DAISY EN 09 Print2The UK pool industry operate with Cryptosporidium parasitic infection rates 10 to 20 times higher than Germany. The pool industry in Germany have much tighter standards that enforce showering prior to entering a public pool. Showering and good personnel hygiene will certainly reduce the incident rates, but there is such a huge difference that this cannot be the only reason. Horizontal disease transmission rates should be the same, so this only leaves the performance of the filtration system.
Under DIN regulations, many public pools use sand filtration followed by ozone and activated carbon. 100 % Ozonation to 1 mg/l followed by activated carbon is an effective means of control, but it is very expensive to operate and maintain, and the system can still produce high levels of chlorine disinfection by-products. UV irradiation is another option to help deactivate the parasites, but UV can also form noxious disinfection by-products that are more toxic than trichloramine. UV irradiation is under investigation by the French authorities and it is a requirement to monitor for THM`s when UV irradiation is used to treat the water for chloramines and parasites.

The UK pool industry water quality standards are inferior to the German DIN standard, by way of example, the UK operate with 5 to 10 times the concentration of THM`s and combined chlorine. Swimming is a very health exercise and should be encourage, but only if the pool is well managed with good air and water quality.
A good pool, what is a good pool? Simple question but difficult to answer, what comparison can we make to distinguish between a good pool and one that is not acceptable. If we compare UK pools against the standards followed in Germany and most of Europe, we could argue that there are very few “good pools” in the UK. This becomes self-evident when you compare the pool water treatment guidelines in the UK against the water quality DIN Standards followed in Germany, Austria, Switzerland, Netherlands, Romania, Slovenia etc. etc.

The UK is the only country in Europe that does not follow the DIN norm, or an equivalent high Standard, and as a consequence we place the health and well-being of the public and pool staff at greater risk in the UK. Is this an acceptable situation? if a risk or a hazard is identified then it automatically becomes part the facility COSHH assessment and the responsibility of the employer. However it would be unrealistic for the employer to be aware of all the hazards and risks. To this end it is important to have formal Standards that can be applied to mitigate the risks. Dryden Aqua therefore advocates that the UK adopts the German DIN Standard, indeed to be in compliance with COSHH assessments pools really have no option but to comply with the DIN standard.

90 % of the work by Dryden Aqua in the pool industry is with countries that comply with the DIN Standard. Dryden Aqua is a research and development company dedicated to providing practical solutions to water and air quality problems. We work very closely with the authorities in Europe, but for what every reason there is a resistance to change, innovation and new developments in the UK. Change is always difficult; a great deal of training will be required to bring pool plant operators up to speed to achieve the same professional level as operators in Germany. The pool water treatment systems will also require modification, but in many cases, all that is required is an alteration to the way the systems are operated. In other cases it will not be possible to up-grade a facility without a major refit. However in all cases a template can be established, a strategy formulate and a formal Standard can be followed, this will make it easier to manage and operate a public swimming pool, it may also save a great deal of resources.

swim stbart2Dryden Aqua has developed an Integrated Pool Water Treatment process that may be used to upgrade almost any public pool in the UK. The process may bring the pool into compliance with the DIN Standard, and in some cases we can exceed the DIN Standard. The system will reduce the chlorine demand by 70 % to 90 %, and reduce all chlorine disinfection by-products by a similar percentage. Water quality is dramatically improved, nitrogen trichloride smells are gone, and operating costs for the facility drop to a point that the capital cost of the refit can be recovered out of revenue savings in 1 to 2 years.

Integrated Water Treatment, there is no magic bullet, in order to bring a pool in to compliance you need to look at the whole system, it is not sufficient just to change the media or install a new black box. One of the products developed by Dryden Aqua is AFM® (Activated Filter Media), Dryden Aqua manufacture AFM® from virgin grade glass and a proportion is manufactured specifically for Dryden Aqua from special glass components. The material is processed in our factory to have a high surface negative charge (zeta potential) and high redox potential. AFM® is in compliance to European standards and certified under Reg 31 drinking water regulations in the UK. There are now several companies promoting waste crushed glass in the UK, and advocating that it is used in public pools. It will not be possible to comply with DIN standards with such products, there is also health and safety issues and this should be reflected in the pool COSHH risk / hazard analysis.

In order to achieve the reduction in chemical consumption and achieve the best water and air quality, everything in the pool water treatment system must be optimised, the equipment must work together. To achieve these objectives, it is best to use equipment in full compliance to the DIN standard, and the pool should be operated in accordance to DIN procedures. Dryden Aqua have advanced the DIN procedures and developed a range of products and flocculants that now make it much easier to comply with the DIN performance requirements while not necessarily complying with the DIN standard in respect of system design.

Dryden Aqua has many thousands of pools operating around Europe, as well as many public pools in the UK. We are now at a point close to completion of pool water treatment technology and are closing the loop on system design. There are still a few issues to be resolved and fully quantified, but to this end a detailed examination is in progress with a large swimming pool in the south of England. Case studies and peer reviewed reports by the German authorities will follow over the next 12 months, but we can now confirm that we have taken a 30 year old pool and up-graded the system, and within 3 months the system is now exceeding the German DIN standard with regards to water and air quality.

The facility is a typical 25 m pool with leisure pool, and 500 to 1000 bathers per day. Data is still being collated on operating costs, but it would appear that the pool will achieve a return in capital expenditure out of revenue savings in under 18 months. There is no nitrogen trichloride smell in the building, there is zero water turbidity <0.01 ntu and combined chlorine is under 0.2 mg/l. With similar pools upgraded in France we have found that attendance usually increases by around 20 % over the following 12 months because the public are attracted to the better swimming conditions.

Dryden Aqua have identified that there is a health and safety risk associated with the pool industry in the UK when compared against pools operating in compliance to the German DIN standard. It would take a decade or more for UK pools to come into compliance with the DIN standard with regards to equipment and systems design. However with the new technology developed by Dryden Aqua, and with an integrated approach to pool water treatment it is now possible to up-grade existing pools and bring them into compliance with DIN water quality performance while saving chemicals and resources.

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