Many people think waste water is cleaned just by using a couple strainers to remove the dirt and grime that collects in it; however, there are many more steps in use to not only remove debris, but bacteria and chemicals that may harm the environment and the population. There are many high-tech machines at a water treatment plant that remove harmful bacteria and chemicals. At the Ina Road Water Pollution Control Facility there are currently a total of 11 cleansing steps that the wastewater must go through before being released into the Santa Cruz River.
The cleaning process begins at the head works where large solids such as wood, rocks and rags are removed so they don't harm the equipment further along the cleaning process. The solid waste removed at this state is then sent to the Tangerine Road Regional Sanitary Landfill. The wastewater is then raised vertically using large screw pumps so it can flow by gravity throughout the rest of the process. After the head works the wastewater moves into the Grit Chambers where grit, sand, and similar debris that can harm the pumping equipment is removed. This material is disposed of at the Tangerine Road Regional Sanitary Landfill as well. The wastewater then enters the Primary Clarifiers where it then rests for several hours while more solids settle out and sinks to the bottom. This solid waste is then sent to the Thickeners for further treatment. The Primary Clarifiers are covered to help prevent odors from entering the air; instead, the gases are collected and treated by a counterflow wet scrubbing system to reduce the odor before entering the atmosphere. Next, the wastewater moves into the Oxygen Reactor Tanks where oxygen is introduced to help microorganisms break down some of the waste that has yet to be removed from the water. The microorganisms that naturally occur feed on the organic matter in the wastewater. The Oxygen Production Facility provides high-purity oxygen for the microorganisms to use in the oxygen reactor tanks. After the Oxygen Production Facility, the wastewater is moved to the Secondary Clarifiers where, just like the Primary Clarifiers, the wastewater sits while solids are settled out of the water, but some of this solid is sent back to the Oxygen Reactor tanks to feed the microorganisms, but the rest is sent to the thickeners. The wastewater then moves through the Chlorine Contact Tank where chlorine is introduced into the water to treat it and kill any bacteria left in it before it is dispensed back into the Santa Cruz River. The zigzag structure of the Chlorine Contact Tank is used to maximize contact area. Just before the water is discharged into the Santa Cruz River it is dechlorinated to prevent environmental hazards.
The solid waste removed from the primary and secondary Clarifiers is sent through the Thickeners, which are used to increase the concentration of the solid matter and reduce the volume of the liquid, thereby reducing the space needed for storage. After the Thickeners the waste is sent to the Anaerobic Digester where it is mixed and heated for several weeks until it becomes stable. After the waste is stable it is transferred to the Centrifuge Building where it is spun at high speeds to remove even more liquids, which are then sent back to the head of the facility for treatment. The sludge remaining of the solid waste is then used on farms as fertilizers.
