1. Physical Activity and Leisure Management Ltd POOL PLANT OPERATIONS INFORMATION UPDATE SEMINAR (on-line option)

2. Physical Activity and Leisure Management Ltd Carlton Associates Ltd (c) 2013 MODULE 4: Current trends in Water Treatment 3. Carlton Associates Ltd (c) 2013 This module re-enforces the recommended pH values, as well as Free Chlorine levels for the various disinfectants that we use. The reasons for these values are explained. The chemical process of disinfection is also covered, here, together with the more commonly used chemicals, and our innovative traffic light water test guidelines! In this Module we will be focusing on: 4. Carlton Associates Ltd (c) 2013 Revision of the Essentials Protecting Swimmers from Themselves Harmful Organisms found in Swimming Pools Preventative Measures Surface Biofilms The Balance Tank 5. Carlton Associates Ltd (c) 2013 New Guidelines on pH Correction The effect of pH on Chlorine Chemistry Free Chlorine levels and Combined Chlorine Levels Popular Treatments How does it all Work? Organic Chloramines 6. Lets start by considering how much have we forgotten? The names of chemicals that we use? Why we have target readings? COSHH documents? When we should test, and why? Backwash? What happens? Carlton Associates Ltd (c) 2013 7. PROTECTING SWIMMERS FROM THEMSELVES The lack of high personal hygiene standards means that:- Pollution levels are high Risks are greater The use of man-made chemicals are high Costs are unnecessarily high Carlton Associates Ltd (c) 2013 8. PROTECTING SWIMMERS FROM THEMSELVES But if we cant do anything to change this, then we must be aware of the consequences. Poor standards of pre-swim hygiene, means that we use more man-made chemicals. The pool can become a chemical soup, if were not careful! WE SHOULD BE REDUCING THE AMOUNT OF MAN-MADE CHEMICALS THAT WE MAKE PEOPLE SWIM IN ! Carlton Associates Ltd (c) 2013 9. Some of the other harmful organisms that can be found in swimming pools, include:- Pseudomonas Aeruginosas This is a parasitic virus that can be passed from human to human, in water. Its symptoms range from a mild ear ache or infection, respiratory difficulties, or to a very distressing rash that can affect any part of the body. It is easily destroyed by good disinfection, and so its presence indicates poor disinfection. It is also one of the prescribed tests of a microbiological analysis. Carlton Associates Ltd (c) 2013 10. 10 Legionella Virus This is a virus that is transmitted in water vapour, and sprays. The effect is to the respiratory system, and can prove to be fatal in certain circumstances. The virus itself, enjoys conditions between 20 C and 60 C , in stored water areas. These include circulation dead- legs, standing water, etc. such as showers; spas; air-conditioning units; etc. Carlton Associates Ltd (c) 2013 11. PREVENTATIVE MEASURES Stored water to be kept at 60 C, or above. Regular flushing of domestic hot water systems, and air-conditioning units (twice per annum). Daily running of showers and wash-basin taps prior to opening, especially in facilities that are seldom used. Carlton Associates Ltd (c) 2013 12. 1212 SURFACE BIOFILMS !!!!! The build up of greases and surface film on vinyls, plastics, rubber, etc Warmed water encourages bacteriological growth. Surface biofilms are the combination of both! Biofilms need to be cleaned off. How will you clean and disinfect inflatables; floats; pool covers; hose- pipes; etc., etc Carlton Associates Ltd (c) 2013 13. 13 THE BALANCE TANK In deck-level pools, the water flows into a Balance Tank, before it flows into the rest of the system. It is there to balance the level of water in the pool! This is a bio-film which forms on surfaces, and can house bacteria! CLEANING !! Carlton Associates Ltd (c) 2013 14. 14 PH CORRECTION: NEW GUIDELINES For disinfectants to work properly, the pH value of the pool water is critical. It is recommended that the pH value should be maintained between 7.2 7.6 (7.0 to 7.6 in Spa Pools) as disinfection will be more effective (as may be coagulation) Target pH should be set at 7.2-7.4 as this allows the disinfectant to work more effectively. Dosing with an acid stabiliser is normally required with alkaline disinfectants to maintain the correct pH value. Carlton Associates Ltd (c) 2013 15. 