Tuesday
December 22, 1992
Part tt
Environmental
Protection Agency
40 GFR Part T3t
Water Quality Standards; Establishment
of Numeric Criteria for Priority Toxic
Pollutants; States;' Compliance; Final Bute
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Federal Register / Vol. 58. No. 103 / Tuesday, June 1. 1993 /.Rules and Regulations
31177
31178
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 131
(WH-^RL-WSO-SJ
Water Quality Standard*;
Establishment of Numeric Criteria for
Priority Toxic Pollutants; States'
Compliance
• AGENCY: Environmental Pro!(K:tiou
Agency.
ACTION: Correction notice; final rule.
SUMMARY: EPA is correcting .
typographical errors in the final rule for
water quality standards for priority toxic
, pollutants which appeared in the
Federal Register on December 22.1992.
57 FR 60848.
FOR FURTHER INFORMATION CONTACT:
David K. Sabock. Chief. Wator Quality
Standards Branch (WH-585). Office of
Water. Environmental Protection
Agency. 401-M Street. SW. Washington.
DC 20400. Telephone number is 202-
260-1318.
SUPPLEMENTARY INFORMATION: EPA
promulgated a final rule to establish
numeric water quality criteria for
priority toxic pollutants applicable to
State water quality standards under
section 303(c) of the Clean Water Act on
December 22.1992 (57 FR 6084C). These
criteria bocame the enforceable criteria
for all purposes under the Clean Water
Act for lha 12 States and 2 territories
listed in the rule on February 5.1993.
Description of Error* and Correction*
On Page 60911. EPA has been advised
that the legibility of the matrix on.some
of the printed notices is such that it is
not dear that Arsenic it identified as
number 2 on the table and Silver is
number 11. In addition, pollutant
number 12 is Thallium.
On pace 60917. middlo column, lino
48. the phrase "• • • the lethal
concentration of • • ••• l» Incorrect. It
should wad "•• -the concentration
lethal to* • •."
On page 60910. in the middle column
dealing with paragraph (6) Florida. In
subparagraph (ii), the applicable .criteria
for Class U and Class III (marine) were -
inadvertently omitted from the text. The
applicable criteria for both Clasi H and
Class III (marine) should read: "Thia
classification is assigned the criteria in:
Column D2-J18."
On page 60920. dealing with
paragraph (10) California. In
subparagraph (ii). the applicable criteria
for Waters of the Sacramento-San
Joaquin Delta" should also include
pollutant 187 in Column Dl; this
pollutant was inadvertently omitted
from the list .-
On page 60921 dealing with
paragraph (l 0) California, in
subparagraph (li). tho fifth paragraph
beginning "All enclosed bays and
estuaries" under the heading "Water
*nd Use Classification", the words "thai
do not include an MUN designation"
wore omitted from the first line. The
correct wording is: "All enclosed bays
and estuaries that are waters of the
'Sj!X£StalM thal do not Delude an
MUN designation and that the State •
On page 60922. dealing with
paragnph (12) Alaska, in •ubparagraph
(n). the applicable criteria assigned^
"!? ^fif8"0* <»KA)(U) U tecorrectly
printed as Column Dl. The correct
reference should be to Column D2.
, Dated: May 25. 1993.
Tudor Da vU«.
Acting AtsistantAdminittntor for Water
IFR Doc, 93-12845 Filed 5-28-03; 8:
— " — "
COOC
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Corrections
I XLtfUUr.
Vol. 58. No. 121
Friday. Juno 25. 1993
;TN«,««ctJon o« the FEOERAJL REGISTER
contain* editorial correc«on« of prtvlou*»y
published PtulduAil. flule,%Ptppc»*d
''
are
.
Register. -A&«ncy"f(rtf««J cpfbrionii , 'fa
luuw M tlQnod docunwrts'and appear In •
thf ipprppria't* document bal*gpcia*
•iMwhor* In th* I
ENVIRONMENTAL PROTECTION
AGENCY
.Water Quality Standards;
Establishment of Numeric Criteria for
Priority Toxic Pollutants; State's .
Compliance
Correction
In rule document 63-12845 beginning
on page 31177 in the issue of Tuesday.
June 1.1993. make the following
correction: .
•On page 31178. in the first column, in
tho fifth full paragraph, in the fourth
line. "(l)(A)(ii)" should read
"(iHAKiii)".
•ituwa cooc itot-oi-o
DEPARTMENT OF THE INTERIOF
Bureabf Land Minagemer
6: WYW
rawa>tnd Opportunity
Proposed Wit
for Public Me
' Correction "
In notice document &3-W009.
appearing oXpage 3153aN,n the issue of
Thursday/June 3.1993 in latjd
doscript&n T.41 N.. R. 117 W.. "34 and
25" should read "34 and 35",
• COOC 1(04-014 .'" .
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Federal Register / Vol. 58, No. 127 / Tuesday, July 6, 1993 / Rules and Regulations
3G141
ENVIRONMENTAL PROTECTION
AGENCY
40 CFH Part 131
Water Quality Standard*;
Establishment of-Numeric Criteria for
Priority Toxic Pollutants; State's
Compliance
AG£NCY: Environmental Protection
Agency.
ACTION: Final rulo. _ •
SUMMARY: EPA is (unending a rule
issuud oa Docembor 22, 1902. to
withdraw a portion of that rulo as it
applies to the Stole of Washington. The
aquatic life criteria for arsenic and
selenium adopted by Washington and
approved by EPA make the Federally
promulgated criteria for these pollutants
unnecessary.
EFFECTIVE DATE: This amendment is
effective July 6,1093.
ADDRESSES: The administrative record
for tho consideration of Washington's
revised standards is available for public
inspection from the Environmental
Protection Agency, Region X Office.
Water Division, 1200 Sixth Avenue,
Seattle, WA. 98101, during normal
business hours of 8 a.m. until 4:30 p.m.
FOR FURTHER INFORMATION CONTACT:
David K. Sabock, Chief, Water Quality
Standards Branch (WH-585). Office of
Water. Environmental Protection
Agency, 401 M Street. SW.. Washington,
DC 20460. The telephone number is
202-268-1315.
SUPPLEMENTARY INFORMATION: A filial
rule to establish numeric water quality
criteria for those States and Territories
•that failed to comply fully with section
303tc)(2)(B) of tho Clean Water Act was
published in the Federal Register on
December 22,1992 (57 FR 60848).
Federal criteria were promulgated for 12
States and 2 Territories, and these
criteria became the legally enforceable
water quality standards in the named
States and Territories for all purposes
and programs under the Clean Water
Act on February 5.1993.
As indicated in the preamble to the
final rulo. EPA would amend the rule to
withdraw criteria from the rule when a
State adopted and EPA approved
criteria that met the requirements of the
Clean Water Act (see 57 FR 60860). On
, November 25,1992. the State of
Washington adopted revisions to the
State's surface water quality standards,
Chapter 173-201A of the Washington
Administrative Code, regarding aquatic
life criteria for arsenic and selenium.
The State adopted criteria identical to
those promulgated by EPA for both fresh
and marine waters. These criteria wore
approved by EPA on March 25,1993.
EPA's promulgated criteria for arsenic
and selenium are now duplicative of
EPA-npproved State criteria and are no
longur noodocl to moot tho roquiromunts
of the Act. It is EPA's policy to
withdraw promulgated water quality
standards when the State adopts new or
revised standards which meot the '
requirements of-the Act (57 FR 60848).
Accordingly. EPA is amending its-rule
promulgated December 22.1992. to
withdraw tho criteria for arsenic and
selenium for the protection oi aquatic
lifu for Washington. Other criteria
36142
promulgated by EPA for Washington
remain in force.
Washington complied with the public
participation requirements in its
adoption of State standards.
Additionally, because Washington
•adopted, and EPA approved, water
quality criteria for arsenic and selenium
for the protection of fresh and marine
aquatic life identical to those being
withdrawn in today's rule, EPA has
determined that additional public
participation in this action is
unnecessary and constitutes good cause
for issuing this final rule without notice
and comment. For the same reasons, the
Agency has determined that good cause
exists to waive the requirement for a 30-
day period before the amendment
becomes offectivo and therefore the
amendments will bo immediately
effective.
This action imposes no now
regulatory requirements but merely
withdraws a Federal regulation.
Therefore, this rule imposes no costs
and does not require a regulatory impact
analysis under Executive Order 12291.
The Agency has determined that this
action will have no significant impact
on a substantial number of small
entities. The rule also does r* it impose ;
any requirements subject to thu
Paperwork Reduction Act.
List of Subjects in 40 CFR Part 131
Water pollution control. Water quality
standards, Toxic pollutants.
Dated: Juno 8.1993.
Carol M. Browner, ,
Administrator. . •
For the reasons set out In the
preamble title 40. Chapter I. part 131 of .
the Code of Federal Regulations is
amended as follows:
PART 131—WATER QUALITY .
STANDARDS
1. The authority citation for part 131
continues to read as follows:
Authority: 33 U.S.C. 1251 et leq.
§131.36 [Amended]
2. Suction 131.3ti(d)(.i4)(ii) is
amended in "Fish ciid Shellfish: Fish" .
use classification; undor tho listing of • .
applicable criteria, by removing the
entries "Column Bl and B(2)—82,10"
and "Column Cl—*2.10" in their
entirety and by removing "*2" and
••*10" from t!iu entry for Column C2.
IFR Doc. 93-15302 RUd 7-2-93r8:45 ami
feiuuuG CODE'
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Tuesday
December 22, 1992
Part K
Environmental
Protection Agency
40 CFR Part T3t . '..'!'•
Water Quality Standards; Establishment
of Numeric Criteria for Priority Toxic
Pollutants; States' Compliance; Final Rote
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60848 .Federal Register / Vol. 57. No. 246 / Tuesday. December 22, 1992 / Rules and Regulations
ENVIRONMENTAL PROTECTION
•AGENCY
.40CFRP«rt131
IWH-FRL-4543-SJ
Water Quality Standards;
Establishment of Numeric Criteria for
Priority Toxic Pollutant*; States'
Compliance
AGENCY: Environmental Protection
Agency. . .
ACTON: Final rule. .'
SUMMARY: This rule promulgates for 14
States, the chemical-specific, numeric
criteria for priority toxic pollutants
necessary to bring all States into
compliance with the requirements of
section 303(c){2){B) of the Clean Water
. Act (CWA). States determined by EPA to
•fully comply with section 303(c){2)(B)
requirements are not affected by this
yule.
The rule addresses two situations. For
• faw States, EPA is promulgating a
limited number of criteria which were
previously identified as necessary in
.disapproval letters to such States, and
•which the State has failed to address.
EOT other Stales, Federal criteria are
necessary for all priority toxic
pollutants for which EPA'has issued
•action 304(a) water quality criteria
guidance and that are not the subject of
1 approved State criteria; -.--,.••• •
When these standards takeeffect, they
will be the legally enforceable standards
In the named States for all purposes and
programs under the Clean Water Act.
including planning, monitoring, NPDES
permitting, enforcement and
compliance.
EPA is also withdrawing today the
human health criteria published La the
1980 Ambient Water Quality Criteria
documents fon beryllium, Cadmium,
Chromium, Lead, Methyl Chloride,
Selenium, Silver, and 1,1,1
Trichloroethane. A summary of the
criteria recommendation and the notice
of availability of each criteria document
were published at 45 FR 79318,
November 28,1980.
EFFECTIVE DATE: This rule shall be
affective February 5,1993.
ADDRESSES: The public may inspect the
administrative record for *m«
zulemaldng, including documentation
supporting the aquatic life and human
health criteria, and all public comments
received on the proposed rule at the
Environmental Protection Agency,
Standards and Applied Science
Division, Office of Science and
Technology, room 919 East Tower,
Waterside Mall, 401M Street, SW...
Washington, DC 20460 (Telephone:
202-260-1315) on weekdays during the
Agency's normal business hours of 8
a.m. to 4:30 p.m. A reasonable fee will
be charged for photocopies. Inquiries
can be made by calling 202-260-1315.
FOR FURTHER INFORMATION CONTACT:
David K. Sabock or R. Kent Ballentine.
Telephone 202-260-1315. .
SUPPLEMENTARY NFORMATON:
This preamble is organized according
to the following outline: . • •
A. Introduction and Overview
1. Introduction
2. Overview , ' -•-.-•:
B. Statutory and Regulatory Background ;
li Pro-Water Quality Act Amendments of •
1987 (Pub. L. 100-4) ,.
2. The Water Quality Act Amendments of
1887 (Pub,L. 100-1)
a. Description of the New Requirements
b. EPA's Initial Implementing Actions far
sections303(c)and304(1) . ". :
3.-EPA's Program Guidance for section
303(c)(2)(B)
CState Actions Pursuant to section •
. 303(c)(2HB) •-.-.:
D. Determining State Compliance with •'
section 303(c)(2)(B)
1. EPA's Review of State Water Quality •
Standards for Toxics • ..• •- ..
2. Determining Current Compliance Status
E. Rationale and Approach For Developing
the Final Rule
1, Legal Basis
2. Approach for Developing the Final Rule
3; Approach for State* that Fully Comply
• Subsequent to Issuance of this Final Rule
F. Derivation of Criteria .
1. Section 304(a) Criteria Process "• •
2. Aquatic Life Criteria . ,. - "• ...
3. Criteria forHuman Health ' •
4. Section 304(a) Human Health Criteria
Excluded
5. Cancer Risk Level
6. Applying EPA's Nationally Derived
Criteria to State Waters
7. Application of Metals Criteria
G. Description of the Final Rule and Changes
from Proposal •- • •
1. Changes from Proposal. • '
2. Scope ' ~ :
3. EPA Criteria for Priority Toxic Pollutant*
4. Applicability . -
H. (Reserved) -" .'-.,
L Response to Public Comments
: i. Legal Authority • . ' ' '
2.Sdence ' ''"'
3. Economics •' • '.'
4. Implementation ' ' •
5. Timing and Process - •
6. State Issues •
J. Executive Order 12291 ...
K. Regulatory Flexibility Act •
L. Paperwork Reduction Act
A. Introduction and Overview
3. Introduction •
This section of the Preamble
introduces the topics which are
addressed subsequently and provides a
brief overview of EPA's basis and
rationale for promulgating Federal
criteria for priority iloxic pollutants, '
Section B of this Preamble presents a
description of the evolution of the
Federal Government's efforts to control.
toxic pollutants beginning with a
discussion of the authorities in the
Federal Water Pollution Control Act
Amendments of 1972. Also described in
some detail is the development of the
water" quality standards review and
revision process which provides for
establishing both narrative goals and
enforceable numeric requirements for
controlling toxic pollutants, this V
discussion includes the changes enacted
in the 1987 Clean Water Act v- ' :
Amendments which are the basis for • :
this rule. Section C (tummarizes State
efforts since 1987 to comply with the.
requirements of section 303(c)(2)(B).
Section D describes EPA's procedure for
determining whether a State has fully
complied with section 303(cK2)(B).
Section E sets out the rationale and
approach for developing the final-rule,
including a discussion of EPA's legal
basis. Section F describes the
. development of the criteria included in'
this rule. Section G """iTpTfygy the .'• •
provisions of the final rule. (Section H ••
is reserved.) Section I contains the
response to major public comments
received on the proposal. Sections J.K,
and L address the requirements of , -
Executive Order 12291. the Regulatory'
Reduction Act, respectively. Section M
provides a list of subjects covered in . •
this rule.
• A public hearing on the proposed rule
was held on.December 19,1991, in
Washington, DC. A total of 26 non-EPA
people registered at Hhe hearing. The
public comment period closed on
December 19,1991.1EPA received a total
of 153 written comments on the
proposed rule. .
2. Overview
This rule, which establishes Federal
criteria for certain priority toxic -
pollutants in a number of States, is
important for several environmental,
programmatic and legal reasons.
First, control of toxic pollutants in
surface waters is an important priority
to achieve the Clean Water Act!* goals
and objectives. The most recent
National Water Quality Inventory
indicates that one-third of monitored
river miles, lake acres, and coastal
waters have elevated levels of tcodcs. •
Forty-seven States and Territories have
reported elevated levels of toxic
•pollutants in fish tissues. Slates have
issued a total of 586 fishing advisories
and 135 bans, attributed mostly to •
industrial discharges and land disposal.
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Federal Register / Vol. 57, No. 246 / Tuesday. December 22, 1992 / Rules and RegjrlaaoBS new risk
failedto fuEy coaply wfth-section
3B3fcK2KBJ.33aCWA.authoiiaes.EPA
followed in this preamble, the spirit of
tii9guidfiBceikiaSectedv. •
Moraowr, EPA hwimtiated a review
w y.-u-...-. -f, —-latgnrfmirfew/haacB .
necessaiy tomeetthfrrequlrement&of .
the Act Where SUte6.ha.va.Bot satisfied
the CWA requirement to adept water
quality standards for todc pollutants* .
which was, reempbatfand by Congress in
1957, it is imperative that EPA take .
' - -
.methodote^es. These ttpdeteswillbe
conducted inconfonuance with me risk
characterizatioa gnWance-aad include
B. Statutory and Kegulatory
EFA*s.
*s.abiBty t
irrtiMMtfrn
- . .
to- aversee Stale
PreJSata QoaKtyAct Amendments
. .
place complete toxics criteria, as part o£
r poUutkra-
. ^. . ~. ~T '
correct deffdenctoft in State water ,
quality standards is critical to the '
effective fniplamastatten"ofseetfon' •
3036cK2KBl- Tbjffraliefaa necessary and
importHntcoHrponentofEPA's
as waB asEPA.'s «wetattefforts.to
control VoxiepeBjitants.ia!»urface-
waters. '
Section 303Ce>ofth« 19?Z Federal
Water Poluuion Cental Act
.
1313(c)) establiahed the statutory besift
for the cunent water qantity atmWfardit
moguaa. Hcontpleted the-faagsitioB
established program
of watar Qjuali^? standards SOT iotetstate
waters to ene- — :~*~^ "* — *• — *-••—•• *l
most State»recogniaet&e seed far,
enforceable, water quality standards for
toxic poUtttents> thek recant adoption
- - • " * i stymied by a.
Cfearacterizatioa for Risk Managers and
Risk Assessors" which addressesa
•obbtem thatafiscteBfliificiiercn^r
surface, waters ol&e United States.
Aithoog^th«ma}orimievationof Ate
1972 FWPCAwms technology-based
,pft
prioritie*^ and dif&eaik seterttinc. policy/
and legal challenges. Most water qna&y
criteria. SB? taadcpetoiante hmwbeea
aOTHlabJesmt^lflea. Section 3(» of tbe
regulatory dacisionc.The.g*
f,OKhAAMI.^>«^ K^^.1 ••••%*»••* •*tm*^pi i
noted that "wienriA:mlbcm«tu» i»
concept ol water quality standardfrbotii
as a.nracb^nisnzto*6taBlishgoal»forthe
Nation's waters and as a i
IwbeBStenda
dowatocpefeot
ad adopt •pdateoi water qaality .
aadaxm every three years ax past of a.
water
required State
results hscabaaB
estimaterfrisk.- *
•m**mwj- v >• •• i i j' i
considexadand f w
assessment "Tbe'gaidaHce fayrout
prrncrahwandianpterttaDtetioB
prpT^ffaWf^to aAnBgff rif^ tttnf'tmntt
in faoag EPA pjuBuntaiionsy paportemd
'^gy controls- ferpoiBt
po&rt source
re-feederoate. in recent
ys«nv these aoKaJMwatef..—.,
based controlhave recefved aew
emphasis by Congrew and EPA i* the
continuing quest to-enhance- and
. •- mainta£a> wafer qaalSy to protect the
public bee&b aad weHare., . .. •
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60850 Federal Register / Vol. 57. No. 246 / Tuesday. December 22,~1992 / Rules aid Regulations .
Briefly stated, the key elements of
« section 303(c) are: *
(a) A water quality standard is defined
. as the designated beneficial uses of a
water segment and the water quality
criteria necessary to support those uses;
(b) The minimum beneficial uses to be
considered by States in establishing
water quality standards are specified as
public water supplies, propagation of
fish and wildlife, recreation, agricultural
uses, industrial uses and navigation; • •
(c) A requirement that State standards
•oust protect public health or welfare.
enhance the quality of water and serve
tha purposes of the'Clean Water Act;
(d) A requirement that States must
review their standards at least once each
three year period using a process that .
Includes public participation; •
(e) The process for EPA review of
State standards which may ultimately '
result in the promulgation of B
superseding Federal rule in cases where
« State's standards are not consistent
with the applicable requirements of the
CVVA, or in situations where the Agency
determines Federal standards are
necessary to meet the requirements of
"theAct/
Another major innovation in the 1972
FWPCA was the establishment of the
National Pollutant Discharge
Elimination System (NPDES) which '
inquires point source discharges to
• obtain a permit before legally
discharging to the waters of the United
States. In addition to the permit limits
established on the basis of technology
(e.g. effluent limitations guidelines), the
Act requires discharges to meet instroam
water quality standards. (See section
30i(bXlHQ, 33 U.S.C. 1311(b)(D(C)). - .
The water quality standards serve a
dual function under the Clean Water
Act regulatory scheme. Standards
establish narrative and numeric
definitions and quantification of the
Act's goals and policies (see section 101.
33 U.S.C. 1251) which provide a basis
for Identifying impaired waters. Water
quality standards also establish
regulatory requirements which are
translated into specific discharge •
requirements. In order to fulfill this
critical function, adopted State criteria
must contain sufficient parametric
coverage to protect both, human health
and aquatic life.
In Its initial efforts to control toxic
pollutants, the FWPCA, pursuant to
.section 307, required EPA to designate
a list of toxic pollutants and to establish
toxic pollutant effluent standards based
on a formal rulemaldng record. Such
rulemaking required formal hearings,
including cross-examination of
witnesses. EPA struggled with this
unwieldy process and ultimately
promulgated effluent standards for six
toxic pollutants, pollutant families or
mixtures. (See 40 CFR part 120.)
Congress amended section 307 in the
1977 Clean Water Act Amendments by
endorsing the Agency's alternative •
procedure of regulating toxic pollutants
by use of effluent limitations guidelines,
by amending the procedure for
establishing toxic pollutant effluent
standards to provide for more flexibility
in the hearing process for establishing a
record, and by directing the Agency to
include sixty-five specific pollutants or
classes of pollutants on the toxic
pollutant list EPA published the
required list on January 31,1878 (43 FR
4109). This toxic pollutant Hst was the
basis on which EPA's efforts on criteria
development for toxics was focused.
During planning efforts to develop
effluent limitations guidelines and
water quality criteria, the list of sixty-
five toxic pollutants was judged top
broad as some of the pollutants were, in
fact, general families or classes of * •
• organic compounds consisting of many
individual chemicals. EPA selected key
chemicals of concern within the 65
families of pollutants and identified a .
more specific list of 129 priority, toxic
pollutants. Two volatile cfiemicals and
one wateTunstable chemical were '' •
removed from the list (see 46 FR 2266,
January 8.1981; 46 FR 10723. February
4.,1981) so that at present there are 126
priority toxic pollutants. This list is
published as appendix A to 40 CFR part
'423. •'.'.-'•
Another critical section of the 1972
FWPCA was section 304(a) (33 U.S.C.
1314(a)). Section 304(a)(l) provides, in '
pertinent part, that EPA
•• •shall develop and publish*-••
criteria for water quality accurately reflecting
the latest scientific knowledge (A) on the
kind and extent of all identifiable effect* on' '
health and welfare including, but not limited
to, plankton, fiih. shellfish, wildlife, plant .
life, shorelines,beaches, esthetics,and' •'.
recreation which may be expected from the
•presence of pollutants in any bpdy of water* .
* * * md (Q on the efforts of pollutants on
biological community diversity, productivity,
•nditahffity.'*.* • „ .
In order to avoid confusion, it must be
recognized that the Clean Water Act
•uses the term "criteria" in two separate
Ways. In section 303(c). which is . • '
discussed above, the term is part of the
definition of a water quality standard.
That is, a water quality standard is
comprised of designated uses and the
criteria necessary to protect those uses.
. Thus, States are required to adopt
-regulations or statutes which contain
legally achievable criteria. However, in
section 304(a), the term criteria is used
in e scientific sense and EPA develops
recommendations which States consider
in adopting regulatory criteria. .
In response to this legislative mandate
and an earlier similar statutory
requirement, EPA and a predecessor
agency have produced a series of
scientific water quality criteria guidance
documents. Early Federal efforts were
Water Quality Criteria (1968 "Green
Book") and Quality Criteria for Water
(1976 "Red Book"). EPA also sponsored
a contract effort with the National
Academy of Science—National
Academy of Engineering which resulted
in Water Quality Criteria. 1972 (1973.
"Blue Book"). These early efforts were
premised on the use of literature
feviews and the collective scientific
Judgment of Agency and advisory'
panels. However, wltren faced with the
list of 65 toxic pollutants and the need
to develop criteria for human health as
well as aquatic life, the Agency . •"<
determined that new procedures were
necessary. Continued reliance solely on
•existing scientific literature was deemed •.
inadequate, since for many pollutants
essential information was not available.
EPA scientists developed formal
methodologies for establishing
.scientifically defensible criteria. These
were subjected to review by the
Agency's Science Advisory Board of
outside experts and the public. This
effort culminated on November 28.
1980. when the Agency published
criteria development guidelines for
aquatic life and for human health, along
with criteria for 64 toxic pollutants. (See
45 FR 79318.) Since that initial .
publication, the aquatic life
.methodology was slightly amended (50
FR 30784. July 29,1985) and additional
criteria was proposed for public
comment and finalized as Agency
• criteria guidance. EPA summarized the. .
available criteria information in Quality
^Criteria for Water 1986 (1986 "Gold
Book") which is updated from time-to-
time. However, the individual criteria
documents, as updated, are the official
guidance documents. . :
EPA's criteria documents provide a
comprehensive toxicological evaluation
of each chemical. Far toxic pollutants,
the documents tabulate the relevant
acute and chronic to:ddty information
for aquatic life and derive the criteria
maximum concentrations (acute criteria)
'and criteria continuous concentrations
(chronic criteria) which the Agency
recommends to protect aquatic life
resources. For human health criteria, the
document provides the appropriate
reference, apses, and if appropriate, the
carcinogenic slope factors, and derives
recommend criteria; The details of this
process are described more fully in a
later part of this Preamble.
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Federal Register / Vol. 57. No. 246.7 Tuesday. December 22. 1892 / Rules and Regulations '60851
: , Progyammatioally. EPA's Initial efforts
were aimed at converting a program
focused on interstate waters into one
addressing all interstate and intrastate
surface waters of the United States.
Guidance was aimed at the inclusion of
traditional water quality parameters to
• protect aquatic life (e.g.. pH,
temperature, dissolved oxygen and a '
narrative "free from toxitity"
provision), recreation (e.g.,
bacteriological criteria) and general
aesthetics (e.g.. narrative "free from
nuisance" provisions). EPA also •
required State adoption of an •' . .
antidegfadatiori policy to maintain
existing high quality or ecologically
' unique waters as well as maintain
improvements in water quality as they
- occur. "• ' "
The initial water quality standards
regulation was actually a part of EPA's
water quality management regulations
implementing section 303(e) (33 U.S.C.
1313(e)) of the Act It was not
comprehensive and did not address
toxics or any other criteria specifically.
Rather, it simply required States to
adopt appropriate water quality criteria
necessary to support designated uses.
(See 40'CFR 130.17 as promulgated in
40 FR 55334, November 28,1975).
After several years of effort and faced
with increasing public and
Congressional concerns about toxic
pollutants, EPA realized that proceeding
, under section 307 of the Act would not
comprehensively address in a timely
'manner the control of toxics through
either toxic pollutant effluent standards
or effluent limitations guidelines .
because these controls are only
applicable to specific types of
discharges. EPA sought a broader, more
generally applicable mechanism and
decided to vigorously pursue the .
alternative approach of EPA issuance of
scientific water quality criteria
documents which-States could use to
adopt enforceable water quality
-•standards. These in turn could be used
as the basis for establishing State and
EPA permit discharge limits pursuant to
section 301(bXl)(Q which requires .
NPDES permits to contain '
• * ".any jnnrtk ffrtngunt limlhltinn,
Including tboM neoesuiy to meet vnter
•quality standards* ••,.or required to
implement any applicable water quality
standard established pursuant to this Act
Thus, the adoption by Stales of .
appropriate toxics criteria applicable to
. -their surface, waters, such as those :
recommended by EPA in its criteria ,
documents, would be translated by
regulatory agencies into point source
permit.limits. Through the use of water
quality standards, all discharges of
toxics are subject td permit limits and
not-}ust those discharged by particular
industrial categories. In order to
facilitate this process, the Agency
amended the water quality standards
regulation to explicitly address toxic
criteria requirements in State standards.
The cuhnination of this effort was the
promulgation of the present water ,
quality standards regulation on
November 8,1983 (40 CFR part 131,48
FR 51400).
The current-water quality standards
regulation (40 CFR part 131) is much •
more comprehensive than its
predecessor. The regulation addresses in
detail both the beneficial use
component and the criteria component'
of a water quality standard. Section
131.11.of the regulation requires States
to review available information and,
• • * to identify specific water bodies
where toxic pollutants may be adversely
affecting water quality or toe attainment of
the designated water use or where the tarvU
of toxic pollutants are at a level to warrant •
concern and must adopt criteria far such
toxic pollutants' applicable to the water body ~
sufficient to protect the designated use. -
The regulation provided that either or
bom numeric and narrative criteria may
be appropriately used in, water quality
standards. • . ' •
EPA's water quality standards. ' . :
emphasis since the early 1980's ..,.'
reflected the increasing importance
placed on controlling toxic pollutants.
States were strongly encouraged to '.
adopt criteria in their standards for the.
priority toxic pollutants, especially
where EPA had published criteria
guidance under section 304(a) of the
Act , '
Under the statutory scheme, during
the 3-year triennial review period
following EPA's 1980 publication of
water quality criteria for the protection
• of human health and aquatic life, States
should have reviewed those criteria and
adopted standards for many priority
toxic pollutants. In fact. State response
to EPA's criteria publication and toxics
initiative was'disappointing. A few.
States, adopted large numbers of.
numeric toxics criteria, although
primarily for the protection of aquatic
' life. Most other States adopted few or no
water quality criteria-far priority toxic
pollutants. Some relied on a narrative
"free from toxitity" criterion, and so-
called "action levels" for toxic
•pollutants or occasionally calculated
site-specific criteria. Few States
addressed the protection of human
health by adopting numeric human •
health criteria.
In support of the November, 1983.
water quality standards rulemaking.
EPA issued program guidance entitled,
Water Quality Standards Handbook
(December 1983) simultaneously with
the publication of the final rule. The • .
foreword to that guidance noted EPA's
two-fold water quality based approach
to controlling toxics: chemical specific
numeric criteria and biological testing
in whole effluent or ambient waters to
comply with narrative "no toxics in
toxic amounts" standards. Mora . '
detailed programmatic guidance on the
application of biological testing was
provided in the Technical Support •
Document for Water Quality Based
Toxics Control (TSD) (EPA 440/4-85- '
032, September 1985). This document'
provided the needed information to •
convert chemical specific and . '.
biologically based criteria Into water .
quality standards for ambient receiving
waters and permit limits for discharges -
to those waters. The TSD focused on the
. use of bioassay testing of effluent (so-
called whole effluent testing or WET
methods) to develop effluent limitations
within discharge permits. Such effluent
limits were designed to implement the
"free from toxidty" narrative standards '
in State water quality standards. The .•
. TSD also focused on water quality
standards. Procedures and policy were
presented for appropriate design flows
for EPA's section 304(a) acute and
chronic criteria. In 1991. EPA revised
and expanded.the TSD. (Technical
Support Document for Water Quality-
based Toxics Control, EPA 505/2-00-
001, March 1991.) A Notice of . .
Availability was published in the
Federal Register on April 4.1991 (56 FR
13827). All references in this Preamble..
are to the revised TSD. • ..... ,
The Water Quality Standards '
Handbook and the TSD are examples of
. EPA's efforts and assistance that were
intended to help, encourage and support
the States in adopting appropriate water
quality standards for the protection of
their waters against the deleterious
effects of toxic pollutants. La some .
States, more and more numeric criteria'
for toxics were being adopted as well as
more aggressive use of the "free from
toxics" narratives in setting protective
'• NPDES permit limits.. However, by the
time of Congressional consideration and
action on the CWAreauthorization;" '-
most States had adopted few, if any,
water quality standards for priority toxic
pollutants.
Statepracticea of developing case-by-
case effluent limits using procedures
that were not standardized instate
regulations made it difficult to ascertain
whether such procedures were
consistently applied. The use of
approaches to control toxidty that did
not rely on the statewide adoption of
numeric criteria for the priority toxic
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..€0852 Federd Reg&erV VoL 57. No. 246 / Tuesday. December 22. 1992 1 Rules and Regulation*
pollutants generated frustration In
Ckragress. Senator Robert T. Stafford, '•
first chairman and then ranking
minority member of the authorizing
committee, noted during the Senate
debate:
pollutant* listed pursuant to section 307{a)(l)
of thi* Act for which criteria have been -
published under section 3O4M, the discharge
or presence of which in the affected waters
rouMzeMonabryba expected to interim •
with those designated uset adopted by the
State, as necessary to support such
designated ute*. Such criteria shall be
specific numerical criteria for such toxic
pollutants. Where such numerical criteria are
,-~ »~~>.j/yuuuuii»juiu0ujmpowu]ieio not available, whenever a State wviews water
calculate additional discharge limitations for ' quality standard* pursuant to paragraph (1),
toxics* * *. It i* vitally important that the or revue* or adopt* new standards pursuant
~~, i,^^_J..i . tothisi«agra|ih.su<±St«teshalladopt
criteria based on biological monitoring or
•tsestment methods consistent with' .
information published pursuant to section .
304(8X8). Nothing in this section shall be
construed to limit or delay the use of .effluent -
limitation* or other permit conditions based
oa or involving biological monitoring or
assessment methods or previously adopted
numerical criteria. •'• •
An Important problem In thi* regard 1* that
few State* have numeric ambient criteria fa
todc pollutant!. The lack of ambient criteria
(for toxic pollutanu] make it impocdble to
water quality standards pm^m operate In
such a way thit Hsnpports the objectives of
tho Clean Water Act tomtore and maintain
* the Integrity of the Nation's Waters.
(bracketed matarial added). A Legislative '
Hlrtory of the Water Quality Act of 1987
(Wb.1. 100-4)rS ith« States to move more quickly and
comprehensively, Thus Congress
developed the water quality standards'.
. amendments to the Clean Water Act for
reasons simthr to those strongly stated
, during the Senate debate by a chief
sponsor,- Senator John H. Chafee, " ...'
A cornentone of the bHTs'hew toxic
pollution control requirement* is theso • •'" • -
calledbeyond-BATprogram* • •.Adopting
tt« beyond BAT provi«km* will assure thai:
EPA continues to more forward rapidly on
too program* * *• If we are going to repair
- the damage to tho*« water bodies that h«re-
become highly degraded a* a result of toxic
subrtance*. we are going to have to move
forward expedltloualy on thi* beyond-BAT-
. prc^rtm.TbeN«tIoncannottolerate endless '
delays and negotiations between EPA and
States on this program. Both entities must
XBOVP aggressively in taking the necessary
stops to make this program work within the
time fiame esiabUsneoYby this BUI* • *.
MA, at page 1300. • " _•>
This Congressional impatience with
the pace of State and EPA progress and
- an appreciation that the lack of State
standards for toxics undermined the
•fiectiveriess of the entire CWA-based
scheme, resulted In the 1987 adoption
of stringent new water quality standard
provisions in the Water Quality Act
amendments.
2.The Water Quality Act Amendments "
cflS87(Pub.L.~100-4) [•• '
«. Description of the New Requirements .
The 1387 Amendments to the dean
Water Act added-Section 303(c)(2)CB)
b. EPA's Initial Implementing Actions
for Sections 303(c) and 3040)
The addition "of this new requirement'
to the existing water quality standards
-review and revision process of section
'303(c) did.not change the existing
procWural or timing provisions. For
example, section 303(c)(l) still requires
that States review their water quality
• standards at-least once each 3 year
. period and transmit the results to EPA
for review. EPA's oversight and '.
schedules in section 303(c)(4) were
Lkewise unchanged. Rather, the ' •
provision required the States to place •
Iteavy emphasis on adopting numeric
chemicatipecific criteria for toxic
. pollutants (Le., rather than just narrative
approaches) during the next triennial '
review cycle. As discussed in the
-previous section. Congress was
frustrated that States were not using the"
numerous section 304(a) criteria that
.EPA had developed,«nd was continuing
to develop, to assist States in-controlling
the discharge of priority.toxic
pollutants. Therefore, for the first time
corollary amendment because it
required States to take actions to •
Identify waters adversely affected by
toxic pollutants, particularly those
waters entirely or substantially Impaired
by point sources. Section 3040) entitled
"Individual Control Strategies for Toxic
Pollutants." requires in part, that States
Identify and list watarbodies where the
detigBated-raesspecHied-inthe
applicable water quality standards'
cannot reasonably bo expected to bo
achieved because of point source
discharge of toxic pollutants. For each
segment so identified, the State Is
required to develop Individual control
strategies to reduce the diacharge of .
toxics from point sources so that In
conjunction with existing controls on
pointand nonpoint sources, water
quality standards will be attained. To
assist the States in identifying waters
under section 304(1). EPA?s guidance
. listed a number of potential sources of
available data for States to review.
States generally assembled data for a
broad-spectrum of polhitahts, including
could be useful Incomplying with
factions 3040) and 303(c)(2)(B). fa fact,
between February 1888 and October
•1988. EPA assembled: pollutant
candidate lists for«etHon 3040) which
were then transmitted to each "" "
Jurisdiction. Thus, each State had a
lUminarv list of pollutants that had
i as present in, or
in the history of the Clean Water Act,
Congress toox the unusual action of
exph'dtiy mandating that States adopt
numeric criteria for specific toxic
pollutants. : • .
hi response to this new Congressional
'Whenaver a State reviews water quality .
stenlard*pur*uanttopaTagraph(l?ofthi*
sobcoction, or revile* or adopt* new •.
standards puwutnt to thl* paragraph, such •
SUte shall adopt criteria for aUtadT
mandate, EPA redoubled its efforts to
promote and assist State adoption of
water quality standards for priority toxic
pollutants. EPA's efforts included the
development and issuance of guidance
to the States on acceptable
Implementation procedures for several
new sections of the Act Including
sxjctions 303(c)(2)(B>and 3040). . .
The 1987 CWA Amendments added •
to, or amended, other CWA Sections
related to toxics control Section 3040)
,(33 U.S.C. 13140)) was an important .'
discharged to, surfecti waters. Such Usts
were Umited by the quantity and
distribution of availal)le effluent and'
ambient monitoring data for priority ,
toxic pollutants. This listing exercise
iurther emphasized the need for water
quality, standards for (toxic pollutants.
lack of standards increased the
difficulty of identifying unpaired
waters. On the positive aide, the data
gathered In support of the 3040) activity
proved helpful In identifying those
pollutants most obviously In need of
water quality standards.
EPA. In devising guidance for section
303(c)(2)(B), attempted to provide States
the maximum flexibility that complied
with the express statutory language but
also with the overriding congressional
objective: Prompt adoption and : ' -.
implementation of numeric toxics
criteria. EPA believed that flexibility.
was Important so that eachState could
comply with section 303(c)(2KB) and to •
the extent possible, accommodate its
existing water quality standards
regulatory approach. The options EPA
identified are described in the next
Section of this Preamble. EPA's program
•guidance was Issued In final form on
December 12,1988 but was not
-------
Federal Register / Vol. 57, No. 246 /Tuesday, December 22, 1992 / Rules and Regulations 6O8S3
: substantially different from earlier drafts
available for review by the States. The
availability of the guidance was
published'in a Federal Register Notice
on January 5,1989 (54 FR 346).
3. EPA's Program Guidance for Section
303(c)(2)(B)
"EPA's section 303(cX2)(B) program
guidance identified three options that
could be used by a State to meet the
requirement that the State adopt toxic
pollutant criteria "• * * the discharge
or presence of which in the affected
waters could reasonably be expected to
interfere with those designated uses
adopted by the State, as necessary to
support such designated uses."
Option 1. Adopt statewide numeric .
criteria in State Water Quality Standards
. for all section 307(a) toxic polhitants for
which EPA has developed criteria
guidance, regardless of whether the
pollutants are known to bepresent
This option is the most
comprehensive approach to satisfy the
'statutory requirements because it would
include all of the priority toxic
pollutants for which EPA has prepared
section 3(k(a) criteria guidance for .
eitner or both aquatic Hfa protection and
••• human health protection. In addition to
a simple adoption of EPA's section
304(a) guidance as standards, a State •' -
must select arisk level for those toxic
pollutants which are carcinogens (Le., •
^B« f-niic^ fir may rainca r-fliy^»r fa
'humans).
Many States found this Option
attractive because it ensured
comprehensive coverage of the priority
toxic pollutants with scientifically
defensible criteria without the need to
conduct a resource-intensive evaluation
of the particular segments and
pollutants requiring criteria. This option
would also not be more costly to
dischargers than other options because
permit limits would only be based on
. the regulation of the particular toxic
pollutants in their discharges and not on
the total listing in the water quality
standards. Thus, actual permit limits
should be the same under any of the
options. •••'-.
Option 2. Adopt chemical-specific
numeric criteria for priority toxic
'pollutants that are the subject of EPA
section 3O4(a) criteria guidance, where
•tine State determines based on available
information that the pollutants are .
•; present or discharged and can .,..'' •
' seasonably be expected to interfere with
.designated uses. .
This option results in the adoption of
numeric water quality standards for
some subset of those polhitants for
which EPA has issued section 304(a)
criteria guidance based on a review of
current information. To satisfy this
Option, the guidance recommended that
States use the data gathered during the
section 304(1) water quality assessments
as a starting point to identify those
water segments that need water quality
standards for priority toxic pollutants.
That data would be supplemented by a
State and public review of other data
sources to ensure sufficient breadth of
Among the data available to be reviewed
were: (1) Ambient water monitoring •
information, including those for the •
•water column, sediment, and aquatic
life (e.g., fish tissue data); (2) NPDES
permit applications and permittee self-
monitoring reports; (3) effluent
guideline development documents,
many of which contain priority toxic
pollutant scans; (4) pesticide and
herbicide application information and
other records of pestidde or herbicide
inventories; (5) public water supply
source monitoring data noting •
pollutants with maximum contaminant
levels (MCLs); and (6) any other relevant
information on toxic pollutants '
collected by Federal. State, industry,
agencies, academic groups, or scientific
organizations. EPA also recommended
that States selecting this option adopt a
translator provision similar to that
described in Option 3 but applicable to
all chemicals causing toxidty, and not
fust priority toxic pollutants.
This Option 2 re view resulted in a
State proposing new or revised water
•. quality gfnnHnrrtc antt providing an •
opportunity for pubUc review and
comment on the pollutants, criteria, and
water bodies included. Throughout this
process, EPA's Regional Offices were
available to assist States by providing
additional guidance and technical
assistance on applying EPA's
recommended criteria to particular
situations in the States.
Option 3. Adopt a procedure to be
applied to a narrative water quality .
standard provision prohibiting toxidty
in receiving waters. Such procedures .
would be used by the State in
r^lrnlntJTip derived numeric criteria
which must be used for all purposes
under section 303(c) of the CWA. At a
minimum, such criteria' need to be ' •
developed for section 307(a) toxic
pollutants, as necessary to support
designated uses, where these pollutants
are discharged or present in the affected
waters and could reasonably be
expected to interfere with designated
uses.
The combination of a narrative
standard (e.g., "free from toxics hi toxic
amounts'O and an approved translator
mechanism as part of a State's water
. quality standards satisfies the
requirements of section 303(c)(2)(B). As
noted above, such a procedure,is also a
valuable supplement to either option 1
or 2: There are several regulatory and
scientific requirements EPA's guidance
specifies are essential to ensure
acceptable scientific quality and full
involvement of the public and EPA in
this approach. Briefly stated these an:
,• The procedure (i.e..narrative
criterion and translator) must be used to
calculate numeric water quality criteria;
• The State must demonstrate to EPA ,
that the procedure results in numeric •
criteria that are sufficiently protective to
meet the goals of the Act;...
• The State must provide for full
opportunity for public participation
during the adoption of the procedure;
• The procedure must be formally
adopted as a State rule andbe
mandatory in application; and
• The procedure must be submitted
for review and approval by EPA as part
of the State's water quality standards
regulation. ..-'-"' • - •
The scientific elements of a translator
are similar to EPA's 3Q4(a) criteria
methodologies, when applied on a sito-
specific basis. For example, aquatic
criteria are developed uring a sufficient
•number and diversity of aquatic species .
representative of die biological
assemblage of a particular water body.
Human health criteria focus.cn
determining appropriate exposure
conditions (eg. amount of aquatic life
consumed per person per day) rather .
than underlying pollutant toxicity. The
results-of the procedures are
scientifically defensible criteria that are
protective for the site's particular
conditions. EPA's review of translator
procedures includes an evaluation of
the scientific merit of die procedure
using the section 304(a) methodology as
a guide. • ,
Ideally, States adopting option 3
translator procedures should prepare a
preliminary list of criteria and specify <
the waters the criteria-apply to .at the ,
time of adoption. Although under .
options the State retains flexibility to
derive new criteria without revising the
. adopted standards, establishing mis
preliminary list of derived criteria at the
time of the triennial review will assist
die public in determining die scope of
the adopted standards, and help ensure
that die State ultimately .complies with
the requirement to establish criteria for
all pollutants that can "reasonably be
expected" to interfere with uses. EPA
. believes dial States selecting solel.
option 3 should prepare an analysis
'(similar to that required of option 2 .
States) at the time of the triennial
review identifying pollutants needing
criteria. \
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60854 Federal Register / Vol. 57, No. 246 / Tuesday. December 22, 1992 / Rules and Regulations
EPA's December 1988 guidance also
• addressed the timing issue for State
compliance with section 303(c){2)(B).
. The statutory directive was clear: All
State standards triennial reviews
. initiated after passage of the Act must
include a consideration of numeric toxic
criteria. • .
* The structure of section 303(c) is to
require States to review their water
quality standards at least once each
three year period. Section 303(c)(2)(B)
instructs State* to include reviews for
toxics criteria whenever they initiate a
triennial review. EPA initially looked at
February 4,1090, the 3-year anniversary
of the 1987 CWA amendments, as a
convenient point to index State
compliance. The April 1990 Federal
Register Notice used this index point for
the preliminary assessment However,
some States ware very nearly .
completing their State administrative
processes for ongoing reviews when the
1887-ttmendments were enacted and
•could not legally amend those .
proceedings to address additional toxics .
criteria. Therefore, in the interest of
fairness, and to provide such States a
full 3-year review period, EPA's FY
1990 Agency Operating Guidance '
provided that "By the end of the FY 88-
60 triennium, States should have . •
completed adoption of numeric criteria '
•to meet the section 303(c)(2)(B)
' requirements." (p.48.) The FY 88-90
triennium ended on September 30,
"1B90.
dean Watar Act section 303(c) does •
not provide penalties for States that do
-not complete timely water quality
standards reviews. In no previous case
has the EPA Administrator found that
State failure to complete a review
within three years Jeopardized the •
public health or welfare to such an
extent that promulgation of Federal
standards pursuant to section
303(c){4)(B) was justified. The pre-1987
CWA never mandated State adoption of
priority toxic pollutants or other -'
specific criteria. EPA generally relied on
its water quality standards regulation
(40 CFR 131.11) and its criteria and
program guidance to the States on
appropriate parametric coverage in State
water quality standards to encourage
State adoption of water quality
standards. However, since the 1987
statutory amendments, the
programmatic environment has
changed. Beyond the increased
Congressional and public concern,
about the relative importance of toxic
pollutant controls, there is increased
evidence of toxic pollution problems in
our Nation's waters. In response, the
Agency in this rulemaldng is proceeding
pursuant to section 303(c)(4)(B) and 40
•CFR 131.22(b) to rectify a longstanding
program deficiency. . " _' •
The current regulation at 40 CFR Part
131 in conjunction with the statutory .
language provides a clear and
'• unambiguous basis and process for •
today's Federal promulgation.
C State Actions Pursuant to Section
303(cH2MB) ,
In recent years, there has been
substantial progress by many States in
the adoption, and EPA approval, of
water quality standards for toxic
•pollutants. Virtually all States have at
least proposed new toxics criteria for
priority toxic pollutants since section
303(c)(2)(B) was added to the CWA in
February of 1987. Unfortunately, not all
such State proposals'address, in a
• comprehensive mariner, the •
requirements of section 303(c)(2)(B). For
example, some States have proposed to
adopt criteria to protect aquatic life, but
not human health; other .States have
proposed human health criteria which
do not address major human exposure •.
pathways. In addition, in some cases
final adoption of proposed State toxics
criteria which would be approvable by
EPA has been substantially delayed due
to controversial and difficult issues
associated with the toxics criteria -
adoption 'process. For purposes of
today's rulemaVdng, it is EPA's Judgment
that 43 States completed actions which •
fully satisfy the requirements of section
303(c)(2)(B). . ; .
• In sum, States have devoted
substantial resources.' and have made
substantial progress, in adopting new or
revised numeric criteria for priority
pollutants. In so doing, they have
addressed a number of significant and
difficult issues. These efforts have .
generated extensive examination by
dischargers.-States, environmental •
groups and the public on all aspects of
the CWA water quality criteria and
related issues. It amounts to a multi-year
consideration of the issues that are
central to this proposed and final
rulemaldng. '
D. Determining State Compliance With
Section 303(cX2MB)
1. EPA's Review of State Water Quality
Standards for Toxics
The EPA Administrator has delegated
the responsibility and authority for
review and approval or disapproval of
all State water quality standards actions
to the 10 EPA Regional Administrators
(see 40 CFR 131.21). State section
303(c)(2)(B) actions are thus submitted
to the appropriate EPA Regional •
Administrator for review and approval.
This de-centralized EPA system for
State water quality standards review
and approval is guided by EPA
Headquarters Office of Water, which
issues national poilides and guidance to
the States and Regions such as the
annual Office of Water Operating
Guidance and various technical
manuals. '
' For purposes of evaluating State
compliance with CWA section
303(c)(2)(B). EPA rolled on the statutory
.- language, the existing water quality
standards regulation, end section
303(c)(2)(B) national guidance to
provide the basis for EPA review. In ..
some cases, individual Regions also
used Regional policies and procedures
in reviewing State section 303(c)(2)(B) .
actions. The flexibility provided by the
national guidance, coupled with subtle
differences in Regional polities and
procedures, contributed to some
differences in the approaches taken by
States to satisfy section 303(c)(2)(B)
requirements. .-•-,
As discussed previously. EPA's final
guidance on compliance with section
303(c)(2)(B) was developed to provide.
States with the necessary flexibility to •
allow State standards revisions that
would complement the State's existing.
water quality standards program and •
still comply with section 303(c)(2)(B).
As guidance, it described the range of
acceptable approaches and EPA's
recommendations. Some innovative
State approaches wrere expected as well
as differences in terms of criteria
coverage, stringency and application
procedures. . •
Although the guidance provided for
State flexibility, it was also consistent • :
with existing water quality standards
regulation requirements of 40 CFR
131.11 that explicitly require State
criteria to be sufficient to protect
designated uses. Such water quality
criteria also must be based on sound *
scientific rationale and support the most
sensitive use designated for a water
body.
The most complicated EPA .
compliance determinations involve' •
States that selected EPA Options.2 or 3.
Since most States use EPA's section '-
304(a) criteria guidance, where States
select Option 1, EPA normally is able to
focus Agency efforts on verifying that all
available EPA criteria are included.
appropriate cancer risk levels are
selected, and that sufficient application
procedures are in place (e.g. laboratory .
analytical methods, mixing zones, flow
condition, etc.). v
However, for States using EPA's
Option 2 or 3, substantially more EPA
evaluation and judgment was required
because the Agency'must evaluate .
which priority pollutants and, in some
-------
Federal Register / VoL 57, No. 246 / 'Tuesday. December 22, 1992 / Rules and Regulations
6O855
cases, segments or Hesignated uses.
require numeric criteria. Under these
options, the State must adopt or derive
numeric criteria for priority toxic ,
pollutants for which EPA has section
304(a) criteria. "•• • the discharge or
presence of which in the effected waters
; could reasonably be expected to
interfere with those designated uses
adopted by the State* • VThe
> necessary justification and the ultimate
coverage and acceptability of a State's
actions vary State-to-State because of
differences hi the adequacy of available
monitoring information, local .
waterbody use designations, the affluent
and nonpoint source controls in place,
and different approaches to the
scientific basis for criteria.
In submitting criteria'for the
protection of human health. States were
not limited to a 1 In 1 million risk level
(10-6). EPA generally regulates
pollutants treated as carcinogens hi the
range of 10"6 to 10~^ to protect average
exposed individuals and more highly -
exposed populations. If a State selects a
criterion that represents an upper bound
risk level less protective than 1 in .•
100,000 (Le., 10-*), however, the State
' needed to have substantial support hi
the record for this level This support
focused on two distinct issues. First, the
record must include documentation that
the. decision maker considered the -
public interest of the State in selecting
the risk level, including documentation
of public participation in the decision
maHng process as required by the water
quality standards regulation at 40 CFR
-131.2O(b); Second, the record must
include an analysis showing that the.
risk level selected, when combined with
other risk assessment variables, is a '
balanced and reasonable estimate of
. actual risk posed, based on the best and
most representative information
available. The importance of the
estimated actual risk increases as the
degree of conservatism in the selected
risk level riiminishm. EPA carefully
evaluated all assumptions .used by a
' State if the State chose to alter any one
of the standard EPA assumption values.
