The Christina River Force Main (CRFM) is an 84 in. prestressed concrete cylinder pipe (PCCP) force main owned and operated by New Castle County, Delaware. The New Castle County sanitary sewer system serves over 122,000 customers and handles 50 million gallons of wastewater every day. The system consists of approximately 45,000 manholes; 1,800 mi of sanitary sewer gravity collection system pipes ranging from 6 in. to 84 in. in diameter; 3 wastewater treatment plants; and 175 pump stations. In 2019, inspections conducted by the owner and engineer revealed that sections of this force main were critically deteriorated due to hydrogen sulfide attack—in some cases, portions of the inner concrete core had become completely disintegrated and/or disbonded and were found on the invert of the pipe. In the most extreme cases, the inner core was missing, the steel cylinder was completely corroded, and the outer core was starting to be attacked and deteriorated by up to about 1 in. depth. Replacement of the line was not possible due to the presence of a high-pressure gas mine running over a portion of the line. Relocation was not practical due to both area congestion and the anticipated duration of the permitting process. After a thorough analysis, New Castle County and AECOM determined that the best path forward was to structurally rehabilitate the CRFM using carbon fiber reinforced polymer (CRFP). The rehabilitation project began in the December 2019 and was completed in March 2020. It consisted of structurally rehabilitating 22 segments and installing a corrosion prevention barrier on 88 segments. The total project length was 1311 LF. This paper will discuss the challenges encountered during installation including cleaning and sanitizing the line; incremental shoring; debris removal; surface preparation/restoration; and installation of CFRP.

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The Christina River Force Main (CRFM) is an 84 in. prestressed concrete cylinder pipe (PCCP) force main owned and operated by New Castle County, Delaware. The New Castle County sanitary sewer system serves over 122,000 customers and handles 50 million gallons of wastewater every day. The system consists of approximately 45,000 manholes; 1,800 mi of sanitary sewer gravity collection system pipes ranging from 6 in. to 84 in. in diameter; 3 wastewater treatment plants; and 175 pump stations. In 2019, inspections conducted by the owner and engineer revealed that sections of this force main were critically deteriorated due to hydrogen sulfide attack—in some cases, portions of the inner concrete core had become completely disintegrated and/or disbonded and were found on the invert of the pipe. In the most extreme cases, the inner core was missing, the steel cylinder was completely corroded, and the outer core was starting to be attacked and deteriorated by up to about 1 in. depth. Replacement of the line was not possible due to the presence of a high-pressure gas mine running over a portion of the line. Relocation was not practical due to both area congestion and the anticipated duration of the permitting process. After a thorough analysis, New Castle County and AECOM determined that the best path forward was to structurally rehabilitate the CRFM using carbon fiber reinforced polymer (CRFP). The rehabilitation project began in the December 2019 and was completed in March 2020. It consisted of structurally rehabilitating 22 segments and installing a corrosion prevention barrier on 88 segments. The total project length was 1311 LF. This paper will discuss the challenges encountered during installation including cleaning and sanitizing the line; incremental shoring; debris removal; surface preparation/restoration; and installation of CFRP.

**[Access the Conference Proceedings Paper on ASCE Library](https://ascelibrary.org/doi/10.1061/9780784483626.012)** 


Emergent Rehabilitation of a Critically Deteriorated Force Main for New Castle County, Delaware

Papers from sessions of Pipelines 2021, held virtually August 3–6, 2021. Sponsored by the Utility Engineering and Surveying Institute of ASCE. The conference provides a forum for pipeline engineers and practitioners from all around the world to share their experiences in meeting the challenges of today's pipeline infrastructure. This premier industry event has become the conference of choice for utility and pipeline owners, design and consulting engineers, contractors, manufacturers, suppliers, students, educators, researchers, and pipeline professionals. The conference includes surveying as it relates to pipeline and utility projects. This event will provide a dynamic and inspiring venue for participants to share and gain valuable knowledge related to planning, designing, constructing, renewing, operating, managing and maintaining the pipeline assets.

[Paper Proceedings](https://doi.org/10.1061/9780784483602)

Conference DOI: https://doi.org/10.26226/m.6454f875c8d4320012b71046