Core Team

Through the leadership and coordination of our core group, working hand-in-hand with our extended team of seasoned practitioners, we are well equipped to advise and advocate for our clients and partners.

Marianne Horinko

Marianne Horinko

President, The Horinko Group


Marianne L. Horinko is the President of The Horinko Group (THG). Ms. Horinko’s expertise is in watershed-based approaches to cleanup and revitalization, corporate sustainability, and collaborative solutions to environmental progress through unique public-private partnerships. Prior to joining THG, she served as Assistant Administrator for the Office of Solid Waste and Emergency Response (OSWER) at the U.S. Environmental Protection Agency from 2001 to 2004, and Acting EPA Administrator in 2003 between Administrators Christine Todd Whitman and Michael O. Leavitt.

Following the events of September 11, Ms. Horinko served at EPA assisting in environmental cleanup activities at Ground Zero in lower Manhattan, the Pentagon in Washington DC, and the U.S. Capitol due to anthrax contamination. In 2003, she oversaw EPA’s response to the Columbia Space Shuttle Disaster. As a result of these experiences, she crafted the groundbreaking National Approach to Response. She brought new approaches to environmental protection using partnerships, flexibility, and innovation to create environmental improvement. The Brownfields program, signed into law by President Bush in 2002, is the embodiment of these new approaches. Under her leadership, the budget for the Brownfields program more than doubled.

During the first Bush Administration, Ms. Horinko was Attorney Advisor to Don Clay, EPA’s Assistant Administrator for OSWER. Subsequently, she served as President of Clay Associates, Inc., a national environmental policy consulting firm, where she launched the RCRA Policy Forum. Ms. Horinko is an alumna of the University of Maryland, College Park (B.S. in analytical chemistry, 1982) and Georgetown University Law School (J.D., 1986).

Brendan McGinnis

Managing Partner, The Horinko Group
Director, Water Resources Policy, Development & Sustainable Communities Group


Brendan P. McGinnis is Managing Partner of The Horinko Group. In January 2008, he founded the organization with former U.S. EPA Acting Administrator, Marianne L. Horinko and colleague, Justin Oberst. In 2009, he launched the firm’s Water Resources Policy, Development & Sustainable Communities Group, assembling a team of thought leaders to develop and advance actionable strategies for addressing domestic and international water quality-quantity and infrastructure issues. Since then, he has worked closely with leading practitioners to provide case development, management, and raise greater awareness for a number of resource leveraged efforts, including the Lower Passaic River Restoration Project, Fox River Cleanup Group, and Kalamazoo River Superfund Site. He continues to provide counsel and oversight for federal government outreach and brand awareness to advance public-private partnering and funding opportunities for the National Great Rivers Research and Education Center. He also oversees The Horinko Group’s business development line, creating overall content and design for its marketing and outreach efforts.

In 2010, Mr. McGinnis became a Founding Member of the Water Resources Action Project, Inc. (WRAP), a volunteer, non-profit organization that seeks to improve public health for underserved communities in the Middle East through greater water stewardship. WRAP sponsors, designs, and implements the installation of rainwater harvesting systems at schools throughout the region, complemented by a strong educational component. In May 2011, he traveled to Israel and Palestine to dedicate the organization’s pilot project at the Sur Baher Girls School in East Jerusalem, and finalize plans for the group’s second project, the Al-Afaq School for the Learning Disabled (completed February 2012). In September 2012, the Board of Directors unanimously appointed Mr. McGinnis as President of WRAP. In November 2012, he completed his second trip to the region, identifying the group’s third project, the Battir Girls High School, located near Bethlehem in the West Bank. He continues to devote his time and resources to the communities served by WRAP, while working closely with its grassroots partners, Friends of the Earth Middle East and Only Green Environmental Center.

Prior to forming The Horinko Group, Mr. McGinnis served as Project Manager at The Global Environment & Technology Foundation in Arlington, Virginia (2005-2007). In this capacity, he provided research, analysis, and project management support for a suite of domestic and international water, energy, and general sustainability projects including the Global Water Challenge, U.S. Agency for International Development’s Powering Health Guidebook; International Center for Environmental Finance, Green Highways Partnership, and on-site coordination of the Fourth Biennial International Waters Conference in Cape Town, South Africa.

Mr. McGinnis received his Bachelors of Art in Business Administration (2004) and Masters in Business Administration (2005) from Southern Illinois University.

Justin Oberst

Managing Partner, The Horinko Group
Director, Regulatory & Legislative Support Group


Justin H. Oberst is a Managing Partner of The Horinko Group. Previously, Mr. Oberst served as a Project Manager for the Global Environment & Technology Foundation, focusing primarily on research and analysis in support of a wide range of environmental projects. He supported a variety of programs, including the Mid-Michigan Regional Management System, Green Highways Partnership, and the Water and Development Alliance (a $10 million partnership between Coca-Cola and the U.S. Agency for International Development). He has substantial experience working with the highest levels of government and corporate America. In this role, Mr. Oberst has utilized his law degree and legal experience to provide an analytical approach to support a wide range of projects across environmental media. He excelled during his time at University of Nebraska College of Law, receiving multiple awards and graduating with distinction in 2005.

