Purified: How Recycled Sewage Is Transforming Our Water by Peter Annin
My rating: 4 of 5 stars
Toilet to Tap. That’s how opponents have characterized the process of recycling sewage into drinking water. That yuck factor has killed many such projects from San Diego to Tampa. But the reality is that purification is effective, safe, and cheaper than most other ways of augmenting drinking water supplies. This book explains the science only briefly and in layman’s terms. Instead it focuses on the politics behind it, and there are plenty. As droughts increased, aquifers dropped to record lows, and rivers dried up, opponents stopped finding the idea so repulsive. It became a lifeline in some places. There were politicians who supported it, then opposed it, then supported it again, all depending on the public attitudes. In reality we’ve all been drinking reclaimed sewage all our lives. Where do you think all that sewage goes from people uphill from you? And all the birds and beasts – yes they do it in the woods and that ends up in the rivers, reservoirs and groundwater that feeds our wells and systems. With climate change and overpopulation threatening our water supplies in so many places now, purifying sewage to augment drinking water just makes sense and is really the option for many places, at least until a low-energy, reliable, cheap, desalinization process is invented.
The book educated me to the different methods used to purify (West Coast and East Coast) and their advantages and disadvantages. Reverse osmosis (WC) uses a lot of energy and produces brine waste, but Southern California has lots of solar energy and an ocean to absorb the brine. Activated charcoal (EC) avoids those, but produces greenhouse gases and ash and is not quite as pure. Sanitation districts find resistance not only from the public but also from water districts who see them nosing in on their turf. There’s more to it, so read the book to find out. It does become a bit bureaucratic at time and spends a lot of time on identifying the people involved and their backgrounds.