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HomeMy WebLinkAbout01-22-26 Public Comment - A. Epple - Preservation of Dark Skies From: Andy and Paulette EDDIe To: Bozeman Public Comment Subject: [EXTERNAL]Preservation of Dark Skies Date: Wednesday,January 21,2026 3:21:37 PM Attachments: SAS letterhead-screenshot ona_ imaae.Dno imaae.ona image ona imaae.Dno SAS Comments on Dark Skies Preservation to City Commission.Ddf DarkSky MOR-007b 2025 Bozeman July 2025-Analysis by Dark Skies International.odf Comments re Bozeman D Dark Sky Preservation Se ember 2025.df CAUTION:This email originated from outside of the organization.Do not click links or open attachments unless you recognize the sender and know the content is safe. Sacajawea Audubon Society ••Mo. PO Box 1711•Bozeman,Montana 59771-1711 Sarnia weaaudubon.ora January 21,2026 Dear Mayor Morrison and Members of the Commission: We are writing to you on behalf of our membership regarding artificial light pollution and preservation of the night sky. Sacajawea Audubon Society(SAS)is a non-profit grassroots membership organization,(1000 members)serving the northern Greater Yellowstone Ecosystem of Montana since 1967.We are a chapter of the National Audubon Society.SAS builds on an interest in birds to promote the conservation of our natural environment. According to Dark Sky International,light pollution is increasing globally at an astounding rate of ten percent per year.Light pollution disrupts wildlife, impacts human health wastes money and energy,contributes to climate change,and blocks out our view of the universe.Consequently,more communities are working to enact dark sky-friendly practices and policies.With the rapid population growth in Bozeman and the Gallatin Valley,our night sky is under increasing threat.We urge you to take concrete steps now to protect the night sky and to prevent artificial light pollution. Impacts of Light Pollution Birds and other species rely on the stars and moon for navigation.Lighting up the sky disrupts migration patterns.According to the U.S.Fish and Wildlife Service,artificial lighting can attract large numbers of night-migrating birds from several kilometers away.Birds drawn into lights often become entrapped and circle the lit area,depleting their energy stores and putting them at risk of colliding with buildings and infrastructure.According to Massachusetts Audubon,brightly lit buildings cause more than 100 million bird deaths in North America annually.and as many as 1,000 bird deaths per major structure. Light pollution interferes with reproduction,increases predation,and disorients migration for species such as monarch butterflies and others that navigate using the stars and moon. Humans are profoundly impacted as well.Many studies have shown that exposure to artificial light at night negatively affects human health,including increased risk for obesity,depression,sleep disorders,diabetes,and breast cancer. Bozeman's Municipal Lighting Codes Update Needed to Comply with Dark Sky-Friendly Guidelines SAS appreciates that Bozeman has an Outdoor Lighting Code(Division 38.570)as well as Design and Construction Standards specifically regarding streetlights and lighting adjacent to roadways.We also appreciate that the Code recognizes in the Purpose section that protection of the night sky is important,and that light pollution has negative impacts.There are several excellent elements in the Code to help prevent or reduce artificial light pollution.However,significant aspects are not covered in the Code that are critical to ensuring preservation of the night sky and preventing light pollution,including addressing glare and maximum correlated color temperature.Much has changed in the realm of lighting technology and our knowledge of the negative impacts of light pollution in the 20-plus years since Bozeman's Code was implemented. We are aware that Dark Sky International(DSI),the leading organization worldwide working to protect the night sky,has analyzed Bozeman's municipal codes and made recommendations as to how the codes could be improved to better protect the night sky and reduce light pollution.We urge you to review the DSI analysis and recommendations,and to update the Outdoor Lighting Code and Design and Review Standards,based on the DSI recommendations.Comments submitted to the Commission on September 3,2025 by Bonnie Rice and Dr.Joseph Shaw,along with the DSI analysis, detail where Bozeman's code should be updated in order to better comply with current DSI dark sky-friendly guidelines for municipalities. Thank you for your consideration of our comments as you develop FY 2026-27 priorities for the City of Bozeman and consider updates to the Uniform Development Code.Bozeman can be a Montana leader to ensure that we preserve the benefits of a dark,star-filled sky for people,birds and other wildlife,and plants—all of which depend on dark skies for long-term health and well-being. For your convenience a copy of the September 2025 comments and DSI Analysis is attached at the end of this letter. Sincerely, Chris Nixon,President Sacajawea Audubon Society XSACAJAWEA V i. Board Members: Chris Nixon*Doug McSpadden*Brad Frazee*Mikaela Howie*Loreene Reid*John Edwards*Emma Narotzky* Vicki Saab*Frank Marchak* Ken Sinay*Ben Goodheart*Hallie Nienhaus*Bret Davis To:Bozeman Community Development Board and City Commission Re:Update of Development Code-Dark Sky Preservation Date:September 3,2025 From:Bonnie Rice, Dr.Joseph Shaw—Director,Optical Technology Center(OpTeC),Montana State University Sent electronically via:comments@bozeman.net Appreciation for dark skies is entering the social consciousness.Lightpollution is one ofthe only types ofpollution that's completely and immediately reversible.I don't think we'll realize the value of seeing the Milky Way,until it's gone."—Bettymaya Foott,Dark Sky International Dear Members of the Community Development Board and City Commission: We write to you today as community members concerned about light pollution and preservation of the night sky in Bozeman,the Gallatin Valley,and beyond. The City's ongoing public process to update its Development Code presents an excellent opportunity to help address goals and directives contained in Bozeman's Outdoor Lighting Code,the Gallatin Valley Sensitive Lands Plan,and the Gallatin Valley Growth Policy to preserve the night sky and to prevent and reduce pollution from artificial light.Preservation of the night sky is a community value and was raised by community residents in the public engagement meetings regarding the update of Bozeman's development code in the spring of 2025.As has been well documented,Bozeman and the Gallatin Valley are experiencing unprecedented population growth with no end in sight,with associated housing and infrastructure development and services attempting to meet the demands of our growing population.All of this raises profound implications for preservation of the night sky and the health and well-being of people and ecosystems in the Gallatin Valley and beyond.We are in danger of losing our night sky and all of the benefits that a dark sky provides. Preservation of the night sky is also important to the economy of Bozeman and the Gallatin Valley.As explained further below,the Montana State University (MSU)Optical Technology Center was established in the early 1990s to promote optics/photonics education and research for economic development,and there are now more than 40 photonics companies here. A key competitive advantage for MSU photonics research is the natural Montana environment, including our dark sky. We urge you—as members of the Community Development Board and City Commission—to ensure that preservation of dark skies is an integral component in the current UDC process and other ongoing community processes and policies related to growth and development in Bozeman and the broader Gallatin Valley. ® DarkSky Recognized Municipal Ordinance Review DarkSky ur,cal—onnx IDNumber:D1-MO1-007b Contact Name:Bonnie Rice Munlci all Name:Bozeman Contactemaik I State:MT Contact Phone:4066402857 Review Document Bozeman Outdoor Lighting-Code Re view Date:7/31/2025 Overview: The DarkSky Recognized Code