I went about 50 sols without building any waste rock dumps, because they appeared to have a pretty low capacity, and the drones were happy to just sit the waste rock around extractors anyway. Around sol 50 my water extractor became so surrounded by rock that this wouldn't happen anymore, and I had a giant ugly crater from a dead concrete extractor I thought I would fill in with a few rock dumps. I placed the dumps, they were immediately filled, and a day or two later the water extractor's waste storage was full again. This time, though, there was tons of space around it, because it had been cleared filling the dumps. The drones didn't seem to want to sit rock around the extractor like they once had; it was like they had been spoiled by the previous availability of the dumping sites. I salvaged the dumping sites so that I have none anywhere on the map, but the drones still don't want to sit waste rock around the extractor like they used to. Is this normal? Should I avoid building dumping sites forever and just manually cart my waste rock off in RC transports to preserve the ability to have rock stored around extractors?