How We Clean Wastewater

Breadcrumbs

How We Clean Wastewater

Ever wonder what happens to the dirty water that goes down the drain in Alexandria? The City of Alexandria’s underground pipes and AlexRenew’s interceptor sewer system, pump stations, and treatment facility play an integral role in making that dirty water clean before it is released back into our waterways

An elaborate system of underground pipes brings sanitary flow to AlexRenew. The City of Alexandria owns and maintains the small pipes that collect water from businesses and neighborhoods within its boundaries. AlexRenew owns and maintains the large interceptor sewers that transport flows to our treatment facility.

Our interceptors are designed to allow wastewater to flow by gravity to our treatment facility, or route it to a pump station to be lifted high enough to flow to our facility. AlexRenew maintains four, off-site pump stations with a total pumping capacity of about 25 million gallons per day.

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AlexRenew Service Area Map

Our Water Resource Recovery Facility is designed to treat an average daily flow of 54 million gallons per day and is among the most advanced in the world. 

Once flows reach our facility from our interceptor system, they go through coarse screens, fine screens, and grit removal to remove large solids (like food and trash) that can damage our equipment. Flows are then transported into rectangular settling tanks for primary treatment and removal of suspended solids and fats, oils and grease. Afterwards, the flow goes to our Biological Reactor Basins (BRBs) for nutrient removal. While in the BRBs, flows are added to microorganisms, called activated sludge, for nitrogen removal. The water settles again and then we remove the phosphorous and filter out any remaining solids. 

Finally, flows are disinfected using ultraviolet (UV) light.

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AlexRenew - In Urban Area