The Dirty Details
In 1986, amendments to the federal Safe Drinking Water Act mandated “lead-free” pipes and plumbing materials—although lead-free was a misnomer as the law allowed the products to contain up to 8 percent lead. In 2011, the law was again amended to define lead-free as no more than 0.25 percent lead, but the new standard didn’t take effect until 2014. Therefore, the older the pipes are in your home, the more likely they are to contain potentially harmful levels of lead. What’s more, the plastic pipes that are replacing metal pipes may contain other chemicals of concern.
The drinking water in older homes is at risk of lead contamination due to old plumbing systems. Pipes in homes built before 1930 are the most likely to contain lead, and homes built before 1980 are likely to have lead solder connecting copper pipes. Brass faucets or Copper or polypropylene pipes “Lead-free” joint materials, with less than 0.20 percent lead “Lead-free” faucets and fixtures, with less than 0.25 percent lead fittings may also contain and leach lead even though they are labeled as “lead-free.” Themore these pipes, solder and faucets are corroded by acidity, the more lead contamination of tap water will occur.
Water contaminated with lead—even at low levels—can be harmful, especially to kids and pregnant woman.
The only way to know for sure if your drinking water is contaminated with lead is to have it tested by a state-certified commercial laboratory. Contact your local water utility or your local public health department and ask for their list of recommended labs. Some communities offer free lead testing kits.
Carcinogenic vinyl chloride can leach from pipes made from polyvinyl chloride, or PVC, especially in pipes made before 1977. The U.S. Green Building Council says that considering the lifecycle of PVC, from manufacturing to disposal, the material is clearly more of a health hazard than other types of pipes.
Other Plastic Pipes
A type of polyethylene plastic called PEX has become a popular choice for pipes. PEX piping is flexible, durable and resistant to corrosion. But because it is somewhat permeable, pesticides, gasoline or other soil contaminants can migrate through the pipe into drinking water. Studies have also shown that PEX piping can leach MTBE, a toxic petroleum byproduct, into drinking water. A 2009 California Building Standards Commission study found that MTBE leaching from PEX pipes declines rapidly over time, but some leaching may still occur.