1. To Sample, or not to
Sample?
- By Nemco Utilities
(www.nemco-utilities.co.uk)

2. To Sample, or not to Sample?
With the exception of high risk processes such as cooling
towers and evaporative condensers the issue of whether or not
to take either routine samples, or at the point of risk
assessment, from standard domestic water systems has been
and continues to be a topic of much debate. It is hoped that the
upcoming British Standard for risk assessment will shed some
light, or at least some standardisation, on specific
requirements though early indications show this may not be
the case.
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.

3. To Sample, or not to Sample?
ACOP L8 (Approved Code of Practice for Legionnaire’s
Disease) states that routine water sampling is not a
requirement, except in the following circumstances;
1. Where biocides are used and distribution temperatures are
reduced
2. Where control levels are not consistently achieved
3. In an outbreak or suspected outbreak scenario
4. In hospital wards with ‘at risk’ patients
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.

4. To Sample, or not to Sample?
Despite this a large number of organisations spend vast
amounts of money on water sampling every year and in some
instances rely purely on test results with the absence of any
other control mechanisms. What we do know is that Legionella
are naturally occurring bacteria and in any given building if we
look long enough and hard enough, and take enough samples,
the bacteria will be found. In addition to this, simply taking a
few samples and getting negative results does not mean that
water is safe.
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.

5. To Sample, or not to Sample?
All that water sampling will tell us is if there are bacteria there
on that day at that point in time, they may subsequently be
flushed away with the next use of the outlet, indeed the
majority of positive samples relate simply to outlet
contamination rather than a systemic problem with the water
system. Is it then better to spend time and money managing
the conditions suitable for growth rather that testing to see if
they are there or not?
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.

6. To Sample, or not to Sample?
Certainly processes deemed to be ‘high risk’ or those that meet
the chain of events should be subject to a regular water sampling
regime such as paint plants and those domestic systems that
have proved problematic in the past. A good example being an
elderly care home with old corroded pipework and a history of
positive samples, this would certainly meet the criteria of
containing ‘at risk’ individuals and possibly not meeting the
necessary control levels as often older buildings cannot afford the
installation of TMVs (blender valves) at all outlets meaning that
temperatures have to be reduced to prevent the creation of a
scald risk – surely a case for water sampling?
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.

7. Nemco Utilities Limited
Address Email:
Nemco Utilities Ltd  info@nemco-utilities.co.uk
12 Kempson Way
Hillside Business Park  sales@nemco-utilities.co.uk
Bury St Edmunds  accounts@nemco-
Suffolk utilities.co.uk
IP32 7EA
Website: http://www.nemco-
Telephone: 01284 724503 utilities.co.uk/
Fax No.: 01284 724826
It remains the case that there are no hard and fast rules precisely when and how often samples should be taken – if
in doubt refer to the risk assessment or contact us at www.nemco-utilities.co.uk for assistance.