Coal waste products, like flyash, have long been used as complimentary cementitious materials to improve strength and durability of concrete while reducing cement content and therefore the embodied carbon of concrete. Until recently, even the EPA has been supportive of the commercial use of such materials. Now the EPA is taking a second look at the heavy metal content in these byproducts. A final ruling on whether to classify these materials as hazardous waste remains in limbo, but the uncertainty has angered the largest coal waste producers who have filed suit against the EPA demanding a deadline for the ruling.
Jim Vallette of the Healthy Building Network has published an interesting article outlining the positions of each side on this case. Online at https://app.e2ma.net/app/view:CampaignPublic/id:1405374.11099227719/rid:e87b8c542d06d8efb7270d2f375cc924
This issue was addressed in a previous blog article on this website: House Bill Takes on EPA Ruling Process