By a few estimations, U.S. foundries dispose of 6–10 million tons of spent sand into landfills every year, after numerous rounds of internal sand recycling. Line up enough 30-ft.-long dump trucks carrying 20 tons each, and you might be counting that convoy from Chicago to San Diego. That’s a lot of sand. But the metalcasting industry has an opportunity to divert spent sand away from local landfills toward beneficial use projects––the options are many, the barriers are manageable, and the cost savings are worthwhile.

Over a decade ago, AFS Corporate Member Grede St. Cloud (Minnesota) had a stable beneficial use system in place for its 500 tons of spent sand per month. Although the sand could be used as daily cover at a local landfill, the foundry chose to follow its own corporate sustainability directive and, until late 2024, hauled the majority of spent sand 200 miles to a Portland cement plant in Mason City, Iowa for beneficial use. Hauling at such a distance was slightly better than break-even compared to the cost of landfill tipping fees and county taxes, says Environmental Project Engineer Don Scheele, but finding a closer beneficial use site was certainly more desirable, which would cut the cost of hauling as well as the CO2 emissions created by diesel trucks. 

Working with the State of Minnesota eventually produced the optimum solution. 

While the state had a solid waste beneficial reuse program in place, administered by the Minnesota Pollution Control Agency (MPCA), spent sand was not included among the industrial wastes that were granted standing approval for certain reuse applications. Foundry wastes required a Case-Specific Beneficial Use Determination (CSBUD), Scheele explained. 

Then, around 2015, the Metal Casters of Minnesota, a Twin Cities-based association that is no longer active, formed a working group with MPCA to identify beneficial use options for foundry waste.

“This effort resulted in creating a list of foundry residuals that could be considered for beneficial use projects,” Scheele said. “For spent foundry sand, three beneficial use options were specified: (1) as an ingredient in concrete, brick or asphalt, (2) construction fill, or (3) as soil amendment. MPCA guidance set limits on the trace metal content of the spent sand considered for each option. On behalf of its members, MCM obtained CSBUD approvals to use spent foundry sand in two different ways: either as (1) flowable fill or (2) as an ingredient in manufactured soil.”
Working with a waste broker, Grede St. Cloud ultimately located a new beneficial use application that reduced diesel fuel consumption by 2,000 gallons and shrank the foundry’s carbon footprint by about 2,000 metric tons per year, according to Scheele. Having obtained a CSBUD from the state, the foundry was able to send its spent sand to fill manure pits at animal feedlot operations in Minnesota, all within a 50-mile radius of the foundry. After two pits were filled and capped, the foundry then found a construction fill site to which over 350 tons of spent foundry sand were hauled––this sand was used as subbase for building a road.

“We would like to increase this so that 100% of our spent sand is recycled,” said Scheele. “This spring, there were weather issues with freeze, thaw, and snow, and it’s been tough to get into these sites, but we’re going to start going back now, and this is construction season, too. So, we’re probably sending about 75% or better.

“I think there are many opportunities to reuse foundry sands, Scheele added. “The only obstacle to finding ways to manage spent foundry sand is a lack of imagination.”

Rules and Regulations

Foundries may tend to associate the EPA with bad news, but on the subject of beneficial sand use, EPA is the foundry’s recycling advocate. The agency states at epa.gov that, based on conclusions from its 2015 risk assessment–– in conjunction with the U.S. Department of Agriculture and the Ohio State University––“silica-based spent foundry sands from iron, steel and aluminum foundries, when used in certain soil-related applications, are protective of human health and the environment, and yield environmental benefits.” (Note: The study did not include sand from leaded brass or bronze foundries, which may possess different characteristics.)

Further, EPA asserts, “The beneficial use of spent foundry sand, when conducted in an environmentally sound manner, can have positive environmental and economic benefits, particularly in the area of reducing impacts associated with food production and in the construction of roads and other infrastructure. 

“Environmental benefits include energy savings, reduction in greenhouse gas emissions, and water savings. Economic benefits include job creations in the beneficial use industry, reduced costs associated with spent foundry sand disposal, increased revenue from the sale of spent foundry sand, and savings from using spent foundry sands in place of more costly materials.”

Based on a 2008 EPA analysis, environmental benefits from using spent foundry sand in soil-related applications and road base include:

The energy savings equivalent to the annual electricity consumption of 800 homes;
Water savings equivalent to the amount of water to fill 12 Olympic swimming pools; and
Carbon dioxide emissions reductions equivalent to removing 840 cars from the road from one year.

