There’s a good chance that you have consumed water that was once wastewater. If the thought seems surprising, don’t worry. Wastewater and water treatment plants have streamlined processes that ensure treated water is safe for human consumption.
Proper wastewater management is an important type of pollution control. It is critical for protecting human and environmental health. Despite the crucial role these facilities play in our country’s infrastructure, many people have no idea how water treatment plants work.
At O&M Solutions, we specialize in equipment operations, water treatment facility management and more. We’re here to support you with any water treatment tasks. Contact us to see how we can support operations in your facility.
When wastewater leaves your home after being flushed down your toilet, it flows through sewers and pipes before ending up at your city’s local treatment facility. This is where it will undergo the process that turns it back into clean, potable water.
If you want to learn more about this critical process for supporting every city’s infrastructure, read on.
The Wastewater Treatment Process
There are two separate types of water treatment facilities: one to treat drinking water and one to treat wastewater.
Wastewater treatment plants filter and clean wastewater so it can be safely discharged into an open water source such as a stream or lake.
Here are the processes that take place at a wastewater treatment facility.
1. Pretreatment and Screening
The first step at every wastewater treatment plant is screening. The initial screen is called a bar screen. These are large vertical bars that stand at the inlet of every plant. Their purpose is to catch larger items such as dead animals, wood, toys, trash and any other large debris.
This step is critical to the process as it prevents large debris from getting into the plant and damaging pumps and other machinery. Removed items are disposed of by wastewater maintenance personnel.
2. Pumping and aerating
Next, wastewater must go through a series of filters to remove as much particulate matter as possible. There are a variety of ways to do this. One common option is called a grit chamber.
A grit chamber filters out smaller particles that the bar screen misses, making the wastewater more homogenous. These smaller particles can't be removed using chemicals, so they need to be filtered in order to prevent clogs and damage to pumps later in the process.
There are three types of grit chambers:
Horizontal
Aerated
Vortex
All three types perform the same function, but those designing a treatment facility select the option that best suits their plant’s layout.
Another step in this process involves aeration. In this step, wastewater is shaken up by rapid oxygen bubbles which dissolve organic matter and release gasses. During this process, a separation between organic matter and any remaining small particles occurs, allowing the remaining grit to be removed from the water.
3. Sludge and scum removal
The next tank that the wastewater enters is called a primary clarifier. In this stage of the treatment process, the organic matter that settles to the bottom is called sludge. Once removed, the sludge can be processed in a separate tank.
Organic matter that floats to the top of the tank is called scum. This can include oils, soap, and plastics. In order to be removed, technicians thicken the scum and then pump it into the same tank as the sludge to be processed.
After sludge and scum removal, the water can go through another stage of filtration. During this process, the water is allowed to flow and filter down through a substance, commonly sand or carbon. This can help remove additional organic matter including bacteria and odor.
4. Disinfection
Now that the wastewater has been clarified, it is considered effluent water. At this point, it is 85% clean and considered safe to drink. Before releasing the effluent water into an open water source, however, it must be disinfected.
There are three ways water treatment plants disinfect water. They are as follows:
Chlorine: This option involves chemical disinfection. Water is treated using chlorine to kill any remaining bacteria. Plants that use this option must remove or neutralize the chlorine before discharging the water, however, or they risk damaging the open water source they plan to discharge into.
Ozone: This option involves pumping electrical current through the water. Ozone causes damage to cells, killing any remaining bacteria in the effluent water and rendering it safe for discharge into open water.
Ultraviolet: This option scrambles the bacteria’s DNA so it can’t reproduce or multiply. This doesn’t kill bacteria, but it does render it sterile and therefore unable to cause harm to anyone drinking the effluent water.
Once the water is disinfected, it is safe to be discharged into an open water source.
5. Effluent Release
At this point, the treated water is released back into an open water source such as a stream or lake.
In rare cases where water is scarce, water can be released to another treatment plant where it will be treated for consumption.
Drinking Water Treatment Process
Water treatment plants turn open-source water into potable water. Here’s the process water goes through at a water treatment plant to ensure it is completely safe for human consumption.
1. Coagulation
The first process that water goes through at a water treatment plant is called coagulation. This process involves introducing chemicals into the water which neutralize any dirt or organic particles.
If the word “chemicals” makes you squirm, don’t worry. Chemicals commonly used during this stage include salt, aluminum and iron.
2. Flocculation
Once the water has undergone coagulation, it moves onto the flocculation stage. This is when the water is mixed to form larger particles known as flocs.
3. Sedimentation
Now that the water contains flocs, sedimentation can occur in which solids are separated from the water. During this sage, flocs settle to the bottom of the tank.
4. Filtration
After the flocs have settled to the bottom of the tank, the water at the top of the tank is separated and filtered. Clean water moves through a substance such as sand or charcoal in order to filter out any unwanted particles. Germs, dust, bacteria and other toxic agents are removed in this process.
Some other types of filtration that vary by the facility include:
Ultrafiltration: In this process, water moves through a manufactured filter. This process only allows tiny particulates to move through along with the water.
Reverse osmosis: This process is used when processing recycled water or salt water.
5. Disinfection
In order to further remove any remaining bacteria, water treatment plants add low levels of chemicals to the water. This is the final stage in the process and can also help prevent future bacteria from infecting the water as it makes its way to your tap.
Once the disinfection process is complete, the water is ready to be transported to taps in homes and businesses around the city.
Wastewater Treatment in New Jersey
In New Jersey, the Division of Water Quality oversees all water treatment plants and processes to ensure the utmost quality and adherence to public safety guidelines.
Water from the Delaware River is safely consumed by New Jersey residents every day because of the hard work and dedication of those at our local wastewater management facilities. In order to ensure public and environmental safety, wastewater and water treatment plants follow strict protocols and testing standards.
Professional Wastewater Management in New Jersey, Pennsylvania and New York
The work that takes place at wastewater and water treatment facilities is necessary for human and environmental well-being. Without it, cities could face public health crises and ecological destruction.
At O&M Solutions, we provide water treatment operation and management solutions for the public and private sectors in New Jersey, Pennsylvania and New York. Our fantastic reputation comes from years of industry experience delivering excellent results to our clients.
For more information about how we can assist you with repairs, management, and assessments at your facility, contact us today.