UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 10

s 1200 Sixth Avenue Suite 900

Seattle WA 98101 3140 OFFICE OF

WATER AND

WATERSHEDS

MAY 1 0 2012

Mr Barry Burnell

Water Quality Programs Administrator

Idaho Department of Environmental Quality

1410 North Hilton

Boise Idaho 83706 1255

Re EPA Disapproval of New and Revised Human Health Water Quality Criteriafor Toxics Idaho

Docket 5801020503

DearMr Burnell

The US Environmental Protection Agency has completed its review of Idaho's new and revised human

health water quality criteria for toxic pollutants and revisions to Footnotes b c d and I that are

applicable to certain human health criteria These new and revised water quality standards WQS were

adopted by the Idaho legislature in March 2006 The WQS were submitted to the EPA for review under

the Clean Water Act CWA on July 7,2006

Under CWA Section 303c 33 USc 1313 c and the Code of Federal Regulations CFR at

40 CFR 131 the EPA is disapproving 167 ofIdaho s revised human health criteria for 88 toxic

pollutants applicable to all surface waters of the State of Idaho In addition the EPA is not acting on

Idaho's revisions to Footnotes b c d and I because the changes are non substantive With respect to

Idaho's revisions clarifying the existing mixing zone language and a new provision specifying the

frequency and duration component for aquatic life criteria which were contained in the July 7,2006

submittal the EPA will provide the Idaho Department of Environmental Quality DEQ or the State with

our review and decision on these provisions in a subsequent letter

Background

Idaho announced it was updating the State's human health criteria for toxics in the Idaho Administrative

Bulletin on April 5 2005 DEQ held its first public meeting on the updates in Boise on April 28 2005

and three additional meetings followed on May 20 June 22 and July 12 2005 The public participation

process resulted in a proposed rule which was published in the September 7,2005 Idaho

Administrative Bulletin with a 30day comment period Following the comment period the pending rule

was adopted by the Idaho Board of Environmental Quality on November 16 2005

Revising Idaho's human health criteria for 88 toxic pollutants was a result of the State's incorporation of

a revised fish consumption rate and newer information in the Integrated Risk Information System IRIS

database on health effects DEQ's basis for revising specific human health criteria for toxic pollutants

was a change in the EPA's nationally recommended fish consumption rate from 6.5 grams per day

gday to 17.5 gday The fish consumption rate is one factor used in the calculation of toxic criteria In

addition DEQ revised the human health criteria for the 88 toxic pollutants to reflect updated information

on toxicity to humans contained in the EPA's IRIS database These factors relate to the reference dose

for non carcinogenic chemicals or the cancer slope factor for carcinogens as well as bioconcentration

EPA004187
rates More detail about the development of toxic criteria is contained in the EPA's Methodology for

Deriving Ambient Water Quality Criteriafor the Protections ofHuman Health 2000 2000 Human

Health CriteriaMethodology

The final rule was approved by the Idaho Legislature in March 2006 By letter dated July 7,2006 DEQ

submitted the following revisions to the EPA for review and approval new and revised human health

criteria for 88 toxic pollutants revisions to Footnotes b c d and I that are applicable to certain human

health criteria in Idaho's table of toxic criteria clarification to the existing mixing zone language and a

new provision specifying the frequency and duration component for aquatic life criteria While the

submittal also included revisions to cadmium aquatic life criteria the EPA approved these revisions on

March 7 2011 In the 2006 submittal to the EPA DEQ stated that no information on Idaho specific fish

consumption rates was available with which to calculate alternative human health criteria values

However DEQ acknowledged that questions remained regarding the most appropriate fish consumption

rate

Under Section 303 of the CWA 33 USC 1313 states are required to establish WQS and submit them

to the EPA for approval or disapproval Likewise revisions to a state's WQS must also be submitted to

the EPA for approval or disapproval The EPA must review new and revised WQS under CWA 303c

and 40 CFR 131.5 to ensure that the designated uses for all affected waterbodies are protected and

criteria are based on a sound scientific rationale

WQS describe the desired condition of a waterbody and consist of three principle elements

1 the designated uses of the state's waters such as public water supply recreation propagation of

fish or navigation 2 criteria specifying the amounts of various pollutants in either numeric or

narrative form that may be present in those waters without impairing the designated uses and 3

antidegradation requirements providing for protection of existing water uses and limitations on

degradation of high quality waters The EPA's regulations at 40 CFR 131 describe the minimum

requirements for each of these three elements of WQS

In accordance with 40 CFR 131.11 the EPA must ensure that new or revised criteria are based on sound

scientific rationale and contain sufficient parameters or constituents to protect designated uses When

establishing criteria states should develop numerical criteria values based on 1 the EPA's CWA

304 a Guidance 2 CWA 304a Guidance modified to reflect sitespecific conditions or 3 other

scientifically defensible methods

Idaho's human health criteria were developed to protect human health from longterm exposure to toxic

pollutants in drinking water and through eating fish containing pollutants With respect to selection of a

fish consumption rate utilized in calculating human health criteria the EPA is aware that exposure

patterns in general and fish consumption in particular varies substantially The EPA understands that

highly exposed populations may be widely distributed geographically throughout a given state or tribal

area The EPA recommends that priority be given to identifying and adequately protecting the most

highly exposed population Thus if the state or tribe determines that a highly exposed population is at

greater risk and would not be adequately protected by criteria based on the general population and by

the national 304a criteria in particular the EPA recommends that the state or tribe adopt more stringent

criteria using alternative exposure assumptions

1EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health

EPA822BOO004 Available at http www epagov waterscience criterialhumanhealth method complete pdf

EPA004188
EPA's Decision

The revisions addressed in this disapproval action are Idaho's 167 new and revised human health water

quality criteria for 88 pollutants also known as toxic pollutants at IDAPA 58.01.02.210.01 and the

provision at IDAPA 58.01.02.21O 05bi specifying the fish consumption rate of 17.5 gday The EPA is

disapproving Idaho's human health criteria for toxic pollutants because the criteria derivation does not

demonstrate that the criteria protect Idaho's designated uses Specifically EPA is unable to ensure that

the use of a fish consumption rate of 17.5 gday in deriving statewide criteria is consistent with 40 CFR

131.11 a

The EPA reviewed whether local andor regional information on fish consumption was relevant and

applicable when considering if the national default fish consumption rate is appropriate for calculating

human health criteria for Idaho's waters The EPA identified several sources of information on local and

regional fish consumption which Idaho did not consider before using the national default fish

consumption rate The information the EPA reviewed suggests that fish consumption among some Idaho

population groups is greater than 17.5 gday Consequently EPA cannot ensure that the criteria derived

based on a fish consumption rate of 17.5 gday are based on a sound scientific rationale consistent with