Where States selected Option 3. EPA
reviews must also include an evaluation
iof the scientific defensibility of the
translator procedure. EPA must also
verify that* requirement to apply the
translator whenever toxics may
"reasonably be expected to interfere with
designated uses (e.g., where such toxics
. exist or are discharged) is included in
the State's water quality standards.
Satisfactory application procedures
must also be developed by States '
selecting Option 3..
In general, each EPA Region made
- compliance decisions based on
whatever information was available at
the time of the triennial review. For
some States, information on the
presence and discharge of priority toxic
pollutants is extremely limited.
Nevertheless, during the period of
February 1988 to October 1990. to
supplement State efforts, EPA
assembled the available information and
provided each State with various
pollutant candidate lists in support of
die section 304(1) and section
303(c)(2)(B) activities. These were based
in part on computerized searches of
existing Agency data bases.
Beginning in 1988, EPA provided
States with candidate lists of priority
toxic pollutants and water bodies in
support of CWA Section 304(1)
implementation. These lists were
developed because States were required
to evaluate existing and readily
available water-related data in order to
comply with Section 304(1). 40 CFR
130.10(d). A similar "strawman"
analysis of priority pollutants
'"potentially requiring adoption of
. numeric criteria .under Section
303(c)(2)(6) was furnished to most
States in September or October of 1990
for their use in on-going and subsequent
triennial reviews. The primary
Differences between the "strawman"
analysis and the section 304(1)
candidate lists were mat the
"strawman" analysis: (1) Organized the
•results by chemical rather than by water
.body, (2) included data for certain •
. STORET monitoring stations that were
not used in constructing the candidate .".
lists, (3) included data from the Toxics
Release Inventory database, and (4) did
not include a Dumber of data sources
used in preparing the candidate lists
,(e.g. those, such as fish kill information,
.that did not provide chemical specific
information). '•-...
In its 1988 section 3O3(c)(2HB)
guidance. EPA urged States, at a
minimum, in ncn tfcn fnfnfp^Btlon •
gathered in support of section 304(1)
requirements as a startingpoint for '.
. identifying which priority toxic
pollutants require Adoption of numeric
criteria. EPA also encouraged States to
consider the presence or potential
construction of facilities that '
manufacture or use priority toxic
pollutants as a strong indication of the
need for toxics criteria. Similarly, EPA
indicated to States that the presence of
priority pollutants hi ambient waters
(including those m sediments or in
aquatic life tissue) or m discharges from
point or nonpoint sources also be
considered as an indication that toxics '
criteria should be adopted. A Umited
amount of data on the effluent •
characteristics of NPDES discharges was
readily available to States. States were
also expected to take into account newer
information as it became available, such
as information in annual reports from
die Toxic Chemical Release Inventory
requirements of me Emergency Planning
and Community Right-To-Know Act of
1986. (Title m, Pub. L. 99-499.)
m summary, EPA and die States had
access to a variety of information
gathered in support, of section 304(1),
section 303(cK2KB). and section 305(b)
activities. For some States, as noted
above, such Information for priority
toxic pollutants is extremely limited. In
die final analysis, die Regional '
Administrator made a judgment on a •
duly submitted State standards triennial
review based on die State's record and
die Region's independent knowledge of
die facts and circumstances surrounding
die State's actions. These actions, taken
In consultation with die Office of Water,
determined which State actions were
sufficiently consistent with die coverage
contemplated in die statute to justify . •
approval. These approval actions
Include allowable variations among
State water quality standards. EPA.
approval indicates dial, based on die
record, die State water quality standards
met die requirements of die Act
2.-Determining Current Compliance
Status
The following summarises die process.
generally followed by die Agency in
assessing compliance with section
303(c)(2KB).
' A State was determined to be in full
compliance with the requirements of
section 303(cK2)(B) if,
' a. The State had submitted a water
quality standards package for EPA
review since enactment of die 1987 ;
Clean Water Act amendments or was
determined to be already In compliance,
and,
b. The State adopted water quality
standards are effective under Stale law
and consistent with die CWA and EPA's
implementing regulations TEPA's
December 1988 guidance described
three Options, any one, or a
combination of which EPA suggested
States could adopt for compliance with
die CWA and EPA regulations), and
. c. EPA has Issued a formal approval
determination to die State.
States meeting dtese criteria are not
included in HM? fin«1 ruf
States which adopted standards -
following Option 1 generally have been
found to satisfy section 303{cH2)(B). An
exception exists for selected States
which attempted to follow Option 1 by
adopting all EPA section 304(a) criteria
by reference. EPA has withheld
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60856
Federal Register / Vol. 57, No. 246 / Tuesday. December 22. 1992 / Rides and Regulations
approval for one State which has
adopted such a reforence.into their
standards because the adopted
standards did not specify.application
factors necessary to implement the
criteria (e.g., a risk level for
carcinogens). Other States have
achieved, full compliance following
options 1,2,3. or some combination of
these options.'
As of the date of signature of today's
rule, the Agency has determined that 43
States and Territories are in full
•compliance with the requirements of
.section 303(c)(2){B). Compliance status •
for all States and Territories is set forth
in Table 1. ... -
FABLE 1.—ASSESSMENT OF STATE COM-
•PUANCE WITH CWA SECTION
303(C){2){B)
CfJanrin
In**
touWw*.
U*lo«_
NodhCarema
South Caretoa.
TSOOMIII
Iftth,
fjli- f-Klnj-ii-ii-i
Trt«f»nQioo.
Comnxxnw«Mi of *M Nonhtm Msr-
kStatcIn
compUanc*
wtti section
303(eK2XB)?
YM.
Na
YM..
Na
Na
YM.
YM.
YM.
Na
YM.
Y8S.
Na
YM.
YM.
YM.
Na
YM.
YM.
YM.
Na
YM.
YM.
YM.
YM.
YM.
Na
YM.
Na
YM.
YM.
YM.
YM.
YM.
YM.
Na
YM.
YM.
YM.
YM.
YM.-
Na
YM.
Na
YM.
YM.
YM.
YM.
YM.
No.
TABLE 1.—ASSESSMENT OF STATE COM-
PLIANCE WITH CWA SECTION
303 _._._,., t
Tf. T«PftOf<«5 r , , ,u
Vhtfn tihmrt" ,
to State ta
connpltenos
wMh Motion
S03(e)(2XB)?
YM.
Na
YM.
YM.
NotMtoTablel .
(1) At the initiation of this zulemaUng,
Kentucky was determined to be in
compliance with the Act On January 27,
1992, the Commonwealth of Kentucky
deleted the water quality criteria for dioxin
from the Kentucky water quality tfyid«»df
Although EPA has not formally acted to
disapprove Kentucky's action to delete the
criteria, information is available which '
documents the need for dioxin criteria for the
Commonwealth of Kentucky. Any potential
EPA promulgation arising from a future EPA
action to disapprove the deletion of the
dioxin criteria for Kentucky will be through
• rulemaldng independent of today's rule.
(2) At the initiation of this rulemaldng,.
New Mexico was determined to be in •
compliance with the Act On October 8, •
1991, New Mexico adopted revisions to Its
standsrds which affected compliance with
acute toxidty criteria. On January 13." 1992,
EPA disapproved the State's action, thus •
initiating the possibility of Federal
promulgation should the State fail to adopt
acceptable standards within 90 days from the
. EPA notice. Any potential EPA promulgation
•rising from this disapproval will be through
a rulemaking independent of today's rule;
EPA policy has been and continues to be that
we prefer States and Territories to adopt their
• own standards consistent with the
requirements of the Clean Water Act
(3) EPA has become aware that several of -
the'State water quality standards approved as"
complying with section 303(cX2HB) have
been challenged in State courts for various
reasons. Additional such challenges may
occur in the future. In cases where such State
rules are remanded or otherwise set aside, or.
•intentionally withdrawn by the State for.any
reason, and the State does not pursue in good
fclth correcting such defects in a timely
manner, it is EPA's intention to Initiate
appropriate rulemaldng to put in place
appropriate criteria far priority toxtc '
pollutants to bring Steto water quality'
standards into compliance with the Glean
Water Act . . .
E. Rationale and Approach for ..'.
Developing the Final Role
The addition of section 303(c)(2)(B) to
the Clean Water Act was an unequivocal
signal to the States that Congress
wanted toxics criteria in the State's
water quality standards. The legislative
history notes that the "beyond BAT"
program (i.e., controls necessary to
comply with water quality standards
that are more stringent than technology-
based controls) was the cornerstone to
the Act's toxic pollution control ' •.
requirements. "
The major innovation of the 1972 :
Clean Water Act Amendments' was the
concept of effluent limitation guidelines
which were to be incorporated into
NPDES permits. In many cases, this
strategy has succeeded in halting the
decline in the quality of the Nation's
waters and, often, lias provided •
improvements. However, the effluent
limitation guideUnss for industrial
discharges and the similar technology-
based secondary treatment requirements
for municipal discharges are not
capable, by themselves, of ensuring that
the nshable-swimmable goals of the
Clean Water Act will be met for all
waters.
.. The basic mechanism to accomplish
this in the Act is water quality
standards. States aie required to
periodically .review and revise these
standards to achieve the goals of the
Act In the 1987 CWA amendments,
Congress focused on addressing toxics
in several sections of the Act, but .
special attention was placed on the
section 303 water quality standards
program requirements. Congress
intended that the adoption of numeric'
criteria for toxics would result in. direct
improvements in water quality by
forcing, where necessary, effluent limits
. more stringent than those resulting from
technology-based effluent limitations
guidelines. ' ..
As the legislative history
demonstrates, Congress was dissatisfied
with the piecemeal, slow progress being
made by States in setting standards for
'toxics. Congress reacted by legislating
new requirements and deadlines
directing the States to establish toxics
criteria for pollutants addressed in EPA •
section 304(a) criteria guidance,
especially for those priority toxic
pollutants that could reasonably be'
expected to interfere with designated •-
uses. In today's action, EPA is
exercising its authority under section
303(c)(4) to promulgate criteria where
States have failed to act in a timely
manner.
The previous section of this preamble
explains EPA's approach to evaluating
the adequacy of State actions in .
response to section 303(c)(2)(B). This
•action explains EPA's legal basis for
issuing today's rule, and discusses
EPA's general approach for developing
the State-specific requirements in
Section 131.36(d).
In addition to the 'Congressional
directive and the legal basis for this
action, there are a number of '
environmental and programmatic
reasons why further delay in
-------
Federal Register / Vol. 57. No. 246 / Tuesday. December 22. 1992 / Rules and .Regulations 6O857
establishing water quality standards for
toxic pollutants is no.longer acceptable.
Prompt control of toxic pollutants in
surface waters is critical to the .success
of a number of Clean Water Act
programs and objectives, including -
permitting, enforcement, fish tissue
quality protection, coastal water quality
-; improvement, sediment contamination
control, certain nonpoint source
controls, pollution prevention planning,
. and ecological protection. The decade
lone .delay in State adoption of water
quality standards for toxic pollutants
has had a ripple effect throughout EPA's
water programs. Without clearly
established, water quality goals, the
effectiveness of many water programs is
Jeopardized. For too long, the absence of
. water quality standards has had a
. chilling effect on toxic control progress
in many State and Federal programs;
.Failure to take prompt action at this -
juncture would also undermine the
continued viability of the current
. statutory scheme to establish standards.
Excessive delay subverts the entire
concent of the triennial review cycle
• which is intended to combine current
scientific information with the results of
previous environmental control
. programs to direct continuing progress
in enhancing water quality.
. Finally, another reason to proceed
expeditiously is to bring closure to this
..•long-term effort and allow State
. attention and resources to be directed
- towards important, new national
program initiatives. Until standards for
. toxic pollutants are in place, neither
EPA nor the States can fully focus on
.-the emerging, ecologically-based water
quality activities such as wetlands
..criteria, biological criteria and sediment
criteria. -
1. Legal Basis
Clean Water Act Section 303(c)
specifies that adoption of water quality
standards is primarily the responsibility
• of the,.States, However, Section 303(c)
also describes a role for EPA of
overseeing State actions to ensure
. compliance with CWA requirements. If
; the Agency's review of the State's
standards finds flaws or omissions, then
-the Act authorizes EPA to initiate
.promulgation to correct the deficiencies •.
- .(see section 303(c)(4)}. The water quality
standards promulgation authority has
been used by EPA to issue final rules on
nine separata occasions. These actions .!.
have addressed both insufficiently
. protective State criteria and/or
designated uses and failure to adopt
. needed criteria. Thus, today's action is
not unique, although it would affect
more States and pollutants than - ' -
previous actions taken by the Agency. ~
The Clean Water Act in section
303(c)(4) provides two bases for
promulgation of Federal water quality
standards. The first basis, in paragraph
(A), applies when a State submits new
or revised standards that EPA
determines are not consistent with the
" ements of the Act If,
after EPA's disapproval the State does
not promptly emend its rules so as to be
consistent with the Act, EPA must
promulgate appropriate Federal water
qualify standards for that State. The
second basis for EPA's action is
paragraph (B), which provides that EPA
shall promptly initiate promulgation
/««• • • in any case where the
Administrator determines that a revised
or new standard is necessary to meet the
requirements of this Act" EPA i» ;
•reiving on both section 303(c)(4)(A) and
section 303(c)(4)(B) as the legal basis for
thisrule.. '
Section 303(c)(4)(A) supports today's
action for several States. These States
have submitted criteria for some number
of priority toxic pollutants and EPA has
disapproved the State's adopted .
standards. The basis for EPA's .
disapproval generally has been the lack
of sufficient criteria or particular criteria
that were insufficiently stringent In
these cases, EPA has. by letter to the
State, noted the deficiencies and ' •
specified the need for corrective action.
Not having received an appropriate
correction within the statutory time
frame, EPA is today promulgating the
' needed criteria. The action in today's
rule pursuant to section 303(cH4)(A)
may differ from those taken pursuant to
section 303(c)(4)(B) by being limited to
criteria for specific priority toxic
pollutants, particular geographic areas,
or particular designated uses-
Section 303(c)(4)(B) is the basis for
EPA's requirements for most States. For
these States, the Administrator has
.determined that promulgating criteria is
necessary to bring the States into
compliance with the requirements of the
CWA. In these cases. EPA is
promulgating, at a min<»niimj criteria for
aU priority toxicpollutants not .
addressed by approved State criteria.
EPA is also promulgating criteria for
priority toxic pollutants where any :
previously-approved State criteria do
not reflect current science contained in
revised criteria documents and other,
guidance sufficient to fully protect all
designated uses or human exposure
pathways, or where such previously-
approved State criteria are not
applicable to all appropriate designated
uses. EPA's action pursuant to section -'•
304(c)(4)(B) may include several .
situations. ..-,•' /. .
In some cases, the State has failed to
adopt end submit for approval any
criteria for those priority toxic
pollutants for which EPA has published
.criteria. This includes those States that
have not submitted triennial reviews. In
other cases, the State has adopted and
EPA has approved criteria for either
aquatic life or human health, but not
both. In yet a third situation. States have
submitted some criteria but not all
necessary criteria. Lastly, one State has
submitted criteria that do not apply to
all appropriate geographic sections of
the waters of the State. . .
The use of section 303(c)(4)(B) .
requires a determination by the '
Administrator "•*. ". that a revised or
new standard is necessary to meet the
requirements of * * •"toe Act The
Administrator's determination could be
supported in different ways.
research and miirrfi«fl data to
demonstrate the need for promulgation
for each criteria for each .stream segment
or waterbody in each State. This would .
include evidence for each Section 307{a)
priority toxic pollutant for. which EPA
has Section 304(a) criteria and that'there
is a "discharge or presence" which •
could reasonably "be expected to
interfere with" the designated use. This
approach would not only impose an
enormous administrative burden, but
. would be contrary to the statutory ' •".
scheme and the compelling --, •• • ••'.'• *
Congressional directive for swift action
reflected in the 1987 addition of section
303(c)(2)(B)totheAct .
An approach that is more reasonable
and consistent with Congressional
intent focuses on the State's failure to
.complete the timely review and /
adoption of the necessary standards
required by section 303(c)(2)(B) despite
information that priority toxic
pollutants may interfere with designated
uses of the State's waters. This approach
is consistent with the fact that in -
enacting section 303(c)(2)(B) Congt^
expressed its determination of the . .
necessity for prompt adoption and -
'implementation ofwaterquality• '• -'- •'.
standards for toxic pollutants. .
Therefore, a State's failure to meet this
fundamental 303(c)(2HB) requirement of
adopting appropriate standards ./ .
constitutes a failure "to meet the ~
requirements of the Act" That failure to
act can be a basis for the Administrator's
determination under section •
303(cX4)(B) that new or revised criteria
are necessary to ensure designated uses
are adequately protected. Here, this .
determination is buttressed by the -•
existence of evidence of the discharge or
presence of priority toxic pollutants in
-------
60858 Federdtg/VoL *7. No, 246 / Tuesday, December 22, 1992 / Rules and Regula&ms
* State's Waters for which the State has
»•*« **WM£*«WU *<*U^U*M*W *raiQ4 uuajuiy
criteria. The Agency has compiled an .
• Impressive volume of Information In the
1 record for thfcrulemakmg on the
• discharge or presence of toxic pollutants
In State vraters. This data support* the
Administrator''* determination pursuant
to sect!on 303(cX4HB). The record was
• •*Tailableto1hepubHcfarrevIew^during
tola rulemakfng period and continues to
boon file. " • -
The Agency* choice to base the
determination on th« second approach
Is supported by both the explicit '.
. languago of the statutory provision and
by ualeglslatrva history. Congress
S^0!?1?!??0113°3fcK2KB) to section
•303 with full knovrJftdgo of the existing -
wqulremBntf in section 303(cHl) for
triennial vratar quality standards review
and submission to EPA and In section
303(cKt*d earlier, chief•Senate-spoasers; " • -•
* In'du ding-Sonatorc Stafford, Choffee and
others, wanted the provision to ' '-,
. eliminate State andEPA delaysand ^
force aggi ami re action. . .- :. - -
£a normal cfrcomstances, ft might be
argued that to exercise section •
%.303(cH4)CB)th»AdmrnIsWormlgrrt '
'have the burden of marshaHmg
•conchisrve evidence ofi-necessity*'.for
Federall promulated water uality''
• 303(cJ{2HB), Congress made clear that
the^orrnaT'procedure had become'
• inadequate. The spedEdty and
»>-wMw%^Muw*^««4a *^rw\*«Ui*liV V1IU
deadline fat section 303(c)(2)(B) were
layered on top of * statutory scheme
already dadgned to achieve the
•standards. Congressional action to adopt
« partially redundant provision was
driven by thefr Impatience with tha lack
of State progiesj. Hie new provision
was essentially * Congressional
"detannlnatfon" of the necessity for
new or revised romprahenslve toxic
water quality standards by Stales, hi
eWereoce to tha principle of State
primacy, Congress, by linking section
303tcK2)CB}tothes«ctlQn303(cXl) .
Ihree-yeer review period, save States e,
last chance to correct this deficiency on
their own. However, *fr*t» Congressional •
indulgence
-------
Federal Register / VoL 57. No. 246 / Tuesday. December 22, 1992 / Rules and Regulations 60859
for att priority (oxic pollutants not fully
addressed by State oiteria. The EPA
data supporting this assertion is
discussed more fully in the next section.
2. Approach for Developing the Final
Rule • ,
The State-specific requirements in
§ l31.36(d) were developed using one of
two approaches. In the formal review of.
the adopted standards for certain States,
EPA determined that specific numeric
toxics criteria are locking. For some,
criteria were omitted from (he State
standards, even though in EPA's
judgment* the pollutants ^»y» reasonably
be expected to interfere with designated
uses. In these cases where EPA .
specifically identified deficiencies in a
, State submission, this rule establishes
• Federal criteria for that limited number
of priority toxic pollutants necessary to
correct the deficiency. '
For the balance of the States. EPA
applies, to all appropriate State waters,
the section 304{a) criteria for all priority
toxic pollutants which are not the, ..
subject of approved State criteria. EPA
also is promulgating Federal criteria for
priority .toxic pollutants where any. •
previously-approved State criteria do .'
not reflect current science contained in
revised criteria documents and other'
guidance sufficient to fully protect all -'
designated uses or human health
exposure pathways, where such
previouslyrapproved State criteria do
not protect against both,acute and
chronic aquatic life effects, or where
such previously-approved State criteria '
are not applicable to all appropriate
State designated uses.
Absent a State-by^State pollutant
specific analysis to narrow the list.
existing data sources strongly support a
comprehensive rulemaking approach.
Information in the rulemaking record
from a number of sources indicates the
discharge, potential discharge or •
presence of virtually all priority toxic
pollutants in all States. The data.
available to EPA was assembled into a
"strawman" analysis designed to
identify priority toxic pollutants that
• potentially require the adoption of •
numeric criteria. Information on
pollutants discharged or present was
identified by accessing various national
data sources:. • . •,
—Final section 304(1) short lists
identifying toxic pollutants likely to
impair designated uses; :•
—Water column, fish tissue and
sediment observations in the Storage
Retrieval (STORED data base (Le..
where the pollutant was detected);
—The National Pollutant Discharge
Elimination System's (NPDES) Permit
Compliance System data base to
Identify those poUut/mts limited in
direct dischargers'permits;
—Pollutants included on Form 2(c)
permit applications which hmve been
submitted by wastewater dischargers;
—Information on discharges to surface
waters or POTWs from the Toxics
Release Inventory required by the
Emergency Planning and Community
Right-To-Know Act of 1986 (Title HI,
P.L.99-499); . ..
—Polhitants predicted to be in the
effluent of NPDES dischargers based
on industry-specific analyses
conducted for the Clean Water Act
effluent guideline program.
The extent of this 'data supports a .-
conclusion that promulgation of Federal
criteria for all priority toxic pollutants
with section 304(a) criteria guidance
documents is appropriate .for those
States that have not completed their
standards adoption process. This •• .
conclusion is supported by several other
factors. . ••••.. ' • ;:''
First, many of the available data ' ~
sources have limitations which argue •
against relying on them solely to
identify all needed water quality' • • .
criteria. For example, the section 304(1)
short lists only identified water bodies
where uses were impaired by point
source discharges; State 304(1) long lists
did not generally identify pollutants
causing use impairment by nonpoint
sources. Other available data sources •
(i.e.. NPDES permit limits) have a'
similar narrow scope because .of their
particular purposes. Even the value of
those data bases designed to identify
ambient water problems is restricted oy
the availability of monitoring data. In
many States, the quantity, spatial and
temporal distribution, and pollutant
coverage of monitoring data is severely
limited. For example, the most recent
. Water Quality Inventory Report to
Congress included an evaluation of use
attainment for only one-third of all river
miles and less than one-half of lake
acres. Even for those waters where use
attainment status was reported, many
assessments were based on data which
did not include the chemical-specific
information necessary to identify the
priority toxic pollutant! which pose a
.threat to designated uses. After
evaluating this data, EPA concluded
. that it most likely .understates the
advene presence or discharge of priority
toxic pollutants. . .
Further evidence justifying a broad-
promulgation rulemaking can be found
in the State actions to date in their
standards adoption process. While
many have not come to completion, the
initial steps have led many States to
develop or propose rulemaking
packages with extensive pollutant .
coverage. The nature of these • ••
preliminary State determinations argues
for a Federal promulgation of all section
' 304(a) criteria pollutants to ensure
adequate public health and
environmental protection against
priority toxic pollutant insults.
•The detailed assumptions and
approach followed by EPA in writing
the §131.36(d) requirements for all.
jurisdictions are described below. In the
following discussions, EPA refers to
these assumptions and approach as ' •-.
••rules."
(1) No criteria are promulgated for
States which have been fully approved •
by EPA as complying with the section
303(cM2)(B) requirements.
(2) For States which have not been
fully approved, if EPAhas not,
.previously determined which specific
pollutants criteria/waterbodies are
lacking from a State's standards (La., as
part of an approval/disapproval action
only). aO of the criteria fa Columns B.
C, and D of the S131 J6(b) matrix are
promulgated for statewide application
to all appropriate designated uses.
except as provided for elsewhere in
these rules. That is, EPA brought the -•
State into compliance with section .
303(c)(2HB) via an approach which is
comparable to option 1 of the December
1988 national guidance for section
303(c)(2)(B).
(3) If EPA has previously determined •
which specific pollutants/criteria/
waterbodies are needed to comply with
CWA section 303(c)(2HB) (Le., as part of .
an approval/disapproval action only),
the criteria in §131.36(b) are
promulgated for only those specific
pbllutants/criteria/waterbbdies (i.e.,
EPA brought the State into compliance .
via an approach which is comparable to
option 2 of the December 1988 national
guidance for section 303(cX2)(B)).
(4) For aquatic life, except as provided
for elsewhere in these rules, all waters
with designated aquatic life uses
•providing even pifa>im«l support'to .
aquatic life are included in the rule (i.e^
fish survival, marginal aquatic life, etc.).
• (5a) For human nealth, except as
provided for elsewhere in these rules, •
all waters with designated uses
providing for public water supply
protection (and therefore a potential
water consumption exposure route) or
minimal aquatic life protection (and
therefore a potential fish consumption,
exposure route) are included in the rule.
. (5b) Where a State has determined the.
specific aquatic life segments which .
provide a fish consumption exposure
.route (i.e., fish or other aquatic life are
being caught end consumed) and EPA
approved this determination as part of
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60860 Federal Register / VoL 57, No. 246 / Tuesday. December 22. 1992 / Rules and Regulations:!
standards approval/disapproval
rtlon, the rule Includes the fish
as
action
consumption (Column D2) criteria for
only those aquatic life segments, except
as provided for elsewhere in these rules.
' In making a determination that certain
segments do not support a fish
consumption exposure route, a State
must have completed, and EPA
approved, a use attainability analysis '
consistent with the provisions of 40 CFR
131.10(j). In the absence of such an
approved State determlnation/EPA
promulgated fish consumption criteria-'
for all aquatic life segments. " "
(6) Uses/Classes other than those
which support aquatic life or human
, health are not included in the rule (e.g.,
livestock watering, industrial Water
•upply). unless they are defined in the
SUte standards as also providing
protection to aquatic lire or human
health (te., tinless they are described as
protocting multiple uses including ' •
'aquatic lire or human health). For
example, if the State standards include
•use such as industrial water supply, -
and in the narrative description of the
use the SUte standards indicate that the
UM Includes protection for resident
aquatic life, then this use is included in
-thisrule. •• ••,-'• ". '
(7) Forhuinan health, the "water* ,
fiih" criteria in Column Dl of
.§131.36{b) are promulgated for all '
waterbodies where public water supply
'and aquatic life uses are designated.
• except ai provided for elsewhere in '
those rules (e.g., rule 9).
|8) If the State has public water ' -
supplies where aquatic life uses have •
not boon designated, or public water
supplies that have been determined not
to provide a.potential fish consumption
exposure path way, the "water* '
organisms only" criteria in Column Dl
of §131.36(b) are promulgated for such'
waterbodies, except as provided for
elsewhere in these rules (e.g., rule 9).
(9) EPA is generally not promulgating
criteria for priority tocdc pollutants for .
which a State has adopted criteria and
received EPA approval The exceptions '
to 1hls general rule are described in --
rules 10 and 11;
(10) For priority toxic pollutants
where the State has adopted human
health criteria and received EPA .
' approval, but such criteria do not fully '
* satisfy section 303(c){2)(B) - .
requirements, the rule includes human
health criteria for such pollutants; For •
example; consider a case where a State
has* a water supply segment that poses
an exposure risk to human health from
both water end fish consumption. If the
* Stale has adopted, and received
approval for, human health,criteria
based on water consumption only (e.g..
Safe Drinking Water Act Maximum
Contaminant Levels (MCLa)) which are
less stringent than the "water + fish"
criteria in' Column Dl of § 131.36(b). the
Column Dl criteria are promulgated for
those water supply segments. The
rationale for this is to ensure that both
water and fish consumption exposure •
pathways are adequately addressed and
human health is fully protected. If the
State has adopted water consumption
only criteria which are more stringent or
: equal to the Column Di criteria, the
""water + fish" criteria in fVJmnii DI
criteria are not promulgated.
(11) For priority toxic pollutants *
where the State has adopted aquatic life
criteria and previous to the 1987 CWA
Amendments received EPA approval,.
but such criteria do not fully satisfy
section 303(c)(2)(B) requirements, the
rule includes aquatic life criteria for
'such pollutants. For example, if the
• 'Statelias adopted not-to-be-exceeded
. aquatic life criteria which are less
' stringent than the 4-day average chronic
• aquatic life criteria in § 131.3B(b) (La., in
Columns B2 and C2). the acute and
. chronic aquatic life criteria in'..
§ 131.36(b) are promulgated for those
pollutants. The rationale for this is that
• the State^adopted criteria do not protect
resident aquatic life fromiboth acute and
• chronic effects, and that Federal criteria
are necessary to folly protect aquatic life
-designated uses. If the State has adopted
not-to-be-exceeded aquatic life criteria
' which are more stringent or equal to the
chronic aquatic life criteria In :.
§ 131.36(b), .the acute and chronic
aquatip life criteria in §13L36(b) are not
promulgated for those pollutants.
(12) Under certain conditions
discussed in rules. 8,10. and 11. criteria
listed in $ 131.36(b) are not promulgated
for specific pollutants; however. EPA
made such exceptions only for
pollutants for which criteria have been '
adopted by the State and approved by
EPA. where such criteria are currently
effective under State" law the ' '• •••'
. appropriate EPA Region concluded that'
the State's criteria fully satisfy section
303(cK2)(B) requirements, ' ° ..• ;
3. Approach for States that Fully - .'-'
Comply Subsequent to Issuance of this
Final Rule - ".:-'•
• As discussed in prior Sections of this
Preamble, the water quality standards
program has been established with an
emphasis on State primacy. Although
this rule was developed to Federally
promulgate toxics criteria for States.
'-EPA prefers that Stateomaintain'
primacy, revise their own standards, "
and achieve full compliance. EPA is '•
•hopeful this rule will provide additional *
impetus for non-complying States to
adoptlhe criteria for prioritytoxic '
pollutants necessary to comply, with
section 303(c)(2)(B). . •
Removal of a State from the'riile will
require another rulemaking by EPA '
according to the requirements of the
Administrative Procedure Act (5 U.S.C.
551 et seq.). EPA will withdraw the
Federal rule without a notice and •
comment rulemaking when the State
adopts standardsnoless stringentthan
the Federal rule (U.. standards which
provide;at least, equivalent. . ' •
environmental and human health ' '
protectionVFor example, see 5.1 FR !
11580,; April 4,1986, which finalized
EPA's removal of a Federal rule for the
State.of Mississippi. .-..'-.
However, if a State adopts standards '
for toxics which are less stringent than
the Federal rule but. In the Agency's
judgment, fully meet the requirements
of the Act, EPA will propose to , -
withdraw the rule with a Notice of '
proposed rulemaldjog and provide for
public participation. This procedure
•would be required for partial or •
complete removal of a State from this
rulemaking. Ah exception to tf»fa • •' *•
requirement would be when a State . "
adopts a human health criterion for a ':
carcinogen at a 10-:I risk level where the
Agency has promulgated at a'lflr* risk
level la such a caws, the Agency •'
believes it would bo appropriate to
withdraw the Federal criterion without
notice and comment because the ':- ••. , •
Agency has considered in this ride that
criteria based on either ID"3 or 10^ risk
levels meet the requirements of the Act
A State covered by this final rule could
adopt the necessary criteria using any of
the three Options or combinations of * •
those Options described in EPA's 1989
guidance. . . . ' • . ..
EPA cautions States and the public
that promulgation of this Federal rule
removes most of the flexibility available
to States for modifying their standards
on a.discharger-spednc or stream-
specific basis. For example. Variances
are actions sometimes adopted by the
States. These are optional policies under.
terms of the Federal water quality
standards regulation. Except for the '
water-effect ratio for certain metals, EPA
has not incorporated either optional' '
policy, in general, in' this rulemaking;
that is, EPA has not generally
authorized State modification, of Federal
types of modifications will, in general,
require Federal rulemaking on a case-
by-case basis to change the Federal rule.
Because of the time consuming nature of
reviewing such requests, limited Federal
resources, and the aeed for the Agency
to move into other jirloHty programs
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federal Register / Vol. 57. No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 60861
areas in establishing environmental
cots.V«As. !EP/k olert* Vbo States end the
public that a prompt Agency response to
requests for variances and site-specific
modifications to the Federal criteria is
unlikely. The best course of action, if
such provisions are desired In a State,
is for a State to adopt its own standards
and take advantage, if it so chooses, of
the flexibility offered by these optional
provisions. ' .
The Federal criteria published today
are effective in 45 days. However, this
action does not change existing
applicable State and EPA provisions
related to permit issuance crreissuance
as they affect schedules of compliance.
EPA and the States may continue .
Issuing permits containing enforceable
compliance schedules for these
Federally established water quality
standards if it is consistent with State
policy.' '• . ,
F. Derivation of Criteria
1. Section 304(a) Criteria Pivcess •
Under the authority of CWA section
304(a), EPA has developed
methodologies and specific criteria to
protect aquatic life and human health.
These methodologies are. intended to
• provide protection for all surface water
on a national basis. As described below,
there are site-specific procedures for. • •
more precisely addressing site-specific
conditions for an individual water body.
However, the water quality criteria are '
scientifically sound and will achieve the
statutory objective of protecting
designated uses even in the absence of
' these modification procedures. ' - '
Although the site-specific procedures
may allow for more precise criteria for
certain waterbodies, these procedures
are infrequently used because the
Section 304(a) criteria recommendations
are designed to protect all waterbodies
and have proven themselves to be'
appropriate. The methodologies have
been subject to public review, as have
the individual criteria documents.
Additionally, the methodologies have
been reviewed and approved by EPA's
Science Advisory Board of "*h»rnal
experts. Additional comments on the
methodologies were taken as part of this
action and have been considered and
responded to in developing this final
rule. In addition, these comments will
be considered in the Agency's ongoing
•Sort to propose revised methodologies
-for public review and comment in fiscal
year 1993. .
EPA incorporated by reference into
the record of this rule the aquatic life
methodology as described in "Appendix
B—Guidelines for Deriving Water
Quality Criteria for the Protection of
Aquatic Life and Its Uses" (45 FR 79341,
November 28,1980) as amended by
, "Summary of Revisions to Guildlines
for Deriving Numerical National Water
Quality Criteria for the Protection of
Aquatic Organisms end Their Uses"; (50
FR 30792, July 29,1985).
Note: Throughout the remainder of this •
rule, thi* reference to described a* the 1985
"--*-*-""number reference* are .
to the actual guidance document, not the
notice of availability in the Federal Rtgfetor.
The actual guideline* Hnnimjint ^m
available through the National Technical
Information Service (PBSS-227O49), U in the
record of thU rulemaking, and is abstracted '
in Appendix A of Quality Criteria tat Water,
1988. .'•••, . ; ,--.''_ .;-• •
EPA also incorporated by reference into
the record of this rule the human health
methodology as described in "Appendix
C—Guidelines and Methodology Used
in the Preparation of Health Effects
'Assessment Chapters of the Consent
Decree Water Criteria Documents" (45
FR 79347. November 28,1980).
Note: Throughout the remainder of this
Preamble, thi» reference i» described as the
Human Health Guidelines or the 1980
Guidelines.
EPA also recommends that the
following be reviewed: "Appendix D—
Response to Comments on Guidelines
for Deriving Water Quality Criteria for
the Protection of Aquatic Life and Its
Uses," (45 ;FR 79357, November 28,
1980); "Appendix E—Responses to
Public Comments on the Human Health
Effects Methodology for Deriving
Ambient Water Quality Criteria" (45 FR
79368, November 28,1980); and
"Appendix B—Response to Comments
on Guidelines for Deriving Numerical
National Water quality Criteria for the
Protection of Aquatic Organisms and '
Their Uses" (50 FR 30793, July 29,
1985). EPA also placed into the record.
the most current individual criteria
documents for the priority toxic
pollutants included in today's rale.' -
The primary focus of this rule is the
inclusions of the water quality criteria
for pollutant(s) in State standards as
necessary to support water quality-.
based control programs. The Agency
accepted comment on the criteria
proposed for inclusion in this rule. • "
However. Congress established a very
ambitious schedule for the .
promulgation of the final criteria. The
statutory deadline in section 303(c)(4)
clearly indicates that Congress intended
the Agency to move vary expeditiously
when Federal action Is warranted.
The methodology used to develop the
criteria and the criteria themselves (to
the extent not updated through IRIS)
nave previously undergone scientific
peer review and public review and
comment, and nave been revised as
appropriate. For the most part, this
review occurred before Congress •
amended the Act in 1987, to require the
inclusion of numeric criteria for certain
toxic pollutants in State standards.
Congress acted with full knowledge of
and the Agency's recommendations
under section 304(a). EPA believes it is
consistent with Congressional intent to
rely in large part on existing criteria
rather than engage in a time-consuming
nevaluation of the underlying basis for
water quality criteria. Accordingly, the
Agency stands by its prior decisions
regarding its published methodology .'
and criteria even after review of the
comments received. It is the Agency's
belief that this approach will best
achieve the purpose of moving forward
in promulgating criteria for States not in
compliance with section 303{c)(2)(B) so
that environmental controls intended by
Congress can be put into place to protect
public health and welfare and enhance
water quality. . ' •
It should be noted that the Agency is
initiating a review of ibe basic
guidelines for developing criteria and
that comments received during this
rulemaking will be considered in thatx
effort Future revisions to the criteria
guidelines will be reviewed by the
Agency's Science Advisory Board and
submitted to the public for review and
comment following the same process . '•
that was used in issuing the existing
methodological guidelines. Subsequent
revisions of criteria documents and the
issuance of any new criteria documents
will also be subject to the public review.
2. Aquatic Life Criteria
Aquatic life criteria may be expressed
in numeric or narrative forms. EPA's
1985 Guidelines describe an objective.
internally consistent and appropriate
way of deriving chemical-specific,
numeric water quality criteria for the
protection of the presence of, as well as
the uses of, both fresh and marine water
aquatic organisms.
An aquatic life criterion derived using
EPA's section 304(a) method "might be
thought of as an estimate of the highest
concentration of a substance in Water
which does not present a rfgnifloqnt risk
to the aquatic organisms in the water
and their uses." (45 FR 79341.) The term
"their uses" refers to consumption by
humans and wildlife (1985 Guidelines, '
page 48). EPA's guidelines are designed
to derive criteria that protect aquatic
communities by protecting most of the
species and their uses most of the time,
but not necessarily ill of the species all
of the time (1985 Guidelines, page 1).
Aquatic communities can tolerate some
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SUBt>2 federal Register / Vol. 57. No. 246 /' Tuesday. December 22. 1992 / Rules and Regulations
stress end occasional adverse effects on
* fow^pociea so that total protection oi
all spedes all of the time is not
necessary. EPA'* 1985 Guidelines
attempt to provide a reasonable and
adequate amount of protection with
' only a small possibility of substantial
overprotection or underprotecUon. As
discussed in detail below, there are
several individual factors which may
make the criteria somewhat
overprotective or underprotective. The
approach EPA is using is believed to be
. as.vrell balanced as possible, given the.
cUU of the science.
Numerical aquatic life criteria derived
using EPA'* 1S85 Guidelines are
expressed as short-term and long-term
numbers, rather than one number,'in
order that the criteria more accurately
reflect lexicological and practical
realities. The combination of a criteria
maximum concentration (CMC), a one-
hour average acute limit, and a criteria
continuous concentration (CCC), a four-
day average concentration chronic limit,
• provide protection of aquatic life and its
urn from acute and chronic toxidty to
animals and plants, and from
bloconcentratibn by aquatic organisms,
without being as restrictive as a one-
. number criterion would have to be.
(1885 Guidelines, pages 4-5.)
The two-number.criteria are intended-
to Identify average pollutant
concentrations which will produce
water quality generally suited to .
maintenance of aquatic life and their
. uses while restricting the duration of
excursions over the average so that total
exposures will not cause unacceptable
adverse effects'. Merely specifying an
insufficient unless the time period is -
short, because excursions higher than
the average can Idll or cause substantial
damage In short periods.
, A minimum data set of eight specified
families Is required for criteria
•development (details are given In the
1885 Guidelines, page 22). The eight
specific families are in tended to be
representative of a wide spectrum of
aquatic life. For this reason it is not
necessary that tha specific organisms
tested be actually present in the water
body. States may develop site-specific
criteria using native spedes, provided
that the broad spectrum represented by
the sight families Is maintained. All
aquatic organisms and their common I
mo* are meant to be considered, but not
necessarily protected, if relevant data
are available.
EPA's application of guidelines to
develop the criteria matrix in the fuial
rulo is Judged by the Agency to be
applicable to all waters of the United
States, and to all ecosystems (1985
. Guidelines, page 4). There are waters
and ecosystems where site-specific
criteria could be developed, as
discussed below, but it Is up to States
to identify those waters and develop the
appropriate siterspedfic criteria.
Fresh water and salt water (induding
both estuarine and marine waters) have
different chemical compositions, and
freshwater and saltwater species rarely
inhabit the same water «Jtnn1t«nAmiit1y.
• To provide additional accuracy, criteria
developed recently are developed for
fresh water and-for salt water. . •
Assumptions which may make the '
criteria underprotective include the met
that not all spedes are protected, the
use of criteria on an individual basis,
with no consideration of additive or
synergistic effects, and the general lack
of consideration of impacts on wildlife,
due prindpally to a lack of data.
Chemical toxidty is often related to
certain receiving water characteristics.
(pH, hardness', etc.) of a waterbody.
Adoption of some criteria without
consideration Of these parameters could
result in the criteria being • ...
overprotective.
3. Criteria for Hmnantiealtii
. EPA's section 304(a) human health .
guidelines attempt to provide criteria
which TninimiTa or specify the potential
risk of adverse human effects due to
substances in ambient water (45 FR •'
. 79347). EPA's section 304(a) criteria for
human health are based on two types of .
. biological endpoints: (1) Cardnogenidty
and (2) systemic toxidty (Le~. aU other
adverse effects other than cancer). Thus,
there are two procedures for assessing
these health effects: one for carcinogens
end one for non-carcinogens. •
EPA's human health guidelines
assume that cardnogenidty is a "non-
threshold phenomenon," that is, there
are no "safe" or "no-effect levels"
because even extremely small doses are .
assumed to cause a finite increase in the
inddence of the response (Le., cancer).
Therefore, EPA's water quality criteria
for carcinogens are presented as
. pollutant concentrations corresponding
to increases in the risk of developing ' .
cancer. • . . • . - -
For pollutants that do not manifest
any apparent carcinogenic effects in
animal studies (Le., systemic toxicants),
. EPA .assumes that the pollutant has a
threshold below which no effects will
be canned. This.assumption is based •
on the premise that a physiological
mechanism exists within living
organisms to avoid or overcome the
adverse effects of the pollutant below •
the threshold concentration. ... '.•-.'
The human health risks of a, substance
cannot be determined with any degree
of confidence unless dose-response
relationships are quantified. Therefore.
a dose-response assessment is required
before a criterion can be calculated. The
. dose-response assessment determines
the quantitative relationships between •
the amount of exposure to a substance .
and the onset of toxic injury or disease.
Data for determining dose-response
relationships are typically derived from
animal studies, or less frequently, from
epidemiological studies in exposed
populations.
The dose-respoiise tnfrMTUfflHo"
needed for carcinogens is an •stimnta of
the carcinogenic potency of the _. .
compound. Carcinogenic potency is
defined here as a general term for a .
chemical's human re»npnfw«iictnp.
potential. This term is often used"
loosely to refer to the more specific
carcinogenic or cancer slope factor
which is defined its an estimate of
carcinogenic potency derived from
animal studies or apidemiological data •
of human exposure. It is based on
extrapolation from test exposures of
high dose levels over relatively abort
periods of time to more realistic low
dose levels over a lifetime exposure
period by use of linear extrapolation .
models. The cancer slopefactor, ql*.is
EPA's estimate of carcinogenic potency
and is intended to be a conservative
upper bound estimate (e.g. 05% upper
bound confidence limit). .
For non-carcinogens, EPA uses, the
reference dose (RfO) as the dose
responseparameUT in calculating the
criteria. The RfD was formerly referred
to as an "Acceptable Daily Intake" or
ADL The RfD is uiiehd as a reference
point for gauging the potential effects of
other doses. Doses that are less than the
RfD are not likely (to be associated with
any health risks, and are therefore less
likely to be of regulatory concern. As the
frequency of exposures exceeding the
RfD increases and as the size of the
excess increases, the probability
increases that adverse effects may be
observed in a human population.
Nonetheless, a dear conclusion cannot
be categorically drawn that all doses
below the RfD are.'"acceptable" and that
all doses in excess of the RfD are
"unacceptable." In. extrapolating non-
carcinogen unimnl test data to humans
to derive an RfD. EPA divides a lib-
observed-effect done observed in animal
studies by an "uncertainty factor"
which is based on profession judgment
of toxicologists ana typically ranges
from 10 to 10,000.
For section 304(u) criteria
development, EPA typically considers
only exposures to a pollutant that occur
through the ingestion of water and
contaminated fish and gh«Hfiish.. This Is
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Federal Register / Vol. 57. No 246 / Tuesday. December 22. 1992 / Rules and Regulations 6O863
TOXNET system, and through diskettes
from the National Technical Information
Service (NT1S). (NTIS access number is
PB 9O-591330). .
For the criteria included in today's
rule. EPA used the criteria
recommendation from the appropriate
Section 304(a) criteria document (The
availability of EPA's criteria documents
has been announced in various Federal
Register Notices. These documents are
also placed in the record for today's
rule.) However, if the Agency has
changed any parameters in IRIS used in
criteria derivation since issuance of the
criteria guidance document, EPA
recalculated the criteria ' .
recommendation with the latest •
information, invited comment on the
updating procedure and the numbers
that would be derived from it (This -
information is included in the record.)
Thus, there may be differences between
the original criteria guidance document
recommendation, and those in this rule.
but this rule presents the Agency's most
current section 3O4(a) criteria
recommendation. The recalculated -
human health numbers are denoted by .
the exposure default assumption
although the human health guidelines
provide for considering other sources
where data are'available (see 45 FR
79354). Thus the criteria are based on an
assessment of risks related to the surface
water exposure route only.
The assumed exposure pathways in
calculating the criteria are the
consumption of 2 liters per day at the
criteria concentration and the
consumption of 6.5 grams per day of
fish/shellfish contaminated at a level
equal to the criteria concentration but
: multiplied by a "bioconcentration
factor." The use of fish consumption as
an exposure factor requires the
quantification of pollutant residues in
the edible portions of the ingested
species. Bioconcentration factors (BCFs)
are used to related pollutant residues in
aquatic organisms to the pollutant
concentration in ambient waters. BCFs
are quantified by various procedures
depending on the lipid solubility of the
pollutant For lipid soluble pollutants,.
the average BCF is calculated from the
weighted average percent lipids in the,
edible portions of fish/shellfish, which
is about 3%; or it is calculated from
theoretical considerations using the
-octanoVwater partition coefficient For
non-lipid soluble compounds, the BCF
is determined empirically. The assumed
water consumption is taken from the
National Academy of Sciences
publication'Thinking Water and
Health" (1877). (Referenced in Human
Health Guidelines, 45 FR 79356): The
'. 6.5 grains per day contaminated fish
consumption value is equivalent to the
average per-capita consumption rate of
all (contaminated and non-
contaminated) freshwater and estuarine
fish for the U.S. population. (See
Human Health Guidelines, 45 FR
79348.) .
EPA also assumes in calculating water
quality criteria that the exposed
individual is an average adult with body
weight of 70 kilograms. The issue of
concern is dose per kilogram of body
weight EPA assumes 6.5 grams per day
of contaminated fish consumption and 2
liters per day of contaminated drinking
water consumption for a 70 kilogram
person in calculating the criteria.
Persons of smaller body weight are
' expected to ingest less contaminated
fish and water, so the dose per kilogram
of body weight is generally expected to
be roughly comparable. There may be ."
subpopulations within a State, such as
subsistence fishermen, who as a result
of greater exposure to a contaminant are
at greater risk than the hypothetical 70
kilogram person eating 63 grams per
day of maximally contaminated fish and
shellfish and drinking 2 liters per day of
maximally contaminated drinking
water. / .
For example, individuals that ingest
ten times more of a pollutant than is
assumed in derivation of the criteria at
a 10-6 risk level will be protected to a
1(T5 level, which EPA has historically
considered to be adequately protective.
There may. nevertheless, be
circumstances where rite-specific ..
numeric criteria that are more stringent
. than the State-wide criteria are
necessary to adequately protect highly
exposed subpopulations. Although EPA
intends to focus on promulgation of
appropriate State-wide criteria that will
reduce risks to all exposed individuals,
including highly exposed
subpopulations, site-specific criteria
.may be developed subsequently by EPA
or the States where warranted to
provide necessary additional protection.
(See Human Health Guidelines. Issue 8.
45 FR 79369.)
For non-carcinogens, oral RfD
assessments (hereinafter simply "RfDs")
are developed based on pollutant
concentrations that cause threshold
effects. The RfD is an estimate (with
uncertainty-spanning perhaps'an order
• of magnitude] of a daily exposure to the,
.human population (including sensitive
subgroups) that is likely to be without
appreciable risk of deleterious effects
during a lifetime. (See Human Health
Guidelines. 45 FR 79348.) '•
Criteria are calculated for individual
chemicals with no consideration of
additive, synergistic or antagonistic
effects in mixtures. If the conditions
within a State differ from the
assumptions EPA used within flie '
constraints of the Federal rule, the'
States have the option to perform the
analyses for their conditions.
EPA has a process to develop a "
scientific consensus on oral reference
dose assessments and cardnogenidty
assessments (hereinafter simply cancer
slope factors or slope factors). Reference
doses and slope factors are validated by
two Agency work groups (Le., one work
group for each) which are composed of
senior Agency scientists from all of the
program offices and the Office of
Research and Development These work
groups develop a consensus of Agency
opinion for RfDs and slope factors
which are then used throughout the
Agency for consistent regulation and •
guidance development EPA maintains
an electronic data base which contains
the official Agency consensus for oral
RfD assessments and cardnogenidty
, assessments which is known as the
11 Integrated Risk Information System
(IRIS). It is available for use by the
public on the National Institutes of
Health's National Library of Medicine's
an "a" in the criteria matrix in
subsection 131;36(b) of today's rule.
. A difficult and controversial -problem •
facing both the States and EPA in
attempting to comply with the
requirements of section 303(c)(2)(B)
involved selecting a criterion for
2&73-TCDD (dioxin). EPA, the States.
dischargers, environmental groups and
the public at large have been involved
in discussions concerning the ambient
level of protection that is protective of
public health. At issue during the State
debates on selecting criterion for dioxin
and in comments to this rulemaking are
stientific questions specific to dioxin .
such as determining the carcinogenic
potency of the pollutant and the extent
to which the pollutant tends to
accumulate in fish tissues. Other issues
are raised that are more generic to EPA's
human health criteria. Most of these
issues relate, directly or indirectly, to
concerns expressed by dischargers
regarding the cost of complying with
water quality-based effluent limits for
dioxin. . •
In order to base its regulatory
decisions on the best available science.
EPA continuously updates its
assessment of the risk from exposure to
contaminants. On September 11, 1991,
EPA's Office of Research and ~
Development (QRD) began reassessing
the scientific models and exposure
scenarios -used to predict the risks of
biological effects from exposure to low
levels of dioxin. This reassessment has
the potential to alter the risk assessment
for dioxin and accordingly the Agency's
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60BB4 Federal Register / Vol. 57, No. 246 / Tuesday. December 22. 1992 / Rides and Regulations
regulatory decisions related to dioxin.
* At thle time, EPA is unable to say with
any certainty what the degree or
• directions of any changes in risk
estimates might be. Moreover, the
. results of the assessment and any
potential impact on the criteria limit
will not be known for quite some time.
Considerable comment was received
that the Agency not include dioxin in
the rule pending the results of the
dioxin reassessment. However, no
additional data was submitted by the
commenters that adds to the
information available upon which to
make a decision. Baaed on information
currently available to the Agency an'd in
the face of known uncertainties, the
limit promulgated today is within the
range of scientific defonribility. • .
A State may adopt a different limit
subsequent to this rule, following the
normal procedures for adopting or
' xavWng water quality standards {40 FR
131). The adoption by a State of a new .
or revised criterion for dioxin, whether
more or less stringent than the existing
section 3M(a) guidance, will be
accepted by the Agency based on the
results of the Agency's reassessment '
without any further justification. Once a
'.State adopts a new dioxin criterion, the
permitting authority, either EPA or the *
State (if authorized to administer a
permit program), may change the
•fQuent limitation for dioxin in a permit
•ubjocttothaantibacksliding. ••
requirements of sections 402(o) and •.
303(d){4) of the CWA and the
«ntidegradation policy of the State.
• 'This final rub Includes criteria for "•
dioxin- This action encourages and
'supports the ongoing efforts of fourteen
States actively considering adopting
criteria for dioxin. Most of these States
are relying on the same data used by '"
EPA in deriving its criterion for dioodn.
In addition, dioxin limits are Included
•* appropriate in Individual Control ' '•
Strategtes (ICS*s) developed under
" aecfion 304(1), to there should be no
'immediate regulatory action that will be
* based upon the promulgation -of Federal
.criteria.' • •••.••
Moreover, as diseased in more detail
In Section J, Executive Order 12291, •
example 5, it is unlikely that the •-
practical impact of including dioxin at•
, the 0.013 ppq level in this rule^rffl •
affect the neea for treatment and ftmt,
istmlikelytobethebacisforany '.
incremental costs for pulp and paper*'
mills to reduce dioxin discharges, ' •
4. Section S04(a) Human Health Criteria
• Excluded •• • • -
Today's rule does not contain certain
of the section 304(a) criteria for priority
toxic pollutanU because 1hoso criteria :
were not based on toxidty. The basis for
these particular criteria are organoleptic
effects (e.g., taste and odor) which
would make water and edible aquatic
'life unpalatable but not toxic. Because
the basis for this rule is to protect the
• public health and aquatic fife from
toxidty consistent with the language
and intent in section 303(cH2)(B), EPA
is promulgating criteria only for those
priority toxic pollutants whoae criteria
recommendations are based on toxidty.
