This plastic tank is in a crawlspace and has an electrical connection. I am not able to identify it and can’t get very close to it due to all the debris (image included) in the crawl, it is like they dumped all their garbage in the crawl. Anyway, it is not a sump pump, there is no well or septic system. Maybe it is an irrigation system that is no longer used?
old boiler parts?..usually in the attic, though.
Crawlspace. Not sure if the house ever had a boiler.
Reservoir tank and pump for old water source. This was common in rural areas that did not have a well and needed water. The tanks allowed a small amount of cleaning water and then would fill up again. The pump was needed because the tanks had no head pressure.
The little line you see ran to a filter system so you could drink from the water also.