15 THE EFFECT OF PH ON CHLORINE CHEMISTRY Carlton Associates Ltd (c) 2013 16. Carlton Associates Ltd (c) 2013 17. FREE CHLORINE LEVEL To achieve the best possible water quality, it is recommended that the free chlorine residual should be at the lowest level that gives satisfactory microbiological quality. This should be possible at less than 1mg/l to an absolute minimum of 0.5mg/l with a pH of 7.2 to 7.4, provided everything about the design and operation of the pool is in line with the recommendations in this manual and the Pool Water Guide. But, your target levels must have come from a Risk Assessment. Carlton Associates Ltd (c) 2013 18. COMBINED CHLORINE The combined chlorine residual should be as low as possible, less than the free chlorine level, ideally half or less. Pools that do not operate to an optimum design may need to have higher residuals Pools that occasionally have large influxes of extra bathers, or have bathers with specific needs, may have to meet this extra demand with higher levels of disinfection. Carlton Associates Ltd (c) 2013 19. Most common/popular treatments Carlton Associates Ltd (c) 2013 Disinfectants Stabilisers Sodium Hypochlorite Calcium Hypochlorite BCDMH (Bromine) Chlorine Gas Chlorinated IsoCyanurates Sodium Bisulphate Hydrochloric Acid Carbon Dioxide Sodium Carbonate 20. Which are acids, and which are Alkalis? Carlton Associates Ltd (c) 2013 Disinfectants Stabilisers Sodium Hypochlorite (Alkali - Liquid) Calcium Hypochlorite (Alkali - Liquid) BCDMH (Bromine) (Acidic - Solid) Chlorine Gas (Acidic - Gas) Chlorinated IsoCyanurates (Acidic - Solid) Sodium Bisulphate (Acidic - Solid) Hydrochloric Acid (Acidic - Liquid) Carbon Dioxide (Acidic - Gas) Sodium Carbonate (Alkali - Solid) 21. How does it all work, then? When Chlorine (hypochlorites) are mixed with water, they form HYPOCHLOROUS ACID (Hypobromous Acid if you use BCDMH) The Hypochlorous Acid reacts with Ammonia (pollution), to form MONO-CHLORAMINES. These are not harmful, but dont neutralise bacteria either. Further addition of Hypochlorous Acid to the mono-chloramines produces DI- CHLORAMINES. It is the Di-Chloramines which we also refer to as COMBINED CHLORINE, because it is this element that reacts with the pollution. Carlton Associates Ltd (c) 2013 22. How does it all work, then? When Chlorine (hypochlorites) are mixed with water, they form HYPOCHLOROUS ACID (Hypobromous Acid if you use BCDMH) The Hypochlorous Acid reacts with Ammonia (pollution), to form MONO-CHLORAMINES. These are not harmful, but dont neutralise bacteria either. Further addition of Hypochlorous Acid to the mono-chloramines produces DI-CHLORAMINES. It is the Di-Chloramines which we also refer to as COMBINED CHLORINE, because it is this element that reacts with the pollution. Carlton Associates Ltd (c) 2013 23. QUESTION: WHY IS THERE ALWAYS A COMBINED CHLORINE READING FIRST THING IN THE MORNING, IF THE CHEMICAL TREATMENT, CIRCULATION AND FILTRATION SYSTEMS HAVE BEEN OPERATING PROPERLY ALL NIGHT? ANSWER: Because there is something called ORGANIC CHLORAMINES in pool water nearly all the time. 23 Carlton Associates Ltd (c) 2013 24. 24 ORGANIC CHLORAMINES As well as reacting with ammonia, chlorine reacts with organic, nitrogen compounds that mainly come from proteins in bather pollution. The resulting chlorinated organic amines (PROTEINS) are not removed by filtration or by chlorination, and are shown as part of the combined chlorine readings. Only dilution will significantly reduce the level unless ultra violet irradiation, or ozone and carbon filtration is used to treat the pool water. Carlton Associates Ltd (c) 2013 25. Carlton Associates Ltd (c) 2013 That is the end of Module 4 What you need to do now: 1. Return to the course page 2. Download the module update notes and save them on your computer 3. Read through the notes 4. Print out the notes and insert them in your manual 26. Carlton Associates Ltd (c) 2013 End of Module 4 Presentation