An Act to Update Certain Water Quality Standards and to
Maine Legislature, Session 132, LD 2187
Committee: Environment and Natural Resources
Amends: 38 MRSA §465, 38 MRSA §465-A, 38 MRSA §465-B, 38 MRSA §467

Legislative Document
No. 2187
S.P. 892
In Senate, February 3, 2026
An Act to Update Certain Water Quality Standards and to 
Reclassify Certain Waters of the State
Reported by Senator TEPLER of Sagadahoc for the Joint Standing Committee on 
Environment and Natural Resources pursuant to the Maine Revised Statutes, Title 38, section 
464, subsection 3, paragraph B.
Reference to the Committee on Environment and Natural Resources suggested and ordered 
printed pursuant to Joint Rule 218.
DAREK M. GRANT
Secretary of the Senate
Be it enacted by the People of the State of Maine as follows:
Sec. 1.  38 MRSA §465, sub-§1, ¶B, as amended by PL 2021, c. 551, §9, is further 
amended to read:
B.  The aquatic life, Except for activities associated with fish stocking and fish 
management that are approved by a state agency, the aquatic life of Class AA waters 
must be as naturally occurs.  The dissolved oxygen and bacteria content of Class AA 
waters 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 or MPN per 100 milliliters 
over a 90-day interval or 236 CFU or MPN per 100 milliliters in more than 10% of the 
samples in any 90-day interval.
Sec. 2.  38 MRSA §465, sub-§2, ¶B, as amended by PL 2021, c. 551, §10, is further 
amended to read:
B.  Except for activities associated with fish stocking and fish management that are 
approved by a state agency, the aquatic life of Class A waters must be as naturally 
occurs.  The dissolved oxygen content of Class A waters may not be less than 7 parts 
per million or and 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 
areas.  Except as provided in section 464, subsection 4, paragraph C, the pH of Class 
A waters must fall within the 6.5 to 9.0 range.  The aquatic life and bacteria content of 
Class A waters 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 or MPN per 100 
milliliters over a 90-day interval or 236 CFU or MPN per 100 milliliters in more than 
10% of the samples in any 90-day interval.
Sec. 3.  38 MRSA §465, sub-§3, ¶B, as amended by PL 2021, c. 551, §11, is further 
amended to read:
B.  Class B waters must be of sufficient quality to support all aquatic species indigenous 
to those waters without detrimental changes in the resident biological community.  The 
Except as provided in section 464, subsection 4, paragraph C, the dissolved oxygen 
content of Class B waters may not be less than 7 parts per million or and 75% of 
saturation, whichever is higher calculated as a daily average, except that for the 
dissolved oxygen of any individual reading at any time may not be less than 6 parts per 
million.  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 areas.  Except as provided in section 464, subsection 4, paragraph C, the 
pH of Class B waters must fall within the 6.5 to 9.0 range.  Between April 15th and 
October 31st, the number of Escherichia coli bacteria in these waters may not exceed 
a geometric mean of 64 CFU or MPN per 100 milliliters over a 90-day interval or 236 
CFU or MPN per 100 milliliters in more than 10% of the samples in any 90-day 
interval.
Sec. 4.  38 MRSA §465, sub-§4, ¶B, as amended by PL 2021, c. 551, §12, is further 
amended to read:
B.  Class C waters must be of sufficient quality to support all species of fish indigenous 
to those waters and to maintain the structure and function of the resident biological 
community.  The dissolved oxygen content of Class C water waters may not be less 
than 5 parts per million or and 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 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.
Except as provided in section 464, subsection 4, paragraph C, the pH of Class C waters 
must fall within the 6.5 to 9.0 range.  Between April 15th and October 31st, the number 
of Escherichia coli bacteria in Class C waters may not exceed a geometric mean of 100 
CFU or MPN per 100 milliliters over a 90-day interval or 236 CFU or MPN per 100 
milliliters in more than 10% of the samples in any 90-day interval.   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. 5.  38 MRSA §465-A, sub-§1, ¶B, as amended by PL 2021, c. 551, §13, is 
further amended to read:
B.  Class GPA 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 GPA 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.  Except for activities associated with fish 
stocking and fish management that are approved by a state agency, the aquatic life of 
Class GPA waters must be as naturally occurs.  Except as provided in section 464, 
subsection 4, paragraph C, the pH of Class GPA waters must fall within the 6.5 to 9.0 
range.  The number of Escherichia coli bacteria in these waters may not exceed a 
geometric mean of 29 CFU or MPN per 100 milliliters over a 90-day interval or 194 
CFU or MPN per 100 milliliters in more than 10% of the samples in any 90-day 
interval.