40 CFR 131.11 a and protect Idaho's designated uses Idaho must evaluate the relevance of available

information including the studies that the EPA identified in assessing a fish consumption rate

appropriate for protecting consumers of fish taken from state waters and use that information to ensure

criteria are protective of designated uses

The EPA is also disapproving IDAPA 58.01.02.21O 05bi that requires DEQ to use a fish consumption

rate of 17.5 gday when deriving water quality criteria to protect human health With respect to revisions

to footnotes to the toxic criteria the EPA does not consider revisions to Footnotes b c d and I to be

substantive revisions to the WQS under Section 303 c of the CWA therefore the EPA is not taking

action on those footnotes These footnotes remain in effect for CW A purposes A detailed discussion of

the rationale supporting the EPA's action is included in the enclosed Technical Support Document

This action applies only to water bodies in the State of Idaho and does not apply to waters that are

within Indian Country as defined in 18 U Sc Section 1151 In addition nothing in this letter shall

constitute an approved or disapproved water quality standard applying to waters within Indian Country

The EPA or authorized Indian Tribes as appropriate will retain responsibilities for WQS for waters

within Indian Country

Remedy to Address EPA's Disapproval

Under CWA 303 c3 and the EPA's implementing regulations at 40 CFR 131.21 and 131.22 when

the EPA disapproves a state's new or revised water quality standard it must specify the changes

necessary to meet the applicable requirements of the Act and the EPA's regulations The CW A requires

that this disapproval of the new and revised human health criteria for 88 toxic pollutants be addressed in

a timely manner The EPA prefers that Idaho address this disapproval under its regulatory development

process However if the State does not adopt necessary changes the EPA will promptly propose and

promulgate appropriate human health criteria for Idaho

To address this disapproval action Idaho must evaluate local and regional fish consumption information

to determine whether its statewide criteria are protective of designated uses The EPA's 2000 Human

Health Methodology advises states to develop criteria to protect highly exposed populations such as

3

EPA004189
subistence fishers and to rely on local or regional fish consumption data in developing a fish

consumption rate that is more representative of target populations

The EPA relies on the 2000 Human Health Methodology both to develop new water quality criteria for

additional pollutants and to revise existing water quality criteria The 2000 Human Health Methodology

also provides states and tribes flexibility in establishing WQS by providing scientifically valid options

for developing their own criteria that consider local state or regional conditions For example states

and authorized tribes should consider use of local data use of data reflecting similar

geography population groups use of data from national surveys and use of the EPA's default intake

rates including a subsistence rate of 142 gday

Among the available and relevant information on fish consumption the EPA believes that the Columbia

River Inter Tribal Fish Commission survey CRITFC 2 is particularly relevant for Idaho to consider in

revising human health criteria The CRITFC study is a well designed survey and is directly applicable to

a population of people ie the Nez Perce Tribe fishing in state waters There are also several other

local and regional studies including several that have been published since 2006 that are relevant when

evaluating fish consumption rates in Idaho These studies are listed in the enclosed Technical Support

Document

As the State reviews the available studies and determines what revisions to make to the human health

criteria there are other issues that the State should consider

First Idaho should evaluate how its revised human health criteria will protect recreational users and

subsistence fishers in Idaho as well as downstream WQS During tribal consultation the EPA heard

from several tribes that they rely on fish and other resources in Idaho waters for subsistence and

religious practices In addition some of the information the EPA reviewed suggests that recreational

anglers in Idaho also consume fish at rates higher than the national default rate With respect to

downstream waters the State should address 40 CFR 13 1.10 b which provides in pertinent part that

when setting water quality criteria a state shall take into consideration the water quality standards of

downstream waters and shall ensure that its criteria provide for the attainment and maintenance of such

standards

Second the EPA notes that in deriving the human health criteria for acrolein and phenol Idaho utilized

reference dose values that have since been superseded Idaho utilized the reference dose RID values in

the EPA's IRIS database as of May 17 2002 The RID values for acrolein and phenol were

subsequently updated in June 2003 and September 2002 respectively The EPA integrated the updated

IRIS values into its current 304 a criteria recommendations and published the recalculated criteria as

the Agency's current national recommended criteria 3 The current recommended criteria were finalized

in 2009 and supersede any recommended criteria that the EPA previously published for acrolein and

phenol Idaho's revisions to the human health criteria must be based on a sound scientific rationale and

must be protective of the State's designated uses In keeping to these requirements the EPA

recommends for acrolein and phenol that Idaho derive revised criteria incorporating these updated RID

values

2 CRITFC 1994 A Fish Consumption Survey ofthe Umatilla Nez Perce Yakama and Warm Springs ofthe Columbia River

Basin Columbia River Inter Tribal Fish CommissionPortland Oregon Technical Report 943 Available at

http www critfc orgtech 943reportpdf

374 FR 27535 Notice of Availability of National Recommended Water Quality Criteriafor Acrolein and Phenol June 10

2009 Federal Register Vol 74 No 110 pp 27535 27536

4

EPA004190
Finally the EPA notes that Idaho does not a have human health criteria for copper The EPA has a

recommended human health water organism criterion for copper Since the human health risks from

copper are primarily from drinking water the criterion was established at the level of the EPA's

drinking water criterion under the Safe Drinking Water Act and therefore does not utilize a fish

consumption rate The EPA suggests that Idaho also incorporate adoption of that criterion into any

revisions to the State's WQS

Human Health CriteriaCurrently in Effect in Idaho

Until Idaho develops and adopts and the EPA approves revisions to human health criteria for these

88 pollutants the criteria applicable to the designated uses in Idaho that are effective for Clean Water

Act purposes are the previous human health criteria for these 88 pollutants which were approved in

1996 To the extent allowable under state and federal law the EPA urges Idaho to continue to

implement the criteria adopted pursuant to state law until such time as future revisions are adopted

Idaho also may want to consider undertaking additional fish consumption surveys of high fish

consuming populations within Idaho If the State is interested in exploring work in this area the EPA is

available and interested in providing assistance

The EPA looks forward to working with the State to revise Idaho's human health criteria to ensure

protection of Idaho designated uses If you have any questions regarding this letter please contact me at

206 553 4198 or you may contact Lisa Macchio Idaho WQS Coordinator at 206 5531834 Sincer eJly

•

2 J L 0

Michael A Busell Director

Office of Water and Watersheds

Enclosure

cc Mr Michael McIntyre Surface Water Program Manager

Idaho Department of Environmental Quality

Mr Don Essig Water Quality Standards Manager

Idaho Department of Environmental Quality

5

EPA004191
Technical Support Documentfor EPA's Disapproval Action on Idaho's Revised Human Health Criteria

