Wastewater treatment plants can capture and use methane, or biogas, which is a 100% renewable byproduct of the biosolids treatment process, anaerobic digestion. Anaerobic digestion is a biological process where microorganisms consume the wastewater solids. These microorganisms kill harmful bacteria, break down pollutants, and release methane gas. The methane, or biogas, is generally captured and used to generate electricity, heat, low carbon transportation fuel, or injected directly into the natural gas pipeline. Such uses mitigate climate change and reduce the reliance on fossil fuels.