Protect your entire home with Quad Whole House BB UV water treatment. Filters and purifies for clean, safe water | AMPAC USA
View detailsFrequently Asked Questions
What causes the rotten egg smell in well water, and at what concentration does it become detectable?
The rotten egg odor in well water is caused by hydrogen sulfide, a gas produced when sulfate-reducing bacteria metabolize sulfate in anaerobic groundwater conditions. Humans can detect hydrogen sulfide at concentrations as low as 0.0005 mg/L, which is far below any health threshold. Even at very low concentrations, the odor makes water objectionable and causes corrosion in copper and silver fixtures, hot water heaters, and appliances.
What treatment methods remove hydrogen sulfide from well water?
The three practical approaches are aeration, chemical oxidation followed by filtration, and chlorination followed by carbon filtration. Aeration works well for hydrogen sulfide concentrations below 2 mg/L by stripping the dissolved gas out of solution. Higher concentrations respond better to oxidation with air, ozone, chlorine, or potassium permanganate, which converts the gas to elemental sulfur or sulfate that can then be filtered from the water.
How does an oxidizing media filter remove hydrogen sulfide without chemical addition?
Oxidizing filter media such as manganese greensand and catalytic iron media use dissolved oxygen or the manganese coating itself to oxidize hydrogen sulfide to elemental sulfur, which is then captured in the media bed. The media requires periodic backwashing to flush out accumulated sulfur and may need occasional regeneration with potassium permanganate to restore its oxidizing capacity. These systems work without a chemical feed pump when dissolved oxygen in the feed water is adequate, typically above 1-2 mg/L.
Does iron in the water affect how hydrogen sulfide treatment should be designed?
Yes, significantly. Iron and manganese co-occurring with hydrogen sulfide are common in anaerobic groundwater, and all three must be addressed in the correct sequence. The gas must be oxidized before iron removal media is contacted, because hydrogen sulfide passivates iron removal media and causes rapid capacity loss. Our designs place aeration or chemical oxidation ahead of iron filtration for this reason, and we always test for iron, manganese, and pH alongside hydrogen sulfide when sizing a sulfur removal system.
What hydrogen sulfide concentrations require professional water treatment versus a simple carbon filter?
Carbon filters alone are inadequate for hydrogen sulfide removal because it is a gas and carbon has limited capacity for gaseous compounds at low contact times. Concentrations below 0.3 mg/L can sometimes be addressed with a well-maintained catalytic carbon filter, but anything above that level benefits from proper oxidation treatment upstream. AMPAC USA recommends a water test before selecting equipment, because the most common mistake in sulfur treatment is underestimating the concentration and installing a system that fails within weeks.