Welcome to Double Branch WWTP's home on the Web, and thank you for visiting. I hope you will find your visit interesting and informative, and if you have any questions at all about our facility, please feel free to e-mail me and ask -- I'll do my best to get you an answer.
Double Branch WWTP is located on the western outskirts of the City of Monroeville, which is the county seat of Monroe County in south Alabama. The plant uses an extended-aeration activated sludge process to treat wastewater, and is rated by the Alabama Department of Environmental Management (ADEM) to handle a maximum daily average flow of 1.0 MGD daily. The plant went on-line in January of 1998, replacing an older plant that was constructed in 1978 which was simply no longer able to reliably maintain compliance with increasingly-stringent NPDES permit limits.
Double Branch serves the vast majority of the residential customers in the greater Monroeville area, as well as accepting wastewater from the towns of Excel and Frisco City, also located in Monroe County. The system has another plant, Hudson Branch WWTP, which is located on the other side of the city and primarily handles the wastewater flow from Monroeville's Vanity Fair clothing manufactory along with a handful of residential customers. Raw wastewater travels to the plants through a network of approximately 75 miles of gravity sewer, eighteen lift stations, and about three miles of force main.
At Double Branch the incoming wastewater is first degritted, degreased, and aerated before it is mixed with return sludge. The mixed liquor then flows into one of two aeration basins, which at full design flow have a detention time of sixteen hours, giving the activated sludge process plenty of time to do its job. Each basin is racetrack-shaped, holds 330,000 gallons of mixed liquor and has a mechanical aerator at each end. The aerators serve a dual purpose -- they keep the basin contents well-mixed and help to ensure an adequate supply of dissolved oxygen is maintained in the liquor. Both of these are very important in ensuring good treatment of the wastewater.
From the aeration basin, the mixed liquor flows to one of two clarifiers. In the clarifiers, the activated sludge which was mixed in at the head of the plant settles to the bottom, leaving the water to flow out of the clarifier and to a UV disinfection unit. Once disinfected, the treated water leaves the plant for discharge into Double Branch Creek, a tributary of the Alabama River.
Questions? Comments? E-mail the Sludgemaster!