The Section 304(a) human health
criteria based on organoleptic effects for
copper, zinc, 2,4-dimethyIphenol, and
3-methyl-4-chloTophenol are excluded
for this, reason.
5. Cancer Risk Level
EPA's section 3O4(a) criteria guidance
documents for priority toxic pollutants
that are based on cardnogenidty .
present concentrations for upper bound
risk levels of 1 excess cancer per
100,000 people (lOr4), per 1,000.000
people (10-^, and per 10.000,000 ' »•'
people (lO-T), However, the criteria
documents do cot recommend a •
particular risk level as EPA policy. .
In the April, 1990, Federal Register
notice of preliminary ^y^>M'iiwit of
Stirta rnmpUnTim, RPA nrrnnrmf-nH 4t« . •'
intention to propose this rule with an
incremental cancer risk level of one in "•'
a million (10-*) for all priority toxic
pollutants regulated as carcinogens (55
FR 14351). This risk lovel was in fact
proposed in the November 19,1991
Federal Register Notice of proposed *
rulemhlring. However, EPA's Office of .
Water's guidance to the States has
' consistently reflected the Agency's
policy of accepting cancer risk polides '
from the States in the range of 10~* to
10-* (see 45 FR 79323, November 28,
1980; Guidance for State ••
Implementation of Water Quality •
Standards for CWA section 303(cX2)(B).
November 12.1988 (54 FR 348); aee also
document described in footnote's of this•
•preamble).-EPA reviews individual State
polides as part of its water quality -
standards oversight function and
• determines if Stateslxave at
consulted their dtizenry and applied
good sdence in adopting water quality
criteria. • • -• " • • '
In the proposal, EPA not only sought •
public comment on its decision to
propose criteria based on a 10-< risk
level, but also specifically solldted
comment on en alternate risk level of
10-'. EPA received extensive comments
that the proposed application of the
criteria at the 10-* risk level was
contrary to Agency policy, contradicted
other risk levels accepted by EPA in -•
States included in the proposal,
oversteps EPA authority by failing to •
recognize that such a decision more
properly should bo a State decision,
given their primary authority to
establish water quality standards, and
that EPA should not indude a risk level
in the final rule.
Upon consideration of these
comments, EPA agrees that establishing
a single risk level (for all States departs
from Agency policy in the standards
program. The application of the human
•health criteria in today's rule, on a
State-by-State basis, therefore, has been
changed In today's rule, the risk level
for each State is Ijftsed on the best
information available to the Agency as
to each State's poEcy or practice
. regarding what risk level is, or should
be, used in regulating carcinogens in
surface waters. ID most cases the risk •
levels were based on a State-adopted or
formally proposed risk level, or in the
case of Idaho. Rhode Island, and Nevada
on an expression of State policy
preference, EPA is therefore :
promulgating criteria at either the 10-*
or, 1CT6 risk level, «lther of which is.
consistent with EPA policy and with the
requirements of tiw Clean Water Act ..
the Agency recognizes .that it made •''
some of its dedsloias regarding the . .
appropriate risk tarel«n limited data.
However, in die time, available to. the
Agency, we reUed ink the best available
Information. The'. Agency believes it is:
important to intwe forward with this .
rule based on available information. To
ensure that the Agency has selected the
.appropriate risk level for eedy State, the
Agency is providing a final i.
for the Governor of each State {or other
official with authority to determine risk
levels with respect to water quality .
criteria) to inform EPAlf they believe a.
different risk level should be selected. -
for their State."...'-.: ....
..'Today> regulation will become
. effective '45 days from publication in thy
Federal Register: However,-Jf within 30
Airy* ntjtq$\l{ftilfafgpft'ht*rnl» tn flm '
Federal Register,4lie .Governor or other
•ppinpriiita nfBHul ^int^yn^nfff ^**t thft
final rule is not based on the correct -
State policy or practice with regard to .
risk levels, the Gov«mor (or other
appropriate official) may request the
Adininlstrator.ih writing to adopt a
different risk level Ibr the State,
rtateTbe Govtoaof is aotcaosbrtiiMd to
suigtoHsUevelfcralll
compounds. It i*«t
tosatect
For
'D adopt
l(r* far Clan A and E:«
tat Out C cardnofeams. In this rule, EPA b
. pcnrmilyitlng the two. riik level concept for
New 'jottcy* ~i 00 GovBEiwtf must explai& fba
basicfcr the wqaert brdwuigB the risk levaL
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Federal Register / Vol. 57, No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 60865
If EPA a^ennines. after receipt of ;
such a letter from the Governor or other
appropriate State official, the State's
preference is consistent with EPA
policy, as set out in this rulemaking,
and the requirements of the Clean Water
Act. EPA will amend the rule
As noted above, in this rulemaking
EPA is adopting risk levels that it .
believes .best reflects the expressed
preferences of the covered States (10~°
or 10~3 for all carcinogens). If there
. were, however, no clear expression of
preference by a State. EPA also believes
It is reasonable for States to adopt a risk
• level of 10~* for many of the covered
carcinogens and a more stringent risk
level of 10-* for those carcinogens with
substantially higher bioconcentratian
• factors, Bamgnigfag the-current
limitations oJthe scientific date
' available for this rulemaking, .EPA.
beUeves it would be reasonable to
• conclude that carcinogens that
bioaccumulate, particularly given the *'
•' exposure of fishermen'to such.
• cardnogens, may justify a more
protective risk level of 10-* for the'
• average fish consumer, but for other
•cardnogens a less conservative level .
(10-*) may be appropriate. \
6. Applying EPA't Nationally Derived
Criteria to State Waters '
• Toessist States fa modifying EPA's
water quality criteria, the Agency has
provided guidance on developing site
spedfic-cnteria for aquatic life and
human health (see Chapter 4, Water
Quality Standards Handbook,
Guidelines for Deriving Numerical
National Water Quality Criteria for the
Protection of Aquatic Organisms and
Their Uses, and the Guidelines and
Methodology Used fa the Preparation of
Health Effect Assessment Chapters of
the Consent Decree Water Criteria
Documents). This guidance can be used
~ by the appropriate regulatory authority
to develop alternative criteria. Where
such criteria are more stringent than the
criteria promulgated today. Section 510
of the Clean Water Act (33 U.S.C. 1370)
allows their implementation and ' *
enforcement fa lieu of today's . •
promulgated criteria. .•
. EPA's experience with such site-
specific criteria has verified that the -
national criteria are generally protective
and appropriate for direct use by the
States. (See Response to Comments on
the 1985 Aquatic Life Guidelines.
Comment 57,50 FR 30796, July 29,
1985.)
7, Application of Metak Criteria
A substantial number of comments
were received requesting Agency
guidance on the implementation of
metals criteria for aquatic life. In
response, the Agency has prepared
guidance on this issue, which is
described in general terms below, and
which is being applied to the metals
criteria being promulgated today.
Responses to individual comments may
be found in section I. comments 19 to
53.- - - ' • : ' ' • -••'.' - • .
In selecting an approach for
finplflni«m**"g the tnatflln criteria, the
principal issue is the correlation
between metals that are measured and
•metals oat are biologically available
. and toxic, as discussed more fully in
EPA's TutnriTn Guidance on .' •
Interpretation and Implementation of
Aquatic Life Criteria for Metals. US,
EPA. 1992, Office of Science and .
technology. May 1992. (Notice of -
availability published at 57 FR 24041.
June5.1992. . ..-- . .'...
In order to assure that the metals
criteria are appropriate for the rK*mi<«yl
conditions under which they are
applied; EPA is promulgating the
criteria in terms of total recoverable
metal and providing for adjustment of
the criteria through application of the
"water-effect ratio" procedure as '- ' .
described and recommended in the • .
above Guidance document This
procedure was developed in the early
1980's. and was originally set forth,
applications, as the Indicator Species • *
procedure in Chapter 4 of the Water .
Quality Standards Handbook (U.S. EPA
1983 at page 4-12). EPA notes that
-performing the testing to use site-
specific water-effect ratios is optional on
the part of the States. . . . - V
• In natural waters metals may exist hi
a variety of dissolved and particulate
forms. The bioavailability and toxidty
of metals depend strongly on the exact
physical and chemical form of the
metal Generally, dissolved metal has
greater toxidty than particulate metal,
and far some metals, such as copper.
certain dissolved forms have greater "
toxidty than other dissolved forms.
Because the spedation among the •
various farms of a particular metal may .
vary from place to'place, fo° same metal
.concentration may cause different
toxidty from place to place. ,
'With one exception (selenium). EPA's
metals criteria for aquatic life protection
are developed from laboratory toxidty
data. Use of laboratory toxidty testing is
usually much more cost-effective for •
obtaining data on (1) the toxidty of J
substances to a variety of spedes, and
(2) the effect of various water quality
characteristics on toxidty, (See 1980
Aquatic Life guidelines, comment 21,45
FR7936O. See also responses to .
comments 17.18.19.20.) The dilution
water used in laboratory toxidty tests is
ordinarily low hi particulate matter (Le.
suspended solids), and low in organic
matter compared to many ambient
waters. As a result, laboratory toxidty.
tests are ordinarily more likely to
overestimate the toxidty than
underestimate the toxiaty of metals in
some ambient waters, particularly fresh .
waters. . . •
Because of the complexity of metals
spedation and its effect on toxidty. the
relationship between measured : •
concentrations and toxidty is not
precise; Consequently, any method that
could be recommended would not
iparabllity
concentrations measured in the'
field and concentrations employed in
the toxidty testa underlying the criteria.
For metals criteria derived from
laboratory toxidty tests, the best
approach is to use a biological method
to compare bioavailability and toxidty
in receiving waters versus laboratory
test waters (the water-effect ratio) and to
adjust the criteria values accordingly.: •"
•This involves running toxidty tests for
at least two spedes, each preferably '.'
from a different family, measuring acute
_. ring
(and possibly chronic) toxidty .values
for the pollutant using (a) the local
receiving water, end (b) standard * •
laboratory toxidty testing water, which
is also the source of toxidty test . .
dUution water. A water-effect ratio is
the acute (or chronic) value in site water
divided by the acute (or chronic) value
fa standard laboratory water. An acute
value is an LC50 from a 48-96 hour test,
as appropriate for the spedes. A-chronic
value is a concentration resulting from
hypothesis testing or regression analysis
of measurements of survival, growth, or •
reproduction in life cycle, partial life
cycle, or early life stage tests on aquatic
spedes. . ' -.
. .Chemical approaches for defining and
comparing bioavailable metal are
subject to greater uncertainty than the
above biological approach.
dissolved and total recoverable metals
are easier to .apply than biological
approaches. One approach that EPA ha*
approved fa State standards is to
measure metals fa ambient waters fa
terms of dissolved ""*t*], and to
compare such measurements to criteria
appropriate for dissolved metal Since
.effluent limits, far both technical and
CTR 122.45) reasons, should be "^
expressed fa-terms of total recoverable
metal, ft is necessary to translate . .
between the dissolved and .total •
recoverable concentrations. EPA has not
incorporated the alternative of dissolved
-------
60866 Federal Register / Vol. 57, No. 246 / Tuesday. December 22, 1992 / Rules and Regulations
metals criteria into this rule, because the
'• us« of the water-effect ratio * •
accomplishes the same ends but is
- technically superior and subject to
lower uncertainties than •'
• implementation of the criteria as
dissolved concentrations.
The simplest approach for ambient
metals standards is the use of the total
recoverable analytical method without a
water-effect ratio adjustment This is a •'
. reasonable, albeit environmentally
conservative strategy, for applying* • .
-. EPA's'aquatic life criteria, where the '
* toxidty tasting necessary td develop an
alternative water-effect ratio has not " ;'
been performed, this rule will apply the'
total recoverable analytical method.
without a water-effect ratio adjustment
This occurs because EPA assigns the
water-effect ratio a value of i'.O, subject
to bo Ing rebutted by toxidty testing" .
remits, ' •/•..': '
•Because of the comments received, • .
. and because of the desire to achieve the
" greatest possible-degree of accuracy, ''•''
EPA has chosen to apply the total."% •• '.
. . recoverable metals criteria unadjusted '."
. for sllft-spodfic water chemistry, unless
the State adjusts the criteria through:the;'
- tiM of a water-affectTatio as provided'/'.'.••'
; for in this rule.'Allowance for'water- •.-•'•'
effect ratio adjustment also satisfies the '
concerns of comments requesting"^" :"
conridoration of dissolved criteria.'"•
The water^effect ratio approach . *'••
compares bioavailability and toxidty of
• a specific pollutant in receiving waters ' •
and in laboratory test waters. It involves
running toxidty tests for at'least two ~
apedes an appropriate number of times,
as determined by the States, ordinarily
on samples collected in at least two
seasons (or more where large metal •
'loadings ara involved).* As with-other '
site-spedfic procedures, the basic
analysts or testing maybe performed by
* the State, a permittee, or any other •
• Interested party. Acute or chronic'
* toxidty for the pollutant are measured '
uiingfo) the local receiving water where
the criterion is being implemented, and'
*.. (b) standard laboratory toxidty testing
, water, as tho source* of toxidty test •'••• '
dilution water. The water-effecttatio is •:
calculated as the acute or chronic'value
in site water divided by respective acute
or chronic values in standard laboratory •
water. Ordinarily, the geometriamean
water-effect^atio from the valid testa is •
; used for calculation of the criterion,
•xcapt where" protection of sensitive
species requires a more stringent value.
Because the metal's toxidty in standard"
laboratory water is the basis "forEPA's, :
criterion, this comparison is used to .' ••'
adjust the national criterion lo~a site*
ap^dfic value. Because the procedure is
a biological measure of differences in • -;
water chemistry, the water-effect ratio,
even when derived from acute tests,
usually may be assumed to also apply
to chronic criteria.
For criteria that do not vary with
hardness, the criterion for a specific site
, equals the acute or chronic value
tabulated in the rule (Le., the matrix in
40 CFR 131.36(b)) multiplied by the
site-specific water-effect ratio for that
pollutant The result may either reduce
or increase the 'stringency of the criteria.
For criteria whose toxidty varies with
. hardness, the criterion for a specific site
equals the criterion calculated at the
' design hardness (see 40.CFR •
131.36(c)(4)). multiplied by the aite-
• specific water-effect ratio. • -
"- The water-effect ratio is assigneda
•value .of 1.0, unless adentificauy.
defensible data clearly demonstrate that
a value less than 1.0 is necessary or a
[value greaterihah 1.0 is suffident to
•fully protect the designated uses of the
. water body from die toxic effects' of the. ;
:pollutant Any data accepted for :
.calculation of the water-effect ratio is to
be generated through standard toxidty
testing protocols (EPA recommends" the.
methodology in Annual Book of ASTM
Stds'. 1991; V61^1.04V ASTM. "' ."
>.Philadelphia, PA.).-using sampled .
' ambient water representative of ;
'' conditions in the affected water body,
' and using laboratory dilution water
' comparable to that used in toxidty tests
underlying the criteria. The guidance '
documents died at the beginning of this
'" section provides'more guidance on
.'generating the information necessary to
- determine the correct value of the water-
effect ratio. However, EPA intends.
within the next few months to provide '
additional guidance or performing the
analyses necessary to develop
sdentifically defensible water-effect
• ratios for metals. As envisioned at this
time, EPA will expand Chapter 4 in the
Handbook to apply the appropriate
procedures described there' specifically •
.•• -to metals. EPA will look-fit the chemical
'.•characteristics of the laboratory water
used in the toxidty tests'included in the
metals criteria data base; appropriate ':
test organisms, analytical methods, -'- °
•• safeguards against unintended metals
contamination during toxidty testing,
and appropriate data handling and
'• statistics.. While EPA believes the
• current guidance is adequate for,
application of the water-effect ratio, the
additional guidance should help •
KtanHm-dirn procedures and make >• .
results more comparable and defensible.
The'rule as promulgated is -• ' '
; constructed as a rebuttable '•'.-' ~
presumption. The water-effect ratio is
. assigned a value of 1.0 but provides that
a State may assign « different value •.
derived from suitable tests. As EPA has
noted elsewhere, the actual decision as '
to the numeric value assigned to a
water-effect ratio may be made during a
State or EPA NPDES permit proceeding.
provided that adequate notice and
opportunity for public participation is
provided. It is the responsibility of the
permit writing authority to determine
whether to apply the water-effect ratio
in an NPDES permit However, EPA
believes use of the ratio will lead to
more appropriate permit l<»">t« States
may wish to allow permittees to fund
State-administered studies necessary to
'develop the-ratio for particular . :-': -
waterbodies. .. . .
EPA reviews State issued NPDES
permits.'To Cadlitate EPA consideration
of a State-developed water-effect ratio..a
State should specify in documentation
supporting that action what decisions '•;
were made for critical parameters such ?
as toxidty testing protocols used, .:
'frequency of testing, critical periods for;
sampling and-testing, »nA analytical
quality control and assurance. Each of
.the factors must be articulated in a
'record as a basis for a determination that
the water-effect ratio iisdentifically •
defensible.. • •.''."*• •
The procedure applies only to aquatic
life criteria derived from laboratory ..:..r
toxidty data. That is, ilt applies to the . '..
acute and chronic critaria (Columns'B
and C In 40 CFR 13i.36(b)j for arsenic,
cadmium, chromium, copper, lead,
nickel, and zinc. It also applies to the
acute criteria for mercury and silver,.
and the saltwater acutB and chronic .
criteria for selenium. It does not apply '••
to the chronic criteria for mercury. .
because they are residue based, or to the
freshwater acute and chronic criteria for
selenium, because they are field based.
The water-effect ratio is affected hot .
. only by spedatiph among the various . .
dissolved'and particulate forms, but abb '
by additive, synergistic, and ; : ' ••
antagonistic effects of'Other irm
the affected site watent. As such, the
wateMffect ratio is a rather ."•. . •••
comprehensive measure of the effect of •
water chemistry on tbxj toxidty of a .-
pollutant Because the procedure • . •
accounts for any reduction in" -.
bioavailability resulting from binding of
the metal to particulato matter, all • ••••-.
metals criteria have been appropriately
expressed as total recoverable metal in •
thurule. '. . . : <• '•• - •• ' •
i
I
-J'
. Where measured water-effect ratios •
•are used in deriving NPDES permit
limits, data from appropriate testing •.; •'.
during theterm of the permitshould be
accumulated so that tfaie value of the
water-effect ratio can iwreevaluated .,.,'
each time the permit fai reissued. Thus, •
were measured wateMjffect ratios-are '
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Federal Register / Vol. 57. No. 246 / Tuesday, December 22. 1992 / Rules and Regulations 60867
involved. EPA. recommends that NPDES
permits establish monitoring
requirements that include periodic
determinations of water-effect ratios.
G. Description of the Final Rule and
Changes From Proposal
- J: Changes From Proposal
Several changes were made in the
final rule from the proposal both as a
result of Agency and State action with
respect to the ongoing adoption of water
quality standards by the States and
because of the Agency's consideration of
issues raised in specific public .
comments. • -
The States of Arizona, Colorado,
Connecticut, Louisiana, New
Hampshire, Virginia, the .
Commonwealth of the Northern Mariana
Islands, and Hawaii are not included in
the final rule as their standards were
duly adopted and approved by EPA as
fully meeting the requirements of -
section 303(c)(2)(B). Arizona's water
: quality standards were approved on
March 2,1992; Colorado's standards
were approved by EPA on DecemberlO,
1991; Connecticut on May 15,1992;
Louisiana on January 24,1992; New
Hampshire on June 25,1992; Virginia
on June 30,1992; CNMI on January 13,
1992; and Hawaii on November 4,1992:
Copies of die approval letters are
• included in the record to this final ' .
julemaJdng.
In addition, human health criteria
adopted by the State of Arkansas were
approved by EPA on January 24.1992,
and such criteria were removed from
today's rule as it affects Arkansas. EPA
is not promulgating and aquatic life
criterion in Arkansas for arsenic because
, a review of monitoring data from 1985
to the present reveals no reason to
conclude that arsenic will interfere with
designated aquatic life uses. Additional
details on EPA's action with respect to
Arkansas may be found in Section I—
Response to Public Comments,
subsection 6.
Except for dioxin, criteria for the State
of Florida for both human health and .
protection of aquatic life were approved
by EPA on February 25,1992. Florida is
.included in the rule only for the : .
purposes of establishing a criterion for
dioxin. More details, on Florida's action
are included in the Florida section of .
subsection 6 of the Response to
Comments section of this preamble. .
The criteria applicable to California
have been revised to reflect a partial
approval of the State's water quality
standards on November 6,1991. .
Additional comments with respect to
California may be found in subsection 6
of Section I—Response to Public . .
Comments. ' '
The rule aa it applies to the State of
Washington was revised after discussion
with the State as to EPA's interpretation
of the uses designated by the State. The
rule is now based on use categories
rather than use classes. Additional
details on *h<« chan
subsection 6 of
Public Comments.
The rule as it applies to Alaska was
modified to delete the assignment of
criteria to a seafood processing use. This
use fclln under the standards program.
However, because it applies to food
preparation only, it is not appropriate to
apply to it aquatic life or human health
criteria. Additional aquatic life and
human health criteria were added to
several use classifications after
discussions with the State clarified the
State's use classifications. Additional'
details on this change may be found in
subsection 6 of Section I—Response to
Public Comments. • ' • ... . •
•The rule as it applies, to Idaho was
modified to add additional criteria for
the protection of primary contact ,
recreation after, discussions with the •. .
State concerning that use. Additional.
details may be found in subsection 6 of
Section I—Response to Public '-. ;•'•'
Comments.
The rule as it applies to Kansas was
changed by removing the .promulgation
of silver.for sections (2) (A). (B). (C), and
(6)(C) as the State has an EPA approved
aquatic life criterion more stringent than
.the EPA criterion. The human health .
criterion for diver was removed because
EPA has withdrawn its silver human
health criterion. - ;...
The rule as it applies to New Jersey
, was revised to reflect comments
'received from the New Jersey
Department of Environmental Protection
and Energy to add waters classified as
Pinelands and to extend coverage of the
criteria to the mainstem Delaware River
• and Delaware Bay (zones 1C-6).
Additional details on this change may
be found in subsection 6 of Section I—-
Response to Public Comments. • • •
Clarifications on several-aspects of the
rule -with respect to implementation
procedures are addressed in the
response to public comments section of •
this preamble (section I).
Language was added in § 131.36(c)(4)
dealing with the application of metals
criteria as discussed in -section F-7 of ,
this preamble. We also added
requirements to clarify how hardness
should be handled in doing water-effect
ratio determinations (see . • -
131.36(c)(4)(iii), footnotes °«" and ''m" -
to 131.36(b)).
-The criteria for carcinogenic . •
compounds included in this rule are
applied at a risk level based on State
preference as reflected by. adopted or . •
proposed standards, or in the case of
Idaho. Nevada, and Rhode Island, on
expression of State policy preference,
rattier than at an across-the-board 1(T*
risk level as was proposed by the
Agency. The rationale for this change is
discussed in detail in section F-5 and ,
there is additional discussion in the
Response to Public Comment Section.
The basis for EPA's selection of a risk
level for an individual State is described
In the following paragraphs: - -
Alaska: Risk Level: 10-* .
In July 1992, the State proposed
human health water quality based on
achieving a 10"3 risk level for two
carcinogens: Dioxin and chloroform.
Also, on November 16, 1992, the
Commissioner of the Alaska Department
of Environmental Conservation wrote
the Director. Water Division, in EPA
Region X. and indicated that ". . . I also
had this matter reviewed by our
Attorney General's Office, and hereby -
confirm the appropriateness of utilizing
a 1
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60868 Federal Register / Vol. 57. No. 246 / Tuesday, December 22. 1992 / Rules and Regulations
comment in the next several months.
. , < "'Until we know what standard the
public in Idaho prefers, we believe it is
prudent to adopt the more protected
standards of ten to the mimic six."
EPA Region X is the permit issuing
authority for the State and applies lir6
for water quality based human health
requirements, These permit* have been
carufied by the State under section 401
as meeting water quality standards.
J&rwoRWsk Level: 10-*
• The State completed a series of public
hearings in August 1992 on proposed
water quality standards revisions and is
DOW processing public comments
leading to the final, formal adoption
hearing scheduled for January 1993.
Formal adoption is scheduled lor
February 1B93. The risk level in the •
current proposed standards is IQr6. See
proposed ICAJL 28-16-23e{c](4)(B).
Risi Level: 10-* ' .
For »evexftl years Michigan has been
controlling* toxics through application of
tha Guidelines for Rule 57. These
guideline* are. applied at a 10~s risk
level. See R 323. 1057{2Hd).
On November 3, 1992, EPA received
. a letlor.from the Administrator of the '
Division of Environmental Protection,
Department of Conservation and Natural
. Resources, M. . .that the public health
risk level that DEP would prefer to see '
in'foderal regulations is 10~s (one in one
hundred thousand), unless a state can
provide substantial support in the'
record that a risk level of 10-4 (one in
tan thousand) Is appropriate and
Srotective. This gives states the
todbility to use a more conservative
10-* risk level if they see fit, but without
requiring it when it is not necessary."
Newfasey: Risk Level: 10-* For Class A
and B Carcinogens, 10~5 For Class C •
Carcinogens . * "
New Jersey, on October 20/1992, : . '
solicited public comment on proposed
surface water quality standards. The
comment period is to close on December
18, 1992. The proposed, human health
criteria for carcinogens are established
on a two-tiered system for risk levels.
See proposed N.JA.C. 7.-9B-l,5(a}4. The
State previously had indicated their
intention to do this hi a letter to EPA on
December 19, 1991:
JPuerfoA'corRisk Level: ItT5 '
In 1990, the State proposed and held
public hearings on criteria for human
health using a 10~f .risk level. . •
Subsequently, the proposed standards .
were revised. Just recently the State
completed public hearings on the mart
recent revision to standards. Hie
standards are under review by the
Environmental Quality Board. Hie risk
level remains at MT*.
Bhode Island: Risk Level: lOr*
On November 2,1992. the EPA
Regional Administrator received a letter
from the Director, Department of
Environmental Management, that, along
with the Department of Health, the
State's4'* * * policy choice on the
promulgation of the human health
criteria is for the adoption of a cancer
risk level of 10-V The Director also
indicated that "• -*. *iiiture
modifications of this risk level, whether
it be to 10~* or 10-*, could be considered
on a pollutant and subpopulation basis
to produce a site specific risk
assessment and protection of human'
health." -
Vermont Risk Level: 10-« ,. ... .
On May 27. 1991. State submitted to
EPA final water quality standards which
reference the EPA section 304(a) criteria
to be applied at a 10-*. risk level
However, the effective date .of these
standards is not until January 1,1995. '
This delayed effective date was die
reason Region I advised the State that
the State did not comply with section
303(c)(2)(B). . . .
During the summer of 1992, the State
formally proposed and held public
hearings on revisions to its water quality
standards. The standards, scheduled for
adoption in late November 1992, •
include a risk level of 10"6.
On December 18, 1991, in itsoffidal -
comments on the proposed rule,' the
Department of Ecology urged EPA to
promulgate human health criteria at
10-6. Specifically. "The State of •
Washington supports adoption of a risk
level of one in one million for
carcinogens. If EPA decides to
promulgate a risk level below one in one
million, the rule should specifically
address the issue of multiple.
contaminants so as to better control •
overall site risks." . •
The final phrase in § 131.36(c)(2)
relating to the applicability of the rule
was amended by deleting the taXt '
beginning "but only ••*" EPA
received numerous comments that the
Federal criteria should be implemented
consistently with current State ' •
practices. EPA amended the language
because the Agency, had not intended to
• be inconsistent with the provisions of
the water quality standards regulation
(40 CFR 131.21{c)), which provides Oat
a State, water quality standard remains
in effect even though disapproved by
EPA, until the State revises it or EPA
promulgates a rule that supersedes the
State water quality standards.
Although not directly resulting in a
change to the rule, this preamble
clarifies, at the public's request, whether
schedules of compliance were .
applicable to this rule. In Section E-3 .
EPA clarifies that schedules of
compliance for thecie criteria are not
provided for in there rules, but that
available in NPDES permits if ' • •
authorized by State regulations. See In
the Matter of Star-Kiel Caribe,Inc.,
NPDES Appeal No. 88-5. Before the ;
' Environmental Appeals Board, EPA.
May 26. 1992.
Several deletions were made to the
proposed human health criteria as a .
result of the Agency's review of data
submitted in public: comments and to
reflect the pertinent impact of other
relevant Agency actions. The revisions
are as follows: • • . • .• •
(1) Criteria for three pollutants
included hi the matrix of the proposed
rule are not included in the final rule for
(A) acenaphthylens, (B) • -
benzo(ghi)perylene> and (C) •
phenanthrene. Hie criteria for these
pollutants were removed because they •
•are not recognized by the Agency as •
carcinogenic compounds nor do they :
have a reference dose that would allow'
the Agency to calculate a criterion leveL
(2) Silver: .The human health criteria • '
for silver were deleted from this final
rule because the criteria were
based on a cosmetic effect impact
not a toxidty endpoint
(3) f^n^tnium, Chromium, Selenium
and Beryllium: As described below, the
Agency has determined mat the .
proposed criteria for these contaminants
are no longer scientifically defensible
and accordingly bail withdrawn these " '
criteria pending evaluation of relevant
data regarding their toxidty. EPA notes
that the criteria promulgated for aquatic
life will provide adequate protection for
human health in most instances. • '
(4) Methyl Chloride. Lead and 1,1,1,
Trichloroethane: Ail described below,
the Agency has determined that there is
currently an insufficient basis for
^•Ifnilnf tnp Immim HiauMi crftftrifl for
these three «tmtamiii«nt«- Accordingry,
EPA has withdrawn the proposed - . «fc
criteria for these caahimTnsnts pending
further analysis. •• • • '
In addition to the above changes, the
Agency is today withdrawing the
human health criteria recommendations
previously published in the 1980
Ambient Water Quality Criteria
Documents for silver, cadmium, -
chromium, selenium, beryllium, lead,
-------
Federal Register / Vol. 57, No. 246 / Tuesday, December 22, 1992 /Rules and Regulations 60869
methyl chloride, and 1.1.1.
Trichloroethane. Summaries of the
human health criteria were also
published in Quality Criteria for Water.
1986. These summaries are also being
officially withdrawn today.
EPA's final rule establishes a new ,
§131.36 in 40 CFR part 131 entitled.
'Toxics Criteria for. Those States Not
Fully Complying with Clean Water Act,
section 303(c){2)(B)."
2.Scope '•' • • - '
'• Subsection (a), entitled "Scope",
clarifies that this Section is not a general,
promulgation of the section 304(e)
criteria for priority toxic pollutants but
is restricted to specific pollutants in
specific States.
3. EPA Criteria for Priority Toxic
Pollutants
As proposed, subsection (b) presents
a matrix of the applicable EPA criteria
for priority toxic pollutants. Section
.303(c)(2)(B) of the Act addresses only
pollutants listed as "toxic" pursuant to
section 307(a) of the Act As discussed.
earlier in this preamble, the section .'
307(a) list of toxics contains 65
compounds and families of compounds,
which potentially include thousands of
specific compounds. The Agency uses
the list of 126 "priority toxic pollutants"
for administrative purposes (see 40 CFR
131.36(b) herein). Reference in this rule
'to priority toxic pollutants, toxic
pollutants, or toxics refers to the 126
•priority toxic pollutants. .-
However, EPA has not developed both
aquatic life and human health section
304(a) criteria for all of the 126 priority
. toxic pollutants. The matrix in
paragraph (b) contains human health
criteria in Column D for 91 priority
toxic pollutants which are divided into
criteria (Column 1) lor water '•
.consumption (Le., 2 liters per day) and
aquatic life consumption (Le., 6.5 grains
per day of aquatic organisms), and
, Column 2 for aquatic life consumption
onry. The term aquatic life includes fish
-and shellfish such as shrimp, clams,
oysters and mussels. The total number
of priority toxic pollutants with criteria
promulgated today differs from the total
'number of priority toxic pollutants with
section304(a^critBria because EPA has
developed and is promulgating
chromium criteria for two valence states
with respect tQjquatic life criteria.
Thus, although chromium is a single
priority toxic pollutant, there are two
criteria for chromium for aquatic life.
However, the human criterion is based
on total chromium consistent with
Agency policy. See pollutant 5 in
Sl31.36(b). .
The matrix contains aquatic life
criteria for 30 priority pollutants. These
are divided into freshwater criteria
(column B) and saltwater criteria
(Column C). These columns are further
divided into acute and chronic criteria.
The aquatic life criteria are considered
by EPA to be protective when applied
under the conditions described in the
section 304(a) criteria documents and in
the "Technical Support Document for
Water Quality-based Toxics Control/*
For example, waterbody uses shouldte
protected if the criteria are not
exceeded, on average, once everr three
year period. It should be noted that the"
criteria maximum concentrations (the
acute criteria) are one-hour average
concentrations and that the criteria
continuous concentrations (the chronic
criteria) are four-day averages. It should
also be noted that for certain of the .
metals, the actual criteria are equations .
which are included as footnotes to the
matrix The toxidty of these metals are.
water hardness dependent and may be
adjusted by determining appropriate
water-effect ratios. The values shown in
the table are based on a hardness
expressed as calcium carbonate of 100
mg/1 and a water-effect ratio of .1.0.
Finally, the criterion for • .
pentachlorophenol ispH dependent
The equation is the actual criterion and
is inqluded as a footnote. The value ••
shown in the matrix is for a pH of 7.8
units.
. Several of the freshwater aquatic life
criteria are incorporated into the matrix
in the format used in the 1980 criteria'
methodology which uses a final acute
value instead of a continuous mirifimmn
concentration. This distinction is noted
in footnote (g) to the table. * .
^Applicability .
Section 131.36(c) establishes the
applicability of the criteria for each
included State. It provides that the
criteria promulgated for each. State
supersede and/or complement any State
criteria for that toxic pollutant EPA :
believes it has not superseded any State .
criteria for priority toxic pollutants ,
unless the State-adopted criteria are
disapproved or otherwise insufficient
The approach followed by the Agency
in preparing § 131.36(d) is described in
section E.2. and further rationale is
provided in section E.3.of this preamble.
promulgate the toxics criteria necessary
to comply with section 303(cM2)(B).
However, in order for such criteria to
achieve their intended purpose the
implementation scheme must be such
that the final results protect the public
health and welfare. In section F of this
preamble a discussion focused on the
factors in EPA'« assessment of criteria
for carcinogens. For example, fish
consumption rates, bioaccumulatidn
factors, and cancer potency slopes were
discussed. When any one of these ' -
factors is changed, the others must also
be evaluated so that, on balance,
resulting criteria are adequately
protective.
Once an appropriate criterion is >
selected for either aquatic life or human
health protection, then appropriate
conditions for ««lnplEt
-------
60870 Federal Register / VoL 57, No. .246 /Tuesday. December 22, 1992 / Rules and Regulations
States have not yet adopted such design
three dynamic models to perform
. wasteload allocations. Dynamic
wastoload models do not generally use
specific steady state design flows but
accomplish the same effect by factoring
in the probability of occurrence of
stream flows based on the historical
flow record. For simplicity, only'steady
state conditions will be discussed here.
. Clearly, If the criteria were implemented
using inadequate design flows, the
• rsfuluhg toxics controls •would not be
fully effective, because the-iesulting
ambient concentrations would exceed •
EPA'* criteria^ . •.--.-
In the case of .aquatic life, more
frequent violations than the once in 3 .
yaars assumed exceedences would
result in diminished vitality of stream
ecosystems,characteristics by the loss of
desired spoties such as sport fish. • .
Numeric water quality criteria should '
•apply at all flows that are equal to or •
, greater than flows specified below. The .
low flow values are: • \ - •
AquaticLife " - * . . "
acute criteria (CMCHl.Q 10 or IB "
,3 . ••*•"'- * • •-'.'•"
chronic criteria (CCCJ 7Qlpor4B
3 '-•*•:> : .? ' •'" '. .- '.,
Human Health'-.?•''.' ••
non-carcinogens 30Q5 • . .
carcinogens harmonic mean flow
Where: ' V • '., ;-'.r;1-" •' * '.
1Q10 is the lowest one'day flow with
an avenge recurrence frequency of
. «oc0 in 10 years determined'- •
hydrologically; ' ' -
1B 3 is biologically based and .
• indicates an allowable exceedence
.* of once every 3 years. It is. ,-.'•
determined by EPA's computerized
method (DELOW model);'. ."- .
.7Q10isihelowestavenge-7..'.'-* -
. ^consecutive day low-flow within • -
. average recurrence frequency of. •
once in 10 yean determined. •
. • 'hydrologically; *'•.»;• 1 f. •
4B 3 is biologically basedand . • -
indicates an allowable-exceedence"
for 4 consecutive days once every 3 •
* years. Jt is determined by EPA'a .. '
computerized method (DFLOW - '
model}; • •',
30Q5istheloweetaverage30 ,.
consecutive day low flovr withan •_.
* aval age recurrence frequency oT ••*
once in 5 years determined . -
the harmonic mean flow is a long
term mean flow value calculated by
dividing the number of daily flows
analyzed by the sum of the •• .
reciprocals of those daily flows.
EPA is promulgating the harmonic •
mean flow to be applied with human
health criteria for carcinogens. The
concept of a harmonic mean is a • .
standard statistical data analysis
technique. EPA's model for human
health effects assumes that such effects
occur because of a long-tarm exposure
to low concentration of a toxic
pollutant For example, two liters of
water per day for seventy years. To
estimate the concentrations of the toxic
pollutant in those two liters per day by
withdrawal from streams with a high
daily variation in flow,. EPA believes the
harmonic mean flow is the correct
statistic to use' in computing such
design flows rather than other averaging
techniques.* •
All waters, whether or not suitable for
such hydrologic calculations but
'included in this rule (including lakes..
.estuaries, and marine waters), must'
attain the criteria promulgated today. ''
Such attainment must occur at me end
of the discharge pipe, unless the State
has a mixing zone regulation. If the
State has a mixing zone regulation, then
the criteria would apply at the' locations
stated in that regulation. For example,
. the chronic criteria (OCC) must apply at
the geographically defined boundary of
.the mixing zone. Discussion of and .
guidance oathese factors are included
in the revised TSD in chapter 4. '
'•EPA is aware that the criteria \.
promulgated today for some of the
priority toxic pollutants are at
concentrations less man EPA's current
analytical.detection limits Analytical .
detection limits have never been an
acceptable/basis for setting standards
since they are not related to actual '
•environmental impacts. The .
environmental impact of a pollutant is
based on a scientific determination, not -
a measuring technique which is subject
to change. Setting the criteria at levels •
..that reflect adequate protection tends to;
Guidelines, page 21.) As the methods - -,
improve, limits doserto the actual
criteria necessary to protect aquatic life
and human h»»l*h became measurable.
The Agency does not believe it is . :
appropriate to promulgate criteria that.
are not sufficiently protective.
.EPA does believe, however, mat the ;
use of analytical detection Umftsare
appropriate for determining compliance .-
with NPDES permit limits. This view of
the role of detection limits was recently •
articulated in guidance for translating . •
dioxin criteria into NPDES permit limits
which is the principal method used: for :
water-quality standards enforcement3
This guidance presents a model for
addressing toxic pollutants which have
criteria recommendations less than
current detection limits. This guidance
is equally applicable to other priority
toxic pollutants with (criteria
recommendations les» than currant
'detection limits.' The (guidance explains
that standard analytical methods may be
used for purposes of determining
compliance with permit limits, but not
for purposes of establishing water
quality criteria or permit limits. Under •
the Clean Water Act analytical methods
are appropriately used in connection •
.with NPDES permit limit compliance
determinations. Because of the function
of water quality criteria. EPA has not
considered the sensitivity of analytical
.methods in deriving the criteria
* promulgated today. ' .'
EPA has added provisions in
' paragraph (c)(3) to determine when •
fresh water or saltwater aquatic life
criteria apply. In response to comments,
this provision was expanded to :
incorporate a time parameter to better •
define die critical condition; The'. •'-- •'
structure of the paragraph is to establish
presumptively applicable rules and to .
"allow for site-specific exceptions where
the rules are not consistent with actual
field.conditions. Because a distinct ; •:•
separation generally does not exist .•
between fresh water and marine water
aquatic communities. EPA is .
establishing the following: (1) The'fresh
water criteria apply at salinities of 1 part
per thousand and below at locations
where this occurs 95% or •more of the
time; (2) marine water criteria apply at.
.salinities of 10 parts per thousand and .
above at locatipns.whine this occurs •.
95% more of the time; and (3) at . •
.salinitiesbetween 1 and. 10 parts per "
tiiousandthrmore stringent of the two
apply unless. EPA approves .the
application .of the freihwater or . --. ....
'saltwater criteria baswa on a biological •'
assessment The percentiles hichided .
here were selected to minimize the. •.
chance of overlap, that is, one site
meeting both criteria. Determination of
these percentiles can be done by any
reasonable means such as interpolation
between points with measured data or
by flie application of calibrated and.
verified mathematical models (or "
hydraulic models), ft is not EPA's intent
*DM%a Straun Flows B*Md GD Hmaolc MM*.*'
LawU A. Kottmu. j. of-Hyditulio BagtaHriaf.
VoMl6.No.7.)uly.lMO,7hliarticUiscaataiaMl:
In th«.noord tor thlj ptopouL •• . .
W«M of (fa* United State*, mrnxmntam boa th«
.Actbtnt A4Bjatttnte far Water
Wcte Ufo^aaaoi Divisloa Dincton and NPDES
StMvOiractaa.Mqr21.lMiX
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Federal Register / Vol. 57. No. 246 / Tuesday. December 22. 1992 /Rules and Regulations 60871
health and welfare and enhance the
quality of water. Section 303(c){4) of the
Clean Water Act authorizes the .
Administrator of EPA to promulgate
Federal standards applicable to a State
when: (1) The State submits standards
for EPA approval and EPA determines
that the State standards fall to meet the
requirements of the Act. or (2) in any
case where the Administrator
determines a new or revised'standard is
necessary to meet the requirements of
to require actual data collection at
particular locations.
In the brackish water transition zones
of estuaries with varying salinities, there
generally will be a mix of freshwater
and saltwater spedes. Generally, .
therefore, it is reasonable for the more
stringent of the freshwater or saltwater
criteria to apply. In evaluating
appropriate data supporting toe
alternative set of criteria, EPA will focus
on the spedes composition as its
preferred method.
This assignment of criteria for fresh,
brackish and marine waters was
developed in consultation with EPA's "
research laboratories at Duluth,
Minnesota end Narragansett. Rhode . *
Island. The Agency believes such an
approach is consistent with field
erience.
_a paragraph (c)(4)(!) EPA included a
limitation on the amount of hardness '
that EPA can allow to antagonize tfie
• toxidtyof certain metals (see footnote
• (e) in the criteria matrix in paragraph (b)
of the rule). The data base used for the
Section 304(a) criteria documents for
metals do not include date supporting
. the extrapolation of the hardness effects
on metal toxidty beyond a.xange of -•
hardness of 25 mg/1 to 400 mg/1
(expressed as caldum carbonate). Thus.
the 'aquatic Kfeyalues for the'CMC '' •
(acute) and CCC (chronic) criteria for
these metals in waters With a hardness
less than 25 mg/1, must nevertheless use
25 ing/1 when «^C"^
-------
60872 Federal Register / Vol. 57, No. 246 / Tuesday, December 22. 1992 / Rules and Regulations
expressly limits the application of the"
criteria in the final rule to the States
named in the rule. (40 CFR 131.36(o))
As explained more fully In the
preamble, water quality standards
consist of designated beneficial uses of
* State's waters and the criteria
necessary to protect those uses. The
comment urges a waterbody-by- .
waterbody approach. For purposes of
this rulemaklng, EPA is presuming that
the States havo adequately made such
designated use determinations for its •
waters. EPA is merely adding criteria for
priority toxic pollutants on a State-by--
State basis sufficient to protect the • - -
State's designated uses. EPA believes its
approach accomplishes the commenters
objectives but in a more* comprehensive
manner. Moreover. EPA doesn't believe
this approach is more burdensome on- •
dischargers in affected States. Because
permit limits are incorporated into ..
NPDES permits only for constituents
having a reasonable potential to exceed
State water quality standards, a.-.; • •.
discharger does not receive a limit in its
permit unless its discharge contains the
pollutant Thus, comprehensive criteria
coverage in water quality standards does
. not translate into unnecessary permit .
limits. . '• •*.' • • .., ,
• EPA is unparsuaded that somehow ft-]
would have been easier or more efficient
for the public to comment on twenty- •„
two separate rules covering the same ~.
• issues than to deal with the issues in a -'
single rulemaldng.lt would most likely
result in EPA receiving the mfria type
comments on each separate rule which
would do nothing other than increase
the administrative burden to EPA and
•further delay getting water quality
standards in place. * .
3. Comment: A comment was made
that several proposals for reauthorizing
the Clean Water Act considered by. '
Congress in 1991 contemplated giving
EPA authority to promulgate* Federal '
standards thus indicating that EPA does"
not have such authority now. •
.Response: A response to a comment *
, above describes EPA's current authority
, to act under terms of the Clean Water
• Act The principal CWA'reauthorization
* bills considered by Congress in 1991 ,.
would neither question nor limit.this
existing authority. Rather they would
alter the water quality standards
program as it now exists by providing
specific deadlines for States to act in
adopting standards based on •
recommendations published by EPA :
and then mandating Federal
promulgation by a date r«rt»in. Rather
than suggesting that EPA does not now
have such authority, these proposals
support EPA's view that Congress is
becoming increasingly impatient with
the slow pace at which States adopt new
criteria recommendations issued by EPA
under section 304(a) and is willing to
consider supplementing EPA's currant
discretionary promulgation authority.
4. Comment: Several comments
suggested that EPA's promulgation
action should be limited to the
waterbodies and pollutants reported on
? the section 304(1} lists or information
contained in section 305(b) Water
Quality Inventory Reports. The basic
• thrust of these comments were that such
' lists, prepared by the States, contain
sufficient information necessary to
identify all potential toxic problem -
areas within the State. Some of these
commenters also suggested these
limited sources were more accurate than
the broader approach relied on in EPA's
• proposal. . "-:-
Response: A detailed description of
the approach the Agency followed in
developing this final rule is included in
.section E-2 of this preamble. As '
•indicated in that section. EPA used .-
information from a variety of sources in
determining which criteria to include in
the rule for each State. The Agency did
'not rely on a single source, such as
304(1), 305(b), or any other set of
information. • •-•••'".' • •
. Each of the data sources suggested by
.the commenters are valuable tools
• which serve specific purposes under the
dean WaterAct However, as described
bisection E-2, each source has . •••
limitations either as to coverage of
•" waterbodies or sources of pollution,
extent of information included, or a
narrow focus because of their particular
purpose; Even when information from* a •
variety of sources is used as described
as the Agency's "strawman", there
remain inherent weaknesses in the .
underlying" data. .
EPA behoves there is a greater
possibility of achieving the statutory
purpose of protecting water uses by
' .relying on a range of available data '
sources rattier than selecting one or two
narrow databases. EPA believes that by
not directing the Agency to use the .
results of the other statutory sections the
'commenters identified, and by use of
-the."could reasonably be expected to "
interfere" language, Congress directed
. the Agency to be more inclusive rather
than less inclusive in the applicable
criteria coverage. Thus. EPA urged a low
• threshold for inclusion of priority toxic
pollutants In the guidance transmitted
.to the States.
5. Comment: One commenter argued
that EPA's strawman systematically
overestimates the presence of priority
toxic pollutants because of its use of
industry wide default assumptions for
particular SIC codes. The commenter
further argues that comparisons between
the number of toxics adopted in States
who evaluated available data for toxics
and established criteria based on that
data to the results of the strawman
predictions show that a substantially •
smaller number of pollutants resulted.
The commenter urged that only section
3040) short list pollutants should be
used for this rule. ; •
Response: EPA's sitrawman analysis
was designed to use all of the Agency's
data bases to develop candidate lists of
toxics on a State spedficbasis. States
were urged to use thils information as a
starting point in evaluating the need for
particular priority toxic pollutants.
• EPA intentionally designed the
analysis to yield a fist of suspected
priority toxic pollutants that would not
.understate the potential presence of ,
such pollutants. As noted in the
preamble. State monitoring information.
for example, as used in the section
305(b) water quality reports, is not
comprehensive in either geographic or
parametric coverage. That is the reason
EPA used the industry profile data—to
maximize the data base. . '•
Thus. EPA was providing the States .
with a listing that identified potential
toxics end where those were potentially
located. The State was encouraged to
verify the lists. EPA lias not used the list
to identify pollutants for States included
in this rulemaking. Rather EPA has
viewed the. analysis as supporting its
contention that priority toxics exist in .
State waters and therefore, a broad .
promulgation for priority toxic
pollutants is Justified.
In arguing for limiting the
promulgation to the section 304(1) short
list pollutants, the commenter failed to
compare the criteria the example State
adopted in its water quality standards
versus the pollutants identified in its
section 3040) short list The State used .
as an example placed substantially more
criteria in their standards than in then* '
section 3040) short list The reason for
this disparity is because the threshold
for inclusion in water quality standards.
is much lower than for inclusion in the
section 304fl) short list
"6. Comment-EPA solicited comment
concerning the acceptability of the
review process used by EPA to
determine compliance with the Act—-
this process is described in section O of
this preamble. EPA received few public
comments in response to this request.
beyond the general comment that EPA
exceeded its authority to promulgate
Federal standards, an issue addressed '
earlier in this section. One view offered
was that the reviewprocess used by the
Agency makes it difficult to evaluate
whether adequate consistency was '
-------
acceptability of State standards.
Response: Each State's water quality
standards submission IB different They
require case specific review for
adequacy and consistency with
environmental and human health
requirements and statutory and
•regulatory provisions. Hie statute
allows for State flexibility. Given these
factors, EPA established broad guidance
parameters and Regional Offices
reviewed each submission for •
consistency. EPA Headquarters staff
exercised oversight on mis process to
, assure appropriate inter-Regional
consistency. This process did not
produce identical standards, hi each
State but that is not required. All State
standards that were approved were
judged by EPA to meet the twin tests of
protection of water body uses and
scientific defensibitity.
Both the criteria development and the
standards programs are iterative
programs and EPA expects to request
States to continue to focus on adopting
criteria for additional toxic pollutants
and revising existing criteria in future
triennial reviews which new; •'«•• •-•
infonnafion indicates iff appropriate. In -
no sense should States or the regulated
community assume that the task of
addressing pollution from toxics is
: completed by what the States have
'adopted or EPA is promulgating in the -
way of criteria for toxic pollutants. -
7. Comment: EPA did not propose
criteria for inclusion in State standards
when the criteria were based on
• TOganoleptic effects! The Agency .
specifically solicited pnTmnant on this
issue. Most of the comments received
indicated that EPA was correct in not
includin&such criteria in the rule. -
There were several comments to the
contrary indicating that such criteria
•should be included because the
- pollutants are on the section 307(a) list
and EPA did issue a criteria •
recommendation for the pollutant under
section 304{a). Therefore, they argue
that the requirements of section
Nonetheless, because section -'
303(c)(2)(B) focuses on tenacity of the
priority toxic pollutants, EPA believes
its rule should likewise focus on
toxidty. The 304(a) criteria documents
for these pollutants do not recommend
a criteria based on toxidty and therefore
such criteria are outside the intent of a
ralemaktag for section 303M2XB).
This decision notwithstanding, it
Federal Register / Vol. 57, No. 246 / Tuesday, December 22, 1992 7 Rules and Regulations 6O873
legal requirements of section.
303(c)(2)(B). The centaU.ob/ectfro o/
section 303(c)(2)(B}—establishing
chemical specific numeric limits—is
achieved by this approach.'There is no .
statutory bar to it and the Agency sees
no reason not to continue to support
this approach by States. .> .
Ultimately, EPA believes all State
toxic control programs will be
strengthened by adoption of both . .
chemical specific standards and a
translator mechanism for those -
pollutants where water quality criteria
have yrt to be developed.
' 9. Comment: EPA invited comment on
whether to promulgate a translator
mechanism for the States in this final ;
rule. A translator mechanism would
enable the States to derive numeric -
limits for pollutants beyond those hi.
this promulgation based on a State's
general narrative criterion. The Agency
received comments both supporting and
Response; While a translator
mechanism could be a valuable
supplement to State standards to deal
with toxics for which no section 304(a)
criteria recommendation is available, it .
is not necessary for EPA to promulgate
. a translator at this time to meet the . ".
objectives of section 303(c)(2)(B).
Today'* promulgation of chemical. .
specific criteria fulfills that obligation.
For fo"t reason a translator mechanism
is not included Jn today's final action.
However, EPA believes that such a
mechanism should be available hi all .
States. Therefore, hi revisions to the
basic water quality standards regulation,
EPA may propose a requirement for a
translator mechanism which would be
applicable to all jurisdictions included
in the standards program. .--•".'
10. Comment-Comment* were
received that EPA is attempting to •.
establish use classifications in this rule
and that such action is a right belonging
to a State. -
.Response: The use classifications to.
which Federal criteria are applied in :
rtit» rule are the classifications
. established and defined by each State
affected by the rule. EPA is not creating
State use classifications nor assigning
use classifications to any water bodies
' if? fMf. rula. In *ha £avr ingfanrmt'
described in Section G of this preamble,
appropriate adjustments to uses and •
criteria were made as necessary to
accurately reflect State use
classifications. Further, EPA believes
•the regulated community fa fully aware, .•
of the uses adopted by a State and to
which water bodies the uses apply. ••
Specific revisions in the rule pertaining
' to State use classifications are discussed •
303(c)(2)(B) apply.
