Diagnosing Water Odor: Causes and Fixes for Smelly Well Water

May 5, 2025

Turning on the tap and being hit with an unpleasant odor from your well water can be frustrating—and concerning. Whether your water smells like rotten eggs, musty soil, or bleach, the odor is more than just a nuisance; it’s a sign that something deeper is going on in your water system.

At Mad River Well Services, we know how important clean, fresh-smelling water is for your home and health. In this guide, we break down the most common causes of well water odors and the best ways to eliminate them for good.

Common Well Water Odors and What They Mean

1. Rotten Egg Smell (Sulfur or Hydrogen Sulfide)

This is one of the most recognizable and common odors in well water. It usually stems from:

Naturally occurring hydrogen sulfide gas in the groundwater.

Bacteria that feed on sulfur in the well or plumbing system.

Corroded anode rods in water heaters.

Fixes:

Shock chlorination of the well to eliminate bacteria.

Installing an activated carbon filter or an aeration system.

Replacing the anode rod in your water heater.

2. Musty, Earthy, or Moldy Smell

These odors are often caused by:

Decaying organic material in the water source.

Algae, fungi, or bacterial growth in the plumbing.

Stagnant water in unused plumbing lines.

Fixes:

Cleaning and flushing plumbing lines.

Installing point-of-use filters.

Regularly using all fixtures to prevent water stagnation.

3. Bleach or Chlorine Smell

If your well water smells like a swimming pool, you may be:

Over-chlorinating your system during disinfection.

Picking up chlorine from nearby municipal treatments (if you’re using a hybrid system).

Fixes:

Adjust the chlorine levels during disinfection.

Use a carbon filter to remove residual chlorine.

4. Gasoline or Chemical Smell

This is rare but serious. It could be caused by:

Contamination from a nearby fuel or chemical spill.

Improperly sealed well caps or casing.

Fixes:

Immediate professional testing for VOCs (volatile organic compounds).

Sealing or relocating the well.

Installing advanced filtration systems designed to remove chemical contaminants.

Steps to Take if Your Well Water Smells

1. Don’t Drink or Use the Water Until It’s Tested

Water with a strong odor should be considered unsafe until it's professionally tested. Contact Mad River Well Services to schedule a comprehensive water quality analysis.

2. Identify the Source

Is the odor present in hot water only, or both hot and cold? Does it come from one faucet or all of them? This can help narrow down whether the issue lies in the well, the plumbing, or the water heater.

3. Inspect and Maintain Your Well System

Regular inspections can catch small issues before they become major problems. Our team at Mad River Well Services offers complete well evaluations and routine maintenance.

4. Choose the Right Filtration System

Based on your water test results, we can recommend a custom treatment solution—ranging from aeration tanks to chemical injection systems or reverse osmosis setups.

Protecting Your Home’s Water Quality

Smelly water is never just about inconvenience—it often signals underlying problems that need immediate attention. With the right diagnosis and solution, you can enjoy clean, odor-free water again.

At Mad River Well Services, we specialize in pinpointing the cause of water odor and implementing lasting fixes tailored to your home and water system. Our experienced technicians are just a phone call away.

Concerned about the smell of your well water? Contact Mad River Well Services today to schedule a professional water test and system inspection. Let’s get your water back to pure, clean, and odor-free.