How did the water become contaminated?
Surface waters, such as streams, creeks, and lakes, will almost always contain some degree of contamination. This is due to exposure to animals, humans, aquatic life, etc. Raw surface waters should always be treated prior to domestic use, and must include disinfection and filtration to remove turbidity and parasites that are resistant to simple disinfection. Wells and springs can become contaminated by faulty construction, poor protection from surface activity including rain and flooding, a shallow water table, entrance of unfiltered surface water via rock fractures, close proximity to a sewage disposal system or leaky sewer pipe, and/or contamination during repair or reconstruction. A false, positive coliform count can occur by contaminating the water sample (e.g., putting one’s finger into the water sample bottle) or by using a non-approved water sample bottle. A well or spring should be super-chlorinated prior to the coliform test, especially if a repair has been made and the system
