55 gallon Drum / Barrel residue liquids

I have a source for metal drums / barrels and would like to know if anyone can give me advice on (who, how, where) disposal of the residue chemical liquids that remain.



I have the option of scrapping these at the local yards or selling on CL.

The problem is that the yards of course want liquid free / minimal residue barrels and I prefer not to have the people I sell to on CL to dump this stuff or hurt themselves in anyway.

Any advice is appreciative, looking for a low cost solution. This is to CMA (cover my a@#) and be socially responsible to the environment (ground water is my biggest worry). I have contacted the state and was referred to Clean Harbor, now I'm just waiting for a return call.

I'm located in Maryland.