Tewksbury’s curbside recycling collection is switching to a single-stream program this month. With the change, residents no longer have to separate recyclables — paper, cardboard, metals, plastics, and glass can all be deposited in the same bin. The change was effective with the first regular recycling day for each household this month. For more information, contact the town manager’s office at 978-640-4300. Tewksbury, Burlington, and Tyngsborough all made the switch to single-stream recycling as part of contract extensions they jointly negotiated with Republic Services, their trash hauling contractor, according to Town Manager Richard Montuori.