The Big Berkey has a 2.25 gallon capacity can provide water for medium-sized families of one to four people. According to the manufacturer this system purifies water, addressing over 200+ contaminants in tap water or raw, untreated freshwater sources like ponds, rivers and streams.

Manufacturer's description on Amazon: At Berkey® by NMCL, we strive to provide high-quality, rigorously-tested water purification products. We believe Berkey® Systems have become a necessary layer of protection for millions of families amid a growing concern regarding the deterioration of America’s water infrastructure. We believe Berkey® Systems are essential tools for emergency preparedness. We value helping families, and we respect the universal need for clean water.