View all text of Subpart D [§ 131.31 - § 131.47]

§ 131.47 - Aquatic life criteria for aluminum in Oregon.

(a) Scope. This section promulgates aquatic life criteria for aluminum in fresh waters in Oregon that are jurisdictional under the Clean Water Act.

(b) Criteria for aluminum in Oregon. The aquatic life criteria in Table 1 to this paragraph (b) apply to all fresh waters in Oregon that are jurisdictional under the Clean Water Act to protect the fish and aquatic life designated uses.

Table 1 to Paragraph (b) - Aluminum Aquatic Life Criteria for Oregon Fresh Waters

Metal CAS No. Criterion maximum concentration (CMC) 3
(µg/L)
Criterion continuous concentration (CCC) 4
(µg/L)
Aluminum 1 27429905Acute (CMC) and chronic (CCC) freshwater aluminum criteria values for a site shall be calculated using the 2018 Aluminum Criteria Calculator (Aluminum Criteria Calculator V.2.0.xlsx), or a calculator in R or other software package using the same 1985 Guidelines calculation approach and underlying model equations as in the Aluminum Criteria Calculator V.2.0.xlsx, as defined in EPA's Final Aquatic Life Ambient Water Quality Criteria for Aluminum. 5

1 To apply the aluminum criteria for Clean Water Act purposes, criteria values based on ambient water chemistry conditions must protect the water body over the full range of water chemistry conditions, including during conditions when aluminum is most toxic.

2 These criteria are based on aluminum toxicity studies where aluminum was analyzed using total recoverable analytical methods. Oregon may utilize total recoverable analytical methods to implement the criteria. For characterizing ambient waters, Oregon may also utilize, as scientifically appropriate and as allowable by State and Federal regulations, analytical methods that measure the bioavailable fraction of aluminum (e.g., utilizing a less aggressive initial acid digestion, such as to a pH of approximately 4 or lower, that includes the measurement of amorphous aluminum hydroxide yet minimizes the measurement of mineralized forms of aluminum such as aluminum silicates associated with suspended sediment particles or clays). Oregon shall use measurements of total recoverable aluminum where required by Federal regulations.

3 The CMC is the highest allowable one-hour average ambient concentration of aluminum. The CMC is not to be exceeded more than once every three years. The CMC is rounded to two significant figures.

4 The CCC is the highest allowable four-day average ambient concentration of aluminum. The CCC is not to be exceeded more than once every three years. The CCC is rounded to two significant figures.

5 EPA-822-R-18-001, Final Aquatic Life Ambient Water Quality Criteria for Aluminum - 2018, December 2018, is incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available from U.S. Environmental Protection Agency, Office of Water, Health and Ecological Criteria Division (4304T), 1200 Pennsylvania Avenue, NW, Washington, DC 20460; telephone number: (202) 566-1143, www.epa.gov/wqc/aquatic-life-criteria-aluminum. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [email protected] or go to www.archives.gov/federal-register/cfr/ibr-locations.html.

(c) Applicability. (1) The criteria in paragraph (b) of this section are the applicable acute and chronic aluminum aquatic life criteria in all fresh waters in Oregon that are jurisdictional under the Clean Water Act to protect the fish and aquatic life designated uses.

(2) The criteria established in this section are subject to Oregon's general rules of applicability in the same way and to the same extent as are other federally promulgated and state-adopted numeric criteria when applied to fresh waters in Oregon that are jurisdictional under the Clean Water Act to protect the fish and aquatic life designated uses.

(3) For all waters with mixing zone regulations or implementation procedures, the criteria apply at the appropriate locations within or at the boundary of the mixing zones and outside of the mixing zones; otherwise the criteria apply throughout the water body including at the end of any discharge pipe, conveyance, or other discharge point within the water body.

[86 FR 14845, Mar. 19, 2021]