People seem to forget that the mine unit where alkaline was...

People seem to forget that the mine unit where alkaline was previously used was successfully demonstrated as suitable for low pH mining. The restoration following the mining too was successfully demonstrated. Refer to the ann on 1 April 2019 and 2 September 2019. https://www.pel.net.au/projects/lance-projects-wyoming/project-updates/. So it's not that there's something wrong with the ground in the new mine unit, it is that the pump formula was not yet optimised. Perhaps, the old mine unit was sufficiently oxidised due to the use of alkaline leach so that in transitioning it to low pH, no oxidants were required.