Ozone for MAHC Secondary Disinfection


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DEL Ozone secondary disinfection systems for commercial pools meet Model Aquatics Health Care (MAHC) guidelines. The MAHC is an emerging comprehensive set of best practices for public pool and aquatics operators.

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Ozone for MAHC Secondary Disinfection

  1. 1. Ozone Secondary Disinfection System Public Swimming Venues 2010
  2. 2. Public Health Responsibility • Swimming is the second most popular sport in the United States; encompassing all age groups • It is estimated that there are about 360,000 public pools in the U.S. • Considering that most public swimming venues are essentially communal baths, there is an enormous task to protect public health from communicable diseases and other health hazards • There are existing technologies currently available to help provide a safe and healthy aquatic experience to all swimmers that cannot be ignored
  3. 3. Cryptosporidium parvum Outbreaks (136 outbreaks of cryptosporidiosis worldwide from 1988 to 2004 (68 in U.S.) with 92% in disinfected venues - Centers for Disease Control in Atlanta)
  4. 4. Water Quality Issues and Cryptosporidium parvum Outbreaks • CDC swimming pool surveillance reports show that of the 21,500 inspections conducted between May and September of 2002, water chemistry violations were found at 38.7% of these facilities, 14.3% of the violations were for inadequate disinfection levels at therapy pools (CDC. Surveillance Data from Swimming Pool Inspections --- Selected States and Counties, United States, May – September 2002. 2003. MMWR 52(22); 513-516.) • In one of the largest outbreaks reported, approximately 2,300 persons developed cryptosporidiosis following exposure to a New York spray park (Surveillance for Waterborne Disease and Outbreaks Associated with Recreational Water Use and Other Aquatic Facility -- Associated Health Events --- United States, 2005—2006 MMWR Surveill Summ. September 12, 2008 / 57(SS-9);1-38.
  5. 5. Recreational Water Illness • Chlorine has been the standard water treatment chemical for public pools since 1961 (U.S. Public Health Service) • Chlorine is effective in reaching certain water quality standards, however scientists are learning more about its limitations and hazards in public swimming venues • Recreational Water Illness (RWI) has become wide spread in the US in public pool venues and is increasing annually; posing a significant public health and liability risk • RWI is a term coined by the Centers for Disease Control and Prevention (CDC) to describe illnesses caused by microorganisms as well as those from chloramines – Some microorganisms including Pseudomonas aeruginosa, E. coli, Staphylococcus aureus, Giardia and Cryptosporidium parvum (Crypto), can cause serious illness in swimmers – Chloramines can cause breathing disorder illnesses such as “Swimmers Asthma”
  6. 6. Model Aquatic Health Code (MAHC) • Currently there is no uniform national standard for water quality or RWI response • To address this, the CDC has developed a Model Aquatic Health Code (MAHC) • State and Federal public health officials along with industry professionals from across the US, have participated for two years in the creation of the MAHC which includes the best available standards and practices for protecting public health • The MAHC is formatted to be easily adopted by state and local health departments • The CDC states it is “intended to transform the typical health department program into a data-driven, knowledge-based, risk reduction effort to prevent disease and injuries and promote healthy recreational water experiences”
  7. 7. Secondary Disinfection Systems SDSs • When the MAHC is published later this year, it will include a section on the importance of Secondary Disinfections Systems (SDSs) to significantly reduce RWIs (caused by microorganisms and chloramines) • According to the MAHC – All Secondary Disinfection Systems (SDSs) must be certified by an ANSI-Accredited third-party testing and certification organization to verify that they provide the minimum inactivation of Cryptosporidium parvum in the full flow – All Secondary Disinfection Systems (SDSs) must provide a minimum of 3 log (99.9%) inactivation of Cryptosporidium parvum in the full flow, prior to return of the water to the pool or aquatic feature at the minimum turnover rate • Approved SDSs are Ozone systems and UV systems
  8. 8. MAHC Swimming Venue Code • “Due to the risk of outbreaks of Recreational Water Illnesses (RWI’s) associated with sanitizer- resistant pathogens such as Cryptosporidium and Giardia it is strongly recommended that all aquatic facilities include Secondary Disinfection Systems (SDSs) to minimize the risk to the public associated with these outbreaks.” • “However, there are specific types of facilities that pose a greater risk to bathers, and therefore, Secondary Disinfection Systems are required for: therapy pools, wading pools, swim school pools, and aquatic play facilities/features.”
