Hydrogen Sulfide “rotten egg” smell
What is Hydrogen Sulfide (H2S)?
Hydrogen sulfide (H2S) is a dissolved gas that gives water a characteristic "rotten egg" odor and taste. It corrodes piping, creates odors in the house, and turns water and your fixtures black. Homemakers will notice that it can change sterling silver to a black color almost instantly. (H2S can cause odor problems at a concentration level as low as 0.05 mg/l (ppm).
H2S in well water
H2S often occurs naturally in well water, or can be caused by the presence of sulfate reducing bacteria in a well or water system. Since bacteria are the most common cause, treatment to control them should be tried first. Shock chlorination is the standard treatment for control of sulfate reducing and iron bacteria in a well.
Solutions
Manganese Greensand Iron Filter (has been around for decades)
A properly maintained manganese greensand filter will effectively remove low levels of (H2S, typically less than 5 mg/l (ppm). This type of filter oxidizes the (H2S and filters out the resulting sulfide particles. It is very important that these filters have an adequate supply of water for backwash and are adequately regenerated with potassium permanganate. (H2S requires 3 times the oxidizing power that iron does so the greensand filter must be regenerated more often than it would for an equal amount of iron. Manganese stripping, from the manganese greensand, can also occur. This stripped manganese can cause black staining. The injector must be cleaned at least once per year, and the chemical tank float valve assembly removed and soaked in a water solution to dissolve the potassium permanganate that has crystallized onto the float valve assembly. The filter pad above the grid inside the tank should be replaced every 2 to 3 years. Potassium permanganate will accumulate insolubles in the tank and on the grid pad.
Alternative System
Greensand Plus: The Latest and Best Way
Inversand, the company that has produced Greensand for decades, has developed a new synthetic product which is equivalent to the Greensand media, only without the use of chemicals. This newer product, called Greensand Plus, has been successful in taking the place of the Greensand media and other similar non chemical medias that will remove sulfur and/or iron. The advantage that Greensand Plus has over these other non chemical medias is that it is lighter weight, requiring a lower backwash rate at a lower cost. We provide this product for sulfur levels up to 8 mg/l (ppm), iron levels up to 15 mg/l (ppm) and manganese, a brown staining material that a water softener also removes.