Foundry Sand Reuse in Arkansas

Planning to reuse spent foundry sand in Arkansas? 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. In Arkansas, DEQ authorizes beneficial use case by case. If the use is not shown to be beneficial and protective, the material stays a solid waste under Rule 22.

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.

Arkansas’s recovered materials rule

Arkansas’s solid waste rule is APC&EC Rule 22, codified as 8 CAR pt. 60. Its definition of industrial solid waste lists waste from iron and steel manufacturing and from nonferrous metals manufacturing and foundries (8 CAR § 60-106(46)).

Recovered materials are not solid waste (8 CAR § 60-106(76)). They have known recycling potential, can be feasibly recycled, and are removed from the waste stream for sale, use, or reuse as raw materials. They do not include materials destined for any use that constitutes disposal.

Under 8 CAR § 60-104(g), using a recovered material is not disposal when it is:

1. directly reused;
2. used in a manufacturing process;
3. used as a construction material; or
4. inert material used as beneficial fill.

The use must not harm air, surface water, or groundwater quality. DEQ may rescind this authorization. Approval may not be required, but the Director may set case-by-case conditions on the use of materials otherwise classified as solid waste.

The rule lists beneficial fill materials: asphalt, brick, concrete, ceramics, and uncontaminated soil or dirt. The Director may consider other materials case by case before filling starts. Fill projects should generally be finished in less than 60 days (8 CAR § 60-106(6)).

DEQ’s Beneficial Use Guidance sets out how to request authorization. If the documentation does not show the use is both beneficial and protective, the material stays a solid waste. It must then be managed under 8 CAR pt. 60.

Working with DEQ

• How: complete DEQ’s beneficial use request form in its ePortal, with a Beneficial Use Plan and a waste stream analysis.
• Beneficial Use Plan: describe storage, runoff controls, transport to the site, the application process and equipment, buffer zones, locations and acreage, a site map, property ownership and right-of-entry records, and site restrictions.
• Waste stream analysis: report the compounds or nutrients present, their concentrations by weight, and the benefit each provides.
• Land application: land application of industrial waste needs a permit from DEQ’s Office of Water Quality. A soil scientist or agronomist certifies the effects on water and health, and the loading rates.
• After approval: authorization does not release you from environmental liability. Unauthorized disposal may bring penalties under Arkansas Code § 8-6-204.
• Recycling facilities: a material recycling facility is exempt from permitting only if it handles recovered materials. It must show that substantially all incoming material is sold, used, or reused within one year (8 CAR § 60-1002).

DEQ Regulated Waste Program: solid waste (501) 682-0877, hazardous waste (501) 682-0873.

Hazardous waste determination

Arkansas’s hazardous waste rule is APC&EC Rule 23. It follows the federal program in 40 CFR Parts 260–279 and uses the federal section numbers. State additions appear in italic type.

DEQ lists the state-specific requirements. A generator of a waste newly found to be a toxicity characteristic waste must notify DEQ, even after notifying of other hazardous waste activity. Generators give waste only to permitted transporters, file annual reports instead of biennial reports, and pay annual fees.

Under APC&EC Rule 23, § 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.

Arkansas requires generators to keep determination records for at least 3 years.

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 a beneficial use request, DEQ asks for analytical results that show what the material contains, at what concentrations by weight, and what benefit each constituent gives.

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.

DEQ decides case by case. Check any destination and proposed use with DEQ before scheduling delivery.

When you talk to DEQ, describe the proposal using the uses in 8 CAR § 60-104(g). For example, is the sand used in a manufacturing process, or as a construction material? 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.

Storage and records

Store spent sand on a defined pad or in bins, control dust and runoff, and keep other foundry wastes out. Describe storage and runoff controls in the Beneficial Use Plan. Storage tied to a beneficial use may need a permit from DEQ’s Office of Water Quality. A recycling facility must move substantially all incoming material within one year.

Keep the waste determination, lab reports, DEQ authorizations, and the receiving site’s acceptance together. Record tonnage shipped, dates, and destinations.

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 with DEQ, and submit the ePortal request with the Beneficial Use Plan and analysis.
5. Get written acceptance and arrange pickup.

Common questions

Rules and guidance

• Arkansas DEQ: Beneficial Use Guidance
• 8 CAR pt. 60 (APC&EC Rule 22): Solid Waste Management Rules
• Arkansas DEQ: Solid Waste Exemptions and Other Guidance
• APC&EC Rule 23: Hazardous Waste Management
• Arkansas DEQ: State-Specific Requirements of Regulation 23
• 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