# MAHC
MAHC Table of Contents ANNEX viii
MAHC Table of Contents ANNEX xiv
MAHC Table of Contents ANNEX xv
MAHC Table of Contents ANNEX xvii
MAHC Table of Contents ANNEX xxi MAHC Table of Contents ANNEX xxii MAHC Table of Contents ANNEX xxiii MAHC Table of Contents ANNEX xxiv

# Rationale
With hundreds of millions of visits 1 to AQUATIC FACILITIES, waterparks, and natural recreational water sites each year, BATHERS expose themselves to many potential dangers in and around AQUATIC FACILITIES. In recent decades, public health practitioners have seen a dramatic increase in waterborne disease outbreaks associated with public disinfected AQUATIC FACILITIES (e.g. swimming pools, water parks, etc.). 2 Drowning and falling, diving, chemical use, and suction injuries continue to be major public health injuries associated with AQUA CILITIES, particularly for young children. 3,4,5,6,7,8,9,10 TIC FA Thus, public health and SAFETY is essential to consider starting with the design, construction, operation, and maintenance of public AQUATIC FACILITIES.

# Recreational Water-Associated Illness Outbreaks and Injuries

# RWI Outbreaks
Since 1978, the number of recreational water-associated WATERBORNE DISEASE outbreaks (WBDOs) reported annually has increased dramatically. 11 This increase is probably due to a combination of factors including:
- The emergence of PATHOGENs, especially CHLORINE-tolerant Cryptosporidium,  Increased participation in aquatic activities,  Increases in the number of AQUATIC FACILITIES, and  Increased recognition, investigation, and reporting of outbreaks that may have previously gone undetected.
1.0 Preface ANNEX 26 Over 2009-2010, a total of 81 recreational water-associated WBDOs and 1,366 cases of illness and 62 hospitalizations were reported to the CDC. CDC documented that 57 of these outbreaks and 78% of the cases were associated with disinfected water venues. 12 Multiple challenges exist for providing adequate cleaning and disinfecting of swimming water. Sunlight, urine, exposure to air, and inorganic and organic matter (i.e. sweat, saliva, and feces) can quickly deplete FREE AVAILABLE CHLORINE, the primary disinfectant used in POOLS. AQUATIC FACILITIES also provide potential exposure to FECAL contamination from other swimmers. These incidents are common in AQUATIC FACILITIES, especially from diaper-aged BATHERS who are not toilet trained (babies and toddlers). 13

# Significance of Cryptosporidium
One such pathogen is Cryptosporidium 14 (fecal-orally spread from person to person or from contaminated objects/media like pool water), which can survive for days in resistant. 15 , 16 , 17 chlorinated AQUATIC FACILITIES because it is extremely CHLORINE Cryptosporidium causes a profuse watery diarrhea that contains large numbers of infectious OOCYSTS so, if the water or surfaces at AQUATIC FACILITIES get contaminated, an outbreak can occur. Cryptosporidium and other waterborne pathogens have a low infectious dose and can still be excreted from the body weeks after diarrhea ends. These factors increase the potential for a waterborne disease outbreak. Waterborne diseases and outbreaks can include the following:  Gastrointestinal illness resulting from exposure to pathogens such as Escherichia coli O157:H7 or Cryptosporidium,  Infections of the brain, skin, ear, eye, and lungs,  Wounds, and  Exposure to pool-related chemicals.
There were 21 treated recreational water-associated outbreaks reported in 2009-2010 that were caused by Cryptosporidium, a substantial increase from the eight reported for treated AQUATIC FACILITIES in 1997 In addition, during 1999-2008 Cryptosporidium was identified as the cause of 74.4% of gastroenteritis outbreaks at 1.0 Preface ANNEX 27 disinfected AQUATIC FACILITIES, making it the leading cause of diarrheal disease outbreaks at disinfected AQUATIC FACILITIES. 20

# Drowning and Injuries
Drowning and falling, diving, chemical use, and suction injuries continue to be major public health injuries associated with AQUATIC FACILITIES. Drowning is a leading cause of injury death for young children ages 1 to 4, and the fifth leading cause of unintentional injury death for people of all ages. 21,22  Typically, CODE adoption bodies (federal, state, and local governments) publish a notice of their intent to adopt a CODE, make copies available for public inspection, and provide an opportunity for public input prior to adoption. As is also outlined in the FDA Model Food Code, this is usually done in one of two ways.
- The recommended method is the "short form" or "adoption by reference" approach where a simple statement is published stating that certified copies of the proposed CODE are on file for public review. This approach may be used by governmental bodies located in states that have enabling laws authorizing the 1.0 Preface ANNEX 29 adoption of CODES by reference. An advantage to this approach is a substantial reduction in the cost of publishing and printing.  The alternative method is the "long form" or "section-by-section" approach where the proposed CODE is published in its entirety. Both methods of adoption allow for the modification of specific provisions to accommodate existing law, administrative procedure, or regulatory policy.

# The MAHC Revision Process

# MAHC Revisions
Throughout the creation of the MAHC, the CDC accepted concerns and recommendations for modification of the MAHC from any individual or organization through two 60-day public comment periods via the email address

# Future Revisions
CDC realizes that the MAHC should be an evolving document that is kept up to date with the latest science, industry advances, and public health findings. As the MAHC is used and recommendations are put into practice, MAHC revisions will need to be made.
As the future brings new technologies and new aquatic health issues, the Conference for the Model Aquatic Health Code (CMAHC), with CDC participation, will institute a process for collecting national input that welcomes all stakeholders to participate in making recommendations to improve the MAHC so it remains comprehensive, easy to understand, and as technically sound as possible. These final recommendations will then be weighed by CDC for final incorporation into a new edition of the MAHC. Given the vision, mission, and goals of the MAHC as discussed in MAHC Section 1.3, the CDC will be especially interested in addressing any problems identified. CDC encourages interested individuals to consider raising issues and suggesting solutions through the CMAHC process.
User Guide ANNEX 30

# User Guide

# Overview

# MAHC Structure and Format
The MAHC utilizes the format also found in the FDA Model Food Code; thus within the MAHC, references are made to the FDA Model Food Code and the Conference for Food Protection. These are purely for reference and to gain a better scope of perspective and protocol.

# Annex

# Rationale
The annex is provided as a supplement to the code; thus, the annex material is not intended to be interpreted or enforced as model code in order to keep future laws or other requirements based on the MAHC straightforward. However, the annex is provided specifically to assist users in understanding the intent behind code provisions and applying the provisions uniformly and effectively.

# Content
To use the MAHC more effectively, users should preview the annex contents before using parts of the MAHC model code language. The annex is structured to present the information by the specific MAHC section number to which they apply. The Annex and Appendices also provide information and materials intended to be helpful to the user such as forms and checklists.
Glossary of Acronyms & Terms ANNEX 31

# Glossary of the MAHC Code and Annex

# Acronyms and Initialisms Used in This Code and Annex

# Facility Design Standards and Construction
The MAHC has worked extensively with ICC and IAPMO to eliminate conflicts between the three codes. These discussions, along with NEHA participation, have resulted in changes in the MAHC and plans to change items in the other codes as they are brought up for revision. The MAHC is committed to resolving these conflicts now and in the future as these codes evolve.

# Filtration Flow Rate
The particle contamination burden determines the filtration flow rate for a given AQUATIC FACILITY. It is not possible to predict the particle contamination burden for every individual AQUATIC VENUE because the sources will likely vary significantly from one AQUATIC FACILITY to another. However, it is important to understand the upper limit of particle contamination to provide information for filtration designs. If the upper limit of the particle contamination burden is known, then it should be possible for the designer to specify a filtration system that can handle the maximum particle burden and ensure that water turbidity does not increase above an allowable or desirable level. Essentially, the RECIRCULATION SYSTEM needs to be designed to remove particles at least at the same rate at which they are being added by the environment (e.g., windblown and settling dust), BATHERS (e.g., personal care products, body excretions), and other sources.

# Determining Maximum Rate of Particle Contamination
The best means for determining this maximum rate of particle contamination is through direct measurement at operating facilities to ensure the data are indicative of normal activity. The rate of contamination (n, particles/time/gallon) is likely to vary by AQUATIC VENUE location, BATHER COUNTS, BATHER age, time of year, time of day, weather, and proximity to urban and desert environments.
Data Search An extensive literature search turned up no relevant data defining the particulate contamination burden in AQUATIC FACILITIES. It is recommended that a model be developed that describes particle addition and subsequent removal by the filtration system. This would include developing a correlation between particle size and turbidity or clarity index; this correlation is needed from a practical point of view since regulations are likely to be developed based on turbidity or clarity. These data could then be used for making concrete, data-based decisions on removal rate requirements and help with defining the required filtration and circulation capacities.
Facility Design & Construction ANNEX 34 The rate of CHLORINE loss can be reduced by the use of other oxidizers, including potassium monopersulfate and ozone, or UV, which can destroy CONTAMINANTS which would otherwise react with CHLORINE. Additional research on the contributing factors to disinfectant demand (i.e. nitrogenous waste) may be warranted in the future as treatment methods are developed to reduce or eliminate them by means other than OXIDATION. It is anticipated that this research would identify the introduction rate of the CONTAMINANT, resulting concentrations, and the effect that reduction or elimination of this CONTAMINANT would have on disinfectant demand or other ancillary benefits (i.e. reduction of combined chlorines).
Chemical Feed Pump Sizing Further data collection on CHLORINE usage in real world AQUATIC VENUE situations under different environmental and operational conditions could be used to develop an effective rate law from which the sizing of chemical feed pumps could then be calculated. 31,32 The criteria for specifying a chemical feed pump for an AQUATIC VENUE are based on its ability to feed against the process piping pressure and to provide sufficient feed rate to maintain a disinfectant residual in the water. Several states require chemical feed pumps for CHLORINE to be capable of providing up to 10 PPM of CHLORINE in the pipe returning water from the RECIRCULATION SYSTEM back to the POOL. Once actual CHLORINE usage is obtained, a surplus SAFETY factor could be introduced to slightly oversize the feed pump to ensure that the disinfectant dosing amount can be increased to meet increases in demand. Any such sizing requirements need to specify the timeframe within which the pump must be able to satisfy the CHLORINE dosing required.
Disinfection By-Product Issues
Chlorination of Water Chlorination, using CHLORINE as the disinfectant, is the most common procedure for AQUATIC VENUE water DISINFECTION and inactivation of waterborne microbial pathogens. BATHER activity and environmentally-introduced material provides a broad range of precursors with which disinfectants can react (e.g., perspiration, urine, mucus, skin particles, hair, body lotions, fecal material, soil, etc.). When CHLORINE reacts with these precursors, a variety of chemical reactions take place, including the formation of DISINFECTION BY-PRODUCTS (DBPs) 33,34,35,36,37 . DBPs may also be introduced into the AQUATIC VENUE via the water used to fill the AQUATIC VENUE depending on the supply water quality. Municipal fill water can also include chloramines as some municipal
Facility Design & Construction ANNEX 35 systems switch from chlorination to chloramination to meet EPA DISINFECTION byproduct requirements. 38

# C
. 39,40,41 HLORINE gas, if used, is also extremely toxic
Types of Disinfection By-Products DBPs can be organic 42 ,43  or inorganic ,44, 45,46 (e.g. chloramines and cyanogen chloride). The major by-products of DISINFECTION using hypobromous acid (HOBr) and hypochlorous acid (HOCl) are bromoform (CHBr 3 ) and chloroform (CHCl 3 ), respectively. Chloroform and bromoform are highly volatile compounds that can be inhaled in AQUATIC VENUE environments and also readily absorbed through the skin. 47,48,49
Classes of Organic DBPs Some classes of organic DBPs 50 are:  TRIHALOMETHANES (total trihalomethane is the sum of the concentrations of chloroform, bromoform, bromodichloromethane, and dibromochloromethane);  Chlorinated phenols (2-chloro-, 2,4-dichloro-and 2,4,6-trichlorophenol),  58,59,60,61 . The one prospective study available 62 suggests swimming does not increase the risk of asthma. To the contrary, the study found swimming increased lung function and reduced the risk of asthma symptoms at age seven. The health benefits associated with swimming include improvement of asthma symptoms and cardiovascular fitness. Pediatricians have long recommended swimming for asthmatic children because of its lower asthmogenicity compared to other forms of exercise. The Belgian Superior Health Council 63 reviewed the available science related to AQUATIC VENUE swimming and the development of childhood asthma. The Council, in its 2011report No. 8748 (and reiterated in its 2012 concludes swimming remains highly advisable, even in the case of asthma. According to the Council, "For this target group, the advantages of swimming under good hygienic conditions in monitored AQUATIC VENUES outweigh the risk of toxicity linked to CHLORINE and its by-products." 64,65,66,67,68  World Health Organization, states that "the risks from exposure to chlorination byproducts in reasonably well-managed AQUATIC VENUES would be considered to be small and must be set against the benefits of aerobic exercise and the risks of infectious disease in the absence of DISINFECTION." 75 Improved water quality management is recommended to minimize formation and accumulation of these compounds.
haloketones (1,1-dichloropropanone, 1,1,1-trichloropropanone);  Haloketones ( bromopropanone, 1,1-dichloropropanone, 1,1,1 trichloropropanone,
Urea Concentrations in Pool Water A major CONTAMINANT in AQUATIC VENUE water is urea. Urea is chiefly derived from swimmers urinating in AQUATIC VENUE water, but is also present in swimmer's sweat. It has been shown that urea reacts with hypochlorous acid to produce TRICHLORAMINE. However, while breakpoint destruction of ammonia is very fast, reaction of hypochlorous acid with urea is very slow. Therefore, urea is difficult to remove quickly by shocking the AQUATIC VENUE water. There are no guidelines in the U.S. for MONITORING the urea concentration in AQUATIC VENUE water or suggested levels of concern. Input of urea is most effectively minimized by changes in swimmers' behavior and hygiene. 76,77,78,79,80
Technical Details Detailed specifications are required to ensure that there is no misunderstanding, ambiguity, or omission between the design professional and the AHJ reviewer.
75 . Guidelines for safe recreational-water environments, Volume 2: Swimming pools, spas and similar recreational-water environments.
76 Blatchley E, et al. Reaction mechanism for chlorination of urea. Environ Sci Technol. 2010 Nov 15;44(22):8529 34. doi: 10.1021/es102423u. Epub 2010 Oct 21. 77De Laat J, et al. "Concentration levels of urea in swimming pool water and reactivity of chlorine with urea", Water Research, 2011, 45(3) 1139-1146. 78 Schmalz C, et al. "Trichloramine in swimming pools -Formation and mass transfer", Water Research, 2011 2681-2690. 79 Fuchs J. Chlorination of pool water: urea degradation rate. Chemiker Ztg. -Chem. Apparatur (1962);86( 3

# Plan Approval
The construction of public AQUATIC FACILITIES should not be undertaken without a thorough review and approval of the proposed construction plans by the AHJ. Construction costs for AQUATIC FACILITIES can be in the millions of dollars and very costly mistakes in design and equipment choices can occur if plans are not reviewed before construction. These mistakes could result in both public health hazards and additional remodeling costs.
Most of the states require that plans be submitted for review and approval by the regulatory authority before a public AQUATIC FACILITY can be constructed. Although there is considerable variation in the amount of information and detail required on the plans, most of the jurisdictions require at least a plot plan with sufficient detail to allow for a reasonable review of the proposed project.
The licensed professional engineer or architect should have at least one year of previous experience with public AQUATIC FACILITY design. Most states will allow any professional engineer or architect to design an AQUATIC FACILITY. However, since AQUATIC DESIGN technology is sufficiently complex, specific prior experience in AQUATIC FACILITY construction and design is strongly recommended. A minimum of one year of previous experience in AQUATIC FACILITY design and construction is recommended.
Any final approval of plans by the AHJ should be dependent on approval by all other appropriate agencies.
For example, the assumption of responsibility for reviewing plans for structural SAFETY and ensuring the AQUATIC FACILITY is designed to withstand anticipated loading, not only the POOL shell, but also in cases where the POOL may be located on an upper floor of a building or a rooftop is generally that of the local building department. If there is no local building code department or requirements, the design engineer or architect must assume responsibility. This may include requiring the architect or engineer to certify the structural stability of the POOL shell during full and empty conditions.

# Replacements
Most jurisdictions allow for replacements in-kind.
Compliance Certificate
Design Parameters There are multiple forms of acceptable finishes available including but not limited to: paint, marcite plaster finish, quartz plaster finish, aggregate plaster finish, vinyl or PVC liner / paneling systems, stainless steel, tile, etc. Each system shall have advantages and disadvantages associated with cost, durability, clean-ability, etc. These advantages and disadvantages are also subject to installation design issues (e.g. indoors/outdoors, above/below water level, environmental effects, freezing or temperature exposures, etc.).
Smooth Finish SKIMMER POOLS require a six inch (152 mm) to 12 inch (305 mm) high finish due to the varying height of water associated with in-POOL surge capacity of SKIMMER POOL systems. Gutter or perimeter overflow systems require a minimum finish height of two inches (51 mm). If dark colors are utilized for the POOL finish, the POOL finish should not exceed a maximum height of 12 inches (305 mm) for contrasting purposes. Typical finishes include: tile, stainless steel, vinyl, fiberglass, etc.
Slip Resistant "Slip resistant" is usually considered to mean having a static coefficient of friction of 0.6 or better for both wet and dry conditions. Water three feet (0.9 m) and less is considered shallow water and the majority of BATHERS are capable of walking on the POOL bottom at these depths, so a slip-resistant surface is required. At depths greater than three feet (0.9 m), most BATHERS are sufficiently buoyant making the coefficient of friction for the POOL floor surface less important. Slip resistant surfaces shall meet or exceed the minimum coefficient of friction (typically 0.8 for ramped surfaces and 0.6 for other wet surfaces; currently, ASTM standard C1028 is under revision.) as set forth by the following groups: Cold Weather Paints suitable for use as vapor retarders usually have high solids, and must be carefully applied to achieve a rating of 0.4 perm for one coat. It is important to get very good coverage without gaps or thin spots. The paint supplier or manufacturer should be consulted for ratings and BEST PRACTICEs.
Paint or Coating One U.S. perm equals 1.0 grain of moisture per square foot per hour per inch-of mercury differential pressure. One U.S. perm equals 57 SI perm.
Mechanical Systems

# Indoor Aquatic Facility Air Pressure
Air-pressure-supported INDOOR AQUATIC FACILITIES may require pressurization of adjoining or connected SPAces.
Air Ducts Refer to the 2011 ASHRAE Applications Handbook on Natatorium Design for recommendations.
Indoor Aquatic Facility Doors Where exterior doors of an INDOOR AQUATIC FACILITY may be exposed to temperatures below the freezing temperature of water, the frames should be constructed to minimize the risk of the door freezing closed. The issue here is one of emergency exit. There is a large amount of water vapor available to freeze into the gap between doors, etc., that can inhibit emergency exiting.

# Exception:
Other doors should be acceptable, subject to approval by the AHJ, where heating systems are so arranged as to maintain such doors at least 5F (-15C) above the freezing temperature of water.
Indoor Aquatic Facility Windows Windows are usually maintained above -air dew point to prevent condensation and mold growth by heated supply air flowing over them. Heavy window frames on the interior side interfere with the proper flow of this heated air by the Coanda effect (a corollary of Bernoulli's principle). There are many ways to mechanically address window condensation issues. Air supply can be dumped on glazing from both above and below. Fin tube heaters have also been effectively employed along sills in many instances.

# Overflow System / Gutters
At the release date of the MAHC 1 st Edition, overflow system gutters products are currently listed by NSF to an engineering specification. Language is ready for ballot into NSF/ANSI Standard 50.

# Skimmers
At the release date of the MAHC 1 st Edition, NSF/ANSI Standard 50 2013 is the current version of the applicable STANDARD for SKIMMERS.

# Main Drain System
At the release date of the MAHC 1 st Edition, American National Standards Institute /Association of Pool and Spa Professionals (ANSI/APSP) STANDARD 16 -2011, titled "American National Standard for Suction Fittings for Use in Swimming Pools, Wading pools, Spas and Hot Tubs" is the current version of the applicable STANDARD for main drain systems.

# Multiport Valves
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for multiport valves.

# Face Piping
At the release date of the MAHC 1 st Edition, face piping products are currently listed by NSF to an engineering specification. It is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI Standard 50.

# Diaphragm Valves
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 14 -2008e is the current version of the applicable STANDARD for diaphragm valves. Product is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI.  Standard 14 -2008e is the current version of the applicable STANDARD for check valves. Product is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI Standard 50 as well.

# Fittings
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 14 -2008e is the current version of the applicable STANDARD for fittings. Product is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI Standard 50 as well.

# Pipe
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 14 -2008e is the current version of the applicable STANDARD for pipe. Product is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI Standard 50 as well.

# Pumps
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, UL 1081(non-metallic pumps up to 5 hp), California Assembly Bill 1953and United States National Electrical Code NFPA-70 (2008 are the current version of the applicable STANDARDS for pumps.

# Strainers
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for strainers.

# Gauges
At the release date of the MAHC 1 st Edition, gauges are currently listed by NSF to an engineering specification. It is currently at the Task Group Level for development of language for inclusion into NSF/ ANSI Standard 50.

# Flow Meters
At the release date of the MAHC 1 st Edition, flow meters are currently listed by NSF to an engineering specification. Language is ready for ballot into NSF/ ANSI Standard 50.

# Notes About Component Requirements: Heaters

# HVAC and Dehumidifiers
At the release date of the MAHC 1 st Edition, UL 1995 is the current version of the applicable STANDARD for HVAC and dehumidifiers.

# Solar Pool Heaters
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for solar POOL heaters.
Facility Design & Construction ANNEX 46 Furnaces At the release date of the MAHC 1 st Edition, ANSI Z83. 8-2006 Gas Heaters andGas-Fired Duct Furnaces, CSA 2.6 -2006 Gas Heaters and Gas-Fired Duct Furnaces and UL 757 Oil-Fired Furnaces are the current version of the applicable STANDARDS for furnaces.

# Boilers
At the release date of the MAHC 1 st Edition, ASME Boiler Code, ANSI Z21.13 -CSA 4.9 Gas Fired Hot Water Boilers are the current version of the applicable STANDARDS for boilers.

# Gas-Fired Pool Heaters
At the release date of the MAHC 1 st Edition, ANSI Z21.10.3 CSA 4.3 and ANSI Z21.56/ CSA 4.7 is the current version of the applicable STANDARDS for gas-fired POOL heaters. Language is ready for ballot into NSF/ ANSI Standard 50.

# Flues
At the release date of the MAHC 1 st Edition, UL 1777 is the current version of the applicable STANDARD for flues.

# Notes About Component Requirements: Filtration

# Rapid Sand Filters
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for rapid sand filters.

# High-Rate Sand Filters
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for high-rate sand filters

# Precoat Filters
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for precoat filters. Filters previously known as diatomaceous earth filters changed to precoat filters based on significant use of alternate filter media such as perlite.

# Filter Media
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for filter media.

# Cartridge Filters
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for cartridge filters.
Facility Design & Construction ANNEX 47 Other Filter Types At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for other filter types.

# Notes About Component Requirements: Disinfection Equipment

# Mechanical Chemical Feeding Equipment
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013 and UL 1081, CSA C22 are the current versions of the applicable STANDARDS for mechanical chemical feeding equipment.

# Ozone
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, UL 1081, CSA C22 and United States National Electrical Code NFPA-70 (2008 are the current versions of the applicable STANDARDS for ozone generators.

# Ultraviolet Light
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, which includes testing for Cryptosporidium validation, CSA C22 and United States National Electrical Code NFPA-70 (2008) are the current versions of the applicable STANDARDS for ultraviolet light systems.
Other potential guidance can be found in the U.S. EPA UV Design Guidance: .

# In-line Electrolytic Chlorinator
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, UL 1081, CSA C22, United States National Electrical Code NFPA-70 (2008) and Canadian PMRA are the current versions of the applicable STANDARDS for in-line electrolytic chlorinators.

# Brine Batch Electrolytic Chlorine or Bromine Generator
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, UL 1081, CSA C22, United States National Electrical Code NFPA-70 (2008 and Canadian PMRA are the current versions of the applicable STANDARDS for brine batch electrolytic CHLORINE or bromine generators.

# Copper/Silver and Copper Ion Generator
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 -2013, UL 1081, CSA C22, United States National Electrical Code NFPA-70 (2008 and Canadian PMRA are the current versions of the applicable STANDARDS for copper/ silver and copper ion generators.

# Chemical Storage
At the release date of the MAHC 1 st Edition, United States National Fire Code NFPA-1 (2009) is the current version of the applicable STANDARD for chemical STORAGE.  (2008) are the current versions of the applicable STANDARDS for AUTOMATED CONTROLLERs.

# Water Quality Testing Device
At the release date of the MAHC 1 st Edition, NSF/ ANSI Standard 50 2013 is the current version of the applicable STANDARD for WATER QUALITY TESTING DEVICEs.

# Notes About Component Requirements: Electrical Equipment

# National Electrical Code
At the release date of the MAHC 1 st Edition, United States National Electrical Code NFPA-70 (2008) is the current version of the applicable STANDARD for general electrical.

# Lights
At the release date of the MAHC 1 st Edition, UL 1241 -Junction Boxes for Swimming Pool Luminaires, UL 676-Underwater Luminaires and Submersible Junction Boxes, UL8750-Light Emitting Diode (LED) Equipment for Use in Lighting Products, and UL379-Transformers for Fountain, Swimming Pool, and Spa Luminaires are the current versions of the applicable STANDARDS for lights.

# Notes About Component Requirements: Deck Equipment

# Diving Boards and Platforms
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003 is the current version of the applicable STANDARD for diving boards and platforms.

# Starting Blocks
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003, FINA, NFSHSA, and NCAA are the current version of the applicable STANDARDS for starting blocks.

# Life Guard Chairs
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003 is the current version of the applicable STANDARD for lifeguard chairs.

# Ladders
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003 is the current version of the applicable STANDARD for ladders.

# Handrail
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003 is the current version of the applicable STANDARD for handrail.

# Facility Design & Construction ANNEX Stairs
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003 is the current version of the applicable STANDARD for stairs.

# Handicapped Lifts
At the release date of the MAHC 1 st Edition, the AMERICANS WITH DISABILITIES ACT is the applicable STANDARD for handicapped lifts and is regulated by the Department of Justice.

# Safety Covers
At the release date of the MAHC 1 st Edition, ANSI/ NSPI-1 2003, ASTM 1346, and UL2452 are the current version of the applicable STANDARDS for SAFETY covers.

# Aquatic Venue Operation and Facility Maintenance 
4.5 Aquatic Venue Structure

# Design for Risk Management
Working with the owner and/or aquatic risk management consultant, the designer can outline the anticipated zones of PATRON surveillance and place fixed lifeguard stations accordingly. It is important to have a person knowledgeable in aquatic risk management to advise on placement of fixed lifeguard stations and the general design of the AQUATIC VENUE as it relates to placement of lifeguards so to avoid blind spots, glare issues, and other obstructions being included in the design. This also allows the owner to influence design so it meets the anticipated labor requirements. In some operations where the AQUATIC VENUE design requires more lifeguards, this puts pressure on owners to minimize labor by extending zones of PATRON surveillance. Small design changes could reduce zone size without taking away from PATRON enjoyment. This is also a critical need when considering alterations such as the addition of new AQUATIC FEATURES (e.g., waterslides, mushroom) that change visibility and the PATRON zones of surveillance and increase the number of lifeguards needed. This knowledge is important to have while deciding on the benefits of the new AQUATIC FEATURE so they can be balanced with the increased labor cost.
Under Five Feet A maximum slope of 1:12 is used in water under five feet (1.5 m) for consistency with ADA since these ramps can be used for access. Variances may be considered by the AHJ.
Facility Design & Construction ANNEX 50 4.5.2.4 Drain POOLS should be designed to allow for the water to drain to a low point in order to prevent standing water from creating a contamination issue.
Pool Access / Egress 4.5.3.1 Accessibility As required by the Department of Justice, all POOL designs shall be compliant with the Americans with Disabilities Act (ADA). The POOL design shall not create SAFETY hazards with regards to maintaining necessary clearances, not infringing upon the recirculation of AQUATIC VENUE water, or creating areas for potential entrapment.

# Stairs

# Deep Water
It is common, especially in high-end diving wells with ten-meter towers, for there to be "swim-out" stairs underneath the dive tower. This provision is allowing for those types of deep water stairs without requiring the stairs to continue down to the bottom of the POOL (which may be 17 feet deep and impractical in the diving well example).   Perimeter Gutter Systems It is not the intent of this section to eliminate the "roll out gutter" as they need to be a minimum six inches (15.2 cm) from DECK to water level.  ADA 34 inch (86.4 cm) standards. The current MAHC language stipulates that 28 inches (711 cm) is a minimum, which does not preclude a designer from using 34 inch (86.4 cm) railings.
ADA Accessibility The outside diameter that the handrail configuration and dimensions need to conform to for the POOL access requirements outlined in ADA are not associated with ADA requirements, but these parameters are intended to address the necessary structural requirements which are not addressed in ADA. In the end, ADA STANDARDS will always take precedence over anything in the MAHC.
Another source for guidance is the Architectural Barrier's Guide -refer to Swimming Pools, Wading Pools, and Spas section numbers 242 and 1009.
Dimensions Dimensions of handrails should conform to requirements of MAHC Table 4.5.5.7 and MAHC Figure 4.5.5.7.1.  This pertains to the handrail comments in MAHC Annex Section 4.5.5.5. The MAHC does not intend to choose only certain aspects of ADA to enforce; the MAHC agrees that all components of the current ADA requirements will stand irrespective of the MAHC language. However, ADA does not address structural requirements.
Pool Wall This is a design criterion for POOLS in some of the western states. The initial intent was to design against entrapment between the railing and the POOL wall --both for fingers and also the hands/wrists/arms of smaller children. CPSC recommends four inches (10.2 cm) based on child anthropometry tables. Anthropometric charts were reviewed in establishing the current allowable range.
Support The structural requirements in the ladder, handrail, railing section are taken from commercial manufacturers and their recommended data.
Zero Depth (Sloped) Entries The term "light pastel color" should be consistent with Munsell color value 6.5 or higher.
School, facility or team logos incorporated on the POOL finishes are acceptable but will require review by the AHJ to ensure the design of such logos do not impede the color and finish functionality listed above.
Ultimately, water clarity is the primary criteria with which to be concerned. If a POOL has crystal clear water conditions and a BATHER is lying on the floor of a POOL with a blue finish versus one with a white finish, it's logical to think that the BATHER would be more identifiable against the darker finish. However, there's also the argument for recognizing dirt and debris at the bottom of the POOL.

# Munsell Color Value
The State of Wisconsin uses the Munsell color chart and requires values of 6.5 or greater. The Munsell color system looks at color purity, hue, and lightness to assign a value. This system is used in other industries and information on this system is easily available.
A contractor could provide a mock-up during the submittal process to the AHJ or engineer for review and approval. Plaster and other quartz aggregate manufacturers have reflectance testing that is available for finish samples.
The American Plasterer's Council defers to ASTM Standard E 1477 -98a title "Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating Sphere Reflectometers" to determine LRV values. It's a fairly simple test method where "Test specimens are measured for (total) luminous reflectance factor by standard color-measurement techniques using a spectrophotometer, tristimulus (filter) colorimeter, or other reflectometer having a hemispherical optical measuring system, such as an integrating sphere. The specular component is included to provide the total reflectance factor condition. The instrument STANDARD is referenced to the perfect reflecting diffuser. Luminous reflectance factor is calculated as CIE tristimulus value Y for the CIE 1964 (10) standard observer and CIE standard illuminant D 65 (daylight) or F 2 (cool white fluorescent).

# Structural Stability
Expansion and/or CONSTRUCTION JOINTs should be utilized when determined prudent by a licensed structural engineer. Any joints should utilize waterproofing strategies such as water stops as they are subject to compromising a POOL'S integrity regarding water tightness. The condition of all joints should be inspected regularly to ensure their condition.

# Hand Holds
Based on anthropometric data for children between the ages of 6.5 to 7.5 years of age, the difference between their stature and vertical grip reach averages 9.3 inches (23.6 cm) so this measurement has been reinstated to nine inches (22.9 cm)  is an inaccessible area because the DECK needs to end in order to achieve the "infinity" effect-typically this is achieved by an elevation difference-the DECK continues to extend around the POOL perimeter, but below the edge. The MAHC goal was to allow these types of design features while ensuring that these areas of the POOL are safe and still readily accessible for emergency response.
Handholds INFINITY EDGES can be accomplished with an obtuse angle or knife edge, or even a C701 handhold. It is typically submerged a fraction of an inch.
Maximum Height Building CODES typically require a railing for heights greater than 30 inches (76.2 cm) for SAFETY purposes.

# Underwater Benches
UNDERWATER BENCHes are intended to allow BATHERS to sit in locations along the POOL wall. These chair/bench-like structures either protrude into the POOL from the POOL wall or are recessed into the POOL wall. To accommodate the size of most people, the seat itself is often 16 inches (40.6 cm) to 18 inches (45.7 cm) wide and is located 12 inches (30.5 cm) to 24 inches (61.0 cm) below the water line.
Slip Resistant Slip-resistant surfaces shall meet or exceed the minimum coefficient of friction as set forth by the following groups:  Americans with Disabilities Act (ADA)  Occupational Safety and Health Administration (OSHA)
Maximum Water Depth The five foot (1.5 m) depth restriction is to address the potential safety issue of stepping or otherwise moving off a bench into deep water. The seat depth below the water line is limited to 20 inches (50.8 cm) maximum so a non-swimmer may be comfortable at that depth but once they move from the bench into a greater water depth it may exceed their comfort and/or skill level.  (1.5 m). They may be provided at the deep end of a competition POOL or other POOL with swim lanes. A ledge for resting may also be provided along the sidewalls of the same POOLS to allow resting for swimmers using the POOL for recreational swimming.
Five Feet or Greater A ledge for resting should not allow a person to use the ledge to cross from a shallow area into a deeper area of a POOL.
Structural Support UNDERWATER LEDGEs for structural support for an upper wall (structural ledge) are often located at a water depth of about three feet (0.9 m) depending on the wall manufacturer. The upper wall is a product manufactured of stainless steel, fiberglass, acrylic, or other materials. The support ledge and wall below the ledge is concrete, gunite, or other materials that the wall manufacturer specifies. Although POOLS using this wall structure are generally smaller POOLS, these POOLS can be any depth.

# Underwater Shelves
UNDERWATER SHELVES can be areas such as an expanded top tread of a stairway or a separate area many feet wide and long. The main purpose is often for small children, lounging in very shallow water or in chairs, or contoured as couches.  (2.5 cm) of letter height to ten feet (3.0 m) of viewing distance for oversized letters or one inch (2.5 cm) of letter height to 16.6 feet (5.1 m) which is ideal. A one inch (2.5 cm) letter height to 30 feet (9.1 m) of viewing distance is the minimum.
Feet and Inches Some states may require both units of measurement in feet, inches, and meters. Some states do not allow for abbreviation of units.
No Diving Markers

# Depths
The symbol is required as it is the universally recognized symbol for "No Diving" and can be understood by those who do not read and non-English speaking individuals. Diving boards are permitted only when the diving envelope conforms to the STANDARDS of the certifying agency that regulates diving at the facility -National Collegiate Athletic Association (NCAA), the National Federation of State High School Associations (NFSHSA), the Federation Internationale de Natation Amateur (FINA), or U.S. Diving. If the AQUATIC VENUE does not have competitive diving, then the diving envelope must conform to these diving envelope STANDARDS. The intent of this section is to prohibit recreational and/or unsupervised users from performing DECK level diving into water five feet (1.5 m) or shallower. It is not intended to apply to competitive divers competing under the auspices of an aquatics governing body (e.g., FINA, U.S.A. Swimming, NCAA, NFSHSA, YMCA) or under the supervision of a coach or instructor. The vast majority of current STANDARDS allow for diving off the side of the POOL in water five feet (1.5 m) deep or greater. Water depths of at least five feet (1.5 m) are generally considered as safe for diving from the edge of a POOL where the coping/DECK is the typical six inches (150 mm) above the water surface. AQUATIC VENUE size and geometry may necessitate additional depth marking placements about all sides of the AQUATIC VENUE.
The American Red Cross recommends nine feet (2.7 m) of water depth based on analyses of spinal cord injuries. 82 The organization has clarified this recommendation to state, "Be sure water is at least nine-feet deep unless performed with proper supervision and in water depths that conform with the rules of the concerned regulating body, such as USA Swimming, the National Collegiate Athletic Association (NCAA), the Amateur Athletic Union (AAU), the National Federation of State High School Associations (NFSHSA), YMCA of the USA, and the International Swimming Federation (FINA)."
Facility Design & Construction ANNEX 60 Although there are some national data on spinal cord injuries (SCIs) in general, data on diving-specific SCIs are limited, particularly for SCIs involving public POOL-related competition diving.
General data on spinal cord injuries: For SCIs in general, approximately 40 SCIs/million population occur each year in the US (about 12,400 injuries for 2010) with approximately 4.5% related to diving injuries. 83 SCIs are a catastrophic public health problem leading to disability and decreased life expectancy with a large economic and social burden for those that suffer the injury. 84,85 The MAHC recommends that these national databases be re-analyzed with aquatics in mind to gather more detailed information on SCIs related to diving in treated AQUATIC VENUES, particularly public AQUATIC VENUES.  (1.5 m). Only one injury occurred in water between six and seven feet (1.8 to 2.1 m). Another global review study showed that 89% of diving-associated neck injuries occurred in water less than five feet. 89 These data support keeping non-competition DECK level diving to water depths greater than five feet (1.5 m).

# Deck level diving and swimming pool-related
An example of an international "No Diving" Marker:
Dual Marking System A symmetrical AQUATIC VENUE design is a design which is circular in nature where there is a shallow end around the entire perimeter and the bottom slopes from the perimeter towards a deeper portion in the center.
Wading Pool Depth Markers A WATERSLIDE RUN-OUT in a WADING POOL may hold up to six inches (15.2 cm) of water without necessitating a no-diving sign or depth marker.

# Aquatic Venue Shell Maintenance 

# Special Use Aquatic Venues
During the final comment period, SURF POOLS were identified as different from WAVE POOLS, and many of the requirements for MAHC Section 4: Design and Construction are not applicable to SURF POOLS. The term SPECIAL USE AQUATIC VENUE has been added to potentially allow construction and use of SURF POOLS and any other, yet to be identified, AQUATIC VENUE or POOL that, while meeting the intent of CODE applicability to public AQUATIC FACILITIES, cannot practically be designed to meet existing design standards and keep the intended use. It is anticipated that appropriate design standards will be developed and incorporated in the CODE as part of the MAHC revision process.
There are three types of SURF POOL systems currently available or being developed. Manual controls would almost certainly be set based on time of day. As the amount of daylight fluctuates throughout the year, these would need to be adjusted.
Light Levels

# Minimum Levels
The minimum light levels are as recommended in the Illuminating Engineering Society of North America (IESNA) RP-6-88, "Recommended Practice for Sports and Recreational Area Lighting" for the recreational class of use. Higher light levels are recommended for various competitive classes of use. There is a difference between indoor and outdoor settings because outdoor settings usually have a higher contrast with darkness that does not occur indoors.
Overhead Lighting Avoid glare by keeping overhead lighting directed 60-90 degrees horizontal of the eye. Glare on water can be avoided by direct lighting (i.e., the more direct the light, the less opportunity for glare). Also consider maintaining a close ratio of the lighting underwater and overhead to obtain a balance thus avoiding glare.
Artificial Lighting Glare from artificial light that interferes with the lifeguard's view of the swimmers shall be avoided. For today's light sources for higher-efficiency lamps (i.e., more light output per watt), this requirement no longer makes sense. Consider using a measure of light output (e.g., lumens) instead.
Based on an existing 300W General Electric R40 AQUATIC VENUE lamp that produces 3,750 initial lumens of light output, the conversion between watts and lumens is as follows: 0.5 watts/sq.ft. x 3,750 lumens/300 watts = 6.25 lumens/sq.ft.

# Example:
Lighting comparison between Incandescent & LED lamps for a 2,400 square foot (223 m 2 ) AQUATIC VENUE. Notice that LED lamps are 90% more efficient (lumens/watt) than Incandescent lamps.
"A replacement lamp will need to provide 6.25 lumens per square foot of surface area."

# Additional Information:
The incandescent lamp has an average life of 2,000 hours. For an AQUATIC VENUE that is operational 12 hours per day for 365 days (4,380 hours per year), the incandescent lamp failure rate would be approximately two times a year. Note that in-water AQUATIC VENUE lighting remains on when the AQUATIC VENUE is closed to swimming. For the 50,000 hour life of an LED lamp, the failure rate would be 11.4 years.
The AQUATIC VENUE surface replacement would be a determination of replacement lamps and not the lamp itself. Annual energy savings per lamp would be 1,183 KWH.
Minimum Requirement A common practice has been to express underwater lighting requirements in watts per square foot of POOL surface. Light output efficacy (lumens per watt) can vary greatly depending on the light source. Incandescent lighting, the most historically prevalent underwater light source, also has the lowest or worst efficacy. Some of the most common incandescent lamps are listed below, along with their initial lumen output and calculated efficacy:
4.0 Facility Design & Construction ANNEX 64
For the purposes of these requirements, the underwater lighting requirements have been converted from incandescent watt equivalents to initial lamp lumens using a conversion factor of 12.0 lumens per watt. The converted watts per square foot of POOL surface requirements are 0.5 watts , 1.5 watts , 1.5 watts , 2.5 watts .
It is recommended that future studies be conducted to determine minimum lighting requirements based on water depth, hours of operation, and overhead lighting design. The main goal is to be able to see the bottom of the POOL, in particular a person on the bottom, at all times when the POOL is open to the public.
Night Swimming with No Underwater Lights Providing higher lighting levels (15 footcandles (161 lux)) than the minimum requirements (10 footcandles (108 lux)) of MAHC Section 4.6.1.3.1 eliminates the requirement for underwater lighting in outdoor POOLS.
Emergency Lighting This section isn't intended to provide less stringent requirements, just a baseline STANDARD of design for locales that may not address this requirement. The industry commonly uses 0.5 foot-candle (5.4 lux)as an industry design STANDARD.
Glare Consider the sun's positioning through different seasons as well as the window placement to avoid glare. Consider moveable lifeguard stands or positions to avoid glare in different seasons. Consider tint and shades when natural light causes glare.
Windows and any other features providing natural light into the POOL space and overhead POOL lighting should be arranged to avoid glare on the POOL surface that would prevent identification of objects on the POOL bottom.
Careful consideration should be given to the placement of windows and skylights about the POOL. Natural light from directly overhead is less likely to create glare than light through windows at the sides and ends of the POOL.
Control of glare from artificial light is more likely if the angle of incidence of the main light beam is less than 50 degrees from straight down. Diffuse or indirect light sources may also help to minimize glare.

