I am in the process of landscaping my backyard and preparing for future pool services (electrical & gas). I pulled a permit to run gas (2" PE) & electrical (2" PVC) to my backyard and stub it just past my proposed side-yard concrete. Gas was installed by licensed plumber already. Electrical still awaiting installation (considering doing myself because only conduit & no tie-ins at the moment). I am not sure what the general electrical codes are for installing electrical conduit in Contra Costa County, CA. Does gas & electrical need any separation when in same trench, or can they just sit on one another? Can I just place a conduit cap on each end that I stub out of the ground, or do I need a junction box? Can I back-fill the trench was the soil that was excavated, or do I need sand,...?