I saw a video once (might have been Dirtiest Jobs) where the "honey wagons" pulled into what appeared to be a large concrete parking lot. There were "depressions" spaced a couple hundred feet apart. The truck would back up to the top of the depression and "unload" !
This was in an area of the country where they had a lot of sunshine. The load would quickly "dry out" because the run to the bottom of the depression was long. The next day, when it was completely dry, they used a power broom on a tractor to sweep up any dried up solids