# Facility Design & Construction ANNEX 65
The MAHC had a very difficult time coming to a consensus on MAHC wording regarding glare that could be defended and enforced from a regulatory standpoint. How does a plan reviewer determine that glare based on design documents are excessive (perhaps only in certain months of the year)? The MAHC felt that design recommendations would best be addressed in the Annex. As a result of this varied and sometimes vague approach to defining "proper" ventilation, it is critical that the MAHC begins to better define AIR HANDLING SYSTEMS and establish parameters for air quality that reduces the risk of potential health effects. The aquatics industry has always had a challenge with indoor air quality. With the relatively recent increases in building large indoor waterparks, which have high BATHER COUNTs and contamination burdens and exposure times unseen before, indoor air quality is an increasingly important health concern. The media focus in recent years has highlighted this challenge.
Although the AIR HANDLING SYSTEMS of these AQUATIC FACILITIES are quite sophisticated, there are many variables to consider. In addition, much research is still needed in water chemistry and the use of other technologies to improve indoor air quality. The MAHC outlines the design, performance, and operational parameters that can be detailed using data available at the current time. The Annex information provides insight into the Ventilation and Air Quality Technical Committee's rationale and also identifies areas where more research is needed before additional parameters can be set.
The MAHC's intent is to require the design of an INDOOR AQUATIC FACILITY to be conducted by a licensed professional engineer with experience in the design of mechanical systems. The MAHC approached this section assuming designs will be evaluated by the AHJ in the location in which the system is to be installed. Following the first public comment period, the ventilation requirements were dramatically changed and draft material was removed from both the Code and Annex. The thinking behind those initial recommendations was saved for future consideration in MAHC Appendix 2. is to assure the health and comfort of the users of the AQUATIC FACILITY. A variety of health effects can occur as a result of poor ventilation that leads to accumulation of chemical and biological products in the air. The following section reviews some of the issues of concern for INDOOR AQUATIC FACILITIES.

# Chemical By-Products
The OXIDATION of waterborne organic and inorganic compounds by CHLORINE-or other halogen-based products is a complex process leading to creation of a large number of OXIDATION and DISINFECTION BY-PRODUCTS (DBPs) during the drinking water and aquatic water treatment processes. The source of these compounds is variable but includes source water CONTAMINANTS, BATHER waste (e.g., feces, urine, sweat, skin cells), and environmental introductions (e.g., dirt). Although the identity of many of these compounds is known, many others are uncharacterized and the health effects associated with short and long-term exposure to these compounds are only just starting to be characterized for the aquatic environment. Several of these compounds are known to be volatile and can accumulate in the air surrounding an INDOOR AQUATIC VENUE. Multiple publications discuss the acute and potentially long-term health effects of exposure to these compounds in the aquatic setting. 90,91,92 The nitrogenous OXIDATION by-products DICHLORAMINE and TRICHLORAMINE (e.g., chloramines) are known to be irritants that cause acute eye and lung distress. Accumulation of these compounds in indoor settings has been previously documented in several occupational settings where workers routinely use chlorinated solutions to rinse organic products such as poultry 93,94 and uncooked produce. 95 Similar symptoms of ocular and respiratory distress have been documented in outbreaks associated with use of INDOOR AQUATIC FACILITIES. 96,97,98,99,100,101  Other DISINFECTION BY-PRODUCTS (DBPs) such as the TRIHALOMETHANES have been studied extensively due to their production during treatment of drinking water. These investigations have greatly impacted U.S. EPA water treatment regulations, so there is now a major emphasis on reducing production of DBPs. The effects of these compounds in model systems show long-term exposure associated with chronic health effects such as bladder cancer. 102,103 Investigators are beginning to examine the long term health effects of exposure to DBPs during swimming. Although limited, some data suggests the potential for INCREASED RISK of asthma 104,105 and bladder cancer. 106 However, many of these studies are ecologic in design, which makes it difficult to definitively link exposures, actual exposure levels, and swimming. 107,108,109 Biological By-Products A variety of biological organisms that grow naturally in the environment (e.g., Legionella, Mycobacterium avium complex and other non-tuberculous mycobacteria, gram negative bacteria) or their constituents (e.g., proteins, lipo-polysaccharides, endotoxin) can be spread in the INDOOR AQUATIC FACILITY environment and cause infections 110 , 111 and hypersensitivity/allergic reactions (e.g., "Hot tub lung"; "Lifeguard lung", Pontiac fever). 112,113,114,115,116 The levels of pathogens and their constituents can be minimized with adequate INDOOR AQUATIC FACILITY ventilation, maintenance, and required water quality.
Facility Design & Construction ANNEX 68 4.6.2.2 Exemptions The MAHC decided that only "buildings" as defined in the building code would be included in the scope of the INDOOR AQUATIC FACILITY definition since there are many variables to consider for places like open buildings (may not have a roof or missing sides) such as variations in weather, geographic zone, etc. that would impact AIR HANDLING SYSTEM design even if one was needed. The guidelines in this module are meant to address the SAFETY and health of users in environments in which air quality is managed by mechanical means due to the "closed" environment since fresh air is not able to freely flow through the building. There are two SAFETY functions of the AIR HANDLING SYSTEM: to bring in fresh air and to protect the PATRONS and the building, which requires movement of air. The current ASHRAE 62.1 standard states 0.48 cfm/ft 2 fresh air is the minimum but still requires an air change. The MAHC needs to consider air delivery rate like TURNOVER for AQUATIC VENUES. To assure good indoor air quality, it is likely that the design should consider THEORETICAL PEAK OCCUPANCY, water type (e.g., flat, agitated, hot) and the size and use of the building.
The current STANDARDS approach to ventilation is based on square footage of the AQUATIC FACILITY and yet AQUATIC FACILITIES vary in size. Some facilities have a 20 foot (6.1 m) ceiling and in the case of indoor waterparks and stadium-style INDOOR AQUATIC FACILITIES, the ceiling heights can reach 60+ feet (18.3 m). In addition, the water surface area has a great deal to do with the amount of CONTAMINANTS released into the air but this is generally not included in design criteria.
There are many microclimates in larger AQUATIC FACILITIES with varied AQUATIC VENUES and AQUATIC FEATURES. Air movement will need to be targeted within these microclimates.
The challenge is that ASHRAE 62.1 only takes into account the building square footage and number of spectators rather than bathers. ASHRAE fundamentals require an air delivery rate for the volume of air. Designers felt water chemistry, fresh air, THEORETICAL PEAK OCCUPANCY, water surface area and type, and distribution of air (barring condensation) are more or equally as important as the air delivery rate. The MAHC discussed the various chemical and biological contaminants, the availability of testing protocols, and data to support developing health effect thresholds.
The researchers on the committee were able to provide a list of research regarding the thresholds of such CONTAMINANTS that produced symptoms in users of INDOOR AQUATIC FACILITIES. More detailed summaries of these data can be found in Appendix 1: Summary of Health and Exposure Data for Chemical and Biological Contaminants.
After evaluating possible CONTAMINANTS, the committee felt the most frequently detected adverse health symptoms associated with indoor air quality were related to chemical CONTAMINANTS. In evaluating the various chemical CONTAMINANTS, it was found that was the most prevalent reported 117 TRICHLORAMINE CONTAMINANT . Therefore, this section of the MAHC focused on TRICHLORAMINE as the major chemical CONTAMINANT for design considerations.
The table below summarizes findings on the threshold amounts that produced adverse health symptoms. In evaluating the TRICHLORAMINE research, it was apparent there is not a single test method used throughout the research. Without a validated test method, it is difficult to compare and benchmark the data from the various studies. As a result, a firm threshold could not be determined solely on the published research to date. Also, without a validated and simple test method, there is not an easy way for health departments or owner/operators to test routinely or with any consistency. For these two reasons, the MAHC felt it could not establish a threshold to be enforced by this section of the MAHC at this time. More research using a validated test method may lead to determination of a threshold level in the future. To enforce such a threshold level, the test also needs to be commercially available and easily performed by aquatics staff and health officials.
Therefore, the performance requirements for the AIR HANDLING SYSTEM have parameters for fresh air and dew point/humidity. To accomplish this, several design criteria were kept in mind:  Fresh air requirements are established to specific levels. The theory is that if the building mechanical system is able to evacuate enough air to remove TRICHLORAMINE, then by default the other airborne CONTAMINANTS would also be evacuated.  Dew point/humidity levels are set to avoid mold growth and damage to the building structure. The efficacy of UV and ozone are well documented for their effect on biological CONTAMINANTS but the photochemistry taking place is a different reaction for DISINFECTION versus controlling combined CHLORINE levels. Further research is needed to determine the effectiveness of UV and ozone on destroying DBPs before they can be considered in the design of an AIR HANDLING SYSTEM. Guidance is included in the MAHC for the use of UV and ozone for DISINFECTION. It is unknown at this time if the parameters for the equipment to achieve DISINFECTION will also result in the reduction of DBPs.
The initial draft of the MAHC Ventilation and Air Quality Module included discussion of fresh air requirements for facilities utilizing UV and ozone, which allowed for a reduction in the amount of fresh air required for ventilation compared to basic water treatment. However, until the efficacy of these technologies in reducing DBP formation can be established and parameters can be set in which any installation of these technologies can meet minimum requirements, we cannot include these technologies as a method to reduce fresh air requirements. Such information should be considered when efficacy data become available.
For future development of minimum performance requirements for UV and ozone, one should consider dose as a function of concentration and contact time. Many systems are designed for full flow treatment but contact time is very limited. These minimum parameters may help to attain efficacy, but as noted, more research is required. Below are some proposed statements for use once system efficacy can be determined: Minimum Outdoor Air Requirements Significant numbers of public comments were received regarding the proposed increase, above ASHRAE 62.1 STANDARDS of required outdoor air. The commenters noted that the requirements will result in increased costs for equipment and operation while lacking adequate data to support the increase. Based on the potential negative impact and the need for additional research and data to differentiate the causes and sources of indoor air quality problems on design criteria (e.g., design, inappropriate operation, inadequate maintenance), the MAHC decided to defer to ASHRAE 62.1 outdoor air requirements in this version of the MAHC. The MAHC thought it important to preserve the work done by the Technical Committee, so the proposed code language for additional outdoor air has been moved to Appendix 2: Air Quality Formula in the MAHC along with preserving the corresponding Annex discussion. A research agenda should be developed and should be a priority to better address the contributing factors to indoor air quality problems and the appropriate design and operational requirements needed to address those factors.
System Alarm There are several methods to add a MONITORING station to the outside air portion of the AIR HANDLING SYSTEM to establish the volume of outside air being introduced into the AQUATIC FACILITY. Such a MONITORING station should be installed. In addition, it should be noted that a negative pressure must be maintained during all operating modes. This negative pressure must be set-up at the commission stage by the installing contractor or by means of automatic operation by the AIR HANDLING SYSTEM or Building Automation System.
Relative Humidity Relative humidity is a ratio, expressed in percent, of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated. Since the amount of atmospheric moisture is dependent on temperature, relative humidity is a function of both moisture content and temperature. For consideration in designing the facilities structure, dew point is a better measure of absolute moisture levels. Dew point has a relationship with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. Relative humidity of 100% indicates the dew point is equal to the current temperature and that the air is maximally saturated with water. For human comfort factors, the maximum relative humidity has been specified for a very narrow range of indoor temperatures and thus is an easily measured and understood metric by users and owners of an AQUATIC FACILITY. For the building design, dew point is a more important metric because the outdoor conditions can be over a very wide temperature range. The design professional must be able to calculate the internal dew point for all building structure components to avoid condensation. Condensation occurs when the inside surface temperatures equal the dew point of the space.
Using a properly calibrated instrument designed to measure relative humidity eliminates the complexity of calculating relative humidity by hand. It is important to collect a series of representative relative humidity measurements inside the INDOOR AQUATIC FACILITY. The building should be divided into representative areas if necessary, depending upon size and various AQUATIC FEATURES. Measurements should be taken from each occupied area. Measurements should be taken at DECK level and recorded. Arithmetic average of measurements will provide an estimation of the relative humidity in the INDOOR AQUATIC FACILITY. This may require consultation with design professionals.
Disinfection By-Product Removal It is the MAHC's intent not to limit the development of new technologies. Although the efficacy of these technologies are not readily apparent, in the future there is a hope that the CODE will allow for the design professional to decrease the outside air requirements when secondary technology is used and the design professional can prove the efficacy of the added technology. Other methods and technology for decreasing DBPs include:  Ventilating surge tanks to remove off-gassing TRICHLORAMINE before the water re enters the POOL area, and  Use of a cooling tower to force water to off-gas TRICHLORAMINE before reintroducing water to the POOL area.
Purge When an AQUATIC FACILITY has an event (e.g. pool is shocked) that requires the introduction of a larger volume of outdoor air, the PURGE mode can be manual triggered to provide a flush of the INTERIOR SPACE. The intent is to run the air handling system at purge capacity until the contaminant causing odor/eye/lung discomfort has dissipated to 4.0 Facility Design & Construction ANNEX 74 an acceptable level. The lack of an assay for airborne chloramines, means that "acceptable" is arbitrary and unenforceable since it relies on an operator assessment. When appropriate tests are available, the MAHC would like to set a numerical action threshold that would be enforceable.
Air Handling System Filters Manufacturers/designers could consider developing/incorporating specialized solid phase (e.g., activated carbon or other media) chloramine removal air filtration as another means to sequester chloramines and potentially reduce fresh air requirements. However, such systems need to show proven efficacy. With new methods development, such systems could eventually be designed with sensors confirming that the combined CHLORINE levels are at an acceptable level (when such air measurement methods become available). If levels increased, then the AIR HANDLING SYSTEM could proportionally increase the amount of outside air.

# Air Quality -Health
No rapid, simple, and commercially available tests for di-and tri-chloramine exist at the current time. However, MONITORING for TRICHLORAMINEs can also be effectively accomplished by training POOL operators to be on alert for the distinctive chloramine odor and eye and lung irritation it causes. The odor threshold for TRICHLORAMINE is 0.1 mg/m 3 and health symptoms start happening around 0.3-0.5 mg/m 3 , so odor MONITORING generally works well as an early warning system. 124,125,126,127,128,129

# Air Turnover Rates
Monitoring combined chlorines in the water or VOC concentrations in the air can be used as an alternative to measuring air quality. The AQUATIC FACILITY design engineer should specify what the alternative measurement limit should be in establishing an alternate ventilation AIR DELIVERY SYSTEM.
Facility Design & Construction ANNEX 75

# Indoor Aquatic Facility Electrical Systems and Components
Nothing in this code should be construed as providing relief from any applicable requirements of the NEC or other applicable code.

# General Guidelines Wiring
Wiring located near or associated with equipment for bodies of water should be installed in compliance with the NEC or with other applicable code, except where the MAHC is more restrictive.

# Metal Raceways
Metal raceways should be equipped with a grounding conductor sized according to NEC Article 250 to maintain device ground potential in the event of degradation of the raceway.
- See ANSI/IEEE 241, Section 5.17.6.  250-110(2).

# Electronics
All electrical equipment, devices and fixtures should be listed and labeled for the expected atmosphere of the space.
- See NFPA 70HB08, Article 100: Labeled, Explanatory Note.  See NFPA 70HB08, Article 100: Listed, FPN.

# Light Switches
Any light switches installed inside interior CHEMICAL STORAGE SPACES should be approved for use in wet and corrosive atmospheres, or shall be otherwise protected, as by a weather-proof actuator cover with a gasket.  See NEC Article 110.11: Deteriorating Agents.

# Permanent Electrical Devices
All permanently connected electrical devices should be grounded per the NEC or other applicable code, using a separate grounding conductor which does not depend on the conductive integrity of any metal conduit exposed to chemical-STORAGE space air.

# Uncontrolled Condensation
Uncontrolled condensation in a building can lead to the growth of molds, with subsequent health effects. Uncontrolled condensation in a building can lead to property damage from rust, rot, ice pressure, and other.
Condensation can be controlled by:
- Controlling the evaporation rate of the water,  Controlling the temperature and relative humidity of the room air, and  Maintaining all exposed building surfaces above room-air dew point.

# Facility Design & Construction ANNEX 80

# Evaporation Rate
The POOL evaporation rate is affected by the:  Size of the POOL,  Agitation of the water,  Heat of vaporization of the water at that temperature and pressure,  Temperature difference between the POOL water and the room air and the associated difference in vapor pressures, and  Speed of the air over the POOL'S surface.  See Places of Assembly, ASHRAE Handbook of Fundamentals 131 Example for Note: A design POOL-water temperature is 82F (27.8C) with a design air temperature of 84F (28.9C). It is decided to raise the POOL water temperature to 83F (28.3C); the air temperature should be raised to 85F (29.4C) to maintain the same evaporation rate. Any surface which is exposed to room air and which cools below the dew point of the room air will become wet with condensation. Such surface may not be visible, e.g. inside a wall.

# Space Heating
- Space heating should be available year-round.  Space heating should not be disabled seasonally.

# Exceptions may include:
- Space heating need not be provided during such times as the POOL(s) may be drained completely, all AQUATIC FEATURES and other evaporative loads are disabled and drained, and the room relative humidity does not rise above the design range.  Space heating may not be required if ventilation with outdoor-air is sufficient to prevent room temperature from falling below the design range, and room relative humidity from rising above the design range.

# Seasonal Disabling
Where POOLS are filled or partially filled, the evaporation rate will increase as room air temperature decreases. Seasonal disabling of space heating could allow a drop of room temperature, with a subsequent increase in evaporation rate and possible uncontrolled condensation.
Surfaces where the temperature may decrease below the design dew point of the space under normal operation shall be identified as part of the design process. At least one inspection should be done during the first heating season to identify any other such surfaces. The addition of heat to surfaces identified may be necessary to maintain their temperature above the design dew point for the space. Where forced air is used to heat identified surfaces, the heating method specified shall be so installed as to heat the 4.0 Facility Design & Construction ANNEX 81 room's air supply. The temperature, flow rate, and delivery of the supply air for each identified surface shall be such as to heat that surface above the design dew point of the space, under the worst-case design conditions. Such surfaces may have low values of thermal resistance. Such surfaces may include, but are not limited to windows and their frames, doors and their frames, any metal structural members that penetrate the vapor retarder, and any under-insulated sections of walls or roofs.
- See Thermal and Water Vapor Transmission Data, ASHRAE Handbook of Fundamentals 132

# Combustion Heaters
Where combustion space heaters or combustion heaters required are located inside a building, the space in which the heater(s) or an assembly including the heater(s) is located shall be considered to be an EQUIPMENT ROOM for the purposes of MAHC Section 4.9.1. The requirements of MAHC Section 4.9.1 shall apply. Exceptions may be made for space heaters listed and labeled for installation in the atmosphere shall be acceptable without ISOLATION from chemical fumes and vapors.
Note: Not all space heaters listed for heating INDOOR AQUATIC FACILITY air are listed for installation in an INDOOR AQUATIC FACILITY. Combustion space heaters should not be installed in an INDOOR AQUATIC FACILITY, unless the heater is rated for the atmosphere.
High Temperature This temperature limit shall not be construed to be the maximum limit of the bulk water (water in the heater) temperature. Bulk-water temperature limits can be much higher. The temperature limit of MAHC Section 4.6.4.1 is for water in contact with bathers. To meet the limits set in 4.6.4.1, water heaters can:  Heat the water stream to the limit of MAHC Section 4.6.4.1 and return the water directly to the AQUATIC VENUE, or  Heat the bulk water above the limit set in 4.6.4.1 and then use mixing or other methods to ensure that BATHERS are not exposed to temperatures above the limit of MAHC Section 4. 6.4.1. 133 Examples of "applicable CODES" include but are not limited to: Equipment Room Requirements Combustion heaters should not be installed in an INDOOR AQUATIC FACILITY, or exposed to other chemical fumes, unless the heater is rated for the atmosphere.
First Aid Area 4.6.5.1 Station Design A conveniently designated first aid station location should be provided for use when BATHERS report with minor injuries and/or illness. The first aid station must be easy to locate and must have first aid supplies to care for minor injuries and more serious injuries until emergency assistance can arrive. Some AQUATIC FACILITIES may have a formal First Aid Station that is a stand-alone and others may have a location for first aid equipment. The MAHC felt it would allow for flexibility in design to call out the location for first aid equipment rather than designate a stand-alone station. Some AQUATIC FACILITIES are large and a single first aid station is not as practical as distributing first aid equipment throughout the AQUATIC FACILITY (e.g., to individual aquatic venues). From a design standpoint, the designer must address the location of such equipment and as stated in MAHC Section 4.5.1, should work with the owner and/or aquatic risk management consultant to designate these locations.
Emergency Exit
Drinking Fountains 4.6.7.1 Provided A drinking fountain is required at an AQUATIC FACILITY simply to encourage swimmers not to drink the POOL water and to keep swimmers hydrated. At an outdoor AQUATIC FACILITY, the drinking fountain can be located inside an adjacent building to allow year-round use when the AQUATIC FACILITY is closed for the winter. The drinking fountain would not need to be winterized. When a drinking fountain is not located in the AQUATIC FACILITY, it should not be located more than 25 feet (7.6 m) from the AQUATIC FACILITY entrance. The AHJ may approve a bottled water supply in place of a drinking fountain. The water from a bottled water supply shall be as readily accessible to BATHERS as would the water from a drinking fountain.

# Additional Width
The MAHC tried to distinguish the word "BARRIER" from "ENCLOSURE." Those definitions are in the glossary. As currently defined, a "BARRIER" is simply intended to be an obstacle intended to deter direct access from one point to another. For example, a simple post and rope solution would meet MAHC intent.

# Balcony
The intent is to prevent people from using a balcony as a diving platform. If a balcony is close to overhanging an AQUATIC VENUE, some people may try and use it to jump or dive into the AQUATIC VENUE. The more substantial and preventive the BARRIER at the balcony is, the less likely is that a person will use it.
Bleachers Many building code jurisdictions may not be aware of the new ICC 300 bleacher STANDARD. Once jurisdictions adopt the 2007 International Building Code and supplements, the bleacher STANDARD will become better known.

# Recirculation and Water Treatment
Recirculation Systems and Equipment

# General

# Rationale for Prescriptive Approach
Recirculation and water treatment systems guidance tends to be more prescriptive than performance based because it is quite difficult and expensive to measure the performance of the filtration and RECIRCULATION SYSTEM with regard to pathogen removal and/or inactivation. Even the measurement of water clarity (e.g., turbidity) can be difficult (due to potential bubble formation, instrument fouling, and instrument calibration procedures) and can cost more than a thousand dollars to continuously measure turbidity at a single point.

# Reasons to Exceed the Minimum Standards
There is no single TURNOVER time or one type of filtration system that is optimal for every AQUATIC VENUE. Requiring the most aggressive design for every AQUATIC VENUE is not the intent of the MAHC (or even necessary). However, some AQUATIC VENUES, particularly those with high numbers of BATHERS per unit water volume or a BATHER population more likely to contaminate water (e.g., children less than five years old), could need higher recirculation rates and more efficient filtration than the minimum STANDARDS. Since it is not always possible to predict the number of BATHERS in an AQUATIC VENUE, the MAHC recommends a modest overdesign of the RECIRCULATION SYSTEM pipes and thus ample space be left for expansion of pumping and filtration capacities, which will be referred to henceforth as the hydraulic flexibility 4.0 Facility Design & Construction ANNEX 84 recommendation. Future editions of the MAHC could have higher minimum STANDARDS that AQUATIC FACILITIES might wish to comply with without having to remove and replace a lot of concrete to accommodate slightly larger pipes.

# Hydraulic Flexibility Recommendation
The hydraulic flexibility recommendation made in the section above will also reduce friction losses in the pipes that may lead to energy savings and reduced operating costs. With the formalization of a new turndown system for AQUATIC VENUES, it is hoped that AQUATIC VENUES may be designed for worst-case conditions and then operated according to the demands placed on the system. A turndown system could be used to operate below the minimum operational STANDARDS set by the MAHC when the AQUATIC VENUES is not occupied as an additional cost-saving measure as long as water quality criteria are maintained.
Combined Aquatic Venue Treatment There are some important considerations to take into account when considering combined AQUATIC VENUES treatment, and this practice is generally discouraged for most installations. First, to respond to a contamination event, it would be necessary to shut down all AQUATIC VENUES and water features on a combined AQUATIC VENUE treatment system since contamination of one AQUATIC VENUE would rapidly contaminate all combined AQUATIC VENUES. Second, including an INCREASED RISK AQUATIC VENUE on a combined system would require secondary DISINFECTION to be installed for all AQUATIC VENUES on the RECIRCULATION SYSTEM. The two scenarios would involve isolating Cryptosporidium to a single AQUATIC VENUE (limiting the number of bathers exposed while keeping the concentration high) or diluting it as much as possible between all AQUATIC VENUES (to limit the maximum concentration or exposure level while increasing the number exposed).
Based on the infectious dose concept (i.e., the number of oocysts required to be ingested to cause an infection), diluting Cryptosporidium or other CONTAMINANTS is one way of reducing outbreak potential but the high numbers of Cryptosporidium OOCYSTS that may be excreted (e.g., 10 8 -10 9 per contamination event134,135) may overwhelm modest dilution factors while greatly increasing the number of people exposed. While the number of BATHERS exposed may increase, the exposure level will decrease if circulation rates were the same, meaning dilution of a very small AQUATIC VENUE into a large POOL might reduce the Cryptosporidium level from 1000's of OOCYSTS per mL swallowed to less than 1 per mL in the combined system. However, smaller AQUATIC VENUES can be circulated at faster rates through the SECONDARY DISINFECTION SYSTEM and therefore can have OOCYSTS loads reduced faster if they are in a small volume, rapidly circulating AQUATIC VENUE.
Design modeling is needed to compare the efficacy of these two scenarios under different OOCYST concentrations. The dilution scenario only works if an INCREASED RISK AQUATIC VENUE of small volume is combined with a large volume AQUATIC VENUE. For
Facility Design & Construction ANNEX 85 AQUATIC VENUES similar in size, the impact of dilution is small while the number of people exposed might double or more. There could also be benefits with a combined system that would make it easier to provide more stable water quality parameters (in terms of pH and chlorine level) because larger water volumes tend to be easier to control. Again, the potential positive impact of combined water treatment is limited to combining small POOLS with much larger POOLS, which is not likely if the DISINFECTION requirements differ between the AQUATIC VENUES. Hydraulically isolating a given AQUATIC VENUE on a combined treatment system with valves is discouraged because doing so necessarily prevents filtration and recirculation of the water. However, ISOLATION capabilities are recommended for maintenance purposes (as well as separate drain piping).

# Inlets

# General

# Flow Velocity
The velocity of flow through any INLET orifice (at between 100% and 150% of the total recirculation flow rate chosen by the designer) should normally be in the range of seven to 20 feet per second (2.1 to 6.1 m/s). The range of velocities through the INLETS was selected to balance two competing goals.( 1) The velocity should be high enough to push water effectively to the center of the POOL (or to within the range of the floor inlets for wider pools), but ( 2) the velocity should not be so high as to waste an unnecessary amount of energy. The INLETS still being within design range at 150% of the design recirculation flow rate is to accommodate the hydraulic flexibility recommendation discussed previously. This recommendation ensures proper operation at both the current and any future flow rates up to at least 150% of the recirculation flow.

# Floor Inlets

# Maintain and Measure
The use of floor INLETS might require additional considerations for draining them when the POOL is not in use. The likelihood of biofilm proliferation in pipes not in use is thought to increase significantly as the FREE CHLORINE RESIDUAL is dissipated. Drinking water distribution pipes are normally coated with biofilm even in the presence of a constant CHLORINE residual 136 , 137 . Since it is more difficult to inactivate microorganisms in a biofilm 138 , there is potentially increased risk of human exposure to pathogens shielded by biofilm once the POOL reopens. Leoni and coworkers found mycobacteria in 88.2% of POOL water samples analyzed and reported that swimming POOLS provided a suitable habitat for the survival and reproduction of mycobacteria 139 . Significant damage to the RECIRCULATION SYSTEM pipes and surroundings can result from the expansion of water as it freezes. Both dangers may be alleviated by simply draining water from the pipes For standard POOLS, since the majority of the water leaving the POOL does so at the surface, locating the INLETS 24 inches (61.0 cm) below the design operating water level would reduce short-circuiting of water from the INLETS to the surface removal system.

# Inlet Spacing
Wall INLETS have a limited range for how far they can push water out toward the center of the POOL especially as the flow of water is being pulled out of the POOL at the wall via gutters or SKIMMERS. The likelihood of forming regions in the center of the POOL that are not efficiently filtered or chlorinated increases as the width of the POOL increases. For POOLS less than 4 feet (1.2 m) in depth, the average velocity of the water is thought to be increased as the volume of water served by a single INLET is expected to decrease assuming equal spacing.
Step areas, swim outs, and similar recessed or isolated areas are likely to create a dead zone. Placement of one or more INLETS in these areas will help ensure distribution of chlorinated, filtered water to these areas.

# Dye Testing
Dye testing should be performed to determine and adjust the performance of the RECIRCULATION SYSTEM. Dye studies tend to be qualitative in nature 140 .
A dye test may not be necessary for "standard" designs previously determined to provide effective mixing. It may be particularly important for irregular shaped POOLS.
Some judgment is generally required to determine whether a dye study should be classified as passing or a failing. In general, dead zones (or areas of poor circulation) would indicate a failure that could be fixed by adjusting the INLETS or other system hydraulics. If the POOL does not reach a uniform color within 15-20 minutes, then adjustments are required.
Refer to Appendix 3: Dye Testing Procedure for additional information.
The use of SKIMMERS could be limited to POOLS with surface areas of less than 1,600 square feet (149 m 2 ), and the maximum width for POOLS using SKIMMERS could be restricted to less than 30 feet (9.1 m).The use of SKIMMERS has been limited to smaller POOLS with light BATHER COUNTs since their inception. The limitations of SKIMMERS versus gutters appear to be physical in nature. For example, a 30 feet x 50 feet (9.1 m x 15.2 m) POOL may be served by three SKIMMERS rated at 500 square feet (46.4 m 2 ) each. If each SKIMMER is one foot (30.5 cm) wide, then all of the skimmed water is being drawn off from only three foot (0.9 m) of the POOL perimeter (i.e., 1.9 % of the total perimeter). This would lead to higher water velocities over the floating weirs and water being collected from a greater depth (as opposed to actual surface skimming) relative to a gutter system that extends around the perimeter of the POOL. In this example, 98.1% of the perimeter of the POOL is not being used to skim water and could produce regions of limited flow and scum collection. Theoretically, enough SKIMMERS might be added to produce effective skimming comparable to a gutter system, but the research to demonstrate this in practice could not be found. Practical experience says that having no scum lines or dead zones in corners with stagnant debris are inherent advantages. There could also be practical hydraulic limitations for heavily BATHER loaded POOLS related to use of in-POOL surge as opposed to a surge tank. Equalizer lines are recommended to prevent SKIMMERS from pulling air into the pump and potentially causing loss of prime, flow surges, and interference with proper filter operation.

# Hybrid Systems
Hybrid systems that incorporate surge weirs in the overflow gutters to provide for in-POOL surge shall meet all of the requirements specified for overflow gutters Since the number of BATHERS determines the type of surface overflow system in use, the hybrid systems should be able to meet all code requirements regardless of how many BATHERS are present and which components are in active use.
When the POOL is inactive (no bathers in the water) the surge weirs provide surface skimming. The operating water level during the period when there are no BATHERS in the water is designed to be below the rim of the gutter and flows over the surge weirs by gravity. When BATHERS enter the water, the level rises (in-pool surge capacity), the surge weir openings close, and the water flows over the gutter as in standard gutters.

# Surge Weir
The manufacturers of these gutter systems typically have flow capacities (gpm/surge weir) established for their surge weirs. The number of surge weirs necessary to accommodate the portion of the recirculation rate to be removed from the surface is
Facility Design & Construction ANNEX 90 calculated by using the percentage of the total recirculation rate for surface skimming (i.e., 80 % of total flow) divided by the flow rate for each surge weir. The total recirculation rate must not be used for this calculation, as it will result in a greater number of surge weirs; operationally less water will need to be removed from the surface, which will likely result in inadequate flows over the weirs for effective surface skimming.
The required number of surge weirs are to be uniformly spaced around the POOL perimeter in the gutter. The 100 percent of the total recirculation flow rate chosen by the designer is recommended as part of the hydraulic flexibility recommendation.
Skimmer Flow Rate SKIMMERS should provide for a flow-through rate of 30 gallons per minute (114 L/min), or 3.75 gallons per minute (14 L/min) per linear inch (2.5 cm) of weir, whichever is greater. The AHJ may approve alternate flow-through rates so long as the SKIMMERS are NSF or equivalent listed and manufacturer's design specifications are not exceeded.

# Flotation Test Procedure

# Materials Needed:
- Yellow wooden stars (55 -110 minimum depending on the pool's surface area)  Video camera  Tripod

# Conditions Prior to Test:
- TURNOVER time and recirculation flow rate are operated as normal for the POOL  INLETS and outlets are positioned as normal for the POOL  SKIMMERS or gutter system is not flooded  If using SKIMMERS, make sure that the weirs are present  Water level is at the appropriate height above the weir/gutter (about 14 inch or 6.4 mm)  Set up video camera to record Test 1: Circulation 1. Determine how many stars are necessary by using the following:
- POOL surface area  2,500 square feet (232 m 2 ). use a minimum of 110 stars. 2. Randomly toss the stars into the POOL. Try to toss the stars so that there is an even distribution throughout the surface of the POOL. 3. Record and observe the stars as they travel.
Facility Design & Construction ANNEX 91 4. Record the motion of the stars in each area of the POOL (e.g., clockwise, counter clockwise, no movement) and any other observations. 5. Passing criteria may vary, but suggestions include 90% removal within one hour.

# Test 2: Skimmer/Gutter Draw
1. Stand behind one of the SKIMMERS or the gutter and drop a star into the water at arm's length distance (about 2 feet (61 cm)) in front of it. 2. Record how long it takes for the star to enter the SKIMMER or gutter. Then repeat this process at the same location three times.
Submerged Suction Outlet Note that in the VGB Act, no specific distances are listed. CPSC's question and answer section for implementation indicates three feet (0.9 m) measured center to center.

# Flow Distribution and Control
The 125% of the total recirculation flow rate chosen by the designer is recommended as part of the hydraulic flexibility recommendation in MAHC Annex 4.7.1.1. The proportioning valve(s) are recommended to restrict flow by increasing the head loss in the pipe(s) typically on the main drain lines where flow rates are less than those from the surface overflow system lines.
The main drain system shall be designed at a minimum to handle recirculation flow of 100% of total design recirculation flow rate. A minimum of two hydraulically balanced filtration system suction outlets are required as protection from suction entrapment. The branch pipe from each main drain outlet shall be designed to carry 100% of the recirculation flow rate so in the event that one drain outlet is blocked the other has the capacity to handle the total flow.
Where three or more main drain outlets are connected by branch piping in accordance with MAHC Section 4.7.1.6.2.1.1 through 4.7.1.6.2.1.3,it is not necessary that each be designed for 100% flow. Where three or more properly piped drain outlets are provided, the design flow through each drain outlet may be as follows:
- Q max for each drain= Q(total recirculation rate) / (number of drains less one)
- Q max =Q total / (N-1)
The result is that if one drain is blocked, the remaining drains will cumulatively handle 100% of the flow.

# Example:
- Q total = 600 gpm recirculation rate  N = 3 drains RECIRCULATION SYSTEM piping should be designed so the water velocities should not exceed eight feet (2.4 m) per second on the discharge side of the recirculation pump. This is a maximum value as opposed to a good design value. The head loss in a pipe (and hence the energy loss in the recirculation system) is proportional to the square of the velocity in the pipe (i.e., if you cut the velocity in half, then you reduce the head loss to 14 (25%) of the original value). In the interest of conserving energy, velocities in the range of six to eight feet (1.8 m to 2.4 m) per second are recommended. Without a minimum INLET velocity, uniform water distribution within the supply piping will not happen. Absolute pressure on the liquid surface -friction losses in the suction line -vapor pressure of the water + static head of liquid above impeller eye.
Hydraulic calculations for piping and pumps should be prepared by a qualified engineer.

# Additional Considerations
Gravity piping must be sufficiently sized to accommodate the recommended flow (including surges) without water surcharging above the INLET. Careful consideration of available head, the head losses, and the combined flow from multiple inputs into a 4.0 Facility Design & Construction ANNEX 93 single pipe is a necessity. The two feet (61.0 cm) per second value is a value derived from common practice with no clearly identifiable theoretical basis.

# Drainage and Installation

# Draining Recommendation
The draining recommendation for all equipment and piping serves multiple functions. First, any sediment or rust particles that gather in the pipe can be flushed by means of the drainage system. Since bacteria and biofilms are mostly water, drying out a biofilm can be an effective means of controlling growth. Whereas leaving a pipe full of water during a period of maintenance or no use could lead to dissipation of the CHLORINE residual and proliferation of a biofilm inside of pipes and/or equipment. Biofilms can lead to bio-corrosion of metal components of the RECIRCULATION SYSTEM and serve as protection for microbes and pathogens.

# Designed
All equipment and piping should be designed and constructed to drain completely by use of drain plugs, drain valves, and/or other means. All piping should be supported continuously or at sufficiently close intervals to prevent sagging and settlement. All suction piping should be sloped in one direction, preferably toward the pump. All supply and return pipe lines to the AQUATIC VENUE should be provided to allow the piping to be drained completely.

# Individual Drain
The individual drain to facilitate emptying the POOL in case of an accidental gross contamination event is intended to prevent further contamination of any pipes, pumps, multi-port valves, filters, or other equipment associated with the RECIRCULATION SYSTEM, which might be more difficult to clean than the inside of the AQUATIC VENUE. In the case of combined AQUATIC VENUE treatment systems, this drain could prevent crosscontamination of multiple AQUATIC VENUES. Clearly marking pipes will prevent misidentification that could lead to cross-connections and contamination of the AQUATIC VENUE. Pipe marking will also facilitate easier identification of locations for additional equipment installation and/or sample lines.
Color Coding Recommendations: Pipes and valves, when color-coded, may be colorcoded in accordance with the following: Variable frequency drives (VFDs) may be allowed because the energy savings could be substantial if flow is reduced at night and water quality criteria are continuously maintained. At this time, we are not aware of public health benefits or deficits associated with VFD use so these pumps are allowed but not required. Operators should be aware that VFDs can flatten out a pump curve so if they are installed on a filter pump, operators may want more active control to maintain operations. It is recommended that operators use VFDs with a compatible flow meter with a feedback control to optimize VFD function.

# Total Dynamic Head
The recirculation pump should be selected to meet the recommendations of the designer for the system. However, the following guidelines are suggested as starting points for designers. The recirculation pump(s) must be selected to provide the recommended recirculation flow against a minimum total dynamic head of the system, which is normally at least 50 feet (15.2 m) for all vacuum filters, 70 feet (21.3 m) for granular media and cartridge filters, or 60 feet (18.3 m) for precoat filters. A lower total dynamic head could be shown to be hydraulically appropriate by the designer by calculating the total head loss of the system components under worst-case conditions.

# Operating Gauges

# Pressure Measurements
A second set of pressure measurement ports could be recommended (tapped into the pump volute and discharge casing) to accurately calculate the flow of the pump. These gauges are a way of verifying the pump curve is correct. One can also use the pressure/vacuum gauges and pump curve to verify the flow meter reading and look for differences between the two. During startup, it is possible to shut off a valve on the discharge side of the pump and verify that the maximum discharge pressure measured agrees with the value on the pump curve.
It is recommended that all pumps be located on a base so as to be easily accessible for motor service.

# Facility Design & Construction ANNEX 95

# Vacuum Limit Switches
The vacuum limit switch is intended to shut down the pump if the vacuum increases to a point which could cause damage to the pump (cavitation).
Flow Measurement and Control 4.7.1.9.1 Flow Meters Over 22% (approximately 20,000) of the POOL inspections that led to POOL closures in the state of Florida in 2012 were caused by non-functioning flow meters. This section of the MAHC is intended to improve this flow meter reliability problem (as well as to address a problem with accuracy). Since flow rates are critical for proper filtration, sizing, and operational calculations, it is recommended that operators purchase a more accurate flow meter for all systems or when replacing older flow meters on their existing system. Improved accuracy improves an operator's chance of understanding the true flow in their system. Operators should be mindful of flow meter placement by installing according to manufacturer recommendations and adhering to recommended distance parameters.
A flow meter or other device that gives a continuous indication of the flow rate in gallons per minute (L/min) through each filter should be provided. If granular media filters are used, a device should be provided to measure the backwash flow rate in gallons per minute (L/min) for each filter. Flow meters should have a measurement capacity of at least 150% of the design recirculation flow rate through each filter, and each flow meter should be accurate within +/-5% of the actual design recirculation flow rate. The flow measuring device should have an operating range appropriate for the anticipated flow rates and be installed where it is readily accessible for reading and routine maintenance. Flow meters should be installed with 10 pipe diameters of straight pipe upstream and 5 pipe diameters of straight pipe downstream or in accordance with the manufacturer's recommendations. Acrylic flow meters will not meet the accuracy requirement (and are prone to fouling/clogging) and hence should not be installed as the primary flow meter on any RECIRCULATION SYSTEM. However, acrylic flow meters could prove useful as a backup or auxiliary flow meter. A paddle-wheel flow meter, when used, should be located on the effluent side of the filter to prevent fouling.
More accurate flow meters are recommended to conserve energy and increase regulatory compliance. Magnetic and ultrasonic flow meters offer greater accuracy (typically less than +/-1% error) and less potential for fouling, but the aforementioned flow meters tend to be more expensive (e.g., $1,000 or more). An ultrasonic flow meter (such as clamp-on transit-time models) can be used to measure flows through the wall of a pipe, so they can be installed and uninstalled without modifying the existing plumbing. One ultrasonic flow meter could be used to routinely verify the flow readings of multiple other flow meters that are more prone to error. An annual cleaning and evaluation of flow meter accuracy could be useful in maintaining compliance with existing regulations.  For example, here is a set of example calculations for an indoor POOL in a hotel that is 20 feet (6.1 m) wide by 30 feet (9.1 m) long with an even floor slope that goes from 4 feet (1.2 m) at the shallow end to 6 feet (1.8 m) at the deep end.
Facility Design & Construction ANNEX 100 When POOL recirculation rate recommendations are broken down to their essential elements, it is essentially about removing suspended matter (including microbial contaminants) with the filters and effectively maintaining uniform FREE CHLORINE RESIDUAL at the proper pH. Both the FREE CHLORINE RESIDUAL and the microbial concentrations are a function of the number of BATHERS in a given volume of water. While it is not possible to always accurately predict the BATHER COUNT for a given POOL on a given day, it is generally possible to estimate the maximum number of BATHERS likely to be in any given type of POOL per unit surface area (since most batherS have at least their head above water most of the time and the primary activity in a pool often dictates the comfort level in regards to bathers per unit surface area and hence the likelihood of bathers entering or leaving the pool). After establishing a maximum sustainable bather load (MSBL) or maximum number of BATHERS expected in a POOL, it is possible to calculate the recommended flow of recirculated water necessary to be treated in order to handle the pathogen load and CHLORINE demand imparted by the BATHERS. An empirically-derived multiplier was used by PWTAG 141 to convert the MSBL to the recommended recirculation rate. The empirical multiplier used in this code was derived independently using English units specifically for use in the U.S. The value of the U.S. multiplier is approximately 29% smaller than the PWTAG value using equivalent units because POOL design in the UK is more conservative than in the US.

