If a farmer or village has access to even a stream, they have a massive source of fresh water. The trick is to put the brown water under 1m of vacuum – using a wind turbine or solar power pump.
To create that level of vacuum, and pump the pure water vapour to a tank or reservoir. The water will boil under 1m of vacuum, losing all salts and contaminants.
We get distilled water, which as it hits the air, will condense out as water drops, which fill the reservoir. No over priced mains water. As we use the water, it will fill up the stream.
And the next village can repeat the trick, so the stream will actually flow into a river, slightly brown – from al lthe contaminants.
And the pump way be provided by the UN – ending global thirst and hunger.
We can do the same for sea ater, getting limitless fresh water to irrigate the deserts of the world.