Federal findings aside, foundries must pay close attention to state regulations related to beneficial use. While some states have mature, well thought-out rules, others are more restrictive, according to Mike Lenahan, executive vice president, industrial sales, at AFS Corporate Member Badger Mining Corp., and a past AFS President. He noted Wisconsin, Michigan, Indiana, and Ohio are examples of states with favorable beneficial reuse rules. A helpful Beneficial Reuse State Resource Locator can be found at: https://bit.ly/State-Resources.

“The first place to start is with understanding your state and the regulations that apply to the material you are going to recycle,” Lenahan said. “Each state is different and typically has analytical requirements in order to reuse your sand, and each state will have different applications that you are allowed to utilize.”

In some cases, old stigmas still cling to culture and legislative policy.

“A lot of people––especially people just starting out in life–– make the assumption that if it’s a byproduct generated by industry, it’s probably bad,” Lenahan added. “But with regard to foundry sands, the data really tells a different story. “Somebody once told me, ‘The only reason you’re [repurposing sand] is because it’s going to save the businesses money.’ And I said, ‘Yeah, that’s kind of true. It is going to save the business money, and that is really a key driver, because we’re taking something that’s being thrown away that shouldn’t be thrown away."

Many Choices

A wide range of beneficial-use applications are well suited for foundry spent sand. Common end-use projects include use as a sub-base for asphalt and as an ingredient in cement for applications including roadbuilding and parking lots. It can also be used as daily cover in landfills. Agriculture applications include feed pad construction, barn expansions, and manure pits, such as those to which Grede St. Cloud supplied sand. And the sand works nicely in a variety of geotechnical fill applications (aka backfill) for excavation businesses. Mine reclamation is another example. Many states have rules that legacy mines must be reclaimed for both safety and aesthetic purposes––and the local community is typically pleased to have the land restored, says Bryant Esch, corporate sustainability manager at AFS Corporate Member Waupaca Foundry.

“Also seek projects that have a value-add element to them,” Esch added. “If you’re taking foundry sand and putting it into a mix to make bricks or incorporating into a manufactured soil application to be bagged and sold at a garden center, now you’re making something with a higher value-add use.” 

In Northwest Indiana, AFS Corporate Member Hiler Industries has been supplying spent foundry sand to the manufactured soil industry for over 30 years. The region is rich in peat moss created 150 years ago when the federal government drained a large swath of marshland and turned it into farmland. As a result, counties near Lake Michigan benefit from rich farming soil, and hence the growth of manufactured soil businesses. Nevertheless, diversity is the name of the game in beneficial use for Hiler, which operates two separate foundries as well as a pattern shop and machine shop. The foundry has, in fact, developed numerous end-user relationships, which gives them alternatives and a backup plan if, for example, one user changes their mind or lake-effect weather conditions prohibit truck delivery to an inaccessible site. 

In the past 18 years, Hiler has beneficially reused over 130,000 tons of foundry sand, which, says Director of Innovation and Engineering Earl Miller, is enough to fill a four-story building as big as a football field. 

While beneficial use options abound, foundries must be discerning and discriminating about where they send their sand. Miller said he leaves little to chance. He conducts his own in-depth “reconnaissance” on every prospective end-user––and their proposed project site–– to ensure ethical business character and that the sand won’t be used for purposes that violate state or federal law.  

“I want to deal with financially stable companies and individuals,” he said. “I’m also looking at national wetland maps, because maybe they are telling me they need it for a driveway, but really they have a wetland on their property and they’re planning to fill it in. That’s going to be traced back to us and I don’t want that to happen. I create a binder on every single beneficial-use site that we work with, complete with a table of contents, documentation, and photos of their site. I even create my own legal document that clearly states what we’re providing and what they can and can’t do with it.

“I try to do my due diligence, and I need to talk to them personally,” Miller added. 

Another key to success for beneficial use is knowing exactly what you’ve got and adopting a new mindset: Your spent sand is no longer a waste––it’s a product and has to be treated that way. Sand characteristics need to fit the specifications of the application. The foundry needs to test its sand through an outside lab and screen it to make sure it’s free of debris and metal. 