Response: to the final rule, EPA has
not included criteria for pollutants
, where the section 304(a) criteria
recommendation was based on
organoleptic effects. Such effects cause
taste end odor problems which may
increase treatment costs in drinking
'water ex the selection by the public of
alternative but less protective sources of
drinking water and may cause *»t«*fag
of or off flavors in fish flesh and other
edible aquatic life reducing their
marketability and resource value. EPA is
also aware that some States have
adopted such criteria in their ffondqT^6
should be noted that the criteria
on organoleptic eSacts still represent'
the Agency'sheet scientific -
recommendations at this time and are
within the range of scientific
acceptability for a State's use.. -
8. Comment: One commenter asserted
that EPA's Option 3 (Le. adoption of;a
narrative standard coupled with a.
translator mechanism to compute a
derived numeric limit) of its December
'1988 guidance on complying with the
Act does not meet the legal
requirements of section 303(c)(2)(B). It
is argued that EPA should therefore •
standards which rely solely on a
narrative "free from" toxics water •
quality standard and a translator
mechanism, A related commentls that "•
this translator procedure maybe -'• =• •
appropriate as a supplement to adopting
specific numeric criteria.,--
Aesponse: The legality of Option-Sis
not an issue in this rulemaldng. We are
not promulgating any water quality-
standards based on Option 3. Option 3
is only a potential issue" in the
.subsequent approval of standards for
those States which are not included in
this rule. -••••:' ,. • -
Nevertheless, as noted in the -
December 1988 guidance, EPA believes
the combination of a narrative standard -
along with a translator mechanism as a
part of a State's water quality standards
can satisfy the substantive requirements
of the Clean Water Act Such translators
would need to be subject to all the
State's legal and administrative
requirements for adoption of standards
plus review and either approval or
disapproval by .EPA, and result in the
, development of derived numeric criteria
for specific section.307(a) toxic / ,
pollutants. ."••-•
EPA's guidance presented several
factors that EPA expected to be ,-
incorporated into a translator process in
order to comply with the Act In
essence. EPA expected that the
technical mechanism used would need
to be equivalent to a criteria
development protocol That is, it would
need to include an appropriate number
of sensitive species using suitable
'testing and analytical methodologies.If
established and applied correctly* EPA
has .indicated that it could meet the '
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60874 Federal Register / Vol.-57. No. 246 / Tuesday. December 22. 1992 / Rules and Regulations
in subsection 6 of the Response to
• Public Comments Section.
13. Comment.-During the pendency of
this rulemaking, several States asked if
adopting an emergency rule would be
^ sufficient to allow removal of the State
* from the final promulgation. Several
Sutos also indicated they should be
removed from the rule because they had
plans to adopt standards.
J?e5/>o;i$e;£inergency rulemaldng
actions by States are not judged by EPA
as sufficient batis'for removal from this
tulemaking. In most cases. State -
emergency rules have a limited duration
and expire at a date certain. There is no
assurance that enforceable permanent .
water quality standards would be in-
plsce at that time. If EPA were to allow
emergency rulomakings to be the basis
for removal from this package, given the
long delays.to date by these States, there
is the strong possibility promulgation .
• action would have to be commenced •
again by EPA iiythe near future.'The
delays and related program disruptions.
experienced by EPA have already been
too great. There has to be closure on the
standards adoption portion of our toxic
control-efforts. Reliance on temporary
emergency State actions would not" -
produce that closure. * ' " -
There is also the question of legal
vulnerability to the adoption of .' '
emergency rules and whether the State
emergency rule procedures allow for •
• sufficient public review. Moreover, the
emergency xules adopted would have to
fully comply with the Act States which
contend they should be dropped from •'
this rule because they now plan to adopt
standards remain in this rule because '•
EPA has no reasonable means of being
assured standards will be adopted as •
planned. Since passage of the •
amendments in 1987, many. State plans
for standards adoption have not been
completed as anticipated. -When States *.
complete approvable adoptions, EPA'
will take timely action to remove the
promulgation as applicable to that State.
12. Comment. Cfaecommenter
asserted that States do not have the
oecetsary legal authority under State •
law to use national water quality . • •
standards in State permits. •;.:•"* .
* Response. Without more information,
we cannot determine the precise •
concerns of this commenter. However, •
section 402(b) of the Clean Water Act
requires that States approved to ,
administer the National Pollutant
Discharge Elimination System (NFDES)
program must have adequate authority
to issue permits which comply with any
applicable requirements of section 301 .
of the Act Among those requirements .
are limitations to meet water quality
standards, and the criteria promulgated
today are"* ** applicable water •
quality standard(s) established pursuant
to this Act" Section 301(b)(l)(C).
Once promulgated, Federal standards
will be the basis of all environmental
' control programs designed to meet
water quality standards. States which .
had inadequate criteria for toxics will
'have a much more complete basis for ,
determining if {here are toxic
contamination problems in their waters.
If problems are identified, the State and
EPA will need to work together to see •
if the sources of these problems can be .
identified and controlled. The most '
direct impact will be on NPDES permits
for individual point source discharges.
The permitting agency, whether it be the
State or EPA will have to determine on
• a case-by-case basis whether to re-open
an individual permit or wait until a .
permit expires before introducing new
limits. ... . •'•'.• \
13. Comment. One commenter '
described ongoing judicial and
administrative proceedings to establish
the authority of the state to set permit
limits for dioxin by interpreting the ~
state's narrative criterion using EPA's •
section 304(a) dioxin guidance. The
commenter indicated that the state has ' '
consistently implemented its narrative
water quality criterion to control dioxin
discharges by. interpreting that criterion
'using EPA's guidance. It is the .
commenter's view .that if the state - • .
prevails in the ongoing litigation, it will
effectively have a numeric criterion for
dioxin. .''.'-,.-. '
Response The critical flaw in the •
commenter's argument is that the State
does not have in-place an EPA-epproved
numeric criterion for dioxin. or an
approved translator to generate a -
numeric criteria for dioxin. Moreover,
conclusion of the litigation would not
establish an approved numeric criterion,
even if the State were to prevail/EPA • .
understands that States often implement
their narrative criteria by interpreting •
those criteria using EPA guidance. EPA
supports this process by 2ie States. .
However, section 303(c)(2)(B) is clear
that States are to adopt numeric water
quality criteria for toxic pollutants. The .
purpose of this rulemaldng is to finally
establish the necessary numeric toxic
criteria in all States, and only those
states with the necessary approved
numeric criteria are excluded from the
rule. • - - •;'•••
2.Science' . ; '• . • " •
The response to comments in this
subsection are included under the
following headings: (AT General .
Comment. {B) Aquatic life Criteria, and •
(C) Human Health Criteria. . ..
A. General Comments • . .
14. Comment-Numerous comments
were received that EPA's water quality
criteria were published as scientific
guidance and were never intended to be
used as regulatory'pro visions without
modification to reflect local
environmental conditions. Related '
comments Indicated that because the'
criteria were published as guidance, the •
public comment received on the draft
water quality criteria documents were
restricted since reviewers did not'
antidpate their use as enforceable
limitsT. . .'..' V - :
Response: Water quality criteria are.
published as scientific information or
guidance under section 304(a) of the Act
because that is what the Clean Water .
Act specifies. EPA's implementing
water .quality standards regulation
recognizes that the section 304(a)
criteria may .be used as a basis for States
to establish .enforceable standards. See
40 CFR 131.11(b). To imply that the
section 304(a) criteria are merely . .
informational and not directly related to
establishing water quality standards
under section 303(cJ is not only reading
the Act in.an crabbed manner, it also •
ignores 26 years of program^history
which demonstrates that States
generally rely on the criteria
recommended by EPA in establishing •
Standards. Moreover, this rulemaking is .
the process which transforms these. .
recommendations into enforceable .,.',
regulatory requirements for specific ;
States. Any specific issues related to
establishing these criteria as applicable
to State standards could have been
raised during this rulemaldng even if
the issues were raised or considered in
the earlier publication of criteria . .
documents. .-. ' • •••
Furthermore, although the EPA water
quality standards regulation allows -..'-, *
State modification of water quality .
criteria to reflect local, site-specific .
conditions, it is not a requirement to do
so. EPA is also not obligated to modify
criteria to reflect local environmental
conditions although ideally EPA would -
consider any data submitted in support
of establishing a site-specific criterion in
determining whether site-specific • .:
criteria would be appropriate. In
addition, EPA believes the methodology
and the extensive data base used by the
criteria that will be protective for most
species in Virtually all waterbodies • •
throughout the counter.- (See 1985
Guidelines, page 4.)
Congress has given substantial •
credibility to the section 304(a) criteria
as well For example, in section .
301(hHe) applicants must meet the .
. I .
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Federal Register-/ Vol. 57. No. 246./ Tuesday. December 22. 1992 / Rule? and Regulations 60875
section 304(a) criteria as if they were
. Finally, it should be noted that when
announcing the availability of draft and
final criteria documents, it is stated in
the EPA announcement that such
criteria may form the basis for
' enforceable standards. EPA believes that
adequate notice of the uses of the
section 304(a) criteria has been provided
tothe.public. : ,
15. Comment: Commentere suggested
in general that the EPA criteria are
- outdated and need to be revised ,
extensively to reflect the latest scientific
' information available before they can be
appropriately used in rulemaldng. Fora
few pollutants data were submitted to
substantiate this claim. (See response to
, comments onspedfic pollutants below.)
.Response: EPA does not agree with
these comments" for several scientific,
programmatic, and statutory reasons. -
Scientific information is constantly '
evolving. Additional research is always
being done, test methods and theories
'improve, and more precise analytical
methods become1 available. There can be
a long lag time between conducting the
research, analyzing the data, issuing the
criteria documents for review, revising •
the documents.-and working through .•'••
the State or Federal administrative ;
processes to adopt standards. There ' -
comes a point in this process, where the
administering agendes/both EPA and."
'. the States, have to act using the existing
" 'criteria recommendations based on the
methodology by which they are derived.
and put standards into place so that
control programs can be implemented to.
. protect toe health of the public and the
environment One basic reason why
criteria and standards is an iterative
• process is to continuously evaluate and
incorporate new information. Through ,
this process, many of EPA's criteria
have been updated since issuance of the
formal criteria documents,
. Moreover, once standards are in .-,.
. 'place, applications can be made through
the 'mathematical models used to derive
total pfiMffaniiiin daily loads and .-. '
wasteload allocations. These ..'•'. -. '•;
determinations are associated with the;
NPDES permits process and result in
permit limits being established that
. £ave sufficient latitude to adequately.
account for other than major
adjustments to individual criteria' - " •
recommendations. '-* '
Finally, it must be recognized that
Federal promulgation is the end of the
process-to establish water quality
standards, not the beginning. In this
case, the beginning was in I960 when • ,
most of the criteria and the first/ . - v
' generation criteria development ' :
methodologies were issued. By 1983,
due to lack of response by the States,
EPA revised its basic water quality,.
.emphasis on the adoption of water
quality criteria and control of toxic
pollutants. This too failed to engender
adequate State response which in turn
led to the directive from Congress
contained in section 303{c)(2)(B). Now.
five years later, and two years .after the
States should have'taken action, this
final rule completes the process of
establishing the first set of ..
comprehensive standards for toxic
pollutants. This final Federal
r promulgation ands this current effort- i - •
but the revision of criteria based on new
research, the revision of applicable
.standards, alterations in analytical *•
•methods, and the evolution of control
technologies will continue. ••'•'"
. EPA asserts, as we have elsewhere in
.this preamble, that the promulgation
process established under the Clean
Water Act is a process designed to bring
to closure the act of putting enforceable
standards into place as basis for '••'."
environmental control programs ; - ,.
designed to protect public health and
the environment The promulgation. ;
• process is not designed or intended to
be the vehicle for a~reevaluation of the ' '
scientific underpinnings of water •
quality criteria. It is also not the process.
for protracting the debates about the
• scientific merits of various pollutants.-"
That debate is essential, necessary, and •
' is constantly ongoing but as a separate. •
• activity. The promulgation process
envisioned must go forward and the
Agency must make decisions based oh
the available data. It is clearly a means
to end such debates and to get'
environmental controls started based on
. available information. ':
EPA believes the criteria promulgated
today are scientifically sound as they '
are based upon a technically and -. '
scientifically acceptable methodology;
.Detailed descriptions of the formulation
of aquatic life criteria and human health
. criteria are included in section F (1,2. ..••.
and 3). As discussed below, we have -.'.
made some revisions to the criteria .' •
based on public comments. Our criteria .
for both human health and aquatic life
- provide a reasonable amount of
protection with only a small possibility
of substantial overprotection or
. -underprotection. • " •'.' - ? .-
-:' -To completely review all the criteria
as some suggested'would take a
TpiritmnTn oTseveral years during which <
time the humanIwalth and • ' .'.".'
• environmental problems associated with
. the continued discharge of toxic - •:•;.
pollutants would worsen. There is no •
predetermined result from an extended
reviews-some criteria might become
more stringent. Mtne less,
remain the same. In the meantime, the
States that failed to comply with the Act
are rewarded for their .failure. These
States have delayed while 43 of the
jurisdictions included in the program
have adopted water quality standards
for the most part relying on EPA's
section 304(a) criteria guidance.
As indicated in this preamble, .we are
currently re-examining our basic criteria
development methodology, which is a
normal course of action for the Agency
We anticipate some changes will be...
made and we assume some changes in
the.criteria1 will be made over the yean. '
This, however, is rid reason to suspend
action now. ;-.-.• • •" "' .
16. Comment: the use of information
contained in the Agency's Integrated
Risk Information System (IRIS) to
update human health criteria was
questioned by several commentere. The
central concerns were that the
information contained in the system •'
was not subject to external peer and
public review, the background - . :
information-contained in IRIS is not
readily available for review, and the..;
public had little chance to review the
results of the recalculations.,:.;. ••..•
flesponse. A detailed discussion of '
the QUS may be found in Section F-3 of
this preamble. To summarize the salient
points: (1) Reference doses and cancer "
classifications are validated by two
Agency work groups composed of senior
Agency scientists .from all other program
offices (Le., internal peer review), (2).the
• consensus opinion for reference doses'
and slope factors are then used
throughout EPA for consistent • .
regulation and guidance development.
(3) the data are available through the •.
TOXNET System maintained by Nffi
• and through diskettes available from the
National Technical Information Service
(NTIS). (4) the information used to . . ,.
recalculate the section 3O4(a) criteria hi
today's rule was included in die record
of this rulemaking, and (5) through the
proposal of this rule, the public had an
' opportunity to review and comment on
the revised criteria: In addition, some of
the RfD values and the cancer potency
slope factors undergo public review
during rulemaking for other Agency.
prograihs such as drinking water,
•• pesticides, and Superfuni Thus. EPA •'
believes that adequate notice about IRIS
and its use m Agency programs has .
: been provided to the public, at least as
it concerns its use in this rulemaking..
17. .Comment- Several commenters:
•indicated that the criteria should be
subjected to apeer and public review
process similar to that followed by the •
. Agency in jyf'fag proposed criteria'" •
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60876 Federal Register / Vol. 57, No. 246 / Tuesday. December 22, 1992 / Rules and Regulations'
under section 405 of the Act concerning
, the disposal of wastewater!sou*ds.
Response:tb9 proposed regulations ,
for the disposal of wastawater .solids
represented the. first time EPA proposed
* a memodology and specific criteria were
proposed by EPA for wastewater solids.
Therefore, tha extensive review for that
proposed regulation was appropriate.
Tho situation is not tha cams tor the
criteria promulgated in today's rule.
EPA and tha States have been regulating
the discharge of pollutants Into surface.
waters far many years. The ' . .. "
methodologies fat deriving criteria for
tha protection of both human health and
aquatic life ware peer and publicly . •
reviewed in 1980. The aquatic life :
. guidelines wars revised with peer and
public review in 1085. Both . . , -. .-
methodologies are currently being
* xevimved for posdbia revisions. As .
discussed elsewhere in this section, this
xulemaldng males use of the existing
criteria ana therefore is not the most
effective vehicle for revising either the
. meth'odologiei or fee actual criteria.-
18. Comment; Several commehters
objected that applying criteria, as ; '• .
standards when the criteria are below '.
• analytical detection limits is , "
•unreasonable because this may force the
-imposition o'f unreasonable permit
limits and "&be poeitive^indications
of non-compliance. Others suggested
that it was not clear-how detection
limits affect permit limits and '
compliance.- There were also comments
supporting EPA's position as described .
'in the proposal. •" -." - v "
Responsc:ln consideration of .
statutory 'requirements that water
quality standards' are to be protective of
designated stream uaes.-EPAhas .' .
.determined ttm^ consideration of " '*'.
analytical detectability would not be-an
appropriate factor to muddm- when
calculating the water qualify criteria
component of water quality standards. •
This hac been tha Agency's position
sinca tha inception of the water quality
standards program in 1965. • :-''••'
Although the sensitivity of analytical •
methods are not appropriate for setting
Vfatar quality criteria, they may be . ••
appropriate in determining compliance
with permit limits baaed water quality
standards. It should also be noted that •
by tha time standards are converted into
permit limitations after .calculating total
maximum daily load and wasteload
allocations, the actual permit limitmay
be In tho range of standard analytical
methods dtea by EPA fax 40 CFR part
136. -' • . • ..
. EPA's criteria development methods
for aquatic life are generally based on .•
laboratory bioassays with sensitive .
aquatic life. The results from theaa tests.
are analyzed by «™»tX<«mitft^|
procedures outlined in EPA's criteria
methodology guidelines. EPA human
health criteria are developed from
protocols generally using toxidty . . .
studies on laboratory animals such as
mice and rats. Thus, EPA's criteria an .
.effect-based without regard to chemical
analytical methods or technique*.
Because water quality standards
developed pursuant to section 303(c) of
the Clean Water Act are not self-
enforcing. the measurement of thase
chemicals in a regulatory sense is -.
generally in the amiext of an NPDES
' '
authority, either .a State or EPA, in-
conjunction
to be used in determining c^ppHi
with tha permit limit. , .....'- . -.
As noted in footnote 3 of this ; ' ..
preamble, EPA baa issued guidance on
how constituents with water quality
.criteria specified ti less than tXft. . ...
l methods
sensitivity of official anatytica
(i.e., those listed in;40 CFR part 136) are
established*inpermits, *.....<• ••'.• .
EPA's water quality standards'- -.;.• ..
•regulation at 40 CFR 131.11 requires ..
that criteria be adopted by States at
' designated uses. The criteria
promulgated today meet that "•.
.requirement while EPA's policy with
'• ' " "* '
nin trttn
consideration. ..
:B.AquiticLiie •'••'."'.,'"' .,
:• 19. Comment: A few comments :.-
questioned the role of biological criteria
in tiie standards program with one . ;.
commenter suggesting that establishing
numeric limits is contrary to achieving
the biological goals of the Clean Water
ACL ,- •-.. .. •" : :••' .•".. •
Response: Together, rfiamfaJ «nd
'
integrity define the overall
iQ' of an aquatic ecosystem. State
regulatory agencies should strive to. -
fully integrata all threa fiDnroachfic since
t .
each has its respective capabilities and
-
approach as repreoented by wholn
effluent tOXknty '
,
•specific criteria, and bioassessment .
approaches i&independantly applicable
•(see Policy .on Use of Biological . .;
Assessments and Criteria in tha Water
Quality Program, OS. EPA, May 1891).
, . , .
A description of the integration of ihesa
-approaches along with a detailed . - - •
analysis of the capabilities anji •;
limitations of each approach may be, .-
found in the Technical Support
Document far Water Quality-baaed . .
Toxics Control, March 1991. See TSD
Section 1.5 beginning on page 20, and ;
references dted therein. . •
20. Coounent: A commenter argued .
that EPA's proposed national aquatic
life criteria will be overprotective for
many surface waters oecause they dp •.
not account for atte-spedfic conditions.
At a minimum, any federal water •
quality criteria must take into account
broad aquatic life categories. . .
JtesponcerThe devolopment of EPA's
criteria is based on a broad aquatic life
data set The 1985 guidelines
recommend that eight species from eight
separate families be vised intbe, ...
development of the n«shwater and' ...""
saltwater criteria. Wtlleto is always ....
benafidalto have mcro data, EPA's. peer
.reviewed guidehnes ostablish that. , : 1.. .
•criteria developed from this yntntmiiAi-
data set adequate^ protect squatic. , .
communities (1985 Guidelines^ see . .
section m, p, 22). Tho apparent level of
protection is different for each Idnd of ,
effect (acute or chronic toxictty .to ' ' '
of the quality and qutmtity of
\nttarruillrfn, .
f »Vo In^n ^nyynin^ yii
ftiA •
importance of the effix^-thetiuaHty of ,
the available data, and the probable . . .•
ecological relevance of the test methods.
The present apprcecli to aquatic toxidty -
.allows conclusions to be made about the
abUity of •.substance to sdveraely affect
aquatic organisms an
-------
Federal Register / Vol. 57, No. 246 /'Tuesday, PeCTmber'-22^i892-/:-Rules and Regulations 6O877
above the criteria will not result in
adverse impacts.The data indicate &at
if ambient water quality criteria are met,
organisms in the receiving water are
protected from adverse impacts.
22. Comment: Comment was received
that EPA should clarify that the aquatic
life water quality criteria for arsenic are
; based on the bivalent form of arsenic.
Response: The arsenic criteria
promulgated today are applied on total
recoverable, inorganic arsenic. The 1885
arsenic criteria document is derived
from data on Arsenic pH). However,
because there is no readily available or
practical analytical method to quantify
the various forms of arsenic in
monitoring applications for aquatic life,
EPA has concluded that it is reasonable-
to quantify environmental arsenic ,
concentrations as total recoverable
inorganic arsenic (EPA Methods 206.2,
206.3,206.4,206.5.) " • .
. in addition, EPA reevsluated the .
acute and chronic toxidty data oa the
two most prevalent forms of arsenic in .
aquatic systems (bivalent and. .. ;
pentavalent arsenic) in the Arsenic '
criteria document These data show that
arsenic tm) and arsenic (V) toxidty is
similar for both sensitive freshwater and
saltwater spedes. For five of the six . '•:'.'
freshwater spedes and all of the •'
•saltwater spedesiised in the arsenic
calculation where .there was comparable
JTifnrmatirT) O" JMftlta UnA oVimnir
toxidty, values wen within a factor of
two or three. Certain plants, for example
Selenostrum capricornufum (alga), are
45 times more sensitive toarsenic(V)
than to arsenic (IE). Therefore, it is -L
reasonable to combine forms of arsenic
to specify the criteria. The measurement
of total recoverable arsenic has both
tqxicological and practical advantages
approach is used by most States. la the
context of this rule it represents a
technically acceptable approach to
cover a variety of waters, and the only
feasible one. (See also the response to.
comments for the 1980 Guidelines. Nos.
17 and 19.45 FR 79359, November 28,
1980.) .
In response to the second comment,
the scientist running thei specific -
toxidty test referenced by the comment
noted that its accuracy is only •.
guaranteed for the specific water tested.
However, applying these tests to other
waters is an acceptable approximation.
(See response to public comments for . *
the 1980 Guidelines, 45 FR 79359-
79360, comment §20 and §21.)
Additionally, laboratory toxidfy testing
is the most reasonable and practical way
to develop a database which is large
enough to develop criteria, and diverse
enough in spedes, which generally "•
represent a larger source of variability.
. while most States have not chosen to
perform sUe^pedfic toxidty tests, any
State may develop site specific-criteria.'
These criteria wifl be more appropriate .
and tailored to the site for setting
NPDES permit limits than EPA's
'national criteria. Because they ere' ...-•;
. amended water quality standards, site
specific criteria are subject to EPA . -
review. Other than the water-effect ratio
life toxldties of arsenic compounds.
-•••.-. 23. Comment; Several commenters
- asserted that criteria Based on laboratory
'-,.• tests are overprotective when applied in-
• -the field. Another commenter quoted"
laboratory study reportsstating that the
results are appUcable only to the- .'"•
particular water tested. .- '.
JtespanfeeVEPA agrees that waters - -•
used.for laboratorytoxidtytesting ere -..'
generally cleaner than many natural
.systems. In cases where ambient waters
contain constituents which alter the
toxidty of chemicals, an increase hi _
accuracy may be provided by rerunninR
* the toxidty tests in site-water. (For ,
example, the water-effect ratio approach
for metalspromulgated today.) In most
- instances, this correction will be smalL
• (TSD,March 1991, p£).Therefore,., •
applying the criteria values developed
. from laboratory testing provides an '
acceptable level of accuracy, «nd this
State-developed site specific-criteria <__
not replace the criteria promulgated in
todays rule unless the site specific-
criteria are approved by EPA as meeting
the requirements of the Act and EPA
•mends the rule adopted today*
24. Comment; Comment was received
that the proposed rule includes some
aquatic life criteria computed using the
1980 guidelines methodology and others
were computed using the 1985 " .
guidelines methodology. It was asserted
-that the simplistic approach of the 1980
mirfinArilnny luniaVarthn fr^»r^HRr! r -
improvementsbfihe-1985-guidelines. :,
Thf TxrtnnH»nti»?vTBft^ that these criteria-'
shouldl» updated to provide consistent
-methodology end adherence to the.' ;
Jtespbnsc: As the commenter noted, .
some of the aquatic life criteria in this '
rule are based on 1980rguidelines. EPA
reviewed the-data bueior these criteria •
and determined that in general they .
could not be recalculated by the 1985 .
guidelines because of difbrenoBS in data
base requirements between the two
guideUnesuoed species specific
requiremente whereas the 1985 .
' guidelines expanded this to-broader
taxonomic categories.) EPA beUeves that
the data used in the 1980 criteria
. document are sound. As a practical -
matter,* reasonable approximation to a
criteria maximum concentration can be
obtained by simply dividing the fine] •
acute values in tne matrix by" 2. The
criteria in the matrix in today's rule
were not changed from the results of the
respective 1980 and 1985
methodologies. Therefore, EPA has
reconsidered these aquatic life criteria at
the commenter's request and considers
them to be within the acceptable range
based on uncertainties associated with
computing water quality criteria. These
criteria are protective of aquatic life and
are scientifically sound. '
The development of aquatic life
criteria is a dynamic process which
responds to the influence of improved
sdence. It is expected that this science
will be constantly evolving as new
analytical techniques become available -
and new studies are evaluated. To this
end, EPA is also reviewing the'current .
methodology for developing aquatic life
criteria. The current methodology will
be reviewed, and if needed, revised to •*
incorporate the latest concepts of .
aquatic toxicology. . ' •
25. Conunenr/A commenter asserted .
that the proposed aquatic life criteria
may be underprotective since they fail
to account for synergism and additivity
and fall to consider wildlife impacts.
Response: EPA agrees that the aquatic
life criteria do not deal with - /
simultaneous exposure to more than one
pollutant This is largely because few .
data are available, the data which are
available do not allow for development
of useful principles and there are so"
many possible combinations of •* .•' . -
pollutants present to prevent
EPA h»g considered the effects of
.multiple toxics discharged into -
receiving waters. (Technical Support •- -
Document for Water Quality-based
Toxics Control; March 1991.) The -
studies dted in the TSD indicate that -
themedian combined effect of a mixture
of acutely toxic poUutanbin receiving -
water is additive. EPA recommends,
that intheabsence of site-specific data.
• regulatory authorities consider: • . '.
combined acute toxidty to be additive.
Thus, the combined acutely lethal
toxidty to fish and other aquatic
organisms is approximately the simple
addition of the proportional ; .
contribution from each tnxfcnn£ •
However, available data do not -
indicate additivity for chronic toxidty.
EPA further recommends that chronic
toxidty not be considered additive, and
that each toxic be considered •
individually. - : :
Synergism has not been demonstrated
to be an important factor in the toxidty
of effiuents. Field studies or efQuent
toxidty and laboratory tests with '
-------
60878 Federal Register / Vol. 57. No.' 246 / Tuesday, December 22. 1992 / Rules and Regulations
specific chemicals support an inference
'that synergisin is a rare phenomenon.
(See TSD, page 24.) (See also response
- to comments in the 1980 Guidelines,
Comment *9,45 FR 79358, November
.28,1980.) Theoretically, antagonism is
just as likely to occur, which might
< suggest that the criteria are overly
protective in an environment exposed to
contaminant mixtures. ,
EPA considers the criteria, when
applied with the appropriate frequency
and duration of exposure, to adequately
protect wildlife. Three of the aquatic life
criteria in this rulemaldng are based on
wildlife toxidty and exposure, ,.
(Selenium. DDT and Folychlorinated
Biphenyls). EPA is in the process of -
developing a wildlife criteria ' •
development methodology to provide
further guidance for wildlife concerns.
Onco this tool is developed, EPA will
have a method of focusing criteria on.
wildlife issue*. =.-•... ,-• . . . .;.,
26. Comment: Several commenters.'
argue that the criteria do not apply to
semi-arid ecosystems; None of the
guidance issued.to date expressly
address the means to apply those
criteria to semi-Arid ecosystems found
in Arizona.*Ephem0ral streams.and
effluent-dominated waters are distinct
classes of waters that should be , -
regulated to protect the aquatic species r
that typically inhabit them,/ •••.-"
• fiespontt: Water quality criteria are •
toxidty based values, usually chemical
specific. The criteria are based on toxic >.
•Efocts to ft broad taxonomlc group and
do not consider the types of water . '
bodies, such as semi-arid ecosystems, •
they may be .applied to.. Aquatic life
criteria, whan implemented as part of
water quality standards, are meant to be
protective of aquatic life. These -
standards are applied to specific -* •:
waterbodies through designated uses.
For this rulemaldng, EPA assumes that
States correctly define designated uses
and the specific waterbodies to which '•
those tisas apply.-EPA agrees that- •'
rphomeral ttceams'an'd effluent' ..-. ' --~
dominated waters are distinct classes of'
waters. If a State feels an aquatic life use
designation is appropriate for these
watarbodlw, then the .aquatic Ufa.;.— - -
critaria will apply to protect-that use. If
not, then'they will not apply. EPA is not
promulgating designated uses for State
water*. EPA is only applying , '. •
appropriate aquatic life criteria to
waters that States designated for aquatic
life protection. ••..'•• -. .. • :
27. Comment: Comment was'made
that EPA should allow an alternate
methodology for calculating the Final
Acute Value when dealing with small
data sets.
Response: EPA has considered '
alternate methods for calculating the
Final Acute Value (FAV). The present
methodology was developed by the
Agency's guidelines committee,
subjected to outside peer and public
review, and is a reasonable technique.
EPA develops a Final Acute Value on as
f large a data set as available. The
guidelines generally require eight
separate families for derivation of acute
values (1885 Guidelines, p. 23). EPA'
considers this to be an adequate* data §et
for calculation of the FAV. As the data
set growsit only provides additional
confidence of the scientific basis for ,'"
calculating the Final Acute Value. The.
present methodology has been reviewed
both within and outsidethe EPA for
scientific merit EPA considers the
. present methodology to be sound. The '
guidelines are presently under review. •
• The method suggested by the
commenter is relatively new, and it and'.
other statistical bases for criteria •
. development are being reviewed in the ".
Agency's current effort in reviewing the
criteria development guidelines. It is ";.
intended that the guidelines reflect the •-'
. best science and to that end EPA wrill; '"
' consider all.aspects to continue'to V. V '
provide a sound and scientifically based.
/methodology. : ..- '.'"'.'•'.' *' I
28.' Comment: Comment was received *
•thatthe aquatic life criteria and */ '
guideline methodology, contrary to ; :".""
•EPA's assertions, hive not undergone __'' '•
sufficient scientific peer review. ' .
Response: EPA does not agree. The .
criteria end underlying methodology
guidelines were widely distributed to ••
interested parties. These drafts were .' •'
made available to and thoroughly
discussed with experts within EPA,
industry, end ecademia. These '' . "
interactions have provided many useful
mTTimtrnffi anrf InffirmnHrm igtitrti• .• •. .
the criteria and methodologies. The
, methodologies wore further reviewed by"
an independent Sdence Advisory Board
which EPA considers to constitute '«
externalj>eerreview. (SAB Water- ';v "".
Quality Criteria," A Report of the. Water;
Quality Criteria Subcommittee, April '
1985). The SAB noted that since EPA's
''initial efforts in developing water
quality criteria, the process has ' '
undergone considerable evolution. The
SAB f eh that each revision represented
a more sophisticated and realistic. , "'.
approach: EPA encourages and makes .
every reasonable attempt to include as
much of the scientific community as "
practical in carrying out its, ' :
responsibility under the dean Water
Act '"."'— -•' :':
29. Comment: Comment was received
that EPA states in the proposal that the
methodology for developing aquatic life
criteria have been approved by the .
Science Advisory Board (SAB); however
this approval was not unqualified.
Response: In its comments on EPA's
1985 guidelines, the SAB committee .
noted that EPA had developed a more
scientifically sophisticated and realistic
set of guidelines. (SAB Water Quality
Criteria. A Report of the Water Quality
Criteria Subcommittee, April 1085.) It
noted approvingly that EPA considers
such issues as mode of expooure. level •
of protectiveness and ecosystem
protection. It further iioted that the
.guidelines took advantage of advances •'•
in recent scientific research. The report.
being a critique, did itote areas where .'
the guidelines could lae improved and .
areas where additional research might
be helpful Overall the SAB report was
supportive of the Agency's aquatic life
criteria development guidelines. '
30. Comment: Numerous comments '
were received with regard to the metals •
criteria. It was noted tibat the draft rale
did not m«Va clear wliat analytical '
method wasto.be used for'. ' .
implementation and that metals criteria
should not be interpreted in terms of "
total recoverable or add soluble metal .
ft wasrasserted mat dissolved criteria
. would be more appropriate, and in; '.-
many cases effluent limits based on •
dissolved metals onrjf would be more /
appropriate: ManyTX>mmenters urged
that the rule should implement the- ' •
metals criteria using the site-specific ' '•
water-effect ratio, in order to target the
bioavailable fraction of pollutant
. Moreover, it was asserted that the
copper criteria document states that
organic carbon-has a iitrong effect in
reducing copper, toxicdty. end that the
copper criterion'should be recalculated
for waters having TXX2 greater than 2—
3 mg/L Furthermore, it was argued, the
.toxidty of several meltals are related to
pH, total organic carbon tTQC), _' '
spedation, as well as the hardness.
•The cornmenten^asserted that the
criteria are overiy protective when
applied to the field, and are overly
..protective because they are not site-;
specific.'','. '•"": .,-',. ". - ," •
. Another commenter argued that the
criteria are underprotoctive because •
they do not account for synergism or
additive effects.
.Response: These diverse and
recurring comments have been
aggregated above because they deal in
large measure with the phenomenon
that the same metal concentration may
cause different toxidty from place to
place due" to chemical differencesifrom '
place to place. In natural waters metals
may exist in a variety of dissolved and
paiticulate forms. As discussed • • •
-------
copper and silver, can exist in a variety
of dissolved forms that differ greatly in
toxidty. The water-effect ratio is the
best procedure EPA currently has for
measuring such differences.
The water-effect ratio is also a
reasonable method now available for
accounting for synergistic and additive
effects of pollutants. Regardless of
whether a value less than or greater than
one is measured lor the water-effect
ratio, synergistic and additive effects of
other pollutants in the site water are
working against the antagonistic effects
federal Register / Vot. 57. No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 6O879
significant, levels of organic carbon and
suspended partides that are in the range
of a significant number of receiving
waters. In the case of heavy metals, for
example, certain particulate forms may
be partially bioavailable and particulate
forms in effluents may become
dissolved after discharge into receiving
waters. It is not appropriate to attribute
toxidty solely to a particular form of
metal: This has never been dearly
demonstrated for any metal, being only
questionably inferred under very
restrictive conditions. (See response to
public comment for the 1980
Guidelines, comment nos. 17.-19. fc-20; •
45 FR 79359.)
Because water quality, criteria are •
derived to be protective in almost all .-.
situations, they may be overprotective
in some situations. Moreover, sits water
effects may be most prevalent for heavy
metals, this rule thus provides for site-
specific determination of criteria values
for metals based on local water-effect .
ratios. -.'••-
32. Comment EPA's aquaticlife
criteria for metals do not take into.
account the effect that water chemistry
and metals spedation has on toxidty.
EPA should withdraw criteria (such as .'
risewhere in the preamble, the
Y>>oaw&UbiUty and toxicvty oi a metal
depends strongly on its exact physical
end chemical form. See Section F.7. It
also depends on the site-specific
chemistry of the water, and on the other
materials contained in the water.
Because of (a) the complexity of
metals speciation. B>) the varying
degrees of bioavailability and toxidty of
the many forms and complexes, and (c)
the additive, synergistic, and
antagonistic influences of other , •. - •
materials in the water, there is no one .
chemical method that can assure that a
_-unit of concentration measured in the .
field wcwld always be lexicologically
equivalent to a unit of concentration
'occurring in the laboratory toxidty tests
underlying the criteria. Consequently,
•simply choosing a .particular chemical
method (such as total recoverable metal
or dissolved metal) to measure
- attainment of this metals, criteria would
not assure the appropriateness of the'
criterion for the water chemistry of the
- various sites at which theoiteria apply.
In response to comments, EPA is ,
• implementing; the criteria in terms t»f -.
. -total jecoverabla metal while calculating
the criteria value using the water
. chemistry adjustment provided by the .
"water-effectratk»" procedure for .
certain metals.as described and ./
reocmmended in its current Guidance -•'-
on Interpretation and Implementation of
Aquatic Life Criteria for Metals. May
1992. This approach takes into account.
- oUracUy, water/characteristics such as
.total organic carbon, pH, metals
speciation and hardness, as suggested
by the commenter.' . .
The water-effect ratio approach - ,
compares bioavailability and toxidty of
a specific pollutant in receiving waters ,
. and in laboratory test waters. It involves
running toxidty tests for at least two
srwdes, measuring LCSOs for the
pollutant using (a) the local receiving :
water collected from the site where the
criterion is being implemented, and (b)
laboratory toxidty testing water made
comparable to the site water in terms of
chemical hardness. Because the water-.
~ effect ratio procedure, described in the
. above referenced guidance, provides a
biological measure of differences in
4 water chemistry ."the ratio between site
water and lab water LCSOs is used to
adjust the national starts and chronic •'
criteria to site-specific .values.
Because the water-effect ratio is a
comprehensive measure of :differences
in bioavailability and toxicity, including
the differences between dissolved and.
particulate bioavailability, it will' .
produce a more appropriate criterion
than simply expressing the criteriaas
dissolved metaL Some metals, such as
. EPA recognizes.that I—
comprehensive qualities of the water-
effect ratio do come at a cost The
procedure will yield results that are
locally the most appropriate, but it is
more difficult and expensive, than •
purely chemical approach.
juently, performii
^ ing such an
analysis is not mandatory. In the
absence of acceptable data, the rule
assigns the ratio a value of 1.0, which
yields no change in the national criteria.
The rule also stipulates that the water- .
effect ratio cannot be set at a value •• .
•different than 1.4 unless such value
protects the water body from the toxic .
effects of the pollutant, and is derived -
from suitable testa on samples •
appropriately representative of the . .
.water body. Consequently.;
'inadequacies, uncertainties, or
ambiguities in the data will also result
in the water-effect ratio being set at 1.0.
The type of specific data needed to
implement the method is described in
guidance: The 1992 Guidance on
Interpretation and Implementation of •
Aquatic Life Criteria for Metals, and the
1983 Water Quality Standards /
Handbook As discussed in Section 7 of
the preamble, EPA is currently
developing more specific procedures
and methods to assist States in
implementing the water-effect ratio ;
approach..
31. Comment* A commenter asserted
that laboratory tests using artificial
testing conditions have little or no
direct applicability to actual discharges
and receiving water situations, therefore
the criteria are overprotective.
Response: Laboratory tests are not
conducted in pure water and pollutants
are not solely in a free ionic form
(complexed by nothing but water). (For
example, laboratory waters'are
described in some detail in various ••>
standard protocols for doing toxidty .
testing, e.g., American Sodety for
Testing Materials (ASTM), Standard
E729, "Practice for Conducting Acute
Toxidty Tests with Fishes, .
Macroinvertebrates and Amphibians.")
Laboratory waters have low, but still .
zinc and copper), and provide criteria
that vary with pH, total organic carbon
. (TOCi. and other factors that affect
- spedation and toxidty. • .:. - -
Response: While |t is true that .
spedation and site water chemistry can
. modulate toxidty and that the national
criteria do not account for most of these
factors, we do'not agree with the . •
comment that we should withdraw the
criteria. There is inadequate data on
enough spedes and conditions to adjust
for aU important factors in the national
criteria, although current work is trying
to address this situation. However, this
uncertainty is insufficient reason to not
issue and apply criteria; criteria are
sufficiently applicable without '••.
modification to most receiving waters
. and can be appropriately adjusted for
other waters by the water-effect ratio
approach. The purpose of water effect
calculation, is to provide a means for
setting the value appropriate for the site-
specific water chemistry, where
sufficient data are available; By
providing for such a calculation in the
rule, the criteria thereby appropriately
incorporate such factors.
33. Comment' EPA's aquatic life
criteria do not take into account
acclimation. As a result, the criteria are
overly protective.
Response: Acclimation is the ability
' of organisms to tolerate higher.
concentrations or pollutants or other ••
conditions, developed through«n
exposure to such chemical or condition
-------
60880 Federal Register / Vol. 57, No. 246 /Tuesday. December 22. 1992 / Rules and Regulations
without apparent advene effects.
. Studlea.with fish have not documented
l&rge changes In sensitivity because of
acclimation effect*, the typical factor
" being about two. Furthermore,
significant changes have usually been
•reported under very restrictive and
unusual exposure conditions—* '
prolonged exposure in a narrow
concentration range near chronic ~
toddty value* followed by a •harp rite
to acutely toxic concentrations.
Acclimation of individuals under most
exposure conditions would be less and .
does not persist for long once exposures
drop significantly below toxic levels. To
try to account for such conditions in
nationally applicable criteria is not .
feasible. Adaptation of populations can
occur due to natural selection, but is not
vrell described; in any event, it cannot '
be accounted for in any generally , .*.
applied presumptive standard but only
documented on a site specific basis.. .
34. Comment: Several commenters
asserted that the metals criteria aria
« below natural background levels, as :
shown by'EPA's own studies. Thus, .
such crltorla.are overprotective and
invalid. . • '
Response: EPA studies which . .
examine USGS data, appear to indicate
that the natural background1'. - '_•• •
concentrations in undisturbed •• ' '
'Watersheds at times exceed the criteria
•for copper, lead, zinc, iron, and • --
aluminum. However, recent work by
*. USGS and by others (for example, , '
-Windom et aL in Environ. Sd. TecbnoL
VoL 25,1137) indicates that much of
this date, that is the copper, lead, and
zinc data, are not valid! The measured
concentrations of these metals are.'.
•largely artifacts of external
contamination of the sample during
collection and processing. At this time
USGS has suspended collecting data on
, these metals nationwide, until improved
methods can be implemented in their •
central laboratories. <.
•. • EPA notes that USGS generates a large
portion of the data available for the
•nation's ambient waters, and that the •
federally approved protocols are used
bya variety of other agencies that
collect ambient data. Consequently, It' •
appears likely that many waters may be
improperly determined not to be
attaining the metals criteria.- :
* Based on USGS results, the data for
the metals on the priority toxic
pollutant list most likely to be affected
by external contamination are arsenic,
beryllium, cadmium, copper, mercury, *
lead, and zinc. The nickel data is . • .
unlikely to be affected. USGS suspects
that filtering artifacts, father than °
contamination, may produce anomalies
In dissolved data for other metals not in
today's rule. USGS has not yet
ascertained quality of its selenium and
silver data. Moreover, EPA has reviewed
the data used in establishing the EPA
metals criteria end does not believe
these criteria are affected by the
analytical problems noted by USGS.
(Erickson, 1992, personal
communication, in KPA's record).
To assure the reliability of the data in
the lower microgram per liter range,
priority toxic pollutant metals should be
sampled and analyzed using protocols
that involve ultraAdoan reagents, ultra- .
dean Teflon or polyethylene labware,
and ultra-clean laboratory, '.
environments.
EPA is not aware of reliable analytical
data showing excursion of aquatic life
criteria by natural background
concentrations of the metals covered by
tbisrule. '
35. Comment: Commenters asserted
that the acute and chronic averaging ;
periods are unnecessarily restrictive,
and were set in an arbitrary manner. As
the acute criteria are derived-from 48-
96 hour tests, the EPA's one-hour
averaging period for acute criteria
cannot be correct As the chronic ' '
.criteria are derived from 3O-3BO .day
tests, the EPA's four-day period for -
chronic criteria cannot be correct
Pollutant spedfid averaging periods
should be used, based on the latest' •
scientific information, including the
1983 work of Mandni (Water Res. 17:
1355), which dealt with the effects of
time varying concentrations.
,' Response; The quality of ambient .
water typically varies in response to
variations in effluent quality, stream
flow, and other factors. (Organisms in
•the receiving water are not experiencing
• essentially constant exposure as in
laboratory bioassays, but fluctuating
exposures which may include short
periods of high concentrations
•potentially causing adverse effects. :
EPA's criteria formulations therefore .
include an exposure period for
concentration averaging which must be
•sufficiently short to limit elevated
concentrations that might cause barm to
• aquatic life. •• .. ..- ." - • : '
The 1-hour average exposure for the
criteria mmdmmn concentration (CMC)
was derived to protect against the effects
of fast acting toxicants lii«i ammonia
and cyanide. Thus, shprfetonn spike .
increases in certain of these toxicants
have been observed to cause toxic
:. effects. (See 1991 technical Support
Document, appendix DJ.
The 4-day averaging period for the
criteria continuous concentration (CCC)
is based on the shortest duration in
which chronic effects are sometimes
observed for certain spedes and
toxicants. The most important
consideration in establishing duration •
criteria is how long the exposure •
concentrations can exceed the criterion
without affecting the endpoint 6f the
test (e.g., survival, growth or
reproduction).'EPA believes 4 days
should be fully protective even for the
fastest acting toxicants.
The approach of Mandni (or similar
modeling cited in Chapter 2 of EPA's '
Technical Support Document) is
certainly a promising cine for •
establishing averaging periods. It and
similar methods are being evaluated for
incorporation as options into new water
quality criteria guidelines. However, the.
validity and applicability of these
methods an still not completely .
resolved. Applying Mandni's model to
available toxidty data forces an analyst
to immediately deal with problems of
delayed mortality .and limitations on
observation times. The fit of the model
to data is also only appiroxiinate and .
roouires i^pf^'im^ft*QTi^i Bi^ipwi««n¥ MI * (
appropriately applying it ~ . :
Because of such cohirideratidns, EPA's
current approach remains reasonably
protective and is therefore appropriate.
36. Comment: Comments™ asserted ".
that the three-year return Interval is too
stringent for'marginal excursions of-
water .quality criteria. As a result the
criteria are overpretective. It is argued
that: EPA's Technical Support . •' '
Document has cited information on. ••.
recovery from severe or catastrophic- • •.*->
acute stresses as the basis for its
recornmended return iaterval for both
acute and chronic criteria; EPA's '
criteria, however, are intended to avoid
even slight stresses; and cites on EPA •
draft staff analysis showing that a three-
year return interval for slight excursions
results in a billion-year return interval.
for a severe stress. ' ~.-.
Response: EPA'is promulgating its. • •
proposed general rules; of applicability
(40 CFR 131.36fc)(2)) for the return '
interval based on guidance contained in
chapter 2 and appendix D of the TSD.
As discussed in the TSD. EPA expects
the three-year return interval to provide •
"a very high degree of protection'* (TSD •
at page 36). The throe-yearreturn •••'-•
interval approximates the same degree
' of protection as a once-in-ten-yeer
seven-day average low flow design
condition (7Q10J, the use of which has
historical precedent and is* in many • •
State water quality standards, (fd.) .... -
Given the state of the science, and the':
limitations of. available data, EPA as a
matter of .policy, takes the position that
it should assure adequate protection and
takes a conservative approach. This .
policy is also consisteiitwith and '
recognizes historic program practices
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Federal Register / VoL 57, No. 246 7- Tuesday, December 22t 1992 / Rules and Regulations -60881
end procedures used by both the
Agency and the States In implementing
the water quality standards and related
implementation programs. (Guidelines
for Developing or Revising Water
Quality Standards. April 1973. p.7.)
. The draft EPA staff analysis referred
to by the commenter was prepared
solely as background information for .
- discussions by the committee reviewing
the methodological guidelines. EPA •...
•neither confirms or rejects the - •'..-. -
calculations. /'•'•'"
• 37. Comment.-The Guidelines .' • '
indicate that criteria may be derived •'
using data that have not undergone ~ '••"•
. formal peer review, but the Guidelines'
do not offer meaningful guidance to . ;
determine the acceptability of test
results. Inappropriate data are used to
derive criteria. . "'•-.'•
.Response: .Toxidty tests methods
have changed over time to improve
precision and accuracy. This requires •.
use of judgment in evaluation of test
Acceptability and .results. EPA utilizes ":
the Guidelines and professional ":.. •
.judgment to reject unacceptable data ' v
. . (see Unused Data sections, of Criteria •' "
'Documents). .Reservations about data are
. .considered when judging acceptability ••-;;
' .of results in the context of criteria—;. -.•:•.
Development EPA also receives [public •
comments on the criteria documents. : •
• •- EPA's criteria for accepting or •"
rejecting data do not depend on-whether
Jhe data were published in peer-
reviewed journals. The guidance ^
provided in the 19,85 Guidelines is
.predicated on more explicit review'. ' .
considerations than may be provided by
most publishers of peer-reviewed .
journals addressing, toxidty tests with
aquatic organisms. EPA has observed
that the public comments have also
•raised specific technical issues .. - - ..
regarding the validity of peer-reviewed
'••results.- .'-••' ••• • •.-.- ...-•••: •..*. , .
•Occasionally values in publications .
are'not used because they are not '•...-
. biologically important w statistically
> . different Jn addition, recalculation of -w
authors raw data may •
.sensitive-values are representative of the
-lowest 12.5% of the species and the fifth
, percentile would be expected to be'near
.the middle of these values'. And if is not
Just the fifth percentile that is expected
to change but the entire distribution—'
for a sample size of 8 the mean will be
near the highest of the four most
sensitive values: fora sample size of 32
the mean would be far above the tour
most sensitive values (near the sixteenth
most sensitive value)..- ', .••'•_
Therefore; the response of the FAV
cited in this comment Is fully expected *
.and appropriate; it in no way indicates
a deficiency in the procedure or the
database requirements. Similarly, the •
response of the FAV cited in site-- " /•
specific calculations is alsoieasonable.*
If site calculations are based on fewer ".
spedes and if these species tend to be ;
. more sensitive on average man the total'
vdataset, the FAV shouldbe lower. " ? •
• 39. Comment: A comment was
received, that most of the data used to "
derive the criteria were not developed
for that purpose. ' '
'. Jtespo/ise.-The reason a toxidty test -
was originally conducted is not ..'.' •
important If the dataare considered to
be pertinent, of acceptable quality, and
meet our protocols and other data :. •
- requirements in the 1985 Guidelines,
..they should be used in the derivation of
water-quality criteria.-Moreover, as -
stated in'the 1985 Guldllnes. p. 28.
"confidence in a criterion usually- ' /
increases as the amount of pertinent
' data increases." . • ' •
40. Comment: A commenter asserted •
that since EPA has acknowledged that
spedes can exhibit a significant
substance tolerance range and inter- •,
laboratory variability, the databases for
many of the criteria must be
significantly improved before.they can
be considered suitable for use in:the
.promulgation of water quality ~,v
standards. The commenter cited.' °°
Schimmel,S,C, 1981.Results: ; •• • '
Interlaboratpry Comparison-^Acute'
Toxteity Tests Using Estuarine-. • -
Organi«mstEPA-600/4-81-001). -; .
Response: Inter- and intra-laboratory
variation is expected and unavoidable.
.Variation that causes imprecision is '. ;
undesirable; but is not nearly as '-.••.
undesirable as is error that causes bias '
..(Lemke. AJE.; 1981; Inter-Laboratory •• ••
Acute Testing; EPA 600/3-87-005).
More dataare always, desirable, and *
EPA welcomes the submissi6n of .• •.:
. additional high quality pertinent data,
whether or not they have been peer^ . .-
. reviewed. The guidelines for deriving
water quality criteria for aquatic life
specify mlnunum data requirements •
: that ere intended to ensure reasonable
resulting criteria.'
The Sdence Advisory Board review .
referenced earlier at comment 29 . ^ -
accepted this EPA aquatic life 1985 >:
Guidelines which permit the use of a" ..
single test to fulfill the minimum data ,-i
base requirement The results dted by
the .commenter when referring to a ...-"., -.
study conducted by Schimmel,1981. ' •
were .used by the Agency in developing
the revised aquatic life guidelines in
1985. The guidelines specifically allow
the-use of a single-species test to fulfill •
the requirement for a species mean •
acute value. (1985 Guidelines, p. 29.)
41. Comment: A commenter asserted
that very faw of the studies used to -
-develop the criteria dted any • ' v .•: • '':-
assessment of precision or accuracy and --
there was no standardization of testing. '
-protocols. Consequently, the commenter
•believes that the data are inadequate for
the promulgation of water quality ~ --•- '
•• standards; and that only data from :-'
currenttestingprotocolsshould.be
.used, ,' •:- •* '- '.- ••."--
flecponse: There is no way to fully .
assess the accuracy of a toxidty test
because the "real" toxidty of the test
material cannot be Icnown. Various lines.
of evidence including results of toxidty
tests and correlations between species : '••
• 'and between test materials can help '. *
increase confidence in an estimate of
toxtdty. Studies of inter-'and intra-
laboratory variation are conducted to
• .allow assessments of predsion. Very A
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60882 Federal Register / Vol. 57, No. 246 / Tuesday, December 22. 1992 /Rules and Regulations
few, if any. studies are perfect, even if
. they exactly foUowed a "current testing
protocol"; the acceptability of each
study must be judged individually.
