Lead in Drinking Water
Under the authority of the Safe Drinking Act, the USEPA set the action level for lead in drinking water at 15 ppb. The action level is the concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow. This means utilities must ensure that water from the customer's tap does not exceed this level in at least 90 percent of the homes sampled (90th percentile value). The Village of Western Springs completed its mandated Lead and Copper Rule sampling in September 2017 with a 90th percentile value of 2.71 ppb. One location exceeded the 15 ppb action level; however, the residence had been vacant for sometime and has since been torn down following sampling.
Everyone is exposed to background levels of lead, given its widespread distribution. The most common route of lead exposure is from soil, paint chips, or dust. One of the ways humans are exposed to lead is through drinking water. The amount of lead in drinking water is typically very low. Lead enters drinking water primarily as a result of the corrosion, or wearing away, of materials containing lead in lead service lines and household plumbing. These materials contain lead-based solder used to join copper pipe, brass and chrome-plated brass faucets, and in some cases, a home's service lines, pipes made of lead that connect your house to the water main.
The Village of Western Springs has taken proactive steps to prevent corrosion from occurring. Prior to the retrofit of the Water Treatment Plant in 2012, the Village utilized a lime-softening water treatment system which prevented corrosion by depositing a protective layer on the interior of the ductile iron water mains preventing the water from forming chemical reactions that could leach lead out of metallic service lines and solder materials used to join copper piping. Following the retrofit of the Water Treatment Plant, the Village began treating the finished water with a chemical corrosion inhibitor. This polyphosphate/orthophosphate proprietary blend is designed to prevent lead and copper corrosion and control the sequestration of iron and manganese in solution.
Regulatory measure takes during the last two decades have greatly reduced human exposure to lead in drinking water.
- In 1974, Congress passed the Safe Drinking Water Act. This law requires the EPA to determine the level of contaminants in drinking water at which no adverse health effects are likely to occur with an adequate margin of safety.
- In 1991, the EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule. The EPA revised the regulation in 2000 and 2007.
- Congress has also set limits on the amount of lead that can be used in plumbing products. These requirements were first enacted in 1986 and then reduced to even lower levels in 2014. Currently "lead-free" plumbing products must contain less than 0.2 percent lead by weight, as opposed to, 8 percent lead by weight.