Mr. Oberst’s legal and environmental careers began after he had achieved tremendous success in the entertainment field. He founded Saddle Creek Records in the mid-1990’s, a company that grew under his watch into a multi-million dollar international success story. Mr. Oberst continues in his capacity as strategic advisor to current label executives, including traveling internationally to take part in negotiations. Mr. Oberst’s diverse career path informs every aspect of his strategic vision and work ethic. He continues to draw upon those myriad experiences to advise clients and create solutions to the most difficult challenges facing them.

Andrew M. Manar

Andrew Manar

Senior Advisor, Public-Private Partnerships & Stakeholder Engagement, The Horinko Group


Andrew Manar serves as Senior Advisor on Public-Private Partnerships & Stakeholder Engagement. As a former Midwest rural community mayor, County Board Chairman, and State Senate Chief of Staff, Mr. Manar brings a boots on the ground perspective on how to effectively engage local communities and state program managers and budget officers. Elected to the Illinois State Senate in 2012, his experience in state and local governance brings valuable insights into navigating fiscally challenged state budgetary processes and understanding resource constraints of local governments.

Mr. Manar’s extensive experience in state government includes four years as Director of Policy and Budget for the Illinois Senate Democratic Caucus where he became skilled in all aspects of the state’s finances. In late 2008, Illinois Senate President John Cullerton named Mr. Manar as his first Chief of Staff to oversee the complex operations and procedures of the State Senate. When nominating Mr. Manar as his Chief of Staff, Senate President Cullerton noted the respect Mr. Manar had earned amongst Democrats and Republicans in the Legislature, his patient demeanor, knowledge of the state budget, and a proven ability to work closely with members from rural and urban regions of Illinois.

Mr. Manar graduated from Southern Illinois University at Edwardsville with a degree in History and resides with his family in Bunker Hill, Illinois.

Sean McGinnis

Director, The Horinko Group
Director, Public-Private Partnerships & Resource Solutions Group


Sean M. McGinnis serves as Director of Finance & Business Development of The Horinko Group. In this capacity, he is responsible for the firm’s entire financial operations, including close coordination with its partners and clients. Also managing the firm’s outreach efforts, brand equity development, and marketing strategies, Mr. McGinnis provides incubation for service capabilities that accelerate strategic company growth, including the development and execution of the firm’s executive stakeholder forums on behalf of its public-private clients. In 2012, Mr. McGinnis launched the firm’s Public-Private Partnership & Resource Solutions Group, assembling and leading a team of thought leaders to advance market-based and alternative strategies to environmental and infrastructure needs. He works closely alongside federal, state, and local governments, NGOs, and the private sector to examine complex environmental challenges and provoke collaboration in a shared-solutions manner.

Mr. McGinnis draws on his background in finance, corporate banking, and global investment fund services. He brings a timely international perspective rooted in business development and risk-based policy, analytics, and management to the team, proving invaluable to clients exploring market-based resource solutions. Mr. McGinnis was previously with The Northern Trust Company as an International Credit Portfolio Manager and currently also serves as Treasurer for the Water Resources Action Project, Inc., a non-profit seeking to improve public health in the Middle East through greater water stewardship.

Mr. McGinnis received his Bachelors of Science in Finance from the College of Business at University of Illinois. He is pursuing his Executive Masters in Natural Resources from the Center for Leadership in Global Sustainability at Virginia Tech University.

Isaac Chapman

Isaac Chapman

Program Manager, Midwest Relations, The Horinko Group


Isaac T. Chapman is Program Manager for Midwest Relations at The Horinko Group. Mr. Chapman provides strategic communications support and manages client services for the National Great Rivers Research and Education Center on behalf of The Horinko Group’s Water Division. Additionally, Mr. Chapman maintains The Horinko Group’s website, assists with database management, and provides communications support for the Water Division’s Water Salon Series.

Mr. Chapman graduated from Webster University with a degree in Media Communications with an emphasis in Public Relations. Mr. Chapman is proficient with web development applications and excels with technical writing, strategic analysis, interactive media, social networking and communications.

Prior to joining The Horinko Group, Mr. Chapman worked in web site design and development, both independently as a web consultant and as an Assistant Webmaster at Lewis and Clark Community College.

Andrew Sachs

Andrew Sachs

Project Coordinator, The Horinko Group


Andrew M. Sachs is a Project Coordinator for The Horinko Group, currently majoring in Ecological Sustainability at George Mason University and pursuing his master’s in Environmental Science and Policy with a concentration in Aquatic Ecology. Mr. Sachs’ education and research has centered around stormwater best management practices, green infrastructure, and urbanization and has held various leadership roles to promote environmental mindfulness and leadership to fellow students and the community.

Previously, Mr. Sachs’ has worked with the Mason Water Forum conducting water-related speaker events, Angler Environmental supporting wetland ecologists, and Ryan Homes as a project management intern overseeing safety and environmental compliance.