Why Does My Well Water Smell? Causes & Solutions

Identify the Smell

Quick Diagnosis

Hot vs Cold Water Test

• Hot water only: Problem is in water heater
• Cold water too: Problem is in well or plumbing
• One faucet only: Problem is in that fixture/drain
• All faucets: Problem is in well or main line

Sulfur / Rotten Eggs Smell

Causes

• Hydrogen sulfide gas: Naturally occurring in some groundwater
• Sulfur-reducing bacteria: Bacteria that produce H₂S as byproduct
• Water heater reaction: Anode rod reacting with sulfur in water

Hot Water Only?

If rotten egg smell is only in hot water, it's usually your water heater's magnesium anode rod reacting with sulfur in the water. Solutions:

• Replace magnesium anode with aluminum/zinc anode
• Remove anode (shortens tank life)
• Flush and chlorinate water heater

Cold Water Too?

Problem is in well or plumbing:

• Shock chlorinate well
• Install aeration system
• Install oxidizing filter (iron/sulfur filter)
• Install activated carbon filter (low levels)

Health Risk?

Low levels are an aesthetic issue, not health hazard. Very high levels can cause nausea. The smell itself is usually more offensive than dangerous.

Musty / Earthy / Swampy Smell

Causes

• Iron bacteria: Creates biofilm that smells musty
• Organic matter: Decaying vegetation in water
• Algae: In storage tanks or exposed systems

Signs of Iron Bacteria

• Slimy deposits in toilet tank
• Reddish-brown or yellow slime
• Musty odor with iron staining
• Rainbow sheen on water surface

Solutions

• Aggressive shock chlorination
• Physical well cleaning (if severe)
• Continuous chlorination system
• Good well maintenance practices

Chlorine / Chemical Smell

Causes

• Recent shock chlorination: Chlorine not fully flushed
• Chlorination system: Overdosing chlorine
• Chloramine formation: Chlorine reacting with organics

Solutions

• Run water to flush remaining chlorine
• Adjust chlorinator dosing
• Install activated carbon filter
• Allow chlorine to dissipate (leave water in open container)

Note

If you haven't chlorinated and smell chlorine/chemicals, have water tested—could indicate contamination.

Sewage Smell

Causes

• Bacterial contamination: Coliform or E. coli present
• Septic system issue: Contamination reaching well
• Drain problem: Odor coming from drain, not water

Important!

Do not drink water with sewage smell until tested. This is a potential health hazard.

Steps

1. First check if smell is from drain (pour water in glass, smell away from sink)
2. If water itself smells, stop drinking immediately
3. Test for bacteria (coliform, E. coli)
4. Shock chlorinate well if positive
5. Investigate source of contamination

Metallic Smell/Taste

Causes

• High iron: Most common
• High manganese: Often with iron
• Copper: From corroding pipes
• Low pH: Acidic water leaching metals

Solutions

• Iron/manganese filter
• Water softener (mild cases)
• Neutralizer for low pH
• Replace corroded pipes

Treatment Options by Problem

We use Hach and LaMotte professional water testing equipment for field analysis, with comprehensive lab testing through certified California laboratories.

Frequently Asked Questions

Why does my well water smell like rotten eggs?

Hydrogen sulfide gas from sulfur bacteria or naturally occurring sulfur. If hot water only, it's the water heater anode rod.

Is smelly well water safe to drink?

Most odors (sulfur, iron, minerals) are aesthetic, not health risks. Sewage smell = stop drinking and test immediately.

Will a water softener fix smelly water?

No—softeners remove hardness, not odor-causing compounds. You need specific treatment for the odor source.

How do I get rid of well water smell?

First identify the cause. Then: shock chlorination for bacteria, aeration or filters for sulfur, carbon filters for mild odors.

Why does my water smell only in the morning?

Water sitting in pipes overnight can concentrate odors. If it clears after running, the issue may be mild and in the plumbing.