UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION I

5 POST OFFICE SQUARE, SUITE 100

BOSTON, MASSACHUSETTS 02109-3912

MEMORANDUM

SUBJECT: Tribal Technical Consultation: Maine Water Quality Standards and Human Health Criteria

FROM: Michael Stover, EPA Region 1 Indian Program Manager

TO: file

DATE: March 31, 2016

On Wednesday, September 9, 2015 from 1:00 – 2:00pm, a technical conference call was held with the Maine 

tribal environmental directors regarding the application of water quality standards pertaining to waters in 

Indian lands in Maine. Present on the conference call were:

Fred Corey, Environmental Director, Aroostook Band of Micmacs

Sue Young, Natural Resources Director, Houlton Band of Maliseet Indians

Sharri Venno, Environmental Planner, Houlton Band of Maliseet Indians

Jane Stedman, Attorney, Kanji & Katzen (Houlton Band of Maliseet Indians)

Dan Kusnierz, Water Program Manager, Penobscot Indian Nation

Marvin Cling, Environmental Planner, Passamaquoddy Tribe at Pleasant Point

Trevor White, Environmental Director, Passamaquoddy Tribe at Indian Township

Martin Dana, Environmental Director, Passamaquoddy Tribe at Indian Township

Tim Williamson, Deputy Director, Office of Regional Counsel, EPA Region 1

Ann Williams, Office of Regional Counsel, EPA Region 1

Ken Moraff, Director, Office of Ecosystem Protection, EPA Region 1

Ralph Abele, Chief, Water Quality Branch, EPA Region 1

Ellen Weitzler, Municipal Permits Section Chief, EPA Region 1

Jeanne Voorhees, Water Quality Standards Coordinator, EPA Region 1

Matt Hoagland, Branch Chief, Wetlands, EPA Region 1

Sara Levinson, Office of Regional Administrator, EPA Region 1

Michael Stover, Indian Program Manager, EPA Region 1

Tracy Bone, Office of Water, EPA Headquarters

Claudia Fabiano, Office of Water, EPA Headquarters

Nicole Shao, Office Research and Development, EPA Headquarters

Pete Ford, Office of General Counsel, EPA Headquarters

Andrew Baca, American Indian Environmental Office, EPA Headquarters

EPA hosted this technical conference call with the tribal environmental directors to explain how water 

quality standards are established, particularly for human health criteria (HHC), and to solicit feedback from 

the tribes regarding appropriate fish consumption rate(s) and other factors including trophic levels and 

relative source contributions employed in determining protective standards. Prior to the call, EPA provided 

the tribes with an “HHC Primer” as a tool for the tribes to better understand how criteria are developed. 

During the call, EPA sought input from the tribes regarding use of geographically distinct fish consumption 

rates (FCRs) and asked Dan Kusnierz about the FCR approach that the Penobscot Nation undertook in 

developing their water quality standards. Dan shared that the Nation derived 286 grams/day from the 

“Wabanaki Study” as a representative FCR for resident fish, since anadromous fish are not present above the 

Milford dam in any appreciable numbers. However, the Nation hopes to see salmon come back in larger 
2

numbers now that the Penobscot River has been restored through a number of dam removals and a new fish 

passage on the Milford Dam, allowing tribal members to consume at higher sustenance levels. 

Sharri Venno of the Houlton Band of Maliseet Indians supported using aspirational goals for the eventual 

return of anadromous fish to the Meduxnekeag River, and hopes that a barrier dam (Mactaquac Dam in 

Frederick, NB) will be removed in the future. Marvin Cling reported that the Passamaquoddy Tribe initiated 

a fish consumption study, and found that lack of access and concerns around fish advisories hampered the 

desire of the tribal members to fish and the completion of the study was tabled. Tribal members do consume 

resident fish: introduced “new” species such as large-mouth bass, marine fish and land-locked salmon. 

Marine fish used to come to shore such as pollock, but not so much anymore. 

