UNITED STATES ENVI RONM ENTAL PROTECTION AGENCY Region 1

December 2, 2013 Michael Kuhns Director 5 Post Office Square, Suite 100 Boston, MA 02109 - 3912

Burea u of Land and Water Quality Department of Env ironmental Protect'io n 17 S tate House Stat i on Augusta , M aine 04333

- 0017 Dear 

### Mr. Kuhn s: I wou ld like to take thi s opportunity to highlight for you EPA 's recent p ub li ca tion of fmal ammonia and recreational water quality criteria recommendations, and urge you to co n s ider adopt ion of these cr iteria into your water quality standards. These recently publi s hed criteria documents reflect once again the Agency's commitment to improving and updating the science bol stering protection of our Nation's water resource s . As you know, EPA's water quality standards regulations at 40 CFR 13l.ll(a)(l) requ ire states to adopt pro tective criteria that are based on soun d sc ientific rationale. The publication of EPA recommendations un d er Clean Water Act sect ion 304 (a) provides an excellent opportunity for you and your stakeholders to review exi sting water quality criteria and determine whether those existing criteria a r e still , 

### in fact, protective and based on so und sc ientific rationale. I encourage you to consider adoption of these or equival e ntl y · protective criteria, and to use your triennial public hearings (required by 40 CFR 131 .20(a)) to provide a venue for public fe edback on the need to adopt new or modify exi stin g WQS t o reflect the la test science. EPA's CWA section 304(a) cr iter i a recommendations provide sc ientific recommendatio ns to s tates and authorized tribes 

### in developing new or revised water quality standards. States and authorized tribes have the discretion to adopt E PA' s criteria recomm endations; E PA's recommendations modified to reflect site-specific co nditions; or criteria based on other sc ientifically defensible methods

. E PA last issued final ambient water quality criteria recommendations fo r recreational waters in 198 6 and for ammon ia in 1999. The new water quaRity cr it

eria reflect the s ignificant research that has taken place between then and now on th ese pollutants and the levels that are protective of designated uses. Recreational Water Quality Criteria The recreational water quality criteria were deve loped based on a review ofhistoric studies and more recent scientific information including the National Epidemiolog ical and E nvironmental Assessmen t of Recreational water s tudies at U.S. beaches in 2003,2004, 2005, 2007, and 2009. Those studies enrolled 54,250 participants, encompassed nine locations, and collected and analyzed numerous samples from a combination of fresh, marine, tropical, and temperate waters. The resulting criteria have numerous improvements over the 1986 criteria:

• The criteria consist of both a geometric mean and stati stical threshold value. • The criteria now comprise a magnitude, duration, and frequency. • States may choose from two d ifferent sets ofrecommended criteria values to protect primary contact recreation waters. • The criteria recommendations for fresh and marine waters are based on the same illness rate. • The criteria no longer refer to different use intensities.

. • States may take advantage of newly-developed rapid**tes~** (qPCR) methods in adopting WQS. • States may now use Beach Action Values in their beach notification programs. As you know, as a BEACH Act state, Maine has specific requirements regarding recreational water criteria. Section 303(i)(l)(B) of the Clean Water Act (as amended bY. the BEACH Act of 2000) directs each state with coastal recreational waters to adopt and submit to EPA new or revised water quality standards for those waters for all pathogens and pathogen indicators to which the new or revised water quality criteria are applicable. The deadline for state adoption and submittal to EPA ofrevised WQS is three years from EPA publication of new recommendations. Since EPA published fmal recreational water quality criteria recommendations in December 2012, states should complete this action by December 2015. EPA's 2012 recommendations apply to all waters designated for primary contact recreation

. You can find more information on the 2012 recreational water quality criteria on EPA's website, at http:/ / water.epa.gov/scitecb! sw guidance/standards/criteria/health/recreation/. Ammonia Criteria In updating the 1999 ammonia criteria, EPA conducted an extensive literature review that incorporates new toxicity data from 69 studies, including new data on freshwater mussels and gill

-bearing snails , which are both sensitive to ammonia toxicity. In particular, the freshwater mussels are more sensitive to ammonia than the organisms included in the 1999 criteria dataset. You can fmd more information on the 2013 ammonia water quality criteria on EPA's website, at http: //water.epa.gov / scitech/swguidance / standards /criteria!aqlife / arnmonia/. Because both these newly published criteria rely on the latest research and science, I encourage you, when re-examining your water quality standards during the next triennial review, to consider adoption of these criteria into your water quality standards. If, after you review your existing water quality standards, you conclude that updates to your ammonia and recreational water quality standards are not necessary to protect the designated uses, I urge you to submit, in your triennial review, your rationale for not making a change. I hope these new criteria provide you with the information you need to move forward as you consider changes to your water quality standards in the near future. I appreciate your 2commitment to protecting water quality, and look forward to continuing to work collaboratively towards our mutual goals. Ifyou s hould have any additional questions, please feel free to contact me or Ellen Weitzler for more information. Sincerely, 

# (h / v-- Ken Moraff, Director Office ofEcosystem Protection

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