An Act To Update Maine's Water Quality Standards
Maine Legislature, Session 128, LD 1298
Committee Amendment CA_A_H574 (House)
Amends: 38 MRSA §465, 38 MRSA §465-A, 38 MRSA §465-B

COMMITTEE AMENDMENT "A" to H.P. 895, L.D. 1298, Bill, "An Act To 
Update Maine's Water Quality Standards" 
Amend the bill by striking out all of sections 4 to 10 and inserting the following: 
'Sec. 4. 38 MR.SA §465, sub-§1, ~' as enacted by PL 1985, c. 698, §15, is 
amended to read: 
B. The aquatic life, dissolved oxygen and bacteria content of Class AA waters shall 
must be as naturally occurs. except that the number of Escherichia coli bacteria in 
these waters may not exceed a geometric mean of 64 CFU per 100 milliliters over a 
90-day interval or 236 CFU per 100 milliliters in more than 10% of the samples in 
any 90-day interval. 
Sec. 5. 38 MRSA §465, sub-§2, ~' as enacted by PL 1985, c. 698, §15, is 
amended to read: 
B. The dissolved oxygen content of Class A waters saall be may not be less than 7 
parts per million or 75% of saturation, whichever is higher, except that for the period 
from October 1st to May 14th. in order to ensure spawning and egg incubation of 
indigenous fish species, the 7-day mean dissolved oxygen concentration may not be 
less than 9 .5 parts per million and the one-day minimum dissolved oxygen 
concentration may not be less than 8.0 parts per million in identified fish spawning 
~. The aquatic life and bacteria content of Class A waters shall must be as 
naturally occurs. except that the numbers of Escherichia coli bacteria in these waters 
may not exceed a geometric mean of 64 CFU per 100 milliliters over a 90-day 
interval or 236 CFU per 100 milliliters in more than 10% of the samples in any 90-
day interval. 
Sec. 6. 38 MRSA §465, sub-§3, ~' as amended by PL 2005, c. 409, §1, is 
further amended to read: 
B. The dissolved oxygen content of Class B waters may not be less than 7 parts per 
million or 75% of saturation, whichever is higher, except that for the period from 
October 1st to May 14th, in order to ensure spawning and egg incubation of 
COMMITTEE AMENDMENT 
~,it;. 
COMMITTEE AMENDMENT ·A "to H.P. 895, L.D. 1298 
indigenous fish species, the 7-day mean dissolved oxygen concentration may not be 
less than 9 .5 parts per million and the -Hiay one-day minimum dissolved oxygen 
concentration may not be less than 8.0 parts per million in identified fish spawning 
areas. Between May April 15th and SeptembeF 30th October 31st, the number of 
Escherichia coli bacteria of human and domestio aaimal origin in these waters may 
not exceed a geometric mean of 64 CFU per 100 milliliters over a 90-day interval or 
an i-astaB.taneous le:r,rel of 236 CFU per 100 milliliters in more than 10% of the 
samples in any 90-day interval. hi determmiag human and domestio animal origia, 
the department shall assess lioeased and 'l:mlieeased sourees :asmg availaele 
diagnostio proeed:ares. 
Sec. 7. 38 MRSA §465, sub-§3, ,c, as amended by PL 2007, c. 291, §4, is 
further amended to read: 
C. Discharges to Class B waters may not cause adverse impact to aquatic life in that 
the receiving waters must be of sufficient quality to support all aquatic species 
indigenous to the receiving water without detrimental changes in the resident 
biological community. 
(1) This paragraph does not apply to aquatie pestieide or ehemieal diseharges 
approved by the department and eoadueted by the department, the Departmeat of 
Inlaad Fisheries and Vlildlife or an agSRt of either ageney for the purpose of 
restoriag biologioal eommuaities affeeted by an iavasive speoies. 
(1-A) 
For the purpose of allowing the discharge of aquatic pesticides or 
chemicals approved by the department and conducted by the department. the 
Department of Inland Fisheries and Wildlife or an agent of either agency to 
restore resident biological communities affected by an invasive species, the 
department may find that the discharged effluent will not cause adverse impact to 
aguatic life as long as the materials and methods used do not cause a significant 
loss of any nontarget species and allow restoration of nontarget species. The 
department may find that an unavoidable, temporary loss of nontarget species 
does not constitute a significant loss of nontarget species. 
(2) For the purpose of allowing the discharge of aquatic pesticides approved by 
the department for the control of mosquito-borne diseases in the interest of public 
health and safety, the department may fmd that the discharged effluent will not 
cause adverse impact to aquatic life as long as the materials and methods used 
provide protection for nontarget species. When the department issues a license 
for the discharge of aquatic pesticides authorized under this subparagraph, the 
department shall notify the municipality in which the application is licensed to 
occur and post the notice on the department's publicly accessible website. 
