Among the board-approved action items on Nov. 21 was the Zoning Ordinance amendment regarding outdoor lighting around Turner Farm Park Observatory in Great Falls. As stated in Virginia Code §15.2-920, “In addition to any other authority granted to localities by law, any locality may by ordinance regulate outdoor lighting within an area one-half mile around planetariums, astronomical observatories, and meteorological laboratories."
Fairfax County staffer Carmen Bishop, of planning and zoning, said that the purpose of the outdoor lighting provisions in the zoning ordinance includes light pollution. But it is also to promote safety and security. “So, this amendment strikes a balanced approach,” Carmen said.
The amendment took effect at 12:01 a.m. on the day following adoption. It applies to 525 parcels zoned low-density residential surrounding Turner Farm Park Observatory in Great Falls, which is located at the intersection of Georgetown Pike and Springvale Road. There is another observatory on the George Mason University campus in Fairfax; however, the Zoning Ordinance does not apply to properties owned by the Commonwealth and utilized for Commonwealth purposes.
The amendment allows legally existing lights to remain. This means there are no additional expenditures needed to comply with the amendment, according to Bishop. She explained that the amendment for the observatory area “modestly pulls back” on the current zoning ordinance standards.
The amendment reduces the maximum brightness, or lumens, allowed for motion-activated lights on single-family properties to 1,500, in line with the maximum lumens allowed for other exempt light fixtures. “This is equal to one 100-watt incandescent bulb,” Bishop said.
The amendment allows for flexibility while protecting the night skies. Any number or brightness of full cut-off lights is allowed, as is any number of unshielded motion-activated lights around doors and garages up to 1,500 lumens.
Any type of light, such as landscape and decorative string lighting with a maximum brightness of 20 lumens, is allowed, as are any number of uplights or spotlights up to 300 lumens per fixture; 300 lumens is generally equivalent to 25-40 watts with an incandescent bulb.