Whether this water derives from rivers, lakes, reservoirs, or aqueducts, it is purified before entering the water works system. However, introducing clean water into this system doesn’t guarantee the delivery of clean water to people’s homes, since there are plenty of opportunities for the water to be tainted from leeching as it travels through the existing piping and infrastructure.
The latest revision of NSF/ANSI 61-2016 - Drinking water system components - Health effects helps to prevent the presence of contaminated water in systems by establishing the health effects that chemical components and impurities, coming from products, components, and materials, can have on those who drink it, along with detailing methods for finding those health effects and manufacturer considerations that limit their likelihood. The products and materials covered by this standard include, but are not limited to:
- Process media (e.g. carbon, sand)
- Protective materials (e.g. coatings, linings, liners)
- Joining and sealing materials (e.g. solvent cements, welding materials, gaskets)
- Pipes and Related Products (e.g. pipes, tanks, fittings)
- Mechanical devices used in treatment/transmission/distribution systems (e.g. valves, chlorinators, separation membranes, point-of-entry drinking water treatment systems)
- Mechanical plumbing systems (e.g. faucets, endpoint control valves)
The materials chosen during the construction of these products play a key role in the impact that they can have on the water system during their lifetimes. Because of this, NSF/ANSI 61-2016 only calls for the selection of certain materials that are known to be more suitable for coming into contact with drinking water.
In addition, NSF/ANSI 61-2016 makes it clear that there should be no lead added as an intentional ingredient in any relevant product, with a few exceptions. These include the heads of fire sprinklers and brass, bronze, or flux that meets the definition of “lead free” under the Safe Water Drinking Act of the United States. Specifically, this is defined in the Act as:
“When used with respect to solders and flux refers to solders and flux containing not more than 0.2 percent lead”
“When used with respect to pipes and pipe fittings refers to pipes and pipe fittings containing not more than 8.0 percent lead”
NSF/ANSI 61-2016 also touches upon methods for evaluating the material by exposing a representative sample to varying temperatures and intensities of water that replicate the effects it could have on water. However, the testing varies among the different materials and products. For example, copper pipe and tubing should be analyzed with pH 6.5 and pH 10 exposure water. After this procedure is completed on any copper pipes, tubing, or fittings, the manufacturer’s literature should reference the standard as:
“Copper [tube, pipe, or fitting] (Alloy [alloy designation]) has been evaluated by [Testing Organization] to NSF/ANSI 61 for use in drinking water supplies of pH 6.5 and above. Drinking water supplies that are less than pH 6.5 may require corrosion control to limit leaching of copper into the drinking water.”
Along these same lines, manufacturers should include information on the testing and the products’ composition that is relevant to their exposure with water systems.
With this information, users of the NSF/ANSI 61-2016 standard are able to determine the contaminants that could emerge in the water that travels through the piping system over time, even when factoring in a variety of conditions. This can provide the means to protect those who depend on this water in their everyday lives.
Users should also note that water exposure could vary depending on the water age, which can be incredibly high in certain situations in which the water does not regularly flow through the piping. For example, this might occur in schools, where the buildings would be stagnant for months at a time, and thus, the water might not be regularly accessed.
For guidelines on the effects of chemicals used in the water treatment process, please refer to NSF/ANSI 60-2015 - Drinking water treatment chemicals - Health effects.
NSF/ANSI 61-2016 - Drinking water system components - Health effects is now available on the ANSI Webstore.