PEPPERELL -- Dozens of residents have participated in the 17th annual Pepperell Green-Up, a town tradition that encourages people of all ages to beautify the town by picking up trash along local streets, hiking paths and bike trails.

This year's Green-Up began last Saturday and will continue until tomorrow. During this time, interested residents can go to Lawrence Library to sign up, pick up trash bags and claim the stretch of road they want to clean. Participants then leave the bags of trash roadside, where they are picked up by the Highway Department at the end of the week.

David Armstrong, a hydrologist, founded the Green-Up in 1996 when his son was in Cub Scouts. He said the program has continued to be successful because of the number of return volunteers it gets each year.

"It is always heartening to see this grassroots community effort come together -- to see people signing up in the library and working together to clean up the roads," Armstrong said. "It always makes me smile to drive around and see the piles of orange bags along the roads and then to drive around Pepperell later in the spring after the Green-Up and see the town greening up and flowers coming out -- with clean roadsides."

As of Tuesday night, 35 groups had signed up to participate in the Green-Up.

This year, the Nashoba Conservation Trust, Donelan's Market, North Middlesex Savings Bank and the Pepperell Garden Club provided the bags.

John Ganem, president of NCT, said the trust has supported the Green-Up for years. "Pepperell is a small community and we try to help out different organizations," Ganem said. "We know Dave (Armstrong) well, and we try to help out every year because the event is great for the community."

He said the response of Pepperell residents each year sets an example for how people can do something positive for the town.

"If you look around at any time this week you'll see bags that are sitting in different places, in both the more populated and less populated parts of the town," he said. "Just to see them out there is a great example for others as to how you can help the community by cleaning up."

Tina McEvoy, assistant director of Lawrence Library, said she has seen a varied group of participants checking in at the library this week. She credits the high turnout partially to the fact that the event is held during school vacation week, but said that more volunteers are still needed.

"A really good portion of town has already been claimed, but there are still more streets that need help," she said. "We have had a good turnout so far, but more downtown areas are still open."