Scientists Want to Use Wastewater to Fill Potholes

When wastewater is treated at sewage plants, a sandy substance known as grit is left behind. Grit is made up mostly of sand and gravel but also contains organic solids such as coffee grounds and eggshells. It is non-biodegradable, non-recyclable, and carries disease-causing bacteria, which is why it's normally sent to landfills. But researchers at California State University-Bakersfield say they might have figured out a way to repurpose it.

Researchers have found that by adding calcium oxide, magnesium oxide, and a weak acid to the grit, they could turn it into a mortar and create a 'grit assisted patch,' or GAP.

In initial tests, GAP was found to have comparable strength to traditional asphalt. Researchers say the use of this material could not only remove waste from landfills, but also reduce the reliance on asphalt which contains hydrocarbons that can be dangerous to humans and the environment.

Researchers say the next step is to test GAP on roadways with traffic and test its durability when exposed to different environmental conditions.