Surface Water Quality

​​​Sanitary Sewer Overflow​s​

Charlotte Water is the City's department that is responsible for the collection and treatment of wastewater (sewage) from households and businesses in Charlotte and Mecklenburg County.  On average, Charlotte Water collects over 30 billion gallons of wastewater annually through over 4,000 miles of pipes which it then treats at five wastewater treatment facilities. With the vast amount of wastewater transported through the large network of pipes, it may come as no surprise that some wastewater escapes the system. The good news is that 99.998% of wastewater is typically treated, but the bad news is that what does escape has negative impacts on streams and lakes. The most common way it escapes is through leaks in the system and sewage overflows. Sewage has high levels of bacteria and other microorganisms that are harmful to public health and aquatic life. Sewage that enters surface waters consumes oxygen in the water which can lead to fish kills. 

Sewage overflows happen when substances block the line, causing sewage to back up and come out of manholes.  Grease is a common cause of sewer line blockages.  Please see Charlotte Water's websitefor more information about common causes of sewage overflows and what residents can do to help prevent them.

To help locate sewage overflows into streams and lakes, Storm Water Services staff conducts extensive sampling in surface waters for fecal coliform bacteria, an indicator of sewage discharges. If results are above a specific action level, staff continues testing to determine if a sewage leak or overflow is suspected. If one is suspected, they notify Charlotte Water and work collaboratively to determine if the source is from their sewer collection system. 

To reduce sewage overflows, Storm Water Services and Charlotte Water also team up to educate multi-family residential communities.  Each year, staff targets 100 multi-family complexes with information about requirements to develop an Operation and Maintenance Plan for their private sewer system.  They provide one-on-one assistance to these residential complexes, offer optional workshops, and conduct follow-up inspections to help ensure that the plans are being implemented.  Please find more information and guidance documents related to the mul​ti-family residential permits and community education program on Charlotte Water's website.​​