WAILUA — A vehicle traveling in the right-hand lane of Kuhio Highway near Leho Drive was struck by an exploding manhole cover Thursday night.
An investigation found that the sewer gravity main pipe had eroded, allowing the cover soil to fall into the sewer line and clog it.
“There was enough pressure in the sewer line built up with air, that the onrush of the water hitting the clog caused the cover to pretty much burst into the air,” said Acting County Engineer Lyle Tabata.
One person reported non-life threatening injuries when the Silver Honda Pilot drove over the manhole.
EMT personnel responded and treated the 63-year-old passenger of the vehicle for pain to her arm. The injury did not require hospitalization.
An estimated 1,000 gallons of sewage leaked from the burst pipe and crews have been working nonstop to clean up the mess. They’ve used sodium hypochlorite, a powdered chlorine, to wash down the roads.
“Some of it spilled into the Wailua River, so we have signs up and we’ll be conducting testings of the water,” Tabata said.
The spill caused extensive delays in rush-hour traffic Friday morning, with vehicles backed up all the way to the north end of the Kapaa bypass road, about four miles, and to Kealia Beach on Kuhio Highway.
Frustrated drivers, for the most part, waited calmly and accepted the hour-long delay as part of life on Kauai.
Friday night, northbound traffic was backed up for miles, again, because traffic was reduced to one-lane around the site of the pipe break.
About 30 people have been working in shifts on cleaning up the spill and repairing the damage.
Because that part of the system is gravity fed, Tabata said they’ve had to create their own above-ground bypass system to carry the waste to the next manhole.
A portion of the outer northbound lane of Kuhio Highway – at the north-junction of Leho Drive near the Hilton Garden Inn – will remain closed until Saturday evening as crews continue work to repair a damaged sewer line.
The goal is to have traffic returning to normal by the Monday morning rush hour, Tabata said.
Motorists should expect severe traffic delays and adjust their travel times as needed.
Officials are asking the public to avoid the area.
Tabata said in his most recent recollection, this is the first sewage break they’ve had in this area, but they’ve had other clogs due to grease and foreign matter making it way into the manhole system, so they’ll be taking a closer look at this section of the system.
“Before, this area was a sewage forced main pumped from the Wailua pump station. This is where it daylights, meaning it’s not under pressure anymore, it goes on gravity,” he said.
Anytime you switch from gassing the sewage, it causes corrosion of the pipe, Tabata said.
The Hawaii State Department of Health is also testing the water, but it will take several days for the tests to be completed, he said.
“We’ll alert the public to the findings,” Tabata said.
Robert Minicola, Hilton Garden Inn general manager, said the incident caused minimal disruption to hotel operations, and praised the county.
“Last night they came right away. They had fantastic teamwork and a lot of them stayed up all night working and throughout the day,” he said.
The spill is in a bad location, Minicola said.
“It’s difficult for them. I know for all of the local people who have to go up and down it was a little inconvenient for them this morning, but I think they have it under control,” he said.
Bethany Freudenthal, crime, courts and county reporter, 652-7891, firstname.lastname@example.org