OAR 340-122-0330
Cleanup Rules for Leaking Petroleum UST Systems: Evaluation Parameters

The site-specific parameters are to be scored as specified in this section. If any of the parameters in sections (1)–(5) of this rule is unknown, that parameter must be given a score of ten:

(1)

Depth to Groundwater: This is the vertical distance (rounded to the nearest foot) from the surface of the ground to the highest seasonal elevation of the saturated zone. The score for this parameter is:

(a)

> 100 feet, 1;

(b)

51-100 feet, 4;

(c)

25-50 feet, 7;

(d)

< 25 feet, 10.

(2)

Mean Annual Precipitation: This measurement may be obtained from the nearest appropriate weather station. The score for this parameter is:

(a)

< 20 inches, 1;

(b)

20-45 inches, 4;

(c)

> 45 inches, 10.

(3)

Native Soil or Rock Type: The score for this parameter is:

(a)

Low permeability materials such as clays, silty clays, compact tills, shales, and unfractured metamorphic and igneous rocks, 1;

(b)

Moderate permeability materials such as fine and silty sands, sandy loams, loamy sands, and clay loams; moderately permeable limestones, dolomites and sandstones; and moderately fractured igneous and metamorphic rocks, 5;

(c)

High permeability materials such as sands and gravels, highly fractured igneous and metamorphic rocks, permeable basalts and lavas, and karst limestones and dolomites, 10.

(4)

Sensitivity of the Uppermost Aquifer: Due to the uncertainties involved in the Matrix evaluation process, this factor is included to add an extra margin of safety in situations where critical aquifers have the potential to be affected. The score for this parameter is:

(a)

Unusable aquifer, either due to water quality conditions such as salinity, etc.; or due to hydrologic conditions such as extremely low yield, 1;

(b)

Potable aquifer not currently used for drinking water, but the quality is such that it could be used for drinking water, 4;

(c)

Potable aquifer currently used for drinking water; alternate unthreatened sources of water readily available, 7;

(d)

Sole source aquifer currently used for drinking water; there are no alternate unthreatened sources of water readily available, 10.

(5)

Potential Receptors: The score for potential receptors is based on both the distance to the nearest well and also the number of people at risk. Each of these two components is to be evaluated using the descriptors defined in this section:

(a)

The distance to the nearest well is measured from the area of contamination to the nearest well that draws water from the aquifer of concern. If a closer well exists which is known to draw water from a deeper aquifer, but there is no evidence that the deeper aquifer is completely isolated from the contaminated aquifer, then the distance must be measured to the closer, deeper well. The distance descriptors are:

(A)

Near, < 1⁄2 mile;

(B)

Medium, 1⁄2-2 miles;

(C)

Far, > 2 miles.

(b)

The number of people at risk is to include all people served by drinking water wells which are located within two miles of the contaminated area. For public wells, count the number of users listed with the Oregon Health Division, Drinking Water Systems Section. For private wells, assume three residents per well. In lieu of a door-to-door survey of private wells, it may be assumed that there is one well per residence. The number descriptors are:

(A)

Many, > 3000;

(B)

Medium, 100-3000;

(C)

Few, < 100.

(c)

The score for this parameter is taken from the combination of the two descriptors using the following grid: [NOTE: View a PDF of the Grid by clicking on “Tables” link below.]

(6)

The Matrix Score for a site is the sum of the five parameter scores in sections (1)–(5) of this rule.
[ED. NOTE: To view attachments referenced in rule text, click here to view rule.]

Source: Rule 340-122-0330 — Cleanup Rules for Leaking Petroleum UST Systems: Evaluation Parameters, .

