A Cure for Unnecessary Treatment

There’s no single solution to inflow and infiltration, but the right approach will help reduce the load.

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Welcome to I&I – Inflow & Infiltration Solutions and Equipment. It’s the premiere issue of the magazine, and a serious issue for your utilities. 

Inflow and infiltration cause significant problems, furthering degradation of infrastructure, contributing to sewer overflows, and increasing flow to treatment plants, all of which come at a high cost. Preventive maintenance and rehabilitation can be expensive, but proactive utilities can save millions in the long run by taking the necessary steps to keep I&I out of their collections systems. 

This magazine features projects, technical columns, case studies and how-to stories demonstrating the tools, technology and approaches utilities are using to improve their systems. 

One of the stories in this issue, “A Comprehensive Approach,” reveals some startling facts about the severity and impact of I&I. They should make everyone in the public sector stand up and take notice. 

One study cited in the story shows only 30 percent of flow to treatment plants is sewage. Another shows that in the state of Tennessee, I&I represents approximately 1.4 billion gallons of flow to treatment plants per year. I won’t go too far into the rest of the story, but I’d like to take a few of its numbers a little bit further. 

The EPA estimates it costs utilities somewhere between $2 and $5 per thousand gallons to treat that excess flow. 

In a fairly unscientific manner of illustrating this point, let’s assume all 50 states absorb roughly the same volume of I&I as the largely rural state of Tennessee — some are certainly lower, and some no doubt considerably higher. 

If we multiply that volume by the high end of the EPA’s estimated cost for treatment, we see an overall volume of approximately 70 billion gallons, representing roughly $350 million in unnecessary treatment costs. And that’s $350 million per year. Year after year. Plus the cost of treatment plant upgrades that may not be necessary if not for all that excess flow. 

Eliminating that I&I and reallocating the funds required for treatment wouldn’t solve the nation’s wastewater infrastructure problems, but it would make a big difference. We’re currently throwing that money away without solving the problem, and all the while the cost of making those necessary infrastructure improvements is growing.

Some I&I is inevitable, but there are much better alternatives to just accepting the problem and treating every gallon of water that flows into porous collections systems. We’re highlighting those alternatives with this magazine. 

This first quarterly issue of I&I focuses on manholes. The next will cover pipes, followed by inspection and monitoring. All four themes are critical pieces of the puzzle, and we hope to address them in a way that gives you a better picture of how to approach the problem. 

If you want to talk about I&I, tell me your story, or share what’s worked for your utility, you can get in touch any time. I’d be happy to hear from you. 

Thanks for checking out the new magazine.


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