A boil water advisory was issued on Wednesday night for the entire District of Columbia due to algal blooms in the Potomac River triggered by high temperatures.
The District of Columbia Water and Sewer Authority (DC Water) said the precautionary advisory encompasses those at the Pentagon, Arlington National Cemetery, and Reagan National Airport.
The agency said the advisory comes in response to a significant drop in water supply from the Washington Aqueduct, which has raised concerns about water quality.
DC Water stated, “Customers should not drink the water without boiling it first.” The agency added, “We have no information that this incident contaminated the water, but we issue this advisory as a precaution while we test the water.”
All affected residents and individuals are being urged to boil water before consumption.
The advisory specifies that water should be boiled for at least one minute and then cooled before use. This precaution is needed to ensure safety against potential contaminants, including bacteria, viruses, and parasites, which may cause symptoms like nausea, cramps, diarrhea, and headaches.
The advisory includes specific guidelines for customers. This includes discarding any beverages and ice made after 9 p.m. on July 3, running cold water prior to boiling, and, if there are known sources of lead, running the water for two minutes before boiling.
Water used for drinking, brushing teeth, food preparation, washing fruits and vegetables, preparing baby formula, making ice, washing dishes by hand, and water given to pets should be boiled and cooled first, the agency said.
The advisory came about after the Army Corps of Engineers’ Washington Aqueduct flagged a spike in water turbidity, or cloudiness, on July 3 from the Dalecarlia Water Treatment Plant. To handle this, they cut back production at Dalecarlia and moved operations to the McMillan Treatment Plant to ensure the best possible water quality to meet everyone’s needs.
The turbidity has been linked to algal blooms in the reservoirs of the Potomac River.
“Blooms generally occur during high temperatures, causing conditions in water where nutrient levels are high,” the Army Corps of Engineers stated.
Turbidity may not directly affect health but assessments of the water quality are crucial for ensuring public health. Particles in the water that cause the increased turbidity can interfere with the disinfection process at water treatment plants, creating a chance for germs to grow. This may in turn impact the color, taste, and smell of drinking water.
“Upon observing the increase in algae and resulting turbidity today, Washington Aqueduct staff implemented additional mechanical and chemical treatment solutions to help meet system water supply demands and EPA standards,” the Army Corps of Engineers stated.
They washed filters to remove any particles blocking the flow of water, adjusted chemical levels by adding more coagulants to prevent clogs, and brought additional filters online. The EPA has also authorized the use of copper sulfate and sodium permanganate to combat the algal blooms in the reservoirs.
The Washington Aqueduct supplies an average of 150 million gallons of water per day to DC Water, Arlington County, and Fairfax Water.
