Technical Support Document for Action on the State of Oregon’s New and Revised Human Health Water Quality Criteria for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011 October 17, 2011


U.S. ENVIRONMENTAL PROTECTION AGENCY - REGION 10

Technical Support
Document

for Action on the State of Oregon's New and
Revised Human Health Water Quality Criteria for
Toxics and Associated Implementation Provisions
Submitted July 12 and 21, 2011

October 17, 2011

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

Contents

I.	INTRODUCTION	4

II.	ORGANIZATION 01 DOCUMENT	7

III.	BACKGROUND	8

A. ODEQ'S JULY 12 AND JULY 21, 2011 SUBMITTALS	12

IV.	ODEQ'S NEW AND REVISED HUMAN HEALTH CRITERIA	14

A.	EPA REVIEW OF OREGON'S HUMAN HEALTH CRITERIA REVISIONS	14

1.	Human Health Criteria Applicability to Oregon's Waters	14

2.	Non-Carcinogens: Criteria Methodology and Input Variables Used by Oregon	18

a)	Reference Done (RfD)	19

b)	Body Weight (BW)	20

c)	Drinking Water Intake Rate (DI)	20

d)	Bioaccumulation/Bioconcentration Factor (BAF/BCF)	20

e)	Fish Consumption Rate (FC)	22

f)	Relative Source Contribution (RSC)	23

3.	Carcinogens: Criteria Methodology and Input Variables Used by Oregon	25

a)	Body Weight, Drinking Water Intake Rate, Bioaccumulation/Bioconcentration
Factor and Fish Consumption Rate	26

b)	Cancer Slope Factor	27

c)	Carcinogenic Risk Level	27

4.	EPA Review of Input Variables for All New and Revised Human Health Criteria
except Methylmercury and Arsenic	28

B.	EPA ACTION ON ODEQ'S NEW HUMAN HEALTH CRITERIA	28

C.	EPA ACTION ON ODEQ'S REVISED HUMAN HEALTH CRITERIA	30

D.	VII • T11YI. VII • R ("1 R Y CRITERION	33

1.	Methylmercury: Criteria Methodology and Input Variables Used by Oregon	33

a) Relative Source Contribution (RSC) for Methylmercury	36

2.	New human health criteria for methylmercury	37

3.	EPA Action and Rationale Regarding Oregon's Methylmercury Criterion	38

E.	INORGANIC ARSENIC CRITERIA	39

1.	Background	39

2.	Numeric Criteria Revisions	41

a)	Freshwater Criteria	42

b)	Saltwater Criteria	47

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria

for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

c) EPA Review of Oregon's Revised Arsenic Criteria	50

(1)	I RI'SI IWATHR CRITERIA	50

(2)	SALTWATER CRITERIA	53

(3)	GENERAL CONSIDERATIONS	54

3. EPA Action and Rationale Regarding Oregon's Arsenic Criteria	55

F.	NEW, REVISED AND WITHDRAWN FOOTNOTES	58

1.	New Footnotes	58

2.	Revised Footnotes	60

3.	Withdrawn Footnotes	62

G.	WITHDRAWN HUMAN HEALTH CRITERIA WHICH WERE REPLACED BY
MORE SPECIFIC CRITERIA	63

H.	TABLE 40 HUMAN HEALTH CRITERIA SUMMARY	66

V.	NARRATIVE STATEMENT	68

VI.	BACKGROUND POLLUTANT CRITERIA PROVISION	70

A.	BACKGROUND	70

B.	ODEQ'S JULY 21, 2011 SUBMITTAL	73

C.	EPA ACTION ON ODEQ'S NEW BACKGROUND POLLUTANT CRITERIA
PROVISION	77

\ II.	VARIANCE PROVISION	87

A.	BACKGROUND	87

B.	ODEQ'S JULY 21, 2011 SUBMITTAL	89

C.	EPA ACTION ON ODEQ'S REVISED VARIANCE PROVISION	93

VIII.	BACTERIA	99

IX.	REVISED RULES REGARDING IMPLEMENTAIN FOR NONPOINT SOURCES. 100

A.	STATEWIDE NARRATIVE CRITERIA	 100

B.	OTHER IMPLEMENTATION OF WATER QUALITY	101

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

TECHNICAL SUPPORT DOCUMENT

For Action on the State of Oregon's New and Revised Human
Health Water Quality Criteria for Toxics and Associated
Implementation Provisions
Submitted July 12 and 21, 2011

I. INTRODUCTION

In consideration of current information relative to fish consumption in Oregon, the Oregon
Department of Environmental Quality (ODEQ) proposed revisions to Oregon's water quality
standards (WQS) located in Chapter 340, Division 41 of Oregon's Administrative Rules (OAR
340-041). ODEQ proposed new and revised human health water quality criteria for toxics and
associated implementation provisions on December 21, 2010. ODEQ provided a formal public
comment period on the proposed revisions and held nine public hearings. The public comment
period extended from December 21, 2010 through March 21, 2011. 1,075 written comments
were received and responded to by ODEQ. Revisions were adopted by the Oregon
Environmental Quality Commission (EQC or Commission) on June 16, 2011, and filed with
Oregon Secretary of State on July 13, 2011. Oregon's submittal included a letter dated July 20,
2011, from Larry Knudsen, Assistant Attorney General, certifying that the revisions were
adopted in accordance with Oregon State law. In accordance with Section 303(c) of the Clean
Water Act (CWA) ODEQ submitted these revisions to EPA for review and approval on July 21,
2011.

ODEQ revised their human health criteria for iron and manganese in a separate submittal dated
January 18, 2011, which EPA approved on June 9, 2011. ODEQ also revised the human health
criteria for arsenic in a separate submittal dated July 12, 2011, which EPA is now approving as
part of this action. ODEQ accepted public comments on these revisions from August 25 to
September 30, 2010, and held public hearings in Portland and Pendleton. ODEQ also conducted
further public comment on the proposed rule, including revised proposed numeric criteria from
February 1 to February 23, 2011. These revisions were adopted by the EQC on April 21, 2011
and became effective under State law upon filing with the Oregon Secretary of State on June 30,
2011. ODEQ submitted the revisions to the human health criteria for arsenic to EPA for review
and approval on July 12, 2011. Oregon's submittal included a letter dated July 11, 2011, from
Larry Knudsen, Assistant Attorney General, certifying that the revisions were adopted in
accordance with Oregon State law.

The June 16, 2011 rule package adopted by the EQC included revisions to the States' Total
Maximum Daily Load (TMDL) and National Pollutant Discharge Elimination System (NPDES)
permitting regulations found in OAR 340-042 and 045. These are revisions to Oregon's
implementation rules and are not water quality standards. Accordingly, Oregon did not include

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

them in the materials submitted for review under Section 303(c) of the CWA and EPA does not
address them in today's action.

Revisions addressed in today's decision can be divided into the general categories described
below.

1. New and revised human health criteria for carcinogens and non-carcinogens at OAR
340-041-0033.

ODEQ adopted new and revised human health criteria for 104 toxic pollutants (48 non-
carcinogens and 56 carcinogens) based on a fish consumption rate of 175 grams per
day. The criteria for these toxic pollutants are consistent with EPA's 304(a)
recommended criteria values1 and were derived using the methodology presented in
EPA's 2000 Methodology for Deriving Ambient Water Quality Criteria for the
Protection of Human Health2 and EPA's 2001 Methylmercury guidance.3 The new and
revised human health criteria for toxic pollutants are contained in Table 40.

Additional revisions related to the human health criteria include:

• The removal of 13 pollutants consistent with EPA's removal of 304(a)
recommended criteria values for these same pollutants. Most of these recommended
criteria were withdrawn since EPA developed individual criteria for the most toxic
of chemicals in the family of chemicals represented by those 13 pollutants.

• Several new, revised and withdrawn footnotes to the criteria in order to provide
clarification.

• Revisions to the water quality standards provision at OAR 340-041-0033 which
revise regulatory citations and table numbers referencing the human health and
aquatic life criteria tables.

2. Revised arsenic human health criteria.

ODEQ adopted revised human health criteria for arsenic and submitted the revised
criteria separately to EPA on July 12, 2011.

3. New implementation provision entitled "Site-specific background pollutant criteria"
at OAR 340-041-0033(6).

ODEQ adopted a new provision that allows it to develop a site-specific criteria for a
portion of a waterbody in the vicinity of an NPDES permitted discharge in limited
instances. The criteria is only applicable for criteria addressing carcinogenic effects on

1 EPA. 2009. EPA National Recommended Water Quality Criteria. U.S. Environmental Protection Agency Office
of Water. Office of Science and Technology. Available at:
http://water.epa.gov/scitech/swguidance/standards/current/upload/nrwac-2009.pdf

2 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, EPA-822-B-00-004. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

3 EPA. 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S. Environmental
Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

human health and for pollutants that are taken into a facility through their intake water
and discharged to the same waterbody at an equal or lower mass. The instream criterion
concentration is limited to three percent above the ambient condition and may not
exceed a 10"4 risk level as calculated using the same input variables as used to calculate
the criteria in Table 40.

4. Revised variance provision at OAR 340-041-0059.

ODEQ has removed the variance authorizing procedure found at OAR 340-041-0061(2)
and replaced it with a new procedure at OAR 340-041-0059. ODEQ's objective for
these revisions was to ensure that variances and their accompanying pollutant reduction
plans continue to ensure progress toward meeting standards, to streamline the
administration process, and to require pollutant reduction plans with specific milestones
that will result in water quality improvement, and add general clarification to the rule.
All variances adopted under this provision require EPA approval.

5. A correction to a cross-reference in the bacteria provision found at OAR 340-041-
0009(10).

ODEQ adopted a revision to correct the cross-reference in this provision to reflect rule
numbering revisions in OAR 340-041-0061.

6. Revised rules explaining how the mechanisms for forestry and agricultural nonpoint
sources work to meet water quality standards and the total maximum daily load
(TMDL) load at OAR 340-041-0007(5) and OAR 340-041-0061(9)(a)(E), (10), and
(11).

ODEQ adopted revisions to clarify how nonpoint sources will be addressed in TMDLs
and how ODEQ will interact with the Departments of Forestry and Agriculture to
ensure needed programs are in place to address these sources of pollution.

II. ORGANIZATION OF DOCUMENT

This document is organized in the following manner. Part III of this document contains
background on ODEQ's process to adopt new and revised human health criteria and information
regarding the July 12 and 21, 2011 submittals.

Part IV contains the basis for EPA's decisions under section 303(c) of the Clean Water Act
(CWA) and implementing regulations found in the Code of Federal Regulations (CFR) at 40
CFR § 131.11 to approve Oregon's new and revised human health criteria. This section includes
information regarding EPA's review of Oregon's human health criteria revisions which
specifically evaluates the applicability of the human health criteria to Oregon's waters along with
the methodology and input variables used by Oregon for their non-carcinogenic and carcinogenic
criteria. This includes an evaluation of Oregon's revised fish consumption rate of 175 grams per
day used to derive the State's new and revised human health criteria. Separate subsections
include the EPA's action on Oregon's new methylmercury human health criteria and revised
human health criteria for arsenic. Finally, this section outlines EPA's review and action on new,
revised and withdrawn footnotes, withdrawn human health criteria which were replaced by more
specific criteria and the Table 40 summary language.

Part V of this document contains EPA's review and action on revisions to Oregon's narrative
statement at OAR 340-041-0033.

Parts VI and VII of the document contain EPA's review and approval of two implementation
procedures included in the July 21, 2011 submittal - the background pollutant criteria and the
revised variance provision.

Part VIII of this document includes EPA's review and action on a minor editorial change to
Oregon's bacteria provision to correct a cross-referencing error.

Part IX discusses the revised rules regarding implementation of criteria by forestry and
agricultural nonpoint sources. These provisions are not WQS under the CWA and therefore EPA
is taking no action on them.

III. BACKGROUND

In 1999, ODEQ initiated a Water Quality Standards Review (triennial review) to update
Oregon's criteria for toxic pollutants which were based on the 1986 EPA Gold Book4 and that
were contained in OAR 340-041-0033 and Table 20 of Oregon's water quality standards. This
review was completed in 2003. During this review, ODEQ made significant revisions to both
their aquatic life and human health criteria based on the updated EPA methodologies and science
for deriving aquatic life and human health criteria that had occurred since the Gold Book had
been published. The Commission adopted these new and revised water quality standards on May
20, 2004. Upon adoption, ODEQ submitted these criteria changes along with revisions to the
narrative toxics provision to EPA on July 8, 2004.

One goal of Oregon's 1999-2003 WQS review was to update its human health criteria for toxic
pollutants in order to reflect the latest scientific information and EPA's most recent national
CWA § 304(a) human health criteria recommendations.5 In 2000, EPA published a revised
methodology for deriving § 304(a) human health criteria recommendations titled Methodology
for Deriving Ambient Water Quality Criteria for the Protection of Human Health (hereinafter
referred to as the "2000 Methodology").6 In separate updates published in 2002 and 20037'8
along with 2009,9 EPA updated the § 304(a) human health criteria recommendations to reflect
this new methodology and to consider updated toxicological information in EPA's Integrated
Risk Information System (IRIS).10

The new and revised human health criteria adopted by Oregon in 2004 were based on EPA's
recommendations provided in these documents. The human health criteria were derived using a
fish consumption rate of 17.5 grams per day (about 0.6 ounces per day or three 6-ounce meals
per month), which represents the 90th percentile of consumption among consumers and non-
consumers of fish nationwide. This is the national default fish consumption rate recommended

4 EPA. 1986. Quality Criteria for Water ("Gold Book"). U.S. Environmental Protection Agency, Office of Water,
Washington, D.C. EPA 440/5-86-001. Available at: http://www.epa.gov/waterscience/criteria/librarv/goldbook.pdf

5 ODEQ. 2003. Toxic Compounds Criteria: 1999-2003 Water Quality Standards Review Issue Paper. Oregon
Department of Environmental Quality, Portland, Oregon. Available at:

http://www.dea.state.or.us/about/eac/agendas/attachments/mav2004/5.20.04.ItemB.AttchH.pdf

6 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

7 EPA. 2002. Revision of National Recommended Water Quality Criteria. U.S. Environmental Protection Agency,
Office of Water, Washington, D.C. Federal Register, Volume: 67, Issue: 249, Page: 79091 (67 FR 79091),
December 27, 2002. Available at: http://www.epa.gov/fedrgstr/EPA-WATER/2002/December/Dav-27/w32770.htm

8 EPA. 2003. National Recommended Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. Federal Register, Volume: 68, Issue: 250,
Page: 75507 (68 FR 75507), December 31, 2003. Available at: http://www.epa.gov/fedrgstr/EPA-
\VATER/2003/Dcccmbcr/D;iv-3 I /w32211 htm

9 EPA. 2009. EPA National Recommended Water Quality Criteria. U.S. Environmental Protection Agency Office
of Water. Office of Science and Technology. Available at:
http://water.epa.gov/scitech/swguidance/standards/current/upload/nrwac-2009.pdf

10 EPA. Integrated Risk Information System (IRIS). U.S. Environmental Protection Agency, Office of Water,
Washington, D.C. Available at: www.epa.gov/iris

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

by EPA in the 2000 Methodology for use when local, regional or other data is not available.
During the public process Oregon received comment regarding concerns that the fish
consumption rate used in the criteria may not accurately represent Oregonian's consumption
patterns. Following review of these comments ODEQ recommended, and in 2004 the
Commission adopted, criteria derived using a fish consumption rate of 17.5 grams per day.
However, in recognition of this expressed public concern, the Commission requested that ODEQ
seek resources to conduct a fish consumption rate study in Oregon.

Following Oregon's 2004 adoption of these criteria, the Confederated Tribes of the Umatilla
Indian Reservation (Umatilla Tribe) and other tribal governments raised objections to EPA,
stating that the criteria did not protect tribal members who eat higher amounts of fish and for
whom fish consumption is a critical part of their cultural tradition and religion. In response, EPA
evaluated the protectiveness of the criteria in light of local and regional fish consumption data
and initiated discussions with Oregon regarding this issue. Local data was available from a study
conducted by the Columbia River Inter-Tribal Fish Commission (CRITFC)11 (hereinafter
referred to as the "CRITFC Study"), which included surveys of four Columbia River Tribes, two
of whom reside in Oregon, the Confederated Tribes of the Umatilla Indian Reservation (CTUIR
or Umatilla Tribe) and the Confederated Tribes of the Warms Springs Reservation. In addition,
several regional fish consumption studies were also available.

Oregon was not able to obtain funding for a study of Oregon fish consumption rates specific to
Oregon but did agree to review available literature and data in collaboration with EPA and the
Umatilla Tribe. In the fall of 2006, ODEQ launched the fish consumption rate review project
involving seven public workshops and two workgroups. The workgroups were charged with
providing ODEQ with information relative to the available science and the potential
implementation and fiscal concerns that may be associated with criteria based on a higher fish
consumption rate. The Human Health Focus Group (HHFG), made up of public health
professionals and toxicologists, reviewed the available data on fish consumption patterns in the

12

Pacific Northwest and elsewhere. The group wrote a report summarizing the science and made
recommendations about the quality and appropriate use of the available information. ODEQ
considered the HHFG's analysis and the other information obtained during this project to select a
fish consumption rate they felt appropriate for use in developing criteria for Oregon's waters.

Oregon addressed several issues during the process of determining an appropriate fish
consumption rate for Oregon. These included:

•	Which studies should be considered when developing a fish consumption rate for
Oregon?

•	Should the criteria be based on a fish consumption rate that includes Oregonians who

11	Columbia River Inter-Tribal Fish Commission (CRITFC). October 1994. . I Fish Consumption Survey of the
Umatilla, Nez Perce, Yakama, and Warm Springs Tribes of the Columbia River Basin. Technical Report 94.3.
Available at: http://www.critfc.org/tech/94-3report.pdf

12	ODEQ. June 2008. Human Health Focus Group Report. Oregon Fish and Shellfish Consumption Rate Project.
Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/HHFGFinalReportJune2008.pdf

9

eat large amounts of fish and shellfish for cultural, economic, health or other reasons, or
a fish consumption rate reflective of Oregon's total (general) population, including
people who do not eat fish or eat it rarely?

• What proportion or percentile of the population(s) should be protected by the criteria?
(Within any group, whether Native-Americans, Asian-Americans, commercial
fishermen or the general population, there will be some individuals who eat more than
any chosen rate and some who eat less than that rate.)

• How should the consumption of salmon (an anadromous fish) and/or marine fish be
considered when determining the rate to be used for freshwaters?

• Should the same rate be used for all waters of Oregon or should multiple rates be
considered based on known consumption patterns?

Following review of all the information obtained during the fish consumption rate review
project, ODEQ determined that a fish consumption rate of 175 grams per day was a reasonable
and protective fish consumption rate to use when driving the human health criteria applicable to
Oregon's surface waters. A fish consumption rate of 175 grams per day equals approximately 6.2
ounces per day (or approximately 23 8-oz fish or shellfish meals per month). This rate represents
the 95th percentile value from the CRITFC study and is within the range of the 90th percentile

values from various studies from the Northwest assembled by the HHFG. ODEQ found the
175 grams per day rate to be consistent with the HHFG recommendation to use 90th or 95th
percentile values to represent the proportion of the population the criteria should be designed to
protect. ODEQ also found the rate to be consistent with HHFG recommendations to use a fish
consumption rate that represents fish consumers only, rather than a rate derived from the overall
population including both consumers and non-consumers of fish, and to include salmon and
other marine species in the rate. Finally, ODEQ recommended that the rate be applied
statewide.14

On October 23, 2008, ODEQ presented the EQC with a recommendation to revise Oregon's
toxics criteria for human health using a FCR of 175 grams per day.15 The Commission agreed
with this recommendation and directed ODEQ to:

1. Revise Oregon's toxics criteria for human health based on a fish consumption rate of 175
grams per person per day;

13 EPA. June I, 2010. Technical Support Document for Action on the State of Oregon's New and Revised Human
Health Water Quality Criteria for Toxics and Revisions to Narrative Toxics Provisions Submitted on July 8, 2004.
U.S. Environmental Protection Agency. See Appendix A for a summary of the studies considered by Oregon.
Available at: http://www.epa.gov/regionlO/pdf/water/oregon-hhwac-tsd iune2010.pdf

14 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 8-10. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

15 ODEQ. October 6, 2008. Memo from Dick Pederson, Director ODEQ, to the Environmental Quality
Commission. Agenda Item G, Action Item: Oregon's Fish Consumption Rate - For Use in Setting Water Quality
Standards for Toxic Pollutants October 23, 2008 EQC Meeting. Oregon Department of Environmental Quality.
Available at: http://www.dea.state.or.us/about/eac/agendas/attachments/2008oct/ItemG.pdf

2. Propose rule language that will allow ODEQ to implement the standards in National
Pollutant Discharge Elimination System (NPDES) permits and other Clean Water Act
programs in an environmentally meaningful and cost-effective manner;

3. Propose rule language or develop other implementation strategies to reduce the adverse
impacts of toxic substances in Oregon's waters that are the result of non-point source (not
via a pipe) discharges or other sources not subject to section 402 of the Clean Water Act;

4. Develop a proposed rule and implementation methods that carefully consider the costs
and benefits of the fish consumption rate and the data and scientific analysis already
compiled or that is developed as part of the rulemaking proceeding.

Pursuant to this directive, ODEQ established a Rulemaking Workgroup in December 2008. The
purpose of this group was to provide input and feedback to ODEQ as it developed its proposed
rulemaking to revise human health criteria using the revised fish consumption rate and to address
potential issues associated with implementing the revised criteria. The workgroup met on a
monthly basis from December 2008 until October 2010. In addition, to address the third element
of the EQC directive, ODEQ formed other workgroups to address the reduction of toxic
pollution from sources not regulated by NPDES permits and to assist in the development of a
comprehensive, cross media toxics reduction strategy.16

On December 21, 2010, ODEQ issued a proposed rule for public comment that included new and
revised human health criteria for toxic pollutants, a revision to their variance rule, a new
background pollutant provision and several proposed additions and revisions to rules relating to
the implementation of the NPDES program and nonpoint source programs. As detailed in
Section I, ODEQ revised the proposed rule in response to comments received, presented it to the
Commission for adoption on June 16, 2011, and submitted it to EPA on July 21, 2011.

On June 1, 2010, consistent with a Consent Decree entered in the U.S. District Court in the

District of Oregon, EPA acted on the revised human health criteria which Oregon had
submitted to EPA on July 8, 2004. As part of this action, EPA disapproved all of Oregon's new
and revised human health criteria that were derived using a fish consumption rate of 17.5 grams
per day as well as three footnotes associated with those criteria and footnote K insofar as it
applies to the "organism only" human health criterion for manganese. EPA found that these
human health criteria, derived using a fish consumption rate of 17.5 grams per day, were not
protective of Oregon's designated use of fishing consistent with the Commission's October 2008
directive. In the June 1, 2010 letter to ODEQ, EPA stated that it "believe[d] that Oregon's
adoption of human health criteria consistent with the Commission's Directive to develop criteria
using a fish consumption rate of 175 grams per day statewide would be adequate to address
EPA's disapproval of the new and revised human health criteria as well as [3 of the 4]

footnotes." As part of the 2010 action, EPA approved the human health criteria for asbestos

16 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, pages 8-9. Available
at: http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

17 Northwest Environmental Advocates v. U.S. EPA, No. 06-479-HA (D. Or. 2006).

18 EPA. June 1, 2010. Letter from Michael A. Bussell, Director, Office of Water and Watersheds, EPA Region 10 to
Neil Mullane, Administrator, Water Quality Division, ODEQ, Re: EPA's Action on New and Revised Human
Health Water Quality Criteria for Toxics and Revisions to Narrative Toxics Provisions in Oregon's Water Quality

and copper since those criteria value were not derived based on a fish consumption rate, footnote
K as it applies to the "water + organism criteria for iron and manganese, the withdrawal of eight
human health criteria, and revisions to the narrative toxic provisions at OAR 340-041-0033(1)
and (2).

A. ODEQ'S JULY 12 AND JUL Y 21,2011 SUBMITTALS

In order to address the Commission's October 2008 directive and EPA's June 1, 2010
disapproval action, on July 21, 2011 Oregon submitted new and revised numeric human health
criteria and two WQS implementation provisions to EPA for action under CWA §303(c). This
submission also contained a correction to a regulatory citation in the bacteria criteria provision
and several other regulatory changes that are not WQS. Revised criteria for arsenic were
adopted separately by the Commission on April 21, 2011 and submitted to EPA on July 12,
2011. All of the numeric criteria adopted in these actions were derived using a fish consumption
rate of 175 grams per day.

The new and revised criteria, which serve as the basis for NPDES permit limits and other
regulatory decisions, are located in Oregon's WQS in a new table called Table 40. ODEQ has
consolidated the human health criteria which were previously contained in Tables 20, 33A and
33B into Table 40. The adoption of the new and revised human health criteria based on a fish
consumption rate of 175 grams per day is ODEQ's remedy to EPA's disapproval of ODEQ's
2004 human health criteria based on a fish consumption rate of 17.5 grams per day.

Consistent with CWA §303(c)(2)(B), in adopting these new and revised human health criteria,
Oregon has adopted human health criteria for all of the priority toxic pollutants for which EPA
has published criteria under CWA §304(a). Forty-eight of the 104 pollutants for which Oregon
adopted new or revised human health criteria are characterized as non-carcinogens (i.e., not
having the potential to cause cancer). The remaining 56 pollutants are carcinogens (i.e., having
the potential to cause cancer).

The calculations that Oregon used to derive the human health criteria for non-carcinogens and
carcinogens differed depending upon the primary exposure pathway appropriate to the pollutant
for which the criteria were derived and are further described separately in section IV below.
Oregon's criteria were adopted to protect human health from chronic (lifetime) exposure to toxic
substances through drinking water and eating fish19 obtained from surface waters. Where the
criteria are derived to protect human health from exposure through both drinking water and
eating fish (in combination), Oregon has adopted "water + organism" criteria. Where the criteria
are derived to protect human health from exposure through eating fish alone (not in combination
with drinking water), Oregon has adopted "organism only" criteria. These two sets of criteria
(i.e., "water + organism" and "organism only") are reflected in the column headings of Table 40

Standards. Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/EPAHHLetter20100601 .pdf

19 As used throughout this technical support document, the term "fish" refers to finfish as well as shellfish.

in Oregon's WQS. Additional information can be found in ODEQ's Human Health Criteria
Issue Paper.20

The criteria adopted by Oregon for methylmercury and arsenic were derived using variations to
the methodology used for all other criteria. Thus, those two pollutants and the methods used to
derive those criteria are addressed separately below.

Additional revisions related to the human health criteria, which are discussed below, include:

• The removal of 13 pollutants consistent with EPA's removal of 304(a) recommended
criteria values for these same pollutants. Most of the previous criteria recommendations
addressed families of pollutants for which the criteria recommendations were withdrawn
when EPA developed criteria recommendations for the individual pollutants within each
family of chemicals that present the greatest human health risk.

• Several new, revised and withdrawn footnotes to the criteria in order to provide
clarification.

• Revisions to the water quality standards provision at OAR 340-041-0033 which provide
narrative language explaining the human health and aquatic life criteria tables.

In response to the second, third and forth directives issued by the EQC on October 23, 2008,
ODEQ also revised OAR 340-041 to include two WQS implementation provisions - a revised
variance procedure and a site-specific background pollutant provision - and revised rule
language addressing implementation for nonpoint sources. In addition, ODEQ adopted an intake
credit rule (an NPDES permitting provision) and several changes to the TMDL rules in OAR
340-042 and 045. These latter changes were not submitted to EPA for consideration under CWA
303(c), are not WQS under the CWA, and are not addressed in this action.

20 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality.
Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

IV. ODEQ'S NEW AND REVISED HUMAN HEALTH CRITERIA

A. EPA REVIEW OF OREGON'S HUMAN HEALTH CRITERIA
REVISIONS

This section contains the basis for EPA's decisions under section 303(c) of the CWA and
implementing regulations found at 40 CFR § 131.11 to approve Oregon's new and revised
human health criteria. This section includes information regarding EPA's review of Oregon's
human health criteria revisions which specifically evaluates the applicability of the human health
criteria to Oregon's waters along with the methodology and input variables used by Oregon for
their non-carcinogenic and carcinogenic criteria. This includes an evaluation of Oregon's
revised fish consumption rate of 175 grams per day. Separate subsections address EPA's action
on Oregon's new methylmercury human health criteria and revised human health criteria for
arsenic. Finally, this section outlines EPA's review and action on new, revised and withdrawn
footnotes, withdrawn human health criteria which were replaced by more specific criteria and the
Table 40 summary language.

1. Human Health Criteria Applicability to Oregon's Waters

Oregon's water quality standards designate beneficial uses for waters of the state for each basin
in OAR 340-041-0101 to 0340 and Tables 101(A) through 340(A), incorporated into Oregon rule
by reference. Oregon's designated uses consist of the following:

•	Public Domestic Water Supply

•	Private Domestic Water Supply

•	Industrial Water Supply

•	Irrigation

•	Livestock Watering

•	Fish and Aquatic Life

•	Wildlife and Hunting

•	Fishing

•	Boating

•	Water Contact Recreation

•	Aesthetic Quality

•	Hydro Power

•	Commercial Navigation and Transportation

Oregon's human health criteria were developed to protect human health from long-term exposure
to toxic pollutants in drinking water and through eating fish and shellfish containing these
pollutants. Waters to be protected for drinking water are those designated as either "Public
Domestic Water Supply" or "Private Domestic Water Supply." Waters to be protected for
consumption of fish and shellfish are designated as "Fishing."

14

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

Oregon's "water + organism" criteria were established to limit the pollutant to levels that protect
the safe consumption of drinking water and fish, including shellfish. These criteria are applied
where Oregon has designated public or private domestic water supply, and fishing as beneficial
uses. Table 1 below identifies those waters in Oregon that have both a fishing designated use
and either a public domestic water supply or a private domestic water supply designated use.

Both the "water + organism" criteria and the "organism only" criteria apply to these waters.

The "organism only" criteria apply where Oregon has designated a fishing use but not a domestic

21

or private water supply use. Table 2 below identifies those waters in Oregon that have a
fishing designated use but neither a public domestic water supply nor a private domestic water
supply designated use.

Table 1: Waters in Oregon that have both a fishing designated use as well as a public domestic
water supply or a private domestic water supply designated use. Both the "water + organism"
criteria and the "organism only" criteria apply to these waters	

Ok WQS
Table No.

liasin N;tme

Segment Names

101A

Mainstem Columbia River

Columbia River (Mouth to RM 86); and Columbia River
(RM 86 to 309)

121A

Mainstem Snake River

Snake River (RM 176 to 409)

130A

Deschutes Basin

Deschutes River Main Stem from Mouth to Pelton
Regulating Dam; Deschutes River Main Stem from Pelton
Regulating Dam to Bend Diversion Dam and for the
Crooked River Main Stem; Deschutes River Main Stem
above Bend Diversion Dam and for the Metolious River
Main Steam; and All Other Basin Stems

140A

Goose and Summer Lakes
Basin

Freshwater Lakes and Reservoirs; and Freshwater Streams

151A

Grande Ronde Basin

Main Stem Grande Ronde River (RM 39 to 165) and All
Other Basin Waters

160A

Hood Basin

Hood River Basin Streams

170A

John Day Basin

John Day River and All Tributaries

180A

Klamath Basin

Klamath River from Klamath Lake to Keno Dam (RM
255 to 232.5); Lost River (RM 5 to 65) and Lost River
Diversion Channel; and All Other Basin Waters

190A

Malheur Lake Basin

All Rivers and Tributaries

21 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality, page
11. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf
Also described in ODEQ. 2004. Toxic Compounds Criteria. 1999-2003 Water Quality Standards Review. Issue
Paper. May 20-21, 2004 EQC Meeting. Agenda Item B, Rule Adoption: Water Quality Standards, including Toxics
Criteria. Attachment H. Oregon Department of Environmental Quality, pages H-14, H-17. Available at:
http://www.dea.state.or.us/about/eac/agendas/attachments/mav2004/5.20.04.ItemB.AttchH.pdf

15

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

OR W'QS
Table No.

liasin Name

Segment Names

201 A

Malheur River Basin

Malheur River from Namorf to Mouth; Malheur River
from Beulah Dam and Warm Springs Dams to Namorf;
Willow Creek from Brogan to Mouth; Willow Creek from
Malheur Reservoir to Brogan; Bully Creek from Reservoir
to Mouth; Malheur Reservoir, Bully Creek Reservoir,
Beulah Reservoir, Warm Springs Reservoir; and Malheur
River and Tributaries Upstream from Reservoirs

220A

Mid Coast Basin

Fresh Waters

23 OA

North Coast Basin

All Other Streams and Tributaries Thereto

25 OA

Owyhee Basin

Owyhee River (RM 0 to 18); Owyhee River (RM 18 to
Dam); Antelope Reservoir, Cow Creek Reservoir, and
Owyhee Reservoir; Owyhee River and Tributaries
Upstream from Owyhee Reservoir; Main Stem of the
South Fork of the Owyhee River from the Oregon-Idaho
River border to Three Forks (the confluence of the North,
Middle, and South Forks of Owyhee River); and Main
Stem Owyhee River from Crooked Creek (RM 22) to the
mouth of Birch Creek (RM 76)

260A

Powder/Burnt Basin

All Basin Waters

Rogue River Main Stem from Estuary to Lost Creek Dam;
Rogue River Main Stem above Lost Dam and Tributaries;
and All Other Tributaries to Rogue River and Bear Creek

286A

Sandy Basin

Sandy River; and All Other Tributaries to Sandy River

300A

South Coast Basin

All Streams and Tributaries Thereto

310A

Umatilla Basin

Umatilla Sub-basin; Willow Creek Sub-basin; Umpqua
River Main Stem from Head of Tidewater to Confluence
of North and South Umpqua Rivers; North Umpqua River
Main Stem; South Umpqua River Main Stem; and All
Other Tributaries to Umpqua, North Umpqua, and South
Umpqua Rivers

330A

Walla Walla Basin

Walla Walla River Main Stem from Confluence of North
and South Forks to State Line; and All Other Basin
Streams

340A

Willamette Basin

Main Stem Willamette River from Mouth to Willamette
Falls, including Multnomah Channel; Main Stem
Willamette River from Willamette Falls to Newberg;
Main Stem Willamette River from Newberg to Salem;
Main Stem Willamette River from Salem to Coast Fork;
Clackamas River; Molalla River; Santiam River;
McKenzie River; Tualatin River; and All Other Streams
and Tributaries

16

Table 2: Waters in Oregon that have a fishing designated use but neither a public domestic water
supply nor a private domestic water supply designated use. "Organism only" criteria apply to
these waters.

OR W QS
Tsihle No.

IJnsin

Segment N:ime

I40A

Goose and Summer Lakes
Basin

Goose Lake; and Highly Alkaline and Saline Lakes

190A

Malheur Lake Basin

Natural Lakes

220A

Mid Coast Basin

Estuaries and Adjacent Marine Waters

23 OA

North Coast Basin

Estuaries and Adjacent Marine Waters

271A

Rogue Basin

Rogue River Estuary and Adjacent Marine Waters; and
Bear Creek Main Stem

286A

Sandy Basin

Streams Forming Waterfalls Near Columbia River
Highway

300A

South Coast Basin

Estuaries and Adjacent Marine Waters

320A

Umpqua Basin

Umpqua River Estuary to Head of Tidewater and Adjacent
Marine Waters

Oregon's application of human health criteria is consistent with EPA's guidance to states and the
methodology inherent in developing the criteria. EPA's Water Quality Standards Handbook
recommends that states adopt human health criteria to protect waters designated for public water
supply. In addition, for waters where fish ingestion is considered an important activity, EPA

recommends that the criterion applicable to fish consumption be applied to protect the use.
Oregon's human health criteria are applied consistent with this recommendation.

EPA has published guidelines for developing criteria that protect human health endpoints and
separate criteria guidance to protect aquatic life endpoints. Consistent with the science used to
derive the criteria, EPA recommends that human health criteria be applied to uses where human
health could be affected by exposure from consumption of water and/or aquatic life and aquatic
life criteria be applied to uses associated with the protection of aquatic life. Thus, most states,
including Oregon, have adopted two sets of criteria for toxic pollutants, one to address the effects
to human health and the other to address the effects to aquatic life. For some pollutants, this
results in a waterbody segment having multiple criteria for a single pollutant, in which case the
WQS require the attainment of all of the applicable criteria.

Oregon's human health criteria are developed pursuant to methods presented in EPA's 2000

Human Health Methodology. These criteria take into consideration the cancer potency or
systemic toxicity of a pollutant, the exposure related to surface water exposure and a risk
characterization. The criteria generated pursuant to the 2000 Human Health Methodology
protect humans from toxicological effects from chronic exposure to a pollutant through drinking
water or from eating fish living in a water body to which the criteria apply.

22 EPA. 1994. Water Quality Standards (WQS) Handbook: Second Edition. August 1994. United States
Environmental Protection Agency, Office of Water. EPA-823-B-94-005a. page 3-15. Available at
http://water.epa.gov/scitech/swguidance/standards/handbook/index.cfm

23 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. EPA-
822-B-00-004. Available at: http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

EPA's guidance for developing aquatic life criteria recommends that such criteria use toxicity
information for aquatic life, establishing pollutant levels necessary for protection of aquatic life

from both short and long term effects of the pollutant. Toxicity tests are used to evaluate
pollutant effects on survival, growth and reproduction of aquatic organisms.

EPA has reviewed Oregon's new and revised human health criteria in order to assess whether
they are sufficient to protect Oregon's designated uses from human health impacts associated
with the pollutants for which they were adopted. Other endpoints and uses (e.g., Fish and
Aquatic Life) are addressed by other provisions in Oregon's WQS and are not before the Agency
for review under § 303(c)(3) of the CWA as part of this action.

2. Non-Carcinogens: Criteria Methodology and Input Variables
Used by Oregon25

EPA's 2000 Human Health Methodology provides guidance for deriving human health criteria
for toxic pollutants.26 Pursuant to Section 304(a) of the CWA, EPA has published a table of
recommended criteria for use by states in adopting and revising criteria.2 For each pollutant,
this table also identifies whether EPA recommends the methodology specific to carcinogens or
non-carcinogens, based on information relative to the human health endpoints of greatest

significance. For criteria recommendations for non-carcinogens, the values in this table reflect
criteria derived using the 'national default' values identified in the 2000 Methodology: the
reference dose (RfD) contained in the Integrated Risk Information System (IRIS) at the time of
publication; the use of EPA's recommended bioconcentration factors (BCFs) (as opposed to site-
specific bioaccumulation factors (BAFs)); and relative source concentration factors (RSC) as
provided by the latest 304(a) recommendations.

While the 2000 Methodology provides national default values, it also provides guidance
necessary to adjust criteria to reflect local conditions and encourages states to use the guidance to

appropriately reflect local conditions and/or protect identifiable subpopulations. Numerous
states have adopted criteria derived through the use of site-specific input variables instead of the
national default values, thus ensuring the criteria are protective of the human health uses

24 EPA. 1985. Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic
Organisms and Their Uses. Available at:

http://water.epa.gov/scitech/swguidance/standards/criteria/aalife/upload/85guidelines.pdf

25For methylmercury, Oregon used an alternate approach that will be addressed in a separate section.

26 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. EPA-
822-B-00-004. Available at: http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

27 EPA. National Recommend Ambient Water Quality Criteria for the Protection of Aquatic Life and Human Health.
Published pursuant to section 304(a) of the Clean Water Act. Available at:
http://www.epa.gov/waterscience/criteria/wactable/index.html

28 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. pages 1-3. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

29 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. pages iii, 1-11.
Available at: http ://www. epa. gov/waterscience/criteria/humanhealth/method/complete .pdf

designated in the waters where those criteria apply.

Criteria calculated pursuant to the 2000 Methodology are derived by applying a number of
pollutant-specific and general risk-assessment values to an equation that generates a criteria
protective of human health uses. Where a state uses this equation to develop criteria, the
protectiveness of those criteria are dependent on whether the values used for each input variable
are appropriate for protection of the uses specific to a pollutant and/or waterbody. With the
exception of the methylmercury criterion, Oregon has directly applied this equation when
deriving the new or revised human health criteria for the non-carcinogenic pollutants included in

EPA's 2009 table of 304(a) criteria recommendations. A simplified version of this equation is
provided in Figure A below, followed by a discussion of the variables in the equation and the
values utilized by Oregon to derive their new and revised criteria, and supporting information
provided by Oregon. EPA's review of the protectiveness of the criteria is contained in a later
subsection.

Figure A: Simplified version of the equation used by Oregon in deriving the human health
criteria for non-carcinogens.

AWQC = RfD •

RSC • fBWl

[DI + [FCR • BAF)]

where:

AWQC

= Ambient Water Quality Criterion (milligrams per liter)

RfD

= Reference dose for noncancer effects (milligrams per

kilogram per day)

RSC

= Relative source contribution factor to account for non-

water sources of exposure (unitless)

= Human body weight (kilograms)

= Drinking water intake (liters per day)

FCR

= Fish Consumption Rate (kilograms per day)

BAF

= Bioaccumulation factor (liters per kilogram)

a) Reference Done (RfD)

For non-carcinogens, EPA's 2000 Methodology recommends deriving human health criteria
using a reference dose. A reference dose is defined as "an estimate (with uncertainty spanning
approximately 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 over a

lifetime." In other words, individuals should not suffer from appreciable risks of deleterious
effects if their exposure to a chemical is at or below the reference dose for that chemical. Thus,

30 EPA. 2009. EPA National Recommended Water Quality Criteria. U.S. Environmental Protection Agency Office
of Water. Office of Science and Technology. Available at:
http://water.epa.gov/scitech/swguidance/standards/current/upload/nrwac-2009.pdf

31 EPA. 1993. Reference Dose (RfD): Description and Use in Health Risk Assessments. Integrated Risk Information
System (IRIS). Intra-Agency Reference Dose (RfD) Work Group, Office of Health and Environmental Assessment,
Environmental Criteria and Assessment Office, U.S. Environmental Protection Agency, Cincinnati, OH. Available
at: http://www.epa.gov/ncea/iris/rfd.htm

the reference dose serves as a threshold level and is specific to each individual pollutant.

In deriving both the "water + organism" and "organism only" criteria for non-carcinogens,
Oregon utilized the most recent reference doses recommended by EPA's current § 304(a)
criteria.

b) Body Weight (BW)

Oregon used EPA's national default value of 70 kilograms for the body weight as recommended
in the 2000 Methodology. The source of data for the human body weight value of 70 kilograms
is the National Health and Nutrition Examination Survey (NHANES) conducted between 1988
and 1994 using a nationwide probability sample of over 30,000 persons. Body weights of 73
percent of those individuals included in the survey were carefully measured by survey staff (i.e.,
weights were not self-reported). The mean body weight value for men and women ages 18-74
years old from this survey was 75.6 kilograms. Another survey by the National Cancer Institute
measured a mean body weigh value of 70.5 kilograms for adults aged 20-64 years old, and
EPA's Exposure Factors Handbook recommends 71.8 kilograms for adults based on an earlier

NHANES survey. While these data are slightly higher than 70 kilograms, the derivation of
cancer slope factors identified in EPA's IRIS database are based upon a body weight of 70
kilograms. Since consistency is advocated between the dose-response relationship and the
exposure factors, a default value of 70 kilograms was recommended by EPA for use in deriving

human health water quality criteria.

c) Drinking Water Intake Rate (Dl)

Oregon used EPA's national default value of two liters per day for the drinking water intake rate
as recommended in the 2000 Methodology. This rate was based on the 1994-1996 Continuing
Survey of Food Intake by Individuals (hereinafter referred to as the "CSFII survey") conducted
by the U.S. Department of Agriculture. This rate represents the 86th percentile of drinking water
intake data for adults collected from the CSFII survey.34 While this rate was utilized for "water
+ organisms" criteria, a drinking water intake rate of zero liters per day was used for "organism
only" criteria because the criteria are not intended to address human health effects from the
consumption of drinking water.

d) Bioaccumulation/Bioconcentration Factor (BAF/BCF)

Bioconcentration factors (BCF) describe the uptake and retention of a pollutant by an aquatic
organism from water only while bioaccumulation factors (BAF)describe the uptake and retention
of a pollutant by an aquatic organism from all sources (e.g., water, ingestion, and sediment). The

32 EPA. 1997. Exposure Factors Handbook. U.S. Environmental Protection Agency, National Center for
Environmental Assessment, Office of Research and Development, Washington, D.C. EPA/600/P-95/002Fa.
Available at: http://cfbub.epa.gov/ncea/cfm/recordisplav.cfm?deid= 12464

33 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. pages 4-18 to 4-19.
Available at: http ://www. epa. gov/waterscience/criteria/humanhealth/method/complete .pdf

34 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. pages 4-21 to 4-22.
Available at: http ://www. epa. gov/waterscience/criteria/humanhealth/method/complete .pdf

magnitude of bioconcentration or bioaccumulation by aquatic organisms varies widely
depending upon the pollutant but can be extremely high for some highly persistent and
hydrophobic pollutants. For highly bioaccumulative pollutants, concentrations in aquatic
organisms may pose unacceptable human health risks from fish consumption even when
concentrations in water are too low to cause unacceptable health risks from drinking water
consumption alone. EPA's 2000 Human Health Methodology recommends the use of national
BAFs in the calculation of ambient water quality criteria. However, to date, EPA has only
provided guidance on the calculation of national BAFs. BAF values have not been calculated for
individual pollutants. EPA uses bioconcentration factors in their nationally recommended
criteria. As explained below, States have the option to use these BCFs or to calculate BAFs
using guidance documents published by EPA.

EPA's 2000 Human Health Methodology provides guidance on developing bioaccumulation

factors for the protection of human health. A subsequent technical support document to the
2000 Methodology entitled Technical Support Document Volume 2: Development of National
Bioaccumulation Factors (2003) provides added detail to the BAF calculation procedures
outlined in the Methodology.36 In 2009, EPA published the Technical Support Document
Volume 3: Development of Site-Specific Bioaccumulation Factors. This document provides
guidance on different approaches that investigators can take to develop site-specific BAFs, and

the factors that should be considered when selecting an approach for a given situation.

EPA recommends that states use these methods when adopting human health criteria. Neither of
the bioaccumulation technical support documents should be used alone to derive BAFs but
should be used in conjunction with the 2000 Human Health Methodology. The bioaccumulation
methodology documents encourage developing site-specific BAFs because EPA recognizes that
BAFs vary not only between chemicals and trophic levels, but also among different ecosystems
and waterbodies. National average BAF values for a given chemical and trophic level may not
provide the most accurate estimate of bioaccumulation for certain water bodies in the United
States. At a given location, the BAF for a chemical may be higher or lower than the national
BAF, depending on the nature and extent of site-specific influences.

While EPA's 2000 Human Health Methodology recommends the use of bioaccumulation factors
in deriving human health criteria, development of bioaccumulation factors is a time and resource
intensive process and BAFs can vary from site-to-site. Thus, it is difficult to develop BAFs on a
national or statewide scale and this has rarely been done. Therefore, until such time as

35 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. Section 5. Available
at: http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

36 EPA. December 2003. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human
Health (2000). Technical Support Document Volume 2: Development of National Bioaccumulation Factors.
Available at:

http://water.epa.gov/scitech/swguidance/standards/upload/2005 05 06 criteria humanhealth method tsdvol2.pdf

37 EPA. September 2009. Methodology for Deriving Ambient Water Quality Criteria for Protection of Human
Health (2000). Technical Support Document Volume 3: Development of Site-Specific Bioaccumulation Factors.
Available at:

http://water.epa.gOv/scitech/swguidance/standards/criteria/health/methodologv/upload/2008 07 01 criteria human
health method tsdvol3.pdf

bioaccumulation factors are developed, EPA's national CWA § 304(a) human health criteria
guidance values continue to be based upon the use of bioconcentration factors which reflect the
uptake and retention of a pollutant by an aquatic organism from water alone. Given the lack of
any Oregon-specific BAFs and consistent with EPA guidance, Oregon utilized bioconcentration
factors instead of bioaccumulation factors in deriving its new and revised human health criteria.
The bioconcentration factors utilized by Oregon are pollutant-specific and are consistent with the
bioconcentration factors recommended by EPA in the most recent national CWA § 304(a)
human health criteria recommendations.

e) Fish Consumption Rate (FC)

When establishing a single value/criterion as a regulatory endpoint, States and EPA must make
several policy decisions relative to the members of the population that will be protected when
using the waters for activities protected by the designated uses and the established criteria. In
EPA's 2000 Human Health Methodology, EPA provides guidance to the States on the use of
local and regional data to develop an appropriate fish consumption rate for the use in criteria
derivation and encourages the states to use this data to determine the level of protection
appropriate for State waters.

Between 2006 and 2008 Oregon conducted extensive outreach and information gathering and
consulted with a group of public health experts (the Human Health Focus Group (HHFG)) in
order to inform their decision-making regarding an appropriate fish consumption rate for use in
developing human health criteria for Oregon. Based on the information gathered in this effort
and the review of available fish consumption studies, ODEQ concluded that a fish consumption
rate of 175 grams per day (about 23, 8 ounce fish meals per month) is a protective rate to use as
the basis for Oregon's human health criteria. Oregon found that this rate reflected the goal of
providing sufficiently clean water in the state such that people who wish to regularly eat fish for
cultural, health or economic reasons may do so without risk of adverse health effects due to

contaminants contained in the fish.

Further detail regarding Oregon's process, information considered and the decision to use a fish
consumption rate of 175 grams per day is available in Oregon's Human Health Criteria Issue

Paper and the Human Health Focus Group Report and outlined in a separate EPA memo.

38 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 21. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf
ODEQ. June 2, 2011. Memorandum from Dick Pedersen to Environmental Quality Commission; Agenda item C,
Rule adoption: Revised water quality standards for human health and revised water quality standards
implementation policies, June 15-17, EQC meeting. Oregon Department of Environmental Quality, page 5.
Available at: http://www.dea.state.or.us/about/eac/agendas/attachments/2011iune/C-WOStdsStaffRpt.pdf

39 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality. At:
http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf
ODEQ. June 2008. Human Health Focus Group Report. Oregon Fish and Shellfish Consumption Rate Project.
Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/HHFGFinalReportJune2008.pdf
EPA. October 17, 2011. Memorandum from Jannine Jennings to Record. Fish Consumption Rate Analysis -
Oregon's New and Revised Human Health Water Quality Criteria for Toxics and Associated Implementation
Provisions Submitted July 12 and 21, 2011.

f) Relative Source Contribution (RSC)

Criteria for pollutants that are non-carcinogens are based on a total cumulative dose over time
that causes an observable effect. Because the human health water quality criteria address
exposure only through drinking water and eating fish and not from other sources (e.g. skin
absorption, inhalation, other foods and occupational exposure), a relative source contribution
(RSC) factor is used to calculate the criteria. The RSC represents the proportion of exposure
from water and fish relative to the total exposure (including water and fish - and other exposures
such as air, food, dermal, etc.). This estimate allows for adjustment of the criteria value to reflect
exposure from only water and fish. This is intended to make sure that the total exposure from all
sources does not exceed the reference dose for lifetime exposure.

Developing an RSC value for a pollutant requires an evaluation of both the sources of potential
exposure and quantifying the relative exposure from each source. EPA has derived RSC values
for 17 of the pollutants with 304(a) recommended human health criteria. Most of these RSC
values were developed by EPA's drinking water program under the Safe Drinking Water Act.

Oregon used 15 of the 17 RSC values recommended by EPA. These 15 RSC values are listed in
table 5 below. Oregon chose to use RSC values that vary from those recommended by EPA for
endrin (80% instead of 20%, discussed in more detail below) and methylmercury (a value of zero
instead of 2.7 x 10"5 mg methylmercury/kg/day, discussed in the methylmercury section below).

Table 5: Criteria where Oregon applied EPA's recommended RSC values.

I'olllllillll

RSC \ :ilue

Antimony

40%

Chlorobenzene

20%

Chlorodibromomethane

80%

Cyanide

20%

Ethylbenzene

20%

gamma-BHC (Lindane)

20%

Hexachlorcyclopentadiene

20%

Thallium

20%

Toluene

20%

1,1,2-Trichloroethane

20%

1,1 -Dichloroethylene

20%

1,2,4-Trichlorobenzene

20%

1,2-Dichlorobenzene(o)

20%

1,2-trans-Dichloroethylene

20%

1,4-Dichlorobenzene(p)

20%

RSC for Endrin

EPA's recommended RSC value of 20% for endrin was developed by the drinking water
program and takes into account exposure through multiple pathways. Endrin is a pesticide that
was banned under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) in the 1980s,
thus limiting current sources of exposure. Following the review of available data and

information, ODEQ determined that an RSC of 80% was appropriate for use in deriving the
human health criteria for endrin.40 Oregon's rationale is described below.

Due to the chemical properties of endrin and its prohibition by FIFRA in the 1980s, ODEQ
believes it is unlikely that people in Oregon would gain only 20% of their exposure from water
and fish while gaining 80% of their exposure from other sources identified in the RSC
calculation performed by EPA and used in EPA's recommended 304(a) criteria.41 The 80% RSC
calculation for endrin used by Oregon accounts for the two main sources of exposure which they
considered to have a potential to impact human health in Oregon: (1) drinking water and (2) the
bioconcentration of endrin in aquatic organisms and thus potential accumulation in fish tissue.
ODEQ found that the other sources or routes of exposure to endrin considered by EPA were not
expected to occur in Oregon for the following reasons:

1) The use of endrin has been banned in the US since the 1980s. Endrin is not mobile in
soil, it volatizes into the air rapidly, and has a conservative half life estimate in soil of 14
years.

2) The U.S. Food and Drug Administration concluded in 1995 that exposure to endrin
through food products was no longer a concern, thus reducing concerns regarding
exposure to endrin from food sources.

3) The one possible route of exposure to endrin that was identified in the literature was at
hazardous waste sites where endrin has been detected in contaminated soils; however, no
such sites were identified in Oregon. 42'43

Based on the above considerations, Oregon found that human health exposure to endrin through
routes other than fish tissue and drinking water is unlikely. In addition, although endrin
bioconcentrates in aquatic organisms, it is not very soluble in water and therefore is not likely to
be found in drinking water sources. Since the bioconcentration factor used to derive the human
health criteria is very high (3970), the endrin criteria values for "water + organism" and
"organism only" are the same when rounded to significant digits.44 Therefore, Oregon
concluded that the primary routes of exposure for endrin are anticipated to be through

40 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 14-15. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

41 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 14-15. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

42 U.S. Department of Health and Human Services. August 1996. Toxicological Profile for Endrin. Public Health
Service. Agency for Toxic Substances and Disease Registry. Available at:
http://www.atsdr.cdc.gov/toxprofiles/tp89.pdf

43 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 14-15. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

44 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 14-15. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

bioconcentration in aquatic organisms and its accumulation in fish tissue. These two exposure
routes have already been accounted for through the BCF and fish consumption rate.

The purpose of the RSC is to ensure that the level of a chemical allowed by a criterion or
multiple criteria, when combined with other identified sources of exposure common to the
population of concern, will not result in exposures that exceed the RfD.45 Where a state reviews
exposure data and develops an alternate RSC value, EPA recommends that the RSC not be lower
than 20% or higher than 80%.46 Where it can be demonstrated that other sources and routes of
exposure are not anticipated for the chemical in question (based on information about its
known/anticipated uses and chemical/physical properties), EPA recommends a ceiling of 80%.
This 80%) ceiling is a way to provide adequate protection for those who experience exposures
(from any or several sources) higher than available data may indicate.47 Oregon adjusted the

RSC value for endrin to 80%> consistent with this guidance.

3. Carcinogens: Criteria Methodology and Input Variables Used
by Oregon49

As noted above, EPA's 2000 Methodology provides guidance for deriving human health criteria
for toxic pollutants50 and has published a table of recommended criteria for use by states in
adopting and revising criteria.51 For human health criteria, the values in this table reflect criteria
derived using all of the 'national default' values identified in the 2000 Methodology, the
reference dose (RfD) contained in the Integrated Risk Information System (IRIS) at the time of
publication, the use of EPA's recommended bioconcentration factors (BCFs), relative source
contribution factors (RSC) as provided by the latest 304(a) recommendations and a 10"6
carcinogenic risk factor. While the 2000 Methodology provides national default values, it also
provides necessary guidance to adjust criteria to reflect local conditions and encourages states to
use the guidance to appropriately reflect local conditions and/or protect identifiable

subpopulations. Numerous states have adopted criteria derived through the use of site-specific
input variables or a carcinogenic risk level other than lxlO"6.

45 November 3, 2000. Federal Register, Volume: 65, Issue: 214, pages: 66472-3 (65 FR 66472-3). Available at:
http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-03/w27924.htm

46 November 3, 2000. Federal Register, Volume: 65, Issue: 214, pages: 66472-3 (65 FR 66472-3). Available at:
http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-03/w27924.htm

47 November 3, 2000. Federal Register, Volume: 65, Issue: 214, pages: 66472-3 (65 FR 66472-3). Available at:
http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-03/w27924.htm

48 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality,
pages 14-15. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

49 Note: For arsenic, Oregon used an alternate approach that will be addressed in section IV.E of this document.

50 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

51 EPA. National Recommend Ambient Water Quality Criteria for the Protection of Aquatic Life and Human Health.
Published pursuant to section 304(a) of the Clean Water Act. Available at:
http://www.epa.gov/waterscience/criteria/wactable/index.html

52 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. pages iii, 1-11.

Available at: http ://www. epa. gov/waterscience/criteria/humanhealth/method/complete .pdf

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

For carcinogens, EPA's 2000 Methodology recognizes that states have the flexibility to adopt
human health criteria within a risk level range of 1 x 10"6 to 1 x 10~5, as long as highly exposed
populations would at least be protected at the 1 x 10"4 (1:10,000) risk level. Furthermore, the
2000 Methodology recognizes that states have the flexibility to adopt human health criteria that
protect the general population at a more protective risk level or target the protection of a higher
proportion of its population at the targeted risk level. Oregon's new and revised criteria for
carcinogens (except arsenic) target the protection of high consumers at the 1 x 10"6 risk level
through the use of a fish consumption rate representative of the 95th percentile consumption from
a study of a highly exposed subpopulation.

EPA's 2000 Methodology describes procedures that can be used as guidance by states for
deriving human health water criteria. The 2000 Methodology includes an equation that Oregon
used in deriving the "water + organism" and "organism only" new and revised human health
criteria for 56 carcinogens. A simplified version of this equation is provided below in Figure B.
Descriptions of the variables included in these equations, and the values that Oregon utilized for
each variable, are also provided below.

Figure B: Simplified version of the equation used by Oregon in deriving the human health
criteria for carcinogens.

AWQC =

fRisk Level • BW1



[CSF • [DI + (FCR • BAF))]

where:



AWQC

= Ambient Water Quality Criterion (milligrams per liter)

Risk Level

= Risk level (unitless)

CSF

= Cancer slope factor (milligrams per kilogram per day)

BW

= Human body weight (kilograms)

DI

= Drinking water intake (liters per day)

FCF

= Fish Consumption Rate (kilograms per day)

BAF

= Bioaccumulation factor (liters per kilogram)

a) Body Weight, Drinking Water Intake Rate,
Bioaccumulation/Bioconcentration Factor and Fish
Consumption Rate

Four of the input variables used by Oregon in deriving its numeric human health water quality
criteria for carcinogens are the same as those used by Oregon in deriving its numeric human
health water quality criteria for non-carcinogens. A body weight of 70 kilograms and a drinking
water intake of two liters per day were used, consistent with the default values that EPA utilized
in deriving its national CWA § 304(a) human health criteria guidance values. Oregon also used
bioconcentration factors consistent with those used by EPA in deriving its national CWA §
304(a) human health criteria guidance values.

Consistent with the criteria for non-carcinogens, a fish consumption rate of 175 grams per day
was used in deriving the new and revised human health criteria for carcinogens. This value was

26

used by Oregon following an evaluation of local and regional data (discussed in greater detail
above).

b) Cancer Slope Factor

For toxic pollutants identified as carcinogens and assumed to exhibit a linear dose-response
relationship at low doses, EPA derives its national CWA § 304(a) human health criteria
recommendations to correspond to incremental lifetime cancer risk levels, applying a risk
management policy that ensures a reasonable level of protection for the general population.53
Accordingly, a cancer slope factor is included in the calculation. A cancer slope factor expresses
incremental, lifetime risk of cancer as a function of the rate of intake of the contaminant, and is
combined with exposure assumptions to express that risk in terms of an ambient water
concentration. Cancer slope factors are specific to individual pollutants. In deriving both the
"water + organism" and "organism only" human health criteria for carcinogens, Oregon utilized
the cancer slope factors recommended by EPA.

c) Carcinogenic Risk Level

EPA has identified a risk level range of 1 x 10"6 (1:1,000,000) to 1 x 10"5 (1:100,000) to be an
appropriate risk management goal for the general population. EPA characterizes this acceptable
risk range as the "upper-bound estimate of excess lifetime cancer risk," ranging from one case in
a population of one million to one case in a population of one hundred thousand. The nationally
recommended 304(a) criteria are intended to protect the general population at a cancer risk of 1 x
10"6.

EPA's 2000 Methodology states that criteria based on a 10"5 risk level are acceptable for the
general population as long as States and authorized Tribes ensure that the risk to more highly
exposed subgroups (sport fishers or subsistence fishers) does not exceed the 10"4 risk level. If a
state does not find that the 1 x 10"6 risk level adequately protects highly exposed populations, it
has the flexibility to adopt water quality criteria based on a more stringent risk level or at a level
more representative of highly exposed population groups. This flexibility extends to all variables
used to calculate the criteria.54

Except where specifically identified, Oregon's new and revised human health criteria for
carcinogens are calculated using a risk level of 1 x 10"6 (1:1,000,000). As discussed earlier, these
criteria include the use of a fish consumption rate of 175 grams per day, a level representative of
high fish consumers in the state. Oregon's goal in adopting the criteria was to protect high end
consumers (as opposed to the general population) at a risk level of 10"6.

53 EPA. 2000. Revisions to the Methodology for Deriving Ambient Water Quality Criteria for the Protection of
Human Health (2000). U.S. Environmental Protection Agency, Office of Water, Washington, D.C. Federal
Register, Volume: 65, Issue: 214, page: 66443 (65 FR 66443), November 3, 2000. Available at:
http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-03/w27924.htm

54 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 822-B-00-004. page 2-6. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

4. EPA Review of Input Variables for All New and Revised Human
Health Criteria except Methylmercury and Arsenic55

As discussed above, EPA's 2000 Human Health Methodology provides guidance for deriving
human health criteria for toxic pollutants. For each variable used in the criteria calculation, EPA
provides a "national default value" and guidance on specific adjustments that may be necessary
to reflect local conditions and/or protect identifiable subpopulations. As part of evaluating
whether Oregon's criteria protect the designated uses, EPA looked at the input values used by
Oregon and whether there was Oregon-specific information relative to each value that should be
considered in the review.

