OAR 340-150-0450
Automatic Tank Gauging Release Detection Method
(1)
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.(3)
For 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:(a)
Daily for pressurized piping.(b)
Once every 30 days for suction piping.(4)
An owner and permittee must:(a)
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 (Reporting Suspected Releases)) and immediately begin investigation under OAR 340-150-0510 (Suspected Release Investigation and Confirmation Steps); and(b)
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 records.(6)
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(c)
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 (Inventory Control Method of Release Detection)) if the ATG does not meet the requirements of section (1) of this rule.
Source:
Rule 340-150-0450 — Automatic Tank Gauging Release Detection Method, https://secure.sos.state.or.us/oard/view.action?ruleNumber=340-150-0450
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