### MEMORANDUM

TO: Bill Swietlik, EPA

FROM: Jill Lucy, ERG

DATE: April 19, 2013

SUBJECT: Fish Consumption Rate for Cohorts for the Steam Electric ELGs Environmental Assessment (DCN SE01963)

The U.S. Environmental Protection Agency (EPA) is proposing revised effluent limitations guidelines and standards (ELGs) for the Steam Electric Power Generating Point Source Category (40 CFR 423). In support of th e development of the revised ELGs, ERG supported EPA in conducting an environmental assessment (EA) to evaluate the potential environmental and human health impacts of pollu tant loadings released under current (i.e., baseline) discharge practices and assess the po tential improvement from pollutant loading reductions under varying regulatory options.

EPA developed a receiving water model to quantify the impacts to surface waters, wildlife, and human health from the waste stream s evaluated for the EA (i.e., fly ash transport water, bottom ash transport water, flue gas de sulfurization (FGD) wastewater, and landfill and surface impoundment leachate). The receiving wate r model calculates the bioaccumulation of pollutants 1 in fish tissue for trophic level th ree (T3) or trophic level four (T4) 2 fish, using the model-calculated pollutant concentration in the water column and a pollutant-specific bioconcentration factor (BCF). For mercury, the model calculates the concentration of methylmercury in the fish. 3 Using the calculated T3 and T4 fish tissue concentrations, the model estimates the daily contaminant (i.e., metal) doses for human receptors as a result of eating T3 and T4 contaminated fish. Using the daily dos es, the model evaluates the cancer risk and potential to cause non-cancer hea lth effects from the consumpti on of fish within the following age and consumption categories:

 Child recreational fishers;

1 EPA included ten pollutants in the receiving water model: ar senic, cadmium, copper, chro mium VI, lead, mercury, nickel, selenium, thallium, and zinc.

2 T3 fish (e.g., carp, smelt, perch, catfish, sucker, bullhead, sauger) are those that consume invertebrates and plankton, while T4 fish (e.g., salmon, trout, walleye, bass) are those that consume other fish.

3 “(E)lemental mercury isn’t expected to deposit significantly onto soils and surface water. Therefore, it’s assumed that there is no transfer of elemental mercury into fish . Fish are assumed to be exposed only to the divalent and organic forms of mercury that exist in the water and soil/sediment media. However, as with the conservative approach adopted by previous guidance documents, all of mercury in the fish is assumed to exist or be converted to the methyl mercury (organic) form after uptake into the fish tissue” [U.S. EPA, 2005. Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities (HHRAP). EPA 520-R-05-006. Washington, DC. (September).[DCN SE01926]. Child subsistence fishers;

 Adult recreational fishers; and

 Adult subsistence fishers.

This memorandum documents the development of fish consumption rates used for human receptors (cohorts) in the r eceiving water model. EPA’s Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (EA Report) (DCN SE01995) provides more detailed information on the receiving water model, incl uding the water quality, wildlife, and human health portions of the model (see se ction 4.1.2 and Appendices C, D, and E).

1.0 D ESCRIPTION OF H UMAN C OHORTS IN THE R ECEIVING W ATER M ODEL

EPA’s assessment of the potential human health impacts from steam electric plant discharges involved defining specific human coho rts based on the exposed individual’s age and fishing frequency (recreational vs. subsistence) 4 . The receiving water model included the following 14 cohorts:

 Recreational fishers

o Adult

o Child, age 1 to < 2 years

o Child, age 2 to < 3 years

o Child, age 3 to < 6 years

o Child, age 6 to < 11 years

o Child, age 11 to < 16 years

o Child, age 16 to < 21 years

 Subsistence fishers

o Adult

o Child, age 1 to < 2 years

o Child, age 2 to < 3 years

o Child, age 3 to < 6 years

o Child, age 6 to < 11 years

o Child, age 11 to < 16 years

o Child, age 16 to < 21 years

The child cohort age ranges co rrespond to the ranges provided for body weights in U.S. EPA 2008 Child-Specific Exposure Factor Handbook [EPA/600/R-06/096F], Washington, DC. (September) [DCN SE01876].

4 “ Subsistence fishermen are those individuals who consume fresh caught fish as a major source of food. Their intake rates are generally higher than those of the general population.” Reference: U.S. EPA Exposure Factors Handbook: 2011 Edition (EPA/600/R-09/052F), National Center for Environmental Assessment and Office of Research and Development (September) [DCN SE01912].Memorandum April 19, 2013 Page 3

To determine the average daily pollutant dos es from fish consumption, EPA needed the following information that did no t depend on the specific cohort:

 Concentration of pollutant in fish (T3 and T4) – calculated in the receiving water model.

