HONOLULU -- Acting Honolulu Mayor Kirk Caldwell said Wednesday the city next month will begin a $37 million project to dig a tunnel for a new permanent sewer main pipe in the Waikiki area.

The 5,800-foot line, called Beachwalk Force Main, is expected to be finished in December 2012. It will run underground from behind Ala Wai School to Ala Moana Beach Park.

"It is historic because it will be the longest micro-tunnel in the history of the state of Hawaii," said Caldwell.

That means the ugly, above-ground sewer pipes the city has been using in one of Hawaii's most beautiful tourist and residential areas all will be removed by December 2012.

That was good news to residents tired walking past of the above ground sewer pipes running through the back of Waikiki and into popular Ala Moana Park.

"The pipe is definitely not pretty right at the entrance to our beautiful park. So I think, all in all, it is time it should be gone," said Waikiki resident Kristin Zambucka.

The temporary above ground pipes were an emergency fix installed after a massive sewage spill in March 2006 sent 48 million gallons of raw sewage into the Ala Wai Canal where it flowed directly into Waikiki, closing beaches after bacteria reached dangerous levels.

The story made world headlines and damaged Hawaii's image as a tourist mecca.

Caldwell said the new sewage main will guarantee such an environmental disaster will never again happen.

The sewer main that broke and caused the massive spill has since been repaired and will remain in place to be used as a back up in case of an emergency in the new sewer main system.

"So that if we have trouble with one system, we can switch over to the other system and that is good, particularly in the Waikiki area," said Caldwell.

The new sewer project is part of the city's settlement with the U.S. Environmental Protection Agency to upgrade Honolulu's sewers.

City officials promised work on the new sewer pipe will not be as disruptive to traffic as most projects because most of the work will be done underground instead of in open trenches.