Water & Wastewater Treatment Plants
Below is an overview of the city's water and wastewater treatments plants that services a population of approximately 435,000, throughout Raleigh, Garner, Rolesville, Wake Forest, Knightdale, Wendell, and Zebulon.
Water Treatment Plants
- 2 city owned and operated plants
- provides drinking water for 175,000 metered customers
Wastewater Treatment Plants
- 3 city owned and operated plants
- processes wastewater for 156,000 customers
E.M. Johnson Water Treatment Plant

Collects from Falls Lake
Volume
- 47 million gallons per day
- Maximum of 86 million gallons
Recognition
- Equipped with a sophisticated laboratory used to perform extensive water quality analysis
Phone: 919-996-2870
View LocationDempsey E. Benton Water Treatment Plant

Collects from Swift Creek Watershed, including both Lake Benson and Lake Wheeler
Volume
- Maximum capacity of 20 million gallons per day
Recognition
- Raleigh's newest plant, opened May 2010
- LEED silver certified facility
Neuse River Wastewater Treatment Plant

Volume
- Treats 44 million gallons per day
- Maximum capacity of 60 million gallons per day
- Treated over 16 billion gallons of wastewater last year
Recognition
- Has nine consecutive years of 100% compliance with a clean performance record
- Will received a Platinum IX Award issued by the National Association of Clean Water Agencies in 2012
- LEED silver certified Administration and Training facility
Smith Creek Wastewater Treatment Plant

Originally served Wake Forest & Transferred to Raleigh on July 1, 2005
Volume
- Maximum capacity of 2.4 million gallons a day
- Treated 456 million gallons of wastewater last year
Recognition
- Has seven consecutive years of 100% compliance and a clean performance record
- Will receive the Platinum VII Award issued by the National Association of Clean Water Agencies in 2012
Little River Wastewater Treatment Plant

Originally served Zebulon & Transferred to Raleigh on October 1, 2006
Volume
- Maximum capacity of 1.85 million gallons a day
- Treated 254 million gallons of wastewater last year
Recognition
- Has six consecutive years of 100% compliance with a clean performance record
- Will receive the Platinum VI Award issued by the National Association of Clean Water Agencies in 2012
Water Treatment Process
The treatment process used at the new Dempsey E. Benton Water Treatment Plant begins with adding ozone to the raw water and ends with ultraviolet (UV) disinfection and chloramination.
Suspended solids is coagulated with ferric sulfate, settled in a solids contact clarifier, and gravity fed through a two-stage filtration system.
The filtered water is then disinfected with both ultraviolet light and chloramines before it is stored in a 5-million gallon, on-site storage reservoir. From the storage reservoir, water is pumped directly to customers in Raleigh and Garner.
Wastewater Treatment Process
Advanced or tertiary treatment means that wastewater undergoes three stages of treatment: primary, secondary and advanced treatment.
- Primary treatment is a physical process removing debris, sand, heavy organic solids, and grease and oils.
- Secondary treatment is a biological process referred to as "activated sludge" in which microorganisms convert ammonia-nitrogen to nitrogen gas through the process of nitrification/denitrification. Secondary clarification separates the microorganisms from the treated water and returns them to the biological process.
- Advanced treatment is the process of filtering the clarified water in sand filters and disinfecting the water by ultraviolet (UV) light before the water is metered and returned to the Neuse River.
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