Foundry Sand Reuse in Oregon

Planning to reuse spent foundry sand in Oregon? This guide covers the rules that apply, the tests that decide how the sand can be managed, and what DEQ needs before the sand can be reused.

Key terms

Spent foundry sand

Foundries bond silica sand into molds and cores for casting metal. The sand is reused many times in the plant. Spent foundry sand is molding and core sand that can no longer make molds or cores.

Green sand and chemically bonded sand

Green sand is bonded with clay, usually bentonite, plus water and additives such as carbon. Chemically bonded sand uses resin binders. Most cores are chemically bonded. The binder system affects what the spent sand contains.

Beneficial reuse

Beneficial reuse puts a waste material to productive use instead of disposing of it. Oregon uses two kinds of “beneficial use determination”: standing determinations listed in the rule, and case-specific determinations that DEQ issues. Solid waste managed under either one is not regulated as solid waste.

TCLP

The Toxicity Characteristic Leaching Procedure (EPA Method 1311) measures how much of certain contaminants can leach from a sample. It is one part of deciding whether a waste is hazardous.

What’s in your spent sand?

Spent sand carries what the casting process added: binder residue, metal fines, and burnt core material. The alloy matters most. Sand from iron, steel, and aluminum foundries is the most commonly reused. Sand from leaded brass and bronze foundries is often regulated as hazardous waste.

Keep each stream separate. Baghouse dust, shotblast fines, cupola slag, broken cores, and core room sweepings need their own evaluation. Mixing them into spent sand can change how the whole load is managed. Track the alloys cast, the binder system, and any process changes.

Oregon’s beneficial use rules

Oregon’s beneficial use rules are OAR 340-093-0260 to 340-093-0290.

Standing uses for foundry sand

The standing beneficial use table in OAR 340-093-0270 lists two uses for foundry sand produced by iron, steel, or aluminum foundries:

1. Aggregate in asphalt mixtures, concrete, Portland cement, or masonry mortar. The table sets no conditions beyond the rule’s general requirements.
2. Nonresidential construction fill, utility trench fill, or roadbase. Hazardous substances must be below the higher of DEQ-approved human health occupational risk-based screening levels or natural background. Place the sand where it will not contact or harm waters of the state. Cover it in a way that limits exposure to ecological receptors.

A standing use needs no DEQ approval when you meet every general requirement:

• manage the sand until use, including storage, transport, and processing, to prevent releases and nuisance conditions;
• use it consistent with engineering, commercial, and agricultural or horticultural standards;
• keep hazardous substances at or below a comparable raw material or product, natural background, or acceptable risk levels;
• do not increase a hazardous substance in a sensitive environment; and
• follow all federal, state, and local rules.

Case-specific determinations

Any other use needs a case-specific determination. DEQ may approve one under OAR 340-093-0280 when:

1. the applicant has characterized the waste and use well enough to show compliance;
2. the use has an identified or reasonably likely market and is not speculative;
3. the use is a valuable part of a manufacturing process or an effective substitute for a raw material or commercial product, and is not disposal;
4. the use follows engineering, commercial, and agricultural or horticultural standards;
5. the material is not a hazardous waste;
6. hazardous substances do not significantly exceed a comparable raw material or product, do not exceed natural background, or stay within acceptable risk levels; and
7. the use does not increase a hazardous substance in a sensitive environment or create odors, dust, or other nuisance conditions.

Applying to DEQ

• Standing use: no application. Give the receiving party written documentation or labels that name the material, its hazardous substances if known, the approved uses, and the conditions.
• Who files: any person may apply for a case-specific determination.
• How: apply through Your DEQ Online. DEQ links user guides for the application and reports.
• Tier One ($1,000): for use in a manufactured product, without hazardous substances significantly above a comparable raw material. Give applicant and generator contacts, the material, how it is generated, and the yearly quantity. Compare its properties with the material it replaces, and show it meets OAR 340-093-0280.
• Tier Two ($2,000): for land application or elevated hazardous substances. Add sampling and analysis, a risk screening against DEQ-approved screening levels, the land use, and management measures.
• Tier Three ($5,000): for proposals that need research or a demonstration project. Add the justification, the expected time, and safe management methods.
• Review: DEQ decides the tier and fee and may ask for more information. It then issues a written determination with conditions, denies the request, or authorizes a demonstration project.
• Demonstration projects: authorized for up to one year. Submit a progress report within the year. DEQ may extend it once, for up to one more year.
• After approval: DEQ may require a material management plan, inspections, and compliance reports. It may modify or revoke a determination for misrepresentation, noncompliance, violations, or new risks.

Oregon DEQ: 503-229-5696, or toll free in Oregon, 800-452-4011.

Hazardous waste determination

Oregon adopts the federal hazardous waste rules by reference in OAR 340-100-0002. It covers 40 CFR Parts 260–268, 270, and 273, and Subparts A and B of Part 124, as enacted through July 30, 2020.

