Delaware Engineering, D.P.C. Share: Engineering/Land Surveying Delaware Engineering, D.P.C. Visit Website Request Info 55 South Main Street Oneonta, NY 13820 (607) 432-8073 (607) 432-0432 (fax) Facebook About Map About We assist the public and private sectors in project planning and permitting, grants and loans, shared services, and “green” innovations. What's Nearby? Distance: 5 10 15 20 25 50 mi.