Sec. 8. 38 MRSA §465, sub-§4, ~' as repealed and replaced by PL 2005, c. 
409, §2, is amended to read: 
B. The dissolved oxygen content of Class C water may ae not be less than 5 parts per 
million or 60% of saturation, whichever is higher, except that in identified salmonid 
spawning areas where water quality is sufficient to ensure spawning, egg incubation 
and survival of early life stages, that water quality sufficient for these purposes must 
COMMITTEE AMENDMENT 
~ Co· 
. Cl 
~· 
COMMITTEE AMENDMENT .. fl "to H.P. 895, L.D. 1298 
be maintained. In order to provide additional protection for the growth of indigenous 
fish, the following standards apply. 
(1) The 30-day average dissolved oxygen criterion of a Class C water is 6.5 parts 
per million using a temperature of 22 degrees centigrade or the ambient 
temperature of the water body, whichever is less, if: 
(a) A license or water quality certificate other than a general permit was 
issued prior to March 16, 2004 for the Class C water and was not based on a 
6.5 parts per million 30-day average dissolved oxygen criterion; or 
(b) A discharge or a hydropower project was in existence on March 16, 
2005 and required but did not have a license or water quality certificate other 
than a general permit for the Class C water. 
This criterion for the water body applies to licenses and water quality certificates 
issued on or after March 16, 2004. 
(2) In Class C waters not governed by subparagraph (1), dissolved oxygen may 
not be less than 6.5 parts per million as a 30-day average based upon a 
temperature of 24 degrees centigrade or the ambient temperature of the water 
body, whichever is less. This criterion for the water body applies to licenses and 
water quality certificates issued on or after March 16, 2004. 
The department may negotiate and enter into agreements with licensees and water 
quality certificate holders in order to provide further protection for the growth of 
indigenous fish. Agreements entered into under this paragraph are enforceable as 
department orders according to the provisions of sections 347-A to 349. 
Between May April 15th and Septemher 30th October 31st, the number of 
Escherichia coli bacteria of hl:Hllali aad dom.estie animal origin in Class C waters may 
not exceed a geometric mean of -bU 100 CFU per 100 milliliters over a 90-day 
interval or an mstantaneous le-vel of 236 CFU per 100 milliliters in more than 10% of 
the samples in any 90-day interval. In determming hlimaa aad domestie aRimal 
origin, tee depa:rtmeRt shall assess lioensed ana 1.-H'J.lioensed souroes :asing availahle 
eliagaostie proeedures. The board shall adopt rules governing the procedure for 
designation of spawning areas. Those rules must include provision for periodic 
review of designated spawning areas and consultation with affected persons prior to 
designation of a stretch of water as a spawning area. 
Sec. 9. 38 MRSA §465, sub-§4, ,re, as amended by PL 2005, c. 182, §5, is 
further amended to read: 
C. Discharges to Class C waters may cause some changes to aquatic life, except that 
the receiving waters must be of sufficient quality to support all species of fish 
indigenous to the receiving waters and maintain the structure and function of the 
resident biological community. This paragraph does :aot apply to aq:aatie peatieide or 
ehemieal eliseharges approved hy the department a:ad eo:ad:aeted by tee depahm.eat, 
the Department of Ialaad Fisheries aad Wildlife or an age:at of eitaer aget19J' for the 
purpose of restoring biologioal eom.m.1:H'J.ities affeeted by aa i:av-asive speeies. For the 
purpose of allowing the discharge of aquatic pesticides or chemicals approved by the 
COMMITTEE AMENDMENT 
~ 'i). 
~· 
COMMI'ITEE AMENDMENT" A 
"to H.P. 895, L.D. 1298 
department and conducted by the department. the Department of Inland Fisheries and 
Wildlife or an agent of either agency to restore biological communities affected by an 
invasive species, the department may find that the discharged effluent will not cause 
unacceptable changes to aguatic life as long as the materials and methods used will 
ensure the support of all species of indigenous fish and the structure and function of 
the resident biological community and will allow restoration ofnontarget species. 
Sec. 10. 38 MRSA §465-A, sub-§1, ,rB, as amended by PL 2017, c. 137, Pt. B, 
§2, is further amended to read: 
B. Class GP A waters must be described by their trophic state based on measures of 
the chlorophyll "a" content, Secchi disk transparency, total phosphorus content and 
other appropriate criteria. Class GP A waters must have a stable or decreasing trophic 
state, subject only to natural fluctuations, and must be free of culturally induced algal 
blooms that impair their use and enjoyment. The number of Escherichia coli bacteria 
of humaR aRd domestie aaimal origm in these waters may not exceed a geometric 
mean of 29 CFU per 100 milliliters over a 90-day interval or an mstantaneous le:r:el of 
CFU per 100 milliliters in more than 10% of the samples in any 90-day interval. 
