How many units can I take at a UC school in CA during summer session?

I am currently attending UCI in California. I would like to know if taking 2 quarter-unit classes during each summer session is too much plus if I am going to taking Writing 39C ( a 4 unit class) during the 10 week session. Is this too much to take? I also have a part time job during the weekend. Each summer session is 5 weeks long.|||You should be fine. The summer courses are more condensed, but you are taking fewer units, so the workload evens out.