History

The City of Raleigh’s E.M. Johnson Water Treatment Plant has been an important part of the community since it was first built in 1965. When it opened, it could treat 25 million gallons of water per day, but thanks to several upgrades over the years, it can now treat 86 million gallons per day.

The plant gets its water from Falls Lake Reservoir, which is fed by the Neuse River. After the water is taken from the lake, it’s stored in two large reservoirs, each holding 70 million gallons of raw (untreated) water.

From there, the water moves through the plant using gravity and passes through several treatment steps:

• Rapid mixing – where treatment chemicals are quickly blended into the water
• Flocculation – where small particles in the water stick together to form larger clumps
• Sedimentation – where those clumps settle to the bottom and can be removed
• Ozonation, filtration, and disinfection – final steps that clean and sanitize the water so it’s safe to drink

The proposed improvements will upgrade the rapid mixing, flocculation, and sedimentation parts of the process. These changes will increase how much water the plant can treat and help prepare the facility to eventually reach a treatment capacity of 120 million gallons per day.

Schedule