MAWSS Nears Completion of $36 Million Sewer Overflow Mitigation Project in Mobile
MAWSS is nearing completion of its $36 million Nortons SWAT storage basin project, the fourth phase of a two-decade effort to keep wastewater out of Mobile-area creeks and rivers during heavy rain.
MOBILE, Ala. — The Mobile Area Water and Sewer System (MAWSS) has nearly finished construction on the latest phase of a long-running effort to keep wastewater out of the area’s creeks and rivers during heavy rain.
The project, known as the Nortons Severe Weather Attenuation Basins, or SWAT, has been under construction for more than two years.
“This is something that is much needed for the community and much needed for MAWSS,” said Terry Herman, MAWSS lift stations operation manager.
Herman and Russell Lomax, MAWSS water and sewer operations manager, have overseen the project from the start.
“Just an amazing transformation for the area. Before it was completely wooded. We’ve tried to take great care working with certain entities to try to camouflage it in here,” Lomax said.
Storage Capacity
Each of the project’s storage tanks can hold 12 million gallons of wastewater. An additional tank downstream adds another 8 million gallons of capacity, which MAWSS says will help keep wastewater from reaching nearby waterways during major storms.
“Whenever you see the true magnitude of just how high these tanks are and how large they are… just standing out by the fence just doesn’t do it justice,” Lomax said.
“The biggest reason for these here is because of the wet weather — wet weather and trying to mitigate weather SSOs,” Herman said, referring to sanitary sewer overflows.
The tanks and the nearby lift station together cost more than $36 million. While the tanks themselves are ready, construction is still underway at the lift station across Eslava Creek.
Once the system is fully online, it will operate automatically. During a major rain event, the lift station will pump wastewater through a large pipe to the storage tank facility on the other side of Eslava Creek. The tanks will hold that water until conditions return to normal, then release it at a controlled, automated rate.
Fourth SWAT Project Since 2000
The Nortons basin is MAWSS’ fourth SWAT project since 2000, bringing the utility’s total investment in this type of infrastructure to more than $74 million. Earlier projects targeted the Three Mile basin, followed by Eslava and then Halls Mill.
MAWSS says the approach has proven effective elsewhere in the system. The Three Mile project was upgraded in 2021, adding two tanks and another 20 million gallons of storage capacity.
“We have 28-million gallon capacity at that facility and we’ve filled it up a couple of times — but in the early years we would be in double-digit sanitary sewer overflows on the trunk,” Herman said.
“I’m a boater. I’m a fisherman — I love Dog River… Halls Mill… all of these basins that we have. And for me personally what it means — it’s less wastewater going into the system — going into the creeks — that was the whole purpose of this. Is to seal up the system and keep in the ground, keep in tanks, keep it out of the waterways,” Lomax said.
MAWSS expects the Nortons SWAT project to be fully online later this year.
What Sanitary Sewer Overflows Are
A sanitary sewer overflow occurs when untreated wastewater escapes the collection system before it reaches a treatment plant, often because heavy rain seeps into pipes and exceeds their capacity. Such discharges are prohibited under the federal Clean Water Act, and utilities in Alabama must report them to the Alabama Department of Environmental Management.
Eslava Creek and Halls Mill Creek are tributaries of Dog River, which empties into Mobile Bay, while Three Mile Creek flows into the Mobile River.
