Mayor Kirk Caldwell is asking Gov. David Ige to issue an emergency proclamation to speed up critical sewer line improvements in the West Kapolei region near the Ko Olina Resort to prevent potentially “catastrophic spills.”

“With pipes potentially weakened at unknown points by corrosion, even a single major rain storm event could create such disastrous consequences as sewage spills into the surrounding areas and potentially the ocean,” Caldwell said in a letter to Ige on Tuesday.

An emergency proclamation would allow for a waiver of state permits or clearances, including noise variance and archaeological assessments, “or for their requirements to be reduced or addressed by the city after the fact,” the letter said.

An Ige spokeswoman said the state administration is working to make that happen.

“The state is actively working with the county on this request and stands ready to support the mayor’s request,” said Jodi Leong, a spokeswoman for Ige.

The area has been beset by a number of breaks in recent years, and the city considers the situation an emergency, Caldwell wrote.

The two high-volume, pressurized force mains — West Beach Wastewater Pump Station Force Main No. 1 and Force Main No. 2 — serve a substantial number of residential neighborhoods as well as several hotels, Caldwell wrote in the letter dated Tuesday.

“Within the last four years, these two underground force mains experienced a noticeable increase in breaks caused by corrosion, leading to sewage spills,” the mayor said. “Due to the nature of these spills, the city cannot predict when or where the next spill will occur.”

Force Mains Nos. 1 and 2, which have been in service since 1988 and 1990, respectively, are made of concrete cylinder pipe and “were designed and sized for full development of the West Kapolei area, and were expected to provide service well into the future,” Caldwell said.

But the two force mains experienced six breaks in the last four years due to corrosion. And while the breaks were repaired immediately and the city has stepped up visual monitoring, “with the recent increase in spills with common causes, the city believes that future spills are likely, requiring immediate replacement of the force mains with pipe material that is not susceptible to corrosion as well as the installation of hydraulic surge protection devices critical to preventing damage to the new pipes,” Caldwell said.

Most recently, nearly 140,000 gallons of untreated wastewater spilled from a pipe break near West Beach Force Main No. 2 in early January, about 30 feet away from the section where a November break resulted in more than 200,000 gallons being spilled onto about an acre described as near the Ko Olina Golf Club.

Neither spill reached the ocean, although a portion of the January spill reached a drainage basin.

Environmental Services Director Lori Kahikina said Friday that the improvement project likely couldn’t get started for another year unless Ige issues an emergency proclamation.

The Honolulu City Council set aside $33.6 million for the project in this year’s capital improvements budget. If the proclamation is issued, Kahikina said she hopes work can get underway by the end of the year.

“We’re thinking once we get the shovel in the ground, we’re hoping no more than two years (to complete the project),” she said.

The project would involve primarily a “slip-lining” procedure that involves putting a pipe within a pipe, Kahikina said.

The city also needs some federal permits. Kahikina said federal regulators have told the department that as long as the state gives its clearance, they can issue their approvals in about two weeks.

Councilwoman Kymberly Pine, who represents West Oahu, initially voiced concerns about the situation. Pine said she supports the call for a state emergency proclamation.

“This is a highly unusual, emergency situation that could affect the health, safety and environment of that area,” she said.