Potomac Interceptor Incident Information
Be Informed!
Data and The viability of the Potomac River exceeds the potential harm from the Potomac Interceptor break. We monitor the implications and results that impact us from this unfortunate event. We assembled sites that explain and update real time conditions of the river.
Summary - Yes the river is swimmable!
On January 19, 2026, a section of the Potomac Interceptor sewer line collapsed near the Clara Barton Parkway in Montgomery County, MD, releasing untreated sewage into the Potomac River. The repairs were completed on March 14, 2026. Since Feb 25, the Potomac River returned to normal e.Coli readings at swimmable standards. Multiple government agencies continue to coordinate on environmental monitoring.
DOEE: Leading information source
E. coli sample, in MPN/100 mL, collected at: National Harbor site on March 31, 2026 by Potomac River Keeper w/UMD:
14.8 (out of 410 which is considered swimmable by EPA standards)
#1 Open Water Swimming spot in the DC Metro region!
National Harbor
National Harbor consistently ranks #1 for swimmable areas along the Potomac River as ranked by data from DOEE and the Potomac Riverkeeper network. WaveOne calls National Harbor home since 2009 with over 25,000 swimmers attending practice swims, clinics and races. Our experience and relationships with environmental agencies and organizations keep us informed to provide the best swimming experience possible.
Table showing E.coli readings since February from Maryland Department of the Environment. Note: we sustained heavy rains March 17-19.
Media Ignores the Data: Get the Facts
When it comes to areas of health, data is more important than clicks.
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Potomac Interceptor Account and Timeline
On January 19, 2026, a section of the Potomac Interceptor sewer line collapsed near the Clara Barton Parkway in Montgomery County, MD, releasing untreated sewage into the Potomac River. The repairs were completed on March 14, 2026. Multiple government agencies continue to coordinate on environmental monitoring. This dashboard consolidates E. coli testing from DC Water, DC Department of Energy & Environment (DOEE) with U.S. EPA, Maryland Department of the Environment (MDE), Virginia Department of Environmental Quality (VADEQ), and the Potomac Riverkeeper Network with University of Maryland (UMD).