This industry often sings the praises of water. This makes sense; it’s essential to life, industry, and commerce. But what we often ignore is, during its transport and treatment, water actually is working against us.
Water is like a predator. It’s always searching out the weakest spots of a pipe, pump, or tank and then attacking. First, a few drops slip into a tiny crack. Then, if freezing temperatures occur, the ice widens the crack and more water flows. The process continues until the material splits.
More common in collections systems — since freezing temperatures are rare — the flow supports bacteria that feed on the wastewater and produce corrosive chemicals that deteriorate concrete.
Of course, there’s no consciousness driving these forces, but that doesn’t change the outcome: Wrangling water, especially wastewater, takes diligence and skill. Luckily, utilities and engineers continually are developing new techniques and tools to help fight the battles.
The articles in this issue describe two of those new techniques. “Maximize Pump Performance” looks at how coating the interior chambers of pumps with epoxy can prevent water from corroding and creating deposits in the pumps. Not only does this simple procedure protect the metal, it recaptures efficiency, reducing energy costs.
On the concrete side of things, “Calculating Corrosion” tells how a utility in Alabama teamed up with modeling engineers to create a tool to point out pipe corrosion quickly and inexpensively. The model they developed indicates where hydrogen sulfide damage is most likely along 92,000 ft (28,000 m) of reinforced-concrete interceptor. By following the model’s guidance the utility saved about $350,000 in line inspection costs.
Maintaining and repairing transport and treatment systems is never-ending battle. Send me an e-mail describing what tools and techniques you use to fight back against corrosion and degradation.
— Steve Spicer,
©2010 Water Environment Federation. All rights reserved.