As infrastructure continues to age and population centers grow, massive water supply projects emerge to meet the country’s water needs. PC Construction is leading several such projects in the southeast including one in the City of Atlanta. The project is slated for completion in 2018 and is valued at an estimated $300 million.
PC Construction, along with our joint venture partner H.J. Russell & Company, is leading this construction management-at-risk project to provide Atlanta, Georgia with a reliable supply of drinking water for the next 100 years, increasing the City’s emergency raw water reserve from three days to more than 30 days. The project includes converting an existing rock quarry to a 2.4 -billion-gallon water facility while digging and boring and installing a 5-mile, 10-foot diameter tunnel to connect the quarry facility to the Hemphill Water Treatment Plant and Chattahoochee Water Treatment Plant. Work also includes the construction of two new pump stations to support the system.
Conversion of the quarry and beginning the tunnel are the initial project components. Before work could commence, scalers removed lose rock from the quarry walls to prevent falling rocks while work is underway at the bottom the quarry. Blasting has begun to carve two circular 20- and 35-foot diameter, 200- and 300-foot deep shafts near the quarry that will connect to the tunnel. Each shaft requires approximately 20 blasts over the next four months. Preparation for each blast takes four days to ensure safety and accuracy.
A 400-foot long tunnel boring machine (TBM) will be used to complete the work. Delivery of the TBM will begin later this month on more than 30 flatbed trucks before it is assembled in the bottom of the quarry. Tunneling is slated to begin in September of this year and will continue through 2018 when it reaches the Chattahoochee Water Treatment Plant.
Using blind bore drilling, five eight-foot shafts will soon be drilled at the Hemphill Water Treatment Plant, which will eventually connect to the tunnel.
When complete, the project will address Atlanta’s goal of achieving a sustainable water infrastructure for future generations and flexibility in systems operation. In the event of a crisis or loss of water service, the project provides redundant water storage and can save the City as much as $100 million per day.
Members of the PC Construction team in the quarry, a part of the Atlanta Water Supply Program Phase 1 project