I'm biased obviously but is American University one of your available options? Would highly recommend (again, HUGE bias)
It's where I got my BA from :P That said, the faculty I know were very invested in their students' success and I really learned a lot and benefited from the school's location. That said, I was an international relations major, not a math/science major. One of my very good friends got her degree in physics and I knew a few math majors I don't know how good the departments are. I know it's not a huge science school because politics/international relations are their big sells so the programs might suffer for that. There's a pretty strict divide between the math/sciences and softer sciences; they don't even require IR majors to take statistics. So it might not be the best fit for your purposes.