US ENVIRONMENTAL PROTECTION AGENCY REGION 10

Technical Support Document

EPA Disapproval of the State of Idaho's Revised

Human Health Water Quality Criteria for Taxies

Submitted on July 7 2006

May 10,2012

1

EPA004192
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

Technical Support Document

EPA Disapproval of the State of Idaho's Revised Human

Health Water Quality Criteria for Toxics

Submitted on July 7 2006

Contents

I INTRODUCTION 3

II BACKGROUND 4

A CLEAN WATER ACT REQUIREMENTS FOR WATER QUALITY STANDARDS 4

B OVERVIEW OF IDAHO'S JULY 7 2006 WQS SUBMISSION 4

III IDAHO'S NEW AND REVISED HUMAN HEALTH WATER QUALITY CRITERIA 5

A HUMAN HEALTH CRITERIA AND APPLICATION TO IDAHO'S DESIGNATED USES 7

B CRITERIA METHODOLOGY AND INPUT V ARIABLES USED BY IDAHO 8

IV EPA'S REVIEW 10

A RELEVANT AND AVAILABLE LOCAL AND REGION AL FISH CONSUMPTION INFORMATION 12

V EPA DISAPPROVAL OF IDAHO'S NEW AND REVISED HUMAN HEALTH CRITERIA 13

VI NO ACTION ON REVISED FOOTNOTES 17

A FOOTNOTE B17

1 Description ofFootnote 17

2 EPA Review and Action 17

B FOOTNOTE c 17

1 Description of Footnote 17

2 EPA Review and Action 17

C FOOTNOTED 18

1 Description ofFootnote 18

2 EPA Review and Action 18

D FOOTNOTE L 18

1 Description of Footnote 18

2 EPA Review and Action 18

E OTHER FOOTNOTES NOT REVISED 18

2

EPA004193
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

Technical Support Document

EPA's Disapproval of the State of Idaho's Revised

Human Health Water Quality Criteriafor Toxics

Submitted on July 7 2006

I INTRODUCTION

On July 7,2006 the Idaho Department of Environmental Quality DEQ submitted new and

revised water quality standards WQS l to the US Environmental Protection Agency EPA or

the Agency for review and approval These new and revised WQS were adopted by the 2006

Idaho legislature effective April 11 2006 Idaho's WQS are located in the Idaho Administrative

Procedures Act 58 Title 01 Chapter 02 IDAPA 58.01.02

DEQ's submittal contained 167 new and revised human health criteria for eighty eight 88

pollutants that are applicable to all surface waters of the state By this action EPA is

disapproving these human health criteria for surface waters of the State of Idaho based on an

evaluation of whether the above described WQS revisions are protective and based on sound

scientific rationale

The revised WQS addressed in this action include new and revised human health criteria for 88

toxic pollutants see Table 1 below revisions to footnotes b c d and 1 applicable to certain

human health criteria contained in Idaho's table of toxic criteria and a provision specifying the

fish consumption rate to be utilized in calculating human health criteria These WQS revisions

were submitted to EPA on July 7,2006 Included in the submission was a document entitled

Technical Justification Idaho Rulemaking Docket 580102 0503 Idaho Cadmium Aquatic Life

Criteria and Update ofHuman Health Toxic Criteria prepared by DEQ staff In this document

DEQ summarizesthe changes and the bases for the new and revised human health criteria In

addition DEQ stated they lacked information on Idaho specific fish consumption rates with

which to calculate alternative human health criteria values

The revisions addressed in today's disapproval action include Idaho's new and revised human

health water quality criteria for all 88 pollutants carcinogens and non carcinogens also known

as toxic pollutants at IDAPA 58.01.02.210.01 and the provision at IDAPA 58.01.02.21O 05bj

specifying the fish consumption rate

Part II of this document provides additional background information about Idaho's July 7 2006

WQS submittal Parts III IV and V of this document provide the basis for this action under

I DEQ 2006 Letter dated July 7 2006 from Barry Burnell Administrator Water Quality Division Idaho

Department of Environmental Quality Boise Idaho to Michael Gearheard Office of Water Region 10 US

Environmental Protection Agency Seattle Washington

3

EPA004194
Technical Support Document or EPA's Disapproval Action on Idaho's Revised Human Health Criteria

section 303c of the Clean Water Act CW A and EPA implementing regulations found in

the Code of Federal Regulations CFR at 40 CFR 131.1 Part VI of this document provides the

basis for EPA's determination that revised footnotes b c d and 1 included in the submittal are

non substantive and therefore EPA is taking no action on these revisions

While the July 7,2006 submittal included revisions to the cadmium aquatic life criteria EPA's

approval under CWA 303c of the revised cadmium WQS for aquatic life was finalized on

March 7 2011 and the cadmium criteria for aquatic life will not be addressed further in this

document With respect to the revisions clarifying the existing mixing zone language and a new

provision specifying the frequency and duration component for aquatic life criteria also included

in the July 7,2006 submittal EPA will provide DEQ with our review and decision on these

provisions in a subsequent letter

II BACKGROUND

A Clean Water Act Requirements for Water Quality Standards

Under CWA 303c and EPA implementing regulations at 40 CFR 131.4 states have the

primary responsibility for reviewing establishing and revising WQS which consist of the

designated uses of a waterbody or waterbody segment and the water quality criteria necessary to

protect those designated uses This regulatory framework allows states to work with local

communities to adopt appropriate designated uses 40 CFR 131 lOa and to adopt criteria to

protect those designated uses 40 CFR 131.11 a

CWA 303 c2B requires states to adopt water quality criteria for toxic pollutants listed

pursuant to 307aI for which EPA has published criteria under 304 a where the discharge

or presence of these toxics could reasonably be expected to interfere with the designated uses

adopted by the state In adopting such criteria states should establish numeric values based on

one of the following 1 304 a criteria 2 304 a criteria modified to reflect sitespecific

conditions or 3 other scientifically defensible methods 40 CFR 13lI1b In addition

states can establish narrative criteria where numeric criteria cannot be determined

From time to time states are required to review applicable WQS and as appropriate modify and

adopt these standards 40 CFR 131.20 CWA 303 c also requires states to submit new or

revised WQS to EPA for review as EPA must ensure that any revisions to surface water

designated uses are consistent with the CWA and that any new or revised criteria protect the

designated water uses In addition the state must follow its own legal procedures for adopting

such standards 40 CFR 131.5 and submit certification by the state's attorney general or other

appropriate legal authority within the state that the WQS were duly adopted pursuant to state

law 40 CFR 131.6 e

B Overview ofIdaho's July 7,2006 WQS Submission

On AprilS 2005 DEQ published an announcement to update Idaho's human health water

quality criteria for toxics through a negotiated rulemaking process in the Idaho Administrative

4

EPA004195
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

Bulletin The rulemaking was also announced on DEQ's web page and in newspapers around

the State

The proposed rule revisions accounted for revised fish consumption rates FCR and updated

information in the IRIS database2 on health effects and several footnotes applicable to the human

health criteria DEQ's basis for revising specific human health criteria for toxic pollutants as

stated in background information to the rulemaking was a change in EPA's nationally

recommended FCR from 6.5 grams per day gday to 17.5 gday The FCR is a factor in the

calculation of criteria3 Other factors include updated information on toxicity to humans

contained in EPA's IRIS database which change the reference dose for non carcinogenic

chemicals or change the cancer slope factor for carcinogens and provide new information on

bioconcentration rates

DEQ held its first public meeting addressing the rulemaking on April 28 2005 in Boise and

three additional meetings followed on May 20 June 22 and July 12 A proposed rule was

announced in the September 7,2005 Idaho Administrative Bulletin along with a 30day

comment period DEQ received no requests for a public hearing and none was held Following

the public comment period DEQ sent the pending rule to the Idaho Board of Environmental