Sec. 11. 38 MRSA §465-B, sub-§1, ,rB, as enacted by PL 1985, c. 698, §15, is 
amended to read: 
B. 
The estuarine and marine life, dissolved oxygen and bacteria content of Class 
SA waters shall must be as naturally occurs. except that the number of enterococcus 
bacteria in these waters may not exceed a geometric mean of 8 CFU per 100 
milliliters in any 90-day interval or 54 CFU per 100 milliliters in more than 10% of 
the samples in any 90-day interval. 
Sec. 12. 38 MRSA §465-B, sub-§2, ,rB, as amended by PL 2005, c. 409, §3, is 
further amended to read: 
B. 
The dissolved oxygen content of Class SB waters must be may not be less than 
85% of saturation. Between May April 15th and September 30th October 31st, the 
nl:llllbers number of enterococcus bacteria of humaR and domestie animal origm in 
these waters may not exceed a geometric mean of 8 CFU per 100 milliliters in any 
90-day interval or an instEmtaneous ltv,rel of 54 CFU per 100 milliliters in more than 
10% of the samples in any 90-day interval. h1 determiniag ln1man aad domestie 
aBiillal origm, the departmeat shall assess lieeased and 1:1:Rlieeased sollfees 1:1siag 
availaale diagaostie proeedares. The l'll:llli-6ers number of total coliform bacteria or 
other specified indicator organisms in samples representative of the waters in 
shellfish harvesting areas may not exceed the criteria recommended under the 
National Shellfish Sanitation Program, United States Food and Drug Administration. 
Sec. 13. 38 MRSA §465-B, sub-§3, ,rB, as amended by PL 2005, c. 409, §4, is 
further amended to read: 
· 
B. 
The dissolved oxygen content of Class SC waters m1:1st be may not be less than 
70% of saturation. Between May April 15th and September 30th October 31st, the 
al:llllbers number of enterococcus bacteria of human and domestie ammal origin in 
these waters may not exceed a geometric mean of 14. CFU per 100 milliliters in any 
90-day interval or an mstantanem.iS le:r,rel of 94 CFU per 100 milliliters in more than 
COMMITTEE AMENDMENT 
~· 
} 
COMMITTEE AMENDMENT" A 
"to H.P. 895, L.D. 1298 
10% of the samples in any 90-day interval. In detertR-li'Hng human and domestic 
animal origin, the def)artm.ent shall assess licensed and 1:Hliicensed solH'ees "tising 
a1.•ailable diagnostic proeedlH'es. The 1i1,1m.bers number of total coliform bacteria or 
other specified indicator organisms in samples representative of the waters in 
restricted shellfish harvesting areas may not exceed the criteria recommended under 
the National Shellfish Sanitation Program, United States Food and Drug 
Administration.' 
SUMMARY 
This amendment amends the provisions of the bill that update Maine's water quality 
standards by aligning state law with federal Clean Water Act requirements for pesticide 
application to control invasive plants and mosquito-borne disease and adds provisions to 
align state law with such requirements for dissolved oxygen. The amendment further 
updates Maine's water quality standards to be consistent with guidance issued by the 
United States Environmental Protection Agency regarding recreational water quality 
criteria for bacteria. The amendment retains the provision of the bill that authorizes the 
Department of Environmental Protection to use an alternative low-flow requirement when 
assessing the impact of nutrients on water quality, contingent upon the department's 
adopting nutrient rules. 
FISCAL NOTE REQUIRED 
(See attached) 
COMMITTEE AMENDMENT. 
Fiscal Detail and Notes 
Approved: 01/23/18 :wae 
LD 1298 
LR 738(02) 
An Act To Update Maine's Water Quality Standards 
Fiscal Note for Bill as Amended by Committee Amendment,~,{ f-1~ S7Y J 
Committee: Environment and Natural Resources 
Fiscal Note Required: Yes 
Fiscal Note 
Minor cost increase • General Fund 
This bill will update Maine's water quality standards by aligning state law with federal Clean Water Act requirements 
for water quality standards. Any additional costs to the Department of Environmental Protection to conduct 
rulemaking and implement the changes are anticipated to be minor and can be absorbed within existing budgeted 
resources. 
LR0738(02) · Fiscal Note· Page 1 of 1