Table S-1

Analytical methods, precision, and reporting limits for selected constituents.

Constituent / Method / Precision (RPDa or RSDb) / LRL
Aqueous samples—Major constituents % mg/L
ANC (as CaCO3) / titration / 0.6a / 5
Cl / Ion chromatography / 0.2a / 0.12
SO4 / Ion chromatography / 0.6a / 0.18
NO2+NO3 (as N) / Colorimetry / 1a / 0.04
NO2 (as N) / Colorimetry / 26a / 0.002
DOC / IR / 1.1a / 0.4
TOC / IR / 4a / 0.60
Na / ICP/AES / 0.6a / 0.12
NH3 (as N) / Colorimetry / 10a / 0.02
Aqueous samples—DOC characteristics % 1/cm
DOC fractions / XAD resinsc / na
UV254-UV-280
Absorption / Ultraviolet spectrometry / 0.2-0.3a / 0.014, 0.012
Aqueous samples—trace elements % mg/L
As (u, f) / cICP/MSd / 5.4, 4a / 0.12, 0.12
B (f) / ICP/AESe / 15.5a / 2
Fe (u, f) / ICP/AESe / 15, 3.7a / 14, 4
THg (u, f) / CVAFS (NWQL) / 7, 24a / 0.01, 0.01
THg (u, f) / CVAFS (WIML)f / -- / 0.00003, 0.00003
MeHg (u, f) / CVAFSf / 0, 6a / 0.00003, 0.00003
Pb (u, f) / ICP/MSe / 4, 1.4a / 0.1, 0.06
Zn (u, f) / cICP/MSd / 5.9 , 1.1a / 2, 2
Sediments—recoverable metals (HCl or HCL/HNO3 extraction) % mg/kg
Hg / CVAFSf,g / 20b / 0.0072
As / cICP/MSd / 8b / 0.1
Sediments—total metals (digestion by HCl, HNO3, HF, HClO4) % mg/kg
Major, trace elements / ICP/MS h, i / 4-11b / 0.003-40
Hg / CVAFSj / 2.5-8.5b / 0.1
Total, organic carbon / LECOk / 0.5-3b / 100

RPD = relative percent difference; RSD = relative standard deviation; LRL = Lower reporting limit (2x minimum detection limit for water samples); ICP = inductively coupled plasma spectrometry; ICP/AES, inductively coupled plasma atomic emission spectrometry; cICP/MS = collision/reaction cell inductively coupled plasma/mass spectrometry; IR, infrared spectrometry; UV, Ultraviolet ; CVAFS, cold vapor atomic fluorescence spectrometry; u = unfiltered sample; f = filtered sample; na = not applicable; -- = no data.

a RPD from replicates (this study).

b RSD from USGS NWQL or GD data.

c Aiken et al. 1992

d Garbarino et al., 2006.

e Gararino and Struzeski 1998, Fishman and Friedman, 1989

f www.epa.gov/epawaste/hazard/testmethods/sw846/pdfs/3051a.pdf--accessed 08/30/2010

g Olson and DeWild

h Briggs and Meier, 2002.

i Arbogast, 1996.

j Hageman 2007

k Taggart, 2002

Also, see http://water.usgs.gov/pubs/twri/ for method references.

Aiken GR, McKnight DM, Thorn KA,Thurman EM. Isolation of hydrophilic acids from water using macroporous resins. Org Geochem 1992;8:567-73.

Arbogast BF. Analytical methods for the Mineral Resource Surveys Program. US Geological Survey 1996;Open-File Report 96-525.

Briggs PH, Meier AL. The determination of forty-two elements in geological materials by inductively coupled plasma mass spectrometry. US Geological Survey 2002;Open-File Report 02-223-I.

Fishman MJ, Friedman LC. Methods for determination of inorganic substances in water and fluvial sediments. US Geological Survey 1989 Techniques of Water-Resources Investigations bk5, chapA1.

Garbarino JR, Struzeski TM. Determination of elements in whole water digests using inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-mass spectrometry. US Geological Survey 1998;Open-File Report 98-165.

Garbarino JR, Kanagy LK, Cree ME. Determination of elements in natural water, biota, sediment and soil samples using collision/reaction cell inductively coupled plasma-mass spectrometry. US Geological Survey 2006; Techniques and Methods bk5,chap1.

Hageman PL. Determination of mercury in aqueous and geologic materials by continuous flow-cold vapor-atomic fluorescence spectrometry. US Geological Survey 2007; Techniques and Methods bk5, chapD2.

Olson ML, DeWild, JF. Techniques for the collection and specific analysis of low levels of mercury in water, sediment, and biota. U.S. Geological Survey 1999; Water-Resources Investigations Report 99-4018B.

Taggart, J.E. (Editor). Analytical methods for chemical analysis of geologic and other materials, U.S. Geological Survey. U.S. Geological Survey 2002; Open-File Report 02-223.