Albuquerque Bernalillo County Water Utility Authority, NM
Final Contract Amount: $8,647,400.00
Albuquerque Bernalillo County Water Utility Authority (ABCWUA) took a proactive instead if reactive approach to addressing aging and failing interceptor sewer lines. This project consisted of two trenchless rehabilitation methods, sliplining and cured in place process (CIPP) for the rehabilitation of large diameter sewer lines. AUI installed approximately 12,210 LF of the project utilizing sliplining, 5,625 LF of CIPP rehabilitation and 500 LF using open cut. Pipe diameters varied from 12-inch to 78-inch. There was also extensive manhole rehabilitation that incorporated strong seal and Zebron Coating treatment with several of the new 6’ and 8’ diameter manholes reaching depths of 14’. The segments of the project were located within various locations, and when combined with the several rehabilitation methods used, several challenges were created throughout this project.
During the CIPP installation, the project was especially complicated due to the use of dewatering and by-pass pumping in challenging scenarios. The by-pass of 48-inch SAS main across busy roadways was accomplished by AUI setting up over 5,300 LF of 18-inch HDPE which was used as the discharge line to support the by-passing of the sewer line. With bypass flows up to 10 MGD for a consecutive 1 ½ month period, this constituted a 24-hour pump watch. The 48-inch SAS snaked through the backyards of residences and businesses, with one manhole actually located on a homeowner’s property. AUI worked with property owners and various city and county entities to assure all interests were considered, while maintaining project schedule and scope. The 12-inch CIPP took place under Interstate 40. The old sewer line cut across the interstate at a depth of 14 VF. By-pass pumping was accomplished through a series of storm drains under the interstate so the CIPP process could proceed. Once the sewer line was by-passed the CIPP was installed within 6 hours. A siphon that ran under a major storm drain concrete channel was the location of the 30-inch RCP line that was to be cured in place. With the depth of the sewer line in excess of 25 VF, the siphon had to be dewatered. The line was also severely congested with caked grease and debris. AUI subcontracted Pro Pipe Services to clean the line with the use of a special chain and nozzle combination to dislodge the grease buildup, and clean the inside of the siphon so that the dewatering and CIPP process could be completed, and flows returned to normal.
Over 17,000 LF of both Slip line and CIPP were used as successful trenchless methods to rehabilitate Albuquerque’s aging interceptor sewer lines. AUI once again provided efficient and effective management of both in-house personnel and subcontractors to achieve project success.