Our Team


Bryce Aaronson, Interim Executive Director
Bryce Aaronson is passionate about promoting cleaner and safer access to water. He works full time in a financial role at Carnegie Mellon University. Bryce was the program manager for the River Alert Information Network, a source water protection nonprofit in western PA and northern WV. He previously worked as a technical consultant with a water quality robotics start-up. He graduated with a Masters in International Development from the University of Pittsburgh’s GSPIA focusing on global water and sanitation projects. While pursuing his degree, Bryce assisted with long term development projects in South Africa and Colombia. In his free time you’ll find him walking his dogs in Brookline.

Board of Directors – April 2021

Lisa Werder Brown, President
Lisa Werder Brown is the Executive Director of Watersheds of South Pittsburgh, formerly the Saw Mill Run and Streets Run Watershed Associations. She works closely with watershed communities, local governments, academic, and nonprofit partners to identify the issues and explore opportunities for storm water mitigation in the Pittsburgh region. Lisa is a graduate of Chatham University with a BS in biology and holds a Certificate in Nonprofit Executive Management from Georgetown University. She has served on the Board of Directors of Three Rivers Waterkeeper since June 2012 and is currently the Board President. Lisa also serves on the strategic working group for the South Western PA Water Network and is a member of the ALCOSAN Municipal Advisory Committee.

Sarah Quesen, PhD. MPH, Vice-President                                                   Sarah Quesen, PhD, MPH, is a senior research scientist with Pearson and an adjunct instructor in statistics at the University of Pittsburgh. Sarah is an avid open water swimmer, and provides information on safety and river conditions throughout the summer season for local swimmers. Sarah is Vice President of the Western Pennsylvania Wheelman, the longest-running cycle clubs in the region. Sarah joined the Three Rivers Waterkeeper in April 2019, and currently serves as Vice President.

Ben Mack, Treasurer                                                                                            Ben Mack has spent his entire career in the environmental sector. He began his career as an Americorps VISTA volunteer with Friends of the Cheat, a watershed group in West Virginia. Ben also served as a Research Associate at the West Virginia Water Research Institute, where he designed and implemented water treatment projects for the remediation of acid mine drainage. He also served as an Environmental for the State of Delaware, where he managed long-term environmental cleanups on polluted sites. He is currently an environmental consultant with Tetra Tech where he works on a variety of environmental projects. Ben has a Master of Science in Plant and Soil Science and a dual Bachelor of Science in Agronomy and Environmental Protection, both from West Virginia University. In his spare time, he enjoys spending time with his family and being outside.

Rebecca Kiernan, Secretary
Rebecca Kiernan is a Principal Resilience Planner with the City of Pittsburgh, focusing on building social, ecological, economic, and physical resilience to city-wide shocks and stresses. Her work includes developing and implementing initiatives such as the ONEPGH Preliminary Resilience Assessment, Resilience Strategy and Investment Prospectus; the Pittsburgh Equity Indicators Reports; and aligning the City’s work with the UN Sustainable Development Goals. She also supports the City’s Climate Action Plan with a focus on transportation electrification, zero waste, and urban ecosystems initiatives. Rebecca was previously Sustainability Coordinator for the Township of Moon, worked in coastal livelihoods restoration in Indonesia, and has 7 years of experience in education and facilitation. She holds a BA in English and Education from SUNY Geneseo, and an MS in Public Policy and Management with a focus on Environmental Policy from Carnegie Mellon University. She serves on the City’s Shade Tree Commission and ALCOSAN’s Municipal Advisory Committee. Rebecca enjoys long road trips, growing stuff, and kitchen projects.

Sean Brady, Director
Sean is the Executive Director of Hollow Oak Land Trust, a conservation organization that protects and connects greenspace in the Pittsburgh International Airport Corridor. With a BA in Biology from Allegheny College and an MA in Professional Writing from Carnegie Mellon University, Sean helped build Venture Outdoors as a regional leader in outdoor recreation from its inception in 2001 to 2010. He also served as Development Director for Riverlife, supporting sustainable riverfront development in downtown Pittsburgh. Currently, Sean manages the six conservation areas owned by Hollow Oak Land Trust and works with municipalities and private landowners to develop greenways in the airport corridor.

Tim Fitchett, Director

Tim Fitchett is a staff attorney and resident director at Fair Shake Environmental Legal Services, a non-profit environmental law firm based out of Pittsburgh, PA and Akron, OH. Tim is also on the Board for Calliope House, an organization devoted to promoting folk music in Pittsburgh and the surrounding area. Tim joined Three Rivers Waterkeeper in December of 2020 and is excited to help our rivers flourish. 

Kimberly Refosco, Director

Kimberly Refosco is an educator and leader in both the classroom and the outdoors.  After studying Political Science and Spanish at the University of Pittsburgh, Kim earned her M.S. in Education from Franciscan University.  She currently teaches Spanish and English as a Second Language.  In addition to teaching, Kim is a consultant in diversity, equity, and inclusion, leading organizations to implement change and strive for justice.  In spare time, you can find Kim fishing, reading, and spending time with her two teenagers.  

Kate Zidar, Director

Kate Zidar is a PhD student at the University of Pittsburgh and a native Pittsburgher. At Pitt, she is a member of the Elliot Lab, where she participates in research that examines the impact of human activities on aquatic and terrestrial ecosystems. Previously, she worked as an Environmental Planner with a professional focus on green infrastructure, resilience and communications.  Kate earned a M.S. at the Pratt Institute in City and Regional Planning where she also taught for seven years.  She was a founding member of the Stormwater Infrastructure Matters (S.W.I.M.) Coalition, a policy think tank that figured centrally in establishing Green Infrastructure as a mainstream practice in New York City. She also began the North Brooklyn Compost Project, one of the many community garden-based efforts that ultimately “made the road by walking”, preceding city-wide collection of organic waste in NYC.  Today, Kate’s research explores the underlying biogeochemical processes of Green Infrastructure.

Kelsey McNaul, Director

Kelsey McNaul is a regional organizer for The Climate Reality Project, working to build coalitions in the Ohio River Valley to stop the petrochemical buildout of the region. Growing up in Lancaster PA, Kelsey has always fostered a passion for environmentalism and social justice. Her activist spirit led her to obtain a dual degree in Environmental Studies and Sociology at Washington College in Maryland, where she coordinated grassroots environmental campaigns on campus. Upon graduation Kelsey furthered her activism work as a field organizer for the Fund for the Public Interest. An avid traveler, her time hiking, kayaking, snorkeling, and scuba diving domestically and around the world have only solidified her love of the environment. In her free time, Kelsey enjoys exploring natural and urban areas, snuggling with her dog Lila Rae, and dancing like no one is watching.

Joshua Powell, Director

Joshua Powell is an engineer at Broadcom, Inc., a designer, and supplier of semiconductors and infrastructure software products. Joshua has spent the past 15 years working closely with non-profit organizations focused on environmental conservation and restoration by building award-winning software. Joshua joined Three Rivers Waterkeeper in December 2020. In his free time, he enjoys gardening and spending time outdoors with his family.

Josh Eisenfield, Director