As water travels over the surface of the land or under the ground, it dissolves naturally occurring minerals and material. It also picks up substances left by animal or human activity as it travels to its destination. For instance, microbial contaminants may come from septic tanks, livestock, wildlife and wastewater treatment plants. Pesticides and herbicides come from agricultural and excess residential runoff. Other contaminants come from urban runoff, petroleum products, mining, and industrial wastewater.
Radioactive materials can occur naturally in surface water.
Members of the public are encouraged to provide their input by attending City Council meetings.