For now, here are some academic papers on the topic. I'm aware of one large-scale plant that uses vacuum distilation, but nothing small-scale excepting individual trials.
- Waste to water: a low energy water distillation method
Department of Electrical Engineering, Florida Atlantic University
http://coldfusionnow.org/wp-content/uploads/2012/09/8931.pdf
30" of water column is about 75cm, that is well below 1 bar of pressure differential. You need about 75cm of mercury or 10m (more than 30 foot) of water column.
And even if you get boiling at the top of a 10m water column, you have to get the vapor out of it. You can not do distillation with static pressure only.
EDIT: I just had a look at the linked pdf. Seems possible. But what is the reason for a 100:1 pumping ratio? That's very high.