The Beachwalk Wastewater Emergency Bypass project hit another milestone when contractors floated a large pipe under a bridge that serves as a gateway to Waikiki.
The 42-inch High Density Polyethylene (HDPE) pipe ran under the McCully Bridge June 30 and is well on its way to its final destination.
Workers are able to float between 200 and 250 feet of pipe a day into the canal. Each 50-foot length must be prepared and then welded together. Each piece must then be allowed to cool for over an hour before moving it by crane into the canal.
The emergency bypass pipe will eventually stretch some 5,000 feet. The pipe will be sunk and hook up to existing lines on the Ala Wai Boulevard in Waikiki, and near the Diamond Head entry to Ala Moana Beach Park. The wastewater will then flow down another existing sewer line and be deposited at the Sand Island Wastewater Treatment Plant. (see map on this site).
Once the 5,000 foot bypass line is built and turned on, the second phase of the emergency project can begin. That involves micro-tunneling two 1,200 foot long permanent lines under Kaiolu Street. All this is designed to prevent future diversions from the existing wastewater force main in the Waikiki and Ala Wai area.
Contractors are working long days in not only putting the pipe in the canal, but planning on how to get it to its final destination inside Ala Moana Beach Park. That work will start July 5, and will result in temporary detours and possible closures over the next 30 days at the Diamond Head entrance to the park.
The day and night-time work at the park entrance involves a combination of jet grouting and trenching. The jet grouting is necessary because the 42-inch pipe will be buried 11 feet under the road and the watery soil needs to be stabilized.
Also starting July 5, workers will start the process of placing six pumps along Ala Wai Boulevard between Lewers and Walina Street to divert wastewater from the existing pipes to the emergency bypass pipe. There will be no on-street parking on that five block stretch until the project is completed in December. Pedestrians will be rerouted to the makai side of the street. The bikepath will also be closed for that five block stretch.
On the mauka side of the canal, directly across from Kaiolu Street, workers will start driving sheet piles for the microtunneling pit at the end of this week.
All this activity is being viewed closely by residents on both sides of the canal. The BWEB team will brief members of the Waikiki Improvement Association on July 11.
”’Check this site (www.beachwalkbypass.com) for weekly updates. Also a reminder that the project hotline continues to be manned Monday thru Friday from 8am to 5pm. That number is 808-203-5777.”’