  9. 9. Definitions of Ozone and UV • Ozone is a gas that is dissolved in water to kill microorganisms, destroy organics, and break down chloramines by oxidation. This occurs immediately at the ozone gas injection point, and continues as the side-stream remixes with the main return. A small residual (~0.1 PPM) of dissolved ozone will enter the pool, providing further oxidation of contaminants. • UV light inactivates microorganisms and breaks down chloramines with light energy. This happens while the water is in the UV chamber only, and as long as the water has no turbidity. No further process occurs once the flow leaves the chamber. UV provides no oxidation except as trace amounts as a result of the formation of a limited number of hydroxyl free radicals in or near the UV chamber.
  10. 10. Properties of Ozone • Ozone (O3) is a gas derived from oxygen which can be readily dissolved in water • Ozone has a fresh scent at low concentrations and smells pungent at higher concentrations • Gaseous Ozone dissolved in water is referred to as Aqueous Ozone (which has no odor) • Ozone is a powerful antimicrobial oxidizer and sanitizer • Aqueous Ozone is an effective micro-flocculant • Aqueous Ozone is an effective anti-foaming agent • Aqueous Ozone is an effective antimicrobial agent • 1 PPM Aqueous Ozone, on average, is equal to 200 PPM Cl (Air Liquide Corp. James T.C. Yuan, PhD, 2000) • Ozone is compatible with Chlorine in Swimming Pools
  11. 11. Benefits of Ozone • Ozone controls the chloramine levels in the water to 0.2 PPM or less • Ozone can eliminate “shock-oxidizing” for chloramine reduction • Ozone offers significantly more oxidation than free available chlorine (FAC) alone (1/200 ratio) • Ozone provides a minimum 3 log (99.9 percent) kill of Cryptosporidium parvum and other RWI pathogens in a side- stream applied single-pass • Ozone will destroy emerging pharmaceutical pollutants such as endocrine disruptors • Ozone provides micro-flocculation to aid filtration and noticeably improve water clarity (eliminates foam from spas) • Ozone destroys biofilm • Chlorine consumption is reduced by 50-75% while still maintaining an FAC residual; at the lowest applied O3 dose of 1.6 PPM
  12. 12. Can Ozone Stand Alone? • Ozone’s role is actually as the primary sanitizer, but maintaining an ozone residual in the pool that is high enough to ensure continuous in-pool protection from bather-to-bather cross-contamination can be expensive; and present the risk of ozone off-gas • With current technology it’s impractical to expect ozone to perform as a stand-alone sanitizer in a public swimming venue without a residual halogen in the pool (0.3-1.0 PPM) • A low residual of chlorine, in conjunction with an appropriately sized and maintained ozone system, will be virtually undetectable even by the most sensitive bathers, and keep operating costs very low
  13. 13. How is Ozone Measured? • Dissolved ozone is measured by an Oxidation Reduction Potential (ORP) monitor/controller in a swimming pool • The ORP reading can range between 600 mV to 900 mV at the point of introduction into the main return line before entering the pool • An ORP of 800 mV is ~ 0.2 PPM dissolved ozone which equates to ~40 PPM Cl in terms of oxidation and efficacy
  14. 14. Breakdown of Pool Types Based on bather load and water temperature, four categories have been identified 1. Recreation/Lap Pool (78-85°F) 2. Therapy/Swim School Pool (86-94°F) 3. Wading Pool/Spray Pad (80-88 °F) 4. Spa (94-104°F)
  15. 15. Ozone Sizing Parameters • In each of the 4 categories, 1.6 PPM Ozone (D) is applied to the total volume of the pool based on time, using an additional conversion constant of 0.227 • The time value changes with each category 1. Recreation/Lap Pool 1.6PPM/24 hr (1440 min) 2. Therapy/Swim School Pool 1.6PPM/12 hr (720 min) 3. Wading Pool/Spray Pad 1.6PPM/4 hr (240 min) 4. Spa 1.6PPM/2 hr (120 min)
  16. 16. Ozone Retention Parameters • Ozone efficacy is measured by the combination of applied Ozone Dose and Retention Time in the side stream (CT Value [Concentration X Time]) 1. Recreation/Lap Pool 4 minutes 2. Therapy/Swim School Pool 2 minutes 3. Wading Pool/Spray Pad 40 seconds 4. Spa 20 seconds
