by MAURA KELLER
The construction and demolition industry continues to experience tremendous growth in new construction of housing and commercial buildings across the U.S.
As such, gypsum drywall scrap (from both demolition and construction activity) is also growing exponentially.
However, according to Isabelle Kavanagh, sustainability engineer at BuroHappold in New York, current estimates indicate a very low recycling rate for gypsum and data from the Environmental Protection Agency (EPA) suggests that just two percent of the millions of tons of gypsum waste produced annually is recycled into wallboard.
“Clearly there is significant room for growth, given this extremely low recycling rate,” Kavanaugh said. “And it’s critical to make progress for many reasons – including the fact that gypsum is a natural mineral that must be mined. An industry that adapts to reuse and recycle gypsum whenever possible will help avoid exploitation and depletion of natural resources.”
Terry Weaver, owner of USA Gypsum Drywall Recycling in Denver, Pennsylvania, said that gypsum drywall recycling in the U.S. is currently limited to a handful of successful recyclers but is well established in Canada and the European Union. For 24 years USA Gypsum has recycled new gypsum drywall trim scrap and recycles them for beneficial use in agricultural, Portland cement and closed loop wallboard manufacturing.
“The outlook is strong because the demand for gypsum is growing while production in the U.S. is diminishing as coal fired power plants, which produce synthetic gypsum, are being closed and mines struggle to expand due to environmental challenges,” Weaver said. “Reduced production is offset by imports which are subject to supply chain and transportation costs. Gypsum reclaimed from drywall will increasingly be viewed as a competitive source.
Indeed, the good news is that industry pressure and organizations like Building Product Ecosystems, founded by Amanda Kaminsky and the Durst Organization, are pushing for growth in this area.
“This is important because decomposing gypsum can produce dangerous gases such as hydrogen sulfide, so not only is a potentially valuable resource being wasted, but there is the possibility of harm to the health of those who live near landfills,” Kavanaugh said.
Most gypsum sent to landfills comes from the demolition of older buildings. In these cases, the gypsum is not source-separated during demolition, and therefore cannot be recovered for proper recycling and/or reuse. Also, the recycling infrastructure is still developing and expanding to meet this need.
According to Matt Dunyon director of operations at DTG Recycle, there is a noticeable increase in volume from builders and drywall installers due to the current construction boom.
“It is a topic of conversation in the industry, especially with landfills facing more and more scrutiny around hydrogen sulfide gas emissions that result from landfilling drywall,” Dunyon said. “Based on these concerns, we believe drywall recycling will have a significant upside in the near term.”
Currently, DTG Recycle uses recycled gypsum as a soil amendment for the agricultural market for farms, including cherries, apples, and potatoes, and mixing it with topsoil and manure for compost.
“We also have a robust product development pipeline through our Recycling Innovation Center, where we have partnered with local universities to develop a variety of gypsum-based construction and plant nursery-related products,” Dunyon said.
Challenges Aplenty
Michael McCamley, manager, technical services and market development at New West Gypsum Recycling (NWGR), said that one of the key issues for gypsum recycling is keeping it free from asbestos and lead. Lead based paints are a concern but asbestos is the biggest danger. NWGR recycles post-consumer gypsum waste into a product that’s used in the wallboard manufacturing process. Since 1985, the company has recycled more than six million tons of gypsum waste.
As McCamley explained, until the late 1970s asbestos was used in the mud joint compound to plaster walls and ceilings. It was never used in the production of wallboard. It is an important practice to test for asbestos prior to any deconstruction or renovation if the building was built before 1990.
“It’s also paramount that gypsum recyclers never accept gypsum that contains asbestos. For that to happen they need to have robust safety and screening procedures for incoming loads before accepting pre-1990 gypsum waste, third-party testing in place to test waste to be processed and the end product before is shipped out to re-ensure there is no asbestos,” McCamley said. “If asbestos is discovered, all operations need to cease and abatement of facilities must occur.”
This was the case for New West Gypsum Recycling (NWGR) in 2015 at its British Columbia, Canada operation.
“All it took was one bad actor to upset the market. We ended up paying the price for this bad actor and the toll it took on the local construction industry,” McCamley said. “In total, all the gypsum waste recycling came to standstill in the Metro Vancouver area. The reason being is that we receive the vast majority of gypsum waste for recycling within Metro Vancouver. Meanwhile NWGR worked closely with WorkSafeBC to strengthen our policies, which are more robust and stricter than ever before, for accepting gypsum waste. In my opinion, every gypsum recycler should be made to police themselves as well as being regulated by local work authorities, for their safety, for employee safety, for customer safety and for those who use recycle gypsum as a product. Asbestos is most dangerous when airborne and everyone must do their due diligence to reduce the risk of exposure.”
