Chattahoochee Water Treatment Plant
Drinking Water Service Area
About Chattahoochee Water Treatment Plant The Chattahoochee Water Treatment Plant (WTP) has a permitted capacity of 64.9 million gallons of water per day (MGD). It supplies drinking water to approximately 35 percent of Atlanta’s service area, including portions of Fulton County south of the Chattahoochee River and Atlanta’s wholesale water customers. The treatment plant employs conventional treatment that consists of rapid mixing, hydraulic flocculation, sedimentation, dual media filtration, disinfection, finished water chemical application, and finished water storage. Finished (treated) water is stored in two clearwells at the WTP until pumped into the distribution system. Solids, once processed at the Chattahoochee Settled Solids Facility using plate and frame presses, are now processed with newer filter press technology.
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The City of Atlanta has 12 finished water storage tanks with a total storage capacity of 37 MGD.
75
Sandy Springs
285
285
85
ATLANTA
Decatur
Chattahoochee WTP Pump Room
Raw water from the Chattahoochee River is conveyed to the WTP via three raw water mains consisting of 48-inch, 60-inch, and 78-inch steel pipes. There is a 48-inch line leaving the raw water pumping station that combines with the 78-inch line to form a single 60-inch pipeline just before entering the Chattahoochee WTP. The Chattahoochee WTP was completed in 1962 and initially contained three flocculation and sedimentation basins and six filters with an initial capacity of 20 MGD. In 1972, the plant capacity was increased to 50 MGD by replacing the top 15 inches of sand in the existing filters with
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Fulton County
East Point
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College Park Chattahoochee WTP
Union City
Chattahoochee Hills
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Palmetto
Fairburn 85
● Water Treatment Plants ■ Retail ■ Wholesale Finished Water Storage Tanks
Atlanta’s first water system was constructed in 1851 and consisted of five artesian (aquifer-drilled) wells. In 1891, the City’s Water Commission recommended withdrawing up to 10 MGD from the Chattahoochee River to address water shortages. Three years later, the City constructed its first pumping station and river intake, a 30-inch-diameter pipeline located on the east bank of the Chattahoochee River just north of Peachtree Creek, and treated the river water at the new Hemphill WTP. In 1957, the construction of the Chattahoochee WTP was approved.
Chattahoochee River
anthracite coal, and by the addition of seven filters; making a total of 13 filters. The Chattahoochee Settled Solids Facility was placed in operation to mitigate the pollution of the Chattahoochee River. Chattahoochee WTP is part of a $36.2 million Schneider Guaranteed Energy Savings Performance Contract, which consists of seventeen energy conservation measures at the Department of Watershed Management facilities.
Chattahoochee Water Treatment Plant Filtration Process COLLECTION
COAGULATION & SEDIMENTATION
Aluminum Sulfate (alum) Sodium Hypochlorite (chlorine) Lime
Water is drawn from the Chattahoochee River to the treatment plant.
Chemicals are added to form sticky particles in the water. These particles sink to the bottom, and the water moves on.
Chattahoochee River Raw Water Intake
Flash Mix Basin
Raw Water Pump Stations (x4)
Flocculation Basins (x6)
Clarifier
Settling Basin
Phosphate Sodium Hypochlorite Fluoride Lime
Sedimentation Basins (x6)
Clearwell No. 1: 6.4 Million Gallons Clearwell No. 2: 4.6 Million Gallons
Coal Sand Gravel
Finished Water Storage Tanks (x12)
Finished Water Pump Station (x4)
Underground Clearwells (x2)
Post Flash Mix/ Disinfection
Filtration Basins (x13)
DISTRIBUTION
DISINFECTION
FILTRATION
Clean, safe water travels through miles of pipes and comes out of your faucet.
Sodium Hypochlorite (chlorine) is added to inactive waterborne bacteria or microorganisms that are found in untreated water.
The water passes through layers of charcoal, sand, and gravel to remove smaller particles.
