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Lead and Drinking WaterBackgroundLead is a naturally occurring metal that was used regularly in a number of industrial capacities for most of the 20th century. Lead was used as a component of paint, piping (including water service lines), solder, brass, and as a gasoline additive until the 1980's. According to the U.S. Environmental Protection Agency, lead paint and the contaminated dust and soil it generates is the leading household source of lead exposure. Research has confirmed that lead is highly toxic. Lead can cause serious health problems if too much enters your body from drinking water or other sources. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered IQ in children. Adults with kidney problems and high blood pressure can be affected by low levels of lead more than healthy adults. Lead is stored in the bones, and it can be released later in life. During pregnancy, the child receives lead from the mother's bones, which may affect brain development. Contamination of WaterLead contamination almost always occurs after water has left the treatment plant when it travels through piping and plumbing containing lead. Water is naturally corrosive, and in some cases will corrode the pipes and plumbing through which it passes. This corrosion can occur in home fixtures as well. If these fixtures are made of materials, like brass, which contain lead, the fixtures can add dissolved lead to the drinking water. Brass fixtures and lead-based solder used in home plumbing prior to 1986 are significant sources of lead exposure in drinking water. Grounding of electrical circuits in homes to water pipes and galvanic action between two dissimilar metals may increase corrosion that could cause lead to leach into the water. Customers who soften their water or otherwise change its corrosivity can affect the lead content of the water. Federal ActionsIn 1986, Congress passed amendments to the Safe Drinking Water Act, prohibiting the use of pipe, solder or flux containing lead and had USEPA require specific public notification about the presence of lead in its drinking water or drinking water system. In 1991, USEPA published the Lead and Copper Rule, to require water utilities to reduce and maintain the corrosivity of water in order to minimize the leaching of lead from pipes and plumbing into drinking water. The LCR requires public water systems to monitor first flush lead levels in a predetermined number of homes based on system size. The homes where monitoring is to occur are selected based on the high likelihood that they will have lead service lines or plumbing that contains solder with high concentrations of lead. Based on data from this monitoring pool of homes, a public water system must meet a 15 parts per billion (ppb) action level at the 90th percentile for taps monitored. Based on the initial monitoring and analysis under the revised LCR, public water systems determine the needed process to maintain "optimal corrosion control." The primacy agency reviews and approvs the proposed control strategies and must approve subsequent changes. If the lead action level is exceeded, a utility is required to develop and undertake a lead service line replacement program. The LCR requires that a system replace 7 percent of the lead service lines which the system owns each year until all such lines have been replaced, or until tap water monitoring indicates that its 90th percentile lead level is equal to or less than the 15 ppb action level. As part of their corrosion control strategy, many public water systems add a corrosion inhibitor such as zinc orthophosphate to the water. While this is often effective as a means of corrosion control, it does increase the phosphate content in wastewater generated by that community. Phosphate is a limiting nutrient in many surface waters to which wastewater is discharged, and is regulated under the Clean Water Act because of its high potential to contribute to the eutrophication of lakes and rivers. In September 2007, USEPA promlgated Short-Term Revisions to the Lead and Copper Rule. The revisions include seven regulatory changes in the areas of sampling, monitoring, customer notification, public education, and changes in the lead service line test-out procedure and lead service line replacement. Current AWWA ActivitiesAWWA in early 2008 submitted comments on EPA's draft guidance for the Short-Term Revisions rule, including public education and consumer notification requirements and comments on the agency's plan for long-term changes to the LCR. The Water Utility Council and AWWA volunteers have developed guidances to help utilities navigate lead issues, including Assisting Schools and Child Care Facilities in Addressing Lead in Drinking Water. Utilities can link to consumer information related to lead in drinking water at AWWA's DrinkTap.org site. A consumer brochure on Lead in Your Drinking Water is available through AWWA's Bookstore. For more information, contact AWWA Public AffairsGreg Kail, Senior Public Affairs Manager |
