City of Punta Gorda: Weekly Highlights Report March 3, 2023

Last week I discussed the future of the city's Wastewater Treatment Plant (WwTP). A resident reached out and asked some great questions. He inquired about the current average daily flow, if it was at or near the four million gallons per day (MGD) capacity, and Should the flow be increased with more manpower if necessary?

The Florida Administrative Code requires WwTP's to perform a Capacity Analysis Report (CAR) within 180 days of reaching 50% of the rolling three-month average for the first time. (FAC 62-600.405) If the plant's capacity will be exceeded more than 10 years in the future, the plant must perform a CAR every five years. Once the CAR documents show the rated capacity will be equaled or exceeded with the next 10 years, the utility must complete a CAR annually. If the initial capacity analysis report or an update of the capacity analysis report documents that the permitted capacity will be equaled or exceeded within the next five years, the report shall include a statement, signed and sealed by a professional engineer registered in Florida, that planning and preliminary design of the necessary expansion has been initiated.

The city's most recent CAR indicates that the city will not exceed the rated capacity until 2038. This will be re-evaluated every five years, and once we pass the 10-year trigger, we will be required to evaluate the future capacity annually. We would not expand the capacity beyond the four MGD today because the Peak Hour Flow (PHF) plant records indicate a PHF as high as 3.3X our Annual Average Million Gallons per Day (AAMGD). The design of the improvement project is to pass the peaking factor of three hydraulically. The headworks and the deep well are designed for a peak hourly flow of 12 MGD (Builtin 2001 – 4x3), so the most we could rate the plant without replacing the headworks would be 4MGD. If the city can show a reduced peak hourly flow as our flows increase, there may be an opportunity to have the plant re-rated to a higher flow in the future. By today's standard, the existing plant would be rated at 1.64 MGD with a maximum three-month rolling average of 2.34. This project will allow the plant to be rated at the intended four MGD, re-establish the CAR for 2038, and enable additional inflow and infiltration work on the collection system to reduce further the PHF (replacing old leaking pipes), which is a more cost-effective way to increase the long term capacity of the facility. This also, then, allows debt repayment before additional debt is required for capacity upgrades were it necessary.

The WwTP Improvement Project's Construction Manager at Risk provided draft 100% plans for guaranteed maximum pricing for staff review last week. While developing the proposal, every effort is made to identify cost savings and get the best prices for ratepayers. Funding sources will include wastewater impact fees and financing through the State Revolving Loan Fund. Debt service will be repaid through wastewater impact fees and user fees.

Click Here To View The City of Punta Gorda: Weekly Highlights Report March 3, 2023