(0) zero denotes none present, NA means not reported and * means milligrams of substance per liter of water. It is important to note, none of the tests exceeded the Maximum Contaminant Levels (MCL) as set by the Environmental Protection Agency (EPA) except for the presence of Coliform." http://web.archive.org/web/20061029201637/http://www.harvesth2o.com/rainwater_safe.shtml http://www.harvesth2o.com/rainwater_safe.shtml