# Unfiltered Water
Unfiltered water shall not factor into TURNOVER time. This section is to address/clarify water that may be withdrawn from and returned to the AQUATIC VENUE for such AQUATIC FEATURES as slides, features, etc. by a pump separate from the filtration system. That flow rate from the separate pump system shall not be included in the turnover time calculation.

# Turnover Times
The recommended design TURNOVER time can then be calculated by dividing the volume by the recommended flow. This procedure can be performed for individual sections of a POOL or the entire POOL depending on the number of zones, which are based on depth of the water. Adjustments can then be made to this calculation to account for extraordinary conditions. For example, since a SPA has higher water temperature than a POOL, a PATRON would be expected to sweat more; an indoor POOL might experience less contamination from pollen, dust, and rain than an equivalent outdoor POOL; and a POOL filled with diaper-age children would be considered an increased-risk POOL requiring more aggressive treatment. Aquatic facilities that enforce showering prior to POOL entry could reduce the organic load on the POOL by 35-60% with showers lasting only 17 seconds 142 . The BATHER LOAD calculation based on surface area of the POOL has been proposed by PWTAG 143 in 1999 and has influenced the CODES proposed by the World Health Organization 144 and Australia 145 . This approach has been adapted for use
Facility Design & Construction ANNEX 101 in the U.S. by slightly increasing the area recommended per BATHER in shallow waters and decreasing the area in deep POOLS to account for the intensity of deep water activities, the relatively low surface area to volume ratios of deep waters relative to shallow waters, the typically poorer mixing efficiency in deeper water, the increased amount of time typically spent underwater in deeper water, and the larger average size of bathers commonly found in deeper water. These values were empirically derived for the MAHC to match typical U.S. practices at the time of this writing and can be changed as necessary to achieve the desired water quality goals.
Effectively handling BATHER COUNT in terms of pathogen removals and CHLORINE demand is a paramount concern for which the above calculations should provide some science-based guidance. However, there are other factors that must be considered when selecting a recirculation rate for an AQUATIC VENUE. For example, effectively distributing treated water to avoid dead spots recommends minimum water velocities to reach the POOL center and extremities. Similarly, effective surface skimming recommends adequate velocities at the surface of the POOL to remove floating CONTAMINANTS. Due to the kinetics of DISINFECTION and CHLORINE decay, CHLORINE must be replenished at some minimum intervals to maintain the recommended FREE CHLORINE RESIDUAL. For these reasons, MAHC Table 4.7.1.10 was developed to provide some maximum TURNOVER time limits for AQUATIC VENUES that are not dominantly influenced by BATHER LOAD to help ensure proper physical transport of CONTAMINANTS and DISINFECTANT. Values in this table are derived from historical practice and design experience worldwide. All AQUATIC VENUES must be designed to meet the lesser of the two maximum TURNOVER times.
Reuse Ratio This section is intended to address those INTERACTIVE WATER PLAY VENUE designs that remove water from the INTERACTIVE WATER PLAY treatment tank by an AQUATIC FEATURE pump separate from the filtration system pump. The limit/ratio of INTERACTIVE WATER PLAY FEATURE water pump rate to the filtration system water pump rate is to acknowledge the typically high level of contaminates and turbidity introduced to the INTERACTIVE WATER PLAY treatment tank. The introduction and build-up of turbidity can exceed the rate at which it is removed by the filtration system which can result in interference with chemical DISINFECTION and UV treatment.
Flow Turndown System The flow turndown system is intended to reduce energy consumption when AQUATIC VENUES are unoccupied without doing so at the expense of water quality. A turbidity goal of less than 0.5 NTU has been chosen by a number of U.S. state CODES (e.g., Florida) as well as the PWTAG 146 and WHO 147 . The maximum turndown of 25% was selected to save energy while not necessarily compromising the ability of the RECIRCULATION SYSTEM to remove, treat, and return water to the center and other extremities of the POOL. The
Facility Design & Construction ANNEX 102 MAHC does not allow stopping recirculation since uncirculated water would soon become stagnant and loose residual disinfectant likely leading to biofilm proliferation in pipes and filters. This could compromise water quality and increase the risk to bathers. Future research could determine that more aggressive turndown rates are acceptable. Some POOLS are already reportedly using the turndown system without a turbidimeter or precise flow rates. The intent of this section is to formalize a system for doing the turndown that does not compromise public health and SAFETY. Additional research in this area could identify innovative ways to optimize and improve this type of system. The likelihood of turbidimeters being cleaned and maintained is likely to be good because turbidimeters tend to give higher reading when not maintained properly. AQUATIC VENUES designed above the minimum design STANDARDS would have the flexibility to increase system flows to maintain excellent water quality during periods of peak activity. The flow turndown system is intended to reduce energy consumption when AQUATIC VENUES are unoccupied without doing so at the expense of water quality.
An electronic turbidity and RECIRCULATION SYSTEM flow feedback system would provide a quantifiable means of determining the water quality suitability if a facility desires to "turndown" the recirculation pumps to achieve a flow of up to 25% less than the minimum required recirculation flow rate when the AQUATIC VENUES is not occupied. The integration of feedback from both the flow meter and turbidimeter must be maintained for the VFD to be able to reduce the system flow rate below the level required to achieve the TURNOVER time requirement.

# Variable Frequency Drives
Variable frequency drives (VFDs) offer the benefits of energy savings, operational flexibility, and in most cases the ability to automatically increase the pump flow as the filter clogs by interfacing the VFD with a flow meter (or potentially a filter effluent pressure transducer) by means of a proportional-integral-derivative (PID) controller. VFDs may also offer the added benefits of protecting piping, pumps, and valves. Energy savings and benefits will vary depending on the design of the system.

# Filtration
System Design
The filtration system should be designed to remove physical CONTAMINANTS and maintain the clarity and appearance of the AQUATIC VENUE water. However, good clarity does not mean that water is microbiologically safe. With CHLORINE-tolerant human pathogens like Cryptosporidium becoming increasingly common in AQUATIC VENUES, effective filtration is a crucial process in controlling waterborne disease transmission and protecting public health.

# Water Quality
If filtration is poor, water clarity will decline and drowning risks increase since swimmers in distress cannot be seen from the surface as well as needed. DISINFECTION will also be compromised, as particles associated with turbidity can surround microorganisms and shield them from the action of disinfectants. Particulate removal through coagulation and filtration is important for removing Cryptosporidium OOCYSTS and Giardia cysts and some other protozoa that are resistant to chemical DISINFECTION. 148

# Pathogen Removal
One of the most significant recommended changes of the MAHC is changing the filtration system from one that only provides good clarity and appearance to one that efficiently removes waterborne human pathogens from the AQUATIC VENUE water. Water clarity is only an indicator of potential microbial CONTAMINATION, but it is the most rapid indicator of possible high CONTAMINATION levels. CHLORINE residual can be sufficiently high to kill indicator bacteria while leaving protozoa relatively unharmed and infective. Therefore, testing for indicator bacteria may not be useful as a measure of AQUATIC VENUE water quality, and testing for Giardia cysts and Cryptosporidium is very expensive and time-consuming. So, both measures are impractical as an operational tool for water quality measurement. Cryptosporidium is a widespread threat responsible for causing outbreaks in AQUATIC VENUES each year in the U.S. 149,150 With CHLORINE-tolerant human pathogens like Cryptosporidium becoming increasingly common in AQUATIC VENUES, effective filtration is a crucial process in controlling waterborne disease transmission and protecting public health. 151 , 152 Furthermore, an accidental fecal release could overwhelm the DISINFECTANT residual and leave physical removal as the only means of removing pathogens. 153 Filtration has been cited as the "critical step" for the removal of Cryptosporidium, Giardia, and free-living amebae that can harbor opportunistic bacteria like Legionella and Mycobacterium species. 154

# Cryptosporidium
Cryptosporidium is a CHLORINE-tolerant protozoan pathogen that causes the majority of waterborne disease outbreaks in swimming POOLS in the U.S. as shown in MAHC

# 3-Log Reduction
The current CT VALUES for a 3-log reduction in viability of fresh Cryptosporidium OOCYSTS with FREE CHLORINE are 10,400 mg/Lmin (Iowa-isolate) and 15,300 mg/Lmin (Maine-isolate) at pH 7.5. 160 At a concentration of 1 mg/L, FREE CHLORINE can take more than 10 days to inactivate 99.9% of Cryptosporidium OOCYSTS (CT=15,300 mg/Lmin), but many people are likely to be swimming in the AQUATIC VENUE during that 10-day period and risk being exposed to infective parasite concentrations. Infected individuals may then return to the AQUATIC VENUE and/or visit other AQUATIC VENUES to perpetuate the spread of the parasite. Sand filters are commonly used and often serve as the only potential physical BARRIER to Cryptosporidium in U.S. AQUATIC VENUES, but sand filters without coagulant typically only remove about 25% of OOCYSTS per passage through the filter 161 . Based on the slow kinetics of CHLORINE inactivation of Cryptosporidium, the known inefficiency of sand filter to remove OOCYSTS, and the recent increased incidence of cryptosporidiosis in the U.S., additional measures appear necessary to effectively safeguard public health.

# Review of Recreational Water Filtration Research Findings

# Sand Filters
Sand filters often provide the only physical BARRIER to Cryptosporidium in U.S. AQUATIC VENUES, but sand filters meeting the recommendations of pre-existing POOL CODES typically only remove about 25% of OOCYSTS per passage through the filter 165 . A quantitative risk assessment model of Cryptosporidium in AQUATIC VENUES confirmed there is a "significant public health risk". 166 Some changes are necessary to effectively safeguard public health and will be discussed subsequently. Recent research in the U.S. and U.K. has shown that sand filters can remove greater than 99% of OOCYSTS per passage when a coagulant is added prior to filtration 167,168 . The addition of coagulants to swimming POOL filters used to be common practice in the U.S. with rapid sand filters, but it fell out of favor as high-rate sand filters began to dominate the U.S. POOL market. The importance of coagulant addition to efficient pathogen removal in drinking water is well-documented and recommended in all U.S. surface water treatment facilities for drinking water production by the U.S. EPA. 169 , 170 , 171 , 172 , 173 The U.S. EPA expects
Facility Design & Construction ANNEX 108 drinking water treatment facilities to remove or inactivate a minimum of 99% (2 log) of Cryptosporidium OOCYSTS and up to 99.997% (4.5 log) for facilities treating source water with the highest concentration of OOCYSTS. 174 While more research and quantitative risk assessment models will be recommended to determine the safe level of removal in most AQUATIC VENUES, it is clear that the current removal rates of approximately 25% can lead to a significant number of outbreaks each year. Based on the research available for existing AQUATIC VENUE filtration technologies and risk models, a new minimum removal goal for Cryptosporidium removal by filters used in new and renovated swimming POOLS is recommended to be at least 90% (1 log) per single pass.

# Filtration Systems
Multiple types of AQUATIC VENUE filtration systems have already been shown to achieve removals exceeding 99% depending on the filter design, water quality, and operational variables.
MAHC Annex Table 4.7.2.1 (below) contains a current summary of published research on Cryptosporidium or Cryptosporidium-sized microsphere removals via filtration in pilot-scale trials. Bench-scale results were not included due to concerns that the laboratory results might not be reproducible at pilot-or full-scale as has been observed in previous studies. MAHC Annex Table 4.7.2.1 is sorted in order of increasing filter removal efficiency, and the data is roughly divided into three groupings (i.e., 99% removal). Operating conditions falling into the first group would not be expected to reliably meet the new 90% (single pass) removal recommendation that is recommended for all new and renovated AQUATIC VENUES. Coagulant dosage, surface loading rate, and media depth can significantly impact filtration removals. Careful selection of both design and operating values is essential to achieving excellent pathogen removal with AQUATIC VENUE filters.
Facility Design & Construction ANNEX 109

# Filtration Products
At the time of this writing, the following filtration products are believed to be untested for Cryptosporidium/4.5-micron carboxylated microsphere removal in AQUATIC VENUE water:  Regenerative media filters,  Sand followed by cartridge, (with 5-micron absolute or 1-micron nominal rating),  Macrolite filter media,  Charged zeolite media,  Crushed-recycled glass filter media, and  Any others not listed in MAHC Annex Table 4.7.2.1.

# Brief Historical Review of Water Filtration Practices for Aquatic Venues
In the U.S. in the 1920s, rapid sand filters on swimming pools were typically operated at 3-5 gpm/ft 2 (7-12 m/h) with coagulation prior to filtration, but high-rate sand filters have largely replaced rapid sand filters because they operate at 15-20 gpm/ft 2 (37-49 m/h) without coagulant. 176,177 While high-rate sand filters are definitely cheaper and smaller, they are also less effective at removing Cryptosporidium-sized particles. The majority of U.S. drinking water treatment facilities still use rapid sand filters with coagulation and typically operate them at 3-5 gpm/ft 2 (7-12 m/h). The U.S. EPA, after an extensive review of peer-reviewed research, decided to give drinking water treatment facilities credit for removing 99% of Cryptosporidium OOCYSTS for properly employing this technology (i.e., granular media filtration with coagulation prior to filtration). Research has shown that More efficient filtration of AQUATIC VENUE water will, in most cases, lead to higher rates of pressure development in filters and more frequent backwashing of filters. The smaller the pores in the filter media at the surface of the filter, the more rapidly pressure would be expected to increase. Fortunately, there are a number of options available to design engineers that could reduce the rate of pressure development. These options include:  The use of more uniformly graded filter media,  Skimming fines from filter media prior to startup,  More efficient backwashing of filters,  Lowering the flow rate per unit surface area, and  The use of two types of filter media in filters.
Granular Media Filters
General Design Tip: When a single pump feeds two filters at 10 gpm/ft 2 (24 m/h), redirecting the entire flow through one filter into the backwash line of the other should result in a backwash rate of approximately 20 gpm/ft 2 (49 m/h). The backwash water would be unfiltered water that would have to be plumbed to bypass the filter. With three filters, it would be possible to redirect water from two filters into the backwash influent pipe of the third filter to provide clean backwash water.

# Listed
Equipment testing of filters to industry STANDARDS is critically important, but it is only one aspect of performance. A filter certified with the hydraulic capability to pass water at 20 gpm/ft 2 (49 m/h) does not mean this filter should be operated at 20 gpm/ft 2 (49 m/h). Granular media filters perform better at removing particles and microbes at lower filter loading rates (all other factors equal), and this finding has been repeatedly observed in practice and can be explained theoretically. Filters might need to be held to higher STANDARDS of performance in terms of water quality than the current industry STANDARD. Filter Location and Spacing Sufficient floor space should be available to accommodate installation of additional filters to increase the original filtration surface area by up to 50% should it be recommended by future regulations or to meet current water quality STANDARDS. This is part of the hydraulic flexibility recommendation of newly constructed POOLS. The idea is to recommend space for additional filters should they become necessary at some point in the future. The 'extra' space could be utilized to make EQUIPMENT ROOMS safer and more functional.
A port and ample space for easy removal of filter media is also recommended. Filter media might be changed every 5 years. This process could be exceedingly difficult if filters are not designed with a port for this purpose or if the filters are installed without proper clearance to access the media removal port.
Filtration and Backwashing Rates The granular media filter system should be designed to backwash each filter at a rate of at least 15 gallons per minute per square foot (37 m/h) of filter bed surface area, unless explicitly prohibited by the filter manufacturer. Specially graded filter media should be recommended in filter systems backwashing at less than 20 gpm/ft 2 (48.9 m/h) to be able to expand the bed at least 20% above the fixed bed height at the design backwash flow rate, which is subject to approval by the local authority. Filtration and backwashing at the same flow rate is likely to lead to poor performance of both processes. Backwashing at double the filtration rate is not all that complicated with a 3-filter system, where the flow of two filters is used to backwash the third. Further, backwashing with unfiltered water is possible in a 2-filter system by backwashing with the entire recirculation flow through each filter individually. Variable drive pumping systems and accurate flow meters also contribute to the likelihood of successful backwashing as well as effective filtration.

# Effective Filtration
Filtration at 10 gpm/ft 2 (24 m/h) is really pushing the envelope for attaining effective filtration and would not be recommended for a municipal drinking water system using sand filters due to doubts about the ability of such a filter to remove particulate CONTAMINANTS reliably. There are instances where multi-media deep bed filters or monomedium filters with large diameter anthracite and 6 foot (1.8 m) deep or greater beds of media are used, such as those owned and operated by the Los Angeles Department of Water and Power.

# Facility Design & Construction ANNEX 112
Effective filtration of drinking water at high filtration rates recommends careful and exact management of coagulation. Whereas filtration rates are not explicitly addressed in much of the research on water filtration, the experience of researchers, regulators, and consultants is that high rate filtration recommends extra attention and talent. For example, over three decades ago, the State of California allowed the Contra Costa Water District to operate filters at 10 gpm/ft 2 (24 m/h) but other water utilities were not allowed to do this. The exception was permitted because of the design and the high level of operating capability at the plant where the high rate was used.
Operation at very high rates either causes very rapid increases of head loss in sand filters (water utility experience resulted in the conclusion that operating sand filters at rates above 3 or 4 gpm/ft2 (7-10 m/h) was impractical) or very little particle removal occurs as water passes through the sand bed, thus enabling filters to operate for a long time at high rates. For this reason following World War II, the use of anthracite and sand filters became the norm for filters designed to operate at 4 or 5 gpm/ft 2 (10-12 m/h) or higher. Finally, in the 1980s, workers in Los Angeles showed that a deep (6 foot (1.8 m)) filter with 1.5 mm effective size anthracite media could effectively filter water at rates of close to 15 gpm/ft 2 (37 m/h).
However, for very high rates of filtration to be effective, pretreatment has to be excellent, with proper pH and coagulant dosage, probably use of polymer, and in some cases, use of a pre-oxidant to improve filter performance. This is well understood by filter designers and professors who specialize in water filtration. Articles published on the Los Angeles work done by James Montgomery Engineers showed the importance of proper pretreatment. Papers written by experts on filtration have noted the importance of effective pretreatment (including proper coagulation) for dependable filter performance, and those writers were focused on rates employed in municipal filtration plants (e.g. 3 to 10 gpm/ft 2 (7-24 m/h)). As filtration rate increases, water velocity through the pores in the sand bed increases, making it more difficult for particles to attach to sand grains and remain in the bed instead of being pushed on through the bed and into filter effluent. When filters do not work effectively for pathogen removal, the burden is put on DISINFECTION to control the pathogens. For Cryptosporidium, the DISINFECTION approach that is typically most cost-effective is UV, so a very high rate filter may need to be followed by UV for pathogen inactivation, and the very high rate filters would just have to clarify the water sufficiently that there is no interference from particulate CONTAMINANTS with the UV inactivation process.

# Backwash System Design
For a granular media filter system to be able to backwash at a rate of at least 15 gallons per minute per square foot (37 m/h) of filter bed surface area, the pump(s), pipes, and filters must be designed accordingly. As many professionals have sought to improve water quality by decreasing the filtration rate to values lower than 15 gpm/ft 2 (37 m/h), they have sometimes failed to recognize that while lowering the filtration rate may generally produce a positive change in performance, a similarly lower backwash rate could lead to a total filtration system failure. In cases where a backwash rate of 15 gpm/ft 2 (37 m/h) is explicitly prohibited by the filter manufacturer, the filter may still be used, provided that specially graded filter media is installed that will expand to a minimum of 20% bed expansion at the specified backwash flow rate. Viewing windows 4.0 Facility Design & Construction ANNEX 113 are highly recommended in all filters since they will allow direct observation of the bed expansion during backwashing, cleanliness of the media and backwash water, and the depth of the sand in the filter. Croll and coworkers 179 used a backwashing rate of 25 gpm/ft 2 (61 m/h) to achieve 25% bed expansion of their filter.

# WHO Recommends
The WHO recommends a backwash rate of 15-17 gpm/ft 2 (37-42 m/h for sand filters, but the media specifications are not given nor is it clear whether or not air-scour is expected prior to backwashing. 180 Backwashing swimming POOL sand filters with air scour is common in the UK and elsewhere. 181.182 It has also been reported that air-scour washed AQUATIC VENUE filters are more efficient than filters washed by water only. 183 It is reasonable that lower backwashing rates would be used for water backwash when following air-scour since the air-scour dislodges most of the particles attached to the media grains (as opposed to relying on the sheer force of the water passing over the surface of the particles). It is not feasible to operate sand filters in drinking water treatment plants without an auxiliary backwash system such as air scour. 184 The practice of operating AQUATIC VENUES and filters (that were not using coagulation) without air scour has been STANDARD practice in the U.S. for many years, which has seen mixed results ranging from no problems to total system failures requiring replacement of all filter media. PWTAG recommends air-scouring filters at 32 m/h (13 gpm/ft 2 ) (at 0.35 bar). 185

# Polyphosphate Products
Polyphosphate products are sometimes used to sequester metals in POOLS, but this practice is not recommended when granular media filters are used because polyphosphate is an effective particle dispersant that can reduce the removal efficiency.

# Filter Bed Expansion
Sufficient freeboard (or space between the top of the media and the backwash overflow) to allow for a minimum of 35% filter bed expansion during backwashing adds a factor of SAFETY when the target bed expansion is 20% to prevent the washout of filter media during backwashing.
The regions underneath the lateral underdrains in granular media filters can become stagnant when filled with sand or gravel, which can lead to low disinfectant residuals and ultimately biofilm growth. Filling this area with concrete at the time of installation
Facility Design & Construction ANNEX 114 may prevent this potential problem. 186 It is fundamentally difficult to suspend (i.e., fluidize) and hence clean filter media or gravel that is below the level where the backwash water enters the filter.
Minimum Filter Media Depth Requirement The performance of high-rate granular media filters at removing pathogens and particles is contingent upon the depth of the filter media (as shown in MAHC Annex Table 4.7.2.1), especially at rates of 15 gpm/ft 2 (37 m/h), which is why these filters recommend at least 24 inches (61.0 cm) of filter media. The WHO recommends filtration at 10-12 gpm/ft 2 (24-29 m/h) for sand filters while the PWTAG recommends 4-10 gpm/ft 2 (10-24 m/h) as the maximum filtration rate for all non-domestic POOLS using sand filters. 187,188 The STANDARD sand filter bed depth typically varies from 0.55 to 1 m (22 to 39 inches) in the UK. 189

# Minimum Depth
For swimming POOL filters with less than 24 inches (61.0 cm) of media between the top of the laterals and the top of the filter bed, lower filtration rates (e.g., 10 gpm/ft 2 (24 m/h) are recommended to efficiently remove particles and pathogens. Improvements in particle removal with decreasing filtration rates have been documented. 190 Drinking water treatment facilities typically limit filtration to less than 4 gpm/ft 2 ,(10 m/h), which is similar to the filtration rates recommended in AQUATIC VENUES in the 1920s. 191,192 The minimum depth of sand in POOL filters was 36 inches (0.9 m) in 1926. 193 Sand filters are typically designed in drinking water treatment for an L/d ratio of 1000 or greater, where "L" is the depth of the media and "d" is the diameter of the media grain. 194 For example, a 0.6 mm effective size sand would recommend a minimum 0.6 m (23.6 inches) bed depth, and a 12 inch (30.5 cm) deep sand bed with 0.5 mm grains would have an L/d of only 610.
The minimum depth of filter media above the underdrains (or laterals) is recommended be 24 inches (61.0 cm) or greater with sufficient freeboard (or space between the top of the media and the backwash overflow) to allow for a minimum of 35% filter bed expansion during backwashing. Sand or other approved granular media should be carefully graded to ensure fluidization of the entire filter bed during backwashing.
Facility Design & Construction ANNEX 115 A design backwash rate of at least 30% higher than the minimum fluidization velocity of the d90 size of the media in water at the larger of 86F (30C) or the maximum anticipated operating temperature is recommended. A backwash rate higher than the minimum could be necessary to effectively clean the media during backwashing. Variations in the media type, density, water temperature, effective size, or uniformity coefficient may cause changes in the recommended backwash flow rate and/or bed expansion, which should be subject to approval by the local authority provided hydraulic justification by the design engineer.
Sand or other approved granular media should be carefully graded to ensure fluidization of the entire filter bed during backwashing. The specifications of POOL filter sand (or lack thereof) can lead to filter media being installed that cannot be effectively cleaned during backwashing. Sand that cannot be properly cleaned can lead to filter failures and/or biofilms in the bottom of a filter. Researchers have found nematodes, rotifers, ciliates, zooflagellates, amoebic trophozoites and cysts, as well as bacterial masses in the backwash water of swimming POOL sand filters. 195 A design backwash rate of at least 30% higher than the minimum fluidization velocity of the d90 size of the media in water at the larger of 86F (30C) or the maximum anticipated operating temperature is recommended, but a backwash rate higher than the minimum could be necessary to effectively clean the media during backwashing. These backwashing recommendations are based on drinking water treatment practice. 196 For a sample of AQUATIC VENUE filter sand examined at UNC Charlotte, the d90 size (i.e., 90% of the grains smaller than this diameter) of the media was estimated from the sieve analysis results in MAHC Annex Figure 4.7.2.1.4.1 (below) to be 1.06 mm. The calculated minimum fluidization velocity of this sized sand grain in water at 86F (30C) was calculated to be 16.7 gpm/ft 2 (41 m/h). Since this backwash velocity would be expected to leave approximately 10% of the grains in the filter that were larger than the d90 unfluidized, common practice is to recommend a backwashing rate 30% greater than this minimum value (or 21.7 gpm/ft2) (53 m/h). The recommended backwash flow for this media by Kawamura 197 was graphically estimated to be 20.9 gpm/ft 2 (51 m/h) at 68F (20C). This is the rationale for requiring at least a 15 gpm/ft 2 (37 m/h) backwashing rate of all swimming POOL sand filters.
To ensure compatibility with the minimum recommended backwashing rate of 15 gpm/ft 2 (37 m/h), filter sand should pass through a number 20 U.S. standard sieve or equivalent (i.e., all sand grains should be smaller than approximately 0.85 mm). While this recommendation of "#20 Silica sand" is common in swimming POOL manuals and by filter manufacturers, it does not appear to be representative of the actual sand that might be installed. Sieve analyses of two brands of commercially available "pool filter sand" are provided in MAHC Annex Figures 4.7.2.1.4.1 and 4.7.2.1.4.2. Sand can also be specified by an effective size (E.S.) of 0.45 mm with a uniformity coefficient (U.C.) of less than or equal to 1.45, which is roughly equivalent to a 20/40 mesh sand. A 20/40
Facility Design & Construction ANNEX 116 mesh sand would pass through a #20 (0.85 mm sieve) and be retained on a #40 (0.42 mm) sieve. In order to reduce the rate of headloss accumulation at the top of the filter bed (and the frequency of backwashing), a 20/30 mesh sand could be specified where the smallest grains at the top of the filter would be approximately 0.60 mm (30 mesh) instead of 0.42 mm (40 mesh).  The depth of the expanded bed during backwashing should be at least 20% greater than the depth of the fixed bed after backwashing. Experiments to determine the backwashing rates recommended to fluidize a bed of POOL filter sand in 3-inch (7.6 cm) and 6-inch (15.2 cm) diameter clear PVC filter columns based on visual observation were conducted. Fluidization is somewhat subjective when observed visually because sand grains could be moving sluggishly prior to fluidization and because the smaller grains at the top of the filter will fluidize long
Facility Design & Construction ANNEX 117 before the larger grains at the bottom. For this reason, bed expansion was measured and recorded along with visual observations of when the bed actually fluidized. Fluidization was visually observed to occur between 20 and 23 gpm/ft 2 (49-56 m/h), which coincided with 19-23% bed expansion in both sized columns for the unaltered commercial filter media at 68F (20C). Expansion data from the 3-inch (7.6 cm) diameter filter column is shown in MAHC Annex Table 4.7.2.1.4.1 (below). The 20/30 mesh fraction of the same filter media was examined under the same conditions, and the experimental results are provided in MAHC Annex Table 4.7.2.1.4.2. The media was observed to be fully fluidized at 19.9 gpm/ft 2 (49 m/h)with a bed expansion of 21.8% at 68F (20C). Calculations based on Cleasby and Logsdon 198 indicate that filter backwashing rates should increase by approximately 18% for this media as the temperature is increased from 68 to 86F (20 to 30C) due to changes in the viscosity of water with temperature.
Fluidization can be somewhat complicated to estimate, but filter bed expansion can be easily measured in the field with granular media filters that use viewing windows. Furthermore, a model exists that can be used to calculate filter bed expansion of sand in a filter during backwashing. 199 This model tends to be sensitive to fixed bed porosity, but using a value of 42% porosity with a sphericity of 0.85 and density of 2.65 g/cm 3 yielded a bed expansion of 22.7% at 20 gpm for water at 86F (30C). This is the rationale for requiring the depth of the expanded bed during backwashing being at least 20% greater than the depth of the fixed bed. PWTAG recommends 15-25% bed expansion following air scouring at 32 m/h (13 gpm/ft 2 )(at 0.35 bar). 200 In a study funded by PWTAG, researchers used a backwashing rate of 25 gpm/ft 2 (61 m/h) to achieve 25% bed expansion of their filters. 201 Variations in the media type, density, water temperature, effective size, or uniformity coefficient may cause changes in the recommended backwash flow rate and/or bed expansion, which should be subject to approval by the local authority provided hydraulic justification by the design engineer.

# Facility
Design & Construction ANNEX 118

# Coagulant Injection Equipment Installation
To enhance filter performance, a coagulant feed system, when used, should be installed with an injection point located before the filters and, for pressure filters, on the suction side of the recirculation pump(s) capable of delivering a variable dose of a coagulant (e.g., polyaluminum chloride or a pool clarifier product) to enhance filter performance. Pumps should be properly sized to allow for continuous delivery of the recommended
Facility Design & Construction ANNEX 119 dosage of the selected coagulant. Products used to enhance filter performance should be used according to the manufacturers' recommendations. The coagulant feed system should consist of a pump, supply reservoir, tubing, ISOLATION valve, and BACKFLOW prevention device. Sand filters used as pre-filters for membranes or cartridge filters with 1-micron nominal or 5-micron absolute size ratings or less should not be recommended to have coagulant injection equipment. Specialized granular filter media capable of removing Cryptosporidium OOCYSTS or an acceptable 4.5-micron surrogate particle with an efficiency of at least 90% (i.e., a minimum of 1 log reduction) without coagulation should not be recommended to provide coagulant injection equipment, but this media should be replaced or reconditioned as recommended to sustain the minimum recommended particle removal efficiency stated above. Sand filters located ahead of a UV or ozone DISINFECTION system may be excluded from supplying coagulation equipment with the approval of the local authorities. Local authorities should consider the efficiency of the supplemental DISINFECTION process for Cryptosporidium inactivation but should also consider that a side-stream system does not have any effect on the Cryptosporidium OOCYSTS that bypass the system on each TURNOVER. For example, a UV system that is 99.999% effective at inactivating Cryptosporidium that only treats half of the recirculated water flow is on average only 50% effective (per pass) because all of the Cryptosporidium in the bypass stream remain unaffected by the UV.
Coagulation is the key to effective granular media filtration, which has long been recognized in the drinking water industry. 202,203,204,205,206 Operation of granular media filters without coagulation is not permitted by U.S. EPA regulations for drinking water treatment, with the exception of slow sand filters. Thus, if pathogen removal is a goal of water filtration for swimming POOL sand filters, coagulation would be essential. This is the rationale for recommending future consideration of coagulation in swimming POOLS. A coagulant feed system should be installed with an injection point located ahead of the filters to facilitate particle removal by filtration (instead of settling to the bottom of the pool), and injection ahead of the recirculation pump(s) will provide mixing to evenly distribute the coagulant among the particles. A variable dose of a coagulant (e.g., polyaluminum chloride, or pool clarifier) is recommended because coagulant dosages may vary with BATHER LOAD. Products used to enhance filter performance should be used according to the manufacturers' recommendations since overfeed or underfeed of coagulants is known to impair performance.
Although polyaluminum chloride (PACl) is not a widely used coagulant in the U.S. at present, it has been used extensively abroad. 207,208 However, recommended dosages abroad may not be optimized for pathogen removal. PWTAG recommends a
Facility Design & Construction ANNEX 120 polyaluminum chloride dosage of 0.005 mg/L as Al, but research has shown that 0.05 mg/L is recommended to exceed 90% removal and 0.21 mg/L or higher could be optimal with filters operated based on U.K. STANDARDS. 209

# New Challenges: The Impact of Coagulation on Backwashing
Coagulation is likely to make cleaning of sand filters more challenging. Drinking water treatment facilities in the U.S. employ auxiliary backwash systems such as air-scour to improve the cleaning process. Using water alone for backwashing has not been found to be effective for media cleaning in drinking water treatment applications. 210 Air scour systems are common in European AQUATIC VENUE filters and should be investigated further in the U.S. More frequent backwashing is recommended with water-only backwash, and the clean-bed headloss (pressure) should be recorded after each backwash to detect early signs of ineffective backwashing and prevent filter system failures.

# Initial Headloss and Headloss Accumulation Rate
Increased headloss (or pressure buildup) in filters is expected with coagulation as particles are likely to be removed faster (more efficiently) and closer to the top of the filter thereby clogging the top of the filter more quickly. This is actually a sign that the coagulation/filtration system is working effectively. The initial headloss after backwashing should remain relatively constant however. Coagulants have been used successfully in the U.S. in the past and are currently being used in POOLS abroad. 211,212,213,214 In systems not properly designed to backwash with filter effluent from other filters, the coagulant feed system should not be operated during backwashing so as to prevent introduction of coagulant into the backwash water.
Precoat Filters

# Filtration Rates
The design filtration rate of 2.0 gallons per minute per square foot (4.9 m/h) might be overly conservative and is the same upper limit on filtration rate typically used in drinking water treatment applications. 215 However, drinking water applications typically use finer grades of precoat media at application rates of 0.2 lbs/ft 2 (1 kg/m 2 ). 32 Lange and coworkers 216 have used filtration rates up to 4 gpm/ft 2 (10 m/h) with no adverse effect on Giardia cyst removal although the removal of turbidity and bacteria were

# Precoat Media Introduction System Process
The precoat process shall follow the manufacturer's recommendations and requirements of NSF/ANSI Standard 50.

# Separation Tank
Precoat filter media has the potential to settle out of suspension in sewer pipes depending on the flow velocities, which could lead to fouling or clogging of sewer pipes. Local authorities may recommend removal of precoat media prior to discharge in sewer systems so POOL operators should check the AHJ.
Continuous Filter Media Feed Equipment Filter performance can be significantly impacted by the selection of the precoat filter media, which could alter water clarity, pathogen removal, and cycle length. Multiple grades of precoat media are available in the marketplace. Precoat media can be specified by median particle size of the media or by permeability of the media.   Cleaning procedures for cartridges are not well-established and education in proper cleaning procedures is likely necessary to avoid contaminated cartridges being reinstalled into filters potentially providing a protected region for proliferation of biofilm bacteria the could lead to an outbreak. Cartridge filter elements are typically cleaned manually, usually by hosing them down with a water hose and replacing them. Exposure concerns exist since concentrated streams containing Legionella, Mycobacteria, Cryptosporidium, and other pathogens can potentially be sprayed or splashed on the operator/lifeguard as well as the surrounding environment perhaps even including the inside of the filter or the surfaces surrounding the AQUATIC VENUES.
Facility Design & Construction ANNEX 122 An extensive survey of manufacturers' cleaning recommendations was conducted after there was a Legionella outbreak in a facility with cartridge filters. Legionella, Pseudomonas, and biofilms were found in the filters. The cleaning procedure employed was to take them outside, rinse them with a water hose, and replace them. Operators reported that they would occasionally degrease or bleach them. Further investigation revealed that this cleaning procedure was common at other facilities.
Filter manufacturers were surveyed for cleaning procedures and most often did not have a cleaning process and simply deferred to the cartridge manufacturer since many filter manufacturers do not make the cartridges. The cartridge manufacturers also did not have a cleaning procedure or a very minimal one that did not account for biofilms or heavy organic loads commonly encountered in SPAS. CHLORINE is generally ineffective at inactivating bacteria in a biofilm or removing particulate or organic filter foulants. One effective way to control the biofilms is to completely dry them out.
Based on the known poor performance in removing pathogens increasing the likelihood of waterborne disease outbreaks and the potential for dangerous microbial (and perhaps chemical) exposures to the operators during routine maintenance and cleaning, cartridge filters are not currently recommended. This is not to say that all of the current issues and/or concerns with cartridge filters could not be resolved.
Filtration Rates Cartridge filter elements should have a listed maximum flow rate of 0.375 gallons per minute per square foot (0.26 L/s/m 2 ), but the design filtration rate for surface-type cartridge filter should not exceed 0.30 gallons per minute per square foot (0.20 L/s/m 2 ).Cartridges don't recover 100% capacity when cleaned after fouling. Systems designed to the maximum limit cannot sustain performance (or minimum pool turnover requirements) over time. For example, if a filter only recovers to 80% of the original flux after cleaning, then a filter flow rate of 0.375 gallons per minute per square foot (0.26 L/s/m 2 ) would become 0.30 gallons per minute per square foot (0.20 L/s/m 2 ). Cartridge replacement would be necessary following fouling levels greater than 20% of the maximum rated capacity.

# Supplied and Sized
The pore size and surface area of replacement cartridges should match the manufacturer's recommendations.
Spare Cartridge An extra set of elements, with at least 100 percent filter area, and appropriate cleaning facilities and equipment should be provided to allow filter cartridges to be thoroughly cleaned. Two sets of filter cartridges should be supplied to allow for immediate replacement and cleaning procedures that involve complete drying of the filter elements. To provide for a healthy and safe swimming environment in INDOOR AQUATIC FACILITIES, it is important to consider a number of issues that could impact health. Proper ventilation and humidity control are important in removing excess heat, moisture, noxious odors, and harmful  Proper Chemical Use
In addition, proper usage of chemicals can also improve the quality of the indoor air environment. 221,222,223 High Chloramines
High levels of chloramines and other volatile compounds in the air can increase the possibility of health effects such as upper respiratory illnesses and irritation of the mucous membranes including eyes and lungs. 224,225 Furthermore, these CONTAMINANTS can also cause metal structures and equipment to deteriorate.

# Shock Oxidizer
While proper ventilation is critical for INDOOR AQUATIC FACILITIES, water chemistry also can dramatically affect air quality. Levels of chloramines and other volatile compounds can be minimized by reducing CONTAMINANTS that lead to their formation (e.g., urea, creatinine, amino acids, and personal care products), as well as by supplemental water treatment. Effective filtration, water replacement, and improved BATHER hygiene can reduce CONTAMINANTS and chloramine formation. Research has shown that the use of non-CHLORINE shock oxidizers is selective in OXIDATION and may not prevent nor reduce inorganic chloramines though they may reduce some organic chloramines. 226 The EPA final guidelines state that manufacturers of "shock oxidizers" may advertise that their "shock oxidizer" products "remove," "reduce," or "eliminate" organic CONTAMINANTS. 227 Shock dosing with CHLORINE can destroy inorganic chloramines that are formed. SECONDARY DISINFECTION SYSTEMS such as ozone and ultraviolet light may effectively destroy inorganic as well as some organic chloramines.

# Facility Design & Construction ANNEX 124

# Swimmer Education
In addition, swimmers should be educated that their behavior (e.g., failing to shower, urinating in the pool) can negatively impact air quality by introducing nitrogen-containing CONTAMINANTS that form volatile compounds. 228

# Reduce and Minimize Impact
These steps can help reduce the chemical role in creating poor indoor air quality, and help maintain an environment that minimizes health effects on BATHERS as well as decrease deterioration of AQUATIC FACILITIES and equipment.
Feed Equipment

# General
If recirculation pumps stop but chemical feed pumps continue to pump chemicals into the return lines it can result in a high concentration of acid and CHLORINE being mixed so that eventually when concentrated solutions of CHLORINE and acid are mixed, CHLORINE gas will be formed. The CHLORINE gas could then be released into the AQUATIC VENUE when the recirculation pump is turned on again or in the pump room if there is an opening in the line as has been documented in CDC's Waterborne Disease and Outbreak Surveillance System 229 . To prevent the hazardous release of CHLORINE gas, the chemical feed system shall be designed so that the CHLORINE and pH feed pumps will be deactivated when there is no or low flow in the RECIRCULATION SYSTEM.
Sizing of Disinfection Equipment High use facilities, such as water parks and health clubs, require a greater capacity of feed equipment and production. These facilities generally have higher recirculation rates and experience accelerated consumption and should be sized differently to provide the minimum dosing.
Types of Feeders All UV units shall be installed into the system by means of a bypass pipe to allow maintenance on the UV unit while the AQUATIC VENUE is in operation.
Feeders for pH Adjustment It is recommended that the solution's reservoir supply be sized to hold a minimum of one week's supply.
Automated Controllers Constant and regular MONITORING of key water quality parameters such as the disinfectant level and pH are critical to prevent recreational water illness and outbreaks. AUTOMATED CONTROLLERS are more reliable as a MONITORING device than personnel and The SECONDARY DISINFECTION SYSTEM is to be designed to reduce an assumed total number of infective Cryptosporidium OOCYSTS in the total volume of the AQUATIC VENUE from an assumed 100 million (10 8 ) OOCYSTS to a maximum concentration of one infective OOCYST/100 mL by means of consecutive dilution.

