Ellingson-DTD completed a continuous dewatering well at the base of a dry-stacked ash pile. The well was completed at contact between native material and the ash, and was mostly drilled in fly ash. Total well length is 1,712’ (1,616’ screen), consisting of a 4” diameter schedule 80 PVC screen and casing.
The drilling was completed using biodegradable drilling fluids, and well development consisted of washing, jetting, and pumping with a submersible pump.
Pumping notes from client – October 2024.
· Initial pumping rate 60 gpm
· Current pumping rate 30 gpm
· They are pumping about 140 hours a week – generally M-F. At 30 gpm that is a total of 252000 gal/week.
· A piezometer has seen about 5’ of drawdown since pumping started – My notes indicate that Craig said that the water level in the piezometer on the east side of the landfill near the horizontal well has gone from 8’ to 5’ (3’ of drawdown). Note that the bottom of the screen is above the well. · Client indicated that there were 51 acre feet of water to be removed from the landfill (assume that is from when the landfill was covered) and that it would take ~36 months – so from October 2022 to October 2025.
