We all experience it daily—flush the toilet, take a shower, or wash our clothes—and POOF, the dirty water disappears. But have you ever wondered where it all goes? Or, more importantly, how is it cleaned before it returns to our environment?

The Journey from Source to Sanitation

The Chesapeake Bay, although capable of naturally filtering some pollutants, can easily become overwhelmed by excess waste. This overload reduces water quality and harms the delicate plants and animals that depend on the Bay. Without wastewater treatment, millions of gallons of sewage and wastewater would pollute these waters, causing long-term damage.

In Hampton Roads, the journey from "flush" to "clean" begins as water is carried from home and businesses through sewer pipes and makes its way to one of our14 wastewater treatment plants owned and operated by HRSD. Our treatment plant process ensures that wastewater is properly cleaned before it is released back into the Atlantic Ocean or rivers leading to the Chesapeake Bay.

So, how does it work? Here’s a step-by-step breakdown of the process:

Collection and Screening

Once the wastewater—also known as "raw influent"—flows into the treatment plant, it passes through large bar screens that capture larger debris. These screens help ensure that only the right materials make it through for cleaning. Remember: items like "flushable" wipes, paper towels, and food scraps should never be flushed down the toilet or washed down the drain.

Sedimentaion

Once the water passes through the screens, it enters large tanks called primary clarifiers. Here, the heavier particles, such as food bits and dirt, sink to the bottom, forming a sludge. Lighter particles, like oil and grease, float to the top.

Biological Treatment (Aeration)

The next stop is the aeration tanks. This is where the magic of biology happens! Tiny organisms—microscopic bacteria—are introduced to the water to break down the remaining waste. These little creatures thrive on the leftover organic material, eating it up and helping to clean the water. To keep these bacteria healthy, air is pumped into the tanks to give them the oxygen they need to grow.

Solid Separation

After the water has been biologically treated, it moves to a centrifuge, which spins the water at high speeds to separate any remaining water from the solid waste. This leaves behind a dry, solid material that is similar to organic compost. With further treatment, these solids may even be used as fertilizer to enrich soil, helping us recover natural resources to protect public health and the environment.

Disinfection and Return to Nature

Finally, the water moves to the secondary clarifier, where any remaining microscopic organisms are either recycled or discarded. The water is then disinfected in chlorine contact tanks before being released back into the environment.

 

The Truth About Wastewater

While wastewater may seem like an invisible mystery, understanding the treatment process is crucial for the health of our communities and our environment. Thanks to the hard work of HRSD and innovative treatment technologies, we are able to reclaim valuable resources, protect our waters, and minimize environmental impact.

Next time you flush, you’ll know that the process behind the scenes is far from simple—but it’s vital for the health of the Chesapeake Bay and our region as a whole.