OAR 340-150-0435
Statistical Inventory Reconciliation Method of Release Detection

(1)

An owner and permittee using statistical inventory reconciliation (SIR) as a release detection method must meet the requirements of this rule. SIR cannot be used as a release detection method for pressurized underground piping.

(2)

The method must be capable of detecting a least a 0.2 gallon per hour leak rate from any portion of the UST that routinely contains a regulated substance with a probability of detection of at least 95 percent and a probability of false alarm of no more than 5 percent.

(3)

The SIR method used must be an approved leak detection method that meets the requirements of section (2) of this rule as listed by a national organization (e.g., the National Work Group on Leak Detection).

(4)

Daily inventory control regulated substance measurements and data gathering must be performed in accordance with OAR 340-150-0430 (Inventory Control Method of Release Detection)(4)–(9).

(5)

An UST system must be monitored for releases on a monthly basis when the SIR method is used. To meet the monthly monitoring requirements, an owner and permittee must, within 22 days after each calendar month or 30-day period, submit the daily inventory records to and receive the SIR results back from the SIR vendor they have hired to perform the statistical analysis. An owner and permittee must follow up with the SIR vendor if there are delays and make any changes necessary to their service agreement or contract to prevent late report submittals.

(6)

The results of a SIR analysis that shows a 0.2 gallon per hour or greater leak rate in any single month is considered to be a release detection failure.

(7)

An owner and permittee must report to the department any single release detection failure and any two inconclusive results (as reported by the SIR vendor) obtained within a consecutive two-month period within 24 hours as a suspected release (OAR 340-150-0500 (Reporting Suspected Releases)) and immediately begin investigation in accordance with 340-150-0510 (Suspected Release Investigation and Confirmation Steps); additionally

(a)

An owner and permittee must investigate and attempt to remedy or repair the cause of inconclusive results; and

(b)

SIR must be discontinued as the release detection method and immediately substituted with one of the release detection methods listed in OAR 340-150-0450 (Automatic Tank Gauging Release Detection Method) through 340-150-0470 (Other Methods of Release Detection) if:

(A)

An owner and permittee is unable to correct the cause of the inconclusive results after tank and piping tightness testing results or other investigation methods confirm that the UST system is not leaking; and

(B)

More than four inconclusive results are recorded within a consecutive 12-month period.

(c)

An owner and permittee must immediately investigate all larger-than-normal, unusual 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.

(8)

An owner and permittee must retain at a minimum the most current 12 consecutive months of release detection records, including SIR vendor results and inventory control records.

Source: Rule 340-150-0435 — Statistical Inventory Reconciliation Method of Release Detection, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=340-150-0435.

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
Last Updated

Jun. 8, 2021

Rule 340-150-0435’s source at or​.us