Otto, C.J., Townley, L.R., Bartle, G.R., and Watson, G.D. (1995), Dual pump recovery tests at the Baldivis Kwinana Nickel Refinery tailings pond, Report to WMC Kwinana Nickel Refinery, CSIRO Division of Water Resources Consultancy Report No. 95/43, 22pp., November. [Confidential]

The results of the Dual Pump Recovery (DPR) tests are specific to the P2A site. Further tests are required at other recovery sites or at a new site.

The DPR system worked in the sense that it was able to maintain the AMSUL interface at its initial pre-pumping position. The packer in P2B inhibits AMSUL entering the upper pump from below.

An increase in EC at P2A was achieved when the pumping ratio P2A/P2B was between 0.6 and 1. A ratio of 1.5 showed a moderate decline in EC at the P2A outlet. During all tests and independent of the pumping ratios, EC at P2B increased above 5000 μS/cm.

Electromagnetic logging with the EM39 has shown that the hydraulic conductivities vary and that the vertical distribution of AMSUL is not uniform over the aquifer thickness. Consequently, pumping rates should be estimated based on the ratio of transmissivities in the fresh and dense layers.