Not knowing where You are located makes it a little difficult ta say wether its even legal . BUT I will give You my opinion since I,ve been digging up several old dumps for the last 2 years on our property thats been there for 50 years or better .
The top layers are stuff that definatlly should not be buryed & I had to pay to have it Properlly disposed of . Some of the other stuff was Burnable lumber & such. Tons of Scrap metal , iron, copper, aluminum & a lot of oil field trash & iron , also probablly 300 tires, that cost 4 bucks a piece to dispose of . that was Buryed when it wasn,t worth anything or illegal . Which selling that helped recoop some of the money spent as well as fuel for cleaning it up .
So I would suggest not burying it as a favor to the next owners, Family, neighbors & yourself. These days it could come back to haunt You or the next owners later .
Anything You put in the ground will eventually affect the water supply as it Seaps or decays into the ground. Thats the Main reason I started cleaning things up. There is no good water around Our area . it Smells like Petrolium & I wouldn,t even think about drinking it or cooking with it. Several attempts of drilling wells with no better luck.
Just My opinion .
1* Just because people have been doing it for many many years don't mean its a good or acceptable idea .
. Bob