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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
regulations, water stagnation (in sanitary installations with 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 on
The European standard EN 806 5 requires that those training those responsible for the water system,
sections of the installation that are used infrequently it is embedded and pursued in Germany
Stagnation prohibited 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 the programmes monitored by the Water Safety Group).
school holidays, campsites out of season, unoccupied
hospital rooms, etc. Training those responsible
helps to control bacterial
The German Directive of April 2013, Hygiene in proliferation.
Drinking Water Installations VDI/DVGW 6023,
requires purging to be carried out after 72 hours of
stagnation in a sanitary installation (this also includes
Bypass prohibited Circulating loops
WC cisterns). Note that the water in the bypass is not A circulating loop up to the point-of-use is not
sufficiently renewed. They are therefore prohibited. recommended. It doubles the length of the pipework
If an installation is not used for 72 hours, rigorous and therefore doubles the water volume. The biofilm
protocols are put in place. DELABIE sees this as a step surface is increased and, as a result, also the risk of
forward and proposes technical solutions to meet this
requirement (see opposite: electronic controls). bacterial development. Moreover, it makes it difficult
to maintain high temperatures at all points in the
circulating loop.
The German directive requires Finally, it also makes it difficult to keep the pipe run
purging to be carried out volume to less than the 3 litres recommended by
after 72 hours of stagnation. European directives. Indeed, if the water temperature
Measuring pressure in a circulating loop is less than 50°C or 55°C
(depending on the country), the water volume
Undersized pipework in the circulating loop must be included
The German regulation strictly prohibits oversized in the 3 litre maximum calculation.
pipework because they promote bacterial growth
by reducing the water velocity. A circulating loop up to the point-
DELABIE, along the same lines, recommends slightly of-use is not recommended.
decreasing the diameter of the pipes to increase
the water velocity to 2 m/sec. (likewise the French
regulation (DTU) recommends 1.5 m/sec.).
This measure prevents the excessive development Building Management Systems
Measuring the temperature of biofilm and helps to reduce the risk of contamination Contrary to popular belief, Building Management
without increasing noise levels. Systems are not recommended by European
directives as they can be complicated, difficult
to handle and extremely costly and do not take away
Oversized pipes are
liability if a problem occurs.
strictly prohibited.

Training relevant personnel

14 Solutions for Public and Commercial Places