Most above ground and underground oil tanks last only 15 to 20 years. At Tanktech Environmental we have noticed that one in five tanks have started to leach contaminants into the surrounding soil at the time we remove the tank. In such cases, property owners are generally faced with soil remediation to cleanse the area surrounding the tank.
Even tanks that have been pumped out still contain a relatively thick layer of hydrocarbons that will seep into the soil region around and below the tank when the tank fills with groundwater. Any crack or tear in the tank’s exterior allows groundwater to leak into the tank. The water rinses the hydrocarbons from the tank’s interior and allows them to flow out of the tank into the surrounding soil. The sludge quickly causes soil contamination and if left unchecked the sludge may seep down into the surrounding groundwater and cause even more extensive and costly contamination. In some cases, the oil can leach into the soil to a depth of 4 meters or more.
Over time, all tanks will start to decompose as the iron of the tank reverts to a stable form — known as rust. It is a natural metamorphic process that cannot be stopped. Many factors influence how fast a tank will rust such as the moisture in the surrounding soil, the soil’s pH balance, the backfill material, and the location of the tank. Other determining factors include the tank’s thickness, the amount of groundwater that has leaked into the tank, any damage the tank might have sustained during its early days of installation, and the age of the tank. Rust is an inevitable outcome for any tank. Even a small pinhole of rust is enough to compromise the tank’s structure and cause a slow leak of the oil into the soil which will require soil remediation to clean up. Over time all oil tanks will need to be removed. Ideally, the tanks should be removed before a leak occurs.
Home’s built during the turn of the century usually had coal for heat. As oil became widely available, homeowners quickly started turning to oil instead of coal to heat their houses. This produced a mass exodus of underground and aboveground oil tanks being installed. Most homes built from the 1920s to the 1960s relied on oil to heat their homes. However, by the mid 1960s natural gas pipelines had been installed throughout urban areas and into the countryside so most homeowners stopped using oil tanks for heat. Unfortunately, in most cases, the tanks were left to decompose and rarely removed. It was not until recent years when new laws were enacted that homeowners who wanted to sell their property, purchase homeowner’s insurance, or take out a mortgage on their house started facing the reality that they would have to have the oil tank removed to go forward with their plans.
At Tanktech, we are an environmental contracting firm that takes soil remediation seriously. We offer economical, safe tank removal, environmentally friendly pumping and remediation services.
Any time there is a tank removal, we will check the soil for possible contamination, offer soil remediation services and advice if contaminants are detected. Please give us a call and we will be happy to answer all of your questions about tank removal or soil remediation.