  17. 17. Sample Pool Ozone Sizing • Sample Pool – 100,000 Gallon Recreation/Lap Pool (6 hour turnover) – Volume/Minutes = Flow (F) – Generator Sizing Formula: F * D * 0.227 = Grams per hour Ozone Required – Retention Tank Sizing Formula: F * T (minutes) = Size of Retention in Gallons • 100,000 * 1.6 X 0.227/1440 = 25 grams/hour • 69 * 4 = 278 gallons
  18. 18. Non-Compliant Ozone Systems are NOT Identified as SDSs • Only ozone systems that are certified by an American National Standards Institute (ANSI)-Accredited third-party testing and certification organization to verify that they provide a 3 log (99.9%) inactivation of Cryptosporidium parvum in the side-stream applied full flow are qualified to be an SDS – This is in addition to the current ANSI/NSF Standard 50 • All ozone systems must be sized in accordance with the MAHC • The MAHC does not allow undersized ozone systems; they are not in compliance
  19. 19. Ozone Regulatory 1976 EPA Approves Ozone as an Antimicrobial Oxidizer 1982 IBWA Bottled Water Approve Ozone as an Antimicrobial for Product and Disinfectant for Filler Lines 1999 EPA Lists Ozone as Safe for Surface and Ground Water 2001 FDA/USDA Approve Ozone as an Antimicrobial Food Additive 2001 FDA/USDA Approve Ozone as a Food Contact Surface Disinfectant 2001 USDA National Organic Program Allows Ozone as an Antimicrobial Food Additive and Food Surface Disinfectant 2010 Ozone is added to the FDA Model Food Code as an approved antimicrobial surface sanitizer 2010 Ozone is recommended as a Secondary Disinfection System in the Model Aquatic Health Code
  20. 20. Ozone Safety • EPA approved – As a pesticide, ozone equipment must be registered by the EPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). DEL Ozone is an EPA registered establishment (EPA Estab. No. 071472-CA- 001). • OSHA Regulations for Ozone (Gaseous Only) – Health Hazard Data • Inhalation /Respiratory System, Eyes, Blood – PEL (Permissible Exposure Limit) • 8 hour Time Weighted Average 0.1 PPM Vol. – STEL (Short Term Exposure Limit) • 15 Minute 0.3 PPM Vol. – IDLH (Immediately Dangerous to Life and Health) • 5 PPM • No OSHA Regulations apply to Aqueous Ozone; it is not harmful to humans
  21. 21. OZONE SAFETY • Vacuum Generated Ozone Ensures User Safety – No ozone gas can escape in the event of loss of vacuum – Systems provide complete isolation in the event of any shutdown • Vacuum Operation Optimizes Mass-transfer Efficiency – Venturi Injectors operate under negative pressure; a vacuum ozone system provides ease of injector adjustment and operation – Mass-transfer is optimized and consistent – Optimized mass-transfer results in more dissolved ozone – Undissolved ozone is degassed and destroyed
  22. 22. A Sanitizer is one of the three groups of antimicrobial agents registered by the USEPA for public health uses. Disinfectants are antimicrobial agents that are applied to non-living objects to destroy microorganisms, the process of which is known as disinfection. Sanitizers are substances that reduce the number of microorganisms to a safe level. The main difference between a sanitizer and a disinfectant is that at a specified use dilution, the disinfectant must have a higher kill capability for pathogenic bacteria compared to that of a sanitizer. Definition of Sanitizers & Disinfectants
  23. 23. Ozone is an EPA Approved Antimicrobial, Disinfectant and Sanitizer by all Definitions Ozone Performs these Functions as an Oxidizer In Use for a Century Worldwide as a Water Disinfectant
  24. 24. Ozone Biocidal Behavior 1. Ozone oxidizes cell membranes, causing osmotic bursting 2. Ozone continues to oxidize enzymes and DNA Before ozone treatment After ozone treatment E. coli dried as a biofilm on a porous surface
  25. 25. Public Bath Tubs Ozone Anti-Microbial Validation under NSF Protocol P308 Pass compliance requires a 3-log (99.9%) reduction of E. coli, Staphylococcus aureus, Pseudomonas aeruginosa, Trichophyton mentagrophytes and Candida albicans in 30 minutes Actual Microbial Reductions in 30 Minutes E. coli 4.7 log (>99.99%) Staphylococcus aureus 4.7 log (>99.99%) Pseudomonas aeruginosa 3.2 log (>99.9%) Trichophyton mentagrophytes 4.0 log (99.99%) Candida albicans 4.7 log (>99.99%) Test Parameters • Water temperature @ 93° F • 20 PPM oil insult • 1.1 PPM side-stream applied ozone dose • Microorganism destruction was measured in the tub
