Research conducted by NSF International indicates that one-third of PEX plumbing piping samples tested per the NSF 61 drinking water standard exceed California drinking water standards for methyl-tert-butyl-ether (MTBE).
California Code Title 22, Division 4, Chapter 15, Article 5.5 establishes maximum contaminant levels (MCLs) independently from federal drinking water standards. In the state of California, MTBE is regulated with a MCL of 13 µg/L (parts per billion).
When evaluated using the industry standard NSF 61 test method three out of nine samples of PEX plumbing pipe demonstrated MTBE levels ranging from 15% – 92% above the California maximum contaminant level.
According to the State of California, MTBE levels above the 13 µg/L MCL present a 95% degree of confidence of a 10% increased risk of cancer in humans. Since January 1, 2000, at least 24 water sources in California have been shut down due to MTBE contamination as it is illegal in the state for a public water system to provide drinking water that exceeds this 13 µg/L MCL.
What does this mean for California home builders?
At least one builder in Arizona has already faced litigation from homebuyers alleging chemical poisoning due to MTBE water contamination, these suits were eventually settled at a cost of $175,000 per home.
With the public increasing their focus on drinking water quality in the wake of the Flint water crisis, home builders should exercise caution to ensure that their plumbing systems fully comply with California’s MTBE regulations.
What can I do to keep my water safe?
It is important to understand that not all PEX pipes will be a problem, in fact only one-third of PEX brands tested were found to exceed the California limit.
Documents from NSF International submitted as part of the California EIR show that some samples of PEX piping may leach MTBE at levels above 13 ppb after 90 days. If evaluated using NSF 61 procedures and state-regulated maximum contaminant levels, these samples would exceed several state limits. At least one lawsuit has already been settled by a PEX manufacturer and plumbing contractor after allegations of chemical poisoning from the PEX pipe.
If such documentation cannot be produced, there is no way to independently guarantee that your plumbing systems comply with California’s MCL requirements for MTBE. FlowGuard Gold CPVC has been specifically verified by NSF International to comply with state regulations for MTBE contamination.
Want to learn more?
If you’re ready to make the switch to a plumbing system that has been documented to comply with California’s MTBE regulations, download our checklist today.