Favorite Business Categories: Engineering and Professional Services With a staff of approximately 50 employees, including 7 registered engineers, NICET technicians, landscape architects, registered land surveyors, and GIS professionals; Senate has the diversity and expertise to meet our client’s needs. How to Find Senate Engineering Co. 30 S. Main Street Washington Pennsylvania, Washington, Pennsylvania No Records FoundSorry, no records were found. Please adjust your search criteria and try again. Google Map Not LoadedSorry, unable to load Google Maps API. Previous Next