Definitely a series of ponds which I'd imagine will be feeding concentrated brine to the pilot plant...??
Unsure of the exact area / size but to give some comparison (sorry no intention of cross promoting) of scale, AGY have ~37ha of ponds which is designed/forecasted to be capable of producing enough concentrated brine feedstock to produce roughly 1800-2000Tpa of Li2Co3.
See below comparisons (the length of the timestamp square is ~400m or thereabouts)
At a guess I would say this earthworks & first series of ponds will be about 30Ha in total. Plenty of room around the nearby (flat) area for more down the track but to go to DFS designed scale (25ktpa) they will need a much larger area roughly about 500Ha, based on 40Ha producing sufficient feedstock to produce 2000Tpa.