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Performance Report
UST Program - LG 113

UST Program - LG 113

Issue Date: July 16, 2008

Clearstone Engineering Ltd.

GreenScan SIR



Leak rate of 0.2 gph with PD > 99% and PFA < 1% for both single and manifolded tank systems.
Leak rate of 0.1 gph with PD > 98% and PFA < 2% for single tank systems.
Leak rate of 0.1 gph with PD > 99% and PFA < 1% for manifolded tank systems.

Leak Threshold

If the absolute value of the calculated leak rate (gain or loss) is less than the leak threshold and the minimum detectable leak rate is less than or equal to 0.2 gph (0.1 gph for the 0.1 gph test), the test result is "pass." If the absolute value of the calculated leak rate is greater than or equal to the leak threshold, the result is "fail." If the minimum detectable leak rate exceeds 0.2 gph (0.1 gph for the 0.1 gph test) and the absolute value of the calculated leak rate is less than the leak threshold, the test result is "inconclusive."


Gasoline, diesel. 
Other more viscous liquids may be tested after consultation with the vendor.

Tank Capacity

Maximum of 30,000 gallons for single tank. 
Maximum of 45,000 gallons cumulative capacity for manifolded tank systems with no more than 4 tanks in the system.

Data Requirement

Minimum of 26 days of data is required.

System Features

This system requires a detailed evaluation of daily inventory measurements by a trained technician located at the corporate office.


The evaluation showed significant differences in results from manifolded tank systems and single tank systems resulting in different PA/PFA when used for leak rates of 0.1 gph.
51% of data sets evaluated were from manifolded tank systems. 
Of 41 data sets submitted for evaluation, all were analyzed with conclusive results. 
Median monthly throughput of tanks evaluated was 24,175 gallons. 
Variable leak rates ranging from .047 gph to .233 gph were used in the evaluation. 
Data sets evaluated were supplied by the evaluator.
Gains (water ingress) are analyzed and evaluated on an individual basis. If found significant, an investigation flag will be triggered, indicating an action is required by the operator.
This system is primarily designed as a service provided by the vendor.

Clearstone Engineering,
Ltd.700, 900-6 Avenue S.W.
Calgary, Alberta, Canada  T2P 3K2
Tel:  (403) 266-8820
E-Mail: goran.palibrk@clearstone.ca
URL:  www.greenscan.ca/sir/index.htm
Evaluator:  Ken Wilcox Associates
Tel:  (816) 443-2494
Date of Evaluation:  4/14/2003


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