Issue Date: November 22, 1995
Revision Date: May 23, 2011
Tank Test System
VOLUMETRIC TANK TIGHTNESS TEST
Hasstech is no longer in business.
|Leak rate of 0.1
gph with PD = 95% and PFA = 5%.
A tank system should not be declared tight if the test result indicates a
loss or gain that equals or exceeds this threshold.
aviation fuel, fuel oil #4.
|Maximum of 12,000
Tank must be minimum 100% full.
|Test data are
acquired and recorded by system's computer that calculates a leak rate
every minute, and determines waiting time for satisfactory data (test is
finished when the standard deviation of 30 sequential leak rates is less
than half of the last leak rate determined).
There must be no dispensing or delivery during waiting time.
|Minimum of 1
hour, 10 minutes.
Test data are acquired and recorded by system's computer.
Leak rate is calculated from data determined to be valid by statistical
There must be no dispensing or delivery of product during test.
product is determined by a minimum of 7 thermistors.
|If depth to
groundwater in tank excavation backfill cannot be determined, tank must
pass a two level test with at least a 3 foot difference in product level.
If depth to groundwater in tank excavation backfill can be determined, a
single level test can be conducted provided a minimum net pressure of 1
psi exists at bottom of tank during test.
|Level sensor must
be calibrated before each test.
Thermistors must be checked and, if necessary, calibrated in accordance
with manufacturer's instructions.
using manifolded tank systems.
Evaluated at EPA Edison Risk Reduction Engineering Laboratory prior to the
EPA standard protocols being written.
System no longer being manufactured and no support is available.
U.S. EPA Risk Reduction