Water Plant and Laboratory Services staff members analyze many water supply parameters at various times. Some parameters are tested daily, some annually, and some only once every nine years.
The following is further explanatory information regarding water supply analysis and reporting:
National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. Click here for the National Secondary Drinking Water Regulations.
Microbiological standards allow no more than 5.0% of all samples to test total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.) Every sample that tests positive for total coliform must be analyzed for either fecal coliforms or E. coli. If two consecutive total coliform-positive samples are detected and at least one is also positive for E. coli or fecal coliforms, the system has an acute MCL violation. Click here for the Microbiological Standards.
Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L. Click here for the EPA's Lead and Copper Rule.