A core samples was subjected to laboratory testing , from which some projections were made. The question of subsidence is still open and requires further investigations. We also need more information on the nature of the transition zone between the playas and the alluvial fan deposits. Many production wells, such as the Keeler, Olancha and Cartago wells, are in this transition zone. Additional information is required on the properties of this area and the way it is interconnected with the deep confined aquifers underneath the lake.
Some questions remain on the confined aquifers.
The technical team has also been looking at what information is needed to complete the water balance. Many studies have been done, but they may not have picked up long-term variations. With regard to the conceptual model, the team has found that the physical framework concepts identified previously are generally sound and unchanged, and that the deep confined aquifers and surrounding alluvial fan aquifers are interconnected. There are many areas where a shallow, unconfined aquifer exists. It will be important to look at how these shallow aquifers on top of the clays interrelate with the deeper, confined zone and with the alluvial fan zones.