You should always check your oil tank for signs of damage or wear and tear which could lead to leaks or spills. Some common things to look out for are:
- Dents and scratches on the surface
- Damp patches underneath the tank
- Rust patches (for metal tanks) or splits (in plastic oil tanks)
- A strong oil smell
- Damage to grass around your oil tank
- In some cases there may be an obvious leak