Despite making up less than 2% of the U.S. waste stream, e-waste is responsible for two-thirds of heavy metals in landfills. And when improperly disposed of in a landfill, these toxic chemicals can leach into the soil and even contaminate groundwater.

https://pirg.org/edfund/articles/what-is-e-waste/#:~:text=Despite%20making%20up%20less%20than,soil%20and%20even%20contaminate%20groundwater.