Sterile water sampling to determine the potability
Hi everybody, so we are upgrading our entire water treatment process. Our water source is what the regulatory body will refer to as "raw water". So we have to treat it to ensure that it is potable. We do get a positive result now and again. As I learned we have to flame and sterilize a sample point before we can do sampling of our water. There is now a question mark around the sampling in order to ensure that we do not get false results. We take in fresh produce to process - its washed, cooked and aseptically filled. Now,
1. Can one sample water from a regular tap inside of the facility to determine the potability of the water instead of just sampling at the main tank from where the water is treated. 2. If predetermined sample points have to be installed - what type of valve is the most hygienic? 3. Can someone please provide me of a sampling procedure so that I can see how far I am off with mine because I am now a bit unsure about my procedure. 4. Do I need to test the final products for MRL's? Best regards
Nope, you cannot
You need to test the water from the point directly after treatment to ensure that it is clean
AND you need to test from varying spots within the facility to ensure the water lines aren't a source of contamination
If you're concerned about MRL's, then ideally you're testing raw untreated water prior to treatment, some things cannot be removed with traditional water treatment, so I would suggest that is actually step 1
My first career was environmental technician (water/waste water treatment)
Nope, you cannot
You need to test the water from the point directly after treatment to ensure that it is clean
AND you need to test from varying spots within the facility to ensure the water lines aren't a source of contamination
If you're concerned about MRL's, then ideally you're testing raw untreated water prior to treatment, some things cannot be removed with traditional water treatment, so I would suggest that is actually step 1
My first career was environmental technician (water/waste water treatment)
Hi Scampi,
IIRC the EC Standard SOP recommends to sample at operational distribution points. That's what BRC requested from us. However I agree that directly after treatment is also a valuable assessment point from a contamination POV.
Logically it depends on what the SA Standard says.
Also never seen a flame etc requirement. Normally IMEX need to sanitize the connection then time flush the sampling point.
PS @ Zahn, it's normally not expected to be 100% "sterile" (although SA drinking water is maybe "special" :smile: )
I would agree Charles, if they weren't also treating the water onsite!
I would agree Charles, if they weren't also treating the water onsite!
Hi Scampi,
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). -
wat0(2021).pdf 139.17KB 8 downloads
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.
wat1,2009.pdf 397.71KB 3 downloads
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.
wat2,2015.pdf 289.93KB 5 downloads
This appears to be the current SABS analytical requirements -
wat3,2015.pdf 341.55KB 4 downloads
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.