How does gypsum drywall create odor problems when disposed in landfills?
When gypsum drywall is disposed in landfills, a series of biological and chemical reactions can occur that have the potential for adverse environmental impacts. When drywall in a landfill gets wet, some of the sulfate from the gypsum dissolves into the water. If this “leachate” reaches the groundwater, contamination with sulfate may result. The US federal secondary drinking water standard for sulfate is 250 mg/L. Concentrations above this level have been observed in the groundwater at unlined C&D debris landfills. The sulfate also contributes to the high total dissolved solids (TDS) concentrations observed in groundwater at many C&D debris landfills. Another issue results form the biological conversion of dissolved sulfate to hydrogen sulfide (H2S). H2S is a foul-smelling gas (rotten eggs). It is produced under wet, anaerobic conditions, such as those that often occur in landfills. The presence of organic matter such as yard trash or cardboard is needed for the microorganisms to thrive
