Emily Silence

Emily joined Potomac Riverkeeper Network in 2018 as the Development Associate. She received her undergraduate degree in Political Science and Economics from American University, in Washington D.C. and her Masters in Public Policy, with a focus on Environmental Policy, from American as well. Prior to joining PRKN, she interned for the Pisces Foundation, assisting the Water Program by conducting research, assisting with grantmaking activities, and analyzing other materials to support water strategic plan implementation. Emily has also interned for the Democratic Party of Virginia, assisting with grassroots organizing efforts for the Hilary Clinton campaign. On her days not at PRKN, Emily enjoys many outdoor activities such as hiking, camping and kayaking.
Dean Naujoks

Dean Naujoks joined Potomac Riverkeeper Network in 2015 as the Potomac Riverkeeper.
Dean Naujoks has over 20 years of environmental non-profit experience. He began his non-profit career in 1991 with the NC Wildlife Federation. After graduating from NC State University, with a self-created degree in Environmental Policy and Sustainable Development, he was hired as the first Upper Neuse Riverkeeper, serving from 2001 to 2008. He became the first Riverkeeper on the Yadkin River with Yadkin Riverkeeper, Inc. in 2008, also serving as Executive Director until 2014.
Dean has been awarded River Network’s 2009 National River Heroes Award. River Network’s River Heroes Award celebrates rivers and those who protect them by recognizing victories and honoring those who provide leadership and inspiration along the way. Yadkin Riverkeeper also won the 2011 North Carolina Wildlife Federation Governor’s Achievement Award Water Conservation Organization of the Year.
Most recently, he has been recognized by Waterkeepers Chesapeake as a recipient of their 2019 Waterkeeper Outstanding Win (WOW) Award for his fight against Dominion and accomplishments in making safe disposal of coal ash a requirement in Virginia.
Potomac Pollution Hotline: 202.871.8289
Brent Walls

Shortly after joining Potomac Riverkeeper, Inc. in 2009, Brent Walls now works as the Upper Potomac Riverkeeper and is responsible for defending the public trust of the rivers and streams in the Upper Potomac by advocating for clean water and ensuring the the virtues of the Clean Water Act are enforced. Brent Walls has been an advocate for clean water for over a decade. With an Environmental Science background in fresh water ecology, Brent has brought a valuable scientific perspective to Potomac Riverkeeper since 2009. His experience in water quality sampling has ensured defensible enforcement actions and has been a unique advising asset with local watershed groups. Brent’s love of maps and proficiency with Geographical Information Systems has inspired the development of Water Trail maps in the Upper Potomac and has provided PRK with valuable interactive web maps and the creation of a mobile application to report water pollution.
Mark Frondorf

Mark joined Potomac Riverkeeper Network in 2015 as the official Shenandoah Riverkeeper. Having guided on the Shenandoah and Potomac for almost twenty years, Mark Frondorf comes to the Shenandoah Riverkeeper position used to hard work and recognizing the importance of a hands-on approach to protecting our rivers. His passion for the water, combined with his people and analytical skills, honed over 25 years as a think tank senior policy analyst tackling some of the most vexing issues facing our nation, make him ideally suited to defend the Shenandoah against pollution, protect our right to clean water, and promote the recreational use of this beautiful river. Mark was the principal investigator and author of a government study that examined the ocean dumping of U.S. chemical weapons and explored the full-range of issues, challenges and potential solutions to this complex problem.
As the former president of the Potomac River Smallmouth Club, he successfully lobbied both Virginia and Maryland officials to implement and expand catch and release regulations and he was instrumental in getting the federal government to revise the Code of Federal Regulations to permit wade fishing on portions of the Potomac. Mark also served on the Board of Directors for the Mid-Atlantic Federation of Fly Fishers. He holds an M.A. from the George Washington University Elliott School of International Affairs.
Nancy Stoner

Nancy Stoner is president of Potomac Riverkeeper Network. One of the nation’s most experienced water policy experts, Nancy has a rich and distinguished background in protecting our nation’s water.
Nancy began her career as an attorney in the Environment and Natural Resources Division of the U.S. Department of Justice in Washington, DC, where she litigated and analyzed legislative proposals on a broad range of environmental and natural resource statutes. She also worked for many years at the Environmental Protection Agency (EPA), where she recently served as Acting Assistant Administrator for Water. In that position Nancy managed the agency’s program for implementing the Clean Water Act and Safe Drinking Water Act nationwide to protect surface water resources and ensure the safety of tap water, supervising a staff of more than 600 and a budget of more than $3 billion in grants, loans and contract support. She also supervised the development of national rules to protect surface waters, drinking water sources and tap water and represented the agency in congressional hearings, national conferences, symposia and press conferences. Nancy also served as Co-Director, Water Program, Natural Resources Defense Council, where she co-directed a national program to promote sound water resource management nationally and in specific watersheds, such as the Great Lakes, Chesapeake Bay, and Anacostia River.
Nancy most recently served as Water Program Director and Senior Fellow for the Pisces Foundation where she developed the foundation’s strategy to protect freshwater resources in the U.S. using integrated water management (IWM) to maximize the value from water resources for people and nature. She also supervised a $7 million investment annually to implement IWM in urban and agricultural watersheds.
Nancy graduated from the Yale Law School, New Haven, CT and was awarded a Juris Doctorate in 1986. She was also awarded a Bachelor of Arts with Highest Distinction, Phi Beta Kappa, from the University of Virginia, Charlottesville, VA.
She lives in Silver Spring, MD with her husband, Marc Machlin. She has two grown children, Laura and Jared. She enjoys whitewater rafting, tubing, canoeing, birding, and gardening.
Emily Franc

