Damage by heavy equipment, possibly unintentional, to a 20-inch force main sent tens of thousands of gallons of untreated sewage into the ocean near Kahului.

The county Department of Environmental Management discovered the leak at 9 a.m. Thursday behind the Y Hata warehouse on the corner of Waiehu Beach and Kahului Beach roads, where the county has an easement.

County crews immediately worked to contain the spill, completing the construction of a protective berm by 11 a.m.

Crews found suspicious damage to the pipe, along with about 20 tires of various sizes piled on top, possibly as concealment.

“It’s a clean, straight cut,” department Director Stewart Stant said in a statement Friday. “It’s not corrosion because we just put in this force main seven years ago. It definitely looks like someone hit it using heavy equipment and damaged it and it wasn’t one of our crews.”

An estimated 68,000 gallons of wastewater flowed over a dirt access road to the Wailuku Pump Station and into the ocean. The remaining 136,000 gallons of wastewater were contained on-site after a dirt berm was constructed.

The discharge did not enter Kahului Harbor, the county said. But the public was advised to remain out of the waters between Kanaloa Avenue and Linekona Street, north of the harbor.

The area was cleaned and disinfected, bacteriological tests were conducted and warning signs were posted.

The county will turn over all findings to the state Department of Health, the reporting authority for wastewater spills, which will conduct its own investigation.

2 rescued after boat capsizes near Hilo

Hawaii island fire crews rescued two mariners whose boat capsized near Hilo on Friday.

Two companies, two medic units, a helicopter and a rescue boat responded to a report at 10:40 a.m. of an overturned boat either in Hilo Bay or near Kaloli Point, Hawaiian Paradise Park.

A search of Hilo Bay turned up nothing, but the helicopter spotted a 20-foot Bayliner partially submerged about a quarter-mile offshore near Kaloli Point.

Two people were treading water nearby and were rescued without incident. There were no injuries, the Hawaii County Fire Department said by email.

The Coast Guard was working with the owner to salvage the boat.