Which type of water generally contains more hydrogen sulfide?

The type of water that generally contains more hydrogen sulfide is well water. This is because well water often comes from underground aquifers that can be influenced by geological conditions conducive to the formation of hydrogen sulfide gas. When groundwater traverses sulfide-bearing geological formations, bacteria can reduce sulfate to hydrogen sulfide, especially in low-oxygen environments.

Rainwater typically has very low levels of dissolved solids and gases, as it is collected directly from atmospheric moisture. Surface water may have some hydrogen sulfide levels but usually undergoes more aeration and interaction with atmospheric conditions, which helps to oxidize hydrogen sulfide into sulfate before it accumulates significantly. Groundwater can also contain hydrogen sulfide, but it is less common in comparison to well water that often comes from isolated sources within aquifers that provide ideal conditions for its presence.