Understanding the Earthy or Musty Taste and Odor in Your Water

At the Macon Water Authority (MWA), we work around the clock to provide clean, safe, and great-tasting drinking water to every customer.

From time to time, especially during certain seasons or weather conditions, you may notice a temporary earthy or musty smell or taste in your tap water. We understand this can be concerning, and we want to explain what causes it, why it happens, and what we are doing about it.

🌿 What Causes the Smell or Taste?

Two naturally occurring organic compounds called Geosmin and MIB (short for 2-Methylisoborneol) are typically responsible for changes in taste or odor. These compounds are produced by various microorganisms, including some algae and bacteria, that live in lakes, rivers, and soil. While the microorganisms that produce Geosmin and MIB are generally considered harmless, it is important to note that some algae and bacteria can be harmful. However, Geosmin and MIB are natural parts of the ecosystem and are not harmful to your health.

Geosmin and MIB are not harmful. Still, people can detect them at extremely low concentrations, such as parts per trillion (ppt).

To understand how small that is, imagine this:

• Picture a football stadium filled with 1 trillion ping-pong balls.
• Now imagine just 5 to 10 ping-pong balls in that entire stadium.
• Those few balls represent the same range of Geosmin or MIB (5 to 10 parts per trillion) that many people can smell or taste in their water.

Some people are that sensitive to taste and smell. Many customers may notice an earthy or musty smell at these low levels, even though the water remains clean and safe to drink.

(Graphic: Illustration of a football stadium filled with white ping-pong balls and a few red ones -parts per trillion.”)

⛅ When Does It Happen?

These natural taste and odor events are most common when conditions in the reservoir or lake change.

They may occur:

• During warm weather, especially in late summer and early fall, when algae activity can increase.
• After heavy rain, which can wash natural organic material into the lake or stir up sediments.
• During seasonal turnover, when layers of warm and cool water in the lake mix and bring naturally occurring compounds from deeper water up toward the surface.

At MWA, these conditions can sometimes impact Javors Lucas Lake, which is our primary drinking water source.

⚙️ How We Treat It

While Geosmin and MIB do not pose a health risk, we know that taste and odor are important to our customers. Our Amerson Water treatment team and the Laboratory & Environmental Compliance team closely monitor water quality and respond quickly when these natural events occur.

Our actions may include:

• Using activated carbon in the treatment process to help remove odor-causing compounds.
• Increasing the frequency of testing for Geosmin and MIB in both the source water and finished water.
• Monitoring lake conditions, including algae activity and changes in temperature or water movement.
• Making operational adjustments at Frank C. Amerson. Jr, Water Treatment Plant, to reduce taste and odor as much as possible.

💬 What You Need To Know

• Your water is safe to drink.
• Geosmin and MIB affect taste and smell only, not safety.
• These events are temporary and usually improve as weather and lake conditions stabilize and as treatment adjustments take effect.
• MWA staff are aware of these conditions and actively manage them to protect both water quality and customer confidence.
• MWA performs approximately 200 water quality tests daily to ensure the water delivered to homes and businesses remains safe, clean, and reliable.

📞 Have Questions or Notice a Change?

If you notice a change in the taste or odor of your water, we invite you to contact us so we can document the issue and provide you with information.

Laboratory & Environmental Compliance: (478) 464-5678

Visit our Contact Us page for more ways to reach us.

We appreciate your trust in the Macon Water Authority. Nature occasionally adds its own flavor, but your Macon Water Authority team is always on top of it — ensuring your water stays clean, safe, and reliable.

 🧠 Quick Facts

What causes the smell?

Naturally occurring compounds called Geosmin and MIB.

Is the water safe?

Yes. These compounds affect taste and odor only, not safety.

Where do they come from?

Harmless algae and bacteria in lakes, rivers, and soil.

When does it happen?

Often during warm weather, heavy rain, or seasonal lake turnover.

What is MWA doing?

Using activated carbon, increased monitoring, and treatment adjustments.

What can you do?

Pour the water into a clean pitcher and let it sit uncovered in the refrigerator for a few hours. Chilling the water or adding a slice of lemon can help reduce the earthy or musty taste.