During excavation and ...

During excavation and construction, apply force air ventilation enough to reduce LEL and other undesirable gases(use gas analyzer to monitor such- you should be aware of the displacement principle).Make a gas analyzer available at all time so it will alarm once the gas increases, the workers then temporarily vacate will the Air displaces the undesirable gases. Forced-air ventilator must be on-line towards the excavation. Once the gas analyzer stops the alarm, its a signal that the gas again is low and is safe to work. On the materials of construction, 20 m diamter x 13 m deep. The thickness as I recommend will be 12 to 20 inches made of concrete( class A mix )with 4 quadrant (a post on top and bottom- 4 lines crossing the center). On the inner diameter to be constructed with CPVC plate - 1/4" thick. All connecting lines should be welded well of same CPVC material. The purpose of the concrete posts crossing the center and the solid concrete is to ensure that your well can hold such huge weight of a waste( you are dealing with appx. 1500MT weight of wastes). The CPVC is both protecting the concrete from erossion by the waste quality and leach from outside cant penetrate towards the well. I hope I help. Edwin