Recycling Day

By Dr. Mark LeChevallier – November 29, 2011 – Comment

Today is recycling day where I live – the day I’m supposed to put out bottles, cans and newspapers for pick-up and eventual recycling.  It’s important and I’m glad to do my small part to reduce the volume of garbage that might otherwise wind up in a landfill.  Equally important, though, is the growing need to increase the amount of water that we recycle and reuse in this country.

All water on Earth is eventually recycled and reused, of course. The water cycle  ensures that the planet’s finite supply of water is never “used up” but simply shifts phases at any given moment from liquid to vapor or ice and back to liquid over a period of time.

That doesn’t guarantee that we have an adequate supply of water when and where we need it, however.  Population growth and climate change together are increasingly resulting in water scarcity in many areas of the world, including here in the U.S., where we often take our water supply for granted. Texas and parts of surrounding states are currently in the grips of a catastrophic drought that is having devastating effects on agriculture and beef production. In fact, years ago government agencies warned that as many as 36 states will face water shortages of varying degrees by 2013.  Looks like they were right.

One step towards sustainability in areas where water demand is outstripping supply is water reuse, which is also called water recycling.  This is the term given to the process of treating wastewater to a high quality that meets state criteria for non-drinking uses. When you consider that drinking water makes up just 1% of overall demand, there is a huge opportunity to provide recycled water to meet the other 99% of demand, such as for irrigation, industrial use, toilet flushing, and fire protection.  Advancements in treatment technologies mean that water can be recycled and reused more efficiently than ever before.  It can be applied directly for the beneficial uses outlined above, or used “indirectly” where treated water percolates down to aquifers to replenish groundwater supplies. This indirect use is an increasingly favored approach over discharging wastewater directly to surface water supplies or ocean outfalls.

More than 2 billion gallons of water per day are already reused in the U.S., and that volume is growing at an estimated 15 percent per year.  Although that sounds dramatic, only about 6% of the wastewater in the US is beneficially recycled. (Compare that to Israel where over 90% of municipal wastewater is recycled!)  I’m looking forward to highlighting several examples of successful reuse or recycling programs in upcoming posts. Though reuse alone can’t solve water scarcity issues, it’s an environmentally sustainable and cost-effective tool that needs to be increasingly deployed.

I’ll end here for now, because it’s time I put my recycling bins out by the curb!