EPA has not identified any local or regional data to indicate that the national values used by
Oregon for the reference dose, relative source contribution, body weight, drinking water intake
rate, or bioaccumulation factors are inappropriate for use in Oregon.

EPA's review indicates that there is local and regional fish consumption data available and that it
should be considered consistent with EPA's 2000 Methodology. The 2000 Methodology
recognizes the variability of fish consumption rates among population groups and by geographic
region. In employing the 2000 Methodology to derive criteria, EPA urges States and Tribes to
use a fish intake level derived from local or regional data instead of the national default
recommendation to ensure the fish intake level chosen is protective of highly exposed
subpopulations. A four preference hierarchy concerning the use of fish consumption rate data is
set forth: (1) use of local data; (2) use of data reflecting similar geography/population groups;
(3) use of data from national surveys; and (4) use of EPA's default intake rate.

As discussed in greater detail above, in 1996 Oregon initiated an extensive review of the fish
consumption rate used for deriving its human health criteria. This process resulted in ODEQ and
the Commission determining that a fish consumption rate of 175 grams per day was a reasonable
and protective fish consumption rate to use as the basis for Oregon's human health criteria.
EPA has reviewed the available information and the basis for ODEQ's determination and has
found that Oregon has considered all relevant local and regional data, applied that data consistent
with EPA's 2000 Methodology to select a fish consumption rate that would result in a level of
protection consistent with that recommended by EPA in the 2000 Methodology. Thus, EPA
finds that the FCR utilized to derive Oregon's criteria is consistent with EPA's recommendations
in the 2000 Methodology.

B. EPA ACTION ON ODEQ'S NEW HUMAN HEALTH CRITERIA

ODEQ has adopted new human health criteria for 41 pollutants (excluding methylmercury which
is discussed in further detail below). Previously, Oregon did not have EPA-approved values for
these criteria in their WQS. These new criteria, found in Table 40 of Oregon's WQS, are

55 Methylmercury and arsenic are addressed in sections IV.D and IV.E of this document.

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

consistent with EPA's current 304(a) criteria recommendations and utilize the 175 grams per day
fish consumption rate.

Tab

e 6: Oregon's new human health criteria.

No.

I'olllllillll

Csircinogen

Wilier + ()r»:inism

Or^iinisin Only







(MR/1-)

(M8/I-)

1

Acenaphthene



95

99

2

Anthracene



2900

4000

3

Benzo(a)anthracene

~

0.0013

0.0018

4

Benzo (a)pyrene

~

0.0013

0.0018

5

Benzo(b)fluoranthene 3,4

~

0.0013

0.0018

6

Benzo(k)fluoranthene

~

0.0013

0.0018

7

Bromoform

~

3.3

14

8

Butylbenzyl phthalate



190

190

9

Chlorobenzene



74

160

10

Chlorodibromomethane

~

0.31

1.3

11

Chloronaphthalene 2



150

160

12

Chlorophenol 2



14

15

13

Chrysene

~

0.0013

0.0018

14

DDD 4,4'

~

0.000031

0.000031

15

DDE 4,4'

~

0.000022

0.000022

16

DDT 4,4'

~

0.000022

0.000022

17

Dibenzo(a,h)anthracene

~

0.0013

0.0018

18

Dichlorobenzene(o) 1,2



110

130

19

Dichlorobenzene(p) 1,4



16

19

20

Dichlorobromomethane

~

0.42

1.7

21

Dichloroethylene 1,1



230

710

22

Dichloroethylene trans 1,2



120

1000

23

Dichloropropane 1,2

~

0.38

1.5

24

Dimethylphenol 2,4



76

85

25

Dinitrophenol 2,4



62

530

26

Dinitrophenols



62

530

27

Diphenylhydrazine 1,2

~

0.014

0.020

28

Endosulfan alpha



8.5

8.9

29

Endosulfan beta



8.5

8.9

30

Endosulfan sulfate



8.5

8.9

31

Endrin aldehyde



0.030

0.030

32

Fluorene



390

530

33

Heptachlor epoxide

~

0.0000039

0.0000039

34

Indeno( 1,2,3 -cd)pyrene

~

0.0013

0.0018

35

Methyl bromide



37

150

36

Methyl-4,6-dinitrophenol 2



9.2

28

37

Methylene chloride

~

4.3

59

38

Nitrosodi-n-propylamine, N

~

0.0046

0.051

39

Pyrene



290

400

40

Trichlorobenzene 1,2,4



6.4

7.0

41

Zinc



2100

2600

29

EPA Approval

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves Oregon's new human health toxic criteria for these 41 pollutants that are
consistent with EPA's current CWA § 304(a) criteria recommendations because they are
protective of Oregon's fishing and water supply designated uses.

EPA Rationale

EPA's WQS regulations at 40 C.F.R. 131 require that criteria protect the designated uses. As
noted previously, Oregon's human health criteria apply to waters with fishing and water supply
uses and thus must be established at a level that will protect those uses. Therefore, EPA must
evaluate whether the criteria protect Oregon's human health uses.

EPA's 2000 Human Health Methodology provides guidance for deriving human health criteria
for toxic pollutants. For each variable used in the criteria calculation, EPA provides a "national
default value" and guidance on specific adjustments that may be necessary to reflect local
conditions and/or protect identifiable subpopulations. As part of evaluating whether Oregon's
criteria protect the designated uses, EPA looked at the input values used by Oregon and whether
there was Oregon-specific information relative to each value that should be considered in the
review. As discussed above EPA has found that ODEQ has appropriately considered local and
regional data in selecting input variables for use in deriving the criteria identified in Table 6.

The 2000 Methodology document provides an extensive technical basis and justification as to
how EPA's recommended human health criteria adequately protect human health uses. Oregon's
new criteria were developed consistent with these recommendations, therefore, EPA has
determined that Oregon's new criteria protect human health uses in accordance with 40 C.F.R.
Part 131.11(a)(1).

C. EPA ACTION ON ODEQ'S REVISED HUMAN HEALTH CRITERIA

ODEQ has adopted revised human health criteria for 62 pollutants (excluding arsenic which is
described in further detail below). These revised criteria, found in Table 40 of Oregon's WQS,
are consistent with EPA's current 304(a) criteria recommendations and utilize the 175 grams per
day fish consumption rate.

Table 7: Oregon's revised human health criteria

No.

Polliiliinl

C'ii rcin<)»cn

\Y siler + Oiiiitnism
(MS/I.)

Onanism Only
(MJi/1 )

Acrolein56

0.88

o.y3

Acrylonitrile

0.018

0.025

Aldrin

0.0000050

Antimony

5.1

56 Based on June 10, 2009 updates to EPA's IRIS system, Oregon's previous ADI value of 15.6 ug/kgram per day
was replaced with an RfD value of 5.0 x 10~4. EPA. Integrated Risk Information System (IRIS). U.S. Environmental
Protection Agency, Office of Water, Washington, D.C. Available at: www.epa. gov/iris

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

No.

Polllllillll

C:i mitogen

\\ :ilor + ()r»;inisin
(MB/I.)

Or^iinisin Only
(MR/I-)

5

Benzene

S

1.6

5.1

6

Benzidine

V

0.000018

0.000020

7

BHC Alpha

V

0.00045

0.00049

8

BHC Beta

S

0.0016

0.0017

9

BHC Gamma (Lindane)



0.17

0.18

10

Carbon tetrachloride

s

0.10

0.16

11

Chlordane

V

0.000081

0.000081

12

Chloroethyl ether bis 2

V

0.020

0.05

13

Chloroform57



260

1100

14

Chloroisopropyl ether bis 2



1200

6500

15

Chloromethyl ether, bis

s

0.000024

0.000029

16

Cyanide0



130

130

17

Dichlorobenzene(m) 1,3



80

96

18

Dichlorobenzidine 3,3'

s

0.0027

0.0028

19

Dichloroethane 1,2

V

0.35

3.7

20

Dichlorophenol 2,4



23

29

21

Dichloropropene 1,3

s

0.30

2.1

22

Dieldrin

s

0.0000053

0.0000054

23

Diethyl phthalate



3800

4400

24

Dimethyl phthalate



84000

110000

25

Di-n-butyl phthalate



400

450

26

Dinitrotoluene 2,4

s

0.084

0.34

27

Dioxin (2,3,7,8-TCDD)

s

0.00000000051

0.00000000051

28

Endrin



0.024

0.024

29

Ethylbenzene



160

210

30

Ethylhexyl phthalate bis 2

s

0.20

0.22

31

Fluoranthene



14

14

32

Heptachlor

s

0.0000079

0.0000079

33

Hexachlorobenzene

V

0.000029

0.000029

34

Hexachlorobutadiene

V

0.36

1.8

35

Hexachlorocyclo-hexane-
Technical

s

0.0014

0.0015

36

Hexachlorocyclopentadiene



30

110

37

Hexachloroethane

s

0.29

0.33

38

Isophorone

V

27

96

39

Nickel58



140

170

40

Nitrobenzene



14

69

41

Nitrosamines

s

0.00079

0.046

57	Based on June 10, 2009 updates to EPA's IRIS system, Oregon's previous ql* value of 6.1 x 10"3 was replaced
with an RfD value of 0.01 mg/kgrams per day. EPA. Integrated Risk Information System (IRIS). U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. Available at: www.epa.gov/iris

58	Oregon's revised human health criteria for nickel are less stringent than Oregon's previous values despite
Oregon's adoption of a 175 grams per day fish consumption rate. However, the equation used to calculate the
revised criteria is consistent with EPA's current 304(a) recommendations. It is unclear how ODEQ derived their
previous values for nickel. Nonetheless, EPA assessed protectiveness of the revised criteria using EPA's 304(a)
recommendations and Oregon's human health designated uses.

31

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Technical Support Document for EPA 's Action on Oregon's New and Revised Human Health Water Quality Criteria
for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

No.

Polllllillll

C:i mitogen

\\ :ilor + ()r»;inisin
(MB/I.)

Or^iinisin Only
(MR/I-)

42

Nitrosodibutylamine, N

~

0.0050

U.U2

43

Nitrosodiethylamine, N

~

0.00079

0.046

44

Nitrosodimethylamine, N

~

0.00068

0.30

45

Nitrosodiphenylamine, N

~

0.55

0.60

46

Nitrosopyrrolidine, N

~

0.016

3.4

47

Pentachlorobenzene



0.15

0.15

48

Pentachlorophenol

~

0.15

0.30

49

Phenol59



9400

86000

50

Polychlorinated biphenyls
(PCBs)l

~

0.0000064

0.0000064

51

Selenium60



120

420

52

Tetrachlorobenzene 1,2,4,5-



0.11

0.11

53

Tetrachloroethane 1,1,2,2

~

0.12

0.40

54

T etrachloroethylene

~

0.24

0.33

55

Thallium



0.043

0.047

56

Toluene



720

1500

57

Toxaphene

~

0.000028

0.000028

58

Trichloroethane 1,1,2

~

0.44

1.6

59

Trichloroethylene

~

1.4

3.0

60

Trichlorophenol 2,4,5-



330

360

61

Trichlorophenol 2,4,6

~

0.23

0.24

62

Vinyl chloride

~

0.02

0.24

Footnote G: They cyanide criterion is expressed as total cyanide (CN)/L

Footnote L: This criterion applies to total PCBs (e.g. determined as Aroclors or congeners).

EPA Approval

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves Oregon's revised human health toxic criteria for these 62 pollutants, consistent
with EPA's current CWA § 304(a) criteria recommendations, because they are protective of
fishing and water supply uses.

EPA Rationale

EPA's WQS regulations require that criteria protect the designated uses. As noted previously,
Oregon's human health criteria apply to waters with fishing and water supply uses and thus must
be established at a level that will protect those uses. Therefore, EPA must evaluate whether the
criteria protect Oregon's human health uses.

59	Based on updates to EPA's IRIS system, the RfD value of 6.0 x 10"1 was replaced by Oregon with an RfD value
of 3.0 x 10"1. EPA. Integrated Risk Information System (IRIS). U.S. Environmental Protection Agency, Office of
Water, Washington, D.C. Available at: www.epa.gov/iris

60	Oregon's revised human health criteria for selenium are less stringent than Oregon's previous values despite
Oregon's adoption of a 175 grams per day fish consumption rate. However, the equation used to calculate the
revised criteria is consistent with EPA's current 304(a) recommendations. It is unclear how ODEQ derived their
previous values for these two pollutants. Nonetheless, EPA assessed protectiveness of the revised criteria using
EPA's 304(a) recommendations and Oregon's human health designated uses.

32

EPA's 2000 Human Health Methodology provides guidance for deriving human health criteria
for toxic pollutants. For each variable used in the criteria calculation, EPA provides a "national
default value" and guidance on specific adjustments that may be necessary to reflect local
conditions and/or protect identifiable subpopulations. As part of evaluating whether Oregon's
criteria protect the designated uses, EPA reviewed the input values used by Oregon and whether
there was Oregon-specific information relative to each value that should be considered in the
review. As discussed above EPA has found that ODEQ has appropriately considered local and
regional data in selecting input variables for use in deriving the criteria identified in Table 7.

EPA provides an extensive technical basis and justification as to how its recommended human
health criteria adequately protect human health uses in EPA's 2000 Methodology document.
Oregon's revised criteria were developed consistent with these recommendations, therefore, EPA
has determined that Oregon's revised criteria protect human health uses in accordance with 40
C.F.R. Part 131.11(a)(1).

D. METHYLMERCURY CRITERION

1. Methylmercury: Criteria Methodology and Input Variables
Used by Oregon

On January 8, 2001, EPA published61 a new national CWA § 304(a) human health criterion
recommendation for methylmercury62 which replaced EPA's previous recommendations for total
mercury. The new recommendation is expressed as a fish tissue value, thus reflecting the latest
science that indicates consumption of contaminated fish and shellfish is the primary human route
of exposure to methylmercury.

In 1980, EPA published a water quality criterion for total mercury. The criterion was partially
updated in 1997 to incorporate a change in the reference dose (RfD). Consistent with Section
304(a) of the Clean Water Act, EPA periodically revises water quality criteria to reflect the latest
scientific knowledge on the type and extent of identifiable effects on human health from the
presence of pollutants in a waterbody. In 2001, EPA completed a review of the water quality
criterion for protection of human health for methylmercury. This criterion recommendation
considered the bioaccumulation of methylmercury as well as the latest science and data
regarding health effects from intake of mercury and the primary routes of exposure. The new
criterion for methylmercury was derived consistent with the Methodology for Deriving Ambient
Water Quality Criteria for the Protection of Human Health (2000). The 2001 recommendation

61 EPA. January 8, 2001. Water Quality Criteria: Notice of Availability of Water Quality Criterion for the
Protection of Human Health: Methylmercury. U.S. Environmental Protection Agency, Office of Water,
Washington, D.C. Federal Register, Volume: 66, Issue: 5, page: 1344 (66 FR 1344). Available at:
http://www.epa. gov/fedrgstr/EPA-WATER/200 l/Januarv/Dav-08/w217.htm

62 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

is expressed as a fish tissue concentration for methylmercury and replaces the water column
concentration for mercury that was contained in EPA's previous recommendation.63

As part of the 2001 reevaluation of the mercury criterion, EPA evaluated the sources and form of
mercury that humans are exposed to when eating fish or consuming water from the nation's
waters. It was found that humans are exposed primarily to methylmercury rather than to
inorganic mercury and that the dominant exposure pathway is through consumption of
contaminated fish and shellfish rather than from ambient water.64 EPA found that if a criterion
addressed the potential health effects from methylmercury, it would protect humans from the
most toxic form of mercury and the primary route of exposure. Thus, in considering the fate of
mercury in the environment and available toxicological data, EPA concluded that it is more
appropriate to derive a water quality criterion for methylmercury rather than inorganic mercury.
In addition, "EPA believes that the latest data and science on methylmercury exposure, effects,
and environmental fate support the derivation of a fish tissue residue criterion," instead of a
water column criterion.65

"Methylmercury is highly bioaccumulative and is the form of mercury that bioaccumulates most
efficiently in the aquatic food web. Methylation of mercury is a key step in the entrance of
mercury into food chains. The biotransformation of inorganic mercury species to methylated
organic species in water bodies can occur in the sediment and the water column. Inorganic
mercury can be absorbed by aquatic organisms but is generally taken up at a slower rate and with
lower efficiency than is methylmercury."66

"Methylmercury continues to accumulate in fish as they age. Predatory organisms at the top of
aquatic and terrestrial food webs generally have higher methylmercury concentrations because
methylmercury is typically not completely eliminated by organisms and is transferred up the
food chain when predators feed on prey; for example, when a largemouth bass feeds on a bluegill
sunfish, which fed on aquatic insects and smaller fish, all of which could contain some amount of
methylmercury that gets transferred to the predator. Nearly 100 percent of the mercury that
bioaccumulates in upper trophic level fish (predator) tissue is methylmercury (Bloom, 1992;
Akagi, 1995; Kim, 1995; Becker and Bigham, 1995.)"67

63 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. page 1-1. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

64 EPA. January 8, 2001. Water Quality Criteria: Notice of Availability of Water Quality Criterion for the
Protection of Human Health: Methylmercury. U.S. Environmental Protection Agency, Office of Water,
Washington, D.C. Federal Register, Volume: 66, Issue: 5, Page: 1344 (66 FR 1344). page 1345. Available at:
http://www.epa. gov/fedrgstr/EPA-WATER/200 l/Januarv/Dav-08/w217.htm

65 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. page 1-2. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

66 EPA. January 8, 2001. Water Quality Criteria: Notice of Availability of Water Quality Criterion for the
Protection of Human Health: Methylmercury. U.S. Environmental Protection Agency, Office of Water,
Washington, D.C. Federal Register, Volume: 66, Issue: 5, Page: 1344 (66 FR 1344). page 1348. Available at:
http://www.epa. gov/fedrgstr/EPA-WATER/200 l/Januarv/Dav-08/w217.htm

67 EPA. January 8, 2001. Water Quality Criteria: Notice of Availability of Water Quality Criterion for the
Protection of Human Health: Methylmercury. U.S. Environmental Protection Agency, Office of Water,

In consideration of the environmental fate of mercury, a fish tissue residue water quality criterion
was found to be appropriate for many reasons. "Such a criterion integrates spatial and temporal
complexity that occurs in aquatic systems and that affects methylmercury bioaccumulation. A
fish tissue residue water quality criterion is more closely tied to the CWA goal of protecting the
public health because it is based directly on the dominant human exposure route for
methylmercury. The concentration of methylmercury is also generally easier to quantify in fish
tissue than in water and is less variable over the time periods in which water quality standards
are typically implemented in water quality-based. Thus, the data used in permitting activities can
be based on a more consistent and measurable endpoint. A fish tissue residue criterion is also
consistent with how fish advisories are issued. Fish advisories for mercury are based on the
amount of methylmercury in fish tissue that is considered acceptable, although they are usually
issued for a certain fish or shellfish species in terms of a meal size. A fish tissue residue water
quality criterion should enhance harmonization between these two approaches for protecting the
public health."68

Consistent with EPA's 304(a) recommendation published in 2001, Oregon has replaced its
"water + organism" and "organism only" water column human health criteria for total mercury
with a new fish tissue-based "organism only" human health criterion for methylmercury. Similar
to the 2000 Methodology, the computation of the methylmercury criterion uses several input
variables, described in Figure C below.

Figure C: Simplified version of the equation used by Oregon in deriving its new fish tissue-
based "organism only" human health criterion for methylmercury.

TRC

—

fRfD - RSG • fBWl
[FCR)

where:

TRC

= Fish Tissue Residue Criterion (milligrams per kilogram)

RfD

= Reference dose for noncancer effects (milligrams per
kilogram per day) = O.OOOlmg/kg-day

RSC

= Relative source contribution factor to account for non-

water sources of exposure (milligrams per kilogram per day) = 0

= Human body weight (kilograms) = 70 kg

FCR

= Fish Consumption Rate (kg/day) =175 g/day

In the 2001 methylmercury criteria document, EPA strongly encourages States and authorized
Tribes to consider developing a criterion using local or regional data over the default values if
they believe that appropriate for protection of the target population. EPA recommends that these

Washington, D.C. Federal Register, Volume: 66, Issue: 5, Page: 1344 (66 FR 1344). page 1348. Available at:
http://www.epa. gov/fedrestr/EPA-WATER/200 l/Januarv/Dav-08/w217.htm

68 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. page xv. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

adjustments be applied consistent with the guidance provided in the 2000 Human Health
Methodology.69

Consistent with EPA's recommendation, Oregon replaced its "water + organism" and "organism
only" water column human health criteria for total mercury with a new fish tissue-based
"organism only" human health criterion for methylmercury equal to 0.040 micrograms per
kilogram (mg/kg). In deriving this new criterion, Oregon used the equation below and the
following values for each variable: reference dose equal to 0.0001 milligrams per kilogram per
day; relative source contribution of 0; body weight equal to 70 kilograms and; fish consumption
rate equal to 175 grams per day. As discussed in greater detail above, the reference dose and
body weight are the values recommended by EPA and the fish consumption rate was derived
using local and regional data. The RSC is discussed below.

a) Relative Source Contribution (RSC) for Methylmercury

Following review of available data and information specific to the exposure pathways for
methylmercury, Oregon used EPA's subtraction method to derive an RSC of zero for use in

deriving the human health criterion for methylmercury.

In establishing a recommended RSC value, EPA found that the most significant source of
exposure to methylmercury was the ingestion of marine fish. EPA also found that the estimated
exposure from ambient water, drinking water, nonfish dietary foods, air, and soil were all, on
average, at least several orders of magnitude less than those from marine fish ingestion.
Therefore, these later exposure pathways were not factored into EPA's recommended RSC
value. An RSC of 2.7 x 10"5 mg methylmercury/kg/day is recommended by EPA as an estimated
exposure from marine fish intake.71

EPA's above recommendation is based on the assumption that the fish consumption rate does not
include fish of marine origin (as would be the case for most inland states/waters and is true of
EPA's national default value for fish consumptions of 17.5 grams per day). However, as part of
Oregon's reevaluation of local and regional data and the selection of a fish consumption rate of
175 grams per day, Oregon did take into consideration the consumption of salmon (an
anadromous species identified as marine in the CSFII study) and regional consumption rates that
included estuarine finfish and shellfish. Therefore, in reviewing this information, Oregon
determined that it was not necessary to provide additional protection from ingestion of marine
fish through the use of an RSC value. As a result, Oregon subtracted out the exposure related to
marine fish, resulting in an RSC of zero.

69 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001, page 7-2. Available at:
http://www.epa.gov/waterscience/criteria/methYlmercurv/document.html

70 November 3, 2000. Federal Register, Volume: 65, Issue: 214, pages: 66472-3 (65 FR 66472-3). Available at:
http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-03/w27924.htm

71 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. page xiv. Available at:
http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

EPA's 2000 Human Health Methodology recognizes that if States include marine fish in the fish
consumption rate they may need to adjust the RSC consistent with this decision to appropriately
represent overall exposure to a pollutant.

"States and Tribes need to ensure that when evaluating overall exposure to a contaminant, [and
that] marine fish intake is not double-counted with the other dietary intake estimate used.

Coastal States and authorized Tribes that believe accounting for total fish consumption (i.e.,
fresh/estuarine and marine species) is more appropriate for protecting the population of concern
may do so, provided that the marine intake component is not double-counted with the RSC
estimate ." 2

Oregon's use of the subtraction method for deriving the RSC for methylmercury is consistent
with this guidance.

2. New human health criteria for methylmercury

Oregon has adopted the following new criterion for methylmercury:

Table 8: Oregon's criterion

br methylmercury.

Polluliinl

C'iirciiio»en

\Y siler + Orgsinism

()r»;inism Only

(ue/U

(ue/i.)

Methylmercury (mg/kg)J

—

0.040 (mg/kg)

Footnote J: This value is expressed as the fish tissue concentration of methylmercury.
Contaminatedfish and shellfish is the primary human route of exposure to methylmercury.

Oregon's new criterion of 0.040 mg/kg is expressed as a fish tissue residue concentration, not a
water column concentration as all other human health criteria adopted by Oregon. Thus, when
applying the criterion, ODEQ may need to consider data collected from either the water column
or fish tissue or express a limitation as a water column value (e.g. provide a discharger with an
effluent limit in an NPDES permit that can be measured in their effluent). Recognizing this fact,
EPA has encouraged "states and authorized tribes to develop a methylmercury criterion
implementation plan to ensure environmentally protective and effective administration of all
water quality related programs with respect to methylmercury". Furthermore, to assist the States
in this process, in April 2010 EPA published recommended methods for implementing these

criteria. In recognition of this need, Oregon's Human Health Criteria Issue Paper states that
".. DEQ intends to develop implementation procedures similar to EPA's Guidance for

Implementing the January 2001 Methylmercury Criterion

72 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. EPA-
822-B-00-004. page 4-25. Available at: http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

73 EPA. January 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA 823-R-01-001. pages 21-22. Available
at: http://www.epa.gov/waterscience/criteria/methvlmercurv/document.html

74 ODEQ. May 24, 2011. Human Health Criteria Issue Paper. Oregon Department of Environmental Quality, page
26. Available at:

http://www.deq.state.or.us/wq/standards/docs/toxics/humanhealth/rulemaking/HumanHealthToxicCriteriaIssuePaper.pdf

3. EPA Action and Rationale Regarding Oregon's Methylmercury
Criterion

EPA Action

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves Oregon's new human health criterion for methylmercury, consistent with EPA's
current CWA § 304(a) criteria recommendations, because it is protective of Oregon's fishing and
water supply uses. EPA is also approving the first sentence of footnote J which states: This value
is expressed as the fish tissue concentration of methylmercury.

EPA Rationale

EPA's WQS regulations require that criteria protect the designated uses. As noted previously,
Oregon's human health criteria apply to waters with fishing and water supply uses and thus must
be established at a level that will protect those uses. Therefore, EPA must evaluate whether the
criteria protect Oregon's human health uses.

EPA's 2000 Human Health Methodology and 2001 Criteria Recommendations for
Methylmercury provide guidance for deriving human health criteria for methylmercury. For
each variable used in the criteria calculation, EPA provides a "national default value" and
guidance on specific adjustments that may be necessary to reflect local conditions and/or protect
identifiable subpopulations. As part of evaluating whether Oregon's criteria protect the
designated uses, EPA reviewed the input values used by Oregon and whether there was Oregon-
specific information relative to each value that should be considered in the review.

For all input variables except for the fish consumption rate and the RSC value, Oregon used
EPA's recommended 304(a) national default values for calculating the methylmercury criterion.
EPA has not identified any local or regional data to indicate that the national values for the
reference dose, body weight, or drinking water intake rate are inappropriate for use in Oregon.

Oregon has used local and regional data to develop the fish consumption rate and RSC values
used to calculate the methylmercury criterion. EPA has reviewed the information used in
developing these values and has found that ODEQ appropriately considered the available data
and developed input values consistent with EPA guidance.

EPA's 2001 Methylmercury Criteria document provides an extensive technical basis and
justification as to how EPA's recommended criterion adequately protects human health uses.
Based on Oregon's consistency with EPA's recommendations in the 2001 Methylmercury
Criteria document and as discussed above, EPA has determined that Oregon's new
methylmercury criterion protects human health uses in accordance with 40 C.F.R. Part
131.11(a)(1).

In addition, EPA is approving the first sentence of footnote J which states: This value is
expressed as the fish tissue concentration of methylmercury. This sentence of the footnote
provides clarification that the human health criterion for methylmercury is expressed as a fish
tissue concentration rather than as a water column concentration. Oregon's new footnote

language along with the human health criterion value for methylmercury are consistent with
EPA's recommended 304(a) national default values for calculating the criterion. This sentence
of the footnote establishes a legally binding requirement under state law and helps describe a
desired ambient condition of a waterbody to support a particular designated use and is therefore
considered a WQS subject to EPA review and approval under 303(c) of the CWA. The
description of the applicable expression of methylmercury is a component of the overall level of
protection afforded by the criterion. Since this sentence of the footnote specifies the applicable
expression of the methylmercury criterion Oregon adopted, EPA has approved this sentence of
the footnote as a WQS.

EPA acknowledges the second sentence of footnote J which states: Contaminatedfish and
shellfish is the primary human route of exposure to methylmercury. This sentence of the
footnote provides details on the primary route of human exposure to methylmercury, but does
not establish a legally binding requirement under State law and it does not describe a desired
ambient condition of a waterbody to support a particulate designated use. For this reason, this
sentence of footnote J is not considered a WQS subject to EPA review and approval under 303(c)
of the CWA. As a result, EPA is taking no action to approve or disapprove the second sentence
of footnote J for methylmercury.

E. INORGANIC ARSENIC CRITERIA

1. Background

The Oregon Environmental Quality Commission directed ODEQ to revise Oregon's human
health criteria for toxic pollutants based on an increased fish consumption rate of 175 grams per
day as well as to carefully consider cost effective and environmentally meaningful
implementation of the criteria and review the data and science behind the criteria for earth

metals. ODEQ reviewed the science supporting the EPA's recommended 304(a) arsenic
criteria and considered the appropriateness of revising the criteria to more closely reflect the
levels of arsenic that naturally occur in Oregon waters. Oregon's revised arsenic criteria,
submitted to EPA on July 12, 2011 are the result of that review. Oregon's goal in reevaluating
the criteria was to protect human health, reduce toxic pollutants and to achieve meaningful
environmental results commensurate with the cost.76

Oregon made the following arsenic-related regulatory revisions (including some changes other
than revisions to arsenic criteria):

75 Oregon Environmental Quality Commission (OEQC). October 23, 2008. Oregon Environmental Quality
Commission Minutes of the Three Hundred and Forty-sixth Meeting. Available at:
http://www.dea.state.or.us/about/eac/minutes/2008/2008octEQCMinutes.htm

76 ODEQ. April 5, 2011. Memo from Dick Pedersen, Director ODEQ, to the Environmental Quality Commission.
Agenda Item E. Rule adoption: Amending water quality standards for arsenic, April 21-22, 2011EQC meeting.
Oregon Department of Environmental Quality, pages 1-2. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/EOCItemEStaffReport.pdf

• Revised the numeric criteria human health criteria for arsenic in OAR 340-04-0033 Table
20.

• Identified the form of arsenic addressed by the criteria as inorganic arsenic.

• Added footnote A which states "The arsenic criteria are expressed as total inorganic
arsenic. The 'organism only' criteria are based on a risk level of approximately 1.1 x

5 4 77

10" , and the 'water + organism' criterion is based on a risk level of 1.1 x 10" ."

• Revised the drinking water M.C.L. from 0.05 mg to 10 jj.g/1 in Table 20 and added
footnote 1 which states "The arsenic value is shown here for informational purposes only
and is not a water quality criterion."

• Added a new provision, OAR 340-04-0033(2)(b), that states the arsenic criteria become

effective for purposes of State law and the CWA at the time of EPA approval.

• Added an arsenic reduction policy under State law to address the reduction of arsenic
from some anthropogenic sources in the vicinity of public drinking water intake
supplies.79

The revised arsenic criteria were adopted through a public notice and rulemaking action separate
from that used to adopt the June 16, 2011 human health criteria revisions. This separate
rulemaking process is described in Section III above.

ODEQ reviewed the available scientific literature on bioaccumulation of arsenic and the ratio of
inorganic arsenic to total arsenic in freshwater and marine environments. ODEQ also reviewed
data specific to waters in Oregon and used the information to derive arsenic criteria for Oregon's
waters.

