Table 12. Minimum, median, and maximum concentrations of priority trace elements detected in Hood River basin, Oregon, surface waters and national and State water-quality standards and exposure responses from literature.

[Source: Oregon Department of Environmental Quality, 2004; U.S. Environmental Protection Agency, 2005a, 2009b. All concentrations reported in micrograms per liter. Abbreviations: USEPA, U.S. Environmental Protection Agency; CMC, criteria maximum concentration; CCC, criterion continuous concentration; wk, week; m, month; h, hour; d, day; LC50, 50 percent lethal concentration; —, not detected, no water-quality standard or no literature values]

Traceelement	Description	Number of samples	Number of detections	Detected concentration				USEPA			Oregon			Literature values
				Minimum	Median	Maximum		CMC(acute)	CCC (chronic)		Acute	Chronic		Concentration	Exposure duration	Response	Source
Aluminum	Dissolved	42	25	13	44	530		750	87		–	–		539	2 wk	Olfactory stimulation	Tierney and others, 2010
	Total	4	4	127	543.5	1,590		–	–		–	–		–	–	–	–
	Total recoverable	158	146	12	410.5	9,690		–	–		–	–		–	–	–	–
Cadmium	Dissolved	25	11	0.1	0.25	0.42		10.32–1.23	10.07–15					100	10 m	Olfactory stimulation	Tierney and others, 2010
											1.5–37.9	–		LC50	Buhl and others, 1991
	Total	4	1	0.11	0.11	0.11	–	–	–	–	–	–		–	–
	Total recoverable	204	32	0.1	0.145	0.43	–	–	30.46–2.20	30.26–0.76	–	–		–	–
Copper	Dissolved	25	3	0.83	1.1	1.49	1,22.34–8.65	1,21.77–30			1–200	30 m–4 h		Olfactory stimulation	Tierney and others, 2010
														0.1–6.4	–	Avoidance
														330	–	Attraction
														2–20	3 h	Alarm response
														0.18–2.1	3 h	Alarm response	Hecht and others, 2007
														0.75–2.4	20 m–21 d	Avoidance
														5–25	6 d - indefinite	Migration
														9–57	96 h	LC50
	Total	4	4	0.77	2.72	3.54	–	–	–	–	–	–		–	–
	Total recoverable	205	116	0.31	1.29	26	–	–	32.97–11	32.34–7.64	–	–		–	–
Nickel	Dissolved	25	10	0.26	1.875	4.32	194–304	110–32	–	–	6	–		Attraction	Tierney and others, 2010
	Total	4	4	0.43	0.565	0.96	–	–	–	–	23.9	–		Avoidance	Tierney and others, 2010
	Total recoverable	156	103	0.2	0.65	3.7	–	–	3285–921	332–102	–	–		–	–
Silver	Dissolved	25	0	–	–	–	10.12–1.34	–	–	–	11.1–19.2	–		LC50	Buhl and others, 1991
	Total	4	3	0.21	0.3	0.3	–	–	–	–	–	–		–	–
	Total recoverable	156	10	0.23	0.27	0.43	–	–	30.16–1.69	–	–	–		–	–
Zinc	Dissolved	24	10	0.78	51.95	278	123–76	124–33	–	–	5.6	–		Avoidance	Tierney and others, 2010
	Total	4	4	2.49	5.085	10.4	–	–	–	–	–	–		–	–
	Total recoverable	205	115	0.54	3.87	36.1	–	–	323–76	321–69	–	–		–	–

¹Hardness-dependent criterion based on hardness range of 15-60 mg/L, the general range of hardness values available in the basin from 1999 through 2009. Criteria were calculated using USEPA (2005a) National Recommended Water-quality criteria Appendix B: Parameters for Calculating Freshwater Dissolved Metals Criteria That Are Hardness-Dependent. The USEPA reports these criteria based on 100 mg/L hardness as CaCO₃.

²USEPA criteria for copper were calculated using the hardness-dependent formula. The USEPA now uses the Biotic Ligand Model (BLM), which uses 11 parameters to calculate copper criteria. The BLM could not be used here because data for all 11 parameters in the basin do not exist.

³Oregon hardness-dependent criteria are based on older USEPA guidelines, which use different calculation parameters than USEPA currently uses. Oregon criteria refer to total recoverable metal concentration, while the USEPA uses dissolved concentration (Oregon Department of Environmental Quality, 2006).

First posted June 17, 2011