Wired has an article on water recycling, also known as “toilet to tap”. A stat I didn’t know is that about 10% of California’s wastewater is currently recycled. As they point out, getting new membrane plants up and running requires a lot of lead time, so if we want them up and running in a decade now is the time to start.

Singapore has invested heavily in membranes, although the water scarcity situation there has an added geopolitical dimension that makes it somewhat of a no-brainer. Their recycled water is pure enough to be used for industrial purposes such as semi-conductor plants. For drinking water, they just divert the recycled water back into a reservoir, suck it out again and put it through the normal treatment process, which somewhat ironically makes it a bit dirtier. But as this article points out, you don’t really want to drink nothing but distilled water.

Thinking about the west though, agricultural is a big issue, and for agriculture you don’t need membranes. Plain old wastewater treatment will work just fine.

Chemicals are a concern for me. The membranes won’t necessarily remove all those cleaning chemicals, personal care chemicals, lawn and garden chemicals, pesticides and pharmaceuticals we use on a daily basis. Nor will regular old water and wastewater treatment. If we are serious about doing something about those, we need to tackle them at the source and find safe, effective substitutes.