Quality which adopted it on November 16,2005 The final rule was approved by the Idaho

Legislature in March 2006

In accordance with 40 CFR 131.6 e DEQ's July 7,2006 WQS submission also included a

letter from Doug Conde Assistant Attorney General at the Idaho Department of Justice

certifying that the new and revised WQS were duly adopted pursuant to state law

III IDAHO'S NEW AND REVISED HUMAN HEALTH WATER

QUALITY CRITERIA

In its revision to state WQS Idaho stated that the update to its human health criteria for 88 toxic

pollutants was to reflect the latest scientific information as well as EPA's 2002 CWA 304 a

human health criteria recommendations 4 The 2002 recommendations reflected EPA's thinking

on establishing human health criteria for toxic pollutants and provided recommended criteria

values derived using the default values in the Methodology for Deriving Ambient Water Quality

Criteriaforthe Protection ofHuman Health 2000 Human Health Methodology 5

2 EPA Integrated Risk Information System IRIS US Environmental Protection Agency Office of Water

Washington DC Available at www epa ovliris

3

EPA822 EPA 2000 Methodology for Deriving Ambient Water Quality Criteria for the Protection ofHuman Health

B00 004 Available at http vlww epa gov watersc ie nce criterialh umanhealthlmethod complete pdf

4 IDEQ 2006 Technical Justification Idaho Rulemaking Docket 580102 0503 Idaho Cadmium Aquatic Life

Criteria and Update of Human Health Taxies Criteria July 7 2006

5 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC EPA 822B00004 Available at

httpwww epa Q'OV waterscience cri teri alhumanhealth methoc complete pc f

5

EPA004196
Technical Support Document or EPA's Disapproval Action on Idaho's Revised Human Health Criteria

The 2000 Human Health Methodology accounts for the cancer potency or systemic toxicity of a

pollutant the exposure related to surface water exposure and a risk characterization for a

pollutant and uses that information to develop criteria to protect humans from the adverse

effects from chronic exposure to a pollutant through drinking water and or from eating fish living

in a water body

In separate updates published in 2002 and 2003,6.7 EPA provided numeric values associated with

each of its 304 a human health criteria recommendations These values were calculated using

the 2000 Human Health Methodology default input variables provided in the methodology

current toxicological information in the IRIS database8 and a 10 6 1 1,000,000 cancer risk

level for carcinogenic pollutants EPA recommends that states evaluate these input variables

consistent with the recommendations in the 2000 Human Health Methodology when developing

criteria

Idaho's 2006 new and revised human health WQS submittal included criteria changes to

seventy five 75 pollutants based on EPA's 2002 National Recommended Water Quality

Criteriaupdates to recommended criteria since publication of National Toxics Rule NTR in

1992.9• 10 Prior to Idaho's 2006 new and revised human health criteria submittal the majority of

Idaho's human health criteria were the same as those that EPA had promulgated under the NTR

The criteria changes to the thirteen 13 remaining pollutants were based on EPA

recommendations published in Federal Register 68 page 75507 on Dec 31 2003

Idaho's revisions included one hundred sixtyseven 167 new or revised human health criteria

for 88 toxic pollutants For nine 9 of the pollutants the organism only criterion is unchanged

because EPA has not revised the organism only criterion for these pollutants Since they were

not revised they are not addressed in this action

Idaho's human health criteria are included in a table found at IDAPA 58.01.02.210.01 Criteria

for Toxic Substances Idaho's new and revised criteria that are addressed in this action are listed

in Table 1 below

6 EPA 2002 Revision ofNational Recommended Water Quality Criteria US Environmental Protection Agency

Office ofWater Washington DC Federal Register Volume 67 Issue 249 Page 79091 67 FR 79091

December VATERl7007IDecemberlDav77 27 2002 Available at http www epa gov fednrstrIEPA

w32770 htm

7 EPA 2003 National Recommended Water Quality Criteriafor the Protection of Human Health us

Environmental Protection Agency Office of Water Washington DC Federal Register Volume 68 Issue 250

Page 75507 68 FR 75507 December 31,2003 Available at httpwww epagov fedrgstrIEPA VATERI 003lDecemherlDav 31w37211 htm

8 EPA Integrated Risk Information System IRIS US Environmental Protection Agency Office of Water

Washington DC Available at www epagov iris

9 National Toxic Rule NTR 57 FR 60848 Water Quality Standards Establishment of Numeric Criteria for

Priority Toxic Pollutants States Compliance Final Rule

10 EPA 2002 National recommended water quality criteria 2002 US Environmental Protection Agency Office

of Water Washington DC EPA 822R 02047

6

EPA004197
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

A Human Health Criteria and Application to Idaho's Designated Uses

Idaho's human health criteria were developed for the most part in accordance with EPA's 2000

Human Health Methodology to protect human health from long term exposure to toxic pollutants

in drinking water and through eating fish containing these pollutants In Idaho surface waters

used for drinking water are designated as Domestic Water Supply DWS Surface waters

used for consumption of fish are designated as Primary or Secondary Contact Recreation PCR

or SCR and Aquatic Life Use Idaho's aquatic life uses include

• Cold water communities COLD

• Salmonid Spawning SS

• Seasonal Cold Water Communities SC

• Warm Water Communities WARM and

• Modified Communities MOD

Idaho's water organism criteria column C1 of the Table of Numeric Criteriafor Toxic

Substances contained in IDAPA 58.01.02.210.01 were established to limit the pollutant to levels

that provide for the safe consumption of drinking water and fish These criteria are applied

where Idaho has designated DWS as a beneficial use The organism only criteria column C2

of the Table of Numeric Criteria for Toxic Substances contained in IDAPA 58.01.02.210.01

apply where Idaho has designated a recreational use either PCR or SCR and aquatic life uses

but not a DWS use All waters in Idaho are designated for PCRlSCR and aquatic life use The

DWS designation is in addition to a recreational use designation Therefore the organism only

criteria column C2 apply to all surface waters of the State of Idaho However not all surface

waters in Idaho are designated for protection of DWS consequently the water organism

criteria column C1 apply only to a subset of surface waters of the State of Idaho

Idaho's WQS designate beneficial uses for waters of the State for each subbasin by waterbody

segment in IDAPA 58.01.02.110 through 160 For those waterbodies of the State not

specifically identified in IDAPA 58.01.02.110 through 160 or those waterbodies that are

included in these sections but do not have designated uses assigned to them Idaho's WQS

specify the uses and criteria that apply to undesignated surface waters The provision at IDAPA

