Philadelphia, PA — Partner Engineering and Science, Inc. one of the nation’s leading environmental due diligence and engineering consulting firms has expanded its Mid‐Atlantic presence with the hiring of Aaron Epstein to head the firm’s newly-opened Philadelphia office.
Epstein, a Professional Geologist registered in Pennsylvania, Delaware, and Virginia brings to Partner a depth of experience in environmental and geotechnical services for federal, municipal, legal and commercial clients, specifically Phase I Environmental Site Assessments, Superfund, RCRA, litigation support for environmental/toxic tort cases, and remediation. Epstein was formerly with the local office Pozo Engineering and Geotech where he consulted with lenders and investors on a wide variety of environmental due diligence matters. Previously, he managed the East Coast operations for AEI Consultants, a San Francisco‐based environmental services firm. Epstein earned his BS from the University of Oregon.
One of the fastest growing private companies in the United States, Partner Engineering and Science, Inc. is a national environmental and engineering consulting firm focusing on real estate due diligence including Phase I and II Environmental Site Assessments, building sciences, construction monitoring, and environmental site remediation services. Since its inception in 2008, the firm has grown to become one of the leading environmental due diligence firms in the nation.
Philadelphia is the firm’s 16th U.S. office and brings further depth to the other regional offices in New Jersey, New York and Maryland, according to President Joseph Derhake, PE.

June 22, 2026
Partner has named Frederick Ellington, AIA, LEED AP, as Technical Director in its Construction Services division. With 30+ years of experience, he strengthens the firm's construction risk management, due diligence, and project advisory capabilities for commercial real estate clients.

May 27, 2026
Capital planning in commercial real estate has entered a new phase. In addition to traditional lifecycle replacements, managers now face a growing set of capital needs driven by energy ordinances, decarbonization goals, and climate risk. These drivers are no longer peripheral considerations; they are central to how capital plans are developed, prioritized, and executed.

June 05, 2026
Partner Property Consultants, the European subsidiary of Partner Engineering & Science, Inc. (Partner ESI), announces that Antoine Yeprem joined the company in June 2026 as Senior Consultant, Real Estate Due Diligence, in Germany.




