STATE OF MAINE

DEPARTMENT OF ENVIRONMENTAL PROTECTION

PAUL R LEPAGE PATRICIA W AHO

GOVERNOR COMMISSIONER

AUGUSTA

17 STATE HOUSE STATION BANGOR PORTLAND PRESQUE ISLE

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web site www maine gov dep

October 6 2011

Ms Ellen Weitzler PE

Water Quality Standards Coordinator

USEPA Region 1

5 Post Office Square Suite 100 OEP06 2

Boston MA 02109 3912

RE Revisions to 06096 CMR 584 Surface Water Quality Criteria for Toxic Pollutants

Protection of Sensitive Subpopulations

Dear Ellen

As you know from our ongoing interactions Maine is proposing revisions to our Surface Water

Quality Criteria for Toxic Pollutants Chapter 584 rules This rule revision was initiated

pursuant to PL 2011 c 194 LD 515 An Act to Review State Water Quality Standards

attached and at the direction of the Maine Legislature’s Joint Standing Committee on

Environment and Natural Resources Consistent with PL2011 c194 this rule revision changes

the cancer risk level for inorganic arsenic used in calculating ambient water quality human

health criteria and establishes revised inorganic arsenic criteria accordingly Further at the

Department’s initiative this revision updates Maine’s ambient water quality and human health

criteria for pollutants for which USEPA has updated criteria pursuant to 304 a of the Clean

Water Act since Maine’s last revision in 2005 using Maine specific parameters such as the fish

consumption rate where applicable This letter serves to further describe the proposed changes

to inorganic arsenic criteria and the provisions to ensure protection of sensitive subpopulations

Maine’s current inorganic arsenic human health criteria consist of 0.012 micrograms liter ugL

for freshwater based on consumption of water and organisms and 0.028 ugL for marine water

based on consumption of organisms only The criteria are calculated utilizing the same

methodology that USEPA uses based on several factors including a cancer risk factor for

consumers and a daily fish consumption rate However as some of Maine’s standards are more

stringent than USEPA’s this has resulted in many cases in criteria that are more stringent than

ambient background levels and permit limits that are unattainable for the regulated community

Hence the adoption of PL2011 c 194 and the need for these rule revisions

EPA000469
Ms Ellen Weitzler USEPA Page 2 of 4

October 6 2011

1

ChemRisk 1992 Consumption of freshwater fish by Maine anglers A Technical Report Portland ME ChemRisk

a division of McLaren Hart Revised July 24 1994

2

EbertE Harrington NW Boyle KJ Knight JW Keenan RE 1993 Estimating consumption of freshwater fish

among Maine anglers North American Journal of Fisheries Management Vol 13737745

3

USEPA 1997 Exposure Factors Handbook US Environmental Protection Agency Office of Research and

Development Washington DC EPA600P95002Fa

Historically Maine has used a cancer risk factor of one case per one million people 1 x 106 or

10e6 in calculating human health criteria The current proposal revises this risk factor for

inorganic arsenic to one case per 10,000 people 1 x 104 or 10e4 which is within USEPA’s

guidelines as specified below The resulting revised ambient water quality human health

criteria are 1.2 ugL for freshwater and 2.8 ugL for marine water USEPA’s Methodology for

Deriving Ambient Water Quality Criteriafor the Protection of Human Health 2000 EPA822

B00004 EPA’s AWQC Methodology Section 2.4 indicates “EPA believes that both 10e6

and 10e5 may be acceptable for the general population and that highly exposed populations

should not exceed a 10e4 risk level.” “EPA understands that fish consumption rates vary

considerably especially among subsistence populations and it is such great variation among

these population groups that may make either 10e6 or 10e5 protective of those groups at a

10e4 risk level Therefore depending on the consumption patterns in a given State or Tribal

jurisdiction a 10e6 or 10e5 risk level could be appropriate In cases where fish

consumption among highly exposed population groups is of a magnitude that a 10e4 risk level

would be exceeded a more protective risk level should be chosen Such determinations should

be made by the State or Tribal authorities and are subject to EPA’s review and approval or

disapproval under Section 303 c of the CWA.”

“Adoption of a 10e6 or 10e5 risk level both of which States and authorized Tribes have

chosen in adopting water quality standards to date represents a generally acceptable risk

management decision and EPA intends to continue providing this flexibility to States and Tribes

EPA believes that such State or Tribal decisions are consistent with Section 303 c if the State or

authorized Tribe has identified the most highly exposed subpopulation has demonstrated that

the chosen risk level is adequately protective of the most highly exposed subpopulation and has

completed all necessary public participation States and authorized Tribes also have flexibility in

how they demonstrate this protectiveness and obtain such information.”

