Cadmium
Fact Sheet: Notice of Availability
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United States
Environmental Protection
Agency |
Office of Water
4304 |
EPA-822-F-01-002
April 2001 |
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Summary
The U.S. Environmental Protection Agency (EPA) has revised
its aquatic life criteria for cadmium and announced the availability
of the completed document entitled, 2001 Update of Ambient Water
Quality Criteria for Cadmium. EPA revised its aquatic life criteria
for cadmium to reflect the latest scientific knowledge regarding
the effects of cadmium on aquatic organisms. The revised criteria
are average concentrations of cadmium that can be present in a water
body, but should not result in unacceptable effects on aquatic organisms
and their uses.
Background
Section 304(a)(1) of the Clean Water Act requires the EPA to develop,
publish, and from time to time revise, criteria for water. Water
quality criteria developed under section 304(a) are based solely
on data and scientific judgments and should accurately reflect the
latest scientific knowledge. They do not consider economic impacts
or the technological feasibility of meeting the criteria in ambient
water.
Under the Clean Water Act, States and Tribes are to establish water
quality criteria to protect designated uses. EPA has promulgated
regulations to implement this requirement (see 40 CFR part 141).
EPA's recommended water quality criteria do not substitute for the
Act or regulations, nor are they regulations themselves. Thus, EPA's
recommended water quality criteria cannot impose legally binding
requirements on EPA, States, Tribes or other regulated community.
State and Tribal decisionmakers retain the discretion to adopt approaches
on a case-by-case basis that differ from this guidance when appropriate.
EPA may change this guidance in the future.
How does this new criteria for cadmium protect water quality?
The updated cadmium criteria reflects the latest scientific data
and results in criteria that better protect aquatic organisms. Section
304(a) criteria provide guidance in adopting water quality standards
and provide a scientific basis to develop controls of discharges
or releases of pollutants. The criteria also provide a scientific
basis for EPA to develop federal regulations under section 303(c).
Why is EPA notifying the public about the completed cadmium
document?
EPA is notifying the public about the availability of the completed
criteria document entitled, 2001 Update of Ambient Water Quality
Criteria For Cadmium, according to its new process for developing
criteria (63 FR68354). In following the Agency's new process for
developing criteria, EPA notified the public of its intentions to
revise the aquatic life criteria for cadmium in the Federal Register
on October 29, 1999 (64 FR58409). At that time, EPA made available
to the public all references identified by a recent literature review
and solicited any additional pertinent data or scientific views
that would be useful in revising the aquatic life criteria. EPA
revised the aquatic life criteria for cadmium based on the new data
and prepared a draft document. EPA then announced the peer review
and the availability of the peer review draft on August 17, 2000
(65 FR50201). Again EPA solicited views from the public on issues
of science pertaining to the information used in deriving the draft
criteria. EPA considered the comments from the peer reviewers and
the public and has revised the document accordingly. The completed
document is now available.
Where can I find more information on EPA's Revised Process
for Developing New or Revised Criteria?
The Agency published detailed information about its revised process
for developing and revising criteria in the Federal Register on
December 10, 1998 (63 FR68354) and in the EPA document entitled,
National
Recommended Water Quality-- Correction (EPA 822-Z-99-001,
April 1999) (PDF, 292KB).
Is the completed document different than the draft document?
In addressing the peer reviewers' comments and the scientific issues
raised by the public, revisions were made to the draft document.
These revisions resulted in no changes in the saltwater criterion
maximum concentration (CMC or "acute criterion") or the saltwater
criterion continuous concentration (CCC or "chronic criterion"),
but did result in significant changes in the freshwater criterion
maximum concentration and the criterion continuous concentration.
The freshwater criterion maximum concentration changed due to several
factors including the addition of data for bull trout and rainbow
trout, the elimination of some data and the recalculation of species
mean acute values for a few species. Two species mean acute values
were recalculated based on all applicable data rather than only
giving preference to flow-through measured test results, as in the
draft.
EPA's freshwater metals' criteria are expressed as hardness dependent
values because water quality characteristics such as hardness (and
other parameters that covary with hardness) influence the toxicity
of metals on aquatic organisms. Therefore, hardness slopes were
established to normalize all freshwater acute and chronic values
to the same hardness in order to derive the criteria. These hardness
slopes were revised in the completed document. The revision to the
acute slope was minor, but the chronic slope revision was more significant
and resulted in a less stringent criterion continuous concentration
compared to the draft document. The revised criterion continuous
concentration, however, is still more stringent than EPA's 1995
criterion continuous concentration.
What are the revised criteria?
Freshwater
criterion maximum concentration ug/L
e(1.0166[ln(hardness)]-3.924)
criterion continuous concentration ug/L
e(.7409[ln(hardness)]-4.719)
Saltwater
criterion maximum concentration ug/L
40
criterion continuous concentration ug/L
8.8
Additional Information
For additional information contact Cindy Roberts, Health and Ecological
Criteria Division, US EPA, Ariel Rios Building, 1200 Pennsylvania
Avenue NW, Washington, D.C. 20460; (202) 566-1124; roberts.cindy@epa.gov
You may view the Federal Register notice and completed aquatic
life criteria document for cadmium at: http://www.epa.gov/waterscience/criteria/aqualife/cadmium/
on the Internet.
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