58.01.02.101.01 entitled Undesignated Surface Waters states undesignated waters shall

be protected for beneficial uses which includes all recreational use in and on the water and the

protection and propagation offish shellfish and wildlife wherever attainable Further IDAPA

58.01.02 101.0 Lb specifies that IDEQ will apply cold water aquatic life and primary or

secondary contact recreation criteria to undesignated waters Thus the human health criteria

in column C2 of the Table of Numeric Criteriafor Toxic Substances contained in IDAPA

58.01.02.210.01 apply to these waters

For human health protection EPA recommends that states apply human health criteria for toxics

to all waters with designated uses providing for public water supply protection and therefore a

potential water consumption exposure route recreation and or aquatic life protection and

7

EPA004198
Technical Support Documentfor EPA's Disapproval Action on Idaho's Revised Human Health Criteria

therefore a potential fish consumption route 11 Consistent with EPA's recommended approach

DEQ applies the water organism human health criteria for toxics to waters designated as

domestic water supply This provides protection from a potential water exposure route Also

consistent with EPA's recommendations DEQ applies the organism only human health criteria

for toxies to recreational and aquatic life uses as these waters provide a potential fish

consumption exposure route ie fish or other aquatic life are being caught and consumed

Idaho's 2006 human health criteria for toxic pollutants are developed for the most part pursuant

to methods presented in EPA's 2000 Human Health Methodology 12 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 calculations for non carcinogens

and carcinogens differ depending upon the exposure scenario for which the criteria are derived

and are further described below

EPA reviewed Idaho's 2006 revised human health criteria for toxic pollutants to assess whether

they were consistent with the Clean Water Act and its implementing regulations EPA's

evaluation focused on whether the criteria were consistent with 40 CFR 131.11 a which states

that criteria must be based on sound scientific rationale and contain sufficient parameters or

constituents to protect designated uses

B Criteria Methodology and Input Variables Used by Idaho

Pursuant to CWA 304 a EPA has published recommended criteria for use by states in

adopting and revising criteria 13 For human health criteria the values reflect the national

default values for the risk assessment parameters provided in the 2000 Human Health

Methodology the reference dose values RID contained in IRIS at the time of publication and

the use ofbioconcentration factors BCFs as opposed to site specific bioaccumulations factors

BAFs While the 2000 Human Health 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 andor protect identifiable

subpopulations 14 The revised human health criteria Idaho adopted were derived for the most

part using EPA's 2000 Human Health Methodology and criteria updates published in 2002 and

2003

The risk assessment based procedures EPA puts forth in the 2000 Human Health Methodology

are specific to whether the endpoint is cancer or noncancer When using cancer as the critical

11 EPA 1994 Water Qllality Standards Handbook US Environmental Protection Agency Office of Water

Washington DC EPA 823B94005a August 1994

12 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC EPA 822B00004

13 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 QOV waterscience criterialwqctable index htm L

14 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC EPA 822B00004 Pages iii 111

8

EPA004199
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

risk assessment endpoint the criteria are presented as a range of concentrations associated with

specified incremental lifetime risk levels The following briefly provides the key features of

each procedure A simplified version of this equation is provided in Figure 1 below

Figure 1 Simplified version of the equation used by Idaho in deriving the human health criteria

for carcinogens

AWQC Risk Level BW

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

FCR Fish Consumption Rate kilograms per day

BAF Bioaccumulation factor liters per kilogram

Note that criteria calculations for organism only criteria are not shown and can be derived by removing the

drinking water intake DI term

When noeffect using noncancer effects as the critical endpoint the criteria reflect an assessment of a

level Criteriafor non carcinogenic pollutants are calculated through an equation that

relies on pollutant specific and general riskassessment values for each parameter A simplified

version of this equation is provided in Figure 2 below

Figure 2 Simplified version of the equation used by Idaho in deriving the human health criteria

for non carcinogens

AWQC RfD RSC BW

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 nonwater source contribution factor to account for

sources of exposure unit less

BW Human body weight kilograms

DI Drinking water intake liters per day

FCR Fish Consumption Rate kilograms per day

BAF Bioaccumulation factor liters per kilogram

Note that criteria calculations for organism only criteria are not shown and can be derived by removing the

drinking water intake DI term

Idaho's new and revised criteria were derived using the following input variables

9

EPA004200
Technical Support Documentjor EPA's Disapproval Action on Idaho's Revised Human Health Criteria

RID values recommended by EPA in the 2002 and 2003 304a criteria

recommendations 15 16

RSC values recommended by EPA in the 2002 and 2003 CW A 304a criteria

recommendations l7 18

BW 70 kilograms 19

DI 2 liters per day

FCR 17.5 grams per day20

BAF values recommended by EPA in the 2002 and 2003 CWA 304a criteria

recommendations

Cancer risk level 1 x1O6

CSF values provide in EPA's Integrated Risk Information System IRIS database as

of May 17,2002

Further information regarding each of these variables is available in EPA's 2000 Human Health

Methodology

IV EPA's Review

As described above Idaho's human health criteria are calculated using several exposure and risk

variables The criterion value is further determined by the level of risk found to be acceptable

while still protecting the use in this case the level of protection provided to consumers of

organisms and water taken from the state waters to which the criteria apply In presenting the

criteria to the Idaho Legislature the Idaho Board of Environmental Quality and stakeholders

DEQ stated that these criteria were consistent with EPA's national recommendations 21 22

15 See EPA 2002 National Recommended Water Quality Criteria 2002 Human Health Criteria Calculation

Matrix US Environmental Protection Agency Office of Water Washington DC EPA 822R020l2 Available

at http www epa gov waterscience criterialwqctable hh calc matrixpdf

16 See EPA 2003 National Recommended Water Quality Criteriafor the Protection of Human Health US

Environmental Protection Agency Office of Water Washington DC Federal Register Volume 68 Issue 250

Page 75507 68 FR 75507 December 31 2003 Available at http www epagov fedrgstrIEPAW ATER 2003 December Day31w32211 htm

17 See EPA 2002 National Recommended Water Quality Criteria 2002 Human Health Criteria Calculation

Matrix US Environmental Protection Agency Office of Water Washington DC EPA 822R02012 Available

at http www epa 20v waterscience criterialwqctable hh calc matrixpdf

18 See EPA 2003 National Recommended Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC Federal Register Volume 68 Issue 250

Page 75507 68 FR 75507 December 31 2003 Available at http www epa 20v fedrgstrIEPAWATER 2003 DecemberlDav 311w3221l htm

19 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC EPA 822B00004 Pages 418 to 419

20 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection ofHuman Health US

Environmental Protection Agency Office of Water Washington DC EPA 822B00004 Page 424 to 425

