There are some important caveats to this data. First, there’s no way to know if you’re drinking water from a contaminated well without calling your water provider. State regulators have provided a contact number for most of the tested wells, which you can find in the info box on the map. Second, even if you drink from a contaminated well, it’s possible that your water is mixed with multiple water sources before it reaches your tap. The water is tested at the source, and in some cases the water is treated before it’s sent to consumers. There’s no way to know if your water is mixed or treated without calling your water utility. State regulators mandated testing at roughly 600 wells deemed at high risk for contamination. Those included water sources close to airports or landfills and sites that previously tested positive. While more wells will be tested in the future, many thousands of wells at a lower risk for contamination have not been tested. Scientists have called them “forever chemicals” because they persist indefinitely and accumulate in the human body. The chemicals were developed in the 1940s and used in countless household products, from Teflon cookware and Scotchgard to waterproof clothing and food packaging. There is no agreed-upon safe level of PFOS and PFOA. The Environmental Protection Agency has classified the chemicals as an “emerging contaminant” and has delayed setting a national standard for limiting the levels in drinking water. In 2016, the agency issued a nonbinding health advisory recommending that water utilities notify the public if levels of the chemicals reached a combined 70 parts per trillion. Read more about the chemicals in Monday’s Times story.
Nearly 300 wells across the state of California are said to contain harmful chemicals ordinarily found in furniture, clothing, packaging and fire-retardants. The chemicals, known broadly as PFOS or PFOA, have been linked to cancer, developmental issues in children and damage to the liver and immune system. The discovery was made following the state mandating the testing of 600 "at-risk" wells. There is no agreed upon safe level of these chemicals. Consumers have been told, however, some water from the contaminated wells is mixed with other sources before reaching taps. In a statement released on Wednesday, Governor Jerry Brown said, "The governor has directed his staff to conduct an independent investigation into this issue so that Californians can be assured they will not suffer any health consequences associated