© Stockwell Safety 2017 All rights reserved. No part of this study material may be stored in a retrieval system, reproduced or transmitted in any form, or by any electronic, photographic or other means without the express written permission of Stockwell Safety. Information sourced from the Health and Safety Executive and Government Departments has been reproduced and / or adapted under the terms of the open government license for public sector information version 2.0, as presented by the National Archives at: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ Information obtained from other sources has been properly acknowledged and referenced. Whilst every effort has been made to ensure the currency and accuracy of the information contained within, Stockwell Safety bears no liability for any omissions or errors; or any concepts and interpretations advanced by the authors 1 Contents Bather Load .......................................... 19 Turnover Period .................................... 20 Physical Pollution ....................................... 21 01. Introduction to Swimming Chemical Pollution.................................... 21 Pools ...................................................... 6 Total Dissolved Solids (TDS) ................. 22 History of Swimming Pools in the UK ........ 6 Source Water ........................................ 23 Swimming Pool Construction ................... 6 Alkalinity ................................................. 23 02. The Management of Hardness ................................................ 23 Swimming Pools .................................... 7 Sulphates ............................................... 23 Management Responsibility .................... 7 Bather-Added Chemicals and Disinfection By-Products ..................... 23 Duties under Section 3 of the HSWA .. 7 Biological Pollution .................................... 24 Management of Health and Safety at Work Regulations 1999 .......................... 7 Infectious Agents ................................. 25 Approved Codes of Practice .............. 7 Microbiological testing ............................ 36 Guidance Notes ..................................... 8 Aerobic Colony Count ....................... 37 Enforcement ........................................... 9 Total Coliforms ...................................... 37 Confined Spaces Regulations 1997.... 9 E. Coli...................................................... 37 The Reporting of Injuries, Disease sand Pseudomonas Aeruginosa ................. 37 Dangerous Occurrences Regulations Gross Microbiological Contamination 2013 (RIDDOR) ...................................... 10 ................................................................. 37 The Construction, Design and Legionella .............................................. 38 Management (CDM) Regulations Pre-Swim Hygiene ..................................... 39 2015......................................................... 10 Exclusion of Swimmers .............................. 39 Training ................................................... 10 Pool Safety Operating Procedures ....... 11 04. Swimming Pool Normal Operating Procedures .......... 11 Environment: Design, Emergency Action Plans .................... 11 Cleanliness and Hygiene .................... 41 Fires and Explosions.............................. 12 Pool tank ..................................................... 41 Chemical Incidents ............................. 12 Emptying and Refilling ........................ 41 Chemical or Microbiological Pool tank profile ................................... 42 Contamination Outbreaks ................. 14 Pool tank edge..................................... 43 Pool Plant Operations/Swimming Pool Pool tank detailing............................... 43 Technical Operations .......................... 18 Pool tank bottom ................................. 43 O&M Manuals & Health and Safety Files .......................................................... 18 Movable floors and bulkheads ......... 44 Inlets and Outlets ................................. 45 03. Pollution ........................................ 19 Balance Tanks ...................................... 46 Relative Pollution ...................................... 19 Access to the pool and the pool hall ... 46 Bather Load and Turnover Period ......... 19 Pool Covers ........................................... 46 2 Circulation in ‘wet’ areas and around Adsorption ............................................. 68 the pool.................................................. 47 Heat Exchanger ........................................ 68 Access to the pool tank ..................... 47 Recommended Pool Temperatures...... 69 Design of steps and ladders .............. 48 Valves .......................................................... 69 Design of ramps ................................... 48 Butterfly Valves ..................................... 69 Floors ........................................................... 48 Multi-port valves ................................... 70 Cleaning ................................................ 48 Periodic removal of hard water 06. Circulation..................................... 71 scaling and body grease ................... 49 Flow Rate, Turnover Time and Pool Slip resistance........................................ 49 Volume ........................................................ 71 Movement joints ................................... 50 Recommended Turnover Times ............. 73 Drainage gullies and transfer channels Single or Multiple Pumps .......................... 73 ................................................................. 50 Variable Speed Drives ........................ 74 Walls ............................................................ 50 Circulation for Multiple Pools .................. 74 Glazing ....................................................... 50 Dye Tests ..................................................... 74 Ceilings ....................................................... 50 Public toilets .............................................. 50 07. Filtration/Coagulation ................. 76 Changing facilities ................................... 51 Pool Water Clarity ..................................... 76 Toilets .......................................................... 51 Filter Design and Construction ............... 76 Showers ...................................................... 52 Inspection and Maintenance ................ 76 Baby change facilities ............................ 52 Filtration Rates............................................ 80 Stainless Steel ............................................ 53 Backwashing .............................................. 80 Air Scouring ........................................... 81 05. Main Features of a Pool Other types of filter and filtering Plant System ....................................... 54 medium ....................................................... 84 Surface Water Draw-Off System ........... 56 Cartridge filters ..................................... 84 Deck-Level System ............................... 56 Diatomaceous earth ........................... 84 Skimmer Basket System ....................... 58 Glass ....................................................... 84 Scum Trough System ............................ 58 Carbon ................................................... 84 Outlets ........................................................ 60 Membrane ............................................ 84 Entrapment Hazards ............................ 62 Zeolite ..................................................... 84 Entanglement Hazards ....................... 64 Coagulation ............................................... 85 Balance Tank ............................................ 64 Flocculation ............................................... 87 Pre-Pump Strainer(s) ................................ 64 Dosing Coagulants ................................... 88 Circulation Pumps .................................... 66 Filters ........................................................... 67 08. Primary Disinfection ..................... 89 Straining ................................................. 68 Primary Disinfection .................................. 89 Sedimentation ...................................... 68 Calcium hypochlorite ......................... 89 3 Sodium hypochlorite ........................... 90 Circulation feeders ............................ 113 Electrolytic generation of sodium Chemical dosing operations ............... 114 hypochlorite .......................................... 91 Day Tanks ............................................ 114 Chlorinated isocyanurates ................. 91 Preparing dosing chemicals ............ 114 Bromochlorodimethylhydantion ....... 92 Manual Dosing ....................................... 115 Elemental liquid bromine .................... 92 Increasing Chlorine............................ 115 Sodium Bromide ................................... 93 Superchlorination ............................... 116 Chlorine gas .......................................... 93 Decreasing Chlorine ......................... 118 Chlorine Dioxide ................................... 94 Increasing or Decreasing pH Value 119 Tetra-Chloro Deca-Oxygen ............... 94 Increasing or Decreasing Calcium Polymeric Biguanide............................ 94 Hardness .............................................