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Aaron S. Mapes


  • University of Maryland School of Law (J.D., concentration in Environmental Law, 2011)
  • University of Pittsburgh (B.S. in Business and Economics, Dean's List, 2007)

Bar Memberships

  • Pennsylvania, 2011


  • Pennsylvania Bar Association
  • Philadelphia Bar Association
  • Delaware Valley Environmental Inn of Court

Aaron S. Mapes



(215) 587-1005

(215) 320-4144 Fax

Aaron S. Mapes is an Associate in the Firm's Environmental Practice Group. He counsels clients on a wide-variety of environmental matters, including environmental diligence and contract negotiations for real estate transactions and large-scale industrial projects, regulatory compliance assistance for brownfields redevelopment and commercial/industrial operations, and filing and defending administrative appeals and environmental litigation. Mr. Mapes' clients include real estate private equity funds, local municipalities, and companies in the oil and gas generation/distribution, electric power generation, and product manufacturing and recycling businesses.

Mr. Mapes’ transactional practice focuses on the acquisition, financing, and selling of real estate. He has experience managing and advising clients on all environmental aspects of real estate transactions, including selecting and retaining qualified environmental consultants; advising clients on environmental investigation and remediation scopes and strategies; reviewing and commenting on technical reports; working with clients, lenders, and consultants to comply with lender protocols; negotiating favorable provisions in purchase and sale agreements, loan agreements, and environmental indemnities; negotiating with insurance companies to obtain broad coverage in environmental insurance policies; and counseling clients on the nature and extent of environmental risk, and risk management options, for contemplated transactions.

Mr. Mapes regularly works on single- and multi-property transactions in gateway markets across the United States (US), as well as transactions involving large portfolios of properties located in multiple states. He also has significant experience counseling clients on international real estate transactions, particularly in the United Kingdom (UK), Germany, and France.

Mr. Mapes’ practice also includes environmental diligence for oil and gas distribution, electrical power generation, and other large-scale industrial projects. In this capacity he coordinates and evaluates a broad array of environmental studies, including assessments of wetland and stream crossings, threatened and endangered species, historic and cultural resources, noise and visual impacts, hazardous materials usage, and air emissions. Mr. Mapes has particular expertise in evaluating wetland delineations, classifications, and mitigation plans, having served as counsel in a federal lawsuit involving a wetland delineation dispute and a high-profile administrative appeal alleging improper and insufficient wetland delineation, classification, and impact mitigation.

Mr. Mapes routinely assists clients with regulatory compliance issues arising during brownfields redevelopment and building renovations, working with clients to navigate complex regulatory schemes and develop cost-effective remediation, abatement, and waste management strategies. He also assists commercial/industrial clients in obtaining environmental permits, pursuing environmental insurance claims, completing environmental audits, negotiating administrative penalties, and litigating administrative appeals. As a litigator, Mr. Mapes has practiced in state, federal, and administrative courts, and is skilled at taking and defending depositions, drafting complex motions and briefs, conducting efficient legal research, and assisting with trials and trial preparation.

Prior to joining Post & Schell, Mr. Mapes served in the Environmental & Toxic Tort group of a large, regional law firm, where he focused primarily on litigation associated with underground storage tank releases and exposure to asbestos-containing products. He is a graduate of the University of Maryland School of Law with a concentration in Environmental Law. During law school, he was president of a student group that provided legal assistance to disadvantaged communities and completed clerkships at the Environmental Protection Agency (EPA) Headquarters and Region 3 offices.