Water and wastewater treatment are integral parts of a water utility’s role. Drinking water must be treated to prevent contamination with potential pathogens or other issues before it reaches consumers, and may require the addition of other additives such as fluoride for public health reasons. Sewage requires extensive treatment to prevent health and environmental hazards, regardless of whether it is bound for non-potable reuse, such as in irrigation, or to be released back into the waterways. Depending on how it will be used, harvested stormwater may also require treatment. Water and wastewater treatment often involve various types of filtration, treatment with chemical or even biological agents, and various other processes.