Puerto Nuevo Flow Monitoring

The Puerto Nuevo Regional Wastewater Treatment Plant treats approximately 80 MGD of sanitary sewer, making it one of the largest wastewater treatment plants in Puerto Rico. Abnormal increases of flow observed at the wastewater treatment plant during significant rain events suggest that the system is affected by excessive amounts of infiltration and inflow. Flow was monitored at nine different locations mostly along the sewer system trunk sewers. The diameter of the trunk sewer selected for flow monitoring varied between 42 and 90 inches. The selected flow monitoring points represented a significant challenge due to the high amount of flow conveyed by the trunk sewers and the large amount of debris transported by the system. To ensure data quality and minimize data losses, a multiple flow sensor configuration was used at each of the locations. This arrangement provided redundancy in case any of the sensors was affected by the adverse conditions. In addition, an aggressive maintenance plan was implemented thought the monitoring period ensuring high quality data and keeping data losses to a minimum. The maintenance plan included daily remote monitoring of flow data and regular visits to each site. In addition to nine flow monitors, four rain gauges were installed along the system to assess the relationship between sewer flow and rainfall. For over 100 days, ENTECH collected high quality, continuous and synchronous sewer flow and rainfall data exceeding PRASA’s expectations. These results were obtained thanks to the highly qualified staff assigned to this project and rigorous safety protocols.