The piping used in home plumbing, whether it is copper or PVC, has very smooth interior surfaces which don't permit bacteria to settle and grow. However, over time, hard water results in scale formation on the interior surfaces of those pipes and that provides a perfect home for bacteria. This problem can be rather widespread as nearly 90 percent of American homes have hard water - water containing high levels of calcium and magnesium, according to The U.S. Geological Survey.
The Arizona State University researchers found that microbial biofilms do not form on pipes that have no scale on them but can grow on both regular pipes filled with hard scale and soft scale. Soft scale is created with some forms of water conditioning. This converts the water hardness minerals into a form of scale that remains in an amorphous mass within the plumbing. Hard scale forms crystals that adhere strongly to the plumbing surface. Both hard and soft types of scale showed a similar tendency to support the growth of microbial films in the research.
The only solution is to remove the scaling in the pipes entirely and only a traditional water softener can do that. These work by running the incoming hard water through a resin filter that traps the calcium and magnesium in the water - as well as any iron, manganese or radium ions - and replaces them with sodium ions. Many of the alternative water conditioners do not completely remove these harmful hard minerals.
The occurrence of biofilms can cause serious hygienic problems in water systems. The development of biofilms depends on a variety of factors such as water flow rates as well as the different plumbing materials. When pathogenic microbes inhabit these biofilms, home plumbing ends up being an ideal home with a direct line of contact with humans. Colonization of plumbing by disease-causing bacteria is well-documented, especially in hospital buildings and hotels. Once in the piping, the bacteria can be distributed through the showerheads. The hot water and steam created are then inhaled along with the bacteria, increasing the risk of exposure to consumers.
This study is the first one to demonstrate the significant benefits of traditional water softeners to prevent the development of biofilms in home plumbing. You can test your water yourself to check for hardness with home water testing kits or you can have a water treatment professional do the testing. The Water Quality Association has a webpage enabling searches by company name, state or ZIP code. For more information on water softening, visit www.saltinstitute.org.