Keep all pipe connections clean and tight. Check for drips from the fittings and the filter. Clear snow, ice, insect nests or other debris from the tank vent to allow the tank to properly breathe. Look for signs of spillage near the fill and vent pipes. Stained soil and rock or distressed vegetation could indicate a fuel spill has occurred.
Water can collect inside a tank from condensation and cause internal corrosion.
Trapped water can be controlled by removing the water from a drain plug, using water absorbent socks, or periodically using additives. Buried tanks can corrode and leak without obvious signs on the surface. Be alert for unexplained fuel losses that might point to leakage. For inside tanks, be alert for signs of oil in the sump pump pit and floor drains, and for any oil smell in the basement or crawl space. All indoor tanks should have a vent alarm that alerts the fuel deliverer before the tank is full.