The carbon footprint of your water

Published Tuesday, February 28, 2017 in the New Brunswick Telegraph Journal and the Fredericton Daily Gleaner.

“Water has a carbon footprint?  Impossible – it’s made up of two hydrogen atoms attached to one oxygen.”

True, there’s no carbon in water.  But the water we use does indeed have a carbon footprint.  Here’s an overview of what it is, and what you can do to help reduce your share of it.

Embodied energy

Virtually every product or service has what’s referred to as ‘embodied energy’ – the energy that was used in the creation of that product or service, from start to finish.

For example, the embodied energy of a carrot at the grocery store would include sunlight, but also fuel for tractors and trucks; electricity for storage and processing; plus packaging, fertilizer and more.  The embodied energy of a Google search would include a portion of the energy it took to manufacture and install all those wires and computer servers that transmit and process your search, plus a portion of the massive amount of electricity it takes to keep the internet up and running.

Since so much of our energy comes from fossil fuels, a product or service’s embodied energy is essentially its carbon footprint.

The carbon footprint of water

The water that flows from our taps has embodied energy in four main areas:

Raw water extraction and treatment: the energy required to pump water from wells or reservoirs and through treatment plants.  Among NB’s three largest cities, Fredericton is lucky: its water is drawn from wells in the downtown area.  Both Saint John and Moncton pump their water from reservoirs 10 kilometers away. 

Distribution: the energy required to pump water through underground lines to towers, tanks and end users.  Distribution energy is often high owing to three factors.  First, water needs to be supplied to users at 30-80 pounds per square inch of pressure, and pressure takes energy.  Second, it takes more energy to distribute water over hilly terrain, as is the reality in Saint John and Fredericton.  Third, it’s estimated that, in the average municipality, 20-30 per cent of water is lost through leakage; the figure can be much higher with older systems.  Leaks mean a lot of wasted pumping. 

Wastewater collection: true, water runs downhill unaided.  But wastewater often needs a boost to help it get to the local sewage treatment plant, so lift stations – IE pumps – are required en route.  Fredericton has about 30 scattered throughout the city. 

Wastewater treatment: the energy required to run circulating pumps, compressors to aerate water in treatment lagoons and UV lights to disinfect water before it’s released.

Add everything up and it’s easy to see: every liter of water we use has embodied energy and thus a carbon footprint.  In the US, it’s estimated that four per cent of all electricity goes into pumping and treating water and wastewater.  (And, rural residents, don’t feel totally smug – unless, of course, your system runs on gravity.)

Lighten your footprint

How can you reduce your ‘water carbon footprint’?

  • Fix leaky faucets; they can lose up to 10,000 litres a year
  • Check if your toilet is leaking by placing a drop of food coloring in your toilet tank and seeing if any color seeps into the bowl; if so, replace the flapper (a simple job and a cheap part)
  • Turn off the tap while brushing your teeth; turn it off or run it at a trickle while washing your hands.
  • Install a low flow showerhead (and save on hot water too)
  • Replacing your clothes washer?  Make sure your new one is a high efficiency model.
  • Replace your toilet with a low-flow model, even a dual-flush low flow model
  • For the hard-core: when it’s yellow, leave it mellow...
  • If your municipality has flat water rates, lobby leaders for water meters so everyone pays in accordance with their usage.  It’s an up-front investment that typically leads to a 20 percent reduction in water consumption.

So use water as wisely as you can: to save on your water bill and reduce your ‘water carbon footprint’.