Increased Water Quality Standards Require Innovative Solutions
As the waste stream generated by modern society grows larger and more complex, the preservation of public health and the natural environment requires thoughtful improvements in wastewater engineering and treatment processes. Located in southeast Iowa, the City of West Burlington required just that remedy when their wastewater facility was notified their current treatment methods didn’t meet the state’s updated water quality standards.
Significant facility upgrades were necessary to meet National Pollution Discharge Elimination System (NPDES) compliance regulations pertaining to the treatment of ammonia-nitrogen, E. coli, and dissolved oxygen limits. To spearhead this effort, the wastewater professionals with Snyder & Associates provided complete wastewater facility planning and design services, as well as administering all aspects of construction management.
Extensive Facility Improvements Lead to NPDES Compliance
The original city-owned treatment facility included a gravity sewer main, lift stations, and a combination of an activated sludge wastewater treatment plant and a three-cell aerated lagoon. While this facility configuration effectively treated the community’s wastewater for many years, this process didn’t account for increased capacity and stringent regulation updates.
The project included the construction of a new headworks building with grit removal and screening, a process the old facility didn’t previously contain. The addition of an ultraviolet (UV) disinfection system was included to treat E. coli concerns. Using the latest in Aero-Mod, Inc. technology and controls, the physical upgrades provided more efficient aeration equipment and blowers, as well as nutrient removal. The construction of a cast-in-place tank consisting of four aeration basins, four clarifiers, and two selector tanks greatly increased the total capacity of the plant.
Two of the existing aerated lagoon cells were converted to equalization basins to minimize the sizing of the mechanical treatment equipment, while the other became a stabilized sludge storage space. This transition made the plant 100 percent treated by activated sludge. The activated sludge process uses a mass of organisms to aerobically treat wastewater and remove biodegradable organics from both municipal and industrial wastewaters. This process was determined to be the best fit for West Burlington as it resolved the ammonia-nitrogen and nutrient complications.
Improvements also included new controls and electrical upgrades, the rerouting of subsurface piping, and the installation of a standby generator. Our team created a design that kept all of the upgrades confined to the existing wastewater treatment plant property.
Thoughtful Modifications & Efficient Planning Reduces Project Budget
With input from city staff and leaders, Snyder & Associates designed this treatment facility with an eye toward future growth in the city and the potential for increased nutrient reduction requirements, as well. Our team’s foresight to plan for both eventualities saved the city countless hours of planning and construction.
Additionally, utilizing much of the wastewater system already in place and simply modifying it to meet the new regulations minimized the required upgrades, creating lower overall project costs in the end. Once crews completed construction, the project’s total cost came in nearly $1 million under the proposed budget. The Snyder & Associates team is proud to provide efficient designs that keep communities in compliance with ever-changing regulations and within the means of an ever-tighter city budget.