An owner and permittee using equipment
for automatic tank gauging (ATG) that tests for the loss of a regulated
substance and conducts inventory control as a release detection method must use
equipment that meets the requirements of this rule. The ATG system must:
(a) Be able to detect a 0.2 gallon per hour
leak rate with a probability of detection of at least 95 percent and a
probability of false alarm of no more than 5 percent for all portions of the
UST that routinely contain a regulated substance; and
(b) The ATG system must be an approved leak
detection method or equipment as listed by a national organization (e.g., the
National Work Group on Leak Detection).
(2) For USTs, an owner and permittee must
monitor and test for releases at least once every 30 days and record the
results for each month.
underground piping, an owner and permittee must monitor and test for releases
if the ATG system is designed to detect a release from any portion of the
underground piping that routinely contains a regulated substance and record the
results for each month as follows:
for pressurized piping.
every 30 days for suction piping.
An owner and permittee must:
Report to DEQ any leak test results
indicating the possibility of a release (i.e., test failure) within 24 hours as
a suspected release (OAR 340-150-0500
) and immediately begin investigation
under OAR 340-150-0510
Immediately investigate all larger-than-normal or reoccurring variations in
results, including widely fluctuating water levels in the tank and report such
variations as a suspected release if the variation cannot be accounted for,
without waiting to obtain a second month of data.
(5) An owner and permittee must retain at a
minimum the most current 12 consecutive months of release detection
ATG systems installed
before December 22, 1990, are exempt from the leak rate quantities, probability
limits and third party evaluation requirements of this rule, except:
(a) The ATG system must be able to detect a
0.2 gallon per hour leak rate from any portion of the UST that routinely
contains a regulated substance; and
The ATG equipment must meet the inventory
control (or other test of equivalent performance) requirements of 340-150-0430
and the test must be performed with the system operating in one of the
(A) In-tank static testing
conducted at least once every 30 days; or
(B) Continuous in-tank leak detection
operating on an uninterrupted basis or operating within a process that allows
the system to gather incremental measurements to determine the leak status of
the tank at least once every 30 days.
An owner and permittee may only use the
ATG system to obtain daily regulated substance volumes for the inventory
control release detection method (OAR 340-150-0430
) if the ATG does not meet
the requirements of section (1) of this rule.
Or. Admin. R.
DEQ 6-2003, f. & cert.
ef. 2-14-03; DEQ 3-2008, f. 2-29-08, cert. ef. 3-10-08;
188-2018, amend filed 05/14/2018, effective
Statutory/Other Authority: 466.994, 466.995 & ORS
Statutes/Other Implemented: ORS