Recycling Gypsum

When this column last addressed gypsum panel recycling in 2016, the focus was on development of an ASTM standard designed to facilitate closed-loop recycling of clean cutoffs from new construction. Four years later, ASTM C1881 Standard Guide for Closed-Loop Recycling of Scrap Gypsum Panel Products was published. Just in case readers are unaware, a four-year timeline for ASTM standard development is hardly unusual. However, moving into the third year of the standard’s existence, the conversation around gypsum panel recycling has shifted as diverse stakeholders struggle to identify plausible scenarios for greater recycling of clean scrap.

The universe of gypsum recycling stakeholders is quite varied and includes state government officials who wield oversight authority, waste management officials concerned about their operations, sustainability professionals anxious to garner additional LEED points, gypsum panel manufacturers expected to accept scrap, and construction and demolition businesses, to name a few. Add to the group associations representing various players—like the Gypsum Association and the Construction and Demolition Recycling Association—and the list of stakeholders remains far from complete. After all, building owners, consumers, and general and specialty contractors also will be affected by the shift from landfilling drywall scrap to recycling it. More and different work will be expected of manufacturers and contractors. Owners and consumers will likely be expected to help pay for it.

While the Standard Guide has undoubtedly generated greater confidence in the prospect of recycling clean scrap, what it cannot do is point a clear path toward how the gypsum panel industry, the A/E/C industry and the C&D industry will have to change to accommodate recycling. While waste management officials, state governments and sustainability consultants have frequently urged the gypsum industry to take a “get-‘er-done” approach to recycling, the complicated and messy reality eludes easy solutions.

Change Drivers

Trash disposal is nothing new. Prehistoric humans used landfilling as a means of dealing with their waste. Discovered in Crete, the first known landfill dates to 3,000 B.C.E. As early as 500 B.C.E., the city of Athens, Greece, mandated that waste be removed a mile outside the city so that streets could remain clean. Seemingly, trash has presented a problem since humans began to congregate in significant numbers. The U.S. produces 292.4 million tons of municipal solid waste (MSW) every year. Just under half of that goes to landfill.

C&D materials often account for more than 50 percent of the materials in a landfill, with gypsum panels representing roughly 2.5 percent of total C&D debris. In 2018, Waste Business Journal predicted total landfill capacity in the U.S. would decrease more than 15 percent by 2021. Current national data is hard to find, but many states, particularly those in the northeast, are facing imminent shortages of landfill space. According to the Massachusetts Department of Environmental Protection, landfill capacity for municipal solid waste and C&D debris is projected to decline to virtually zero by the end of 2030.

The Environmental Protection Agency reports that about 15 million tons of gypsum waste is generated yearly and only 2.1 million tons is reprocessed for secondary uses in markets such as agriculture, cement and gypsum panels. While gypsum waste represents only 2.5 percent of total C&D debris, when landfilled, its chemical composition contributes to the production of hydrogen sulfide (H2S) gas during natural bacterial decomposition. Unlike other landfill gases, such as methane, H2S is not a greenhouse gas but it smells like rotten eggs, and even low levels can cause irritability, watery eyes, asthmatic symptoms and headaches. Keeping gypsum out of landfills reduces the problems caused by H2S.

Another hope is that robust gypsum recycling programs will prompt the segregation of gypsum from other recycling streams, thereby limiting the generation and spread of gypsum fines—small pieces of gypsum that drywall readily generates when not stored properly or attached to framing. Gypsum fines contaminate other construction materials, interfering with their reusability or recyclability. Additionally, gypsum fines wear down equipment used by waste-to-energy producers.

Assuming proper implementation, recycling programs that segregate gypsum waste and replace outright demolition with careful deconstruction could diminish fines and preserve some landfill space. Gypsum panel manufacturers will not accept demolition waste for recycling at this time. Why? Material product safety concerns related to contamination during use by lead paint, asbestos in old joint compound and the possibility of encountering off spec or contaminated foreign drywall or another similar problematic product prevent manufacturers from embracing demolition waste. Until these concerns can be adequately addressed, demo will continue to be landfilled.

To seek applications for demo gypsum waste, the GA is co-sponsoring Phase II research into the use of C&D gypsum in concrete. Gypsum is commonly used in cement manufacturing in small percentages; however, Dalhousie University’s Phase I research demonstrated that gypsum could be a viable supplementary cementing material when combined with fly ash in concrete. Project outcomes from the initial study already have been shared in the prestigious Journal of Cleaner Production. Phase II involves durability testing and results, so far, are positive.

Gypsum manufacturers are more willing to accept recycled feedstock made from clean gypsum scrap i.e., the cutoffs generated at every new construction site. An estimated 10 to 15 percent of drywall delivered to a project site is ultimately discarded as trim scrap. If this scrap is segregated from other job site wastes such as food and beverage containers, packaging, paint cans, etc., clean cutoffs would be viable for recycling.

Gypsum Industry Recycling Experience

Recycling isn’t a new concept for gypsum panel manufacturers. Recycled paper facers have been manufactured and used by the gypsum industry for more than six decades. Also, waste, scrap and dunnage is regularly recycled into new panels at most plants. However, internal recycling efforts are easier to implement than external efforts because every step of the process is controlled and managed by a single entity. In fact, some GA member companies are engaged in using recycled clean scrap feedstock where it is available and where it makes sense. Gaining plant-level experience in managing and using a new feedstock source is a great first step toward potential adoption.

