Answers To Frequently Asked Questions:


Q: Can SIR be used for monthly tightness testing of the piping?

A: Yes. SIR tests the entire UST system. Losses are reported regardless of their origins. This is to say, whether you are losing product as a result of a tank leak, a line leak, miscalibrated equipment or theft. An INVESTIGATE status results if the estimated leak rate exceeds the leak detection threshold.



Q: What are "estimated leak rate", "action threshold" and "MDL"?

A: The estimated leak rate is the amount of product your tank appears to be losing. This number is usually expressed in US gallons per hour or liters per day.

The action threshold is the estimated leak rate, above which SIR declares an INVESTIGATE status.

The MDL is the Minimum Detectable Loss. The MDL is the smallest loss rate SIR v3.0.1 can determine for the data provided with a probability of detecting a leak >95%.



Q: What is the difference between "qualitative" and "quantitative" SIR methods?

A: Qualitative methods do not provide estimated leak rates but simply report results in terms of PASS, MONITOR or INVESTIGATE. Quantitative methods also categorize results in such terms, but they go further by actually providing an estimate of the leak rate, typically in US gallons per hour or liters per day.



Q: Can SIR be used on manifolded tanks?

A: Yes. SIR can be used on tank systems that have multiple tanks linked together. This generally requires that each tank in the manifold system be individually dipped for inventory management. As with single tank systems, no product deliveries or sales should be made during the time sticking and totalizer readings are being taken.



Q: Why did a SIR fail my tank for a leak under 0.2 US gph?

A: Even small leaks over long periods of time can result in extensive contamination that can cost you substantial time and money for soil and groundwater clean up. Typically, an INVESTIGATE status will be declared for leak rates of 0.1 US gph or greater.



Q: How much does SIR cost?

A: Unlike most other methods, SIR has no installation costs and equipment costs are minimal - a well-calibrated dispensing meter and a good dip stick are about all you need. Analysis cost per tank vary depending on the number of tanks you want us to analyze. For further details please contact us.