October 29, 2024
Palo Alto Planning and Transportation Commission
Re: Sierra Club Loma Prieta Chapter and Santa Clara Valley Bird Alliance Comments on the Draft Dark Sky Ordinance
Dear Chair Chang and Commissioners,
The Santa Clara Valley Bird Alliance and the Sierra Club Loma Prieta Chapter are organizations united by our shared commitment to the protection of the environment, nature, and open space. We have been advocating for a reduction of light pollution in the region, and have engaged with the City of Palo Alto Council and the Planning and Transportation Commission in promoting human and environmental health through reducing and preventing the proliferation of artificial light at night.
We would like to extend our sincere gratitude for your decision to require that all light sources be fully shielded and maintain a correlated color temperature of 2700K. This is a significant commitment to minimizing light pollution and protecting the natural night environment, and it will greatly benefit both our community and the surrounding ecosystems.
We have two major recommendations to improve the draft ordinance, which we hope you will consider.
-
Reinstate applicability to include new luminaires (light fixtures) and replacement lighting
Staff removed, “(3) Installation of new outdoor lighting, replacement of existing outdoor lighting fixtures, or changing the lighting type or system.” We recommend reinstating this provision. For buildings that cannot comply with this standard, we recommend adding a hardship exemption (see below).
The hardship exemption could read as follows: For any structures that are unable to meet the standards of this chapter due to financial hardship or technical infeasibility, they may apply to the Planning Director for an exemption, provided the applicant still complies with the standards of this Chapter to the greatest extent practicable.
Why this is important: Without new or replacement lighting fixtures being subject to the ordinance, Palo Alto’s light pollution will not reduce over time, therefore failing to achieve the expressed purpose of the ordinance. This creates a loophole which allows new development to replace dark sky-compliant luminaires with non-compliant luminaires after initial construction. Without any requirements for new and replacement lighting, this ordinance effectively has no teeth or ability to affect the lighting situation in Palo Alto over time. This provision, which was present in earlier drafts of Palo Alto’s Dark Sky ordinance, should be reinstated.
There was some concern expressed by PTC Commissioners that certain older multi-family buildings may not be able to easily modify their lighting due to these structures having older wiring systems. We believe that a hardship exemption (see above) can be written for edge cases such as this without diluting the requirements for buildings that can comply with dark sky standards.
Examples of Applicability from other cities’ Dark Sky Ordinances that include new and replacement lighting include the following.
- Cupertino: “New or replacement exterior lighting”
- Brisbane: “All outdoor light fixtures installed or replaced after the effective date of the ordinance from which this chapter is derived shall comply with this chapter.”
- Malibu: “All outdoor light fixtures installed after the effective date of the ordinance codified in this chapter shall comply with this chapter.”
- San Louis Obispo: “no modification or replacement shall be made to a nonconforming fixture unless the fixture thereafter conforms to the provisions of this section.”
-
Prohibit light trespass entirely rather than establishing a threshold (which may be difficult to enforce and allow nuisance lighting)
The standard would read as follows: "No direct glare from a light source shall be visible from any other property or public right of way".
Palo Alto’s Current Draft: “No lighting shall trespass more than 0.5-foot candle as measured at the abutting property line.”
Why this is important: 0.5 foot candle (Palo Alto’s current draft limit) is still a lot of light. Light sources at or even below 0.5 foot candle can often be the source of nuisance complaints. Palo Alto could instead take the very simple approach that Brisbane took by prohibiting light trespass entirely. This makes light trespass requirements easier to enforce for the City, and easier for residents to understand when they install their own lighting systems. Should Palo Alto decide to allow some light trespass, we include language from Cupertino, which uses a more stringent threshold.
Examples of more stringent light trespass language from other cities’ Dark Sky Ordinances
- Brisbane: “Light trespass is prohibited”
- Cupertino: “No exterior light, combination of exterior lights, or activity shall cast light exceeding zero point one (0.1) foot-candle onto an adjacent or nearby property, with the illumination level measured at the property line between the lot on which the light is located and the adjacent lot, at the point nearest to the light source, except if two adjacent properties are non-residential, or function as a shopping center, and agree to coordinate lighting.”
In addition, we have listed a few minor clarifications and suggestions.
-
Change the duration of motion sensor lighting to deactivate after 5 minutes of inactivity instead of 10 minutes
5 minutes should be sufficient to allow for any activity, especially considering that motion sensor technology will keep lights on when there is continuous activity on a site.
- The 10-minute duration is currently used in
- (e) Lighting Standards (1) Shielding (iii)
- (f) Special Purpose Lighting (A)
-
Add definitions for the following terms
- “Low intensity lamps”
- Used in (d) Lighting Guidelines (2)
- “Low voltage”
- Used in (e) Lighting Standards (C) (i) and (ii)
- “Short term lighting”
- Used in (h) Exemptions (3)
-
Replace “fixture” with “luminaire” in all places where “fixture” is used
“Light fixture” should be added to the definition of “Luminaire”. These terms are used interchangeably, so clarifying the definition will help avoid confusion between the two terms.
-
Clarify language regarding string lighting
As currently written, the draft could be interpreted as requiring either 2,700 Kelvin or 42 lumens. Our recommendation is to clarify that both the 2,700 Kelvin and 42 lumens requirements apply and that they are not mutually exclusive.
- Current draft: (5) String Lighting (A): “String lighting must not exceed 2,700 Kelvin or 42 lumens, and shall not be blinking or chasing.”
- Recommended language (changes in red): String lighting must not exceed 2,700 Kelvin and no individual lamp that is part of a string lighting installation may exceed a rating of 42 lumens, and shall not be blinking or chasing.
Thank you for your time and consideration,
Dashiell Leeds
Conservation Coordinator
Sierra Club Loma Prieta Chapter
Julianne Wang
Environmental Advocacy Assistant
Santa Clara Valley Bird Alliance