One Size Does Not Fit All

There are basically three types of public water systems in common use throughout the country today:

Community water systems regularly serve at least 15 connections, or 25 people.

Nontransient/noncommunity systems serve a factory, school or the like where more than 25 people drink the water each day.

Transient noncommunity systems serve a facility, such as a restaurant or highway rest stop, where 25 or more different people may drink the water each day. They are regularly tested for nitrates and coliform just like a community system.

All public water supply systems test for more than 80 different substances. Because people may live in the same community, or work in the same factory or school for many years, this water is tested for many substances that pose a health hazard only after continued exposure for many years.

Private wells typically are tested by their owners for bacteria and nitrates, unless there is reason to believe other substances might be present. Cost is one of the limiting factors in what substances private wells are typically tested for.