340‑122‑0010
Purpose 340‑122‑0030
Scope and Applicability 340‑122‑0040
Standards 340‑122‑0047
Generic Remedies 340‑122‑0050
Activities 340‑122‑0070
Removal 340‑122‑0071
Site Evaluation 340‑122‑0072
Preliminary Assessments 340‑122‑0073
Confirmation of a Release 340‑122‑0074
Development of Confirmed Release List 340‑122‑0075
Development of Inventory 340‑122‑0076
Inventory Ranking 340‑122‑0077
Initiation of Process for Delisting Facilities from the Confirmed Release List and Inventory 340‑122‑0078
Inventory Delisting — Public Notice and Participation 340‑122‑0079
Delisting — Determination by the Director 340‑122‑0080
Remedial Investigation 340‑122‑0084
Risk Assessment 340‑122‑0085
Feasibility Study 340‑122‑0090
Selection or Approval of the Remedial Action 340‑122‑0100
Public Notice and Participation 340‑122‑0110
Administrative Record 340‑122‑0115
Definitions 340‑122‑0120
Security Interest Exemption 340‑122‑0130
Involuntary Acquisition of Property by the Government 340‑122‑0140
Exemption for ORS Chapter 709 Trust Companies Acting as Fiduciaries 340‑122‑0205
Cleanup Rules for Leaking Petroleum UST Systems: Purpose 340‑122‑0210
Cleanup Rules for Leaking Petroleum UST Systems: Definitions 340‑122‑0215
Cleanup Rules for Leaking Petroleum UST Systems: Scope and Applicability 340‑122‑0217
Cleanup Rules for Leaking Petroleum UST Systems: Requirements and Remediation Options 340‑122‑0218
Cleanup Rules for Leaking Petroleum UST Systems: Sampling and Analysis 340‑122‑0220
Cleanup Rules for Leaking Petroleum UST Systems: Initial Response 340‑122‑0225
Cleanup Rules for Leaking Petroleum UST Systems: Initial Abatement Measures and Site Check 340‑122‑0230
Cleanup Rules for Leaking Petroleum UST Systems: Initial Site Characterization 340‑122‑0235
Cleanup Rules for Leaking Petroleum UST Systems: Free Product Removal 340‑122‑0240
Cleanup Rules for Leaking Petroleum UST Systems: Investigation for Magnitude and Extent of Contamination 340‑122‑0243
Cleanup Rules for Leaking Petroleum UST Systems: Low-Impact Sites 340‑122‑0244
Cleanup Rules for Leaking Petroleum UST Systems: Risk-Based Concentrations 340‑122‑0250
Cleanup Rules for Leaking Petroleum UST Systems: Corrective Action Plan 340‑122‑0252
Cleanup Rules for Leaking Petroleum UST Systems: Generic Remedies 340‑122‑0260
Cleanup Rules for Leaking Petroleum UST Systems: Public Participation 340‑122‑0320
Cleanup Rules for Leaking Petroleum UST Systems: Soil Matrix Cleanup Options 340‑122‑0325
Cleanup Rules for Leaking Petroleum UST Systems: Evaluation of Matrix Cleanup Level 340‑122‑0330
Cleanup Rules for Leaking Petroleum UST Systems: Evaluation Parameters 340‑122‑0335
Cleanup Rules for Leaking Petroleum UST Systems: Numeric Soil Cleanup Standards 340‑122‑0340
Cleanup Rules for Leaking Petroleum UST Systems: Sample Number and Location 340‑122‑0345
Cleanup Rules for Leaking Petroleum UST Systems: Sample Collection Methods 340‑122‑0355
Cleanup Rules for Leaking Petroleum UST Systems: Evaluation of Analytical Results 340‑122‑0360
Cleanup Rules for Leaking Petroleum UST Systems: Reporting Requirements 340‑122‑0510
Solid Waste Orphan Site Account: Purpose 340‑122‑0520
Solid Waste Orphan Site Account: Definitions 340‑122‑0530
Solid Waste Orphan Site Account: Eligible Sites 340‑122‑0540
Solid Waste Orphan Site Account: Funding Factors 340‑122‑0550
Solid Waste Orphan Site Account: Grants and Loans 340‑122‑0560
Solid Waste Orphan Site Account: Application Process 340‑122‑0570
Solid Waste Orphan Site Account: Funding Conditions 340‑122‑0580
Solid Waste Orphan Site Account: Application of Surcharge Proceeds 340‑122‑0590
Solid Waste Orphan Site Account: Limitations
Last Updated

Jun. 8, 2021

Rule 340-122-0330’s source at