National Tap Water Consumption
Survey for England & Wales
Key Intake and Exposure
- Accent was commissioned by Defra to undertake the National
Tap Water Consumption Survey in order to update the 1995 survey. The
overarching objective of the survey was to provide a robust
estimate of the average total daily tap water consumption in England
and Wales and the proportion of total daily liquid consumption
that this represents, and to detect whether there had been a change in
average consumption of tap-water based drinks since the previous survey
- As well as providing the latest picture on drinking water
habits, the survey asked other exposure related questions at the same
time, including questions about showering and bathing, whether
consumers would reject water based on aesthetic considerations and
whether they would follow “do not drink” or
- The whole study took place over two phases: the first was
undertaken in Spring 2008 and the second phase in summer 2008. The
purpose of the second phase was to determine whether consumption of tap
water was greater during the summer than the spring. This report
details the findings of the second wave and compares the results with
the first wave and with earlier surveys. Each wave comprises interviews
with a target of 1000 households, where possible, the same households
were used in both waves. The surveys used three different survey
instruments as follows:
- initial Head of Household/Chief Organiser
- individual competent Household
- all competent Household members to complete
- In order to maintain consistency with the
previous survey, a two-stage sampling strategy was adopted to select
and recruit households. The first involved selecting the same ten
planning regions as those used in the 1995 survey, across England and
Wales. The second element was to identify, as near as possible, the
same local authority districts used previously.
- When assessing the comparative consumption data
(in terms of drinks’ consumption and water used for baths and
showers) the following differences between the survey profiles
should be noted:
Direct comparisons are possible, therefore, in the
consumption data between the adult data for the 1995 and 2008 surveys.
Other consumption comparisons between phases have been presented, but
the different profiles of the sample need to be borne in mind.
- 1978 survey: the consumption of children was
included in the overall sample, with children being classified as aged
0-17 and adults as aged 18+
- 1995 survey: the consumption of children was
included in the overall sample, with children being classified as aged
0-15 and adults as aged 16+
- 2008 survey: the consumption of children was
not included in the overall sample, with adults being classified as
Valid comparisons can be made between the two phases of the 2008 study
and on the majority of the other data presented within the report
however, ie for all general household behaviour and trends, as the
targets for this element of the study were consistent across all phases
(ie the Head of Household).
Key Conclusions on
Consumer Behaviour, Perceptions and Observations
- Across the whole sample there was a total of 79,117 drinks
consumed in the summer months compared to 76,621 in phase one, an
increase of 3.3%. The 1995 report did not report the total number of
drinks consumed across the adult population, so it is not possible to
make any comparisons between the two surveys.
- The arithmetic mean of the total daily liquid consumption,
using weighted data from phase two, is 2.003 litres per day (lpd)
compared to 1.931 lpd in phase one. This represents a marginal and
insignificant increase 0.072 lpd (3.7%) from phase one and compares to
the 1995 and 1978 estimates of 1.713 lpd and 2.042 lpd respectively1.
As the 1995 survey was only carried out in late winter/early spring it
is only possible to make valid comparisons with phase one of the 2008
survey, which was carried out at a similar time of year. There is an
observed difference of 0.218 (11.29%) between phase one of the 2008
study and the 1995 survey which, when subjected to statistical
analysis, is a significant difference.
- The arithmetic mean of tap water consumption in phase two
was 1.329 lpd compared to 1.284 lpd in phase one. This represents a
small and insignificant increase of 0.045 lpd (3.5%). The adult
consumption of tap water in 1995 was 1.275 lpd and 1.113 lpd in 19782.
As stated above, valid comparisons are not possible between the second
phase of the 2008 survey, carried out in the summer, and the 1995
survey. However, the observed difference between phase one of the 2008
survey and the 1995 survey is therefore a statistically insignificant
increase of 0.009 lpd (0.7%).
The latter does not include data for 16-17 year olds who were
considered children in the 1978 survey
2 As above.
- The proportion of tap water in drinks increases with age,
such that those 40 or over consume the most tap water, while the
youngest age groupconsumes the least. As with both the previous
studies of 1978 and 1995, the survey has shown that men drink more
liquid overall, but women drink more tap water.
- Analysing water consumption by people’s weight is
a new feature in this study and is the first time such data has been
collected. The data is taken from the consumer diaries and the results
below show that, in terms of overall liquid consumption, the results
are consistent with phase one in that those who weigh less consume less.
- The mean tap water consumption of boiled water drinks eg
tea, coffee and HMD, was 0.827 lpd in the spring survey and 0.552 lpd
on the summer survey. This represents a significant reduction
of 33% in the mean tap water
consumption of boiled water drinks and reflects the fact that
considerably less hot drinks were consumed in the summer.
- For the first time, this study has captured the liquid
intake from sports bottles. While still a small proportion compared to
some of the other containers used for consuming drinks,
respondents consumed 0.025 lpd from sports bottles.