Studies that follow approved
methodology are more likely to be high
• Quality, but'some are not; some studies
that deviate from approved
methodology do provide useful
information,
42. Comment: A commenter suggested
that EPA provided no data to support its
. contention that acute-chronic ratios are
* similar in fresh and salt vrater.
•Response: As quoted by the
commonter.the 2985 Guidelines, p. 15,
* states that "When data are available to
indicate thai tbesa ratios and factors are
probably similar, they are used • '
• lnleichangoably."The guidelines do not
contend that a cute-chronic ratios are
similar; the guidelines state that the • •
ratios should be considered similar only
when data-are available to support the
decision of similarity. Ratios are usually
, considered to be dissimilar if the range
is greater than a factor of 10 {1985 '
Guidelines, p. 45). • : *
•4.3. Comment: A commenter asserted
that EPA should establish a separate '
* *-warm-water cadmium criterion, because
the national criterion Is set based on •
rainbow trout, a cold-water fish.
.Response: The commenter
misconstrue* EPA's criteria
development protocol EPA's aquatic
" life guidelines require data for .the
. family Salmonidae as one of the .
* minimum eight spodes required to
calculate a water quality criterion (1,985
' Guidelines, Section m. p. 23). EPA did
—not base its criteria for cadmium solely
on ralnbow'trout data. (Rainbow trout is
a member .of the family Salmonidae.)
EPA used this data to meet one of the
requirements for tested spedes required
by the guidelines (Ambient Water
Quality Criteria for Cadmium-1984,
Table 2, p. 6). Moreover, a review of .
tdxidty data in EPA's criteria'document
does not indicate that the sensitivities of
so-called cold water for vrarmwater
spede* differ significantly (Ambient
Water Quality Criteria for Cadmium-
1084, Tabls 2, pp. 46-47). EPA had no
scientific basis to develop separate
cadmium criteria based on the division
of aquatic spades into coldwater or.
vrarmwater type*. •
44. Comment: A commenter argued "
that bocauwEPA did not follow its own
Guidelines, EPA should withdraw the
lead criteria'document, update and • _ •
completejtbe spedes database, and,.
recalculate an appropriate freshwater
lead criterion. , . V-
Response: EPA recognizes that the _-
load criterion is based on seven rather
than eight freshwater acute testa as
recommended in the equatic life
guidelines. EPA has determined that the
criteria are valid and that an additional
test would not cause a sufficiently large
change in the criteria (in the
computation formula {see pace 97,
appendix 2' of the Aquatic Life
Guidelines] increasing N. the number of
spedes tested, by one with an LC50
value that is higher than the four most
sensitive values only increases the acute
criterion from 34 to 37 ug/L at*
hardness of 50). (See Memorandum to
the Record. Kennard Potts. March 12,
1992.) This change does not warrant
,. withdrawing the current criteria. This
••decision to establish the criterion based
on seven tests is consistent with Section
12 — Final Re view; paragraph B. page 57
of the Guidelines, which allow "On the
• basis of all available pertinent
laboratory and field information.
determine if the criterion is consistent
with sound scientific evidence. If it is
not, another criterion, either higher or
lower, should be derived using'
'• appropriate modifications of these
Guidelines," '.-.-• . . .-•.;, . • .
• 45. Comment- A conunenter asserted
that there is a significant-error in the
lead saltwater acute database, and it has .
implications on the validity (ur lade .-•
thereof) of the saltwater acute-chronic
'.ratio for lead. ".'.-.
Response: EPA recognized the error in
the ambient water quality criteria •
• document for lead in the genus mean
acute value (GMAV)-for Fiinduhis and
corrected that error in the criteria matrix
induded in the proposed rule. The . .
result of this correction was to increase . .
• the criteria maximum concentration •
(CMC) to 220 ug/1 and criteria
continuous concentration (COG) to 8.5
' '
. .
The use of the acute-chronic ratio
(ACR) of 51.29 for lead ^reasonable. .
given the available information (see p. 9.
Ambient Water Quality Criteria for -
Lead). The GMAV:far Mysidopsis
induded in the criteria document for .
lead (p. 26), is ranked 7th of the 11
lerefore, Afys/dopsis might be • -
^considered among the less sensitive
genera as suggested by the commenter.
•However, the GMAV foiMysidopsisis
less than' 10 times the value for Mytilus
suggesting the acute sensitivities of two
genera are not greatly different (/OK?.)
•Other factors are more important man
spedes sensitivity jn selecting the final .
acute to chronicratio (PACK) for lead.
EPA did not believe that the data 1mm .
.diroiik tests with freshwater spedes ••
clearly .demonstrated flsat acute-chronic
ratios changed with acute sensitivity for
the following reason. Acute values lor .
•the copepod (Acoitia). amphipod
(Ampelisca) and duhgeness crab
(Cancer) are within a factor of less than
2 times Ihe value for Mytilus. EPA then
assumed that the ratio was not related
to acute sensitivity. Even if an ACR of
2.0 could be justified for. larval molluscs
and lead, this valuo should not be •
applied to crustaceans when an
experimentally derived value for
Mysidopsis and Daphnia are available. '
See Table 3. Ambient Water Quality
Criteria for Lead. . '
The commenter felt EPA was .
inconsistent in its use of ACR values
from toxicity tests and the ACR of 2JO.
when the most .acutely-sensitive
•organism is larval molluscs. EPA used
acute-chronic ration-from tooddty tests
for lead and silver imd the value of 2.0 .
for copper (see anibiienl water quality •
•criteria documents for lead and copper,
and the draft water quality criteria
document for silver, 55 PR 19988. May
: 14,1990. The reason experimental ACR
values were selected for lead instead of *
the vahie of 2.0 are described above.
46,Conunent-Aix»nmentersuRRested
that the saltwater silver criterion to not
valid and submitted test results to-
support this claim. •'• *•"•.-'.
. Response: Some of the data presented •
by the commenter (NumberSO)-to show
• problems in the silver data base actually
supports its validity. Acute and chronic
values for Mysidopds are within the
range repotted by cithers. Silver** acute
.ioxicHy to sheepshead minnows is at .
. silver's sorabih'ty.l'hisprobabry
accounts for the large range in reported
. silver toxidty. For tbece spedes only '•
flow-through tests with measured silver
: concentrations worn used. The data
submitted in the public comment did
•not include information Oa the test
conditions, and would not be used in
criteria derivation without that .
information. See Ambient Water Quality
Criteria Document for Silver. 1980; see
also,draft criteria document referenced
in 55 FR19938, May 14.1990.
Results from silver tests from Cardin
.(1986) where control mortalities .'
exceeded 10% ware not used. In tests
'with copepods and llanralsilversides ".
and flounder, control mortality of <20%
is judged acceptable by those who
conduct tests with fragile life stages of
-these species. Control survival :
requirements for chronic tests (ASTM
protocol) are more liberal than those for.
acute tests. . .
are not appropriate last methods for
deriving chronic values for water ~ "'
quality criteria derivation because they
are not true chronic tests. Only early
i
life-stage tests with JJah and partial and
entire life-cycle testit with fishes and -.
invertebrates are acceptable as provided
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Federal Register 7 Vol. 57, No. 246 / Tuesday. Decembg^22.v1992 / Kules end Regulations 60883
for in "the 1985 Guidelines, section VI.
part'E. pages 37-39. "
• 47. Comment: Comment was received
that the proposed diver numeric
standards should be revised to apply to
the free silver ion. The commenter
asserted thatavailable information •
.demonstrates that only the free, silver
ion is highly toxic to aquatic organisms
while most other common forms of -
silver, whether soluble or insoluble, are
several orders of magnitude less toxic.
Response: It would be appropriate to
interpret the criterion In terms of the
free silver ion only if mil the silver that
was included in the measured or
nominal concentrations of silver in the
pertinent toxidty tests would have teen
measured as free silver ion. Some silver
would be completed by-such things as
chloride, hydroxide, or carbonate in
acute toxidty tests. Moreover, tire _ .
feeding of the organisms in the chronic
tests would result-in comptexation of at
least some silver. This has been -. .
postulated as the explanation as to why
(a) the addition of food to an acute
-toxidty test raises the EC50 for
daphnids and{b) attverhas appeared to
be more-toxic to daphnids in some acuts
toxkaty tests than in comparable -
chronic tests. Absent a criterion that -
correctly applies to thefree silver ton, '
the water-effect ratio procedure . •-
incorporated into today's rule is *n
appBtoriatemeaiis to deal with •".'•.
diffeences in toxUdty caused by silver ',
spedation,
48. Comment: A comment was made
that the numeric silver standards should
not be proposed until EPA's May 14.
1990 proposed revisions to me current
ambient silver water-quality criteria are
finalized to reflect comments about the
current science as submitted for the
record of that proposal
Response: EPA agrees with some of .
the comments on the May 14,1990
proposed silver criteria. Asa result,
additional testing is planned and*
. revised document for silver wfll be
prepared, bat this is not entidpeledin .
ibe near future. With this role, EPA is •
promulgating its 1980 criteria for silver.
because the Agency believes die criteria
is protective and within the acceptable
Response: EPA agrees that there may
be differences in metals toxicity
between laboratory test waters and
ambient waters. For this reason. EPA
has incorporated use of water-effect
ratios in this rule (see Section F-7 of
this preamble and an earner response to
public comment).
SO. Comment: A comment was made
that EPA should not use the metals
toxidty data from Dinnel et at 1983.
who were evaluating alternative*
conditions in order to refine the testing'
i t
J?eponse:EPA disagrees. VaHd
toxicity data can come from tests used
to develop test inethodologEes andEPA
determined that the Dinnel, etaL
with deriving water quality criteria. In
addition, the water-effect ratio, • .
promulgated in this rule offers
development of appropriate «ke-*pedfic
criteria. .
49. Comment: A commenter asserted
^ro. i^uuuimtb. n *M iiiiis»»ii»p« ••^>w»
that m the studies of Celabrese end
Nelson 1974,Calabrese etaL 1973,«nd
Cbglianese 1982,the properties of the
dilution water significantly affected the
metals toxicity.
toxidty data was •valid toxicity data. For
example, see draft Ambient Water '
Quality Criteria for Silver. September
24.1987." . , '-•'•.,
51. Comment: A commenter argued
mat the metals toxidty datairom EJsfer
1977 are nrtvatid because mey tnyolve
168^htmr static tests. TheEmrpntly '• .
recommended nnx*'"Vm duration Sat
such tests is 48 hours.." ' 'f..
• Reponse: EPA disagrees. Most-values
reported in criteria documents are 96- ..
hour LCSOs for adult dims. EPA : "
considers tiieEisler data to be from
valid and reKable-tests even though they
were based on other man 96-hour tests.
52. Cbmment.-CommeutiHiBS received.
that the"20-25 degreeCelsitts .- .
temperatures and 12:12 hour light cycle
-used to obtain the metals taddty data
of Lussier 1985, do not match, current
- mysid protocol's 26-27 degree Celsius
temperature and 16 hour lights npur'
•dark light cycle.
• flesponse: The submitted comments
provided no data to show the effect of
temperatureI or lighting on the chronic
value. EPA does not consider Lussier's
results to be artifacts because test
conditions duplicate conditions found
•in nature. ., . j •
53. Comment: The zinc and '.'.,.
chromium toxidty data of Nelson 1972
should not be used because it involves
an endpoint not recognized by EPA
approved protocols. . ' - .
fteponse.-EPAdisagrees.Thetest v
endpomt (the development of a hinge '
after 48 hours) Is the same as mat of the
American Sodety for Testing Materials
(ASTM). which is a standara.
recognized protocol -/
C.HtaaanHeatihCHtena
- The guideline references JD the sub-
section refer to Guidelines and ' .
Methodology Used in tiwPreperetiontrf
Health Effect Assessment Chapters of
the Consent Decree Water Quality .
Criteria Documents, 45 FR 79347,
November 28.1980. The short reference
in this sub-section U "the 1980
Guidelines." •••--. .
54. Comment: A comment was
received that use of the harmonic mean
flow is a new technique and is not
consistent with the way sampling is in
fact done.
Response. Harmonic mean flow
determinations have been adopted
because the underlying hydrology
support this analytical procedure: Such
flows are applied only to human health
criteria where human exposure is
expected over a long period of time. It
is derived by analyzing the pollutant
mass a consumer would received by, for .
example, cq««t»«"i"g a uniform amount .
of water everyday from a natural • .
wmterbody receiving « uniform mass
loading of a pollutant ' - •
Theoretical development as shown to
the reference dted in footnote 2 of the .
preamble of the proposed rule (56 FR .
584S8) demonstrates that actual human
exposure is best ascertained by using
harmonic mean flow to account for
concentration variation in computing
the actual exposure to a pollutant
55.Commenf.-The exposure
assumptions used by EPA in developing
human health criteria do not account for
> theyariabiHtyofthepopulation'northfr
consideration of-exposure to more than
one chemical and more than one
reroute. • • • ' ' . •"
_ anserThe EPA-assumedexposure
„ ..was based on estimates or ;
measures of national norms tsee
preamble discussion on human health
criteria. Section F-3 and 1980
GuideHnes.45FR79347.Nov.28,
1980). EPA has suggested in theseand
other documents that States select more
appropriate fish and other aquatic life ^
consumption rates for local populations..
Some States have done so. ..' .'
EPA's risk calculations aim to protect
Individuals exposed at an average level -
(JoicQ. Thus, EPA does the calculation
for avenge dally consumption of 2 liters
of water and 6.5 -grains of aquatic fife for
a 70 kg size individual over a 70-year
lifetime. Then the Agency selecU a
conservative risk level (e.g.. 10-*or 10"5)
People who donot fitftisnorm ere
subjected to more or less-exposure to die
pollutants of concern. For example. -
Bgff1itnin£ e criterion based on a lO^risk
level, a person who consumes 65 grams
of contaminated aquatic life per day .
from amtnent water at the criterion level
wouldbe protected at the Kr»risk level.
rtillvfell within EPA's desired risk
._j effects of multiple toxicants is a
more difficult problem. The sdence of
toxicology has not developed generic
ways to combine multiple risks. For
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60884 Federal Register / Vol. 57, No. 246 / Tuesday, December 22, 1992 / Rules and Regulations
specific chemicals, analysis would focus
on*\vheih°er the same organ and mode of
toxidty were implicated. For example,
it may be more significant if two
chemicals both caused liver cancer as
compared with a situation where one
chemical was carcinogenic and the
other caused other systemic effects.
Thus, a case-byrcase approach is
currently the only feasible approach
available. • •
EPA has clearly delineated the human
health models it uses. That is,, one for*
systemic toxidty and one for
cartinogenidty. The Agency's accepted
. factors are available in the Integrated .-•
Risk Information System (IRIS) and in •
the section S04(a) water quality criteria
documents, and in the 1980 Guidelines,
page 70353. Locally specific risk can be
estimated using the readily available
information based on monitoring data
for local public water supplies or fish
tissue analysis for specinc chemicals.
' However, in a rule affecting large
areas of the country, EPA> view is that.-.
it should focus on the average exposure.
as a protective basis for this rule. States
may take subsequent actionio provide
the means to account for specific cases.
This rule attains that goal * ..-•-."•
.58. Comment: Since EPA is "...
iindertaking a-dioxln reassessment, it •
should not be included in this rule. '
Response: We believe there are sound
reasons for proceeding to promulgate •
dloxin criteria. First, the dioxin criteria
are within the range of scientific
defensibility. EPA'* action'will also
encourage and support the fourteen
States now considering adopting a ' ,
; dloxin criterion to complete their
'action. Most of those States are relying .
on the same data used by EPA to derive
its criterion. Individual Control .
Strategies developed under section
304(1) of the Actcontain limits on
dloxin as appropriate, so there will be
DO immediate impact from this
promulgatipn. It is too early in the
process of scientific reassessment to .'
support major changes in either the
•substance or timing of regulatory"~
decisions related to dioxin.'*
It should also be pointed out that 42 •
states and territories have adopted
criteria or translator procedures for
dloxin; EPA approved 40 of those - ' . •
actions, ' . - '.
.57. Comment; Several commenters,
raised questions concerning the ,
' methodology used to develop the - ~ •
human health criteria. Some stated that.
' the CWA methodology did not reflect .-
changes in risk assessment and therefore
was obsolete. Some commenters noted
tho differences between the risk ranges
under the CWA and the SDWA and
argued that the acceptable range of
cancer risk should be the same under
both statutes. Several commenters
discussed specific contaminants and
argued that the regulatory levels under
the CWA and SDWA should be the
same. One commenter provided a list of
contaminants where drinking water
standards were more stringent than the
proposed criteria and urged that criteria
should be established equal to ^**>>V*l>c
water MCLs. •
Response: EPA has developed. 'risk
assessment methodologies to protect . •
human health from contaminants in- .
.drinking water and ambient waters.
'.Although there are some differences in- -
the methodologies, both are
scientifically defensible. Both
methodologies stem from Agency risk
assessment values for noncancer effects
(the Reference Dose or Rfd) and Cor
cancer effects (the cancer potency factor,
ql*). See Water Quality Criteria
' documents (the '1980 Guidelines). 45 PR
793180 (November 28, 1980) and 56 FR
3526 (January 30, 1991) (SDWA Phase H
regulations). .'-.'•
Both methodologies follow the
Agency's Guidelines for Carcinogen. '
Risk Assessment (the Cancer '
Guidelines). 51 FR 33992 {September .
24, 1986). Under both programs, the .
Agency takes the position that there is
no threshold for carcinogenic effect \
unless there is convincing evidence to
the contrary. Both programs therefore •
recommend that contaminant •
concentration for carcinogens should be
zero based on this "no threshold"
presumption. See SDWA Phase n . •
regulations at 56 FR 3533 and the 1980
Guidelines at 45 FR 79324.
The nature of the human exposure to
contaminants is somewhat different in
the two programs, and the assumptions
used in the methodologies reflect those
differences. Under the SDWA, it is
protection from exposure to • '
contaminants in drinking water that is
the concern^ The maximum
coTitflminnnt level goals (MGLGc) reflect
the level of contamination where "no
known or anticipated adverse effects on
the health of persons occurs and which
.allows en adequate margin of safety." 42
U.S.C. 300g-l(b)(4). For those
contaminants that are not- suspected of
•posing carcinogenic risk for drinking
water, the Agency bases the MCLG.on
noncancer effects and adjusts the RfD to
reflect drinking water consumption of
an average of two liters of tap water per :
•day by'a 70 kg adult This value is
further adjusted by exposure . ". .-
assumptions; the key assumption in the •
drinking water program is that
significant exposure to
comes from sources other than drinking
water (e.g., ingestion of food,
inhalation), and it is prudent to allow
for the contingency that other exposure
may occur. While EPA uses actual •
exposure data where they are available,
the Agency assumes, as a default
position, that drinking water contributes
20%-80% of the total exposure to a -
contaminant 56 FR 3532. MCLs can
also be adjusted for non-health reasons,
such as treatability and detectability.
. Under CWA section 304(a). EPA
developed human health criteria to
protect for exposure to ambient water
contaminants. In *^<« case, exposure
comes from ingeetion of surface water •
and consumption of aquatic organisms *.
which are assumed to have
bioconcentrated pollutants from the
water in which Ihey live. Accordingly, •
the 1980 Guidelilnes'assumes the
consumption of two liters of water and
the ingestion of 6.5 grams of fish per
day, and the bioconcentration potential
of a contaminant in fish tissue may be
a significant factor in the human health
criteria value. The exposure assumption
in the 1980~Guidelines differs from that
in the drinking water program. If data •
were available on exposure to a
contaminant from other media such as
air or norwaquatiic diet, such data could •
be used in setting criteria. Absent such-
data, EPA assumes, as a default'
position, that ambient water (Le., - ' ••
aquatic exposure and organism • , •
ingestion) contributes 100% of the •
exposure to a contaminant 1980
Guidelines. 45 FR 79323. -EPA considers
both methods to be protective of human
health for their respective exposure
scenarios. • ' .- •
EPA agrees with, commenters that the
Agency' has chosen somewhat different
.risk levels in the two programs for
determining MCLs and .criteria for ', '•
carcinogens, but does not agree that the
different levels indicate major scientific'
differences. Under the SDWA, it is EPA
.policy to establish MCLs at a range •
associated with excess risks of one in
ten thousand (ICC4) to one in one million
(10*). In the CWA water quality criteria
documents, the Agency presents a range
of concentrations corresponding to •
incremental cancer risks of one in one
hundred thousand (10-*) to one in ten
million (IO-7); the risk ranges are •
presented only as information.-Under
the usual process in which States
develop water quality criteria* the risk •
management decision on an appropriate
.risk level is made by each State.-m these
circumstances, States have the
flexibility to choose a risk level as long .
as the decision i» well documented, was
subject to public notice and comment. ,
and protects water uses. In this . "":.•'
rulemakingi EPA proposed criteria with
an incremental cancer risk level of one
-------
Federal Register / .Vol. 57, No. 246 / Tuesday.'December 22, 1992 I Rules and'Ilegulations 60B85
ln._a tniUion ClQ-*) tor carcinogoiw.
Todav's action promulgates a risk level
for each State to reflect the State's risk
management decision where such *
decision is discemable. "See discussion
In section F-5 of the preamble. In the
Agency's view, the considerable overlap,
between the risk ranges in the two
programs indicates that they are not
significantly different. • '
Accordingly, EPA does not agree with
commenters' teguments that the Agency
must have identical risk assessments
under theCWA and SDWA. At theeame
time, the Agency is studying the extent
to which both methodologies might start
with the sanie presumptions. If any
changes to the methodologies soem
appropriate. {he changes would be
proposed for public comment IB the '•
meantime, because both methodologies
stem from the same Agency risk _ . * .
particularly the default vaiuM chosen to
estimate exposure. These assumptions
are reasonable policy choices for
implementing the statutory directives of
the two programs. Since the CWA
section 1980 Guidelines are adequately
protective of human health. EPA does
not consider it necessary to •undertake a
.large scale revision of the proposed..
criteria in this rule to make them
correspond to the SDWA standards.
Moreover.EPAdoes'not agree that .
MCLs are an appropriate •vame for a
human health criterion since MCLs are
are considered approprUts^for deriving
human health criteria for water ^.. ,
rnntnminnntg Therefore, as a general.
matter, EPA doesiiot intend to revise
. the human health criteria unless end .
until there are changes in the 3Q4(a)
methodology." " . . . •' •
• One commeBter urged the Agency to ~
establuh human health criteria equalto
MCLs when the 304(al saeilhodoloVr '
resulted in lessatringent criteria, tbe * ,
commenter provided a list of- •
contaminants for which gyto'«chieve&e
regulatory level and the cost of men .
treatment, ft is the MCLG that Taflects .'.
solely health txmsiderations. - . ; • .
Accordingly, ^he Agency wfflaot •''
-promulgate criteria equal to M(3a.in -
lieu of less stringent proposed human
health criteria. Except as noted below, ..
the human health criteria are ,..,;.• .
promulgated as proposed. . '• . % . ,". . •
..The Agency does find It necessary to
• critaria for, seven contaminants pendtng
further nmsideradon.2nihe.caM of ...
.
trichlcuoethane, mefcyl chloride, ana -
•lead— there is currenuy an Insufficient^
basis foT-calculating human health ;
criteria. For cadmium, chromium, •
. selenium, and beryltium.the proposed
criteria are no longer scientifically
defensible. EPA is withdrawing the *
criteria whfle ft evaluates allimevant
dataregardmgthetoxidtyofthese
d^eferring action on &e human health .
criteria for these contaminants is
discussed further below. For several of
these contaminants, the Agency Is today
promulgating aquatic life criteria that
are more stringent than the proposed
human health criteria,- However, the ' •
Agencyiecognizeslhatihiiinfted .
fMttl^i»«ir« mjght be regulatory
voids in the absence of promulgated
potential problem, the Agency has •
added a footnote, footnote n, to the table
setting out the criteria "inf 131.36(b) ftat
directs permit authorities tospecjfically
.address these contaminants In NPDES
permit actions using the States* existing .
nanative "free from tuxJiIly** ulletia. •
(A). 1.1,1-Trichloroethane ' V
No public comments were received on
•the proposed human health criteria for
this contaminant. However, in response
ite, EPA evaluated the
proposed criteria and has decided not to
promulgate human health criteria. EPA
proposed the human health criteria.. .
using an RfD'based on inhalation data.
- Hoiravei.ftiB Agency Jims vritbdrami
that RfD from the BUS database since it
is generally-not appropriate to use
inhalation data to estimate oral risk. As
noted above, EPAbases the proposed
criteria on Agency-wide RfDs In IRIS.
Since BO vucn RfD currently exists,
there is no basis to support the proposed
values. . . . , '
(B). Methyl Chloride ..
(S8. t?pmnienI:Axommenter stated
that .the criteria should not be based on
cardnogenldty but pn'jystemlc toidctly.
Another commenter staled that it Is'..
Inappropriate to establish criteria for.
methyl chloride baiffd vn $** - ••
, RespansKEPA agrees »hete aio now
data available on jnethyl chloride itaelf,
anditisnoJonger«d«ntificaHy •••:•..
defensible to rely oo •unogatedaU for
chloTofozm.£PAis^curraotly«valuating
a qt*«ad^fDlarnMthylchloride Cor -
developing an SfQ.io,v1ew)of tin -' ••
and the ongoing risk asaosamont - • -.
process, EPA does not beiteveit is ' •
^n pprff pn Bftfl yff Tyff^nft^inffff^ SXOODBQ '-frffftitfl
j/fvTj^T^^v^-• * •^r**vi. .-.*!...
CTUBIlfl JOT 3
(Q. Selenium
. SQ.Cctnmei
flint 'n t^* Vf f^tvfl^an^a*n,
proposed* human healdicriterion of
100 ug/1 even tiiough&ecarrent MCI.
for selenium if SOvg/ltthe same «s tiie
MGLG}.ThecdnuBenterbeBeves<(he •
numbers should be the. same and urged
EPA to «et wBfl fl •
Selenium is an essential nutrient In
-humans andplays a vital zole m cell .
metabolism. See HealOi Criteria ' ; : '
Document for Selenium, {May 1989). hi
such instances, the Agency must
evaluate evidence of the compound's '
: essentiality .as well as evidence of
toxicologlcal effects. The A^encjV
Science Advisory Board has noted that
between •elenlum and other Inorganic
i uti I '
consideration *^ -g^^flrmiTtii^p ^Bciuatorv
standards. Moreover.there are ... ..•
individuals wno. whether from diet or.
Icantly.."
[mates .of
average consumption levels.
-------
60886 Federal Register / Vol. 57, No. 246 / Tuesday. DecemberX 22. 1992 / Rules and Regulation^
During the development of drinking
water regulations for selenium, the
Agency discussed new epidemiological
data that were becoming available. See
56 FR 3526 at 3538-30 {January 30.
2991). In view of these new data, the
numerous complex issues concerning
essentiality, the consumption of
elevated levels by some members of the
population, and the need to ensure a
protective level. EPA is unable to
determine the scientific defensibility of
the human health criteria, end therefore
will not promulgate human health- '
criteria for selenium at this time.' '
(D).Bery]Uinm. ""'" :" " .""'"."
60. Comment: One commenter stated
that EPA's beryllium criterion is too low
(Le., 0.0077 ug/1). The commenter :
alleged three serious flaws irithe
proposed criterion fcVberyllium. These
fro: (1) Beryllium does riot pose a • '•
- 'carcuiogenicriskbylngestion;(2)EPA's
lisa of animal inhalation and injection '
data to support a cancer risk by human
ingestion Is arbitrary and capricious and
Is not consistent with EPA's •-•.-•
methodology In setting human health •
criteria for other motels; and (3) the -•'
, proposed criteria are less than natural . •
ambient levels as well as EPA's '
proposed drinking water standards end
;would have very rigntfjfeant and • "• v ••:'
unwarranted economic impacts.'--" /"
. .The commenter further argued the-
defects in the data upon which EPA •
• rolles are so fundamental that the ••
classification of beryllium asa Group B2
substance is unreasonable; and%the EPA.
should classify beryllium in Group D for
purposes of its potential ingestion - •
caidnoganidty, and should adopt a
human health criterion for beryllium of
1.6 rng/1, based upon a no-observed •
adverse effects calculation for anon- .
cardnogenic substance. .Information on
the Agency's classification system for
carcinogens is IndudedinU.S.-« '••.-
Environmental Protection Agencyi -
(EPA), 19S6, Guidelines for Carcinogen
Risk-Assessment 51 FR 33992, . :. •
September24M986:'. -,- .'• ' - "
-Hwponsff.-EPA does not agree with"" .
the commentor's argument that the "-"
Agency's weight of evidence . '^
classification of beryllium as* a B2" , '
carcinogen ii incorrect There is clear
' evidence of cardnogenidty through J
• ..Inhalation or injection in monkeys, rats
and rabbits, ana «Ti
-------
' ' -- ••.':••-;' j:- • •- •»i-::.\:. • • / -
Federal Register / Vol. 57, No. 24.6 / Tuesday. December 22. 1992 / .Rules and Regulations 60887
on/y potential adverse effect from
exposure \osilveT in drinking-water is
argyria (a discoloration of the skin). EPA
considers argyria a cosmetic effect since
it does not impair body function.
However, free silver ion is highly toxic
to fish. Therefore, to protect aquatic life,
silver will be regulated with' aquatic life
criteria as promulgated in today's rule.
(I). Acenaphthylene, Phenanthrene,
Benro(g,h.i)Perylene <
65. Comment: Several comments were
.received which stated that (1) the EPA
. has expanded the list of polynudear
aromatic hydrocarbon (PAH) - . .. ..
compounds to be regulated as
carcinogens. Specifically, the
commenters do not agree with the
Agencythat acenaphthylene,
phenanthrene. benzo(gi4)perylene, and
chrysene should be treated as
carcinogens, and (2) the proposed rule
establishes human health criteria for a
. diverse'class of compounds (such as
. polynuclear aromatic hydrocarbons) ,.
based.solely on structural .similarity,
and Ihe assumption that all of the
compounds are of equal toxidty to die
-most potent compound within the
"classi".- \'
Response: The Agency agrees with the
several comments that the water quality.
criteria for acenaphthylene. ...'
phenanthrene, and benzo(g.h4)perylene
should be based on non-cartiriogenic
effects of these chemicals since
. inadequate toxidty data are available to
assess carcinogenic potential of these
chemicals. However, there are
insufficient toxidty data available to
provide risk assessment for these three
compounds at this time. Therefore, they
have been deleted from this rule.
The Agency does not agree with the
comment regarding chrysene. Chrysene
has shown cardnogenidty in several
animal studies. (U.S. EPA, 1991.
Drinking Water Criteria Document for .
Polynuclear Aromatic Hydrocarbons
(PAH's) Office of Water.) Chrysene
produced tumors (as did other PAHs *
included in this rule) in several mouse
strains when applied topically in assays
for complete skin cardnogenidty or in
initiation/promotion protocols. Several
early studies employing intramuscular
< or subcutaneous injection of mice and
rats produced negative or equivocal
results. Three studies wherein neonatal
mice of two strains were exposed.
tumor incidence in liver and other sites
-(Jo/d). Chrysene produced mutations in
Salmonella and chromosome . '. ';.•.-
aberrations anil morphologic -" •• '
transformation in mammalian-cells.
' The Agency recognizes (hat ~..
cardnogenidty of various PAHs vary
with each PAH, however,
Benzo(a)pyrene being the most potent
carcinogen of this class, was used to
develop criteria for all the PAHs.
fj). Other Pollutants
66. GomnjenfcA commenter requested
that EPA explain the origin of the use
of safety (uncertainty) factors.
.Response: The safety factors (now
.referred to as uncertainty factors [UF])
used in calculation of the Acceptable
Daily Intake (now referred to as the
Reference Dose [RfD]) were developed
from the National Academy of Science
guidelines (1977) with modification by
the EPA. These factors are similar to
thosoused by the World Health
Organization (Food Chemistry :
Toxicology, Vol. 27. No. 4, pp. 273r-274.
1989). The EPA is presently working on
new approaches to calculation . . .
(estimation) of a RfD (ADI).. ..
The term "safety factor" (now UF)
was initially used by the Food acid Drug
Administration (FDA). They used no- .
effect levels (in mg/kg .of diet) from •
chronic animal feeding studies and
divided by 100 to get an Acceptable' .
Daily Intake (ADI) level. For less-than-
lifetime (or sub-chronic) studies, they
divided the no-effect level by 1000. The
National Academy of Sdence .,
recommended that EPA use a similar
approach and outlined the use of 10-
fold-UFs for intra- and interspedes .-
variation. An additional 10-fold UFis
also induded-to calculate a lifetime
• number from a less-than-lifetime study.
The term "RfD (Reference Dose)", is now.
•used by the EPA instead of the ADL The
above referenced information is -
induded in the Agency's Risk
Assessment Guidelines published at 51
FR 33992, September 24,1986.
67. Comment: A commenter stated -
that EPA should not use Structure- ...
Activity Relationships (SAR) techniques
• to regulate chemicals, such a* methyl.
chloride, when data on the specific
chemical are available. ",-'•-••
• ' Response: The EPAnises SAR only .
when data on specific chemicals of a
chemical group ore lacking (see 1980
Guidelines, Section D, page 79355). SAR
is a technique used to compare the " .'
toxidty of individual chemical in the
group with the known toxidty of one
member of the group based on chemical
structural similarities. For example,
. SAR was used in criteria development
for polynuclear aromatic hydrocarbons
(PAHs), pblycnlorinatedbi-phenyls •
(PCBs), and tri-halomethanes (THMs)
because the EPA does not have adequate
health data on most of the chemicals in
the dassunder 'review. For a detailed
discussion on methyl chloride, see
previous comment. •
68. Comment: A commenter Slated
.that the toxicities of inorganic arsenic
(As) and the organic arsenic derivatives
present in fish may be quite different
.Response: EPA agrees with the
commenter—the organic arsenic forms
are known to be less acutely toxic then
inorganic arsenic forms ("Threshold
Cardnogenidty Using Arsenic as an
Example," Advances In Modem
Environmental Toxicology. 15:133-158.
1988). In addition, since the organic
forms found in fish appear to be
excreted as the parent molecules, they
are likely to have less long-term toxidty.
A footnote has been added to section .-
131.36(b) stating that the criteria for .
arsenic refers to the inorganic form only.
69. Comment: A commenter stated
that the arsenic standard is based on an .
IRIS recalculation that has never been
openl._ f .
Response: The 0.018 ug/1 (water and
aquatic life consumption) and 0,14. ug/
1 (aquatic life consumption) criteria. •
were calculated from the unit risk factor.
of 5xlQ-s (ug/lj-1. The unit risk factor.of
SxlO-3 Oig/1)"1 is on IRIS and available
for public inspection. Although EPA
incorrectly indicated In the proposal
that the criterion was calculatedusing
an addendum to the prior criteria '••
document and not IRIS, in fact the
addendum induded the IRIS '
information and this information was in
the record. There is an IRIS submission
.desk for public comments. Moreover. • •
this rulemaking provided an - ; • • •
opportunity for public comment. '
. .70. Comment: A commenter claims •
that the EPA's Sdence Advisory Board'
(SAB) is critical of EPA's criteria for
arsenic. .-' -/ • - • ••.*-.
Response: The SAB stated that "at .
doses below 200 to 250 ug As*3/person/ •
day there is a possible detoxication
rppf>innlBm"4»nH rnrnmtnnnrinH thilt
EPA "develop a revised risk-assessment •
based on estimates of the delivered dose
on non-detoxified arsenic." (EPA-SAB-
EHG-89-038. Letter from SAB to .
William Reilly, September 28.1989.)
Since it is not known exactly when' '
' and how arsenic can be considered to be
detoxified, EPA cannot, at present, .'" ,
calculate this "delivered non- •
detoxified" dose. It has been postulated
by Marcus and Rispin ("Threshold - ••
cardnogenidty using arsenic as an
.example" Adv. Modern Environ. •
Toxicol. 15:133-158,1988) that
.methylation is a detoxification process.
While methylation certainly decreases
the acute lethality of arsenic,-we do not
: have enough toxidty data to regard the
mono- and dimethylated methobolites.
as"non-toxic'V - " ; • • " : '••• •-.•'
71. Comment: A commenter noted
that no significant health effects from.'
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reaeraf Register /• Vol..57; No. 24&-/ ttaasdayy December 22,.1992 /.Rales aid
arsenic.exposure has-been- foundin.tne
Tahvarr.
JRe$pame;The cancer potency foe
arsenic fa. calculated using standardt
Agency mathods. Tha available- thS.
epidfltnlaiogy etudiaa ara-small *ttd'do
not have Its- statistical'power to. state
whethat the affects, and ricks irtthfrlLS.
•10 dtspfm|l<>r to thoaenntimnnytarsanic..mercury and
thullium which are sCIZLin today *a>xula..
The other four metals have been
deleted. See comment number S7>. (See
that
Arsenicas an Example! '.."Advance* ia .
Mod«m Tesdcology.l5cl33-45a; 1988.)
on whathat arsenic, soarts tha-i
effects at low do»ea feat it does, at highei
dowa-Toaxtrtpobtotolowdaiia
exceed e^gAfay. EPA fens' soggested •
that States,s«tect more appropriate fish.
and other aquatic life csnsumptlaB rate*
Sarlocml popujations> SboieSbite»have
donaso. (SeeTSB, pJ7.)The
commented is- corractfliatthg6.5igram» .
data reflects.consuEiptron of both-
has snggeainrithnf States- mayaelpct
* more apropriale^sJi i
y auu zci
In developing-BCFvid'
more apuruuiiattily naflect local
"• f * _. ^
i*
i whfcb would
BCFs and the TedadcaLSi
Documeht for Water 'Quality
.damopstratas that arsenichasja ':'. '
.
and Rispm:tli surface waterlor their BtfetiJtB* is .•'
reasooabteaHormeettfeagoeiof&e
CWA. Driatiag watwrdnecfly froav
surface- svppbes is not always regnkted
under theSDWA: There are many
cfrcumstBBees whkh aTe-not regu&ted
bytheSDWA-SDWAiegulationsare
onfy epplka&Ie- to-public water suppUea.
serving popylatrao^ of 2? people or , •
• more.or in wJikh thevaoielSor more
service cooaecfibns.
. 7R.
, March, 1991 atpp;aJ-41.1-Sbme States
havechosen to oo so. •' '.-.''
78. Conurieati'A ocimmenter stated. '
that EPA -utilized a high degree of :
overprotection.m deireloping, criteria for .
antimony. The commenter requested! :. ••-
EPA ta update the ffilSandHealth.
ESecfs. Asseasment Summaqt TabTes.hy.
'USlhg itgafTflMn Hittn irfpmvffat
intnmtatiri
', iffmanr*t*. 1
Aoponse: IB developing toftariafer .
availahk data wliciTisAraiy limilwifar
antimony compounds. Thagieatest
icnl^irm^pf IrtfinTmarifirt h\ ^fjm^^t '
queslioeed A»fisb and water • ' '•• ' '
. consumption rates of kaman»«sce.doae:(R&ttibr
iwuaby adding;£bctnot8,«rinVtng.
Annie -
'Prnriiiynt
'-Cadmium
• that EPA siuraMastal^tskaeparaft '
criteria for the WB aclnbb.aodi .- . . .. ;. •
commercially mon< importaat nnrfa~<«»»
oxide*. Th»IRIS datateaa iniicaraca:. •
ifMt MflA^f :-frrr m nUit miy.. •
'
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Federal Register / Vol. 57. No.-246 7 Tuesday, December" 2%: 1992 I Rules and Regulations 60889
.Response: As stated above, thfl
Agency is setting criteria which -would
result in protection from all soluble
forms of antimony, not just the most
common forms. It is true that antimony
oxide is much less toxic than potassium
antimony tartrate. However, the Agency
„ is taking a conservative approach and
assuming that there is the potential for '
toxic organic antimony compounds,
such as the tartrate compound, to form
under ambient water conditions. For
this reason, the Agency chose the more
stringent of the two RfDs listed on IRIS
for antimony compounds. (See 1980
Guidelines discussion, p. 79355.) '"' '
.80. Comment: A commenter stated
that EPA should use a less conservative
application of uncertainty factors in
developing the RfD for antimony. :
Response: The JUD for antimony,
based on the lifetime rat study by
Schroederet el cited in IRIS (1992).
Includes an uncertainty factor of 1000
/since the study resulted in a Lowest
Observed Adverse Effect Level (LOAEL).
A No Observed Adverse Effect Leyel -
(NOAEL) could not be determined from
this study. It is Agency policy to assign
an uncertainty, factor of 1000 to a -
- LOAEL from an animal study of lifetime
duration. If there had been a higher •-•
degree of certainty that this LOAEL was
indeed close to an observed NOAEL,
then the uncertainty factor assigned may
have been reduced. However, given the
paucity of data on antimony, the Agency
assigned the full 1000 uncertainty factor
in developing an RfD. (See discussion in
the 1980 Guidelines, pp. 79353-54.)
81. Comment: A commenter stated ,
that EPA should use the revised
bioconcentration factor (BCF) of 0.5 '
recently developed by'EPA for antimony
instead of the outdated BCF (1.0) used
in calculating the criteria. . . •
Response: It is not true that the BCF
for antimony has been officially revised
since the 1980 ambient water Quality
cnteria (AWOjC) was developed, there
are draft updated BCFs under
development by the Agency. However,
an opportunity for comment on the new
' BCF as it has for the revised RfD values
'• which were derived from IRIS.
Information on IRIS is considered •'
* /public information, *asily accessed and
open to public review. The Agency
decided it would be unfair to include
revised BCF values into this rulemaldng
without giving all interested parties a
chance to comment on them. For this
with 1980 BCF values. EPA will revise
the criteria for human health onde a
revised methodology is developed. At
that time we will also include all
• updated BCF values. '' ;
82. Comment: Several commentere
stated that the polychlorinated •
biphenyls (PCBs) criteria needed
revisions. These included: (1) Revising
the cancer potency {actor estimated by
EPA, (2) setting criteria for each of the
Aroclor mixtures separately rather than
for a single Aroclor mixture, (3)
translating the animal evidence of
cartinogenicity into human risk values.
In support of their argument
concerning the cancer potency of PCBs,
thg comT"nn*BrB cited from the import,
"Reassessment of Liver Findings in PCS
Studies in Rats by Pathology Working ; :
Group" prepared by the Institute for •/
Evaluating Health Risk fJKHR). The' •"--
report reviewed five chronic studies in
rats using Aroclor 1260, Aroclor 1254, •
Clophen A-60 and Clophen A-^30, PCBs
with chlorine content of less than 60%
i.e., Aroclor 1254 and Clophen A-30
bad Uttle or no evidence of ' \':"---
cardnogenicity. With respect to Aroclor
1260 study, the commenter- ', - . .
recommended that the EPA_should use ••
a cancer potency factor of either 5.1 or '••
1.8 (mg/kg/dayrl. The EPA potency '
factor of Aroclor 1260 is 7.7 (mg/kg/ -
day)-1* The cancer potencyiactor of Svl.
(mg/kg/day)-1 was calculated from the
same study (Norback and WeUman) as
used by the EPA. Use of geometric -,.-
means of all the studies with chlorine
content of 60% resulted in the cancer -•'
potency factor of 1.9 (ing/kg/dayf-1. . - ;
The commenter argues since there is
no evidence that the PCBs with chlorine
content of less than 60%, are •.'" _
carcinogenic, the Agency should seta-
separate criterion for each of the :
mixtures i.e.. Aroclor 1242. Aroclor
1254, etc. , . '.-.•-••
J?esponse;EPA disagrees with the
commenter concerning Che cancer ••
potency calculations using geometric -
means of several studies resulting in
value of 1.9 (mg/kg/day)-1. Utilization of
a^eometric means approach for, the * '-.
calculation of potency estimates from''
the available studies is not reasonable '
because different animal strains and age
levels were used in these studies.Tn•.-'•
addition, the study of Norback and "
WeUman, cited in IRIS (1992). from '
which EPA calculated its potency factor
of 7.7 (mg/kg/day)-1, was much superior
in its design and conduct than the other-
studies. Therefore, the Norback and
WeUman study is expected to provide a
more precise criterion. The re- - ,
examination of sh'des front the Norback
and WeUman study by a group of ~
private pathologists and the use of the '.
revised data is alleged to a yield cancer
potency factor of 5.1 (mg/kg/day)-1. This
potency factor is not very different from
that calculated by the Agency. '
The Agency believes that it is not
•reasonable to develop a criterion for
each of the PCB Aroclor mixtures. PCBs
are mixtures of chlorinated biphenyls.
Each mixture may contain up to 209
possible individual compounds. These
mixtures are prepared by treating
biphenyls and chlorine under alkaline , ,
conditions and are characterized by the
chlorine contents of the mixtures. For
example Aroclor 1242,1254 and 1260
contain 42,54 and 60 percent chlorine
contents respectively. These mixtures
are not characterized by the occurrence
of each possible compound in the -
mixture. Each of the mixtures would be "
expected to T*yn*"*" all combinations of -
chlorinated compounds even though
^»ome of them in small or trace amounts. *
IB summation, all the Aroclors arei • .1
expected to contain chlorinated •
carcinogenic PCB isomers. Besides -.
•expecting carcinogenic compounds in
each mixture, these mixtures cannot ~ .
adequately be analyzed with commonly .'
available methods. . . .
The Agency believes that the evidence
of carcmogenidty observed in animals
can'be used to estimate risk values. The
Agency has used this approach in ibis
• regulation based on the existing Agency *
1980 Guidelines (51FR33992). v
' 83. Comment: One commenter noted ;
that there is a marked range of
. .carcinogenic potencies between the
various nitrosamines with some • .
nitrosamines exhibiting no carcinogenic
activity. The commenter argued mat ;
reliance on structural similarity
methodology could therefore result hi
misclassification errors as to.whether
specific compounds should be treated as --
carcinogens.- , - . .-
flesponserEPA agrees that there is a-
marked range of carcinogenic potencies .
between the various nitrosoamines with
some nitrosoamines exhibiting no '
carcinogenic activity. If there are
nitrosoamine, EPA uses such data in
-evaluating the health risks that such a
'•chemical may present However, such
-data are often not available. As a • ' • '
consequence, EFA must, as a practical
matter, infer the toxicity of one ,'.
- compound from the toxicity of a
chemically ytmtliir analogue. ' ' ' •
."'-84. Comment: A commenter ' .
submitted a document entitled, '
-.^Biological Risk Assessment of N- '
Nitrosodimethylamine." While this
document does not recommend a
specific human health criteria for N-
nitrosodimethylamine(NDMA),itdoes
conclude that: 0.0044 ug NDMA/kg/day
will present the public with, a lifetime .
10~s risk level of cancer.
Response: It is not at all clear how the
authorfs) of ^'Biological Risk Assessment
-------
6OH9O 'F«d«trd Register A Vol. 57..No. 246 / Tuesday, Pacember 32. 1992 / Rulea -and.'-Regulation*
of N-NitrosodSmethylainine'* arrived at
•the OJKHX ng NDMAAg/day with KT5
rial. hrveL Assuming die fngostion of.2,
. L.of watex/dayby &70 ^gpaduhX-(XO(M4
ug NDMA/kg/dsy ixaqurvalent to a. level
.of ND&CA. in. drinking water of O.2&ug
NDMA/L.Otsad on the same data, IRIS
" 1 that the lO^iisktoveifor
with water qoaUty-based permits, would , U.S. Governrbent Standard Form S3,
be based on nnmerons-assumptions; Request for OMB Review, includes a. -
results arasaositivetb. those • section for OMB to waive the
Hoirmpfio^fi? flnri COnff^OU^flT iV»• *'™^F ypfinyf^ypflHr^i fa} OOnfyJCt ff HiPfmBfltOBV
resuJU-woetldHotprovide-meanhignrl Impact Anarysiir so OMB does.hav»
(i.e, l/^Dtiwr vakwof "Biologrcat Rfsk
s, EPA disagrees with the
cotESMBf s&Kvist
ing'process. such, authority^
For the final rule, tike Agency has 87. Crimmft"*: ^
undertflkattacostas8essnrentto.expresft asserted that EPA Bas;notdeniuuBUHtaa
a range of compliancs coats'lor saroral
combinatHxis-of industries and
pollutants. Tha; Agency, has. also.
estfcnatad and/or duscribsd a range of -
heaftkandacologicstasi»fits:teth& „, . .. _
_ -r-r^r— . . WaflacAct eswariBg:wBtai quality
^T^^nmnCT ale GUUUUtUlfilXS&ft
fa th* taU* fia pareatnes«*} are for
comi
Analysis, tha.
criteria tk*I9SQ.crttert»«Mtaa>hw coot and
conclusion. appiiM-te»d«teil«diaBaIyai»
and (c) EPAfc «nar.i». relying en-, the
difficulty o£theUckafr a- reason toe not
iafonafttira,sugphadiathacsauaairts-. FlmrihtHfj Art BlJnfliHha.niiiiiniiiiin
i*.nat*u{!Rr-taTTife».ra<»«a>iBn.*]i<»-£m»tn*4- agjn,inpfi. -. smaU enfitifiSwNsAs&eleas^as.described
-Agaocyfa decision ta&UU it* statutory
estimate
-cost* fotthasulat As «-varyBria£
eiimmary,
compliance castest
that then wiB aeaaif pificaBlk
•a subctoBtifill Bunibef tff cmalll entifisc; -
Analysis is not TequimdC
4
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Federal Register /Vol. 57. No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 60891.
"66.. Comment: Several commenters !
asserted that "EPA should consider
current economic conditions in .
determining whether to promulgate
Federal criteria. .:
Response: While EPA acknowledges
that prevailing .economic conditions
affect individual business decisions .
concerning investment in pollution
control. Congress clearly Intended the
Agency to move expeditioualy when
Federal action is warranted, In ••
compliance with congressional intent, •
EPA is promulgating these criteria at
this time. •••• ''"?••''.,?. .'•• '
fa addition, it is not dear which -'•'"
"current economic conditions'* should
be taken into account in establishing
federal criteria. Theiimitation of toxic
discharges is intended to be a .-
continuing process, with this rule a part
of the on-going control process. Since •
«» uia uu-guuix UULUUI jmroesa. autue
the criteria wiu be in effect during all
phases of business cycles, current .
conditions cannot be the sole •• •' :
determinant of economic conditions •' ;
when analyzing the economic impact df
a regulation, Likewise, the impact of. "" '.
this rule will not be incurred • ... ^ •-'-;•
immediately because the criteria will be
written into new discharge permits as ':. •
the current permits' expire. . , :*
90. Comment: Several commenters," •'_
representing Industrial and municipal " r
dischargers, assarted that the economic
impacts of complying with EPA- '. • - r.
imposed criteria will be substantial and '
will be burdensome. ".,'.'• • '..
Response: While itis likely that some
dischargers will fara»i* mmpfinnm costs
when the EPA-imposed numeric toxic .
pollutant criteria are translated into *
specific NPDES permits, it is not certain
that such costs or their impacts will be
unreasonable. For several industries, as .
described in the Agency's cost .
assessment, large segments of the . .
discharging community will not be • •
affected by this nile because, for ' -
example, costs to comply 'are very small,
'Or tt>f'nna1pgy-bftBft<^ -UrnHnHrtny gig £
sufficient basis foe effluent control that '
will also control pollutants to the .level •','
neededio comply with in-stream water,
quality criteria. " ' "
• 91.
, representing municipal interests stated
that EPA is incorrectin the assumption . :
that industr^l sources are the primary .
source of toxics discharges by POTWs.
Response: EPA recognizes that there •.-"
are several sources of toxicpollutant -
contributions to POTWs. Industrial :. • ~. .
indirect dischargers, while not the only
source, are often the primary source, •
and the toxic influent from these __-. ."
sources can often be controlled through
pretreatment programs. .•
92. Comment: Several commenters
stated that promulgation of Federal
criteria removes the flexibility to reduce
impacts .that States would have had by
adopting their own standards. Further,
they argue. EPA is incorrect in its
assumption that impacts are no different
than what would occur if States had
acted to adopt their own standards.
. Response: States continue to have the
opportunity to adopt their own
standards that include numeric criteria
for toxic pollutants. As they adopt and
EPA approves their water quality
standards, the flexibility provided in the
standards-implementation and permit-
writing phases of the standards process
will return to the States. For a
•discussion of the effect of this '
promulgation on various
flexibility, see subsection 4 of this
section. -• ',-• '''.', . ••';•
- In the cost assessment. EPA has
investigated the potential incremental .
effects of EPA netting standards instead
of State&DrieQy, EPA finds that for
certain dischargers, incremental costs -'',
may be incurred in States where toxic
.pollutant criteria are adopted at EPA's •
levels. If a State "were to adopt less
stringent criteria, it is possible that the ;.
impacts would be reduced. It is • _
.-important to consider that in some of
the examples. EPA's criteria did not
result in incremental costs.
.... As-discussed elsewhere in this
preamble. EPA encourages States to
adopt their own standards and make use
of site-specific criteria as appropriate. .
4. Implementation ' . .
93. Comment: The Agency received
substantial comment on 40 CFR •;. . •
13I-36(c) which described the proposed
implementation procedures for priority
toxic pollutant criteria. Comments
divided on whether such factors should
be included or left to the discretion of-
.the States. '..-'•" .
Response:¥ax reasons stated in the '
preamble to the proposed rule (56 FR
58437,»ection 3, Applicability). EPA ,
beh'evec that baseline application
. conditions must be included in order to
provide the intenided environmental -and
human health protection of the criteria.
