Storing commercially prepared water v. personally prepared water?

When individuals bottle water themselves, they're more likely to get contaminants in it that could risk harm after years of germination. By switching out personally bottled water more often an individual citizen can ensure that their stock is safe, as opposed to professionally bottle water which is likely packaged in cleaner and lower risk environment. Also, commercial grade plastic is High Density Polly Propylene, are less porous than soda bottles which individual citizens might use for bottling, and are therefore less likely to leach in outside agents.