Client: El Paso Water Utilities (EPWU)
Project Date: June 2005
Type of Pipeline: Transmission Main
Pipe Material: Lined Cylinder Pipe (LCP)
Length: 0.64 miles
The City of El Paso is the fifth largest in Texas, with a population of approximately 750,000. To serve the needs of this burgeoning city, El Paso Water Utilities (EPWU) operates over 2,200 miles of water transmission mains. EPWU is in the midst of conducting a thorough evaluation of the condition of its water transmission system.
In early 2005, John E. Balliew, Water System Division Manager for EPWU, was concerned in particular about a 24' Lined Cylinder Pipe (LCP) pipeline, known as the Roseway Water Transmission Main. 'This line had recently experienced a failure, and it is situated next to a natural gas pipeline,' explained Balliew. 'Given that it is possible that stray currents from the natural gas pipeline's cathodic protection system had a role in the Roseway line failure, we needed to know the condition of the balance of the water line.”
In June 2005, Pure Technologies conducted a non-destructive evaluation of two areas of the Roseway Water Transmission Main using electromagnetics. As this pipeline is too small for manned entry, Pure Technologies elected to use it a robotic inspection tool called PipeCrawler. PipeCrawler is an unmanned water transmission pipeline inspection tool that expands the delivery of electromagnetic pipeline evaluation service to PCP with a diameter range of 18' and up. PipeCrawler is a tethered steerable all wheel drive inspection vehicle, with a maximum range of 2,000 ft. As the tool is unmanned, a pipeline does not have to be dewatered to permit its use.
A distance of approximately 0.64 miles was inspected using PipeCrawler. Analysis of the data obtained during this inspection determined that there were no pipes in the area tested that displayed evidence of prestressed wire breaks.
'As a result of this inspection, EPWU has been able to avoid replacing the pipeline,' stated Balliew. 'The total cost savings is in excess of $3.1 million dollars'.
Recently, EPWU has engaged the consulting engineering firm CH2MHill to develop a tool that incorporates condition assessment results from a number of electromagnetic, Sahara®, and Acoustic Emission Testing (AET) inspections. The aim of this project is to establish an asset condition index and an asset risk index. For example, pipelines with distressed wires, identified leaks, or known to be in a corrosive area will be combined with pipelines that pass beneath an interstate or near a hospital to help set levels of service as well as prioritize repairs and rehabilitation. The goal of this integrated asset management plan is to optimize the level of investment for the water pipeline facilities in a logical and organized manner with financial savings to EPWU through planned maintenance and timed capital expenditures.
Case study - El Paso Water Utilities (EPWU)