Does Recycling Waste Precious Water?




Photo credit: jcheng @ Flickr

We recently received the following comment from a reader: "The greatest saver of water for families is to stop trying to recycle. Each time you wash out a can, bottle, or plastic container, you are wasting over half a gallon of water. In California, 37 million people can easily waste 37 million gallons of water daily."

My fellow writers asked me to take this question. So, does it use more water to recycle than to simply throw something in the trash?It is true that the rinsing out of jars, cans, and other containers uses water. We could assume that properly rinsing out a 15 ounce can takes about 15 ounces of water. If we assume one can per day this adds up to 43 gallons per year per person, or 12.9 billion gallons per year in the US. Add the rinsing of glass and plastic containers and we are looking at a lot of wasted water.

Do you even need to rinse?

Some people make sure that there recyclables are absolutely clean (hi dad!), which uses a lot of water in the home but reduces the need for cleaning in the recycling plant later, not to mention that it also reduces the transport weight (and therefore greenhouse gas emissions). Other people do not rinse at all, while most are somewhere in between.

Most recycling companies will ask you to rinse containers that held food. This not only reduces the amount of mess and stink that they have to deal with in the sorting facility, but it also reduces the level of contamination. When materials are recycled they are first separated, oftentimes shredded, rinsed to remove labels, bugs, remaining food waste, etc., and then they are melted down (in the case of plastic, glass and metals). The melting process not only burns off any remaining glue, ink, and contaminants, but also any remaining food waste.

Can you improve the way you rinse?

If your idea of rinsing is to blast the debris down the sink with hot tap water you have room for improvement. First begin by mechanically scraping food waste into your compost bucket (you have one, right?) or trash. Then save the container until you are done with the dishes and use your dirty dish water. This way you will be using water that would be going down the drain anyway. If you don't have any dishwater handy don't use hot water, cold will do just fine.

What other reasons are there for recycling?

It turns out that recycling actually saves water. This is because the extraction of virgin raw materials and manufacturing them into single use packaging uses quite a bit of water. Recycling reduces the need for materials from virgin sources and therefore reduces water use.

For some help on the numbers I turned to James Norman, a life cycle analysis expert and the Director of Research at Planet Metrics. A small mason jar weighing 185 grams requires about 1.5 liters of water to manufacture from virgin materials and a 200 gram "tin" can requires 9.2 (steel) or 13.7 liters (aluminum) of water to manufacture from virgin materials!

In conclusion, rinsing can be done in a way that wastes no water at all and recycling saves much more water than is used in even the most wasteful rinsing. So reduce your consumption of single-use packaging materials, reuse them where possible, and keep on recycling the rest!

Ask Pablo is a weekly column that aims to answer your pressing eco-quandries. Want to ask Pablo a question? Simply email Pablo(at)treehugger(dot)com. Wondering why Pablo's qualified to answer? As the Vice President of Greenhouse Gas Management at ClimateCHECK, he helps major corporations measure and manage their greenhouse gas emissions.
Additional Resources on Recycling
TreeHugger Forum on Rinsing Recyclables
iRecycle iPhone App Makes Local Recycling a Breeze
Recycling is Bullshit

Tags: Aluminum | Composting | Disposable | Drinking Water | Environmental Footprint | Life Cycle Analysis | Recycling