The Merrimac Police Department is on duty 24/7 to safeguard the Town of Merrimac, Massachusetts and its nearly 6,500 residents. Our Department consists of seven full-time officers including a Chief, two Sergeants, and Four Patrolmen. We are located at 16 East Main St., Merrimac, MA 01860 Merrimac is located in the Merrimack River Valley. Our town is bordered by Haverhill to the South, Amesbury to the East, and Plaistow, N.H. and Newton, N.H. to the North. The Merrimack River, to the south, separates us from the Town of West Newbury.