Traffic patterns on Palani Road, between Kailua Pier and Kuakini Highway, will be altered beginning Tuesday as work begins to replace an aging sewer line.
The mauka-bound lane on Palani Road will be closed to traffic for approximately 45 days while Jas. W. Glover crews replace the nearly 60-year-old, 6-inch cast iron pipe sewer force main. The project costs nearly $1 million.
The replacement of the Lanihau Force Main is a prime concern for the Department of Health Waste Water Division, according to a May 2019 report by the Department of Health. The existing 6-inch cast iron force main was constructed in 1962.
The force main’s deteriorated condition led to a rupture on June 12, 2017, that resulted in an accidental discharge of untreated wastewater into Kailua Bay. The two points of failure were found under Palani Road and emergency repairs were completed on June 15, 2017.
The cast iron pipe material has deteriorated from likely both internal corrosion from sewage flow as well as external corrosion from the environment the pipe is buried in, according to the report.
“The consequences of failure for the Lanihau Force Main are substantial considering the high indirect cost associated with damage to the environment and closure of Kailua Bay,” the report reads.
The decision to replace the force main was made taking into account its age, high consequence of failure, history of previous failure, and strong likelihood of future failure based on the corrosion levels observed when the pipe was exposed during the repairs.
The work to commence Tuesday includes the removal of an existing 6-inch diameter cast iron force main beneath the roadway and installation of a new 8-inch diameter PVC pipe force main in the same location at a depth of up to 10 feet. It will then be connected to existing discharge piping inside of the Lanihau Waste Water Pump Station valve vault.
Meanwhile, work to repair the Keopu force main has been completed after a break in July sent nearly 20,000 gallons of untreated sewage onto the roadway and into Kailua Bay.
Hawaii County Department of Environmental Management Wastewater Division Superintendent Alika DeMello said repairs on the Keopu force main were completed by West Hawaii Sewer Maintenance and the large fenced pump at Emma Square will be handling the sewage diverted from the Lanihau Force Main while replacement work is being done.
The division is also performing preventative maintenance work on the gravity sewer pipes along Alii Drive from Emma Square to the pier using cured-in-place pipe (CIPP) to reinforce clay pipes, sealing any cracks and deteriorating rubber gaskets.
Using CIPP will save the county a substantial amount of money over replacing the line, said DeMello. CIPP costs $250 per foot versus $1,250 per foot for a contractor to replace the pipes plus work is performed by county employees. In addition, the road does not needs to be torn up as the work can be done via existing manholes.
DeMello said the manufacturer states the epoxy pipe lining will last 100 years.
“The repair and replacement of our sewer collection system in Kona is a continuing process,” Department of Environmental Management Director Bill Kucharski said in July. “It is a result of many years of minimal funding which has started to be remedied by the first sewer fee increase in over 10 years.”
Kucharski said the department is trying to catch up and trying to repair and replace the aged system.
“This work cannot be done overnight and there will be years of work ahead, and having said that, progress, however slow it might appear, is happening,” he said.
“I’m really happy with the progress so far,” said DeMello. “Our priority first and foremost is the public’s health and safety.”