Are there any requirements to test for Legionella in natural outside ponds(with fish in etc) /water features and what are the required tests/inspections?

I'm sure L8 mentions this., no time to check...

But the temperature is too low for legionella to grow so no risk - Wiels disease is another matter though!

http://www.hse.gov.uk/pubns/indg84.pdf

Where are legionella bacteria found?

Legionella bacteria are common in natural water courses such as rivers and ponds. Since legionella are widespread in the environment, they may contaminate and grow in other water systems such as cooling towers and hot and cold water services.

They survive low temperatures and thrive at temperatures between 20-45°C if the conditions are right, eg if a supply of nutrients is present such as rust, sludge, scale, algae and other bacteria. They are killed by high temperatures.

Source: http://www.hse.gov.uk/pubns/iacl27.pdf

Legionnaires disease is a disease caused by the organism LEGIONELLA PNEUMOPHILA, which is found naturally in water and soil where it is normally harmless. However, when it gets the right conditions of temperature, nutrient supply and pH, it multiplies rapidly, and if there is aerosol formation and a susceptible population, are all the ingredients are in place for an outbreak.

Surely the pertinent part is that it is found naturally, so as the original post concerns a natural pond then the control of legionella is not an issue for H&S in this scenario.

Does the water feature you noted include a fountain ?, this could be a source of aerosol, and does the pond have submerged lighting, which has been identified as providing a heating effect allowing growth in indoor fountains ?

Not sure what you could do about it, though.

Chris

The ponds have water features which create aerosols. My own thoughts are to monitoring temperature, ph , conductivity levels and dip-slids weekly using the levels recommended in L8 for water features. . with 6 monthly cleaning of the ponds and legionella and TVC sampling. If a positive results for legionella is detected isolate the spray features, remove fish, drain and clean. Refill and re-sample......

So are these water features natural or not????
L8 doesn't mention outdoor water features. This doesn't mean they can be ignored. A recirculating fountain from a shallow pond would be a potential risk were the spray to reach beyond the edges of the pond - as they sometimes do.

Fish for dinner anybody?

Please look at things in proportion as this is a natural environment where your control is limited otherwise we will have to close off every slow moving waterway/ fountain etc in the UK!

As an example a hazard in most workplaces is vehicle windscreen wash as that is a spray/mist and in certain conditions can be problematic but there is nothing U can do about it except to stop the process of cleaning a window in this way; and no U will not be able to control that problem either!

My advice is to look at what is reasonable all things considered and look to manage your high risk areas first

OMG,

I have been SCUBA diving in some seriously mucky water all over the UK, and I must have swallowed a few litres, I don't think I have ever contracted Legionairres disease....

Errr, summer, what is that?

Ron,
In terms of Biocides, I understood that the bacteria develops an immunity after a period - if you don't alternate the Biocides being used?!

This may be of interest:

http://www.erentals.co.u...ires-disease-181339.html