There are generally two types of oil tanks, above

Containment tanks are structures or systems that are used to prevent the accidental discharge of environmentally harmful products such as radio-active substances or oil-based substances. The United States environmental protection agencies have devised a system of regulations called SPCC which stands for Spill Prevention, Control and Countermeasure. It was produced to safeguard the pollution of the environment with these harmful substances. These guidelines state that companies who store large quantities of oil or other such materials must have an over-all plan in place should a spill ever occur from their oil containment tanks. Oil containment tanks will usually have secondary containment systems in place. One such method would be the use of a concrete catch-basin, but this method is now out dated and is often superseded by more modern and cost effective clean-up methods. Another method for catching spills is using a berm, which is a pillow or groundsheet which will capture and hold a certain amount of the oil that has leaked out. Another effective and inexpensive method would be to use a geotextile boom, which is a specially made textile barrier which can be filled with oil solidifying substances known as polymers. These polymers, although they allow water to pass through, will harden when in immediate contact with oil based substances preventing the oil from seeping into the soil or nearby bodies of water or shorelines. Sometimes oil containment tanks are required to be mobile, for example, oil drums or tankers and for these situations a portable or mobile containment berm needs to be used. These do not usually contain the oil solidifying products and are more likely to be a catch-basin design to catch any spills during transportation. If you need to buy an oil tank, for whatever purpose, you should make sure that you approach reputable companies. With a good reputation, these companies are more likely to have a vast knowledge and awareness of the products they are selling and the problems that can be involved with something as potentially hazardous as an oil tank. They will probably be able to advise you on the best choice for your requirements, as regards the material it is made from or the type of skin needed, i.e. single or double. If the company is reliable then they should be able to offer you value for money with your purchase, and not just try and sell you the top-of-the-range product just to make a profit. Research the companies well and ask for a few different quotes to ensure you get the best deal.