In 2019, the City of Lake Park was issued a new NPDES permit which included more stringent effluent limits for water quality parameters including ammonia nitrogen, dissolved oxygen, and E. coli bacteria. Future nutrient reduction requirements, including total nitrogen and phosphorus limits, are anticipated based upon the City’s receiving stream and proximity to the nearby Iowa Great Lakes. The existing WWTF includes a lagoon and constructed wetland system. Since the City is still paying on the loan from the improvements completed in the early 2000s, the City was sensitive to the selected alternative needed to provide a long-term wastewater treatment solution to meet anticipated future regulatory requirements. The City engaged McClure to complete a facility plan and antidegradation alternatives analysis which evaluated existing conditions, alternative treatment methods, and determined the most cost-effective solution to future regulatory requirements. The planning process was a collaborative effort between McClure and City operations staff, which included multiple site visits to treatment facilities to observe treatment equipment and processes in operation and valuable insights into operational and design considerations for the project team.
Through the planning process, the project team settled on the selection of a SEQUOX Aero-Mod activated sludge system, which includes mechanical preliminary treatment and ultraviolet disinfection. The treatment system was also designed with Enhanced Biological Phosphorus Removal and Biological Nitrogen Removal to achieve compliance with anticipated future regulations and allow the City to meet the goals of the Iowa Nutrient Reduction Strategy. McClure assisted the City in developing a financing strategy to address the capital needs of the project, including applications and administration of an SRF Planning and Design Loan, SRF Construction Loan, and acquisition of a $300,000 Wastewater and Drinking Water Treatment Financial Assistance Program grant through the Iowa Finance Authority.