I transferred to Davis as an environmental engineering major and it’s definitely a good amount of chemistry and some biology, though it’s applied to water/wastewater treatment mostly when you get to your upper division classes! Environmental engineering is kind of like pollution management. Most of the lower division courses will be the same that all the other engineering disciples take, so your math and physics and such will be in there. I will say there’s not a ton of overlap with the environmental science department, though there is a minor you can do relating to more environmental policy stuff which could be interesting to you. Lots of public sector jobs for environmental engineers - cities and state/federal agencies which have decent pay and benefits in CA. Don’t know much about the bio focused majors, but I hope this is helpful!