Any chemicals, including pesticides, that are spilled or applied to the land surface, have the potential to find a way into drinking water supplies. For public drinking water systems, the U.S. Environmental Protection Agency (EPA) mandates that pesticides cannot be over certain concentrations called maximum contaminant levels (MCLs). Your local water supplier must test and report any detectable pesticide concentration found in your drinking water, even when it is below the MCL. Concentrations below the MCL for any chemical contain a relatively low level of risk. If you use a private drinking water supply you are not likely to know if pesticides are in the water without specifically testing for them. You may suspect pesticides in your well if they are used or stored nearby, particularly if other indicators of land-use impacts, such as nitrate, are elevated. If you are concerned about the possibility of pesticides in your private well, contact your state or local health department. These officials can provide information about pesticide contamination issues in your area or specific testing recommendations. Have your water tested at a state-certified water testing lab.