It is possible, under certain circumstances. If you have a concrete tank that has been in place for a number of years, it is unlikely that you will have this problem. However, certain conditions and locations increase the possibility that a septic tank might “float” to the top of the ground. Be mindful if you are in an area with high water, such as near a lake or pond. Newly installed tanks are a concern due to the loose ground around the tank. Sandy ground might also allow a tank to “float” up and plastic tanks are more susceptible. In the nearly forty years we have been in business, we have rarely seen this problem. If you have a plastic tank or you are concerned that your tank might “float” up, we suggest running 500 to 1000 gallons (for a 1500 gallon tank) of water into the system after having it pumped.