# Equation
In considering the potential for outbreaks, it was decided that a treatment system should be designed to limit the outbreak to a reasonable period of time, preferably to a single day of operation. By this, it is meant that all pathogens of concern that may still be present at infective concentrations at the close of operations are reduced to below a level of infectivity by the opening time of the following day. This approach has been recommended because numerous multi-day outbreaks have been well documented. 231,232,233 In order to design a treatment system that can reduce the duration of exposure to a single day, the MAHC Committee made the following assumptions:  (16-128 mL) would be a reasonable target for overnight remediation of the water to reduce the risk of transmission beyond the day of initial contamination. 236 , 237 The concentration chosen was one OOCYST/100mL.  The only effective means currently to reduce the concentration of OOCYST in an
AQUATIC VENUE while open for bathing is by dilution (this does not include hyperchlorination that requires closure of the water to bathers). Accomplishing this through the introduction of sufficient makeup water is not practical. Instead, the solution is to remove a portion of the water, treat it to reduce the concentration of infectious OOCYSTS, and then return that water to the AQUATIC VENUE. Any treatment system that demonstrates this reduction in Cryptosporidium OOCYSTS specified herein is suitable for use. It is not the intent of the MAHC to limit technology only to UV and ozone as discussed in the CODE, but rather to specify the outcome of the treatment.

# Facility Design & Construction ANNEX 128

# Purpose
The purpose of secondary DISINFECTION is to reduce the viable Cryptosporidium OOCYSTS to a number below that which is considered an infective concentration, should the parasite be introduced into an AQUATIC VENUE. While 100% UV treatment of recirculated water is an option, it is important to note that this will not ensure the SAFETY of the BATHERS immediately following a fecal event, but it will reduce the time required for the system to get below an infective dose. While this is beneficial, mandating UV on 100% of the recirculated water flow may lead owners and designers to minimize the total recirculated flow so as to not incur the additional capital and operating cost of the required additional UV, ozone, or other SECONDARY DISINFECTION SYSTEMS. Cryptosporidium control is not the only consideration when designing an INCREASED RISK AQUATIC VENUE, and it is important that this requirement does not negatively influence other design considerations-such as amount of filtration needed for particulate removal and control of turbidity.
Consideration was therefore given to what should be the maximum time a system takes to reduce the viable OOCYST concentration to below an effective dose. Because a fecal event can release 100 million OOCYSTS and an infective dose is as little as one OOCYST per 100 mL, it is impossible with available technology today to ensure the SAFETY of BATHERS in the AQUATIC VENUE both at the time the fecal event occurs and in the immediate aftermath. A reasonable and logical maximum time for reducing the OOCYST concentration to below one OOCYST/100mL was determined to be the lesser of nine hours or 75% of the time an AQUATIC VENUE is closed in a 24-hour period. The goal of this is to ensure an AQUATIC VENUE is free of viable Cryptosporidium OOCYSTS, or at least have the number below an infective concentration every day the AQUATIC VENUE opens to the public.

# Example of Equation
The actual calculation used to determine the amount of needed SECONDARY DISINFECTION is based upon the understanding that the treatment of recirculated AQUATIC VENUES involves serial dilution, whether we are talking about particulate removal or rendering Cryptosporidium OOCYST ineffective. Assuming an initial concentration of 10 8 OOCYSTS, recognizing the limit of an infective dose is one OOCYST/100 mL, and allowing for a 99.9% reduction in infective OOCYST by the SECONDARY DISINFECTION SYSTEM, it can be derived that needed flow through the SECONDARY DISINFECTION SYSTEM is as given in the MAHC code. For a 100,000 gallon (378,541 L) AQUATIC VENUE which is closed 12 continuous hours out of every 24 hours, 75% of which is 9 hours:  100,000 x {  / (60 x 9)} = 609 gpm Therefore, the 100,000 gallon (378,541 L) AQUATIC VENUE would require a SECONDARY DISINFECTION SYSTEM which has a flow rate of at least 609 gpm. If this AQUATIC VENUE is designed with a two hour filtration TURNOVER rate, the flow through the filters would be 833 gpm. An owner or designer can choose to size the SECONDARY FILTRATION SYSTEM to be 609 gpm, 833 gpm, or anything in between. If the owner or designer chooses to size the SECONDARY DISINFECTION SYSTEM equal to the filtration flow rate (833 gpm) the time it would take to reduce 10 8 OOCYST to 1 OOCYST/100 mL would be 6.6 instead of 9 hours.

# An example of how to calculate for the needed flow is as follows:
Q = V x {[14

# Flow Rate Measurements
Consideration was given for simplifying the sizing of the SECONDARY DISINFECTION SYSTEM and having the flow rate through the SECONDARY DISINFECTION SYSTEM equal to the overall treatment system flow rate. While this was initially recommended by the MAHC, ultimately this approach was rejected. A basic premise of the MAHC is to establish performance-based STANDARDS supported by data and science whenever possible. Sizing the SECONDARY DISINFECTION SYSTEM equal to the overall treatment system flow rate, while simplifying the design and operation of the facility, does not meet any defined criteria for reducing or eliminating risk to the PATRONS using the AQUATIC FACILITY. It was felt that establishing specific criteria for sizing the SECONDARY DISINFECTION SYSTEM independent of the criteria for sizing other treatment system processes (e.g. filtration flow rate) was the approach most likely to protect the public's health.

# Maximum Concentrations
In developing this approach, the MAHC considered establishing maximum permissible concentrations of OOCYSTS, which would be monitored and verified, but the MAHC rejected that approach as impractical since this would require actual lab testing.
Establishing a concentration based STANDARD for the water cannot readily be implemented because:
- There is no practical method to rapidly determine the number of OOCYSTS in the water and thus no method to enforce the STANDARD.  There are multiple and interrelated biological variables in exposure estimations.
These include the number of OOCYSTS released per fecal incident, the number of incidents per day, strain differences in pathogenicity, the amount of water swallowed, and differences in individual susceptibility.  The circulatory patterns in facilities are complex and unique to each AQUATIC FACILITY.
Requiring that the SECONDARY DISINFECTION SYSTEM deliver a treatment that ensured the OOCYST concentration was reduced to a specified level would require multiple biological Validation is a process by which any UV unit is tested against a surrogate microorganism in order to determine its performance. Validation is required because there is no on-line test of a UV unit's ability to disinfect and, due to the relatively short contact time, it is impossible to size units accurately based on just calculations.
It is important to note that evidence of testing is not the same as validation.
Validation must adhere to the following criteria:
- Follow one of the approved validation systems, preferably the USEPA DGM 2006,  Have been carried out be a genuine third party, and  Include all the required validation factors and RED bias.
The validated performance is based on the flow and transmissivity of the water to be treated. Therefore it is essential that the system is used within its validated performance range. A system operated outside its validated range is NOT acceptable.

# Validation Factor
The validation factor is used to account for statistical variations in the recorded data during third party testing. The validation factor is required to ensure that the equipment's actual performance will always be equal to or better than it's validated performance. This figure can be between 15% and 35% depending on the quality of the testing and must be included in any validated performance curve.

# Transmissivity (Transmission)
The transmissivity (often called transmission) of the water to be treated is an important design factor in sizing a UV system. The transmissivity is normally quoted as a % value in either a 1 cm, 4 cm, or 5 cm cell. It is measured in a UV Spectrophotometer.
Facility Design & Construction ANNEX 131 In many water treatment applications, this value will vary considerably but AQUATIC VENUES are for the most part consistent, due to the bleaching effect of the CHLORINE used as a residual disinfectant.
Typically AQUATIC VENUES will have a transmission of between 94% and 95% in a 1 cm cell, with splash pads and other INTERACTIVE WATER PLAY VENUES between 92% and 94%.
The installation of a UV unit itself will increase the transmission by perhaps 2% due to the improvement in the POOL water quality so the values noted above refer to a situation where a UV unit is installed and operational.
Design transmissions over 94% are not recommended, and exceptionally heavily loaded AQUATIC VENUES may consider using a lower number as a design basis.
It is also important to understand that as transmission is reduced, the performance of the equipment is reduced and the RED bias increases, requiring the UV to deliver more performance. For this reason, the performance difference between any equipment's validated performance at 98% transmissivity and actual field performance at 94% transmissivity can be 40% lower. When presented with validated performance data at 98% transmission, operators should therefore be aware that the equipment may only deliver half the performance when installed.

# Validation Range
A validated system will have different performance levels at different water qualities and flows. The relationship between these is traditionally represented as a performance curve where the performance can be noted at any point on this curve. However the lowest transmission test point and the highest flow tested are normally considered the extents of the validated range. This means that any UV unit tested at 95% and above is NOT validated at transmissions lower than 95%. For the same reason, a unit tested at a maximum flow of 500 gpm is NOT validated for any flow over 500 gpm.
Validation factors can reduce equipment validated performance by 30%, so it is essential that systems without validation factors built into performance curves are not considered validated.
The performance of a UV system in the field is measured by a combination of flow and intensity readings from the UV sensors. Performance in the field can be verified on inspection by regulators who will compare actual sensor readings with those indicated on the performance charts, so these charts must be retained at the AQUATIC FACILITY for each validated system.
UV equipment is utilized for its ability to disinfect CHLORINE-tolerant pathogens and for its ability to reduce combined CHLORINES in the POOL water. For the latter, typically a calculated dose of 60mJ/cm 2 is utilized based on the total UV-C and UV-B spectrum. This is similar to the validated dose requirements of the SECONDARY DISINFECTION SYSTEMS.
Facility Design & Construction ANNEX 132 Where UV is fitted as a SUPPLEMENTAL TREATMENT SYSTEM the CODE allows some operational and equipment concessions. Operators should note that the regulations as stated represent BEST PRACTICE; but where specific circumstances dictate, then the equipment specifications may be reduced.
For a SUPPLEMENTAL TREATMENT SYSTEM, the operator may consider reducing the dose applied to the process. This will reduce performance accordingly and operators should consider carefully such reduction in performance, and assure themselves that the equipment will still provide a beneficial level of performance.  240 , and Pseudomonas aeruginosa 241 , along with any other microorganism potentially found in AQUATIC VENUES, and is a strong oxidizer. Exposure to ozone gas can result in irritation to the eyes and respiratory tract if not generated and handled correctly. Therefore the Occupational Safety and Health Administration (OSHA) has identified a time weighted average (TWA) of 0.1 PPM (0.1 mg/L) as the permissible exposure limit for ozone.

# Third Party Validation
Validation is a process by which any ozone unit is tested against a surrogate microorganism in order to determine its performance. Validation is required because there is no on-line test of an ozone unit's ability to disinfect and, due to the relatively short contact time, it is impossible to size units accurately based on just calculations.
It is important to note that evidence of testing is not the same as validation.  Standard 50; it is not an Annex but a portion of the ozone section in the whole STANDARD and was published in the 2013 STANDARD.

# Suitable for Use
All materials must be ozone resistant.
The strong oxidizing power of ozone shall be considered when choosing materials for pipes, valves, gaskets, pump diaphragms, and sealant. Materials for water piping, tanks, and other conveyance shall be nearly inert.
For generators that produce ozone under pressure and utilize a negative pressure (Venturi) ozone delivery system, or introduce ozone under pressure (such as a pressurized diffuser into an atmospheric holding tank), any leak or break in the system will immediately cause the release of ozone gas.
Suitable materials and their uses are: Properly applied Teflon tape may be used successfully for sealing joints; however, threaded fittings shall be avoided where possible. Hypalon and silicone sealers which do not contain rubber filler are also successful. For generators that produce ozone under pressure and utilize a negative pressure (Venturi) ozone delivery system, or introduce ozone under pressure (such as a pressurized diffuser into an atmospheric holding tank), any leak or break in the system will immediately cause the release of ozone gas.
Copper / Silver Ion System The scientific data available on efficacy of these systems is predominantly for bacterial 242,243 inactivation and usually includes FREE AVAILABLE CHLORINE. There is limited scientific literature that documents the efficacy of these systems on viruses and parasites.
Facility Design & Construction ANNEX 135 Given the importance and frequency of recreational water illnesses associated with these other microorganisms (viruses and parasites), it is essential that DISINFECTION chemicals / systems are also effective against such microorganisms as well.
Ultraviolet Light / Hydrogen Peroxide Systems UV/peroxide systems have not been registered by the US EPA as primary disinfectant systems for recreational water. Although UV is a disinfectant, it does not impart a persistent residual disinfecting property to water. To overcome this, UV/peroxide systems claim, or in some cases imply, that the inclusion of hydrogen peroxide in the system supplies a disinfectant in the bulk water in the AQUATIC VENUE. Hydrogen peroxide is used as a hard surface disinfectant and has been granted registration for this purpose by the US EPA. When used as a hard surface disinfectant, hydrogen peroxide is normally used at around 3%. When used in recreational water, hydrogen peroxide is used at 27 to 100 PPM (mg/L), which is 1111 and 300 times, respectively, more dilute than that used on hard surfaces. At these low concentrations hydrogen peroxide is not an effective disinfectant. Thus, UV/peroxide systems do not provide a persistent disinfectant in the bulk of the water in the AQUATIC VENUE. Further, hydrogen peroxide is not registered by the US EPA for use as a disinfectant in recreational water. Since it is not EPA-REGISTERED, the use of hydrogen peroxide as a disinfectant, or any market claims that implies hydrogen peroxide provides any biological control, is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). UV/peroxide system should not be used as a SUPPLEMENTAL TREATMENT SYSTEM on CHLORINE treated AQUATIC VENUES. The addition of hydrogen peroxide to a CHLORINEtreated POOL will inactivate the hypochlorous acid. If sufficient hydrogen peroxide is added, the hypochlorous acid will be completely eliminated and no disinfectant for inactivation of pathogenic organisms will remain.
Water Quality Testing Devices and Kits Water Quality Testing Devices (WQTDs) should be stored as specified by the manufacturer's instructions. Failure to properly store WQTDs will result in incorrect readings. NSF/ANSI Standard 50 for WQTDs in 2013 currently contains specified precision and accuracy requirements for measuring pH, free & total CHLORINE, and free & total bromine. There are three levels of accuracy and precision deemed level 1, 2 and 3, with the highest accuracy and precision in level 1 devices. The test water specifications include alkalinity, calcium hardness, and total dissolved solids.
It is important for a QUALIFIED OPERATOR to use equipment that is easy to read and as objective as possible. The current, common means of testing AQUATIC VENUE water using colorimetric test kits is subjective because the color and intensity must be compared. Titration testing for free and combined CHLORINE is an objective test, which is accurate to 0.2 mg/L with an easily recognizable start and end point. Therefore, titration testing is recommended over colorimetric testing. Due to the use of inconsistent concentration gradations (i.e., the difference in concentration between adjacent color blocks) and the subsequent rapid darkening of the color blocks (e.g., above 1.5 mg/L), the accuracy of colorimetric test methods is likely to be lower than for titration test methods. Visual colorimetric methods are accurate only to +/-half the difference
Facility Design & Construction ANNEX 136 between the adjacent color blocks, and thus the confidence limits for these methods are wider at higher concentrations (e.g., above 1.5 mg/L). Where portable colorimeter test kits are affordable, these are the most accurate kits available for use at POOLSIDE.
Most water tests involve color development. Interferences in the water can cause them to produce a different color, or produce the wrong color intensity, or be unable to produce the expected color. Color matching tests for CHLORINE/bromine provide accuracy equal to approximately half the difference between known values of the color STANDARDS. As the CHLORINE/bromine concentration rises, the greater the difference will be between the known color STANDARDS. Thus, the readings become subjective as the difference increases. The following MAHC Table 4.7.3.5 summarizes some common interferences and how they impact the test color in disinfectant tests. If the water sample indicates high CHLORINE levels, usually over 10 PPM (10 mg/L), the DPD reagents may partially or totally bleach out, resulting in a false low or zero CHLORINE reading. The addition of double the quantity of DPD reagent during testing may minimize this interference or the analyst can use a smaller sample size or dilute the sample with distilled or deionized water (DI) water. Reference the WQTD's use instructions to guard against false readings and interferences.

# High Chlorine Effects on pH Testing:
If the CHLORINE reading is high, the tester must wait until it is lowered to a normal level before retesting the pH, to assure an accurate reading. Some analysts neutralize the DISINFECTANT first by adding a drop of CHLORINE neutralizer (i.e., sodium thiosulfate). This is not recommended since the reaction between thiosulfate and CHLORINE can change the pH of the sample and give an inaccurate reading.

# High Chlorine Effects on Total Alkalinity Testing:
High CHLORINE will affect the Total Alkalinity reading. Some reagents will bleach out and the color change will be from blue to yellow instead of the expected green to red/pink. Refer to the WQTD's instruction manual to prevent false readings and interferences.

# Metals:
Be sure to identify the source of the metal in order to remove the problem for the AQUATIC FACILITY owner. Likely sources are copper from algaecides or corroded pipes, or iron and manganese from the fill water.

# Effect of Metals on Calcium Testing:
For the calcium test, copper, iron, and manganese dissolved in the water may prevent the expected blue color (indicating the end of the test) from fully developing. As the end of the test approaches blue, it fades to a light purple instead, which results from the metals in the water. Repeat the test, but before proceeding with the test instructions, add 5 or 6 drops of titrant. Remember to add the 5 or 6 drops to your final drop count when finished to determine the calcium concentration.

# High Calcium Effects on Chlorine Testing:
When high calcium levels are in the water, the sample may turn cloudy with the addition of DPD #1 liquid reagent, which is alkaline. Addition of DPD #2 liquid reagent may not clear up the cloudiness. With high calcium water, adding DPD #2 prior to adding DPD #1 will acidify the sample, turning it slightly pink, and the cloudiness will not appear. Add DPD #1 to complete the test and obtain the proper pink color for the amount of CHLORINE in the water.

# Potassium Monopersulfate Shock:
Potassium monopersulfate produces a false high combined CHLORINE reading whenever it is present in the water. Monopersulfate will also produce a false positive FREE RESIDUAL CHLORINE reading when the monopersulfate concentration is high (over 25 PPM). Monopersulfate interference can be removed by a variety of products found in the market place. Refer to the WQTD's instruction manual to prevent false readings and interferences. It is known that certain microorganisms, because of their ecology and/or structure, can be tolerant of chemical disinfectants (e.g., chlorine, bromine). Legionella pneumophila, Pseudomonas aeruginosa, Cryptosporidium parvum, Entamoeba histolytica cysts, and Mycobacterium avium complex are a few examples of pathogenic microbes that have been reported to show some tolerance to chemical disinfectants. In addition, sessile (in the biofilm) microorganisms in biofilm are likely to receive additional protection from oxidizers (such as chlorine) when the exposure concentration of these oxidizers is reduced at the interface with the biofilm due to reaction with biofilm material.

# Facility Design & Construction ANNEX 140
Biofilm is a complex community of microorganisms which attach to the sides, piping, and filters of AQUATIC VENUES 249 . Even at elevated concentrations, oxidizing and nonoxidizing chemicals have reduced effectiveness in controlling biofilm when their concentrations and contact times are not sufficient for penetrating the biofilm 250 . Biofilm formation in AQUATIC VENUES is also a concern because microorganisms in the biofilm or the biofilm itself can detach and multiply 251 . Following BEST PRACTICE guidelines for AQUATIC VENUE cleaning and continuous DISINFECTION is critical to avoid biofilm growth and expansion problems 252,253 .
If biofilm-related problems arise, it can be useful to incorporate biofilm sampling to develop a comprehensive evaluation of the risk factors for water quality impairment and potential solutions to identified problems 254 .
MAHC Annex Table 4. 7.3.6 (below) identifies microorganisms for which chlorination may have, or is known to have, reduced efficacy 255,256,257 . MAHC Annex Table 4.7.3.6 also identifies methods that may be used to detect these microbes in AQUATIC VENUE systems, but the methods identified are not necessarily rapid. Additional research is needed to evaluate the benefits of microbiological testing data for AQUATIC VENUES, especially for improving public health protection. This is particularly important for the protozoans, amoebas, and sessile bacterial pathogens that co-exist in biofilms. It should be noted that the use of fecal indicator organisms for AQUATIC VENUE water quality evaluation may not be sufficient for certain AQUATIC VENUE operation, maintenance, and public health investigations, especially in public health investigations related to inhalation, skin breaks, or ocular exposure routes. Since health risks in AQUATIC VENUES and similar environments may be fecal or non-fecal in origin, investigation of fecal indicators and non-fecally-transmitted microorganisms (e.g. P. aeruginosa, S. aureus and Legionella spp.) may be warranted. 1. NOTE a. Many elderly and/or immuno-compromised people use SPAS making them more susceptible to disease; b. P. aeruginosa can be tolerant of CHLORINE and is found in biofilm; c. Hot tub folliculitis is the most common illness associated with hot tubs; and d. Coliform testing is not an indication of P. aeruginosa contamination; e. Since this is a non-reportable disease, we have no information on the incidence of this disease. 2. Grobe, Wingender, & Flemming, 2001;Price, 1988;Clements, 2000. 3. Muraca, Stout, & Yu, 1987Clements, 2000. It is not feasible or cost effective to test for all infectious organisms. Therefore MAHC Annex Table 4.7.3.6 identifies those organisms which have readily available test methods and/or cause illnesses that are common, very serious, or fatal. It is important to note that these test methods may not allow for rapid remediation, decision making, or public health intervention on a timely basis.

# Facility
Design & Construction ANNEX 141
The Heterotrophic Plate Counts (HPC) method has not been included in the list of microbial water quality tests in MAHC Annex Table 4.7.3.6. While HPC data are generally a good indicator of microbial water quality and efficacy of POOL operations (e.g., water treatment), this parameter has been reported to show no correlation to the presence of Legionella 258 , planktonic pathogens 259 , or the presence of biofilm 260 . HPC tests (as do all culture tests) under-report the actual concentration of viable bacteria. Therefore, it is recommended that the use of this test be restricted for assessing the level of planktonic, non-pathogenic bacteria only. HPC data are not sufficient to assess the public health risk of POOLS, SPAS, and waterparks 261 .
Since the MAHC is intended to be a living document with changes anticipated as our knowledge increases, it is prudent to acknowledge that a paradigm shift is occurring in the world of microbiology that likely will impact how pathogen testing will be conducted and interpreted in the future. Culture tests are gradually being replaced with cultureindependent test methods such as Polymerase Chain Reaction (PCR) testing and microarray testing. Years ago when PCR was first used commercially, the cost of the tests was prohibitively expensive. Now test costs have decreased and are competitive with culture dependent tests. A recent development is the commercialization of microarray testing which can screen for the presence of a wide variety of bacterial and viral pathogens without the need for an isolation step. However, the costs associated with microarray testing are prohibitively expensive as of this MAHC publication.
Facility Design & Construction ANNEX 144 EPA is re-evaluating the use of culture-based fecal indicator bacteria (FIB) tests in recreational water testing (i.e., total and fecal coliforms, E. coli and Enterococcus) and is researching the use of PCR for Bacteroides and Enterococcus testing as a possible replacement for these culture tests. Two of the most compelling reasons for this re evaluation are:  Incubation times for culture tests prevent quick decision-making to minimize public exposure to water with a potentially elevated disease risk, and  Molecular tests are generally considered to have higher specificity (lower false positive rates) than traditional culture tests.
PCR can be a good method for investigating whether pathogenic microbes were present in AQUATIC VENUES (e.g., sampling filter backwash) since the technique detects the DNA of pathogens regardless of whether they are live, dead, or viable-but-not culturable. Another benefit is that PCR culture tests can be completed in hours versus days. However, while PCR can be effective for determining whether pathogens have been present in an AQUATIC VENUE, the technique is less effective as a measure of DISINFECTION effectiveness since it detects DNA from both viable and non-viable organisms. New techniques, such as the use of propidium monoazide (PMA) have been reported to enable PCR to characterize the viability status of microorganisms, so in the future PCR may be an effective option for DISINFECTION studies 262 .

# Water Replenishment System
A WATER REPLENISHMENT SYSTEM allows for POOL water to be removed from the POOL and properly disposed of so that it can be replaced with fresh water containing lower concentrations of dissolved CONTAMINANTS. A WATER REPLENISHMENT SYSTEM should be used to control the dissolved organic CONTAMINANT concentrations (e.g., sweat, oils, chlorination by-products, and urine) and dissolved inorganics (e.g., salts and metals) because POOL filtration systems are not effective at removing dissolved CONTAMINANTS.

# Discharge and Measure
A means of intentionally discharging and measuring or calculating the volume of discharged POOL water (in addition to the filter backwashing system) should be provided and designed to discharge a volume of water of up to four gallons (15 L) per BATHER per day per facility through an air gap. Knowing pump gallons per minute and knowing how much time one is backwashing can be used to calculate the volume discharged. Water replacement or replenishment at a rate of eight gallons (30 L) per BATHER per day per AQUATIC VENUE 263,264,265 have been widely used. PWTAG 266 states that as much as half of the recommended amount could be associated with filter backwashing. There does
Facility Design & Construction ANNEX 145 not appear to be any research to support the use of the 30 L/day/BATHER number used abroad. So, since gal/day/BATHER is roughly half of this amount (and typically met by filter backwashing alone), it seems like a reasonable place to start incorporating this practice into operations. A requirement could be made once the science is there to support a higher or lower value. With a WATER REPLENISHMENT SYSTEM in place, AQUATIC FACILITY operators will be able to experiment with higher WATER REPLENISHMENT rates to obtain improved water (and indoor air) quality. It should also be easy to comply with any future regulations related to WATER REPLENISHMENT as only the flow rate would require adjustment. WATER REPLENISHMENT for a large AQUATIC FACILITY would be based on the number of BATHERS in the entire AQUATIC FACILITY (not the total number swimming in a particular aquatic venue on a given day since most BATHERS are expected to distribute the bather count over a range of aquatic venues and/or rides on a given day). However, WATER REPLENISHMENT should be proportional to the number of BATHERS in each individual treatment system. It would not be allowable to send to waste all of the water from the WAVE POOL and none from the other attractions (unless the water was shared through a combined aquatic venue treatment system).
Alternate Systems The code allows for use of alternate systems to meet the intent for removal of organic compounds and salts. Currently, the MAHC is not aware of such systems.  Fundamentally, these sources all seek to eliminate standing water from the DECK, typically recognizing that smoother surfaces convey water more efficiently than rougher ones. Relating slopes to texture, rather than specific materials, provides the ability for any otherwise suitable DECK material or finish to be considered by the adopting jurisdiction.
There is an inherent conflict in sloping of DECKS. Steeper slopes provide more construction tolerance and surety in conveying water, particularly in active soil 4.0 Facility Design & Construction ANNEX 147 conditions. Shallow slopes are required to meet accessibility guidelines -particularly for cross-slopes. It is the intent of this section to encourage positive and proper drainage without running afoul of accessibility guidelines.
Cross Connection Control Consult local AHJ regarding specific chemical handling and use to properly dispose, including discharge to the watershed or sanitary sewers where appropriate.

# No Drain
This requirement prevents sewage from backing up into the AQUATIC VENUE water. This isolates the treated system and does not allow mixing of other sources of water that could contaminate.
Materials / Slip Resistance ASTM is developing a STANDARD to define a method to test for slip resistance.
Slip Resistance While much research has been done and several STANDARD tests created for defining "slip resistance", no industry STANDARDS exist specifically related to aquatic environments. Most studies have been performed in the interest of SAFETY in employment, providing guidance with respect to work surfaces and footwear. The most commonly accepted test for slip resistance, using a device called the James Machine (ASTM D2047), is not suitable for testing wet surfaces, and is not portable for testing in the field 267 .
Carpet Carpet and artificial turf have been found to be inappropriate finish materials for the wettest area immediately around the POOL, i.e. PERIMETER DECK. Although the materials that carpet is manufactured from are durable and do not support mold growth, when they are installed over a relatively impermeable surface, water flows very slowly through the carpet. Soil and CONTAMINANTS entering into the carpet are not easily removed. Since the carpet stays wet longer, soil and CONTAMINANTS remain in the carpet, and mold and algae growth can occur. Therefore carpeting is not an acceptable finish material in the wet PERIMETER DECK.
Finish materials for the PERIMETER DECK should not block DECK drains or impair water flowing to DECK drains.
Carpeting may be installed beyond the DECK drains, i.e. DRY DECK.
Wood Properly treated or composite wood materials may be a suitable material for DRY DECKS provided all other decking requirements are maintained. Fasteners must be regularly
Facility Design & Construction ANNEX 148 inspected to ensure structural integrity and that all heads are flush or recessed into the DECK surface.
Dry Deck Regional materials, local practices, and particular facility design intentions vary widely with respect to DRY DECK. This section intends to provide the opportunity for regulatory oversight of DRY DECK, without limiting these variables best understood by AHJ.
Landscaping It is acknowledged that landscaping near AQUATIC VENUES is not an uncommon practice in enhancing an AQUATIC VENUE environment. Landscape materials themselves and the design of special AQUATIC VENUES vary so widely as to require special consideration with respect to landscaping. This section intends to provide the opportunity to allow landscaping, but only through the lens of the AHJ.
The landscaping materials are not intended to be placed in the wet PERIMETER DECK area. It is assumed here that the POOL DECK will be designed and sloped to prevent drainage from landscaping materials from reaching the POOL.
For an outdoor AQUATIC VENUE, it is not possible to prevent wind from moving dirt, bugs, plant material, etc. around and perhaps into the AQUATIC VENUE. The landscape designer must consider the type and location of landscape materials placed inside or outside of an outdoor AQUATIC VENUE ENCLOSURE.

# Textured Surface
The walking surface should not be rough so as to cause injury or discomfort to BATHERS. ANSI defines where a trip hazard is considered as a level change that is greater than 14 inch (6.4 mm). Other definitions include an abrupt or unexpected level change in surfaces. The separated areas may have differing uses, flow rates, currents, or water depths.

# Perimeter Overflow System
The MAHC Committee defines WING WALLS as interior elements of the POOL and interior to the PERIMETER OVERFLOW SYSTEM, so the MAHC did not feel it was appropriate to say that WING WALLS longer than some specified length should require PERIMETER OVERFLOW SYSTEMS. It would be a function of the width of the WING WALL as to whether or not it can be properly constructed. If the POOL has a gutter system, it would probably need four feet (1.2 m) of width to get a normal trough on either side. SKIMMERS could be achieved for narrower walls because they could be staggered.
Pool Perimeter WING WALLS do not contribute to the overall POOL perimeter so should not be included in AQUATIC VENUE perimeter calculations that are used as part of multiple critical design calculations.
Deck Drainage The MAHC did not feel that DECK drains should be required on WING WALLS since they are considered part of the POOL and not subject to regular foot traffic. As for DECK level POOLS, the WING WALLS would be at or below water level making drains impractical.
Islands A seven foot (2.1 m) minimum clearance overhead is required since it is consistent with requirements of building code minimum ceiling clearances.
Heated Decks Heated DECKS are occasionally used in cold climates to provide pedestrian paths to and around outdoor heated AQUATIC VENUES. This section provides that when heated DECKS or snow-melt systems are provided, a minimum slope must be uniformly provided. Clear delineation is required because icy areas and/or pathway edges near otherwise DRY DECK poses an unsafe condition. Diving Envelope This code is designed to encourage POOLS to be built to the STANDARDS of the agency that will certify the diving at the AQUATIC FACILITY. The code dimensions are purposely a compilation of the most conservative STANDARDS of diving envelope dimensions and are in no way intended to supersede the certifying agencies dimensions, but instead are intended to be used only when there is no certifying agency for the AQUATIC FACILITY. Since NCAA, USA Diving, and FINA do not have STANDARDS for boards less than one meter in height, the State of Michigan table (R325.21.33, Table 1), shown below as MAHC Table 4.8.2.2, was revised to the most conservative STANDARD found for 0.5 meter and 0.75-meter boards. These minimum dimensional requirements were then dictated to be more conservative in certain instances based largely on interpolations.
Concerning use of diving boards higher than 1-meter, these boards are not recommended for non-competitive use. However, if the boards are constructed to this code or NCAA standards, then non-competitive use can be allowed under careful adult supervision or with QUALIFIED LIFEGUARDS on duty. However, non-conformance with these STANDARDS is unsafe for recreational diving purposes.
Steps and Guardrails Although there are some national data on spinal cord injuries (SCIs) in general, data on diving-specific SCIs are limited, particularly for SCIs involving public POOL-related competition diving.

# General Data on Spinal Cord Injuries:
For SCIs in general, approximately 40 SCIs/million population occur each year in the US (about 12,400 injuries for 2010) with approximately 4.5% related to diving injuries. 268 SCIs are a catastrophic public health problem leading to disability and decreased life expectancy 269 with a large economic and social burden for those who suffer the injury 270,271 .

# Non-Deck Level Diving, Competition Diving, and SCIs:
Data related to SCIs occurring as a result of competition diving off starting platforms are limited. Since starting platforms are several feet above the POOL, the entering velocity of swimmers is greater than for DECK level diving making it more difficult to alter trajectory once executed 272 . One large study investigated 74 SCIs in non-competitive divers occurring with use of springboards and/or jumpboards; 45% of the POOLS were public 273 . Of these injuries, 12.2% occurred in water less than 4 feet (1.2 m); 66.2% occurred in water less than 5 feet (1.5 m); 94.6% occurred in water less than 6 feet (1.8 m). All SCIs occurred in water of less than 7 feet (2.1 m). The MAHC requires that starting blocks be removed, if possible, or blocked off to prevent recreational divers from using them when not in use by competitive swimmers.
Data demonstrates that competitive swimmers can be trained to perform shallow water dives from starting blocks to reduce the risk of SCIs 274,275,276 . As a result, competitive aquatics governing bodies (e.g., FINA, U.S.A. Swimming, NCAA, NFSHSA, YMCA) allow starting blocks to be placed over water as shallow as 4 feet (1.2 m) in depth as long as competition is conducted under the auspices of the governing body or by a coach or instructor. A progressive training regimen can be used so that diver training is conducted in deeper water until the diver has mastered the technique before the certified personnel approve their starting block entries into shallower depths 277 .
Facility Design & Construction ANNEX 153 However, further data are needed on the adequacy of an intervention, like training, that relies on correctly performing a technique to prevent injury; aquatics governing bodies state they have not documented injuries since this progressive training regimen has been adopted. However, it is noted that high speed video of competing athletes during competition dives from starting platforms illustrates the following:  About 3% of athletes diving into 4 feet (1.2 m) of water 278 (the pool had the minimum depth recommended for athletes using starting blocks) touched the bottom;  Nearly half approach within 0.5 meters (1.6 ft) of the bottom;  Over half exceeded head speed thresholds deemed possible to cause severe head trauma; and  There was some anecdotal information suggesting some divers touched intentionally.
Conversely, filming of athletes diving into 7.5 feet (2.3 m) of water (the pool studies exceeded Olympic competition depths of 6.5 feet (2.0 m) below starting platforms) showed that very few swimmers approach to within even one meter (3.3 ft.) of the POOL bottom 279 . These data suggest that injury risk from using starting platforms is likely to be higher for older, presumably heavier, or inexperienced divers, particularly when diving into shallower depths.

# Future Directions and Research
The MAHC recommends that these national databases be re-analyzed with aquatics in mind to gather more detailed information on SCIs related to diving in treated AQUATIC VENUES, particularly public AQUATIC VENUES to further inform this discussion. Future analysis of national databases should be undertaken, if possible, to assess the occurrence of SCIs in competitive swimmers and platform heights and water depths at which the injury occurred. Historical analysis and peer-reviewed publication of data or reports collected by aquatics governing groups on SCIs and other diving injuries would also be important to understand POOL-specific diving injuries occurring in competitive swimmers and the efficacy of current progressive training or other interventions.

# Emergency Communication Equipment
A communication device is required in the Operations (MAHC 5.0) section of the MAHC, but it also needs to be considered in the design so the designer can plan for the wiring for such devices. Consider larger facilities or other types of facilities who may have a phone in the nearby building. Consider a telephone labeled with location of
Facility Design & Construction ANNEX 154 phone/address. Some facilities may be so equipped to properly respond to an event and phones may not be required. Large AQUATIC FACILITIES with lifeguard/trained response may not need phones installed everywhere. The intent is for BATHERS to have access to a phone to call for help when help is not necessarily part of the AQUATIC FACILITY operation.
QUALIFIED LIFEGUARDS or other emergency response staff are to be trained and may have communication devices such as whistles or radios which initiate their emergency response which includes the ability to contact outside emergency personnel when necessary. Often AQUATIC VENUES can be at a distance from support personnel and the designer should consider methods for personnel to communicate whether via radio, telephone, intercom, or other method. For alternate communication systems or devices, the intent is that an emergency phone or communications system or device is immediately available to PATRONS from all AQUATIC VENUES within an AQUATIC FACILITY. Some alternate communication systems might include a handset or intercom system to a location that is constantly manned whenever the AQUATIC VENUE is open for use (e.g. a front desk at a hotel, the check in desk at a fitness club, or other continuously manned location); a commercial emergency contact device that connects to a MONITORING service, or directly to 911 dispatch; or devices that alert multiple staff on site when activated (e.g. pagers systems, cellular telephone systems and radio communication alert systems). Also see MAHC Section 5.8.5.2.1 for additional requirements.
Safety Equipment Required at Facilities with Lifeguards

# Lifeguard Chair and Stand Placement
This section refers to only those chairs that are permanently installed and does not indicate that a permanent chair or stand is required. The location of the chairs must give the QUALIFIED LIFEGUARD complete visibility to all parts of the zone of PATRON surveillance. The number of chairs is determined by the ability to provide surveillance of the AQUATIC VENUE by creating zones of PATRON surveillance. It is intended that the designer should be working with an aquatic consultant or the owner/operator to make sure the location of chairs and stands allows for clear line of sight.

# Lifeguard Chair and Stand Design
Chairs and stands are exposed to elements; therefore, they should be made to withstand the environment. The intent for such a chair is to facilitate better surveillance and such the chair should be elevated sufficiently above the heads of BATHERS to have a better view and combat glare. Considerations for the SAFETY of QUALIFIED LIFEGUARDS using these chairs should include access and egress as well as BARRIERS to unauthorized access if installed at an elevation.

# UV Protection for Chairs and Stands
Protection from ultraviolet radiation exposure can include a shade attached to the stand, a shade structure external to the stand, or other types of shade such as surrounding features. The designer should consider which method will be employed to provide UV protection for the stand.  10.2 cm) sphere in the body of the code. From a building code perspective, this is not consistently enforced and these CODES don't regulate that small of an opening. Building codes allow standard 2 14 inch (5.7 cm) mesh fencing and is not necessarily specific for AQUATIC VENUES. Building codes typically dictate minimum height and proximity to property lines -unless it's a fall issue. With AQUATIC FACILITIES, we are mainly concerned with discouraging unauthorized entry / break-ins.
Emergency Exit Paths It is the intent of this section to prevent emergency egress routes from exposing building occupants to unguarded AQUATIC VENUE areas. It is not the intent of this section to permanently segregate multiple AQUATIC VENUES on the same site. Temporary or seasonal ENCLOSURES (properly maintained and employed) may be used to segregate paths of egress from a building or adjacent AQUATIC VENUE to SAFETY. For example, where a seasonal outdoor AQUATIC VENUE is operated in conjunction with a year-round indoor AQUATIC VENUE, a seasonal exit pathway separation ENCLOSURE may be used to maintain exiting in the off-season. During the outdoor swim season (when the outdoor aquatic venue is in operation), it is acceptable to egress via the AQUATIC VENUE DECK to EXIT GATES.
Height The MAHC discussed this issue at length. The prevailing "BEST PRACTICE" in the industry is for 4 foot (1.2 m) high fencing around unguarded AQUATIC FACILITIES. However, the MAHC decided to make the BARRIER height the same for all AQUATIC FACILITIES (6 feet or 1.8 meters) since 4 foot fences are scalable even with smaller mesh. Generally, even unguarded AQUATIC FACILITIES have some hours of use and these POOLS also need to discourage use outside of operational hours by youth and others. The MAHC's collective logic was that if an AQUATIC FACILITY is designed for unsupervised use at all times then there is no real advantage to a fence higher than 6 foot (i.e., 8 foot or taller).

# Other Barriers Not Serving as Part of an Enclosure
The 42 inch (1.1 m) BARRIER height is consistent with STANDARD building CODE requirements for a guardrail, which serves substantially similar purposes. This height provides for consistency across CODES for like appurtenances.

# Gates and Doors
This section is intended to address large AQUATIC FACILITIES where there may either be multiple AQUATIC VENUES, multiple grade elevations, or both. EXIT GATES must be provided to permit adequate emergency egress. For example, an AQUATIC FACILITY with ten AQUATIC VENUES split between different grade elevations should have the required number of exits spaced reasonably around the perimeter and not all at one grade elevation.
Wall Separating A minimum overhead clearance of 6 feet 8 inches (2.0 m) is required since it is consistent with requirements of building code minimum doorway clearances. Materials that do not pose a possibility of physical injury may be suspended from the structure to help contain the INDOOR AQUATIC FACILITY environment.
Multiple Aquatic Venues Rationale of 24 inch (61.0 cm) deep rule is that if adjacent water is not substantively deeper than the WADING POOL, there is no need to segregate the two. If it is the only AQUATIC VENUE within the facility, then normal fencing and perimeter ENCLOSURE requirements would apply. If WADING POOLS are a part of a larger facility with other types of AQUATIC VENUES, then the requirements proposed in MAHC Section 4.12.9.2 would apply.

# Aquatic Venue Cleaning Systems
The MAHC encourages draining SPAS for cleaning. A vacuum likely would not be required for very small AQUATIC VENUES, such as SPAS less than 75 square feet (7.0 m 2 ).
A simple wall brush with pole can adequately and efficiently clean the floor.
No Hazard Pumps shall not exceed 3 horsepower because the suction hydraulic of a larger pump through the small vacuum tubing would force the pump to operate at unacceptable hydraulic conditions. Strong suction forces provide a greater risk for bodily harm in the event of a vacuum system mishap.
POOL vacuum systems must use suitably-sized pumps, proper diameter vacuum hoses, and reasonable hose lengths to provide optimum hydraulics for vacuuming operations. Conventional suction requirements call for a maximum 15 feet (4.6 m) of water at a flow of 4 gpm per lineal inch of suction cleaner head for the total suction head loss.
GFCI Connection Not allowing extension cords prevents the possibility that the high voltage power supply unit has enough cord to potentially be dragged into the POOL causing a potential SAFETY risk.
The power cord length needs to be shorter than the distance between the receptacle and the edge of the POOL in order to prevent the power supply from accidentally entering the POOL water while connected.
Ventilation  See International Mechanical Code Section 502.
Markings Pipes may be color coded according to use with either labels or a reference chart; directional arrows with permanent labeling on the pipes; or by other means deemed suitable by the AHJ.

