The city has hired an outside contractor to excavate a 1.5-acre parcel of undeveloped Navy land along the coast of Waipahu where 614,400 gallons of raw sewage spilled out of a broken wastewater force main late Saturday night.

The contractor is tasked with determining the cause, extent of damage and necessary repairs for the broken 48-inch force main near the Waipio Soccer Complex, city spokesman Andrew Pereira said.

None of the sewage reached either nearby West Loch or the ocean, and the busy soccer complex kept to its regular hours.

Crews from the Department of Environmental Services diverted the spill from the break to a 42-inch parallel force main, thereby minimizing the overflow, Pereira said.

The spill was confined to a low-lying area that is surrounded by mounds on all sides, he said. The area affected by the spill is about the size of an Olympic-scale swimming pool and is inaccessible to the public, Pereira said.

Environmental Services crews responded about 7:25 p.m. Saturday and secured the flow at about 2:45 a.m. Sunday, city officials said. The state Department of Health was notified and city crews spent much of Sunday and Monday cleaning, disinfecting and deodorizing the affected area.

The Navy land is marked with “no trespassing” signs at its entrances and the city is posting additional signs around the affected area and the entrances, officials said.

A call for residents between Halawa and West Loch to conserve water to reduce the flow while the city addresses the force main break issue was dropped Monday.