OAR 340-150-0430
Inventory Control Method of Release Detection

(1)

An owner and permittee using inventory control as a release detection method must meet this rule’s requirements. Inventory control may not be used as a release detection method for underground piping.

(2)

Use of inventory control as a release detection method is allowed for a period of:

(a)

Ten years after the installation of the UST system; or

(b)

Ten years after the UST system achieved compliance with corrosion protection requirements; except

(c)

In no case may inventory control be used as a primary release detection method after December 22, 2008; and

(d)

After the period of use has expired as listed in subsections (a) through (c) of this section, an owner and permittee must use one of the release detection methods in OAR 340-150-0435 (Statistical Inventory Reconciliation Method of Release Detection) or 340-150-0450 (Automatic Tank Gauging Release Detection Method) through 340-150-0470 (Other Methods of Release Detection).

(3)

Regulated substance (i.e., product) inventory control must be recorded daily and reconciled monthly to detect a release of at least 1.0 percent of flow-through plus 130 gallons on a monthly basis.

(4)

Inventory volume measurements for regulated substance inputs (deliveries), withdrawals and the amount still remaining in the UST must be recorded each operating day.

(5)

The equipment used to measure the level of regulated substance in the UST (e.g., stick or automatic tank gauge) must be capable of measuring the level of the regulated substance over the full range of the tank’s height to the nearest one-eighth of an inch.

(6)

Regulated substance inputs must be reconciled with delivery receipts by measuring the tank inventory volume before and after each delivery.

(7)

Regulated substance deliveries must be made through a drop tube that extends to within one foot of the tank bottom. To meet Stage I air quality vapor control requirements, drop tubes must be within six inches of the tank bottom.

(8)

Regulated substance dispensing must be metered and recorded within the local standards for meter calibration or an accuracy of six cubic inches for every five gallons of the regulated substance withdrawn.

(9)

The measurement of any water level in the bottom of the tank must be made to the nearest one-eighth of an inch at least once a month.

(10)

Any monthly inventory reconciliation (positive or negative) that exceeds the comparison number of 1.0 percent of flow-through plus 130 gallons or greater leak rate in any single month is considered to be a release detection failure. If this occurs, an owner and permittee must:

(a)

Report to DEQ a release detection failure that occurs for two consecutive months within 24 hours as a suspected release (OAR 340-150-0500 (Reporting Suspected Releases)) and immediately begin investigation as 340-150-0510 (Suspected Release Investigation and Confirmation Steps) specifies; and

(b)

Immediately investigate all larger-than-normal or reoccurring variations in results, including widely fluctuating water levels in the UST, and report such variations to DEQ as a suspected release if the variation cannot be accounted for, without waiting to obtain a second month of data.

(11)

An owner and permittee must have USTs tightness tested (OAR 340-150-0445 (Tank Tightness Testing for Release Detection and Investigation)) at least once every five years when inventory control is used as the sole or primary release detection method.

(12)

An owner and permittee must retain at a minimum the most current 12 consecutive months of release detection records and the last two tightness test results.

(13)

An owner and permittee may use the practices described in the American Petroleum Institute RP 1621, "Bulk Liquid Stock Control at Retail Outlets” to comply with the requirements of this rule.
[Note: Publications referenced are available from DEQ or from the publisher.]

Source: Rule 340-150-0430 — Inventory Control Method of Release Detection, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=340-150-0430.

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 340-150-0430’s source at or​.us