Issue Date: March 10, 2000
Revision Date: April 17, 2002
(originally listed as Tracer Research Corp.)
2000 Automated Tank Tightness Test
BULK UNDERGROUND STORAGE TANK
LEAK DETECTION METHOD (50,000 gallons or greater)
||Leak rate of 0.1
gph with PD = 100% and PFA = 0%.
||A tank system
should not be declared tight when tracer chemical or hydrocarbon greater
than the background level is detected outside of the tank system.
aviation fuel, fuel oil #4, waste oil.
||Not limited by
||Ranges from 7 to
30 days (normally 2 weeks) after tracer is added to tank.
||Tracer is added
to tank manually at tank fill or automatically using a metered injection
pump at pipeline flowing into tank.
Manual dosage of tracer is based on tank size, product volume in tank, and
frequency and volume of tank refills according to manufacturer's
Automated dosage at pipeline flowing into tank is based on pipeline size
and flow rate.
All tanks and piping downstream of the injection point are dosed with
must readily allow tracer movement through the tank excavation backfill
(greater than 1 Darcy).
influence of each tracer sampling probe is maximum 10 feet.
All tank surfaces must be within the zone of influence of a sampling
Probes must be installed per Manufacturer's guidelines.
groundwater in tank excavation backfill must be determined.
For test method to detect a release of tracer chemical below groundwater,
the hydrostatic pressure of product in the tank must exceed the
hydrostatic pressure of groundwater during test.
To accomplish this, product level must be maintained at least 6 inches
above groundwater for a minimum of 17 hours during the first three days
following addition of tracer to the tank.
At the discretion of the regulatory agency, water ingress measuring
devices may be used to supplement test method in high groundwater
||The presence of a
layer of water saturated soil, that is also frozen, above the location where
a leak may exist, may inhibit the effectiveness of the method by impeding
the transport of the tracer labeled product into the unsaturated zone.
Groundwater above bottom of tank may limit effectiveness of test method
(e.g. when applied to tanks containing water-miscible products or products
whose specific gravity is greater than 1).
Test method may not be effective in some tank excavation backfill (such as
clay) because it may plug holes in tank and retard tracer movement through
Third party evaluation of the ALD 2000 System tested the device's ability
to collect a sample, transport sample through 2700 feet of 3/32 inch
tubing, and analyze sample.
Sample collection, analysis, data storage, and alarm activation is
controlled by system's computer.
Prior evaluations tested PD, PFA, leak threshold, dose, tracer movement
through soil, and waiting times.
Praxair Services, Inc.
Ken Wilcox Associates
3755 N. Business Center Dr.
Dates of Evaluation:
Evaluator: Control Strategies Engineering (out of business)
Tel: Contact Praxair Services, Inc.
of Evaluation: 05/92