The final commissioning of the municipal wastewater treatment plant in Melrose, Minnesota, is slated for August 2024. The US$ 9 million expansion and upgrade project delivered improved plant efficiency and treatment capacity to better meet expected population growth and industry expansion. PENETRON ADMIX SB, a crystalline concrete waterproofing admixture, was specified for durability and to extend the service life of the new treatment plant.
Situated on the banks of the Sauk River, and surrounded by the Big and Little Birch Lakes, Lake Sylvia, and even more lakes beyond – a landscape typical of Minnesota – Melrose is a city of around 4,000 people on the I-94 highway corridor in the center of the state. Incorporated in the late 19th century once the railroad boom reached the area, the city today has a vibrant downtown, a K-12 public school system (and private schools), a modern hospital and medical center, and even a historical society.
The town continues to grow and prosper, which has recently begun to strain municipal infrastructure. Residential waste and output from three local industrial plants make up about 80% of the raw wastewater coming into the Melrose wastewater treatment plant. Originally commissioned in 1963, the plant is a three-million gallon a day (MGD) class "A" treatment facility which has since undergone several upgrades and capacity expansions, including a series of lift stations and wastewater lines to convey the wastewater to the plant for treatment.
“Recent inspections revealed substantial concrete deterioration of key concrete structures at the Melrose plant,” noted Christopher Chen, Director of The Penetron Group. “To meet the increase in demand for treatment capacity due to the expected growth in population and increased capacity needs for the local industry, an expansion of the plant’s treatment capacity was needed.”
Improving the corrosion resistance of concrete structures in wastewater treatment plants depends primarily on optimal protection of the imbedded steel reinforcement. The project engineers at Short Elliot Hendrickson (SEH) underlined the importance of a robust waterproofing solution to protect the plant’s concrete structures from corrosion, chemical attack, and permanent exposure to the aggressive environment of the effluent.
The new upgrades to the wastewater treatment plant include a new headworks building (new pumps and screens), both new and refurbished clarifiers, new splitter structures, and updated metering equipment. The resulting gain in efficiency provided the Melrose plant with an additional 500,000 gallons per day of treatment capacity.
Worms Lumber & Ready Mix, the ready-mix concrete supplier, added PENETRON ADMIX SB to the concrete mix for the facility’s new concrete structures.
“PENETRON ADMIX SB was chosen over a number of competitive admixtures under review as the best product to enhance concrete impermeability and extend the service life of the expanded Melrose facility,” adds Christopher Chen. “The ease of dosing with soluble bags and technical assistance throughout the project also helped tip the decision to Penetron.”
Gaining efficiency and durability: The new treatment tanks of the Melrose plant provide an additional 500,000 gallons per day of treatment capacity and a longer service life thanks to Penetron.
