---
title: Combating Inflow and Infiltration
description: Reducing the presence of I&I and preventing combined sewer overflows (CSOs) requires more than traditional rehabilitation methods. Learn more.
---

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# Download a Free Guide to Combating Inflow & Infiltration

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### Download Free Guide

## About Inflow and Infiltration

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## **Inflow and infiltration (I&I) is a risk in any wastewater system.**

Excessive amounts of I&I are dangerous because they can cause flow to exceed a treatment plant or collection system's capacity, which puts the facility at risk of sewer damages and sanitary overflows. These untreated water discharges are particularly hazardous; they endanger our natural environment and can cause health issues in communities.

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## **Yet in regions with older infrastructure, groundwater and stormwater that enter a sewer system can account for as much as 50% of flow.**

The cost of this disruption should not be underestimated; in 2014 the EPA reported that wastewater collection and treatment expenses ranged from **$2 to $5** per thousand gallons. An annual I&I volume of 150 million gallons would cost between **$300,000** and **$750,000** per year to transport and treat. Given that even small amounts translate into substantial costs, where should you draw the line on I&I? How much is too much?

Reducing the presence of I&I and preventing combined sewer overflows (CSOs) requires more than traditional rehabilitation methods. A proactive, strategic approach is essential to tackling the issue head-on, and the result is a more successful one—using fewer resources.

Our guide, *Combating Inflow and Infiltration From the Inside Out*, walks you through the steps you should be taking to reduce the presence of I&I in your system and avoid combined sewage overflow.

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[Download Whitepaper](https://inbound.envirosight.com/combating-ii-lp#lp-form)

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