GA member companies have also participated in various good faith efforts to use clean scrap over the years. In 2006, plans were made to recycle clean scrap in Massachusetts. A gypsum scrap processor was established in the Boston area and two local gypsum panel manufacturers committed to accepting clean scrap feedstock from that source.

Despite the existence of a statewide ban on landfilling of clean scrap, the recycling facility was shuttered because not enough clean scrap was delivered to the processing facility to provide a consistent stream of post-consumer gypsum feedstock to manufacturers. The lack of clean scrap for processing was attributed to the ease with which clean scrap gypsum board could be landfilled inexpensively across state lines.

More recently, a panel manufacturer in Colorado was persuaded by local stakeholders to engage in recycling. The company purchased equipment for processing clean scrap. Again, the volume of clean scrap delivered was very low, likely due to the fact that the plant was in a remote location, away from major population centers. As a result, equipment was idled because it was difficult to justify its maintenance given the low volumes received.

There are valid reasons a project owner or contractor committed to recycling might balk at a significant roundtrip haul, and not only because of the expense. The greenhouse gas generated by transportation is significant. EPA explains that carbon dioxide emissions from transportation is the largest single contributor to total U.S. greenhouse gas emissions and accounts for approximately 27 percent of total GHG generation in the United States. At times, environmental goals can be in conflict.

The issue of conflicting goals is not unusual in the sustainability arena. When the California Statewide Commission on Recycling Markets and Curbside Recycling (the “Commission”) convened to advise state agencies and the legislature on the “complicated industry” of recycling, it recognized that fact early on. Among its four preliminary policy recommendations, one specifically states, “Commit to ensure that materials separated for recovery will not be processed in a manner that contradicts the environmental and social intent of recovery efforts.”

When the Commission took on the issue of drywall recycling in early 2021, it initially focused on using its power as a major consumer state to encourage greater recycling of gypsum. By mandating that all wallboard sold in the state contain post-consumer recycled gypsum feedstock in percentages that escalated over time, the Commission likely hoped to influence manufacturers beyond its borders. California has used its purchasing power in combination with its regulatory powers to successfully encourage better environmental outcomes in other industries. Most people drive cleaner cars and use more energy-efficient appliances because California’s regulations and large market persuaded manufacturers to change.

Given the gypsum industry’s experience with clean scrap recycling efforts failing due to lack of adequate volumes, this approach seemed like a recipe for failure. For six months, the GA, its member companies and one of the Commission’s committees worked together to try to crack this nut. While the Commission pressured the industry to commit to a meaningful percentage of PCR content in new products, the industry was appropriately hesitant to suggest a specific percentage. After all, acquisition of clean scrap was, by and large, beyond its control and would be determined by the willingness of other stakeholder groups to engage.

GA member companies are manufacturers and not C&D processors. As the GA and member companies surveyed the scene in California and engaged with other stakeholders, including members of CDRA, it became clear that California lacked a processor of feedstock-grade PCR gypsum. Some plants in California had equipment for recycling but most did not. The potential problem associated with greater clean scrap recycling were myriad and included storage and permitting concerns.

Moreover, in such a large state, the potential environmental impacts from transporting clean scrap to processors and PCR feedstock to gypsum panel plants and other secondary markets are a real concern. Gypsum industry members have long engaged in life cycle assessments at both the industry and company level. LCA is a framework for examining, identifying and evaluating the energy, material and environmental implications of a process, product or system across time. Industry average environmental product declarations, as well as plant and product specific EPDs, transparently report impacts like global warming, ozone depletion, emissions to water and air that cause damage, smog formation potential and primary energy use. What impact will recycling gypsum panels have on the environment in comparison to the existing state?

Another unknown that is tied to the feasibility of any recycling scenario is the economics around potential parts of the value chain and impacts on relevant stakeholders. Every stakeholder will need to adjust behaviors and operations to engage in recycling. Gypsum panel manufacturers will likely need to make adjustments to the production process and work with scrap processors to ensure feedstock meets spec. Product performance must be maintained, especially fire resistance. Project owners will likely pay more to a GC or subcontractors to “source separate” clean scrap cutoffs at the job site. These are just a few stakeholder considerations.

Ultimately, the Gypsum Association and the member companies it represents decided that a reasonable commitment was to research. Conducting mass flow analysis on wallboard scrap material to determine how much scrap will be available in California and where it is concentrated vis-à-vis manufacturing facilities is the first step. This work has begun and is already providing insights. For example, given that three plants are located in the San Francisco Bay area, that geography would seem to represent a promising recycling scenario. However, preliminary research reveals that the majority of clean scrap ends up in the Los Angeles area and further south. This doesn’t mean that recycling wallboard in and around San Francisco will not work, but it certainly informs how much PCR feedstock would be available if and when a processor establishes.

It can take time to recognize and reconcile potential discord in aims or objectives related to sustainability. However, it is time well spent whenever a major change to the status quo is proposed. Understanding material flows (in this case, clean scrap) for specific geographic areas, the economics around potential parts of the value chain and impacts on relevant stakeholders, as well as the environmental impacts associated with the totality of flow scenarios, will allow all stakeholders to assess risks and opportunities associated with various scenarios and manage them appropriately.