WSSC's Systematic Approach to the CFRP Liner Installation Process

Abstract

Washington Suburban Sanitary Commission (WSSC) serves approximately 1.8 million people in Montgomery and Prince George’s counties in Maryland and is the eighth largest water and wastewater utility in the country. Because of past issues with certain pre-stressed concrete cylinder pipe (PCCP), WSSC has an active inspection and monitoring program in place that focuses on their large diameter PCCP. WSSC utilizes all types of repair and rehabilitation techniques including extensive use of Carbon Fiber Reinforced Polymer (CFRP) liners for in-place trenchless repairs. Over the past several years, WSSC has developed a tailored Quality Assurance and Quality Control (QA/QC) Program in collaboration with the manufacturer of the CFRP liner. The Program addresses all aspects of the CFRP lining installation process and has tailored QA/QC forms and procedures for the critical steps in the overall process. The accelerated construction schedule of typical CFRP lining projects made the implementation of a QA/QC program, which is managed online, ideal for ensuring close communication between all involved parties. In addition to facilitating communication during construction, the online project tracking system serves as the permanent archive for all documents related to the renewal of the pipeline system. The uploaded documents include original as-builts, plans, profiles, and specifications which address the original construction of the PCCP system. In addition, inspection results for the pipeline, preliminary CFRP lining drawings and calculations, construction photos and QA/QC records, and as-built CFRP lining drawings and calculations are stored in the system. This paper will serve to highlight the development of WSSC’s real time Quality Assurance approach for CFRP liners and how this process has aided in their overall document control and communication regarding PCCP asset management. Readers and attendees will gain valuable insight from one of the country’s most diligent and proactive PCCP owners.