CHEYENNE, Wyo. (AP) - Officials say recycled water may be the cause of spruce trees dying in Cheyenne parks and cemeteries.

Dozens of trees have been dying over the last few years, and the Cheyenne Board of Public Utilities says the higher salinity in recycled water may be the cause.

Cheyenne has used recycled water to irrigate public spaces as a way to conserve drinking water since 2007. The water is treated to close to drinking water and is safe for irrigation and human contact.

Cheyenne Parks and Recreation Director Rick Parish says salt alone is not the cause, as drought in recent years, pests, root damage and temperature variations have also caused the decline.