OAR 340-150-0445
Tank Tightness Testing for Release Detection and Investigation

(1)

An owner and permittee using tightness testing in combination with a primary release detection method or as a method for investigating a suspected release must use a test method or procedure that:

(a)

Is able to detect a 0.1 gallon per hour leak rate from any portion of the UST system that routinely contains a regulated substance, while accounting for the effects of thermal expansion or contraction of the regulated substance, vapor pockets, tank deformation, evaporation or condensation and the location of the water table;

(b)

Meets a probability of detection of at least 95 percent and a probability of false results (or false alarm, depending on method used) of no more than 5 percent; and

(c)

Is an approved leak detection method or equipment as listed by a national organization (e.g., the National Work Group on Leak Detection).

(2)

All tightness testing must be performed by a service provider or supervisor licensed by DEQ, except as provided by OAR 340-150-0156 (Performance of UST Services by Owners or Permittees).

(3)

Some automatic tank gauge equipment may meet the leak rate and probability requirements and may be used in place of a separate tightness test. To qualify as a tightness test, the automatic tank gauge must meet the requirements of section (1) of this rule.

(4)

If an UST system fails a tightness test (after the tank tester has ensured that all test protocols were properly performed), an owner and permittee must report the failure to DEQ within 24 hours of receipt of the results as a suspected release (OAR 340-150-0500 (Reporting Suspected Releases)) and immediately begin an investigation under OAR 340-150-0510 (Suspected Release Investigation and Confirmation Steps).

Source: Rule 340-150-0445 — Tank Tightness Testing for Release Detection and Investigation, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=340-150-0445 (accessed May 26, 2025).

340–150–0001
Purpose and Scope 340–150–0006
Applicability and General Requirements 340–150–0008
Exemptions and Deferrals 340–150–0010
Definitions 340–150–0020
UST General Permit Registration Certificate Required 340–150–0021
Termination of Temporary Permits 340–150–0052
Modification of Registration Certificates For Changes in Ownership and Permittee 340–150–0080
Denial, Suspension or Revocation of General Permit Registration Certificates 340–150–0102
Termination of General Permit Registration Certificates for Installation, Operation and Temporary Closure 340–150–0110
UST General Permit Registration, Annual Compliance and Other Fees 340–150–0135
General Requirements for Owners and Permittees 340–150–0137
UST Systems with Field-Constructed Tanks and Airport Hydrant Fuel Distribution Systems 340–150–0140
Requirements for Sellers of USTs 340–150–0150
Depositing Regulated Substances in USTs 340–150–0152
Requirements for Distributors of Regulated Substances for Deposit into USTs 340–150–0156
Performance of UST Services by Owners or Permittees 340–150–0160
General Permit Requirements for Installing an UST System 340–150–0163
General Permit Requirements for Operating an UST System 340–150–0167
General Permit Requirements for Temporary Closure of an UST System 340–150–0168
General Permit Requirements for Decommissioning an UST System by Permanent Closure or Change-in-Service 340–150–0180
Site Assessment Requirements 340–150–0200
Training Requirements for UST System Operators and Emergency Response Information 340–150–0210
Training Requirements for UST Operators 340–150–0250
Expedited Enforcement Process 340–150–0302
Installation of Used USTs 340–150–0310
Spill and Overfill Prevention Equipment and Testing Requirements 340–150–0315
Periodic operation and maintenance walkthrough inspections 340–150–0320
Corrosion Protection Performance Standards for USTs and Piping 340–150–0325
Operation and Maintenance of Corrosion Protection 340–150–0350
UST System Repairs 340–150–0352
UST System Modifications and Additions 340–150–0354
UST System Replacements 340–150–0360
Requirements for Internally Lined USTs 340–150–0400
General Release Detection Requirements for Petroleum UST Systems 340–150–0410
Release Detection Requirements and Methods for Underground Piping 340–150–0420
Release Detection Requirements for Hazardous Substance UST Systems 340–150–0430
Inventory Control Method of Release Detection 340–150–0435
Statistical Inventory Reconciliation Method of Release Detection 340–150–0440
Manual Tank Gauging Release Detection Method 340–150–0445
Tank Tightness Testing for Release Detection and Investigation 340–150–0450
Automatic Tank Gauging Release Detection Method 340–150–0465
Interstitial Monitoring Release Detection Method 340–150–0470
Other Methods of Release Detection 340–150–0500
Reporting Suspected Releases 340–150–0510
Suspected Release Investigation and Confirmation Steps 340–150–0520
Investigation Due to Off Site Impacts 340–150–0540
Applicability to Previously Closed UST Systems 340–150–0550
Definitions for OAR 340-150-0555 and 340-150-0560 340–150–0555
Compliance Dates for USTs and Piping 340–150–0560
Upgrading Requirements for Existing UST Systems 340–150–0600
Delegation of Program Administration 340–150–0620
Approval of More Stringent Performance Standards

May 26, 2025

Rule 340-150-0445's source at or​.us