21 Idaho DEQ Presentation to 2nd Session of 58th Legislature WQS Docket 580102 0503 2005 Update to toxics

criterianot dated

22 Idaho DEQ 2005 Presentation to DEQ Board on Docket 58 0102 0503,2005 Update to toxics criteria November

16,2005

10

EPA004201
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

The water quality standards regulations at 40 CFR 131.11 a state that new or revised criteria

must be based on sound scientific rationale and contain sufficient parameters or constituents to

protect designated uses To ensure Idaho's criteria are consistent with this requirement EPA

evaluated the appropriateness of the exposure variables used by Idaho in deriving its criteria

specifically whether these were based on sound science and led to criteria that would protect

human health endpoints consistent with the designated uses of Idaho's waters

As stated above Idaho relied on EPA's 2000 Human Health Methodology to derive human

health criteria with the goal of basing the criteria'on exposure and risk variables consistent with

EPA's latest recommendations With the exception of the fish consumption rate variable the

variables Idaho relied on for all pollutants except acrolein and phenol are consistent with EPA's

recommendations for developing human health criteria and therefore are consistent with EPA's

304a criteria recommendations With respect to acrolein and phenol the RID values for these

pollutants were subsequently updated in June 2003 and September 2002 respectively EPA

integrated the updated IRIS values into its current 304 a criteria recommendations and

published the recalculated criteria as the Agency's current national recommended criteria in

2009.23

The 2000 Human Health Methodology provides states and tribes flexibility in establishing WQS

by providing scientifically valid options for developing their own criteria that consider local

State or regional conditions For example states and authorized tribes should consider use of

local data use of data reflecting similar geography population groups use of data from national

surveys and use of EPA's default intake rates

EPA recommends that a state consider the population that may be exposed to adverse health

effects from consuming fish from the state's waters and select a fish consumption rate that is

appropriate to protect that population The 2000 Human Health Methodology provides three

default consumption rates 17.5 gday for the general population 17.5 gd for recreational

fishers and 142.4 gd for subsistence fishers The rate recommended for protection of the general

population represents an estimate of the 90th percentile consumption rate for the US adult

population based on the US Department of Agriculture's Continuing Survey of Food Intake by

Individuals CSFII 1994 96 data 24

As part of its review EPA evaluated whether local state or regional data was available and

relevant in developing human health criteria for Idaho's waters EPA identified several sources

of information that bear on the question of fish consumption but were not included in Idaho's

rationale for selecting the 17.5 gd national fish consumption rate EPA has determined that a

consideration of this information is necessary to a scientifically sound evaluation of the

protectiveness of human health criteria in Idaho such that the absence of such consideration

from the 2006 revisions to Idaho human health criteria indicates that those revisions do not rest

on a sound scientific rationale

23 74 FR 27535 Notice of Availability of National Recommended Water Quality Criteria for Acrolein and Phenol

June 10,2009 Federal Register Vol 74 No 110 pp 27535 27536

24 USDA 1998 US Department of Agriculture 1994 1996 Continuing Survey ofFood Intakes by Individuals and

1994 1996 Diet and Health Knowledge Survey Agricultural Research Service USDA NTIS CDROM Accession

number PB98500457

11

EPA004202
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

A Relevant and Available Local and Regional Fish Consumption

Information

As previously noted when establishing WQS states and authorized tribes should consider use of

local data use of data reflecting similar geographypopulation groups use of data from national

surveys and use of EPA's default intake rates

EPA's search for available and potentially relevant data and information on fish consumption

rates in Idaho identified several sources of local state and regional data The following are

several studies relevant to evaluating fish consumption in Idaho

1 A Fish Consumption Survey of the Umatilla Nez Perce Yakama and Warm Springs

Tribes of the Columbia River Basin CRITFC 1994.25

2 The Relationship of Human Levels of Lead and Cadmium to the Consumption of Fish

Caught in and Around Lake Coeur D'Alene Idaho 19896

3 Consumption Patterns of Anglers Who Frequently Fish Lake Roosevelt Washington

19977

4 Yakama Nation Exposure Scenario for Hanford Site Risk Assessment RichlandWA

2007 8

5 Fish Consumption Survey Spokane River Washington 1998.29

6 Exposure Scenario for Confederated Tribes of the Umatilla Indian Reservation

Traditional Subsistence Lifeways 2004.30

7 The Spokane Tribe's Multipathway Subsistence Exposure Scenario and Screening Level

RME 2002 31

8 A Fish Consumf tion Survey of the Tulalip and Squaxin Island Tribes of the Puget Sound

Region 1996 2

9 Fish Consumption Survey of the Suquamish Indian Tribe of the Port Madison Indian

Reservations Puget Sound Region 2000 3

25 CRITFC 1994 A Fish Consumption Survey of the Umatilla Nez Perce Yakima and Warm Springs Tribes of the

Columbia River Basin Columbia River Intertribal Fish Commission Portland Oregon CRITFC Technical Report

No 943 October 1994

26 US Department of Health and Human Services Agency for Toxic Substances and Disease Registry ATSDR

Division of Health Studies 1989 The Relationship of Human Levels of Lead and Cadmium to the Consumption of

Fish Caught in and Around Lake Coeur D'Alene Idaho September 1989

27 Washington State Department of Health Office ofEnvironmental Health Assessments 1997 Consumption

Patterns of Anglers Who Frequently Fish Lake Roosevelt September 1997

28 Ridolfi 2007 Yakama Nation Exposure Scenario for Hanford Site Risk Assessment Richland W A

29 Spokane Regional Health District AssessmentEpidemiology Center 1998 1998 Fish Consumption Survey

Spokane River Washington Survey Report November 1998

30 Confederated Tribes of the Umatilla Indian Reservation 2004 Exposure Scenario for CTUIR Traditional

Subsistence Lifeways

31 Harper BL Flett B Harris S Abeyta C Kirschner F 2002 The Spokane Tribe's Multipathway Subsistence

Exposure Scenario and Screening Level RME Society for Risk Analysis Risk Analysis Vol 22 No 3

32 Toy KA Polissar NL Liao S Mittelstaedt GD 1996 A Fish Consumption Survey of the Tulalip and Squaxin

Island Tribes of the Puget Sound region Tulalip Tribes Department of Environment Marysville W A

12

EPA004203
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

10 Asian and Pacific Islander Seafood Consumption Study 199934

The materials provided to EPA by DEQ do not indicate that any of these sources of information

were considered when Idaho decided to use the national default rate of 17.5 gd to derive its new

and revised human health criteria Furthermore DEQ stated that no such information was

available at the time they adopted the revisions

At the time Idaho reevaluated its human health toxics criteria for protection of Idaho's waters

Idaho did not consider the available studies listed above Furthermore EPA believes that the use

of the national default fish consumption rate as protective of Idaho's designated uses lacks a

sound scientific basis unless it considers the information contained in the above listed studies

ie including those studies published after Idaho acted in 2006 EPA therefore determines

that the criteria derived using 17.5 gday and submitted to EPA on July 7 2006 are not based on

a sound scientific rationale and thus are not consistent with 40 CRF 131.11 a

EPA's preliminary review of the listed studies indicates that statewide human health criteria

based on a fish consumption rate of 17.5 gd would not be protective of the designated uses of

