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LeadLead is a heavy, soft, and malleable metal found in natural deposits (such as ores containing other elements) and has no characteristic taste or smell. It is used to make pipes, cable sheaths, batteries, solder, paints, and glazes. Where drinking water is concerned, lead has been used to produce service lines and solder (both banned since 1988), and a variety of brass pipes and plumbing devices. Effects of Lead on Human Health and How It Enters Drinking Water Most lead enters our drinking water through the interaction of the water and plumbing materials containing lead, that is, through corrosion and the solubilization of lead-based corrosion by-products. Water chemistry, the age of the piping, and the amount of exposed lead at the surface of the material in contact with the water are the most important factors contributing to lead leaching into our drinking water. Plus, trace amounts of certain soluble contaminants, including lead, can be adsorbed by corrosion deposits within distribution systems. Changes in water chemistry or physical changes within the system can later cause concentrated amounts of these contaminants to be rereleased into the water supply. Although lead is rarely found in source water, lead mining and smelting operations may contribute to the contamination of source water in certain areas. To prevent lead from entering our drinking water, there are three categories of control:
RegulationsRegulations to reduce human exposure to lead are:
These regulations are called the National Primary Drinking Water Regulations. All public water utilities are required to abide by them. Most regulations require sampling at entry points to the distribution system to ensure conformance; however, because increased levels of lead in drinking water are primarily due to the corrosion of distribution and household plumbing materials, water utilities must collect water samples at kitchen or bathroom taps of residences and other buildings. This requirement significantly complicates sample collection and requires that water utilities coordinate with consumers to ensure that proper sampling and conformance is achieved. If the levels of lead in your drinking water are found to be consistently above the action level, your water supplier must take steps to reduce the amount of lead so that it is consistently below that level. Additional actions, such as providing alternative drinking water supplies, may be required to prevent serious risks to public health. Technical Contact:Darren Lytle (513) 569-7432 See Also:National Primary Drinking Water Regulations List of Drinking Water Contaminants and MCLs Lead Contamination Control Act of 1988 Lead and Copper Rule Revisions of 2001 and 2006 Safe Drinking Water Act Amendment of 1996 Lead Contamination Control and Asbestos Information Acts of 1988 Lead and Copper Rule Targeting and Sampling Requirements Lead in Drinking Water in Schools and Non-Residential Buildings |