Foundry Sand Reuse in Louisiana

Planning to reuse spent foundry sand in Louisiana? This guide covers the rules that apply, the tests that decide how the sand can be managed, and what LDEQ 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. Louisiana calls this beneficial use. LDEQ approves each use through a beneficial use plan.

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.

Louisiana’s beneficial use rule

Louisiana’s beneficial use rule is LAC 33:VII, Chapter 11. It applies to all solid waste generators. It covers waste streams that would typically go to a solid waste disposal facility. LDEQ reviews each beneficial use plan under LAC 33:VII.1105.

An approved plan exempts the reuse from the solid waste permitting requirements and processing and disposal standards. LAC 33:VII.303.A.11 exempts solid waste reused in a way that protects human health and the environment, as shown by a beneficial use plan approved by LDEQ. The waste must be managed in an environmentally sound manner.

After approval, the sand must be handled, stored, and used as the approved plan describes. LDEQ may revoke an approval if you cannot show a market for the material and compliance with the approval.

Stored waste has a limit. No solid waste may be stored on site for more than one year without approval from LDEQ’s Office of Environmental Compliance.

Applying to LDEQ

• Who files: the facility owner or operator files LDEQ’s Solid Waste Application – Beneficial Use. The applicant and the person who prepared the application both sign the certification.
• Waste information: give the site of origin, the chemical and physical characteristics, and the quantity, quality, consistency, and source. Describe the process that generates the waste and how the generator has minimized its quantity and toxicity.
• Market and end use: show a known or reasonably probable market, such as a contract to buy or use the material. Name the end users and end-use locations. Show that the end use protects public health, safety, and the environment.
• Handling plan: describe quality-control testing, storage, and recordkeeping. Storage must address run-on and run-off, maximum inventory, soil and groundwater protection, and wind dispersion.
• Storage turnover: acknowledge that at least 75 percent of the material placed in storage during a year will go to market or other secure storage within the following year. The exception is a particular order that you show needs more than one year of storage before shipment.
• How: mail paper copies to LDEQ, Office of Environmental Services, Waste Permits Division, P.O. Box 4313, Baton Rouge, LA 70821-4313. LDEQ’s completeness checklist calls for five paper copies.
• Fees: an initial or renewal application carries a $1,325 review fee for each facility. A modification carries an $813 fee. Send the fee with the application (LAC 33:VII.1501).
• After approval: submit an annual report by August 1 for July 1 through June 30. Apply for renewal at the end of the approved term.

LDEQ Waste Permits Division: (225) 219-3181.

Hazardous waste determination

Louisiana’s hazardous waste rules are in LAC 33:V, the state’s program under RCRA. LDEQ writes most federal requirements into this text and adopts selected federal provisions by reference. The toxicity characteristic is in LAC 33:V.4903.E. The solid waste rules require the same determination (LAC 33:VII.119).

Louisiana’s generator rules go beyond the federal rules. All generators, including very small quantity generators, must get an EPA identification number. File LDEQ’s Form HW-1 within 14 days after first generating hazardous waste (LAC 33:V.1017.A). Large quantity generators file an annual report by March 1 (LAC 33:V.1021).

Under LAC 33:V.1005, 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, LDEQ, 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 plan, LDEQ requires testing under Louisiana Environmental Laboratory Accreditation Program (LELAP) rules. Results are compared with appropriate standards, such as RECAP.

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.

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

A landfill may use alternative daily cover only with LDEQ approval, and LDEQ may require testing (LAC 33:VII.711.B.2.c). When you talk to LDEQ, describe the proposal using the items in LAC 33:VII.1105. Show the market, the end users, and where the sand will be used. 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. Do not store solid waste on site for more than one year without approval from LDEQ’s Office of Environmental Compliance. Keep records of how long it has been stored (LAC 33:VII.503.A.1).

Before the first off-site shipment of industrial solid waste, submit LDEQ’s Notification Form for Generators of Industrial Solid Waste. Include analysis or process knowledge showing the waste is not hazardous. Get an industrial waste code number from the disposal facility (LAC 33:VII.501.B). Generators of industrial solid waste also file an annual report of waste disposed of off-site by August 1. Keep those records for two years.

Keep the waste determination, lab reports, LDEQ approvals, and the receiving site’s acceptance together. Record tonnage shipped, dates, and destinations. 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 at a LELAP-accredited lab.
3. Choose a destination and get its material specifications.
4. File or confirm the LDEQ beneficial use plan for that sand and use.
5. Get written acceptance and arrange pickup.

Common questions

Rules and guidance

• LDEQ: Solid Waste Permitting (beneficial use plans)
• LDEQ: Solid Waste Application – Beneficial Use
• LDEQ: Guidance for the beneficial use application
• LDEQ: Beneficial use plan completeness checklist
• LDEQ: Notification Form for Generators of Industrial Solid Waste
• LAC 33:VII.1105: Beneficial use of other solid waste
• LAC 33:VII.303: Wastes not subject to permitting or processing and disposal standards
• LAC 33:VII: Solid Waste (Office of the State Register)
• LAC 33:V: Hazardous Waste (Office of the State Register)
• 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