Why Does My Water Corrode My Plumbing?

Signs of Corrosion

• When copper dissolves from piping and enters the water, it often deposits blue stains. Oxidized copper creates blue stains on bathtubs, sinks and other fixtures and may even stain laundry. High levels of copper can also be harmful to health when levels are higher than 1.0 mg per liter. Iron pipes, on the other hand, leave rust stains when they erode. Such pipes may produce water with a reddish tint, similar to rust, and a telltale metallic smell.

Acidity

• Water with a low pH, which is acidic, can corrode piping by dissolving it slowly over time. Private wells often have acidic water, but it may also be found in small municipal systems. You can use a pH tester to determine if this is the source of the problem. Raise the pH of your water system by installing a calcite neutralizer tank or soda ash feeders. These systems are designed to help you increase alkalinity to a more neutral range (between 7.0 and 8.0).

Physical Corrosion

• When corrosion cannot be blamed on chemical imbalances, it may be due to the abrasive effect of sediment or other small particles present in the water. Over time, sand and other sediment can grind away at piping due to the hydraulic force of water. Physical corrosion also occurs in systems with high water velocities. Generally a velocity higher than 4 feet per second can be problematic for pipes and may lead to a fast breakdown of the copper oxide layer that protects copper pipes.

Chemical Corrosion

• Various chemical conditions lead to a breakdown of plumbing systems. Oxygenated water degrades metal piping, resulting in oxidized and rusty metal. Such metal is weak and releases corroded material into the water. Contact with dissimilar metals can also spead up pipe deterioration, which is called galvanic corrosion. This can be fixed with the addition of dielectric fittings.