The Hemphill Water Treatment Plant (WTP), located at 650 Bishop Street, is a manually operated water treatment plant that is staffed 24 hours a day, 7 days per week and has a maximum capacity of 136.5 mgd. The Hemphill WTP is one of three water treatment plants in the City of Atlanta’s water treatment system that provides potable water for the City of Atlanta and parts of Fulton County. (In addition to the Hemphill WTP, the Atlanta-Fulton County Plant also supplies water to citizens in Atlanta. The Atlanta-Fulton County plant is owned jointly by the City of Atlanta and Fulton County and is operated by the Atlanta-Fulton County Water Resources Commission.) The Hemphill Water Treatment Plant supplies water to retail, residential, commercial, and industrial customers within the City and portions of Fulton County south of the Chattahoochee River and in South Fulton County. Two reservoirs located at the Hemphill WTP supply water to the plant; Reservoir No. 1 and Reservoir No. 2. The reservoirs are located adjacent to 1350 Howell Mill Road. Hemphill Raw Water Reservoir No. 1 has a capacity of 180 million gallons (mg). Reservoir No. 2 has a capacity of 345 mg and is the sole source of raw water for the Hemphill WTP.
The capacity of the Hemphill WTP has been increased over time. In 1875, the Atlanta Canal and Water Works Company was established to secure a constant and plentiful supply of water for growth and fire protection. The system began with one pump and one reservoir. Due to rapid growth, the system became inadequate in only ten years. In 1891, the Chattahoochee River was selected as the source for Atlanta’s water by Mayor William Hemphill. At the close of 1907, approximately 65% of Atlanta’s residents had metered water. In 1923, a second raw water reservoir was built and the Hemphill WTP was upgraded to 42 mgd by the addition of seven new filters. In 1941, a second upgrade was necessary to increase the filter rate to 106 mgd. Seven filters were added during this expansion. Due to the rapid growth and demand of Atlanta’s water system, the final three filters were added in 1987 bringing the filter rate to the current 136.5 mgd total.