Arsenic is a known carcinogen that may cause cancer in skin or internal organs such as the liver,
kidneys, lungs and bladder. Other potential health impacts from arsenic include cardiovascular,

kidney, central nervous system and hyper-pigmentation or keratosis effects. In its 304(a)
criteria recommendations EPA states that arsenic criteria should be based on cancer endpoints
and be applied as inorganic arsenic.

Naturally-occurring arsenic in Oregon comes from geologic sources. It is typically present at
natural levels in fresh surface waters at background levels that range from less than 1 microgram
per liter (ju.g/1) to 3 |ig/l. ODEQ data indicate that much higher arsenic levels (greater than 5-10
|ig/l) may be present in some south central and southeastern Oregon watersheds but it is not
known whether these levels represent solely natural geologic sources or are elevated due to

77 Footnote A for arsenic was established in Table 40 in ODEQ's July 21, 2011 submittal to EPA.

78 This language was deleted as part of ODEQ's July 21, 2011 submittal to EPA since effective dates of the criteria
are addressed in OAR 340-041-0033(1), which includes arsenic.

79 To accommodate additional revisions associated with ODEQ's submittal to EPA on July 21, 2011 ODEQ moved
the location of this rule from OAR 340-041-0033(4) to OAR 340-041-0033(7). However, the rule language was not
revised.

80 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. page 2-6. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

anthropogenic activity. ODEQ's review of the scientific literature indicates natural total

arsenic levels of the oceans to be in the range of 1 to 3 jj.g/1.

EPA's current 304(a) human health criteria recommendations for arsenic, published in 1986, are
derived using a fish consumption rate of 6.5 grams per day and a cancer slope factor of 1.75 and

are recommended to be applied as inorganic arsenic. As is the case for all pollutants, EPA's
2000 Human Health Methodology encourages states to use local and regional data when making
risk management decisions inherent in developing criteria, including decisions inherent in

selecting the appropriate fish consumption rate, target risk level and bioaccumulation factor.
2. Numeric Criteria Revisions

Based on its review of current data and information, ODEQ found differences in the
bioconcentration (BCF) of arsenic in freshwater and saltwater organisms. In addition, DEQ
found the ratio of inorganic arsenic relative to total arsenic differs in the freshwater and marine
environments. Based on these findings, Oregon adopted two sets of criteria, one applying to
freshwater and the other to saltwater. The revised criteria and the input variables used to
calculate the criteria are presented in Tables 9 and 10 below.

Oregon has adopted the following new criterion for inorganic arsenic:

Table 9: Oregon's revised arsenic criteria (as inorganic arsenic).

PolllllSIIll

('sircino<>eii

\Y siler + Orgsinism
(Mii/U

Or^iinism Only (iiii/l.)

Arsenic (inorganic)'

2.1

2.1 (freshwater)
1.0 (saltwater)

Footnote A: The arsenic criteria are expressed as total inorganic arsenic. The "organism only" criteria
are based on a risk level of approximately 1.1 x 10~5, and the "water + organism " criterion is based on a
risk level of 1.1 x 10~4.

Table 10. Input variab

es for Oregon's revised arsenic criteria.

\Y siler + orjiitiiism:
I'reshw siler

()i»itnism only:
I'reshw siler

()r»;inism only:
ssillw siler

Revised Criteria

2.1 J-ig/1

2.1 jig/1

l.O^ig/1

Input Variables

FCR=175

81 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 6. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

82 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 14. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

83 EPA. May 1, 1986. Quality Criteria for Water. U.S. Environmental Protection Agency, Office of Water. 440/5-
86-001. At: https://owpubauthor.epa.gov/scitech/swguidance/standards/upload/2009 01 13 criteria goldbook.pdf

84 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. page 2-6. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

BCF=14

BCF=26

IF=10%

CSF=1.5

Risk level=lxl0"4

Risk level=l.lxl0"5

Risk level=lxl0"5

FCR = Fish Consumption Rate IF = Inorganic Factor

BCF = Bioconcentration Factor CSF = Cancer Slope Factor

Oregon's arsenic criteria revisions were adopted into Table 20 (Water Quality Criteria
Summary), OAR 340-04-0033. It should be noted that in Oregon's June 16, 2011 action, all
human health criteria in Table 20 were moved to Table 40. Thus, the arsenic criteria are now
located in Table 40.

Oregon's revised numeric criteria for arsenic were derived using the same general methodology
and equation used to calculate EPA's current 304(a) criteria for carcinogens. However, based on

its review of scientific studies and Oregon specific data, Oregon applied an inorganic to total
arsenic ratio in the criteria calculation because the arsenic criteria are expressed in terms of
inorganic arsenic, but the toxicity data used to develop EPA's BCF are reported in the form of
total arsenic. Therefore, Oregon applied the inorganic to organic arsenic ratio to the criteria
calculated using BCF values they derived based on state-specific data. Oregon also applied a
fish consumption rate based on state-specific data. Oregon used the cancer slope factor listed in
EPA's IRIS database available at the time of criteria adoption (April 2011). The input variables
used by Oregon to derive their revised criteria are listed in Table 10 above.

a) Freshwater Criteria

Body weight and drinking water intake rate

Oregon used EPA's recommended national default rates for body weight and drinking water
intake rates. These are the same values that Oregon used to derive all other criteria addressed in
this action. Further detail on these variables was provided above.

Fish consumption rate

A fish consumption rate of 175 grams per day was used to derive the freshwater arsenic criteria.
This is the same fish consumption rate that Oregon used to derive all other criteria addressed in
this action. As discussed in detail above, this rate was determined by ODEQ to be appropriate
for use in Oregon's human health criteria following a thorough review of local and regional data.

The fish consumption rate of 175 grams per day was selected by Oregon to ensure protection of
all people in Oregon who may consume fish and shellfish from state waters including those who
traditionally consume large amounts of fish for subsistence, health, economic or other reasons.86
It reflects the 95th percentile of tribal members surveyed as part of the CRITFC Survey and the

85 For more detail, see previous description in this document of methodology for deriving criteria for carcinogens.

86 ODEQ. October 6, 2008. Memo from Dick Pederson, Director ODEQ, to the Environmental Quality
Commission. Agenda Item G, Action Item: Oregon's Fish Consumption Rate - For Use in Setting Water Quality
Standards for Toxic Pollutants October 23, 2008 EQC Meeting. Oregon Department of Environmental Quality,
page 7. Available at: http://www.dea.state.or.us/about/eac/agendas/attachments/2008oct/ItemG.pdf

90th percentile of subsistence consumers surveyed in regional fish consumption studies. The
Human Health Focus Group formed by ODEQ to provide technical recommendations for
selecting a fish consumption rate appropriate for Oregon found that fish consumers generally eat
a variety of species that are the most readily available geographically and seasonally and that the
range of consumption rates among fish consumers tend to be comparable regardless of the

species that are available at any given time. Thus, Oregon determined the rate of 175 grams
per day appropriate for protection of high consumers from both freshwater and saltwater
environments throughout the state.

Bioconcentration factor

Limited data are available regarding bioaccumulation (BAF) and bioconcentration (BCF) of
arsenic in aquatic species. As discussed above, EPA recommends bioaccumulation data be used
when available in order to take into consideration all pathways of accumulation, not merely the
concentration that is received from water as reflected in bioconcentration data. EPA review of
the literature found no relevant BAF data was available and thus EPA recommended that BCF

data be used by Oregon to determine appropriate BCFs for use in deriving their arsenic criteria.
EPA reviewed the available literature that might be relevant to recalculating a BCF specific to

Oregon's waters and provided that information to ODEQ. Only six published studies were
identified and only four of the studies were found suitable for use in recalculating a BCF.
Limitations in the data reported in two of the studies resulted in EPA determining they were not
appropriate for use and thus were not used in either ODEQ's recalculations or EPA's review of
the recalculated BCFs. The four studies found to be appropriate for this purpose and thus used
provided data for only three species. One data set is from a test of a saltwater mollusk, the
eastern oyster, and the others tested two freshwater finfish, bluegill and rainbow trout.

Additional information on these studies can be found in ODEQ's April 2011 review document.90

Oregon determined that a BCF of 14 was appropriate for use in developing arsenic human health
criteria for freshwaters of the state based on their review of the data contained in the above
mentioned studies. A BCF of 14 represents the geometric mean of the data available from the
studies of freshwater organisms (two publications on rainbow trout91 and one on bluegill92).
Oregon determined that the BCF data for the eastern oyster, a marine mollusk, was not
appropriate for use in deriving a freshwater BCF because the oyster was a marine organism and
available data indicate marine organisms are more likely to bioaccumulate arsenic than
freshwater organisms. Furthermore, DEQ stated that they were not aware of data showing

87 ODEQ. June 2008. Human Health Focus Group Report. Oregon Fish and Shellfish Consumption Rate Project.
Oregon Department of Environmental Quality, pages 18-19. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/HHFGFinalReportJune2008.pdf

88 EPA. November 2011. Oregon Arsenic BCF and 304(a) Calculations.

89 EPA. November 2011. Oregon Arsenic BCF and 304(a) Calculations.

90 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

91 McGeachy and Dixon, 1990. Canadian Journal of Fisheries and Aquatic Sciences. 47: 2228-2233; Rankin and
Dixon, 1994. Canadian Journal of Fisheries and Aquatic Sciences. 51:372-380.

92 Barrows, et al. 1980. Ann Arbor Science Pub., Inc., Ann Arbor, MI. pages 379-392.

harvesting or consumption of mollusks or other shellfish from freshwaters in Oregon and thus,
freshwater mollusks were not likely to comprise a significant portion of the fish consumed from
freshwaters in Oregon. Thus Oregon assumed finfish would be the primary exposure route for
arsenic ingested from freshwaters and therefore, used only the data from finfish studies to
calculate the freshwater BCF.93'94 Based on this evaluation, ODEQ found that a BCF of 14 was
a reasonable and protective value to use in calculating the arsenic criteria for Oregon's
freshwaters.

Cancer Slope Factor

Similar to all other criteria addressed in this action, for arsenic, ODEQ used the cancer slope
factor identified in EPA's Integrated Risk Information System (IRIS) data base at the time of
rule adoption (April 2011). For arsenic this value is 1.5 (mg/kg/day)"1 and was last modified in
1998.

Inorganic Proportion Factor (Inorganic to Total Arsenic Ratio)

Arsenic is present in the environment and in fish tissue in both organic and inorganic forms.
Inorganic arsenic, specifically arsenite (trivalent or As III), is the form that is most toxic to
humans and used to develop toxicity data for cancer and other end points. Thus, EPA
recommends that human health criteria for arsenic are developed specific to inorganic arsenic
and apply to the inorganic portion of arsenic in the water column. The inorganic portion may be
referred to as either "inorganic arsenic" or "total inorganic arsenic". When both inorganic and
organic arsenic are included, it is referred to as "total arsenic".95

All of the bioconcentration studies identified by EPA and used by Oregon reported arsenic as
total arsenic, not inorganic arsenic. In order to address this difference in form and toxicity,
Oregon multiplied the BCF by an "inorganic proportion factor" that reflects the ratio of inorganic
to total arsenic likely to be present in the water. The proportion varies geographically and
between fresh and marine waters so must be determined using state or local data.

Only limited data are available relative to the ratio of inorganic to total arsenic in Oregon's
freshwaters. Previous studies have reported the proportion of inorganic arsenic found in fish
tissue collected in the Columbia and Willamette rivers to contain an average of 6.5% inorganic
arsenic while the ratios reported for individual species of fish ranged from 0.5% to 9.2%
inorganic arsenic.96 ODEQ also found several other sources of information indicating that an

93 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 12-13. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

ODEQ. March 2011. Summary of Public Comment and Agency Response. Amending Oregon's Water Quality
Standards: Revising Human Health Criteria for Arsenic. Oregon Department of Environmental Quality, pages 16-
17. Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AttCArsenicPublicComment.pdf

94 EPA's review of this decision is documented later in this subsection.

95 EPA. 2009. EPA National Recommended Water Quality Criteria. U.S. Environmental Protection Agency Office
of Water. Office of Science and Technology. Available at:
http://water.epa.gov/scitech/swguidance/standards/current/upload/nrwac-2009.pdf

96 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 13. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

inorganic proportion of 10% or less was typical of freshwater environments. Based on these
findings, Oregon determined that an inorganic factor of 10% was a conservative ratio and
appropriate for use in deriving the arsenic criteria for Oregon's freshwaters.

To incorporate the inorganic factor (IF) into the calculation, ODEQ used the following revised
equations:

Water + fish ingestion Criterion (|ig/L) = 1000 x RF x BW

ql*[DW + (BCF x FCR x IF)]

Org Only Criterion (|ig/L) = 1000 x RF x BW

ql*[BCF x FCR x IF]

Carcinogenic Risk Level

In the 2000 Human Health Methodology EPA states that it believes States and authorized Tribes
have the flexibility to adopt the carcinogenic risk level they find appropriate for protection of the
designated uses as long as the general population is protected at a 10"5 or 10"6 risk level and
highly exposed populations are protected at a risk level that does not exceed 10"4.98 With the
exception of arsenic, Oregon has used a risk rate of 10"6 when developing water quality criteria
for carcinogenic pollutants. However, due to the natural levels of arsenic in Oregon's waters
and the exposure levels resulting from natural sources of arsenic, Oregon has chosen to use a risk
level of 10"4 for the arsenic criteria. Oregon made this policy decision following consideration of
several alternatives and consideration of public comments received on the proposed criteria. The
lower level of protection afforded by the proposed criteria was clearly identified by ODEQ in the
documents provided to the public during both public notice periods and in the materials
presented to the EQC at the time the rule was adopted." ODEQ has stated that they made this

EPA. 2002. Columbia River Basin Fish Contaminant Survey, 1996-1998. U.S. Environmental Protection Agency,
Region 10, Seattle, Washington. EPA 910-R-02-006. Available at:

http://vosemite.epa.gov/rl0/oea.nsf/0703bc6b0c5525b088256bdc0076fc44/c3a9164ed269353788256cQ9005d36b7/
$FILE/Fish%20Studv.PDF

EVS Environmental Consultants. November 21, 2000. Human Health Risk Assessment of Chemical Contaminants
in Four Fish Species from the Middle Willamette River, Oregon. Prepared for the Oregon Department of
Environmental Quality, Portland, Oregon. Available at:
http://www.dea.state.or.us/wa/willamette/docs/studies/hhrarpt.pdf

97ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 13. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

98 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C. EPA-822-B-00-004. page 2-6. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

99 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

ODEQ. April 5, 2011. Memo from Dick Pedersen, Director ODEQ, to the Environmental Quality Commission.

Agenda Item E. Rule adoption: Amending water quality standards for arsenic, April 21-22, 2011EQC meeting.

Oregon Department of Environmental Quality, pages 1-2. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/EOCItemEStaffReport.pdf

decision because of the special circumstances associated with natural levels of arsenic but
believed that the 10"6 risk level used to derive all other criteria continued to be appropriate.100
In determining the acceptable risk level for the arsenic criteria, ODEQ considered the natural
background levels of arsenic commonly found in Oregon and evaluated the likely risk associated
with exposure to these levels for the general population and high fish consumers. As noted
earlier, ODEQ found that naturally occurring arsenic in many surface waters of the state range
from less than 1 |ig/l up to 3 |ig/l and may occur at much higher levels. Therefore, ODEQ
evaluated the risks that would be associated with arsenic criteria of 2-3 jj.g/1.

Using the input variables identified above, Oregon determined that a freshwater water plus
organism (water + org) criterion of 2.1 (J.g/1 would result in a carcinogenic risk of lxlO"4 Since
this value would protect high fish consumers of the State (those consuming 175 grams of fish per
day) at a 10"4 risk level, Oregon found this criterion would protect the human health uses in State
waters at a level consistent with the risk levels recommended by EPA in the 2000 Human Health
Methodology.101 Thus, Oregon adopted an arsenic water plus organism criterion of 2.1 |ig/l for
freshwaters.

Oregon similarly evaluated the criterion for protection of waters where fish consumption was a
designated use but drinking water was not a designated use (organism (org) only criterion).

Using the same variables discussed above, Oregon determined that a criterion of 19 |ig/l would
protect at a lxlO"4 risk level while a criterion value of 1.9 |ig/l would protect at a lxlO"5 risk
level. Oregon noted that establishing the org only criterion at the same risk level as the water +
org criterion would result in a criterion that was nearly an order of magnitude less stringent than
the water + org criterion. Therefore, after reviewing several options Oregon established the
organism only criterion at the same level as the water + org criterion (2.1 ju.g/1). Oregon's
revised freshwater arsenic org only criterion of 2.1 jj.g/1 represents a carcinogenic risk of 1.1 x
10"5 to high consumers of the State (at a fish consumption rate of 175 grams/day). Oregon found
this level of protection appropriate as it was within the risk range identified in EPA's 2000
Human Health Methodology and took into consideration the natural levels of arsenic found in
Oregon's waters.102

ODEQ. April 21, 2011. Recommended Revisions to Oregon's Human Health Criteria for Arsenic, Presentation to
the EQC. See Action Item E audio presentation. Available at:
http://www.dea.state.or.us/about/eac/minutes/2011/201 laprEOCMinutes.htm

100 ODEQ. March 2011. Summary of Public Comment and Agency Response. Amending Oregon's Water Quality
Standards: Revising Human Health Criteria for Arsenic. Oregon Department of Environmental Quality, page 25.
Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AttCArsenicPublicComment.pdf
ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 10-11. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

ODEQ. April 5, 2011. Memo from Dick Pedersen, Director ODEQ, to the Environmental Quality Commission.
Agenda Item E. Rule adoption: Amending water quality standards for arsenic, April 21-22, 2011EQC meeting.
Oregon Department of Environmental Quality, pages 4-5. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/EOCItemEStaffReport.pdf

101 ODEQ. April 5, 2011. Memo from Dick Pedersen, Director ODEQ, to the Environmental Quality Commission.
Agenda Item E. Rule adoption: Amending water quality standards for arsenic, April 21-22, 2011EQC meeting.
Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/EOCItemEStaffReport.pdf

102 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon

b) Saltwater Criteria

Oregon's objectives in developing an arsenic criterion for saltwater was to protect those who
consume fish and shellfish from Oregon's marine and estuarine waters to which a criterion
applies, taking into consideration the presence of naturally occurring levels of arsenic in marine
waters. Uncertainties in the scientific community's current knowledge of the various species of
arsenic in the saltwater environment and in marine and estuarine species also were considered in
the evaluation.103

Oregon has not designated any saltwaters of the state as a drinking water use. Consistent with
this designation, the only human health criterion applicable to and derived for saltwaters in
Oregon are the organism only criteria (i.e. developed to protect humans from health effects
incurred while ingesting fish and shellfish). As identified in Table 9 above, Oregon adopted an
organism only criterion of 1.0 |ig/l inorganic arsenic for all saltwaters of the State. The
following discusses the input variables used and the conclusions reached by ODEQ in
establishing this criterion.

Body weight, fish consumption rate and cancer slope factor

The input variables used for body weight, fish consumption rate and the cancer slope factor to
derive Oregon's arsenic human health water quality criteria applicable to saltwater are the same
as those used to derive the freshwater criteria discussed above.

Bioconcentration factor and inorganic proportion factor

Oregon's arsenic criterion for saltwater was calculated using a BCF of 26 (the geometric mean of
all BCFs for fresh and saltwater species combined) and an inorganic proportion factor of 10%.

As discussed in the freshwater section above, bioconcentration data for arsenic is limited. EPA's
review of the literature found only four studies appropriate for use in calculating BCFs and only
one of those tested an organism from a saltwater environment (eastern oyster).104 When ODEQ
reviewed the available studies, they found a large difference in BCF values found in the study of
the Eastern oyster (BCF of 350) relative to those found in the freshwater finfish studies (BCFs of
4 to 27). Given the differences in the BCFs and recognizing that people consume both mollusks
and finfish from the Oregon waters where this criterion would apply, ODEQ evaluated potential
options for criteria using two scenarios (see Table 11 below). The first scenario considered
criterion calculated using a BCF of 26, the geometric mean of all available BCF data (both
saltwater and freshwater). The second evaluated options using a BCF of 350, the geometric
mean from the one study of a saltwater organism. Under both scenarios, the criteria that would
result from using inorganic proportion factors of 1% and 10% were calculated. Results of the
various options were compared to levels of arsenic naturally present in estuarine and marine

Department of Environmental Quality, page 14. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

103 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 14. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

104 Zaroogian and Hoffman. 1982. Arsenic uptake and loss in the American oyster, Crassostrea virinica.
Environmental Monitoring and Assessment 1:345-358.

waters. Following analysis of the options generated under the two scenarios ODEQ evaluated
the level of protection provided by each and compared the criteria to the concentrations of
arsenic naturally present in estuarine and marine waters. Based on this analysis ODEQ
determined that a criterion of 1.0 |ig/L inorganic arsenic was appropriate for protection of the
fish consumption use in Oregon's saltwaters.

Table 11. Scenarios evaluated by Oregon and/or EPA.

Scenario

Fish Consumption

175 g/day

Bioconcentration

350

Inorganic portion

10%

7.3%

Risk level

1 x 10"5

lxlO"6

1 x 10"5

1.3 x 10"5

9.6 x 10"5

Natural ocean level

1 — 1-2 jJ.g/1

Resultant Criterion

1.0 ng/1

0.8 jig/1

1.0 ng/1

1.0 jig/1

As part of this evaluation, ODEQ evaluated the appropriate species to be considered in deriving a
BCF value, the ratio of inorganic to total arsenic in the ocean environment, and the natural level
of arsenic in Oregon's salt waters. When evaluating BCF data, ODEQ found that
bioconcentration of arsenic in the tissue of invertebrates tended to be higher than that for
vertebrates. In particular, they found that crustaceans and mollusks tended to accumulate more
inorganic arsenic in their tissue (the form toxic to humans) than anadromous or marine fish.
While data specific to consumption levels of various species from Oregon's saltwaters was not
available, ODEQ knew that both shellfish and finfish were harvested and consumed from
saltwaters in Oregon. ODEQ's literature review also indicated that, for the general US
population, estuarine and marine mollusks represent only a small percent (3-13%) of the total
fish and shellfish consumption. Given the small percentage of shellfish consumption relative to
fish consumption and the much higher bioconcentration rate in shellfish, ODEQ concluded that a
criterion calculated using only the oyster data (BCF = 350) was likely to be overly
conservative.105

Oregon's literature review found a growing body of literature indicating that while saltwater
organisms may contain more total arsenic than freshwater fish, the predominant form of arsenic
in marine species is organic arsenic (i.e. rather than inorganic arsenic).106 One analysis of five
types of ocean finfish and ocean shrimp found that inorganic arsenic in the organism's tissues

107

was less than 0.1% of the total arsenic present in tissues. Other literature reported values of

108

less than 3% and more recent surveys report values less than 1%. A summary of the data from

105 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 15-16. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

106 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 16-17 in EPA 2003; Neff 1997; Schoof and Yager 2007; Tanaka and
Santosa 1995; TetraTech 1996, IN EPA 2002; and Williams et.al. 2006. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

107ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 16-17 in Schoof et. al., 1999 in BorakandHosgood. 2007. Available
at: http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

108 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon

20 studies is provided below and indicates that the inorganic arsenic in tissues of marine fish and
marine shellfish ranged from 0.0001% to 7.3% of the total arsenic present; anadromous fish
ranged from 0.3% to 3.04% and freshwater fish tissue contained between 0.5% and 26.6%
inorganic arsenic.109

Inorganic arsenic as a % of total arsenic in seafood measured as ng/g wet weight

Mean

Ranee

Freshwater

7.2

0.5-26.6

Anadromous fish

1.1

0.03-3.04

Marine fish

1.0

0.001-6.9

Marine Crustaceans

1.3

0.001-7.3

Marine Mollusks

1.8

0.04-6.5

Based on the review of the above information, ODEQ concluded it appropriate to use an
inorganic factor of 1% if used in association with a conservative BCF of 350. However, if using
the less conservative BCF of 26, ODEQ used a more conservative inorganic factor of 10% in
their initial scenarios. ODEQ found comparison of these scenarios was a reasonable approach
to take into account the variability and uncertainty in both the BCFs and inorganic factors while
not resulting in an overly conservative criterion.110

Natural ocean levels and complexities in the marine environment

Oregon's review of the literature found natural total arsenic levels of oceans waters to be in the
range of 1 to 3 |ig/l. Data cited from the Pacific Ocean indicated average concentrations of 1.1 -
1.2 iig/1.111

Oregon did not have any data from Oregon's marine waters where inorganic and total arsenic
were measured simultaneously. Thus, they relied on the above literature for their conclusion that
the natural concentrations of arsenic in Oregon salt waters contain 1.0 |ig/l or more of inorganic
arsenic and that a waterbody criterion of 1.0 |ig/l should not present any greater human health

112

risk than that naturally present.

Department of Environmental Quality, pages 16-17 inBorak and Hosgood, 2007; EPA 2003; Neff, 1997. Available
at: http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

109 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 16-17 in Schoof and Yager, 2007. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

110 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

111 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 15-16 in Tanaka, Shigeru and Sri Juari Santosa. 1995. The
concentration distribution and chemical form of arsenic compounds in sea water. Biogeochemical Processes and
Ocean Flux in the Western Pacific, Eds. H. Sakai and Y. Nozake, page. 1590170. Terra Scientific Publishing
Company, Tokyo. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

112 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, page 15. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

Carcinogenic Risk Level

For the saltwater organism only criterion of 1.0 jj.g/1 inorganic arsenic represents a carcinogenic
risk level of 10"5. Since this value would protect high fish consumers of the State (those
consuming 175 grams of fish per day) at a 10"5 risk level, Oregon found this criterion would
protect the human health uses in State waters at a level consistent with the risk levels

113

recommended by EPA in the 2000 Human Health Methodology. Furthermore, ODEQ
determined it was appropriate to use a different carcinogenic risk level for this criterion than that
used for other criteria in the state (10~6) since the resultant criterion concentration reflected that
which naturally occurred in marine waters.114 (See the discussion regarding carcinogenic risk
level for the freshwater arsenic criteria for more detail regarding EPA's 2000 Human Health
Methodology.)

Based on the above findings, Oregon considered the scenarios in Table 11 above when selecting
an appropriate org only criterion for arsenic in Oregon's saltwaters. Based on the conservative
nature of a BCF of 350, the variability in the data, the uncertainties in the scientific communities
current knowledge and ODEQ's determination that "there does not appear that an unacceptable
human health risk with eating fish from an unpolluted marine environment," Oregon revised the
saltwater criterion for inorganic arsenic to 1.0 jj.g/1.

c) EPA Review of Oregon's Revised Arsenic Criteria

EPA has reviewed the information provided by Oregon regarding the literature considered during
their review of the arsenic criteria. EPA determined that Oregon's review considered the
relevant and available information relative to selecting appropriate input variables for deriving
the arsenic criteria. EPA conducted a more detailed review of several of the variables used in
deriving the criteria. This review is presented below.

(1) FRESHWATER CRITERIA

BCF for Freshwater Criteria

EPA has reviewed the literature used by Oregon to calculate a BCF and finds that all relevant
studies were identified. The use of a geometric mean value from available studies is appropriate
for deriving a single BCF value. As determined by Oregon, a BCF of 14 is representative of the
available BCF data relative to freshwater species.

In EPA's review of the literature relative to bioaccumulation of arsenic in aquatic organisms, no
BAF studies specific to bioaccumulation in Oregon or models which could readily produce

113 ODEQ. April 5, 2011. Memo from Dick Pedersen, Director ODEQ, to the Environmental Quality Commission.
Agenda Item E. Rule adoption: Amending water quality standards for arsenic, April 21-22, 2011EQC meeting.
Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/EOCItemEStaffReport.pdf

114 ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality, pages 15-16 in Tanaka and Santosa. 1995 National Academy of Sciences,
1972 and EPA. 2003. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

bioaccumulation factors specific to Oregon's waters were found. Thus, ODEQ's use of a
bioconcentration factor is appropriate in this situation.

In selecting the appropriate BCF for use in deriving freshwater criteria, Oregon reviewed the
available data for both saltwater and freshwater organisms and considered whether that data was
representative of organisms likely to be consumed from waters to which the criteria would apply.
In evaluating the use of the data from a study of the eastern oyster, a saltwater mollusk, Oregon
noted that saltwater mollusks are not present in freshwaters of Oregon and that they were "not
aware of any mollusks or other shellfish harvested and consumed from Oregon's freshwaters".115
In order to verify this assertion, EPA consulted the Oregon Department of Fish and Wildlife
website.116 According to the regulations posted on this site, Oregon prohibits the harvest or
possession of all freshwater mussels or clams (except for Zebra mussels or Asian clams) except

117

as authorized by a Scientific Take Permit. Furthermore, EPA noted that no freshwater
mussels or shellfish were included in the species identified in the CRITFC Fish Consumption
Study. While this later fact does not speak to all mussels or shellfish from freshwaters of
Oregon, it is one indication that traditional and cultural consumption of these organisms is not
occurring in a large portion of Oregon. Based on this information, EPA finds the assumption
made by Oregon as to type of organisms consumed from Oregon's freshwaters to be reasonable.
While including BCF data from the eastern oyster in the calculations would have expanded the
scope of represented species to include mollusks, it would have also contributed BCF data from a
marine species into the calculation of freshwater criteria. EPA concludes that Oregon's decision
not to include the BCF data from the eastern oyster was appropriate, in light of the above data
with respect to the low likelihood of human consumption of freshwater mollusks in Oregon.

One commenter provided numerous comments relative to the use of a BCF instead of a site-
specific BAF. In the 2000 Human Health Methodology EPA recommends using a BAF in cases
where data are available. EPA's review of the literature indicates that data and models are not
currently available to develop a state-specific BAF for waters in Oregon. Additional information
on this topic can be found in the above description of the methodology used to develop criteria
for noncarcinogens and in EPA's Response to Comments document developed in association

118

with the recent June 1, 2010 action on Oregon's human health criteria adopted in 2004.

The same commenter noted that recent studies of arsenic bioaccumulation indicate use of a
regression approach to developing arsenic criteria may be more appropriate than using a single
criterion applicable to all waters. EPA reviewed the cited study and agrees that it is an approach
that has been applied on a site-specific basis and could be applied by a state in developing
criteria for arsenic. However, EPA has not developed a recommended approach for

115ODEQ. April 4, 2011. Issue Paper: Water Quality Standards Review and Recommendations: Arsenic. Oregon
Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AppEArsenicIssuePaper.pdf

116 Oregon Department of Fish and Wildlife (ODFW). Oregon Wildlife Species: Sport Fish Species of Oregon.
Available at: www.dfw.state.or.us/species/fish/index.asp

117 Oregon Department of Fish and Wildlife (ODFW). 2011 Sport Fishing Regulations. Available at:
http://www.dfw.state.or.us/fish/docs/2011 Oregon Fish Regs.pdf

118 EPA. June I, 2010. Supplemental Response to Comments Submitted by Northwest Environmental Advocates
(NWEA) as They Pertain to Oregon's New and Revised Human Health Water Quality Criteria for Toxics Submitted
on July 8, 2004.