EPA explained that the 2015 EPA recommendations refer to a default relative source contribution of 20%, 

and solicited feedback from the tribes. Dan Kusnierz commented that many anadromous fish may not be 

impacted by discharges. Sharri Venno recommended consideration of alternate exposure pathways. 

EPA commented that the Wabanaki Study combined anadromous fish and marine species into one category. 

The two categories listed in the study was “resident fish” and anadromous fish/marine species.” Absent any 

considerations from the tribes, EPA would likely default to the 2015 updates to the national criteria. Adult 

weight is used in the formula as targets, not children weight. EPA considers a lifetime of exposure, even 

though fish advisories target pregnant women and children. 

Sharri Venno commented that the Houlton Band desires fish consumption rate/water quality standards that

protect tribal youth and pregnant women. Fred Corey relayed that fish advisories are a detriment to public 

health. He also relayed that in the Micmac tribe, there are high fish consumers, typically between 20-40 

years old, who fish regularly and consume as much fish as they can. Marvin Cling reported that tribal fishers 

conduct ice fishing in winter months, bring the catch back to the tribal school and share with the community 

in fish fry meals.

EPA relayed that the standards goal is to establish protective standards to protect sustenance consumption 

levels. The tribes voiced that the goals of the tribes should be emphasized, and expressed the concern that 

data used in developing water quality standards may not reflect the goals of the tribes.

Fred Corey stressed his earlier point that fish advisories are a detriment to public health by referring to a 

University of Maine fish consumption advisory study and presentation at an EPA-sponsored “contaminants 

and fish” forum in Alexandria, VA. The link is 

http://water.epa.gov/scitech/swguidance/fishshellfish/fishadvisories/fishforum2014present.cfm
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Background Information for Tribal Consultation September 2015 

Primer on Derivation of Ambient Water Quality Criteria for the Protection of Human Health (HHC) 

The following is provided as background information to explain the various factors that EPA considers 

when developing ambient water quality criteria to protect against adverse effects to human health 

when the water body is used as a drinking water supply and fish and shellfish are consumed from the 

water body. 

History: EPA issued guidance in 2000 on a methodology for deriving HHC for the protection of human 

health from the consumption of water and organisms and for the consumption of organisms only, 

known as the 2000 Human Health Methodology1. EPA uses this guidance when updating or adding to 

the human health criteria in its National Recommended Water Quality Criteria (NRWQC)2. For example, 

EPA used the 2000 methodology to derive the 2015 update of the NRWQC, which updated the HHC for 

94 organic chemicals by incorporating new exposure parameters. EPA also uses, and recommends that 

states and tribes use, the 2000 Human Health Methodology when deriving criteria for pollutants or 

exposures not included in the NRWQC. 

Equations used to derive HHC differ slightly depending on the nature of the toxic effect (cancer vs. noncarcinogenic effects) related to ingestion of the pollutant and by the mode of action of the compound 

(threshold vs. non-threshold). In cases where a chemical exhibits multiple adverse effects, 

concentrations protective of each effect may be derived. In these instances, the HHC is selected based 

on the lowest concentration protective of each effect. The two equations utilized for deriving AWQC 

include: 

HHC for non-carcinogenic effects and nonlinear low-dose extrapolation carcinogens = 

 RfD* x RSC x BW x CF 

 DWIR + ∑4

i=2 (FCRi x BAFi) 

HHC for carcinogenic effects with linear low-dose extrapolation = 

 target cancer risk level x BW x CF 

 CSF x [DWIR + ∑4

i=2 (FCRi x BAFi)] 

 Where: 

HHC = Human Health Criteria (ug/l) 

RfD* = Reference Dose (mg/kg-day). Note: for non-linear low-dose carcinogens, a POD/UF (discussed 

below) may substitute for the RfD. See discussion below and EPA 2000 for further explanation. 

