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Fighting corrosion with corrosion

No one likes to see a river of water rushing down a city street, or a stream of water blasting out of a pipe.

Those are scenes Denver Water’s corrosion control team works to prevent every day.

“Our goal is to protect against corrosion — one of the main reasons that pipes break,” said Antonio Flori, a corrosion engineer at Denver Water.

 Corrosion is a naturally occurring process in which a chemical reaction causes metal to decay when it is in contact with humidity, soil and water in the surrounding environment.

 The corrosion problem isn’t unique to Denver Water. In 2002, a study for the U.S. Federal Highway Administration pegged the cost of corrosion on the American economy at $552 billion a year. Today, that’s about $772 billion a year.

One way Denver Water fights corrosion is by installing cathodic protection systems on pipes made of steel and ductile iron that are more than 2 feet in diameter.

The systems divert the corrosive effects of the environment away from the water pipe toward a second, less-important metal, such as magnesium or zinc.

Protecting our pipes from corrosion is a cost-effective way to extend the life of the pipes that carry water to our customers.

But cathodic protection systems can’t be installed economically on every pipe. Because of that, Denver Water also replaces an average of 60,000 feet of pipe every year. The 2019-2023 Capital Improvement Plan calls for investing $100 million on water main replacement and repair projects.
 

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Fighting corrosion
Installing cathodic protection systems onto large pipes involves connecting the pipes to bags of magnesium or zinc with wires.