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for Toxics and Associated Implementation Provisions Submitted July 12 and 21, 2011
October 17, 2011

incorporating this approach into a water quality criterion and no state has used it to develop a
water quality criterion. Utilization of a regression approach would result in a criterion expressed
as an equation for calculating a criterion concentration which varies with the ambient level of
arsenic present in a waterbody in order to take into account the fact that the fraction of total
arsenic that is inorganic arsenic tends to decrease as the concentration in the tissues increase.
Additional questions regarding whether the criteria would more appropriately be expressed as a
water column or tissue concentration would also need to be addressed. While utilizing this
approach to developing a state-wide criterion would result in a site-specific criterion that may
more accurately reflect the desired level of protection at any particular site (i.e. a 10"5 risk level),
it would not necessarily provide for a greater level of protection. Given that this level of detail is
not needed to protect the use and that this method has never been applied to derive a water
quality criterion, EPA finds that it was reasonable for Oregon to establish a single criterion
concentration and not use this new approach in this rule revision.

Inorganic Proportion Factor for Freshwater Criteria

EPA's review of available information finds that an inorganic proportion factor of 10%
represents a reasonable and conservative estimate of the proportion of total arsenic present in an
inorganic form in the tissue of organisms collected from freshwaters in Oregon. EPA notes that
this same value was used by EPA when conducting site-specific risk assessments in the
Columbia and Willamette Rivers that considered the same data set. No additional data have
become available since the EPA assessments.

Level of Protection Provided by the Freshwater Criteria

Oregon's arsenic criteria for fresh waters are established at a level that protect high fish
consumers in Oregon at carcinogenic risks levels of between 1 x 10"4 to 1 x 10"5 (see more
detailed discussion above). EPA's 2000 Human Health Methodology states that states have the
flexibility to choose an appropriate risk level for use in deriving water quality criteria as long as
it protects the use to the levels recommended by EPA. Those risk levels are a 10"5 or 10"6 risk
level for the general population and a risk level that does not exceed 10"4 for highly exposed
populations.

Oregon's criteria were established using a fish consumption rate of 175 grams per day, reflective
of the 95th percentile of consumption in a high-consuming subpopulation in Oregon and the 90th
percentile of data from regional surveys of high consuming subpopulations. Therefore, the
criteria represent the level of exposure expected to occur in highly exposed populations of
Oregon. As such, Oregon's freshwater arsenic criteria protect highly exposed populations of
Oregon at a level consistent with EPA's recommendations (does not exceed 10"4 risk level).

EPA has recommended using a fish consumption rate for the general US population of 17.5
grams per day if no local or regional data is available. There is currently no available fish
consumption data specific to the general population of Oregon. If one were to evaluate the
protectiveness of Oregon's arsenic criteria at EPA's default fish consumption rate of 17.5 grams
per day, the result would indicate a carcinogenic risk level between lxlO"6 and lxlO"5. This risk
level is consistent with that recommended by EPA. Therefore, EPA finds that ODEQ's revised
arsenic criteria for freshwater are established at a level protective of both the general population
and high fish consuming populations consistent with the levels recommended by EPA in the

52

2000 Human Health Methodology.

(2) SALTWATER CRITERIA

BCF for Saltwater Criteria

EPA has reviewed the literature used by Oregon to calculate the BCF used to derive the saltwater
criterion and finds that all relevant studies were identified. EPA also found the use of a
geometric mean value to be appropriate for deriving a BCF. As considered by Oregon, a BCF of
26 is representative of all available BCF data for both saltwater and freshwater species (one
study of a saltwater mollusk and three studies of freshwater finfish). A BCF of 350 reflects all of
the available BCF data for saltwater species (one study of a saltwater mollusk). Oregon
considered both of these BCF values when evaluating the protectiveness of the revised criterion.

As noted by Oregon, there is relatively little BCF data available for arsenic and only one study
that addresses saltwater species. Given the limited data and the differences in BCF between the
finfish and mollusk data, EPA finds Oregon's approach of comparing the outcomes of scenarios
for both a BCF of 26 and a BCF of 350 in terms of protectiveness to be reasonable. (See Table
11 above). Given the limited data and the variability in the available data, EPA believes that
evaluating the level of protection provided by a range of inorganic proportion factors in
association with the different BCF values is also appropriate. EPA's evaluation of whether the
criteria derived using these input values is protective of the use is provided below.

Inorganic Proportion Factor for Saltwater Criterion

EPA's review of the literature relative to the ratio of inorganic to total arsenic in the tissue of
saltwater organisms indicated that ODEQ reviewed the available information on this subject.
EPA concurs that the information is limited, especially specific to Oregon waters, but it does
indicate that the ratio of inorganic to total arsenic in tissues of saltwater organisms is typically
lower than that found in freshwater organisms. Thus, using the 10% inorganic ratio that is also
used in the freshwater criteria serves to provide a conservative estimate of the ratio—i.e., one
that is larger than the mean ratio values found in various studies (1 to 3%). Given the variability
in these factors and in the BCF values discussed above, EPA believes it was appropriate for
ODEQ to have considered several different exposure scenarios when developing this criterion
and that ODEQ's use of inorganic factors of 10% and 1% in the scenarios was also reasonable.
EPA's evaluation of whether the criteria derived using these input values is protective of the use
is provided below.

Level of Protection Provided by the Saltwater Criteria

Oregon adopted a saltwater criterion of 1 |ig/l and relied on multiple lines of evidence in
determining it is protective of Oregon's human health uses. Consistent with Oregon's approach
at evaluating scenarios, EPA has evaluated the level of protection provided by each scenario
presented. As illustrated in Table 11 above, when the more conservative BCF (350) was paired
with the less conservative inorganic proportion factor (1%), a criterion of 1.0 |ig/L was found to
protect high fish consuming populations (175 g/day) at a 1.3 x 10"5 risk level. When the less
conservative BCF (26) was paired with the more conservative inorganic proportion factor (10%),
a criterion of 1.0 |ig/l was found to protect high consumers (175 g/day) at a 1.0 x 10"5 risk level.
Both of these scenarios provide a level of protection consistent with that recommended by EPA

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October 17, 2011

in the 2000 Human Health Methodology. However, when EPA evaluated the level of protection
that would be provided using the more conservative of both factors (BCF of 350 and inorganic
proportion factor of 10%), a criterion of 1.0 |ig/l resulted in a 1.3 x 10"4 risk level. This level is a
higher risk than that recommended by EPA in the 2000 Human Health Methodology. EPA notes
that the highest ratio of inorganic to total arsenic in fish tissue of saltwater organisms identified
by ODEQ was 7.3%. ODEQ used 10% as a conservative inorganic proportion value for marine
criteria (incorporating data from freshwater species) but EPA believes 7.3% is also a
conservative estimate for marine organisms as it is the highest data value reported. Combining
an inorganic factor of 7.3% (not as conservative a value as selected by Oregon but still
sufficiently conservative based on a reasonable assessment of the available data) with a BCF of
350 (more conservative than the value ultimately selected by Oregon), EPA calculated that a
criterion of 1.0 |ig/L would protect high fish consuming populations at a risk level of 9.6 x 10"5.
Thus, a criterion of 1.0 |ig/l calculated using a conservative inorganic proportion factor of 7.3%
would protect high fish consumers in Oregon at a level consistent with that recommended by
EPA in the 2000 Human Health methodology.

Oregon has presented a reasonable scientific basis to not rely solely on the BCF from the eastern
oyster (350) in calculating the saltwater criterion, and instead rely on a BCF that incorporates
data from other species (26).119 Furthermore, the percentage of total arsenic that occurs in an
inorganic form that Oregon paired with this BCF (10%) was more than sufficiently conservative
based on the available data. Based on the calculations discussed in the paragraph above and
these additional considerations, EPA believes that Oregon's saltwater criterion for arsenic will
protect human health consistent with the level recommended by EPA.

(3) GENERAL CONSIDERATIONS

Risk level applied to arsenic criteria relative to that applied to other criteria

EPA reviewed the information provided by Oregon related to establishing criteria for arsenic at a
level different than that used for all other criteria in the State. EPA notes that ODEQ stated that
they were addressing arsenic as a special case and clearly stated their reasons for evaluating risk
management decisions relative to this pollutant. The public notice, memorandum presenting
recommendations to the EQC and ODEQ's document presenting its review and
recommendations for the arsenic criteria all clearly identify that the criteria recommendations
were established at a level providing less protection than for other pollutants in Oregon. Thus,
the Commission was made aware of the policy decision inherent in their decision to adopt the
recommended criteria. Thus, EPA finds that Oregon was reasonably exercising its discretion
when establishing an alternate risk level for the arsenic criteria.

Cancer Slope Factor

One commenter noted that a cancer slope factor of 1.75(mg/kg/day)_1 was used by EPA to
develop the current 304(a) criteria recommendation while another stated that EPA was currently

119 Mollusks tend to accumulate arsenic to a greater extent than other species and mollusks represent only a small
percent (3-13%) of the U.S. general population's total fish and shellfish consumption. A marine BCF that is only
based on mollusk data is therefore not ideally representative of marine species overall. EPA concludes that it was
reasonable for Oregon to incorporate data from non-mollusk species to arrive at a more representative BCF, even
though those non-mollusk species were not marine species.

54

reviewing the science behind the cancer slope factor. Both of these assertions are correct.

EPA's 304(a) criteria recommendations for arsenic were first published in 1986 and uses a
cancer slope factor of 1.75(mg/kg/day)_1. This recommendation has not been updated to reflect
the latest value identified in the IRIS database, in part because the science behind that number is
currently under review. A draft document was circulated for public comment and peer review by

120

the Science Advisory Board in 2010. EPA is currently reviewing these comments and has yet
to make a final determination on potential revisions to the cancer slope factor for arsenic. Thus,
EPA does not believe it appropriate for ODEQ to use the draft value in revising these criteria.
EPA expects to coordinate with ODEQ regarding the potential need for reevaluation of the
criteria if a new value is established in IRIS and/or changes are made to EPA's 304(a) criteria
recommendations for arsenic.

3. EPA Action and Rationale Regarding Oregon's Arsenic Criteria

EPA Action

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves Oregon's revised human health toxic criteria for inorganic arsenic because they
are protective of Oregon's fishing and water supply uses. EPA is also approving footnote A
which states: The arsenic criteria are expressed as total inorganic arsenic. The "organism
only " criteria are based on a risk level of approximately 1.1 x 10~5, and the "water + organism "
criterion is based on a risk level of 1.1 x 10~ .

EPA Rationale

As discussed in detail above, EPA has found that Oregon considered the available and relevant
literature in revising Oregon's arsenic criteria. Oregon provided a reasonable basis for the
decisions made in developing the criteria. All three of the criteria adopted by ODEQ were found
to protect human health uses consistent with recommendations provided in EPA's 2000 Human
Health Methodology.

Inorganic Arsenic and Footnote A in Table 40

EPA's current 304(a) human health criteria recommendations are specifically identified as
criteria for inorganic arsenic. As noted above, inorganic arsenic is the form most toxic to
humans. As such, EPA's recommendations relative to this criteria and the associated risk
assessment input variables are expressed as inorganic arsenic. In this revision, Oregon
specifically identified that the criteria as inorganic arsenic in Table 40 by placing the word
"inorganic" in parentheses.

120 February 19, 2010. Federal Register, Volume: 75, No.: 33, page: 7477 (78 FR 7477). Available at:
http://www. gpo.gov/fdsYs/pkg/FR-2010-02-19/pdf/FR-2010-Q2-19.pdf

In addition, EPA is approving footnote A to the arsenic criteria in Table 40 which states: The
arsenic criteria are expressed as total inorganic arsenic. The "organism only " criteria are
based on a risk level of approximately 1.1 x 10~5, and the "water + organism " criterion is based
on a risk level of 1.1 x 10~ .

The first sentence of the footnote provides clarification that the human health criterion for
arsenic is expressed as total inorganic. This new footnote language for arsenic is consistent with
EPA's recommended 304(a) national default expression for the arsenic criterion. The second
sentence of the footnote clearly articulates the input variables regarding risk levels that were used
to derive the arsenic criteria. This footnote establishes a legally binding requirement under State
law and helps describe a desired ambient condition of a waterbody to support a particular
designated use and is therefore considered a WQS subject to EPA review and approval under
303(c) of the CWA. The description of the applicable expression of arsenic associated risk level
is a component of the overall level of protection afforded by the arsenic criteria. Therefore, EPA
approves this footnote as a WQS.

Acknowledgement of Maximum Contaminant Level (MCL) in Table 20

ODEQ revised the drinking water MCL for arsenic from 0.05 mg to 10 ju.g/1 in Table 20 and
added footnote 1 which states: The arsenic value is shown here for informational purposes only
and is not a water quality criterion.

Drinking water standards are regulations that EPA sets to control the level of contaminants in the
nation's drinking water. In most cases, the standard is a MCL, the maximum permissible level of
a contaminant in water which is delivered to any user of a public water system. The Safe
Drinking Water Act gives individual states and tribes the opportunity to set and enforce their
own drinking water standards if the standards are at least as stringent as EPA's national
standards. When making a determination to regulate, the Safe Drinking Water Act requires
consideration of these three criteria:

• the potential adverse effects of the contaminant on the health of humans;

• the frequency and level of contaminant occurrence in public drinking water systems; and

• whether regulation of the contaminant presents a meaningful opportunity for reducing
public health risks.

ODEQ revised their MCL value for arsenic from 0.05 mg to 10 ju.g/1 in Table 20. This revision
reflects the current level set under the Safe Drinking Water Act and is consistent with EPA

121

recommended drinking water MCL. ODEQ also added a clarifying footnote which explains
that the MCL value is not a water quality criterion.

121 January 22, 2001. Federal Register, Volume: 66, No.: 14, page: 6976 (66 FR 6976). Arsenic and Clarifications to
Compliance and New Source Contaminants Monitoring Final Rule. Available at: htto://www. epa. gov/fedrgstr/EP A-
WATER/200 l/Januarv/Dav-22/wl668.htm

March 25, 2003. Federal Register, Volume: 68, No.: 57, page: 14501 (68 FR 14501). Minor Clarification of
National Primary Drinking Water Regulation for Arsenic; Final Rule. Available at:
http://www.gpo.gov/fdsvs/pkg/FR-2003-03-25/html/03-7Q48.htm

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October 17, 2011

Since Oregon has not adopted the arsenic MCL value as a water quality criterion, is not
considered WQS under the CWA. Instead, the MCL is a value that the State uses to set the
maximum permissible level of arsenic in drinking water delivered to the tap (after treatment)
consistent with the Safe Drinking Water Act, not a value that surface waters of the State must
meet. MCLs are enforceable standards under the Safe Drinking Water Act, and are not required
under the Clean Water Act unless determined by the State to be needed to protect the designated
uses. For these reasons, EPA is taking no action to approve or disapprove the revised MCL
value for arsenic.

Based on the above, EPA has determined that Oregon's MCL value for arsenic is not a WQS
subject to EPA review and approval under Section 303(c) of the CWA. As a result, EPA is
taking no action to approve or disapprove this MCL value.

Provision Establishing the Effective Date for Arsenic at OAR 340-041-0033(2)(b)

The following language was added to Oregon's WQS at OAR340-041-0033 - Toxic Substances
as part of Oregon's April 21, 2011 rule revisions submitted to EPA on July 12, 2011:

OAR 340-04l-0033(2)(b) The arsenic criteria in Table 20 established by this rule do not
become applicable for purposes of ORS chapter 468B or the federal Clean Water Act unless and
until they are approved by EPA pursuant to 40 CFR 131.21 (4/27/2000).

As part of Oregon's subsequent June 16, 2011 rule revisions submitted to EPA on July 21, 2011,
Oregon removed and renumbered the provision cited above language at OAR 340-041-
0033(3)(b) when it reformatted the toxics criteria tables, thus moving the arsenic criteria to Table
40. Since the deleted language was submitted to EPA as part of the June 16, 2011 rule revisions,
the provision is no longer applicable under state law and there is no requirement for EPA to act
on the provision under Section 303(c) of the CWA.

OAR 310 011 0033(3)(b) The arsenic criteria in Table 20 established by this rule do not become
applicable for purposes of ORS chapter 168B or the federal Clean Water Act unless and until
they arc approved by EPA pursuant to 10 CFR 131.21 (1/27/2000).

Since ODEQ deleted the language l as part of the July 21, 2011 submittal to EPA, the provision
is not applicable under State law and there is no requirement for EPA to evaluate the provision
under Section 303(c) of the CWA.

In the July 21, 2011 submittal, ODEQ addressed the effective dates of the criteria, including
arsenic, in the associated revisions at OAR 340-041-0033(1) which describe the dates when the
toxics criteria in Tables 20, 33A, 33B and 40 become effective under State law and the Clean
Water Act. EPA's rationale for approval of OAR 340-041-0033(1) is explained in section V of
this document.

Acknowledgement of the Arsenic Reduction Policy at OAR 340-041-0033(7)

In conjunction with this rule and in recognition that the revised criteria provide a lower level of
protection than other human health criteria in Oregon, an Arsenic Reduction Policy was adopted
under State law at OAR 340-041-033(4). To accommodate additional revisions associated with
the rulemaking submitted to EPA on July 21, ODEQ reorganized the location of the rule and

57

moved the arsenic reduction policy section to OAR 340-041-0033(7). However, ODEQ did not
revise any of the rule language that was previously adopted. The policy was included in
Oregon's WQS regulation in the same section as the arsenic criteria to help ensure it was applied
where applicable. The policy requires that, in situations where water bodies have background
levels below the arsenic criteria, dischargers with the potential to affect a drinking water supply
develop an arsenic reduction plan and take feasible steps to reduce arsenic loading.

The new policy does not establish a legally binding ambient condition for a waterbody to support
a particular designated use. Nor does it establish a binding process whereby the State would
establish an alternate ambient condition for a waterbody following a public process. Rather, this
policy outlines permitting requirements that the State will place on selected dischargers (those
located in a surface water drinking water protection area as delineated under the Safe Drinking
Water Act). These permitting requirements are not tied to what is necessary to protect the
designated uses of Oregon's waters, but rather to what measures are "feasible" to reduce arsenic
loading. The permitting requirements are to be used in association with other implementation
tools to encourage further arsenic reductions below the established criteria, but they do not
modify those criteria.

In the Response to Comments, ODEQ states that the arsenic reduction policy is an important
component of Oregon's WQS but that the intent of the policy is not to alter the numeric criteria.
Furthermore, ODEQ specifies that the policy applies to specific sources and circumstances and
requires that feasible reduction steps be taken. 2

Based on the above, EPA has determined that this policy is not a WQS subject to EPA review
and approval under Section 303(c) of the CWA. As a result, EPA is taking no action to approve
or disapprove this provision.

F. NEW, REVISED AND WITHDRA WN FOOTNOTES

As part of the July 21, 2011 submittal, ODEQ added, revised and withdrew several footnotes. In
addition to footnote J (for methylmercury) and footnote A (for arsenic) which are discussed
separately above with those individual criteria, these changed footnotes are described in further
detail below.

1. New Footnotes

ODEQ has added new footnotes for the following three pollutants: barium, cyanide, and PCBs.
Footnote C: Barium

The human health criterion for barium is the same as originally published in the 1976 EPA Red
Book which predates the 1980 methodology and did not utilize the fish ingestion BCF approach.
This same criterion value was also published in the 1986 EPA Gold Book. Human health risks
are primarily from drinking water, therefore no "organism only " criterion was developed. The

122 ODEQ. March 2011. Summary of Public Comment and Agency Response. Amending Oregon's Water Quality
Standards: Revising Human Health Criteria for Arsenic. Oregon Department of Environmental Quality, page 26.
Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/metals/AttCArsenicPublicComment.pdf

"water + organism " criterion is based on the Maximum Contaminant Level (MCL) established
under the Safe Drinking Water Act.

Footnote G: Cyanide

The cyanide criterion is expressed as total cyanide (CN)/L.

Footnote L: PCBs

This criterion applies to total PCBs (e.g. determined as Aroclors or congeners).
Acknowledgement of Barium Footnote C

The new footnote C for barium clarifies the source of information upon which the criterion is
based. However, the footnote does not establish a legally binding requirement under State law
nor does it describe a desired ambient condition of a waterbody to support a particular designated
use. Therefore this footnote is not considered a WQS subject to EPA review and approval under
303(c) of the CWA. As a result, EPA is taking no action to approve or disapprove the new
footnote for barium. The underlying criterion for barium was unrevised and therefore EPA is not
reviewing the underlying criterion as part of this action.

EPA acknowledges that the footnote provides accurate information respecting the human health
criterion development for barium. The new footnote for barium explains that the criterion is
based upon a Safe Drinking Water MCL value along with the rationale for why an "organism
only" criterion does not exist. The human health criterion for barium was not derived using
EPA's 2000 Methodology, but instead was based upon EPA's national 304(a) criteria
recommendations in EPA's 1986 Gold Book.

EPA Approval of Footnotes for Cyanide (footnote G) and PCBs (footnote L)

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves Oregon's addition of the two footnotes, Footnote G for cyanide and Footnote L
for PCBs, as consistent with EPA's current CWA § 304(a) criteria recommendations.

EPA Rationale Regarding Footnotes for Cyanide (footnote G) and PCBs (footnote L)

Oregon's new footnote G for cyanide explains that the criterion is expressed as total cyanide
(CN)/L. EPA has reviewed this footnote language and the 304(a) criteria recommendation,
which states that the "recommended water quality criterion is expressed as total cyanide, even
though the IRIS RfD used to derive the criterion is based on free cyanide. The multiple forms of
cyanide that are present in ambient water have significant differences in toxicity due to their
differing abilities to liberate the CN-moiety. Some complex cyanides require even more extreme
conditions than refluxing with sulfuric acid to liberate the CN-moiety. Thus, these complex
cyanides are expected to have little or no 'bioavailability' to humans. If a substantial fraction of
the cyanide present in a water body is present in a complex form (e.g., Fe^FeCCN)^), this

123

criterion may be over conservative." Oregon's new footnote language along with the human

123 EPA. National Recommend Ambient Water Quality Criteria for the Protection of Aquatic Life and Human
Health. Published pursuant to section 304(a) of the Clean Water Act. Footnote jj. Available at:
http://www.epa.gov/waterscience/criteria/wactable/index.html

health criterion values for cyanide are consistent with EPA's recommended 304(a) national
default values for calculating the criterion.

This footnote establishes a legally binding requirement under state law and helps describe a
desired ambient condition of a waterbody to support a particular designated use and is therefore
considered a WQS subject to EPA review and approval under 303(c) of the CWA. The
description of the applicable form of cyanide is a component of the overall description of the
level of protection afforded by the criterion. Since this footnote specifies the applicable form of
the cyanide criterion Oregon adopted, EPA approves this footnote as a WQS. EPA is approving
the associated numeric criteria for cyanide as discussed above in section IV.

Oregon's new footnote L for PCBs explains that the criterion applies to total PCBs. EPA has
reviewed this footnote language and the 304(a) criteria recommendations, which states that the
"criterion applies to total PCBs, (e.g., the sum of all congener or all isomer or homolog or

124

Aroclor analyses.)" Oregon's new footnote language along with the human health criterion
values for PCBs are consistent with EPA's recommended 304(a) national default values for
calculating the criterion.

This footnote establishes a legally binding requirement under state law and helps describe a
desired ambient condition of a waterbody to support a particular designated use and is therefore
considered a WQS subject to EPA review and approval under 303(c) of the CWA. The
description of the applicable form of PCBs is a component of the overall description of the level
of protection afforded by the criterion. Since this footnote specifies the applicable form of the
PCB criterion Oregon adopted, EPA approves this footnote as a WQS. EPA is approving the
associated numeric criteria for PCBs as discussed above in section IV.

2. Revised Footnotes

ODEQ has revised the footnotes below for the following six pollutants: footnote B: asbestos,
footnote D: chlorophenoxy herbicide (2,4,5,-TP), footnote E: chlorophenoxy herbicide (2,4,-D),
footnote F: copper, footnote I: methoxychlor, and footnote K: nitrates.

Table 12: Revised Footnotes.

III.

Pol 1 ut nut

Prc\ ions loolnolc

Now I'ootnolo

Aslvslos

Human health criteria for
carcinogens reported for
three risk levels. Value
presented is the 10-6 risk
level, which means the
probability of one cancer
case per million people at
the stated concentration.

The human health risks from asbestos are
primarily from drinking water, therefore no
"organism only " criterion was developed.
The "water + organism " criterion is based on
the Maximum Contaminant Level (MCL)
established under the Safe Drinking Water
Act.

Chlorophenoxy
Herbicide (2,4,5,-TP)

This value is based on a
Drinking Water regulation.

The Chlorophenoxy Herbicide (2,4,5,-
TP)criterion is the same as originally

124 EPA. National Recommend Ambient Water Quality Criteria for the Protection of Aquatic Life and Human
Health. Published pursuant to section 304(a) of the Clean Water Act. Footnote N. Available at:
http://www.epa.gov/waterscience/criteria/wactable/index.html

published in the 1976 EPA Red Book which
predates the 1980 methodology and did not
utilize the fish ingestion BCF approach. This
same criterion value was also published in the
1986 EPA Gold Book. Human health risks
are primarily from drinking water, therefore
no "organism only " criterion was developed.
The "water + organism " criterion is based on
the Maximum Contaminant Level (MCL)
established under the Safe Drinking Water
Act.

Chlorophenoxy
Herbicide (2,4,-D)

This value is based on a
Drinking Water regulation.

The Chlorophenoxy Herbicide (2,4,-D)
criterion is the same as originally published
in the 1976 EPA Red Book which predates the
1980 methodology and did not utilize the fish
ingestion BCF approach. This same criterion
value was also published in the 1986 EPA
Gold Book. Human health risks are primarily
from drinking water, therefore no "organism
only " criterion was developed. The "water +
organism " criterion is based on the Maximum
Contaminant Level (MCL) established under
the Safe Drinking Water Act.

Copper

This value is based on a
Drinking Water regulation.

Human health risks from copper are primarily
from drinking water, therefore no "organism
only " criterion was developed. The "water +
organism " criterion is based on the Maximum
Contaminant Level (MCL) established under
the Safe Drinking Water Act.

Methoxychlor

No BCF was available;
therefore, this value is based
on that published in the 1986
EPA Gold Book.

The human health criterion for methoxychlor
is the same as originally published in the
1976 EPA Red Book which predates the 1980
methodology and did not utilize the fish
ingestion BCF approach. This same criterion
value was also published in the 1986 EPA
Gold Book. Human health risks are primarily
from drinking water, therefore no "organism
only " criterion was developed. The "water +
organism " criterion is based on the Maximum
Contaminant Level (MCL) established under
the Safe Drinking Water Act.

Nitrates

No BCF was available;
therefore, this value is based
on that published in the 1986
EPA Gold Book.

The human health criterion for nitrates is the
same as originally published in the 1976 EPA
Red Book which predates the 1980
methodology and did not utilize the fish
ingestion BCF approach. This same criterion
value was also published in the 1986 EPA
Gold Book. Human health risks are primarily
from drinking water, therefore no "organism
only " criterion was developed. The "water +

organism " criterion is based on the Maximum
Contaminant Level (MCL) established under
the Safe Drinking Water Act.

EPA Review

All six of these revised footnotes clarify the sources of information upon which the criteria are
based. The footnotes are not considered water quality standards because they do not establish
legally binding requirements under State law and do not describe a desired ambient condition of
a waterbody to support a particular designated use. Therefore they are not water quality
standards subject to EPA review and approval under 303(c) of the CWA. As a result, EPA is
taking no action to approve or disapprove the revised footnotes for these six pollutants.

The revised footnotes identified above explain in more detail than the previous footnotes that the
criteria are based upon a Safe Drinking Water MCL value in addition to an explanation
concerning the rationale for why an "organism only" criterion does not exist. These human
health criteria were not derived using EPA's 2000 Methodology, but instead were based upon
EPA's national 304(a) criteria recommendations in EPA's 1986 Gold Book and developed under
the Safe Drinking Water Act. EPA has reviewed these footnotes and found them to be accurate
regarding the human health criteria development for these six pollutants. The underlying toxics
criteria for asbestos and copper were approved by EPA on June 1, 2010. The underlying toxics
criteria for chlorophenoxy herbicide (2,4,5,-TP), chlorophenoxy herbicide (2,4,-D),
methoxychlor, and nitrates have not been revised and thus are not addressed in this action. These
values remain consistent with EPA's current 304(a) criteria recommendations.

3. Withdrawn Footnotes

ODEQ has removed the footnote below for the three pollutants to which it applied:

hexachlorocyclo-hexane-technical, nitrosamines, and nitrosodiethylamine, N:

No BCF was available; therefore, this value is based on that published in the 1986 Gold Book.

EPA Review

EPA's current CWA 304(a) criteria recommendations include the following BCF values for
these three pollutants:

• Hexachlorocyclo-hexane-technical: BCF value = 130

• Nitrosamines: BCF value = 0.20

• Nitrosodiethylamine, N: BCF value = 0.20

At the time of Oregon's previous adoption of human health criteria for these three pollutants,
EPA's 304(a) criteria recommendations were not derived using a methodology that accounted for
bioconcentration through the use of a BCF. EPA now recommends the use of the BCF values
listed above. Consistent with EPA's recommended 304(a) national default values for calculating
the human health criteria, ODEQ has updated the criteria for these three pollutants to include
EPA's recommended BCF values and therefore the three footnotes are no longer accurate or
relevant. EPA is approving Oregon's human health criteria for hexachlorocyclo-hexane-

technical, nitrosamines, and nitrosodiethylamine, N as discussed above in section IV as
consistent with EPA's 304(a) guidance.

Therefore, as a result of updating the human health criteria for these three pollutants, the
footnotes are no longer accurate and relevant and removing them is appropriate. Furthermore,
these three footnotes were not water quality standards because they did not establish legally
binding requirements under state law and they did not describe a desired ambient condition of a
waterbody to support a particulate designated use. Rather, the footnotes clarified the source of
information, EPA's 1986 Gold Book, upon which the criteria were based. For this reason, the
footnotes were not considered WQS subject to EPA review and approval under 303(c) of the
CWA. As a result, EPA is taking no action to approve or disapprove the removal of the footnote
as applied to hexachlorocyclo-hexane-technical, nitrosamines, and nitrosodiethylamine, N.

G. WITHDRAWN HUMAN HEALTH CRITERIA WHICH WERE
REPLACED BY MORE SPECIFIC CRITERIA

During this rule revision, Oregon updated its numeric human health toxics criteria to reflect
EPA's most recent science and refinements as published in EPA's current CWA § 304(a) criteria
recommendations. Included in the refinements recommended by EPA was the removal of 13
general human health criteria developed for families of pollutants and the replacement of these
criteria by other criteria that address the specific chemical(s) of concern for human health
protection. The 13 chemicals that ODEQ has removed and replaced with criteria for specific
chemical compounds are consistent with EPA's current 304(a) criteria recommendations. They
are listed and explained in Table 13 below.

Tnhlc 13: Withdrawn human health criteria replaced with more specific criteria

No.

\\ illulniwn C'rilerin

Rep hi conic ill C'rilcriii

Kxpliiiiiition

Dinitrotoluene

Dinitrotoluene 2,4

More specific and more
stringent of the two compounds
was retained.

Dinitro-o-Cresol 2,4

Dinitrophenol 2,4; Dinitrophenols

Alternative compounds,
including a synonym, in the
same family identified.

Diphenylhydrazine

Diphenylhydrazine 1,2

More specific compound in the
same family identified.

Endosulfan

Endosulfan Alpha; Endosulfan Beta;
Endosulfan Sulfate

More specific compounds in the
same family identified.

Halomethanes

Chlorodibromomethane;
Dichlorobromomethane; Bromoform;

Chloroform

More specific compounds in the
same family identified.

Monochlorobenzene

Chlorobenzene

Identical compound, the two
criteria names are synonyms.