 

1

 EPA, Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health (2000), EPA822-B-00-004, October, 2000. 

http://water.epa.gov/scitech/swguidance/standards/upload/2005_05_06_criteria_humanhealth_method_comple

te.pdf 

2

 Provided at: http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm 
2 

RSC = Relative source of contribution. Refers to the total permissible exposure allocated to the water 

body of interest (via ingestion of water and organisms) relative to all other sources of exposure 

to the pollutant (unitless). 

Target cancer risk level = target excess cancer risk desired for the AWQC (unitless). 

CSF = cancer slope factor (mg/kg-day)-1 

BW = Body weight (kg) 

CF = unit conversion factor (1000 ug/mg). 

DWIR = Drinking water ingestion rate (l/day). 

∑4

i=2 = summation of values from trophic level 2 to trophic level 4 

FCRi = Trophic specific fish/shellfish consumption rate by the population of interest of aquatic trophic 

levels i=2-4. Consumption rates are expressed in units of kg fish and shellfish/day. 

BAFi = Fish/shellfish contaminant bioaccumulation factor for aquatic trophic levels i= 2-4. BAFs are 

expressed in units of l/kg. Note: in instances where a chemical specific bioaccumulation factor is 

not available, a bioconcentration factor (BCF) may be substituted. 

PARAMETERS DEFINED 

Toxicity Values: RfDs, CSFs, and POD/UF 

The Reference Dose (RfD) is defined as an estimate (with uncertainty spanning perhaps an order of 

magnitude) of a daily oral exposure to the human population (including sensitive groups, such as 

asthmatics, or life stages, such as children or the elderly) that is likely to be without an appreciable risk 

of deleterious effects during a lifetime. In general, RfDs are used in describing non-carcinogenic effects. 

The Cancer Slope Factor (CSF) is used to describe the potency of a carcinogen and is used in 

characterizing carcinogenic effects of compounds EPA deems suitable for use with a linear low dose 

extrapolation model that relates dose to the response (cancer). 

For certain compounds exhibiting carcinogenic effects, EPA has found the linear low-dose extrapolation

is not appropriate (e.g., the carcinogenicity may be a secondary effect of toxicity or of an induced 

physiological change that is itself a threshold phenomenon). In these instances, a non-linear low dose 

extrapolation method may be used based on point of departure (POD) and uncertainty factors (UF) as 

described in EPA 2000. 

In general, EPA’s Integrated Risk Information System (IRIS) has been used as the primary source for most 

toxicity values used in deriving HHC, but other assessments may be used. 

Target Cancer Risk Level: 

EPA uses a cancer risk level of one in one million (10-6) in deriving NRWQC or promulgating water quality 

criteria for states and tribes, which EPA believes reflects an appropriate risk for the general population.3 

 

3

 EPA, Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health (2000), EPA822-B-00-004, October, 2000, page 2-6. 

http://water.epa.gov/scitech/swguidance/standards/upload/2005_05_06_criteria_humanhealth_method_comple

te.pdf.
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Relative Source of Contribution (RSC): 

For pollutants exhibiting threshold effects (non-carcinogenic compounds and carcinogens with a nonlinear low-dose extrapolation), the objective of the HHC is to ensure that an individual’s total exposure 

does not exceed threshold levels (e.g.; RfD or POD/UF). Since individuals may be exposed to pollutants 

in other foods not considered in the derivation of the HHC and via other exposures pathways (e.g., 

inhalation and dermal contact), EPA applies a relative source of contribution (RSC) so that the entire RfD 

or POD/UF is not apportioned to drinking water and fish consumption alone. Guidance is provided in 

EPA’s 2000 Human Health Methodology for determining the relative source of contribution factor to be 

used for a particular chemical. Where there is no data to indicate otherwise, EPA uses a RSC of 20%. 

Body Weight (BW):

In its 2015 NRWQC update, EPA revised the national default body weight for human health criteria to 80

kilograms based on National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2006 

(USEPA 2011). This represents the mean body weight for adults ages 21 and older. EPA’s previously 

recommended default body weight was 70 kilograms, which was based on the mean body weight of 

adults from the NHANES III database (1988-1994). 

