09/17/2026
We want to share some helpful info from our neighbors at the City of Manassas.
Seasonal changes in Lake Manassas, which is a source for some of the Park's drinking water, can result in temporary earthy taste or odor. As explained below, this is caused by naturally occurring compounds and DOES NOT POSE A PUBLIC HEALTH RISK.
If you've noticed a change recently, take a look at the info below to learn more about what's happening and why.
If you have recently noticed a different taste and odor in your tap water, it is being caused by changes in Lake Manassas, the City's water source, which also supplies water to parts of Prince William County. Tests showed slightly higher concentrations of Geosmin and Methyl-Isoborneol (MIB)—which are naturally occurring compounds—in Lake Manassas. Both compounds can give your water an earthy/musty taste and odor, but do not pose a public health risk.
Why are there more of these compounds in the water now? It has to do with the changing temperatures, and usually happens twice a year. When it gets colder or warmer, lake water moves from top to bottom and stirs up natural compounds. The Water Department is working to reduce the taste and odor, and always monitors the water supply and finished water for these and other compounds.