As Weaver noted, end markets are another big challenge surrounding gypsum recycling. In addition, gypsum is a low valued commodity that is expensive to transport.
According to Weaver, of the 42 million metric tons supplied, 10 percent is used to manufacture Portland cement, 36 percent for agriculture and miscellaneous. and 53 percent for wallboard and plaster.
“Producing quality recycled gypsum for beneficial use with chemistry similar to mined or synthetic gypsum begins by removing foreign material and paper facing,” Weaver says. “Understanding the physical characteristics, such a moisture and particle sizes the specific market needs, are the key to determining the type of process needed to successfully replace competing sources of gypsum.”
DTG’s current end markets require the gypsum to be contaminant free. Accordingly, they spend a great deal of time educating construction customers on how to separate and keep their drywall scraps clean and free of contamination.
Successful gypsum recycling requires attention to source separation: intentional efforts by contractors on construction and demolition sites to separate materials before they are sent to recycling facilities.
“This requires behavior change, which can be challenging,” Kavanaugh said. “Also, what constitutes end of life for recycled gypsum is evolving. For example, factory scrap and some trim scrap from new construction can be used to constitute new wallboard, but demolition scrap is trickier. Some potential end-of-life scenarios for demolition scrap include use in soil amendment or cement manufacturing.”
A Concerted Effort
Due to the growing interest in recovering gypsum from the C&D waste stream the Construction and Demolition Recycling Association (CDRA) recently formed a gypsum recycling committee with key stakeholders including gypsum drywall manufacturers, contractors, recyclers and building owners to move the industry forward. The CDRA Gypsum Recycling Committee’s mission is to provide guidelines and other assistance in developing and expanding recovery and end markets for recovered gypsum.
According to Weaver, who is the first chairman of the committee, the initial action steps that the committee will take include:
•Creating a drywall diversion policy to develop clear definitions on what types of wallboard can and should be recovered and marketed back to manufacturers of drywall with the goal of closing the loop on this construction product.
•Developing end product specifications recyclers have to meet in order to sell the recovered material back to drywall manufacturers.
•Creating best management practices (BMPs) for contractors and processors to increase the diversion of drywall.
•Working with drywall companies to set post-recycled content for new drywall.
•Promoting that recyclers must be third-party certified using a program developed to an ISO level so accurate diversion rates can be obtained and that drywall manufacturers would use a similar certification program to demonstrate the recycled content of their products.
•Defining specifications for other end products made from recycled drywall.
Kavanaugh said that everyone in the construction and demolition industry needs to be more ambitious with their targets for waste recycling. She noted that setting a high bar will help increase demand for effective recycling infrastructure for gypsum wallboard and other C&D materials, ultimately helping create more circular supply chains.
“Continued industry pressure can also help make source separation of gypsum more common practice on job-sites,” Kavanaugh said. “Also the creation of new, innovative products that use recycled gypsum, will increase demand for the resource.”
Weaver said that there is a consensus that more gypsum can be recovered by source separating at the job-site and not adding the drywall scrap to mixed C&D containers where the gypsum can become contaminated. As it is crushed and gets wet, it crumbles in small pieces that cannot easily be recovered and contaminates other materials that become more difficult to recover.
“We expect this practice to become more widespread,” Weaver said.
In addition, Weaver pointed out that drywall scraps in mixed C&D that are processed mechanically are mostly lost to C&D process screens and become mixed with other fines such as soil and aggregate which are often used as alternative daily cover (ADC) in landfills.
“The sulfate in the gypsum can produce hydrogen sulfide which in addition to odors can contaminate leachate. For this reason, many landfill operators refuse to accept or limit the use of ADC,” Weaver said. “Regulators in various states have reacted to sulfate problems in landfills and a patchwork of landfill bans and restrictions has emerged around disposal of gypsum drywall in landfills. Because disposing of gypsum is problematic in landfills and demand for gypsum is increasing, we expect gypsum drywall recycling in the U.S. to increase following successful examples set by Canada and the European Union.”
So what is the outlook for the gypsum recycling segment of the industry? Industry experts agree that it’s bright.
“I personally have seen a greater interest in the subject of gypsum recycling, which is awesome. Of late, there have been a lot of emerging gypsum recyclers entering the market, which is good, but with the gypsum recycling industry growth will come the bad actors looking to make a ‘quick buck’ ultimately setting back our industry on whole,” stated McCamley. “With that all being said, NWGR is proud to be a part of the CDRA Gypsum Recycling Committee in the protection of our industry by promoting best practices and to help guide the gypsum recycling industry with all the other major gypsum industry stakeholders involved in the committee. With due care, NWGR has proven it safe and possible to recycle gypsum wallboard and we want to keep it that way.”
Published in the June 2022 Edition