 Fraction of consumed fish that are classified as T3 or as T4 – calculated value based on data provided in U.S. EPA Exposur e Factors Handbook: 2011 Edition [EPA/600/R09/052F], Washington, DC. (September) [D CN SE01912]. See Appendix E of the EA Report.

To determine the average daily pollutant dos es from fish consumption, EPA needed the following information that did depend on the specific cohort:

 Body weight of cohort – literature sources used incl ude U.S. EPA 2008 Child-Specific Exposure Factor Handbook [EPA/600/R-06/096F ], Washington, DC. (September) [DCN SE01876] for child cohort body weights a nd U.S. EPA Exposure Factors Handbook: 2011 Edition [EPA/600/R-09/052F], National Center for Environmental Assessment and Office of Research and Development (September) [DCN SE01912] for adult body weights.

 Consumption rate of cohort – see Section 2 of this memorandum.

2.0 E STIMATING THE C ONSUMPTION R ATE FOR H UMAN C OHORTS

Table 2-1 presents the cohort specific input values used in the receiving water model. Section 1 of this memorandum explains the c ohorts listed and the source of the cohort body weights. The development of the consumption ra te values is described after the table.

Table 2-1. Cohort-Specific Input Va lues for the Receiving Water Model

Receptor Cohort Body Weight (kg) Consumption Rate (g/day)

Child Recreational Fisher 1 to <2 years 11.4 2.5 2 to <3 years 13.8 3 3 to <6 years 18.6 3.5 6 to <11 years 31.8 5.1 11 to <16 years 56.8 5.7 16 to <21 years 71.6 7.2 Child Subsistence Fisher 1 to <2 years 11.4 13.7 2 to <3 years 13.8 16.6 3 to <6 years 18.6 26 6 to <11 years 31.8 35 11 to <16 years 56.8 39.8 16 to <21 years 71.6 50.1

Adult Recreational Fisher 80 20

Adult Subsistence Fisher 80 88
Acronyms: kg (kilograms); g/day (grams per day).Memorandum April 19, 2013 Page 4

To determine the consumption rates for use in the receiving water model, EPA used data documented in the U.S. EPA Exposure F actors Handbook: 2011 Edition (EPA/600/R-09/052F) [DCN SE01912]. The fish intake rates provi ded in the handbook are recommended for the general population; however, th e handbook notes that the selecti on of consumption rates for exposure assessment purposes may vary dependi ng on the exposure scenarios being evaluated.

To be consistent with other data used in the EA Report, EPA used the mean consumption rate

values where available. Data were also available for the 95 th percentile values, representing the most conservative (highest) fish consumpti on rate values. However, the use of the 95 th percentile values may not be appropriate for a national-scal e assessment. Mean values were available for

adult recreational fishers and adult subsistence fishers.

For child cohorts, EPA identified consumpti on rates for the genera l population, but did not find consumption rates specific to subsistence fishers. EPA used the mean values provided in the U.S. EPA Exposure Factors Handbook: 2011 Edition (EPA/600/R-09/052F) [DCN SE01912]

for child recreational cohorts. As defined in the handbook, subsistence fishers are those individuals who consume fresh caught fish as a major source of food and their intake rates are generally higher than those of the general population. Therefore, ERG used best professional judgment to select the 95 th percentile consumption rates for the general populat ion to represent consumption rates for child subsistence cohorts.

Child Cohorts – Recreational and Subsistence Fishers

EPA determined consumption rates for child cohorts using data in Table 10-1 of the U.S. EPA Exposure Factors Handbook: 2011 Edition, Recommend Per Capita and Consumer-Only Values for Fish Intake (see Attachment 1 of this memo randum). EPA determined the model consumption rates for recreationa l and subsistence child cohorts based on values for finfish, excluding values for shellfish. The majority of steam electric discharges and those being

modeled for the EA are fresh water bodies. EPA used the mean values for recreational fishers

and 95 th percentile values for subsistence fishers. Mean values are prov ided for both per capita 5
and consumer-only 6 children. EPA used the per capita consumption rates for finfish.

To convert the data in the Exposure F actors Handbook to the correct units for the receiving water model (grams per day), EPA mu ltiplied the listed consumption rate (grams per kilogram-day) by the mean body weight for each cohor t as listed in Table 2-1 above [U.S. EPA, 2008 Child-Specific Exposure Factor Handbook (E PA/600/R-06/096F) [DCN SE01876]]. Table

2-2 shows the calculation of the consumption rates for use in the receiving water model.

The child recreational fisher consumption rates range between 2.5 to 7.2 grams per day. For comparison, the adult recreational fisher consumption rate is 20 grams per day.

5 Per capita intake rates are "generat ed by averaging consumer-only intakes of the entire survey population (including those individuals that reported no intake). In general, per capita intake rates are appropriate for use in exposure assessments for which average dose estimates ar e of interest." Reference: U.S. EPA Exposure Factors Handbook: 2011 Edition (EPA/600/R-09/052F) [DCN SE01912].