Drinking Water Ingestion Rate (DWIR): 

In its 2015 NRWQC update, EPA revised the national default drinking water consumption rate for human 

health criteria to 2.4 liters per day based on NHANES data from 2003 to 2006 (USEPA 2011). This 

represents the per capita estimate of community water ingestion at the 90th percentile for adults ages

21 and older. This value of 2.4 liters per day replaces the previously recommended default drinking 

water consumption rate of 2 liters per day, which represented the per capita community water ingestion

rate at the 86th percentile for adults surveyed in the US Department of Agriculture’s 1994-1996 

Continuing Survey of Food Intake by Individuals (CSFII) analysis and the 88th percentile of adults in the 

National Cancer Institute study of the 1977-1978 Nationwide Food Consumption Survey. 

Bioaccumulation Factor (BAF) and Bioconcentration Factor (BCF): 

Aquatic organisms can accumulate certain chemicals in their bodies when exposed to chemicals through 

water, their diet, and other sources. This process is called bioaccumulation. The magnitude of 

bioaccumulation by aquatic organisms varies widely depending on the chemical. Additionally, 

concentrations of chemicals may increase in aquatic organisms of each successive trophic level (refer to 

discussion below regarding trophic levels) due to increasing dietary exposures (e.g., increasing 

concentrations going from algae, to zooplankton, to forage fish, to predatory fish). 

In order to prevent harmful exposures to waterborne chemicals through the consumption of 

contaminated fish and shellfish, HHC must address the process of chemical bioaccumulation in aquatic 

organisms. EPA incorporates bioaccumulation factors (BAFs) into the HHC to capture the relationship 

between the concentration of a chemical in water to its expected concentration in commonly consumed 

aquatic organisms of different trophic levels. 

EPA’s methodology for deriving HHC emphasizes using, when possible, measured or estimated 

bioaccumulation factors, which account for chemical accumulation in aquatic organisms from all 

potential exposure routes (e.g., the water, sediment, and diet). In order to account for the variation in 
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bioaccumulation that is due to trophic position of the organism being consumed, EPA’s Human Health 

Methodology recommends that BAFs be determined and applied to three trophic levels of fish 

corresponding to trophic levels 2 -4 (discussed below). EPA has recommended using a framework for 

deriving national trophic level-specific BAFs. In June 2015, EPA updated several BAFs using fieldmeasured BAFs and laboratory-measured bioconcentration factors available from peer-reviewed, 

publicly available databases to develop national trophic level specific BAFs. If this information was not 

available, EPA selected octanol-water partition coefficients (Kow values) from peer-reviewed sources for 

use in calculating national trophic level specific BAFs. 

Historically, EPA’s 1980 Methodology emphasized use of a bioconcentration (BCF) factor for deriving 

HHC that was usually determined from laboratory data, field data, or from octanol-water partition 

coefficients where lab or field-measured data were not available. Because bioconcentration 

characterizes the uptake and retention of a chemical by an aquatic organism from water only, in 

contrast to bioaccumulation which characterizes the uptake of chemicals by aquatic organisms from 

water, sediment, and the diet, EPA’s 2000 Methodology emphasizes measurement of a chemical’s 

bioaccumulation by aquatic organisms for use in deriving HHC. 

Trophic Levels: 

While it is easy to refer to all aquatic species as fish and shellfish, in actuality numerous species of 

aquatic organisms exist, each of which represents a very different location in the food web. The trophic 

level of an organism refers to the organism’s place in the food web. Organisms with higher trophic 

levels have higher exposures to environmental contaminants. 

• Trophic level 1 organisms are primary producers (e.g., plants and algae). 

• Trophic level 2 organisms are herbivores, also called primary consumers (e.g., benthic filter 

feeders). 

• Trophic level 3 organisms are carnivores that consume herbivores (e.g., forage fish). 

• Trophic level 4 organisms are carnivores that consume other carnivores (e.g., predatory fish). 

• Trophic level 5 organisms are apex predators. 

