Your Government » Departments & Offices » Environmental Services » Water Utilities » Drinking Water » Water QualityYour water supply continues to meet all drinking water standards.All PFAS test results found are considerably below state adopted response levels.Su agua continua cumpliendo con todos los estándares de agua potable.Todos los resultados de las pruebas PFAS están considerablemente por debajo de los niveles de respuesta adoptados por el estado.Your water supply continues to meet all drinking water standards.All PFAS test results were found to be significantly below the state-adopted response level.Información Importante Sobre la Calidad de su Agua/ Preguntas Frecuentes Important Information about Your Water Quality / Q&APFAS (per- and polyfluoroalkyl substances) are a large group of chemicals referred to as “forever chemicals” that are potentially harmful to humans.They have been used in products due to their ability to repel heat, oil, and water.These chemicals are man-made and do not occur naturally, so they are found in our environment because of human activity and contamination.PFAS has been produced in the US since the 1940s.Some PFAS compounds, such as PFOS, are no longer made due to environmental and health concerns but they still exist in the environment in small amounts.Source: America Water Works AssociationThe State Water Resources Control Board's Division of Drinking Water Division (DDW) and Environmental Protection Agency (EPA) sets standards for water suppliers like the San José Municipal Water System to follow so that we can all continue to provide safe drinking water.The drinking water standard is known as the maximum contaminant level (MCL).The MCL for a contaminant is the highest level of that contaminant that can be in a drinking water supply.When an MCL is established, water suppliers are required to monitor the contaminant and ensure that the MCL is not exceeded.There are no MCLs for any PFAS chemical.When there is no MCL for a contaminant, Notification Levels and Response Levels may be established by DDW.A Notification Level (NL) is a non-regulatory health-based advisory, while a Response Level (RL) is a non-regulatory health based advisory level for which DDW recommends either treating the water source or removing it from use.DDW has issued NLs and RLs for the following PFAS compounds:*ng/L = nanograms per liter.One ng/L is equal to one part per trillion, or “ppt.”One part per trillion is equivalent to about one square inch in 250 square miles, or one second in 31,500 years.The US Environmental Protection Agency has shared the following guides to help residents learn more about PFAS exposure and ways to reduce your risk.