What is a Sanitary Sewer Overflow vs. a Release?

An overflow is the release of untreated sewage or partially treated sewage into the water.  An overflow typically occurs when one or more of the following happens:

• Blocked sewer lines often due to grease, rags, or other materials wrongfully put into these sewer lines.
• Infiltration/inflow of excessive stormwater into the sewer system during heavy rainfall.  
• Malfunctions of pumping stations, other equipment, or electrical outages.
• Broken sewer lines caused by construction, line failure, or geologic conditions.

A release is the flow of sewage from any portion of the collection or transmission system owned or operated by the city other than through permitted outfalls that does not add pollutants to waters.

Cities are required to notify the Tennessee Department of Environment and Conservation of all overflows.

Sanitary Sewer Overflow Summaries

2025 Brentwood Overflow Summary

2024 Brentwood Overflow Summary

2023 Brentwood Overflow Summary

2022 Brentwood Overflow Summary

2021 Brentwood Overflow Summary

This video is an example of how water gets into our sewer system through holes in the pipes.  Over the years, Brentwood has aggressively worked to repair leaky pipes.   Since 2006, Brentwood has invested $30 million to reline 166,000 feet of pipes, repair 1,732 manholes, and rehabilitate 15% of the Little Harpeth River sewer.   This plan has reduced system overflows and removed 700 Million gallons of infiltration/inflow annually.