The Tampa Water Department delivers 82 million gallons of water to close to 717,000 people every day. Every year we take over 9,000 water samples throughout our service area and conduct over 40,000 water analyses to ensure that we remain in compliance with federal and state drinking water regulations. Our water treatment process is a 24/7 operation with work crews operating around the clock to ensure that you always have access to safe, clean drinking water.
A brief description of our water treatment process
The Hillsborough River is the main source of water for Tampa Water Department customers. By the time the water reaches the water treatment plant, it has travelled over 50 miles southwest from the Green Swamp, a lush watershed deep in the heart of Central Florida. The tea-like color of the water is due to the natural organic matter that is released from the decomposing vegetation within the swampy flatlands.
Screens for large debris removal
Powerful intake pumps force water from the Hillsborough River through screening equipment that filters out and removes large debris including plants, fish, and trash. These large items remain trapped on the screens while the water passes through. The large items that remain are removed for eventual disposal.
The water flows into a mixing tank where several chemicals, such as ferric sulfate and sulfuric acid, are carefully added into the water then blended thoroughly using a rapid mix unit. The coagulant, ferric sulfate, acts like a magnet to attract all of the natural organic matter within the river water, gradually forming clumps of soft, solid material called floc. The water mixing process slows down to a gentler stir to provide additional opportunities for the water and coagulants to continue to come into contact and allow the floc to increase in size. Midway through this process, polymers are added to encourage larger, heavier, stronger clumps of floc to form.
Once the flocculation process is complete, the water travels into sedimentation basins. The heavy clumps of floc sink to the bottom and are removed. The water is now visibly clearer and ready for the next step in the water treatment process.
The stabilization process helps improve the water’s taste, odor and color. The addition of lime and caustic soda help balance the pH and alkalinity of the water. Neutralizing the acidity of the water prevents corrosion problems that can cause metals to leach from water mains and household plumbing systems, causing health problems. It also helps water mains to last longer so they don’t need to be replaced as often.
The clarified water is treated with ozone. Ozone gas is a powerful disinfectant that destroys harmful bacteria and viruses and inactivates microbial pathogens. The ozone gas is produced onsite by using electricity to break apart oxygen molecules (O2) and reform them into ozone molecules (O3).
The water is filtered again to improve taste and odor and further remove natural organic matter. This filtration process involves passing water through a layer of granular activated carbon and a layer of fine sand to catch and remove any remaining particulates. The carbon also acts as a growth medium for beneficial bacteria to grow and consume impurities in the water. The water will now have a very clear appearance.
In this final step in the treatment process, the filtered water is treated with chlorine to kill any remaining bacteria and viruses. Additionally, caustic is added to adjust the pH and fluoride is added as a dental health measure. At the end of this step, ammonia is added to convert the chlorine to chloramine. The chloramine will help ensure that the water remains disinfected as it travels through the water main distribution system. The water is now considered “finished” and ready for consumption.
Treated Water Storage
The finished water is temporarily stored in large cement underground tanks called clearwells.
High service pumps send the finished water from the storage tanks out to the City’s water distribution system to homes and businesses throughout our service area. We also have five repump stations with elevated or ground storage tanks to boost the pressure throughout the City and to make sure that enough water and pressure is available when needed for fire protection.