program is established by DarkSky lidemational(DarkSky)to recognize government entities or private developments that adopt ordinances,bylaws,or municipal codes that meet or exceed DarkSky approvedrequirements and provisions for reducing light pollution.Per your application request,submitted through the Da rkSky website.DarkSky has conducted a review to ompare your ordinance/bylaw/code against the DarkSky Municipal Code template.This review,shown In detail on page two of this report.will show adherence and gaps with the submitted ordinance/bylaw/code as compared to the DarkSky Municipal Ordinance template.This reviewwillgive the applicant an understanding of how close the ordinance/bylaw/code isto being DarkSky Recognized. Review Instructions: Page two of this review wilt identify the req uiremehts ofthe DarkSky Municipal Code template.The document submitted bythe a p plicant will be reviewed for adherence and/or gaps compared to the template.The resubswill be indicated for each requirement with a(Green Y),meaning yes it meets DarkSky criteria,an(Orange N).meaning no it does not meet DarkSky cmeria,or a(Yellow,P). eareng the provision would be preferred but is not mandatory.The absence of any orange N would indicate an ability to achieve Da n6ky Recognized status.See legend below, Meets DarkSky requirements =Does NOT meet DarkSky requirements P =DarkSky would prefer you meet this requirement but it's not mandatory Review Summary: Previously evaluated in March 2025 as MOR-003b,Bowmen has now submitted their 10/26 COB Design and Construction standards (COB-DCS)as a supplemernal document capable of fur stilling previously missing ordinance requirements. Further review by Da"and a new review of the COB-DCS did help the Bozeman outdoor lighting ordinance comply with three previously failed requirements.However,COB-DCS svery stmedighting oemric so the opportunity to add additional scope,like non- adjacent Institutional orcomm ucial developments with pedestrian right-ot-way,would be required to meet DarkSky's application requirement DarkSky continues to commend Bozeman on having a lighting Ord thence,there are many good characteristics within. The purpose section is Very strong and meets DarkSky expectations.The sports lighting section is aiso strong,stronger than most but fell jug shy of meetingthe exact DarkSky requirements.Other sections meet about 50%of DarkSky exiiectation s.Missing mandatory elements include applicabi nyto residenoatand planned unit developments along with.at a minimum,a compliance trigger authority for hazards to public safety.Also missing are elements related to the five principles for responsible outdoor Lighting,Including some over-lighting protections based on lighting standards that are more current than 1998.and very high angle glare reduction above 80-. While the Bozeman ordinance is average for Its use of metrics and effective requirements:as written,this vers Ion would tall short of achieving DarkSky Recognized status.We encourage Bozeman to consider a stakeholder d iscussion in an effort to make some ad ditions/updates to resolve the missing elements and achieve DarkSky mcogn ltlon. Page Iof 3 DarkSky Recognized Municipal Ordinance Review DS-MOR4K)7b 1.2"ammat A­p­ C Visual Safety y Energy v Sky QdRARy Y 1]30.570.010(C)PIRI-neen—I Rh­9H1kyfln,n­RRIIP1.ItIl.nd E,,ds"tenn Welfare I, =d love to See Iregeleng the naz­of a-1.1 I.gll at night ki­Iena,­-.9 haleat and crops Thelteee­ 11onq Zone ReIpdnnlilild, P end, D—kyl—Inteld, a table. epplltat,lllyA-c—pledd 11Pd..1.7.e0 m Ide1 dr1nas el t.9held g b—td adjacent public ROW are e ader—ed.n Ile design and 1e--e,n dIeled eennk-stamens. l. dr.p.1—.1 - open/are not It.Ieln.e scope,e,; are­—from -In—I and mould net be 111mggerm Triggers and AeonlZatiOn __ne_n.and =7.Inweddbe nROo sea re-Id—gdhe ae emlinalion ofI dude.. SA EaempH.ln Accepted c—amards lawlulITh—R,ed­­atkrlowtadgem..In,a..,or elate —ad I,,RdkR,,led, 10thl,F.—ptelS Y zligntegnwemer own zadrequiremems.Thank-. 1 III. led. Accepted Caleaddrd,1'.f,ty it,�mfe­­ y 2.0 Ughtft Req,i,,,,,t, ­epted CM.rkaR..1.l1e1W ar 1Re.1en,.l Legal 020(lC l)does enotnte drdI nneg—R'. l code " — —111RlR­­­ld.n E l standards.I.A., led. r Ilse enne RsI1 Iron 1—.sane.1­1 ane.111SIa ey 20U-nd— (e.g.. Light Level belb�enanal..lteadof RPA351to301ox langt Additional In— mer by Clanton&Aek—al-are­­.,and listed in he da,a and It=,ted,eed,appendix. ­,­g Iu-1.111 IIIn dlk­ a-t 0pt1,,,nd­I.OWI,,,,, d—ned specific n..1h.-Ie­(.Ke)10..s realty t1del...could meatne D.R.1, Ib­HR,fiR1I ­ vein G2r­,df5%enR­.ab..8M, HabllalTrespass N wog­dIaereanden2 akne-I Curlew ­W.mank— Conbds 1we.d.—IR, I cc, e-711.11­00k,W­.1.1 2A Sports Lighting Accepted Cadeakeell, en 1171 1—, Ind("`­1 help I- l,not spemgcally I ell—light theproperly cwle be very large. Skyward Light L111t 3g.S10.050(B)talks about aimingfa max candela angle but does not speciM1cally limn emission above g0° All­P,1,e,cc intensityLimn S'dd___._aR__ Accepted C.....11 Page 2.13 Tire permit process�cDapter 1.6.1j antl Ma sudnitlal process�chepter3.2.b}aretlacameMetl in IM1e Appiication Aby Bweman Design and Combuclion SlantleNs.TDeu procesus meet OarSky expectalionsfor ureetligMs,bd itwoultl alu be expectetl forany lilprtswilM1in the public FgMQway,institutional rcial a�-.<mpnnnta,ana apona rcew:. ReWewCnntluctetl tMcitys Engircering D'nision,tM lim.processm—dy—m Npter 22d antl CamtmctioeEMorceme3B.Slo.og0 meek Me Da r ky regu M1ement wiM posti—WtionIrttpec— Penally355JD090 meets Me De.Skyrequlremant with 30tley remetlial action 1.00eilnllbns Acceple0 Comments Overview P any tlefinitiors.If n—M.D-Sky rec ends listing tlefinitions. Page 3 of 3 Sacajawea Audubon Society PO Box 1711 •Bozeman,Montana 59771-1711 �= Socaiaweaaudubon.ora Dear Mayor Morrison and Members of the Commission: We are writing to you on behalf of our membership regarding artificial light pollution and preservation of the night sky. Sacajawea Audubon Society (SAS) is a non-profit grassroots membership organization, (1000 members) serving the northern Greater Yellowstone Ecosystem of Montana since 1967. We are a chapter of the National Audubon Society. SAS builds on an interest in birds to promote the conservation of our natural environment. According to Dark Sky International, light pollution is increasing globally at an astounding rate of ten percent per year. Light pollution disrupts wildlife, impacts human health, wastes money and energy, contributes to climate change, and blocks out our view of the universe. Consequently, more communities are working to enact dark sky- friendly practices and policies. With the rapid population growth in Bozeman and the Gallatin Valley, our night sky is under increasing threat. We urge you to take concrete steps now to protect the night sky and to prevent artificial light pollution. Impacts of Light Pollution Birds and other species rely on the stars and moon for navigation. Lighting up the sky disrupts migration patterns. According to the U.S. Fish and Wildlife Service, artificial lighting can attract large numbers of night-migrating birds from several kilometers away. Birds drawn into lights often become entrapped and circle the lit area, depleting their energy stores and putting them at risk of colliding with buildings and infrastructure. According to Massachusetts Audubon, brightly lit buildings cause more than 100 million bird deaths in North America annually, and as many as 1,000 bird deaths per major structure. Light pollution interferes with reproduction, increases predation, and disorients migration for species such as monarch butterflies and others that navigate using the stars and moon. Humans are profoundly impacted as well. Many studies have shown that exposure to artificial light at night negatively affects human health, including increased risk for obesity, depression, sleep disorders, diabetes and breast cancer. Bozeman's Municipal Lighting Codes Update Needed to Comply with Dark Sky-Friendly Guidelines SAS appreciates that Bozeman has an Outdoor Lighting Code (Division 38.570) as well as Design and Construction Standards specifically regarding streetlights and lighting adjacent to roadways. We also appreciate that