By David Purkiss
From the October 2017 Issue
Facility executives should always ensure that the components in their buildings’ plumbing systems meet the local plumbing code requirements. However, with the heightened concern over lead in drinking water, it can be useful to understand the sources of lead contamination and the specific requirements of the various laws, regulations, and standards related to lead and plumbing systems.
- Lead service lines connecting the building plumbing systems to the public water distribution system, which most often occur in buildings constructed prior to 1950
- Lead solder used in copper piping systems, which mainly occurred prior to 1986
- Lead-containing brass or galvanized pipe and fittings that are not certified to the NSF/ANSI 61: Drinking Water System Components-Health Effects standard
Additionally, products that do not comply with the “lead-free” content requirements of the U.S. Safe Drinking Water Act (SDWA), effective January 1, 2014, could also serve as a source of lead.
U.S. Safe Drinking Water Act (SDWA)
The U.S. SDWA requires all products that convey or dispense drinking water that were sold or installed in the United States after January 1, 2014 to have a weighted average lead content of 0.25% or less. This is what the SDWA defines as “lead-free.” The weighted average lead content is calculated from the lead content and relative wetted surface area of each part. This evaluation method is contained in the standard NSF/ANSI 372: Drinking Water System Components-Lead Content. Product certification organizations have listings of “lead-free” products that have been tested and certified to NSF/ANSI 372 on their websites. For example, NSF International maintains certified lead content product listings (found here on the NSF website).
NSF/ANSI 61: Drinking Water System Components-Health Effects
The lead content requirement of the U.S. SDWA does not directly address the measurement of lead or other contaminants that may migrate from a plumbing product into drinking water. This is addressed in NSF/ANSI 61: Drinking Water System Components-Health Effects. This standard contains evaluation criteria to measure the concentration of any chemical contaminant added by a material or device to drinking water.
Plumbing codes across the U.S. require potable water products to be certified to NSF/ANSI 61. This ensures that the products do not add harmful levels of lead or any other chemical contaminants to drinking water. NSF/ANSI 61 also requires products to comply with the lead content requirements of the U.S. SDWA, but it is worth mentioning that under rare circumstances a product could meet the 0.25% weighted average lead content requirement but still leach lead into drinking water above the 5 microgram per liter requirement of NSF/ANSI 61.
Facility managers should check to confirm that a product labeled as a “lead-free” plumbing fitting has been tested and certified to NSF/ANSI 61. NSF International provides a list of certified product listings for drinking water system components (online here).
Lead Contamination Control Act
Those who are managing a school or daycare facility should be aware of the Lead Contamination Control Act (1988). This Act banned lead-lined water coolers and provided guidance on sampling water from faucets and drinking fountains in schools and daycare centers for lead.
The recommended procedure is collecting a 250 mL first-draw sample from the outlet, after water has stagnated in the building for between eight and 18 hours. The acceptable limit on the concentration of lead in the 250 mL first-draw sample is 20 micrograms per liter.
Searching For Sources Of Lead
Trying to locate the exact source of lead within a plumbing system can be a complicated. For that reason it may be advisable for stakeholders to take sequential water samples to attempt to locate the source of contamination.
There are many potential contributors, including drinking fountains, faucets, piping, valves, and sealing/joining materials. There are also various factors to consider when trying to determine why plumbing products are contributing lead. There could be a corrosion issue where the aged plumbing infrastructure is releasing lead into the water supply. The plumbing products could have been installed incorrectly or are being used in a manner for which they were not intended.
On its website, the U.S. EPA has useful advice on locating sources of lead contamination in a plumbing system. This resource can be found online here.
When purchasing new plumbing fittings, facility managers should make sure the products that they choose are tested and certified by an independent, accredited third-party certifier to NSF/ANSI 61 and the “lead-free” requirements. That is the best way to avoid lead and other chemical contamination problems in building plumbing systems.
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