An Act to Update Certain Water Quality Standards and to Reclassify Certain Waters of the State

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STATE OF MAINE
_____
IN THE YEAR OF OUR LORD
TWO THOUSAND TWENTY-SIX
_____
S.P. 892 - L.D. 2187
An Act to Update Certain Water Quality Standards and to Reclassify
Certain Waters of the State
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:
APPROVED
APRIL 3, 2026
BY GOVERNOR
CHAPTER
616
PUBLIC LAW
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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
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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
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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:
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(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.