Drinking Water from Plastic Pipes May Not Be Safe, Chemical Additives Found
Drinking water from plastic pipes is used more often in construction than traditional copper piping for delivering water to homes and within homes to the faucet. Previous studies on plastic pipe safety for drinking water were limited to issues regarding taste and odor. Today, however, a recent study reveals its findings on not only the taste and odor of drinking water from plastic pipes, but also on leakage products consisting of residues from chemical additives used in the manufacture of plastic pipe.
Drinking water in the U.S. is provided by approximately 161,000 public water systems. Most of our drinking water comes from community water systems that serves roughly 268 million people and is monitored by the Environmental Protection Agency (EPA). The water comes from either surface water sources such as lakes and reservoirs or from groundwater sources such as aquifers.
After water from a source is processed through a treatment plant, it travels up to thousands of miles though complex piping systems before it finally arrives in your home and through your faucet. The average American home uses approximately 90 gallons of water a day, which many consider excessive in comparison to the average European who uses 53 gallons a day and an individual in the sub-Saharan desert who uses only 3.5 gallons per day.
In recent years, the price of copper has forced builders to switch to plastic pipes for delivering water to homes. The types of plastic piping used include polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene, high-density polyethylene (HDPE) and more recently a form of polyethylene called cross-linked polyethylene known by its abbreviation PEX. Prior to using plastic for water systems, all of the types were approved and certified by NSF International, an independent certification, standards and testing organization, and the American National Standards Institute (ANSI).
The popularity of using PEX over copper is that it has proven to be just as reliable as copper, is more flexible, easier to install and of course—much cheaper. However, with some consumers, the use of PEX or other forms of plastic pipe for drinking water has met with resistance. Chief among the claims against plastic piping is that it can cause the water to have an odor or taste that has been described as being fruity, waxy or plastic-like in character.
When chemical experts were called upon to assess the complaints, they determined that at times—especially with a new plastic pipe water system—that the water can have an odor or taste to it that differs significantly from a tasteless test control water sample. However, in almost all cases, the malodor and bad taste of the water disappeared after two months of use in a home. They said that why some homes may be affected and others not could be due to differences in the water itself dependent upon the water treatment plant that supplies the water.
Another concern of using plastic pipe for drinking water is that chemical additives used in the manufacture of plastic pipes may leach out and contaminate the water. In a recent study published in the Journal of Water and Health, researchers from the Norwegian Institute of Public Health decided to examine ten different types of PEX pipes used in delivering drinking water for odor and taste as well as evidence of leached chemicals from the plastic.
Using standardized laboratory tests, they placed water samples into samples of plastic pipes for 72 hours and then analyzed the water samples for chemical breakdown products from the pipes. The results of the study are listed as follows: