An Act to Promote Responsible Outdoor Lighting
Maine Legislature, Session 132, LD 1934
Committee: State and Local Government
Sponsors: OSHER, GUERIN

Legislative Document
No. 1934
H.P. 1295
House of Representatives, May 6, 2025
An Act to Promote Responsible Outdoor Lighting
Reference to the Committee on State and Local Government suggested and ordered printed.
ROBERT B. HUNT
Clerk
Presented by Representative OSHER of Orono.
Cosponsored by Senator GUERIN of Penobscot and
Representatives: CAMPBELL of Orrington, JULIA of Waterville, RIELLY of Westbrook, 
WOODSOME of Waterboro, Senators: BALDACCI of Penobscot, BENNETT of Oxford, 
GROHOSKI of Hancock, TIPPING of Penobscot.
Be it enacted by the People of the State of Maine as follows:
Sec. 1.  5 MRSA c. 21 is enacted to read:
CHAPTER 21
RESPONSIBLE OUTDOOR LIGHTING
§481. Responsible outdoor lighting
1.  Definitions.  As used in this chapter, unless the context otherwise indicates, the 
following terms have the following meanings:
A.  "ANSI/IES lighting standard" means a standard developed by the Illuminating 
Engineering Society and adopted by the American National Standards Institute or 
successor organizations to describe adequate outdoor lighting that does not 
unnecessarily brighten the night sky when used for particular purposes or in particular 
settings, including, but not limited to, the following standards:
(1) RP-6: outdoor sports and recreational areas;
(2) RP-7: outdoor industrial areas;
(3) RP-8: roadway and parking facilities;
(4) RP-40: port terminals; and
(5) RP-43: outdoor pedestrian areas.
B.  "Correlated color temperature" means the measured color appearance of light 
emitted by a light source, described using a nominal value stated in kelvins.
C.  "Fully shielded luminaire" means a luminaire that is shielded in such a manner that 
no light is emitted, either directly or indirectly, at or above a horizontal plane running 
through the lowest light-emitting part of the luminaire. 
D.  "Light level" means the maintained luminance or illuminance value. 
E.  "Light trespass" means artificial lighting illuminating across property lines at night 
without permission.  Unless specified otherwise, light trespass limits are measured at 
any location along a property line both horizontally at the ground plane facing upward 
and vertically at 1.5 meters above the ground plane with the light meter aimed toward 
the light source in question. 
F.  "Lumen" means a unit of measure of the luminous flux of a light source.
G.  "Luminaire" means a complete lighting unit, including the light source, housing, 
optics, electronics and other necessary components for the purpose of providing 
illumination.
H.  "Lux" means the metric system unit of measure for illuminance, the total luminous 
flux incident at a point on a surface.
I.  "Nadir" means a downward vertical vector directly beneath a luminaire, opposite to 
zenith.
J.  "Nighttime hours" means the time between 10:00 p.m. and sunrise or 7:00 a.m., 
whichever comes earlier, except that for facilities, offices, activities and events with 
operating hours later than 10:00 p.m., nighttime hours begin one hour after the end of 
the operating hours.
K.  "Nonessential lighting" means public outdoor lighting that does not improve the 
physical safety of motor vehicles or pedestrians, including, but not limited to, 
landscape lighting, illuminated signage or advertising during nighttime hours, facade 
lighting, vacant sports field lighting, decorative lighting and seasonal lighting.
L.  "Outdoor sports lighting" means public outdoor lighting for illumination of sporting 
events or activities, including, but not limited to, downhill skiing areas, playing fields 
for team sports and similar outdoor recreational facilities. 
M.  "Public entity" means an agency as defined in section 43 and any political 
subdivision or public instrumentality of the State.
N.  "Public improvement" means any improvement or replacement of facilities or 
equipment undertaken by, on behalf of or pursuant to a contract or grant agreement 
with a public entity.  
O.  "Public outdoor lighting" means any public improvement that includes the 
installation or replacement of luminaires for the purpose of providing outdoor 
illumination. 
P.  "Seasonal lighting" means public outdoor lighting that is portable, temporary, 
decorative and used in connection with festivals, celebrations, holidays and traditions.  
"Seasonal lighting" includes, but is not limited to, string lighting, icicle lighting and 
lighted inflatables, none of which are intended for general illumination.
