Other Considerations

Tiosan is, we believe, the best chemical currently available for dealing with the Legionella / Biofilm problem. It will work well providing the correct concentration of the chemical reaches every part of the water system.

Before applying Tiosan you should check the water system for obvious dead legs - look out for areas where the pipework has been modified and a section of pipe still has water in it but is not part of the main flow.

In industrial premises look out for duty/standby pumps where one pump is used and the other is valved off. Look out for washing machines and dishwashers, which are rarely used.

The pipework connecting these to the main flow will be full and may have been static for many weeks. It is obvious that Tiosan cannot get into dead legs. Where possible open the flow to dead legs eg. allow hoses to run.

If all dead legs can be eliminated Tiosan should remove Legionella from a water system. Regular applications of Tiosan will ensure that the biofilm will not return. We would recommend treatment every 6 months if the water distribution pipework is mainly metal and every 4 months if the water distribution pipework is mainly plastic.

Good Legionella control is down to good plumbing practice and compliance with the Water Supply (Water Fittings) Regulations 1999. This includes the prevention of backflow, the use of approval materials for pipework, water fittings and jointing materials. General issues of design, sizing, layout, construction and commissioning are discussed in BS6700:1997.

Hot and Cold systems should be designed to aid safe operation by preventing or controlling the growth of Legionella and to allow easy cleaning and disinfection.

Appropriate tests should be carried out to validate the efficacy of the process.

Natural rubber, linseed oil based jointing compounds, and fibre washers should not be used, use only WRC approved materials.

Use low corrosion metals if possible.

Ensure water storage tanks are covered with a well fitting lid, with insect screens fitted to any pipework open to the atmosphere.

Multiple linked tanks should be avoided.

The diaphragms in accumulator vessels should be accessible for cleaning.

Point of use water heaters with minimal water storage should be fitted.

Minimise the storage of cold water.

Cold-water storage tanks should be sited in a cool place and insulated to protect from extremes of temperature.