# Equipment Rooms Containing Combustion Equipment

# Installed
No code language exists for this section since the MAHC defers to other CODES but the rationale for some of it is still included in the Annex.
No items should be installed, nor shall STORAGE be planned for any items, within the minimum clearances of a COMBUSTION DEVICE, as defined by the manufacturer, or within the minimum clearances as defined the National Fuel Gas Code or other applicable code, whichever are greater.

# Increased Ventilation
Rooms containing combustion equipment may be subject to requirements for increased ventilation and combustion-air intake, as specified by the National Fuel Gas Code or other pertinent CODES. The EQUIPMENT ROOM should be so constructed as to allow for the planned equipment, or should be modified as necessary.
Where an EQUIPMENT ROOM contains combustion equipment which uses equipmentroom air for combustion, no other equipment should be so installed as to reduce the room air pressure beyond the acceptable air-intake pressure range for the combustion equipment.

# Noxious Gasses
All practical flames produce carbon monoxide or nitrous oxides. There is very little chance of being rid of both of them at the same time. Neither is good for human health.
The key is to dilute combustion products and send them up the flue. This does not always work where equipment-room air pressure is lower than outdoor air pressure. Some COMBUSTION DEVICES work by natural draft (buoyancy of hot gases) and cannot tolerate any pressure difference. Other COMBUSTION DEVICES have higher pressure differences which they can overcome.
Where an EQUIPMENT ROOM contains combustion equipment which uses EQUIPMENT ROOM air for combustion, air-handling equipment should not use the room as a plenum. Exceptions may include where the combustion equipment is listed and labeled for the expected use, such installation shall be acceptable where approved by the AHJ.
- See International Mechanical Code Sec. 701.

# Plenum Room
A plenum room uses the EQUIPMENT ROOM as the intake duct for HVAC equipment. Thus, it will have a low air pressure while the HVAC equipment is operating. For an INDOOR AQUATIC FACILITY, the incoming air would contain halogen compounds, e.g. chloramines, and thus should never be used as combustion air.
Where an EQUIPMENT ROOM contains combustion equipment which uses a draft hood, air-handling equipment should not use the room as a plenum. Exceptions may include where the combustion equipment is listed and labeled for the expected use, such installation shall be acceptable where approved by the AHJ.
- See International Mechanical Code Sec. 701.

# Lowered Room Pressure
In this situation, there is a tendency for the lowered room pressure to pull combustion products back down the flue into the room, and thus spread them everywhere.
Rooms containing combustion equipment are also subject to requirements for separation from chemical-STORAGE spaces.
Separation from Chemical Storage Spaces Largely, building STANDARDS do not speak to AQUATIC VENUES; for example, the dangers that chemical fumes pose to combustion equipment. Combustion equipment cannot be allowed to intake halogen compounds, because acids will form in the flue and destroy it, allowing carbon monoxide and other combustion products to enter the occupied space.

# Equipment
Refrigeration Equipment Most refrigerants are heavier than air. When released from containment, most will evaporate rapidly, expanding greatly in the process. If a large enough amount is released, it could displace air to above head-height. For this reason mechanical CODES usually require refrigerant-release to the outdoors when the amount of refrigerant exceeds some fraction of the occupied volume.

# Chemical Storage Spaces
POOL-chemical associated injuries have been routinely documented. 280,281
Eyewash It is the intent to allow re-fillable eyewash bottles and not require plumbed emergency eyewashes and showers unless required by the AHJ.

# Outside
The intent is to allow some flexibility since installation in the CHEMICAL STORAGE SPACE may be prone to failure due to corrosion. External eye wash stations should be close and easily found such as in a location outside the door that all staff must walk past. The MAHC will continue to look for data supporting a maximum distance from the door.

# Construction
As applicable, the STANDARDS of NFPA 400, the IFPC, and the IBC shall prevail. This STANDARD is not intended to provide relief from these other regulations, but to provide BEST PRACTICE where these regulations are not adopted or enforced. The more stringent STANDARD shall prevail as applicable.

# Floor
The floor or DECK of the CHEMICAL STORAGE SPACE should be protected against substantial chemical damage by the application of a coating or sealant capable of resisting attack by the chemicals to be stored.
No Openings Other than a possible door, there should be no permanent or semi-permanent opening between a CHEMICAL STORAGE SPACE and any other INTERIOR SPACE of a building intended for occupation.
Exterior Chemical Storage Spaces As applicable, the STANDARDS of NFPA 400, the IFPC, and the IBC shall prevail. This STANDARD is not intended to provide relief from these other regulations, but to provide BEST PRACTICE where these regulations are not adopted or enforced. The more stringent STANDARD shall prevail as applicable.
Fencing Such part of an outdoor space as does not join a wall of a building should be completely enclosed by fencing that is at least 6 feet (1.8 m) high on all other sides.
Chemical Storage Space Doors As applicable, the STANDARDS of NFPA 400, the IFPC, and the IBC shall prevail. This STANDARD is not intended to provide relief from these other regulations, but to provide BEST PRACTICE where these regulations are not adopted or enforced. The more stringent STANDARD shall prevail as applicable.
Signage Given the high turnover rate or potential for employees to travel between workplaces at some AQUATIC FACILITIES, it would seem prudent to require a posting of the SDS location. Specifying the location of the SDS on the actual entry door to the chemical space may help reduce time for a response to an event. It further strengthens the requirements of OSHA:

# 1910.1200(g)(8)
The employer shall maintain in the workplace copies of the required safety data sheets for each hazardous chemical, and shall ensure that they are readily accessible during each work shift to employees when they are in their work area(s). (Electronic access and other alternatives to maintaining paper copies of the safety data sheets are permitted as long as no barriers to immediate employee access in each workplace are created by such options.)

# 1910.1200(g)(9)
Where employees must travel between workplaces during a workshift, i.e., their work is carried out at more than one geographical location, the material safety data sheets may be kept at the primary workplace facility. In this situation, the 4.0 Facility Design & Construction ANNEX 166 employer shall ensure that employees can immediately obtain the required information in an emergency.

# 1910.1200(g)(10)
Safety data sheets may be kept in any form, including operating procedures, and may be designed to cover groups of hazardous chemicals in a work area where it may be more appropriate to address the hazards of a process rather than individual hazardous chemicals. However, the employer shall ensure that in all cases the required information is provided for each hazardous chemical, and is readily accessible during each work shift to employees when they are in their work area(s).
- See NFPA 704 "Hazard Identification System".
Emergency Egress This usually takes the form of a kick-out panel in the door. When trapped, a person can sit down and kick out the panel, creating an opening usually about six inches (15.2 cm) narrower than the door and about 28 inches (71.1 m) high. Since these are used in most ENCLOSURES where a person can be trapped (e.g. walk-in freezers) the volume is high enough for additional expense to be minimal. Trapping could happen in several ways, but the most common is binding of the door to the jamb. Corrosion products can build up inside a metal door between the jamb and the wall, forcing the jamb away from the wall and toward the door. At some point the door will either fail to open or fail to close. Combustion equipment cannot be allowed to intake halogen compounds, because acids will form in and destroy the flue. Air-handlers have strong negative air pressures inside them. This will draw in any CONTAMINANTS around the cabinet and distribute throughout the ducted system.

# Interior Door
Interior Chemical Storage Space As applicable, the STANDARDS of NFPA 400, the IFPC, and the IBC shall prevail. This STANDARD is not intended to provide relief from these other regulations, but to provide BEST PRACTICE where these regulations are not adopted or enforced. The more stringent STANDARD shall prevail as applicable.
No Air Movement  See ANSI/ACCA Manual SPS 2010 Section 4-4.

# Electrical Conduit System
An interior CHEMICAL STORAGE SPACE that shares any building surface (wall, floor, ceiling, door, etc.) with any other INTERIOR SPACE or that shares an electrical-conduit system with any other space should be equipped with a ventilation system that maintains the air pressure in the CHEMICAL STORAGE SPACE below that of any other INTERIOR SPACE by 0.05 to 0.15 inches (1.3 to 3.8 mm) of water pressure, or by such greater pressure difference as should be necessary to ensure that all air movement through building surfaces or conduits should be toward the CHEMICAL STORAGE SPACE.
Note 1: This can usually be accomplished by maintaining the air pressure in the CHEMICAL STORAGE SPACE at least 0.05 I.W.C. to 0.15 I.W.C. below that of any adjoining space and below that of any space connected to the CHEMICAL STORAGE SPACE by an electrical conduit system. Larger pressure differences may be needed in special cases. This pressure difference should be maintained by a continuously operated exhaust system used for no other purpose than to remove air from that one CHEMICAL-STORAGE SPACE. Gaseous Chlorination Space Many current jurisdictions closely regulate the use of gas CHLORINE from a disaster preparation and response standpoint. This can make CHLORINE gas use prohibitive from a regulatory standpoint to the point that its use is difficult to justify.
Windows in Chemical Storage Spaces 4.9.2.12.1 Not Required These windows are sometimes built into the door, although not always. (There are firerated doors with windows.) Such windows may serve several purposes.
Requirements Such windows are usually installed for free lighting, although there can be drawbacks. Some chemicals may react on exposure to sunlight.

# Hygiene Facilities

# General
Language similar to this section is found in most state CODES.
Minimum to Provide During 2009-2010, 24 (80.0%) of 30 treated recreational water-associated outbreaks of diarrheal illness were caused by Cryptosporidium 284 . These cryptosporidiosis outbreaks tend to disproportionately affect children under five years of age and can cause community-wide outbreaks 285 . Infectious Cryptosporidium OOCYSTS' extreme CHLORINE tolerance allows them to survive for 3.5-10.6 days when free CHLORINE levels are maintained at 1-3 mg/L 286 . The OOCYSTS small size (4.5 m x 5.5 m) also allows them to bypass typical sand and cartridge filters 287 . While secondary or supplemental DISINFECTION can inactivate the OOCYSTS, these ultraviolet and ozone treatment systems are circulation dependent 288,289,290,291,292 .
Thus, changing BATHER behavior in the following ways are needed to help prevent cryptosporidiosis outbreaks:
Facility Design & Construction ANNEX 170  Enforcement of policies that exclude swimmers with diarrhea,  Swimmer education about hygienic swimming behaviors (e.g., taking a cleansing shower before entering the water, not swallowing the water), and  Using secondary or supplemental DISINFECTION.

# Chloramines
During January-March 2007, over 660 BATHERS and aquatic staff at a waterpark experienced respiratory symptoms and eye irritation caused by chloramines. 293 Chloramines form when free CHLORINE oxidizes nitrogenous compounds (e.g., sweat, urine, and personal care products) that wash off BATHERS' bodies. Chloramines can volatilize into the air where it can accumulate in air of indoor AQUATIC VENUES. One in five (17%) American adults reports having ever urinated in a POOL 294 , and elite athletes can sweat over 700 mL/h 295 . Rinsing off in the shower for 60 seconds and wearing bathing caps significantly decreases the amount of total organic carbon and total nitrogen 296 . Studies also suggest that ultraviolet treatment can reduce chloramine levels in the water 297,298 .
Accumulation of chloramines in the air at indoor treated recreational WATER VENUES can be reduced with the following practices:  Policies that require showering before entering the water,  Swimmer education about hygienic swimming behaviors (e.g., taking a rinse shower and using the toilet before entering the water, not urinating in the pool, and wearing bathing caps), and  Using ultraviolet water treatment and improving ventilation. so that they will use restrooms rather than urinating or defecating in the VENUE water, which is common. Unlike other recreational facilities, people feel that it is more acceptable to "pee in the POOL" than to not use sanitary facilities for these bodily functions and other locations. This may not be possible in large waterparks, however, they can possibly be located within 300 feet (91 m) from the AQUATIC VENUE. The distance needed for parents to walk or carry children less than 5 years old should be shorter (200 ft or 61 m) to ensure use. These distances are found in multiple state or local CODES including Wisconsin, Oregon, Florida, and New York. When possible, it is preferable to have a bathroom on the same floor as the AQUATIC VENUE; however, it is not required at this time in the MAHC.
Drinking water should be available so that PATRONS, especially young children, are less likely to drink POOL water and to ensure that PATRONS are kept well-hydrated.
Children Less than Five Years of Age There are specific types of AQUATIC VENUES that pose an INCREASED RISK of fecal contamination of the water and transmission to BATHERS such as WADING POOLS, WATER ACTIVITY POOLS, INTERACTIVE WATER PLAY VENUES, or other AQUATIC VENUES designed primarily for children less than five years old. For these AQUATIC VENUES, diaper changing areas should be located directly adjacent to the kiddie areas to promote use.
It is especially important that HYGIENE FACILITIES be available to these INCREASED RISK groups. Children less than five years of age have the highest incidence of diarrheal illness and are more likely to be a source for spreading recreational water illnesses.

# Design and Construction
Language similar to this section is found in most state CODES.
Floors "Slip resistant" is usually considered to mean having a static coefficient of friction of 0.6 or better for both wet and dry conditions. Currently, this ASTM STANDARD C1028 is under revision.
Floor Base The purpose of coving is to prevent water splashing on the wall when mopping. Six inches (15.2 cm), a common height, was taken from building CODE.
- For further information, also see the FDA Model Food Code for Kitchens.
Floor Drains

# Opening Grill Covers
Holes in floor drain cover openings need to be sized to prevent small children's toes from becoming entrapped when walking over them.
Hose Bibb The purpose of these hose bibs is to permit adequate cleaning of shower and toilet facilities and to permit cleaning of any spills occurring in the HYGIENE FACILITY. See also MAHC 6.5 for further rationale.

# Plumbing Fixture Requirements
Language similar to this section is found in most state CODES.

# General

# Protected
It is fundamental that there be no cross connections between safe (potable) and unsafe (non-potable) water supplies. All hose bibbs should be equipped with a vacuum breaker to prevent back siphonage. This cross-connection protection can also be achieved at lavatories and laundry tub washing facilities through an air gap. As a general rule, the INLET pipe is terminated at a distance about four times the diameter of the pipe and not less than four inches (10.2 cm) above the maximum overflow level of the fixture rim.
Toilet Counts Facilities in jurisdictions with requirements governing the number of sanitary facilities should follow those requirements. AQUATIC FACILITIES with an average PATRON load of over 100 persons should follow the International Plumbing Code (IPC). Facilities with average PATRON loads of less than 100 persons should follow either the IPC or Uniform Plumbing Code (UPC). The IPC may require significantly more toilet facilities for women than for men.

# Gender Potty Parity
Previous issues of the nation's model consensus code mandated an equal amount of toilet fixtures for both men and women. Newer versions of the code will likely provide recommendations that increase the minimum required facilities for women.
Potty Parity discussion from Reasons to Adopt the 2000 IPC, developed by the International Conference of Building Officials (ICBO) as an informational aid to code officials and the public.
The IPC requires far less HYGIENE FIXTURES for various types of occupancies than the UPC. This is contrary to the "potty parity" movement which demands more fixtures for women's toilet rooms to avoid the long waiting lines. The UPC also provides more water closets and urinals in most men's toilet rooms than the IPC and assures adequate water closets by limiting the number that can be deleted by installing additional urinals.
Facility Design & Construction ANNEX 173 the IPC do address the issue of "potty parity" and reflect studies by Dr. Sandra Rawls at the University of Virginia, the Stevens Institute of Technology, the National Restaurant Association, and the ASPE Research Foundation. The issue of "potty parity" is mostly an issue in assembly buildings with large occupant loads, especially where there is a period of high demand such as at intermission at a theater or at halftime at a football stadium. The "potty parity" is not an issue for occupancies where there is no instantaneous demand on the fixture usage. IPC Table 403.1 reflects requirements for twice as many fixtures in the ladies' room compared to the men's room, when the type of occupancy demands such a count. In occupancies where the factors do not demand such an increase, the code does not require it. It should also be pointed out that part of this issue arises because of some CODES requiring both water closets and urinals within the men's restroom. Therefore, the numbers for men were somewhat higher. The IPC does not have a mandatory requirement for urinals. It will generally require the same number of fixtures in the men's and women's restrooms. However, when two or more water closets are required, the IPC will permit up to 67 percent of the fixtures to be replaced by urinals.
- For additional supporting information, see IPC: A Guide for Use and Adoption: .
Some differences between the IPC and UPC CODES on this issue are as follows:
International Plumbing Code:
- Utilizes a fixed fixture to OCCUPANT LOAD ratio.  Does not mandate urinals for men.  Allows up to 67% of the requirement for water closets to be substituted for urinals.  Establishes a separate fixture calculation factor for men and women. In some cases twice as many fixtures are required for women compared to men.  No arbitrary parity requirement.

# Universal Plumbing Code:
- Utilizes a variable fixture-to-OCCUPANT LOAD ratio.  Requires urinals to be installed based on a fixture-to-OCCUPANT LOAD ratio. Does not allow for one to one substitutions. For each urinal added over what is required, you may have one to one substitutions up to 2/3 of what is required.  Requires the total number of water closets for women to be equal to the total number of water closets and urinals for men.

# Cleansing Showers
The purpose of CLEANSING SHOWERS described in this section is to remove dead skin, sweat, nitrogenous waste, and perianal fecal material before BATHERS enter the POOL. This is best done through nude showering using warm water and soap.
An average of 0.14 grams of fecal material can be found on a person's peri-anal surface (the amount of feces for children ranges from 0.01-10 grams and for adults 0.0001 to 4.0 Facility Design & Construction ANNEX 174 0.1 g 299 ). Therefore, fecal contamination of the perianal area is common. This contamination may include the CHLORINE-tolerant parasite Cryptosporidium 300 which is not inactivated by routine disinfectant levels required in AQUATIC VENUES. Since the effectiveness of most halogen-based disinfectants is reduced by the presence of organic material, the purpose of CLEANSING SHOWERS is to reduce the inorganic, organic, and fecal load introduced into POOLS.
Count The THEORETICAL PEAK OCCUPANCY (MAHC Section 4.1.2.3.5) has been accounted for in the one shower per sex per 4000 square feet (372 m 2 ). This assumes using one bather per 20 square feet (1.9 m 2 ), so at 4000 square feet, there will be one shower per 200 bathers. Further research on this topic is recommended and can be addressed in future versions of the MAHC.

# Location
The placement of the showers is intended to encourage BATHERS to see and use the showers before they enter the water.
Enclosed Entryways to CLEANSING SHOWER compartments shall be enclosed to provide privacy. Individual shower stall curtains and doors are not required. Providing privacy for CLEANSING SHOWERS promotes BATHER cleansing prior to entering AQUATIC VENUES.
Exemption "Residential settings" includes condos, apartments, and homeowners associations but does not apply to individual residential pool settings. The intent is for BATHERS to use their rooms/homes for a CLEANSING SHOWER; however, one RINSE SHOWER on the DECK is required at these AQUATIC FACILITIES encouraging BATHERS to shower prior to entering water if a BATHER had not already done so.
Rinse Showers The purpose of the RINSE SHOWERS is to remove inorganic material such as sand or dirt that can bind with CHLORINE and reduce the amount for other pathogen inactivation. Rinsing with water also removes BATHER'S CONTAMINANTS such as sweat, hygiene products, deodorant, hair spray, etc. Rinsing off in the shower for 60 seconds and wearing bathing caps significantly decreases the amount of total organic carbon and total nitrogen 301 .
A rinsing shower can be taken on the DECK in open showers by the AQUATIC VENUE using ambient temperature water so dirt and other CONTAMINANTS are rinsed off before entering the water.
Large Aquatic Facilities The intent is to encourage BATHERS to see and use the RINSE SHOWERS before they enter the water.
Beach Entry The intent of having at least four showerheads every 50 feet (15.2 m) at a beach entry allows multiple people to rinse off at the same time. Showerheads could be provided as wall units, pedestals (one pedestal could have four showerheads or two pedestals could have two showerheads each), allowing AQUATIC FACILITY owners to have versatility in design.
Lazy River BATHERS enter LAZY RIVERS only in designated areas; therefore locating RINSE SHOWERS near these entrances facilitates rinsing before entering the LAZY RIVER.
Waterslide BATHERS congregate into queue lines for access to waterslides. Providing a RINSE SHOWER on the DECK of a queue line encourages use prior to entering the water.
All Showers The intent is to encourage use of showering prior to entering an AQUATIC VENUE. Large AQUATIC FACILITIES, based on their THEORETICAL PEAK OCCUPANCY, would require a large number of CLEANSING SHOWERS which would put an economic burden on these facility types. The MAHC acknowledges CLEANSING SHOWERS are more expensive to install than RINSE SHOWERS, therefore as long as the required number of showers is met, AQUATIC FACILITIES can decide which type of shower is conducive for their PATRONS.
In addition, the 2012 International Swimming Pool and Spa Code (ISPSC) Section 609.3.1 allows flexibility on the ratio of CLEANSING to RINSE SHOWERS above 7500 square feet of water surface area.
Diaper-Changing Stations The material in this section addresses diapering of infants and young children. These are the age groups most commonly involved in contamination of recreational water that can lead to outbreaks of illness associated with recreational water. Although some older persons must wear diapers the incontinence is not likely to be associated with a diarrheal illness so the risk of infection from adults is much less than that from children. Therefore, we do not believe that special regulations are needed for elderly BATHERS. Current DIAPER-CHANGING UNIT designs do not supply all the features needed for sanitary and efficient diaper changing and clean-up to minimize spreading pathogens further in the AQUATIC FACILITY. If a permanently plumbed hand wash sink is not economically feasible to install, a portable HAND WASH STATION can be used as a substitute for one year. Portable HAND WASH STATIONS are used at temporary events and include a water and waste tank that requires frequent refilling and draining for continual use.

# Conform
There appear to be two different configurations of DIAPER-CHANGING UNITS currently available and suitable for this setting. The first type, a fold-down commercial unit commonly mounted on the wall, is addressed by ASTM F2285-04: Consumer Performance Standards for Commercial Diaper-Changing Stations. The second type, a free-standing unit, is addressed by Caring for Our Children: National Health and Safety Performance Standards: Guidelines for Out-of-Home Child Care Programs ().
A major difference between these two designs is that ASTM F2285-04 calls for restraining straps while CFOC prohibits the use of straps and relies on a 3 inch (7.6 cm) lip to keep children from falling off. Both designs have inherent problems. The problems with straps are associated with cleaning and possible hanging hazard. The problem with a 3 inch (7.6 cm) lip is that they are not available on fold-up units. The MAHC language does not discriminate between these two designs, but the unit used should conform to one of these two STANDARDS.
Unisex Increasingly, many AQUATIC VENUES are providing family dressing areas and caregiver rooms to attend to family needs. This provision permits parents to attend to the needs of small children of the opposite sex. Trash Can Trash receptacles are needed to help maintain cleanliness around the DIAPER-CHANGING STATION for any disposable changing unit covers, diapers, sanitizing wipes, or disposable paper towels.
Non-Plumbing Fixture Requirements 4.10.4.6.4 Lockers While some lockers are designed to sit directly on the floor, other lockers may need to be elevated. This prohibits water accumulation beneath the lockers. Such accumulation can lead to the growth of mold, mildew, and slime build up. The MAHC has gone with the current industry standard of 3.5 inches (8.9 cm) high but recommends moving to a new standard of 6 inches (152 cm) to allow better access, cleaning, and drying under the lockers.
Dryers / Paper Towels Hand drying devices or paper towel dispensers should be located adjacent to the hand washing sinks to facilitate use. To prevent overcrowding, they may be positioned to move users away from the sink and toward the exit. In childcare settings, the dispensers and devices are usually within arm's reach of the sink.

# Provision of Suits, Towels, and Shared Equipment
Although providing reusable bathing suits is no longer common, many AQUATIC FACILITIES provide PATRONS with towels and other shared equipment. The purpose of this wording STANDARD is to ensure that these AQUATIC FACILITIES provide adequate equipment and space in their design and construction for laundering, sanitizing, and drying these items.

# Foot Baths
FOOT BATHS with standing water allow the buildup of organic material and bacterial and fungal growth and can lead to the spread of pathogens.

# Sharps
This section was included to address AQUATIC VENUES that provide PATRONS with sharps, especially razors, so that safe disposal is assured. Approved sharps containers are rigid, leak-proof, puncture resistant boxes of various sizes made of hard red plastic. They have a lid that can be securely sealed to keep contents from falling out, and they are clearly marked with the bio-hazard symbol. Occupational Safety and Health Administration (OSHA) regulations describe the design and use of sharps containers for a variety of settings.
Businesses are required by OSHA to deposit sharps into a sharps container that complies with OSHA regulations in order to protect employees. Once that container is full, it must be disposed of according to state and federal regulations. There are several lake and spring sources around the country that have been used for decades to supply water to AQUATIC FACILITIES. As long as the source water quality does not significantly change and can be treated by the AQUATIC FACILITY equipment to protect the health and SAFETY of PATRONS, it can be allowed.
Condensate / Reclaimed Water The steps necessary to make reclaimed water meet source water STANDARDS are beyond the scope of the MAHC. These steps are set by the state and federal agencies that set requirements for drinking water.
This would be up to the AHJ and local conditions. The MAHC felt that, especially considering recent affinities towards sustainability, reclaiming condensate would be acceptable as long as this water met the same STANDARDS as incoming domestic water (even if this required UV or other disinfectants, filters, etc.). A provision for deferring to the AHJ ruling based on locale was important to us as well. For instance, this may be more of a politically important issue in Arizona or Nevada than in other areas of the country. Non-potable use for this water is in keeping with water as a limited resource.
Sufficient Capacity This requirement is for when AQUATIC FACILITIES choose to be open when backwashing (e.g., they can backflush one filter while still maintaining filtration through another system; operating without the recirculation system running is prohibited). A facility may choose to regulate when their backwash cycles occur (such as at closing). Many fully automated backwash systems for HRS filters are programmed to backwash at night when the facility is closed and there are no other demands on the source water coming into the facility. Alternatively, QUALIFIED OPERATORS may choose for an all deep 50 meter POOL to just backwash one filter at a time and allow make-up water to reestablish rim flow before doing the next one, as opposed to doing all six or eight tanks sequentially.

# Fill Spouts
For example, a fill spout located under a diving board or next to a ladder or handrail is less likely to be a trip hazard or be a hazard to swimmers coming up from below.

# Cross-Connection Control
An air gap can be provided through a fill spout at the side of an AQUATIC VENUE, through water supply piping over the edge of an open balance tank or surge tank, or over a fill stand pipe that is connected to the side of an AQUATIC VENUE.

# Facility Design & Construction
ANNEX 179 Splash guards are simply a means to keep fill water from splashing onto adjacent floors and walls. Water cannot be siphoned into the potable water supply through a properly designed splash guard. A proper design often consists of a concentric pipe that is a larger diameter than the fill pipe and that is open to the atmosphere at the top and bottom.
Because of the potential for back pressure or back siphonage, any potable water piping connected directly to any AQUATIC VENUE piping must have an RPZ. Some permitting agencies or CODES may allow pressure vacuum breakers or atmospheric vacuum breakers on water supplies not connected to the POOL piping but supplying potable water to the AQUATIC VENUE through a submerged INLET in the AQUATIC VENUE.
The pressure vacuum breaker would be located upstream of the shut-off valve.
The atmospheric vacuum breaker would be located downstream of the shut-off valve.
The AHJ may allow an elimination of an air gap to control splashing or flow of AQUATIC VENUE wastewater outside the receiving sump onto the EQUIPMENT ROOM floor. This can be accomplished by extending the AQUATIC VENUE wastewater pipe below the rim of the sump. This can be approved if the wastewater disposal pipe from the AQUATIC VENUE does not have a sealed connection to the sewer piping. This constitutes an air break.
An air break can be justified for the worst case scenario of a sewer backup at the AQUATIC VENUE wastewater sump. During a sewer backup, sewage cannot back pressure into AQUATIC VENUE piping through an air break. Further, if the sewage is above the AQUATIC VENUE waste pipe outlet when the AQUATIC VENUE is operating, the normal pressure of the POOL piping leaks AQUATIC VENUE water towards the sewer, preventing the AQUATIC VENUE piping from siphoning wastewater. If the AQUATIC VENUE is not operating, then there is no pressure or suction in the piping that could create a condition for siphoning sewage.
If the permitting agency does not allow an air break, they may allow an air gap with a splash guard.

# Deck Drains and Rinse Showers

# Sanitary Wastes

# Pool Wastewater
AQUATIC VENUE waste streams (including filter backwash water and AQUATIC VENUE drainage water) should be discharged through an air gap to sanitary sewers, storm sewers, drain fields, or by other means, in accordance with local municipal and building official recommendations including obtaining all necessary permits. The discharge should occur in a manner that does not result in a nuisance condition.
Each waste line should have a unique air gap. Waste lines from different sources (e.g. AQUATIC VENUE, spa, overflow, sump pump, etc.) should not be tied together, but multiple waste lines may discharge into a common sump or receptacle after an air gap.
Facility Design & Construction ANNEX 180 4.11.6.2 Ground Surface Filters work to reduce the level of pathogens in the AQUATIC VENUE water by retaining the pathogen in the filter. As a result, AQUATIC VENUE backwash water has been demonstrated to contain detectable pathogen levels (e.g., Cryptosporidium and Giardia). 302 , 303 Therefore, filter backwash water should be considered waste water requiring appropriate disposal.
Separation Tank for Precoat Media Filters If local or state CODES prohibit disposal of backwash filter media (perlite, cellulose or diatomaceous earth) directly to sanitary sewer, a separation tank may be recommended. The separation tank is to be designed for the conditions of the specific facility filtration system. The separation tank should be designed to accommodate the volume of water and spent media recommended for at least a single backwash (media change), without overflowing. The separation tank may include separation screens or a settling pit to allow for the spent media to be removed and properly disposed of according to AHJ requirements. Maximum Water Depth SPAS are designed for sitting and the expectation is that it will not be over the average 11-year-old child's head. That depth is about 48 inches (1.2 m). The MAHC felt that 24 inches (61.0 cm) is reasonable since it is half of the maximum depth previously stated (48 in or 1.2 m) and would allow for the vast majority of the population to sit comfortably with their head above water. The MAHC also consulted the ISPSC and their maximum depth of 28 inches (71,1 cm) is pulled from APSP which has been utilized by the industry for some time. The Committee recommends additional studies to determine if decreasing the SPA seating depth is necessary.
Handholds Even though a person is seated in a SPA, a sufficient number of positive handholds are needed to assist with standing up. Handholds at the edge of the SPA above the water line are visible and easily reachable.
Perimeter Deck This is to provide adequate area for life saving and rescue purposes. The AHJ may allow a smaller rescue area based on the assessment of a local emergency rescue agency.
SPAS elevated for transfer wall or other purposes need to be provided with an effective BARRIER so that the elevated wall is not used as a platform to access an adjacent 4.0 Facility Design & Construction ANNEX 185 cannot swim, and the inherent dangers posed by larger and deeper POOLS in close proximity.
Shallow Water Rationale of 24 inches (61.0 cm) deep rule is that if adjacent water is not substantively deeper than the WADING POOL, there is no need to segregate them.
Facility Operation & Maintenance ANNEX 186

# Facility Operation and Maintenance
The MAHC has worked extensively with ICC and IAPMO to eliminate conflicts between the three codes. These discussions have resulted in changes in the MAHC and plans to change items in the other codes as they are brought up for revision. The MAHC is committed to resolving these conflicts now and in the future as these codes evolve.

# Exemptions

# Variances
The permit issuing official may waive, in writing, any of the requirements of this code, and include the variance as a condition of the permit to operate, when it reasonably appears that the public health and SAFETY will not be endangered by granting of such a variance and adequate alternative provisions have been made to protect the health and SAFETY of the BATHERS and the public. The burden of providing the data and proof that any alternative provision is at least as protective at the code requirement is entirely on the permit holder. Additionally, closed POOLS can be a SAFETY concern, especially for small children. When the POOL is not drained or covered tightly to prevent entry, children may knowingly or accidentally enter the POOL and drown. Because of the slime that often builds on the wall of these abandoned POOLS, it may be impossible for those that enter the POOL to climb out. Abandoned POOLS may also have limited visibility so people falling in cannot be seen by other persons in the area. While fence BARRIERS or SAFETY covers can create a "safe condition" for the POOL, these methods will not prevent the potential mosquito problems mentioned above.

# Equipment Standards [N/

# Long Closures
The closing of an AQUATIC FACILITY for less than seven days is considered a temporary closure. A closure of more than seven days is considered a long term closure. Both types of closure require certain maintenance activities when closing or reopening to ensure a safe environment for PATRONS.

# Drain / Cover
POOLS that use a cover should refer to ASTM F1346-91. For POOLS where covers are not used or are not practical, access should be restricted and routine check of fence integrity is advised. When correctly installed and used in accordance with the manufacturer's instructions, this specification is intended to reduce the risk of drowning by inhibiting the access of children under five years of age to the water.
For long term and seasonal closures, where no residual disinfectant is maintained in the pipes, further research is needed to understand the growth of biofilms during closure. More research is needed to develop protocols for removing biofilms in AQUATIC VENUES. If the AQUATIC VENUE system becomes non-operational, such as during a power outage, the AQUATIC VENUE should be cleared of BATHERS. Prior to reopening, the QUALIFIED OPERATOR should confirm that all systems are operational as required by the MAHC. For example, recoating DE filters will be necessary and it should be confirmed that feed pumps did not continue feeding chemicals during a RECIRCULATION SYSTEM shutdown that may lead to outgassing into the POOL when the system is re-started.
Facility Operation & Maintenance ANNEX 188

# Reopening
The QUALIFIED OPERATOR should refer to previous inspection reports for more details on repairs or replacements needed, and any replacements or new items should be discussed with the regulatory authority to verify they comply with current code requirements. It is recommended that a model reopening checklist be developed in the future.

# Preventive Maintenance Plan
A preventive maintenance plan is a necessary and important part of any AQUATIC FACILITY operation based on data showing 22.8% of pool chemical-related events were due to equipment failure indicating they could have potentially been prevented 306 . The best maintenance plan is one that follows the manufacturer's and POOL designer/engineer's recommendations for all equipment. A POOL maintenance plan is similar in many ways to the purchase of a new vehicle. With the purchase of a new vehicle, a manufacturer's maintenance schedule is included. The schedule lists the maintenance items that should be followed such as rotating tires and performing major tune-ups.
Likewise, the QUALIFIED OPERATOR should perform an inventory of all equipment used in the AQUATIC FACILITY operation. For each piece of equipment, the QUALIFIED OPERATOR should develop a list and schedule of maintenance items. By following this maintenance schedule, the operator can help prevent costly repairs and breakdowns in the future.
Replacing items before they breakdown may prevent system breakdowns that could lead to outbreaks or injuries. For example, a common breakdown leading to loss of DISINFECTION is a break in the tubing leading from feed pumps to the RECIRCULATION SYSTEM. Although inexpensive, lack of replacement has been implicated in outbreaks.
AQUATIC FACILITIES need increased sophistication in plan maintenance and MONITORING.

# Facility Documentation
This equipment inventory should contain information such as:

# Depth Markings
Existing AQUATIC FACILITIES should still adhere to the requirements of MAHC Section 4.5.19 for depth and no diving markers. Existing AQUATIC FACILITIES may have to resort to using non-permanent(i.e., painted) alternatives if not already installed, which will need to be maintained to ensure they are readable and legible

# Pool Shell Maintenance
The MAHC was altered in the final round of public comments to eliminate the wording below. It was decided that this wording was not entirely health and safety related so should be replaced by wording that required repairs if the cracks could cause trips, falls, or lacerations. It is still good operational practice to identify and monitor cracks that could lead to water loss and structural failure and consult a structural engineer for assessment as needed.
CRACKS exhibiting any of the following characteristics shall be evaluated by a structural engineer:  Light Levels System components will deteriorate and eventually need to be replaced, but lamp performance will continue to change prior to complete lamp failure. Indoor overhead lights, outdoor pole mounted lights, and underwater lighting are the key POOL light sources. Building lighting must also be maintained to provide safe AQUATIC FACILITY use, building and area security, and meet the aesthetic goals. Planned lighting maintenance includes group relamping, cleaning lamps, cleaning luminaires, and replacing defective components on a regular basis.
Lamp lumen depreciation is a characteristic of all lamps. Each lamp type has a different lamp life, thus impacting your maintenance schedule. As lamps fail or burn out, the local light levels are decreased and the lighting uniformity is also affected.
Luminaire surface deterioration and dirt accumulation may also occur and can reduce the light reaching the needed areas. During relamping and cleaning, inspect each luminaire for deterioration or damage. Repair or replace components and inspect and clean light fixtures and luminaires as needed to maintain required light levels. Consider regular group relamping combined with cleaning as part of an efficient and effective maintenance plan.
Basic steps for cleaning and relamping operations include the following:
1. Turn off electrical circuits and carefully remove lenses, diffusers, shields and/or lamps. 2. Dispose of replaced lamps and ballasts per state and federal guidelines. 3. Contact the U.S. EPA for more information. 4. Follow the light fixture and lamp manufacturer's recommendations for cleaning, relamping, and maintaining each light in good condition. 5. Routinely monitor underwater lights for proper operation.
Windows and natural lighting need to be evaluated seasonally and throughout the operating day.
Light levels may also be altered by dirty windows. Ensure that windows are cleaned regularly to eliminate any buildup of material that would affect light transmission.

# Main Drain Visible
The requirement for being able to see the main drain from POOLSIDE is a SAFETY issue. If QUALIFIED LIFEGUARDS or QUALIFIED OPERATORS cannot see the main drain, then they are unable to see a person on the bottom of the AQUATIC VENUE and unable to initiate rescue
Facility Operation & Maintenance ANNEX 191 procedures. This is cause for immediate closure and rectification before re-opening. Please refer to the MAHC Section 6.6.3 for more information.
Glare In addition to discomfort, annoyance, interference, and eye fatigue, glare reduces the visibility of an object. Without clear vision, there are increased chances for accidents that can cause injuries or potential drowning. Glare can be from reflections as well as direct lighting problems.

# Assessments
The AQUATIC FACILITY owner or LIFEGUARD SUPERVISOR may consider adjusting lifeguard positions to improve visibility.

# Indoor Aquatic Facility Ventilation Maintenance and Repair
Drains on AIR-HANDLING SYSTEM equipment should be tested before the system is started.
It is important that the drain system be checked regularly to ensure that the condensate drain pan, drain connection, and piping are free from buildup or blockages. In cases where air handling equipment is intended for use with P-trap type drains, the P-trap must be kept filled manually if normal operation does not keep the P-trap filled. If not kept filled, sewer gases, and odors can enter the system.

# Combined Chlorine Reduction Water chemistry affects air quality:
- The amount of disinfectant in the water should always be at sufficient level to disinfect properly, but high residual levels in an indoor environment contribute to the development of DBPs. A higher ratio of CHLORINE to nitrogen content in the water results in the formation of TRICHLORAMINE. Lower levels of CHLORINE/bromine in the POOL results in lower levels of DBPs in the presence of organic and inorganic CONTAMINANTS.  High residual levels have been a requirement for outdoor AQUATIC VENUES that have sunlight exposure, but that requirement may not be necessary for INDOOR AQUATIC FACILITIES.
- FREE CHLORINE levels could likely be maintained at a lower level due to the absence of dechlorination due to sunlight.  Lower pH levels increase the effectiveness of CHLORINE and by maintaining pH less than 7.5, less CHLORINE is required to achieve effective DISINFECTION 307 .

# Facility Operation & Maintenance ANNEX 192
The water quality will affect the air quality in INDOOR AQUATIC FACILITIES. Also BATHER practices will determine not only the water quality but also the air quality. Therefore, if air handling equipment is installed, INDOOR AQUATIC FACILITY operators should develop and implement a program to operate, monitor, and maintain the equipment as designed to reduce combined CHLORINE compounds introduced into the building from the AQUATIC FEATURES in accordance with the INDOOR AQUATIC FACILITY AIR HANDLING SYSTEM design engineer and/or the AIR HANDLING SYSTEM equipment manufacturer's recommendations.

# Electrical

# Electrical Repairs
National Electrical Code Article 225 provides installation requirements for outside branch circuits and feeders that run on (or between) structures or poles.
National Electrical Code Article 680 applies to the construction and installation of electrical wiring for and equipment in or adjacent to all swimming, wading, therapeutic, and decorative POOLS; fountains; hot tubs; SPAS; and hydro-massage bathtubs, whether permanently installed or storable, and to metallic auxiliary equipment, such as pumps, filters, and similar equipment.
Electrical Receptacles NEC Article 680.22 "General Circuitry Pool Pump Motors" states that "all 15-and 20 amp, single-phase, 125-volt or 240-volt outlets supplying pool pump motors shall have GFCI protection." 29 C.F.R. 1910.304 "Wiring Design and Protection" applies to temporary wiring installations that are used during construction-like activities, including certain maintenance, remodeling, or repair activities, involving buildings, structures or equipment.
Ground-Fault Circuit Interrupter GFCI testing should follow the manufacturer's recommendations. However, the minimum test procedure should include:
1. Testing personnel must wear shoes during the entire test. Where exposed terminals may be present, or where conditions warrant, other personal protective equipment may be required. 2. A suitable indicating test load should be connected to the circuit under test, and remain so for the duration of the test. 3. Test personnel should press the "TEST" button on the GFCI device. 4. The test load should then be observed to have ceased operation due to loss of electrical power. 5. Test personnel should next press the "RESET" button on the GFCI device. 6. The test load should then be observed to have resumed operation. 7. Where any of the conditions specified in steps (b) through (f) fail, the GFCI circuit must then be inspected and tested. Replace the GFCI device as necessary. No new electrical devices or equipment should be installed in an interior CHEMICAL STORAGE SPACE used for STORAGE of pool chemicals, acids, fertilizers, salt, oxidizing cleaning materials, or flammable liquids or gases without re-inspection by the AHJ.

