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http://www.darksky.org

The International Dark-Sky Association was incorporated in 1988 as a tax-exempt non-profit organization, exclusively for educational and scientific purposes. IDA operates under formal bylaws, established at the time of incorporation and revised at the annual meeting on 4 February 1989, and again in September 1990.

IDA's goals are to be effective in stopping the adverse environmental impact on dark skies by building awareness of the problem of light pollution and of the solutions, and to educate everyone about the value and effectiveness of quality nighttime lighting.

Until recently the lighting community has not been involved in crafting municipal legislation and the following are concerns resulting from our absence from the process...

• Ordinances are often influenced by local opinions with little or no technical expertise -- (The result is that the intent of the legislation is often not achieved. A key example of this is using full cutoff fixtures to minimize skyglow. Full cutoff optics provide tighter distribution patterns, can require more fixtures to maintain uniformity and often concentrate more light below the fixture causing the reflection off the pavement to create more skyglow that a non cutoff luminaire.)
• Certain products are being restricted -- (full cut-off requirements will exclude many existing fixture designs)
• Restrictions on light source -- (Mercury Vapor is illegal in Flagstaff, AZ. Incandescent will not meet efficiency standards in some areas. HPS is only source recommended in Palm Desert Code. In some municipalities wattage maximums are imposed.)
• Little thought has been given to cost of complying with the new ordinances -- (ordinances stipulate that existing fixtures need to be brought up to code within specific time frames and seldom address who will pay for the upgrades.

The following are examples of specific municipal Dark-Sky requirements...

Palm Desert Municipal Code

• "The city does not encourage the use of street lighting"
• All street lighting in single-family residential districts shall use 5,800 lumen (70W) HPS lamps in full cut-off luminaires unless otherwise approved "non-residential districts will use 100W HPS in a full-cutoff luminaire"
• "All building-mounted luminaires shall be a maximum of fifteen feet, zero inches"

Moab, Utah

• "All security lighting shall utilize full cutoff fixtures"
• Gas Station Canopies have a maximum of 20 initial lumens per square foot and must be fully shielded cutoff fixtures
• All new lighting for streets or highways shall utilize fully cutoff fixtures and existing must be brought into compliance within 7 years
• 2 lumens per square foot allowed on parking lot surface, 40 lumens per square foot allowed for signs.
• "All spotlights or floodlights shall not be aimed or directed above a 45 degree angle"
• "Maximum Lumen Caps: Residential use 8,000 initial lumens per dwelling unit"
• Outdoor lighting for commercial and industrial uses shall be turned off within 30 minutes of close of business
• "Security lighting for display areas shall not exceed 2 initial lumens per square foot"
• "Prohibited Lighting" includes "up-lighting of 2000 or more initial lumens unless shielded by an eave, building roof..."
• Flood lights or spotlights affixed to building for the purpose of lighting parking lots or sales display lot areas also existing non-cut off lighting must be fully shielded within 2 years

Flagstaff, Arizona

• "Low Pressure Sodium lamps are the preferred illumination source throughout the city; their use is to be encouraged"
• The installation, sale, lease or purchase of any mercury vapor light fixture or lamp for use as outdoor lighting is prohibited

Tucson, Arizona (Pima County)

• 300,000 lumens per acre commercial if lights are shielded (900,000 is industry standard)
• 150,000 residential and 65,000 in rural areas.

(See other municipal ordinances)

An attempt to improve consistency and simplify the adoption of Dark-Sky legislation has resulted in the creation of a Model Lighting Ordinance. A draft review document will be posted on http://www.darksky.org.

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