Jersen Construction Group has been appointed general contractor for the next phase of renovations at Harmony Mills Riverview Lofts, creating 141 more apartments. According to Daniel Washock, project manager, Jersen has been awarded a $21 million contract to renovate the northern end of the former cotton mill built in the mid-1800s. "Work is expected to begin early next year," said Uri Kaufman, a Long Island investor who co-owns the mill complex.