by William Jones, Warren Rogers Associates

Printable Copy: The Advantages of Continual Reconciliation on Fuel Profitability

While the population of regulated USTs has dropped dramatically since storage tank rules were first published in 1988, there has been a major trend in the retail petroleum industry toward the development of high-throughput fueling facilities. Hypermarket fueling stations with customers at each dispenser, convenience stores active at all hours of the day, and travel centers with delivery transports lined up to make their drops are now a common sight. The fueling public is drawn to these facilities because of their competitive fuel prices. The business model that supports these complex operations relies upon moving large amounts of fuel products on thin margins.

Naturally, operation of these high-tempo sites imposes wear and tear on fueling equipment. From a leak-detection standpoint, the concern is whether product containment has been compromised in the face of all this activity. From a business perspective, costly fuel inventory losses can take place at active sites because of problems with meters drifting out of calibration or improper blending ratios, theft at the dispenser or upon delivery, or the effects of temperature fluctuations. Many companies with high-volume sites have realized that the best way to manage their complex operations is to rely upon precise measurements of fuel inventory. Warren Rogers Associates (WRA) has worked with operators of such sites to develop a Continual Reconciliation System to enable them to manage their leak-detection requirements and all of the complex transactions and fueling equipment at high-throughput facilities where problems with fuel inventory shrinkage are endemic.

Figure 1

The Continual Reconciliation System

As shown in Figure 1, the Continual Reconciliation System uses a processor (“OSP”) installed at each facility to acquire data from automatic tank gauges, dispenser controllers, and other related systems. The OSP records data for each dispenser and compiles refined inventory data at the conclusion of every sales transaction by querying the tank gauge for product height and temperature measurements. The OSP develops a complete and ongoing record of fluid flows, transfer, and storage occurring on-site.1

Because the Continual Reconciliation System develops precise inventory measurements, it is capable of computing delivery volumes and meter calibration. Further, the system adjusts for the expansion and contraction of product due to temperature change on an ongoing basis. The system also identifies leakage as a continuous loss of product, as opposed to episodic delivery short- falls, theft, or excess product dispensed due to meter miscalibration.

Given that the Continual Reconciliation System works while the UST system is active, its leak-detection applications function differently than conventional automatic-tank-gauge and line-leak detector monitoring. Typically, volumetric monitoring of tanks and associated lines has taken place when the tank systems are dormant, an infrequent occurrence at high-volume sites. The Continual Reconciliation System instead relies on data from both the static and dynamic operations of the tank so that ongoing monitoring of the tank system can occur.

Because the Continual Reconciliation System tracks product from the point of delivery to the dispenser meter, leaks from almost every component of the storage system can be detected. We have found that leaks originating in the tank shell or buried piping runs are much less common today than leaks in flexible connectors, line-leak-detector components, and dispenser components such as impact valves, unions, and meters. Though common, many of these types of leaks are often missed by traditional methods of leak detection.

As a result of its ability to use all of the available data from a tank system, the Continual Reconciliation System is certified as an automatic tank gauge system method for monthly monitoring of tanks and associated lines for complex manifolded tank systems up to 100,000 gallons in capacity and nearly 3 million gallons in monthly throughput.

What about Non-Leak Losses?

The same data the system collects for leak detection purposes can also be used to quickly pinpoint and quantify non-leak losses. Operational problems such as miscalibrated meters, short deliveries, and theft at the pump occur with far greater frequency than leakage, and their costly effects can mount up quickly at a high-throughput site.

For example, an active dispensing position for diesel fuel could be checked for calibration by weights and measures standards and be found to be operating within the acceptable range. However, this same dispenser at an active travel center can be dispensing in excess of 300,000 gallons monthly and during that time could be giving away 650 gallons of product worth nearly $2,000.00 despite the fact that it’s operating in conformance with required tolerances. The Continual Reconciliation System is able to identify such meter- drift effects because measurements are being recorded at the end of every transaction and set of overlap- ping transactions. Therefore the contribution of each individual meter to inventory variations can be identified. Instances of both meter give- away and holdbacks can then be identified to the owner/operator so that they can be corrected. Further, because the duration of transactions is also recorded, dispenser flow rates can be determined to identify clogged filters or problems with flow limiters.

Theft is also common at the point of delivery or at the dispenser, particularly in this era of volatile fuel pricing. While delivery shortfalls may be apparent to the operator of a low- throughput site, they are difficult to identify at a very active facility taking more than one delivery a day. Similarly, dispensers can be jiggered at remote fueling positions of high-throughput sites, resulting in unauthorized fueling transactions.

Dispenser theft at a truck-stop facility, for example, is not a trivial event, since the losses of each individual event could be greatly in excess of 100 gallons of product. The Continual Reconciliation System can calculate on an amount of product delivered to a tank system as well as identify theft events by date, time, and amount.

Marrying Business and Environmental Concerns

Continual reconciliation has an important role for volumetric leak-detection monitoring in high- throughput UST systems. It is a way to motivate tank owner/operators to pay attention to leak detection. As a result of the reconciliation system’s ability to identify specific reasons for loss of product—be it piping or dispenser or theft or meter drift—a report of leakage becomes more visible and understandable to the businessperson who owns or operates that site. Leak detection is enfolded into everyday business practices. If a situation develops at a high-through- put site, the operator can quickly direct his/her attention to the prob- lem at hand rather than undertake a protracted “hit-or-miss” investigation that could allow a leak to persist. It is a win-win solution for both the businessperson and the environment. Currently the Continual Recon- ciliation System is in use at over 400 active travel centers nationwide as well as at high-volume convenience stores and truck terminals.

To find out more about this leak-detection option, go to www.warrenrogers.com or consult the National Work Group on Leak Detection Evaluation’s website at www.nwglde.org and look under the methods listed for Continuous In-Tank Leak Detection
Systems. ■

1. U.S. and foreign patents apply.

Bill Jones is Executive Vice President of Warren Rogers Associates, Inc. He can be reached at wjones@warrenrogers.com. or 800.972.7472.

HOME