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.
Equipment FAQs
Our Equipment FAQs section is designed to help all our existing and future customers learn more about water treatment equipment, whether it be interpreting the various standards and regulations that surround our industry or just giving useful tips on how to solve a problem. The question list is evolving, so if you can't find what you need please call us or get in touch using the contact us form located at the bottom of the page and our sales team will be more than happy to help.
Although there is no formal requirement to do so, the installation of an auto-backwash filter on the mains represents good housekeeping and is extremely commonplace.
HSG274 Part 2 highlights the potential for bacteriological growth within water tanks containing sediment and debris that has entered via the incoming mains supply. Reducing the ingress of this debris – through the use of filtration on the mains – is therefore advisable to minimise this issue and maintain good overall water quality.
For more information check out these videos on our YouTube channel:
Dissolved calcium and magnesium found in mains water supplies forms scale within pipework systems, particularly in hot water services, that cause the following problems:
- Reduced heat transfer resulting in energy inefficiency. Just 12mm of scale on a heat exchanger will increase energy costs – and the water heater’s carbon footprint – by 65%
- Operational issues such as lower flows and damage to hot water generation plant, showers and TMVs.
- Creation of an environment which encourage the growth of bacteria such as legionella.
For these reasons, some method of scale control is extremely important in hard water areas.
This depends on a number of factors.
Base exchange water softening removes the calcium and magnesium that causes scale and is the only treatment that guarantees no scale will form. Water softeners can be large and treated water is not suitable for drinking so consideration needs to be given to their location.
A physical water conditioner creates a temporary and fragile treatment whereby “soft scale” is generated, the majority of which passes harmlessly to service. However, this “soft scale” can cause some operational difficulties in certain conditions. Water conditioners are in-line and maintain drinking water quality.
Typically, we would recommend water softening to ensure scale does not form but the most appropriate treatment for each site differs. Please contact us to discuss your application in more detail.
The treatment generated by a physical water conditioner will typically last approximately 48 hours although this is affected by turbulence, water temperature and how frequently the water is being used.
Legionella is a bacteria commonly found in water systems that can cause Legionnaires' disease, a potentially fatal form of pneumonia. The Health & Safety at Work Act (1974), ACoP L8 and HSG274 provide detailed guidance on how to design, install, manage and treat water systems to minimise the risk to public health that could be caused by legionella.
Other bacteria can also cause health issues as well as form biofilms that provide breeding grounds for legionella to grow. A good standard of water hygiene is vital to protect building occupants from illness.
The latest BSRIA guide on closed system water quality recommends the use of sidestream filtration in systems over 2,500 litres in volume, for the following benefits:
- Improve and speed up the initial pre-commissioning flushing regime.
- Remove suspended solids present in the system following commissioning, or that may be introduced due to inadequate maintenance, that can reduce flow and damage terminal units and boiler/chiller plant
Sidestream filtration is a key factor in maintaining long-term water quality within closed systems.
Ref: BSRIA BG 29/2021
The aforementioned BSRIA document advises that 5% of the re-circulating flow should pass through the sidestream filter. However, consideration should also be given to the system volume to ensure the unit is not over/undersized.
Ref: BSRIA BG 29/2021
The Goodwater Dioxychlor III system is usually installed on the building’s incoming main and introduces treatment proportionally. It contains numerous failsafes to prevent over or inaccurate dosing and can be used in conjunction with a stand-alone chlorine dioxide monitoring cell. It is a reliable system for use in buildings with frequent water consumption.
The Goodwater Dioxychlor Plus system is a designed to continuously re-circulate the water in a cold-water storage tank while also measuring the chlorine dioxide level within this re-circulating water. As measured treatment levels drop – either due to tank water being used or mild “gassing off” – the Dioxychlor Plus doses appropriately to ensure that the pre-agreed treatment level is maintained. It is a sophisticated system complete with various alarms and system shutdowns to provide a consistent, recordable level of treatment and is particularly beneficial in buildings that have large stored water volumes and/or erratic water usage.
Correctly sized UV disinfection units kill in excess of 99.9% of bacteria that pass through them, are in-line so require no floor space, and are low maintenance. They do not provide any treatment downstream which leaves the potential for re-contamination, particularly in areas of low use.
It is important that all treatment equipment using UV light has been independently validated to comply with BS 14897 to ensure that the units are fit for purpose and are verified to provide the treatment levels stated.
Chlorine Dioxide is an oxidising biocide that has been proven to be extremely effective in killing bacteria and preventing the formation of biofilms (as well as removing those that are existing) within which bacteria can thrive. It offers exceptional protection against microbiological activity throughout a water system. Recommended for use within HSG274 and an alternative to traditional thermal disinfection, it is a system that can reduce energy consumption and costs while maintaining excellent water hygiene.
Dosing systems will take up some floor space and require operation and maintenance in order to be fully effective.
Ref: BSRIA TN 2/98 Chlorine Dioxide Water Treatment
The residence time of chlorine dioxide in a treated system will be affected by a number of factors such as the temperature of the water, how and where the chemical is applied and how dirty the system being treated is. Under typical operational conditions we would expect the treatment to still be effective 24-48 hours after being added to the system.
Any bacteria in water passing through a correctly sized UV disinfection unit will be effectively killed during its passage through the unit. However, the disinfection effect will not persist once the water exits the chamber. The effect is said to be non-dispersive.
BS 14897 is essentially a testing protocol that provides a set of requirements – and a stringent procedure – for the testing of UV disinfection devices.
The purpose of this British Standard is to verify a UV dose of 40mJ/cm2 is achieved at the end of the lamp life, at specified (and varying) flow rates and UV transmissions. The testing protocol also includes the use of Bacillus bacteria within a biodosimeter, to verify that bacteria are killed when operating at these flows and UV transmissions. Units that have been tested to this British Standard can state operating flow rates and UV doses, based on differing UV transmissions, which have been independently verified. The units have also been proven to have performed safely under these conditions.
Goodwater is proud to supply the market leading Tucana range of Ultra Violet disinfection units, which has been successfully tested (and independently verified) to this standard, as well as being fully WRAS approved. The unique Flow Management System within the Tucana units is key to their efficiency, please see the link below for a video demonstration.
For more information check out this video on our YouTube channel - Tucana Validated BS EN 14897 UV Disinfection Units
Servicing needs for our products will vary but, typically, six-monthly servicing is the minimum requirement.
HSG274 highlights various water hygiene works that are also necessary – ranging from weekly to annual checks – some of which also relate to the operation of water treatment equipment installed.
Ref: HSG274 (Parts 1 & 2)
HSG274 Part 1 states that water quality checks should be carried out weekly, with additional monitoring also be required monthly and annually.
Ref: HSG274 (Part 1)
Are there any pipework materials that are incompatible with continuous chlorine dioxide dosing?
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In Building Services applications, chlorine dioxide is dosed to provide a maximum total oxidant level of 0.5ppm. At this concentration, it is extremely unlikely that any pipework material will be damaged as a result of the use of chlorine dioxide. However, some manufacturers of polyolefin plastic pipework state that they will not guarantee their pipework if chlorine dioxide is dosed continuously, even at the above levels.
We respect this position and can advise on alternative materials that can be used safely, and have been for many years. Please click the link to this document - TM106 Chlorine Dioxide - Pipework Compatibility - or get in touch with us for more information.