	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.

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