the Code recognizes in the Purpose section that protection of the night sky is important and that light pollution has negative impacts. There are several excellent elements in the Code to help prevent or reduce artificial light pollution. However, significant aspects are not covered in the Code that are critical to ensuring preservation of the night sky and preventing light pollution, including addressing glare and maximum correlated color temperature. Much has changed in the realm of lighting technology and our knowledge of the negative impacts of light pollution in the 20-plus years since Bozeman's Code was implemented. We are aware that Dark Sky International (DSI), the leading organization worldwide working to protect the night sky, has analyzed Bozeman's municipal codes and made recommendations as to how the codes could be improved to better protect the night sky and reduce light pollution. We urge you to review the DSI analysis and recommendations, and to update the Outdoor Lighting Code and Design and Review Standards, based on the DSI recommendations. Comments submitted to the Commission on September 3, 2025 by Bonnie Rice and Dr. Joseph Shaw, along with the DSI analysis, detail where Bozeman's code should be updated in order to better comply with current DSI dark sky-friendly guidelines for municipalities. Thank you for your consideration of our comments as you develop FY 2026-27 priorities for the City of Bozeman and consider updates to the Uniform Development Code. Bozeman can be a Montana leader to ensure that we preserve the benefits of a dark, star-filled sky for people, birds and other wildlife, and plants — all of which depend on dark skies for long-term health and well-being. For your convenience a copy of the September 2025 comments and DSI Analysis is attached at the end of this letter. Sincerely, bl� —:)�- �3I%- r Chris Nixon, President Sacajawea Audubon Society -W SACA)AWEA AUDUBON SOCIETY To: Bozeman Community Development Board and City Commission Re: Update of Development Code-Dark Sky Preservation Date:September 3,2025 From: Bonnie Rice, Dr.Joseph Shaw—Director, Optical Technology Center(OpTeC), Montana State University Sent electronically via:comments@bozeman.net "Appreciation for dark skies is entering the social consciousness.Light pollution is one of the only types of pollution that's completely and immediately reversible.1 don't think we'll realize the value of seeing the Milky Way, until it's gone."—Bettymaya Foott, Dark Sky International Dear Members of the Community Development Board and City Commission: We write to you today as community members concerned about light pollution and preservation of the night sky in Bozeman, the Gallatin Valley, and beyond.The City's ongoing public process to update its Development Code presents an excellent opportunity to help address goals and directives contained in Bozeman's Outdoor Lighting Code,the Gallatin Valley Sensitive Lands Plan,and the Gallatin Valley Growth Policy to preserve the night sky and to prevent and reduce pollution from artificial light. Preservation of the night sky is a community value and was raised by community residents in the public engagement meetings regarding the update of Bozeman's development code in the spring of 2025.As has been well documented, Bozeman and the Gallatin Valley are experiencing unprecedented population growth with no end in sight,with associated housing and infrastructure development and services attempting to meet the demands of our growing population. All of this raises profound implications for preservation of the night sky and the health and well-being of people and ecosystems in the Gallatin Valley and beyond.We are in danger of losing our night sky and all of the benefits that a dark sky provides. Preservation of the night sky is also important to the economy of Bozeman and the Gallatin Valley.As explained further below,the Montana State University(MSU)Optical Technology Center was established in the early 1990s to promote optics/photonics education and research for economic development,and there are now more than 40 photonics companies here. A key competitive advantage for MSU photonics research is the natural Montana environment, including our dark sky. We urge you—as members of the Community Development Board and City Commission—to ensure that preservation of dark skies is an integral component in the current UDC process and other ongoing community processes and policies related to growth and development in Bozeman and the broader Gallatin Valley. 0 DarkSky Recognized Municipal Ordinance Review DarkSky INTERNATIONAL ID Number: DS-MOR-007b Contact Name: Bonnie Rice Municipality Name: Bozeman Contactemail: biricel6Calgmail.com State: MT Contact Phone:406-640-2857 Review Document: Bozeman-Outdoor-Lighting-Code Review Date: 7/31/2025 Overview: The DarkSky Recognized Code program is established by DarkSky International(DarkSky)to recognize government entities or private developments that adopt ordinances,bylaws,or municipal codes that meet or exceed DarkSky-approved requirements and provisions for reducing light pollution.Per your application request,submitted through the DarkSkywebsite,DarkSky has conducted a review to compare your ordinance/bylaw/code against the DarkSky Mu nicipal Code template.This review,shown in detail on page two of this report,will show adherence and gaps with the submitted ordinance/bylaw/code as compared to the DarkSky Municipal Ordinance template.This review will give the applicant an understanding of how close the ord finance/bylaw/code is to being DarkSky Recognized. Review Instructions: Page two of th is review will identify the requirements of the DarkSky Municipal Code template.The document submitted bythe applicant will be reviewed for adherence and/or gaps compared to the template.The results will be indicated for each requirement with a(Green Y),meaning yes it meets DarkSky criteria,an(Orange N),meaning no it does not meet DarkSky criteria,or a(Yellow P), meaningthe provision would be preferred but is not mandatory.The absence of any orange Nwould indicate an abilityto achieve DarkSky Recognized status. See legend below: =Meets DarkSky requirements =Does NOT meet DarkSky requirements P =DarkSkywould preferyou meet this requirement but it's not mandatory Review Summary: Previouslyevaluated in March 2025 as MOR-003b,Bozemen has now submitted their 10/24COB Design and Construction Standards (COB-DCS)as a supplemental document capable offulfilling previously missing ordinance requirements. Further review by DarkSky and anew review of the COB-DCS did help the Bozeman outdoor lighting ordinance comply with three previouslyfailedrequirements. However,COB-DCS is very streettighting centric so the opportunityto add additional scope,Like non- adjacent institutional or commercial developments with pedestrian right-of-way,would be required to meet DarkSky's application requirement. Da rkSky continues to commend Bozeman on having alighting ordinance,there are many good characteristics within. The purpose section is very strong and meets DarkSky expectations.The sports lighting section is also strong,stronger than most,but fell just shy ofineetingthe exact DarkSky requirements.Other sections meet about 50%of DarkSky expectations. Missing mandatory elements include applicabilityto residential and planned unit developments along with,at a minimum,a compliance trigger authority for hazards to public safety.Also missing are elements related to the five principles for responsible outdoor lighting,including some over-lighting protections based on lighting standards that are more current than 1998,and very high-angle glare reduction above 80°. While the Bozeman ordinance is average for its use of metrics and effective requirements:as written,this version would fall short of achieving DarkSky Recognized status.We encourage Bozeman to consider stakeholder discussion in an effort to make some additions/updatesto resolve the missing elements and achieve DarkSky recognition. Page 1 of 3 ® DarkSky Recognized Municipal Ordinance Review Bozeman DS-MOR-007b 1.2 Purpose Accepted Comments Visual Safety 38.570.010(8)and(F)cite safety and glare concerns Energy 38.570.0106 cites conservation of energyfrom excessive lighting Sky Quality 38.570.010(C)protects neighbors and the night sky from inappropriate light Ecosystem Welfare P DarkSkywould love to see a recital regarding the hazards of artificial light at night on wildlife and Other nocturnal ecosystems,including habitat and crops Some IES standards make illuminance recommendations by lighting zone(e.g.,RP43).The Bozeman Lighting Zone Responsibility P ordinance does not mention a community plan for lighting zones. DarkSky recommends municipalities plan for their nighttime character and a hierarchy of transitions by assigning alighting zone overlay or table. 1.3AppUcablUtyIN Comments Street lighting antl adjacent public ROW are addressed in the tlesign and construction standards. New/Replacement However,properties not adjacent to roadway and residential property are not listed within the scope, antl PU D's are exempt from this Ordinance and should not be. 38.570.100 is one trigger that forces compliance and 38.570.110 demonstrates the difference Triggers and Amortizbetween non-conforming and conforming.It would be nice to see re-zoning or the determination of a public hazard be included. 1.4 Exemptions Accepted lComments Lawful P There is no specific acknowledgement of federal or state approved lighting,like FAA. Other Exemptions Historic and sports lighting have their own set of requirements.Thank you. 1.5 Prohibitions Accepted Comments Safety Interference 38.570.040(G)(1),(7),(8),and(10)list prohibitions and does encompass vehicular safety. 2.0 Ughting Requirements Accepted Comments Legal P 38.570.020(C)does not specifically call for lighting to meet lawful code 38.570.040 provides some,but not all outdoor lighting levels found in IES standards.And, unfortunately,the items listed are from 1998,some of which are excessive by 2022 standards(e.g., Light Level building entrances at 50 lux instead of RP43's 1 to 30lux range).Additional street lighting measurement methods have been drafter by Clanton&Associates,are accurate,and listed in the design and construction guide appendix. Zero uptight luminaires are mandated,thank you.However,newer restrictions above 80"are not Optic control>1,0001umens identified specific enough.38.570.040(G)(4)comes really close,and could meet the DarkSky requirement by calling for luminaires with G2 rating of 5%emission above 801. Habitat Trespass We did not see mention of light trespass onto wilderness,habitat,or sensitive land/water. Residential trespass 38.570.040(G)(5)lists values higher than DarkSky's recommendation by a factor of 300%. Curfew 38.570.040(G)(3)lists curfew.Thankyou. Controls I P lWe did not see mention of controlled dimming or motion sensing. Maximum CCT We did not see a CCT limit of 3000K.Very important. 2.4 Sports Lighting 038.570.050(C) Comments 85%Containment 38.570.050(B)-aiming angle and(C)-trespass help this situation,but do not specifically contain light to field/bleacher area.The property could be very large. Skyward Light Limit38.570.050(B)talks about aiming for max candela angle but does not specifically limit emission above 801 Appropriate CCT We did not see mention of limiting CCT for anylighting,including sports lighting. Intensity Limit is an equivalent. 3.0 Administration I Accepted lComments Page 2 of 3 The permit process(chapter 1.4.1)and the submittal process(chapter 3.2.6)are documented in the Application Process N Bozeman Design and Construction Standards.These processes meet DarkSky expectations for streetlights,but itwould also be expected for any lights within the public right-of-way,institutional .ise,commercial developments,and sports fields. Review Y Conducted by the city's Engineering Division,the review process is clearly defined In chapter2.2 of tl"e Design and Construction standards. Enforcement Y 138.570.080 meets the DarkSkyrequirementwith post Installation inspections Penalty r Y 138.570.090 meets the DarkSkyrequirementwith30 day remedial action 4.0Definitlons I Accepted 1cornments Overview I P jWe did not see any definitions.If needed,DarkSky recommends listing definitions. Page 3 of 3 To: Bozeman Community Development Board and City Commission Re: Update of Development Code - Dark Sky Preservation Date: September 3, 2025 From: Bonnie Rice, Dr. Joseph Shaw— Director, Optical Technology Center (OpTeC), Montana State University Sent electronically via: comments(aD-bozeman.net "Appreciation for dark skies is entering the social consciousness. Light pollution is one of the only types of pollution that's completely and immediately reversible. I don't think we'll realize the value of seeing the Milky Way, until it's gone." — Bettymaya Foott, Dark Sky International Dear Members of the Community Development Board and City Commission: We write to you today as community members concerned about light pollution and preservation of the night sky in Bozeman, the Gallatin Valley, and beyond. The City's ongoing public process to update its Development Code presents an excellent opportunity to help address goals and directives contained in Bozeman's Outdoor Lighting Code, the Gallatin Valley Sensitive Lands Plan, and the Gallatin Valley Growth Policy to preserve the night sky and to prevent and reduce pollution from artificial light. Preservation of the night sky is a community value and was raised by community residents in the public engagement meetings regarding the update of Bozeman's development code in the spring of 2025. As has been well documented, Bozeman and the Gallatin Valley are experiencing unprecedented population growth with no end in sight, with associated housing and infrastructure development and services attempting to meet the demands of our growing population. All of this raises profound implications for preservation of the night sky and the health and well-being of people and ecosystems in the Gallatin Valley and beyond. We are in danger of losing our night sky and all of the benefits that a dark sky provides. Preservation of the night sky is also important to the economy of Bozeman and the Gallatin Valley. As explained further below, the Montana State University (MSU) Optical Technology Center was established in the early 1990s to promote optics/photonics education and research for economic development, and there are now more than 40 photonics companies here. A key competitive advantage for MSU photonics research is the natural Montana environment, including our dark sky. We urge you — as members of the Community Development Board and City Commission —to ensure that preservation of dark skies is an integral component in the current UDC process and other ongoing community processes and policies related to growth and development in Bozeman and the broader Gallatin Valley. I. Introduction Recognizing the need to protect the night sky and provide guidance and directives regarding lighting, Bozeman developed an outdoor lighting code (Division 38.570) in the early 2000s. One of the code's stated purposes is to preserve the night sky: "[P]rotect neighbors and the night sky from nuisance glare and stray light from poorly aimed, placed, applied, maintained or shielded light sources;" (38.570.010 "Purpose") There are several excellent elements in the code to help prevent or reduce artificial light pollution. However, there are also large areas that are not covered by the code in regard to outdoor lighting, and there have been many innovations in the lighting industry since the early 2000s when Bozeman's code was developed. Additionally, an ever-growing body of scientific research continues to document the benefits of dark skies and the negative impacts of light pollution. Bozeman should take concrete steps to update its lighting code to incorporate these industry innovations and scientific research, and work with the City of Belgrade and Gallatin County policy makers to develop and enact policies that will preserve the night sky in the broader Gallatin Valley. Dark Sky International (DarkSky, formerly the International Dark Sky Association) is the primary organization working to preserve dark skies and to reduce artificial light pollution around the world. A growing number of municipalities, states and countries are partnering with DarkSky to preserve their night skies. To that end, we have contracted with DarkSky to evaluate a) Bozeman's Municipal Code in regard to outdoor lighting (Division 38.570), and b) Bozeman's Design and Construction Standards Standard Specifications for Lighting Materials and Installation (Revision March 2020) specifically regarding streetlights and lighting adjacent to roadways, in order to assist City and County staff, elected officials, and others in identifying where the existing code and standards are already strong and where they could benefit from improvements to achieve the City's stated goal of preserving the night sky. That analysis is attached. While there are strong elements to the existing code/standards, there are numerous areas where Bozeman's outdoor lighting code needs to be updated and improved in order to truly protect the night sky and to prevent artificial light pollution and light trespass. Key areas where Bozeman's code falls short are highlighted below in this document. II. What is Light Pollution? DarkSky defines light pollution as "any adverse or unintended effect of the use of artificial light at night, including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste." Many of us think about light pollution as the inability to see the stars, especially in cities, but light pollution includes other sources such as glare on roadways at night, or light from a neighbor's residence that shines into our bedroom, or light that shines into wildlife habitat. The good news is that— unlike many other types of environmental pollution — light pollution can be solved relatively easily, many times with a flick of a switch. DarkSky has five principles for lighting that can prevent or greatly reduce light pollution: Make sure it is useful and necessary; Target the light; Use the lowest level required; Use controls such as timers or motion detectors so light is available only when needed; and Utilize warm-colored light. III. Importance and Benefits of Preservation of the Night Sky According to DarkSky, artificial light pollution is increasing globally by an astounding 10% per year. Not being able to experience the awe and wonder that come with gazing up at a star-filled sky, and pondering our place in the universe, would be a deep loss. Today, approximately 80% of people in the U.S. are no longer able to see the Milky Way due to light pollution. Preservation of dark skies is critical for many other reasons as well. For billions of years, all life has relied on Earth's predictable rhythm of day and night. It's encoded in the DNA of all plants and animals. Humans have radically disrupted this cycle by lighting up the night. Research shows that artificial light at night has negative and even deadly effects on many species. Light pollution disrupts wildlife, impacts human health, wastes money and energy, contributes to climate change, and blocks out our view of the universe. Plants and animals depend on Earth's daily cycle of light and dark to govern life-sustaining behaviors such as reproduction, nourishment, sleep, and protection from predators. Two-thirds of invertebrates such as insects are either wholly or partially nocturnal, relying on darkness to fulfil their roles including pollination. Light pollution interferes with reproduction, increases predation, and disorients migration for species such as monarch butterflies and others that navigate using the stars and Moon. Birds also rely on the stars and Moon for navigation. Lighting up the sky can cause them to migrate too early or too late, or to wander off course, or to collide with buildings—often leading to exhaustion and death. Humans are profoundly impacted as well. Many studies have shown that exposure to artificial light at night negatively affects human health, including increased risk for obesity, depression, sleep disorders, diabetes, breast cancer and more. Like most life on Earth, humans adhere to a circadian rhythm —our biological clock— a sleep-wake pattern that is governed by the natural day/night cycle. Artificial light at night can disrupt that cycle. Nighttime exposure to artificial light also suppresses melatonin production, which we need to stay healthy. IV. Relevance of Dark Sky Preservation to Bozeman/Gallatin Valley Municipal Code, Plans and Policies a. Bozeman's Outdoor Lighting Code (Municipal Code, Division 38.570) Three of the five goals enumerated in the "Purpose" section (Section 38.570.010) of Division 38.570 in regard to outdoor lighting address preservation of the night sky, nuisance from artificial light, and energy conservation: "[P]rotect drivers, bicyclists and pedestrians from the glare of non-vehicular light sources that shine into their eyes and thereby impair safe travel; Protect neighbors and the night sky from nuisance glare and stray light from poorly aimed, placed, applied, maintained or shielded light sources;" and "[P]revent excessive lighting and conserve energy." Section 38.570.020 ("General") states that "Unless otherwise approved through a planned unit development, this section applies to all lighting for subdivisions, land uses, developments and buildings. In addition, any site modification that requires a certificate of appropriateness, site plan review or reuse application will necessitate compliance for all existing and proposed lighting on the site." b. Gallatin Valley Sensitive Lands Plan As noted in the Gallatin Valley Sensitive Lands Plan Section 2.2. Dark Sky Lighting, "[D]ark sky lighting is increasingly important as growth continues in the valley. Lighting is an important safety feature in neighborhoods and can extend the use of amenities after dark, especially during the summer. However, artificial lighting can affect animals that sleep at night and can be disorienting for nocturnal animals and insects, including pollinators like moths. Artificial lighting can also disrupt reproduction and mating cycles; benefit predators to the detriment of their prey; alter migration routes; cause foraging avoidance for many species; and result in building collisions, in the case of birds. In some cases, artificial lighting has also caused mammals to avoid typical habitat areas all together. Light fixtures should be selectively placed, hooded/shielded (i.e., not emitting direct or indirect light above an imaginary horizontal plane passing through the light source), and directed downward and away from nearby natural areas. In areas with evening activities that require lighting, such as sports fields, rodeos, and event centers, the location and timing of activities should be considered and lights should be turned off when not needed. Light fixtures with motion or heat sensors may be used to keep lights off when lighting is not required. In addition to the location and type of fixture, it is important to consider the physical properties of the light that is produced. The International Dark Sky Association (IDA) recommends using lighting that has a color temperature of no more than 3000 Kelvin. The IDA has developed the Fixture Seal of Approval program to provide objective, third-party certification for lighting that minimizes glare, reduces light trespass, and doesn't pollute the night sky. Gallatin County and the City of Bozeman's standards for lighting in some areas do meet these recommendations." c. Gallatin County Growth Plan Recognizing the importance of dark sky preservation to public health and safety, the natural environment, wildlife and wildlife habitat, Gallatin County's Growth Policy calls for development of a policy to: "[D]evelop and implement a dark sky policy to address light pollution and preserve our night skies." (p.7.12) and: ,,[E]ncourage development to conserve and emphasize scenic resources and views including preservation of ridge tops and hillsides and protection of dark skies." (p. 7.17) In regard to future land use guidelines, and design standards, the Growth Policy includes direction to: "[M]itigate the impact of uses on neighboring properties or at the growth area boundaries, such as dark skies standards, landscape buffers, and other measures to reduce noise and light pollution." (p. 8.16) And in regard to the Policy's section on the Natural Environment: "[T]he following items may be considered when evaluating a proposed subdivision's potentially significant adverse impacts on the natural environment: [...L]ight pollution on adjacent property." As recognized in these policies, preservation of the night sky and prevention of artificial light pollution are critical to human and wildlife health, and to the economy, ecology, and intrinsic character of Bozeman, the state of Montana, and the Greater Yellowstone Ecosystem. V. DarkSky Analysis of Bozeman's Outdoor Lighting Code (Division 38.570) and Design and Construction Standards (Revision March 2020) Overall Assessment "[D]arkSky commends Bozeman on having a lighting ordinance, there were many good characteristics within. The purpose section was very strong and met DarkSky expectations. The sports lighting section was also strong, stronger than most, but fell just shy of meeting the exact DarkSky requirements. Other sections met about 50% of DarkSky expectations. Missing mandatory elements include applicability to residential and planned unit developments along with, at a minimum, a compliance trigger authority for hazards to public safety. Also missing are elements related to the five principles for responsible outdoor lighting, including some over-lighting protections based on lighting standards that are more current than 1998, and very high-angle glare reduction above 80°." DarkSky analysis of specific components of Bozeman's outdoor lighting code, and where it needs to be strengthened to meet today's lighting standards and preservation of the night sky, follow below. The largest issues include: - Street lighting and adjacent public right-of-way are addressed in the Design and Construction Standards. However, properties not adjacent to roadway and residential property are not listed within the scope for new and replacement lighting sources, and planned unit developments (PUDs) appear to be exempt from this ordinance but should be included. Residential lighting is one of the biggest sources of light pollution. - 38.570.040 provides some, but not all outdoor lighting levels found in Illumination Engineering Society (IES) standards. And, unfortunately, the items listed are from 1998, some of which are excessive by 2022 standards (e.g., building entrances at 50 lux instead of RP43's 1 to 30 lux range). - Bozeman's code does not have a limitation of 3000 Kelvin Correlated Color Temperature (CCT), a measurement used in lighting to describe the color appearance of light emitted by a source and indicates whether the light appears warm (yellowish) or cool (bluish). Blue light contributes more to light pollution and increased glare than warm light, and has been shown to affect human health and wildlife behavior. A limitation of 3000K is very important to limiting light pollution. (Bozeman's Design and Construction Standards do have a 3000K maximum for street lighting and lighting adjacent to roadways, but this maximum is not part of Bozeman's Outdoor Lighting Code for all other development/infrastructure.) - Bozeman's code requires no light output emitted above 90 degrees at any lateral angle around the luminaire fixture; current recommendations reduce that to 80%. Purpose (Section 38.570.010) a. Ecosystem Welfare: Bozeman's code should be strengthened by incorporating language regarding the hazards of artificial light at night on wildlife and other nocturnal ecosystems, including habitat and crops. b. Lighting Zone Responsibility: Some IES standards make illuminance recommendations by lighting zone (e.g., RP43). The Bozeman ordinance does not mention a community plan for lighting zones. DarkSky recommends municipalities plan for their nighttime character and a hierarchy of transitions by assigning a lighting zone overlay or table Lighting Requirements (Sections 38.570.040 and 38.570.060) a) 38.570.040 provides some, but not all outdoor lighting levels found in IES standards. Also, the items listed are from 1998, some of which are excessive by 2022 standards (e.g., building entrances at 50 lux instead of RP43's 1 to 30 lux range). Additional street lighting measurement methods have been drafted by Clanton & Associates, are accurate, and listed in the Design and Construction Standards appendix. b) Fully-shielded lights are mandated, which is very important. However, newer restrictions above 800 are not identified specifically enough. 38.570.040(G)(4) comes really close, and could meet the DarkSky requirement by calling for luminaires with G2 rating of 5% emission above 80°. c) The maximum CCT is very important and DarkSky was not able to find a maximum set in the Bozeman code. The maximum should be 3000 CCT. d) There is no mention of light trespass onto wilderness, wildlife habitat, or sensitive land/water. As noted above, the Gallatin Valley Sensitive Lands Plan notes the importance of preservation of the night sky and negative impacts of light pollution on wildlife and natural ecosystems. e) In regard to residential light pollution trespass, 38.570.040(G)(5) lists values with no unit. Assuming footcandles, which matches the rest of the document, these numbers exceed DarkSky's recommendations by 300%. Applicability a) For new and replacement sources, street lighting and adjacent public ROW are addressed in the design and construction standards. However, properties not adjacent to roadway and residential property are not listed within the scope, and PUD's appear to be exempt from this ordinance but should be included. b) 38.570.100 is one trigger that forces compliance and 38.570.110 demonstrates the difference between non-conforming and conforming. However, we do not see a date for lighting to comply. Sports Lighting (Section 38.570.050) a. Containment: 38.570.050(B)-aiming angle and (C)-trespass help this situation, but do not specifically contain light to field/bleacher area. The property could be very large. b. Skyward Light Limit: 38.570.050(B) talks about aiming for max candela angle but does not specifically limit emission above 80°. c. Appropriate CCT: We did not see mention of limiting CCT for any lighting, including sports lighting. (as noted above, the Design and Construction Standards do specify a limit of 3000K for roadways and projects directly adjacent to roadways) Application Process a) The permit process (chapter 1.4.1) and the submittal process (chapter 3.2.6) are documented in the Bozeman Design and Construction Standards. These processes meet DarkSky expectations for streetlights, but DarkSky would also expect this process for any lights within the public right-of-way, institutional use, commercial developments, and sports fields. VI. Economic Benefits of Dark Sky Preservation to Bozeman, the Gallatin Valley, and Montana a. Light Pollution Wastes Money and Resources One of the most persuasive arguments for improved lighting management is the economic savings aspect of reduced energy usage. Research shows that globally, outdoor lighting makes up approximately eight percent of global energy use with about 60 percent of that wasted as unneeded, overlit or poorly aimed lighting. In the United States, DarkSky estimates that 30 percent of all outdoor lighting is wasted, mostly due to unshielded or excessively bright lights. This adds up to $3.3 billion dollars wasted annually. Installing quality outdoor lighting could cut energy use by 60 to 70 percent, saving billions of dollars. Additionally, light pollution contributes to climate change. Artificial lighting at night and the energy required to produce it has a large carbon footprint. According to DarkSky, in the U.S. alone, unnecessary lighting produces 21 million tons of carbon dioxide each year. 875 million trees would need to be planted annually to offset this waste. b. The Importance of Dark Skies to Bozeman's Photonics Industry and Research Economy Montana State University (MSU) serves as an economic engine for the community, state, and nation through both student training and technology development. The MSU Optical Technology Center was established in the early 1990s to promote optics/photonics education and research for economic development. The goal was to motivate and encourage graduate students to create high-tech photonics companies so that they could stay in Montana instead of leaving after graduation. This has been extraordinarily successful, and the Gallatin Valley is now home to more than 40 photonics companies —one of the highest concentrations of laser and optics companies in the nation. These companies manufacture materials, components, and systems that are used in applications from precision agriculture to self-driving transportation to space exploration. This entire segment of the Montana economy depends fundamentally on MSU research for advanced student training and technology development. A key competitive advantage for MSU photonics research is the natural Montana environment, including our dark sky. MSU researchers are currently developing numerous photonic sensor technologies that require testing in nighttime skies that have minimal light pollution. This provides a strong economic incentive to encourage dark-sky-certified lighting throughout our community. c. The Importance of Dark Skies to Montana's Burgeoning Astrotourism Industry "Crucially, from an economic standpoint, the single most important thing about dark-sky tourism is that it necessitates one or more overnight stays." — Mitchell and Gallaway (2019) Montana is fortunate to have many areas where it is still possible to see the Milky Way and a dark sky. However, we must act now in order to ensure that future generations have the same opportunities, and to protect the remaining wild ecosystems and world-class wildlife of Montana from the increasing negative effects of artificial light pollution. A growing number of cities, states and countries are realizing the economic benefits of astronomy tourism, or"astrotourism." Utah is a leader in this arena, with fourteen International Dark Sky Parks, two International Dark Sky communities and multiple parks and communities currently working through the accreditation process with DarkSky. Here in Montana, we have two designated parks — Glacier National Park and Medicine Rocks State Park. But with over 30 million acres of protected federal and state land and the third- lowest population density in the U.S., there are many more opportunities to explore the night sky in Montana. Following certification in 2020 of Medicine Rocks State Park as an International Dark Sky Sanctuary— the highest certification possible by DarkSky— a collaborative "Trail to the Stars" astrotourism initiative was launched by three travel regions — Southeast Montana, Missouri River Country and Central Montana, with 45 designated star-gazing sites. The initiative won a national Excellence in Tourism Collaboration Award in 2023. In April of this year, the University of Montana's Institute for Tourism and Recreation Research (ITRR released a study' with the goal of understanding stargazing tourists and the economic potential of"dark sky" tourism in Montana, including the newly-designated Trail to the Stars. They found that: lhttps:Hscholarworks.umt.edu/cgi/viewcontent.cgi?article=1470&context=itrr_pubs&_g1=1*1 xr9era*_gd_a u*NjczNDU4OTk5LjE3NTQzNDA4NDY. "...[s]targazing almost always necessitates an overnight stay, as it's rare for people to drive long distances to remote locations and then return home in the same evening. This turns a day visitor into an overnight tourist, with the average stay five nights for those who come for this niche experience. Those five nights facilitate money spent in the local economies that support the trail." According to the National Park Service, average spending per-party per-day for a local day trip is $40.63. This rises to over$430 for parties staying overnight in an NPS lodge and a little over $290 for those staying in motels outside national parks.2 Glacier National Park and its sister park Waterton Lakes National Park in Canada became International Dark Sky Parks in 2021. A quick internet search reveals many sites targeting dark sky tourism in Glacier. Closer to Bozeman, the opportunities for night sky viewing in Yellowstone National Park are increasing, with guiding companies such as Yellowstone Safari Company offering four-hour star-gazing tours starting at $650.3 Importantly, the ITRR study found that: "[F]inally, the survey explored respondents' expectations and assessments of Montana's night sky. Over two-thirds (70%) expected to see a "starry night" sky, and 69% agreed that Montana's night sky is pristine. Almost two-thirds (65%) valued viewing the night sky, and 63% believed Montana has a good reputation for it. However, only 44% felt that observing the night sky was an important part of their Montana experience, and just 23% visited Montana specifically for this reason. These Institute for Tourism and Recreation Research results suggest a mismatch between Montana's reputation for night sky viewing and the primary reasons for visiting the state." This suggests that much more can be done in regard to public education and outreach on Montana as a prime star-gazing destination experience. Additionally, as noted by the ITRR in a press release accompanying its study results, "With Montana recently named 2025's ultimate stargazing destination by National Geographic, the state has all the reason to put effort behind causes that help safeguard its "star-studded" reputation." VII. Preserving the Night Sky Does Not Mean Sacrificing Public Safety Although there is a strong tendency to equate more light with safety and security, lighting up the nighttime environment does not necessarily increase safety and security. "Bright" lighting does not necessarily mean "safer" lighting. Bright glaring lights create sharp contrast between light and darkness, making the area outside of the illuminated area hard to see. This contrast can also create deep shadows that provide concealment. Effective lighting that helps people be safe 2 Mitchell and Gallaway (2016) Estimating the Potential Economic Value of the Night Skies Above the Colorado Plateau. Missouri State University. Retrieved from: https://www.cityofpage.org/images/council_mtg_pdfs/2016/July/July27wsminpt.2.pdf 3 https://yellowstonesafari.com/yellowstone-national-park-stargazing/ —not just feel safe—is a win-win situation for everyone. The appropriate use of"dark-sky friendly" lighting will actually improve overall safety. Lower lighting levels, warmer light temperatures, and better coverage are safer lighting methods. More information can be found at: darksky.org/resources/what-is-light-pollution/effects/safety At home: Poor lighting can create a false sense of security. Poorly designed outdoor lighting can backfire on safety. Bright and misdirected lights create shadows for criminals to hide, and some crimes, like vandalism, thrive in well-lit areas. Floodlights, for example, may highlight potential targets. In town: Light for light's sake doesn't equal increased safety. While towns, cities, and businesses aim to enhance safety with lighting, poorly aimed and inadequately shielded lights can attract criminals. A Chicago study identified a correlation between increased crime and overly bright alleyways. On the road: Bad lighting creates unsafe driving conditions. Inadequate roadway lighting causes glare, contributing to accidents, especially affecting older individuals. A 2015 Journal of Epidemiology and Community Health study revealed that streetlights don't effectively prevent accidents or crime but they do cost a lot of money. Poorly designed outdoor lighting can backfire on safety. Bright and misdirected lights create shadows for criminals to hide, and some crimes, like vandalism, thrive in well-lit areas. Floodlights, for example, may highlight potential targets. Vill. Conclusion Fortunately, light pollution is one of the forms of environmental pollution that can be reversed virtually immediately, by simply turning off the light where it is not needed, and/or by installing "dark-sky" friendly lighting and utilizing DarkSky's five principles of responsible lighting. More and more communities, states and parks are realizing the substantial benefits of preserving the night sky and are working to prevent light pollution. Bozeman can join this trend and be a leader in Montana in preserving the benefits, wonder and awe of a dark, star-filled sky. We urge you to take action to protect the night sky for future generations and for all species who are an integral part of the wild and irreplaceable Greater Yellowstone ecosystem. Sincerely, Bonnie Rice Dr. Joseph Shaw Director, Optical Technology Center (OpTeC), Montana State University 0 DarkSky Recognized Municipal Ordinance Review DarkSky INTERNATIONAL ID Number: DS-MOR-007b Contact Name: Bonnie Rice Municipality Name: Bozeman Contact email: b0rice16C@gmail.com State: MT Contact Phone: 406-640-2857 Review Document: Bozeman-Outdoor-Lighting-Code Review Date: 7/31/2025 Overview: The DarkSky Recognized Code program is established by DarkSky International(DarkSky)to recognize government entities or private developments that adopt ordinances,bylaws,or municipal codes that meet or exceed DarkSky-approved requirements and provisions for reducing light pollution. Per your application request,submitted through the DarkSky website,DarkSky has conducted a review to compare your ordinance/bylaw/code against the DarkSky Municipal Code template. This review,shown in detail on page two of this report,will show adherence and gaps with the submitted ordinance/bylaw/code as compared to the DarkSky Municipal Ordinance template. This review will give the applicant an understanding of how close the ordinance/bylaw/code is to being DarkSky Recognized. Review Instructions: Page two of this review will identify the requirements of the DarkSky Municipal Code template. The document submitted by the applicant will be reviewed for adherence and/or gaps compared to the template. The results will be indicated for each requirement with a(Green Y),meaning yes it meets DarkSky criteria,an(Orange N),meaning no it does not meet DarkSky criteria,or a(Yellow P), meaning the provision would be preferred but is not mandatory. The absence of any orange N would indicate an ability to achieve DarkSky Recognized status. See legend below: =Meets DarkSky requirements N =Does NOT meet DarkSky requirements P =DarkSkywould prefer you meet this requirement but it's not mandatory Review Summary: Previously evaluated in March 2025 as MOR-003b,Bozemen has now submitted their 10/24 COB Design and Construction Standards (COB-DCS)as a supplemental document capable of fulfilling previously missing ordinance requirements. Further review by DarkSky and a new review of the COB-DCS did help the Bozeman outdoor lighting ordinance comply with three previously failed requirements. However,COB-DCS is very streetlighting centric so the opportunity to add additional scope,like non- adjacent institutional or commercial developments with pedestrian right-of-way,would be required to meet DarkSky's application requirement. DarkSky continues to commend Bozeman on having a lighting ordinance,there are many good characteristics within. The purpose section is very strong and meets DarkSky expectations. The sports lighting section is also strong,stronger than most,but fell just shy of meeting the exact DarkSky requirements. Other sections meet about 50%of DarkSky expectations. Missing mandatory elements include applicability to residential and planned unit developments along with,at a minimum,a compliance trigger authority for hazards to public safety. Also missing are elements related to the five principles for responsible outdoor lighting,including some over-lighting protections based on lighting standards that are more current than 1998,and very high-angle glare reduction above 800. While the Bozeman ordinance is average for its use of metrics and effective requirements;as written,this version would fall short of achieving DarkSky Recognized status. We encourage Bozeman to consider a stakeholder discussion in an effort to make some additions/updates to resolve the missing elements and achieve DarkSky recognition. Page 1 of 3 ® DarkSky Recognized Municipal Ordinance Review Bozeman DS-MOR-007b 1.2 Purpose Accepted Comments Visual Safety Y 38.570.010(B)and(F)cite safety and glare concerns Energy Y 38.570.010€cites conservation of energy from excessive lighting Sky Quality Y J 38.570.010(C)protects neighbors and the night sky from inappropriate light Ecosystem Welfare P DarkSkywould love to see a recital regarding the hazards of artificial light at night on wildlife and other nocturnal ecosystems,including habitat and crops Some IES standards make illuminance recommendations by lighting zone(e.g.,RP43). The Bozeman Lighting Zone Responsibility P ordinance does not mention a community plan for lighting zones. DarkSky recommends municipalities plan for their nighttime character and a hierarchy of transitions by assigning alighting zone overlay or table. 1.3 Applicability Accepted Comments [and et lighting and adjacent public ROW are addressed in the design and construction standards. New/Replacement Sources Never,properties not adjacent to roadway and residential property are not listed within the scope, PUD's are exempt from this ordinance and should not be. 70.100 is one trigger that forces compliance and 38.570.110 demonstrates the difference Triggers and Amortization een non-conforming and conforming. It would be nice to see re-zoning or the determination of a lic hazard be included. 1.4 Exemptions Accepted Comments Lawful IP iThere is no specific acknowledgement of federal or state approved lighting,like FAA. Other Exemptions Historic and sports lighting have their own set of requirements. Thank you. 1.5 Prohibitions I Accepted Icomments Safety Interference 38.570.040(G)(1),(7),(8),and(10)list prohibitions and does encompass vehicular safety. 2.0 Lighting Requirements Accepted Comments Legal P 38.570.020(C)does not specifically call for lighting to meet lawful code 38.570.040 provides some,but not all outdoor lighting levels found in IES standards. And, unfortunately,the items listed are from 1998,some of which are excessive by 2022 standards(e.g., Light Level building entrances at 50 lux instead of RP43's 1 to 30Lux range). Additional street lighting measurement methods have been drafter by Clanton&Associates,are accurate,and listed in the design and construction guide appendix. Zero uptight luminaires are mandated,thankyou. However,newer restrictions above 800 are not Optic control>1,000 lumens N identified specific enough.38.570.040(G)(4)comes really close,and could meet the DarkSky requirement by callingfor luminaires with G2 rating of 5%emission above 801. Habitat Trespass N JWe did not see mention of light trespass onto wilderness,habitat,or sensitive land/water. Residential trespass Y 38.570.040(G)(5)lists values higher than DarkSky's recommendation by a factor of 300%. Curfew 38.570.040(G)(3)lists curfew. Thankyou. Controls IP JWe did not see mention of controlled dimming or motion sensing. Maximum CCT E N =we did not see a CCT limit of 3000K. Very important. 2.4 Sports Lighting Accepted Comments 85%Containment Ntabove 570.050(B)-aiming angle and(C)-trespass help this situation,but do not specifically contain light eld/bleacher area. The property could be very large. Skyward Light Limit 570.050(B)talks about aiming for max candela angle but does not specifically limit emission 80° Appropriate CCT did not see mention of limiting CCT for any lighting,including sports lighting. Intensity Limit I Y 38.570.050(C)is an equivalent. 3.0Administration Accepted Comments Page 2of3 [38.570.080 permit process(chapter 1.4.1)and the submittal process(chapter 3.2.6)are documented in the Application Process man Design and Construction Standards. These processes meet DarkSky expectations for etlights,but it would also be expected for any lights within the public right-of-way,institutional commercial developments,and sports fields. Review Y ducted bythe city's Engineering Division,the review process is clearly defined in chapter 2.2 of Design and Construction standards. Enforcement Y meetsthe DarkSky requirementwith post installation inspections Penalty 70.090 meets the DarkSky requirement with 30 day remedial action 4.0 Definitions I Accepted Icomments Overview I P jvve did not see any definitions. If needed,DarkSky recommends listing definitions. Page 3 of 3