Lead Service Lines
It's not just your service lines: how lead gets into your water
Lead is widely recognized as a key contaminant in drinking water. Efforts have been made to reduce the risks associated with lead contamination, but there remains much work to be done. When considering lead in drinking water, lead service lines are often the first thing that comes to mind. Indeed, these service lines are typically the most significant source of lead in tap water [1]. When water sits stagnant in service lines and household plumbing, the pipes will corrode and leach lead into the water (link to Aidan’s article). While perhaps the most talked about, lead service lines are not the sole culprit of lead in drinking water.
The United States Environmental Protection Agency (US EPA) found that lead may also leach into drinking water from brass- or chrome-plated faucets, galvanized iron pipes, or plumbing soldered with lead [1]. Homes, schools, and businesses where lead service lines have been replaced may continue to find lead in their water due to the presence of these fixtures.
The use of lead service lines and fixtures was common in older homes. In 1986, Congress passed amendments to the Safe Drinking Water Act [2], requiring new plumbing to be lead free. At the time, “lead free” meant that pipes could not contain more than 8% lead and solder/flux could not contain more than 0.2% lead. Despite the “lead free” designation, plumbing could still contain a fair amount of lead during this time. To resolve this somewhat misleading designation and further reduce lead risks, Congress passed the Reduction of Lead in Drinking Water Act (RLDWA) in 2011. This act changed the definition of lead free, lowering the maximum permitted content of lead in wetted surfaces of plumbing products from 8% to 0.25% [3]. There is no safe level of lead, but this new definition serves to decrease the risks associated with lead contamination in drinking water.
Understanding lead risks in your home requires a more nuanced awareness of where lead comes from and how the US EPA regulates lead in plumbing. Replacing lead service lines is only part of the solution. The best way to understand the risks in your home is to test your water and take EPA-recommended measures to reduce lead concentrations. Some simple strategies to reduce lead contamination in your home include cleaning aerators on faucets and flushing water through household plumbing prior to use [4]. Aerators are not designed to remove contaminants, but often lead to the buildup of sediment of debris. Backwashing aerators removes any lead-bearing sediment that has been trapped. Since lead is primarily leached into stagnant water, flushing out the water that has been sitting in your pipes will decrease lead concentrations and reduce risks.
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