This project consists of final design of approximately 6,900 linear feet of relief sewer pipelines in 4 locations throughout unincorporated Clark County. The work includes construction of new manholes and laterals, modifications to existing manholes and laterals, pavement replacement, traffic control, and bypass pumping operations, with sewer diameters that range from 8 inches to 24 inches. The project also includes the rehabilitation of existing CCWRD infrastructure in 8 locations in Clark County. The rehabilitation design includes over 13,000 linear feet of pipeline condition assessment inspections as per NASSCO standards, cleaning, and design of the appropriate rehabilitation method. Rehabilitation methods employed include cured-in-place pipe liners, cured-in-place manhole liners, corrosion protection coatings and linings, new manhole construction, and manhole base rehabilitation. Key design issues included coordination and design of pipelines along the resort corridor, NDOT, Clark County and NDEP National Pollutant Discharge Elimination System (NPDES) permitting. The project included coordination with CCWRD in order to confirm the need for the relief sewers. Approximately 3,800 linear feet of planned relief sewers were removed from the package after further analysis was completed by GCW. The coordination efforts with the relief pipeline designs were also required to plan and allow for the future decommissioning of two (2) existing lift stations (LS20 and LS32). In order to maintain all requirements and reduce delays, ongoing coordination with the Agencies was required.
The project faced several unique challenges. The majority of project’s 12 separate locations were in older and more developed areas, requiring strategic planning of alignments to minimize traffic control impacts, utilization of complex sewer bypass pumping procedures for abandonment of several existing lines and installation and connection to new sewers. Also, maintaining continual coordination and communications with affected permitting entities, agencies, and property owners was essential.