Chattahoochee Water Treatment Plant – Treatment Process The Chattahoochee Water Treatment Plant (WTP) is located on Bolton Road in northwest Atlanta, GA, near the Chattahoochee River and adjacent to the City of Atlanta RM Clayton Water Reclamation Center Facility. Chattahoochee and Hemphill WTPs supply drinking water to approximately 75 percent of Atlanta’s service area. The treated drinking water originates from raw water from the Chattahoochee River. The City of Atlanta is permitted to withdraw a maximum of 180 million gallons per day (MGD), using a raw water intake located approximately 250 yards upstream from the Peachtree Creek and Chattahoochee River junction. Water from the raw water intake goes into a pump station located just downstream; four pumps send water from the pumping station directly to the Chattahoochee WTP. The Chattahoochee WTP has a permitted peak day treatment capacity of 64.9 MGD. Raw water from the Chattahoochee River is routed to one of two flash mixing chambers where chemicals are added to help remove contaminants and particles from the water — and to promote coagulation and flocculation. Chemicals added in the flash mix basins include aluminum sulfate (alum) to help separate particles out of the water, sodium hypochlorite (chlorine) for initial disinfection, and lime for pH stabilization. Coagulation and flocculation cause the solid particles in the water to clump together — allowing the particles to settle easier in later treatment plant processes. After the chemicals are added, the water is separated into six flocculation basins where the water is agitated to cause them to clump, or floc, together (see plant flow diagram on previous page). Next in the treatment process is particle settling in sedimentation basins. Each sedimentation basin (six total) consists of a clarifier and a settling basin. The clarifier is a large round basin with long rotating arms. The rotating arms slowly move the flocs (or clumps) to the center of the clarifier, where they settle to the floor of the basin. The flocs are removed through an 8-inch pipe and sent to another facility for further treatment. After clarification, the water moves into the settling basins where the remaining, lighter flocs settle to the bottom of the basin. The settled flocs are called sludge, and the sludge in the settling basins is removed through drainage valves and a sludge pump. After sedimentation, the water enters the filtration basins (13 total), which contain gravity filters that consist
of anthracite (coal) and sand layered over gravel. The filtration basins capture suspended fine particles that may have slipped through the previous stages of treatment. Treated water leaves the filtration system through underdrains located beneath the basins. The water then flows through two vaults to undergo the post flash mix process. This involves further treatment using chemicals, including: sodium hypochlorite (chlorine) for disinfection; increasing the pH using lime; promoting dental hygiene using fluoride; and protecting the distribution system from corrosion using phosphate. After the additional chemicals are added, the treated water is sent to two underground storage tanks called clearwells. The treated water is then pumped by the finished water pump station (four pumps) to the City of Atlanta’s water distribution system.
Fun Facts
Awards 2,790
Atlanta has approximately miles of drinking water pipes
358
water Crews responded to main breaks in FY 2019
Georgia Association of Water Professionals (GAWP) • 2019 Safety Award • 2011-2016 Water Platinum Award • 2007-2010 Water Gold Award
Chattahoochee WTP supplies water to the Georgia Governor’s Mansion
The City currently has a raw water permit of MGD from the Georgia Department of Natural Resources, EPD
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The Future of Raw Water Storage: Bellwood Quarry
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Over people toured the Chattahoochee WTP in 2019 Chattahoochee WTP Flash Mix Basins
Innovations • Solar panels will be placed at the Chattahoochee WTP to support energy conservation • The filter belt press technology used to process solids at Chattahoochee WTP was the first in the state to be approved by the Georgia Department of Natural Resources, Environmental Protection Division
In 2020, the City of Atlanta completed construction of a new Raw Water Storage Reservoir located at the Bellwood Quarry. It adds approximately 2.5 billion gallons of raw water storage for the City. This is almost nine times more raw water storage than was available and supplies the City of Atlanta with 30-90 days of water service if water could not be pumped from the Chattahoochee River.
• System Control and Data Acquisition (SCADA) system upgrades are ongoing to increase the number of processes that can be automated at the Chattahoochee WTP
Tours One-hour guided, walking tours are offered at the Chattahoochee WTP that provide guests a behindthe-scenes look at the water treatment process, the plant’s unique story, and how water travels through the facility and is delivered to your home. Contact our office to schedule a tour today!
Time Slots Monday and Wednesday 10:00 a.m. – 11:00 a.m. or 1:00 p.m. – 2:00 p.m. Please email us at dwmcommunications@atlantaga.gov. Include the following information in your email: Name of school/program/organization, contact person name and phone number, tour date, tour time, name of plant to be toured.
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Thinking about becoming a water treatment plant operator? The State of Georgia requires the following for an operator to become certified: • Take and pass an exam that demonstrates that the applicant has the necessary skills, knowledge, ability and judgment as appropriate for the classification
DEPARTMENT OF WATERSHED MANAGEMENT ADMINISTRATIVE OFFICES
• Have a high school diploma or a general equivalency diploma (GED)
72 Marietta Street, NW Atlanta, GA 30303 Mon-Fri – 8:15 am to 5:00 pm atlantawatershed.org
• Have the defined minimum amount of on-the-job experience for each appropriate level of classification.