Residential Oil Tanks
Interstate Commission on the Potomac River Basin
Without proper care, old and rusted heating oil tanks can cause costly leaks and spills. Underground tanks are especially problematic because they can leak for years without notice.
Large toxic spills may get all the media-fueled attention, but these silent, slow leaks add up to one major environmental problem for the Potomac River basin and its residents.
How to Test for Leaks
- Take a soil sample (ideally, from the soil below the tank).
- Conduct a tank test to determine if there is a leak in the structure. However, this is not recommended for older tanks.
- Watch your oil usage. A sudden spike in usage could indicate a leak.
- Look for signs of unexplained dead or withered vegetation around the tank.
- Check for the overfill whistle sound while the tank is being filled. A silent overfill whistle could indicate a leak.
- If your home has a sump pump, check for evidence of oil in the water.
How to Prevent Leaks and Spills
- Install spill and overfill protection devices on the tank
- Inspect your tank at least once a year. Repair or replace any questionable parts at this time.
- Check your vent pipe often to ensure it is free from obstructions.
- Hire a contractor to clean out the tank every 5 years. This will clear out condensation and sediment build up at the bottom, which can cause corrosion and rust.
- If you don’t know the age of your tank, it is probably time to replace it. The typical lifespan of a tank is about 15 years.
- If your tank is above ground, ensure it is on a sturdy and solid base.
- Ensure the tank is protected from possible tree damage, falling ice/snow, or yard equipment such as lawn mowers.
- Protecting above ground tanks from the weather, such as under a shelter or in a garage, can prevent rust, corrosion, and damage.
- If a tank is removed from service, remove fill and vent pipes to prevent a fuel delivery to a location without an attached tank.
- It is not required, but is highly recommended, to hire a certified professional when closing or removing a tank. Your state can provide you with a list of such professionals.
When to Replace a Tank
Indoor tanks should be replaced after 25 years, while outdoor and underground tanks should be replaced every 15 years. Tanks rust from the inside out, so if you see any signs of rust on the outside of the tank or you do not know the age of the tank, it is time for a replacement. When replacing an underground tank, this is a good time to switch to an above ground tank, which allows for easier monitoring and maintenance.