The oldest cast-iron pipes date back to the late 1800s. They usually have an average useful lifespan of 120 years. But because manufacturing techniques and materials change over time, the lifespan of these cast-iron pipes fell to about 100 years. Of course, the techniques and materials continued to evolve and further reduced the pipes’ lifespan.
But the truth is, pipes, in general, do a lot of work. In the case of America’s water infrastructure, pushing so much water across the nation requires a lot of pressure, force, and energy, which often put a lot of strain on the inner walls of the pipes. Over time, the violent force of the fast-moving water grinds away at the pipes and weakens them.
Pipes used in water distribution are usually made from metals (e.g., steel, galvanized steel, copper, ductile iron, aluminum, etc.). This is because metals are sturdy and can last a long time. However, metal pipes are susceptible to various factors that may wear them down.
According to the Centers for Disease Control and Prevention (CDC), pipes can erode based on their properties, the environmental conditions, the surrounding soil, and stray electric current. Other factors influencing corrosion of pipes include the water’s chemistry and characteristics (pH, alkalinity, and biology), salts and chemicals dissolved in the water, and the physical properties of the water (temperature, gases, and solid particles).
Water treatment strategies also play a role in corrosion. More than 40 different chemical additives can be used to treat drinking water, some of which are very acidic. Acidic chemical additives include ferric chloride and aluminum sulfate. These chemicals are added to water to remove turbidity and other particulate matter. Various chlorine disinfectants also act as acids and can reduce pH, alkalinity, and buffer intensity. These acidic water treatment additives can interfere with corrosion protection. Corrosion inhibitors like fluoride are often used to address the influence of acidic water treatment. Still, you must remove them from your drinking water before drinking it.