Site work and paving for a water / sewer project in Hilo, Hawaii. Completed plans call for site work for a water / sewer project.

The existing 24-inch force main sewer that runs from the Pua Sewage Pump Station (SPS) to the Hilo Wastewater Treatment Plant is exhibiting signs of deterioration. The County did experience a break of the existing force main back in 2011. During that repair, it was discovered that the liner in the pipe was starting to peel away from the inner wall causing potential blockage. New 24-inch Diameter Force Main: The County wants to install a second (dual) 24-inch sewer force main (FM) (approximately 16,600 LF) parallel to the existing 24-inch force main that was installed back in the early 90’s. When the Pua SPS and FM was originally designed back in the late 80’s, the intent was to initially install one 24-inch diameter FM to handle 5 mgd average dry weather flow (ADWF). The Facilities Plan called for an eventual buildout ADWF of 8.3 mgd for Hilo (Design year = 2027) (Hilo District Facilities Plan Amendment (September 14, 1988 DRAFT)). Therefore, the Basis of Design Report (BDOR) for the Pua SPS (October 28, 1988) called for dual 24-inch FM where one was to be installed with the construction of the new Pua SPS and new Hilo Wastewater Treatment Plant (WWTP). (Please recall that the County was moving the existing Hilo WWTP from the grounds where the Pua SPS currently sits to a new location inland south of the Hilo Airport some 3 miles away.) The easements that were established incorporated enough room for the 2 parallel force mains and one 42-inch outfall pipeline to serve the new Hilo WWTP. The expansion of the collection system throughout Hilo town did not occur according to plan due to funding constraints. Therefore, the second 24-inch FM was never installed. As of September 30, 2022, this project is currently under construction. However the completion timeline has not been identified. *Project information, including timeline and contacts, has been obtained through public sources. The content management team continues to pursue additional details; however, the contact(s) listed have yet to disclose or confirm any information. Inquiries should be directed to the contact(s) listed.