The History of the Wilson Bay Wastewater Treatment Plant

The former plant in operation

The Packed Biological Reactor Required to be installed as a part of the major rebuild of the plant, this device never worked to the design specifications according to the City operators. The idea was to remove the organics from the wastewater. Sand, grease and other items helped to prevent the tower from working properly.

Secondary Clarifier One of two on the site, the first added as a part of the major rebuild. The concept was to separate the sludge from the wastewater.

Effluent Treatment This is the entry to the Chlorine Contact Chamber where the last steps were taken in the treatment chain. Here chlorine was added to disinfect the wastewater.

Sludge Treatment Area In the foreground is the Gravity Thickener. The rear round tank was the Aerobic Digester. In the rear, are the Sludge Drying Beds where the sludge was placed to dewater and prepare for burial or spreading on fields.

When the City of Jacksonville discontinued the use of the plant, it actually was the work of many different modifications. Many of the modifications were made in an effort to comply with ever more strengthened regulations to help protect the environment. These ever changing regulations helped to convince the City Council that building a new plant – one that would not discharge into the River or Wilson Bay – was a better idea.

Why it failed.
There were several contributing causes to the failure of the plant in addition to the ever tougher discharge requirements. The chief component of failure was the Biotower. Technically called a Packed Biological Reactor, the concept was sound and is used to treat many types of organic wastes today. But the application in a municipal wastewater treatment system was a failure.

A biofilter is a biological reactor where polluted substances – such as water or air –  can be biologically treated. The principle of a biofilter is as follows: polluted water is passed through a packed bed of compost, wood chips, activated carbon, etc. or a mixture of these ingredients with surface space for bacteria. At the surface of the packing, pollutant degrading microorganisms are present, and degrade the pollutants.

How was it supposed to work?
After all the other treatments to separate out the watery parts of wastewater from the larger solids, the water was then trickled over a three story tower packed with black plastic cores. The cores were designed to allow bacteria to grow on them. The bacteria were selected based on their ability to break down the organic material in the wastewater. The concept was that the bacteria would consume all the organics in the water, leaving it clear and clean. But it did not work in a practical application.

Why? People flush much more down the drains than just human waste. Grease, sand and chemicals did not allow the bacteria to work. Instead, the grease clogged parts of the tower, and allowed too much flow over others. Bacteria in that smaller area could not handle all the waste that was pumped, and so little cleaning was done in that area. The design of the tower did not provide for efficient cleaning and there was no way to stop treating wastewater in order to fix the problem.