Foundry Sand Reuse in Tennessee | Foundry Recycling Services

Planning to reuse spent foundry sand in Tennessee? This guide covers the rules that apply, the tests that decide how the sand can be managed, and what TDEC 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. Tennessee calls this beneficial use. The generator must show TDEC that the proposed use is safe.

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.

Tennessee’s beneficial use rule

Tennessee’s beneficial use rule is Rule 0400-11-01-.02(1)(b)3(xxi). It removes the solid waste permit requirement for the beneficial use of waste that does not constitute disposal. The generator must show, to the Commissioner’s satisfaction, that the use is not detrimental to public health, safety, or the environment.

Two related routes can apply:

Recovered materials: materials diverted or removed from the solid waste stream for sale, use, reuse, or recycling are recovered materials. Recovered materials are not solid waste (Rule 0400-11-01-.01(2)).
Recovered materials processing facilities: a facility that only stores, processes, and resells or reuses recovered materials needs no permit if it notifies TDEC first (Rule 0400-11-01-.02(1)(b)3(xxii)). On request, it must show a viable market or use for the material.

Storage has a limit. Recyclable material may not be stored for more than one year without written approval from the Division (Rule 0400-11-01-.02(1)(b)3(xv)). On request, the operator must show a viable market for all stored waste.

Working with TDEC

Who shows the use is safe: the generator makes the beneficial use demonstration to TDEC.
Scope: describe the specific sand, its waste determination, and the proposed use. Show that the use is not disposal.
Receiving processors: a recovered materials processing facility files Form CN-1605 before it starts. The notice lists the materials it will receive, its maximum storage capacity for each, and its process. TDEC normally processes it in about 60 days. There is no fee.
Changes: a recovered materials processing facility must notify TDEC before changing ownership, location, materials received, storage capacity, or processing method. Where it applies, it files an annual report by March 1.
Manufacturers: a facility that takes recovered materials as a declared commodity for its own manufacturing process does not file the notice.
Disposal instead: industrial wastes are special wastes. A permitted landfill or processing facility may not accept a special waste without written TDEC approval, unless its permit allows it (Rule 0400-11-01-.01(4)). The generator files Form CN-1051 for each designated facility. The fee is $300.

TDEC Waste Management Branch: 615-532-0780, Solid.Waste@tn.gov.

Hazardous waste determination

Tennessee’s hazardous waste rules are Chapter 0400-12-01. They carry the federal rules into state rule, with each section keyed to its 40 CFR counterpart. For example, the toxicity characteristic is in Rule 0400-12-01-.02, keyed to 40 CFR 261.24.

Tennessee asks more of small quantity generators. Under Rule 0400-12-01-.03(5)(b), small and large quantity generators that ship hazardous waste off site file an annual report by March 1.

Under Rule 0400-12-01-.03(1)(b), the foundry must decide whether its spent sand is hazardous:

Make the determination at the point of generation, before mixing or dilution. Repeat it if the waste may have changed.
Check whether the waste is excluded from the hazardous waste rules.
Check whether it matches a listed hazardous waste.
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, TDEC, 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:

TCLP regulatory levels, RCRA metals
Contaminant	EPA waste code	Limit (mg/L)
Arsenic	D004	5.0
Barium	D005	100.0
Cadmium	D006	1.0
Chromium	D007	5.0
Lead	D008	5.0
Mercury	D009	0.2
Selenium	D010	1.0
Silver	D011	5.0

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.

TDEC may inspect special waste generators and take samples to evaluate a waste (Rule 0400-11-01-.01(4)(c)3). Base your beneficial use demonstration on data that represents the sand you will ship.

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.

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

When you talk to TDEC, explain how the use is productive and why it is not disposal. If the receiver is a recovered materials processing facility, confirm it has notified TDEC for your material. Get the receiving site’s specifications and written acceptance. If reuse is not cleared, arrange disposal that fits the waste determination. A TDEC special waste approval does not require a landfill to take the waste, so get the operator’s acceptance too.

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.

TOSHA runs Tennessee’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. Do not store recyclable material more than one year without the Division’s written approval. Be ready to show a viable market for stored sand.

Keep the waste determination, lab reports, TDEC approvals, and the receiving site’s acceptance together. Record tonnage shipped, dates, and destinations. Keep determination records for at least three years.

Before pickup

Identify the alloys cast, sand and binder systems, separate streams, monthly volume, and plant location.
Make the hazardous waste determination and complete the required tests.
Choose a destination and get its material specifications.
Make the beneficial use demonstration to TDEC, or confirm the receiver’s recovered materials notice covers your sand.
Get written acceptance and arrange pickup.

Common questions

Is a passing TCLP test enough?

No. It answers a toxicity question for the substances tested. The full waste determination, TDEC’s review, and the receiving site’s specifications still apply.

Does EPA’s risk assessment approve our sand?

No. It supports three soil-related uses for silica-based sand from iron, steel, and aluminum foundries. TDEC still decides each use in Tennessee.

Who has to show the use is safe?

The generator. Rule 0400-11-01-.02(1)(b)3(xxi) puts the demonstration on the generator. FRS can help gather the material information.

How long can spent sand be stored for recycling?

No more than one year without written approval from the Division. TDEC can also ask you to show a viable market for the stored material.

Does the recycler need a permit?

A facility that handles only recovered materials notifies TDEC on Form CN-1605 instead of getting a permit. A manufacturer using recovered materials as a declared commodity in its own process does not file the notice.

When do we need to test again?

Repeat the determination when the waste may have changed, such as a new alloy, binder, or process. For landfill disposal, special waste approvals are recertified every three years, and a changed waste stream needs a new application.