To account for the difference in the nature of fish and shellfish consumed, in 2000 EPA recommended 

that attention be paid to the trophic level of the species being consumed in derivation of the HHC. 

Example trophic level assignments for several aquatic species include: 

• Trophic level 2: clams, mussels, oysters, scallops, and snails. 

• Trophic level 3: crayfish, shad, lobster, and herring. 

• Trophic level 4: cod, eel, perch, salmon, and trout. 

• Trophic level 5: seal, beluga. 

Fish Consumption Rates and Trophic Level Specific Fish Consumption Rates (FCRi): 

Because the level of fish intake in highly exposed populations varies by geographical location, EPA has 

suggested a four preference hierarchy for states and authorized tribes to follow when deriving 

consumption rates that encourages use of the best local, state, or regional data available. EPA strongly 

emphasizes that states and authorized tribes should consider developing criteria to protect highly 
5 

exposed population groups and use local or regional data over the default values as more representative 

of their target population group(s). EPA suggests a four preference hierarchy for deriving fish 

consumption rates representative of the defined populations being addressed for the particular water 

body. The hierarchy consists of: (1) use of local data from fish intake surveys of local watersheds within 

the state or tribal jurisdiction; (2) use of data reflecting similar geography/population groups; (3) use of 

data from national surveys; and (4) use of EPA’s default intake rates. EPA recommends the use of 

uncooked weight intake values. The recommended four preference hierarchy is intended for use in 

evaluating fish intake from fresh and estuarine species only. In that case, to protect humans who 

additionally consume marine species of fish, the marine portion could be considered another source of 

exposure when calculating an RSC for dietary intake. 

In its 2015 NRWQC update, EPA revised the default adult (21 yrs and older) fish consumption rate for 

the US population for the consumption of fish and shellfish from inland and nearshore waters to 22 

g/day. This value represents a 90th percentile intake based on results from a National Health and 

Nutrition Examination Survey (NHANES) conducted between 2003 and 2010. Also in the 2015 update, 

EPA identified 90th percentile trophic level specific fish consumption rates for this same population 

corresponding to 7.6 g/day, 8.6 g/day, and 5.1 g/day corresponding to trophic levels 2, 3, and 4 

respectively. 

Special Case for Methylmercury 

In January 2001, EPA published a new water quality criterion for the protection of human health 

resulting from exposure to methylmercury that expressed the human health criterion as a concentration 

in fish and shellfish tissue rather than in the water. The equation for calculating the methylmercury fish 

tissue residue criterion used by EPA is: 

TRC = BW x (RfD - RSCHg) 

∑4

i=2 FCRi

Where: 

TRC = Fish tissue residue criterion (mg methylmercury/kg fish) for freshwater and estuarine fish. 

RSCHg = Relative source contribution in mg methylmercury/kg-day (subtracted from the RfD to 

account for marine fish consumption). 

and the other parameters are as previously described. 

This equation is essentially the same equation used in the 2000 Human Health Methodology to calculate 

a HHC, but is rearranged to solve for a protective concentration in fish tissue, rather than in water. Note 

that it does not include a BAF, a drinking water intake value, or consider exposures other than marine

fish in the RSC because non-fish exposures to methylmercury are negligible. Refer to EPA 2001 for 

further information on derivation of the methylmercury fish tissue criterion. 
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References 

EPA, Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health 

(2000), EPA-822-B-00-004, October, 2000. 

http://water.epa.gov/scitech/swguidance/standards/upload/2005_05_06_criteria_humanhealth_metho

d_complete.pdf 

EPA 2001. Water Quality Criterion for the Protection of Human Health: Methylmercury. EPA-823-R-01-

001. January 2001. http://water.epa.gov/scitech/swguidance/standards/criteria/health/document.cfm

EPA 2011. Exposure Factors Handbook: 2011 Edition. EPA-6000-R-09-052F. 

http://www.epa.gov/ncea/efh/pdfs/efh-complete.pdf 

EPA's National Recommended Water Quality Criteria. 

http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm