If your tap water has tasted like dirt lately, you're not imagining it.

Fulton County has notified residents north of the Chattahoochee River, including those in Alpharetta and Milton, that their drinking water may carry an earthy or musty taste and smell, the North Atlanta Star reported Aug. 11. The county says the water remains safe and continues to meet all state and federal standards.

The water is safe.

The culprit is seasonal turnover in the Lake Lanier–Chattahoochee River system, which has elevated two naturally occurring compounds: 2-Methylisoborneol, known as MIB, and geosmin. Neither poses a health risk, but both can produce a noticeable taste and odor even at low concentrations.

What the county is doing

The Tom Lowe Atlanta-Fulton County Water Treatment Plant in Johns Creek, which processes drinking water for Alpharetta, Milton, Johns Creek and Roswell, is adjusting activated-carbon levels to filter out the compounds. Crews are also flushing sections of the distribution system.

Officials caution the taste and odor could take several weeks to clear.

A recurring seasonal issue

The same phenomenon prompted a nearly identical advisory from Fulton County in October 2025. At that time, Public Works director David Clark said the county's testing and treatment processes were effective and that "providing safe and reliable drinking water to our community is our top priority."

The county's 2026 Consumer Confidence Report, released in June, describes a North Fulton water system maintained by more than 250 professionals who test every stage of treatment from source to tap.

What residents can do

A home carbon-filter pitcher can reduce the earthy taste while the county works to resolve the issue. Residents with drinking water concerns can contact Fulton County Public Works at 770-640-3040.