Selector Tank Construction at Waste water Treatment works

Sequence of construction leading to the completion and 7-day testing period of the Selector tank.

Stage 1: Installation of temporary works as per the approved design complete with rescue system complied of Davit Arm, rescue stretcher, gas monitors and 10 minute breathing Apparatus kits.
Stage 2: Excavation of the earthworks and construction of the 8m x 4m base slab c/w 150mm kickers.
Stage 3: Erection of the approved temporary works as per the design for the 3m high tank walls c/w 2 no. cast in-situ 500mm diameter DI pipes.
Stage 4: Following the 18m3 concrete pour and curing time, the shutters were stripped and tie-bar sleeves grouted in preparation for the 7 day testing period as per CESWI 7th edition. The total allowable drop in water level is 10mm or 1/500 tank depth, which equated to 6mm for Cleantech.
Stage 5: Testing, the Selector tank underwent a 7-day testing period after being filled with water. The entire tank was covered to prevent any rainfall entering and the water level was monitored and recorded daily. The tank passed the test with a drop of 3mm in total.
Stage 6: Backfilling around the perimeter of the tank was then 80 % completed and the perimeter secured off awaiting the construction of the new PST-ASF channel adjacent to it.#CleantechCivils #CivilEngineering #Construction #SelectorTank #TestPeriod