Seneca Companies is a diverse group of entities committed to providing unequaled customer attention through a range of related services including: Petroleum Construction, Service & Distribution of Equipment; General Contracting & Aviation Fueling; Hydro-blasting, Industrial Cleaning & Emergency Response Services; Environmental Consulting & Compliance Services; Remediation & Process Systems; Industrial Fluid Power & Handling Solutions as well as Vehicle Equipment Sales & Service. With a corporate office in Des Moines, IA we have roughly 350 employees in nine different branch offices.