Underground (AG) LP Storage Tanks

One popular option for an LP storage tank is an underground one. The apparent reason for this is the aesthetically pleasing idea that these sometimes enormous tanks are out of sight, buried in the ground. The UG LP storage tank decision is acceptable, but some factors must be remembered.

The first issue is that installing a UG LP storage tank requires attention to detail, and, as with everything “propane,” these UG LP storage tanks should always be installed by a licensed propane technician who is experienced and insured. Having your landscaper, building general contractor, or plumber do the installation can be problematic. In the rare case that any tradespeople mentioned above may be licensed to work with propane, they do not always know the perils of improperly doing the job. When installing a UG LP storage tank, great care must be taken in properly securing and anchoring the tank in the ground to keep it from “surfacing” on its own. There’s nothing quite like looking out of your window after a few days of rain and discovering your 500 or 1000-gallon tank popping out of your front lawn, looking like an atomic submarine surfacing from the ocean's depths!

The second issue unique to UG LP storage tanks is the set of regulations by the *NFPA (NFPA 58) in 2014. The new rules focus on preventing tank corrosion and potential environmental contamination due to propane leaks from a rusted tank. These rules proscribe the Cathodic Protection of the UG LP storage tank. Cathodic protection uses anode bags connected to the tank to prevent corrosion to the tank's metal. The rules also call for periodic replacement of the anode bags.

Replacing anode bags does not require removing the UG LP storage tank from the ground. However, it does mean digging a hole and trench alongside the tank to make the connection. Depending on where the UG LP storage tank is located, this digging could result in some unavoidable landscaping work to restore the area to its prior condition.

Is having a UG LP storage tank practical? This question can only be answered by the individual and their willingness to do what is required to keep the tank safely in the ground and free of environmental misfortune.  

*As of October 1, 2014, NFPA 58 LP Gas Code requires that all buried underground LP storage tanks of any size must be cathodically protected using anode bags and that the area around the underground tank is regularly half-cell tested by a Maine state-licensed propane professional and documented with a copy of most recent half-cell testing results available by the LP tank owner. The schedule for half-cell testing is as follows: (1) week after installation, (18) months from the date of installation, and every (3) years thereafter for the duration of the LP tank remaining in the ground. If any half-cell testing results in a negative (or inadequate) reading preventing proper cathodic protection, new anode bags must be installed to re-establish proper cathodic protection of the LP tank. The customer is responsible for the cost of the half-cell testing after the (1) week interval (beginning at (18) months and on) and any materials and labor for re-installation of any future anode bags.