These criteria consict of more than.
quantitative concentrations. EPA's •
•section 304(a) criteria methodology
clearly presents the criteria as criteria
maximum concentrations (CMC) and
•criteria continuous concentrations
(CCQ which contain averaging periods
and return frequencies. The • . .•'
implementing by drolbgical conditions
merely provide mintmnm conditions to
meet these definitions. The salinity
conditions delineating when and where
the freshwater and saltwater criteria,
apply are .also necessary. EPA must
specify where each of these sets of
criteria apply. Likewise the.hardness
limitations for applying the metals
criteria. Each of these paragraphs will be
discussed in more detail below but are
mentioned here to demonstrate their
necessity for implementation of the
criteria. Without these generic
writers, the principal users of the
criteria, would be unable to develop
conditions ****f limits for inclusion in
NPDES permits-within the requisite
ranges of consistency and predictability.
•94. Comment; The ability of States to
develop site-specific criteria and to •
grant variances and exceptions to •
standards received several comments
generally indicating that EPA should
not constrain the ability of States to use
such implementation procedures. • . • ' •
.Response: The development of site-
specific criteria and the use "of variances
to standards are optional procedures
made-available to States that adopt State
criteria (40 CFR 131.11(b)(ii) and
131.13). It is neither a statutory nor a
regulatory requirement to develop site-
specific criteria or to issue variances.
Thepreambk language to this final •
rule clarifies EPA's statement on this
subject in the proposal. Since the
criteria in this rule are Federal criteria
applicable to the State, a State cannot
unilaterally establish site-specific
criteria or grant variances to the Federal
rule. That is whatEPA meant in the
proposal when welndicated that actions
pursuant to State law for Federally .
promulgated criteria are precluded.- •
Such procedures are still available to
the State, but are much more ' '' .
cumbersome as it requires the State to .
meet all ;the regulatory requirements for
developing such procedures, but .then
EPA would need to undertake a Federal
rulemaking process in order to '•'
effectuate changes to the Federal rule in
accordance with the requirements of the
Administrative Procedures Act. EPA
continues to emphasize that this is •'
another strongreason for States to act to
adopt their own standards even after
Federal promulgation action is taken.
95. Comment: One EPA Region "
questioned whether the specification of
the applicable hydrokgical baseline
mandated the use of steady state models
and eliminated the use of dynamic
models for wastaload allocations. • •
... Response: The proposed rule did nor
.intend to eliminate the use of dynamic .
models for wasteload allocations and ',
total maximum daily load .
determinations. Generally the low flows
specified explicitly contain duration
and frequency of occurrence which
-------
60892 Federal Register / VoL 57. No. .246 / Tuesday. December 22, 1992 / Rules and Regulations
represent certain probabilities of • •
occurrence. Likewise the criteria for the
priority toxic pollutant* are defined
with duration and frequency
components. Dynamic modeling
techniques explicitly predict the effects
of variability in receiving water, effluent
flour, and pollutant concentration. EPA
has recommended and described three
dynamic modeling techniques for
performing waste load allocations in
section 4.5 of the 1991 Technical ' '
Support Document: Continuous - •
simulation, Monte Carlo simulation' and
lognonnal probability modeling. These -'
procedures allow for calculating •*• ;•• .-
wasteload allocations that meet the
1 criteria for priority toxic pollutants
.without using a single,-worst-case .
concentration based on a critical • •'•
condition. - , .-..••-••
Thus, EPA believes that either
dynamic modeling or steady Stats
.modeling can be used to implement the
• criteria adopted today..--- . . ' '
, 86. Comment: Several commenters.in.
'addressing implementation conditions
argued that EPA should defer entirely to
' State discretion including the applicable
design flows.- Other cbmmentera urged •
removal of design flows from the rule
and rely on the guidance in the TSD
and/or other EPA guidance. Another
commenter agreed that flow. ' •• .•
'requirements were necessary but that- •
the harmonic mean flow requirement
was flawed. • • .-
Response. As noted in the preamble to
the proposed rule, implementation
, requirements that include limitations on
flow values are required in order to •
Achieve the intended environmental and
human health protection. The
applicable discussion of this issue is. .'
Jfbund in the,preamble to the proposed '
rule on pages 58437-58438 and -
footnotes 1 and 2. The hydrological or
biological basis for the proposed low
flows were taken direcuy from EPA's -
• •Technical Support Document for Water-
Quality-basod Toxics Control. (See TSD,
. Appendix D for aquatic life and section
4.6 for human health.) ••• . • .?, •• ..'•
The argument by the commenter on .;
tha harmonic mean flow was in reality
a disagreement on EPA'* assumed long*
term dose assumption for toxics. The
commenter believes short-term effects -
„ are more relevant, and therefore requires
a different flow, especially for • • •
blooccumulatlve pollutants. However,
EPA continues to support the human
health protocol used in the proposed '
rulftmaking and notes thatit explicitly
accounts for,bioaccumulation in the
'criteria development protocols. For such
long-term human assumed consumption
of water and aqua tic life from such — .
waters containing a pollutant, EPA's
best scientific judgment is that the
harmonic mean flow is the correct flow
to apply in order to correctly estimate
.the exposure dosage of the average
. exposed individual - • . -
97. Comment: One commenter
questioned the applicability of the
specified design flows in waters. " •
downstream from impoundments which
have minimum release rates specified,
as for example hydroelectric dams.
Response: EPA's proposed rule in •
§ 131.36(c)(2)(ii) specifies that the low
flows are applicable to "waters suitable
for the establishment of low flowietum •
frequencies." Thus, free flowing streams •
and rivers wereihe types of receiving .
waters contemplated-In cases where ' •
legally specified low flows exist, as for
example under FERC licenses, these •
become the applicable minimum flows.
In future State water quality standards
reviews. EPA encourages the States to
take into account these specified flows.
and adjust the criteria appropriately to
provide equivalent protection of human
health and the environment to that
applied in today's rule.'; " ^ •'.•'••
• 98. Comment: One commenter noted- •
that "rules" 3(a) and (b) are inconsistent
• with "rule" 8 in the "Assumptions and
Rules Followed by!EPA in Writing the
.proposed S 131.36(d) Requirements for
All Jurisdictions." (Seg the appendix at
• page -58451 in the proposed rulemaking."
package.) .. :' i '' . '-.'. •'.
... Response: "Rules S(a), 5(b) and rule
8" as stated in the appendix are correct
' An incorrect statement of "rule 8"is •:.
contained in the preamble to the • '
proposed rule at page 58432. Briefly
stated, these rules provide:
• f-Rule 5(a) applies appropriate human
~ health criteria to au waters in a State
classified for either public water " '.
. supply-or for minimal aquatic life
--•protection; .' ' • '."_..-•
—Rule 5(b) provides that where a State
has determined the specific segments _
where aquatic life are .caught and
consumed, the human health fifh • •
consumption only-criteria (Cuinnm
•' D2) are being applied to those specific
—Rule B provides that where drinking -
.water uses are designated,£nd even •'
. though the State has determined that
no potential fish consumption uses^ '.
r ..exist, the human health criteria for ..
. "water* fish" in column Dl-are ;.
applied. EPA applies these! criteria
• becati»6 no'Vater only" column is •
available in the section 304(a) criteria
methodology and drinking water uses
must be protected, .••• ;:
99. .'Comment: Several commenters
claimed that EPA was applying the
. criteria too broadly; that is, to waters
where aquatic life propagation or public
water supply uses: were either not
designated or did not constitute existing
uses. In contrast, another commenter •
urged EPA to apply the criteria to all
waters of the State where an EPA-
approved use attainability analysis did
not exist . • • • ~
Response: Water quality standards •
contain both a designated use end the
criteria necessary to support those
designated uses. ID this r»lAm«lcjng EPA
is not addressing (the ..designated use
component at afl. but only the criteria .
component for tha priority toxic ;•
pollutants. EPA-has relied entirely on = •
the existing State water quality
-standards to deteimlne the waters to •
which the criteria apply. In § 131 J6(d)
EPA refers to all .waters within . ,-.
particular designated use classifications.
Because EPA is not addressing the
State designated uses hen, EPA has not
: f „ _ to review State application of
designated use classification through
use attainability analyses or the other .
requirements of 40 CFR 131.10. Any
identified deficiencies will be handled
-during the State triennial water quality
standard review .process with any. . .
necessary Federal, actions being taken .
,-ori a State by State basis.' • '•''
• 100. Comment: One commenter .
objected to EPA specifying Oat EPA- •
approved-State mixing'zone regulations
could be applied to the priority toxic
pollutant criteria promulgated today.
Others stated that EPA should include .•
•procedures to define appropriate mixing
zones, that EPA should allow mixing -
zones in all State» and that EPA should
require mixing zones in all States.
Response: Mixing zones are one of the"
general discretionary policies
.specifically authorized for State
adoption by EPA's water quality . . ,'
standards regulation at 40 CFR 131.13.
Mixing zones have most recentiy-been
defined by EPA in the revised TSD (see
..page "xx") as "an area where an effluent
discharge undergoes
-------
• .--.:«-:.•••.•••. • ,'--v- ••. •. . • ' .-
Federal Register /.VoL 57. No. 246 /Tuesday,.December 22, 1992 / Rules and Regulations 60893
for EPA to impoaa a leas stringent
mixing zone policy in- a State than is
currently authorized. Therefore, in this
rulemaking EPA recognizes State mixing
zones and provides for their application
in implementing the criteria -'
promulgated by this rule. However it
. does not impose mixing zone
requirements on States which do not
have such policies.
101, Comment- Comments were
received that the Federal toxics criteria
are not viable because they have never
been subject to public comment and
review and that the criteria should be
subjectto continuing peer review and
study in order to ensure technical
viability. Commenters stated that it is
improper to require development of
permit limitations on the basis of
technically flawed criteria which may
not be relaxed in the future due to the
anti-backsliding requirements of the : • '
CWA end regulations, and that EPA
must find that criteria changes which
result from peerreviews constitute new
information which qualify as an " •: '"• •
exemption from the anti-backstiding
requirements.:^ - . . - -: -'-:.
JResponse:>Ve disagree with the '..
premise of this comment that provision
lor public review end comment on the '
federal toxics criteria has been" . ' .
inadequate. The criteria methodology
and documents were the subject of
public review when issued. See the ' ~.
discussion of this issue in the preamble
to the proposed rule as well as
discussion of EPA's plans to revise
criteria guidelines in the future and ."..
solicit public comment, 56 FR at 58433.
(See also Section F of this preamble.) To
the extent we received specific .. . .
• information concerning' the criteria in
this rulemaking, we have reviewed and
responded to that information. Indeed,
certain of the promulgated criteria have
been changed to reflect public . •
comments. EPA rejects the assertion that
tiie criteria are ."technically flawed."
.EPA believes the criteria are - , .
scientifically defensible and would not
requirements, that is not an issue to be ;/
decided in; this rulemaking. EPA is .
developing proposed amendments to -
the NPDES regulations that will . ; ,,; .
interpret and implement the provisions
of section 402{o). The commenter** ; . ;
concerns can be addressed in that. • ..*•: •.
rulemaking or possibly in a prior permit
proceeding if the issue is relevant - . •
102. Comment* One commenter
argued that the rule will adversely affect
implementation of the NPDES program
by diverting resources to deal with
permitting and enforcement issues
arising from the use of unscientific
water quality criteria. It is argued
further that no discharger wul accept ,
permit conditions that are unreasonable,
- have no scientific basis, and do not
reflect the naturally occurring .
environmental conditions in the
receiving water.
Response; FederaUy promulgated
water .quality criteria will be .
. implemented in NPDES permits issued
by EPA Regional Offices or authorized
States.-Dischargers'are free to challenge
requirements implementing federally .
promulgated criteria contained m .
modified, reopened, or reissued permits
according to established NPDES permit
appeal proceduresand as permitted by.
law. EPA^ however, disagrees that the *
federally promulgated criteria lack a .
Scientific oasis and has explained in the
/.preamble to this rule and elsewhere in
response to comments, why .-,
promulgation of the criteria as provided
in this rule is necessary to meet the
requirements'df section 303(cK2KB). We
. anticipate thatmanydischargers wfll -.-,
accept permit requirements based upon
the federally promulgated criteria. •
technically flawed regardless of the anti-
becksUdUng implications. With respect :
to the comment that revised criteria
Resulting from peer reviews should
rnnnHtiitn **iu»uf {nfrynttuHmt**
from water-quaHty based
permit Umitations where revised criteria
are developed if they meet the
requirements of CWA sections 402(o) ox
303(d){4) for allowing backsliding in
attained and non-attained waters. ''
103. ConunentrComments were
received that either the proposed -
Federal or State standards should
provide for a schedule of compliance so
that permittees affected by the new
federal criteria could have sufficient
time to come into compliance. ' -.
Besponse: The jproposed rule did not
diiecUy provide for a schedule of
compliance, however, & also did not " .
change existing applicable State and* ~ .• '
EPA provisions related to permit . ..
issuance OTTeissuaace. EPA agrees with
the "tmiruiTftflrg tiigt gome compliance . .
implementation time may, m certain
situations, be necessary and appropriate
for permittees to meet new permit limits
based on the new standards. EPA has
not removed this flexibility in-the
Under the Administrator's
199O decision in an NPDES appeal .
(Star-KistCaribe m&. NPDES Appeal
No. 88-5). the Administrator stated that
the only basis in which a permittee may
delay compliance after July 1.1977 (for
a post July 1977 standard), is pursuant
to a schedule of compliance established
the
State in the water quality, standard ftself
or in other State implementing • •
regulations. (This decision did not affect
compliance schedules in individual
control strategies issued under section
304(e)oftheCWA.)
Standards are made applicable to
individual dischargers through NPDES
permits-which reflect the applicable
Federal or State water quality standards.
When a permit is issued, a schedule of
compliance for water Duality-based >
limitations may be included, as
necessary, and EPA assumes this is the-
'case forrpehnits issued to meet these • •
new Federal criteria where States do not
have existing statutes, regulations or
pnllry pwinffitriiriff yyynpHimrnf • - --
schedules. EPAnotes that some permits
contain a "reopener" clause which may
earlier than the normal re-Issuance - ~Y >
cycle..- However. EPA does not generally:
contemplate nor does it intend to ask . ,
States to undertake permit nissuanoa ••-.
related to these new criteria for toxics
•through anything njfmr-ftu»Tt^h«i nnr|rn>l
wnnit reissuance cycle, except in rare--
Instances.
104. Omuneirt: EPA's section 304(a)
criteria may not be appropriate when
applied to non-conventional discharge •
situations such as stonnwatar • • r.' •-
discharges and discharge to ephemeral
.streams.'. :•••";•" • ..-.v,'".-'••• ..• .
.Response; EPA's criteria for priority-
toxic pollutants were developed to
protect beneficial designated uses. The
criteria are independent of - -~:
considerations about H«i«l« of • •. •-•- •
dischargers whether point or nonpoint
sources. If a State finds that the criteria
•for the current ambient water designated
uses are inappropriate, then EPA's water
quality standards regulations provide
for a use attainability analysis and • •---'
establishment of appropriate designated
uses. Thus the commenter's 1
are misplaced and focus on the wrong
part of the water quality standard.;--' :
.105. Conunenf; Two comments --'-•
addressed the salinity and effects on .-
-determining which criteria apply at -
particular locations in estuaries. One
commenter. a State i
the concept of clarifying I
ranges within which the^various - -:•••
freshwater and marine water criteria
apply. The State was concerned because
the salinity ranges selected by EPA were
different from those the State had :--
recently placed in sediment standards. -
The second commented asserted that the
.proposed rule created an untenable -
situation where fresh and salt waters - -
mix. This commenter suggested that- 'T-
•rather than using the more stringent of
. 3
i -
, i
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federal Register / Vol. 57, No. 246 / Tuesday. December 22, 1992 / Rules and Regulations
the fresh or saltwater criteria. EPA
should interpolate between the two on
the basis of salinity. *
Responss:Ths range of salinities
Incorporated into this rule at 40 CFR
131.36(c)(3) are appropriate, especially
in light of the guidance for the
applications of the metals criteria
addressed elsewhere in this package.
EPA's proposed rulemaldng'on
salinity, however, was silent on the •
percentage of the time that the proposed
salinity limit* could be exceeded but die
respective fresh or saltwater criteria still
apply. It could be inferred that EPA
intended 100% of the time as the
• appropriate limit It is EPA's position
. that a reasonable exceedence should be
specified or otherwise the intermediate
brackish water zone becomes •- •
unnecessarily large. It is EPA's ' '•'
Judgmentthat a factor of S5% of the •
time provides reasonable cut off points.
Ifcus/fbr the freshwater criteria to
. apply.lhe salinity should be less than
,lppt 95% of the time, likewise for the
salinity should be greater than 10 ppt *
85% of the time. - -••".'• . -• • •
' •EPArecognireslhatjudgmentis •
required in providing guidance on the .'.'
,.-—— -^,m-,.mm »j DMB»V»*
ienL This is because a
fundamental understanding is Inr-Ung of
metals form, bloavallability and toxidry
.along with the relative sensitivities at .
.appropriate salinities of species that
= occupy this gradienL EPA's
• recommendations are reasonable given
that (1) the database for most metals
indudes'tests with saltwater and •• -
. freshwater spedes that tolerate these
salinities; (2) that salinities at a ,
particular location change daily with
tide and wind and seasonally; and (3)
that at low salinities, freshwater and .
saltwater species rnlx.lt is reasonable ,
that the presence of both types of •
spedes in" thlsiransition zone require *
application of both freshwater and
saltwater water quality criteria. Given
the temporal variability of salinity in
both the short and long term and the
judgmental bads for EPA's •
recommendations, knowledge of the • *
kinds of organisms at a site of concern
will be particularly helpful in being
confident that the appropriate criterion
has been iipplled to the site. "*
The second commenler's suggestion is
not supported by data or professional
experience of EPA's sdentists. For many
metals; toxidty to saltwater species '
'increases allow salinities. Therefore;,
undorprotection would result from the '•
use of an interpolation approach that
would result in higher criteria at low or •
intermediate salinities. —
S. Timing and Process
106. Comment: EPA should delay
Federal promulgation until current State
efforts to adopt water quality standards
have been completed. .
Response: Without sufficiently
protective and defensible water quality
standards. EPA and the States cannot
effectively control discharges of toxic
pollutants. While the Clean Water Act
dearly gives primary authority for
adopting water quality standards to the
States, Congress dearly signaled its
frustration with State delays in adopting
criteria for toxics in the 1987 Clean ' •
Water Act amendments. Since the 1987 •
amendments, the .States have had over
five years to meet the statute's •
requirements for adopting water quality
standards for toxic pollutants. Further
delay is unacceptable. It is now time for
EPA to exercise its oversight authority
to ensure that human health and the
environment are adequately protected.
' 107. Comment: Several comments
were received relating to the general .-
subject of State action during or ..,'•'.
subsequent to this rulemaking and on
the processes EPA would use to :. ..
withdraw Federal criteria applicable to
a State. A related comment was that *::.
EPA should clarify that partial. . :~. .
withdrawals are possible. Another '; ', ....
comment questioned which criteria ''
would apply in a situation where EPA
approves State standards subsequent to
the Federal promulgation. _.-. -...'
Response: EPA is fully aware that '••
several States are actively involved in .
reviewing and possibly revising their
: standards to meet the requirements of '
the Act simultaneously with the
Agency's action to promulgate Federal -
standards. It is an objective of the .
Federal action to spur State action to
complete their own administrative -
•procedures so as to obviate the need for
Federal promulgation. However, forihe
reasons stated earlier in the preamble as
the basis for this rulemaking, EPA' • •
believes States/have already had more • •
than adequate time to respond to the
statutory requirement and that EPA has'
a responsibility to act to put-standards
in place to serve as a basis for -.
environmental control programs.
Nevertheless. EPA encourages States to ~
continue to'adopt their own standards *
and thereby enabling themselves to '
make use of the flexibility inherent in ":
the. program through use of the various
implementation processes even if such
action will not be completed until after
promulgation of this rule. EPA is ""
committed to timely withdrawal of the
Federal standards after'State adoption" .
and EPA approval of State standards.
The assertion that upon adoption of
standards by the State, EPA's Federal
criteria are no longer applicable within
the State is not correct The Federal
. criteria will continue to be the
applicable water quality standards until
withdrawn. Where the State standards
are less stringent than the Federal
standards, the Federal standards will be
controlling until final action is taken to
withdraw the Federal standards. In this
situation, the permitting agency must
use the more stringent standards in •• •
issuing permits. As a practical matter, it
is assumed that, permit holders would
seek • stay of permit requirements **•' •-•'•
pending the final decision of the Federal
standards, While there maybe a period ' •
in which there are both State and. ' X •
Federal standards in effect, the most' '
stringent standards (either the State'* or
EPA's) would be controlling. '••• ••••'* f-:f"^
As described earlier in the preamble,
EPA willactto withdraw-thisnileas -3.-.
applicable to a State, if the State.-•-5 "-. ••'••.
completes action on adopting standards
that adequately protect their.; :>••-*. •?•: ...•••.
waterbodiesfrom toxic contamination''
and EPA approves those standards The
standards do not necessarily have to be
exactly as those promulgated by EPA- -•• •' .
. but they must meet the requirements of .
.theActand40CFRl31.il; - ^3.,- --:.;.'
. Many commentii were receivM. that v
• EPA should not be required to'receive^
comment and execute a lulemakin&in, *
order to withdraw State-adopted and,'.. .
EPA'approved staiidards that are. less -^:
stringent than those promulgatedby. '.'••--.
EPA. As described in Section &-3 of tHfe.
preamble, EPA withdrawal action :/-;
differs depending upon whether:the .;/.
State standards .are equal to or more or.
less stringent than those promulgated in
this rule. •' '• 1 •.'..'".-..
While it would tie administratively" -
less cumbersome not to provide notice '
and comment in withdrawing a more .
stringent Federal water quality standard,
EPA, however,is constrainedly: the. .'.:.; •
provisions oftiaeAdministrative'•'•"'''''"'
Procedures Act.'5U.S.C. Section 551'(4)
and (5) which we believe prediide die ;
Agency from withdrawing a rule as' ' -
suggested bylhe«unmenters. EPA will
take timely action, to withdraw the' ^'
Federal rule in these cases; EPA has had
experience in withdrawing the Federal -
rule covering each situation.!*. ""' - '"•
standards^qualtoprmoreorless "'••-'
stringent than the Federal rule tSlFR .
11581, April4.1988; 47 FR53372, .-'V:.'
November 28,1982rS6FR 13592, Ap'ril
3.1S91). It has fiot proven to be a':':.' j» «*••
practical problem. ;EPA;T^''"
confirms that partuil approval :6f State "
standards and partial withdrawal of the •
:
-------
-Federal Register / Vol. 57, No. 246 / Tuesday, December 22, 1992 / Rules and Regulations 60895
Federal rule is allowable. (See generally.
Chapter 2, Water Quality Standards
Handbook, December 1983} .
There is an exception to this process.
If a State adopts a 10~3 risk level when
EPA promulgated 10**, the rule can be
withdrawn without notice and comment
because we raised the possibility of
different risk-levels in the proposal and
we have accepted both risk levels as
meeting the requirements of the Act
108. Comment: EPA received
comment that mere is no procedural .
necessity for this rule because Congress
did not seta specific deadline for State
action to comply with section - •"—•' - •
303(C){2)(B), '•-,; •••••".•
Response: For the reasons set forth
elsewhere in this preamble, EPA has the
requisite statutory authority to •
promulgate these criteria and that such
criteria are necessary, as a basis for water
quality-based control programs designed
to protect the public health and the
environment;. •'••- . •-• .-'••
Section 303(cH2)(B) of the Act .
requires StateVaction to address toxic
pollutants'"whenever a State reviews
water quality.standards pursuant to >
paragraph (1) of this subsection * * *'V
Paragraph (1) refers to the requirements
to review and revise, if necessary,
standards at least .once each three year
period—the triennial review cycle for
standards.• ' ", , '. : ""''.-"
. Notwithstanding arguments -
concerning timeliness of EPA And State
actions, the. Agency has made a decision
that toxics criteria for priority toxic .
pollutants should be in place; The
Administrator's action has started the
process described in CWA section " .
303(c)(4) for Federal promulgation.
Thus, because of the Agency's action,
the comment at this point is moot
109. Comment: EPA received
numerous comments concerning the 30-
day public comment period. Some .
. industries and municipalities expressed
concern that the rulemaking was too
extensive to allow meaningful comment
•within 30 days. Some commenters ;
.-requested extensions up to six
, additional months. Several commehters
noted that EPA had never before
promulgated a final water quality .
ffnnHarHn Ttilo uqthin On Hnyg nf
'proposal..: • ,'. ...-./
Response: EPA appreciates that 30 .
, days is a short comment period but -
believes that it is fully consistent with
section 303(c)(4) (33 U.S.C. 1313(c)(4))
which requires EPA to promulgate a. •
final regulation within 90 days of ... -
proposal. The fact that EPA only met
this requirement once in'its nine final
promulgation actions does not change
the statutory requirement •
In most of those previous cases (and
in 2 cases today) the Agency was in fact
superseding a State rule; Pursuant to the
Agency's regulation at 40 CFR 131.21(c)
the State rule stayed in effect until'
EPA's final rule took effect Today's
action is different Here, by and large,
there are no State criteria for priority
toxic pollutant in place-and EPA is
acting to fill that void. This EPA action
has a greater sense of urgency and .
justifies the Agency's effort to meet the
90 day statutory time schedule In CWA
section 303(c)(4). : ....
The addition of section 303(c)(2)(B) to
the dean Water Act was a clear and .:
unequivocal signal from Congress that it
was dissatisfied with the slow pace at .
which States were adopting numeric •
criteria for toxic pollutants. This intent
is made clear in the legislative history '
of that provision. It is the only tiine in
the 26-year history of the program that .
Congress explicitly directed the States \
to address certain pollutants in their . "•
standards. Moreover, section 3Q3(c){4). .
which authorizes Federal promulgation
has explicit deadlines and . .-.. -"-.-'''
Congressional directives to act : ''.
promptly. The intent of the Federal.-.••"• '
promulgation section of the Act is to -
accelerate human health and ecological
• protection by establishing water quality
. standards as a basis for pollution control
programs. To achieve these objectives .
• and meet the statutory deadline, we : -'
need sufficient time to re view public
comments and make any necessary"
•revisions. •• !. •-- - : v
.• -Although .the State and pollutant' .
coverage of this, final rule is large, the
issues involved ara neither new nor
numerous. The primary focus of this
rule is the narrow issue of whether a
State has adopted sufficient water ,• .
fuality criteria for toxic pollutants in •"
tate standards as necessary to support.
water quality-based control programs..
EPA alerted the public to its
intentions and the planned contents of •
the proposal on April 19,1990, in an
announcement in the Federal Register.
In addition, we notified the ; " '
administrators of the Slate agencies
responsible for the water quality
standards program of each potentially *
affected State of pur plans on April 9,
1990. In the April 19.1990. notice. EPA
described what would be in the .
proposal, including: Which pollutants,
which States, the cancer risk level, and
EPA's intention to update criteria using
publicly available information in the .
Integrated Risk Information System.'
Since that notice; EPA has apprised the
public of its intentions and status of its
.action through State and Regional; . .
meetings and quarterly newsletters on
the criteria and standards program. EPA,
through both ite Headquarters and
Regional Offices have met with the
States, and the regulated community
individual and public meetings and
public hearings to discuss EPA's plans
and progress. This lengthy lead time has
allowed potential commenters to
prepare for the proposal and should
. nave facilitated preparation and
' submission of meaningful comments
within the 30-day pubuc comment
period.
As discussed previously in this ' '"
. preamble and .the preamble to the
Sroposed rule, the methodology used to
evelop the. criteria and the criteria
themselves have previously undergone-
scientific peer and public review and ' .
comment and were revised as.
appropriate. Some human health criteria
were updated by recalculating the ....
criteria using revised reference dose
information contained and publicly .
available in the Agency's Integrated; Risk
•Information System. Information in ft»fa
system was peer reviewed within EPA
and, as a matter of policy, is the.-.
information which was recommended to
' the States for their use. Most of these.
reviews occurred before 1987. Congress
. acted to amend the Act withrfull -• ., "
knowledge of the EPA process for :-
developing criteria and the Agency's v •
recommendations under section 304(a).
EPA believes it is consistent with
Congressional intent to rely On existing
criteria rather than engage in'a time- •
consuming reevaluation of the . '• '• .
underlying basis for water quality
.criteria. At some point in the standards
setting process .the States and EPA must
-act recognizing that scientific research
leading to improved water quality
information is an ongoing process. In
the case of this rulemaking, EPA affirms
that in addition to all the . '
environmental, programmatic, and .
statutory factors supporting the rule, the
basic criteria methodologies are .
scientifically sound as are the resulting
criteria. -. . . • .•_
In the five yean since the February
1987 enactment of section 303(c)(2)(B).
most States have worked extensively to •
adopt waterquaUty standards for toxics
pollutants. The issues in this proposal
are the same ones that States,
. dischargers, public interest groups, and
EPA have discussed and debated in-
depth during those deliberations. The
comments prepared for State and EPA
meetings and hearings are to a great
extent the same as those to be made on
this Federal action and made it easier •
for the commenters to prepare
submissions on this rule. The arguments
presented in the public comments that
EPA's action is new or that the States
are not in compliance because they are
-------
Federal Regkter / Vol. S7rNb;. 246 /
. Jfrxaonber 22, 1992 4 .Roles and Ungulationa .
carefully reviewing'their standards ell -
tend tor ignore the fact .that many of the -
criteria were available as early as 1980.
Because of* lack of State action, EPA
made it a priority emphasis in the
revision to the water quality standards
regulation in 1963 end, most
importantly of all, that section
303(c)(2)EB) was not the start of the
process but the signal from Congress
that delays had to cease. H is now
eleven years after Jhe criteria ware first-
made available to the States, five years .
aftar Congresa specifically directed the .•
State* to Act Given 'this background. 80
days was sufficient for co'mmentan to '•
and the eutu
t, ft i» the Agency's and
conunentSi tns extensive' nsttus of me ~
cxinimenls submitted stippoil this
ptaJti on. Pnrther delay gifitgpiootssfe
totally kmfcygttpT"Hdie».-
Eariiw in Ibiff preamble, in secBonE-C
.of this meambfe/we-described that :>.:.'
• ratkarasleforvrhy EPA could aot -
tindsitaka extensivestudiesineech • -
State. . • ' *. x: • : -
InresponteetopteTioiiscomnwnt* -
earfiec in this section, we deecribed
, EPA's legal sormority tbtmdertake this
' prtxnulgatiocsctian including why it is
not necessary for EPA to promulgate
' daidtpoll "
.
(1) EPA has sufficient dat* to indicate
the vrfdojprwkdprCTojxe of tadc .
administi
(2)
atrvBijr, |
Ccnffr»«cleor]rf-nev6xintBnd»dEPAto •
conduct in-depth State analysis, (3) •
EPA,ia its December 1S68 guidance on
irtdtartodarpoBcypoeaibBthat-* * *>
the-pretence- or potentM tMaAimJSvB at
position lhat a raore conaerrative
approach is warranted, end (6) actual
dischargers of such pollutants should
expect to hate control Mmfts placed in
their pectnxta far such poUotanta while
otherdrschargerewainotbearTected. •
• -111. Comment Since EPA published
a range of risk levels in to water quality
criteria documents, itshcmld allow *
range in tMarale or eflow States to ..
select the appropriate nakfeveL • —
' Response:E'A's pnblfcatioa of a
range of risk levels in indrwidual water
criteria docnmerrts was stmpijr
imtsoathe
appropriateness of &e Individual.
criteria groups applied to the State
beneficial use *™A
make to the proposfldiules EPA notes
that the pres^Dbletoibe proposed role
laid oat m0-intent aiiuipurpoees. of this
action extensively. BegirmiBg on page.
58431 of the praesnlAe to the pcoposed
rule, EPA described the 12,rnIss" ,.w; .
• priuijujf autiiority of States'toaJu^iL • • •
waterqiiaTity^fandard&andlQiat Agency
poBcjre21ows Stater to-sdect'an : : .".'.
- 8QjL1ume~ZlAk. lAVflt wHuuX lU0'2A110f Al
6. EPA modified tin*
criteria at the risk-level adopted or
proposed by the State for an or a •'. -:
•ypjiiny^*yy|j toyi^ p^J*uy^^\t TOjUft^T-
applfiaoleStatewBterqaa:^ standards
regulsfions.or in*&ecase of fdsho, -" -
Nevada; andEhode Island, .on an
.expression of State preference. EPA; ' '.
''notes that ina majority of cases, the 10~*
..risk level &1he one adopted by -••<•' _-.'-. -•'::••'•'•••'.•.
errors
•quatic life criteria are indudedfaiftfe
rule. tSee>conegpoaidenosboti>utuitts
State sfid EPA in 1b» record^ Also, •& .
human fcosWii*rttgiitffnrra'r>"Mi|jsiia'
''
polhttautapproBch. (^iu a matter of
tect inrmaniieeKh-
adopted « riA torol .MII] 11 •«^fc»e.
cannot cataAKeor.app)ysjpp« (if • is te-
critaris. jorcarrfnogans. Thechioaic
•that
the Gold Book sod imada note stringent
u
.1
-------
Federal Register / Vol. 57, No, 246 / Tuesday, December 22, 1992 / Rules and Regulations 60897
The seafood processing use (2)(AKii)
was deleted from rule because it is an
industrial use category to which the
criteria promulgated today do not
appropriately apply.
Additionally, in 40 CFR
i31.36(13)(iii), the risk level for
carcinogens was changed to 10~5 to
reflect the State's July 1992, proposal to
amend its water quality standards and
to reflect an indication of State policy
preference received on November 16,
1992. - . . •••."..-...
Hie following changes were made :
with respect to the State of Washington.
After discussion with the State. EPA has
assigned appropriate criteria to use ••.--"
categories rather than to classes. The
rule was revised as follows (see 40 CFR
(22)(i) Fish and Shellfish
. Fish
Water Supply (domestic) ~
Recreation '• "• ' " ' • . •
(22)(ii) Fish and Shellfish; Fish "
BlandBZ— #2.10 '•*'-'• -
Cl— #2.10
;C2— #2,6,10,14
Water supply (domestic) y
'Dl — All • - : •'•••".'.
Recreation . . " *'..',.- •-•'
D2— All marine waters ' : ;~-
D2 — freshwaters not protected .for
domestic water supply ~" ; ' : :
The following changes were made
with respect to the Stataof Idaho. After '
discussion with the State, EPA '
renumbered the use classifications to
reflect the reorganization of the State =
' standards and made the following , .
changes in the criteria assigned (see 40
-CFR131.36(d){18)):
l.b Domestic Water Supplies
Remove cyanide and asbestos
3.a Primary Contact Recreation . ' • - •
Remove Bl— All
Remove B2— All ~
AddDl— All . ,
3.b Secondary Contact Recreation
,-, Remove Bl-rAU
Remove B2— All
Alaska. . -. • . ".' ..; •/ .-
. 113. Comment: EPA has incorrectly .
included CMC (acute) aquatic life
criteria for freshwater and saltwater for
Alaska in the proposed rule ..... •
JResponse: EPA's inclusion of CMC .
aquatic life criteria in the rule is
appropriate. Alaska's water quality
standards state that, "Substances shall
not * * • exceed criteria cited in EPA.
Quality Criteria for Water." Whether or ,
not the State has adopted both acute and
chronic criteria by reference is . • '• :
ambiguous and requires clarification _
through thi« ruleniaking, especially in .
light of language included in the
following three documents issued by the
State:
1. The State's Water Quality
Standards Workbook, published in July
1991, and widely distributed in order to
"understand what water quality.";
standards and criteria are, how to
interpret the Alaska water quality
standards regulation * " *", states that,
••• • • EPA has developed a two-
number criterion for acute and chronic
conditions. The state adopts .only the
chronic criterion."
. In the same state WQS workbook.
Table 1, "Alaska's Water..Quality .:
Criteria for Toxic Substances in ',
Freshwater and Saltwater*', is said to .
"represent the toxic substances criteria
adopted by reference in the AWQS."
- This table does not include any acute
values for the priority toxic pollutants.
'2. An August 30,1991 letter from
John A. Sandor. Commissioner of ADEC,
to Harold Geren, Chief of EPA Region
. iO'c Water Permits and Compliance
Branch, states, "The Department affirms
its decision to continue to use "Gold • .
Book" chronic criteria to establish •
receiving water criteria and effluent
limits in NPDES.permits." (emphasis
added) :. .- . .
114. Comment: Alaska was not
informed of EPA's intention to include
acute criteria in this rulemaking. .
. Response.'On November 4,1991, EPA
Region 10's Water Division Director sent
via fax and hard copy, a letter to ADEC's
•Chief of Water Quality Management,
notifying the State of EPA's intention to
include'acute criteria in this - . . -•>. ,€
Tulemaking. The letter stated, "These "
letters affirm Alaska's use of "Gold
Book" chronic criteria for freshwater
and marine systems and have convinced
us that Alaska is in compliance • « "
with the following exceptions: * * *
Acute aquatic life criteria for all .
pollutants •• • •/'
115. Comment;The statement '
included in the rule that, "Alaska is
included in today's proposal because
.although the State had previously
adopted all section 304(a) criteria by
reference, the St&te Attorney General '
has decided that the adoption by
reference is invalid", ism error and .
should be deleted from the final rule.
Response: EPA concurs that the • .
statement was in error and no such •'
statement is included in this final rule.
• Arkansas " . '
116. Commentr Any promulgation of
human health criteria for the State of
Arkansas should be withdrawn from the
rulemaking because the state-has
adopted such criteria. :
Response: A State's standard must be
reviewed and approved by EPA before
the State can be removed from the rule.
Arkansas formally submitted their water
quality standards containing human
health criteria to EPA on December 17,
1991. EPA's review found that the
human health criteria were supportive
of designated uses and therefore no
human health criteria are promulgated
in this rule. The State's criteria to
protect human health were approved by
EPA on January 24,1992. EPA also
disapproved Arkansas* water quality
standards for failing to adopt the criteria
for priority pollutants to protect aquatic
life .as required by section 303(c)(2)(B).
Necessary aquatic life criteria are •
promulgated today and include the .
following: Cadmium, chromium, i
copper, lead, mercury, nickel, selenium.
silver, zinc, and cyanide. ,- •
117, Comment: Arkansas is not • .'-
required by the Act to adopt numeric
criteria for metals because it has not
been established that the metals listed
"could reasonably be expected to :
•interfere with those designated uses
adopted by the State." • •"•
Response: EPA'* policy:!«that the. •
presence.of any Section 307(a) - '
pollutants raises an issue as whether . •
they could reasonably be expected to " -
interfere with designated uses. The "
presence in ambient waters and the-
discharge of metals is documented in .
several databases, including the Toadc
Release mventory, STORET, end • ~
discharge monitoring reports. The State
could have submitted supporting ' •
documentation that demonstrates that
the presence or .discharge of these
'. metals is not expected to interfere with
designated uses. The State submitted no
such information. In the absence of any
demonstration to the contrary. EPA
must conclude that the metals can
reasonably be expected to interfere with.
designated uses.
118. Comment: The documentation on
which'EPA based its assertion that • -
'designated uses "could reasonably Toe
• expected to be interfered with" should
be provided.under this rulemaking '
process. - , ' : '
, Response; The documentation that
: showed the widespread occurrence of
metals in Arkansas'waters in
concentrations exceeding EPA's
recommended levels was part of the "
record for this rulemaking and was
available for review at the Region 6 •
office as well as at EPA headquarters.
119. Comment: All pertinent data /
developed by EPA under the 304(1)
process should be made available
without special request to ensure its •
availability to potentially affected ..
parties. >- . • • . -
Response: The material developed by
the States with respect to section 304(1)
•\
-------
6O898 "Federal .Register / Vol. 57. No. 246 / Tuesday, December 22. 1992 /Rules and. Regulations
was publicly available at the time the
list vrts compiled. A complete
discussion of the relationship between
the 3M{1) list and today's rule is
included earlier in this section.
Moreover, because EPA did not rely on
tho State's section 3O4(1) materials for
this rulamaking, it was unnecessary to
place such materials in the record.
•California
120. Gcrnmenfi A camrnenter; urged '
.that tho national nzle should clarify that
far*el«cJtim Jess -stringent than 5 pg/l
• vrill be *lkn«»dfa California's San •
Francisco Bay. Commcnlersiuggeeted
that thaNatiooal Rulo should. direct
Region K to darel op sito-tpecific
criteria for selenium in San Fcaticdaco
Bay It w*s further suggested that the
National Rnla should state that the 5
Jig/1 «eJeninm criterion (B2) applies only
to fish and aquatic invertebrates, ntot to
moro s*nsiiiv* uses such as wildlife.
The BJHrativestanc*ards should govern .
for the more sensitive use*. •
EPA's freshwater criteria for selenium of
aCCCof5^g/1^4dayav«rage)anda *
CMC of 20 (jg/lU hour average) for San .
Francisco Bay and Delia-lnEPA's • .
No veeober 6,1S91 approval letter on .
California's Enclosed Bays and Estuaries
Plan. EPA approved California's
decision to allow regional water quality
control boards (RegkmalBoards) to
determine where in an estuary it is
appropriate to apply freshwater or-
saTtwat&r criteria. Although most . .
Regional Boards Lave not yet specified
th* appropriate standard, EPA generally
agrees with, this process. However, the
EPA standards approval letter
•pacifically found that utilization of the
saltwater criteria'Jor talanhim in the.,
San Fran dsco Bay/Delta would be ' .
inappropriate. This fining is based on.
substantial scientific evidence that there
are high lavals of selanhun
vblocccannnk!ionin San Francisco Bay
,udthdsaltwatsrcrii8Tia£aU&to ' '
account for food rfi'atn effects.:. •-. .
Accordingly, in the absence of Regional
Board action, consistent with EPA's
approval lettaxvEPA Hpromulgating the
fetthwidnr criteria for KaWxhiny frq- fog
for selaniuminiraalrwster am derived '•
from laboratory and field data on. the
vertebf*l£a,inv«rtebrate«aad plants and
shouldbo protective of aqoatic • . .
organisms tinder moct conditions. The •
criiaria were &o(.^«v«krp«d
with the intent to ad dress protection of
wildlife such as waterfowl. EPA isin. -.
th« process of developing wildliia-
criteria for *f3/irrtnm. Recent studies and ' todayVpiomulgation will not apply to
analyses have'enhanced our
understanding of avion exposure to
selenium in the field and nave clarified
the importance of food chain
biomagnification and low level toxic
effects on avion reproduction. Such. •
information is, for the most part, new
information available after the Water
Quality Criteria for Selenium was
published in 1987. EPA supports the
efforts of the State to develop selenium
criteria based upon food chain
biomagnification. However, ia the
absence of A final wildlife criteria "
document, or other sufficient
information, EPA 1« unable to
promulgate a criterion-mole stringent
than 5 pg/1 as part of this ruhmaking.
The purpose of this rote is to establish
Federal criteria for all .waters that cto not
have EPA-approved state criteria. R is
not appropriate to use this Federal rule
^c a ^^^^j^nyitKTff yjnr QxEBCQnjt
promulgation enuris era region. • * . ~-
Further, EPA'sTegiilations, guidance .
documents, and the Preamble to the
Federal rule dearly specify the steps to
be taken wnen a i>tate wishes' to adopt
site specific criteria. EPAbeKsvestnat
it is aueady dBarthat both thenumeric
and the narrative standards apply in aH
cases. This information is contained in
EPA's guidance documents and does
need nothe reiterated in this . '
rulemaldng. .' • ' ; •
121. "Comment: EPA should
promulgate freshwater selenium criteria
in California for the Snrrainn^to-^"
Joaquin Delta, Jhe inland surface waters
•including the San Joaouinlliver, and >^|°
Central Valley Wildlife re&iges. .-
Response: The ^T«ft ruTnnmVing •
proposed the national selenium criteria
for all water bodies in California and
included those listed above. On
November 6,1891. EPA approved
California's Inland Surface Waters Plan
which adopted EPA's selenium criteria
for freshwater bodies with the exception
of Salt Slaugh, Mud SJpugh. and the
upper San Joaquin River. EPA approved '
the State's selanium criteria.but did not
approve these n^p. itmt site Specific f^itati* be
developed where physical or chemical
•characteristics of the site alter the
biological availability of the chemical or
where species at the site are more or less
sensitive than those species used in the
development of national criteria. Please
See Science and TmptnmtmtnHn^ nnitar
general comments. •.
123. "Continent! A
indicated that Region DC has placed
impediments on me adoption of site-
specific critmiawhiii make future
adoption of site-apecafic criteria an -
unrealistic alternative. • • • '.
Response: There i« no indication what
"impediments" the ixmmenter refers to.
or the action by wbl<=b Region 9
allegedly created sutdi impediments. "
Please see Implementation under .,
general comments aliout requirements.
for site-specific criteria. .
124." Comment: ff A also received
comment* that the proposed rule-would
establish tnappfepriirte and technically '
unsupported criteria for copper, sickei,
lead, and mercury for South San
Francisco Bay.
£Tbe final]
I ml* has been
amencWd toieflect EPA** November 6,
1991 action on CaMarnla1* Enclosed
Bays and Estuaries Flan and does not
fiodude criteria for copper, nickel,
mercury or lead lor -San FnodecpBayt
approadi directing vtgfonal boards to
two s«ts of criteria-
-------
Federal Register / Vol. 57, No. 246 /Tuesday, December 22, 1992 / "Rules and Regulations: 6O899
(freshwater or saltwater) in en -estuary.
California's saltwater and freshwater
criteria are approved by EPA. At this
point, EPA does not have sufficient
information to conclude that this
approach of allowing Regional Boards to
choose between the two sets of criteria
is inappropriate for copper, nickel, lead.
and mercury in the South Bay. ' ;'
Therefore, criteria for these metals are
Tin* iriHpHnf^n tfiia final/nita
125. (Jnmmextt: Sovtml comment Bit ,
• questioned 4he appropriateness of
water bodies such as ephemeral streams,
constructed agricultural drains, effluent-'
dominated streams, irrigation-flow .
ponds. • • , '
JfesponxerThe criteria contained in
this rule apply to all "waters of the
United States"** denned in the Clean
Water Actaad implementing "
regulations except -where State-adopted/
EPA-*pproved criteria apply, Waters of
the l^S. may include human*
constructed water bodies. Waters of the
Undoes not include waters that fall
. under EPA'* waste treatment system
exsmption. California deferred adopting
water quality «taadards forcartain .
effluent-dominated streams and
. f rrignHnm.flmg riominnf oH Streams. This
deferral was disapproved fay EPA in its
letter dated November 6, 1991 on die
basis that It did not protect 1he -water
y
ejected to interfere with designated -
.uses. EPA Region DC agrees with -••
California that site specific criteria
.would be appropriate for many waters
'in -these categories. If California adopts
aiid EPA approves site-specific criteria
that protect the designated uses, criteria
iorthosewaterawiUneiemavedfiom :'
thic finalrule, •
. 12B. Comment: Several commentors-
found it impossible to comment on the
proposed rnle in the short comment - •
period provided. Specifically,
coramenJennpted that the thirty-day
'coonmant period is •unreasonable and
unfair for HaHfomin given Region DC*
• dekjin acting on California's own
'
California at this time, especially in
lightof RcgionlKfe November fi, iflfll
"
and doesziotrnquin standards to be
proposed for die entire nation at once.
California could be separated from other
states in order to allow reasonable time
to evaluate both octions.
Response: On November 6.1991.
Region IX disapproved California's
Allure to adopt numerical criteria for all
307(a) pollutants for ell "waters of the •••
U.S." in California. According to EPA's
water quality standards regulations {40
CFR part 131). the State has a 90-day
opportunity to correct any deficiencies
end EPA may-then approve adequate'
corrections. If theState doesnotadopt:
the necessary corrections (or additions)
widiin that period, then EPA must
"promptly" propose and promulgate
federal standards in place ofthose '
deficient State standards. are it to .the '
propped FadflnJruie. Also, please seo
'.jy^B^HTj I -JjfjMBfiBunTB BPQ*3ff A.U11U11E BTITi * * .
Process. .;••"• -. • ' , -..- . / "
waters with any aquatic Hie desfgnari
mustmet hmnanlbnkh criteria. A
commenter indicated that assigning
consumption for any aquatic tife
segment is equivalent to Federal
promulgation of new designated
and shooldnothedoneaithis
•dean Water Acteontains no specific-
deadline fot EPA to propose standards
heelthtisesahataretobeprotsctedin *
a particular waterbody. EPA has -no -•"-'
g Andgnntnri nitot in
" '
Asstatedintiie
level criteria as-opposed to MCLs for
: protection of drinking vrater. - •'•-.,
fiesponce: California does not have
any water bodies where drinking^rator
is the «ole exposure pathway. Therefore.
MCLs may notbecufficient to protect
human health ftom exposure to toxics
from combined drinldcg \rater end fish
concamption pathways. See •ecttonF-
5 for a moredetafled discussion of risk
levels included 4n this role. • ' •- ;•••-
•132. GoramentrTheoommentarls
concerned that State scbedules of
'•' complMnce will not apply to Federal
criteria. ' ' ' '
-------
60900 Federal Register / Vol. 57. No. 246 / Tuesday, December 22, 1992 7 Rules and Regulations .
Response: Federal criteria will be
implemented in accordance with
existing state adopted compliance
schedules. For a detailed discussion of .
this subject see a response to comment, '
.in subsection 4 of this section.
133. Comment: A commenter asserted
that EPA did not do enough to educate ,
the State early on of the 303(c}(2)(B) • •
requirements end that EPA's final
303(c}(2)(B] guidance was not . .
transmitted to the States until December
12,1988, almost two years after the •
1987 amendments. This delay left •'
California with inadequate time to adopt
criteria on a pollutant-by-pollutant and
water body-specific basis, and consider
the scientific uncertainties relating to
the Federal data and methodologies!
Response: As stated in the Preamble
to the proposed rule, the December,
198? guidance was not substantially .
different from earlier drafts wKich were
available for review by the stales. That
guidance proposed a pollutant-by ".',
pollutant ana waterbody specific • -' .
approach as an acceptable option."While
recommending certain approaches, the •
guidance also made it hleir that States
retained flexibility to implement their. -
ownpreferred'approaches. Please see"
* SdenraandTuning^andProcessiinder
..generalcomments!- ."_"•'.. " '.'
134. Comment: One commenter stated
1hat Region K's requirement that- .
California adopt criteria for all priority
pollutants is erroneously based on
statements in Califomik's'Functional'
Equivalent Documents and is '
Inconsistent with' national guidance. •
Another commenter stated that this
requirement was unfounded.
Response; Region DC has.consistently •
advised California that it must adopt
criteria for all pollutants for which EPA .
has section 304(a) criteria .-••••
recommendations, with the.exception of
any pollutants whichcannot reasonably
be expected to interfere with designated
uses. Omission of any such pollutant"'-"
must be based on evidence concerning
the presence and effect of that pollutant
in any given waterbody.-This policy is •
consistBnt with national guidance, the •
history of which is set forth in Part B2\
of the Preamble of November 19.1991.
None of the guidance options has ever
allowed tha exclusion of my such •: <•
pollutant from the-requirements of
section 303(c){2)(B) without a factual
scientific basis. In the absence ofsuch -
scientific basis, EPA relied on
California's draft Functional Equivalent
Document which stated that "it is likely
that priority pollutants not covered in,.
this plan will be found [in the State] in
a more extensive analytical survey." _
This statement is sufficient basis for
EPA to have determined that all priority
pollutants would reasonably be
expected to interfere with designated .
uses in all waters of the State.
135. Comment: The Federal criteria
' are more stringent then necessary for
some water bodies in California.
.Response: Without specific
information about which pollutants and
which water bodies the commenter is
referencing. EPA has difficulty
responding to this comment In the
absence of such specific information, -
EPA determined that it was appropriate
'to adopt EPA's section 304(e) criteria for
all "waters of the U.S." that lack State-
adopted, EPA-approved criteria. If, ". ;
based on further scientific information,
the State adopts site-specific criteria '
which are less stringent than the Federal
criteria but, in EPA's Judgment, fully
. meet the requirements of the Act, EPA
will undertake a rulemaking to remove
the affected pollutants from the Federal
rule. For additional information, please
'-see Science under general comments.
. 1.36. Comment: Major wastewater
•dischargers in California have filed a
petition in State court to restrain the
State from utilizing its section • , ' .
303(c)(2)(B) standards for inland waters,
bays, and estuarios. They filed the
petition out of concern over significant
economic impacts caused by blanket -
•imposition of the (EPA) criteria. The '
riling of the petition illustrates the v- '
concerns of many public agencies over ,
• use of EPA criteria as national'- - ••
. standards. • -• . •' - •'•••-'
Response: The petition referred to in
• this comment is a challenge to section .
S04(a) criteria which have been adopted
by the State, ft is a pending proceeding
in State court and does not affect today's
rulemaking. The commenter states that
this matter reflects a widespread
concern over adoption of section 304(a)
•criteria as national standards. That
concern is apparent in the comments
received from several entities,
-particularly in California, and they are •
• addressed in the Economics under
general comrnents. ' , •
137. Comment: A commenter stated
that "only marine criteria should be
'selected lor enclosed bays in California
since these are. by definition, -
indentations along the 'coast which
enclose an area of oceanic water. It is .
not appropriate to apply freshwater
criteria to these water bodies." The
commenter also indicated that States
should be given the discretion to
determine when freshwater or salt water
criteria should apply in an estuary.
: .Response: State standards in. . • .
California's Inland Surface-Waters and
Enclosed Bays and Estuaries Plans have *
•been approved for most of the priority
toxic pollutants. These standards
include both freshwater and saltwater
uses and leave the selection of •
appropriate criteria to the regional
boards. EPA approved the two sets of
criteria on November 6,1991. The • .
Federal rule has been amended to reflect
this approval. The final Federal rule
applies to those parameters and also to
water bodies where State standards are
lacking or not protective. The regional
boards shall determine for both State
and Federal criteria whether freshwater
or saltwater criteria are appropriate at
the confluence of the water^bodies with
.different waterquality objectives.-—
District of Columbia ... .
