Through routine inspection, the City of Tempe discovered that an existing 16-inch ductile iron pipe (DIP) sanitary sewer recently rehabilitated with cured-in-place-pipe (CIPP) liner was leaking. The CIPP-lined DIP spans through a 72-inch reinforced concrete pipe (RCP) storm drain approximately 20 feet north of a storm drain junction structure located at the intersection of Farmer Avenue and 13th Street.
Dibble performed an external observation of the DIP and reported that the DIP was significantly corroded and missing pipe wall, which exposed the CIPP liner. Our team also observed that the DIP was actively leaking at the pipe’s invert location.
Dibble provided professional services to recommend a feasible, expedited solution and design repair options to prevent the pipe from additional damage and potential catastrophic failure. The Dibble team recommended using fiber reinforced polymer (FRP) to encase the sewer line to strengthen and protect it.
The deteriorated areas of the DIP were patched. The full length of the DIP in the junction box was externally reinforced with multiple layers of FRP. A polymer sealant was also placed around and within the area of the pipe where leaking was observed. Dibble provided construction administration and special inspection services during the FRP installation.