As part of the Easterly treatment facility project on the shores of Lake Erie in Cleveland, Ohio, our project team built six 110-foot diameter by 18-foot deep settling tanks. The discharge from these new tanks (as well as four existing tanks) were connected to a NEW concrete junction chamber via 2500 lineal feet of 36-inch through 84-inch diameter Flowtite® fiberglass underground pipe.
This new junction chamber was constructed around two temporarily supported 108-inch diameter concrete pipes. These pipes have carried the treated discharge from the existing plant to Lake Erie since 1931.
Once the new facilities were complete, the challenge was tying the new facilities to the old discharge. To accomplish this, the project team removed 11 feet of pipe from each of those two 108-inch diameter, 10.5-inch thick concrete pipes.
To ensure this process did not interrupt the existing flow to the lake, the project team engaged DOT Diamond Core Drilling who suggested a diamond wire sawing system to make two cuts in each of the two pipes.
To accomplish this feat, the project team first installed temporary pipe supports and made preparations for hoisting and handling both pipes while the chamber was still dry. DOT then began the diamond wire sawing process, aided by external cooling water. When the first in-service pipe’s circumference was penetrated, the plant flow began to flood the chamber. The remaining sawing process was completed without any personnel having to enter the chamber. The resulting cuts totaled 1,620 lineal inches of reinforced concrete.
Once cut, General Crane Rental used a 130-ton capacity crane to hoist out the two 11-foot cut pieces, each weighing about 37,000 pounds.
Making this effort even more impressive is that the pipe removal and subsequent joining of the old and new flow systems were completed during 15-degree temperature and blustery winds in mid-December.
Despite the frigid weather and the difficulty of this task, the entire operation took only two 12-hour days to complete.
This process was part of the larger $74.3 million project which began in September 2013. The overall purpose was to increase the capacity of the Easterly Wastewater Treatment Plant from 140 million gallons per day to 400 million gallons per day, which will help the environment.
The Northeast Ohio Regional Sewer District (NEORSD) contracted the Shook Walbridge Joint Venture to complete these improvements, which were designed by MWH Global and Brown & Caldwell. The design called for the installation of 26 new pumps, piping, automated valves and meters, as well as adding chemical storage, distribution, metering, instrumentation and process equipment to more effectively enhance the treatment process. To accomplish this, the Shook Walbridge team selectively removed, rerouted and replaced interior and underground piping, existing structures, and equipment.
The multi-phase project took four years to complete.