# Isolation Of Chemical Storage Areas
An interior STORAGE space used for storing POOL chemicals, fertilizers, salt, oxidizing cleaning materials, other corrosive or oxidizing chemicals, or pesticides must be kept in ISOLATION from other INTERIOR SPACES, except for entry, egress, material transport, or alarm testing. The period of each instance of entry, access, or alarm testing should not exceed 15 minutes. The sum of the periods of all instances of breach of ISOLATION should not exceed one hour in each 24-hour period. Where the ISOLATION of an interior STORAGE space containing such chemicals from other INTERIOR SPACES containing COMBUSTION DEVICES depends on an interior door, such door should be gasketed to prevent the passage of air, fumes, or vapors, and should be equipped with an automatic door closer and an alarm that will give notice if the door remains open for more than five minutes. Function of this alarm should be confirmed monthly as part of scheduled maintenance. Failures of door gasketing, or of the door closer, or of the alarm should be repaired immediately.

# Unsealed Openings
Where any unsealed openings exist between an interior STORAGE space used for POOL chemicals, acids, fertilizers, salt, or corrosive or oxidizing chemicals and any other INTERIOR SPACE containing electrical equipment, the air pressure in the CHEMICAL STORAGE SPACE should be maintained at a level low enough to insure that all air flow should be toward the CHEMICAL STORAGE SPACE. This pressure difference should be maintained by a continuously operating exhaust system used for no other purpose than to remove air from the CHEMICAL STORAGE SPACE. Function of this exhaust system should be monitored continuously by a pressure switch and alarm. Function of the pressure switch and alarm should be confirmed monthly as part of scheduled maintenance. In the event of failure of the exhaust system or of the alarm, repairs should be done immediately.
In any space containing electrical equipment, ambient conditions such as temperature, humidity, and maximum concentrations of chemical fumes or vapors, or of flammable fumes or vapors should be continuously maintained to meet the operational requirements of installed electrically powered equipment. Labels or other marks indicating the circuits served by fuses, circuit breakers, and disconnect switches should be maintained in a condition readable by a person unfamiliar with the function of the circuits.
For spaces containing fuses, circuit breakers, electric motors, or motor-operated loads, the recommended minimum illumination capability should be maintained as part of the scheduled monthly maintenance. STORAGE should not interfere with the largest of the
Facility Operation & Maintenance ANNEX 195 minimum working clearances specified by the NEC, the equipment manufacturer, CFR 1910, or by local CODES or regulations.

# Replamping
Re-lamping operations within 20 feet (6.1 m) horizontally of the nearest inside edge of a POOL, SPA, FLUME, WATERSLIDE, or other open AQUATIC FEATURE should be carried out in such a way as to minimize the likelihood of lamp breakage. New lamps should be kept in their packing until just before installation. Old lamps should be packed immediately upon removal into a suitable container to prevent breakage. New lamps should not be stored in an interior STORAGE space used for POOL chemicals, fertilizers, salt, or other corrosive or oxidizing chemicals. Neither new lamps nor old lamps should be stored in the INDOOR AQUATIC FACILITY, shower room, locker room, or hallways.
Where visible or accessible, any required bonding jumpers should be visually inspected for damage, breaks, looseness, or corrosion quarterly as part of scheduled maintenance. Where any doubt exists concerning the condition of bonding jumpers, they should be inspected and, if necessary, the effectiveness of such jumpers should be tested.
Grounding The purpose and objective of NEC Article 250 -Grounding is to insure that the electrical system is safe against electric shock and fires by limiting the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and a GROUND FAULT (line-to-case fault). The rules contained in NEC Article 250 identify the installation methods that must be followed to insure a safe electrical installation.
National Electrical Code Article 680 applies to the construction and installation of electrical wiring for and equipment in or adjacent to all swimming, wading, therapeutic, and decorative POOLS, fountains, hot tubs, SPAS, and hydromassage bathtubs (whether permanently installed or storable) and to metallic auxiliary equipment, such as pumps, filters, and similar equipment.
Extension Cords

# Exception
The intent is to prevent the extension cord from reaching the water.
Compliance  See CFR 1910.304 (b)(2) at  DS&p_id=9881

# Communication Devices and Dispatch Systems
National Electrical Code Article 800 covers multi-purpose and communication cable. Multi-purpose cable is the highest listing for a cable and can be used for communication, Class 2, Class 3, and power-limited fire protective cable.

# Facility Operation & Maintenance
ANNEX 196 Communication cable can be used for Class 2 and Class 3 cable and also as a powerlimited fire protective cable with restrictions.
Facility Heating 5.6.4.1 Facility Heating

# Maintenance and Repair
There are a number of CODES which can be consulted. These include but are not limited to the National Fuel Gas Code, National Electrical Code, and certain building CODES.

# Defects
If inspection shows excessive fouling of air filters before the cleaning or replacement period has ended, that period should be reduced to prevent overloading of filters. Filters that become clogged with dirt, mold, or other CONTAMINANTS can become a source of increased operating costs and poor air circulation. In addition to the reduction of system effectiveness, which can result in costly repairs, air-borne CONTAMINANTS can be spread as a result of improper air handling.
Temperature The air temperature of an indoor AQUATIC VENUE should be controlled to the original specifications where possible. Where this is not possible, the air temperature of an INDOOR AQUATIC FACILITY should be controlled so as to prevent unexpectedly high levels of evaporation and to prevent condensation of water onto surfaces not designed for condensation. Particular care should be taken to prevent the condensation of water inside INDOOR AQUATIC VENUE building surfaces such as walls and ceilings. Please note that this code only looks at the part of the facility where the water "vessel" is located and not at other areas of buildings (the building code would cover). Particular attention needs to be given to the prevention of algae and mold growth on surfaces.
First Aid Room  5.6.6 Emergency Exit 5.6.7 Plumbing

# Water Supply
The potable water pressure should be maintained to enable the AQUATIC VENUE and all other water using fixtures to operate to design specifications.
Waste Water In some AQUATIC FACILITIES, backwash water may be recycled for other purposes instead of wasted in order to conserve water. This water must be treated in accordance with local code requirements prior to being re-used. Backwash water is likely to be routinely contaminated with pathogens so its use should be carefully considered and health
Facility Operation & Maintenance ANNEX 197 issues planned for prior to re-use. It should not be re-used in AQUATIC VENUES, but may be used in landscaping or other non-potable water uses with AHJ approval.
Water Replenishment See MAHC Annex Section 4.7.4 for more information.
A minimum of 4 gallons (15 L) of water per BATHER per day must be discharged from the POOL, but a volume of 8 gallons (30 L) per BATHER per day is recommended. Backwash water will count toward the total recommended volume of water to be discharged, but evaporated water will not count since inorganic CONTAMINANTS (e.g., salts and metals) and many organic CONTAMINANTS (e.g., sweat and urine) can simply be concentrated as water evaporates. Backwash water or other discharged water may not be returned to the POOL without treatment to reduce the total organic carbon concentration, DISINFECTION BY-PRODUCT levels, turbidity, and microbial concentrations less than the limits set for tap water by the U.S. EPA.
Solid Waste 5.6.9 Decks 5.6.9.1 Food Preparation and Consumption

# Eating and Drinking
Eating and drinking in AQUATIC VENUE areas may expose BATHERS to CONTAMINANTS. Food particles that fall into the POOL not only contribute to contamination burden, but may also affect POOL DISINFECTION. Additionally, contamination can occur through ingestion. Alcohol increases urine output and therefore creates more chloramines and other DISINFECTION BY-PRODUCTS if BATHERS do not regularly get out of the POOL to urinate. Regular bathroom breaks should be considered to reduce urination in the AQUATIC VENUE that allows designated areas like "swim-up bars" that may increase POOL urination and create compliance issues with MAHC combined CHLORINE levels. However, at this time, the MAHC does not have data suggesting that AQUATIC VENUES containing "swim up bars" have any more issues with water quality compliance issues that those AQUATIC VENUES that do not. AQUATIC VENUES considering "swim-up" bars need to be aware that these areas may also increase the risk of drowning caused by excessive alcohol consumption and should include this thinking in lifeguard training and in-service training.
Currently the majority of states do not allow swim up bars; however, Ohio, Hawaii, Texas, and a few local jurisdictions do, mostly in resort areas. The MAHC defers to local jurisdictions to assess and determine potential risks.
Another topic to consider is nursing mothers and safety and health risk to infants. While many mothers consider nursing in the POOL a pleasant experience for the baby there is a definite safety risk for the infant from hypothermia and a health risk from potentially ingesting contaminated POOL water that may contain organisms such as Cryptosporidium.
Facility Operation & Maintenance ANNEX 198  For more information about this topic, see CDC Healthy Swimming discussion at:  pools.html 5.6.9.2 Glass Glass is prohibited in the POOL DECK area to prevent injuries to PATRONS. Most BATHERS and PATRONS are bare foot, so stepping on glass can cause serious injuries. If a glass container breaks in the AQUATIC VENUE vicinity it could potentially fall into the water. Clear glass is virtually invisible in water and is difficult to remove. The only way to ensure all broken glass is removed from POOL water is to thoroughly drain and clean the POOL structure. Depending on the size, draining and cleaning an AQUATIC VENUE can cost thousands of dollars.
Deck Maintenance
Free From Obstructions DECKS should always be kept clear of obstructions to preserve space that may be needed for rescue efforts. Obstructions also cause tripping hazards and can lead to falls and serious injuries. Attention must also be given to potential fall hazards from slippery DECK areas.
Vermin It is important to maintain these areas free from debris, vermin, and vermin harborage. Animals can carry diseases which could be transmitted through bites or contact with bodily fluids or feces.
Original Design Proper maintenance of surfaces will help prevent abrasions to BATHERS and biofilm growth. 308 5.6.10 Aquatic Facility Maintenance 5.6.10.1
Diving Boards and Platforms Slip resistance can be accomplished by ensuring that the coefficient of friction is greater than or equal to that specified in MAHC Section 4.8.1.4.
Starting Platforms Starting blocks are designed for use by trained persons or those under the supervision of a qualified individual. Use by untrained, unsupervised individuals can lead to serious injury. Since they can be an attraction for unqualified bathers to use, starting block use needs to be clearly prohibited by signage, covers, or other barriers/deterrents. Since bathers are known to ignore signs or barriers prohibiting use, the safest approach for removable blocks is to remove them and store elsewhere when not in use.
Facility Operation & Maintenance ANNEX 199 5.6.10.5
Fencing and Barriers This wording refers to alarms associated with open gates or barriers. It is not meant to include burglar or fire alarms.
Aquatic Facility Cleaning In-POOL cleaning systems must be periodically inspected to make sure they retract and stay flush with the floor.

# Recirculation and Water Treatment
Recirculation Systems and Equipment 5.7.1.1 General The MAHC does not allow shut down of the RECIRCULATION SYSTEM during closure times since uncirculated water would soon become stagnant and loose residual disinfectant likely leading to biofilm proliferation in pipes and filters. This would be likely compromise water quality and increase the risk to BATHERS. MAHC Section 4.7.1.10.6 describes turndown system design. The flow turndown system is intended to reduce energy consumption when AQUATIC VENUES are unoccupied without compromising water quality. A turbidity goal of less than 0.5 NTU has been chosen by a number of U.S. state CODES (e.g., Florida) as well as the PWTAG and WHO. The maximum turndown of 25% was selected to save energy while not necessarily compromising the ability of the RECIRCULATION SYSTEM to remove, treat, and return water to the center and other extremities of the POOL. Additional research in this area could identify innovative ways to optimize and improve this type of system and that more aggressive turndown rates are acceptable.
Gutter / Skimmer Pools The recommendation for gutter or SKIMMER POOLS with main drains to have the majority of the water (at least 80% of the recommended recirculation flow) be drawn through the PERIMETER OVERFLOW SYSTEM and no greater than 20% through the main drain during normal operation is based on subsurface distribution of bacteria data that showed most POOLS had higher surface concentrations of bacteria. 309 For the 65 POOLS examined, surface concentrations of bacteria were an average of 3.4 times greater at the surface. However, about 30% of the POOLS showed the opposite trend with higher subsurface concentrations, which is why some operational flexibility is provided with these values.
For reverse flow (upflow) POOLS, 100% of the recommended circulation flow should be through the PERIMETER OVERFLOW SYSTEM, which is consistent with the German DIN Standards. 310 Efficient removal of surface water is critical for maintaining water quality because surface water contains the highest concentration of pollutants from body oils, sunscreens, as well as other chemicals or particles that are less dense than water.
Facility Operation & Maintenance ANNEX 200 Bacteria appear to follow the same trend in most cases 311 . The distribution of CHLORINEtolerant pathogens like Cryptosporidium is not known at present. The majority of the organic pollution and contamination is concentrated at or near the surface irrespective of the mixing effects of the circulation .
Inlets During regular seasonal operation following initial adjustments, INLETS should be checked at least weekly so that the rate and direction of flow through each INLET has not been changed substantially from the original conditions that established a uniform distribution pattern and facilitated the maintenance of a uniform disinfectant residual throughout the entire facility without the existence of dead spots.
A tracer test (e.g., with a sodium chloride tracer injected on the suction side of the pump) should be conducted annually at startup and documented to quantitatively assess distribution pattern in the POOL. An amount of salt sufficient to increase the baseline conductivity by at least 20% should be added over a one minute period, and the conductivity or TDS should be measured at one minute intervals until the conductivity increases by 20% and/or stops changing for ten consecutive readings after an initial increase. Samples may also be taken at the corners, center, and bottom of the POOL (via a sample pump with the pool unoccupied) in small labeled containers for later measurement to increase the amount of information available to assist in interpreting the results. Increases greater than predicted by the amount of salt added to the POOL volume indicate poor mixing. Areas with conductivities lower than in the return stream at the time the sample was collected are likely to be areas with poor recirculation flows.
Note: It is possible to do a tracer test, which is quantifiable in terms of salt concentration ratios and/or time required to reach equilibrium concentration near the filter.
Piping Winterization may involve dropping the water level below the level of the INLETS, blowing or draining all of the water out of the pipes, adding antifreeze, and closing off both ends. Pipes should be drained or winterized in regions where freezing temperatures are expected to be reached inside of the pipes. This should not be done with car antifreeze, and the antifreeze should not be toxic to humans.
Flow Meters Flow meters are important for the maintenance of proper filtration, backwashing, and recirculation flow rates. It is also feasible to save money on electrical costs by using the flow meter to monitor and adjust the speed of the pump.
Facility Operation & Maintenance ANNEX 205 cartridges (i.e., cartridges that do not recover 100% of the original capacity when cleaned after fouling). Systems designed for a given TURNOVER time with a filter flow rate of 0.375 gallons per minute per square foot (0.26 L/s/m 2 ) would not be in compliance if partially fouled cartridges dropped the flow rate to 0.30 gallons per minute per square foot (0.20 L/s/m 2 ). Therefore, an acceptable operating range is provided beyond which cartridge replacement would be necessary.
Filter Elements Cartridges should be cleaned when the gauge pressure differential is 10 psi (68.9 KPa) and in accordance with manufacturer's instructions. Cleaning equipment should include a soaking container properly sized to immerse the filter elements, a rinsing area with proper drainage, and a drying area protected from contamination (e.g., birds and insects). New filters do not regain 100% of their capacity. Perhaps only about 80% of the capacity is recoverable, regardless of the treatment. If the recommended design flow rate exceeds 80% of the maximum flow allowed on the filter, the filter may be undersized.
Cleaning Procedure
Facilities with cartridge filters are recommended to have the equipment on-site to clean the cartridges. This includes a basin or tub large enough to immerse the entire cartridge. Water from the cleaning and soaking process must be discharged to the sanitary sewer. Proper cleaning is critical. Failure to clean the cartridge properly can lead to disease outbreaks.

# How to Clean Cartridge Filters:
1) RINSE THOROUGHLY: Rinse the cartridge of as much dirt and debris as possible by washing inside and out with a garden hose and spray nozzle.
- DO NOT use a pressure washer. High flow/pressure can drive the dirt into the interior and permanently damage the cartridge. It can also aerosolize pathogens in filter.
DEGREASE: Cartridge filters need to be degreased each time they are cleaned. Body oil, suntan oil, cosmetics, hair products, and/or algae and biofilms can form a greasy coating on the filter pleats, which will clog the pores and reduce the filter capacity. Acid may permanently set the grease and ruin the cartridge.
Facility Operation & Maintenance ANNEX 206 3) RINSE THOROUGHLY

# 4) SANITIZE:
To remove or prevent biofilms, algae, and bacteria growing on the cartridge, add one quart (0.95 L) of household bleach per 5 gallons (19 L) of clean water and soak one hour before rinsing.
RINSE: Remove the clean cartridge from the sanitization soak water and rinse thoroughly with a hose.
DRY: After the filter is cleaned and degreased, it should be allowed to dry completely. Some bacteria (e.g., Legionella spp.) that survive the cleaning process can be killed by drying. Do not allow the filter to become contaminated with dirt or soil after it is cleaned. Put the cartridges in a clean plastic trash bag if they are to be transported and the original boxes are not available.
ACID WASH -ONLY IF NECESSARY: Excessive calcium or mineral deposits on the filter media can be cleaned with a 1:20 solution of clean water and Muriatic Acid. Put a few drops of muriatic acid on the filter. If it foams, it might need to be acid washed. Very few filters need to be acid washed.

# Pressure Washer
A pressure washer should not be used because high flow/pressure can drive the dirt into the interior and permanently damage the cartridge or can aerosolize pathogens in the filter biofilm, which expose and infect workers when cleaning the cartridge filters in an enclosed space 324 .

# Disinfection and pH Control

# Primary Disinfectants

# Chlorine (Hypochlorites)
Although chlorine and bromine are the only primary disinfectants allowed at this time, future research may produce other acceptable primary disinfectants.

# Minimum FAC Concentrations
It is necessary to ensure that FAC is maintained at or above the 1.0 PPM (MG/L) minimum level at all times and in all areas of the POOL. Because CHLORINE efficacy is reduced in the presence of cyanuric acid, higher FAC levels may be necessary for POOLS using cyanuric acid or stabilized CHLORINE.

# Facility Operation & Maintenance ANNEX 207
The minimum FAC level of 1.0 PPM (MG/L) for swimming POOLS is well-supported by available data. The CDC data indicates that a 1.0 PPM (MG/L) FAC residual can provide effective 325 DISINFECTION of most pathogens other than Cryptosporidium.
Substantial laboratory data shows that kill times for microbial CONTAMINANTS are increased in the presence of cyanuric acid. However, the precise impacts on CT VALUES in a swimming POOL environment are not well-established. The impact on CT VALUES is mostly related to the hypochlorous acid (HOCl) concentration that can be calculated using equilibrium constants. In general, studies show that the presence of CYA up to 50 MG/L increases CT VALUES under demand free conditions, and the amount of this increase depends upon the pH and the ratio of CYA to available CHLORINE. Studies suggest that this effect is mitigated with the addition of ammonia nitrogen as low as 0.05 MG/L by producing monochloramine which, although a weaker disinfectant than hypochlorous acid, remains unbound to CYA.
Swimming POOL survey data demonstrates that 1.0 PPM (mg/L) FAC provides acceptable bacteriological quality 326 .
However, another paper suggests that FREE CHLORINE levels significantly higher than 1.0 PPM (mg/L) may be required. Based on data collected from seven chlorinated POOLS, Ibarluzea et al. predicted that 2.6 PPM (mg/L) is needed "in order to guarantee, with a probability of 90%, the acceptability of bathing water at indoor chlorinated swimming pools." 327 A minimum FAC level (3.0 PPM (mg/L)) for SPAS addresses the higher THEORETICAL PEAK OCCUPANCY, higher temperatures, and/or at-risk populations served by these venues. The THEORETICAL PEAK OCCUPANCY and temperatures of these venues favor microbial growth and can lead to rapid depletion of CHLORINE. This minimum
Facility Operation & Maintenance ANNEX 208 requirement is consistent with CDC recommendations to minimize transmission of Legionnaires disease from whirlpool SPAS on cruise ships, published in 1997, which recommends maintaining free residual CHLORINE levels in SPA water at 3 to 10 PPM (mg/L). It is further supported by a study reviewing both bromine and CHLORINE, which states, Pseudomonas aeruginosa were rapidly reestablished in SPAS (greater than 103 cells per mL) when disinfectant concentrations decreased below recommended levels . 328 In general, a range of 2-4 PPM (mg/L) FAC for POOLS (3)(4)(5) for spas) is recommended to help ensure the minimum FAC is maintained and to provide a margin of SAFETY for BATHERS.
For individual POOLS, considerations for ideal FAC levels include:
- Chlorine demand: FAC levels should be sufficient to accommodate peak BATHER LOADS and other sources of contamination.  Temperature and sunlight: FAC levels should be sufficient to accommodate loss of FAC from higher water temperatures and sunlight.  Cyanuric acid: Because CHLORINE efficacy is reduced in the presence of cyanuric acid, higher FAC levels may be necessary for POOLS using cyanuric acid 329,330,331,332 or stabilized CHLORINE.  Algae control: Algae is more difficult to control than most pathogens and may require FAC residuals greater than 3.0 PPM (mg/L) although peer-reviewed data is lacking.  Accuracy of FAC tests: POOL test kits have been reported to give FAC results which diverge significantly from true values although peer-reviewed data is lacking.  Feeder equipment: Automated feeders help reduce variability in dosing and the potential for FAC levels to fall below minimum levels.  Secondary disinfection: While the minimum FAC level must be maintained in all POOLS, approved SECONDARY DISINFECTION SYSTEMS such as UV and ozone reduce risks from CHLORINE-resistant pathogens and may reduce CHLORINE demand. However, the effects of UV/CHLORINE on water chemistry are still largely undefined. Recent research suggests that UV can increases some forms of CHLORINE demand.

# Facility Operation & Maintenance ANNEX 210
The hydrogen gas is dissolved in the water and eventually vents to the atmosphere. The CHLORINE gas then dissociates into hypochlorous acid (HOCl), which provides a residual of FREE AVAILABLE CHLORINE (FAC): Cl2 (g) + H20  HOCl (aq) + HCl (aq) Salt water chlorination units should be sized appropriately to maintain minimum FAC levels during maximum load periods. The units should ideally be controlled by an ORP controller. Operators must still test the FAC residual of the water to ensure that the cell is producing adequate CHLORINE for the POOL. However, a separate chlorinating product may be needed to provide a sufficiently high FAC level for shock treatment or remediation following a fecal accident.
MONITORING and maintaining the pH, total alkalinity, and TDS of the water in the POOL is important. Salt water POOLS intentionally have high concentrations of sodium chloride. The sodium chloride will contribute to TDS, but will not cause decreased disinfectant efficacy or cloudy water.
Electrolytic cells do wear out and need to be replaced. The life of the cell depends upon how many hours the cell operates each day, the pH of the water, and the calcium content of the water. The cells have to be cleaned to remove scale build-up. The systems usually utilize reversal of the polarity on the cells to minimize the scale formation, but eventually the cell will have deposits that require the cell to be removed from the plumbing and soaked in an acid solution.
The cells are also vulnerable to damage if they are operated in conditions of lower than recommended salt residuals or in water that is too cold. The systems have sensors and cut-offs to prevent this damage, but operators must be sure to monitor the unit to recognize when there is a problem.

# Bromine

# EPA Registered
The US EPA Office of Pesticides registers products and approves labels for bromine. Currently bromine products on the market for use in recreational water are registered with use levels ranging from 1-8 PPM (mg/L), depending on the product. The efficacy of these products have been studied by the manufacturers and submitted to the U.S. EPA under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). The efficacy data analyzed by the U.S. EPA is company confidential and has not been reviewed as part of the development of the MAHC. The MAHC welcomes input and supporting data for establishing upper limits.

# Minimum Bromine Concentrations
Bromine concentrations established by state and local jurisdictions have not been found to correlate with data supporting the concentrations being used. However, every state or local jurisdiction that allows bromine as a disinfectant requires bromine at higher concentrations than CHLORINE and almost twice as much in SPAS and warmer POOLS.
Facility Operation & Maintenance ANNEX 211 Commercially available test kits are not capable of distinguishing free bromine (Br 2 , HOBr, OBr-) from combined bromine (bromamines). The bromine value specified in test results is the concentration of total bromine, not the free available halogen that is tested with CHLORINE. To determine total bromine, test kit manufacturers use a CHLORINE value and multiply it by 2.25. The 2.25 conversion factor accounts for the molecular weight difference between elemental bromine and elemental CHLORINE (Br = 79.90 grams per mole and Cl = 35.45 grams per mole). Further, presently used field test kits assay only for total bromine.
Bromine is commonly used in indoor commercial SPAS, probably due to these two factors. First, bromamines (bromine and ammonia combined) do not produce irritating odors as do chloramines. Second, bromine efficacy is less impacted than CHLORINE'S at a higher pH, which typically occurs in a SPA environment. At pH of 7.5, 94% of bromine is hypobromous acid, whereas at the same pH, hypochlorous acid is 55% in chlorinated water. At pH of 8.0 bromine still has 83% hypobromous acid, while in a chlorinated water, hypochlorous acid is 28%. 334 Bromine is also not very common in outdoor POOLS because like CHLORINE, bromine is destroyed rapidly in sunlight. Cyanuric acid was developed to combat the problem in chlorinated POOLS, but does not provide a stabilizing effect for bromine.
While reviewing the literature and surveillance data from CDC, evidence that outbreaks have occurred when required minimum bromine concentrations have been maintained is lacking. Therefore, in absence of any clear research, the decision to use common state requirements as the recommended levels is prudent.
SPAS have been implicated in many skin disease outbreaks throughout the years. One paper suggests that a common culprit, Pseudomonas aeruginosa, were rapidly reestablished in whirlpools (less than 103 cells per mL) when disinfectant concentrations decreased below recommended levels (chlorine: 3.0 PPM (mg/L); bromine: 6.0 PPM (mg/L)). The authors studied the reoccurrence of bacteria following cleaning and halogen shock treatment 335 . This study emphasized the need for maintaining a consistent CHLORINE level in the SPA. CDC recommends 4-6 PPM (mg/L) for bromine.
The MAHC recommends a follow up study to evaluate the efficacy of bromine on P. aeruginosa, since it is so commonly found in SPAS; and because bromine is very common disinfectant used in SPAS, prevention and treatment is essential.
There are few peer-reviewed studies on bromine efficacy in real world POOLS and SPAS in the literature. Brown et al. reported reasonable bacterial control with 2.0 total bromine in an 118,000 gallon (447 m 3 ) INDOOR POOL using BCDMH 336 . Normal day time BATHER
Facility Operation & Maintenance ANNEX 212 COUNTS were around 0.21 persons per 500 gallons (1893 L) per hour but often increased to as high as 0.85 in the evening. The POOL did not use supplemental OXIDATION but did replace 5% of the water daily which likely contributed to the low reported ammonia nitrogen and organic nitrogen. Shaw reports a retrospective analysis of brominated and chlorinated semi-public SPAS in Alberta. 337 The data used was from the microbiological results of the weekly samples required under provincial regulations. The treatment systems compared include BCDMH (oxidation method not specified), bromide salt regenerated by hypochlorous acid/potassium monopersulfate continuous feed, CHLORINE gas, hypochlorite (type not specified), dichlor, and trichlor. The concentrations were generally in line with provincial regulations of 2 PPM (mg/L) total bromine and 1 PPM (mg/L) free CHLORINE. The brominated SPAS had a higher failure rate in all three bacterial parameters. There were several complaints of both contact dermatitis and Pseudomonas folliculitis from the brominated SPAS during the period studied, but due to the nature of the retrospective studies, it was not possible to link the reported RWIs to the concentration of the disinfectant at the time of the complaint. It appears from composite data that when semi-public SPAS are operated using the U.S. EPA minimum halogen concentration of 1.0 PPM (mg/L) free CHLORINE or 2 PPM (mg/L) total bromine that Pseudomonas aeruginosa can be isolated from the brominated SPAS at greater than twice the frequency than from chlorinated SPAS.

# Bromates
Ozone and bromide ions in water form hypobromous acid and bromate ions. Bromates have been classified by the International Agency for Research on Cancer (IARC) as having sufficient evidence of carcinogenicity in laboratory animals. As a result, WHO has set a provisional drinking water guideline value of 10 ug/L. The U.S. EPA has established a maximum CONTAMINANT level of 10 ug/L for bromate in drinking water.
BCDMH (1-bromo-3-chloro-5, 5-dimethylhydantoin) is the most common form of bromine used in commercial POOLS and SPAS today. The function of DMH is to inhibit the formation of bromates.
At present there is little information on the functionality of using DMH in this manner. Since there is not a convenient field test kit available, an operator has no way of knowing what the DMH level is in the water or when it may go below 10 PPM (mg/L) to allow bromates to form. We also do not know what the maximum safe level of DMH should be. To rely on DMH for bromate prevention, suitable test methods and further research are necessary.
Operators should consider that ozone should likely not be used with bromine systems when there is a substantial likelihood of ingestion of the water. When ozone is used in conjunction with organic bromine sources (BCDMH or DBDMH-another common source of bromine), the ozone readily converts residual bromide ion back to hypobromous acid. This process reduces ozone. With the continued addition of BCDMH, DBDMH, or sodium bromide, the bromide levels will continue to climb in the 337Shaw JW. A retrospective comparison of the effectiveness of bromination and chlorination in controlling Pseudomonas aeruginosa in spas (whirlpools) in Alberta. Can J Public Health. 1984 Jan-Feb;75(1):61-8.
Facility Operation & Maintenance ANNEX 213 POOL or SPA. Continuous build-up of bromide will constantly reduce ozone; diminishing ozone's effective OXIDATION (and destruction) of organics and microorganisms in the water. Because of the wide variation in the concentration of bromide and the potential for bromate ingestion at least one ozone manufacturer does not recommend the installation of ozone units in bromine-treated facilities.
Disinfection DISINFECTION using bromine is more complex but less well documented than DISINFECTION using CHLORINE. Hypobromous acid is the putative biocidal chemical species at recreational water pH. Hypobromous acid reacts with inorganic ammonia and forms monobromamine, dibromamine, and nitrogen tribromide, depending on the pH and concentration of ammonia. 338 These inorganic bromamines are all considered more biocidal than their corresponding CHLORINE analogs. Hypobromous acid is converted to inert bromide ion upon biocidal action in a manner similar to that seen with hypochlorous acid. One key difference between bromine and CHLORINE DISINFECTION is that bromide is readily oxidized back to hypobromous acid and chloride is not. Further, hypobromous acid is a much weaker oxidizer than hypochlorous acid. As a consequence of these two differences, exogenous OXIDATION of brominated waters (e.g. shocking with chlorine) is more important for safe operation than it is in chlorinated waters. In reviewing the published epidemiological studies on RWIs, it is often difficult to determine the exact treatment system used because the SUPPLEMENTAL TREATMENT SYSTEM is not described. Further, presently used field test kits assay only for total bromine and are not capable of distinguishing free bromine from biocidal inorganic bromamines or from non-biocidal organic bromamines.

# Bromamines
Current POOL and SPA operating manuals state that combined bromine (bromamines) is as efficacious as free bromine. This may be an over generalization of the complex nature of bromine chemistry. Bromine reacts with inorganic ammonia and forms analogous compounds (Br 2 , hypobromous acid, monobromamine, dibromamine, and nitrogen tribromamide) depending in the pH and concentration of ammonia. 339 All three bromine-ammonia derivatives are biocidal, but all three are also less stable than their corresponding CHLORINE compounds. As with their CHLORINE analogs, the ratios of the bromamines are highly dependent on the ratio of ammonia to bromine. Further, at low ammonia to bromine ratios the biocidal action appears to be substantially reduced 340 . The levels of ammonia that result in loss of bromine efficacy have been detected in SPA water 341 . At these documented concentrations of bromine and ammonia, the predominant bromamine is most likely dibromamine, which has an estimated half-life of 338 Galal-Gorchev H, et al. Formation and stability of bromamide, bromimide, and nitrogen tribromide in aqueous solution. Inorganic Chemistry. 1965;4(6):899-905. 339 Galal-Gorchev H, et al. Formation and stability of bromamide, bromimide, and nitrogen tribromide in aqueous solution. Inorganic Chemistry. 1965;4(6):899-905. 340 Wyss O, et al. The germicidal action of bromine. Arch Biochem. 1947 Feb;12(2):267-71. 341 Kush BJ, et al. A preliminary survey of the association of Pseudomonas aeruginosa with commercial whirlpool bath waters. Am J Public Health. 1980 Mar;70(3):279-81.
Facility Operation & Maintenance ANNEX 214 10 minutes 342 . The MAHC was not able to locate data on the efficacy of organic bromamines.

# Future Research Needs

# Cryptosporidium Inactivation
Methods to hyper-brominate recreational water in response to diarrheal fecal accidents have not been established. Research in this area is lacking.

# Bromine Associated Rashes
Note to readers: These comments have been inserted to point future researchers toward an under-investigated area of public health and are not meant to imply a negative bias toward bromine.
Literature reviews demonstrate a large number of reports describing rashes associated with brominated water. These rashes fall into two general categories:  Contact dermatitis due to brominated species in the water, and  Dermal infections due to Pseudomonas aeruginosa.
These are most easily differentiated by incubation time. The vast majority of contact dermatitis reactions occur within 24 hours of immersion, sometimes within minutes. These are often referred to as "bromine itch" and are widely reported in the medical literature 343 , 344 , 345 . In most cases the putative etiological agent is thought to be bromamines. This type of dermatitis appears to be a result of cumulative exposure to bromine treated water and is particularly prevalent among medical personnel who provide aquatic physical therapy 346 . The exact compounds inducing contact dermatitis have not been identified. One study strongly suggests that the use of bromine with supplemental OXIDATION minimizes contact dermatitis 347 . In numerous epidemiological studies, poor water quality is commonly, but not always, reported (Woolf and Shannon report an extreme example of a foamy pool leading to multiple cases of contact-related RWI 348 ). The typical incubation period for Pseudomonas aeruginosa folliculitis is several days but can be as short as 24 hours. Outbreaks of Pseudomonas aeruginosa folliculitis are routinely associated with inadequate sanitation in both chlorinated and brominated waters. The minimum concentration to prevent such outbreaks has not been established but appears to at least one PPM (mg/L) free CHLORINE and two PPM (mg/L)
Facility Operation & Maintenance ANNEX 215 total bromine. A survey of the literature since the mid-1980s shows more dermal RWI outbreaks reported in brominated waters than in chlorinated waters. It is not known whether the reports reflect the true incidence, a bias in reporting of bromine systems, or a bias in reporting RWIs in SPAS, which tend to use bromine disinfectants.
There are many unanswered questions surrounding bromine-treatment systems commonly used in AQUATIC VENUE DISINFECTION. After reviewing the literature, the MAHC has concluded the following research is essential to understanding bromine DISINFECTION.
Further research needs to address, in priority order:
- The efficacy of bromine to establish a minimum concentration for AQUATIC VENUES and warm water SPAS and THERAPY POOLS,  The maximum bromine concentration that should be allowed,  The contribution of bromamines to DISINFECTION and BATHER rashes,  Methods to better control bromamines,  Creation of a test kit to differentiate free bromine from combined (as is currently practiced with chlorine) in the water,  Use of DMH in respect to bromate formation,  Establish a safe maximum level,  Creation of a test kit to establish levels in the water, and  Fecal accident recommendations to control Cryptosporidium when using a bromine POOL.

# Stabilizers

# Minimum Disinfection
Minimum CHLORINE levels should be increased by a factor of at least two when using CYA. Robinton et al. found that "50 MG/L of cyanuric acid produced pronounced retardation of the bactericidal efficiencies of solutions of calcium hypochlorite, trichloroiso-cyanuric acid, and potassium dichloroisocyanurate such that a four-to eightfold increase in the amount of "free" available residual CHLORINE may be necessary to attain the same degree of inactivation of the same organisms in the same interval of time" 349 .
Laboratory studies by Warren and Ridgway show that addition of 50 MG/L cyanuric acid to 0.5 -1.0 MG/L available CHLORINE resulted in a significant increase in the CT of Staphylococcus aureus, in parallel with the increase in available CHLORINE stability in sunlight. However, higher concentrations of cyanuric acid resulted in little to modest further increases in CT over that for 50 MG/L cyanuric acid. For example, the data suggest that for 50, 100 and 200 MG/L of cyanuric acid, the level of CHLORINE required for 99% kill of Staphylococcus aureus in one minute would be 1.9, 2.15, and 2.5 MG/L, respectively 350 .
The MAHC has adopted a SAFETY factor of 2 so that 2 PPM is the minimum concentration of using stabilized products. More data are needed to understand the impact of increasing cyanurate levels on pathogen inactivation to assess what this level should be so the MAHC has adopted less than or equal to 100 PPM, as has the World Health Organization 351 .
The level of cyanurate allowed in outdoor AQUATIC VENUES is double that for nonstabilized CHLORINE, which is a SAFETY factor for the decrease in oxidative capacity. The MAHC has decided that from a public health standpoint it cannot support a prohibition of the use of cyanurate in most INCREASED RISK AQUATIC VENUES. The SAFETY margin of two times the level of non-stabilized product would also apply for increased indoor settings in addition to the requirement for a SECONDARY DISINFECTION SYSTEM and therefore prohibition in an INCREASED RISK VENUE cannot, at this time, be supported with a public health argument. The exception to this is operation of SPAS and THERAPY POOLS, which have large issues with efficacy of agents against pathogens in biofilms and difficulties with maintaining needed pH levels (spas) and the use by INCREASED RISK groups of patients (THERAPY POOLS). SPAS and THERAPY POOLS will, therefore, not be allowed to use cyanuric acid or stabilized CHLORINE products.
Facility Operation & Maintenance ANNEX 217 Users should be aware that if AQUATIC VENUES using cyanuric acid or stabilized CHLORINE products have a fecal incident, they will need to close for more prolonged periods for a diarrheal fecal incident and HYPERCHLORINATION, circulate water through a SECONDARY DISINFECTION SYSTEM, or replace the water in the AQUATIC VENUE per MAHC Section 6.5.3.2.1 352 .

# Indoor Pools
There appears to be no operational or public health reason for INDOOR AQUATIC VENUES to use CYA. It is a stabilizer for degradation from direct sunlight and so likely has limited benefits for indoor POOLS despite some operators claiming a benefit for indoor POOLS with large glassed areas. However, the level of cyanurate allowed in outdoor AQUATIC VENUES is double that for non-stabilized CHLORINE which is a SAFETY factor for the decrease in oxidative capacity. The MAHC has decided that it cannot support, from a public health standpoint, a prohibition of the use of cyanurate in indoor settings. The SAFETY margin would also apply for indoor settings and therefore prohibition in an indoor setting would require specific data on the direct impact in indoor settings since the MAHC allows it in outdoor settings. CDC still does not recommend cyanuric acid use for indoor POOLS or hot tubs. The recommendation was underscored in a 2000 MMWR after investigating a Pseudomonas dermatitis/folliculitis outbreak associated with indoor POOLS and hot tubs in Maine, noting that cyanuric acid was added to an indoor POOL which reduces the antimicrobial capacity of free CHLORINE 353,354 .
Users should be aware that if AQUATIC VENUES using cyanuric acid or stabilized CHLORINE products have a fecal incident, they will need to close for more prolonged periods for a diarrheal fecal incident and HYPERCHLORINATION, circulate water through a SECONDARY DISINFECTION SYSTEM, or replace the water in the AQUATIC VENUE per MAHC Section 6.5.3.2.1 355 .

# Effects of Cyanuric Acid on Microbial Inactivation
There are a large number of references on the effect of CYA on kill times (CT Values). In general, they show that the presence of CYA increases CT VALUES, and the amount of this increase depends on the pH and the ratio of CYA to available CHLORINE. However, there are few reports that relate specifically to the issue of what levels of available CHLORINE and cyanuric acid are required to maintain a swimming POOL in a biologically satisfactory state.
Studies examining the effect of cyanuric acid on the DISINFECTION capacity of CHLORINE show that using cyanuric acid or stabilized CHLORINE slows down the inactivation times
Facility Operation & Maintenance ANNEX 218 on bacteria, algae, protozoa (Naegleria gruberi and Cryptosporidium parvum), and viruses. Yamashita et al. concluded the addition of cyanuric acid increased the time needed for DISINFECTION of 12 virus types by a factor of 4.8-28.8 compared to free CHLORINE alone 356,357 . In a later study, Yamashita et al. 358 found "Total plate counts ranged from 0 to 1 per mL in the swimming POOLS treated with sodium hypochlorite and 0 to 51 in those with trichloroisocyanurates. In 11 of 12 water samples of 3 swimming POOLS using trichloroisocyanurates, poliovirus type 1 survived after 2 minute contact while in 5 samples poliovirus type 1 survived after 5 minute contact." The researchers concluded this showed that the risk of viral infection is greater in swimming POOL water treated with chlorinated isocyanurates than that with sodium hypochlorite.
The addition of CYA similarly impaired the inactivation of poliovirus 359 . Cyanuric acid, used as CHLORINE stabilizer in swimming POOL waters, had a relatively minor effect on the algicidal efficiency of FREE CHLORINE 360 . There are few data regarding protozoa and the effect of CYA on inactivation though the DISINFECTION rate for Naegleria gruberi was reduced by cyanuric acid in laboratory-controlled CHLORINE demand free conditions 361 .
Facility Operation & Maintenance ANNEX 219 Shields et al. 362 extended the previous findings by demonstrating that cyanuric acid significantly decreases the rate of inactivation for Cryptosporidium parvum OOCYSTS. In this study a three-log reduction of OOCYSTS was found to take place in the presence of 20 PPM (mg/L) FAC. When 50 PPM (mg/L) CYA was introduced, the 10-hour kill rate was less than 12 log.
Pseudomonas inactivation in the presence of CYA was also studied in POOL water and it was found that increased CYA concentrations lengthened the kill times. The effect of cyanuric acid was greater as the concentration of CHLORINE in the water decreased 363 . Favero et al. found that at free CHLORINE concentrations of more than 0.5 PPM (mg/L), P. aeruginosa was rarely found except in those POOLS which used sodium dichloroisocyanurate as a POOL disinfectant. Three private swimming POOLS using sodium dichloroisocyanurate as a POOL disinfectant were found to contain large numbers of the potential pathogen, P. aeruginosa 364 . Fitzgerald found concentrations of 25, 50, and 100 mg of cyanuric acid per liter had large effects on the Pseudomonas kill rate of 0.1 MG/L free CHLORINE but this effect diminished with increasing free CHLORINE content (0.25, 0.5 mg/L). Fitzgerald found concentrations of 25, 50, and 100 mg of cyanuric acid per liter had little effect on the kill rate of 0.5 mg of CHLORINE plus 0.1 mg of NH4-N per liter; however, cyanuric acid did reduce the time required for 99.9% kills when tested in the presence of higher concentrations of ammonia 365 . The basis for this finding should be explored further.

