I had always wondered what I wanted to major as and I was interested by threads on Biosystem Engineering. (I want to design either biological waste management systems or greenhouses) Yet I've looked around and not many schools offer this as a major. What major or double major (or set of major and minor) would be the equivalent of this? Thanks.
The closest to that is Civil, followed by ChemE. You'll have to tailor your classes to your goal, but either of the two are close enough. Civil is a pretty good fit and you'll just have to take a few electives to do it.
Your interest is covered in depts. of Agricultural Engineering. In recent years, many schools re-named their ag engineering depts, calling them ag & biological engineering, biosystems engineering, biological engineering, or similar names.
