Water Quality- legal compliance

Hello All

I hope the knowledge in this forum can help with a query I have....

We use mains water on our produce packing site. This is then used in barrel washers to wash off mud. This water is then sent ot an onsite water treatment works which is then cleaned and tested to potable water standards before being re-used in barrel washers.

This returns water is tested to potable water standards for C.O.D, TVC, Coliforms, E.coli etc. The question is what is the legal obligation for the quality of this water, as it is being used to wash dirty product, and is recycled water?

Testing is being done but we do not have any parameters to work with which would suggest when we should be raising concerns. Obviously Coliforms/ e.Coli are an issue but how do you judge the risk, and what is the legal side? Any and all help appreciated on how to set this up to work in a suitable manner.

I'm no water (nor micro) expert but I'm ok at HACCP so my question is; what is the next step after you've washed the mud off these veggies? Excuse my ignorance but what is the standard for coliforms and E. coli you're working to now? Is it <10 and absent?

These are the criteria for potable water (page 35 onwards), which you may already have.(I think they are still current)

I would suggest that these should be the maximum levels that you should aim for.

Answering GMO's question about the use of the vegetables may lead you to aim for tighter criteria. For instance, are the vegetables then ready to eat or are they peeled and boiled?

You say that the water is cleaned on site. Are there any chlorination or filtration systems involved? Monitoring these should be included in your HACCP study.

The primary water source should also be looked at in your HACCP. Surface water sources are prone to Cryptosporidium and Gardia which are not easily removed by chlorination.

Don't forget the non microbiological parameters as well - clarity and taste are basically free tests that are often overlooked.

If you are dealing with any major retailers or other high profile customers, they may have their own requirements that you need to factor in.

Dear Foodworker,

Thks for the document. Well illustrates the non-simplicity of "drinking water".
One (micro.) comment on the data (see following attachment) -

coliform.png   41.1KB   37 downloads

I believe a criterion (notwithstanding the comment in main text) such as stated for No.4 is unvalidatable within the technical interpretation methodology as currently in use.

it probably dates back to Tables such as McCrady's original publications ca 1915+ despite the current referenced method being attributed to ISO.

The EC have a similar set of water micro. specifications but, fortunately, (from memory) presented (mostly) in more practical style. (on the net somewhere I think.)**

Rgds / Charles.C

PS Of course, the regulatory authorities may have some cunning footnote somewhere which interprets "zero"

PPS - here is an example from BAM to illustrate the point

MPN table.png   14.6KB   38 downloads

ADDED - After some browsing, it is likely that the result quoted in standard derives from a membrane filter (MF) counting procedure. The result "0" should perhaps be more meaningfully stated as the ubiquitous "Not Detected". No idea as to the sensitivity / accuracy of the method but the large sample size is obviously beneficial.
Hopefully ads's samples all give zero.

** Sadly, the EC directive also favours "0".