Thursday, 27 May 2010

Waterprints -- by Hugh Robertson

Copied here with the author's permission, this was first published in the May issue of the Manor Park Chronicle.

Have you ever considered how much water is required to provide you with your morning cup of coffee – excluding the 125 ml in the cup? On average, 140 litres of water is used to grow the coffee, prepare the beans, package and transport them to your kitchen ready to grind. A “water footprint” or “waterprint” is a new technique that measures how much water we each use to sustain our lifestyles – everything from flushing a toilet to buying clothes to drinking a cup of coffee.

Ottawa River: photo Vince Alongi

Our personal or domestic water consumption for cooking, cleaning, washing and flushing is probably only 10 percent of our total waterprint. The food and manufactured products that we buy and the fuel and electricity that we use contain huge quantities of embedded or “virtual water.” Although we may only drink 4 litres of water, we actually “eat” and “consume” another two thousand litres daily.

Our waterprints are composed of 4 major categories:

  • Food
  • Manufactured products
  • Energy generation
  • Domestic
Water consumption in Canada breaks down roughly as follows:
  • Energy generation 55%
  • Manufacturing 15%
  • Agriculture 15%
  • Municipalities 10%
  • Mining 5%
Although it is important to cut our domestic water use, we are deluding ourselves if we believe that residential reductions alone will solve the planet’s water problems. Our waterprints are largely a function of diet, lifestyle and consumption patterns shaped primarily by income and wealth. Per capita, North Americans use more than double the European average and exponentially more than African countries.

Foods -- a major component of our waterprint -- are not all created equal. Crops such as soybeans and rice have a high footprint and, per pound, corn-fed beef uses ten times as much water as poultry production. Eating local produce in season and less meat can dramatically lower your personal waterprint.

Some countries are introducing labels that indicate the level of embedded water in food products. Cultivating fruits and vegetables in Florida and California is water intensive. Importing these products – with their high “virtual water” content -- raises the delicate question of whether we can refuse to sell water to the US in return.

Many consumer products contain high levels of embedded water. For example, manufacturing a cotton t-shirt requires 2,700 litres of water and a pair of leather shoes almost 25,000 litres. Consider applying the various Rs to your lifestyle purchases. Refuse, resist, reject or reduce your shopping impulses and recycle or reuse products, such as clothing by shopping second-hand when possible.

water pollution: scipeeps-com

Various forms of energy, primarily transportation fuels and electricity generation, constitute the largest component of our waterprint. The Tar Sands are notorious for the amount of water used to produce a barrel of oil – excluding the volumes of contaminated water that are flushed into Lake Athabasca after the refining process.

Soy-based biodiesel and corn ethanol use even more water. It is not just the fuel; vehicles are also water hogs. It takes 150,000 litres to manufacture an average sized car. When buying another vehicle, consider a reliable second-hand car. If you buy a new vehicle, drive it until it drops. Properly maintained with lots of TLC should ensure a life of 15-20 years for a quality vehicle. Go small and fuel-efficient.

Coal and nuclear power plants lead in water consumption and their efficiency measured in terms of water use and electricity generated is remarkably low. These disadvantages do not even include carbon emissions, construction and maintenance costs, and radioactive waste. As responsible citizens we should cut our consumption of electricity dramatically to reduce the huge volumes of water wasted in the generating process.

The amount of water on the planet is fixed. For millions of years the hydrologic cycle has been recycling the water supply through a continuous process of evaporation, condensation and precipitation. It is a myth that Canada has endless freshwater. If we consume more than the annual precipitation in the form of rain and snow, water levels will soon drop, as is happening in the Great Lakes.

A domestic water calculator from Go

Excessive use of water is one problem but contaminating our scarce water resources is another. In the hydrologic process, water is purified as it passes through the atmosphere and filters through the ground into the deep aquifers.

Not only are we depleting the aquifers by extracting large volumes of pristine water to green golf courses, for example, but we are also poisoning the groundwater by spreading agricultural chemicals, burying our garbage and pumping sewage underground.

Society has adopted an “out of sight, out of mind” attitude. The latest “bury our problem” approach – euphemistically called geo-engineering – is to sequester carbon dioxide in aquifers that have been pumped dry and also to store nuclear waste deep below the Canadian Shield. Not even the hydrologic cycle can purify groundwater once it has been contaminated with radioactive toxins and carbonic acid.

We are fouling the rain with the hazardous substances that we pump into the atmosphere. Glaciers, like aquifers, are also important repositories of pure water and they are being polluted with soot and other airborne contaminants that mix with snow. The side effects of our material lifestyles are overwhelming nature’s cleaning capacity.

Green algae, Lake Erie: courtesy NOAA

Our lakes and rivers have become repositories of another kind: we dump mine tailings, radioactive tritium, phosphates and mercury and many other industrial and agricultural chemicals. Lake Erie has a vast oxygen-starved dead zone and blue-green algae is threatening lakes across the country.

Water is a fundamental human and natural right. It has passed from generation to generation since time immemorial, constantly recycling and revitalizing itself. Water is our common heritage. It is our moral responsibility to protect a resource so vital to our own well-being and to the health of the planet and to the security of future generations.

See also Environment Canada's water use calculator,

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