Quality and testing

Even though our tap water supplies are considered to be one of the safest in the world, water contamination can still occur.
  • There are many sources of contamination, including:
  • Sewage releases
  • Naturally occurring chemicals and minerals (for example, arsenic, radon, uranium)
  • Local land use practices (for example, fertilizers, pesticides, livestock, concentrated feeding operations)
  • Manufacturing processes (for example, heavy metals, cyanide)
  • Malfunctioning on-site wastewater treatment systems (for example, septic systems)

In addition, drinking water that is not properly treated or which travels through an improperly maintained distribution system (for example, the piping system) may also create an environment for contamination.

The presence of certain contaminants in our water can lead to health issues, including gastrointestinal illness, reproductive problems, and neurological disorders. Infants, young children, pregnant women, the elderly, and immunocompromised persons may be especially susceptible to illness.

The EPA sets standards and regulations for the presence and levels of over 90 different contaminants in public drinking water, including E.coliSalmonellaCryptosporidium, metals such as lead, and disinfection by-products. For more information on these contaminants and maximum contaminant levels, please visit EPA’s Drinking Water ContaminantsExternal page.

Content source: Centers for Disease Control and Prevention