  26. 26. Public Swimming Venues Ozone Anti-Microbial Validation under ANSI/NSF Standard 50, Annex H Pass compliance requires a 3-log (99.9%) reduction of Pseudomonas aeruginosa and Enterococcus faecium in 30 minutes Actual Microbial Reductions in 6 Minutes Pseudomonas aeruginosa 6.6 log (>99.9999%) Enterococcus faecium 6.7 log (>99.9999%) Test Parameters • Water temperature @70° F • 20 PPM oil insult • 9 PPM Urea insult • 1.6 PPM side-stream applied ozone dose • Microorganism destruction was measured in the pool
  27. 27. Public Swimming Venues Pass compliance requires a 3 Log (99.9%) reduction of Cryptosporidium parvum Actual Microbial Reductions in 30 Seconds Cryptosporidium parvum 3.0 log (>99.9%) Test Parameters • Water temperature @76° F • 1.6 PPM side-stream applied ozone dose • Crypto measurements were taken on a single pass [measured after side-stream is diluted in full flow] Ozone Antimicrobial Validation for Cryptosporidium parvum Reduction tested by NSF International
  28. 28. Representation of Crypto Destruction
  29. 29. CT Values for Cryptosporidium parvum Inactivation CT Value Concentration times Time (PPM * Minutes Exposure = CT Value) Chlorine CT is 15,300 [20 PPM for 13 hours (780 minutes)] Aqueous Ozone CT is 0.72 (1.257 PPM for 34 seconds)
  30. 30. • Oxygen molecules (O2) split by adding energy, resulting in two individual oxygen atoms (O1) • Oxygen atoms (O1) unite with other oxygen molecules (O2) to produce Ozone (O3) • (O1) + (O2) = (O3) ELECTRICAL ENERGY ADDED How Ozone is Made
  31. 31. How Ozone Works • The third oxygen atom is held by a weak single bond • An oxidation reaction occurs upon any collision between an ozone molecule and a molecule of an Oxidizable substance • The weak bond splits off leaving oxygen as a by-product • During an oxidation reaction, organic molecules are changed or destroyed and dissolved metals are no longer soluble Weak Bond Oxygen (O2) Oxidizable Substances Bacteria Viruses Fungi Algae Suntan Oils Body Oils
  32. 32. Basic Ozone System
  33. 33. Very Small Ozone System
  34. 34. Small Ozone System
  35. 35. Large Ozone System
  36. 36. Ozone Generation System Components
  37. 37. Ozone Gas Dissolution
  38. 38. Ozone Reaction in Water
  39. 39. Degas Undissolved Ozone
  40. 40. Destroy Undissolved Ozone
  41. 41. Flange to Flange Ozone Skid
  42. 42. Ozone Systems Made Simple • Complex ozone systems of the past have been replaced by modern, compact, affordable systems • Skid-mounted, plug and play ozone systems are the norm for 200,000 gallon pools and smaller • Flange to flange hook-up to the main return line decreases cost and complexity of the installation • The system’s 4’X3’ footprint is compact to easily fit into the equipment room
  43. 43. Costs and Savings with Ozone Assumptions • 100,000 gallon indoor pool • $250/ 10 PPM shock/100K Gal (chlorine @ $2.50/gal) • Shock (without ozone) estimate 52 per year = $13,000 • Annual chlorine use estimate is based on chlorine cost @ $2.50/gal Bather load assumptions • 100 bathers/day = 1,825 gals @ $2.50 = ~$4,563 • 200 bathers/day = 3,650 gals @ $2.50 = ~$9,125 • 300 bathers/day = 5,475 gals @ $2.50 = ~$13,687 • 400 bathers/day = 7,300 gals @ $2.50 = ~$18,250 • Chlorine reduction with ozone is average 50% Ozone System Cost Estimates • End-user purchase price $30,000.00 • Annual power consumption at 0.12 per kWh $2,375.00 • Annual Maintenance parts $300.00 Savings Estimates • Eliminate shock treatments and labor costs $13,000 plus labor cost savings • Chlorine Reduction at 50% avg. 100 bathers/day $2,281 400 bathers/day $9,125 savings Return on Investment (ROI) approximately 1.5 - 2 years
  44. 44. Ozone Compatibility with Cl and Br • Ozone’s reaction with chlorine is minimal • Ozone will break down chloramines • Ozone provides the main oxidation and disinfection in the pool while the chlorine provides a chemical residual • Ideal Chlorine residual is 0.3 – 1.0 PPM • It is not recommended that ozone be used in conjunction with bromine. When used with bromine, ozone oxidizes “spent” bromine (bromide) back to useful bromine. This depletes the ozone before it can oxidize the organic contaminants in the water, and significantly reduces ozone’s efficacy.
