- A rotten egg smell is usually hydrogen sulfide gas, and orange or black stains are usually iron or manganese.
- If the smell is only in hot water, the cause is often inside your water heater, not your well.
- A lab test tells you exactly what you are dealing with before you buy anything.
- Oxidizing filter media can remove iron, manganese, and hydrogen sulfide together, often paired with a softener.
If your well water smells like rotten eggs, or your sinks, toilets, and laundry keep picking up orange or black stains, you are not alone. Iron, manganese, and hydrogen sulfide are some of the most common reasons private well owners in Southeastern Pennsylvania call us. The good news is that all three are very treatable once you know what is in the water.
What causes the smell
The rotten egg smell comes from hydrogen sulfide, a gas that forms naturally underground, often from bacteria that feed on sulfur in the rock. You can usually smell it at levels far too low to be a health concern, but it makes water unpleasant to drink and bathe in, and it can tarnish silver and plumbing fixtures.
Hot water only
If you only smell it from the hot tap, the problem may be your water heater. The magnesium anode rod in many heaters can react with sulfate in the water and produce the smell. Replacing the anode with a different type often fixes it. If both hot and cold water smell, the source is the well.
What causes the stains
- Orange, red, or brown stains point to iron.
- Black or dark brown stains point to manganese.
- A slimy orange or brown film in the toilet tank can mean iron bacteria, which feed on dissolved iron.
Iron and manganese are not usually a health hazard at typical levels, but they stain everything they touch, clog fixtures, and give water a metallic taste.
Test first
How it is treated
The most common whole-home fix is an oxidizing filter. The media inside converts dissolved iron, manganese, and hydrogen sulfide into particles it can trap, and a regular backwash flushes them away. A carbon layer can polish any remaining odor. Because many of these wells are also hard, the filter is often paired with a softener in a two tank system.
Our dual tank well water system does exactly that, with one tank for iron, manganese, and sulfur and one for hardness. If your test also shows bacteria, we add UV disinfection, and if the pH is low we start with an acid neutralizer.