Rotten Egg Smell In Your Water?

Few things are more off-putting than turning on the tap and getting hit with the smell of rotten eggs. The good news for Las Vegas homeowners: this problem is almost always fixable, usually inexpensive, and rarely dangerous. Here's what causes the sulfur smell and exactly how to get rid of it.

First, Diagnose: Hot Water Only, or Both?

This single question tells you almost everything:

• Smell only in HOT water — The problem is inside your water heater. This is the most common scenario in Las Vegas, and the culprit is usually the anode rod.
• Smell in BOTH hot and cold water — The issue is in your water supply or plumbing system more broadly — possibly sulfur bacteria in the lines or, rarely, the municipal supply itself.
• Smell only from ONE faucet or drain — It's not the water at all. It's the drain — bacteria growing in the P-trap or on debris in the drain throw off odor that seems like it's coming from the water. Fill a glass and smell it away from the sink to confirm.

The #1 Cause in Las Vegas: Your Anode Rod

Inside every tank water heater is a sacrificial anode rod that protects the tank from corrosion. As it depletes — which happens twice as fast in Las Vegas hard water — sulfate-reducing bacteria in the tank react with the rod's magnesium, producing hydrogen sulfide gas. That's the rotten egg smell in your hot water.

This is especially common in homes that sit vacant for stretches (vacation homes, rentals between tenants) because stagnant warm water gives the bacteria time to multiply.

Other Causes and Fixes

• Bacteria in drains — If the smell is from one sink, clean the P-trap and treat the drain. Biofilm buildup in bathroom drains is a common odor source mistaken for water problems.
• Sulfur bacteria in the plumbing system — If both hot and cold smell, the system may need chlorination/sanitizing — a job for a licensed plumber.
• Water softener issues — A poorly maintained softener can harbor sulfur bacteria in the resin bed. Regular softener maintenance prevents this.

Is the Smell Dangerous?

At the low concentrations found in residential water, hydrogen sulfide is a nuisance rather than a health hazard — but it makes water unpleasant to drink and shower in, and the underlying cause (a depleted anode rod) means your water heater tank is now unprotected against corrosion. Fixing the smell also protects the heater.

Frequently Asked Questions

Why does my hot water smell like rotten eggs?

The most common cause is a depleted anode rod inside your water heater reacting with sulfate-reducing bacteria, producing hydrogen sulfide gas. In Las Vegas, hard water depletes anode rods twice as fast as the national average, making this especially common here.

How do I get rid of the sulfur smell in my water?

If the smell is only in hot water, replacing the water heater's anode rod — typically with an aluminum-zinc alloy rod — solves it in most cases. If it's in both hot and cold water, the plumbing system may need professional sanitizing.

Is rotten egg smelling water dangerous to drink?

At the low concentrations found in residential water, hydrogen sulfide is a nuisance rather than a health hazard. However, the underlying cause usually means your water heater's corrosion protection is depleted, so fixing it also protects your equipment.

Why does only one sink smell like rotten eggs?

If the smell comes from one faucet only, it's almost always the drain — bacteria in the P-trap or biofilm in the drain line — not the water itself. Fill a glass and smell it away from the sink to confirm. Cleaning the trap and treating the drain fixes it.