Make Your Plan

Foundries have much to consider before stepping into the beneficial use sand box, but they shouldn’t be discouraged. Sources concurred it’s the right thing to do, given the finite nature of the earth’s resources. But they also caution others to keep expectations realistic––beneficial use won’t be a revenue generator, but it will likely lower the costs currently incurred from paying truck drivers, landfill tipping fees, and associated taxes. 

“Even if you’re not making money directly on your beneficial use program, more foundries are receiving inquiries about carbon emission impacts,” said Esch, “and they’re going to be able to support some nice sustainability claims … it may even give them a leg up on their competitors.”

Collectively, experts offered the following advice to help foundries prepare well for successful entry into beneficial use:

1) Upper management must support and drive the initiative.
2) Thoroughly research state and municipal regulations, and proactively communicate with your state’s environmental management agency. 
3) Pick a recognized analytical lab and stick with it. Set them up for success with good instructions, and collect representative samples that follow their sampling instructions. Familiarize yourself with all their methods, terms, and procedures. 
4) Maximize every truck load––it costs the same to haul 10 tons and 20 tons; why send a truck that’s half full? Consider storing the sand till there’s enough to fill the truck. (Also think about how you’ll put the sand in the truck––do you have the necessary loader or excavator?)
5) Clean the sand using screening and magnets––it must be free of all debris.
6) Visit the end-use site to verify the real application and to make sure the truck has ample space for dumping. Don’t let unvetted parties pick up sand at your site.
7) Keep meticulous records. Get everything in writing.
8) Match your volume output to the end use requirement. 
9) Calculate all costs in advance.
10) Consider developing a pilot project to create buy-in from local stakeholders. Demonstrate the EPA facts about foundry sand, and communicate transparently. Initial local reluctance can be turned into an end user waiting list.

Above all, foundries must do it right, sources said. Cutting corners of any kind will either put you in the regulatory soup or will give the metalcasting industry a black eye, potentially undoing decades of progress others have worked hard to create on the beneficial use front. Word of mouth can be positive or destructive, but either way, it’s powerful. 

“Don’t reinvent the wheel,” Lenahan said. “Lots of people have tried many things, so before you go racing down a path, see whether somebody else has tried it and had success. Someone may be doing something really well and could help you avoid a lot of mistakes.”

And where do you find these people?

“Come to the AFS EHS committee meetings, and you’ll find almost all the knowledge available on reuse,” he said. “For the cost of getting yourself to Chicago once a quarter and then showing up at the EHS conference each year, you’ll gain more information faster than anything else you can do. That is where everyone should start.”
Need Some Help?

Despite good intentions, not every foundry will possess the resources to create and manage a beneficial use program, but that doesn’t mean they can’t pursue it.

Some foundries, including Grede, have used brokers to identify end-user projects. Others have benefitted from the services of companies that specialize in sand recycling, such as AFS Corporate Member Kurtz Bros., based in Cleveland. The core of their business, says Director of Business Development Jason Ziss, is industrial beneficial reuse services. 

According to Ziss, the company’s owner, John Kurtz, together with AFS and the Ohio Cast Metal Association worked with EPA about two decades ago and were instrumental in conducting research that led to the agency’s own assessments and approval of recycling certain foundry sands.

The services of a broker or a sand management company will come with a price, so the goal is to achieve a cost reduction over the foundry’s current sand disposal expenses. “Recently, we’ve had more foundries coming to us because they have environmental goals,” Ziss said. “We try to provide the foundry with a cost benefit ... it’s a green approach, and it tends to be a good win-win for everybody.”

AFS Resources

Foundries that are ready to begin the journey toward beneficial use don’t have to sojourn alone. 

For starters, head to: afsinc.org/afs-beneficial-use-manual-foundries, where a free downloadable publication is available from the AFS Library. While there, click through the “Why Recycle” and “How to Get Started” sections.
To participate in the AFS EHS Committee meetings and conference, email George Curry at: gcurry@afsinc.org. To view a variety of foundry case studies, visit: https://www.afsinc.org/case-studies

“If you have not studied the opportunities in your area yet, why not?” said Esch. “If you look across the AFS membership, there’s been so much success out there––not just one or two; there are many foundry leaders on this. There are also a lot of opportunities; it’s just a matter of putting a little bit of energy and focus into it. And once you get a program going, you could really have a nice perpetuating benefit to your foundry.