  45. 45. Ozone compared to UV Sterilizers Both Ozone and UV provide very effective Crypto reduction as documented by NSF Standard 50, Annex H Ozone Destruction of Chloramines • Ozone breaks down Chloramines by oxidation in two ways – By breaking down the N-Cl bonds of the Chloramine molecules through oxidation by ozone (this process occurs at the point of ozone injection and continues the oxidation process as it passes at low levels into the pool) – Ozone also forms hydroxyl free radicals, adding to the Chloramine oxidation process • Ozone reduction of Chloramines is also a function of its powerful oxidation of chloramine-producing organic contaminants; eliminating their initial production UV Destruction of Chloramines • UV can break down Chloramines in two ways – By breaking the N-Cl bonds of the Chloramine molecules with UV light energy (this process occurs in the UV chamber only) – By forming small numbers of hydroxyl radicals with UV light energy, which oxidize Chloramines (this process occurs within nanoseconds, effectively occurring only in, or very near the UV chamber) • UV produces very little oxidation to affect organics in the water
  46. 46. Ozone and UV comparison OZONE UV Ozone kills cryptosporidium parvum  UV inactivates cryptosporidium parvum  Ozone kills microorganisms  UV inactivates microorganisms  Ozone is a powerful oxidizer UV is not an oxidizer  Ozone passes into the pool at low levels to provide additional oxidation UV affects the water only as it passes through the UV chamber  Ozone functions well in cloudy water, and is a micro-flocculent, which aids water clarification Only clear water can be effectively dosed with UV; cloudiness in the water can absorb the UV light  Ozone oxidizes the organics and inorganics that create chloramines, eliminating their production UV breaks down chloramines that have been previously created  Ozone utilizes ORP (REDOX) to measure the cleanliness of the water UV systems utilize a UV intensity meter which measures the UV dose regardless of water quality  Ozone’s reaction with free available chlorine (FAC) is very slow and in a pool will not affect the FAC levels; only chloramine destruction  UV can break down free available chlorine in the water while it breaks down chloramines  Ozone cells require no replacement; require annual periodic cleaning; no hazardous components Mercury vapor lamps are replaced @ 3-12 mos.; disposal procedures must be considered as lamp gases are considered hazardous waste  Ozone destroys biofilm UV does not affect biofilm  Ozone destroys Humic and Fulvic Acid UV does not affect Humic and Fulvic Acid
  47. 47. Ozone and UV Together • Ozone and UV may be used together to create a synergistic approach to water sanitation • This process has been in use for drinking water, food processing, and waste water for many years • It is one of several advanced oxidation processes (AOPs) that are in commercial use today in selected industrial processing • The technology has rarely been used in public pools to date, but with the advent of improved technology and cost reduction, perhaps it will be the wave of the future for RWIs and chloramine elimination
  48. 48. Mobile Ozone Surface Sanitation • Antimicrobial ozone-enriched cold water can be sprayed directly on: – Shower stalls – Toilet stalls – Locker rooms – Pool decks – Play features – Any wettable surface • Ozone-Compatible Materials: – Metals: 304/316 SS – Plastics: ECTFE, PTFE, PVC, PVDF – Gaskets: FPM (Viton), EPDM – Pump seals: FPM (Viton) – All painted surfaces, concrete, wood
