Where would a tank like this go? An industrial fiberglass vertical storage tank standard size is 10 ft in diameter and 12 ft tall. They usually have a 2ft round access port on the top for clean outs and inspections. If it only (truely) had veg oil in it, it can be cleaned provided there's a good amount of air being constantly pumped into it if anyone goes in. At the mill, they use adapted extension ladders to access non-hazmat storage tank. The ladders have carpet or rubber wrapped 2x4s attached to the bottom of the ladders to prevent damage to the tanks.