OK, now we know 'customer owned', PCB free, a 'mat' setup, and old.
I had a few locations in Union County, NJ that I did demo and bringing the elec into the 20th century. Two locations were PCB issues,confirmed by my samples sent to a lab. The legal disposal was $$$ but necessary and a lot cheaper then dealing with a contamination issue. One of these sites had 'leakers' but thecontamination was limited to the concrete slab and 3' of soil.
Both of the above sites were replaced with POCO 2000KVA pad mounts and respective gear.
BTW, Welcome to ECN Forums from one of the 'Jersey Guys'!!