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<br />Ecotox.icology and Environmental Safety 44, 227-235 (1999)
<br />Environmental Research. Section 8
<br />Article ID eesa.l999.l833, available online at hltp:;/www.idealibrary.com on IDE~l@
<br />
<br />COMMENTARY
<br />Water-Sediment Controversy in Setting Environmental Standards
<br />for Selenium
<br />
<br />Steven 1. Hamilton*.l and A. Dennis Lemlyt
<br />
<br />· u.s. Geological Surrey, Columbia Enrironmental Research Center, Ecotoxicology Research Station. 31247 436th Arenue. Yankton, Soulh Dakota 57078-6364.
<br />and tu.s. Forest Sen:ice, Southern Research Station, Coldwater Fisheries Research Unit, Department of Fisheries and Wildlife Sciences.
<br />Virginia Tech Unirersity, Blacksburg, Virginia 2406/-0321
<br />
<br />Received January 29. 1999
<br />
<br />A substantial amount of laboratory and field research on
<br />selenium effects to biota has been accomplished s~nce the national
<br />water quality criterion was published for selenium in 1987. Many
<br />articles have documented adverse effects on biota at concentra-
<br />tions below the current chronic criterion of 5 Jig/L. This com-
<br />mentary wiU present information to support a national water
<br />quality criterion for selenium of 2 Jig/L, based on a wide array of
<br />support from federal, state, university, and international sources.
<br />Recently, two articles have argued for a sediment-based criterion
<br />and presented a model for deriving site-specific criteria. In one
<br />example, they calculate a criterion of 3111g/L for a stream with
<br />a low sediment selenium toxicity threshold and low site-specific
<br />sediment total organic carbon content, which is substantially
<br />higher than the national criterion of 5 Jig/L. Their basic premise
<br />for proposing a sediment-based method has been critically re-
<br />viewed and problems in their approach are discussed.
<br />
<br />1. INTRODUCTION
<br />
<br />The U.S. Environmental Protection Agency (USEPA) is .
<br />currently reevaluating the national water quality chronic
<br />criterion for selenium (USEPA, 1998), which was set at
<br />5 flg/L in 1987 (USEPA. 1987). There is a growing body of
<br />literature that supports a lower chronic selenium criterion.
<br />Beginning in late 1982, investigations of contamination at
<br />Kesterson Reservoir in the central valley of California were
<br />initiated, which revealed that selenium from agricultural
<br />irrigation sources was elevated and causing adverse effects
<br />in fish and wildlife (Ohlendorf et aI., 1986; Saiki, 1986). The
<br />
<br />I Corresponding author. Fax: 605-665-9335. E-mail: steve_hamilton@
<br />usgs.gov.
<br />
<br />@
<br />
<br />National Irrigation Water Quality Program (NIWQP) was
<br />initiated in 1985 to determine the concentrations of poten-
<br />tially toxic constituents, especially selenium, in water,
<br />bottom sediment, and biota at 20 sites in 18 western states
<br />(Engberg and Sylvester, 1993), then expanded to include
<br />six additional areas (Feltz and Engberg, 1994). The NIWQP
<br />investigations in the Green (Stephens et aI., 1988, 1992,
<br />Peltz and Waddell, 1991), Colorado and Gunnison (Butler
<br />et al., 1989, 1991, 1994, 1996), and San Juan (Blanchard
<br />et aI., 1993; Butler et aI., 1995; Thomas et aI., 1997)
<br />rivers suggested that selenium and other elements are suffi-
<br />ciently elevated in water, bottom sediments, or biota to
<br />adversely affect aquatic organisms in those rivers. Research
<br />undertaken in western rivers to assess the hazard of sel-
<br />enium and other elements from irrigation drain water sour-
<br />ces on endangered fish has provided additional information
<br />to suggest that selenium is adversely affecting endangered
<br />fish.
<br />Despite the mounting evidence of toxic effects below
<br />5 flg/L, there is a controversy over whether the current
<br />national criterion is too high or too low. The basis for
<br />this disagreement stems from different views of whether
<br />a water-based or sediment-based method for deriving cri-
<br />teria is more valid in light of the field evidence for
<br />bioaccumulation and toxicity to fish and wildlife (USEPA,
<br />1998). Below, is provided information that supports a water-
<br />based chronic criterion for selenium of 2 flg/L. Also in-
<br />cluded is a discussion of problems in two recent articles
<br />(Canton and Van Derveer, 1997; Van Derveer and Canton,
<br />1997) that propose a sediment-based approach that could
<br />result in substantially elevated selenium concentrations in
<br />water above the current USEP A criterion. Because the
<br />sediment-based approach was proposed primarily for west-
<br />ern rivers, information is presented from the NIWQP in-
<br />vestigations and research with endangered fish from western
<br />flvers.
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