United States
Environmental Protection
  Office of Water
EPA 820-F-16-001
     April 2016
Proposed  Aquatic Life Criteria for
Copper  and  Cadmium  in  Oregon
EPA is proposing a rule to establish federal Clean
Water Act (CWA) aquatic life criteria forfreshwaters
under the state of Oregon's jurisdiction to protect
aquatic life from the effects of exposure to harmful
levels of cadmium and copper.
CWA section 101(a)(2) establishes the national goal
that water quality should provide for the protection
and propagation offish, shellfish, and wildlife, and
recreation in and on the water. To protect aquatic
communities from the harmful effects of pollutants
in surface waters, states must establish aquatic life
criteria for their waters that are designated for such
uses. EPA periodically publishes criteria
recommendations under CWA section 304(a) for
states to  consider using to meet these CWA section
101(a)(2) goals.
On January 31, 2013, EPA determined that the
freshwater copper criteria to limit acute (short-term)
and chronic (long-term) adverse effects, and the
freshwater cadmium criterion to limit acute adverse
effects, that Oregon adopted in 2004 did not meet
CWA requirements to protect aquatic life in the
state. Therefore, to protect freshwater aquatic life in
Oregon from the adverse effects of cadmium and
copper, EPA is proposing the criteria in this rule
using the best available science on cadmium and
copper toxicity.
                            How EPA Derived the Proposed Acute
                            Cadmium Aquatic Life Criterion
                            In 2016, EPA published revised CWA section 304(a)
                            recommended criteria for cadmium, based on the
                            latest science on cadmium toxicity. Ambient water
                            hardness (determined by the presence of calcium
                            and magnesium ions) affects the toxicity of
                            cadmium, such that organisms show more sensitivity
                            to cadmium in water with lower hardness. EPA's
                            freshwater 304(a) recommended cadmium criteria
                            are equations to calculate protective cadmium
                            criteria based on the relevant water body's
                            hardness. EPA is proposing to use the updated CWA
                            section 304(a) recommended acute cadmium
                            criterion equation to protect freshwater aquatic life
                            in Oregon. EPA is also proposing a protective default
                            hardness value to use in the equation when
                            sufficient representative data to determine the
                            water body's hardness are not available.

                            How EPA Derived the Proposed Copper
                            Aquatic Life Criteria
                            In 2007, EPA issued CWA section 304(a) national
                            recommended freshwater aquatic life criteria for
                            copper. These criteria recommendations incorporate
                            use of a Biotic Ligand Model (BLM) for developing
                            criteria dependent on ambient water chemistry. The
                            BLM uses ten ambient water body characteristics to
                            develop water quality criteria on a site-specific basis.
                            EPA proposes to use this 2007 copper BLM to
                            protect aquatic life in Oregon. As with the hardness
                            default for cadmium, EPA is  proposing protective
                            defaults to use in the BLM when sufficient

representative data on the relevant water body's
characteristics are not available. EPA based the
proposed defaults for Oregon on EPA's 2016 Draft
Technical Support Document: Recommended
Estimates for Missing Water Quality Parameters for
Application in EPA's Biotic Ligand Model.

How EPA's Proposal Relates to the State of
Oregon's Efforts to Develop Criteria
Oregon is currently engaging in its own rulemaking
process to develop copper criteria that protect
freshwater aquatic life, and is working closely with
EPA and other technical experts. If Oregon adopts
and submits  new or revised water quality criteria
and EPA approves them before finalizing this
proposed rule, EPA would not proceed  with the final
rulemaking for those waters and/or pollutants for
which EPA approves Oregon's new or revised
criteria. If EPA finalizes this proposed rule, and
Oregon subsequently adopts and submits new or
revised criteria that EPA finds meet  CWA
requirements, EPA proposes that once  EPA approves
Oregon's criteria, they would become effective for
CWA purposes, and EPA's corresponding
promulgated criteria would no longer apply.

Public Hearings on the Proposed  Rule
EPA is offering two virtual public hearings on the
proposed rule so that interested parties may provide
oral comments. The first hearing will be on Monday,
May 16, 2016 from 4:00pm to 6:00pm Pacific Time.
The second hearing will be on Tuesday, May 17,
2016 from 9:00am to ll:00am Pacific Time.
Where can I find more information?
Contact Erica Fleisig at (202) 566-1057,
fleisig.erica@epa.gov or Rochelle Labiosa at (206)
553-1172, labiosa.rochelle@epa.gov. To access the
proposed rule, supporting documents, and more
details on how to make written comments and/or
how to register to make oral comments at the public
hearings, visit EPA's Water Quality Standards
website at: