Achieving Compliance with Nantucket’s Outdoor Lighting Bylaw
| Sponsor: | Nantucket Department of Public Works, Nantucket Energy Office, Nantucket Lights |  |
| Sponsor Liaison: | Paul Berard, Andrew Patnode, Lauren Sinatra, Gail Walker | |
| Student Team: | Jonathan Amirault, Ethan Busa, Arielle Laflamme, Ibrahim Zaka | |
| Abstract: |
Light pollution is a growing problem on Nantucket. The goal of this project was to help the Town of Nantucket achieve compliance with its new Outdoor Lighting Bylaw and lead by example for the rest of the community. We inventoried 868 outdoor lighting fixtures at all 60 town properties and created a database and color-coded GIS map. We found that the Nantucket Public Schools complex, the Landfill, and the Airport were the biggest offenders and recommended ways to reduce light pollution. We conducted an intercept survey that revealed modest public support for a new glass-free decorative streetlight on Main Street that is designed to reduce light pollution and complies with the new bylaw.
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| Link: |
Final Report: Nantucket Outdoor Lighting B24 Report Final Presentation: Final Presentation |
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Executive Summary
Light pollution is a growing problem worldwide, as well as on Nantucket. Excessive and poorly designed lighting is making the stars harder to see and threatening Nantucket’s natural beauty, wildlife, and the quality of life of residents. It is also wasting energy and, in some cases, decreasing visibility and creating unsafe glare.
Nantucket has historically been known as one of the premier locations along the eastern seaboard to observe the night sky. Unfortunately, even on a remote island, light pollution is a growing concern, and the once pristine night sky views are being threatened. Between 2012 and 2020, light pollution on Nantucket increased by 2.4% each year according to satellite data.
A new citizen advocacy group, Nantucket Lights, lobbied for an improved outdoor lighting bylaw that passed at a town meeting in 2023 and went into effect on January 1, 2024. The new law requires all outdoor lights to be compliant by 2029. In general, unless falling within an exception, all outdoor lighting must (1) be fully shielded (meaning no light can be emitted upwards) if the light is brighter than 600 lumens; (2) have a warm color temperature of 2700K or lower; (3) not exceed specified limits on brightness; and (4) be turned off between 11pm and 6am. The town would like to lead by example and bring all town-owned outdoor lighting into compliance as soon as possible.
Goal and Objectives
The goal of this project was to develop recommendations to help the town of Nantucket reduce light pollution from town-owned lighting fixtures, so they comply with the new bylaw (Chapter 102 in the Nantucket Code). The project had four main objectives:
1) Inventory all town-owned outdoor lighting (including streetlights and fixtures on town buildings and parking lots) to identify non-compliant fixtures.
2) Research ways to bring non-compliant fixtures into compliance.
3) Gauge public acceptance of adopting “lens-less” decorative streetlights to satisfy the “BUG” requirement of the new bylaw.
4) Make recommendations to the town about how they can reduce light pollution.
Methodology
We inventoried 868 lights across 60 town properties. For each outdoor town light, we recorded key attributes such as types of light fixture (including model and bulb type, etc.), location (building, pole, etc.), presence of shielding, direction of light, color temperature, lumen output, and which town entity is responsible for the property/fixture.
We conducted online research on lighting companies, suppliers, and other organizations, some of which included wholesale websites such as 1000bulbs, as well as fixtures approved by DarkSky International, to identify potential replacement light bulbs, add-on shielding, and replacement light fixtures. We used sources like DarkSky International to determine how best to reduce light pollution from the different types of outdoor lights in the inventory.
We conducted brief intercept surveys with random members of the public to gauge public opinion regarding a pilot “lens-less” Victorian style fixture that complies with the new bylaw. For this purpose, the DPW installed the pilot fixture on an existing decorative streetlight pole on Main Street adjacent to the fountain. Our goal was to determine if people would accept the pilot fixture as an alternative to the existing fixture on the fountain – which complies with some of the requirements of the new bylaw but not all – if it meant being more dark sky friendly. We supplemented the public survey with interviews with town officials and other stakeholders, including representatives of the Historic District Commission, the Nantucket Conservation Foundation, and the Maria Mitchell Foundation.
Figure A: Existing Fixture on Fountain (left) and Pilot Lens-less Fixture (Right) (Bill Hoenk)
Findings
Public Acceptance of “lens-less” Decorative Streetlights:
We received 56 responses, of which 50% were year-round residents, 13% were seasonal residents, and 38% were tourists. While 73% of respondents aesthetically preferred the fixture on the fountain, 63% would support the installation of the lens-less fixtures on Main Street, knowing that they comply with the new bylaw to reduce light pollution.