•'133; Comment: irhe adequacy pfnew.
human health criteria has not been- ••
proven to be germane to the District of .
Columbia, • . • • r-
Response: As a. general proposition,
EPA is applying criteria for all priority
toxic pollutants not addressed by • •
approved State criteria for those States
not in full compliance with-section ;
303(c) of CWA. EPA's reasoning behind
this approach (and! the exceptions) are
discussed fully in the preamble. .:. ••
However, two reasons deserve repeating
.here. First, existing data sources .•
• indicate the discharge, potential •"
• discharge or presence of substantial •
numbers of priority toxic pollutants in
most States. With ithe failure of some
States to adopt toxic criteria'in a timely
•fashion, coupled with the evidence of
the discharge or potential presence of .
priority toxic pollutants far which the
State has failed to adopt criteria, the .
Agency believes there is a need for
numeric criteria for most priority toxic
pollutants in most States. Second, the
support of each criterion on a state-by-
state and waterbody-by-waterbody basis
by EPA' would be on enormous -
administrative burden on EPA and .
would be contrary to the statutory •.
scheme and Congressional directive for
swift action. Congress directed EPA to
accomplish the promulgation within 90
days and EPA has made every effort to'
expedite this rulemaking. Providing the
adequacy for all criteria for all States
would take yean imd would be counter
. to the directive of swift action.
Florida ..-•.-'•..
. 139. Comment: One commenter stated
that, since the State of Florida adopted
numeric criteria on December f, 1990 .
based on Option II of EPA's section .
303(c)(2KB) guidance, the Federal rule
should not includ a criteria for all
priority toxicjpolliiitants. >
Response: Since the time that the
proposed rulemaking was published;
Florida formally requested EPA's review
•of the criteria adopted by the State on
-------
Federal .Register./ VoL 57, No. 246 / Ifresday, Jtecpmber 22, 1992 / Rules and Regulations 6O901
December 7,1990. EPA approved these
criteria, with the exception of the
absence of criteria fat 2.3.7,8 TCDD (La,
dioodnjoa February 25.1992. Therefore.
EPA has only included criteria for
2.3.7.8TCDD for the State ofFJoridain
' t^ft fitml gy|prffl»1di»p.
Kentucky
140* CLUI uj icnfr.^tao romniiffMlfT stated
that Kentucky lias proposed and
adopted aTerisran to 401KAR 5:031
which deletes the previously adopted
numeric iinmannealtli criteria for
dloxin. ATeguBstwasmadeny the '
commanter aianSPAi detomiiiatioii of
fuU compliance for Kentucky forlhe;
section 3O3(cd(2)CB) requirement be
txraddeced and a Federal water quality
rrljnAi tf'pTT'rraiTgatfftl through *hfo .
.Federal i^inaklng. Alternatively, a
request was inadethMsuch criteria be
- established as an Interim Snal rule in .a
" '
. e EPA published
thq propOBedzulemakiag. the State- .
adopted criteria for 2^,7 A itODJor
the State of JKentuckjr was in effect-as
..part of 4dlxA&&031{Su£bce water ~
standards). EPA is aware thaUfae .
criteria was. put into a£fect on iamary -;.
29, 1992. EPA^« pomtkni tmlCentacky*j
propaaed deletion «f &B Sats-adopted
dioxin criteria wras transmitted to . •*
Kentadyty lattardatDdK
1991. In that letter, EPA's Region IV
Water ManageEBeot Division Director
stated, rsbouldtlM State complete
. adoption of die propoaed amendment .
without raplacingtbeadopted-dioxin
critaiia wun approraWe criteria vataas,
IwiUreconmieiMitothe'Regkmal
Ad^mnistr«tor' . .••-.-•. •••.'••"• . '-.-.
142. Comment: A Nevada commenter
suggested that Column Dltaiteria .
ahould apply only at the point of intake
of any municipal or domesticsupply. .
J?efiponse:OolunmDlcriteria'areto
apply to all-waters designated by the
State of Nevada for municipal of
domestic supply. In tin case of Lake
- Mead.that is€n«ntin1aka«xceptfar
the segment at the end of Las Vegas Bay
recognizing ihat Las Vegas Wash raters
there. All of LakeMeadig anojectto
p^yifljpl^ ^^fjByrm^Tijmh "Bra^M|py CSQXQX . *'
directly fromthelake or downKtream.
' 143. Cojumianf.'ft WMitiftea'lbJBtthB •
State of Nevada/has already cousldured
and rejected criteria similar to Ihe '•• /
proposed amendments, and Nevada's •.
decision is Hot contrary to the- .;.•'• •
requirements «fthet2ean Water Act •
. Response: The State excluded criteria
: similar to those in the proposed ~~ .-.••-::
" ' •- • ttarnualuy
odaredl
Ilbr
^Jha Nevada State . .
. atal Commission (SEC^llie
State did aotjirbvida an adequate " •.
justification for this exclusion: " " •
^pppfflf^,•fift Jjtmmro ^fi| 10^t|^.|3*/\ V' ••
disapprovedihis portionoftheSEC • -t
action** being inconsistent with*ection
303{cX2»3J. WithoTrt aubstantrre '.
jticHfir^tt^tTi'^gnr^i *m mnAanrsnTflmr^r pf
pres«nc»oiparticularpolhrlantsin . -/•,
waters of the State) £&• exdudingany of
the priftitij pr>lhr>imf« fzomState ' • • .
standards.anoflhBminmtfaeadded.
144. Comment: A. Nevada commanter
stated that Lax Vegas Wash shouM be
^y^?I^tufted »POP^*4ff?y"PT^Ptfln'nfiflMn • ~* * * *,
PfOtft(7iifOn ytM* OTfflffWmP"^?^ Ol'ftQUfiuC
or^aoixms under the Federal xule. •-
Respooe: Hie general issue of the
of the existing aquatic life use and'the ,
potential for consumption of aquatic
-vbrganisma.'EPA nas applied cS)lumnD2,2/
criteria to Las Vegas Wash. .'. '"
: €45. Comment- A^evaa^cornmenter^
stated that the propoeed rule does not
. provide sufficient notice-as to why
certain, criteria ware included and
others excluded from the proposed
rulaoaaldog for Nevada. / • : •
Aespons«:'aa&
designed bfiheStafta for tfaense of
••••«M» ^aaa >•*•• *.^** *••** •
administrative record associated witii" ,
• Novada^s adopllou vf numeilc ^lAiidardc
for toxics ^n May 1990 and EPA's
approval/disapproval tni jgB&nary IQ«
1991 and was available to-the public
rule, find during &a public comment
period far fee piopoeodTule. ' . ' , • '- .
tjowjeraey •-.•..v-'., ,«-;•'.•'•>' . '" '•'.
•• :'...- . . -« • ,.. .'.• ., . ;. . . .» . "
, 14&. ffafament • fj-mmmemfttr HrgUBS
•'that N«wr Jersty is in compliance wflh
' section 303tc}[2)(B) of theQaan Water
aaction304(a)
their Water C^iaDty Standards.
Regulation fiar actions involvinge .
development of water'qualityiased
' '
flespohse: While ihe State Water :
Quality Stendards'RBBnlntinri does
inooipuute-secHon ao*(a) criteria fay
reiBEenca,1heatandardsniT*^f*> nfpmiami
actions c&volviDg the devol
sourbas-wni
•iMuedcootrois Jar point
must serve as thnfaastslpr-taontnih 1
all »ouioe«,
,.
that water
.
urlUula vt
.
'in'flm immrn iHHtlon for Dew
ten classified asTL
_
•neodotalinfonoation '
that no '
aquatic life in las^egas Wash- Ceo
: as mainstaa Dela
and :
included Jsilhis final twle.
-------
60902 Federal Register-/ Vol. 57; No.': 246'7 Tuesday, December 22. 1992 / Rules and -Regulations
__ PuertoRico - ' ••" ' '
148. Comment: A commenter stated^ "
that EPA's proposed mla presents' '
serious problems regarding its ' ' .
implementation, specifically in
* determining the waters to which such
criteria would be applicable in the
Commonwealth of Puerto Rico.. .
Response: The Puerto Rico' Water
Quality Standards Regulations is dear .
regarding the designated uses of all
waters of the Commonwealth of. Puerto
Rico. EPA is Assigning necessary and ..
•ppropriate.crlteria' to support those ; . .
UMTS in. order to satisfy .the requirements;
of section 303(c){2)(B) of th'e'Clean .'... ••_"
. Water Act ' ... : .... -I,". r-
•149. Comment: A commenter stated .
that the Puerto Rico W.ater Quality . , - . . ,.
• Standards Regulation, which establishes
the classifications and designated uses."
does not comply with the Federal Water
. Quality Standards Regulation in terms .
* of the adoption of subcategoriesof uses...
;tha need to conduct use 'attainability •
analyses when'standards are eiceeded.'.-
. the adoption of a variety of uses fora' . ,
single waterbody, and in considering- '•
the social and economic needs of the* •'; '
Commonwealth. ••• -,•,•., '•,' ••' • . -. !.'.
% J=le*pon«: While the Federal Water •?".
Quality Standards Regulation authorizes
I the adoption of subcategories of uses, ,
* States are not required to adopt ..-
'' subcateories of uses in.the . .
attained. While the Puerto Rico Water
Quality Standards Regulation defines,
Class SD waters as surface waters
intended for use as a raw water source
for public water supply and the
preservation and propagation of
desirable species, not all Class SD
' waters presently meet these goals.
Designated uses need not be existing .
.uses. Consolidation of various uses (Le.,
fishing and svrimming) into one
classification is an acceptable approach
for designating uses of waterbodies, .and
a necessary one in order to meet the goal
of the dean Water Act Federal .
regulations require that waters have
designated uses .that provide for
fishableVswimmable water quality
where attainable. When establishing
criteria to protect these various . ..
designated uses, criteria may be '•
specified to protect each use.
Washington *•-•
.
notrequlred to complete use
attainability analyses (UAAs) when , ; . -
designated uses .are not met Section •--'
131.10Q) of jhe water quality standards •
regulation requires that States must
complete UAAs -when removing
designated uses that are not existing • •:• •
uses, or when specifying .uses. - - •-•-.
Inconsistent with the goals "of the Glean
Water Act States may not remove .-•:*•
designated uses if they are existing uses.
m the establishment of water quality? • •
standards and water body >.'—.•* *. •
classifications, including requisite -' • '
public participation, Puerto Rico has , . • .
taken social and economic needs.of the
Commonwealth into, consideration, as • .
well as the inherent differences in levels .
-of protection and water quality required
by the various designated uses. ...
Notwithstanding this discussion, the '• •
rule only addresses appropriate criteria
lor priority toxic pollutants". Other .-•" •
elements of State water quality '"'_•''•'
standard* are not addressed. . • .*' -
150. Coznnieni: It was commented that'
the Puerto Rico Water Quality Standards
Reguktibn does not recognize thewes
of waterbodies that are actually attained.
.Response; Designated uses of. . •<'
waterbodies arenot required Jo only - -.
reflect those uses that are actually -'- •
supplies" should be deleted from the
Class AA listingJn (22)(i) becauselt is
incorrect '" ' . \.—. •.
• .Response: EPA.concurs, it was a .
misprint"" '•"-•'" •-'"'••
152.rCoinmenf: Comments were
received that EPA should not "* ' "'
promulgate criteria for ilibxin in the
State of Washington,' The commenters .•
expressed concerns that EPA's actions
would be-disruptive and unnecessarily -
interfere with ongoing State •' " '
administrative and Judicial actions
involving Department of Ecology's
dedsions-in establishing effluent
limitations in permits issued to'- -.-
numerous pulp and paper mills. The • •
Department of Ecology had established
the permit effluent limitations based on
the State's existing narrative-water* •
quality criterion. The commenters urged
EPA to defer action pending the
conclusion of the ongoing State actions
challenging the State's authority to
establish permit limitations based on its.
narrative criterion. In addition -* •-•
commenters said that the current State ;
regulations met the requirements of •
section 303(c)(2)(B) and that the State's
regulations were equivalent to another
State's water quality standards that an
EPA region had approved as being in
- compliance with section 303(c)(2)(B).
-J?esponse.-EPA carefully considerec
. the comments on this issue and has •
decided to exercise its discretionary
authority under section 303(c)(4)(B) to.
promulgate human health criteria for '
dioxin and the other-toxic pollutants.to
be applicable towaten in the State of
-Washington. This action will ensure •
that* there are numeric water quality "*
criteria applicable in the State as
required by section 303(c)(2)(B).
EPA's review of the current
Washington water quality standards for
...toxic pollutants indicates that those
standards do not include the necessary
water quality criteria to satisfy'the
requirements of section 303(cM2)(B). -
While WAC 173-20V-047(1) includes
numeric aquatic life criteria.-protection
of human'health in only addressed
through a narrative criterion that
provides that toxic substances not be
introduced at levels which "adversely
affect public health, as determined by
the department* * V WAG 173-201-
047(4). EPA bellwres that this limited .
narrative criterion, does not satisfy the
requirements of section 303(cM2MB).
EPA acknowledges that the . .:
Department of Ecology relied upon its .
narrative criterion to establish effluent
limitations for dicodn in State NPDES '
permits. EPA supported the • ;*
. Department's reliance in its narrative
criterion in developing necessary -.-
effluent limitations for the control of'
discharge of dioxin. EPA encourages all
States to have narrative criteria for *-. 4.
protection ofaquatic life, wildlife and '
human health in instances whan the '-" *
State does not hairo an applicable •-* --:
numeric criterion. However, section •>'•
303(c)(2)(B) is clear in its directive that
States adopt numeric criteria for toxic -
pollutants if EPA has issued section - ;;
'"presence of such pollutants .could-. •-
reasonably be expected to interfere with
. designated uses in the State.
In the notice of proposed rutemnVing.
EPA discussed th.e basis for its decision
to include Washington in the rule. 56
FR-at 58477, The absence of any ...
• numeric-criteria for human -health and
the acknowledged discharge and
presence of toxic pollutants being -.
expected to interifere with designated
used supported inclusion of Washington
in therule. With respect to dioxin, the
issuance of permits with discharge
• limitations was further evidence that the
discharge or presence of dioxin could
reasonably be expected .to interfere with.
designated basis. .
•.. . EPA does not believe that .: *
promulgation of mumeric criteria for the
State of Washington should be delayed
-pending resolution of the ongoing • •
utigation challenging the Department of
Ecology's authority to establish effluent
• limitations based on the State's. •
- narrative criterion. The State's narrative'
criterion, while it may be the basis for *
• deriving effluent limitations,is not
adequate to satisfy the requirements of
Section 303(c)(2]l(B). Some commenters
. argued that Wasliington had in effect
incorporated by reference EPA's Section
304(a) waterquality.criteria guidance as
the basis for interpreting and ; '. ••.•
-------
Federal Register / Vol. 57. No. 246 / Tuesday, December 22, 1992 / Rules and Regulations 60903
faipiemenung the State's narrative .
'" criterion. The "Washington water quality
standards, however, merely provide that
for toxic substances not listed in the
standards, concentrations shall be
determined "in consideration of
USEPA's Quality Criteria for Water.
. 1986, and as revised, and other relevant
information.":WAC 173-201-047(3).
The State standards neither require use
of EPA's criteria nor limit the State's
decision to use of such criteria, •
Therefore, even a decision by the
Washington .Supreme Court that the
Department of Ecology is authorized to
use its narrative criterion to develop . .
permit (affluent limitations would not ,
'address the specific requirement of
section 303(c](2)(B) that the State adopt
numeric criteria. ./ ,
. ". -In response to the T*V" !"*"*« *n»t the
current Washington regulations are
equivalent to regulations adopted by the
. Commonwealth of Massachusetts which
• is not included in today's rulemaking,.
. EPA believes.thereis a important ;..-.;
differenc&between the two State .
regulations. The Massachusetts '. . ...
reguktions provide that in deriving
• criteria fortmlisted pollutants, the State
. "shall Jise the recommended limit -• •
. published by EPA pursuant to section
-. 304(a) *;" V'lCode of Massachusetts
Reguktions, Title 314. section . .
. 4.05(5)(e). Pursuant to an v ; *
Implementation Policy adopted on ' •
February 23.1990,'Massachusetts stated
that it would use a risk management ....
goal of iCT6 for individual chemicals -
..and 10~3 .for mixtures of chemicals in
deriving criteria for carcinogens. The ..
. regulations contain a specificity -
• regarding what the applicable criteria
will be that is not present in the •
Washington regulations, EPA's Region I
determined that the Massachusetts -
regulations complied with section...
303(c)(2)(B) and approved those
regulations on December 20.1990. See
56 FR 58452. . ..: .'-,:.. "-••'. .
EPA's, decision to promulgate . ...
appropriate human health criteria for
• thft StntA nf Wonhingffin JfCPniriMftnt •
with the Agency's prior statements •_,.'.
regarding the status of Washington's .
-.compliance with Section 303(cK2)(B). In
the Federal Register notice of April 17..
4 1990,:EPA identified Washington as not :
being in compliance1 with section
~303(c)(2)(B). 55 FR U350. By fetter
dated March 27.1990. from the ' . '".-. . '
. Department of Ecology, to EPA, the ..•;''. •>
Department listed the adoption of '•':
. human health criteria as an. action for its
triennial review, that had been requested
by EPA. By letter dated March-21.1991.
from EPA to the Department of Ecology,
EPA explained that the State would .
; remain in noncompliance under section'
303(c)(2}(B) lor human health criteria
even if the State proceeded to adopt.
aquatic life criteria and a human health
risk level. These documents are in the .
record of this rulemaking. . ...
Executive Order 12291
1. Introduction and Rationale for
Estimating Costs . .
Executive Order12291 requires EPA
to prepare a Regulatory Impact Analysis
for major regulations, which are defined'
by certain levels of costs or impacts. For
example, the Executive Order specifies
that a regulation imposing an annual.
cost to the economy of $100 million or
more is considered major.' According to,
the Executive Order, the Regulatory •
Impact Analysis should contain .",.•.-•'..
descriptions of both potential costs'and
benefits. Whilelhe Executive Order ""•
-calls for an estimate of costs, the Statute
mandating today's rule does not allow '
cost to be a consideration in setting ~,7,
.water quality criteria. The following,-.
discussion describes the Agency's'".. ;^fr
consideration of costs u\ the nilemaHng
and decision process even though cost •. .'-
considerations are not included in the
development of num'eriacriteria fore;
toxic pollutants, " ."^ " " " -."; ? "V
In developing the proposed rule, EPA
. considered .various perspectives. - /•
regarding the potential incremental ~~
costs that might be incurred-as a result..':
of the Agency promulgating numeric ;^f
criteria for.todividual States.the :;''. -;~'
Agency concluded that the costs ''.".",..
incurred by individual dischargers as a
result of complying with water quah*ty- "
based permits might be large enough to...
designate the rule as "major,".acconling"
to the definitions included in Executive
Order 12291. The Agency did not - '•"'
include a quantitative estimate of the
costs due'to the. uncertainties of such an
estimate, but instead, described the -
are certain characteristics of the
rule that make the estimation of costs ".
particularly complicated and.difficulL..-.'
Since the rule imposes requirements •
only until the State .submits, and EPA.
approves, the State's own numeric ' •
standards, the cost estimates should be
calculated on a per State and per /
.pollutant basis, so .that State/pollutant
combinations nan be removed as ..,' .
numeric standards, ore approved. .-.-. .. •
Additionally, an analysis of the . •'•'- •.
incremental costs attributed to the rule ..
should reflect information on specific
impaired stream segments and the.-;\ .•:.-.
dischargers on those segments, •-,•-"
Because a detailed analysis of all '-',
affected stream segments is not practical
given the available resources, .die .' -. • '
development of compliance cost
estimates for this rule would require
numerous assumptions, about pollutant
loadings, impacts of technology-based
regulations on loadings, combinations of
pollutants handled by a given treatment
approach, and the costs of each '•
' treatment train. The many sources of
uncertainty associated with estimating .
the costs would produce an estimate .
with limited value for evaluating the
• merits of the rule. In addition, the rule '
does not remove the responsibility of
States to adopt numeric criteria for toxic
pollutants. As the remaining States'
submit their own standards and EPA
approves those standards, the costs
attributed to the rule will decline. T .
Hence. EPA. with the concurrence of ..
OMB, proceeded with this proposed ...
rulemaking without a quantitative '
estimate of compliance costk * -. '
2. Overview of Projected Costs
EPA acknowledges that there will be
a cost to4ome dischargers .for complying
.with new water quality standards as. ••..
those standardkare translated into • •. -
specific NPDES permit limits.' Tie "
addition of Federally promulgated ...
criteria for toxic pollutants could affect
the wastelbad allocations developed for
. each, waterbody segment in affected
States to the extent the pollutant is . -
discharged intoihe stream. Revised •"'.
-wasteload allocations may .result in -
adjustments to individual rjIPDES '•,
permit limits for point source ::\.. ''
dischargers, and these adjustments '-•
could result in increased wastewater •
treatment costs or other, pollution , :• .,.
control activities such as recycUhg or ..
s. The magnitude of.'
ose costs depends on the types of
treatment or other pollution control, the
• number and type of pollutants being
treated, and the level of control that can
.be achieved by technology-based •. ^..
effluent umlts for each industry. ;..:.'
• Similar-sources of costs and the
variables affecting costs may also apply
to indirect industrial dischargers .to the
extent that the industrial discharger is a
.source of toxic pollutants discharged by
the POTW; The POTW may incur costs
'for expansion, operational changes, •..
additional treatment, modified .. v '
• pretreatment programs, and increased
operator trairung. - . .; ., . .
; Nonpoint sources of toxic pollutants
may also incur increased costs to the
extent that best management practices
need to be modified or applied to more
sources to refiect the revised water .
Huality standards. Although .there is no
Federal permit program fotnonpoint '
sources comparable.to that for.point,
.sources, there are State regulatory •
programs to control nonpoint source
-------
-609O4 -^Federal Register / Vol.' 57', No" 246 / Tuesday, December 22, 1992 / Rules an
Monltoring-programs are another
• source of potential incremental costs to
dischargers and States. Monitoring
- programs to generate information on the
existing quality of water and the types
' .and amount of pollutants being.
discharged are potentially affected by
th* imposition of EPA criteria. The
addition of Federal criteria for toxic
pollutants does not require the State to
engage in a program to monitor ambient
waters for such pollutants. Unless there*
is som* reasonable expectation that the
pollutants are manufactured or actually
used In the State with theHkelihood • .
that thoeo pollutants will be discharged
into surface waters, NFDOES permittees '
also would not have to monitor for these
pollutants. »>.«».
analyzing the impacts of this nde. •
however, a meaningful cost estimate
would be extremely difficult and costly.
and it is uncertain whether an RIA •-'
would lend reliable information to the
decision-making process. • •
4. Scope of Cost Impacts
Since this rule directly affects only
those States that have not adopted their
own-numeric criteria for toxic
pollutants, the cost impa^? jjg l'r"ttnd
•fo dischargers in those States. Hie cost
.ImpacU are further limited by several
other factors. First. lT*n roti'
of the rule is limited to traating^.- ^_..
discharges of only those pollutants .'.
jnrlnflnH e Clean . '
Water Act— may bo sufficient to.proTide '
. compliance With water quality criteria. • :.
In other cases, controls implemented to *
meet whole «flluenttdxicit/permit •."*
requirements may prechideihe need to
implement additional cbntrblsto reduce
•« tmdcpolhrtant discharge covered by
the rule." • • •'••' '•' •'•*'' ••'v;'i':.- ••• ;.',---«5..'..- -*"•<-
An •etimate of the number of point '•
sources that could be aXfoctediiegins -'--•
=with the major dischargers fiom-uw 14 ;' ,
States included in to«lav*8 rule'* The
focus on major dischargers (where the
term "major" refers to .the distinction
used in the NPDES program for-fedlities
with the potential for a significant '
impact on water quality) is consistent
wim.the rulemaldng'A focus on toxic ,
pollutants. Any poinlt source with a '
significant discharge of toxic pollutants
isnkely to be included in this category.
The number of major-facilities for the
18 States is 2.055. (See Footnote*.) This
is a subset of the approximately 7,000'
major dischargers in (Sie entire country
(3.OOO industrial, 4,0(30 municipal). Of
these, 22&facilities already have - •'-''
Individual Control Strategies (ICS) Oat
Were established in msponse to section'
3040) of the Clean Water Act These ' "
fMdUtieshaveefflueiitlinritation»«i»f'
' toxic pollutants sufficient: to achieve''";.'
water quality standards in the recaivlng
water. Thus, the number of major ';"-•"•
fadlities that potentiiilly could be'.' ,::i
••ublectto incremenUl requirements is : '•
1^26. The exact xronfiber Is Kkely to be
lowerbebause of the-mimber of " _'~:''''.;;
regulated pollutants iin each Stats and
the »^itn»»*:«'H«rfi*>g«« of the fiMSutties. *"
••All of the analytical difficulties •" •';'::
^described above, sudi:as estimatnig ';*' -*]'
*~ "** ** '*
1
costs; would need resolution to
-accurately estimate die cost impacts for
„ this group of dischargers, fa place of";""
range of costs likely to be incurred in. ;^
specific situations, and some of the '".'"''
problems Involved in. developing " ."''".';
potential compliance costs forties rule.
5. Example: RegulatLttgDioxinfortho •
PuJp ana Paper Industry •'• .;'•
As an example of tlbe range of costs
that could be assodattedwitii the ' ;•
imposition of EPA's numeric criteria. •'
i^Qmrtry ^nfyt utto T^oiiU'^^* *"*o?ciHi*'>' **" **
Dioxm (i.e.. 2^,7^-TCDD. listed asir
Compound tie at S l31^5(b) of me"',-.
, pulped wood. Chlortae bleaching ii'-'
used Dy'approximatelly.lOO pulp *»iii«
-in the United States. *5f those bleach
mills, 22 are located instates that had
not adopted human health criteria 'far'
dibxin as of {he date M,the proposed •"
ntiMd bom. It StaUt to »! State
1MB
-4«l
OtanberorStilt*.
-------
Federal Register / VoL 57, No. 246 /Tuesday, December 22, 1992 /Rules and Regulations 60905
rule. (See Footnote S.) Thus; this rule
could potentially serve as the basis fat
establishing dioxin limitations in the
NPDES permits for those facilities. Of
the 22 bleach mills in "unapproved" :
States, however, 13 already have dioxin
limitations in their discharge permits,
established in response to section 304(1)
of the Clean Water Act Only for the
• remaining nine facilities, then, will this
rule be a potential reason for
establishing dioxin limitations in the
- discharge permits. • :.-.
For those nineiaciliUes, however, the.
effluent levels of dioxin, as reported by .
• 'the facilities,"are all equal to or less than
10 parts per quadrillion (ppq).« This
' effluent data has important implications
for projecting costs and impacts. -
Today's rule will result in water quality .
standards that contain EPA's human
health criteria of 0.013 ppq for dioxin at.
a 10-* incremental risk level (or 0.13
ppq for States that .have expressed a
preference for a 10~3 incremental risk ••
level). This value would then be
reflected in the permits for the facilities
that discharge dioxin, after conducting a
' wasteload allocation and accounting for
stream dilution. If the resulting permit ,
. -fimitatipn is less than 10 ppq. .. ••' ' '.
compUance with the permit is likely to .
. be determined atlO ppq, because that
is level of detection for dioxin for the
EPA analytical method. •'-,•••':•• _• :•
. .The practical interpretation'of the
effluent data for these nine facilities is
' that promulgation of this rule is
unlikely to affect the need for treatment
and thus, thf costs of compliance for
water quality-based permits. - -
. These concluaibns are very much a
function of the laboratory analytical
methods arid their levels, bf detection for
. dioxin. If more precise and reliable
• measurement becomes available and is .
incorporated into the monitoring .
requirements in the permits for these :
, facilities, the small differences between
their effluent levels and the more . ;
stringent water quality-based limitations
.'; could present the need for additional
treatment or revised production -~ , .
• .processes. •- -,".-" .. •'• . ., " '••
. The Agency has collected extensive
information about the pulp industry's
efforts to reduce dioxin discharges from
, chlorine-bleaching facilities. The
. Industry has responded to the need to .
reduce dioxin (and related chemicals)
discharges with a variety of
technological advancements. These
include process refinements, such as
changing input chemicals or altering the
bleaching process. These types of
changes are not necessarily prohibitive
in terms bf investment cost or operating
costs. Substantial dioxin reductions
have been achieved at little or no
incremental compliance costs by
changing certain process chemicals. For
example, a change to dioxin precursor-
free brownstockdefoamers has been
successful in reducing dioxin discharges
at virtually no change in chemical cost
and with no additional equipment
Other process chemical changes, .
however, can result in increased costs.
For example, increased chlorine dioxide
substitution, which is often
accompanied by Increased chlorine
dioxide generation on-site, has been ;
•adopted fy various facilities at on
investment cost of approximately $20
million each. At the costly extreme.
'- dioxin discharge reductions at other
•facilities reflect major renovations, not .
.only to reduce dioxin .discharges., but to -
modernize or otherwise restructure the
..facility; For example, a facility might - • .
'choose to rebuild its bleach plant and
.adopt an entirely new bleaching '"• =• „".'-'•
process. Costs for this type of rebuilding
mayreach $100 million. ."• v •
In summary, the costs associated with
•meeting an EPA-imposed dioxin limit .
.can be estimated omy -with information
on the bleaching process currently used w
'ateach&dlity.itswastewater
finishing industry include numeric
limitations for copper, baaed on the Best
Available Technology Economically
Achievable (BAT), for direct
dischargers. The limitations for copper,
as promulgated, are a daily maximum of
3.38 mg/1 and a monthly average of 2.07
mg/L The technology basis for these
limitations is generally lime
precipitation and clarification.
receiving stream, and the level of
control mandated by a new water
quality-based permit Based on reported
. effluent levels, however, this rule is
unlikely to be the basis, for any
incremental compliance costs for Pulp
and Paper mills to reduce dioxin
discharges.
6. Example: Regulating Copper in the •
'Metal Finishing Industry -: '•
As a second example of the range of
.costs that might be incurred as a result
of complying with water quality-based
permits issued in response to the .
. imposition of EPA's criteria for toxic .
pouutants, we considered the metal . •
finishing category for-the control of the •
pollutant copper. " - .
- Effluent guidelines limitations end
standards, which are technology-based
regulations ......
•U&Eonrbi
Enginaaing end AmOTsU DirUao; ri{»M H^OM!
Onsus of Pulp. Piper, «ndP«p«bo«rd ' '
Report of Qaaittonniin RaspooMi far MiUi Which
Bleach Chemiol Pulp*." October 31. IW1.
pursuant to section 304 of the
Water Act, were promulgated for this
industry in July 1983. Briefly, the
effluent guidelines for the metal .
fintcViing industry set national standards
for all dischargers to surface waters and
to wastewatef treatment "plants
{sometimes called publicly-owned
treatment works, or POTW). The
effluent guidelines for the metal
subject to the regulation was
approximately 2,900. In the Agency's
permit compliance database, which
reflects a more recent assessment there
are approximately 4,000 metal finishing
direct dischargers. The higher, and more
conservative number (in terms of • •
projecting the number of affected -. ''
facilities) is used in this assessment
Of the 18 States included in this
assessment only six will receive EPA's •
aquatic criteria for copper; the • -
remainder have already adopted aquatic
criteria for-copper in their standards;7
. (See Footnote 5.) Approximately 530 of
the direct dischargers are located in •""•
these six States (where two States
account for 93 percent of the facilities).
The number of potentially affected ''
facilities is further reduced for several
reasons. First the number bf facilities
that would actually be considered for
water quality^based permits could be
lower, after •subtracting any facilities •
that have individual control strategies ••
(ICSs) to control the discharge of •••••. .-.
copper. In addition, the Agency has
provided a formula in today's rule to
allow the permitting authority to
determine a water-effect ratio to account
for metals speciation. The practical
•.result is that where determined, the
water quality criteria for copper in
certain waterbodies is likely to increase.
This adjustment will have the effect of
bringing the-water quality-based :
limitation closer to the BAT imitation:
for some facilities, this water-effect
adjustment could eliminate the need for
incremental treatment
Finally, depending on site-specific \
conditions at each facility, such as the
actual discharge concentration of '
copper, treatment-in-place, and the •
.dilution provided by the receiving , .
stream, complying with the in-stream
concentration specified in thd rule • .
could be achieved by merely complying
•with BAT limitations. Alternatively. -
.- bu*d on protecting haiiuahMllli. Far pmpMM c>f
'
to KM tqiutic Ufa prptocttaa eritaU btctaM tfaoM
rritfirli tm iri-rrt Trirrtnt tnt tttiHIiMng Trtt«r
diulity •*^*»«*»»^« ' . - ' .
-------
60BOB Federal Register / Vol. 57, No. 246 / Tuesday. December.22. 1992 / Rules and Regulations
since the in-stream water quality criteria
is mote* stringant than the discharge •
UmiUUon esUbliihed by BAT. it is
.possible that a facility complying with
BAT would need Additional treatment to
comply with a water quality-based •
limitation. • •
For purposes of this assessment, EPA
investigated whether BAT would be
suffidont to meet water quality'criteria-
Many simplifying assumptions are
incorporated into the following . • •
discussion. Tha instigation focused
on metal finishing facilities with water .
teleam of the metal pollutants „• •; -
(Including, but not limited to copper) as,
nported in tha Toxic Release • : •
Invantoiy.* The facilities included in
this assessment ware limited to thoae for
which plant and stream flow data were
readily accessible. While the number of
(facilities meeting all of these criteria ,
Hvas small, the results were indicative of
both scenario* described*bove.'In -'•'..
.Connecticut (whkh is used,far.. •• •;«. J;-,"
ilhistrativa purposes only because it is.,
not Included in the final rule). EPA has • "•
identified a. fedllty for which BAT will.,
be sufficient for controlling "discharges
of copper to the level needed to comply .
with a water quality-baaed limitation for
copper, Btnimtng EPA** criteria leveL •'
At that site, the stream dilution is such
thatjnoaotingtho BATlimltation.at the "-
dischaige point will also likely meet the
water qualify criteria within the stream.
We have al*o identified another&dlity'
in Connecticut for which BAT will not •
be sufficient—that is, the effluent levels
.needed to comply with foe water quality
criteria in the stream are -lower than the
level that BAT-will provide. Thus,
additional treatment controls, end . - -
incremental compliance costs, are
potentially needed for the second
facility. ,. . ••«-'.
Without« detailed water quality and
stream dilution analysis for"ell '••..' '••
dischargers, the number of ladlHiee
' where BAT will be sufficient to also'
tneet water quality criteria is unknown.
For purposes of this assessment, the'
distribution of £udlitiBs where • ...
additional treatment may be necessary
Is assumed to be between 25-and 75 -
11 percent Additionally, the distribution.
ofiadllty and stream characteristics for
f metal finishers in Connecticut is ,-;
'j^sinimdtobaMpneeniQtiveofthe' • .
distribution of characteristics in the
other States. Using theae simplifying
•US.Znri
nUlF
«*"•»•»***»**» «m»*i ii • i r«vw«.Mu tc
WMM Jaimlety, 1MB. A Moch of thpiomotorr
tf^JKw~*» .»»--* t_ *L _ __ _• .1 M_»JI.T *« T
assumptions, EPA estimates that 130 to .
400 facilities are potentially aubject to.
additional treatment requirements. -
During the development of the
effluent guidelines for this industry.
EPA considered several treatment
technologies that control pollutant;.
discharges. In addition to the
precipitation and clarification •. '.. '•
technology that was used as the basis for
effluent limitations, EPA investigated .
and published information about
effluent filtration, which provides more
stringent control of copper discharges.* -
Filtration .was not selected as the basis _••
for BAT because of its Jdgh cost when ,.
considered on a nationwide basis.10 The
removal efficiency for filtration is '...' /•.
.substantially higher than that for '. '•
precipitation and clarification.'Based on
' ' if filtration were
.installed at a facility in addition to the
technology used as the basis tat BAT,
meeting the ill-stream water quality .
criteria for copper would be ... ;••,,'_
technologically feasible. Hence, the.. :
" incremental coet5 for filtration are used
here to estimate tho rang& of costs fhat .
might be attributable to this rule.
• During development of BAT, the
Agency estimated total annual costs to
• add filtration to protipitation.and-- . -,
clarification'for various jdzes of •' ••"
facilities. The Incremental cost. ',.. '
estimates .used here reflect one of .,-.
several combinations nfTf*n^frcti"^nP •
processes .and conditions. The costs are
likely to be an overestimate because ""
they reflect the upper bound of each - ..-
flow jazerange. The potential" •";.' .
incremental total annual costs used to •
estimate the compUance burden for . '
meeting a water quality-based permit .
are approximately $20,000 for .small
'"plants, $43,000 for medium plants, and
$146,000 for large plants. To estimate'
the costs that might be incurred by the
dischargers potentially affected by the
rule, we assume that the distribution of
facility sires for those dischargers is the.
same as the distribution used forBAT
development While specific cost •• i .-
estimates depend on many site-specific.
•factors, the range of costs that could be •
expected for 130 to 4OQ facilities are -
ZtOucDt Unititioai GddeUnM«nd SUodcd* far
fti n t f ml Hnl Jilnt Trilut fiiii i n P^t1" S-
'10&3. -. — . •.-'-. . . .? • ,
VMiaitM ipedfic caufchntico t&eeO. and
•cooomic •dUnrBbQity; ndi oooMtdUnUaa U not
baa BrtibHiricg «wter xjo^tty tteodmli.
proc»«*, bat thafitv-h factor* «re rood d«r»d-«l
oOur point* in &*procau.(od>MwUUliUiig
approximately $7 million to $20 ..
million. • .
It is likely that the assessment
presented here for copper will include
meeting aquatic criteiia for other metals
due to the similarity in treatment'
technology. Thus, the cost impacts
estimatednere will likely provide
sufficient treatment to comply with the.
aquatic criteria for'most of the metals.
Another ""y™ of f*inffHarino fhn
potential costs is to evaluate the coat-.
effectiveness of the additional ."•
treatment where cost-efiactiveneM IsV
defined by the ratio of incremental cost •
toincremental.pollutmtramovaLThe
cost-effectiveness of filtration for those.
facilities projected to need additional °.
treatment is baaed on the coot estimates
shown above, and the polhitant removals
. for not only copper, but five additional
metals that will be removed by . .. •
filtraticoi. Cost-effectiveness ratios are •
expressed as"dollars per pound-.,.- ...
«qidvalentromoved.M where a pound- .
equivalent is a pound of pollutant • -,.-'
pollutant The cost^ffoctiveness of .
filtration for these facilities is $22 per
pound-equivalent reatoved. This resuh .
suggests that filtration is a cost-effective ".
technology.: .. •..•'.. ' .".. . •
In summary, the actual burden to •"
^i«r-hnTg<»y;t In ilia mnfnl Gnlfhlnp • • -.
.industry ranges from iao impact where .
• BAT4s sufficient to pirotect the receiving
' stream, to Jm incremental cost impact of
5 to 13 percent above the cost of BAT, .
where filtration is needed. In addition..
•zoouootoiu to ooiQDxy ^tfj^n XDOKQ ttri iiiy^^*
.standards appears to tie cost-effective..
7. Example: Regulating Priority
Pollutants in the'Organic Chemicals.
• Synthetic fibers, and Plastics Industzy
A third example of
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Federal Register /Vol. 57, No. 248 /.' Tuesday, December .22,-.1992 / Rules and Regulations 6O907
During development of the effluent
guidelines for the organic chemicals
industry, the Agency considered the
potential for pollutant discharges from
all of the priority pollutants.
Approximately half of the priority •,
pollutants were detected in effluents '
, ^ "from chemical manufacturing facilities.
and the effluent guidelines for this
industry include limitations for most of
these pollutants. Hie technology basis
for establishing BAT varies by pollutant
and by industry subcategory, but for
many subcategory/pollutant
combinations is steam stripping and/or
biological treatment ..-. • • •
The promulgated effluent guidelines
for the organic chemicals industry were
• expected to control discharges from
• more than 700 facilities. Of these. 275
are located in the 18 States used in this
• assessment to analyze the economic .
impacts of EPA's human health criteria.
• "(See Footnote 5.) The human iealth
criteria are likely to be the more , .
significant values/fcompared to aquatic •
" life criteria) for purposes of controlling '
'
number of d"irect dischargers in the 18
States is estimated to be 90. based on
the total industry proportion of direct •
• dischargers. These dischargers' are
potentially subject to incremental .
requirements as a result oT today's rule.
The key question for estimating the
effect of the rule is whether BAT is
. sufficient to protect -water quality to the
levels that would be mandated by - v
. Imposition of -the criteria promulgated
today. Water quality modellingTesults
suggest very few exceedances of the
water quality criteria, after the " ..
imposition of BAT requirements.
' . . -The level of control provided by the
effluent guideline reflects die analytical
laboratory level of detection for nearly
half of the regulated pollutants/While
. the niaximum monthly average '• s "..-.
.'expressed in the effluent guidelines may
be higher than the detection linrit (to
account for variability), the level of ". '•
detection corresponds to the long-term
average of the treatment's removal .
efficiency. No water quality'.
exceedances were projected among the
pollutants that are regulated at levels
r fonn fon fWnrfiym tinrlt
• « Thepractical effect of the BAT
limitations, combined with levels of
detection and water quality •
to afiect the behavior of chemical
manufacturers^in fn't"g of -pollution • - •
. control investments. By complying with
* BAT limitations, the facffitieSare ukely
_ , to also comply with more stringent, v ...
• water quality-based limitations. Even. •;:
• •though EPA's human Jbealth criteria -• '..
suggest that -permit requirements for . •/-.
some dischargers will be lower than the
Jevel.of detection, a facility that cannot
demonstrate compliance with the lower
permit value is unlikely to add
treatment or change processes in
response to the revised permit. •'•
In summary, BAT requirements for
thic industry control nearly half of the
/regulated pollutants to the level of
detection for each pollutant It is
unlikely that the rule will result in
. incremental economic impacts for direct
dischargers in the organic chemicals.
plastics, and synthetic fibers industry.
.£. Example: Regulating Priority
-Pollutant for TOTWs
The final example of the range of
costs that might be incurred as a result
of EPA-imposed numeric criteria is for
POTWs. An important aspect of - •
regulatory impact for sewage treatment
jplants is that increases in investment "•.
and operating costs are often passed on •'
to consumers in the form of user fees or
•. taxes. For purposes of this assessment.
, however, we nave not extended the cost
impacts to household burden."
For POTWs, the choice of treatment
.-technology is dependent on many
factors; one of the most important is the
pollutant tor group of pollutants) of
concern and the source of that pollutant.
For example, different technologies are.
recommended if the pollutants of - .. .
concern are dissolved organic ,*
compoundsas opposed to suspended • -
sohos. For this assessment. we relied on
summary cost information presented in
comments the Agency received during
.development of ihe Greet Lakes Water
Quality Initiative and on summary
information from a rulemaking that
focused on the incremental cost for
POTWs to upgrade wastewater
treatment1* The pollutants of concern
and levels of control in those sources
are. similar to the additional controls -
that might be imposed by compliance "
with water quality standards following.
adoption of EPA's numeric criteria for
priority toxic pollutants, '
Several comments-tothe proposed
rule contended that luvtuse .osmosis is
. heededio comply with EPA's criteria
•for metals. According to commenters,
' this technology is ukelyto be Tory-; - ~
expensive when applied to die high •
\ flows found at many POTWs, EPA
believes thct POTWs often nave
' alternatives to installing this type of •
. treatment;1ecbnology. These alternatives
may be attractive from an, overall water
quality perspective because they
prevent^llulidn atthejource.Foi' ..
example, it may be less expensive for a
small number of indirect dischargers to
reduce their metals contribution to the
POTW's wastestream than for the POTW.
to treat all' of its effluent ,' • .
Copper discharges are another •
potential source of difficulty for POTWs
in meeting water quality criteria. Many
drinking water systems use copper to
control algae growth. The copper is then
discharged to the POTW and than to the
receiving stream. Other algae controls,
such as potassium p*"*"mngimmt»- may •
be effective for some drinking water
systems. This example of an alternative
would reduce the copper loading to the
TOTW's receiving stream without /.
requiring expensive treatment such as •
leverse osmosis at the POTW. Reverse >
osmosis was not used in either ofthe .
. cost sources noted above; nor is it used
here. The pollution control technology*
selected for a POTW depends on various
engineering Judgments and site-specific '
conditions. The incremental costs used
in this assessment are based on -:>!,- • : ;
activated carbon for some POTWs and "•-
on polymer addition forothers. •.;"' ;.
s Engineering judgment suggests.that •
many of the organic and metal •'•'•: •••••
compounds of concern will beTemoved
in the final effluent with tiiese type* of
treatment technologies. . ' '
The following cost assessment is ' •
likely to be an overestimate due to the.
-simplifying assumptions 'used in this
procedure. The number of POTWs that
possibly could be subject to incremental
costs that are attributable to this rule is
first limited to POTWs in those States .
that had not-adopted their own numeric .
criteria by the time of the proposed
rulemaking. A total of 18 States was
used to project the number of POTWs .
(See Footnote 5.) Of the approximately.- *
15,000 POTWs in the UA, 3.942 are '\
identified as "majors" in the Permit ^ -
Compliance System. Of these, 952 are
located in the 18 States. Even.as oflhe '--
—proposed rule, however, this number of •
POTWs is an overestimate of the .~
number that nught incur increased costs ;.
• because it includes all States projected^
-to receive any pollutant criteria. In fact
• many of the 18 states need only a
-limited number of.pollutant criteria (for
some States, as few as one). :- '
. . Thenumber/of POTWs that might be-
. subject to new or mote stringent permit •
requirements is further .reduced, because
some portion of thoeepermits already-
include Umitations for some of de -• '.•
pollutants of concern.Soch permit- •'
limitations and ti»eICS« were -• -.•-•""•
established in response to*ection 3040).
of the dean Water AcU Another tsctor.i-
that may eliminate the need for -- •-•:•••-"•:--
additional treatment bythePOTWis the;
use of whole effluent toxicity limits, v'
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60908 Federal Register / Vol. 57, No. 246 / Tuesday, December 22. 1992. / Rule? and Regulations
. which, are possibly already controlling
toxic discharges. In addition, existing
treatment and pretreatment may obviate
" the need for more stringent permit
requirements. Other rite-specific ' •
• analyses, such as wasteload allocations '
and dilution studies are likely to affect
the reasonable expectation that a
. pollutant it discharged. Also, as
mentioned earlier, the water-effect ratio
• . calculation Is likely to eliminate the
need for incremental treatment in
certain waterbodiea. • •
. -FOT purposes of this-assessment. Ihe
number of POTWs that will need ..
. additional treatment has been estimated
by focusing on the results of section
. 3CMO) reviews. During each State's
review of dischargers to identify sources
that-wete discharging toxic pollutants at
. * level that could potentially cause
water Duality impairments, less than 5
percent of tho major municipal . '
•' dischargers ware listed. Applying this '
proportion to the'number.of municipal •
dischargers covered by today's rule . •'.
, -yields an estimated 46 POT\ys that '
. could potentially cause water quality -
• * criteria violations. The provisions of
"c .saction 3040) required States to respond
to these projected violations by ..-•.. •>
" . 'developing Individual Compliance ,"
Strategies and permit limitations for
tcodc pollutants. . ;.X ,-.' * . • • -.
,'The Agency acknowledges that the
/ discharger reviews conducted in ". •
responselo •ection.SMO) were not
comprehensive and probably ^. .
. •undercounted the number of • .
dischargers, In eluding POTWs, that ••
were discharging tcodc pollutants. Some
" of tho reasons for undercounting
include, the lack of monitoring
information; quickly-conducted •
• reviews, varying methodologies among
States, and out-of-date discharga .:
* • information. For purposes of this
assessment, the number of sources that. •
potentially causa water quality criteria
., problems,is assumed to be three times •
the number actually listed; in other
. words, the number of POTWs subject to
additional controls is conservatively
estimated to be triple the 46 actually ,
identified, or 13« POTWs. -• - •
As mentioned, there are various
alternatives that an individual POTW
might undertake to comply with more
stringont permit requirements. While -
. the most costly alternatives involve
* additional pollution control equipment
• to the POTW, there are Other- • '
TntvJhimtgmg tn ItnpTnvfl tViA ipmllty nf .'
the POTW's effluent For example, a .
pretreatment program could require an
,'industrial discharger toreduce.or •
eliminate its contribution of toxic ,
pollutants to the POTW's wastestream. •
Altomativoly, nonpoint sources could . .
undertake better management practices
to reduce runoff. Many of these
alternatives have little or no incremental
cost impact to the POTW. While some
of the alternatives involve a shift in
.costs, the overall effect is likely to be a
lower cost than if incurred solely by the
.' POTW. Even with the availability of
* alternatives for compliance, this
assessment assumes that half of the
POTWs will install additional
treatment Hence, 50 percent, or 69) of .
the potentially affected POTWs are _. '
assumed to incur additional compliance
costs. • . • - -
The'costs of additional pollution
controls are "derived from the two
source* mentioned above. The cost' .
calculations for activated carbon .*
include capital costs, O&M costs, source
controls, and studies (such as mixing .
zone demonstrations, toxidty testing, •'
monitoring, and fish bio-uptake tests).
For purposes of this assessment, •
•simplifying assumptions were then :
applied to those cost calculations to :.
.estimate total annual costs for various '
sizes of POTWs. The incremental total
annual costs for activated carbon are
1 estimated to be $0.4 million for.a small
POTW, $1.4 million for a medium -.--•,.
POTW, and $12.8 million for a large
POTW. The cost estimates for improved..
eecondary treatment by polymer ..•-"-• •. ..
addition include annualized capital'
.-costs and O&M expenses. The - M--
incremental total annnal costs for fo'f
technology are estimated to be less than
$0.1 million for a small POTW, $0.4 .
million for a medium POTW, and $1.5
million for a large POTW. ;
Based on engineering judgment, 75 .
percent of the POTWs are assumed to
. rely on chemical addition to meet
permit limits. The remaining 25 percent,
are assumed to rely on activated carbon
adsorption. To estimate costs for each -
group of POTWs. the facilities are ,
categorized according to flow groups,.
^assuming that the size distribution of
the POTWs in the affected States is the
same as those used in each cost source.
Then, the incremental costs for each •
type of treatment are applied to the . L.
number of POTWs in each sizecategory.
This procedure results in. an
incremental-cost estimate of
approximately $30 million. -.
To summarize, some POTWs may be •
subject to. additional treatment. • '..
requirements as a result of this rule. The
number of POTWs and the .types of
treatment are dependent on many site-
specific conditions and on the '.; '
pollutants includedin today's rule. For .
many of the POTWs that are major '
discharges in the States that will need
to adopt new water quality standards, .",
there is likely to be no incremental cost
Using a conservative estimate of the
remaining POTWs, the upper bound of
an incremental cost estimate is , .
approximately $30 million for POTWs
to comply with new discharge permit •
requirements.
S. Conclusions of EPA' f Cost '•
Assessment .
Today's rule establishes a legal
•minimum standard where States have
failed to comply with the- statutory
mandate to adopt numeric criteria for
toxic pollutants. IHie impacts to
dischargers are difficult to estimate -
because of the numerous assumptions
and unknowns. While the Agency
acknowledges that some dischargers ~
• may incur compliance costs' due to new
water quality standards,' a meaningful
cqst estimate that covers .the entire rule
is not feasible. ' .
.In the absence of a cost estimate, per
se, the Agency has described the types
of costs mat may be incurred by various
types of dischargers. In addition, this '
cost assessment includes four examples
of potential compliance cost scenarios:
reducing dioxin discharges' bom pulp
mills, reducing copper discharges for
metal finfahtng, controlling priority. '
"
pollutant discharges" for organic
chemical manufacturing, and reducing
discharges. from POTVVs. " ' ••;
EPA finds that the. costs to comply •
with toxic pollutant criteria may be less
than anticipated at the tune the rule was
.proposed. Many Slates have adopted -.
their own numeric criteria and are •
therefore exduded from today's
rulemaking. In addition, for some point
source categories, where technology-
based controls have been established,
more stringent water quality-based
controls will result: in no incremental .'
compliance costs. Further. EPA
concludes that additional analysis is not
warranted because the. uncertainty of •
such an analyses would not provide
enough reliable information to assist
decision-makers in evaluating the
mandated rule. ..'. • . .'
JO. Introduction to Benefits Assessment
• The numeric criteria for toxic .!• ;.
pollutants promulgated in today's rule
are essential in implementing toxics
controls and protecting human health
and aquatic ecosystems. Under this -
Rule, a total of 15 States and Territories
will receive criteria for human health
and aquatic life (M.for human health
and 13 for aquatic life). The adopted
standards will result in decreased toxic
pollutant loading discharges which will
result in improved protection of human
health and aquatic life.
