SPCC responsibility for tanks on leased property

What if I leased some parcels, and there are tanks already present? Am I responsible for these tanks?

You could be. If you plan to use these tanks, make sure in your lease agreement, it states who is responsible for these tanks. If the lease does not state who is responsible, you should talk to the property owner to check who is responsible for the tanks under the Spill Prevention, Control, and Countermeasure (SPCC) rule.