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City of Redwood City 2025 Public Health Goal Report <br />5 <br /> <br /> <br />Why Lead is Regulated? <br />In 1974, Congress passed the Safe Drinking Water Act. This law requires the EPA to <br />determine safe levels of chemicals in drinking water which do, or may cause, health <br />problems. These are non-enforceable levels based solely on possible health risks and <br />exposure. <br /> <br />In 1995 the State of California adopted an Action Level of 15 ppb for lead, and requires the <br />lead concentration in 90 percent of the water samples collected at customer taps not to <br />exceed the Action Level. <br /> <br />The California OEHHA revised the PHG for lead in drinking water from 2 ppb to 0.2 ppb on <br />April 24, 2009, based on new studies relating to the most sensitive health risks. <br />Since lead contamination generally occurs from corrosion of household lead pipes, it cannot <br />be directly detected or removed by Redwood City. Instead, EPA requires water systems to <br />control the corrosiveness of their water if the level of lead at home taps exceeds the Action <br />Level. The AL for lead has been set at 15 ppb because the EPA believes, given present <br />technology and resources, this is the lowest level to which water systems can reasonably be <br />required to control the contaminant should it occur in drinking water at their customers <br />home taps. <br />Health Risks <br />Lead has multiple toxic effects on human body. The OEHHA revised the PHG for lead in <br />drinking water based on new studies relating to the most sensitive health risks. These are <br />non-carcinogenic, chronic health effects including neurobehavioral effects (decreased <br />intelligence) in children and hypertension in adults. Lead also has the potential to cause <br />kidney disease and cancer; however, the carcinogenic risks are considered smaller than the <br />risks for chronic toxicity. The public health goal of 0.2 ppb was determined from a maximum <br />daily lead intake through water ingestion of 2.86 μg/day, which corresponds to a level of <br />9.B. - Page 13 of 27 <br />202