# Fecal Accident Response
The use of stabilized CHLORINE is not recommended for HYPERCHLORINATION in RWI outbreaks, or in response to fecal accidents. Present MAHC requirements for HYPERCHLORINATION and POOL remediation are ineffective for POOLS using cyanurate stabilized CHLORINE. Estimated Cryptosporidium inactivation times are much longer, which will require substantially longer closure times 366 .

# Toxicity
The maximum CYA concentration of 100 PPM (mg/L) should be considered protective from a toxicological perspective. Using an assumption that 100 mL of POOL water is swallowed per swim session; the World Health Organization (WHO) concluded that CYA levels in POOLS should be below 117 PPM (mg/L). This is based on a tolerable daily intake (TDI) for anhydrous sodium dichloroisocyanurate (NaDCC) of 2 mg/kg of body weight, which translates into an intake of 20 mg of NaDCC (or 11.7 mg of CYA per
Facility Operation & Maintenance ANNEX 220 day) for a 10 kg child. The U.S. EPA SWIMODEL, relying on somewhat lower exposure assumptions, would yield a higher acceptable level for CYA.

# Research
Though the data shows CYA use increases the inactivation time of many pathogens, the MAHC would like to have a study done on specific pathogens and inactivation rates at differing CYA levels, up to at least 200 PPM (mg/L). Further research on the inhibitory effect of cyanuric acid on DISINFECTION should evaluate the level at which cyanuric acid can still protect CHLORINE from UV and also balance the inactivation rate of the most common AQUATIC VENUE pathogens. The effect of pH in the presence of cyanuric acid should also be investigated. Additionally, a test kit should be created to test lower and higher levels of CYA. The current products on the market are not very accurate and need to operate over a wider range of CYA levels. During RWI outbreaks, it is strongly recommended that the investigation team measure CYA levels.
Compressed Chlorine Gas Installation/use of compressed CHLORINE gas is prohibited for new AQUATIC FACILITIES; however there are existing facilities that continue to use these gas systems. Because of the potential hazard, it is important that existing facilities meet STORAGE, ventilation, handling, and operator training requirements if use is to continue. If these requirements are not met, use must be discontinued and a properly designed/sized and approved disinfectant system installed.
The following design criteria from an existing health code provide additional details for consideration when evaluating acceptability of an existing compressed gas installation.
- Location. The chlorinator room shall be located on the opposite side of the POOL from the direction of the prevailing winds. CHLORINE STORAGE and chlorinating equipment shall be in a separate room. This room shall be at or above grade.  Venting. The CHLORINE room shall have a ventilating fan with an airtight duct beginning near the floor and terminating at a safe point of discharge to the out-of doors. A louvered air intake shall be provided near the ceiling. The ventilating fan shall provide one air change per minute and operate from a switch located outside the door.  Door. The door of the chlorinator room shall not open to the swimming POOL, and shall open outward directly to the exterior of the building. The door shall be provided with a shatterproof inspection window and should be provided with "panic hardware."  Chlorine cylinders. CHLORINE cylinders shall be anchored. The cylinders in use shall stand on a scale capable of indicating gross weight with one-half pound accuracy. STORAGE space shall be provided so that CHLORINE cylinders are not subjected to direct sunlight. STORAGE space shall be in an area inaccessible to the general public.  Injection location. Mixing of CHLORINE gas and water shall occur in the CHLORINE room, except where vacuum-type chlorinators are used.
Facility Operation & Maintenance ANNEX 221  Backflow. The chlorinators shall be designed to prevent the BACKFLOW of water or moisture into the CHLORINE gas cylinder

# Salt Electrolytic Chlorine Generators, Brine Electrolytic Chlorine or Bromine Generators
In-line generators shall use only POOL-grade salt dosed into the POOL to introduce CHLORINE into the POOL vessel through an electrolytic chamber to avoid potential health risks associated with DISINFECTION byproducts forming from salt impurities, including bromide and iodide. For example, Kristensen et al. directly correlated bursts of bromodichloro-methane formation to salt addition to POOL water over a MONITORING period of more than one year. 367 In a comparison study of common disinfectant methods, Lee et al. found salt brine electrolysis formed the highest levels of bromodichloro-methane, dibromochloro-methane and bromoform. 368 Zwiener et al. noted that iodized table salt should not be used in salt POOLS because iodized DISINFECTION byproducts, which are generally more toxic than chlorinated DISINFECTION byproducts, could form. 369 Additionally, there is a perception by some that salt water POOLS can be operated with table salt (which is commonly iodized).
Secondary or Supplemental Treatment Systems Due to the risk of outbreaks of recreational water illnesses (RWIs) associated with halogen-tolerant pathogens such as Cryptosporidium, it is strongly recommended that all AQUATIC FACILITIES include SECONDARY DISINFECTION SYSTEMS to minimize the risk to the public associated with these outbreaks.
All existing regulations covering fecal events or detection of pathogens must still be adhered to when SECONDARY DISINFECTION SYSTEMS are utilized. SECONDARY DISINFECTION SYSTEMS can only minimize the risk and are not a guarantee of treatment due to the possibility of cross contamination of the POOL or water feature and the time required to pass the entire volume of water through the treatment process.
As the general effectiveness of a SECONDARY DISINFECTION SYSTEM is affected by the AQUATIC VENUE TURNOVER rate and mixing/circulation within the AQUATIC VENUE, the MAHC requirements for filter recirculation and TURNOVER rates must be followed. The performance of SECONDARY DISINFECTION SYSTEMS will be enhanced when the shortest TURNOVER times are achieved for any particular type of AQUATIC FACILITY.
The use of certain types of AQUATIC VENUES presents an increased risk of recreational water illness (RWI) to users. These AQUATIC VENUES include THERAPY POOLS, WADING POOLS, SPRAY PADS, swim schools, INTERACTIVE WATER PLAY AQUATIC VENUES, and AQUATIC FEATURES. Given that users of these types of facilities frequently have lesser
Facility Operation & Maintenance ANNEX 222 developed immune systems (children), and/or a higher prevalence of disease (children and older adults), and/or compromised immune systems, and/or open wounds, additional precautions against RWIs are warranted.
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. Of this percentage, 14.3% of the violations were for inadequate DISINFECTION levels at THERAPY POOLS 370 .
The use of INTERACTIVE WATER PLAY AQUATIC VENUES has previously been associated with outbreaks of gastroenteritis. In 1999, an estimated 2,100 people became ill with Shigella sonnei and/or Cryptosporidium parvum infections after playing at an "interactive" water fountain at a beachside park in Florida 371 .
In one of the largest outbreaks reported, approximately 2,300 persons developed cryptosporidiosis following exposure to a New York spray park. The environmental investigation revealed that filtration and DISINFECTION of the recycled water were not sufficient to protect the PATRONS from this disease. In response, emergency legislation was passed, which required the installation of SECONDARY DISINFECTION (e.g., ultraviolet radiation or ozonation) on water returning through the sprayers 372 .
Ultraviolet Light

# 3-log Inactivation
Records of the correct calibration, maintenance, and operation of SECONDARY DISINFECTION SYSTEMS should be maintained by the facility's management.

# Calibrated Sensors
Owners/operators need to consult the unit manual and the manufacturer's manual for guidance on how to accomplish this and who is qualified to do so.
Copper / Silver Ions EPA has set current drinking water STANDARDS at 1.3 PPM for copper and 0.10 PPM for silver, which are generally accepted in the states that have requirements for this treatment. These ion generation systems are not meant to replace disinfecting halogen and the minimum levels must continue to be provided. The manufacturer's recommended procedures should be followed to avoid the potential of staining, and operating the POOL with copper levels outside the recommended range may cause staining. Copper-based algaecides should not be used in these systems 5.0 Facility Operation & Maintenance ANNEX 223 since use of these products increase the level of copper in the POOL and increases the potential to cause health effects or stain surfaces.
In addition, studies have shown that the presence of copper in POOL water has a catalytic effect on the formation of 373 TRIHALOMETHANES .
Other Sanitizers, Disinfectants, or Chemicals The MAHC has opted to not include lists of disinfectants that should not be used in AQUATIC VENUES versus just saying that they must not pose a hazardous issue with the CHLORINE or bromine disinfectants in use and that all water quality criteria must be met.

# PHMB
Polyhexamethylene biguanide hydrochloride (PHMB) is a polymeric antimicrobial that has been used as an alternative to CHLORINE and bromine. PHMB is often referred to as biguanide in the industry. The formal name for PHMB on US EPA accepted labels is "Poly (iminoimidocarbonyliminoimido-carbonyl iminohexamethylene) hydrochloride". The U.S. EPA has registered PHMB for use in POOLS and SPAS as a "SANITIZER" with label directions requiring that the concentration be maintained between 30 and 50 PPM (mg/L) as product (6 to 10 PPM (mg/L) of active ingredient).
PHMB is not an oxidizer and must be used in conjunction with a separately added product. Hydrogen peroxide is the strongly preferred oxidizer.
The vast majority of the PHMB used in POOLS and SPAS is in private residences but a limited number of public facilities have used PHMB.
Because of its limited use in public AQUATIC FACILITIES, there are few independent studies on the efficacy of PHMB in recreational water. Studies report that the rate of kill of bacteria is slower than that of CHLORINE under laboratory conditions. However, the U.S. EPA found that manufacturer's generated data demonstrated adequate efficacy under the EPA guideline DIS/TSS-12 to grant registration under the Federal Fungicide, Insecticide and Rodenticide Act (FIFRA) and without regard to whether the facility is public, semi-public, or private. As part of their registration process, the US EPA does not distinguish between public and private facilities. The efficacy data analyzed by the U.S. EPA is company confidential and has not been reviewed as part of the development of the MAHC.
There are no known published studies of the efficacy of PHMB against non-bacterial POOL and SPA infectious agents (e.g. norovirus, hepatitis A, Giardia sp., Cryptosporidium spp.), under use conditions. PHMB is generally compatible with both UV and ozone, but both UV and ozone will increase the rate of loss of PHMB. Since SECONDARY DISINFECTION SYSTEMS require the use of a halogen as the primary disinfectant, the use of PHMB, even with a secondary system is problematic.
Facility Operation & Maintenance ANNEX 224 PHMB IS NOT compatible with CHLORINE or bromine. POOLS using PHMB have a serious treatment dilemma for control of Cryptosporidium after a suspected outbreak or even a diarrheal fecal accident. The addition of a 3 PPM (mg/L) of CHLORINE to a properly maintained PHMB-treated POOL results in the precipitation of the PHMB as a sticky mass on the POOL surfaces and in the filter. Removal of the precipitated material can be labor intensive.
Testing for PHMB requires special test kits. Conventional kits for halogens are not suitable. PHMB test kits are readily available at most specialty retail POOL stores and on-line.

# Hydrogen Peroxide
Hydrogen peroxide is not registered by the U.S. EPA as a disinfectant for recreational water. Since it is not registered, the use of hydrogen peroxide as a recreational water disinfectant, or any market claims that implies hydrogen peroxide provides any biological control in recreational water is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Hydrogen peroxide has been granted registration by the U.S. EPA as a hard surface disinfectant and several other applications. The U.S. EPA Registration Eligibility Document (RED) on hydrogen peroxide is available from the EPA website at www.epa.gov/oppsrrd1/REDs/old_reds/peroxy_compounds.pdf. The U.S. EPA posts PDF copies of accepted product labels on the National Pesticide Information Retrieval System website (/#.) Product claims for uses and concentration may be verified by reading the PDF of the U.S. EPA stamped and accepted copy of the product use directions at this website.
When used as a hard surface disinfectant, hydrogen peroxide is normally used at around 3%. When used in recreational water, hydrogen peroxide is used at 27 to 100 ppm (mg/L), which is 1111 and 300 times, respectively, more dilute than that used on hard surfaces. Borgmann-Strahsen evaluated the antimicrobial properties of hydrogen peroxide at 80 and 150 ppm (mg/L) in simulated POOL conditions. 374 Whether 150 ppm (mg/L) of hydrogen peroxide was used by itself or in combination with 24 ppb of silver nitrate it had negligible killing power against Pseudomonas aeruginosa, E. coli. Staphylococcus aureus, Legionella pneumophila or Candida albicans, even with a 30 minute contact period. In the same tests, the sodium hypochlorite controls displayed typical kill patterns widely reported in literature. Borgmann-Strahsen concluded that hydrogen peroxide, with or without the addition of silver ions, was, "no real alternative to chlorine-based disinfection of swimming pool water from the microbiological point of view."
Chlorine Dioxide CHLORINE dioxide is not presently registered by the U.S. EPA for any use in recreational water. Since it is not registered, the use of chlorine dioxide as an antimicrobial treatment (e.g. disinfectant, sanitizer, algaecide, slimicide, biofilm control agent) in recreational 5.0 Facility Operation & Maintenance ANNEX 225 water, or any market claims that implies chlorine dioxide provides any biological control in recreational water is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Chlorine dioxide has been granted registration by the U.S. EPA as an antimicrobial for other applications, including drinking water. One product was previously registered as a slimicide for use in PHMB-treated recreational water but that registration has since been dropped. The U.S. EPA Registration Eligibility Document (RED) on chlorine dioxide is available from the US EPA website at .
The U.S. EPA posts PDF copies of accepted product labels on the National Pesticide Information Retrieval System website (/#). Product claims for uses and concentration may be verified by reading the PDF of the U.S. EPA stamped and accepted copy of the product use directions at this website.
Chlorine dioxide has the potential to be an alternative remediation tool, but it has not yet been approved by EPA for this use and can be hazardous unless appropriate SAFETY protocols are included. CDC has determined that chlorine dioxide can be used instead of HYPERCHLORINATION for rapid inactivation of Cryptosporidium (3-log inactivation in 105 to 128 minutes) and that this effect was synergistically enhanced with a FREE CHLORINE RESIDUAL in place. 375 This suggest chlorine dioxide might be very useful in remediating contaminated AQUATIC VENUES in the absence of BATHERS.

# Potential for Using Chlorine Dioxide in the Future
During the drafting of this section of the MAHC, several members of the MAHC had interest in using chlorine dioxide as a remedial treatment for Cryptosporidium and Legionella. Recommendations for this were not pursued because of the status of chlorine dioxide under FIFRA. Published studies, including the EPA Alternate Disinfection Manual for drinking water shows that chlorine dioxide may be a very rapid remedial treatment for these life-threatening pathogens. If the registration status of chlorine dioxide changes, the MAHC suggests that chlorine dioxide use should be reconsidered.

# Provisions for Emergency Use of Chlorine Dioxide
Even though chlorine dioxide is not presently registered for use in recreational water, it is possible to use it under Section 18 of FIFRA. An example of this would be the remediation of a Legionella-contaminated health club SPA where other treatments were proven to be ineffective. More information on emergency exemptions can be found on the U.S. EPA website at /. Because of the lack of existing use directions and potential for occupational exposure, it is strongly suggested that a certified industrial hygienist be included in developing emergency treatment plans. Clarifiers, Flocculants, and Defoamers POOLS and SPAS may benefit from the use of one or more of these types of products. There are numerous brands available that are formulated for commercial POOLS and SPAS. Each product is marketed for a specific procedure. Each may contain one or more natural or synthetic polymers, chemical or metallic ingredients. Neither the efficacy nor the SAFETY of product chemistry of these products has been reviewed by the US EPA or any other federal agency. The state of California does require submission of a detailed data package prior to registration. Products sold in the state of California must have the state registration number on the label. Products registered in California but sold outside of the state usually, but are not required to, have the California registration number on the label. Any local agency concerned about a particular product could request the producer supply the California registration number and then verify the status of the product with the California Department of Pesticide Regulation.
pH There are three reasons to maintain pH:  Efficacy of the CHLORINE,  BATHER comfort, and  Maintenance of balanced water.
Each of these reasons are discussed briefly below:

# Efficacy of Chlorine
The efficacy of CHLORINE/hypochlorous acid is dramatically impacted by pH and therefore pathogen inactivation can be severely affected by higher pH levels where only a small percentage of FREE CHLORINE is active. Lower pH levels below this range allow a greater percentage of FREE CHLORINE to be "active". Further data are needed to ensure that lower levels (e.g., 6.8 to 7.2) do not adversely impact membranes, particularly eyes. The present practice of maintaining the pH between 7.2 and 7.8 has been developed by coupling physical chemistry with empirical observations. There is no definitive peerreviewed study that extensively covers the subject of pH in POOL and SPA water except those showing the titration of hypochlorous acid and the importance of pH for assuring maximal efficiency. The best general authority is the 1972 edition of the Handbook of Chlorination by Geo. Clifford White. The 1972 edition of this widely recognized authority on CHLORINE chemistry is the only edition that has a chapter especially on POOLS. Much, but not all, of the POOL chemistry chapter can be found in subsequent editions. Copies of the 1972 edition are difficult to locate in libraries but are available for sale on the internet as of July 2009. The discussion on efficacy and BATHER comfort is a summary of the 1972 edition discussion on pH.
CHLORINE used in POOLS refers to hypochlorous acid. Hypochlorous acid (HOCl) is a weak acid that readily dissociates to form hypochlorite (OCl-) and hydrogen ion (H+). The mid-point of the dissociation (the pKa) is at pH 7.5. Functionally, this means that at pH of 7.5, 50% of the FREE CHLORINE present will be in the form of hypochlorous acid and 50% will be in the form of hypochlorite. As the pH decreases below 7.5, the
Facility Operation & Maintenance ANNEX 227 proportion of hypochlorous acid increases and proportion of hypochlorite ion decreases. The opposite occurs as the pH increases above 7.5. Numerous investigators have reported that hypochlorous acid is approximately 100 times more effective at killing microorganisms than the hypochlorite ion. Thus from a public health perspective, it is desirable to maintain the pH so as to maximize the portion of hypochlorous acid portion of the FREE CHLORINE present in the water.

# Bather Comfort
As BATHERS enter the water, their skin and eyes come into direct contact with the water and its constituent components. In general, the eyes of BATHERS are more sensitive to irritation than the skin. Studies on the sensitivity of BATHERS' eyes to pH changes of the water show wide variations in tolerance limits. The tolerance of the eye to shifts in pH is also impacted by the concentration of FREE CHLORINE, combined CHLORINE, and alkalinity. Under normal POOL conditions, the optimum limits for BATHER comfort appears to be from pH 7.5 to 8.0.

# Potential for Lowering pH in the Future
During the review of the data, the MAHC had a broad interest in lowering the minimum pH. This would increase the efficacy of the CHLORINE by increasing the proportion of hypochlorous acid (at the expense of hypochlorite) and thus increase DISINFECTION efficacy. This was not recommended because of the lack of data on the impact on BATHERS, particularly the eyes. If additional information on the impact of lower pH on BATHERS' skin and eyes is developed, the MAHC suggests that the acceptable range for pH be reexamined. As part of the reexamination, consideration should also be made concerning how this change will impact the water balance and any possible negative impact on the facility.
Feed Equipment The Chlorine Institute has checklists and guidance for working with compressed CHLORINE gas at: .
Facility Operation & Maintenance ANNEX 5.7.3.7
Automated Controllers and Equipment Monitoring
Ozone System As a secondary treatment system, it is critical to monitor the system to ensure it is performing as required. UV System As a secondary treatment system, it is critical to monitor the system to ensure it is performing as required.  18-inch (45.7 cm) water depth for sample collection is recommended. Both the National Swimming Pool Foundation (NSPF) Certified Pool Operator Manual and the National Recreation and Park Association (NRPA) Aquatic Facility Operator Manual instruct the operator to reach at least 18 inches (45.7 cm) below the water's surface to collect the water sample. In an outdoor POOL, there is chemical interaction with ultraviolet light at the surface which will affect the reading. Most of the chemical CONTAMINANTS in a POOL are located within the top 18 inches (45.7 cm), which is why most studies of POOL CONTAMINANTS are performed by collecting samples at a depth of less than or equal to 30 centimeters (11.8 inches) below the POOL water surface 376,377 . These CONTAMINANTS will give false pH and DISINFECTANT readings in indoor and outdoor AQUATIC VENUES. To sample, plunge the assembly (mouth first) quickly to the marked depth, invert, and let the bottle fill. Remove when full of water and begin testing.
Aquatic Venue Water Chemical Balance Water balance is a term used to describe the tendency of water to dissolve (corrode) or deposit minerals (form scale) on surfaces contacted by the water. Balanced water will neither corrode surfaces nor form scale. Factors that impact water balance are pH, hardness, alkalinity, dissolved solids, and temperature. The presently used water balance parameters are used to protect AQUATIC VENUE equipment and surfaces from deleterious effects of corrosion and scale formation. Improperly balanced water is not in itself a threat to public health. Water balance is expressed in several ways but the most common one is by the SATURATION INDEX. Each factor in the SATURATION INDEX equation can vary within a limited range and the water is still considered balanced. Shifts in pH have a significant impact on water balance. Water balance chemistry is discussed extensively in all pool operator classes and is well beyond the scope of this Annex.
Total Alkalinity Level Total alkalinity is closely associated with pH, but rather than a measure of hydrogen ion concentration, it is a measure of the ability of a solution to neutralize (buffer) hydrogen ions. Expressed in parts per million (PPM), total alkalinity is the result of alkaline materials including carbonates, bicarbonates and hydroxides -mostly bicarbonates. As noted in the MAHC, the ideal range is 60 PPM to 180 PPM. This acid neutralizing (buffering) capacity of water is desirable because it helps prevent wide variations in pH (pH bounce) whenever small amounts of acid or alkali are added to the POOL. Total alkalinity is a measure of water's resistance to change in pH and is a source of rising pH itself from the outgassing of carbon dioxide.
Facility Operation & Maintenance ANNEX 233 the gas phase NCl 3 concentration is dynamic and impacted by BATHER COUNT, swimmer activity, liquid phase NCl 3 concentration. Reliable sampling and analytical methods affect the accuracy of the characterization of the AQUATIC VENUE water and air.

# Health Incidents
Studies of swimming POOL users and non-swimming attendants have shown a number of changes and symptoms that appear to be associated with exposure to the atmosphere in indoor AQUATIC VENUES. CDC has intervened and investigated various health incidents reporting skin and eye irritation and acute respiratory outbreaks that could be associated with exposures to chloramines and other by-products at recreational water facilities, including swimming POOLS 382,383 .

# Lifeguard Exposure
For lifeguards at swimming POOLS, an exposure-response relationship has been identified between NCl 3 , measured as total chloramines, and irritant eye, nasal, and throat symptoms, although not chronic respiratory symptoms or bronchial hyper re sponsiveness 384 .

# Respiratory Conditions
In addition to potential occupational exposures, there have been a number of studies investigating respiratory conditions, including asthma, related to swimming pools.
There appears to be no consistent association between swimming POOL attendance during childhood and the prevalence of asthma or atopic disease 385,386,387 . Studies indicate that asthma is more commonly found among elite swimmers than among other high-level athletes, although it is premature to draw conclusions about the causal link between swimming and asthma because most studies available to date used crosssectional design, because the association is not confirmed among non-competitive swimmers, and because asthmatics may be more likely to select swimming as the activity of choice because of their condition 388 .

# Contact Dermatitis
Chloramines have also been implicated in contact dermatitis (rashes). The number of rashes that occurs among BATHERS in treated recreational water is not known. One cross-sectional study of Australian school POOLS retrospectively examined the incidence rate of rashes in three POOLS. The three POOLS treatment types were 1) CHLORINE alone
Facility Operation & Maintenance ANNEX 234 (hand dosing), 2) CHLORINE plus ozone (automatic dosing and control), and 3) bromine (sodium bromide plus ozone using automatic dosing and control). This study reported 14.4% of the BATHERS in the hand-dosed CHLORINE POOLS experienced rashes 389 . This and anecdotal reports strongly suggests that rashes are the most common RWI.
The greatest number of rashes appears to be among hydro-therapists (aquatic physical therapists). A survey of 190 professional hydro-therapists in Israel reported that 45% developed skin disease after beginning work. Symptoms reported included itchiness, redness, dry skin. The areas affected were the extremities, the face and trunk, and folds in the skin. The authors concluded: 1) exposure to water influences development of irritant contact dermatitis; 2) cumulative exposure of low-potency irritants may be cause of contact dermatitis; 3) contact dermatitis is an occupational disease of hydro therapists 390 . In these and similar reports, the exact chemical species inducing the contact dermatitis has not been identified but the collective opinions of the investigators is that halogenated organic compounds (DISINFECTION BY-PRODUCTS) is the cause. One conservative estimate places the number of halogenated DISINFECTION byproducts, including organic chloramines, in swimming POOLS at greater than 200. The clinical significance of these is likely to vary with the concentration of specific chloramine and BATHER specific factors (length of exposure, underlying health conditions, and cumulative previous exposure).

# Maximum Concentration
After considerable discussion the MAHC decided to recommend an action concentration of 0.4 PPM (MG/L) for combined CHLORINE in all recreational waters. This recommendation is based on the desire to minimize the potential for both respiratory and dermal disease that is known to be associated with exposure to chloramines. The MAHC recognizes that this concentration is arbitrary and that it has not been substantiated by adequate human clinical studies. In the absence of an adequate human study, the MAHC has opted for a conservative value rather than a more lenient value of 0.5 PPM (MG/L) preferred by some operators. The key is that regulators start enforcing regular testing for combined CHLORINE so that POOL operators work towards keeping levels low by responding to this action threshold.
Levels of chloramines and other volatile compounds in water can be minimized by reducing introduction of CONTAMINANTS that lead to their formation (e.g., urea, creatinine, amino acids and personal care products), as well as by use of a shock oxidizer (e.g., potassium monopersulfate) or supplemental water treatment. Effective filtration, water replacement, and improved BATHER hygiene (e.g., showering, not urinating in the POOL) can reduce CONTAMINANTS and chloramine formation.
Facility Operation & Maintenance ANNEX 235 has determined that manufacturers of "shock oxidizers" may advertise that their "shock oxidizer" products "remove," "reduce," or "eliminate" organic CONTAMINANTS  For more information, see: .

# Secondary Disinfection
SECONDARY DISINFECTION SYSTEMS such as ozone and ultraviolet light may effectively destroy inorganic chloramines. As this also has a public benefit and can assist in meeting the MAHC requirements for combined CHLORINE, it is strongly recommended that any installation utilizing UV or ozone as a SECONDARY DISINFECTION SYSTEM consider the positive impact the equipment may have on reducing combined CHLORINE levels in addition to achieving DISINFECTION goals.
To improve chloramine control strategies, future research should be aimed at:
Calcium Hardness Calcium hardness is the amount of dissolved calcium (plus some other minerals like magnesium) in the water. High calcium is not healthy for swimming since it can cause burning of the mucous membranes, as well as skin irritation on sensitive people. Calcium hardness of 200 -400 PPM (mg/L) is preferred for proper calcium carbonate saturation and for avoiding soft-water scale found in SPAS and hot tubs when other water parameters are near their nominal levels. For venues with water temperatures greater than 90 o F (32oC), the range should be 100 to 200 PPM.
Too much calcium causes cloudiness and scale formation. It also reduces the effectiveness of disinfectants. Too little calcium, especially when combined with low pH or low Total Alkalinity can also lead to "aggressive water," which can dissolved calcium carbonate from plaster, as well as metallic parts of the POOL (walls, floor, handrails, ladders, light fixtures, and equipment), and also cause discolored water or stains on the POOL walls and floor.
The maximum permissible concentration of 1000 PPM (mg/L) may not be appropriate for regions with particularly hard source water. In such regions local CODES should reflect the specialized practices needed for source waters containing more than 1000 PPM (mg/L) total hardness.
Facility Operation & Maintenance ANNEX 236 Minor deviations from the calcium hardness levels stated in the CODE do not in themselves present imminent health threats to the BATHERS. As such, minor deviations in hardness levels do not require the immediate closure of the facility. Rather, deviations from permissible hardness levels indicate poor management of the water balance and should indicate a need for a thorough inspection of the entire facility.
Algaecides In practice most algaecides are reasonably effective when applied according their US EPA accepted label directions and the application is coupled with frequent and thorough brushing.
CHLORINE and bromine can be registered and used as algaecides, but must be used in accordance with EPA label directions.
Bromine and bromamine have been demonstrated to be algaecidal 391 .

# Common Types
The two basic types of non-halogen algaecides are copper based algaecides and quaternary ammonia compounds (QACs), often referred to as "quats". Some algaecides contain a mixture of a quat and a copper compound.
Copper-based algaecides can be used to treat against all types of algae, but are especially effective against mustard and green types of algae. These will not cause foam to appear in a swimming POOL as is common with simple quaternary ammonia types of algaecides. There is however a problem with stains on the surface of the swimming POOL if the product is not used properly. Proper pH control is very important to minimize staining potential when using copper-containing algaecides.
The other most common types are quaternary ammonium. These algaecides will not stain a swimming POOL. There are two types of quats: simple and polymeric (more commonly called "polyquats"). Simple quats are mixtures of various alkyl dimethyl benzyl ammonium compounds (ADBACs) or didecyl dimethyl ammonium compounds (DDACs). There are numerous variations of these. The technical name for the active ingredient in polyquats is "Poly". Neither type of quat will cause staining. When overdosed, simple quats tend to cause foam, especially in POOLS with water features (e.g. fountains, waterfalls). Polyquats do not cause foaming, even when used repeatedly at the maximum label dose in POOLS with water features.

# EPA-Registered
In selecting a quat, it is vital that the product has been registered by the U.S. EPA for use in swimming POOLS. The vast majority, but not all, of the products on the market have current US EPA REGISTRATIONS. All products registered by the U.S. EPA will have a registration number on the label (usually it will state "EPA Reg. No." followed a series The U.S. EPA registration process for algaecides is substantially different than the registration process used for disinfectants. As part of the development of the product, the U.S. EPA requires companies to conduct efficacy studies on the product. The U.S. EPA does not consider algae in POOLS or SPAS to be pathogenic and thus not a direct threat to public health. Since algae are not a public health issue, the US EPA does not require companies to submit their efficacy package for an agency data review. Thus, in the registration process the U.S. EPA looks carefully at the toxicology of the product but not the efficacy. The state of California does require detailed efficacy studies prior to registration. Products sold in the state of California must have the state registration number on the label. Products registered in California but sold outside of the state usually, but are not required to, have the California registration number on the label. Any local agency concerned about the efficacy of a particular algaecide could request the producer supply the California registration number and then verify the status of the product with the California Department of Pesticide Regulation.

# Source (Fill) Water
Most public recreational water venues use the PUBLIC WATER SUPPLY as the fill water source. In instances where this is not possible, it is important that the fill water not be a potential source of illness to BATHERS. Since requirements governing water quality vary by jurisdiction, it is not possible to specify every test that might be required by a jurisdiction. Therefore, facilities need to insure that the fill water complies with the jurisdictional requirements. Examples of potential tests that a jurisdiction may require include, but are not limited to the following: bacteria, nitrates, nitrites, iron, manganese, sulfur, and turbidity. It is also recommended that this testing be conducted on an annual basis. It is also important to note that the salt required by saltwater chlorination systems will substantially increase the TDS level. Therefore, in saltwater AQUATIC VENUE, it is best to consider the TDS level after the required amount of salt has been added to a freshly filled AQUATIC VENUE as the baseline level. A small positive value is preferred over a negative value because a slight scale layer provides some protection, and is less harmful than corrosion, which causes permanent damage to mechanical and structural components. While it is always possible to lower the pH, it is not as simple with the total alkalinity or calcium hardness. Lowering the total alkalinity will usually lower the pH as well. Lowering the calcium hardness is not always possible, given the variation in hardness of the fill water. In situations where the calcium level is high, attention should be paid to lowering the pH and / or total alkalinity in order to improve the LSI.
It is not always possible to get the pH and total alkalinity within the proper range, due to the nature of the dissolved minerals. pH is the more important parameter, and should be maintained within the proper range.
If the AQUATIC VENUE is outdoors, and uses stabilized CHLORINE, in order to get a more accurate reading of the LSI, it is recommended that 30% of the cyanuric acid reading be deducted from the total alkalinity test result. However, there are maximum temperatures that can and do have an effect on the health of the PATRON using the facility. Water temperature between 83-86F (28-30C) is the most comfortable temperature for typical recreational water usage. Water temperature may need to be adjusted based upon specific uses of the facility.
The WHO recommends that water temperatures in hot tubs be kept below 104F (40C). High temperatures (above 104F or 40C) in SPAS or hot tubs can cause drowsiness, which may lead to unconsciousness and, consequently, drowning 393 . The Consumer Product Safety Commission has received reports of several deaths from extremely HOT WATER (approximately 109F or 43C) in hot tubs. In addition, high temperatures can lead to heat stroke and death 394 . Further examination of data on the health impact of high temperature water on pregnancy, particularly in the first trimester, is needed.
Minimum temperature requirements are not included in this CODE. Water that is too cold, simply will not be utilized for any extended period of time, and will not be used by individuals seeking a recreational water experience.
Even though minimum temperatures are not included in the CODE, it is important to remember that cold-water basins, such as plunge pools, can present health concerns due to water temperature extremes. These small, deep POOLS generally contain water at a temperature of 46-50F (7-10C) and are used in conjunction with saunas or steam baths. Adverse health outcomes that may result from the intense and sudden changes in temperature associated with the use of these POOLS include immediate impaired coordination, loss of control of breathing and, after some time when the core body temperature has fallen, slowed heartbeat, hypothermia, muscle cramps, and loss of consciousness. In general, exposure to temperature extremes should be avoided by pregnant women, users with medical problems, and young children. 395
Facility Operation & Maintenance ANNEX 244 response systems in healthy males at 104F (40C) 397,398 . However, there did appear to be increased risk of cardiac hypotension and fainting when users stood up that could result in slips or falls, the most common cause of SPA-related injury in the United States 399 . Several studies of sauna-related deaths in Scandinavia find a high percentage of alcohol use and that users were alone 400,401 . Signage to restrict alcohol use, not to use SPAS when alone, and to exercise caution and use handrails to exit is warranted.

# Pregnant Women
Maternal hyperthermia has been shown to be associated with birth defects 402 . Some studies have shown an increased risk of birth defects and miscarriages associated with hot tub or SPA use during early pregnancy 403 , 404 , 405 , 406 . Pregnant women, particularly during the first trimester, should consult their physician before using hot tubs or SPAS. If women in later pregnancy choose to use hot tubs or SPAS, they should keep exposure to a minimum, and ensure the temperature is at or below recommended STANDARDS. Signage should alert pregnant women about the potential risks of hot tub or SPA use and the need to consult with their physician before use. Further expert review of the data is warranted to see if the data support reducing the water temperature and, if so, what temperature should be adopted to proactively protect women of childbearing age who may not know if they are pregnant.

# Young Children
Few studies exist looking at the impact of high temperature on young children although older children do appear to be able to control their temperature as well as adults 407 but the high temperatures in saunas do put great demands on the circulatory system 408 . However, infants cannot control their body temperature as effectively as their older siblings and parents. This is because babies have a small body mass compared to body surface area. Being in water even a few degrees different from normal body temperature (98.6F/37C) can affect a baby's body temperature. Being in very warm or HOT WATER found in hot tubs/SPAS can cause hyperthermia, a dangerously high body temperature. Signage for SPAS and hot tubs should caution users about bringing infants and young children into SPAS or hot tubs, particularly for prolonged use.

# Facility
Operation & Maintenance ANNEX 245
Water Quality Chemical Testing Frequency

# Chemical Levels
When using colorimetric testing methods, combined CHLORINE testing consists of measuring free CHLORINE, measuring total CHLORINE, and subtracting the free CHLORINE from the total CHLORINE. When using titrimetric methods, it is easiest to perform a direct measure. The analyst should simply count each drop of titrant and multiply by the correct factor to attain the combined CHLORINE level.
A properly calibrated automatic chemical MONITORING system which maintains records and can be monitored remotely via a secure website could be acceptable for daily testing, if the system allows for the health department to have access to view a readonly log which monitors the chemistry at a facility.

# Water Clarity
Water clarity is a useful measure of general water quality. Visual observation of main drains is important for BATHER SAFETY to avoid drowning incidents and injury prevention (for BATHER visibility). For POOLS, the use of a Secchi disk is not recommended. If a marker tile of suction outlet is not available, an alternate such as a submersible manikin or shadow doll could be placed at the deepest point of the pool/attraction to check clarity.
For more information about the limitations of Secchi disks, see:
- NOAA

# Equipment Inspection and Maintenance
The absence of this required equipment can adversely affect the effectiveness of a rescue and the SAFETY of the lifeguard. It could also hinder the response from emergency services. For this reason, it is the responsibility of the owner/operator to make sure this equipment is in place prior to opening the AQUATIC FACILITY to the public.
The equipment should be working so it can be used when needed. The word "safe" makes sure the equipment is not modified to be in working condition but posing a risk to the user.
Safety Equipment Required at All Aquatic Facilities

# Emergency Communication Equipment

# Functioning Communication Equipment
As stated in the design section, emergency communication devices should be part of the design but also required to be present in the operation. The intent is that an emergency phone or communications system or device is immediately available to PATRONS from all AQUATIC VENUES within an AQUATIC FACILITY.
Some alternate communication systems might include a handset or intercom system to a location that is constantly manned whenever the AQUATIC VENUE is open for use (e.g. a front desk at a hotel, the check in desk at a fitness club, or other continuously manned location); a commercial emergency contact device that connects to a monitoring service, or directly to 911 dispatch; or devices that alert multiple staff on site when activated (e.g. pagers systems, cellular telephone systems and radio communication alert systems). For larger facilities, this could include internal communication processes such as radio use to a central phone to facilitate emergency communications to outside EMS in place of hard wired publicly accessible phones.

# First Aid Equipment

# Location for First Aid
This is stated in the design section but also stated in the MAHC operations section to require the operator to designate a first aid location for existing facilities. The supplies should be provided at locations where they can be quickly accessed by staff responding to emergencies.

# First Aid Supplies
The first aid supply list is based on the ANSI/ISEA Z308.1-2009 standard for a Workplace First Aid Basic Kit. The listed contents are based on the items needed, but the quantities are not specified to allow for flexibility based on the size of the AQUATIC FACILITY, the anticipated BATHER COUNT, anticipated number and types of injuries, and the number of first aid locations. Topical supplies such as antibiotic cream, burn gels, and antiseptics were removed because this poses a scope of practice issue for the level of training typical to lifeguarding.
The operator should provide enough supplies that the kit does not need continuous restocking. There should be enough supplies to last between first aid kit supply inspections, plus the time needed to obtain and replace the supplies. The contents should be inspected and resupplied often enough to maintain the supplies in good condition.
The supplies must be stored in such a manner as to protect them from moisture and extremes of heat and cold that will cause deterioration. Supplies must be periodically checked for expiration dates and replaced as needed.
Facility Operation & Maintenance ANNEX 248 A biohazard cleanup kit was included as lifeguards often deal with body fluids on surfaces such as vomit, feces, and blood. According to OSHA 410 , "Generally, lifeguards are considered to be emergency responders and, therefore, would be considered to have occupational exposure. Emergency response is generally the main responsibility of lifeguards, therefore, such duties could not be considered collateral. Although it is the employer's responsibility to determine which, if any, of the employees have occupational exposure, employers of lifeguards should examine all facets of the lifeguard's emergency response duties, not just "retrieval from deep water." As a result, lifeguards are covered under OSHA 29 CFR 1910.1030 Bloodborne Pathogens standard, which speaks to having contact with individuals that may be injured and bleeding. As a result, employers are required to offer all the protections of the Bloodborne Pathogens STANDARD. Management should also consider how bloodborne pathogen training is integrated with training for environmental and/or water-based clean-up of feces and other body fluids (See MAHC Section 6.5).
The MAHC chose to compile this list after reviewing the contents of several kits that were commonly available.  It is suggested that a kit be assembled, put in a container and sealed to assure the contents are still intact when needed. After use, a new kit is provided or the container is restocked and resealed.
In addition to the AQUATIC FACILITY kit, lifeguards should carry basic PPE for immediate use during initial exposure to feces, vomit, and small amounts of blood until the full kit arrives at the treatment scene.
Facility Operation & Maintenance ANNEX 252 Administration rules are implemented 412 . These protect against both UVA and UVB rays as long as re-application is conducted periodically. Because SPF ratings only measure UVB effectiveness there is a lot of variability in UVA protection in sunscreens. The CDC recommends a sunscreen with an SPF of at least 15 413 .
There are some questions about the health effects of some of the screening chemicals, but the benefits seem to outweigh the hazards. To minimize exposure to these chemicals, lifeguards should also wear protective clothing, hats, use sun-blocking umbrellas, or any other means to avoid exposure to UV light. Protection is also needed from reflected exposure. Light-skinned individuals can be particularly sensitive to both direct as well as indirect exposure to the sun's UV rays 414 . Employers should educate lifeguards about the risk and protection options but are exempted from requirements to pay for sunscreen as personal protective equipment according to OSHA 1910.132(h)(4)(iii) 415 .
Polarized Sunglasses Glare and reflected sunlight off the water surface can cause significant visibility problems for lifeguards and potentially impact job performance. Lifeguards working at outdoor AQUATIC VENUES are required to wear polarized eye wear to reduce the risk of glare causing reduced visibility. This polarized eyewear should also be a part of any sun exposure awareness training since it also potentially reduces the harmful short-and long-term effects of UV on eyes that include increased risk for cataracts and macular degeneration 416 417 , 418 , 419 , 420 , 421 , 422 . However, employers are exempted from requirements to pay for sunglasses as personal protective equipment according to OSHA 1910.132(h)(4)(iii) 423 .
Polarized eyewear can assist with glare indoors as well but should be tested so it does not impede visibility due to lower light levels.
Polarized 3-D glasses must not be used as they can be disorienting and can disrupt normal vision. Reaching Pole The pole is intended to reach out to a swimmer in distress and to allow them to grab hold of the pole. The pole should be submerged when introducing it to the swimmer to prevent injury. In some cases the "hook" can be used to encircle a non-responsive swimmer to draw them to the side. Use of the device involves reaching out to the swimmer and then pulling the pole straight back to the side, along with the swimmer. The pole cannot be swung around to the side as the strength required exceeds that of most people, and the pole is not that durable.
Since the pole is pulled back to the side, a telescoping pole is not appropriate as it can pull apart. Ideally the pole can reach to the middle of many smaller POOLS making the entire POOL reachable from the side with the pole.
The pole must be equipped with a "life-hook" or "shepherd's crook". For SAFETY, the hook must be a looped frame-type hook, not the single metal hook. The hook protects the swimmer from being injured by the pole, as well as allows a non-responsive swimmer to be pulled in. To prevent injury, use only the hook attachment bolts supplied by the manufacturer. This will prevent hooks and snags, caused by using the improper bolts, which can injure the swimmer.
CPR Posters CPR performed by bystanders has been shown to improve outcomes in drowning victims 425 . CPR started immediately on a drowning victim instead of waiting until emergency responders arrive will have a significant effect on the potential for brain damage in the victim. Posters of CPR explaining basic procedures can be reviewed in seconds and give the provider enough knowledge to assist the victim until emergency responders arrive.
Posters can educate PATRONS to recognize potential causes of, prevention, and spread of RWIs. PATRONS need to be educated to what RWIs are, how they are spread, and how they can be prevented.
Resources for RWI education can be found at . There are many resources for CPR posters that can be found online.
Imminent Hazard Sign A sign indicating reasons requiring closure especially at AQUATIC FACILITIES where a QUALIFIED OPERATOR or QUALIFIED LIFEGUARD is not present should be posted listing specific incidents which would require the AQUATIC FACILITY to immediately close. Examples of such incidents include fecal incidents, broken/missing drain grates, water clarity, water quality issues, and lightning. A contact number should be provided to notify the owner/operator of conditions considered an IMMINENT HEALTH HAZARD.
Facility Operation & Maintenance ANNEX 256 Oxidizers such as calcium hypochlorite, monopersulfate or bleach shall not be mixed with any other chemicals.
Safety Data Sheets A safety data sheet (SDS) is a form containing data, potential hazard information, and instructions for the safe use of a particular material or product. An important component of product stewardship and workplace SAFETY, it is intended to provide workers and emergency personnel with procedures for handling or working with that substance in a safe manner, and includes information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, impact on the environment, first aid, reactivity, STORAGE, disposal, protective equipment, and spill handling procedures. The exact format of an SDS can vary from source to source. It is important to use an SDS that is supplier-specific as a product using a generic name (e.g. oxidizer) can have a formulation and degree of hazard which varies between different manufacturers.

