Havre De Grace Waste Water 395 Wilson St Havre De Grace, MD 21078 Phone : (410) 939-1220 Business Category Government Offices-City Village & Twp Legislative Bodies Hampstead Town Of--waste Water Treatment Plant 395 Wilson St Havre De Grace, MD 21078 Phone : (410) 939-1220 Business Category Government Offices-City Village & Twp Government Offices State & Local Government Offices & Public Schools