Bacteriological Control

As Water Hygiene Specialists, the majority of our focus is on minimising the growth of bacteria, particularly legionella, within HVAC and Domestic Water Systems.

Legionella bacteria, when inhaled via water droplets, can cause the potentially fatal Legionnaires' Disease, a form of pneumonia. The guidance and work that we do is targeted at minimising the conditions that allow legionella to grow.

Pseudomonads also an issue, mainly as they create the conditions for other bacteria to grow as well as making the system less efficient.

During the building design, we will offer up-to-date, honest and technical advice to Building Services consultants, allowing them to specify the right equipment – such as Chlorine Dioxide dosing and UV disinfection, in the right place and to feel confident that they have provided a compliant design for their client, reducing the public health risk.

During the construction of a building, we ensure that the equipment provided is installed, commissioned and operated correctly as well as carrying out disinfection works.

Finally, following Practical Completion, we are on hand to support the client and ensure they comply with ACoP L8 and associated HSE guidance – whether than be assisting them with their legislative requirements, operating and servicing water treatment equipment or taking responsibility for tasks such as recording water temperatures or TMV servicing.

What types of water treatment equipment can be used to minimise legionella growth?

Chlorine Dioxide

The use of chlorine dioxide as a disinfectant for water systems has increased significantly due to both its effectiveness and its inclusion in the Health & Safety Executive’s publication, Legionnaires’ Disease – The Control of Legionella Bacteria in Water Systems – ACoP L8, as a suitable treatment for controlling and preventing the risk from legionella bacteria.

The ACoP permits the use of chlorine dioxide due to its effectiveness against planktonic and sessile legionella in water systems and the DWI prescribes a maximum value of 0.5mg/l for total oxidants in drinking water supplies and this level, if properly managed, can eliminate the presence of legionella bacteria in water.

Goodwater designs, manufactures, supplies, installs, commissions and maintains the Dorado Range of Chlorine Dioxide Treatment Systems – comprising the Dioxychlor III and Dioxychlor Plus units – which are a safe and effective method of delivering a continuous low level dose of chlorine dioxide into water service systems. When used as a continuous on-line treatment, it penetrates and effectively destroys biofilm and kills virtually all bacteria that may be present.

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The main benefits of using a Dioxychlor system are as follows:

  • Removes, and prevents formation of, biofilms
  • Provides a residual treatment throughout the water services
  • Unaffected by the pH of the water being treated
  • Simple to operate
  • Two systems available – proportional dosing or via continuous monitoring of treatment level present
  • Numerous fail-safes to prevent over or ineffective dosing
  • Full WRAS approval

UV Ultraviolet Disinfection

UV Disinfection is quick and reliable and the installed systems are easy to maintain. Apart from its bactericidal effect, UV treatment will not cause any chemical or physical changes to the medium being treated so does not impart smell or taint to the water unlike some chemical treatments. It can therefore be used very effectively with potable water systems for the removal of pathogenic micro-organisms such as legionella, pseudomonas and E.Coli.

The design of the Goodwater Tucana reaction chambers incorporate a unique flow management plate which has been developed through the use of computational fluid dynamic modelling in conjunction with biodosimetric testing. This latest design represents the next generation of UV technology. The advantage of this technology is that, unlike conventionally designed reaction chambers, the fluid passing through the Tucana reaction chamber receives a high minimum UV dose as well as an even higher average UV dose. The use of biodosimetric testing in conjunction with 3rd party validation in accordance with BS EN 14897 is used to confirm the effectiveness of the design.

The Tucana validated range of UV disinfection units is manufactured to exacting standards and includes the following features and benefits:


The main features and benefits of our UV range are as follows:

  • High quality 316L stainless steel reaction chambers
  • Validated flow management system in accordance with BS EN 14897 and to provide guaranteed minimum UV dosage
  • High performance UV lamps c/w high frequency, lamp power supply system
  • Continuous monitoring of lamp performance with lamp on indicator and LCD hours run meter
  • Lamp failure indicator c/w volt free relay output
  • WRAS approval to 16bar
  • Simple, low maintenance operation


More information on Legionnaires' Disease can be found at the links below.

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A contributing factor to biofilm and bacteriological growth is the presence of silt, sediment and other debris entering a water system from the incoming main. Reducing the level of these contaminants by installing a Goodwater Cygnus RRF backwashable filter on the incoming main significantly improves the water quality within the water services as well as increasing the efficiency of any UV disinfection units installed.


Contact us today to chat through your requirements

Our team can provide solutions including any or all of the above services and products to solve your problems and make a difference to your business whilst making sure you are fully compliant in all regards.