125 Explanations in the table were developed with information from EPA's "Gold Book". EPA. May I, 1986. Quality
Criteria for Water. U.S. Environmental Protection Agency, Office of Water. 440/5-86-001. Available at:
https://owpubauthor.epa.gov/scitech/swguidance/standards/upload/2009 01 13 criteria goldbook.pdf

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Polynuclear Aromatic
Hydrocarbons

Acenaphthene; Anthracene; Fluorene;
Fluoranthene; Pyrene; Chyrsene;
Dibenzo(a,h)anthracene;
Benzo(a)anthracene; Benzo(a)pyrene;
Benzo(b)fluorantehene 3,4;
Benzo(k)fluoranthene;
Indeno(l,2,3-cd)pyrene

More specific compounds in the
same family identified.

8

Chlorinated Benzenes

Chlorobenzene

More specific compound in the
same family identified.

9

DDT

DDD 4,4'; DDE 4,4'; DDT 4,4'

More specific compounds in the
same family identified.

10

Dichlorobenzene s

Dichlorobenzene (m) 1,3;
Dichlorobenzene (o) 1,2;
Dichlorobenzene (p) 1,4

More specific compounds in the
same family identified.

11

Dichloroethylene s

Dichloroethylene 1,1;
Dichloroethylene trans 1,2

More specific compounds in the
same family identified.

12

Dichlorobenzidine

Dichlorobenzidine 3,3'

More specific and more
sensitive of the two compounds
was retained.

13

Dichloropropene

Dichloropropene 1,3

More specific and more
sensitive of the two compounds
was retained.

Note: Chemicals listed in italics are criteria that Oregon had previously adopted and which EPA had
previously approved. EPA is taking no action on these criteria. All other pollutants listed in the
replacement criteria column, new criteria have been adopted by Oregon and are approved by EPA as part
of this action.

EPA Review

In 2000 and 2003 EPA refined its "priority" list of toxic pollutants and 304(a) human health
criteria recommendations specific to a number of pollutants on that list.126 The criteria for the 13
pollutants listed above have been refined in three ways:

1. EPA previously had established recommended criteria for large chemical families of
pollutants. Advances in scientific information have allowed EPA to refine its criteria
recommendations by developing criteria for specific chemical forms (i.e. isomers or
congeners) of a pollutant within the larger chemical family. For example, while the
Gold Book published only a single criterion for DDT, subsequent revisions (see
EPA's 2004 National Recommended Water Quality Criteria) have resulted in
multiple criteria for DDT and two metabolites: 4,4' DDT, 4,4' DDE and 4,4' DDD.
Similarly, while the Gold Book recommended a single criterion for dichlorobenzenes
in the Gold Book, EPA's 2004 National Recommended Water Quality Criteria,
recommends criteria for 1,2-dichlorobenzene, 1,3-dichlorobenzene, and 1,4-
di chl orob enezene;

126 November 3, 2000. Federal Register, Volume: 65, Issue: 214, page: 66443 (65 FR 66443). Available at:

http://www.epa.gov/fedrgstr/EPA-WATER/2000/November/Dav-Q3/w27924.htm

December 31, 2003. Federal Register, Volume: 68, Issue: 250, page: 75507 (68 FR 75507). Available at:

http://edocket.access.gpo.gov/2003/pdf/Q3-32211.pdf

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2.	EPA has replaced some of the toxic pollutant names with synonyms for specific
chemicals.1 7 For example, while the Gold Book contained criteria for
hexachlorocyclohexane-alpha, hexachlorocyclohexane-beta, and
hexachlorocyclohexane-gamma, these criteria are now listed under the synonyms
alpha BHC, beta BHC and gamma BHC in EPA's National Recommended Water
Quality Criteria; and

3.	EPA has condensed certain pollutants from several chemical forms of a given
compound into a single compound, such as recommending criteria for total arsenic in
EPA's 2004 National Recommended Water Quality Criteria to replace the previously
recommended criteria for arsenic (tri) and arsenic (pent) as published in the Gold
Book.

In updating its numeric toxics human health criteria, Oregon revised the criteria consistent with
EPA's most recent CWA § 304(a) criteria recommendations, including withdrawing and/or
revising the criteria as recommended by the above changes. The criteria withdrawn based on
these refinements in chemical names are identified in Table 13 above. The table further
identifies the pollutants for which Oregon has adopted new criteria to address the human health
impacts associated with these pollutants. EPA action on the new criteria were addressed
previously as part of EPA's action on Oregon's new criteria in section IV.B.

EPA Approval

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves the withdrawal of Oregon's human health criteria for the 13 pollutants identified
in Table 13, coupled with EPA's approval of new criteria (in section IV.B), as protective of
human health. These changes are consistent with EPA's current CWA § 304(a) criteria
recommendations to replace the specified criteria with more specific criteria for associated
pollutants consistent with the latest science. EPA has approved the more specific pollutant
replacement criteria above as consistent with 40 C.F.R. part 131. Since these new criteria
address the same human health affects as the withdrawn criteria, EPA finds the criteria for the 13
pollutants identified above are not necessary to protect Oregon's fishing and water supply uses.

EPA Rationale

The CWA requires that, whenever a state or authorized tribe revises or adopts new WQS, it
adopt criteria for all toxic pollutants listed pursuant to CWA § 307(a)(1) for which EPA has
developed recommended criteria under CWA § 304(a), the discharge or presence of which in the
affected waters could reasonably be expected to interfere with the adopted designated uses
(CWA § 303(c)(2)(B)). As noted above, Oregon has refined the list of criteria for which it has
established human health criteria to reflect recent science incorporated by EPA into the § 304(a)

127 In addition, the following pollutant names were modified by ODEQ from their previous human health criteria for
consistency with EPA terminology. These compounds are synonyms.

1.	Dibutylphthalate was changed to Di-n-butyl Phthalate

2.	Di-2-ethylhexyl phthalate was changed to Ethylhexyl phthalate bis 2

3.	Hexachlorocyclohexane-alpha was changed to BHC alpha

4.	Hexachlorocyclohexane-beta was changed to BHC beta

5.	Hexachlorocyclohexane-gamma was changed to BHC gamma (Lindane)

65

human health criteria recommendations, including the removal of several pollutants representing
chemical families and replacing them with criteria for more specific chemical compounds within
the same general family. As such, the changes in the pollutant names listed above and the
criteria adopted for these pollutants represent a refinement of criteria for individual chemicals
within families, not withdrawals of criteria identified for pollutants in CWA § 307(a).

Therefore, Oregon's withdrawal of its previous human health water quality criteria for these 13
pollutants is consistent with CWA § 303(c)(2)(B).

As stated above, Oregon's removal of these 13 pollutants and the associated criteria is consistent
with EPA's removal of 304(a) criteria recommendations. Although the criteria for these 13
pollutants have been withdrawn, Oregon has developed individual criteria for the most toxic of
chemicals in that family or retained the more specific criteria or a synonym for the chemical
compounds. Therefore, while withdrawing the criteria for these 13 pollutants, Oregon has
adopted new criteria to protect the same human health endpoints which these criteria were
originally developed to protect. Therefore, EPA has determined that the withdrawal of these
criteria coupled with the adoption of new criteria for similar pollutants (approved above in
section IV.B) will protect Oregon's human health uses in accordance with 40 C.F.R. part
131.11(a)(1).

H. TABLE 40 HUMAN HEALTH CRITERIA SUMMARY

Oregon has added the following summary language prior to the human health criteria in Table 40
which explains the purpose of the criteria, criteria derivation and the format of the table.

TABLE 40: Human Health Water Quality Criteria for Toxic Pollutants

Human Health Criteria Summary

The concentration for each pollutant listed in Table 40 was derived to protect Oregonians from
potential adverse health impacts associated with lons-term exposure to toxic substances
associated with consumption of fish, shellfish, and water. The "orsanism only" criteria are
established to protect fish and shellfish consumption and apply to waters of the state designated
for fishins. The "water + or sanism " criteria are established to protect the consumption of
drinkins water, fish, and shellfish, and apply where both fishins and domestic water supply
(public and private) are designated uses. All criteria are expressed as micrograms per liter
(ug/L). unless otherwise noted. Pollutants are listed in alphabetical order. Additional
information includes the Chemical Abstract Service (CAS) number, whether the criterion is
based on carcinogenic effects (can cause cancer in humans), and whether there is an aquatic life
criterion for the pollutant (i.e. "y"= yes, "n " = no). All the human health criteria were
calculated using a fish consumption rate of 175 grams per day unless otherwise noted. A fish
consumption rate of 175 grams per day is approximately equal to 23 8-ounce fish meals per
month. For pollutants categorized as carcinogens, values represent a cancer risk of one
additional case of cancer in one million people (i.e. 10-6). unless otherwise noted. All metals
criteria are for total metal concentration, unless otherwise noted. Italicized pollutants represent
non-priority pollutants. The human health criteria revisions established by OAR 340-041-0033

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and shown in Table 40 do not become applicable for purposes of ORS chapter 468B or the
federal Clean Water Act until approved by EPA pursuant to 40 CFR 131.21 (4/27/2000).

Acknowledgement of Table 40 Summary Language

The new introductory summary language for Table 40 explains the purpose of the criteria,
criteria derivation and the format of the table. However, this language does not establish a
legally binding requirement under State law and it does not describe a desired ambient condition
of a waterbody to support a particular designated use it is not considered a WQS subject to EPA
review and approval under 303(c) of the CWA. EPA has addressed the new and revised
underlying human health criteria in Table 40 and the narrative language at OAR 340-041-
0033(4) in this technical support document. This summary language further explains how the
state derived the criteria values in Table 40. EPA incorporated the explanatory information
provided in this summary into its analysis of the individual criteria values in Table 40. But
because this summary does not operate as an independent water quality standard, in isolation
from the criteria values in Table 40 and the narrative language at OAR 340-041-0033(4) (which
EPA acted on individually), EPA is taking no action to approve or disapprove this summary
language.

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V. NARRATIVE STATEMENT

Oregon's revisions to its narrative toxics provisions found at OAR 340-041-033(1), (3) and (4)
are shown in underline/strikeout format below. Underlined text represents added text, while text
with a line through the middle (strikeout) represents deleted text. Non-revised words are also
provided below for context. Additionally, Oregon reorganized sections of OAR 340-041-0033,
thus renumbering several of the provisions without substantively changing any of the regulatory
language.

340-041-0033
Toxic Substances

(1) Amendments to sections (4) and (6) of this rule (OAR 340-041-0033) and associated
revisions to Tables 20, 33A, 33B and 40 do not become applicable for purposes of ORS chapter
468B or the federal Clean Water Act unless and until EPA approves the provisions it identifies
as water quality standards pursuant to 40 CFR 131.21 (4/27/2000).

(3)	Aquatic Life Criteria. Levels of toxic substances in waters of the state may not exceed the
applicable aquatic life criteria listed in Tables 20, 33A, and 33B. Tables 33A and 33B, adopted
on May 20, 2004, update Table 20 as described in this section.

EPA Action

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves the new and revised language at OAR 340-041-0033(1) and (3).

EPA Rationale

The new and revised provisions at OAR 340-041-0033(1) and (3) describe dates when the toxics
criteria in Tables 20, 33 A, 33B and 40 become effective under state law and the Clean Water
Act. The effective date of WQS provisions under the CWA is determined by the date of EPA
approval. These timing provisions are WQS that provide for the new and revised criteria to be
immediately in effect at the time of EPA's approval action. EPA has addressed the new and
revised underlying human health criteria in this technical support document. OAR 340-041-
0033(3) clarifies that only aquatic life criteria remain in Tables 20, 33A and 33B. EPA will
address the aquatic life criteria in these tables and their corresponding footnotes in a separate
action.

(4)	Human Health Criteria. The criteria for waters of the state listed in Table 40 are established
to protect Oresonians from potential adverse health effects associated with lons-term exposure
to toxic substances associated with consumption of fish, shellfish, and water.

EPA Action

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves the new language at OAR 340-041-0033(4).

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EPA Rationale

The new provision at OAR 340-041-0033(4) adopts the human health criteria in Table 40. EPA
approves this language which adopts the criteria and describes the intent of the criteria to protect
human health uses in Oregon. This language explains the purpose of the human health criteria
and describes that the criteria in Table 40 are established to protect Oregonians from potential
adverse health effects association with long-term exposure to toxic substances associated with
fish, shellfish and water consumption. EPA's action on each individual criterion in Table 40 is
described in detail above.

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VI. BACKGROUND POLLUTANT CRITERIA PROVISION

A. BACKGROUND

As previously discussed, in October 2008, the Oregon Environmental Quality Commission
directed ODEQ to revise the State's human health criteria to incorporate a fish consumption rate
of 175 grams per day. The fish consumption rate of 175 grams per day was selected by Oregon
to ensure protection of all people in Oregon who may consume fish and shellfish from State
waters including those who traditionally consume high amounts of fish for subsistence, health,
economic or other reasons.128 The rate reflects the 95th percentile of tribal members surveyed as
part of the CRITFC Survey129 and the 90th percentile of subsistence consumers surveyed in
regional fish consumption studies. When providing this direction, the Commission also directed
ODEQ to "propose rule language that would allow [OJDEQ to implement the standards in
NPDES permits and other Clean Water Act programs in an environmentally meaningful and
cost-effective manner" and to carefully consider the costs and benefits associated with elements
of the new rule. This latter directive came following testimony from several stakeholders
regarding potential implementation difficulties and economic burden of adopting the more
stringent criteria.130

In response to this direction, ODEQ not only revised the human health criteria but also
developed several new and revised rules addressing the implementation of the revised criteria.
Each revised implementation rule targeted specific situations raised as potential concerns by
ODEQ staff and stakeholders. The adoption of a new site-specific background pollutant criterion
provision and the revisions to the variance provision (discussed in previous section) were
submitted to EPA for action under Section 303(c) of the CWA while other rules were adopted
pursuant to state law and were not submitted to EPA. All revisions are addressed separately in
this document.

Oregon developed an Issue Paper: Implementing Water Quality Standards for Toxic Pollutants

131

in NPDES Permits, Human Health Toxics Rulemaking that discusses how ODEQ will
implement the revised criteria in NPDES permits. Section IV.3 of this paper speaks directly to
the site-specific background pollutant criterion provision and provides greater detail on its
purpose, development and content as well as providing some discussion of how the resultant

128 ODEQ. October 6, 2008. Memo from Dick Pederson, Director ODEQ, to the Environmental Quality
Commission. Agenda Item G, Action Item: Oregon's Fish Consumption Rate - For Use in Setting Water Quality
Standards for Toxic Pollutants October 23, 2008 EQC Meeting. Oregon Department of Environmental Quality,
page 7. Available at: http://www.dea.state.or.us/about/eac/agendas/attachments/2008oct/ItemG.pdf

129 Columbia River Inter-Tribal Fish Commission (CRITFC). October 1994. A Fish Consumption Survey of the
Umatilla, Nez Perce, Yakama, and Warm Springs Tribes of the Columbia River Basin. Technical Report 94.3.
Available at: http://www.critfc.org/tech/94-3report.pdf

130 Oregon Environmental Quality Commission (OEQC). October 23, 2008. Oregon Environmental Quality
Commission Minutes of the Three Hundred and Forty-sixth Meeting. Available at:
http://www.dea.state.or.us/about/eac/minutes/2008/2008octEQCMinutes.htm

131 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

132

criterion would be applied to NPDES permits. Other issue papers were developed to address
implementation of the criteria outside of the NPDES program including papers that address

133

nonpoint sources, antidegradation and source control.

One situation identified during the workgroup process as potentially problematic to dischargers
as well as ODEQ when issuing NPDES permits as a result of the revised human health criteria is
when a NPDES discharger takes in water from and discharges to the same waterbody, which
contains pollutants from upstream sources over which the discharger has little to no control.
ODEQ adopted an intake credit provision at OAR 340-045-0105 that does not hold facilities
accountable for removing these upstream pollutants if the concentration of the pollutant does not
exceed the water quality criteria, the facility does not chemically or physically modify the
pollutant and several other conditions described in the rule are met.

However, facilities that concentrate pollutants in their discharge above the levels in the intake
water are not eligible for the intake credit rule. For example, such an increase in concentration
may occur when a facility's process involves evaporation (e.g. non-contact cooling water), and
the facility recycles water, thus resulting in the same mass of the pollutant but a lower volume of
water. If the upstream concentration of the pollutant in the waterbody exceeds the underlying
criterion, a permit limit is established such that the criterion is met at the end of the discharge
pipe and the facility would need to treat the water prior to discharge regardless of the upstream

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concentration.

ODEQ discussed numerous options for addressing this type of situation with the objective for
providing an approach that:

• protects human health;

• establishes reasonable implementation of the revised water quality standards for facilities
in the situation described above;

• allocates limited State resources efficiently; and

132 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality. Section IV.3, pages
44-61. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

133 ODEQ. May 26, 2011. Issue Paper: Revisions to the Water Quality Standards and TMDL Rules (Divisions 41
and 42), Clarifications on How Nonpoint Sources Meet Water Quality Standards, Human Health Toxics
Rulemaking. Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/Div4142IssuePaper.pdf
ODEQ. December 29, 2010. Issue Paper: Evaluating the Antidegradation Policy as a Means to Reduce Nonpoint
Sources of Toxic Pollutants to Oregon Waters, Human Health Toxics Rulemaking. Oregon Department of
Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/AntidegIssuePaper.pdf

ODEQ. December 29, 2010. Issue Paper: Source Control Small Group, Human Health Toxics Rulemaking. Oregon

Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/SourceControlIssuePaper.pdf

134 ODEQ. April 20, 2010. Implementing Water Quality Standards for Toxic Pollutants in Clean Water Act Permits.
DRAFT. RWG April 27, 2010 Discussion. Oregon Department of Environmental Quality, page 6. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/BackgroundPollutantsIssuePaper20110427.pdf

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•	ensures that regulatory requirements and costs for a facility are commensurate with the
environmental threat they pose.135

Oregon proposed a draft rule and accepted public comment on that rule during the public process
described above for all other elements of this action submitted by Oregon on July 21, 2011. In
EPA's public comments to ODEQ on March 21, 2011 regarding the previous version of the
background pollutant criteria provision proposed for public comment, EPA stated that ODEQ
could:

•	Implement the criterion on a site specific basis and submit each application to EPA for
evaluation on a case by case basis; or

•	Revise the provision consistent with a performance-based approach as a viable alternative
to submitting each revision to EPA on a site specific basis. If ODEQ were to choose this
option, sufficiently detailed implementation procedures would need to be adopted
directly into the WQS regulations which establish a framework that is binding, clear,
predictable and transparent.

Following consideration of the comments received, ODEQ adopted a performance-based water
quality standard that can be used to adopt site-specific criteria for human health carcinogens
where all of the following conditions apply:

•	The criterion at issue is a human health criterion, for a pollutant identified as a
carcinogen.

•	The discharge does not increase the mass load of the pollutant in the receiving water.
The mass load of the pollutant discharged to a waterbody may not exceed the mass load
of the pollutant taken in from the same waterbody or a hydrologically connected water.

•	The pollutant concentration in the receiving water is not increased by more than 3%
above the upstream ambient concentration.

•	The water body concentration does not exceed a calculated value that represents the
human health criterion calculated at a risk level of 10"4.

•	The discharger uses any feasible pollutant reduction measures known and available to
minimize the pollutant concentration in their discharge.

•	The criterion must be evaluated and revised, if appropriate, when the permit is reissued.

•	No TMDL has been developed for the waterbody and pollutant at issue.136

The provision authorizes ODEQ to develop a site-specific criterion for the waterbody in the
vicinity of a discharge and use that criterion to develop an effluent limit for the pollutant if all
conditions of the rule are met. The criterion established would be based upon the most stringent
of 1) the instream concentration following receipt of the current level of discharge from the

135	ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, pages 45-46.
Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

136	ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, pages 44-45.
Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

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facility, 2) a 3% increase in the ambient instream concentration of the pollutant, or 3) a
concentration value that represents a 1 x 10"4 risk level. In addition, the criterion could not be
established at a level that would allow the facility to increase the mass load of the pollutant from

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that in their intake water.

A site-specific background pollutant criterion may only be developed under this provision if the
waterbody serves as the receiving water for a NPDES discharge and the effluent discharged
meets certain requirements. Oregon's rule limits the criteria developed under this rule by
requiring the criteria be established at the most stringent of several options that are based on
applying certain limitations on the effluent from the facility and on the resultant instream criteria.
Therefore, the process outlined in Oregon's rule uses the same type of calculations made in
establishing NPDES permit limits to calculate the resultant instream concentration at various
effluent conditions. Once a site-specific criterion is adopted, it is to be used to develop permit

138

effluent limits in the same manner as any other criteria.

In order to provide further guidance to their permit writers ODEQ will be developing an Internal

139

Management Directive (IMD) within 180 days of EPA's approval action. This is one of
several items identified by ODEQ as actions necessary to assist ODEQ staff and the public in
implementing the provisions approved in this action.

B. ODEQ'S JUL Y 21,2011 SUBMITTAL

ODEQ has added a new provision which establishes a site-specific background pollutant criteria
at OAR 340-041-0033(6). This provision is a performance-based water quality standard that
results in site-specific human health water quality criteria under the conditions and procedures
specified within the rule. It addresses existing permitted discharges of a pollutant removed from
the same body of water, as defined in the provision.

Below is Oregon's background pollutant criteria provision, found at OAR 340-041-0033(6).
340-041-0033(6)

Establishing Site-Specific Background Pollutant Criteria: This provision is a performance-based water
quality standard that results in site-specific human health water quality criteria under the conditions and
procedures specified in this rule section. It addresses existing permitted discharges of a pollutant

137 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 44. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

138 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 60. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

139 ODEQ. June 2, 2011. Memorandum from Dick Pedersen to Environmental Quality Commission; Agenda item C,
Rule adoption: Revised water quality standards for human health and revised water quality standards
implementation policies, June 15-17, EQC meeting. Oregon Department of Environmental Quality. Supplemental
Attachment 10, Timeline for Follow-Up Actions, WQS for Human Health Toxic Pollutants Rulemaking.

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removed from the same body of water. For waterbodies where a discharge does not increase the
pollutant's mass and does not increase the pollutant concentration by more than 3%, and where the water
body meets a pollutant concentration associated with a risk level of lxl 0~4, DEQ concludes that the
pollutant concentration continues to protect human health.

(a)	Definitions: For the purpose of this section [OAR 340-041-0033(6)]:

(A)	"Backgroundpollutant concentration " means the ambient water body concentration
immediately upstream of the discharge, regardless of whether those pollutants are natural or
result from upstream human activity.

(B)	An "intake pollutant" is the amount of a pollutant that is present in public waters (including
groundwater) as provided in subsection (C), below, at the time it is withdrawn from such waters
by the discharger or other facility supplying the discharger with intake water.

(C)	"Same body of water": An intake pollutant is considered to be from the "same body of
water " as the discharge if the department finds that the intake pollutant would have reached the
vicinity of the outfall point in the receiving water within a reasonable period had it not been
removed by the permittee. This finding may be deemed established if:

(i)	The background concentration of the pollutant in the receiving water (excluding any
amount of the pollutant in the facility's discharge) is similar to that in the intake water;

(ii)	There is a direct hydrological connection between the intake and discharge points;
and

(I)	The department may also consider other site-specific factors relevant to the
transport and fate of the pollutant to make the finding in a particular case that a
pollutant would or would not have reached the vicinity of the outfall point in the
receiving water within a reasonable period had it not been removed by the
permittee.

(II)	An intake pollutant from groundwater may be considered to be from the
"same body of water " if the department determines that the pollutant would have
reached the vicinity of the outfall point in the receiving water within a
reasonable period had it not been removed by the permittee, except that such a
pollutant is not from the same body of water if the groundwater contains the
pollutant partially or entirely due to past or present human activity, such as
industrial, commercial, or municipal operations, disposal actions, or treatment
processes.

(Hi) Water quality characteristics (e.g., temperature, pH, hardness) are similar in the
intake and receiving waters.

(b)	Applicability

(A)	Site-specific criteria may be established under this rule section only for carcinogenic
pollutants.

(B)	Site-specific criteria established under this rule section apply in the vicinity of the discharge

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for purposes of establishing permit limits for the specified permittee.

(C)	The underlying waterbody criteria continue to apply for all other Clean Water Act programs.

(D)	The site-specific background pollutant criterion will be effective upon department issuance of
the permit for the specified permittee.

(E)	Any site-specific criteria developed under this procedure will be re-evaluated upon permit
renewal.

(c)	A site-specific background pollutant criterion may be established where all of the following conditions
are met:

(A)	The discharger has a currently effective NPDESpermit;

(B)	The mass of the pollutant discharged to the receiving waterbody does not exceed the mass of
the intake pollutant from the same body of water, as defined in section 6(a) (C) above, and,
therefore, does not increase the total mass load of the pollutant in the receiving water body;

(C)	The discharger has not been assigned a TMDL waste load allocation for the pollutant in
question;

(D)	The permittee uses any feasible pollutant reduction measures available and known to
minimize the pollutant concentration in their discharge;

(E)	The pollutant discharge has not been chemically or physically altered in a manner that
causes adverse water quality impacts that would not occur if the intake pollutants were left in-
stream; and,

(F)	The timing and location of the pollutant discharge would not cause adverse water quality
impacts that would not occur if the intake pollutant were left in-stream.

(d)	The site-specific background pollutant criterion must be the most conservative of the following four
values. The procedures deriving these values are described in the sections (6)(e) of this rule.

(A)	The projected in-stream pollutant concentration resulting from the current discharge
concentration and any feasible pollutant reduction measures under (c)(D) above, after mixing
with the receiving stream.

(B)	The projected in-stream pollutant concentration resulting from the portion of the current
discharge concentration associated with the intake pollutant mass after mixing with the receiving
stream. This analysis ensures that there will be no increase in the mass of the intake pollutant in
the receiving water body as required by condition (c)(B) above.

(C)	The projected in-stream pollutant concentration associated with a 3% increase above the
background pollutant concentration as calculated:

(i)	For the mainstem Willamette and Columbia Rivers, using 25% of the harmonic mean
flow of the waterbody.

(ii)	For all other waters, using 100% of the harmonic mean flow or similar critical flow

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value of the waterbody.

(D) A criterion concentration value representing a human health risk level of 1 x 10~4. This value
is calculated using EPA's human health criteria derivation equation for carcinogens (EPA 2000),
a risk level of 1 x 10~4, and the same values for the remaining calculation variables that were
used to derive the underlying human health criterion.

(e) Procedure to derive a site-specific human health water quality criterion to address a background
pollutant:

(A)	The department will develop a flow-weighted characterization of the relevant flows and
pollutant concentrations of the receiving waterbody, effluent and all facility intake pollutant
sources to determine the fate and transport of the pollutant mass.

(i)	The pollutant mass in the effluent discharged to a receiving waterbody may not exceed
the mass of the intake pollutant from the same body of water.

(ii)	Where a facility discharges intake pollutants from multiple sources that originate
from the receiving waterbody and from other waterbodies, the department will calculate
the flow-weighted amount of each source of the pollutant in the characterization.

(Hi) Where intake water for a facility is provided by a municipal water supply system and
the supplier provides treatment of the raw water that removes an intake water pollutant,
the concentration and mass of the intake water pollutant shall be determined at the point
where the water enters the water supplier's distribution system.

(B)	Using the flow weighted characterization developed in Section (6)(e)(A), the department will
calculate the in-stream pollutant concentration following mixing of the discharge into the
receiving water. The resultant concentration will be used to determine the conditions in Section
(6)(d)(A) and (B).

(C)	Using the flow weighted characterization, the department will calculate the in-stream
pollutant concentration based on an increase of 3% above background pollutant concentration.
The resultant concentration will be used to determine the condition in Section (6)(d)(C).

(i)	For the mainstem Willamette and Columbia Rivers, 25% of the harmonic mean flow of
the waterbody will be used.

(ii)	For all other waters, 100% of the harmonic mean flow or similar critical flow value
of the waterbody will be used.

(D)	The department will select the most conservative of the following values as the site-specific
water quality criterion.

(i)	The projected in-stream pollutant concentration described in Section 6(e)(B);

(ii)	The in-stream pollutant concentration based on an increase of 3% above background
described in Section 6(e)(C); or

(iii)	A water quality criterion based on a risk level of 1 x 10~4.

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(f)	Calculation of water quality based effluent limits based on a site-specific background pollutant
criterion:

(A)	For discharges to receiving waters with a site-specific background pollutant criterion, the
department will use the site-specific criterion in the calculation of a numeric water quality based
effluent limit.

(B)	The department will compare the calculated water quality based effluent limits to any
applicable aquatic toxicity or technology based effluent limits and select the most conservative
for inclusion in the permit conditions.

(g)	In addition to the water quality based effluent limits described in Section (6)(f), the department will
calculate a mass-based limit where necessary to ensure that the condition described in Section (6)(c)(B)
is met. Where mass-based limits are included, the permit shall specify how compliance with mass-based
effluent limitations will be assessed.

(h)	The permit shall include a provision requiring the department to consider the re-opening of the permit
and reevaluation of the site-specific background pollutant criterion if new information shows the
discharger no longer meets the conditions described in subsections (6)(c) and (e).

(i)	Public Notification Requirements.

(A)	If the department proposes to grant a site-specific background pollutant criterion, it must
provide public notice of the proposal and hold a public hearing. The public notice may be
included in the public notification of a draft NPDES permit or other draft regulatory decision
that would rely on the criterion and will also be published on the water quality standards
website;

(B)	The department will publish a list of all site-specific background pollutant criteria approved
pursuant to this rule. A criterion will be added to this list within 30 days of its effective date. The
list will identify: the permittee; the site-specific background pollutant criterion and the associated
risk level; the waterbody to which the criterion applies; the allowable pollutant effluent limit; and
how to obtain additional information about the criterion.

C. EPA ACTION ON ODEQ'S NEW BACKGROUND POLLUTANT
CRITERIA PROVISION

EPA Action

In accordance with its CWA authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131, EPA
approves Oregon's new background pollutant criteria provision at OAR 340-041-0033(6), as
detailed below, because it is consistent with the Clean Water Act and the implementing Federal
water quality standards regulations governing EPA's review and approval or disapproval of new
or revised water quality standards as required in 40 C.F.R. part 131. In EPA's review of
Oregon's background pollutant criteria provision, the Agency considered information submitted
on July 21, 2011 including ODEQ's NPDES Implementation Issue Paper140 and Response to

140 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality. Available at:

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Comments document.141

In its review and action on the background pollutant provision, EPA also considered the
following three key elements:

•	Whether the site-specific human health criteria to be generated under the provision are
sufficient to protect Oregon's human health uses, as required under 40 CFR 131.6.

•	Whether the site-specific human health criteria to be generated under the provision are
consistent with EPA's regulatory specifications for criteria at 40 CFR 131.11.

•	Whether this implementation procedure contains sufficient detail, and suitable
safeguards, such that additional § 303(c) review of individual criteria generated under the
provision would be redundant.

As described in further detail below, EPA has concluded that the site-specific background
pollutant provision adequately addresses all three of these elements and thus is consistent with
CWA § 303(c) and its implementing regulations.

EPA Rationale

The provision establishes site-specific human health criteria at a level to protect Oregon '.s
human health uses

Oregon's site-specific background pollutant provision contains a binding restriction that any site-
specific criterion to be generated under the provision must be established at the most
conservative (stringent) of the conditions specified in OAR 340-041-033(6)(d) and reflect no net
addition of the pollutant from the discharger to the waterbody segment. In no case may a
criterion developed under this provision represent a carcinogenic human health risk level greater
than 1.0 xlO"4, however, it may be more stringent. Since the least stringent scenario for a site-
specific criterion generated under the provision (i.e., one generated based on a 10"4 risk level) is
itself within EPA's recommended range of risk levels protective of human health designated
uses, EPA concludes that a criterion developed using Oregon's site-specific background
pollutant provision would be protective of Oregon's human health uses.

EPA's Human Health Methodology recognizes that States and Tribes have discretion in selecting
appropriate risk ranges and recommends that states adopt criteria for carcinogens based on either
a 1 x 10"6 or 1 x 10" risk level to protect the general population, as long as highly exposed
populations do not exceed a 1 x 10"4 risk level.142 Consistent with the flexibility accorded to
States in developing risk ranges for carcinogenic pollutants, Oregon has chosen to exercise this
discretion by allowing the risk level for carcinogens in waters in the vicinity of certain NPDES
discharges not to exceed 10"4. As discussed previously, Oregon used a fish consumption rate
reflective of highly exposed consumers and a risk level of 1 x 10"6 for deriving their human

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

141	ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 21. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

142	EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, EPA-822-B-00-004. page 2-6. Available at:
http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf

78

health criteria. In this case, the site specific criteria would continue to protect the highly exposed
consumer but at a risk level between 1 x 10"6 and 1 x 10"4. Thus, EPA concludes that any site-
specific criterion calculated based on a 1 x 10"4 risk level would be consistent with EPA's
guidance with respect to highly exposed populations, since the fish consumption rate already
reflects highly exposed populations. EPA has recommended using a fish consumption rate for
the general US population of 17.5 grams per day if no local or regional data is available. There
is currently no available fish consumption data specific to the general population of Oregon. If
one were to evaluate the protectiveness of a site-specific criterion developed under this provision
at a 10"4 risk level but using EPA's default fish consumption rate of 17.5 grams per day, the
result would protect at a carcinogenic risk level of 1 x 10"5. This risk level is consistent with
that recommended by EPA by EPA in the 2000 Human Health Methodology. Therefore, EPA
finds that criteria established under this provision would be established at a level protective of
both the general population and high fish consuming populations consistent with the levels
recommended by EPA in the 2000 Human Health Methodology.

In response to several comments regarding the use of a 1 x 10"4 risk level, ODEQ affirmed that
the criterion would be established at "the most protective of the following results: the current
ambient pollutant concentration after discharge; the background concentration plus three percent;
or the criteria value calculated at a 1 x 10"4 risk level" (emphasis added)).143 In several other
responses to comments as well as at several places in the Issue Paper, ODEQ has also stated that
a 1 x 10"4 risk would be the greatest possible risk allowed under the criterion and that other
conditions within the provision would often limit the criterion further.144 ODEQ also specifies
this fact in their July 21, 2011 letter to EPA requesting the review and approval of these rules.145
In ODEQ's response to comments, they explained why they found this additional level of risk to
be protective in this site-specific situation. They note that several restrictions have been included
in the rule in order to limit any additional risk to the human health use.

• First, the rule requires that the pollutant be from the "same body of water" and that the
mass of the pollutant associated with the facility may not be increased from its intake
water to the effluent water. These requirements ensure that any discharge limits based on
the site specific criterion would not add any additional mass to the waterbody, although
the discharger may slightly increase the pollutant concentration relative to background
(up to a maximum of three percent). In other words, the pollutant present in the

143 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 54. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

144 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, pages 49; 55-58.
Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf
ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, pages 47; 49; 50; 58.
Available at: http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

145 ODEQ. July 21, 2011. Letter from Neil Mullane, Water Quality Division Administrator, to Michael Bussell,
Office of Water and Watersheds, EPA Region 10. Re: Oregon Submission of Revised State Water Quality
Standards for Toxic Pollutants, Including a New Background Pollutant Provision and a Revised Variance Rule for
EPA Review and Approval.

waterbody segment to which the criteria will apply would have reached the vicinity of the
outfall point had it not been intercepted by the discharger and there is no addition of
pollutants by the facility.146

• Second, the application of the criterion is limited to the sole purpose of accommodating
existing discharges from an existing NPDES discharger. In no case could a criterion
decrease in stringency such that the current discharge concentration to a water body

147

would be allowed to increase as a result of the revision.

• Third, the underlying water quality criterion will remain in effect for all other CWA
purposes including 303(d) listing and TMDL development, (as explained above)

• Finally, the rule requires that the criterion be re-evaluated upon permit renewal (OAR
340-041-0033(6)(b)(E)), thus making the criterion effective only for the duration of the
permit and requiring that the site-specific criterion be reevaluated and revised, if
appropriate, upon permit renewal using current ambient and effluent data in situations

148

where all the prerequisite conditions continue to be present. As noted above, if a
TMDL was established prior to this renewal, a site-specific criterion could not be
obtained under this rule and the facility's effluent limit must be consistent with the WLA
in the TMDL.

ODEQ therefore determined that the relative increase in ambient concentration does not result in
a significant change to human health risk149 and that the criterion developed under this provision
would be protective of the beneficial uses of that waterbody.150

Since this provision establishes a process for developing individual site-specific criteria, the
exact location of each application cannot be specified in advance. However, the provision does
specify criteria location relative to the pertinent discharger ("in the vicinity of the discharge for
purposes of establishing permit limits for the specified permittee"). (OAR 340-041-0033(6)(b)).
Thus, dischargers other than the specified permittee would not be able to use the site-specific
criterion in permit calculations.151 For the specified permitee, a site-specific criterion

146 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 51. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

147 OAR 340-04l-0033(6)(d)(A) and (B)

ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 44. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

148 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 60. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

149 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 44. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

150 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 65. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

151 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 44. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water

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corresponding to a risk level of 1 x 10"4 or safer would be applicable to the water in the vicinity
of the discharge.152 Since the site-specific conditions are themselves predicated on the
characteristics of the discharger, an appropriate matching of the criterion to discharger is an
adequate specification of where the site-specific criteria will apply.

EPA notes that one commenter was concerned that the approach in the proposed rule introduced
an inconsistency into Oregon's water quality criteria. The commenter questioned whether it was
consistent with the Clean Water Act for Oregon to determine that a single risk target is both
protective (where site-specific criteria apply) and non-protective (where site-specific criteria do
not apply) of human health uses. ODEQ addressed this comment by adding additional detail in
the final rule. In addition, EPA evaluated this concern relative to the final rule in light of the fact
that Oregon already had the discretion, consistent with EPA's Human Health Methodology, to
adopt criteria based on a risk range between 1 x 10"6 and 1 x 10"4 (in conjunction with a fish
consumption rate that reflects high-consuming populations). If Oregon had adopted state-wide
criteria reflecting a risk range less stringent than 1 x 10"6, Oregon could have exercised its
discretion, based on its own policy priorities and consistent with CWA § 510, to apply more
stringent site-specific criteria where it deemed appropriate. Under these circumstances, a single
risk target would be both protective (where site-specific criteria do not apply) and non-protective
(where site-specific criteria apply). The only practical distinction between this scenario and the
one raised in public comments is which risk level is treated as the normative baseline, and which
is treated as site-specific departure from the baseline.

Since multiple risk levels for carcinogenic pollutants are within the range identified as acceptable
in EPA's Human Health Methodology, and States/Tribes have the ability to define "local
conditions" when establishing site specific criteria, EPA concludes that Oregon has discretion to
apply both one risk level as a generally applicable value and other risk levels on a site-specific
basis (i.e., as "site-specific conditions" under 40 CFR 131.11(b)). While the target risk level is
combined with other values (based on a scientific rationale) to generate a criterion value for a
carcinogenic pollutant, site-specific variation in the target risk level itself is based on Oregon's
risk management judgment. In order for the overall site-specific criterion to be "based on sound
scientific rationale," under 40 CFR 131.11(a)(1), it is sufficient that Oregon has clearly identified
the rationale for the site-specific criteria as a policy decision within its discretion and consistent
with EPA's Human Health Methodology.

EPA also notes that one commenter expressed concern about the interaction between the
proposed background pollutant provision and Oregon's existing mixing zone policy. EPA
acknowledges that, as with other Oregon criteria, the site specific criteria generated under the
background pollutant provision would be used in developing water quality based effluent limits
for the NPDES permit discharging to the waterbody. EPA also acknowledges that, in certain
instances, Oregon's current mixing zone policy may be applied when developing such limits. In

Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 56. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf
152 As discussed below, Oregon's existing mixing zone policy would still affect the calculation of effluent limits
based on the criterion. Nevertheless, the applicable criterion in the receiving water is constrained, by OAR 340-041-
0033(6)(D), to be at least as stringent as the value calculated based on a risk level of lxlO"4.

81

the Issue Paper ODEQ states that once the site-specific background pollutant criterion has been
determined, the criterion will be used to establish a numeric permit effluent limit using the same

153

procedures and guidance used for establishing permit limits for any human health criteria.
Furthermore, ODEQ's response to comments specifies that any mixing will be determined based
on the guidance provided in [OJDEQ's Reasonable Potential Internal Management Directive
(IMD) and that [OJDEQ's published guidelines (Regulated Mixing Zones IMD) would govern
the siting and sizing of any zones of mixing.154 Any mixing zone allowed would be required
under the CWA to comply with the all requirements of the State's mixing zone provision prior to
a mixing zone being authorized. In certain circumstances it is possible that a mixing zone for a
site-specific criterion generated under this provision (or any other human health criterion for a
carcinogen) may allow a limited area of the waterbody in which the cancer risk associated with
the pollutant concentration would exceed 1 x 10"4. However, EPA does not therefore conclude
that the criterion is inconsistent with its Human Health Methodology. The potential for criteria
to be implemented in concert with an EPA-approved state mixing zone policy is a background
assumption of EPA's Human Health Methodology, not an additional factor that would weigh in
favor of further limiting states' risk management discretion.

Furthermore, the language of OAR 340-041-0033(6)(d)(A) and (B) that speaks to the projected
instream concentration "after mixing with the receiving stream" addresses the calculation of a
projected instream value under specified effluent conditions. It does not establish a new mixing
zone policy. EPA finds it appropriate that ODEQ utilize calculations similar to those used to
develop permits when projecting this instream value as this allows the results of applying
limitations to the effluent to be expressed as an insteam concentration and thus to be directly
compared to the options limited by instream concentration. Furthermore, it provides that, for
purposes of the stringency analysis, all options are expressed in the same units as the final
criterion value. A similar practice is commonly used when EPA and States determine whether a
discharge needs a water quality based effluent limit (see, e.g., 40 CFR 122.44(d)(l)(ii) "When
determining whether a discharge causes, has the reasonable potential to cause, or contributes to
an in-stream excursion above a narrative or numeric water quality standard, the permitting
authority shall use procedures which account for ... where appropriate, the dilution of the
effluent in the receiving water." (emphasis added)).

EPA considered whether implementation of the background pollutant provision is consistent

153 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality, page 60. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

154 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water
Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 55. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf
ODEQ. August 2011. Internal Management Directive: Reasonable Potential Analysis Process for Toxic Pollutants,
Version 3.0. Oregon Department of Environmental Quality. Available at:
http://www.dea.state.or.us/wa/pubs/imds/rpaIMD.pdf

ODEQ. December 2007. Oregon Department of Environmental Quality. Regulatory Mixing Zone Internal
Management Directive. Part 1: Allocating Regulatory Mixing Zones. Available at:
http://www.deq.state.or.us/wq/pubs/imds/rmz/RMZIMDpartl.pdf and Regulatory Mixing Zone Internal
Management Directive. Part 2: Reviewing Mixing Zone Studies. Available at:
http://www.deq.state.or.us/wq/pubs/imds/rmz/RMZIMDpart2.pdf

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with the requirements of 40 CFR 131.10. For the following reasons, EPA concludes that it is.
Oregon has expressly stated that a criterion based on a higher risk level, established pursuant to
the provision, "continues to protect human health." OAR 340-041-0033(6). Thus, the
background pollutant provision does not represent the revision of a human health use, but rather
the articulation (within the range of the state's discretion) of the risk range the State considers
protective of human health uses in this site-specific situation. The revision of criteria within the
State's range of discretion for a designated use does not represent the removal or impairment of
such a designated use. In conclusion, the provision contains a clear, predictable and transparent
restriction that any site-specific criterion to be generated under the background pollutant
provision must not correspond to a human health risk level of less stringent than 1 x 10"4.155
This minimum risk level is the most critical of the restrictions contained in the provision since it
sets the least stringent criterion possible under the procedure. The least stringent criterion
possible under the procedure is protective of Oregon's human health uses and is consistent with
EPA's Human Health Methodology. Thus, EPA's approval of the provision may also serve as
the Clean Water Act § 303(c)(3) approval of the individual site-specific criteria to be generated
under the provision.

The provision generates site-specific human health criteria consistent with 40 CFR 131.11

EPA's regulations at 40 CFR 131.11 require States to adopt water quality criteria that protect the
designated use and must be that are based on sound scientific rationale. It also allows States to
modify criteria in order to reflect site-specific situations.156 In OAR 340-041-0033(6) Oregon
establishes a procedure to develop a site-specific human health criterion for carcinogens in a
limited number of site-specific situations when developed consistent with the procedures
specified in the rule.

Oregon has restricted the use of the site-specific background pollutant criteria provision to
waterbodies where an existing NPDES discharger withdraws water from a waterbody and returns
it to the same waterbody without adding any mass to the pollutant of concern. It is further

157

limited to carcinogenic pollutants and utilizes information about the discharge to limit the
criterion. The rule provides a structured framework for developing a site-specific criterion which
is limited by a number of factors, including a requirement that the criterion never exceed a
criterion calculated at a 1 x 10"4 risk level. Further limitations are derived based on the pre-
existing quantity and quality of the discharge into the receiving water, no greater than a three
percent increase in instream concentration and no increase in mass load of the pollutant from the
discharger. In no case will the criteria allow greater than a 10"4 carcinogenic risk level (as
established using the same methodology used for all other human health criteria addressed in this
action).

EPA has reviewed whether Oregon had supplied appropriate grounds to derive a site-specific
human health criterion for carcinogens, consistent with 40 CFR 131.11. EPA's water quality
standards regulations provide that water quality criteria "must be based on sound scientific

155	OAR 340-04l-0033(6)(d)

156	40 CFR 131.11 (A)(1); 40 CFR 131.1 l(b)(l)(ii)

157	OAR 340-041 -003 3 (6)(b)(A)

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158

rationale," and contemplate that a State may adopt site-specific criteria, and provide that these
site-specific criteria "should . . . reflect site-specific conditions."159 EPA's Human Health
Methodology further clarifies a State's flexibility to derive site-specific criteria for human health
criteria. Human health criteria may be modified to reflect, in a justifiable manner, "local
environmental conditions." Local conditions may be those which prevail over a particular river
reach, an entire river, regionally, or Statewide.160 In other guidance, EPA has acknowledged
that less stringent site specific modifications to human health criteria may be appropriate (in that
case, either based on local variation in fish consumption rates or applicable bioaccumulation
factors).161 Thus, EPA finds that the criteria are based on a sound scientific rationale, will
reflect site-specific conditions and, as discussed above, are established at a level that will protect
Oregon's human health uses.

The provision establishes site-specific human health criteria using the performance-based
criterion approach

Finally, EPA reviewed whether the background pollutant provision contains sufficient detail, and
suitable safeguards, that EPA's approval of the provision may also serve as the Clean Water Act
§ 303(c)(3) approval of the individual site-specific criteria to be generated under the provision.

EPA's water quality standard regulations at 40 CFR 131.21 provide that a state water quality
standard adopted after May 30, 2000 is not applicable for Clean Water Act purposes until "EPA
approves that water quality standard [under § 303(c)(3) of the CWA]." However, when EPA
promulgated this regulation it made clear that states have the option to streamline this process by
pursuing a "performance-based" approach whereby the state adopts a "process (i.e., a criterion
derivation methodology) rather than a specific outcome (i.e., concentration limit for a pollutant)
consistent with 40 CFR 131.11 and 131.13."162 Under the performance-based approach, EPA
conducts a CWA § 303(c)(3) review of the procedure and the criteria that would be generated
under that procedure. EPA approval of the provision can encompass approval of the individual
criteria to be generated under the provision where the procedure is "sufficiently detailed and has
suitable safeguards to ensure predictable and repeatable outcomes." To this end, the procedure
should establish a "structure or decision-making framework that is binding, clear, predictable,
and transparent." 163 EPA further specified that the performance-based approach is particularly
well suited to the derivation of site-specific numeric criteria where the proper construction and
implementation of such an approach can result in defensible site-specific adjustments to numeric
ambient water quality criteria.164

158 40 CFR 131.11(a)

159 40 CFR 131.11(b)

160 EPA. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. U.S.
Environmental Protection Agency, Office of Water, EPA-822-B-00-004. pages 2-13. Available at:
http://www.epa.gov/waterscience/criteria/hunianhealth/niethod/coniplete.pdf

161 40 CFR 132 App. F., Proc. 1, A. 4

162 April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsvs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

163 April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsvs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

164 April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsvs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

Oregon's site-specific background pollutant criterion provision was adopted as a performance-
based approach to develop site-specific human health criteria for carcinogens under the
conditions and procedures specified in their rule.165 Oregon's July 21, 2011 submission letter
specifically states that the provision was "adopted [as] a new performance-based water quality
standard" and that it "establishes the procedure by which a site-specific criterion may be
developed for a limited portion of the waterbody".166 ODEQ's staff report EQC at the time of
rule adoption indicates a clear intent for the rule to be adopted as a procedure by which, when
approved by EPA, could be used to develop site-specific criteria that will not need subsequent
approval by EPA.167

A performance-based approach relies on the State to specify methodologies and decision
thresholds in their water quality standards regulations so that a structure or decision-making
framework that is binding, clear, predictable and transparent is established. As with all other
modifications to state water quality standards, EPA requires that the state provide opportunity for
the public to comment on this rule and that the regulation be adopted consistent with state law.
Oregon's site-specific pollutant criterion provision has been promulgated in OAR 340-041-
0033(6) of Oregon's Water Quality Standards, has undergone public review and hearing through
the process used for all other revisions adopted by the State on June 16, 2011, and has been
certified as having been adopted pursuant to State law.168 Therefore, EPA finds that this
provision provides a regulatory framework for decision-making (i.e. criteria development) that is
binding, predictable and transparent and that the public has had the opportunity to provide
comment on the proposed rule.

EPA's guidance further notes that a performance-based "approach is particularly useful for
criteria which are heavily influenced by site-specific factors."169 In this case, Oregon has
restricted the use of this provision to waterbodies where a waterbody contains a pollutant
upstream of a water supply source and a NPDES discharger withdraws water from the waterbody
and returns it to the same waterbody without adding any mass to the pollutant of concern.
Additionally, the background pollutant provision specifies that it only applies to carcinogenic
pollutants, OAR 340-041-0033(6)(b)(A), and utilizes information about the discharge to limit the
criterion. Thus, EPA believes it is appropriate that such criterion be developed on a site-specific
basis.

165 OAR 340-041-0033(6)

166 ODEQ. July 21, 2011. Letter from Neil Mullane, Water Quality Division Administrator, to Michael Bussell,
Office of Water and Watersheds, EPA Region 10. Re: Oregon Submission of Revised State Water Quality
Standards for Toxic Pollutants, Including a New Background Pollutant Provision and a Revised Variance Rule for
EPA Review and Approval.

167 ODEQ. June 2, 2011. Memorandum from Dick Pedersen to Environmental Quality Commission; Agenda item C,
Rule adoption: Revised water quality standards for human health and revised water quality standards
implementation policies, June 15-17, EQC meeting. Oregon Department of Environmental Quality, page 11.
Available at: http://www.dea.state.or.us/about/eac/agendas/attachments/2011iune/C-WOStdsStaffRpt.pdf

168 Oregon Department of Justice. General Counsel Division. July 20, 2011. Letter from Larry Knudsen, Assistant
Attorney General, Natural Resources Section, to Michael Bussell, EPA Region 10. Re: Certification of Water
Quality Standard Amendment (Fish Consumption Rate).

169 April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsvs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

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Finally, EPA's guidance specifies that such procedures "must include a public participation step
to provide all stake-holders and the public an opportunity to review the data and calculations
supporting the site-specific application of the implementation procedures." The State would also
need to maintain a publically available, comprehensive list of all site-by-site decisions made

using the procedures.170 Oregon's WQS regulation at OAR 340-041-0033(6)(i) establishes the
public notification requirements for any criterion to be adopted under this provision. It
specifically requires ODEQ to provide public notice of the proposal and hold a public hearing.
In addition to other public notification procedures in place by the State, ODEQ will publish the
proposal on their WQS website. Furthermore, the provision requires ODEQ to publish a list of
all criteria approved pursuant to the rule within 30 days of its effective date and identifies the
minimum elements to be contained in this list. EPA believes that the public process required by
Oregon within OAR 340-041-0033(6)(i) is consistent with that described in EPA's guidance and
required by 40 CFR 131.11.

In order to provide further guidance to ODEQ staff and to ensure consistent implementation of
the provision, ODEQ will develop an Internal Management Directive (guidance document)
within 180 days of EPA's action on this provision.17 This document will be available on
ODEQ's website and thus facilitate even greater clarity and transparency for the public.

In consideration of the above factors, EPA concludes that the provision contains a binding, clear,
predictable, and transparent framework such that any site-specific criterion generated under the
provision must not result in a human health risk level of greater than 1 x 10"4 and will protect the
human health uses of Oregon's waters. Therefore, any additional oversight by EPA would be
redundant. Thus, the provision contains sufficient detail, and suitable safeguards, that EPA's
approval of the provision serves as the Clean Water Act § 303(c)(3) approval of the individual
site-specific criteria to be generated under the provision. Since this procedure is adopted into
State regulation and Oregon is bound by the decision-making framework contained therein, any
criteria which are not derived in accordance with the approved procedures would need separate
approval from EPA to be applicable under the CWA.

When EPA reviews the results of Oregon's triennial review, EPA expects to evaluate a
representative subset of the site-specific decisions to ensure that Oregon is adhering to the EPA-
approved procedure. Finally, EPA notes that if Oregon fails to follow these procedures and does
not obtain separate CWA § 303(c)(3) approval for the site-specific criterion, this would provide
EPA with a basis to object to an NPDES permit for not deriving from or complying with the

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applicable standards.

170	April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsYs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

171	ODEQ. June 2, 2011. Memorandum from Dick Pedersen to Environmental Quality Commission; Agenda item C,
Rule adoption: Revised water quality standards for human health and revised water quality standards
implementation policies, June 15-17, EQC meeting. Oregon Department of Environmental Quality. Supplemental
Attachment 10, Timeline for Follow-Up Actions, WQS for Human Health Toxic Pollutants Rulemaking.

172	40 CFR 122.44(d)

April 27, 2000. Federal Register, Volume: 65, No.: 82, page: 24648 (65 FR 24648). Available at:
http://www. gpo.gov/fdsvs/pkg/FR-2000-04-27/pdf/0Q-8536.pdf

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VII. VARIANCE PROVISION
A. BACKGROUND

EPA's regulations at 40 C.F.R. Part 131.13, provides that states may, at their discretion, include
in state water quality standards policies generally affecting the application and implementation of
water quality standards, such as general policies for variances. If a state chooses to adopt such a
variance policy, the regulation specifies that such policies are required to be submitted to EPA
for review and approval.

The objective of the Clean Water Act is to restore and maintain the chemical, physical and
biological integrity of the Nation's waters. The CWA further specifies an interim goal that,
"wherever attainable," water quality provides for the protection and propagation of fish,
shellfish, and wildlife and provides for recreation in and on the water.

40 C.F.R. Part 131.10(g) specifies the factors a state may use to determine that a designated use,
which is not an existing use, is not ultimately attainable. These factors are:

1. Naturally occurring pollutant concentrations prevent the attainment of the use; or

2. Natural, ephemeral, intermittent or low flow conditions or water levels prevent the
attainment of the use, unless these conditions may be compensated for by the
discharge of sufficient volume of effluent discharges without violating state water
conservation requirements to enable uses to be met; or

3. Human caused conditions or sources of pollution prevent the attainment of the use
and cannot be remedied or would cause more environmental damage to correct than
to leave in place; or

4. Dams, diversions or other types of hydrologic modifications preclude the attainment
of the use, and it is not feasible to restore the water body to its original condition or to
operate such modification in a way that would result in the attainment of the use; or

5. Physical conditions related to the natural features of the water body, such as the lack
of a proper substrate, cover, flow, depth, pools, riffles, and the like, unrelated to water
quality, preclude attainment of aquatic life protection uses; or

6. Controls more stringent than those required by sections 301(b) and 306 of the Act
would result in substantial and widespread economic and social impact.

173

In 1977, an Office of General Counsel legal opinion considered the practice of temporarily
downgrading the designated use and criteria, as it applies to a specific discharger rather than

174

permanently downgrading an entire water body or water body segment and determined that

173 EPA. March 29, 1977. Office of General Counsel on Matters of Law Pursuant to 40 CFR Section 125.36(m).
No. 58. U.S. Environmental Protection Agency. Washington, D.C. Available at:
http://water.epa.gov/scitech/swguidance/standards/upload/2008 08 04 standards section40cfr3.pdf

174 "Permanent" used in the context of a designated use is intended solely to differentiate from a time-limited
variance. EPA's regulations at 131.20 require states to review uses that do not include those specified in CWA
section 101(a)(2) and to revise standards accordingly if information becomes available to indicate such uses are
attainable.

such a practice is acceptable as long as it is adopted consistent with the substantive requirements
for permanently downgrading a designated use. EPA continued to articulate this position in its
Water Quality Standards Handbook (Section 5.3) specifically stating:

Variance procedures involve the same substantive and procedural requirements as
removing a designated use , but unlike use removal, variances are both discharger and
pollutant specific, are time limited, and do not forego the currently designated use.

Thus, the six 131.10(g) factors, which are used to justify a designated use change through a use
attainability analysis, consistent with 131.10(g), are the same factors that must be evaluated
when justifying a variance.

Variances allow for a more site-specific and time-limited consideration of attainability than a
permanent designated use revision. They encourage states to maintain the underlying designated
uses and criteria as goals instead of declaring them unattainable prematurely when they may be
attainable in the long term. For example, technology improvements could lower treatment costs
in the future such that attaining the designated use and criteria would no longer cause substantial
and widespread economic and social impact. Variances are typically specific to a pollutant(s) and
either apply to specific permittees or geographic areas. Variances only apply to the pollutants,
permittees and geographic areas for which they were written; all other applicable standards
remain in place.

175

Variances must be of a limited or temporary duration for a fixed term. Variances are time-
limited designated uses and associated criteria and are thus considered water quality standards.
As such, any variances granted by the state must be submitted to EPA for review and approval or
disapproval under CWA section 303(c). The preamble to EPA's 1983 regulation176 states that
EPA has approved state-adopted variances in the past and will continue to do so if each
individual variance is adopted as a water quality standard and subject to the same public review

177

as other changes in the water quality standards. EPA's Water Quality Standards Handbook
reiterates the 1983 Preamble as did EPA's Advanced Notice of Proposed Rulemaking
(ANPRM), in 1998, seeking comments on possible revisions to the Water Quality Standards
Regulation.178

EPA's Water Quality Standards Handbook also specifies that EPA has approved state-adopted
variances in the past and will continue to do so if:

175 EPA. January 24, 1992. Office of General Counsel Memorandum Re: Request for Views on Allowable Duration
of Water Quality Standards Variances. U.S. Environmental Protection Agency. Catherine A Winer, Attorney.
Available at: http://water.epa.gov/scitech/swguidance/standards/upload/1999 11 03 standards variancememo.pdf

176 November 8, 1983. Federal Register, Volume: 48, No.: 217, page 51403 (48 FR 51403). Available at:
http://nepis.epa.gov/Exe/ZvPURL.cgi?Dockev=20003ZVR.txt

177 EPA. 1994. Water Quality Standards (WQS) Handbook: Second Edition. August 1994. United States
Environmental Protection Agency, Office of Water. EPA-823-B-94-005a. page 5-12. Available at
http://water.epa.gov/scitech/swguidance/standards/handbook/index.cfm

178 July 7, 1998. Federal Register, Volume: 63, No.: 129, page: 36759 (63 FR 36759). Available at:
http://water.epa.gov/scitech/swguidance/standards/handbook/upload/1998 07 07 1998 July Dav-07 wl7513.pdf

• The State includes the individual variance as part of the water quality standard.

• The state demonstrates that meeting the standard is unattainable based on one or more of
the factors in 131.10(g).

• The justification submitted includes documentation that treatment more advanced than
that required by sections 301(b)(1)(b) and 306 of the Clean Water Act has been carefully
considered and that alternative effluent control strategies have been evaluated.

• The more stringent State criterion is maintained and is binding upon all other dischargers
on the stream or stream segment.

• The discharger who is given a variance for one particular constituent is required to meet
the applicable criteria for other constituents.

• The variance was granted for a specific period of time.

• The discharger either must meet the standard upon the expiration of this time period or
must make a new demonstration of "unattainability."

• Reasonable progress is being made toward meeting the water quality standards.

• The variance was subjected to public notice and opportunity for comment.

In summary, states have the discretion to include variance policies in their water quality
standards regulation. Such policies are subject to EPA review and approval. In addition, if a
state chooses to revise standards by granting a variance, states must adopt such variances
pursuant to state law and each individual variance is subject to public review, consistent with
EPA's regulations. Variances are not effective for Clean Water Act purposes until approved by
EPA.

B. ODEQ'S JUL Y 21,2011 SUBMITTAL

ODEQ has removed the variance language found at OAR 340-041-0061(2) and replaced it with
new language at OAR 340-041-0059. Oregon's revised variance provision lays out the
necessary process for obtaining a variance, the conditions under which a variance will be
granted, and the requirements during a variance. DEQ's objective for these revisions is to ensure
that variances and their accompanying pollutant reduction plans continue to ensure progress
toward meeting standards, to streamline the administration process, to require pollutant reduction
plans with specific milestones that will result in water quality improvement, and to add general

179

clarification to the rule.

Below is ODEQ's revised variance provision, found at OAR 340-041-0059.

OAR 340-041-0059
Variances

This rule (OAR 340-041-0059) does not become applicable for purposes of ORS chapter 468B or the
federal Clean Water Act unless and until EPA approves the provisions it identifies as water quality

179 ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES
Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality. Available at:
http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

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standards pursuant to 40 CFR 131.21 (4/27/2000).

(1)	Applicability. Subject to the requirements and limitations set out in sections (2) through (7) below, a
point source may request a water quality standards variance where it is demonstrated that the source
cannot feasibly meet effluent limits sufficient to meet water quality standards. The director of the
department will determine whether to issue a variance for a source covered by an existing NPDES
permit. The commission will determine whether to issue a variance for a discharger that does not have a
currently effective NPDES permit.

(a)	The variance applies only to the specified point source permit and pollutant(s); the underlying
water quality standard(s) otherwise remains in effect.