  49. 49. Mobile Ozone Surface Sanitation
  50. 50. • NSF studies of Ozone systems include EPA-required: – Antimicrobial efficacy data (Disinfectant Technical Science Section DIS/TSS - AOAC methods) – Toxicologic profiles – Environmental impact information – Specific label information/technical literature that details recommended use of applications and directions EPA Requirements
  51. 51. • Ozone systems are tested by NSF Toxicology Group for antimicrobial efficacy and human safety • Antimicrobial Efficacy – NSF conducted studies according to EPA established AOAC Official Methodology 961.02 & 960.09, Germicidal Spray Products as Disinfectants and Germicidal & Detergent Sanitizing Action test procedures • Safety – NSF performed safety testing based on Hazard Communications Standard as promulgated through Occupational Safety and Health Act (OSHA) of 1970 and documented in the Code of Federal Regulations Title 29 The Balance of Efficacy & Safety
  52. 52. Third-Party Validation Results • Efficacy – Bacteria • Escherichia coli 5 log reduction (99.999%) • Listeria monocytogenes 4 log reduction (99.99%) • Salmonella choleraesuis 6 log reduction (99.9999%) • Staphylococcus aureus 6 log reduction (99.9999%) • Campylobacter jejuni 4 log reduction (99.99%) – Fungi • Aspergillus flavus 4 log reduction (99.99%) • Pseudomonas aeruginosa 6 log reduction (99.9999) • Brettanomyces bruxellensis 4 log reduction (99.99%) • Trichophyton mentagrophytes 6 log reduction (99.9999%) • Safety – NSF performed safety testing based on Hazard Communications Standard as promulgated through Occupational Safety and Health Act (OSHA) of 1970 and documented in the Code of Federal Regulations Title 29.
  53. 53. Well Known DEL Ozone Customers Resorts, Zoos, Aquariums • Walt Disney World - FL • San Diego Zoo - CA • Atlantis Paradise Island – Bahamas • Vancouver Aquarium - BC • Beijing Aquarium, China • Toledo Zoo – Toledo, OH • Brookfield Zoo – Chicago, IL • Seattle Aquarium – Seattle, WA • Mandalay Bay, Las Vegas, NV • Buffalo Zoo – Buffalo, NY • Silverton Casino – Las Vegas, NV • Metro Miami Zoo – Miami, FL • Houston Zoo – Houston, TX • Audubon Zoo – New Orleans, LA • Calgary Zoo – Calgary, AL • Santa Barbara Zoo – Santa Barbara, CA Pools • Atlantis Paradise Island, Waterpark -Bahamas • Canada Games Pool – Kamloops, BC • Georgetown University – Wash, DC • McDonogh School – Owings Mills, MD • Medicine Hat Aquatic Centre – Alberta • 92nd Street JCC – New York, NY • Ojai Athletic Club – Ojai, CA • Peninsula YMCA – San Mateo, CA • Presidio YMCA – San Francisco, CA • Santa Monica YMCA - Santa Monica, CA • Silverton Casino – Las Vegas, NV • The Palms – Las Vegas, NV • Universal Studios, Islands of Adventure – Orlando, FL • Westminster Aquatic Center - Denver, CO • Mason High School – Mason, OH • The Broadmoor Hotel – Colorado Springs, CO
  55. 55. Atlantis Resort, Paradise Island, Bahamas Outdoor Lagoon Pool
  56. 56. Conclusion • Advances in Ozone Technology have provided the means for affordable and effective ozone systems for commercial pool applications • Commercial pools will benefit from safer, cleaner and more manageable water, free of chloramines and noticeably clearer • Pool water sanitized with Ozone provides a very pleasant swimming experience
  57. 57. Beth Hamil Vice President Corporate Compliance DEL Ozone 800 676 1335 805 441 4444 beth@delozone.com Ozone liaison for:  Water Quality Technical Committee of the MAHC  APSP Recreational Water Quality Committee  FDA Food Code  State Health Department Consultant for ozone applications