Replacing an underground fuel tank at a service station: what's involved

When is a service station tank replaced?

Old storage tanks need replacing once they reach the end of their service life. If your site still runs an older single-wall steel tank, a double-wall replacement adds secondary containment and leak monitoring. Tanks are also replaced when a site is rebuilt, when the owner wants more capacity or different fuel grades, or when the regulator or a site assessment calls for it.

Our single-wall tank check shows which of these reasons apply to your tank.

The steps in a tank replacement

Site assessment

It starts with the site: the grades you sell, how much of each you store, the space available on the forecourt and the ground conditions. That sets the capacity, the number of compartments and the burial depth of the new tank. Send us the site plan and the grades you store and we’ll work out the tank and compartments with you. For a first estimate, use our forecourt tank sizing calculator.

Permits and EPA notification

Taking an underground tank out of service and assessing the site follow your state EPA’s guidance for underground petroleum storage systems (UPSS). Depending on the state, the regulator may need to be notified before work starts, and the site may need approvals. Your state regulator and site engineer set what applies to your site.

Decommissioning and removing the old tank

The old tank is emptied, made safe and removed by a licensed contractor, following your state EPA’s guidance. The excavation and the soil around it are then assessed before the new tank goes in.

Choosing the new tank

Our range has two double-wall options for service stations:

• Double-wall fibreglass (FRP) tanks, from 2,000L to 150,000L with 1 to 4 completely separate compartments. They are made to meet or exceed UL 1316, with integral ribs and Parabeam 3D fibreglass, and are rated to 35kPa. Fibreglass doesn’t rust, and the tanks carry a 30-year warranty against structural failure and internal and external corrosion.
• Glasteel® II tanks, from 2,000L to 200,000L, made to UL 58 and AS 1692. A welded mild steel tank carries the structural load, and an FRP outer wall fully encloses it, so the steel never touches soil or groundwater and needs no cathodic protection.

Compartments let several grades, such as unleaded, premium, diesel and AdBlue, share one tank and one excavation. See our service station tanks for capacities and compartment layouts.

Installation

The new tank is installed by an accredited installer from our installer directory. The underground petroleum storage system is designed, installed and operated to AS 4897, and the tank is bedded, backfilled and anchored to our installation manuals and backfill guidelines. An installation by a non-accredited installer voids the warranty.

Testing and commissioning

After installation, double-wall FRP tanks get a third-party tank test to AS 4897, using USEPA methods. The installer returns the installation checklist, backfill sieve analysis and test report to us within 30 days, which validates the warranty. The site can then be commissioned.

Ongoing monitoring

Once the tank is in service, the space between its two walls is monitored for leaks. More on that below.

What drives the cost

There is no standard price for a tank replacement, because every site is different. The main cost drivers are:

• Capacity of the tank
• Compartments, one for each grade
• Single or double wall, as double-wall adds secondary containment and monitoring
• Excavation, including the burial depth
• Ground conditions, such as wet holes, rock or unstable ground
• Removal of the old tank
• Monitoring and fittings, including risers and manways

We price each tank to your spec, with no obligation. Send us your site details through the contact page and a sales engineer covering your state will reply within 2 business days.

Leak detection basics

A double-wall tank has a primary wall that holds the fuel and a secondary wall around it. Full 360-degree secondary containment means that if the primary wall ever leaks, the outer wall holds the fuel in the interstitial space instead of letting it reach groundwater. Monitoring that space shows the leak.

• Double-wall FRP tanks use Truchek® hydrostatic monitoring. The interstitial space is filled with brine, and a reservoir on top of the tank holds it at a set level. It gives continuous leak detection, lets the owner do a visual tank tightness test and meets EPA requirements.
• Glasteel® II tanks leave the factory with the interstitial space under vacuum and a vacuum gauge fitted. A break in the inner or outer wall causes a loss of vacuum, which shows on the gauge.

AS 4897 calls for secondary containment, non-corroding tanks and pipework and overfill protection on underground petroleum storage systems. Your state EPA sets the leak detection and monitoring rules for each site. To put your own figures on one leak, use our fuel leak cost calculator.

Common questions

Who replaces underground fuel tanks at service stations?

We manufacture the new tank. A licensed contractor removes the old tank, and an accredited installer from our installer directory installs and tests the new one.

How much does an underground fuel tank cost?

It depends on the capacity, compartments, single or double wall, excavation, ground conditions, removal of the old tank and the monitoring and fittings. Contact us for a quote.

Fibreglass or Glasteel® II?

Both are double-wall with a monitored interstitial space. Double-wall FRP is fibreglass inside and out, up to 150,000L. Glasteel® II gives you a welded steel tank inside an FRP outer wall, up to 200,000L. See all underground fuel tanks.

Talk to our team

Contact us about your next tank replacement. This page is general information only and is not compliance or legal advice.