Summer is here -- and most of us won't stir out without carrying a bottle of drinking water. Bottled mineral water is a wasteful expenditure on a regular basis -- but what to do? Few cities offer safe drinking water from the tap.

A team of innovators in Seattle, Washington ( US) -- Halosource -- recently crowd-sourced a drinking water bottle with a purification unit that screws into the neck. It is called Astreawater Mobi-Pure aqua It consists of a 3-stage purifier cartridge that meets the USA National Sanitation Foundation Standards to remove heavy metals like lead and arsenic; chemicals like chlorine and benzene as well as bacteria and viruses like E-coli and Norovirus.

You can fill the bottle from the tap and drink straight: the cartridge does the purifying, in real time. The bottle as sold in India is food grade plastic, but a steel version appears to be under crowdfunding in the US.

Each cartridge is good for about 100 days or 375 litres. The Astrea water bottle costs Rs 1,099 on Amazon and replacement cartridges, around Rs 500.

—IndiaTechOnline