Sunday, April 26, 2009

Greywater Reuse

We have talked a lot in class about the water-energy nexus. In fact, there was an entire lecture dedicated to the topic. I think this is a fascinating study.
Water is essential for all organisms, and is required by every sector of our society/economy. Electricity generation, refining, manufacturing, and construction uses large quantities of water. The U.S. is blessed with enough rain that water scarcity issues don't cross the minds of many Americans. However, in the western U.S. and in Australia, South Africa, northern Africa, and the Middle-East, significant water concerns arise from the cost and/or lack of freshwater supplies. Water scarcity, unlike the dangers from global warming, are real, quantifiable, and truly a matter of life or death.
Therefore, countries around the world and states in this country ought to promote greywater reuse in populated areas as a viable option to conserve water. Greywater can be recycled to irrigate lawns, irrigate parks and golf courses, fill fountains, and flush toilets in buildings and houses. Some home builders are already jumping on the "green" marketing band-wagon to sell their eco-friendly pre-fab houses ( The California companies manufacturing the homes mentioned in the article are selling houses that already include rainwater collection devices, greywater reuse treatment and plumbing, and tankless water heaters.
In terms of policy, states (or countries abroad) can offer tax rebates to people that buy grewater treatment devices for domestic or commerical purposes, can discount property taxes of those individuals or corporations that recycle greywater for flushing toilets, and can promote water conservation at public fairs that highlight the effectiveness and cost savings of greywater reuse. Austin Water Utility even has a toilet replacement program where you can receive a water efficient toilet that uses 1.6 gallons per flush for your old bowl ( Even though some urban areas in Florida, California, and Texas are improving conservation measures, more studies need to focus on cutting plumbing (requires energy to move water) and treatment (requires energy) costs. Currently, the price of water in the U.S. is too low for greywater reuse to gain widespread acceptance. People in the U.S. do not value water enough to go out of their why to save or recycle it.


Toby said...

Correction. The sentence referencing Austin's toilet replacement program should link to

Click Tappet said...

I think this is actually a really important and often overlooked topic - opportunities for greywater use and water conservation. When I studied abroad in Australia in 2006, people talked about water use and saving water all the time. Even three years ago, Melbourne was in stage 2 water restrictions and many other places were already talking about available options for wastewater reprocessing or desalination.
Water restrictions in Australia
vary from state to state but the situation across the country is the same - maximum possible water restrictions are already in place, which typically means cleaning only safety items on your car with water and soap from a bucket and no other outdoor water use. It was strange to come back to America where water use during a 'severe drought' meant lawn watering was only permitted every 3rd day.

I think we should take this opportunity to learn a lesson from Australia - let's not wait until freshwater reservoirs are nearly empty to finally stand up and do something about our consumption habits. While the last thing we want is for people to not pay their water bill because it's too expensive, as we've seen in this class, without an economic incentive, it's unlikely consumer behavior will change. Technology like this but for water use would at least alert people to how much water they consume.

Mandating waterless urinals and dual flush flushometers in all new construction and bathroom remodels, for example, could significantly reduce water use. Caroma, Australia's largest toilet manufacturer, sells dual flush toilets that exceed US federal standards and show that it is entirely possible to make profitable and effective toilets which use even less water (1.28/0.8 gpf instead of 1.6/1 gpf).

Not to go on too long about toilets...the big point is, there are so many opportunities for conservation, we need to implement some policy action which forces water conservation instead of spending that money on heavy-handed and energy-intensive technology to get fresh water where people need it.

Corey James said...

I agree with both the author and the other comment. There are two problems with Americans and their attitude toward water consumption/abuse. One of them is, like Click Tappet said, that we have not explored and implemented the best of technology to help solve this problem. In most cases, like the toilets and urinals, there is already technology out there that can be implemented without some large government program to spend ten years building a urinal that is not any better than the one from Australia. What we need from the government is policy that will motivate the public and industry to do the right thing.
The second issue that I see is one that was brought up by Dr. Webber in class. Looking at the "Top Ten Water Consumers" from last year as published by the Statesman, it is clear that there is a part of society that thinks that conservation or even reasonable behavior does not apply to them. Convincing these folks to change their ways will be difficult. I am certain that convincing Lance Armstrong to stop watering his lawn can only be done by appropriate policy and not the persuasion of a conservation minded public.(yes, even in Austin.) Like many other problems we face, those who are causing the biggest burden are the same ones who have the most influence on the system. The technology is the easy part of this problem, but changing the culture with some reasonable public policy will be a much bigger challenge.