Back in the day the concrete companies used to just dig a hole with the yard loader and dump all their old shit in it before backfilling.
When Inland used to be Consolidated and was over where Costco South is now there was a huge mess when they reclaimed the land. They cleaned it themselves but they were digging out old mixer truck drums they buried there decades ago.
2017 VW Jetta 1.4T (winter car)
2010 F-350 Nortruck Tool Shed
2007 BMW 5 (Wifey's)
2004 Audi A4 1.8T 6spd Stage III w/ Meth
1985 F-250 6.9L IDI w/ATS turbo