How your water gets treated
Where We Get Our Drinking Water
Not many of us think deeply about the origins of our water, but it’s important to be aware of our water resources. After all, the average Sarasota County resident uses about 80 gallons of potable, or drinking, water per day. Our drinking water comes from two main sources: groundwater and surface water. Groundwater sources include wells and springs connected to our underground aquifer systems, while surface waters typically include streams, rivers, lakes, and ponds. In Sarasota County specifically, we get most of our groundwater from the
Floridan aquifer, one of the most productive aquifers in the world. It underlies the entirety of Florida and even parts of Alabama, Georgia, Mississippi, and South Carolina. Our county has 33 wells that draw from groundwater sources, which include the Floridan. When it comes to our other drinking water sources, we get a bulk of our county’s water from the beautiful Peace River and the Manatee River. The treatment used for each water source varies slightly, but all types of treatment provide good, clean drinking water to Sarasota County’s residents.
The potable water that gets treated by the county is then distributed through 1,400 miles of pipes to service over 268,000 customers in Sarasota and beyond.
T. Mabry Carlton Jr. Water Treatment Facility
Sarasota County has three treatment plants. The largest plant is located in the T. Mabry Carlton Jr. Memorial Reserve in Venice, which spans nearly 25,000 acres. This is the largest producing facility, and water treatment professionals use a combination of Electrodialysis Reversal (EDR) and chemical treatment to help desalinate and disinfect groundwater from Sarasota County wells. This facility can provide a daily six million gallons of water to customers.
After it is drawn from underground aquifers, the plant’s well water is processed in a large basin where it begins the sedimentation process. Solids settle to the bottom, and the remaining water flows through large pipes across the facility to be further processed. Some of the water obtained from the Intermediate and Upper Floridan Aquifers is considered brackish, which is not suitable for drinking. Brackish water can be treated in a number of ways to remove its salt content and other dissolved solids that may be present. One method of removing these total dissolved solids (TDS), which is utilized by the Carlton Plant, is known as Electrodialysis Reversal, or EDR. EDR uses electricity to move salt molecules through the water via charged cell membranes.
These membranes are layered on top of each other in several “stacks” that make up an individual EDR unit. Multiple units in series work together to treat about 1.5 million gallons of potable water per day. Any collected solids from the membranes are then pushed out of the system through a separate stream. To clean the membranes of any residual salts, the process is reversed periodically. The leftover water is then relatively free of solids and can undergo the necessary round of chemical treatments to become clean, safe drinking water. EDR is a very efficient process, as it recovers about 80% of the water that is extracted from wells at the facility. The T. Mabry Carlton Jr. Water Treatment Facility has one of the largest EDR plants in the world and has the capacity to process nearly 12 million gallons of potable water per day.
Once solids have been removed from the water, it is then fed a liquid supply of sodium hypochlorite (bleach), followed by ammonium sulfate. This process disinfects the water, clearing it of pathogens as part of the water treatment process. From there, a combination of hydrochloric acid and sodium hydroxide are added to the water to modify its pH in order to prevent corrosion. Orthophosphate is also a corrosion inhibitor used by the plant to prevent lead pipes from leaching in older homes. After treatment, the finished product is transferred to large tanks where it is blended with other treated water from the facility until it gets used by customers. Water samples are tested daily to help make sure that the water leaving the plant meets the Safe Drinking Water Act (SDWA) standards. The plant will typically take 20 to 25 samples per day at every stage of the treatment process. That way, staff can quickly correct any issues before the water reaches your home.
Help Protect Our Water Quality
When it comes to water quality, our drinking water is not the only water that matters. In fact, all of our water is connected through the water cycle, so it is incredibly important for each individual to take action when it comes to preserving our county’s water quality. Though we have surpassed regulatory standards for our drinking water in the past, we can all work hard to make our waters even better by keeping nutrients and litter out of the bay. See below for a quick guide to keeping our waters clean.
Help improve our water quality by…
- Cleaning up your yard waste, like grass clippings and other vegetation that has been removed from the landscape. You can leave grass clippings on your yard to help fertilize your grass, as long as they are not too close to a waterbody. If you do not plan to use it for composting, put other vegetation in the appropriate bin and leave it curbside until it can be collected by county staff.
- Do not fertilize if heavy rain is expected in the next 24 hours. Too much rain can wash away fertilizer before it gets a chance to be absorbed in the soil. This fertilizer can turn into polluted runoff and negatively affect our waterbodies.
- Do not apply fertilizer within 10 feet of waterbodies.
By following these steps, you can help promote healthy freshwater ecosystems. If you are interested in learning more about water quality and conservation, you can visit our Water Resources webpage.
- Curious about the quality of your drinking water? You can check the details in Sarasota County’s annual drinking water report.
- Drink Local! Learn more about the benefits of switching to tap from bottled water on our website.
- Visit Sarasota County’s Public Utilities page to learn more about where your water comes from.