Hydrogen sulfide, if present, will vary by well due to the varying geology and environmental conditions. It is most common in shales and sandstones. Attempts have been made to correlate the occurrence of hydrogen sulfide to various groundwater chemistry conditions, but it is most commonly associated with available hydrocarbons and associated low-redox (i.e., anaerobic) conditions, although presence of sulfide and anaerobic are self-reinforcing, as sulfide depletes oxygen. Groundwater may have low, neutral or high pH, hardness and alkalinity, and levels of iron. It also may be associated with peat formations, and biologically enriched unconsolidated aquifers, where high manganese may be present.
Hydrogen sulfide itself is intensely corrosive to iron and steel (including galvanized) and copper, and accelerates even stainless steel corrosion. It also corrodes cement. Additionally, it combines with iron to make clogging Fe sulfides. Thus, sulfide-enriched water may cause shorter service life for well casings, pipes and pumps, as well as metal in atmospheres where hydrogen sulfide is present, such as ducting and electrical equipment. Hydrogen sulfide depletes oxygen, and can therefore produce a lethal atmosphere in enclosed spaces. Suffocation by hydrogen sulfide is a leading cause of injury and death in the groundwater industry.
Testing for hydrogen sulfide is quite straightforward. First, if you smell rotten egg in water or near it, you can assume hydrogen sulfide is present. At that point, be sure that there is proper ventilation. Because it oxidizes quickly during transport, onsite analysis of sulfide is often preferable to shipping a sample to the lab for analysis. Several reliable colorimetric methods are available for the purpose. To test for hydrogen sulfide for official purposes, contact a certified drinking water laboratory. Visit http://water.epa.gov/scitech/drinkingwater/labcert/statecertification.cfm for state-specific information on certified drinking water testing labs. The certification officer in your state can provide a list of certified labs in your area.
Hydrogen sulfide escapes (volatizes) from water easily, so samples should be tested on-site as mentioned or if shipping, immediately stabilized for laboratory analysis. Laboratory instructions should be followed very carefully.
If you do have a hydrogen sulfide level in your water that is higher than you would like, there are water treatment technologies available to address the problem.