Inflow and Infiltration Affecting the Water Reclamation Facility #2 in Ocala, Florida

Abstract

The Water Reclamation Facility #2 (WRF #2) of the city of Ocala, Florida, is receiving high influent flows on heavy rain events. The hypothesis is that stormwater inflow and infiltration is coming into the sewer system and some possible combined systems may still be in service. Since September 2017, WRF #2 has received high influent flows over the design capacity five times. Hurricane Irma brought more than 10 inches of rainfall over 24 hours, the worst storm over the last three years. The analysis includes registered rainfall, registered flows on heavy rain events and design capacity of the lift stations and the plant. The average sewer flows can be correlated with the received flows during a heavy rain event to confirm the possibility of an inflow and infiltration situation. This correlation showed that sewer flow received after heavy rain events are greater than average, which confirmed the inflow and infiltration hypothesis. Ocala has started a smoke test project throughout the city, and they have found numerous cases of it, including combined systems. This project has been developed understanding the existing conditions and analyzing the best available data in order to identify possible opportunities to minimize the incoming of the inflow and infiltration into the sewer system to help the infrastructure. Key Terms ⎯ combined system, infiltration, inflow, water reclamation facility