It’s been 10 years since Leighton O’Brien conducted its first integrity test for new underground tank installations, which we call Pre Bury Post Bury (PBPB) testing. In reflecting on this the other day, I contrasted where we were ‘back then’ to where we are ‘today’.
‘Back then’ Leighton O’Brien was conducting underground tank testing that contained ‘normal’ fuels – diesel and petrol. Some still had MTBE. Storage tanks could also tolerate a modicum of water in the tank, as long as it remained below the height of the suction stubs.
Today there is an ever increasing range of fuels on the market such as ultra-low sulphur diesel, E10, E15, E85, E100, bio diesel etc – all with specific environmental and material compatibility and maintenance issues that start with the life of a new tank system.
Moreover, small amounts of water in a tank system with reformulated fuels can create maintenance nightmares such as biological activity, increased corrosion, blocked filters and lower pump flow rates. Oh, for the old days.
With the industry changes that have occurred and plethora of new issues arising for tank owners and operators, I’m more convinced than ever that PBPB testing has evolved from a best practice discipline to an absolutely critical part of the underground storage tank (UST) installation and maintenance process.
Until fairly recently, PBPB testing was about ensuring tanks and lines met regulatory requirements and wouldn’t leak into the environment, causing significant clean-up costs and financial penalties.
While that’s just as crucial today, one could argue that the maintenance implications stemming from a lack of storage tank integrity have never been more important due to modern fuel formulations. In fact, my firm belief is maintenance integrity requirements now exceeds environmental compliance requirements.
In the US, while state regulations vary, by and large an ATG or post bury test is required to open a new site. While this ticks the environmental regulatory box, from a maintenance perspective an ATG test will not verify the integrity of the ullage space – ie: any line fittings, tank fittings, manway fittings, VR fittings or offset fill fittings. All of the above are prime sources of water ingress into a storage system and in some cases potential leak sites.
Today PBPB testing is even more valuable because it can save potentially hundreds of thousands of dollars in maintenance programs and reduce the total cost of ownership (TCO) of underground tank systems.
The reason that maintenance costs are lower with tanks that been PBPB tested is because they’re subject to no water ingress from integrity issues, thereby reducing the cost of changing filters, doing water pump outs, cleaning the tanks and disposing of fuel due to phase separation issues and malfunctioning ATGs.
As we compare back then to now, there have been a lot of challenges for storage tank operators in ensuring optimum compliance and performance of their tank network, but some things haven’t changed.
Still today, of the thousands of storage tanks on which our technicians conduct PBPB testing each year, approximately 90% of the time pre bury testing detects an issue not identified by new installation testing processes. This is not a criticism of the quality of installers or poor oil company practice, but simply a fact that independent third party testing with highly accurate technology will identify potential issues that existing methods won’t.
Common pre bury practices involve the installer pressure testing the tank and line using an analogue gauge ± 1 PSI, and using soapy water to check the fittings on tanks and lines. An oil company engineer may also visually inspect the system, but it won’t identify very small leaks that may exist at the site.
These measures DO NOT guarantee the integrity of the storage system because:
- There are leak sizes that you simply will not see, where the resolution on the pressure gauge is around 1 PSI. A more accurate sensor would detect pressure decay without the presence of soapy water bubbles.
- With vacuum testing you are more likely to seal a leaky site and you certainly will not detect the presence of any bubbles.
What has changed significantly is what operators are putting into their tank – which requires a much higher level of diligence. Without a PBPB test, UST operators are locking themselves in to potentially tens of thousands of dollars in maintenance costs during the lifecycle of the storage system.
Pre and post bury testing drives a substantial and quantifiable improvement in the quality of installations in many markets around the world – an added insurance policy that guarantees the integrity of new UST installations.
The advent of reformulated fuels is a game changer for the industry. In our view PBPB testing and an absolute focus on perfect storage integrity has never been more critical for today’s responsible storage tank operator.