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/ Water quality regulations
EUROPEAN WATER QUALITY REGULATIONS
Regular flush Training
According to the French, German and English Understanding the problems associated with
regulations, water stagnation (in sanitary installations bacterial growth in water systems helps to limit
and mixers and taps) is a key factor in bacterial the risk of contamination.
contamination. Although French legislators have not yet focused
The European standard EN 806-5 requires that on training those responsible for the water system,
those sections of the installation that are used it is embedded and pursued in Germany
Stagnation prohibited infrequently should be flushed at regular intervals. (with three training levels, depending on the level
The recommended interval is once a week. of responsibility) and in the United Kingdom
All public and commercial buildings are affected, (with personnel competency and training
in particular schools and council buildings during programmes monitored by the Water Safety Group).
the school holidays, campsites out of season,
unoccupied hospital rooms, etc. Training those responsible helps
to control bacterial proliferation.
The German directive of April 2013, Hygiene in
Drinking Water Installations VDI/DVGW 6023,
requires purging to be carried out after 72 hours of
stagnation in a sanitary installation (this also includes Removable mixers and taps
WC cisterns). Note that the water in the bypass is not In addition to preventative measures, the HSE (Health
Bypass prohibited sufficiently renewed. They are therefore prohibited. and Safety Executive) recommends the use of mixers
If an installation is not used for 72 hours, rigorous and taps that can be easily removed for regular
protocols are put in place. DELABIE sees this as internal cleaning; a mechanical intervention
a step forward and proposes technical solutions that is effective for removing biofilm.
to meet this requirement (see opposite: electronic
controls). Circulating loops
A circulating loop up to the point-of-use is not
The German directive requires recommended. It doubles the length of the pipework
purging to be carried out after and therefore doubles the water volume. The biofilm
surface is increased and, as a result, the risk of
72 hours of stagnation.
bacterial development. Moreover, it makes it difficult
Measuring pressure
to maintain high temperatures at all points in the
circulating loop.
Undersized pipework
The German regulation strictly prohibits oversized Finally, it also makes it difficult to keep the pipe run
pipework because it promotes bacterial growth volume to less than the 3 litres recommended by
by reducing the water velocity. European directives. Indeed, if the water temperature
DELABIE, along the same lines, recommends slightly in a circulating loop is less than 50°C or 55°C
decreasing the diameter of the pipes to increase (depending on the country), the water volume
the water velocity to 2m/sec. (likewise the French in the circulating loop must be included
regulation (DTU) recommends 1.5m/sec.). in the 3-litre maximum calculation.
This measure prevents the excessive development of
biofilm and helps to reduce the risk of contamination
Measuring the temperature A circulating loop up to the point-
without increasing noise levels.
of-use is not recommended.
Oversized pipes
are strictly prohibited.
Building Management Systems
Contrary to popular belief, Building Management
Systems are not recommended by European
directives as they can be complicated, difficult to
handle and extremely costly and do not take away
liability if a problem occurs.
Training relevant personnel
6 Hospital solutions