Removal of the 5,135-foot-long underwaterpipe from the Ala Wai Canal this summer will mark the last phase of a seven-year project to shore up Waikiki’s sewer system, ensuring there is no repeat of the March 2006 rupture that caused the city to pump 48 million gallons of raw sewage into the canal rather than risk a backup into homes, hotels and businesses.
After about $90 million in improvements, the Kaiolu Street main that broke in 2006 has been repaired and reinforced, while a new, 72-inch backup line has been placed on the mauka side of the canal. The "redundancy" allowed by a second pipe should allow the city to avoid the need to dump raw sewage into the canal or allow sewage to back up into homes and businesses, city officials said.
Mayor Kirk Caldwell said at a news conference Friday that if a force main were to rupture as it did in 2006, "we could shut down a pipe immediately and divert the sewage into this second pipe."
The 2006 incident fouled the waters of the Ala Wai and closed some Waikiki beaches.
Caldwell, who was city managing director in 2006, recalled that the force main break occurred in the midst of a 40-day stretch of rain.
Waikiki Beach is "our major growth driver for the entire state of Hawaii," Caldwell said. "We never want that to happen again. It became national news. … It really impacted tourism, and it affected the health and safety of our residents. A few people got major infections and almost died."
Waikiki Neighborhood Board Chairman Robert Finley and Waikiki Improvement Association President Rick Egged were on hand to celebrate the near end of the project, as were officials of ‘Iolani School, on whose campus much of the project equipment was staged.
"Now with the redundancy, I hope to never again see sewage floating into the Ala Wai," Finley said.
Removal of the 48-inch polyethylene "black noodle" pipe is scheduled to take about six weeks. Consisting of 50-foot sections that were fused together, it was installed in the months following the 2006 main break as a temporary line that ran from behind Ala Wai Elementary School to the Diamond Head entrance of Ala Moana Park, where it connected with other lines that took sewage to the Sand Island Wastewater Treatment Plant.
With the pipe coming out of the middle of the canal, some disruption is anticipated for the many canoe clubs that use the waterway daily for practice. City officials said they will try to keep those disruptions to a minimum.
In May 2012 a section of the temporary pipe floated to the surface of the canal near the Hawai‘i Convention Center after air bubbles entered the tube. While there was no damage to the pipe or the surrounding environment, it created a visual spectacle for several days.
Restoration of the mauka side of the canal, required after it was closed down and used as a staging area for the pipe project, is expected to include a dog park, although that project is in a preliminary stage.
Asked why it took seven years, Caldwell said "it had to take that time because of the complexity of it … and the fact that it’s a massive pipe that’s crossing a waterway twice and curving at the same time while crossing that waterway."
City Design and Construction Director Chris Takashige also noted the project took about a year longer than originally projected due to "typical" material and construction delays.
"The good news is we were able to do it all in seven years with minimal disruption to the visitor industry, and there was visual impact from time to time, but it’s going to be all better now," Caldwell said.
The initial emergency repair, which took only several months to complete, cost about $45 million, said city engineer Eldon Franklin, chief of the Department of Design and Construction’s Wastewater Division. The second phase, which began in 2009, included construction of the new 72-inch force main line and cost an additional $44 million, he said.
Franklin said that at some point the city is expected to return to the area and convert the existing pressurized system into a gravity system. Such a project is still in the planning stage, and no cost estimates were available.
Finley said the city is also scheduled to fix the pipes along Kuhio and Kalakaua avenues during the summer. While those projects are expected to cause some temporary traffic headaches, at the end "we should have a very solid system for the next 50 years," he said.