Sec. 6.  38 MRSA §465-B, sub-§2, ¶B, as amended by PL 2021, c. 551, §15, is 
further amended to read:
B.  Class SB waters must be of sufficient quality to support all estuarine and marine 
species indigenous to those waters without detrimental changes in the resident 
biological community.  The dissolved oxygen content of Class SB waters may not be 
less than 85% of saturation.  Except as provided in section 464, subsection 4, paragraph 
C, the pH of Class SB waters must fall within the 7.0 to 8.5 range.  Between April 15th 
and October 31st, the number of enterococcus bacteria in these waters may not exceed 
a geometric mean of 8 CFU or MPN per 100 milliliters in any 90-day interval or 54 
CFU or MPN per 100 milliliters in more than 10% of the samples in any 90-day 
interval.  The 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 as set forth in its publication "Guide for the Control of 
Molluscan Shellfish" (2019 revision) or any successor publication.
Sec. 7.  38 MRSA §465-B, sub-§3, ¶A, as amended by PL 2003, c. 227, §8, is 
further amended to read:
A.  Class SC waters must be of such quality that they are suitable for the designated 
uses of recreation in and on the water, fishing, aquaculture, propagation and restricted 
harvesting of shellfish, industrial process and cooling water supply, hydroelectric 
power generation, navigation and as a habitat for fish and other estuarine and marine 
life.
Sec. 8.  38 MRSA §465-B, sub-§3, ¶B, as amended by PL 2021, c. 551, §16, is 
further amended to read:
B.  Class SC waters must be of sufficient quality to support all species of fish 
indigenous to those waters and to maintain the structure and function of the resident 
biological community.  The dissolved oxygen content of Class SC waters may not be 
less than 70% of saturation.  Except as provided in section 464, subsection 4, paragraph 
C, the pH of Class SC waters must fall within the 7.0 to 8.5 range.  Between April 15th 
and October 31st, the number of enterococcus bacteria in these waters may not exceed 
a geometric mean of 14 CFU or MPN per 100 milliliters in any 90-day interval or 94 
CFU or MPN per 100 milliliters in more than 10% of the samples in any 90-day 
interval.  The 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 as set forth in its publication "Guide for 
the Control of Molluscan Shellfish" (2019 revision) or any successor publication.
Sec. 9.  38 MRSA §467, sub-§1, ¶C, as amended by PL 2009, c. 163, §1, is further 
amended by amending subparagraph (4-A) to read:
(4-A)  Abbott Brook and its tributaries in Lincoln Plantation -  Class AA.
Sec. 10.  38 MRSA §467, sub-§4, ¶G, as amended by PL 2021, c. 551, §24, is 
further amended by amending subparagraph (2) to read:
(2)  Sandy River, tributaries - Class B unless otherwise specified.
(a)  All tributaries entering above the Route 142 bridge in Phillips - Class A 
unless otherwise specified.
(a-1)  South Branch Sandy River and its tributaries - Class AA.
(a-2)  Cottle Brook and its tributaries - Class AA.
(b)  Wilson Stream, main stem, below the outlet of Wilson Pond - Class C.
(c)  Mount Blue Stream and its tributaries - Class A AA.
(d)  Orbeton Stream above Toothaker Pond Road and its tributaries - Class AA.
(e)  All tributaries entering between Avon Valley Road and Mount Blue Pond 
Road west of Route 4 in Avon - Class A.
(f)  Temple Stream and all its tributaries above the confluence with Edes 
Brook - Class A.
(g)  All tributaries to Drury Pond and the stream between Drury Pond and 
Temple Stream - Class A.
Sec. 11.  38 MRSA §467, sub-§4, ¶H, as repealed and replaced by PL 2003, c. 317, 
§9, is amended by amending subparagraph (2), division (a) to read:
(a)  Sebasticook River, East Branch from the outlet of Corundel Lake, also 
known as East Branch Sebasticook River Reservoir and Corundel Bog, to its 
confluence with the West Branch - Class C.
Sec. 12.  38 MRSA §467, sub-§7, ¶E, as amended by PL 2021, c. 551, §§37 to 40, 
is further amended by enacting a new subparagraph (2), division (c-1) to read:
(c-1)  Pleasant River, Middle Branch and its tributaries - Class AA.
Sec. 13.  38 MRSA §467, sub-§7, ¶F, as amended by PL 2021, c. 551, §§41 and 
42, is further amended by amending subparagraph (5) to read:
(5)  Olamon Stream and its tributaries above the bridge on Horseback Road, also 
known as Spring Bridge Road - Class A.
SUMMARY
This bill, which is reported out by the Joint Standing Committee on Environment and 
Natural Resources pursuant to the Maine Revised Statutes, Title 38, section 464, subsection 
3, paragraph B, implements the recommendations of the Board of Environmental 
Protection resulting from its review of the State's water quality classification system and 
related water quality standards.  As recommended by the board, the bill includes specific 
updates to certain water quality standards and water quality classifications based on water 
quality data and recommendations made by the United States Environmental Protection 
Agency, the Department of Environmental Protection and other persons.
The committee has not taken a position on the substance of the bill and by reporting 
this bill out, the committee is not suggesting and does not intend to suggest that it agrees 
or disagrees with any aspect of this bill.  The committee is reporting the bill out for the sole 
purpose of obtaining a printed bill that can be referred to the committee for a public hearing 
and subsequent committee action in the normal course.