Legal Question in Landlord & Tenant Law in California

I am going to assume you mean a boarder, not a lodger. Legally a lodger is a resident of a transient dwelling like a hotel or motel room. A boarder is a person who rents a room in a home, whether the owner lives there or not.

Based on that assumption, the legal grounds for eviction of a boarder are identical to the reasons for a tenant. There are special rules if the owner resides in the home and there is only one boarder, but that is not the situation you describe.