This guest essay cites a Science article by Elizabeth Holley, associate professor of mining engineering, that concluded the U.S. could meet most of its critical minerals and rare earths needs by reprocessing mine waste streams.

Christopher Higgins, professor, Civil and Environmental Engineering, an early researcher of contaminants in sewage sludge, said there wasn't yet an established, cost-effective way of cleaning up a vast area of farmland contaminated with PFAS.

Christopher P. Higgins, professor of Civil and Environmental Engineering, is quoted in this article that notes levels of PFAS in sewage sludge used as fertilizer can pose risks that sometimes exceed EPA safety thresholds by several orders of magnitude.

Christopher P. Higgins, university distinguished professor, Civil and Environmental Engineering, is cited in this article about how the EPA obtained research from 3M in 2003 revealing that sewage sludge, the raw material for the fertilizer, carried toxic “forever chemicals.”

“In a purely commercial sense, it has been hard to justify an investment outside of China even though there is a lot of talk,” said Roderick G. Eggert, a minerals economist at the Colorado School of Mines.

“It’s different from the electricity sector, where widely available alternatives to fossil fuels like wind, solar and batteries have come down dramatically in cost,” Morgan Bazilian, a professor of public policy at the Colorado School of Mines, said ....

“There aren’t many clear winners that have emerged just yet,” said Morgan Bazilian, a professor of public policy at the Colorado School of Mines.

“Broadly the concept could make sense,” said Kip Findley, a professor of metallurgical and materials engineering at the Colorado School of Mines who has done research on advanced steel for vehicles. “This is pushing steel development forward and ....

“Most technologies for PFAS treatment in use today only serve to remove PFAS from water, but that just concentrates the PFAS wastes,” said Timothy Strathmann, an environmental engineer at the Colorado School of Mines.

Morgan Bazilian, director of the Payne Institute for Public Policy and former lead energy specialist at the World Bank, was a co-author on this guest essay.