Oregon also lists state-only hazardous wastes, such as certain pesticide residues, in OAR 340-101-0033. A case-specific determination requires that the material is not a hazardous waste under Oregon law.

Under 40 CFR 262.11, the foundry must decide whether its spent sand is hazardous:

1. Make the determination at the point of generation, before mixing or dilution. Repeat it if the waste may have changed.
2. Check whether the waste is excluded from the hazardous waste rules.
3. Check whether it matches a listed hazardous waste.
4. Check for hazardous characteristics, including toxicity. Use knowledge of the materials and process, testing, or both. Test when knowledge alone is not enough.

Small and large quantity generators must keep records supporting the determination for at least three years after the waste was last sent for treatment, storage, or disposal.

TCLP testing and limits

Tell the lab the alloys cast, the binder system, and which streams the sample includes. Use representative samples. Agree on the sampling plan with the lab, DEQ, and the receiving site before collecting.

A waste is hazardous for toxicity if its TCLP extract meets or exceeds any limit in 40 CFR 261.24. The limits for the RCRA metals are:

Passing TCLP addresses toxicity for the substances tested. It does not approve reuse or rule out other reasons a waste may be hazardous. See material testing for sampling basics.

For fill, trench, or roadbase use, compare hazardous substance levels with DEQ-approved occupational risk-based screening levels and natural background. Tier Two applications need sampling, analysis, and a risk screening against DEQ-approved screening levels.

Finding a reuse destination

EPA’s 2014 risk assessment found three uses protective of health and the environment for silica-based spent sand from iron, steel, and aluminum foundries: manufactured soil, soil-less potting media, and road subbase. EPA and USDA support those uses. The finding does not cover sand from brass or bronze foundries, olivine sand, or sand mixed with other foundry wastes such as baghouse dust or cupola slag. EPA defers to state programs, so the state rules on this page still decide each use.

In Oregon, sand from iron, steel, or aluminum foundries has two standing uses. It can be aggregate in asphalt, concrete, Portland cement, or masonry mortar. It can also be nonresidential construction fill, utility trench fill, or roadbase, under the screening, water, and cover conditions above.

Sand from other alloys, and other uses such as soil blends, need a case-specific determination. Get the receiving site’s specifications and written acceptance. If reuse is not cleared, arrange disposal that fits the waste determination.

Worker protection

• Silica: foundry sand is mostly crystalline silica. OSHA’s general industry standard, 29 CFR 1910.1053, sets a permissible exposure limit of 50 µg/m³ of respirable crystalline silica as an 8-hour average. Exposure assessment starts at the 25 µg/m³ action level.
• Construction use: crews placing sand as fill or subbase fall under the construction silica standard, 29 CFR 1926.1153.
• Lead: brass and bronze foundries that cast leaded alloys also follow OSHA’s lead standard, 29 CFR 1910.1025.
• Dust: control dust during shakeout, storage, and loading.

Oregon OSHA runs Oregon’s OSHA-approved State Plan. For most employers, its standards apply in place of federal OSHA and must be at least as effective.

Storage and records

Store spent sand on a defined pad or in bins, control dust and runoff, and keep other foundry wastes out. Until the sand is used, manage storage, transport, and processing to prevent releases and nuisance conditions.

Keep the waste determination, lab reports, DEQ approvals, and the receiving site’s acceptance together. Record tonnage shipped, dates, and destinations. For fill, trench, or roadbase use, the user must report to DEQ for each calendar year when the sand contains hazardous substances above clean fill criteria. The report covers characterization, hazardous substances, the use, volume, and location. Keep determination records for at least three years.

Before pickup

1. Identify the alloys cast, sand and binder systems, separate streams, monthly volume, and plant location.
2. Make the hazardous waste determination and complete the required tests.
3. Choose a destination and get its material specifications.
4. Confirm the use matches a standing use and its conditions, or get a DEQ case-specific determination for that sand and use.
5. Give the receiver the required material information, get written acceptance, and arrange pickup.

Common questions

Rules and guidance

• Oregon DEQ: Beneficial Use of Solid Waste
• Oregon DEQ: Solid Waste Program in Your DEQ Online
• OAR 340, Division 93: Solid Waste General Provisions
• OAR 340-093-0270: Standing beneficial use table
• OAR 340-093-0290: Case-specific review procedures
• OAR 340-097-0120: Solid waste fees
• OAR 340-100-0002: Adoption of federal hazardous waste rules
• 40 CFR 262.11: Hazardous waste determination
• 40 CFR 261.24: Toxicity characteristic
• EPA Method 1311: TCLP
• EPA: Beneficial Uses of Spent Foundry Sands
• EPA: Risk Assessment of Spent Foundry Sands in Soil-Related Applications
• 29 CFR 1910.1053: Respirable crystalline silica
• 29 CFR 1926.1153: Respirable crystalline silica in construction
• Oregon OSHA