The City of Atlanta’s raw water system infrastructure forms the foundation and starting point for delivering clean and reliable drinking water as well as fire protection service for more than 1 million system users including the world’s busiest passenger airport. In the 1890’s, when Atlanta faced major public health issues with water quality and water availability, the investment in raw water conveyance and storage was the first step in securing a sound future for the City. Since then, that investment has been integral to the success of Atlanta’s economy and the health of its citizens.
The original raw water supply pipelines are still in service. Cast iron mains of 30”, 36”, and 48” in diameter were installed in 1893, 1908, and 1924 respectively. Although these water mains were renewed with a cement liner in the 1950s, they have far exceeded their design life. A fourth line, a 72” steel main, was built in 1975; however, metallurgical weaknesses restrict its operation to warm weather months.
The Chattahoochee River is the source of raw water for the entire metro Atlanta. The path of the new raw water conveyance system will follow closely the path of the current cast iron and steel lines. The new five-mile conveyance line will connect to a quarry site that will be transformed into a new water storage facility at the quarry. The new storage facility will be designed to meet the current withdrawal permit limits and store any excess water not used for daily drinking water. Once filled, this facility will hold 2.4 billion gallons of water to provide the City at least 30 days of reserved water supply. Water treatment will be provided by the Hemphill Water Treatment Plant (WTP).
The scope of this project includes:
• Constructing a deep, five-mile long tunnel with a 10-foot diameter
• Connecting Chattahoochee River raw water intake to the Hemphill WTP and quarry
• Creating storage capacity within the quarry
• Increases the City’s reserve water supply to 30 days
• Reduces corrective and emergency maintenance of existing raw water delivery pipelines
• Enhances operational reliability with improved automation and system redundancy
Project Type: Water Supply Project Start: 05/2014 Proposed Construction Start: 02/2015 Scheduled Completion: 7/2019 Project Budget: $346,832,596 Council District(s): 3, 9 NPU(s): C, D, G, J, K Project Status: Active / Design / Construction Map:Link