Kitchen sink study reveals water use patterns in Europe


Stockholm, Sweden and Bonn, Germany — (METERING.COM) — July 10, 2012 – Dishwashing is responsible for over half of tap water used in the kitchen in countries in Europe, according to the results of a recent study, which also suggests that people who live alone consume double the water per person than those that live in a four or five-person household.

Although average water consumption data is available for European countries, detailed data on how water is used is limited. To this end the study by Paul Richter, standardization and customer satisfaction manager at AB Electrolux, and Rainer Stamminger, professor of appliance technology at the University of Bonn, was aimed to investigate which everyday kitchen duties consume the most water and how much water single person households consume compared to larger households.

Small water meters and webcams were installed at the kitchen sinks of 81 urban households across four European countries – 21 in Germany and 20 in each of Sweden, Italy and the U.K. These then recorded the amount of water used, and purpose, each time a kitchen tap was turned on over a two week period.

The researchers were able to identify specific uses of the water for 96 percent of the 25,000 observations. In each country, dishwashing accounted for at least half of the daily water consumption per person, and averaged 58 percent across the four countries. Cleaning, cooking and drinking accounted for around 10-15 percent each, except in Italy, where drinking water consumed just 2 percent, which may be linked to perceptions of tap water’s quality. Washing hands and “other” accounted for the remaining 5 percent and 3 percent, respectively.
As expected, single person households consumed more water on average per person than larger households. The difference was minimal between one to two person households, but grew larger with household size, with the average person living alone consuming approximately twice as much water in the kitchen as the average person living with three or four others.

Interesting differences between countries also emerged. Daily water consumption was highest in Italy, where the average person used over twice as much water (23.6 l) in the kitchen as the average person in Germany (11 l). This may be partly explained by Italian habits of pre-rinsing dishes with significant amounts of water before putting them in a dishwasher, and a tendency to use more water in cooking and for cleaning than observed in the other countries. Average daily water consumption in the U.K. was 19.8 l, and for Sweden the figure was 21 l.
The researchers concluded that water use patterns are hard to generalize with the large country-specific differences that were observed. However, the finding that dishwashing consumes by far the majority of water in the kitchen is crucial and hints at potential for significant reductions to be made through water conservation.

The study was published in the May 2012 issue of the journal Water Resources Management.