It's not listed on the bottle, but I checked a couple of websites that compared bottled waters. The Ice Mountain sodium is listed at 1.7-4.3 mg/l, which is really low sodium compared to others.

These are the websites I checked

http://eservice.deerparkwater.com/se...p/quality.aspx

Bottled Water Web - The Definitive Bottled Water Site

All I can say from personal experience is this...pH is terrific, worked well with ferts, and runoff from flushing didn't look like there were huge backups of anything in the soil.