Critical El Paso Force Main with High Consequence of Failure Undergoes Multi-Faceted Condition Assessment

The Frontera Lift Station directs 10 million gallons of wastewater per day (MGD) into two (2) parallel force mains (welded steel pipe with cement mortar lining) a distance of 3.67 mi to the John T. Hickerson Water Reclamation Facility (Facility). The 30/36/42-in dual force mains are critical pipelines with a high consequence of failure as they are the only pipeline system that conveys wastewater flow from the entire westside of El Paso to the facility. Additionally, the force mains traverse through residential, commercial, and industrial areas, through open desert and arroyos, and under a recently constructed freeway. Due to the high consequence of failure and the several relocations required to accommodate roadway improvement projects since their installation nearly 20 over 25 years ago, El Paso Water implemented a proactive decision intelligence approach to condition assessment. This includes evaluating the current condition and long-term utilization of the force mains, and to obtaining actionable information on immediate concerns including leaks, gas pockets, and pipes with significant wall loss. Prior to the subject inspection, Jacobs and El Paso Water completed a desktop study, testing, and mapping of existing soils corrosion potential along the pipeline alignment, an initial cathodic protection system analysis, and limited external pipe investigations. Following and based on this work, El Paso water elected to inspect the force mains employing Pure Technologies-Xylem for the subject condition assessment, of the south force main from the Frontera LS to the treatment Facility. The subject condition assessment of the Frontera lift station force main included an internal acoustic leak and gas pocket inspection to detect leaks and pockets of trapped hydrogen sulfide gas, an internal electromagnetic inspection to identify pipes with wall loss, an evaluation of the cathodic protection system, and development of a map of the buried infrastructure alignment.