People are taking a second look at the water pipes in their home after the health crisis in Flint, Michigan. Most of the pipes installed in new homes for the past twenty years have been plastic, which does not have the potential to leach lead into the water flow, like lead pipe or pre-1986 copper pipe with lead solder joints. But there have been concerns about the chemicals in their composition, particularly vinyl chloride, getting into drinking water. 

    An analysis by the American Society of Civil Engineers (ASCE) found concentrations of vinyl chloride that exceeded the maximum safe level in PVC (polyvinyl chloride) pipe manufactured before 1977, but primarily in water utility dead-end pipes where the concentration could build over time. A protocol was designed for water utility managers to flush dead-end lines to reduce the the contamination and, secondarily, the composition was changed after 1977 to solve the vinyl chloride leaching problem.


   All plastic pipe used for drinking water must now be certified by the National Sanitation Foundation (NSF) to meet safety standards for transporting potable water, which specifically checks for contaminant leaching from the material. Plastic pipe that has been approved and rated for potable water will be marked with “NSF-PW” or “NSF-61” in the line of printed data along the side and, obviously, only rated pipe should be installed. Because PVC pipe is used for both water service pipe to a home (but not inside) and drainage pipe, the PVC pipe rated only for drainage will be marked “NSF-DWV,” which stands for Drain Waste Vent.

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Here’s links to a collection of our other blog posts about PLUMBING PIPES:

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Can galvanized steel pipe still be used for new water lines in a house? 

• How can I tell if I have cast iron pipes in my house? 

• Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

• What is the difference between green and white sewer drain pipes?

• Is a washing machine drain hose required to be secured at the standpipe?

• Why is some PVC pipe black?

• What are the code requirements for layout of drain piping under sinks?

• What causes a gurgling sound when a bathtub or sink drains? 

• What is a "combination waste and vent" in a plumbing system? 

• What is a building trap?  

• What is a galvanized nipple?

• What are the pipes sticking out near my water valves?

• If all the plumbing drains have water in them and you can still smell sewer gas, what's causing the problem?  

• How can I tell what type of plumbing pipe I have?

• Why is there a flexible accordion pipe under the sink? 

• What is the difference between PVC and ABS plumbing pipe?

• What is the difference between water service pipe and water supply pipe? 

• What are the pipes on my roof? 

• How can I find out what type of water pipe runs underground from the water meter to the house (service pipe)?

• What is a P-trap?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can you connect CPVC pipe directly to a gas water heater?  

     Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.