Foundry Sand Reuse in Nebraska

Planning to reuse spent foundry sand in Nebraska? This guide covers the rules that apply, the tests that decide how the sand can be managed, and what DWEE 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. Nebraska calls this beneficial use. A waste put to a beneficial use is no longer considered a waste; DWEE calls it a beneficial use material. DWEE reviews proposed uses of foundry sand case by case.

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.

Nebraska’s beneficial use rules

Nebraska’s solid waste rules, Title 132, require solid waste to go to a permitted solid waste facility. Title 132 counts waste from iron and steel manufacturing and from nonferrous metals manufacturing and foundries as industrial solid waste (Chapter 1, §052). Chapter 2, §002 lists activities exempt from the permit requirement. An exemption applies only when the waste is not mixed with other solid wastes and cannot cause contamination that threatens health or the environment.

Case-by-case beneficial use review

DWEE guidance 06-212 lists uses that need no preapproval for coal combustion by-products and steel manufacturing by-products. It names slags, dust, and sludges as the common steel by-products. Uses outside those lists, and similar materials, can be submitted to DWEE for case-by-case review and approval. DWEE asks five questions:

1. Does the material show hazardous waste characteristics? If so, it cannot be a beneficial use material.
2. Is it contaminated with other wastes at levels that threaten health or the environment?
3. Could it threaten health or the environment? DWEE looks at likely contaminants, test data, and leaching.
4. What are the site conditions? Describe the geology, hydrogeology, proposed use, and any engineering design features.
5. Is the end use really disposal? The use must serve a legitimate purpose. The material must perform like the commercial or natural product it replaces, and it must test below the standards DWEE applies.

Foundry sand as landfill daily cover

Title 132, Chapter 3, §004.17B2 lets DWEE approve an alternative daily cover at a municipal solid waste landfill. The landfill must show that the material controls disease vectors, fires, odors, blowing litter, and scavenging without threatening health or the environment. DWEE guidance 06-222 names foundry sand among the waste-like materials a landfill may propose.

• The landfill submits a demonstration plan to DWEE and gets approval before starting.
• A demonstration typically lasts 180 days. The landfill keeps daily performance forms and sends DWEE a monthly report.
• For foundry sand, the landfill should be ready to give analytical data on fire, odor, dust, reactivity, and effects on leachate.
• DWEE then approves or denies continued use.
• For material physically similar to soil cover, DWEE may skip the full field test. A chemical analysis must still show the material is not hazardous waste and is not a threat to health or the environment. These approvals are often temporary, site-specific, and conditioned on limited storage, dust control, and soil cover within set days.

Special waste approval

DWEE classifies special wastes case by case under Title 132, Chapter 13. A special waste may go only to a permitted disposal area, unless DWEE gives prior written approval for another location and management method. DWEE bases that approval on the waste’s properties and on the site: distance to homes, wells, and surface water, floodplains, wellhead protection areas, soils, and depth to groundwater.

Asking DWEE for review

• Beneficial use: submit the proposal to DWEE. Answer its five review questions with the material’s physical and chemical data, leaching results, site conditions, proposed use, and any design features.
• Data: recent sampling or historical data is acceptable, but it must represent the material.
• Treated material: if the sand will be fixed or treated before use, test it after treatment.
• Engineering: DWEE does not evaluate engineering properties. A qualified professional must decide whether the material meets design criteria.
• Daily cover: the landfill owner or operator files the demonstration plan with DWEE.
• Special waste: give DWEE the information in Title 132, Chapter 13, §002. That includes the generator, the industrial process, quantity, physical and chemical analyses, liquid content, and the proposed method and location.

DWEE: (402) 471-2186 or toll free (877) 253-2603, DWEE.moreinfo@nebraska.gov. Hazardous waste compliance assistance: (402) 471-8308.

Hazardous waste determination

Nebraska writes its own hazardous waste rules in Title 128. Federal rules apply where Title 128 adopts them by reference. Under Chapter 26, those references are to the CFR as revised July 1, 2005, unless a section says otherwise.

Nebraska generator duties are in Title 128, Chapters 8 through 10. They still use the conditionally exempt small quantity generator category. Check your generator category and duties against those chapters.

Under Title 128, Chapter 4, § 002, the foundry must decide whether its spent sand is hazardous:

1. Check whether the waste is excluded from the hazardous waste rules.
2. Check whether it matches a listed hazardous waste.
3. Check for hazardous characteristics, including toxicity. Test the waste, or apply knowledge of the materials and processes used.

Nebraska 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, DWEE, 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.

DWEE’s beneficial use review can also call for total metals, VOCs, semi-volatiles, pesticides, PCBs, petroleum hydrocarbons, and the ASTM D3987 water leach test. It compares results with limits in Title 128, Chapter 3, Title 117, Title 118, and EPA Region 9 Preliminary Remediation Goals.

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.

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

When you talk to DWEE, frame the proposal around its five review questions. Show that the sand performs like the product it replaces. A landfill that wants the sand as daily cover needs DWEE approval of its own demonstration. 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. The Title 132 exemptions apply only to waste that is not mixed with other solid wastes. Follow any storage limits set in a DWEE approval.

Keep the waste determination, lab reports, DWEE responses, 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. Get DWEE’s case-by-case approval for that sand and use, or confirm the landfill’s approved daily cover.
5. Get written acceptance and arrange pickup.

Common questions

Rules and guidance

• DWEE Guidance 06-212: Beneficial Use of Coal Combustion By-Products, Steel Manufacturing By-Products, and Similar Materials
• DWEE Guidance 06-222: Alternative Daily Cover Demonstrations
• Title 132: Integrated Solid Waste Management Regulations
• Title 128: Nebraska Hazardous Waste Regulations
• 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