(b)	The department or commission may not grant a variance if:

(A)	The effluent limit sufficient to meet the underlying water quality standard can be
attained by implementing technology-based effluent limits required under sections 301(b)
and 306 of the federal Clean Water Act, and by implementing cost-effective and
reasonable best management practices for nonpoint sources under the control of the
discharger; or

(B)	The variance would likely jeopardize the continued existence of any threatened or
endangered species listed under section 4 of the Endangered Species Act or result in the
destruction or adverse modification of such species' critical habitat; or

(C)	The conditions allowed by the variance would result in an unreasonable risk to
human health; or

(D)	A point source does not have a currently effective NPDES permit, unless the variance
is necessary to:

(i)	Prevent or mitigate a threat to public health or welfare;

(ii)	Allow a water quality or habitat restoration project that may cause short
term water quality standards exceedances, but will result in long term water
quality or habitat improvement that enhances the support of aquatic life uses;
(Hi) Provide benefits that outweigh the environmental costs of lowering water
quality. This analysis is comparable to that required under the antidegradation
regulation contained in OAR-041-0004(6)(b); or

(E)	The information and demonstration submitted in accordance with section (4) below
does not allow the department or commission to conclude that a condition in section (2)
has been met.

(2)	Conditions to Grant a Variance. Before the commission or department may grant a variance, it must
determine that:

(a)	No existing use will be impaired or removed as a result of granting the variance and\

(b)	Attaining the water quality standard during the term of the variance is not feasible for one or

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more of the following reasons:

(A)	Naturally occurring pollutant concentrations prevent the attainment of the use;

(B)	Natural, ephemeral, intermittent, or low flow conditions or water levels prevent the
attainment of the use, unless these conditions may be compensated for by the discharge of
sufficient volume of effluent discharges to enable uses to be met without violating state
water conservation requirements;

(C)	Human-caused conditions or sources ofpollution prevent the attainment of the use
and cannot be remedied or would cause more environmental damage to correct than to
leave in place;

(D)	Dams, diversions, or other types ofhydrologic modifications preclude the attainment
of the use, and it is not feasible to restore the waterbody to its original condition or to
operate such modification in a way which would result in the attainment of the use;

(E)	Physical conditions related to the natural features of the waterbody, such as the lack
of a proper substrate, cover, flow, depth, pools, riffles, and unrelated to water quality
preclude attainment of aquatic life protection uses; or

(F)	Controls more stringent than those required by sections 301(b) and 306 of the federal
Clean Water Act would result in substantial and widespread economic and social impact.

(3)	Variance Duration.

(a)	The duration of a variance must not exceed the term of the NPDES permit. If the permit is
administratively extended, the permit effluent limits and any other requirements based on the
variance and associated pollutant reduction plan will continue to be in effect during the period of
the administrative extension. The department will give priority to NPDES permit renewals for
permits containing variances and where a renewal application has been submitted to the director
at least one hundred eighty days prior to the NPDES permit expiration date.

(b)	When the duration of the variance is less than the term of a NPDES permit, the permittee must
be in compliance with the specified effluent limitation sufficient to meet the underlying water
quality standard upon the expiration of the variance.

(c)	A variance is effective only after EPA approval. The effective date and duration of the
variance will be specified in a NPDES permit or order of the commission or department.

(4)	Variance Submittal Requirements. To request a variance, a permittee must submit the following
information to the department:

(a)	A demonstration that attaining the water quality standard for a specific pollutant is not
feasible for the requested duration of the variance based on one or more of the conditions found
in section (2)(b) of this rule;

(b)	A description of treatment or alternative options considered to meet limits based on the
applicable underlying water quality standard, and a description of why these options are not
technically, economically, or otherwise feasible;

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(c)	Sufficient water quality data and analyses to characterize ambient and discharge water
pollutant concentrations;

(d)	Any cost-effective and reasonable best management practices for nonpoint sources under the
control of the discharger that addresses the pollutant the variance is based upon;

(e)	A proposed pollutant reduction plan that includes any actions to be taken by the permittee that
would result in reasonable progress toward meeting the underlying water quality standard. Such
actions may include proposed pollutant offsets or trading or other proposed pollutant reduction
activities, and associated milestones for implementing these measures. Pollutant reduction plans
will be tailored to address the specific circumstances of each facility and to the extent pollutant
reduction can be achieved; and

(f)	If the discharger is a publicly owned treatment works, a demonstration of the jurisdiction's
legal authority (such as a sewer use ordinance) to regulate the pollutant for which the variance is
sought. The jurisdiction's legal authority must be sufficient to control potential sources of that
pollutant that discharge into the jurisdiction's sewer collection system.

(5)	Variance Permit Conditions. Effluent limits in the discharger's permit will be based on the variance
and not the underlying water quality standard, so long as the variance remains effective. The department
must establish and incorporate into the discharger's NPDESpermit all conditions necessary to
implement and enforce an approved variance and associated pollutant reduction plan. The permit must
include, at a minimum, the following requirements:

(a)	An interim concentration based permit limit or requirement representing the best achievable
effluent quality based on discharge monitoring data and that is no less stringent than that
achieved under the previous permit. For a new discharger, the permit limit will be calculated
based on best achievable technology;

(b)	A requirement to implement any pollutant reduction actions approved as part of a pollutant
reduction plan submitted in accordance with section (4)(e) above and to make reasonable
progress toward attaining the underlying water quality standard(s);

(c)	Any studies, effluent monitoring, or other monitoring necessary to ensure compliance with the
conditions of the variance; and

(d)	An annual progress report to the department describing the results of any required studies or
monitoring during the reporting year and identifying any impediments to reaching any specific
milestones stated in the variance.

(6)	Public Notification Requirements.

(a)	If the department proposes to grant a variance, it must provide public notice of the proposal
and hold a public hearing. The public notice may be included in the public notification of a draft
NPDES permit or other draft regulatory decision that would rely on the variance;

(b)	The department will publish a list of all variances approved pursuant to this rule. Newly
approved variances will be added to this list within 30 days of their effective date. The list will
identify: the discharger; the underlying water quality standard addressed by the variance; the
waters of the state to which the variance applies; the effective date and duration of the variance;

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the allowable pollutant effluent limit granted under the variance; and how to obtain additional
information about the variance.

(7) Variance Renewals.

(a) A variance may be renewed if:

(A) The permittee makes a renewed demonstration pursuant to section (2) of this rule that
attaining the water quality standard continues to be infeasible,

(B) The permittee submits any new or updated information pertaining to any of the
requirements of section 4,

(C) The department determines that all conditions and requirements of the previous
variance and actions contained in the pollutant reduction plan pursuant to section (5)
have been met, unless reasons outside the control of the discharger prevented meeting
any condition or requirement, and

(D) All other requirements of this rule have been met.

(b) A variance renewal must be approved by the department director and by EPA.

C. EPA ACTION ON ODEQ'S REVISED VARIANCE PROVISION

EPA Action

In accordance with its CWA authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131, EPA
approves certain sections of Oregon's revised variance provision at OAR 340-041-0059, as
detailed below, because they are consistent with the Clean Water Act and the implementing
Federal water quality standards regulations governing EPA's review and approval or disapproval
of new or revised water quality standards as required in 40 C.F.R. part 131. These federal
regulations as well as EPA's guidance, to date, on variances are detailed above. EPA outlines
below the sections of the provision it is approving as water quality standards pursuant to CWA
section 303(c) and the sections of the provision which are not water quality standards under
CWA section 303(c) and therefore upon which EPA is taking no action. Oregon may use the full
variance provision (both those sections approved as WQS and those identified as not being
WQS) when developing and implementing any individual variance. Each individual variance the
State adopts consistent with the regulations at OAR 340-041-0059, must be submitted to EPA for
review and approval prior to its use in a NPDES permit or other CWA action. In EPA's review
of Oregon's revised variance provision, the Agency considered information submitted on July

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21, 2011 including ODEQ's NPDES Implementation Issue Paper and Response to Comments

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document.

180ODEQ. May 24, 2011. Issue Paper: Implementing Water Quality Standards for Toxic Pollutants in NPDES

Permits, Human Health Toxics Rulemaking. Oregon Department of Environmental Quality. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/NPDESIssuePaper.pdf

181 ODEQ. May 2011. Response to Comments: Proposed Water Quality Standards for Human Health and Water

Quality Standards Implementation Policies. Oregon Department of Environmental Quality, page 21. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ResponseToComments.pdf

EPA Rationale

EPA has reviewed the provision at OAR 340-041-0059 in Oregon's water quality standards
regulations, entitled, "Variances". EPA previously approved Oregon's existing variance
provision at OAR 350-041-0061(2).

Oregon's revised variance provision adds more definition to what was required in OAR 350-041-
0061(2) and requires the applicant to develop a schedule for improvements by implementing a
pollution reduction plan. These revisions will assist in meeting the goal of facilitating water
quality improvements and attaining the underlying criteria.

EPA is approving the specified sections of Oregon's variance regulation explained below as a
"general policy" under §131.13. ODEQ is still required to submit each individual variance to
EPA for review and action before it is effective for purposes of the CWA because the variances
themselves are also water quality standards. Accordingly, each variance submitted for EPA's
review must include the Attorney General's certification and be consistent with the CWA and
EPA's implementing regulations, including all applicable public participation requirements.

Thus, EPA's review of Oregon's variance authorizing provision need not evaluate each
hypothetical variance the State may issue under OAR 340-041-0059 and consider whether such a
variance would be consistent with the CWA and EPA's implementing regulation. EPA's
approval of Oregon's variance provision at OAR 340-041-0059 is not an automatic approval of
any future variance the State wishes to grant pursuant to these provisions.

Below, EPA outlines the sections it is approving as water quality standards pursuant to CWA
section 303(c) and the sections upon which EPA is taking no action. EPA's approval reflects
EPA's determination that the specific section adopted at OAR 340-041-0059 is consistent with
the Clean Water Act and the implementing Federal water quality standards regulations in 40
C.F.R. part 131.

Introductory Language to OAR 340-041-0059

EPA is approving the introductory language which states, "This rule (OAR 340-041-0059) does
not become applicable for purposes of ORS chapter 468B or the federal Clean Water Act unless
and until EPA approves the provisions it identifies as water quality standards pursuant to 40 CFR
131.21 (4/27/2000)."

In accordance with its Clean Water Act authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131,
EPA approves this new language. This language describes when Oregon's revised variance
provision becomes effective under state law and the Clean Water Act. The effective date of
water quality standards provisions under the CWA is determined by the date of EPA approval.
This language regarding timing is a water quality standard that provides for the sections of the
revised variance provision to be immediately in effect at the time of EPA's approval action.

OAR 340-041-0059(1) "Applicability"

EPA is approving OAR 340-041-0059(1) "Applicability" and OAR 340-041-0059(l)(a) which
reflects that the variance only applies to the specified point source and pollutant; the underlying
water quality standards remain in effect. This scope of applicability is consistent with EPA
interpretive Guidance and the 1977 Office of General Counsel legal opinion discussing

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variances.

Moreover, EPA is approving OAR 340-041-0059(l)(b) and (l)(b)(A) as they are consistent with
131.10(h)(2) which prohibits a State's removal of a designated uses where "[s]uch uses will be
attained.. .by implementing cost-effective and reasonable best management practices for
nonpoint source control." EPA has concluded that Oregon's language at (l)(b)(A) that prohibits
the State from issuing a variance where "effluent limitations sufficient to meet the underlying
water quality standards can be attained by ...implementing cost-effective and reasonable best
management practices for nonpoint sources under the control of the discharger, " is consistent
with 131.10(h)(2) because Oregon's variance authorizing provision only allows the State to issue

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discharger-specific variances. Given this scope of Oregon's variance authorizing provision,
EPA believes it is reasonable for the State to limit the prohibition in (l)(b)(A) to those cost-
effective and reasonable best management practices for nonpoint sources to those practices under

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the control of the discharger.

EPA is approving OAR 340-041-0059(l)(b)(B)-(E) because these sections are not inconsistent
with the CWA and EPA's implementing regulations. While OAR 340-041-0059(l)(b)(D) does
not categorically prohibit the issuance of a variance to a new discharger, neither do the CWA or
EPA's implementing regulations. While 40 CFR 122.4(i) limits discharges from "a new source
or a new discharger" that "will cause or contribute to the violation of water quality standards," a
variance is a revision to the water quality standard itself, and therefore 122.4(i) is not relevant.
EPA notes, however, that the circumstances in which a new discharger will be able to meet the
other requirements for a variance (e.g., a demonstration that [attaining the water quality standard
during the term of the variance is not feasible,") are likely to be significantly more limited for a
new discharger than an existing discharger. EPA acknowledges that granting a variance to a new
discharger may be appropriate under very specific and limited circumstances. It will review the
appropriateness of particular circumstances on an individual variance basis.

182	OAR 340-041-0059(l)(a) provides that the "variance applies only to the specified point source permit and
pollutant(s); the underlying water quality standard(s) otherwise remain in effect."

183	EPA disagrees with the contrary contention, made in public comments, that the BMP requirements of 40 C.F.R. §
131.10(h)(2) must apply to "all nonpoint sources in the consideration of a variance application, not just those under
the control of the applicant." Northwest Environmental Advocates (NWEA). March 17, 2011. Letter from Nina
Bell, Executive Director, NWEA to Andrea Matzke, ODEQ, Re: Proposed Revised Water Quality Standards for
Human Health Toxic Pollutants and Revised Water Quality Standards Implementation Policies, page 32. In support
of this proposition, the commenter cites a 1994 EPA interpretive memorandum ("Tudor Davies memo") and a 1995
EPA economic guidance document. The Tudor Davies memo discusses how the requirements of 40 CFR

131.12(a)(2) apply to antidegradation policies, not the applicability of 40 CFR 131.10(h)(2) to variances. The
citation to the 1995 Interim Economic Guidance for Water Quality Standards is similarly inapposite. This guidance
addresses how an economic analysis under 131.10(g)(6) should be conducted to demonstrate that a variance is
needed. Sections 40 C.F.R. 131.10(d) and (h)(2) are independent requirements from 131.10(g). EPA recognizes
that the introduction section of the guidance document states that polluting entities can be point or nonpoint sources
of pollution and that attainment of water quality standards is not limited to controls placed on point sources.
However, this statement should be viewed in context of the stated scope of the guidance, which is to address
economic factors considered under 131.10(g) and 131.12. Even if this statement could be read to apply to 131.10(d)
and (h)(2), Oregon's provision at OAR 340-041-0059(l)(b)(A) is consistent with EPA's 1995 economic guidance
document because the guidance contemplates that financial impacts are determined by the costs the entity itself
would face by implementing the necessary pollution controls.

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OAR 340-041-0059(2) "Conditions to Grant a Variance"

EPA is approving OAR 340-041-0059(2), (2)(a) and (2)(b) "Conditions to Grant a Variance"
because it is consistent with the substantive requirements of permanently changing designated
uses at §131.10, specifically §131.10(g).

OAR 340-04l-0059(2)(a) requires the state to determine that "[n]o existing use will be impaired
or removed as a result of granting the variance." One commenter argues that this section is
inconsistent with EPA's regulations because it "does not explicitly require variances to meet the
anti degradation policy[,].. .falls short of full protection of existing uses[,]... [and] makes no

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reference to the water quality that is required to maintain and protect existing uses." EPA
disagrees that OAR 340-04l-0059(2)(a) is inconsistent with EPA regulations. OAR 340-041-
0059(2)(a) is consistent with 131.10(h)(1) and (g) which both prohibit a state from removing the
protection for an existing use. While a state's adoption of new or revised water quality standards
is not itself subject to anti degradation review, EPA notes that OAR 340-04 l-0059(2)(a) is also
consistent with 131.12(a)(1): requiring the that "[ejxisting instream water uses and the level of
water quality necessary to protect the existing uses shall be maintained and protected." EPA
believes that prohibiting the impairment or removal of an existing use will achieve the goals of
"maintaining] and protecting]" the "level of water quality necessary to protect the existing
use."

Section OAR 340-04l-0059(2)(b) is consistent with the substantive requirements at §131.10(g).
OAR 340-041-0059(3) "Variance Duration"

EPA is approving OAR 340-041-0059(3) and the first sentence of OAR 340-04 l-0059(3)(a)
"Variance Duration" as a water quality standard that states "The duration of a variance must not
exceed the term of the NPDES permit." EPA understands this section to mean that each variance
will expire five years after the State adopts the variance, the maximum length of a NPDES
permit consistent with federal regulations and OAR 340-045-0035(8), or the variance will
specify a specific expiration date of less than five years after the variance was adopted into state
regulation. As discussed earlier, the 1977 Office of General Counsel legal opinion explains that
time-limited revisions to the designated use and criteria are environmentally preferable as
compared with the permanent removal of a designated use because the more stringent standards
apply to all other dischargers not covered by the variance. EPA is approving this sentence as it
states the specific time limit for which the designated use and criteria have been determined to be
"unattainable" consistent with §131.10(g).

EPA is taking no action on the last two sentences of OAR 340-04 l-0059(3)(a) "Variance
Duration" that states "If the permit is administratively extended, the permit effluent limits and
any other requirements based on the variance and associated pollutant reduction plan will
continue to be in effect during the period of the administrative extension. The department will
give priority to NPDES permit renewals for permits containing variances and where a renewal
application has been submitted to the director at least one hundred eighty days prior to the

184 Northwest Environmental Advocates (NWEA). March 17, 2011. Letter from Nina Bell, Executive Director,
NWEA to Andrea Matzke, ODEQ, Re: Proposed Revised Water Quality Standards for Human Health Toxic
Pollutants and Revised Water Quality Standards Implementation Policies, page 39.

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NPDES permit expiration date." These sections are NPDES permitting requirements because
they describe the permitting process for handling situations where there is a delay in reissuing a
permit. Such language does not affect how long the variance applies as the approved water
quality standard and the administrative extension of a permit is not subject to EPA WQS
approval or disapproval.

EPA is also taking no action on OAR 340-04l-0059(3)(b) "Variance Duration" because that
section of the provision reiterates the permitting provisions at §122.44(d)(vii) requiring the
NPDES permit limit to derive from and comply with the applicable water quality standards once
the variance expires. Therefore, EPA does not consider this section to be a water quality
standard.

EPA is approving OAR 340-041-0039(3)(c) "Variance Duration" as a water quality standard
because it clearly states that the variance is not effective for CWA section 402 permitting
purposes until EPA approves it, consistent with §131.21(c). EPA notes that once an individual
variance has been approved, it is a water quality standard applicable for CWA section 402
permitting purposes (see 40 CFR 131.21) and thus becomes subject to the triennial review
requirements at 40 C.F.R. 131.20.

OAR 340-041-0059(4) "Variance Submittal Requirements"

EPA is approving OAR 340-041-0059(4) "Variance Submittal Requirements" and OAR 340-
041 -0059(4)(a) consistent with §131.10(g) because it requires a demonstration that one of EPA's
regulatory factors precludes attainment of the use. EPA is also approving OAR 340-041-
0059(4)(b)-(f) because these sections provide substantive requirements for what the applicant
must submit to the State to obtain a variance, and are not inconsistent with the requirements of
the CWA and EPA's regulations.

OAR 340-041-0059(5) "Variance Permit Conditions"

EPA is approving OAR 340-041-0059(5), (5)(a) and (5)(b) "Variance Permit Conditions"
because these sections establish the water quality requirements during a variance. While those
requirements might typically be presented in the form of instream water quality criteria, EPA
considers the requirement for a permit limit to include the best achievable effluent quality to be a
surrogate for identifying the instream water quality criteria at the highest attainable condition.
Thus, EPA is approving sections 5(a) and 5(b) because they describe the resulting instream
concentration and together act as a surrogate for interim criterion applicable during a variance.
Based on Oregon's regulatory language in this section, the best achievable effluent quality will
be appropriately determined on a case-by-case basis.

EPA is not taking action on OAR 340-04l-0059(5)(c) and (5)(d) because they are monitoring
and reporting requirements applicable to a discharger's NPDES permit. These requirements are
not considered WQS under CWA section 303(c) or addressed in EPA's water quality standards
regulations because they are NPDES permitting requirements.

OAR 340-041-0059(6) "Public Notice Requirements"

EPA is approving OAR 340-041-0059(6) "Public Notice Requirements" and OAR 340-041-
0059(6)(a) and 0059(6)(b) because they address the requirements for public notice of a variance

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consistent with §131.20(b), and explain what information will be provided to the public. EPA
notes that this section states that public notification for a variance can be included in the public
notification of a draft NPDES permit or draft regulatory decision that would rely on the variance.
In addition, EPA must approve the variance before it can be implemented and thus the State
cannot finalize the NPDES permit with a limit that reflects a variance until EPA has approved
the variance.

OAR 340-041-0059(7) "Variance Renewals"

EPA is approving OAR 340-041-0059(7) "Variance Renewals". EPA is approving OAR 340-
041-0059(7)(a)(A) as consistent with 131.10(g) as it requires the permittee to demonstrate that
attaining water quality standards during the term of the variance is still not feasible based on
factors consistent with 131.10(g)( 1 )-(6). EPA is approving all other language in OAR 340-041-
0059(7) because this regulatory language is not inconsistent with the CWA or EPA's
implementing regulations. EPA notes that since variances are water quality standards, the state
will need to include variances in the applicable water quality standards that the state reviews
during its triennial review processes under §131.20(a). EPA understands that OAR 340-041-
0059(7)(D) ("[a]ll other requirements of this rule have been met.") will require a new round of
public notice, comporting with the requirements of OAR 340-041-0059(6), and all other
requirements in OAR 340-041-0059 to be met when any variance is renewed.

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VIII. BACTERIA

Oregon's revisions to its bacteria provision found at OAR 340-041-0009(10) are shown in
underline/strikeout format below. Underlined text represents added text, while text with a line
through the middle (strikeout) represents deleted text. The revised text corrects a citation based
on renumbering in OAR 340-041-0061.

(10) Water Quality Limitedfor Bacteria: In those water bodies, or segments of water bodies
identified by the Department as exceeding the relevant numeric criteria for bacteria in the basin
standards and designated as water-quality limited under section 303(d) of the Clean Water Act,
the requirements specified in section 11 of this rule and in OAR 340-041-0061(112) must apply.

EPA Action

In accordance with its CWA authority, 33 U.S.C § 1313(c)(3) and 40 C.F.R. part 131, EPA
approves this minor editorial change as a non-substantive revision to water quality standards at
OAR 340-041-0009.

EPA Rationale

The minor editorial change in this provision to correct the citation due to a renumbering revision
in OAR 340-041-0061(12) does not alter the underlying provision that EPA previously approved
and EPA is not acting on the underlying provision. EPA approves this non-substantive revision
to Oregon's WQS under section 303(c) of the CWA and the implementing regulations at 40 CFR
Part 131.

IX. REVISED RULES REGARDING IMPLEMENTAIN FOR
NONPOINT SOURCES

A. STATEWIDE NARRATIVE CRITERIA

Oregon's revisions to OAR 340-041-0007(5) are shown in underline/strikeout format below.
Underlined text represents added text, while text with a line through the middle (strikeout)
represents deleted text. The revised rule clarifies the state regulatory mechanisms for water
quality control applicable to forest management activities.

(5) Logging andforest management activities must be conducted in accordance with the Oregon
rules established by the Environmental Quality Commission and must not cause violation of
water quality standards. Nonpoint sources of pollution from forest operations on state and
private forest lands are sub ject to best management practices and other control measures
established by the Ore son Board of Forestry as provided in ORS 527.765 and 527.770. Forest
Practices operations conducted in sood faith compliance with the best management practices
and control measures established under the Forest Practices Act to minimize adverse effects on
water quality are generally deemed not to cause violations of water quality standards as
provided in ORS 527.770. Forest operations are subject to load allocations established under
ORS 468B. 110 and OAR Division 340-042 to the extent needed to implement the federal Clean
Water Act.

Acknowledgement of OAR 340-041-0007(5)

EPA acknowledges the revised language contained in OAR 340-041-0007(5). ODEQ has
revised their regulations to explain how the control measures applicable to forestry nonpoint
sources under the Forest Practices Act are presumed to meet water quality standards and that

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forest operations are subject to load allocations in TMDLs. Furthermore, the rule clarifies the
water quality regulatory requirements for forest management activities in Oregon.

This rule states that certain activities related to logging and forest management are generally
deemed not to cause violations of water quality standards if best management practices and
control measures under the Forest Practices Act are followed. The CWA requires NPDES
permits for discharges from point sources and compliance with that permit, but does not require
that states develop enforceable regulatory programs for nonpoint sources. Whether a State
chooses to make water quality standards directly enforceable for nonpoint sources is solely a
matter of state law and the State has discretion as to how it enforces its laws. This provision is
applicable only to nonpoint sources and their compliance with water quality standards and
TMDL load allocations. As such EPA does not consider this provision to be a water quality
standard under section 303(c) of the CWA. Water quality standards are provisions of State or
Federal law which consist of a designated use or uses for waters of the United States, and water
quality criteria necessary to protect the uses (40 CFR 131.3(i)).

185 ODEQ. June 7, 2011. Executive Summary. Human Health Toxics Rulemaking. Oregon Department of
Environmental Quality, page 9. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ExecSummarv.pdf

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In addition, this provision does not include language that has the effect of changing the level of
protection provided by Oregon's water quality criteria and therefore does not constitute a new or
revised water quality standard. The provision defines how logging and forest management
nonpoint sources activities must control their discharges in order to comply with Oregon's water
quality standards, but it does not establish or revise any of the components of the water quality
standards themselves.

Therefore, this provision is not considered a water quality standard subject to EPA review and
approval and EPA is taking no action to approve or disapprove this provision.

B. OTHER IMPLEMENTATION OF WATER QUALITY

Oregon's revisions to implementation provisions found at OAR 340-041-006l(9)(a)(E), (10),
and (11) are shown in underline/strikeout format below. Underlined text represents added text,
while text with a line through the middle (strikeout) represents deleted text. The revised rule at
(9)(a)(E) corrects an error to the cross-reference to the antidegradation policy. The revised rules
in (10) and (11) explain how the mechanisms for forestry and agricultural nonpoint sources work
to meet water quality standards and the total maximum daily load (TMDL) load allocations
under the Forest Practices Act and Agriculture Water Quality Management Act.186 Finally, the
revised rule contains revised paragraph numbers for subsections (2) through (16) as the variance
rule in section (2) was moved to OAR 340-041-0059.

(9)(a)(E)	Mass loads assigned as described in paragraphs (B) and (C) of this subsection will not
be subject to OAR 340-041-0004(9-7);

Acknowledgement of OAR 340-041-0061(9)(a)(E)

EPA acknowledges the changed cross-reference located in OAR 340-041-006 l(9)(a)(E) Other
Implementation of Water Quality Criteria. Water quality standards are provisions of State or
Federal law which consist of a designated use or uses for waters of the United States, and water
quality criteria necessary to protect the uses (40 CFR 131.3(i)). EPA has determined this
provision is not a WQS. Instead, the provision at section (9)(a)(E) is a NPDES permitting
implementation provision and corrects an error to a regulatory citation to the antidegradation
policy.

(10)	Forestry on state and private lands. For Nonpoint sources ofpollution from forest
operations on state or private lands, water quality standards are intended to be attained and are
implemented through subject to best management practices and other control mechanisms
measures established under the Forest Practices Act (ORS 527.610 to 527.992) and rules
thereunder, administered by the Oregon Department of Forestry. Tlierefore, under the Forest
Practices Act, (ORS 527.610 to 527.992) Such forest operations that are when conducted in
sood faith compliance with the Forest Practices Act requirements are (except for the limits set
out in ORS 527.770) deemed in compliance with this division. DEQ will work with the Oregon

186 ODEQ. June 7, 2011. Executive Summary. Human Health Toxics Rulemaking. Oregon Department of
Environmental Quality, page 9. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ExecSummarv.pdf

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Department of Forestry to revise the Forest Practices program to attain water quality standards.
generally deemed not to cause violations of water quality standards as provided in ORS 527.770.
Forest operations on state and private lands are subject to load allocations under ORS 468.110
and OAR 340. Division 42, to the extent necessary to implement the federal Clean Water Act.

(11) Agricultural water quality management plans to reduce agricultural nonpoint source
pollution are developed and implemented by the Oregon Department of Agriculture (ODA)
through a cooperative agreement with the department to implement applicable provisions of
ORS 568.900 to 568.933 and 561.191. If the department has reason to believe that agricultural
discharges or activities arc contributing to water quality problems resulting in water quality
standards violations, the department may consult ODA. If water quality impacts are likely from
agricultural sources and the department determines that a water quality management plan is
necessary, the director may write a letter to the director of the ODA requesting that such a
management plan be prepared and implemented to reduce pollutant loads and achieve the water
quality criteria. In areas sub ject to the Agricultural Water Quality Management Act, the Oregon
Department of Agriculture (ODA) under ORS 568.900 to 568.933 and 561.191 develops and
implements agricultural water quality management area plans and rules to prevent and control
water pollution from agricultural activities and soil erosion on agricultural and rural lands.

Area plans and rules must be designed to achieve and maintain water quality standards. If the
department determines that the area plan and rules are not adequate to achieve and maintain
water quality standards, the department will provide ODA with comments on what would be
sufficient to meet WOS or TMDL load allocations. If a resolution cannot be agreed upon, the
department will request the Environmental Quality Commission (EQC) to petition ODA for a
review of part or all of water quality management area plan and rules. If a person subject to an
ODA area plan and implementing rules causes or contributes to water quality standards
violations, the department will refer the activity to ODA for further evaluation and potential
requirements.

Acknowledgement of OAR 340-041-0061(10) and (11)

EPA acknowledges the revised language in OAR 340-041-0061(10) and (11) Other
Implementation of Water Quality Criteria. The revised rules in (10) and (11) explain how state
rules for forestry and agricultural nonpoint sources are to be implemented consistent with water

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quality standards and the total maximum daily load (TMDL) load allocations. These
provisions set forth the extent to which Oregon requires nonpoint sources of pollution from
forest operations under the Forest Practices Act and agricultural activities under the Agricultural
Water Quality Management Act to control their discharges in order to protect water quality.

These rules state that forest operations and agricultural activities generally will not be deemed to
cause violations of water quality standards if best management practices and control measures
under the Forest Practices Act and water quality management area plans under the Agricultural
Water Quality Management Act are followed and identify the process to be used when water
quality concerns arise. Thus, the rule clarifies mechanisms for WQS implementation and

187 ODEQ. June 7, 2011. Executive Summary. Human Health Toxics Rulemaking. Oregon Department of
Environmental Quality, page 9. Available at:

http://www.dea.state.or.us/wa/standards/docs/toxics/humanhealth/rulemaking/ExecSummarv.pdf

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compliance.

Whether a State chooses to make water quality standards directly enforceable for nonpoint
sources is solely a matter of state law. The CWA requires NPDES permits for discharges from
point sources and compliance with that permit, but does not require that states develop
enforceable regulatory programs for nonpoint sources. These provisions are applicable only to
nonpoint sources and how they comply with water quality standards and TMDL load allocations
and as such are not water quality standards under section 303(c) of the CWA. Water quality
standards are provisions of State or Federal law which consist of a designated use or uses for
waters of the United States, and water quality criteria necessary to protect the uses (40 CFR
131.3(i)).

In addition, these provisions do not include language that has the effect of changing the level of
protection provided by Oregon's water quality criteria and therefore do not constitute new or
revised water quality standards. The provisions define the extent to which forest operations and
agricultural operations that result in nonpoint source discharges must control their discharges in
order to comply with Oregon's water quality standards, but they do not establish or revise any of
the components of the water quality standards themselves.

Therefore, these provisions are not considered water quality standards subject to EPA review and
approval and EPA is taking no action to approve or disapprove the provisions.

Acknowledgment of Section Renumbering in OAR 340-041-0061(2)-(16)

The revised rule contains revised paragraph numbers for subsections OAR 340-041-0061(2)
through (16) as the variance rule in section (2) was moved to OAR 340-041-0059. EPA
acknowledges the renumbering for subsections that were previously approved by EPA under
303(c) of the CWA as a non-substantive formatting change which does not require EPA action.

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