Water Treatment Plant Tour

Have you ever wondered where your wastewater goes once it leaves your house? On average each American uses 100 gallons of water every day. That's two 55-gallon drums per person. That's a lot of wastewater that has to go somewhere. In Palm Beach County a good portion ends up across the street from my job at the wastewater treatment plant. Last week I had the privilege to tour the plant and find out exactly where the water at Green Cay comes from (Green Cay is the tertiary treatment process of our county's wastewater).


First the raw plant influent comes in where it is separated from the solids and any gas by-products in the Bar Screening Room. The air coming from this raw influent is sent to the scrubbers pictured above before being released into the air. Even though many people complain about water treatment plants having a smell, I've never noticed anything particularly foul coming from across the street. I think it's more of a misperception than anything. The solids are caught in a 0.25 inch screen and then compressed through a pipe seen below where it's sent to a large dumpster area that is picked up by the landfill. Anything from baseballs to money to drugs to children's toys can be found rolling out of the wastewater.

After the first screening process the wastewater is sent to the aerators. The large pink building seen below houses the large motor that supplies the aerators with power and air. It's the largest engine I think I've ever seen before. Those long pink walls to the right (and left, not pictured) are where the biological activity starts to digest the sludge. These sludge microorganisms are a big part of the water purification process. The aeration beds provide the organisms with plenty of oxygen to speed up the process of digestion. Additional gases are also released here.

The sludge is moved via gravity through the aeration beds to the stilling well where the sludge is removed.

Once in the stilling well the sludge has time to settle to the bottom and is collected. Technicians come out and measure the sludge with a long PVC pipe looking stick which they call the sludge judge. These measurements are taken 3 or 4 times a day. The oily film on top of the water is also scraped off using those long arm like skimmers seen below.

Once the sludge has settled the water is then sent to a clarifier and then to a chlorinator. Finally the water is sent to the large storage tanks you see below.

Once in the storage tanks the water can be transported into three different areas. At this stage it is considered secondary effluent. This water is still high in phosphates and nitrates. For the final cleaning process the secondary effluent is pumped to the wetlands like Green Cay and Wakodahatchee. The wetland plants perform the final filtration of the water and it either percolates back to the groundwater or evaporates into the sky.

The secondary effluent can also be further cleaned and made into reclaimed water which is cleaner than secondary effluent because chlorine is added and more solid materials are removed. This water is pumped to housing divisions and golf courses for irrigation. The high phosphates and nitrates are removed via the plants that they irrigate. This is a phenomenal way to irrigate in South Florida during our drought conditions. The best part is that the water gets completely back into the natural water cycle and drinking water supplies don't have to be used. Reclaimed water is marked by the lavender pipes you see attached to this unit.

During times of peak usage some water may also be sent to the deep injection wells. These wells can be seen below (there are 2 of them) and they can process 15 Million gallons per day per well. The pipes are 24 inches in diameter and go down 3,000 feet. Very little of the Palm Beach County's water goes into the wells due to the high demand for reclaimed water and the water that is pumped into the wetlands.