Imminent Demise of the Dusk-to-Dawn Mercury Vapor Yard Light

Many of us have had to put up with less-than-considerate neighbors who use dusk-to-dawn mercury vapor yard lights. The folly of such lighting is explained clearly in our article "The Top 10 Reasons for Not Installing a Dusk-to-Dawn Mercury Vapor Yard Light." This article was written by DFAC president Dan Heim, has run in local newspapers of several occasions, and may be downloaded and distributed freely for educational purposes. Get your copy by clicking on either of the links below:

BadLight.pdf (106k)

Fortunately, the end is in sight. Here is what ARS Title 49, Chapter 7, Article 1 has to say:

49-1104. Use of mercury vapor light fixtures

A. No new mercury vapor outdoor light fixtures shall be installed after the effective date of this section. No replacement equipment other than bulbs for mercury vapor lighting fixtures shall be sold in the state after January 1, 1991 and the use of mercury vapor light fixtures is prohibited after January 1, 2011.

B. The provisions of this section shall not apply to outdoor light systems erected prior to 1950.

Unfortunately, the "grandfather clause" in paragraph B will allow some existing systems to remain operational. Because of this, these cheap and offensive lighting fixtures continue to be sold at home stores throughout the state. The stores have no way of knowing whether the parts they sell are for new or grandfathered fixtures, so these lights are still being added in some places. If this happens near you, there is a remedy. Simply contact zoning enforcement to report a violation. Contact numbers and links are available on our Light Pollution page. But before you take such action, we recommend talking to your neighbor and providing them with a copy of the article cited above. People are generally good about this, and motivated by the false sense of security these lights are advertised to provide. Most are unaware of the issues explained in our article. File a zoning violation only as a last resort.