-------
Federal Register /..Vol. 57^ No..246 / Tuasday. December-22,.1992 / Rules .and Regulations '60909
The Agency did not include & .
viMsniHative estimate of the benefits in
the proposed rule .for reasons similar to
those cited' above for not including a
detailed cost estimate. Hie •
environmental benefits associated with
this promulgation are difficult to 'assess
and quantify. A comprehensive analysis
of human health and ecological benefits
is not practical given the available
.resources and inherent(limitaUons such
as (1) assuming a linear relationship
. between pollutantioading reductions .
and benefits attributed to the .clean-up
. of surface waters; (2) underestimating . .
the benefits or reducing toxics due to
.. the complexity of «8«fl«shig impacts on
aquaticecbsystems; and (3) the .-..;•• .
uncertainty in estimating the magnitude
of intermedia transfers ttf pollutants. •
. Such uncertainties limit tne value of
. using such estimates to eraluaie the net .
benefits of this rule.' However, the . .
v Agency has undertaken a preliminary '•
' assessment of potential human health
and ecological benefits that might be . .
accrued Ourough promulgatioa of the "
-'• ••-•- ••• •'- •'• '""
'11. Human Health Assessment Scope
> The potential benefits tairoman , . :
. health' of establishing toxkrcriteria"" ••
include: (1) Reducing the potential
JhealthTisks to persons eating fish
. contaminated witii toxic pollutants, (2)
. -'reducing the potential health risks to
persons drinking contaminated drinking
. water, and (3) reducing the potential .
health risks to swimmers from dermal '-
exposure to contaminated surface
- waters. EPA's qualitative assessment is
limited to -assessing (1) potential. -..+•'- . ..
benefitsfrom reducing pollutant levels :
in fish that may be caught by sport and
. _ • subsistence fishermen and subsequently
* consumed by them and their families;
•and (2) potential benefits, that may .also
- result from lowering pollutant levels in. "
• the general population. This-assefsment ,
is limited to assessing only the potential
reduction in cancer risk; no attempt has
been made to assess potential : ,.-. .. .
reductions in risks due to reproductive. .
developmental, or other chronic and . '.
subchronicitoxic effects. ' "
12. Ecological Assessment Scope • , -
:* Some of the ecological benefits are
[difficult to assess due tolhe complexity .
of ecological interactions, the limited
amount of ecological riskinfonnation .
. .available, -and the lack of an established .
: methodology for evaluating ecological _ .
. benefits. In addition, difficulties arise in.
estimating the exposure of aquatic
ecosystems due to the large size of
ecosystems, wide geographical .r:.'. ."..-.'-.,
distribution, heterogeneous . : ...:• .
characteristics and the wide jange of
populations with differing .sensitivities
to impacts. While the benefits of
promulgating this rule were not
quantified due to such uncertainties and
limitations, the potential benefits of
establishing toxic criteria for the : ,
protection of aquatic life "*" be ••
described qualitatively.
The moot recent r4ational Water -
Quality Inventory indicates that ODB-
third of monitored river miles, kke -
acres, and coastal waters have«levated
levels of toxic polhitantc. After. • •
evaluating then data, the Agencj— - -
conduded-that-tbe data most 4ik«ly r - -
understate the prasence^or /discharge of .
toxic pollutants-because-of the limited '
amount of monitoring data J6r«ome
States and Ineonaistandei amocgiha ,
States'in how the data ware generated,
ThimJ <1 |y lit-nly
portions of water bodies in some States
exceed water quality criteria for the -
protection of aquaticufe. These criteria
were developed to protect most-aquatic :
organisms, as well as wildlife that - "
consume aquaticorganisms, £(om acote '•
and chronic toxic effects that" adversely
affect survival, growuVwieprbductioo.
These effects will vary due to the • •-• •--•
diversity of species with Differing
sensitivities to impacts. For example, ...
lead exposure can cause-spinal •
deformities in rainbow trout. Nickel
exposure can affect spawningbehavior
-of shrimp. Nickel, mercury, and copper
exposure can affect the growth activity .
of algae, m addition, copper, mercury.
and cadmium can beacutelytoxicto -
aquatic life inchtding finfiah. These
types of ecological effects an vxpected
to be reduced because this rule should
reduce ambient pollutant levels. In .
addition, tins rule will reduce ;
continuous discharges of toxics wnich
wiUalkrvr |or a natural recovery of the
ecosystem*. •_'..-.' '-.... ......
13. Qualitative Benefits Assessment ~
Human health benefits that can be '
attributed to this mleera axpressed in - '
terms of the reduction in cancer risk.
the analysis performed was limited to
. assessing only the potential reduction in
cancer risk; no assessment of potential "
reductions in risks due to reproductive.
developmental/or other chronic and .
subchrpnic toxiceffects was. conducted.
However, given the number of . •'..-'
pollutants, there could be: (1) Decreased
.incidence of systemic toxidty to vital .-.
The ecological benefits that can oe .
expected from .today's rule include ;
protection of both fresh and salt water
organisms, as well as wildlife that
consume aquatic organismsvToday's
rule will result in a reduction in the
presence and discharge of toxic .
pollutants in the water bodies of these
. States thereby protecting those aquatic
ecosystems currently under 'Stress,
providing the opportunity for the
reestabtishment of productive . .
ecosystems in damaged waterbodies,
and protection of resident endangered
speaes. - " •"
. In addition, the rule would result in
.the propagation and productivity offish.
• and other oranisms
_
recreational purposes. RecroatioQal .".. '
activities such as boating, water skung.
and swimming would also be preserved
alnng wtth thn tn« .
significant impact on a substantial
number of small entities. In the. . ,; •
preamble to the proposed rule, SPA • '
discussed the possibility that the xula i'..'
could result in treatment costs to some
dischargers to comply n«ith water
quaUty standards that incotporate new
criteria for toxic pollutants. The Agency
did not conclude, however, that the rule
would have a significant impact on a r
ttafiyf fmmtt unHtin* Am •
*
to the uncertainties associated with
mti muting totalcosts and impacts. The
difficulties of cost estimation for. : .
• specific groups of dischargers .{such-asv
small businesses or governments) were
••described in the preamble section that
outlined EPA's response to Executive
Order 12291. Similarly, in today's final
Tulemaldng. the" details of EPA's
findings concerning the costs and
' -impacts of this rule are presented in
section!.above.' • ' - -
.Briefly, the complexities and
iecreased extent of learning disability. .
. and intellectual impairment due to the
exposure to such pollutants as lead; and
.(3) decreased risk of adverse ,, -U- .._ .
reproductive effects and genotoxidty.
costs for purposes of economic or. :. --
regulatory analysis similarly apply to.
estimating impacts to small entities. For
purposes of this rulemaVdng, small . . ..
entires are small dischargers, whefher^
industrial or munidpaL Regardless of
-------
60910 Federal Register / Vol. 57, No. 246 / Tuesday, December;22. 1992 /.Rules and.Regulations
tho parameters used to define small
dicchargors (for example, discharge
flow, number of employees, population
served), EPA's expression of costs and
Impacts for this rulemaking Is limited to
the descriptions in section J. EPA does
not find that there will be a significant
Impact on a substantial number of small
entities because Impacts on specific
dischargers cannot be predicted with
certainty, and based on several .
examples La the cost assessment, it
. appears that potential impacts will not-
* bs concentrated among small ; -.
dischargers^ -. '••'••.'•'
In addition^ EPA'again finds that the
Impacts on small entities are best. _•
'considered during standards ' '"
development and implementation when
sdU-spocific costs can be estimated, and
any resulting impacts can be mlnimizea
or alleviated as part of writing the'. . " '
discharge permit It is not the Agency's'
Intent to Ignore the consequences of•' -r
Incorporating toxic pollutant criteria,.-' •
but Instead, that thcse'co'nsequeiices are
xncra appropriately defined and" .*"•"-. "
accountod for In'tne-pennlt-writing '-'..••
' context The water quality standards
regulation provides several means (such
.as adjusting designated, uses, setting
site-e^ddfic criteria) or granting •• •
variances) trf'conslder costs and adjust.
standards to account for the impacts on
»m»11 dischargers. -. * •*. ,
While the imposition of EPA^s '.". '. .
numeric criteria for toxic pollutants may
limit the flexibility that States will have.
to use these procedures to modify
standards, EPA's expectation is that
impacts will not be concentrated on •
small dischargers. Although there can
t be site-specific cases of water quality
' violations due to toxic discharges from
low-flow point sources, EPA generally
finds that priorities for NPDES permits
•'. focus on major dischargers; Small
entities are less Jikely to be included in
this group. ' . ".-•••.-
Other requirements of the Regulatory
Flexibility Act are fulfilled In other .
• sections of this preamble. Specifically,
the Agency's explanation for taking this
action and the legal basis for the rule are
found in section E. The number of email
entities that will be affected by the rule
Is not estimated for the reasons
expressed above. The projected •
reporting and recordkeeping
requirements are discussed in Section L.
•There is no anticipated duplication,
overlap, or conflict with other Federal
rules, except to the extent that
technology-based standards (such as
BAT) are sufficient to also meet water
quality standards. Alternatives to the .
final rule-include any of the
opportunities that States had to adopt
their own standards. Incorporating any'
of the procedures to limit the .
compliance burden; these alternatives
are discussed in Sections B and C.: -'
The Agency concludes that this • '-..
rulemaking, perse, will not result in a
significant'impact on a substantial
number of small entities, and a final
regulatory Jlexibih'ty analysis is not :
•xequiredVy ; • ,: ; < '•_ - •
L; Paperwork Reduction Act ;;'
The information"collection ' . •'."
requirements in thls'rule have been _« ..'•
submitted for approval to the Office of ..
Management and Budget TOMB) under
the Paperwork Reduction Act, 44 tLS.C.
'3501 er seq. These requirements will not
•be effective until OMB approves them
and a technical amendment to that •. • -'
' effect is published In the Federal '. '•
Register. An Information Collection . ' '.
•Request OCR) document has been • .
prepared by EPA OCR No. 0988.04) and
a copy may be obtained from Sandy
Fanner. Information Policy Branch;
EPA;40lMSt,SW.(PM-223Y); .
Washington, DC 20460 or by calling
(202)260-2740. . . . ' ' \
' Public reporting burden for this
collection of Information Is estimated to
average 725 hours per response.
• including time for reviewing ;
instructions, searching existing data
sources, gathering «m
-------
.;-. Federal Register / Vol. 57, No. 2467 Tuesday, December 22, 1992 / Rules-end Regulations 60911
- - ' ' ''*-..•
<#) COMPOUND
1 Antimony .•
2 Arsenic ' . "
3 Beryllium.
•; :. 4 •• .Cadmium'.
. 5a Chromium '(hi).
. b Chromium fVM '• :-
6 Copper
.7. Lead., .' ' ." .. ;;
•8 Mercury". "'. ;
9 ilickel •
: 10 Selenium-
11. Silver. \
- '•: • " .'•.""'
' :12 ThaJUium
13. Zinc _; - ; .
. .14 " Cyanide , • . '
15 -Asbestos-
16 2.3.7.8-TCOO XOioxin)
•. 17 Acrplein
- 18 Acrylomtrile
.< 19 Benzene .''.--•
21 Carbon Tetrachlorider "
.22 Chlorobeniene
23 Chlorodibronooethane
24 : Chloroethane .
25 2-Chloroethyl vinyl Ether
«" 26 . Chlorofors " ;;
• 27- Oichlorobroaonethane
FRESHWATER j SALTWATER
" ! 1
['Criterion Criterion j Criterion Criterion
J Ma*imum Continuous } Maximum Continuous
CAS Cone, d tone, d J Cone, d Cone, d
Hustoer (ug/L) '. . 110 t^ - 95 f» ' , 86 w
'57125} 22 '.5.2. ! -V ; ' 1-
1332214 ! ••'.-..-• ! -
•'"-.' '.,''.. . . '• .
' . 17*6016 {.-.•""-'-.', !
'.-.'•' 107028 J • ; '
107131 \ ....,'. ''.-"•{'-'..-
' .71432 | • ' ' '.'-.'.' •'.."": "
75252 ! .'•-'•.
. /5623Si ' '..""-'. '• ;..'; .','•>. •'-- ':>„ ' • '
108907 j - ' .-''"':.
124481 | •'•' } " -
••*".. ' ' V- • .. " | "
116758 ! . . - !
75274 ! •"•'.-' } . .•"..
" •
HUMAN HEALTH
(10 risk for carcinogens)
For Consumption of :
Water C Organisms
• Organisms Only
. ..-• • -. n •
! n " . "... n
! •*•-.• n :
1 .-••-' '•- '.'•'•'.•'
' . •': n . •;:. ••*'. '
"«, "."''• 0.14 ; 0.15 -1;.
J 610.8 *600 a.
! n n
. '•• ' •*.-••- •. • ' ' ;.'.'.••'
.J , l.:7 a -6.3 a
. • i - .. " • . • - • "•
J "-.. TOO a .220000 «./ .
! 7.000.000 «bers/Lk N
- }O.OOOOOOQ13 c 0.000000014 c
5. . 320 -.. ' .780
j. 61059 a.c 0.66 a.c
,| 1.2 «.c 71 «iC
« 4.3 a.c 360 ».c .
.5 0.25 «.e 4.4 «.c
| 680 » 21000 ».j
\ .O.*1,«.e V34 «.c
i ' " ' ' .
• ' — • ...
. ', . 5;7 >.e 470 «,c
{ •; 0.27 i.e . . 2k a.c
-------
CO912 .FadentlHeglrter / Vol. S7. Nol- 246 / Ttiosday/JtecWber^. -1992 /Rules and Regulations
28 1,1-Dichtorbethane
: ( *t
•29 1<2*Dichloroethane
30 I.I'Dfvhtorocthylene
•31 1,2-Oichloropropane
33 Ethylbenzene '. '•
34 Methyl «ix»ide V
. 35. Methyl Chloride ' •' ''* '
36 -NMetftylene Chloride ,' '•f • . -
.M'-Tetwiehtoroethyiene-' • *" ^
"39 ^Toluene • .'• .~«» • •
.«-,,•• .•••.«,..
'40 1.2-Trans-DichltfroethyleM -
.41 C.1,1,i-Trfchloroeth»ne -
42 1.1.2-THehtoi-oethwx?
*3 THcMoroethylene _" ;
44' Vinyl Oitor.We'.- ' . i.
45 2-CMofppheoot .- "•- ;' ,-'
46' 2,41>lcMorophenol •
48 2-Methyl-4,6-Dihf trophenol
'49 2,4-OlnUrophenot • "
50 'Z-tfUrophenol .! '._
52 -S.H^vl.Stt^Bh.nrt ' '
53. .«,»chlor.o^«x;i ' '
54 «>henot •
55l 2,4;6-TrJc*ilorof*enot
56 « Actnsphthefve •• '
75343
107062
75.354
• -.78875
,542756
100414
.174839
74873
• -75092
:• 79345
127184
-W88S3
,156605
.71556
79005
79016
750 U
95578
120832
105679
534521
51285
«8755
100027
•59507'
87865
106952
88062
83329
| " ! '
^
i ' 5 ' 0.38 «.c
. T i - " ' 0.057 ».e
-.**"«- *-• 1. " •• -.'•
• . '• . '"'« V • •; . • i •
• '• "••-...-• « 10 a
• ' ' . : ' * . *. V •* . -3100 * •
• • •• ' : ' i • • *'-.•• " •{',,; 48*
' ' ^ . .'•; ' ' ' ;'{ .".'" n
•:" -'"J- - --•" { '. 4.7 «.e
'-•'"' '•].•''• ' ' ' "' 0.17 a.:e
'.' '. • -" • • • _ '••'• "."' ' ', « «ob>- "•
• _' • • * ' ' • " , I . . •• ,
. " * . '".'•• I n ..
-'•• •- *• • - - • • j 0.60 a. c
••;-; ."-••'•- ,i 2.7 c
' •••• -:' -•.'•' ••-.!; -•. --. •" '. 'r , '..««..-
•"'.. -•.{•.' •;" ' « •'•":-•• '.
• • • '
. ' '!.-•• i 93 a
• " " ' . ' ' " * ' ,
': ! \ •••."•!•• «•«
/- v ; .'••!• ' ;• " ' 1 . 70.
• " . I • i
1 • . j
.-- '".• ' - '.J - - " :> y •" ".
. . • . " i . ..-.-• i. .
2°* «fs_! 13 'r.1 ,} 0.28 «.<:
-{ i .21000 e
. . i "i 2.1 «,<:
..' ' 1 . "l -' .
" .
• *9*.c
3^ «.e
1TOO »
' '29000 a
-4ppft' f
' '*#•
-UOOa.c
8.85 t
^^oooop*
n "
42 • c
at •=
. . ;.-SS-s '
•• . . ' •' ' ' '
790 *.j
765
14000 • •-
«-« ».e.]
4600000 «.j
*.S"«,e
, • • . . _. '
-------
Federal Register / VoL 57,-Np^ 246
" .--'• *V •".' "A •';• •' i . •'•.
' ' ' • ' . . ' T * E S
/, -Tuesday, December
'a -.;• '
H V A T E R
? , . Criterion. .Criterion
• , . Maximum " Continuous ;
#) COMPOUND CAST } Cone, d , Cone, d
Umber ! "-.
C2
For Consumption of: • - .
.Water & Organisms
' Organisms Only
Methane
67 Bis{2-Chloroisopropyt)E.ther
68 Bis(2-EthyThexyl )Phthalate
, 69 4TBromophenyl .Phenyl 'Ether
70 Butylbenzyl- Phthalate
72 4-Chlorophenyl Phenyl Ether
73 Chrysene .' . • . ' ,'.
74 oibenzo<8.h)Anthracene '
,75 1,2-0'iehXorobenzene :' .
77 1.4-Oichlorobenzene. ..
78 3,3''Diehiorob«izidine
79 Oi ethyl Phthalate. -
80 -Oinethyl Phthalate ..
81 Di-n-Butvl Phthalate x
•82 ,2.,4-0.initrot9luene .-
83 2.6-0 initrotoluene ;
84 Di-n-Octyl Phthalate •
85 1.2-Oiphenylhydrazine
208968 j ! ''•..•=;•'•
120127 J •! ':
'"92875 j , ,-;'• ., _.'; ! '_'•-' ' • • '. . . _"•
- ' - w ' • -: — - '' 1 ^ '- ' * " '••*-.
56553 V .,"• •.. •
50328 ! • '.-":• \ '
205992 j ' ' .... ,
191242 ! J
207089 S : ! :
111911. | . '-,-'.• !
111444 ! ' ! • '
108601 1 ; .'••.- .' i . ; '•-.••
*'"."' -' ''.,','- ~ . • - ?
, r - />' " * 1 " -' - > -
117817 ', ! . .
101553 5 ': ' -'. '. . \ _ ;.;'.. ,; - . l .
;85687'{ -'.- - i. -. . ,,. .jj. ,.- . '•-_'• ;'• _, ,
\91587 ! "-''••" ' '• ' ' ••••!•'.-
7005723 j " j
218019 •{• . - } • :'-•-•
53703*J •'•-.•' '•'•; — * > .''
95501 \ ':' ' ' \ '
541731 ! '!'-'
106467 ( ' i
• 91941 J . -.' .
'84662 { ', " {-'•'•• '.,'-• .
:i3iiis |^ '".' ;/;.' _.-; . ! _ • '•;.
84742 ! " !
121142 ] ' ' . . { . . .
606202 ', - 1 . '
. 117840 { , j '
122667 J v J ' '.''.'
1 - • • • '.
•'••'. 9600 a
0.00012 a.e
'- 0,0028'-e
0.002S c
0.0028 c
• •"' - '••.'-•
• 0.0028 c
'- ' ''•"'.
0,031 a.e
• ' - 1400 »
; 1 JB'«.e-
'.' • . ' •'
'; :.. '-• '•
0.0028 -e
0.0028 c
2700 a
400
; 400 -.
0.04 a.e
23000 a
313000
2700 a
0.11 «
J ' .,-"•' • ''
j 0.040 a.c
.'• . .
, 110000 •
0.00054 ale
0.031 e
0.031 c
0.031 ;e
' • '
«.031 e
-. ''•"" •-
1.4 a.e
.-170000 •
5.9 «.e .
.. -. '' ' -'
0.031 e
.'.''••
0.031 c-.
. ITOOd a
2600
. . 2600
0.077 a.c
. 120000 •
2900000
12000.
.9.1 e
. .
0.54 «.e
-------
60914 JFadaral KegJrtar /Vol. 57, No. 246 / Tuesday, December. 22. 1892 / Roles and Regulations
A
•
(*) COMPOUND
1
t
. J
i
j
i
i
CAS
Nuiber
1
FRESH
'.Criterion
Maximum
Cone, d
. •
C2
• • ' 0 . ':
HUMAN HEALTH
<10"° risk for carcinogens)
For Consumption of:
Water I Organisms
Organisms Only
(ug/L) • Pyrene •
Icophorene '. . , .
NJphthafcne" '
ttttrobcnzene '•• •
K-NixrosodliKthylatiine
•N-«i trosodi -n-Propy laai ne
H-Hitrosodiphenyfeaine •
Ptienanthrene
Pvrer* - « -
1,2.4-THchlorpbenzene :
JUdrin ' . .
aipha-Wffi •" -
beta-IXC ' ' .
.Swma-SHe •
delta-BHC"
CMordane ' •
*-«-TOT _ •'.';•
4.4'-W»E__. '" • •
4.<»-uoo •'
D1eldr5n,;
•Ipha-Endosulfan
,beta-Endosutfan
206440 ,'
'86737 !
118741 J
87683. i
' 77474 !
• 67721 -j
193395 J
7B591 }
" 91203 { - ,
9B953" !
- 62759 ! .
621647 'j .
'86306 i
, 85018 1 f . '
• 129000 !
120821 '! ' .
309003 j ' ' 3 9
319S46.J
' 319857 j
- 58899 ! 2 Q
"319868 |
57749 j-. -2.4 g .
50293 ! " 1.1 .g -
72559 J
•: .72548'! • '
60571 | . 2^5 g .
959988 j 0.22 g
33213659 .j 0.:22 g
• 1 4
1 • . 4
' V .-'.*'
! • {
i i •
1 • . 4
! •'•••'•'«
• ' .. ••'•... '... . •' V
1 ' ' »
. 1 - • ..,.'*
1 • , *
1 1
• 1 • . 4..'~
' 1 , t
i 4
• I-'.'' '•..•" ,-- 1
1 • ' .. 4'
1 ' *.
1 • • , '• . '• 1
' ' - . .4 >
. . '- J -1.3g. {
i ' -' ' '« 4 '
i . , . t
: :-- '•'."•';. {• •'
0.08 «j * ! 0.16 q-' . !
1 . .1
1 • «
0.0043 g i 0.09 g 0.004 « {
• 0.001 g, { 0.13 g 0.001 -v' J
1 ' ' . . " 4 '
,1 ."1
• -'"'"' • • •• '!
0.0019 g i 0.71 g 0.0019 g J
0.056 g ! 0.034 g .0..0087 g ' \
.0.0569 ! 0.034 g 0.0087 g |
300 •
. 1300 • •
0.00075 a.c.
0.44 a,t:
240 a
1.9 m,r.
0.0028 c
. 18.4 *.t:
17 • '•
O.00069 •.«:
.. •
'5-0 «.«
;."
960 a
•
0.00013 a.c
0.0039 a.«:
0.014 .B.I:
0.019 c
-
0.00057 a,<:
0.00059 a,i:
0.00059 •.«: .
0.00083 •«.«
0.00014 a,«:
0.93 a *
•
0.93 a
370 a
MOOO a
O.O0077 a.c
' SO a.c
T7OOO a.i
fl.9.a,c
0.031 . c
400 a.c
1900 a.i
8,1 m.e
* - ,. "
«6 *.c
11000 a
•' 0.00014 m,c
0.013 a.c
0.046 a.c
O.O65 c
.0.00059 a,c
0.00059 m;c
0.00059 a.c
"0^00084 6~c
' 0.00014 ».e
2.0 a
2.0.
-------
Federal Register / Vol. 57, No. 246 / Tuesday, .December 22. 1992 / Rules and Regolatfona
•' • • . .'• • . •*.'••' - •"-•.•/«
• . . •
' ••
. - ' .
<«) COMPOUND CAS
.-,'., Kusber
.',,..
114 • EndosuUan Suliate 1031078
* t
115 Endrin " 7220S
•-•"•• •
8 1
Criterion Criterion
Maxinun Continuous
Cone, d -Cone, d
(USA)
B1 ' -12
! -
! 0.18 a 0.0023 8
-" V :G':;' . i
- " ' , '- /I
Criterion Criterion,
Haxi*un Continuous
Cone, d Cone, d
CU9/U CU9A)
f ei e?
[ " "'. '•: '" ^
* - .
5 O.C37 i 0.0023 «
M U 9 A If
CIO"* risk
for Con
Water t
Organisats
.-'";".^.
'.:. '"•'-''• B.OW *"'''?"• ' *' '"
-; I -O.OK,» "•{'.' .' '^ .. .'
• '".. :.•' clou" 9'< .»•'••" ' . ','• •
0.73 0.0002 ? J P.21
0.0023
0.0036
•.0036
O.03
' 0.03
.; ».P3
0.03
• .0.03
0.03
"o-os
0.0002
9
g
q
g
g
g
9
1
g
r
•... -
i
i
i
t
.§ '
i
>
i
i
i
»
i
i
t
r
t
!
{
J
0.93 •
OV7V a
, 0.715 a '
' 0.0002T a.c
" '0.00010' a.c
0.000044 a.e
0.000044 .a.c
O.OOOO44 a.c
o.oopbu «.c
O.OOOOU ».e
«.0000<« *.c
'O.OOOOU aye
0.00073 ».e
1.0 a"
C.W «.}_.
; 9M
0.00021
o.ooa«
O.000046
0.000045
- OJMOOiS
.•JBWKS
*'"."-*
OLOOOKS
; O.WOOCS
'. • 9MOO&
O.OOSZ5
*.I
•**.
*,c «
*-e.
*-*
*•'.
•»«'/
"•>*' '
».*': •
*.e-'x
«.e -
.Total Ho, erf Criteria .(
MUMQ OOOE MM-W-C
23
27
-------
60916 Federal Register /;VoI. 57,.No..246./ Tuesday, December 22, 1992 / Rules.and Regulations
Footnotes:
a.Oiteria revised to reflect current agency
qt* or MD, as contained La the Integrated
Risk Information System (IRIS). The fish
tissue bloconcentration factor (BCF) from the
* 1080 criteria documents was retained in all
CHOI.
b. The criteria refers to the inorganic form
only.
c. Criteria In the matrix bts«d on
ctidnogenldty (10-« risk). Foe a risk level of
10-*, xnova the decimal point in the matrix
value one place }o the right.
d. Criteria Maximum Concentration (CMC) •
«the highest concentration of a pollutant to
which aquatic life can be exposed far a short
. period of time (1-hour avorage) without
deleterious effects. Criteria Continuous .
Concentration (OCC) * the highest
< concentration of a pollutant to which aquatic
life can be exposed for an extended period
of tlmo (4 days) without deleterious effects,
tig/L«ialaogrami per liter '
=•. Freshwater aquatic life criteria for these
metalc ant axprassed as a function of total
hardness (mg/L), and as a function of the'
pollutant's water efiectratio.-WBR, as --•
defined in §131.36(0). The equations are - ••
.provldediamatrixat5l31.36(bK2).yalues •'
displayed above in the matrix correspond to-
«totalhardness of 100 me/Land a water *
effect ratio of 1.0. ' . ' •. -
•tFrohwater aquatic life criteria for •
peatachlorophenolare expressed as a
Junction of pH, and are calculated as follows.
Valuet displayed above In the matrix
correspond to a pH of 7A. •
CMC«exp(1.005(pH)-*8$0) CCC»
exjXl.005(pH)-5.290) •
g. Aquatic life criteria for these compounds
were issued In 1080 utilizing the 1980
Guidelines for criteria development The
acute values shown are final acute values
(FAV) which by the 1980 Guidelines are
instantaneous values as contrasted with a
CMC which is a one-hour average.
h. These totals simply sum the criteria in
each column. For aquatic life, there are 30
priority toxic pollutants with some type of
fresh water, or saltwater, acute or chronic
criteria. For human health, there are 91
priority toxic pollutants with either "water +
fish" or "fish only" criteria. Note that these
totals count rfii™»inm as one pollutant even
though EPA has developed criteria based cm
twa valence states. In the matrix, EPA has
assigned numbers Sa and Sb to the criteria for
chromium to reflect the fact that the list of
. 126 priority toxic pollutants Includes only a
single listingfor chromium.1 • .
• I. if the CCC. for total mercury exceeds
-O.012 ug/L more than'once in a 3-year period
in the ambient water, the edible portion of
aquatic spades of concern must be analyzed
to determine whether the concentration of • •
methyl mercury exceeds the FDA action level
(1.0 me/kg). If the FDA action level is
.'exceeded, the State must notify the..
appropriate EPA Regional Administrator.
.initiate a revision of its mercury criterion In '•
'its water quality standards- so as to protect
designated Uses, and take other appropriate
•action such as'issuance of a fish.consumption
advisory for the affected area.. • -.
J. No criteria for protection of human
health from consumption of aquatic
organisms (excluding water) was presented
In the 1980 criteria document or in the 1986
Quality Criteria for Water. .Nevertheless,
sufficient information was presented in the
1980 document to allow a calculation of a
criterion, even though the results of such a
calculation were not shown in the document
k. The criterion for asbestos is the MCL (56
PR 3526. January 30,1991).
L This letter not used as a footnote.
m. Criteria for these metals are expressed
as a function of the water effect ratio. WER,
as defined in 40 CFR 131.36(c).
CMC « column Bl or Cl value x WER
CCC -column B2 or CZ value x WBR
n. EPA is not promulgating human health
criteria for this contaminant. However, .
permit authorities should address this
contaminant in NPDES permit actions using
the State's existing narrative criteria for . *
toxics. . .
. General Notes: . . .
1. This, chart lists all of EPA'* priority toxic
pollutants whether or not criteria • . •
ncqmmendations lire available. Blank spaces'
indicate the absence of criteria . .
recommendations. Because of variations in ,
chemical nomenclature systems, this listing
of toxic pollutants does not duplicate the
listing in Appendix A of 40 CFR Part 423..
EPA has added the Chemical Abstracts
Service (CAS) registry numbers, which
provide a unique identification for each
chemical. .".•••
2. The following chemicals have • .
organoleptic based criteria recommendations
that are not included em this chart (for '
reasons which are cUscussed in the
preamble): copper, zinc, chlorobenzene, 2-
chlorophen61,2.4-dichlorophenol,
'aoenaphthene. 2.4-dimethylphenol. 3-"
methyl-4-chloroph(inol, ' ' .
hexachlorocyclopentadiene, . •••••,•
pentachlorophenol, phenol . ..-
3. For purposes of this rulemaking, .
freshwater criteria «nd saltwater criteria - "•
apply as specified la 40 CFR 131-36(c). '•
(2) Factors for Calculating Metais Criteria
-CGC-WER exp{rndrn(hardne*s)l+bc}.
-'•'•.••
Cadmium -
Chmmkim (llfl , • , '
itff ..i ' " ' "
7W ' ' ' ' . ' ' "
nu
1.128
04422
04190
04460
1.72
04473
DA
-1.454
34S8
-1.460
3^3012
.-&S2'
04604
me
0.7852
04545
04190
• 1.273
. 04460
04473
be
-3.490
-1.465
1.561
-4.705
• 1.1645
0.7614
(c) Applicability, ft) Hie criteria in
paragraph (b) of this section apply to the
Slates' designated uses cited in
paragraphed) of this section and -
supersede any criteria adopted by the
Stale, except when State regulations
contain criteria which are more
stringent for a particular use in which •
case the State's criteria will continue to •
•ppiy-
' (2) Hie criteria established In this
section are subject to the State's general
rules of applicability in the same way
and to the tame extent as are the other '
numeric toxics criteria when applied to
the same use classifications including
mixing zones, and low flow values.
below which numeric standards can be
exceeded in flowing fresh waters.
' (i) 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;
otherwise the criteria apply throughout
the waterbody including at the end of
.any discharge pipe, canal .or other
discharge point. '
(ii) A State shall not use a low flow '
value below which numeric standards
can be exceeded that is less stringent
than the following for waters suitable
.for the establishment of low flow return
frequencies (i.e., itreams and rivers): -
Aquatic Life
Acute criteria (CMC)
GbiOQlc criteria (CCC)
1Q100MB3
7Q100T4B3
30Q5
Hannonlc
KoB-cudnogMu
Cvdncgtat
Where: -
CMC—criteria maximum concentration—
the water quality criteria to protect against
acute effects in aquatic life and is the highest
instream concentration of a priority toxic
pollutant consisting of a one-hour average
-------
Federal Ragiatar / Vol. 57. No. 246 / Tueaday. December 22. 19S2 / Rules and
not to ba«sc*edad more th*n ones «r«ry
three-yea" on the average;'
COG—criteria canuauous coocaetxalioB—
tha water quality criteria .to protect agaifist
chronic effect* in aiyiatic life l*u«»Wgn«rt
• of this section, the applicable criteria
are the more stringent of the freshwater
or saltwater criteria. However, the
RegUmalAdminictrator may approve
the •OM of tha alternative freshwater or
saltwater criteria if scientifically
, defeasible information and data
demonstrate that on a site-specific basis
thehfologyaitbewaterbodyis -
dominated by freshwater aquatic' life
and Ant freshwater criteria are more
appropriate; or conversely, the biology
of the waterbodyis dominated by .. ,
saltwater aquatic life and that saltwater
criteria are mote appropriate. ........ ;.
. .{4} Application af metals criteria. &
Forporposea- of calculating freshwater •
aquatic life criteria for metals from the '
eqtuttfons in paragraph (b)W of this '
section, the minimum hardness allowed
for use in those equations shall not be
less than 55 mg/1, as caldum carbonate. •
even if the actual ambient hardness is
less *h?n 25 mg/t as calcium carbonate.
Tha TTin-n' tnmti KflT^""** Value for USB in
those equations shall not exceed 400
mg/1 a* calcium carbonate, even if the
actual •rnhtjmt bazdaess is greater than
40O mg/1 as calcium carbonate. The .
«•*"«» provisionc apply for calculating
the metals critaria for the comparisons
providad for in paragraph (c)(3)(iii) of
thi* section.
• pi) The hardness vahies used shall be
consistent with the design disclu
condirloBS estabKshed inparaj —
(c)(Z) of this section for Sows i
mbdngxone&L , . ....
(nflThe criteria for metals :
(compounds tl-t!3 in paragraph (b) of
this sactlan}.«xe expressed 'as total , .
recoverable. For purposes of calculating
aquatic life criteria for metals from the
equations in footnote M. in the criteria
matrix in pazagraph (b)(l) of .this section
and the aquations in paragraph (bM2) of
this section, Ibewater-eBect ratio is '
computed as aspeofic polhitant's acute .
or chronic toxfcity values measured in
water from thasite covered by the
standard, divided by the respective
acute or chroniciaxicity value 4n
laboratory dilution water. The water-
effect ralio shall be assigned a value of *
1JO, axcapt where the permitting
anlhoritT assigns a different value that •
protects: the decignated uses of the water
body from the toxic effects of the .
pollutant, and is derived from suitable :
tests on sampled water representative of
condition* in tiie affected water body,
consistent with the design duchaxse
conditions established in pexagsaak • .
(c)(2) of this section. For purposes of
this paragraph, the term acute toxidty
value is ttie toxicity test results, such as
•the hthalcoacogtraUon of one-half of •
tha test organisms (Le., LCSO) after 96
hours of exposure (e,g., fish toxicity
tests) ox that effoctconcentration_to one-
half of the taat organisms. (i.e.. EC50)
after 48 boors of exposure (e^., daphnia
toxfefty tests). For purposes of this
paragraph* file turui chronic value is the
result fi-bm appropriate hypothesis
testing or regression analysis of
measurements of growth, reproduction,
or survival from life cycle, partial life
eariyMfe stage tests. The
vahies shall be according to current
standardprotocols (e.g., those published
by me Americsai Society for Testing
Materials (ASTM)) or buier comparable
methods. For calculation of criteria •
using site-specific values for both the
hardness and the water effect ratio, the
hardness used in the equations in '
paragraph (bKZ)of miff section shall be
as required in .paragraph (c)(4)(ii) of mis
section. Water hardness shall be . .
calculated from 'the measured calcium
and magnesium ions present, and the
ratio of caldum to m«gn««for Water PbUttttoa Contnl
adopisd under Chapters 46-12,4Z-47X
•and 42-35 of the General Laws of Rhode
Island ar» subject to the criteria in
paragraph (dXl)(ii) of this section.
wimout exception: ••
».2I Fnebwater 6.22 Saltwater:
f^Tt* A :m---;-'- ..,-Ln.- OauSA .•
OawB ii[ii'i7l.'iii'n'i'iia« " QaiaSS' •"
aasaC'V-."•;' J-,-,:;• Qmm.SC ' '•' ' '
(ii)The following criteria from the •
matrixfaipaiagrBph:tbXl)of tihissectfan-
apply to Dw\»da«ificBtioo*
identifiedia pansjrapk (d)flXQ ofOac
sectkm: . . - - .
Oast A '
Class B water* where
' water supply' us* •,
. is designated , ' •
das* B waters whM*
water supply uaa
.•.is not dWgnatadj .
.QanC: '"•'. . _'! '-
QassSA; ' ' ' •' • .
Qasi SB; . .
Tbese dastlBcatSons
m-an
Each of these dasrf-
• fieatfonc i* as-
si0Beo toe Qxcsfia
(iu}Theh*mfittfaflalthcriteri*shaU
be appfiad at th» ltt< risk level.
consistent with, tha State policy. To - .
determine appropriate vahia for
cardnogenff, see footnote c in me
criteria matrix in paragraph (b)(l) ofmis
section. ••...-«_" -•. , . .
(2) Vermont EPA Region 1. 0) All
waters assigned to tha following uaa
Quality Stasdarda-adopted under the .
authority of tha Yetmont Water
Pollution Control Act (10 V.S.A.,
Ckaptar47) an subject to tha criteria in
•paragraph (dK2)80 of this section,
.
GlastK ;..-i '.'••' •
CiauC . ; •, - - . • -
. (ii) The followiog criteria from the
matrix in paragraph (b)(l) of this section
-------
cyaaa federal Register / Vol. 57. No. 246 / Tuesday. December 22. 1992 J Rules and Regulations
•action:
U*9 classification Applicable criteria
disiA
d«LM B waters where
water supply use
I* deilgnated
Out B water* when
water supply UM
If cot designated
OassC
This classification it
assigned the cri-
teria in;
Column BV-all
Column B2—til
Column Dl—til
Tbeca classifications
are assigned the .
. criteria in:
J . . . Column Bl—all
I - * Column B2—til
' c ' . Column D2—til
" (111) The human health criteria shall
b* applied at the State-proposed 10-6 .
••(3) Newjezsey. EPA Region 2. (i) All
waters assigned to the following use
clarifications in the New Jersey
Administrative Code (N.J.A.C.) 7:9-4.1
etseq., Surface Water Quality
Standards, an subject to the criteria in'
paragraph (d)(3HU) of this section. '
without exception.-
N.JA.C. 7»-4.12(b): Class PL
NJ.A.a 7:8-U2(c): dan FW2
NJ.A.C.7:9-4.12{d): Class SBi .
HJJLC. 7:9-4,12(0): Class SB5
N.J.A.C. 7:9-4.12(1): Class SB3
NJ.A,C.7:B-4.12(g): Class SC '.
NJLA.C. 7#-4.13(a): Delaware River Zones
, lC,lD,andlB
N.J.A41,7:9-t.l3(b): Delaware River Zone 2
NJ.A.a7:1>-4.13(c):DelawareRiverZone3 '
N.J.AXX 7rf>-4.13(d): Delaware River Zone 4
N.J.A.C. 7.H>-l.l3(e): Delaware River Zone S
HJ A.C. 7.-9-*.l3{Q: Delaware River Zone 6
(U) Tae following criteria from the
matrix in paragraph (bKl) of this faction
*PP
-------
Federal Register AVoL 57, No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 6O919
' Use classification Applicable criteria
. Column Cl—elli
. . , except: 4, Sb. 7,
; , 8.10.11.13.
102,105,107.
108,111.112.
113.115.117.
and 126.
• .' Column C2-Hall.
• except: 4,,Sb,
10,13,108.112.
113,115. and
• •:• ' ' 117. ' - . ' '
Column D2—ell,
"' except: 14; 105.
- . , - v-. .112; 113. and- -
-115.
(iii) The hximan health criteria thall
be applied at the State-proposed 10~9
risk leveL To determine appropriate
value for carcinogens, see footnote c. in
the criteria matrix in paragraph (b)(l) of
this section. ' .
{5)'District of [Columbia. EPA
Regions. . ., ''
(i) All waters assigned to the ':•
following use classifications in chapter
11 Title 21DC3MR, Water Quality
Standards of the District of Columbia
are subject to the criteria in4 paragraph
(d)(5)(ii) of this section, without • .
exception: ',
1101.2 Class C waters
(ii) The following criteria from the
matrix in paragraph (b)(l) of this section
apply to the use classification identified
in paragraph (d)(5)(i) of this section:
Use-classification Applicable criteria
identified in paragraph (d)(6)(i) of this
section: .
Ufa classification Applicable criteria
Class!
This classification is
assigned the cri-
teria in:
Column Dl—tt!6
This classification is
assigned the cri-
teria in:
This classification is
assigned the cri- • -
• teria is:
G^iimn D2—f 16
(ill) The human health criteria shall
Class II
Class m (marine)
Class IQ (freshwater)
Class C This classification is
" '"."'' assigned the addi- •
' - • : . . tional criteria in:
• Column B2—410,
_ . 118.126.
, Column Dl—* 15.
16.44,67.68.
. V' '79,80.81,88.
' 114.116,118.
• Column D2—elL
: (iii) The human health criteria shall
beappliedattheStates opte 1
(6) Florida, SPA Region 4.
(i) All waters assigned to the
following use classifications in Chapter
' 17-301 of the Florida Administrative
Code (i.e., identified in Section 17-
302.600) are subject to the criteria in
paragraph (d)(6)(ii) of this section. ..
without exception: .
• dots I • •
. Classn
Qassul .'"'..
..(U) The following criteria from the
matrix paragraph (b)(l) of this section
apply to the use classifications . ' -
Uiy QLUUUwU w» »^*w w»w*v «•»•«••£»"»» —•— — - •
level .
(7) Michigan, EPA Region 5.
(i) All waters assigned to the
following use classifications in the
Michigan Department of Natural
Resources Commission General Rules, R
323.1100 designated uses, as defined at
R 323.1043. Definitions; A to N, (i.e..
identified in Section (g) "Designated
use") are subject to the criteria in
paragraph (d)(7)(ii) of this section,
without exception:
Agriculture • '. , • •
, 'Navigation .
• Industrial Water Supply ' • ' •
Public Water Supply at the Point of Water
..Intake
WarmwaterFish "~ - -
Other Indigenous Aquatic Life and Wildlife
Partial Body Contact Recreation .
(ii) The following criteria from the .
matrix in paragraph (b)(l) of this section
apply to the use classifications
identified in paragraph (d)(7)(i) of this
section: •. : .'
Use classification .Applicable criteria
Public Water sup-
ply /
All other designa-
tions' '
This classification Is
. assigned the criteria
, in:
Column Bl—all,
Column B2—ell,
Column Dl—«1L
These classifications
are assigned the cri-
. teria in:
Column Bl—ell.
Column B2—'•all,
.. and
. . Column D2—elL
• (iii) The human health criteria shall •
be applied at the State-adopted 1Q-S risk
level. To determine appropriate value
for carcinogens, see footnote c in the
criteria matrix in paragraph (b)(l) of this
section. -
(8) Arkansas, EPA Region 6.
(i) All waters assigned to the
•following use classification in section
4C (Waterbody uses) identified in
Arkansas Department of Pollution
Control arid Ecology's Regulation No. 2 • -
as amended and entitled. "Regulation
Establishing Water Quality Standards
for Surface Waters of the State of
Arkansas" are subject to the criteria in
paragraph (d)(8)(ii) of this section,
without exception: , :
Extraordinary Resource Waters
Ecologically Sensitive Waterbody
Natural and Scenic Waterways
Fisheries: . .
(l)Trout .
(2) Lakes and Reservoirs
(3) Stream* . • -
{a) Ozark Highlands Ecoraglon
(b) Boston Mountains Ecoreglon
. (c) Arkansas River Valley Ecoregion
(d) Ouachita Mountains Ecoregkm
(e) typical Gulf Coastal Ecoregion
(f) Spring Water-influenced Gulf Coastal
Ecoregion •
• (g) Least-altered Delta Ecoregkm
0») Channel-altered Delta Ecoregion
•Domestic Water Supply
(ii) The following oiteria from the
matrix in paragraph (b)(l) of this section
apply .to the use classification identified
in paragraph (d)(8)(i) of this section:
Use classification Applicable criteria
"'"*'- ' >---'.-,
Extraordinary Re-
source Waters ... .
Ecologically Sensitive
Waterbody .- . .
Natural and Scenic
"Waterways
Fisheries: .,-.,.• * • ','..•
(1) Trout •
(2) Lakes and Res- ...
ervoirs .._ -
(3) Streams.
]. (a)OzarkHigh-
' ' lands'Ecoregion
' (bj Boston Moun- . /
tains Ecoregion
(c) Arkansas River
Valley -
. Ecoregion
(d) Ouachita . .
Mountains -' •
Ecoregion * ~
(e) Typical Gulf
CoasJal ... • •
Ecoregion '.
(f) Spring Water-
influenced Gulf
Coastal
Ecoregion
\ (g) Least-altered
Delta Ecoregion
(h) Channel-al- ' These uses are '
tend Delta each assigned •
'.. Ecoregion - , the criteria in—«
: , Column Bl—
••••"•' M.Sa.Sb.G.
' , 7,8.9.10.
•.. •. .-•'.•.,.: • '.. n.13,14'
Column B2—-
«4.5a,5b.6
7,8.9.10.
•-'•'.- 13.14
-------
€0320 federal .Register / Vol. 57,-Mo. 246 J Itaaaday.-Decembflr 22, 1932 / Rules end Regulations
(9) Kansa£,£RA flegion 7.
(IJ All-waters »saigneatt>the
followlnguxs classification in •fee
KansariDepartmont of Health and
EnvJtnnnannl regulations, TCAJL '28-16-
* 2fib ChmughlCAJL 2B-a&-28£,«re
subject to tho critorialn paragraph
(dj{9)(li) of thii section, without
exception.
Section (2KA}-Spedal Aquatic lifctJse
.Water*
Section (2KB)— Expected Aquatic life UM
Water*
Wat**
Stcttenf3}-Boen8
-------
Federal Register / VoL 57, No. 246 / Tuesday, December 22, 1992 / Rules and Regulations 60921
.. Water and use classification
Waters of Salt Slough, Mud Slough (north} and the San Joaquin River. Sack Dam to the
mouth of the Merced River •
Waters of San Francisco Bay upstream to and including Suisun Bay and the Sacramento-
• San Joaquin Delta •. . : '
All inland waters of the United States or enclosed, beys and estuaries that are waters of the
United States that include an MUN use designation and that the State has either ex-
cluded or partially excluded from coverage under its Water Quality Control Plan for In-
land Surface Waters of California. Tables 1 and 2. or its Water Quality Control Plan for
, Enclosed Bays and Estuaries of California, Tables 1 and 2, or has deferred applicability of
those tables. (Category (a), (b). and (c) waters described on page 6 of Water Quality Con-
-trol Plan .for Inland Surface Waters of California or page 6 of its Water Quality Control
Plan for Enclosed Bays and Estuaries of California.)
Applicable criteria
In addition to the criteria assigned to these
waters elsewhere in this rule, these waters
are assigned the criteria in:
Column Bl—pollutant 10
Column B2—pollutant 10
These waters are assigned the criteria in:
Column Bl—pollutants Sa, 10* and 14
Column B2—pollutants Sa, 10* and 14
Column Cl—pollutant 14
Column C2—pollutant 14
Column D2—pollutants 1,12,17.18/21.
22, 29, 30. 32, 33, 37. 38, 42-44, 46,
48, 49, 54, 159. 66, 67. 68, 78-82, 85,
89.90,91,93.05,96,98 •
These waters are assigned the criteria for pol-
. -....-• lutants for which the State does not apply
' ••-•_.' . Table 1 or 2 standards. These criteria are:
Column Bl—ell pollutants
'• .'.-•-. • Column B2—all pollutants • ' •
.'•„•..•' . ' ; ' Column Dl—all pollutants except f2
All inland waters" of the United States that do not include an MUN use designation and
that the State has either excluded or partially excluded from coverage under its Water . ."-
QuaUty Control Plan for Inland Surface Waters of California, Tables 1 and 2, or has de- . .
ierred appUcabiliry of these tables, (ate^ory (a), (b), and (c) waters described on page 6 - .
of Water Quality Control Plan for Inland Surface Waters of California.) . ' r . ,
These waters are assigned the criteria for po>
• lutants for which the State does not apply
. ' • - . • , Table 1 or 2 standards. These criteria are:
' ' , Column Bl—ell pollutants
' . ' . • Column B2—all pollutants "
• ' - .'•'.•' '•'..••'•• Column D2-^-«ll pollutants except f2
All enclosed bays and estuaries that are waters of the United States and that the State has
either exduded or partially excluded from coverage under itsi Water Quality Control Plan
for Inland Surface Water* of California, Tables land 2, or its Water Quality Control Plan
for Enclosed Bays and Estuaries of California, Tables land 2, or has deferred applicabil- •
try of those tables. (Category (a), (b). and (c)- waters described on page 6 of Water Quality -
Control Plan for Inland Surface Waters of California or page 6 of its Water Quality Con- . ,
trol Plan for-Enclosed Bays and Estuaries of California.) - ......
• . . ' • These waters are assigned the criteria for pol-
•' • • . lutants for which the State does not apply
. . - . . Table lor 2 standards. These criteria are:
" •'...': . - Column Bl—all pollutants
• .. • _ , . Column B2—fill pollutants. • • •'•-
. ' • . ' .: • • . ^ i. - Column Cl—all pollutants . .
" - . '. ••"'.'"..- . •'...."- Column C2—•ell pollutants
.. ••. -.. . ... -.' CohminD2—all pollutants except «2
•The ft«h,wter tanuum critoiu v* Atdoded for the S«n Bnncitco B«y •ftutiy bKtus* high Itvals of Wo«nmuUtion of •dcninm in the
.Indicate th»t the nit water criteria era mdarprotectiva tat Sta FrmncUco B«y. _ • -
(iii) The human health criteria shall
. be applied at the State-adopted KT6 risk
(11) Nevada, EPA Region 9. (i) AH
waters assigned the use classifications
in Chapter 445 of the Nevada
Administrative Code (NAQ, Nevada
Water Pollution Control Regulations,
which are referred to in paragraph
(dXli)(ii) of this section, are subject to
the criteriarin paragraph (d)(ll)(ii) of
this section,-without exception. These
criteria amend the existing State •
standards contained in the Nevada
Water Pollution Control Regulations.
More particularly, these criteria amend
or supplement the table of numeric
standards in MAC 445.1339 for the toxic
pollutants identified in paragraph
(d)(ll)(ii) of this section.
. (ii) The following criteria from matrix
in paragraph (b)(l) of this section apply
to the waters defined in paragraph
(d)(ll)(i) of this section and identified
.below: • •
-------
€0922 federal Rtigbter 7 Vol..57, "No. 246 / Tuesday, December 22, T992 / Rules «nd Regulations
Watwand'use classification
.Waters that the Slate has Included in NAC 445.1339 Where Munici-
pal or domosUe supply Is a designated use
Waters that ihe Stats has Included in NAC 445.1339 where Munici-
pal DC •fiuuintlu sujjply'birai.a designated -use
Applicable criteria
These water* are assigned the criteria in:
Column Bl—pollutant tllB
Column B2—pollutant #118
Column Dl—pollutants flS. 16. 18.19. 20. 21. 23. 26. 27. 29,
30. 34. 37. 38. 42, 43. 55, £8-62.64. 66, 73. 74. 7.8, 82, 65.
*7-«9.'Bl.-«2.96. "98.100.103.1O4.105,114.116,117,118
These water* an assigned the criteria in:
. Column Bl—pollutant f 118
Column B2—pollutant *118
Column D2—ill pollutants except *2.
^ffijTireiromanlrealtn criteria ihall
be applied attheltr8 rlsklevel,
consistent with State policy. To •
determine appropriate value for
carcinogens, see footnote c in the .
criteria matrix in paragraph (b)(l) of this
section,
(12) Alaska, EPA Region JO.
u) All waters assigned to the
dnrfnlstartivo
:fai'18 AAC
70.020) are subJectiothB criteriain
withoxifexcapQon:
70.020.11) (A) Freshwater
70,020,(1){A) Water Supply
(i) Drinking, cullntry, and food processing.
(Ui) Aqusculruro;
W*ter*ecreetian
7a020.(l)(C) iGrow£h*na':propagstion'Of
fish, s hollfith, ether »quftticllfa.«ad
70.020.(2)(A) Marina Water
70.02a(2)(A) Water Supply
(1) Aqua culture.
70.020(2) (B) Water Recreation
(i) contact recreation,
(U) tecondary recreation;
70V020,(2) (C) Growth and propagation of
fith. *ha1lfigh)«herrimaryContactBecreafion
lB.t>1.2100j03lb Secondary Contact ,
RecreaQon • - .
lkrwiD£ criteria
matrix In j>aragrapli {b}(30 of this section
identified in paragraph (d)(13)(i) of this
section: "".
Use classi-
fication
01* • .
O2.b
02cc
O3.a
O3.b
Applicable criteria '
classification is is-
signed&e criteria in:
Column 3J1—«B1
Tnfl""^ y* ^^^y^ffT^fi" y^Jl^J luulIS.SDCbO21
ADDly OV*XDB ?Uitt CyM^^ijHi?"^T^nff
identified in paragraph (d)(14)(i) of this
section: .
-------
Federal Register /Vol. 57, No. 246 / Tuesday. December 22. 1992 / Rules and Regulations 60923
Uws classification Applicable criteria , Use classification . Applicable criteria '
Fish and Shellfish; These classifications Recreation . This classification is
Fish ' • are assigned the crl- • assigned the criteria
terialn: , . *»: X
. . Column Bland ColumttD2— Ma-
• • • gj2) _ 12 10 '•.-.*. ' . •-. • rine Waters and
: Columnci-42. fpe^aterenot
10 . . ••'•', • protected for do-
Column C2—*2. 6. nwstic water
.. 10.14 "pp^
0olHmn
-------
------- |