- Across the sample the number of baths taken by respondents
in phase two (summer) showed a marginal decrease (1%) compared to phase
one (3181 cf 3221). Whereas the number of showers recorded showed a 6%
increase in phase two compared to phase one (7576 cf 7143). These are
the first data gathered in this respect.
- In terms of the quality of tap water, the vast majority of
households in phase two have not had any problems with the quality or
appearance of tap water in the last 12 to 18 months. In fact, there
were even fewer people in phase two, compared to phase one, who had had
water quality problems. Both phases showed a smaller percentage of
households who had had water quality problems than in1995.
- Where there were water quality issues, people were more
cautious in phase two about using tap water for making drinks and
brushing teeth. The increased caution in peoples’ behaviour
is thought to be mainly driven by an incident involving the issue of
advice to boil water in Northampton. The vast majority in phase two, as
with phase one, (89% cf 93%) said they would follow the advice
completely when they received ‘boil advice’ or
‘do not drink’ notices.
- Exactly the same proportion (97%) in phase two reported
using tap water for making drinks as in phase one; this compares to 99%
in the 1995 survey. The same is true of those households that use the
kitchen cold tap for making drinks or drinking water, where 97% in both
phases reported doing this, whilst 11% in phase two (cf 12% in phase
one), said they used the kitchen hot tap to make drinks. This compares
with 95% and 3% respectively in the 1995 study, and 95% and 8% in the
1978 study who used the cold and hot water taps to make drinks.
- There has been a reduction in the number of households, 49%
in phase one to 41% in phase two, reporting that someone within their
household filled sports bottles with tap water to drink when they were
not at home. As with phase one, the vast majority reported that it was
one or two people who consumed tap water in this way, 88% in phase two
compared to 85% in phase one.
- There was a slight reduction from phase one to phase two in
the number of people who reported owning various appliances like water
filtering jugs and cold water dispensers in fridges. This is possibly
due to the ‘top up’ sample added to phase 2 owning
fewer of the listed appliances. Notwithstanding this, phase two shows a
consistent pattern to phase one compared to 1995, where there has been
a significant increase since 1995 in the proportion of people who own
water filtering jugs, as well as a significant decrease in those who
own soda stream type appliances and teas made machines.
- There was little difference between the two phases in terms
of those who used any extra form of water treatment. Around three
quarters, (76% in phase two cf 74% cf in phase one), did not use any
extra water treatment process. The proportions of people who used
different water treatment processes were virtually the same between the
two phases where nearly one fifth (18% in both phases) filtered the
water and one eighth (13% phase 1 and 12% phase 2) boiled the tap water
(allowing it to cool before using it). In 1995 only 9% filtered their
tap water, so the 2008 proportion represents a significant increase
from the last survey.
- Again, there is little difference between the two phases in
the first use of tap water in the day, where around three quarters (73%
in phase one and 74% in phase two) washed and/or used the toilet before
using tap water to prepare a drink.
- The face to face surveys showed that, in phase two, a total
of 46% of households used bottled water for drinking; this compares
with 44% in phase one and 30% in 1995. There is therefore no real
difference between the two 2008 phases, but they do represent a big
increase since 1995. The second phase is also consistent with the first
phase in that many more households drink still bottled water than its
sparkling counterpart. Around a third of households (33% in phase one
and 35% in phase two), a significant increase from a quarter of
households in 1995, consumed still bottled water and fewer than one in
ten (8% in phase one and 7% in phase two) consumed sparkling water,
which is half the number of households than in 1995.
- Although the number of households drinking bottled water
increased, the actual number of people drinking bottled water, as
indicated by the self completion surveys, has remained fairly
static between the two phases. If
anything, there are slightly fewer consumers of bottled water in 2008
compared to 1995. However, the 2008 study does show that more people
say they drink more bottled water in the summer now than said they did
- There were a variety of different bottled water brands
mentioned, with two imported brands being reported as being most
frequently consumed. Supermarkets’ own brands were also
reported as being quite frequently consumed, particularly where
sparkling water is concerned. It is unclear to what extent bottled
water acts as a substitute for drinking tap water.
- Although the number of cups of tea and also coffee has
dropped between the Spring and Summer waves of research, the
proportions stating that they consume tea and coffee has largely
remained the same between the two phases, which means between two
thirds and three quarters say they drink about the same as they did
five years ago. These proportions are not dissimilar to the 1995 study.
- Again, although the diary data showed that there were
changes in the actual number of showers and baths taken between the
Spring and Summer waves of research (with the number of baths down and
the number of showers up), the actual proportions of people taking
showers and baths remain similar, with the majority of respondents
reporting using both. In both phases, over four fifths (82%) said they
used showers and just under three quarters said they used baths (74%
Copies of this report may be available as an Acrobat pdf download under the 'Post 2000 Reports' heading on the DWI website.