The Department provided information on the origin of Maine’s fish consumption rate in its

Response to Comments on its 2005 revisions to Maine Rule 06096 CMR 584 “ChemRisk

Ebert et al conducted a mailed survey of 2,500 randomly selected Maine anglers for the 1989

1990 fishing season obtaining responses from 1,612 anglers 64 response rate From these

data estimates have been obtained a 95thpercentile fish intake value of 21 grams per day for all

anglers 26 grams per day for fish consuming anglers and 51 grams per day for a subset of

anglers of Native American heritage N148 1,2These above estimates reflect consumption of

recreationally caught fish from all waters The estimate of the 95thpercentile fish consumption

rate for rivers and streams i e waters likely to receive a wastewater discharge license among

fish consuming anglers was 12 grams per day and the corresponding estimate for Native

Americans N43 was 22 grams per day These data have been reviewed by EPA and are listed

as one of the key studies providing information on freshwater recreational fish consumption 3”

EPA000470
Ms Ellen Weitzler USEPA Page 3 of 4

October 6 2011

Maine utilizes a fish consumption rate of 32.4 gramsday the equivalent of one 8ounce fish

meal per week which exceeds USEPA’s current consumption rate of 17.5 gramsday that is

based on the 90thpercentile consumption rate for the US adult population EPA’s AWQC

Methodology Section 1.6 and its previous rate of 6.5 gramsday More importantly it also

exceeds the 22 gramsday 95thpercentile consumption rate for native American recreational

anglers consuming fish from rivers and streams in Maine At this time USEPA is still using the

6.5 gramday consumption rate for calculating arsenic criteria Maine maintains that our

32.4 gramday fish consumption rate is not only protective of the sensitive subpopulation of fish

consuming recreational anglers but is also protective of the higher end sensitive subpopulation

of native American recreational anglers based on the only empirical data of which Maine is

aware This information represents local population specific data the preferred data source

according to EPA’s AWQC Methodology Sections 1.6 2.6 2.8.2 Further as the Ebert et al

ChemRisk study is cited by EPA in the Exposure Factors Handbook in both Section 10.10.3

Recommendations –Recreational Freshwater Anglers and Section 10.10.4 Recommendations –

Native American Subsistence Populations Maine believes that the validity of the study and the

protective nature of its fish consumption rate for sensitive subpopulations 22 gramsday are

demonstrated Maine references the river and stream consumption rates because state statute

allows for possible new wastewater discharges in these waters whereas they are essentially

prohibited in lakes and ponds 06096 CMR 465A1C

Beyond this in the event that sensitive subpopulations andor Maine itself wish to pursue

establishing even more protective standards for specific waters additional protection is provided

in the existing rule 06096 CMR 584 Section 3B2 through the ability for parties to request

establishment of site specific human health criteria “In determining if site specific criteria are

appropriate the Board shall first evaluate whether there is an identifiable population s using a

water body whose uses is distinct from that of the population considered when establishing the

statewide criteria If the Board identifies such a population it shall consider activities or

customs that would constitute a use of the water body substantially different in type or extent

than that upon which statewide criteria are based The Board shall consider among other

things...specific human activities that create a potential exposure to toxics in the water

body,...the importance of organisms affected by a toxic substance,...the potential effect of a toxic

substance in the discharge...on human health,...and unique characteristics of the water body or

organisms depending on it that effect exposure of humans to toxics in the water body.”

Maine believes that the 32.4 gramday fish consumption rate as well as the opportunity to

establish site specific criteria where demonstrated appropriate insures that sensitive

subpopulations will not be exposed to cancer risk greater than 1 in 10,000 10e4 and seeks

EPA’s concurrence on this issue

EPA000471
Ms Ellen Weitzler USEPA Page 3 of 4

October 6 2011

If you have any questions regarding the matter please feel free to call contact project manager

Robert Stratton at 207 215 1579 or via email at Robert DStratton maine gov Thank you for

your attention to this important matter

Sincerely

Brian Kavanah Director Division of Water Quality Management

Bureau of Land and Water Quality

Enc Copy of PL 2011 c 194 LD 515 An Act to Review State Water Quality Standards

Copy of Maine DEP testimony on the above

cc Patricia Aho Commissioner Maine DEP

Michael Mullen Acting Director Bureau of Land and Water Quality Maine DEP

Robert Stratton Division of Water Quality Management Maine DEP

Jan McClintock Assistant Attorney General

Andrew Smith Director Environmental and Occupational Health Programs MECDC

Diane Silverman Toxicologist Environmental and Occupational Health MECDC

EPA000472