With the second phase of construction completed in October 2021, the new Quail Meadows 3 lift station and sewage connectors were commissioned. Penetron’s antimicrobial concrete admixture was specified to provide permanent protection for the lift station’s wet well structures from microbially-induced corrosion, which is known to rapidly deteriorate concrete structures.
Located 14 miles (23 km) south of Des Moines, Iowa, Indianola is a city of about 16,000 inhabitants, home to Simpson College, and the county seat of Warren County. The city hosts an annual National Balloon Classic, a hot air balloon festival, and the Des Moines Metro Opera, a major American Summer Opera Festival.
The Quail Meadows area on the north side of Indianola was recently targeted as a growth area by the Indianola City Council. The planned construction of 50 new homes in the Quail Meadows subdivision meant the previous lift station needed to be relocated to best serve the new homes. The newly completed Quail Meadows 3 lift station is part of the city’s ongoing Capital Improvement Projects (CIP) to improve and expand the local wastewater collection system.
Vanderpool Construction was commissioned by the City of Indianola to complete the $835K project. The Quail Meadows 3 project comprised the construction of a new lift station with a wet well, a dry well, pumps, valves, piping, electrical and control systems, and a relocated generator. A 6” (150 mm) force main exits the dry well and flows to the new downstream 8” (200 mm) gravity sewer. The previous lift station was decommissioned and the wet well was converted to a manhole to allow flow to connect the sewer lines to the new lift station to the north.
Preventing MIC
“The project engineers needed a solution to prevent microbially-induced corrosion (MIC) in the concrete structures of the wet well structure, part of the new lift station,” adds Christopher Chen, Director of The Penetron Group. “We suggested Penetron’s antimicrobial concrete admixture as a solution to the problem.”
Penetron’s unique antimicrobial admixture combats MIC, a little-known but widespread problem that causes billions of dollars in damage to wastewater and sewage-related concrete structures every year. Underground concrete sewage systems deteriorate rapidly due to thiobacillus bacteria converting hydrogen sulfide gas (H2S), found in raw sewage, into biogenic sulfuric acid (H2SO4), which causes severe concrete deterioration, known as microbially-induced corrosion. Penetron’s antimicrobial concrete admixture uses an electro-physical mechanism to destroy the cell walls of the thiobacillus family of bacteria. Eliminating bacterial growth on and in the concrete stops the formation of biogenic sulfuric acid, preventing MIC.
Permanent Protection from Acid-Producing Bacteria
Penetron worked with Norwalk Ready Mix, the concrete ready-mix supplier, to add Penetron’s antimicrobial admixture to the concrete mix during batching. The admixture is permanent; it forms part of the concrete matrix and is leach resistant. The effectiveness of the antimicrobial admixture is not lessened by repeated contact with bacteria.
“Penetron’s antimicrobial admixture provides the much-needed long-term protection from MIC,” adds Christopher Chen. “Our new admixture will ensure the needed durability to the concrete and minimize the need for future repairs of the treated wet well concrete structures.”
