Some of the claims were true; others not quite. Some claims are recent; others are ancient and should have been dismissed long ago.

It is likely that designers and program professionals will encounter myths from time to time, and they should be able to identify them. It is hoped that this article will set the record straight on some popular myths.

Let’s start by defining a term that is gaining attention – ‘greenwashing’, the act of misleading consumers regarding the environmental practices of a company or the environmental benefits of a product or service.

In green building initiatives, claims of water savings through the use of a specific products or practices that are unsubstantiated or based on suspect ‘engineering estimates’ would be examples of greenwashing.

The excellent paper Six Sins of Greenwashing from TerraChoice reports on a study of more than 1,000 products and the false or misleading claims of environmental benefits. The report identified the following sins:
• The hidden trade-off
• No proof
• Vagueness
• Irrelevance
• The lesser of two evils
• Lying

We see some evidence of all six in the plumbing and water efficiency sector – refer to the following examples.

Myth: Sensor-activated lavatory taps save water over manual taps (sin of no proof).
Reality: We have yet to see an independent scientific study that validates this claim. On the other hand, there are four ‘real world’ field studies demonstrating that manual taps are actually more efficient.

The sanitary merits of ‘touch-free’ fixtures are without question, and manufacturers should confine their claims of benefits to that single attribute.

Myth: Tankless water heaters are more water-efficient than storage tank heaters in residential applications (sin of fibbing).
Reality: Here is an example of marketing and sales personnel exaggerating the benefits of their product by claiming savings that do not exist.

A recent Australian study found increased water waste associated with tankless heaters. In addition, there is evidence that people actually use more water by taking longer showers fed by a tankless heater. (In fact, some websites promote the fact that you can take longer showers without ever running out of hot water.)

What’s more, tankless heaters generally require a minimum flow rate through the unit to activate the heating components. In these cases, the first flow from a tankless water heater is cold, resulting in a longer waiting time for hot water.

Myth: Alternate-day watering of the lawn or garden saves water (sin of no proof).
Reality: Most experts agree that watering deeply once or twice a week is far better for the health of your lawn than frequent shallow watering, as deep watering promotes deep root growth. Many water efficiency experts believe odd/even restrictions promote over-watering by reminding people to water every second day.

Myth: Residential use of rainwater tanks will reduce peak summer irrigation demands (sin of no proof).
Reality: Many councils rebate rainwater tanks.