The town has received a $400,000 federal grant for a study of contaminated sites known as “brownfields” to explore their potential for redevelopment. Most of the money will be used to hire a consultant to examine up to 16 contaminated sites that will be chosen based on their potential for redevelopment, as part of an effort to combat blight and add to the town's tax base. Sites in the downtown and southeast areas of town will be the focus, according to an announcement by the town. The federal Environmental Protection Agency earlier this month announced $6.75 million in grants to 33 Massachusetts communities and groups for the study and cleanup of brownfields. The town’s Community and Economic Development office is overseeing the effort.