A long road trip is one of the true joys of summer. Whoever said that the journey is more important than the destination must have been on some great trips. On a recent journey that took me across several states, I noticed a number wastewater treatment plants along the expressway. Sure, they’ve been around for a long time and there’s nothing new or spectacular about them, but this was the first time that I got to thinking about what happens to our wastewater, whether it comes from a household garbage disposal or the runoff from an industrial facility.
Wastewater treatment is an important responsibility for municipalities and certain industries. It’s a process that takes water that can no longer be used for its previous purpose and either returns it to the water cycle or reclaims it for further use. Without wastewater facilities, our communities would face a constant struggle against polluted groundwater and surface water bodies. But how, exactly, does a wastewater treatment plant function?
The treatment process begins as water is passed through a number of concrete aeration tanks that remove small waste particles, such as sand and dirt, while also replenishing the water’s oxygen supply. From there, the water flows into another group of sedimentation tanks that remove organic sludge from the water. Sludge is heavier than water, so it sinks to the bottom of the tank and can be easily removed. These tanks also remove any scum, such as oils and grease, that rises to the top of the water.
In the final step of the process, chlorine is added to the water to kill off any harmful bacteria, much like it does in swimming pools, and is neutralized before the water is reclaimed or introduced back into the environment. Reclaimed water can then be used for landscape irrigation, groundwater aquifers, commercial and industrial purposes, and for drinking.
With all that happens in a wastewater treatment plant, it’s important that each step of the process is as effective and efficient as possible. If it’s not, then serious problems can arise, such as contaminated drinking water, polluted ground water, or dangerous runoff sludge that can introduce excess phosphorus into surface water bodies and lead to the growth of toxic algae.
So, now that you know what happens to our wastewater, perhaps you’ll be inclined to tip your hat to the municipal concrete campuses you see along the road to wherever it is you’re going this summer. And once you get there, whether you’re enjoying a cold glass of water from the tap or making a splash in a freshwater lake, remember the process that makes it possible.