Some respondents gave positive feedback on the lens-less fixture, saying that “the light given off by the lens-less (fixture) looks better” or that it “feels warm” and is “very beautiful.” Others had very negative responses, saying things such as it looks ugly or inauthentic, or that it “looks like a vandalized version of the existing lights.”
We also asked respondents to choose two factors that they think the town should prioritize when selecting new decorative streetlights such as aesthetic appeal/historic character, cost, energy efficiency, mitigation of light pollution, and safety/security. Aesthetic appeal/historic character was the most valued factor by all respondents, with 64% of all respondents indicating it as one of their two priorities. Mitigation of light pollution was the second most valued factor, favored by 57% of all respondents. Cost was by far the least valued factor, with only 9% prioritizing it.
Town Light Inventory:
We found approximately 20% of the inventoried town fixtures were non-compliant, while around 10% of them were compliant. We were unable to classify the remaining 70% of light fixtures due to a lack of precise information about key parameters such as fixture types, light bulb types, shielding status, direction of lighting, lumens, color temperature, and location, typically because the fixture was inaccessible and out of view. Based on our inventory and observations, we determined that the Nantucket School Complex, Nantucket Memorial Airport, and the Nantucket Landfill are major priority areas.
School Complex:
The Nantucket School Complex (see Figure B) has over 200 outdoor light fixtures making up around 25% of all inventoried fixtures on the island of Nantucket. Of the total fixtures from the school complex, around 40 are non-compliant fixtures at Nantucket Elementary School, making up 27% of all currently identified non-compliant lighting on the island. Most of those fixtures are Intertek wallpacks with a color temperature between 4000K-5000K. The school complex also contains roughly 60 parking lot lights on high poles which, while still unconfirmed, are likely noncompliant due to a high color temperature.
Approximately 20 fixtures are floodlights with changeable bulbs which, if found to be noncompliant, can simply have their bulbs switched to a compliant alternative. An add-on shield might be available for the floodlight fixtures that are not fully shielded to make them compliant with the shielding requirement. The football field lights, a notable source of light pollution on their own, appears to lack proper shielding and possibly other features needed to make it dark sky and neighbor friendly pursuant to the guidelines of the Illuminating Engineering Society (adopted by the new bylaw for sports lighting on nonresidential properties).
Landfill:
The landfill is a significant source of light pollution, especially being in an otherwise dark area of the island. This would be a very visible fix and help set a good example to the community.
Figure A: View of Landfill from Hummock Pond (Nantucket Lights)
Airport:
Much of the outdoor lighting at the airport is required by the Federal Aviation Administration (FAA) and exempt from the requirements of the new bylaw. However, airport officials would like to cooperate with the town and follow their leadership with the fixtures that are not regulated by the FAA, such as those in the parking lot. We found 69 Colonial style fixtures in their parking lot that appear to be the same high-pressure sodium fixtures that can be found in the historic districts.
Additional Findings:
Of the 76 compliant lights that we inventoried around the island, we found that the majority of them are compliant because they are on motion sensors, while the few others are compliant due to correct color temperature, lumen output, and/or shielding.
Another finding to come out of our inventory was that the Town uses a large variety of fixtures produced by the brand RAB. We found that this company does not make any fixture with a color temperature less than 3000K, so we know that any RAB fixture that we have seen that is not on a motion sensor is not compliant. Many of these fixtures are fully shielded and well-directed, but because the color temperature is too high, they are not compliant.
Recommendations
Recommendation 1: We recommend that the town continues to run a survey to gauge more of the public’s opinion on the pilot lens-less Victorian style streetlight before coming to a decision on how to move forward with updating the streetlights on Main Street.
Recommendation 2: We recommend that the town conduct another survey to gauge public acceptance of the installation of lens-less Colonial style fixtures by installing a pilot fixture in the historic district and posting a QR code to the pole linking to an online survey.
Recommendation 3: We recommend the DPW complete the missing fields in the outdoor lighting inventory, continue to update the inventory as changes are made and use the inventory as a tool to manage the ongoing maintenance of and upgrades to outdoor lighting on town buildings and properties.
Recommendation 4: We recommend that the town prioritize achieving compliance at the school, airport, and landfill facility based on our observations, conversations with our sponsors, and interviews with organizations such as the Maria Mitchell Association, the Nantucket Conservation Foundation, and the Linda Loring Nature Foundation.
We hope that the Town keeps our recommendations in mind when deciding how to move forward with bringing their lights into compliance, and that our project helps them to lead by example for the rest of the community and spread awareness on the importance of dark skies.