It could be that you are trying to sell your home or may be interested in purchasing one. You may well be looking to lease or purchase some commercial property. It is likely that you will try to find out whether there are any underground storage tanks, and where they are located.
Normally, these underground storage tanks are used for storing fuel oil that is utilized for heating purposes. In addition, these tanks can also hold waste oil, septic waste, or propane.
For the task of locating underground storage tanks, one of the methods that is used is concrete scanning, which provides desired results.
Additionally, it will be easier to locate the tank if you are able to locate the vent and fill. Normally, these are located near the tank, but it is not always the case, and in such situations, you will have to utilize concrete scanning.
Purpose Served by Fill and Vent
An underground storage tanks’ fill is used for filling the tank if it becomes empty. Normally, the fill is located near the tank, but its location can have an offset of 10′ to 15′. The reason for such an offset is that when the oil truck arrives, it needs adequate space to access the storage tank.
On the other hand, the purpose of the vent is to let vapors escape out of the storage tank, and to ensure that tank does not get pressurized at the time it is being filled. As such, it is not necessary for the vent to be near the storage tank if position, design, or layout of the tank does not permit close installation of the vent.
Challenges in Locating Underground Utilities
Locating underground utilities such as storage tanks often become a challenge as these tanks are often situated at odd places, such as parking lots, asphalt driveways, behind garages, near buildings, and other similar locations.
How to identify underground storage tanks?
There are different methods, which can be used to identify underground storage tanks. Let us go through the details in the following sections.
Method #1: Perform Examination for Pipes Present in Basement
In case there was an underground storage tank that was being used earlier, then it is more than likely that there will be associated pipes from the tank that went into the home, so that tank could be utilized. Thus, first thing you need to do is check the basement to know whether there are any supply pipes present for such a tank.
Even if such pipes have been covered up, you will be able to recognize their presence by examining the signs such as a fresh concrete patch in-between a weathered concrete block.
Method #2: Look Out for Presence of Pipes in Backyard
Apart from checking the basement, look for the presence of pipes in your backyard. Usually, these pipes stick out from the ground, and are covered by shrubs and bushes. By performing a detailed examination of the backyard, you will be able to find these pipes if they do exist.
Method #3: Perform Analysis for Depression in Yard
If there are unaccounted lows or highs in your backyard, then such a location will be an ideal place to search for an underground storage tank. Normally, what happens is that in order to install an underground storage tank, it is necessary to dig out a large hole in the ground.
After that, soil is put back in place but it does not completely match other parts of the lawn. You will find there is a depression where the underground storage tank was added, since the soil on top of the storage tank will gradually pack resulting in a significant dent in comparison to other parts of the lawn.
Method #4: Search for Coffee Cans
Coffee cans can often indicate the presence of underground storage tanks in your new home. People often use coffee cans to cover the fill and vent pipes.
This is usually done with the aim of preventing dirt from getting into the pipe and filling it. So, if you find an upside down metal coffee can in your backyard, it may well indicate that there is an underground storage tank.
Techniques Used for Locating Underground Storage Tanks
If it is found that the storage tank is in a shallow position under the ground, then such a tank can be located using a metal detector. However, if the storage tank is situated deep inside the ground, then specialized equipment is required such as ground penetrating radar or a split box.
- Split Box: This equipment can be used for locating metallic objects up to a depth of ten feet from the ground. This is achieved by sending electromagnetic locating signals (ELS) into the ground. Apart from underground storage tanks, it can also detect underground objects such as buried manholes, metallic conduits, wires, and pipes.
- Ground Penetrating Radar (GPR): Another piece of equipment used for locating underground utilities is ground penetrating radar or GPR. This equipment works via the identification of soil density differences underneath the ground.
The benefit of this equipment is that it can be used for identifying tanks on a digital screen and results are available in real time, almost instantly within a few seconds. Here, different frequencies are utilized for retrieving data from different depths.
But, the average frequency that is used for the purpose of locating utilities is about 400 MHz. The positive thing about ground penetrating radar (or GPR), is that you can use it for determination of depth size for utilities.
In addition, they provide good results when the soil is sandy, but are less effective when there is clay soil. Moreover, soil penetration achieved is influenced by factors like soil sanity. Lastly, GPR can only provide short distance penetration.
Thus, if you are concerned about negative situations that can result due to underground storage tanks or have started getting symptoms related to underground storage tank leaks, then it will be necessary to find out where it is before undertaking a costly removal process.
By following the above-mentioned tips, you will be able to figure out the exact location of the storage tank and proceed with its removal.