Idaho waters 35 In addition these studies bolster EPA's recommendation that Idaho further

evaluate levels of intake by recreational and subsistence fishers when evaluating the appropriate

fish consumption rate for use in deriving criteria

V EPA'Disapproval of Idaho's New and Revised Human Health

Criteria

In accordance with 40 CFR 131.11 a EPA must ensure that new or revised criteria are based on

sound scientific rationale and contain sufficient parameters or constituents to protect designated

uses As described above EPA has found that DEQ did not consider the available information

relevant to fish consumption when selecting a fish consumption rate utilized in calculation of

Idaho's human health criteria Therefore these criteria are not based on a sound scientific

rationale Furthermore EPA's preliminary analysis of available information suggests that a fish

consumption rate of 17.5 gd may not be representative of consumption from Idaho's waters and

therefore may not be protective ofIdaho's designated uses to the level identified by Idaho

during their rule adoption process

Based upon the above evaluation and in accordance with its CW A authority 33U SC

1313 c3 and 40 CFR Part 131 EPA disapproves Idaho's new and revised water organism

and organism only human health criteria identified in Table 1

33 Suquamish 2000 Fish Consumption Survey of the Suquamish Indian Tribe of the Port Madison Indian

Reservation Puget Sound region The Suquamish Tribe Suquamish W A

34 Sechena R Nakano C Liao S Polissar N Lorenzana R Truong S Fenske R 1999 Asian and Pacific Islander

Seafood Consumption Study King County Washington EPA 910R9903 May 1999

35Memo Review of Fish Consumption Information Relevant to Development of Idaho AWQC 5812 Draft Lon

Kissinger US EPA Region 10 Office of Environmental Assessment

13

EPA004204
Technical Support Document or EPA's Disapproval Action on Idaho's Revised Human Health Criteria

Table 1 Idaho's July 7 2006 submission of revised water organism and organism only

human health criteria which EPA disapproves and which are found at IDAPA 58.01.02.210.01

I • •

i

t rl

0

o I

E Organism OrQanism

k

Q

0

E

z

0 OJljltllTlt1 4 C

CQ

15 U

•

E x I

Z •

nTTll j

C jc p

••

XtJi

i 8

gIL

i

••

I

1 10 Selenium 7782492 170 4200

2 12 Thallium 744028C 0.24 0.47

3 14 yanide 57125 140 140

4 16 3 7 8TCDD Dioxin 174601E 0.000000005 0.0000000051

5 17 Acrolein 107028 190 290

6 18 Acrylonitrile 107131 0.051 0.25

7 19 lBenzene 71432 2.2 51

8 20 IBromoform 75252 not revised 140

9 21 Carbon Tetrachloride 56235 0.23 1.6

10 22 Chlorobenzene 108907 130 1600

11 23 Chlorodibromornethane 124481 0.40 13

12 27 Dichlorobromomethane 75274 0.55 17

13 29 1,2 Dichloroethane 107062 not revised 37

14 30 1,1Dichloroethylene 75354 330 7100

15 31 1,2Dichloropropane 78875 0.50 15

16 32 1,3Dichloropropene 542756 0.34 21

17 33 Ethylbenzene 100414 530 2100

18 34 Methyl Bromide 74839 47 1500

19 36 ethylene Chloride 75092 4.6 590

20 37 1,1,2,2 Tetrachloroethane 79345 not revised 4.0

21 38 Tetrachloroethylene 127184 0.69 3.3

22 39 Toluene 108883 1300 15000

23 40 1,2Trans Dichloroethylene 156605 140 10000

24 42 1,1,2 Trichloroethane 79005 0.59 16

25 43 Trichloroethylene 79016 2.5 30

26 44 Vinyl Chloride 75014 0.025 2.4

27 45 2Chlorophenol 95578 81 150

28 46 2,4 Dichlorophenol 120832 77 290

29 48 2Methyl 4,6Dinitrophenol 534521 13 280

31 49 2,4 Dinitrophenol 51285 69 5300

31 53 Pentachlorophenol 87865 0.27 3.0

32 54 Phenol 108952 not revised 1700000

33 55 2,4,6 Trichlorophenol 88062 1.4 2.4

34 56 Acenaphthene 83329 670 990

35 58 Anthracene 120127 8300 40000

36 59 Benzidine 92875 0.000086 0.00020

14

EPA004205
Technical Support Document or EPA's Disapproval Action on Idaho's Revised Human Health Criteria