2.  Requirements.  Beginning October 1, 2026, public outdoor lighting that is installed 
or replaced must comply with the requirements of this subsection as follows: 
A. Public outdoor lighting, with the exception of outdoor sports lighting, may not 
exceed 125% of the light level recommended by the applicable ANSI/IES lighting 
standard or a more stringent standard specified by rule adopted pursuant to subsection 
or an ordinance authorized by subsection 5;
B. Light trespass to a federally designated or state-designated wilderness, natural area, 
habitat or reserve may not measure greater than 0.1 lux;
C. Luminaires emitting more than 1,000 lumens must be fully shielded luminaires and 
may not emit more than 5% of their total lumen output above 80 degrees from the 
luminaries' nadir;
D. Nonessential lighting must be extinguished during nighttime hours;
E. The maximum allowable correlated color temperature of outdoor luminaires is 3,000 
kelvins, except for outdoor sports lighting; and
F. Outdoor sports lighting must meet the following standards in addition to the 
standards in paragraphs B to D:
(1) Eighty-five percent of the lumens generated must be confined to within 10 
meters of the playing field or the spectator track or bleacher area, whichever is 
greater;
(2) Lighting applications for sports in which the height of a ball in play would, in 
the normal course of playing the sport, exceed the height of the sports lighting 
poles must have a maximum of 8% of their total lumen output above 80 degrees 
from the lighting's nadir;
(3) Luminaires must use the lowest possible correlated color temperature necessary 
for the sport, class of play and viewing audience, except that the correlated color 
temperature may not exceed 5,700 kelvins; and
(4) Outdoor sports lighting must comply with paragraphs A and E except during 
the seasons and times of day when the activities for which the lighting is designed 
are taking place or maintenance to support those activities is being conducted.
3.  Exemptions.  This chapter does not apply to public outdoor lighting to the extent 
that:
A. Regulations or orders of the United States Department of Transportation, Federal 
Aviation Administration require lighting that exceeds or otherwise fails to comply with 
the standards in subsection 2;
B. Rules adopted pursuant to subsection 4 by the Department of Public Safety require 
lighting necessary to protect public safety or security that does not comply with the 
requirements of subsection 2;
C. Law enforcement officers and authorized first responders use public outdoor 
lighting during emergency procedures that does not comply with subsection 2;
D. Rules adopted pursuant to subsection 4 by the Department of Transportation permit 
temporary lighting to ensure safety and efficiency in completion of road construction 
and repair, as long as such lighting deviates from the standards in subsection 2 to the 
minimum extent necessary; 
E. Luminaires replicating historical character and lighting effect are protected pursuant 
to a law governing historical registration; and
F. Seasonal lighting complies with subsection 2, paragraphs B and D. 
4.  Rulemaking.  The Department of Administrative and Financial Services may adopt 
rules governing the implementation of this chapter.  The Department of Public Safety may 
adopt rules establishing exemptions as described in subsection 3, paragraph B.  The 
Department of Transportation may adopt rules governing temporary lighting necessary to 
ensure safety and efficiency in completion of road construction and repair as described in 
subsection 3, paragraph D.  Any department proposing rules that affect municipalities shall 
confer with the Maine Office of Community Affairs before proposing those rules.  All rules 
adopted pursuant to this subsection are major substantive rules as defined in chapter 375, 
subchapter 2-A.
Sec. 2.  Local ordinances required.  By December 31, 2028, each municipality in 
the State is required to adopt a local ordinance to promote compliance with this chapter and 
to extend its standards as appropriate beyond public improvements governed by this 
chapter.  No later than September 30, 2026, the Maine Office of Community Affairs shall 
develop and share with municipalities a model ordinance for these purposes. 
This section may not be construed to prohibit a municipality from adopting lighting 
ordinances stricter than those adopted by the State pursuant to this chapter.
Sec. 3.  Effective date. This Act takes effect September 30, 2026.
SUMMARY
This bill requires that outdoor lighting installed or replaced after October 1, 2026 
comply with certain standards, including standards established by the American National 
Standards Institute and the Illuminating Engineering Society, intended to reduce the 
amount of unnecessary light emitted.  The bill includes exemptions for certain types of 
lighting such as outdoor sports lighting, temporary lighting and required and emergency 
lighting.  The bill directs certain departments to adopt rules to implement the requirements 
of this bill.  The bill also directs each municipality in the State to adopt a local ordinance 
to promote compliance with the provisions of this bill and allows a municipality to adopt 
ordinances that are more strict than those required by this bill.