What are the most common gases found in groundwater?

The most common gases found in groundwater primarily include Hydrogen Sulfide, Carbon Dioxide, and Methane due to their formation and behavior in aquifers.

Hydrogen Sulfide can originate from biological activity, particularly the decomposition of organic matter in anaerobic conditions, and is often found in deeper groundwater where organic materials are prevalent. Carbon Dioxide is frequently present in groundwater as a result of the dissolution of atmospheric CO2 and organic matter, contributing to the natural acidity of groundwater. Methane can also be produced in groundwater systems due to anaerobic decomposition of organic matter, especially in wetlands and under conditions with low oxygen levels.

These gases are not only typical in groundwater because of their biological interactions and chemical reactions but also play a significant role in the geochemistry of aquifers. Understanding these common gases helps in assessing groundwater quality and making informed decisions regarding groundwater resource management.