6 Consumer-only intake refers to the "quantity of fish and shellfish consumed by individuals during the survey period." Reference: U.S. EPA Exposure Factors Handbook: 2011 Edition (EPA/600/R-09/052F) [DCN SE01912].MemorandumApril 19, 2013Page 5Table 2-2. Calculation of Consumption Rates for Child CohortsAge Group(years)Body Weight(mean),kgaRecreationalSubsistenceConsumption Rate as aFactor of Body Weight(mean),g/kg-daybCalculation of ConsumptionRate for the Receiving WaterModel (mean),g/dayConsumption Rate as aFactor of Body Weight(95th percentile),g/kg-daybCalculation of the ConsumptionRate for the Receiving WaterModel (95th Percentile),g/day1 to <2 11.4 0.22 11.4 × 0.22 = 2.5 1.2 11.4 × 1.2 = 13.72 to <3 13.8 0.22 13.8 × 0.22 = 3 1.2 13.8 × 1.2 = 16.63 to <6 18.6 0.19 18.6 × 0.19 = 3.5 1.4 18.6 × 1.4 = 266 to <11 31.8 0.16 31.8 × 0.16 = 5.1 1.1 31.8 × 1.1 = 3511 to <16 56.8 0.10 56.8 × 0.10 = 5.7 0.7 56.8 × 0.7 = 39.816 to <21 71.6 0.10 71.6 × 0.10 = 7.2 0.7 71.6 × 0.7 = 50.1Acronyms: kg (kilograms); g (grams).a – Table 8-1. Recommended Values for Body Weight, U.S. EPA 2008Child-Specific Exposure Factor Handbook [EPA/600/R-06/096F], Washington, DC.(September) [DCN SE01876].b – Table 10-1. Recommended Per Capita and Consumer-Only Values for Fish Intake (g/kg-day), Uncooked Fish: Per Capita for Finfish, U.S. EPA ExposureFactors Handbook: 2011 Edition [EPA/600/R-09/052F], Washington, DC. (September) [DCN SE01912].Memorandum April 19, 2013 Page 6

Adult Cohorts – Recreational Fishers

EPA determined consumption rates for adult recreational fishers using data from Table 10-5 of the U.S. EPA Exposur e Factors Handbook: 2011 Edition, Summary of Relevant Studies

on Freshwater Recreational Fish Intake (see Attachment 1 of this memorandum). EPA used the mean values for freshwater fish consumpti on (g/day) based on locat ion and population groups. EPA used consumption rates for all respondents and calculated a median value to use in the model. The Exposure Factors Handbook does not provide recommended values for fish consumption, but does present available data for certain geographic areas. Assessors may apply these data, if appropriate, to the scenarios and populations being assessed. EPA used the mean consumption rate across the geographic areas to represent a central-te ndency value for adult

fishers across the United States. A fraction of the adult fisher populat ion may experience higher consumption rates as evidenced by the 95 th percentile values presente d in Table 10-5 of the U.S. EPA Exposure Factors Handbook: 2011 Edition. Table 2-3 shows the calculation of the adult recreational fisher consumption ra te for use in the receiving water model. For the model, the adult recreational fisher consumption rate is 20 grams per day. For comparison, the adult subsistence fisher consumption rate is 88 grams per day.

Adult Cohorts – Subsistence Fishers

EPA determined consumption rates for adul t subsistence fishers based on studies of Native American fish intake using data from Table 10-6 of the U.S. EPA Exposure Factors Handbook: 2011 Edition, Summary of Relevant Studies on Native American Fish Intake . EPA used the mean values for fish consumption base d on location/name of Nativ e American tribe. In some cases, studies looked at adults and adult consumers separately; however, the results did not vary significantly. EPA used values listed for ad ults and converted the data into consumption rates (units of g/day) assuming an adult body weight of 80 kilograms, as provided in Section 8.1 of the U.S. EPA Exposure Factor Handbook: 2011 Edition. EPA then calculated a median value

to use in the model.

As noted above, the Handbook does not pr ovide recommended values for fish consumption but does present available data for certain geographic areas. Assessors may apply these data, if appropriate, to the scenarios and populations being assessed. EPA used the mean consumption rate across the geographic areas to represent a central-te ndency value for adult

fishers across the United States. A fraction of the adult fisher populat ion may experience higher consumption rates as evidenced by the 95 th percentile values presente d in Table 10-6 of the U.S. EPA Exposure Factors Handbook: 2011 Edition. Table 2-4 shows the calculation of the adult recreational fisher consumption ra te for use in the receiving water model. For the model, the

adult recreational fisher consum ption rate is 88 grams per day.Memorandum April 19, 2013 Page 7

Table 2-3. Calculation of Consumption Rates for Adult Recreational Cohort a

Location Population Group Mean Consumption Rate (g/day)

Notes All Respondents Consuming Anglers Alabama Adults 44 53 Calculation: 83% of respondents were

consumers. Connecticut Not specified a 51 53 Fresh and saltwater fish; Calculation: 97% of respondents were consumers. Georgia (Savannah River) Adults Values provided for two ethnic groups; table does not provide value for all adults. Indiana Not specified a 16 20

Maine Not specified a 5 6.4

Michigan Consuming anglers: 21 to 80 years 16 Did not have value for "all" respondents.

