Obviously it isn't, if it was there wouldn't be a user facing cost. The fact this is a private venture basically proves that wherever this is, the municipality or building owner is only committed to providing tap water (which we see here is "free") the cost is for the extra, private, infrastructure that has been added in order to provide cold filtered water. If you aren't US, I'll note that municipal water treatment and filtering vs the more "Britta" level implied here are entirely different and very much a thing for some people.