PROJECT OVERVIEW

Our project involved the comprehensive assessment, design, and rehabilitation of a critical 750 linear feet (LF) segment of a 54-inch diameter sanitary sewer interceptor. This key infrastructure element serves as a conduit for influent wastewater from the City of Garland's collection system to the Rowlett Creek Wastewater Treatment Plant Project (RCWWTP) headworks. The existing conditions raised significant concerns due to the pipeline's severe corrosion, evident from previous CCTV inspections revealing exposed rebar. Furthermore, the highly corrosive nature of the raw wastewater and the turbulence at discharge and junction structures intensified the 37-year-old pipeline's deterioration, causing up to four inches of interior concrete loss at cross sections.

SERVICE DETAILS

To address the urgent need for rehabilitation, we conducted a thorough assessment of rehabilitation methods. Our preliminary engineering report (PER) phase meticulously evaluated the capacity requirements, bypass pumping needs, and general constructability aspects. Based on our assessment, we recommended and proceeded with the final design, focusing on cured-in-place pipe (CIPP) rehabilitation. This encompassed detailed plans and specifications for the 750 LF of 54-inch RCP rehabilitation. Our approach included the addition of two manholes and the rehabilitation of three manholes using epoxy coating. We strategically managed bypass pumping for average and wet weather flows of 1.5 MGD and 7.0 MGD, respectively. Thorough pre-construction and post-construction cleaning and televising ensured a comprehensive solution. The final design and bid documents were completed in less than 90 days, meeting the city's requested schedule.

During the construction phase, we closely supervised the process and implemented effective bypassing methods to maintain continuous wastewater flow. Our team and city personnel conducted thorough inspections and worked closely with Insituform. They carefully installed CIPP using steam curing in segments, while our team closely observed. Inspections before and after CIPP installation confirmed proper cleaning, preparation, and installation quality.

The successful completion of this vital project in June 2021 stands as a testament to our commitment to quality infrastructure. The project's total construction cost amounted to $848,280, reflecting both the challenges addressed and the excellence achieved.