Emergency sewer work on a wastewater pump station serving Ko Olina Resort has been finished, city officials announced this afternoon.

The city Department of Environmental Services recently completed emergency rehabilitation work on both force mains, or pipelines that convey wastewater, at West Beach Wastewater Pump Station (WWPS) to ensure the future safety of the wastewater system at a cost of $12.6 million. Hawaiian Dredging Construction Company was awarded the bid.

The project follows six force main breaks that occurred from 2013 to 2017. Since the frequency of the breaks were increasing, city officials said, it was critical to repair them under an emergency procurement.

Work crews sliplined — or installed a smaller “carrier pipe” into a larger “host pipe” — approximately 9,200 lineal feet of existing, 16-inch force main from West Beach WWPS No. 1 with a 12-inch high-density polyethylene (HDPE) diameter pipe. In addition, work crews sliplined nearly 6,400 lineal feet of the existing 20-inch force main from West Beach WWPS No. 2 with 16-inch HDPE pipe. The system capacity remains the same.

In addition to installing a smaller pi, sliplining involves grouting the ring-shaped space between the two pipes. The contract also included the installation of new air relief valves, vaults, a new valve vault structure, and two new discharge manholes.