Minnesota Consuming anglers a 14 Source lists 50 th (and 95th) percentile for 0-14 year olds; >14 years (male); 15 to 44 (female); and >44 (female). New York (Lake Ontario) Adults 4.9 5.8 Calculation: 84% of respondents were

consumers. North Dakota Consuming anglers a 12 Source lists 50 th (and 95 th ) percentile for 0-14 year olds; >14 years (male); 15 to 44 (female); and >44 (female).

Tennessee (Clinch River) Not specified a20 38 Consumption includes store-bought and selfcaught fish. Washington Adults 10 15 Calculation: 66% of respondents were

consumers. Wisconsin Adults 11 12

For All Respondents: 20.24 Range of mean values: 4.9 - 51 g/day;

Median value is 13.5. For Consuming Anglers: 22.29 Range of mean values: 5.8 - 53 g/day;

Median value is 15.
Acronym: g (grams). a – Table 10-5. Summary of Relevant Studies on Freshwater Recreational Fish Intake, U.S. EPA Exposure Factors Handbook: 2011 Edition [EPA/600/R-09/052F], Washington, DC. (September) [DCN SE01912].MemorandumApril 19, 2013Page 8Table 2-4. Calculation of Consumption Rates for Adult Subsistence CohortaLocation/TribePopulationGroupConsumption RateReported in ReferenceConsumption Rate,g/daybNotesRange or 95thPercentileMeanUnitsRangeaMeana94 AlaskaCommunitiesAll Respondents:Median of 94a16-770 81 g/day 16-770 81ChippewaIndians(Wisconsin)All Respondents:Adults N/A 39 g/day N/A 394 ColumbiaRiver Tribes(Oregon)All Respondents:Adults≤170 59 g/day≤170 59Values also listed for children (5 and younger) andConsumer adults (63 g/day), which are the resultsdivided by 93% consuming.Florida All Respondents≤4.5 0.8 g/kg-day≤4.5 × 80 =≤36064Also have consumer-only values (based onuncooked fish weight).Minnesota All RespondentsN/A 2.8 g/kg-day N/A2.8 × 80 =224Also have consumer-only values (based onuncooked fish weight);mean value is the same asall respondents.MowhawkTribe (NewYork andCanada)All Respondents≤131 25 g/day≤131 25Values also listed for women (13 g/day mean),women consumers (16 g/day mean), children (2years), and consumers (adult (29 g/day mean) and 2year).North Dakota All Respondents≤0.9 0.4 g/kg-day≤0.9 × 80 =≤720.4 × 80 =32Also have consumer-only values;mean value is thesame as all respondents.Tulalip Tribe(Washington)All Respondents:Adults≤2.9 0.9 g/kg-day≤2.9 × 80 =≤2320.9 × 80 =72Values also listed for children (5 and younger),consumer adults (63 g/day), and consumer children.SquaxinIsland Tribe(Washington)All Respondents:Adults≤3.0 0.9 g/kg-day≤3.0 × 80 =≤2400.9 × 80 =72Values also listed for children (5 and younger) andfor consumers.Consumer adult mean value is 1.0g/kg-day.SuquamishTribe(Washington)All Respondents:Adults≤10 2.7 g/kg-day≤10.0 × 80 =≤8002.7 × 80 =216Values also listed for children (5 and younger) andfor consumers.Consumer adult mean value is 2.7g/kg-day (same value as all respondents).For All Tribes Listed:g/day16 - 80088Range of mean values: 25 - 224 g/day;Medianvalue is 68.Acronyms: g (grams); kg (kilograms); N/A (not applicable).a – Table 10-6. Summary of Relevant Studies on Native AmericanFish Intake, U.S. EPA Exposure Factors Handbook: 2011 Edition [EPA/600/R-09/052F], Washington, DC.(September) [DCN SE01912].b – If source reported results as grams per day, no change in value. If source reported results as grams per kilogram-day, multiplied by the mean adult body weight of 80 kg.Attachment 1 April 19, 2013 Page A-1

Attachment 1: Excerpts from U.S. EP A Exposure Factors Handbook: 2011 EditionAttachment 1 April 19, 2013 Page A-2Attachment 1 April 19, 2013 Page A-3Attachment 1 April 19, 2013 Page A-4Attachment 1 April 19, 2013 Page A-5