Bottled spring water, by definition, MUST come from naturally sourced spring water, eg Hepburn.
It would be filtered at factory to ensure its' cleanliness. Spring water has naturally occurring minerals in it, which are good for you. These are collected by the water as it passes through various rock strata underground.
When I was at Zebedee Springs, 'El Questro' Station, WA, was told that water comes underneath the Timor Sea, from South Asian landmass, then 're-appears' in northern WA!