The historic five-span Duck Bridge, built in 1888, crosses the Merrimack River, linking South Union and Union Streets in Lawrence, MA.  The bridge is undergoing a $6-million reconstruction that will preserve its historical character while widening the roadway, refurbishing the pedestrian walkways, and installing new guardrails.  Nitsch Engineering performed the survey services in the preliminary stage of this project, which included bridge detailing, project horizontal and vertical control by means of GPS, utility information, hydrographic work, and right-of-way delineation. The project length, including roadway access on each end of the bridge, totaled approximately 1,200 feet.