Wanted to leap in here to mention tailings from minings projects. The gold that goes into a circuitboard comes from a mine which likely has a tailiings facility and associated dam, which is essentially an open pit filled with water into which tailings are dumped.
They're incredibly toxic materials. We had an engineer go out to the field and take a sample of some tailings, and after 6 months of being left in a lab, the materials had eaten through the stainless steel tube containing the sample.
It's not just power generation that has a negative externality in the form of waste. ALL resource extraction has associated waste.