Emily Franc comes to Potomac Riverkeeper Network with extensive experience and background in environmental research, policy, fundraising and advocacy accumulated through years spent working on Capitol Hill for a prominent member of the House Energy and Environment Committee, as well as for various international agencies and non-profits including the United Nations Environment Program Caribbean Environment Programme (UNEP-CEP), The Ocean Foundation (TOF), and Qatar Foundation International (QFI).
She also has broad executive level experience in non-profit management, strategic development and effectiveness analytics, communications, philanthropic fundraising, and a proven track record in taking organizational capacity to scale during periods of rapid growth and transforming non-profits into thriving financially successful entities.
Prior to this, Emily was the Riverkeeper for Anacostia Riverkeeper. There she was responsible for developing, implementing and raising money for programs that limit pollution from the waters of the Anacostia River watershed; educating the public on water quality issues and best practices; and increasing public awareness of our local waterways as community resources to be valued and protected.
She is an avid explorer and will try most anything once. She has traveled throughout the United States, Europe, Africa, the Caribbean, and the Middle East. Through her passion for volunteerism, she has regularly participated in riverbank cleanups and wetlands restoration projects in Washington, D.C., California, Florida, the Chesapeake Bay Watershed, Zambia, Jamaica and Qatar.
Emily received her undergraduate degree in Political Science from California State University, Hayward and her Masters of Environmental Science from Johns Hopkins University.
Emily believes in lifelong learning, and has an insatiable curiosity. An avid explorer and world traveler, this Maryland native has called the Potomac River watershed home for most of her life, and enjoys fishing, hiking, boating, and any opportunity to be out on the water. She has four adult children who are amazing!
Phillip Musegaas

In his role as Vice President of Programs and Litigation, Phillip works with the Network’s Riverkeepers to develop and carry out their clean water advocacy and grassroots campaigns and serves as PRKN’s in-house counsel on all litigation matters with our experienced and passionate outside counsel. Since joining PRKN in the Spring of 2015, Phillip has led the team to several critical victories for the Potomac watershed, including federal consent decrees with polluters in Maryland that prevented millions of pounds of pollution from being dumped in the Potomac, and passage of legislation in Virginia to address untreated sewage discharges and leaks from toxic coal ash ponds into the river. Prior to joining Potomac Riverkeeper Network, Phillip was the Hudson River Program Director at Riverkeeper in New York for ten years, leading efforts to reduce sewage pollution, clean up historic industrial sites and bring enforcement actions to protect the Hudson River. During his tenure as Director, Hudson Riverkeeper brought successful actions against dozens of polluters, including ExxonMobil for its historic Greenpoint oil spill and numerous concrete companies, scrapyards and other waterfront sites whose operations violated the Clean Water Act and other environmental laws.
Phillip received a J.D. with honors from Pace University School of Law, and a B.A. (magna cum laude) in Geography from the University of Washington.
Alan Lehman

Alan Lehman is the Agricultural Project Manager for Shenandoah Riverkeeper, under Potomac Riverkeeper Network. Since 2009, Alan has been identifying and documenting farming practices that appear to be contributing excessive nutrients, bacteria, and sediment to rivers and streams in the Shenandoah Valley. Shenandoah Riverkeeper attempts to engage landowners and farmers at the most severe sites to begin a dialog about possible solutions. Alan brings 25 years of experience as an investigative photojournalist to this endeavor, as he patrols the rivers and back roads looking for threats to water quality in the valley. Alan also uses volunteer pilots to assist him with aerial reconnaissance missions to investigate hidden sites. He manages files on over 1280 farms in 8 counties. Alan has lived in the Shenandoah Valley for over 44 years.
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Washington DC Headquarters
Potomac Riverkeeper Network3070 M Street, NW
Washington, DC 20007
Shenandoah Mailing Address
Shenandoah RiverkeeperP.O. Box 1251
Berryville, VA 22611
POLLUTION REPORT HOTLINE
Shenandoah 540.252.3465
Upper Potomac 240.366.1875
Potomac 336.809.6041
MEDIA INQUIRIES
Fritz Schneider
Director of Communications
301.728.4811
fritz@prknetwork.org
MAIN OFFICE
202.888.2037
Our MISSION
We work to protect the public's right to clean water in our rivers and streams. We stop pollution to promote safe drinking water, protect healthy river habitats, and enhance public use and enjoyment
Our Location
Potomac Riverkeeper Network3070 M STREET NW
WASHINGTON, DC 20007
Twitter FEED
After July 2025, I won't be pulling styrofoam out of Little Hunting Creek any more.....
@PotomacRiver @AliceFerguson @vasierraclub @VirginiaLCV @River_Friends https://t.co/vSlrgykyBH
Just now: The Virginia General Assembly agrees to a law that will ban all restaurants and food vendors from using polystyrene food containers by July 2025.
The bill will now go to @GovernorVA for his signature. https://t.co/UmeIiVpdZh
A not so gentle reminder that the chemicals we use on our land can have hazardous affects on our ecosystems! @ChesBayJournal
https://t.co/tJgZCEEaIP
Are Riverkeepers secret spies? No, of course not. But sometimes we feel like it. Check out our UPRK Brent discuss how we collect evidence for our work using water samples, drones, and more!
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ACT NOW Ban single-use styrofoam food containers in Virginia! The bill passed the House and Senate will vote soon! Send email to your state senator NOW to stop the #plasticpollution crisis at its source! https://t.co/JdPqPOrCIO #banfoam @PotomacRiver @JRAvirginia @EcoActionArl