WSSC Water Issues Recreational Water Contact Health Advisory for T. Howard Duckett Reservoir
Drinking Water is Not Affected
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Laurel, Md. – July 21, 2026 – WSSC Water has detected high concentrations of blue-green algae (or cyanobacteria), known as a Harmful Algal Blooms (HAB), in the T. Howard Duckett Reservoir. These HABs can cause adverse health effects. The reservoir, located along the Patuxent River in Montgomery, Prince George’s and Howard counties, serves as a drinking water source for WSSC Water and a recreational area for hiking, fishing and boating.
The water contact health advisory will remain in effect for at least one month. The advisory does not affect the Triadelphia Reservoir.
WSSC Water’s drinking water is not affected and continues to meet all Safe Drinking Water Act standards. As a precaution, WSSC Water is closely monitoring water quality conditions at its Patuxent Water Filtration Plant.
Important information for visitors to the reservoir during a health advisory:
- Recreation areas remain open.
- Boating and fishing are allowed.
- Cyanobacteria and their toxins can cause skin irritation and rashes. Any body part that comes in contact with reservoir water should be rinsed with drinking water.
- Do not consume fish livers or digestive organs from fish caught in the reservoir. If you catch a fish in the reservoir, wash the fillets thoroughly with drinking water.
- Do not allow pets to swim in or drink the water (prohibited at all times by WSSC Water watershed regulations).
If you, your pet, or someone you know has come in contact with or ingested water at the reservoir, call the appropriate county office from the following list:
- Montgomery County: 240-777-0311 (Montgomery County 311)
- Prince George’s County: 301-883-4748 (Prince George’s County 311)
- Howard County: 410-313-1773 (Environmental Health Department)
Water quality monitoring is occurring regularly. When the concentration levels decrease below the advisory thresholds, the Advisory will be lifted, and an alert will be posted at wsscwater.com.
For more information on algal blooms, visit WSSC Water’s Algal Blooms page.
WSSC Water is the proud provider of safe, seamless and satisfying water services, making the essential possible every day for our neighbors in Montgomery and Prince George’s counties. We work to deliver our best because it’s what our customers expect and deserve.