Fast Track Replacement of Existing 72-Inch and 90-Inch Pipeline Sections during 60-Day Shutdown Window

The project involves the replacement of two separate sections of the Tarrant Regional Water District (TRWD) existing 72-in. Cedar Creek (CC) and 90-in. Richland Chambers (RC) raw water pipelines. The CC and RC pipelines are existing parallel PCCP pipelines installed within a 130-foot easement. The pipelines convey water from Cedar Creek Lake and Richland-Chambers Reservoir. The CC and RC pipelines were installed in 1971 and 1984, respectively, and supply raw water to the city of Fort Worth, Arlington, and various other customer cities. The replacement sections are bare steel pipe encased in concrete backfill. The steel pipe and concrete encasement is dielectrically similar to PCCP. Since the exterior coating is essentially the same as the existing pipeline, the replacement section does not require the use of isolation joints to dis-bond the new pipe from the existing pipe. The new pipe is protected by the existing cathodic protection (CP) system. The CC and RC pipelines are being replaced as part of a highway expansion project where State Highway (SH) 360 is being improved to include additional main lanes and frontage lanes that cross over TRWD’s existing pipeline corridor. The width of the highway right-of-way (ROW) is approximately 500 ft at the location where the existing pipelines cross. The replacement pipeline sections through this area were constructed in a phased approach during two separate annual shutdowns. Pipe material was pre-purchased to expedite the replacement of both pipeline sections so that the pipe was manufactured and delivered in time for the allocated shutdown periods.