As a regionally-recognized water resources practitioner and leader for 32 years, Mr. Der provides regulatory and scientific expertise for public and private sector clients, with a commitment to equitable and sustainable solutions to complex projects while specializing in creative linkages between ecology and engineering. Mr. Der has been in private consulting practice since 2001, first as an associate and director of Environmental Services for two civil engineering firms, then, since 2013, principal of his own consulting firm, Andrew T. Der & Associates, LLC. He previously completed 17 years of service with the Maryland Department of the Environment as a manager successfully leading major new initiatives to regulate and restore Chesapeake Bay water resources. His specialties include water resource permitting, compliance, assessment, Clean Water Act, wetland and waterway compliance, NPDES, TMDL, and stormwater management. Mr. Der is an appointed industry representative of the U. S. EPA. He is a member of the Chesapeake Bay Program Executive Council Citizens Advisory Committee, Maryland Patuxent River Commission, and Montgomery County, Maryland Executive’s Water Quality Advisory Commission.

Mr. Liebesman is a nationally-recognized environmental lawyer and litigator with more than 40 years of experience. His practices emphasizes wetlands, water pollution, and coastal issues, as well as environmental impact assessment and endangered species law. Mr. Liebesman represents a range of clients in the public, private and nonprofit sectors on a broad range environmental issues at the federal and state levels. He has negotiated Clean Water Act (CWA) and Endangered Species Act (ESA) permits and approvals for commercial, residential, public works and environmental restoration projects, and he has defended challenges to those permits and approvals in court. Mr. Liebesman has also participated in landmark CWA and ESA cases and has authored amicus briefs in seven major environmental cases before the United States Supreme Court. This included the Rapanos case regarding the geographic reach of CWA jurisdiction and submitted comments on the highly-controversial EPA and Corps regulation defining Waters of the United States in response to the Rapanos. He advises clients on stormwater permitting issues and sits on the Maryland State Water Quality Advisory Committee which provides advice to the Maryland Secretaries of Environment, Natural Resources and Agriculture on Chesapeake Bay water quality issues. Prior to entering private practice, Mr. Liebesman spent 11 years as a senior trial attorney at the Environment Division of the Department of Justice including a one year detail to the President’s Council on Environmental Quality during the Carter Administration helping to develop regulations to implement the National Environmental Policy Act (NEPA). While at DOJ, he handled landmark cases under Superfund, the Clean Water Act and NEPA. Mr. Liebesman was lead counsel in NRDC v. EPA which upheld major portions of EPA’s CWA permitting program. Prior to his DOJ service, he spent two years at EPA’s Office of Federal Activities, EPA’s NEPA oversight office. Mr. Liebesman received Special Achievement and Special Commendation awards for his outstanding service at DOJ. He is a Phi Beta Kappa Graduate of Rutgers University and earned his law degree from George Washington University Law School.