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UST Program - LG 113

UST Programs - LG 113

Issue Date: April 18, 1997
Revision Date: May 23, 2011

Tidel Engineering, Inc.

Tidel Environmental Monitoring System, EMS 4000
(Ultrasonic Probe #312-9000)


Tidel Engineering, Inc. no longer manufactures or supports the use of this method.

Certification Leak rate of 0.2 gph with PD = 97.4% and PFA = 2.6% for 2 hour test.
Leak rate of 0.2 gph with PD = 99.9% and PFA = 0.1% for 4 hour test.
Leak Threshold 0.1 gph for leak rate of 0.2 gph. 
A tank system should not be declared tight if the test result indicates a loss or gain that equals or exceeds this threshold.
Applicability Gasoline, diesel, aviation fuel, fuel oil #4. 
Other liquids with known coefficients of expansion and density may be tested after consultation with the manufacturer.
Tank Capacity Maximum of 15,000 gallons. 
Tank must be between 50 and 95% full.
Waiting Time Minimum of 2 hours, 29 minutes between delivery and testing. 
Minimum of 15 minutes between dispensing and testing. 
There must be no delivery during waiting time.
Test Period Minimum of 2 hours to achieve PD = 97.4% and PFA = 1.8% for leak rate of 0.2 gph. 
Minimum of 4 hours to achieve PD = 99.9% and PFA = 0.1% for leak rate of 0.2 gph. 
Test data are acquired and recorded by the microprocessor contained within the EMS console. 
Leak rate is calculated from data determined to be valid by statistical analysis. 
There must be no dispensing or delivery during test.
Temperature Average for product is determined from the measurement of the change in the speed of sound.
Water Sensor Must be used to detect water ingress. 
Minimum detectable water level in the tank is 1.045 inches. 
Minimum detectable water level change is 0.053 inch.
Calibration Gain adjustment on probe must be checked annually and, if necessary, calibrated in accordance with manufacturer's instructions.

Not evaluated using manifolded tank systems. Therefore, this certification is only applicable when there is a probe used in each tank and the siphon is broken during testing. 
Tests only portion of tank containing product. As product level is lowered, leak rate in a leaking tank decreases (due to lower head pressure). 
Consistent testing at low levels could allow a leak to remain undetected. 
EPA leak detection regulations require testing of the portion of the tank system which routinely contains product. 
This is a longer version of model #312-9001.

California regulations require at least one test per month after routine product delivery or when the tank is filled to within 10% of the highest operating level of previous month. If the 0.1 gph test is used as a tank tightness test there must be no water present in the backfill (groundwater must be below the bottom of the tank), the tank must be equipped with an overfill protection device, and the product level in the tank must be at the overfill protection device set point. Local agency pre-approval is required. To use the 0.1 gph test as a monthly option see title 23 CCR Section 2643 (b)(2).


Tidel Engineering, Inc.

Evaluator:  Ken Wilcox Associates

2025 West Beltline Road, #114

Tel:  (816) 443-2494

Carrollton, TX  75006

Date of Evaluation:  03/16/95

Tel:  (800) 678-7577


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