Harford County Water Treatment 3340 Abingdon Rd Abingdon, MD 21009 Phone : (410) 638-3939 Business Category Regulation & Admin Of Communications Electric Gas & Other Utilities Harford County Of--public Works, Water Treatment Plant-abingdon Bel Air, MD 21014 Phone : (410) 638-3939 Business Category Government Offices-County Government Offices & Public Schools Harford County--public Works, Division Of Water & Sewer, Water Treatment Plant Abingdon, MD 21009 Phone : (410) 638-3939 Business Category Government Offices-County Government Offices & Public Schools