Why Permeation Matters & How to Prevent It

Permeation may occur if outside substances present in the environment, such as chemicals, hydrocarbons, petroleum, gasoline, insecticides, and fertilizers get absorbed by piping material, pass through the pipe wall, and mix with drinking water or other contents of the pipe. In the case of drinking water, such contaminants may then pass into homes, businesses, and schools serviced by the system. The risk of permeation depends greatly on the type of piping material installed.

Permeation and Plastic

If a plastic piping option is utilized, the building or home may be at risk of permeation events. According to the American Water Works Association (AWWA), there is a great concern around contaminants’ ability to pass through plastic piping, including hydrocarbons, insecticides and organic materials that may be present in the surrounding soil or environment1. Specific cases examined by the AWWA focused on the permeation of petroleum-based aromatics such as benzene, toluene and ethylbenzene, which can come into contact with underground piping installations through contaminated soils, gasoline and oil spills, or other contaminant-releasing situations. Testing conducted by the AWWA yielded that plastic piping can be rapidly and readily penetrated by gasoline (both free gasoline and aqueous gasoline solutions) by the process of permeation2.

Permeation and Copper

When dealing with copper piping systems, permeation events are not as great of a concern or threat. Copper is an impermeable metal, meaning outside contaminants present in the surrounding soil or environment are not able to breach or be absorbed by copper tubing; this includes gasoline or petroleum, insecticides, fertilizers, hydrocarbons and organic materials.

Risks Posed by Permeation Events

Permeation can allow harmful pollutants to enter drinking water, posing a health risk to those who consume contaminated water and therefore unknowingly consume substances such as gasoline, petroleum, hydrocarbons, chemicals, organic waste, fertilizers and more.

Additionally, the piping that transports water to our homes and facilities is often underground and out of sight, making it difficult for an individual or group of individuals to detect a permeation event. These pollutants can be odorless, colorless and tasteless, making it nearly impossible to prevent their accidental consumption if the water is contaminated.

Preventing Permeation

The best solution for permeation is to prevent it from occurring in the first place. This can be done by selecting an impervious piping material from the beginning of an installation project, or by replacing any pervious piping materials with the assistance of a certified plumbing engineer or contractor. Unfortunately, flushing the line for a lengthy period of time with clean water may not fully resolve the issue.3


  1. Holsen, T.; Park, J. K.; Jenkins, D.; Selleck, R.: Contamination of Potable Water by Permeation of Plastic Pipe; Journal AWWA, August 1991
  2. Mao, F.; Gaunt, J.; Ong, S. K.; Permeation of Petroleum-Based Aromatic Compounds Through Polyethylene Pipes Under Simulated Field Conditions; AWWA Annual Conference, 2006
  3. Selleck, R.; Marinas, B.; Analyzing the Permeation of Organic Chemicals Through Plastic Pipes; Journal AWWA, 1991

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