The town’s Common Sewer Feasibility Study Committee recently issued its report analyzing “smart sewering.’’ The committee was appointed by selectmen in May 2010 to determine the economic feasibility of providing sewer service for the two newly designated village zones. It worked in conjunction with the Charles River Watershed Association to explore options for implementing a local sewer system, which town officials have long identified as critical for expanding economic development. The plan, which can be viewed on the town’s website, www.littletonma.org, illustrates the possibilities for phasing in a limited sewer system, with a priority on affordability, energy efficiency, and environmental protection.