C

Of

rI

• 0 o

I

Q

0E

Z

0

c

I Q

QU 0

E

Zo

follutant CAS Number

I

Q

en

0

I

u

I

3

Water Organism

gL

Organism Only

gL

37 60 Benzo aAnthracene 56553 0.0038 0.018

38 61 Benzo aPyrene 50328 0.0038 0.018

39 62 Benzo b Fluoranthene 205992 0.0038 0.018

40 64 Benzok Fluoranthene 207089 0.0038 0.018

41 66 Bis2Chloroethyl Ether 111444 0.030 0.53

42 67 Bis2Chloroisopropyl Ether 108601 not revised 6500

43 68 lBis2Ethylhexyl phthalate 117817 1.2 2.2

44 70 lButylbenzyl Phthalate 85687 1500 1900

45 71 2Chloronaphthalene 91587 1000 1600

46 73 Chrysene 218019 0.0038 0.018

47 74 lDibenzo ah Anthracene 53703 0.0038 0.018

48 75 1,2Dichlorobenzene 95501 420 1300

49 76 1,3 Dichlorobenzene 541731 320 960

50 77 1ADichlorobenzene 106467 63 190

51 78 3,3 Dichlorobenzidine 91941 0.021 0.028

52 79 Diethyl Phthalate 84662 17000 44000

53 80 Dimethyl Phthalate 131113 270000 1100000

54 81 DinButyl Phthalate 84742 2000 4500

55 82 2ADinitrotoluene 121142 not revised 3.4

56 85 1,2 Diphenylhydrazine 122667 0.036 0.20

57 86 tFluoranthene 206440 130 140

58 87 fluorene 86737 1100 5300

59 88 Hexachlorobenzene 118741 0.00028 0.00029

60 89 rtIexachlorobutadiene 87683 not revised 18

61 90 iHexachloro cyclopentadiene 77474 40 1100

62 91 Hexachloroethane 67721 1.4 3.3

63 92 deno 1 2,3 cd Pyrene 193395 0.0038 0.018

64 93 Isophorone 78591 35 960

65 95 lNitrobenzen e 98953 not revised 690

66 96 INNitrosodimethylamine 62759 not revised 3.0

67 97 INNitrosodin Propylamine 621647 0.0050 0.51

68 98 INNitrosodij lhenylamine 86306 3.3 6.0

69 100 Pyrene 129000 830 4000

70 101 1,204 Trichlorobenzene 120821 35 70

71 102 Aldrin 309001 0.000049 0.000050

72 103 alphaBHC 319846 0.0026 0.0049

73 104 betaBHC 319857 0.0091 0.017

74 105 gammaBHC Lindane 58899 0.98 1.8

75 107 Chlordane 57749 0.00080 0.00081

15

EPA004206
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

CI • •

i

CI

I

o ce0 I

I

a b Water Organism Organism Only

Si lPol1utCt CAS NUIl'lber

c C lglLj lgfL

bI u

0 u I g

E E u10

I

zrS • I 8 C Z

76 108 4DDT 50293 0.00022 0.00022

77 109 4DDE 72559 0.00022 0.00022

78 110 4DDD 72548 0.00031 0.00031

79 111 pieldrin 60571 0.000052 0.000054

80 112 alphaEndosulfan 959988 62 89

81 113 beta Endosulfan 33213659 62 89

82 114 ndosulfan Sulfate 1031078 62 89

83 115 IEndrin 72208 0.059 0.060

84 116 IEndrin Aldehyde 7421934 0.29 0.30

85 117 Heptachlor 76448 0.000079 0.000079

86 118 Heptachlor Epoxide 1024573 0.000039 0.000039

Polychlorinated Biphenyls

87 119 PCBs 0.000064 0.000064

88 120 Toxaphene 800 0.00028 0.00028 Idaho also revised IDAPA 58.01.02.21O 05bi which specifies that when using EPA

recommended criteria to derive water quality criteria to protect human health a fish consumption

rate of 17.5 grams per day shall be utilized The following is that mle language

IDAPA 58.01.02.210.05 Development ofToxic Substance Criteria

b Human Health Criteria

i When numeric criteria for the protection ofhuman health are not identified in

these rules for toxic substances quantifiable criteria may be derived by the Department from the

most recent recommended criteria defined in EPA's Integrated Risk Information System IRIS

When using EPA recommended criteria to derive a water quality criteria to protect human

health a fish consumption rate ofseventeen point five 17.5 gramsday a water ingestion rate

oftwo 2 liters day and a cancer risk level of10 6 shall be utilized

As discussed above EPA's preliminary analysis of available information suggests that a fish

consumption rate of 17.5 grams per day may not be representative of the consumption from

Idaho's waters and thus may not be protective of Idaho's designated uses to the level identified

by Idaho during their rule adoption process

Based upon the above evaluation and in accordance with its CWA authority 33U SC

1313 c3 and 40 CFR Part 131 EPA disapproves IDAPA 58.01.02.21O 05bi

16

EPA004207
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

VI NO ACTION ON REVISED FOOTNOTES

In addition to adopting revised human health criteria described in Part III and Part IV above

Idaho revised four 4 footnotes b c d and 1 associated with numeric criteria for toxic

substances at IDAPA 58.01.02.210.01 Revisions to these footnotes are provided below

Strikeout text indicates text that was removed while underlined text indicates new wording

A Footnote b

1 Description of Footnote

Idaho revised footnote b to the existing and unrevised column heading CMC and CCCof the

table of numeric criteria for toxic substances in IDAP A 58.01.02.210.01 Footnote b refers to

Idaho's definitions of acute and chronic criteria The definitions were not changed however the

section numbering for the definitions changed from IDAPA 58.01.02.003 to 010 Therefore

footnote b was revised to refer to the revised numbering of the definitions section of Idaho's

WQS Footnote b states

b See Definitions Section Qg 010 of these rules

2 EPA Review and Action

EPA does not consider the revisions to footnote b to be substantive revisions to the water quality

standards under Section 303c of the CWA and therefore is taking no action The footnote

remains in effect for CWA purposes

B Footnote e

1 Description of Footnote

Idaho revised footnote c to specify the revised date that Idaho obtained values from IRIS

database used in the calculations of human health criteria The previous date specified was

December 22 1992 Footnote c was revised to refer to the more recent date and informs the

reader where the value came from and does not alter the underlying criteria Footnote c states

c This criterion has been revised to reflect The Environmental Protection Agency's q 1

or RID as contained in the Integrated Risk Information System IRIS as ofDecember 22 1992

May 17 2002 The fish tissue bioconcentration factor BCF from the 1980 Ambient Water

Quality Criteria document was retained in each case

2 EPA Review and Action

EPA does not consider the revisions to footnote c to be substantive revisions to the water quality

standards under Section 303c of the CW A and therefore is taking no action The footnote

remains in effect for CWA purposes

17

EPA004208
Technical Support Documentfor EPA's Disapproval Action on Idaho's Revised Human Health Criteria

C Footnote d

1 Description of Footnote

Idaho revised footnote d to the existing human health criterion for arsenic Footnote d was

revised as follows

d Inorganic form only The criterion for arsenic is the MC'T in effect as of Anril

2000

2 EPA Review and Action

Although Idaho did not revise the arsenic human health criteria in this submission the state did

revise the footnote applicable to this criterion The underlying criterion for arsenic was unrevised

and therefore EPA is not reviewing the underlying criterion as part of this action Footnote d is

only applicable to Idaho's existing human health criterion for arsenic Idaho's revision deletes a

reference to the MCL This does not change the criteria therefore EPA does not consider the

revisions to footnote d to be substantive revisions to the water quality standards under Section

303c of the CWA and therefore is taking no action The footnote remains in effect for CW A

purposes

D Footnote 1

1 Description of Footnote

Idaho revised footnote 1 to the revised human health criteria for carcinogens Footnote 1 was

revised as follows

1 EPl guidance allO'Yvs states to choose a risk factor of 10 4 to 10 6 Idaho has chosen

to base his criterion is based on carcinogenicity of 106 risk

2 EPA Review and Action

Footnote 1 applies to all human health criteria that are carcinogens Idaho's revision deletes a

reference to EPA guidance and replaces it with a statement explicit to the risk level Idaho has

chosen to apply The risk level associated with the criteria 106 was not changed therefore

EPA does not consider the revisions to footnote 1 to be substantive revisions to the water quality

standards under Section 303 c of the CWA and thus is taking no action The footnote remains

in effect for CWA purposes

E Other Footnotes not Revised

Idaho did not change any of the other footnotes included in IDAPA 58.01.02.210.01 Criteria for

Toxic Substances of Idaho's WQS applicable to human health criteria for toxics Thus EPA is

not taking action on these previously approved footnotes This is appropriate since these

footnotes remain applicable to the pollutants with which they are associated and this

18

EPA004209
Technical Support Document for EPA's Disapproval Action on Idaho's Revised Human Health Criteria

applicability is not altered by any WQS revisions included in Idaho's July 7,2006 submittal

These footnotes remain in effect for CWA purposes

19

EPA004210
EPA004211