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" )

I would agree Charles, if they weren't also treating the water onsite!

http://www.wrc.org.z...A_2006_05_9.pdf

I would agree Charles, if they weren't also treating the water onsite!

 

http://www.wrc.org.z...A_2006_05_9.pdf

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   7 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.