I note yr reference is 2006. May still be relevant though, it's hard to tell.
These appear to be current available Standards (Note Reaffirmations). -
The relevant ones seem elusive (without $$)
This is from the most recent non-official publication I could find (2009 !) -
Assessment of plant and final water monitoring practices – Information on daily activities in water treatment plants should be obtained for the purpose of prompt identification of deviations or anomalies. Such information should include operating practices, measurement of flow rate, lime and alum doses, measurement and interpretation of turbidity, pH, temperature, chlorine dose and the state of the filters. Information may be obtained during a tour of the plant as well as interviews with process controllers and plant superintendants. In obtaining information, inspection of infrastructure and equipment noting unusual noises or smells is important. Process controllers are required to take notes of irregular observations in the plant logbook for eventual action by the plant manager or supervisor. Information on final water quality must also be obtained and recorded from various sampling points in terms of the concentration of free chlorine residual and the presence or absence of faecal indicator bacteria.
FWIW here are the current BRC requirements -
4.5.2 An up-to-date schematic diagram shall be available of the water distribution system on site, including holding tanks, water treatment and water recycling as appropriate. The diagram shall be used as a basis for water sampling and the management of water quality.
This appears to be the relevant, basic, current EC sampling requirement -
(d) in the case of water used in a food-production undertaking, at the point where the water is used in the undertaking
However the EC also offer what seems a useful, logical, compromise -
1. Sampling points shall be determined so as to ensure compliance with the points of compliance as defined in Article 6(1). In the case of a distribution
network, a Member State may take samples within the supply zone or at the treatment works for particular parameters if it can be demonstrated that there
would be no adverse change to the measured value of the parameters concerned. As far as possible, the number of samples shall be distributed
equally in time and location.
This appears to be the current SABS analytical requirements -
The maximum value for plate count would readily fail EC requirements.
Regarding sampling procedure (wat2) -
3. Sampling in the distribution network, with the exception of sampling at the consumers' tap, shall be in accordance with ISO 5667-5. For microbiological
parameters, sampling in the distribution network shall be taken and handled according to EN ISO 19458, sampling purpose A.
The useful description of sampling SOP previously included seems to have now been deleted.