From Waste to Resources: Recycling drywall just got easier

Listen to this article

Gypsum wallboard (drywall), commonly used to cover the interior walls of buildings,  represents 20 percent of the waste generated during the construction of new commercial  and residential sites in Wisconsin. Until recently, much of this waste was being  disposed of in Wisconsin’s landfills. However, a new policy put into effect  by the Wisconsin Department of Natural Resources is paving the way for drywall  to become a resource instead of a waste, helping the environment and saving builders  money.

In October, the state DNR approved a low-hazard grant of exemption  that will allow builders and contractors who have completed a simple application  process to store, process and land-spread waste gypsum wallboard as a soil amendment.  

Gypsum, the primary component of drywall, can be used as an agricultural  fertilizer and soil amendment because it is made up of about 20 percent calcium  and 15 percent sulfur, both essential plant nutrients. Plants need calcium in  order to ensure proper cell division and to maintain normal functioning of cellular  membranes. Plants need sulfur in order to produce specific amino acids. Thus,  by grinding and land-spreading waste drywall, waste is eliminated from our landfills,  those responsible for the disposal of the waste drywall save on disposal costs  and a rich fertilizer for agricultural crops is produced.

“The approval  of this low-hazard grant exemption by the DNR will greatly impact construction  waste recycling in Wisconsin,” said Jenna Kunde, executive director of WasteCap  Wisconsin. “Nearly every waste-reduction and recycling project we work on  within the construction industry generates waste drywall that needs to be dealt  with. The ability to recycle this waste, while also providing valuable agronomic  benefits, paves the way for us to significantly reduce this specific waste stream.”

Easy  process

Builders and contractors who wish to use the DNR’s low-hazard  exemption for substituting waste gypsum wallboard for agricultural gypsum need  only to follow several simple steps.

First, a formal exemption from the  local DNR office must be obtained. This can be acquired by submitting a letter  requesting the low-hazard exemption and paying the permit fee.

Second, segregate  the scrap drywall on site. Only new scrap wallboard that has not been treated  with surface chemicals and is relatively free of tape, joint compounds, paint,  nails, screws or other contaminants should be used. In addition, all scraps should  be stored on site in a manner that minimizes rainwater runoff from the storage  area.

Third, grind the drywall. The wallboard should be ground to a size  that allows for easy and even distribution on the farm fields sited for spreading  and in a way that controls the dust generated by the grinder itself.

Fourth,  determine the application rate for land-spreading. The application rate for the  ground drywall will be based on the current sulfate content of the field and the  sulfur needs of the crop to be planted in the field.

Last, apply the ground  drywall to the field in accordance with soil and agronomic nutrient requirements.

Alternatively,  builders who contract with WasteCap Wisconsin for construction waste management  services can take advantage of the blanket exemption granted to WasteCap by the  DNR for its projects.

“We have been working with the DNR for over  two years to see this exemption come to fruition, and we are very excited that  recycling a large component of Wisconsin’s construction and demolition waste  stream just got easier,” said Ralph McCall, project manager for WasteCap Wisconsin.

More  information about the low-hazard grant exemption, how to properly manage  scrap drywall and the application allowing for the processing of gypsum wallboard  can be found on WasteCap Wisconsin’s Web  site.

Amber Zuhlke is an outreach specialist with WasteCap Wisconsin.