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ICPRB 1st Quarter Business Meeting November 30, 2021

On November 30 the Interstate Commission on the Potomac River Basin (ICPRB) will hold its quarterly business meeting.  The meeting will begin at 9:45 a.m. The Section for Cooperative Water Supply Operations on the Potomac (CO-OP) will begin at 8:30 a.m.

During the business meeting, the Commissioners will see a presentation on the recent ICPRB report, Rapid Response Survey of Cyanobacteria Toxin Levels Downstream of North Fork Shenandoah River Algal Bloom After Tropical Storm Ida, 2021which investigated downstream toxin levels after Hurricane Ida blew through and scoured the harmful algal blooms from the North Fork Shenandoah. Commissioners will also get updates on the Land Prioritization Mapping for Protecting Drinking Water Quality project, ICPRB’s evolving Justice, Equality, Diversity, and Inclusion policy, the recent resolution to review water supply agreements, and more of ICPRB’s work over the past quarter.

The draft agenda and historical meeting documents can be found on the Business Meetings page.

The meeting will be virtual. Members of the public who wish to view the proceedings should Contact Us no later than close-of-business on Wednesday, November 24. You will be sent a link to the meeting.

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Potomac River Water Quality at Great Falls: 1940-2019

What’s Past is Prologue

An important part of knowing where we are is knowing where we were. Water quality staff at ICPRB recently reviewed and proofed decades of water data collected by the U.S. Army Corps of Engineers Washington Aqueduct Division, which provides drinking water taken from the Potomac for Washington, D.C, and parts of northern Virginia. Data from 1905 to 2000 had been digitized from fading paper records and checked for accuracy to provide a look at Potomac water quality over time. The long-term trends in water temperature, salt content, and other factors were examined and published in “Potomac River Water Quality at Great Falls: 1940-2019.” Viewing the arc of water quality during more than 80 years of data can provide insights for all research and restoration efforts. Take a look at this video on the results:


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ICPRB looks at downstream risks of harmful algal blooms

Scientist sends testing equipment attached to a rope over the side of a bridge. Shenandoah river is below the bridge.

Rt. 340 bridge over Shenandoah
River near Harpers Ferry, WV

The ICPRB staff has researched algae blooms in the basin for many years. Most of this work has focused on chronic blooms of filamentous algae in the Shenandoah and Cacapon rivers in Virginia and West Virginia. While algae is an essential part of any natural waterway, chronic blooms, where algae forms large mats before decomposing restrict recreational use of stream and rivers and can compromise water quality and damage other aquatic life.

Another type of algae, known as blue-green alga or cyanobacteria can under some conditions produce a toxin that can be harmful to human and pets that ingest the water as well as aquatic life. The upper Potomac basin also has chronic blooms of blue-green algae that seem to be growing over time, most recently on the Shenandoah River, where the Virginia Department of Health issued a Harmful Algae Bloom (HAB) Advisory for a 53-mile stretch of the North Fork of the Shenandoah River on August 10, 2021. The ICPRB was preparing to survey the bloom area with other organizations when Tropical Storm Ida brought torrential rains to the basin that scoured the algae blooms from the river. The ICPRB then ran its Emergency River Spill Model to attempt to track the algae and its toxins downriver. The model estimated the time it would take for the algae and its toxins to reach the Potomac mainstem. The extreme flow conditions and high dilution factors resulted in no detection of cyanobacteria, according to a recent ICPRB Report on the Rapid Response Survey.

The ICPRB is enhancing the spill model with sensing data collected by air and on the river that increases understanding of the river’s hydraulics during different flows and increasing tracking accuracy for algae or spills of oil or other toxics that can compromise river ecology and drinking water supplies.

Learn more…

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DWSPP and ICPRB Host Microplastics Webinar

On October 12, 2021, the Potomac River Basin Drinking Water Source Protection Partnership (DWSPP) and ICPRB held a seminar on microplastics in the Potomac River Basin from a source water protection perspective with a focus on drinking water. The seminar was organized by the Microplastics subcommittee of the Contaminants of Emerging Concern Workgroup of DWSPP.

DWSPP is a voluntary association of water suppliers and government agencies focused on protecting sources of drinking water in the Potomac River basin. This coalition of water utilities and management and regulatory agencies enables a comprehensive approach to protecting raw water supplies in the basin.