The U.S. Forest Service and Coconino Public Works has ignited the annual green waste burn at the Willard Springs Transfer Station south of Flagstaff. The annual green waste burn reduces the existing stockpile of pine needles, tree trimmings and other green waste at the station. The burn is expected to smolder until mid-spring and will be monitored by the Mormon Lake Ranger Station, Pinewood Fire Department and the Coconino County Public Works Solid Waste Division. Smoke may be heavy at times over at least the next three weeks. There will be signs present along Interstate-17 to warn motorists of smokey conditions.