Every time you pour water down your kitchen sink, drain away a bath or flush the toilet, that wastewater has to go somewhere. In the vast majority of cases, it goes into the sewage system and heads to your local treatment plant to be dealt with. Some houses still have an enclosed septic tank system, but even in these cases, the contents usually end up at a wastewater treatment plant for processing.
Why are wastewater treatments so important? Well, it’s mainly because without them we’d be living in a very polluted, dangerous world. A couple of centuries ago, water contamination was the cause of thousands of deaths through cholera, typhoid, and dysentery. With hundreds of thousands of people all crammed together in cities, the sheer volume of (from both people and their animals) was colossal.
Rudimentary sewage systems simply couldn’t cope, so the great Victorian inventors such as James Newlands Borough in Liverpool, and Joseph Bazalgette in London developed systems that not only would remove the majority of sewage from the streets but would also send it to processing plants to be cleaned before it re-entered the environment. Those systems are still in use today (along with some 21st-century upgrades), and are keeping the water that flows out of your tap safe and clean.
What is wastewater?
Wastewater is the liquid that you allow to drain down your kitchen or bathroom sink, and also includes any industrial wastewater that is also allowed to enter the sewage system. This water can contain a huge range of contaminants, ranging from solid matter to the odd goldfish. All of this is transported to a wastewater treatment plant to undergo a series of processes.
Why is it so important to treat wastewater?
For years, it was common for wastewater to be simply pumped out to sea without undergoing any intensive processing. Water treatment isn’t cheap, and we simply believed that the ocean would ‘deal with it’.
However, as we soon discovered, that discarded effluent soon came back to haunt us, with poor quality water at popular beachside resorts.
Not only is effluent deeply unpleasant, but it’s also home to a myriad of bacteria, including E.Coli, Listeria, and a host of microbes that can make you extremely ill. You need to be absolutely sure that the water is not contaminating the drinking supply, either by coming into contact with the groundwater reserves or re-entering the chain via reservoirs and pumping stations. Strict standards are maintained throughout the wastewater processing system to make sure the end result is safe and as clean as it can be.
What is a wastewater treatment plant?
This is a specially designed plant where a region’s wastewater is dealt with to remove as many impurities as possible. The water goes through a series of processes, beginning with Screening. This takes out anything that shouldn’t be there in the first place, from nappies to those goldfish we mentioned earlier.
Once the large material has been removed, the water goes onto the Primary Treatment system. This removes any remaining solid material by putting the water into settling tanks to allow the solids to sink to the bottom. This sludge is then syphoned off and sent for further treatment. The water, now with no solid material in it, passes onto the Secondary treatment stage, where it goes into aeration lanes. Air is pumped into the water to encourage the development of healthy bacteria, which feed on the more unpleasant bugs. Modern plants also use high-tech equipment such as UV lights to kill off any remaining bugs.
The water then goes onto a final settlement tank, before being filtered through a sand bed and finally allowed back into the natural river system.
Does all this really matter?
The simple answer? Yes. It matters. Without water treatment, we’d be at risk of serious diseases. When water treatment systems break down, lives are put at risk. If you think about environmental disasters such as hurricanes and earthquakes, you will always hear the relief agencies emphasising the importance of getting clean drinking water and dealing with the sewage that can contaminate the environment as a major priority.
Without water treatment plants, we’d be sent back to the time before Bazelgette and Newlands Borough designed their incredible systems. We’d be at risk of life-threatening diseases like cholera. Without an effective water treatment system, modern society cannot function, and our environment would be contaminated for decades to come. So thank goodness there are wastewater treatment plants to clean up after us!