Foundry Sand Reuse in Vermont

Planning to reuse spent foundry sand in Vermont? This guide covers the rules that apply, the tests that decide how the sand can be managed, and what DEC 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. Vermont calls this an acceptable use determination. It is issued in writing under § 6-1402 of the Solid Waste Management Rules.

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.

Vermont’s acceptable use rule

Vermont’s rule is § 6-1402 of the Solid Waste Management Rules. Any person may ask the Secretary of the Agency of Natural Resources for a written acceptable use determination for a type or category of solid waste.

The section does not apply to:

• activities that need a solid waste certification;
• limited-duration disposal events that need an insignificant waste management event approval;
• materials or activities exempt from the rules, material that is reused, or solid waste that is recycled;
• solid waste that contains a hazardous waste, or whose use will create one;
• uses that threaten human health, safety, or the environment, or cause a nuisance; or
• waste that contains asbestos or infectious waste, or that is burned for energy or fuel.

Determinations are published. A determination may also cover other people’s use of the same waste for the uses it names. The Secretary denies or rescinds a determination if the use threatens health, safety, or the environment, or causes a nuisance.

Foundry sand as uniform solid waste

The rules name foundry sands as an example of uniform solid waste. That is solid waste the Secretary determines in writing to be consistently uniform, with no yard waste, marketable recyclables, or hazardous waste. A landfill may accept approved uniform solid waste only under the standards in the Secretary’s written approval (§ 6-1005(c)(6)).

Facility certification

Under 10 V.S.A. § 6605, no one may build, substantially alter, or operate a solid waste management facility without certification. Certification lasts up to 10 years. The rules bar treating, storing, or disposing of solid waste outside a certified facility unless § 6-302 exempts it. Recycling facilities that handle less than 50 tons of recyclable materials a year are exempt.

Requesting a determination

• Who files: any person may submit a written request to the Secretary.
• Waste description: the source of the waste, its physical, chemical, and biological characteristics, and the quantities to be used.
• Use description: where the material will be used, for how long, any processing, and the end product’s characteristics if it will be marketed.
• Safety demonstration: a written showing that the use will not harm human health, safety, or the environment, or create a nuisance. Base it on a characterization plan, historic test data, a risk assessment, a risk management plan, or another assessment the Secretary approves in writing.
• Management plan: how the waste is handled from source to final use. Cover storage, quality control, stormwater, risk management, application rates, monitoring, and a contingency plan if the use stops being viable.
• Financial assurance: the Agency may require it to cover the contingency plan.

DEC Waste Management and Prevention Division: 802-828-1138.

Hazardous waste determination

Vermont’s hazardous waste rules are the Vermont Hazardous Waste Management Regulations (VHWMR), effective July 10, 2026. They set out the state program in their own sections.

Vermont lists extra hazardous wastes in § 7-211. For example, code VT01 covers waste with PCBs at 50 parts per million or more. Vermont also has a state corrosivity code, VT20. It covers a solid that gives a pH of 2 or less, or 12.5 or more, when mixed 50 percent by weight with water.

Under Vermont Hazardous Waste Management Regulations § 7-202, 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, DEC, 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 an acceptable use request, the safety demonstration can rest on a characterization plan, historic test data, or a risk assessment (§ 6-1402(b)(3)).

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.

The Secretary decides acceptable uses case by case. Check any destination and proposed use with DEC before scheduling delivery.

Ask whether a published acceptable use determination already covers the same waste and use. If not, request one, or confirm the receiver holds a certification that covers spent foundry sand. 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.

Vermont Occupational Safety and Health Administration (VOSHA) runs Vermont’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. Storage outside a certified facility needs an exemption under § 6-302 (§ 6-304(d)). An acceptable use request must include a plan for storage before use.

Keep the waste determination, lab reports, DEC approvals, and the receiving site’s acceptance together. Record tonnage shipped, dates, and destinations. Keep records that match your management plan. 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 an acceptable use determination or facility certification covers the sand and use, or request one.
5. Get written acceptance and arrange pickup.

Common questions

Rules and guidance

• Vermont Solid Waste Management Rules
• 10 V.S.A. § 6605: Solid waste management facility certification
• DEC: Hazardous Waste Regulations, Statutes and Procedures
• VHWMR Subchapter 2: Identification and Listing of Hazardous Waste
• DEC: Waste Management and Prevention Division contact
• 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
• Vermont Occupational Safety and Health Administration (VOSHA)