SLO publishes target projections for each major. For last year, the projected acceptance rate for Env Earth and Soil Science was around an 80% but it depends upon yield. SLO is a selective campus but major selectivity varies greatly.
You look competitive and SLO admits based on MCA points and major. Here is the MCA point calculator. SLO also uses 9-11th grades in their GPA calculation vs the other Cal states that use 10-11th grades only.
Are you a CA resident?
If not, just be aware SLO will be Full pay at around $42K/ year with little FA.
If you are CA resident, then SLO is a great option. Also with this major, you are looking at attending Graduate school for the best career opportunities.