# Filed
SDSs should be filed anywhere chemicals are being used. An SDS for a substance is not primarily intended for use by the general consumer, focusing instead on the hazards of working with the material in an occupational setting.

# OSHA
In the U.S., OSHA requires that SDSs be available to employees for potentially harmful substances handled in the workplace under the Hazard Communication regulation. The SDS is also required to be made available to local fire departments and local and state emergency planning officials under Section 311 of the Emergency Planning and Community Right-to-Know Act.
Facility Operation & Maintenance ANNEX 259 Biofilms are a complex collection of microbes that attach to a wet surface and form a scum layer that harbors bacteria and other microbes that could cause illness. Once established, biofilms provide a home for a variety of microbes such as Pseudomonas and are hard to remove. Biofilm-associated bacteria are much more resistant to hypochlorous acid compared to free swimming microbes. Design options to reduce biofilm formation as well as sanitizing systems with effective validation, could be useful for reducing biofilm formation. 5.10.5 Provision of Suits, Towels, and Shared Equipment 5.10.5.1 Towels The drying temperature is more important than the wash temperature when destroying potential pathogens.
- See CDC recommendations for laundering entitled, "Environmental Cleaning & Disinfecting for MRSA" at: /.

# Shared Equipment Cleaned and Sanitized
Research has demonstrated that play features, mat materials, and other shared equipment found at AQUATIC FACILITIES and water parks can harbor bacteria, even while submerged in chlorinated water. Damp materials that were not submerged in water contained the highest populations of bacteria. Damp play features designed for infants and toddlers were found to be likely vehicles for transference of gastrointestinal bacteria. 429 Sanitization is defined as reducing the level of microbes that are considered safe by public health STANDARDS. This may be achieved through a variety of chemical or physical means including chemical treatment, cleaning, or drying.
Associations between swimming POOLS and disease outbreaks have been welldocumented in literature. Though an outbreak has never been connected to play features or the type of play feature material specifically, the possibility could exist due to biofilms found on these materials. Outbreaks may be more likely if the AQUATIC FACILITY is not maintained properly.
Biofilms are a complex collection of microbes that attach to a wet surface and form a scum layer that harbors bacteria and other microbes that could cause illness. Once established, biofilms provide a home for a variety of microbes such as Pseudomonas and are hard to remove. Biofilm-associated bacteria are much more resistant to hypochlorous acid compared to free swimming microbes. Design options to reduce biofilm formation as well as sanitizing systems with effective validation, could be useful for reducing biofilm formation.

# Facility Operation & Maintenance ANNEX 260

# Contact
Shared equipment that contact mucous, saliva, eyes, or ears require sanitizing to prevent transmission of potential disease causing pathogens.
Other Equipment Shared equipment which is hand held or used as a flotation device used in aquatic therapy or play have also been found to harbor potential harmful microorganisms, even while submerged in properly chlorinated water. Bacteria found in these environments are most likely from biofilms that have attached to these surfaces. Soaking in disinfectants may not be enough to penetrate the biofilm; so to control biofilm growth, it is recommended to physically remove the slimly film by scrubbing equipment on a routine basis. The array of organisms isolated from damp features suggests that features need to be cleaned, SANITIZED, and thoroughly dried on a routine basis using a combination of chemical and physical methods, preferably as recommended by the manufacturer 430 .

# Water Supply/ Wastewater
Policies & Management ANNEX 261

# Policies and Management
The MAHC has worked extensively with ICC and IAPMO to eliminate conflicts between the three codes. These discussions have resulted in changes in the MAHC and plans to change items in the other codes as they are brought up for revision. The MAHC is committed to resolving these conflicts now and in the future as these codes evolve.

# Lifeguard Training
This portion of the MAHC deals directly with providing QUALIFIED LIFEGUARDS in an AQUATIC FACILITY to first, reduce the risk that could lead to injury and, secondly, appropriately respond to incidents when they happen. The duties of an AQUATIC FACILITY lifeguard have been compared to a number of other occupations including comparing the role of the police officer to that of a lifeguard at a swimming POOL. 446 "The majority of the time, the task is very sedentary, sitting and watching. A quadriplegic could do it; until someone needs rescuing. Then the quadriplegic could not perform the required functions. It does not often happen to a lifeguard that someone needs rescuing, perhaps 0.1 percent of the time. But the ability to jump into the water and save the drowning victim is critical to the job. This is the reason why there has been someone sitting and watching for the other 99.9 percent of the time." Bonneau and Brown's 447 position is that, because the disabled lifeguard is unable to perform the critical and essential part of the job, he is incapable of doing the job of lifeguard. Even if he can do 99.9% of the job, he should not be employed as a lifeguard. The perception of the public is that all lifeguards can perform all that is critical and essential to their job set. Unfortunately, this has sometimes been proven to be false.

# Many
drowning deaths resulted from omissions of basic SAFETY precautions 448,449,450,451,452,453,454,455 . These include absent or inadequate POOL fencing, unattended young children at water sites, faulty POOL design resulting in victims becoming trapped below the surface of the water, poor POOL maintenance resulting in murky or cloudy water that obscured sight of submerged bodies, lifeguards being distracted by socializing with others and doing other chores such as manning admission booths and doing housekeeping chores while on lifeguard duty, and poorly trained lifeguards who did not recognize a person in trouble in the water or had not been properly trained in rescue and resuscitation techniques. In some cases, these are correctable issues that could prevent drowning deaths. We anticipate that if POOL and water SAFETY STANDARDS are strictly enforced, and as lifeguards continue to become better trained and adhere to important basic principles of surveillance, rescue, and resuscitation, the death rate in public AQUATIC FACILITIES should decline. The goal of this section is to give POOL owners and operators BEST PRACTICE guidelines for guarded and unguarded POOLS as tools to make AQUATIC FACILITIES safer for the general public.
Policies & Management ANNEX 270

# Lifeguard Qualifications
Every day, about ten people die from unintentional drowning 456 . Of these, two are children aged 14 or younger. Drowning is the fifth leading cause of unintentional injury death for people of all ages, and the second leading cause of unintentional injury death for children ages 1 to 14 years 457 . From 2005457 . From -2009, there were on average 3,533 fatal unintentional drowning (non-boating related) in the United States per year and more than one in five people who die from drowning are children 14 and younger 458 . More than 50% of drowning victims treated in emergency departments require hospitalization or transfer for higher levels of care (compared to a hospitalization rate of 6% for all unintentional injuries) 459,460 .
Nonfatal drowning can cause brain damage that may result in long-term disabilities including memory problems, learning disabilities, and permanent loss of basic functioning (e.g., permanent vegetative state). 461,462 Appropriately trained lifeguards are one way to reduce this risk at public AQUATIC VENUES.

# Course Content
This section defines a broad scope of lifeguard training which is further described in the section below. These topics are universally found in all currently recognized national lifeguard training programs.

# Hazard Identification and Injury Prevention
Lifeguards have an obligation to know and understand common hazards associated with AQUATIC VENUES, and how they may be mitigated or prevented. A vital component of this obligation is to provide PATRON surveillance, commonly referred to as scanning. In order to prevent injuries, a lifeguard must be taught how to recognize various swimmer conditions that need intervention such as "active," "passive", and "distressed", and to use scanning strategies and techniques to be able to see and identify the emergency. This instruction is incomplete without also teaching lifeguards how to identify factors and circumstances which cause victim recognition to become impeded such as overcrowding, cloudiness of the water, glare, or obstacles on the DECK or in the water such as slides, inner tubes, or structures.
Emergency Response Skill Set Lifeguards should have a clear understanding of the responsibilities and actions of not only the physical skills, but also the cognitive and decision making skills involved in an The ability to identify the lifeguard instructor allows for higher quality control by the training agency. It also aids in the prevention of fraudulent certifications.
Clearly stating the restrictions on water depth for which the lifeguard is qualified allows the employer and the AHJ to quickly ascertain the basic abilities of the lifeguard that were assessed during training.
Expired Certificate A 45-day grace period after certificate expiration, was added to accommodate the numerous lifeguards attending college. Consider a senior in high school who takes their course in April. Subsequently they are now in college and typically will not return from college until early May. A grace period of up to 45 days after certificate expiration allows renewal as opposed to completing a new training course, however the lifeguard is not permitted to lifeguard until renewal training is successfully completed.

# Challenge Program
A challenge course is one in which a lifeguard demonstrates the essential skills and knowledge required by the training agency. This demonstration is performed without prior review and/or instruction at the time of the challenge by the instructor. Prompting or coaching is not performed unless necessary to adequately assess skill level (i.e. "the victim is not breathing").

# Certificate Renewal
A renewal course can also be described as a recertification course. Review / Recertification courses are abbreviated courses designed to be used to assess that a currently certified lifeguard has the necessary skills and knowledge to perform essential competencies required of the training agency.
Although some skills and information are universal to all lifeguard training agencies, there are differences in physical skills. A lifeguard attempting to recertify through a different agency is not likely to have ample time to master these different physical skills. This should not be confused with "crossover" type courses which are specifically designed to teach a currently certified lifeguard the different skills and information from another training agency.

# Certificate Suspension and Revocation
The AHJ is expected to contact course providers with questions about the validity of any certificate or with questions about a lifeguard's performance. In turn, course providers are expected to readily provide verification of certificates and suspensions and revocations of certificates and to notify the AHJ of actions taken in response to its reported concerns.
Policies & Management ANNEX 277 The Food Protection Managers Certification Program Standards, Section 7.5 reflect the following, "A certification organization shall have formal certification policies and operating procedures including the sanction or revocation of the certificate. These procedures shall incorporate due process."
Aquatic Supervisor Training 6.2.2.1 Lifeguard Supervisor Candidate Prerequisites The MAHC agreed that 18 years and above was an adequate age level to consider a person as being mature enough for this position but there are many examples of good supervising at a younger age. This was a starting point but many other factors with regard to experience, training, management skills, and others were equally or more important. For this reason, the minimum age for a LIFEGUARD SUPERVISOR is not specified and is limited to meeting the minimum age requirement of a lifeguard and having the experience that equates to one season of lifeguarding (3 months).
The requirement of the ability to communicate in English is related to the ability to effectively activate the EMERGENCY ACTION PLAN and deliver instructions as well as interface with emergency services. This is similar to the requirement on airlines for emergency exit row seating.

# Lifeguard Supervisor Training Elements
As of the writing of the MAHC, lifeguard supervision and management training courses are limited. In the development of the MAHC, the MAHC recognizes the importance of ongoing AQUATIC VENUE supervision with adequate training in injury prevention and response. What constitutes supervisor and management training was heavily discussed. The concept of "supervisor training" lends itself to far more than simply MONITORING lifeguards and performing essential functions of the lifeguard as needed. Required skills for the supervisor include staff management skills, emergency response, decision making, knowledge of aquatic industry STANDARDS, etc. This list is obviously not comprehensive. This leads to a main concern in the development of a LIFEGUARD SUPERVISOR course which is course content and length. Training agencies are encouraged to develop a system of training LIFEGUARD SUPERVISORS that incorporates the critical components of supervising lifeguards and responding to incidents in an AQUATIC FACILITY as these items directly affect BATHER SAFETY. This may include a variety of levels that address this information in various ways and as appropriate for the intended audience of each level course. The skills and knowledge found in this section are considered by the MAHC to be essential to any LIFEGUARD SUPERVISOR training course, regardless of intended depth of scope. The course outline and requirements mirror that of the lifeguard training course requirements.
LIFEGUARD SUPERVISORS need to have knowledge beyond that of the lifeguard training program. The LIFEGUARD SUPERVISOR is responsible for keeping the lifeguard accountable for their own performance and as such should MONITOR scanning and vigilance within the zone of PATRON responsibility. As situations occur, the LIFEGUARD
Policies & Management ANNEX 278 SUPERVISOR will also need to react to reduce risk while they understand the legal responsibilities of the job.
Due to the nature of the content in the LIFEGUARD SUPERVISOR training, it is possible for this content to be delivered in person or online utilizing various methods such as video and interactive media to establish competency.
Lifeguard Supervisor Training Delivery

# Standardized and Comprehensive
The term standardized is meant to convey that the materials are standard, in writing, and are consistent from one course to another when delivered. This would require that providers, whether an agency or an AQUATIC FACILITY, have a standard method to deliver the course.
Sufficient Time A course length is not specified as each training agency may have their own program that incorporates all the requirements but may also add other topics. The method used to effectively instruct is up to the training agency. Some may take more time than others. The MAHC is not prescriptive on timing but rather on a course timeline that allows for covering the course content.
Lifeguard Supervisor Course Instructor Certification This is the same rationale as for lifeguard training. This allows for an AQUATIC FACILITY to have its own internal LIFEGUARD SUPERVISOR training course or use a training course through a training agency.

# Minimum Prerequisites
This allows for experienced supervisors that may not have the physical skills to do the current lifeguard course as defined by the MAHC but still require the knowledge of lifeguarding.
The LIFEGUARD SUPERVISOR instructor training course utilizes the same rationale as the lifeguard Instructor training course.

# Quality Control
This is the same rationale as for lifeguard training.
Competency and Certification
Lifeguard Supervisor Proficiency LIFEGUARD SUPERVISOR testing could be in many forms from situational-based observations, shadowing with an experienced supervisor, or testing technical knowledge. Some LIFEGUARD SUPERVISOR skill proficiencies can be subjective so the methodology for testing is not prescribed in the code. There are many conditions that result in higher risk for BATHERS in an AQUATIC FACILITY and/or higher risk for any persons attempting to assist a BATHER in distress. These conditions each have their own distinct features that the MAHC felt a QUALIFIED LIFEGUARD presence would reduce those risks. These requirements only apply to AQUATIC VENUES with standing water.
1) Deeper than 5 Feet: The 50th percentile female adult is at least 63.8 inches (162 cm) tall. The rationale is that the average adult BATHER'S head would be above the static water line and they could use the AQUATIC VENUE without difficulty. If a BATHER were in distress, another adult BATHER would be able to assist with equipment or without equipment. Under these conditions, assuming adults are present, the likelihood of providing assistance by untrained persons is high compared to water depths above 5 feet (1.5 m).
The MAHC thinks it necessary to begin working to prevent some of the deaths caused by greater water depth combined with the lack of lifeguard supervision.
The hardship this could cause unguarded AQUATIC FACILITIES is recognized. As a result, the MAHC requirements still allow for existing AQUATIC FACILITIES to be unguarded if they follow the requirements outlined in the MAHC, such as posting required signage. However, new construction of unguarded AQUATIC VENUES will require them to be less than 5 feet (1.5 m) deep.
2) Age 14 or Younger: Many STANDARDS recognize that a person who is under the age of 14 is considered to be a child and that their ability to make decisions, especially when complying with rules, require adult supervision 467 . Because the AQUATIC VENUE presents the risk of drowning at any depth and despite rules being posted, adult supervision is required for compliance with those rules.
The 50th percentile female at age 14 is 63.4 inches (161.0 cm) tall while the 50th percentile female at age 13 is less than 62.1 inches (157.7 cm) tall. This is a critical time frame in which the 1+ inches (3.3 cm)  The phrase "allows for unsupervised children" implies that an AQUATIC FACILITY that does not allow unsupervised children would not need a QUALIFIED LIFEGUARD. The intent for supervision of children is that parents/guardians or other similar adults responsible for the children are present at poolside with the children and the children are in sight. The critical component is how this is enforced. In some cases, the facility may have a sign posted that persons under the age of 14 are not allowed, such as a hotel POOL. In these cases, mechanisms should be in place for MONITORING and enforcing the rule understanding that by posting a sign, it is the responsibility of the adult supervising these persons under 14 to also comply with the rule.
3) Dedicated Surveillance: The responsibilities of a QUALIFIED LIFEGUARD are different from the responsibilities of the chaperone of a youth group. The MONITORING of children in these environments is often more than six children to every chaperone. These responsibilities must be separated by having the presence of a QUALIFIED LIFEGUARD that is not distracted by the activities of the group and is focused on their zone of PATRON surveillance.
The chaperone, even if trained as a lifeguard, cannot manage both PATRON surveillance and the activities of individual children. If the chaperone is not trained as a lifeguard, it puts them at risk if a rescue is required.
4) Group Practice or Instruction: Competitive swimming, sports, lifeguard training, exercise programs, and group swimming lessons all include multiple persons being instructed by one or more persons for a distinctly different objective. The primary focus is on the activity and not on PATRON surveillance. Similar to the rationale for youth groups, there is a need to separate the responsibility of the coach/instructor from that of providing dedicated PATRON surveillance.
Group swim lessons are an obvious reason to have a QUALIFIED LIFEGUARD as participants are not proficient at swimming, thus at higher risk for drowning.
Lifeguard training, sports, exercise programs, and competitive swimming involve exertion and could result in a BATHER in distress. If the instructor is focused on an individual, the risk of a different person drowning unnoticed is higher than if a QUALIFIED LIFEGUARD was assigned just to PATRON surveillance. Waterslide LANDING POOLS have an induced current from the lift pump providing water as lubrication on the slide. This is not to be confused with POOL SLIDES that are on a POOL DECK and do not have water flowing down them. Some smaller slides have a small amount of water on them to lubricate the surface but generally do not have a dedicated POOL to "catch" or "land" riders and do not generate a significant current.
INTERACTIVE WATER PLAY AQUATIC VENUES that do not include standing water are not included in this line item as they have an induced water movement but do not have standing water. There is no QUALIFIED LIFEGUARD requirement for an AQUATIC VENUE with no standing water.

# 7) Starting Platforms and Diving Boards:
The risk of spinal injuries increases with activities involving head first entries from starting platforms and diving boards. As such, the need for QUALIFIED LIFEGUARDS to monitor behaviors and control the use of starting platforms and diving boards is important.

# Safety Plan
The MAHC agreed that there needs to be a SAFETY PLAN that is specific to the AQUATIC FACILITY. Training agencies, ANSI/APSP-1 and -9 STANDARDS for public swimming POOLS and aquatic recreation facilities all speak to having plans written, rehearsed, and reviewed. The MAHC agreed that there are other types of plans that detail processes that directly affect PATRON SAFETY. In the code, the SAFETY PLAN is outlined to contain several PATRON-SAFETY components. The SAFETY PLAN is written dependent on whether or not QUALIFIED LIFEGUARDS are present.
Note that the SAFETY PLAN components are different for guarded and unguarded aquatic facilities.
The AQUATIC FACILITY staffing plan is meant to identify positions in the AQUATIC FACILITY that address specific risks as well as support staff that would be present to assist in cases of emergency or provide support by MONITORING performance of QUALIFIED LIFEGUARDS (for AQUATIC FACILITIES requiring them). In unguarded AQUATIC FACILITIES, this plan would include other staff in the STAFFING PLAN. Training agencies, ANSI standards for public swimming POOLS, and AQUATIC FACILITIES all speak to having plans written, rehearsed, and reviewed for emergency action.
Policies & Management ANNEX 282 Pre-employment testing as well as scheduled training is needed to verify that staff members are qualified for the environment. The MAHC agreed that ongoing in-service training programs for lifeguards, attendants, QUALIFIED OPERATORS, and other aquatic personnel should be required. To address this, the definition for QUALIFIED LIFEGUARD requires ongoing in-service training. Such programs should include drills aimed at raising the awareness of AQUATIC FACILITY surveillance, victim recognition, emergency response, CPR/water drills, and simulations incorporating daily challenges. In addition, in-service training needs to be documented.
Code Compliance Staff Plan In consideration of the requirements of the code as it relates to staff, the MAHC recognizes the need for identifying an individual or individuals to be responsible for compliance with the code and the general operation of the AQUATIC FACILITY. For this reason, certain functions are identified and the AQUATIC FACILITY should designate persons to be responsible for each function even if multiple functions are accomplished by a single person. The AQUATIC FACILITY staffing plan is meant to identify risks and create accountability for the prevention and/or mitigation of such risks by identifying person(s) responsible for each.

# Risk Management Responsibility
It is important to not only address identified risks but to designate persons who shall be responsible for conducting periodic safety inspections to be proactive about finding and mitigating risk as well as making decisions on closure for imminent hazards. Determining who is responsible for deciding on closure of the AQUATIC FACILITY is important as it empowers the designated person but also creates a clear point-person for staff to go to for making this decision. The AHJ may be conducting periodic reviews and may have recommendations or need additional information. It would be beneficial to identify the individual or position responsible for interfacing with the AHJ to most effectively address changes or to provide background information. This makes it clear to stakeholders where to direct information or requests.

# Maintenance and Repair of Risks
Once risks are identified, it is critical to determine who is responsible for mitigating those risks. In some cases, it may be a facility maintenance person responsible for conducting repairs, but ultimately it is the responsibility of management to make sure these risks are addressed. Failure to maintain water and air quality can result in illness and it is the responsibility of the AQUATIC FACILITY to maintain proper air and water quality. In some cases, a maintenance team manages these systems and in some cases it may be a third party contractor or the QUALIFIED LIFEGUARD staff. Nonetheless it is important to determine who is responsible for these systems to minimize the risk to batherS.

# Enforcing Rules and Responding to Emergencies
It is important to identify who is responsible for rule enforcement. One may assume the QUALIFIED LIFEGUARD is the person responsible for rule enforcement, but by identifying the function here, it will make it clear that their primary role is in preventing injury. QUALIFIED LIFEGUARDS will generally be the first responder to an incident but other 6.0
Policies & Management ANNEX 283 support staff may participate in the EMERGENCY ACTION PLAN, whether QUALIFIED LIFEGUARDS are present or not. Identifying QUALIFIED LIFEGUARDS, LIFEGUARD SUPERVISORS, medical specialists, and management are critical pieces of an emergency action plan and should be identified as a part of the staffing plan in any SAFETY PLAN.

# Supervising Staff
It is important to have a person designated as the person responsible for the critical safety functions of an AQUATIC FACILITY. Although each QUALIFIED LIFEGUARD is accountable for their zone, the LIFEGUARD SUPERVISOR makes sure each individual is doing what is expected and is present for responding to emergencies and taking the lead in making decisions about imminent hazards. Accountability for rotations and breaks lies with the LIFEGUARD SUPERVISOR and should be clearly identified in the SAFETY PLAN to show the ability to comply with the CODE.

# Training
Qualified lifeguards who cannot demonstrate proficiency in their lifeguarding skills may be a danger to bathers and to themselves. Serious deficiencies that are not immediately corrected may cause the serious injury or death of a bather, the QUALIFIED LIFEGUARD, or other staff member. For this reason, it is important to identify who is responsible for conducting pre-service evaluations and in-service training. In both cases, it may be someone specifically trained in evaluating skills or trained in training others.

# Zone of Patron Surveillance
The zones of PATRON surveillance are identified in the SAFETY PLAN so that all stakeholders are aware of the zones, how many QUALIFIED LIFEGUARDS are required to effectively cover all parts of the AQUATIC VENUE(S), and show that each zone can be effectively monitored by a QUALIFIED LIFEGUARD in accordance with the code.
The MAHC agrees that having identified zones of PATRON surveillance was one of the most needed components for all AQUATIC VENUES. QUALIFIED LIFEGUARDS should be able to determine their area of responsibility and be able to focus on that area. With the proper coverage, all areas of the AQUATIC VENUE needing to be covered would be assigned. The MAHC thought that one of the challenges in AQUATIC VENUE management is to ensure that QUALIFIED LIFEGUARDS understand the exact scope of their zone of PATRON surveillance. Training agencies and the ANSI STANDARDS for AQUATIC FACILITIES speak to "lifeguards understanding their responsibilities to their assigned stations." This would include understanding what type of position (e.g., elevated, roaming) the QUALIFIED LIFEGUARD should be in for the most effective PATRON surveillance.
Both the ANSI/APSP-1 Public Swimming Pools and ANSI/APSP-9 standards state that the lifeguard "shall be positioned and provided equipment in order to reach the victim within 20 seconds of identification of a trauma or incident (e.g., response time)." Note that this time (20 seconds) addresses the time the rescuer must reach the furthest extent of the zone, which would include addressing size and shape of each zone, among other factors. It does not include the "recognition phase" in this time.
Policies & Management ANNEX 284 For the purposes of maintaining effective surveillance of a zone of PATRON responsibility, the zone is generally set up based on the location of the QUALIFIED LIFEGUARD and their ability to see the entire zone. In some cases, it requires the QUALIFIED LIFEGUARD roam to see the entire zone and in some cases the QUALIFIED LIFEGUARD must be elevated to see the whole zone. For this reason, the SAFETY PLAN must stipulate by what method the QUALIFIED LIFEGUARD can see the whole zone.
Additional responsibilities may include MONITORING of adjacent DECKS or MONITORING activities on a structure such as a WATERSLIDE, play element, or other AQUATIC FEATURE. As the aquatics industry has added other AQUATIC FEATURES to traditional AQUATIC VENUES, it is important to identify these additional responsibilities that may not be apparent if the zone were strictly a flat-water POOL.
An AQUATIC FACILITY may have more than one AQUATIC VENUE and for each AQUATIC VENUE, may have multiple zones of PATRON responsibility. These zones may overlap in some areas and it is important to show there are not unassigned areas. The MAHC does not speak to a time standard for identification of an incident versus the response time, as there are too many variables in the circumstances leading to an incident.

# Rotation Procedures
Studies have documented the effect of critical and non-critical signals on maintaining vigilance in tasks; these may be useful in understanding lifeguarding duties. Jerison and Pickett demonstrated that a high number of critical signals could be processed by the lifeguard for up to 60 minutes with tolerable effects on vigilance. 469 However, the study found that low numbers of critical signals indicated that detrimental effects on vigilance occurred after only 20 minutes. This study also referenced the Mackworth Clock Test, commissioned in 1950 by the British Royal Navy, which found that optimal vigilance cannot be maintained for more than 30 minutes. 470 Researcher N.H. Mackworth developed the visual sensitivity loss model. Using classic clock-task experiments, signal detection performance often declined during the first half hour of the watch. Later experiments found five-to 10-minute breaks reset the vigilance level to its original point. 471 The SAFETY PLAN should specify how breaks or changes in duties will be instituted into the rotation plan without reducing the number of QUALIFIED LIFEGUARDS on PATRON surveillance.
For single QUALIFIED LIFEGUARD AQUATIC FACILITIES, the plan needs to address procedures for keeping PATRONS out of the water while the QUALIFIED LIFEGUARD is on break or performing other alternation of task activities. Other AQUATIC FACILITY staff may need to be at poolside to ensure that PATRONS stay out of the water, unless all PATRONS leave the AQUATIC VENUE and it is appropriately secured against entry. The "off-duty"
Policies & Management ANNEX 285 QUALIFIED LIFEGUARD cannot be responsible for this activity as it does not meet the intent, which is to accomplish a reset of the vigilance level.
Having a sound lifeguard rotation plan and procedures is crucial to the ability of the QUALIFIED LIFEGUARDS to be effective in PATRON surveillance. During the rotation of QUALIFIED LIFEGUARDS there can potentially be a lapse of PATRON surveillance if not done correctly. Because of this, the rotation system must be practiced and evaluated as to eliminate or minimize the lapse of PATRON surveillance time.
Heat, humidity, and high BATHER COUNTS are stresses for QUALIFIED LIFEGUARDS, which may warrant more frequent breaks. Note that DECK areas are part of the zone of PATRON surveillance for some lifeguard stations to prevent incidents from occurring (i.e., stop running on deck, stop diving from deck to shallow water, and otherwise enforcing rules).

# Emergency Action Plan
The MAHC agreed that there needs to be an emergency closure policy that is retained and available for review by the AHJ.
Training agencies educate lifeguards to expect a written EMERGENCY ACTION PLAN created by the AQUATIC FACILITY where they will work that addresses the reasonably foreseeable emergencies that could occur.
There is a need to identify how emergencies are communicated within the AQUATIC FACILITY and external to the AQUATIC FACILITY. The types of emergencies that could occur in AQUATIC FACILITIES include but are not limited to: chemical spills, submersion events/drowning, fire, violent acts, lost children, contamination (fecal incidents and water clarity), and inclement weather.
AQUATIC FACILITY staff will likely be the persons to observe any imminent hazards and should be empowered to close POOLS or other areas of the AQUATIC FACILITY should those hazards be present. In particular, fecal incidents, water clarity, and inclement weather may be encountered more often and the AQUATIC FACILITY staff should know procedures for dealing with those imminent hazards and their authority to close the AQUATIC FACILITY.

# Coordination of Response
The EMERGENCY ACTION PLAN identifies the individuals available and expected to respond. The goal of an EAP for a life-threatening emergency should be to activate EMS and provide for other individuals to assist the QUALIFIED LIFEGUARD with the actions identified in the EAP (such as CPR if needed) as soon as possible. Performing effective compressions is difficult to maintain for more than a few minutes, and the presence of at least one person to take over compressions creates a cycle of rest.
In AQUATIC FACILITIES where there are multiple QUALIFIED LIFEGUARDS and/or other staff persons such as desk or maintenance personnel who are always closely available when the AQUATIC FACILITY is open, it is feasible for many persons who are trained in 6.0
Policies & Management ANNEX 286 CPR/AED and first aid to respond within three minutes. Having a person who is CPR trained who can respond within minutes greatly improves survivability. 472 At an AQUATIC FACILITY with a single QUALIFIED LIFEGUARD, the SAFETY PLAN should identify the options for obtaining assistance, which is likely to include use of bystanders. If bystanders are part of the EAP, pre-service and in-service training should include how to direct bystanders in an emergency.
Pre-Service Requirements

# Safety Team EAP Training
The MAHC agreed that there needs to be a SAFETY PLAN specific to each AQUATIC VENUE. Training agencies, ANSI standards for public swimming POOLS, and AQUATIC FACILITIES all speak to having plans written, rehearsed, and reviewed for emergency action.
It is imperative that EMERGENCY ACTION PLAN training take place before the staff begins their work as an emergency can happen at any time.
Providing a copy or posting a copy for staff ensures staff has access to the information at any time.

# Safety Team Skills Proficiency
Responding to emergencies may require more specific skills and physical abilities, which once learned, must be maintained as emergencies can occur at any time. This demonstration of skill and/or knowledge verifies the staff person is ready to fulfill their role.

# Qualified Lifeguard Emergency Action Plan Training
The QUALIFIED OPERATOR is required to prepare the SAFETY PLAN as a set of policies for the AQUATIC FACILITY. It is imperative that the employees be aware of their responsibilities and have access to the information at all times the AQUATIC FACILITY is open, so they may refresh their memory or seek further information. Training during preservice will allow the QUALIFIED LIFEGUARD to become trained in the SAFETY PLAN of the AQUATIC FACILITY.
Qualified Lifeguard Skills Proficiency It is imperative that all lifeguards hired are currently able to perform effectively in the workplace. AQUATIC FACILITIES need to assess the lifeguard's ability to perform the job skills necessary to be a QUALIFIED LIFEGUARD at the AQUATIC FACILITY, including at any AQUATIC VENUES within the AQUATIC FACILITY where the lifeguard may be assigned, before allowing the lifeguard to be on duty.
Policies & Management ANNEX 288 6. 3.3.4.3 In-Service Training Plan Requiring QUALIFIED LIFEGUARDS to have the ability to respond to a victim and complete a rescue is critical. To not specify this requirement would allow a QUALIFIED LIFEGUARD to demonstrate the individual skills but not necessarily have the ability to do all the skills in consecutive order to complete the whole rescue.
Physical fitness is a critical part of performance when conducting a rescue. QUALIFIED LIFEGUARDS who are newly certified must maintain their physical fitness and skill proficiency throughout the term of their certificate as those skills can be called upon at any time. The required level of physical fitness can be determined by several means.
Schultz and colleagues showed that in order to do CPR at 80 compressions a minute (training now requires 100 compressions a minute) over a 10 minute period of time, the METS (metabolic equivalents) required to perform this task was 4.6  0.7 475 . One would expect this number to increase using the current protocol for CPR. The following logic and calculations was developed by Dr. Timothy Lightfoot 476 using METS values for a variety of activities that lifeguards might be expected to perform. 477,478,479 If someone swims 500 yards (457 m) in 10 minutes, they exert 8 METs/min (so, almost double the CPR cost discussed above); Similar levels of exertion are given by:
- Running at 5 mph on a level grade (running one mile in 12 min or 0.8 mile in 10 minutes)  Riding a bicycle at 14 mph on level grade (riding 2.3 miles in 10 minutes)
If the metabolic cost of doing CPR is about 4.75 METS, then lifeguards that are able to do the above tasks, should be able to do CPR almost indefinitely BECAUSE (and this is important), the metabolic cost of doing CPR is only 60% of the cost of the above exercise. Importantly, this means that when doing CPR, the metabolic cost is not so intense that they will be doing effort that will increase the amount of lactate in their blood (i.e. they won't go above lactate threshold) and if they stay below lactate threshold (60 65% max intensity) they should be able to do CPR a long time.
The United States national average response time for a BLS ambulance is 10 minutes. Paramedics are 12-15 minutes. For this reason, QUALIFIED LIFEGUARDS should be fit enough to do the rescue and do CPR for at least this for this time frame.
Policies & Management ANNEX 291 someone should be responsible for maintaining equipment and knowing when an AQUATIC FACILITY should close and how to mitigate hazards. This level of skill is different from that of the QUALIFIED LIFEGUARD, and each of these skills is important to have onsite anytime the AQUATIC FACILITY is open.
The MAHC considered requiring a LIFEGUARD SUPERVISOR for all AQUATIC FACILITIES; but for a single guard facility, there is no requirement, as a QUALIFIED LIFEGUARD doubling as a supervisor would be a redundancy. The SAFETY PLAN should address the means of providing oversight and direction to QUALIFIED LIFEGUARDS at single guard facilities.
Designated Supervisor For any AQUATIC FACILITY, someone must be designated to make decisions and provide oversight of expected performance. When an AQUATIC FACILITY is required to have two or more QUALIFIED LIFEGUARDS, one of the QUALIFIED LIFEGUARDS may be designated as the LIFEGUARD SUPERVISOR as long as they comply with the training requirements. The QUALIFIED LIFEGUARD cannot fulfill LIFEGUARD SUPERVISOR duties while on scanning duty. For small AQUATIC VENUES, the MAHC was sensitive to requiring an additional person simply to be the LIFEGUARD SUPERVISOR. In this scenario, one of the QUALIFIED LIFEGUARDS is designated as the LIFEGUARD SUPERVISOR to make decisions when appropriate.
Emergency Response and Communications Plans

# Emergency Response and Communication Plan
Chemical STORAGE and EAP/evacuation info also must be filed with local fire/hazmat agency according to quantities and chemical types stored.
Training Documentation It is recommended that EAP Drills are conducted with the staff on a quarterly basis as specified by the American Heart Association; however each operation is unique. Some operations may only be open during specific seasons, etc.
Communication Plan Remote Monitoring Systems Remote MONITORING systems may be used as an additional tool to improve health and SAFETY but are not to replace or substitute for aquatics staff or their duties.
Lifeguard-Based A remote SAFETY MONITORING system is an added value but should not be a substitute for a having a lifeguard present when conditions deem that a lifeguard is necessary.
The following excerpts from YMCA guidance provide an overview and discussion of lifeguard-based remote SAFETY MONITORING systems: Employee Illness and Injury Policy Open wounds may become entry points for pathogens and are the greatest risk to the wounded person. Water-related work could be allowed with physician approval or if the wound is covered with an occlusive, waterproof bandage.

# Facility Management
Facility management is critical in preventing illness and injury as summarized in this section. The Centers for Disease Control and Prevention (CDC) identifies the most frequently reported contributing factors to the spread of recreational water illnesses, in particular gastroenteritis. Another report identified the most frequently reported type of recreational water illness (RWI) outbreak as gastroenteritis, the incidence of which is increasing. 482 Prevention of RWIs at treated venues requires POOL operators to:  Maintain appropriate disinfectant and pH levels to maximize disinfectant effectiveness, and  Ensure optimal water circulation and filtration.
A study of POOL inspection data underscored the need for improved maintenance. 483 A total of 13,532 (12.1%) of 111,487 inspections identified serious violations that threatened the public's health and resulted in immediate POOL closure. Of 120,975 inspections,12,917 (10.7%) identified disinfectant level violations; of 113,597 inspections, 10,148 (8.9%) identified pH level violations. Other water chemistry violations were documented during 12,328 (12.5%) of 98,907 inspections, with the number identified per inspection ranging from zero to four. Circulation and filtration violations were documented during 35,327 (35.9%) of 98,361 inspections, with the number identified per inspection ranging from zero to nine. The following violations also were identified: improperly maintained POOL log (12,656  of 115,874 inspections), unapproved water test kit used (2,995  of 90,088 inspections), valid POOL license not provided and/or posted (741  of 28,007 inspections), and operator training documentation not provided and/or posted (1,542  of 8,439 inspections).
Of the 121,020 inspection records, 59,890 (49.5%) included POOL setting data. Among venues with known POOL settings, child-care POOL inspections had the highest percentage of immediate closures (17.2%), followed by hotel/motel and apartment/condominium POOL inspections (15.3% and 12.4% respectively).
- See Table 1: #tab1 Apartment/condominium and hotel/motel POOL inspections had the highest percentage of disinfectant level violations (13.1% and 12.8%, respectively). Child-care and apartment/condominium POOL inspections had the highest percentage of pH level 6.0
Policies & Management ANNEX 294 violations (11.8% and 10.0%, respectively). Approximately 35% of inspections of apartment/condominium POOLS, hotel/motel POOLS, and water parks identified circulation and filtration violations.
Of the 121,020 inspection records, 113,632 (93.9%) included POOL type data. Interactive fountain inspections had the highest percentage of immediate closures (17.0%). Kiddie/WADING POOL inspections had the highest percentage of disinfectant level violations (13.5%), followed by interactive fountain inspections (12.6%). THERAPY POOL inspections had the lowest percentage of disinfectant and pH level violations but the highest percentage of other water chemistry violations (43.9%). Interactive fountain inspections identified the lowest percentage of circulation and filtration violations (12.8%).
Drowning and falling, diving, chemical use, and suction injuries continue to be major public health injuries associated with AQUATIC VENUES. Drowning is a leading cause of injury death for young children ages 1 to 4, and the fifth leading cause of unintentional injury death for people of all ages. 484  For 2007-2008, 32 POOL chemical-associated health events that occurred in a public or residential setting were reported to CDC by Maryland and Michigan. These events resulted in 48 cases of illness or injury; 26 (81.3%) events could be attributed at least partially to chemical handling errors (e.g., mixing incompatible chemicals). ATSDR's Hazardous Substance Emergency Events Surveillance System received 92 reports of hazardous substance events that occurred at AQUATIC FACILITIES. More than half of these events (55 ) involved injured persons; the most frequently reported primary contributing factor was human error. Estimates based on CPSC's National Electronic Injury Surveillance System (NEISS) data indicate that 4,574 (95% confidence interval : 2,446) emergency department (ED) visits attributable to POOL chemicalassociated injuries occurred in 2008; the most frequent diagnosis was poisoning (1,984]). 486 The information identified in this report, along with existing recreational water injury data and first hand inspector experience, drove the development of the critical risk factors for recreational water injury and illness at treated AQUATIC VENUES. The eight broad critical risk factors for recreational water illness and injury are: violations must be corrected at the time of inspection or the POOL must be closed until the violations are corrected. Whenever a POOL is closed due to a public health violation, signage must be posted stating that the facility is closed due to an IMMINENT HEALTH HAZARD. Before removing the closure sign and reopening in the feature, a follow-up inspection or other evidence of correction of the violations is required to ascertain correction and re-open the POOL.
The factors being considered IMMINENT HEALTH HAZARDS cover known risk areas:  Low or absent disinfectant levels lead to reduced inactivation of pathogens and these conditions have been associated with infectious disease outbreaks.  Low pH has been associated with loss of dental enamel. Dental erosion begins to occur below pH 6.0 and rapidly accelerates as the pH drops. 504,505,506 High pH reduces the efficacy of CHLORINE-based DISINFECTION by reducing the amount of molecular hypochlorous acid (HOCl), the active form that is available for DISINFECTION. At pH 7.0, about 70% of the hypochlorous acid is molecular, at pH 7.5 about 50% is molecular, at pH 8.0 about 20% is molecular, and at pH 8.5 only 10% is molecular. As a result, the MAHC decided to set upper and lower limits for pH as an IMMINENT HEALTH HAZARD.  Injuries/deaths occur to persons using equipment such as vacuums and reach poles at swimming POOLS when this equipment contacts overhead wires which are too close to the POOL.  Clearance in any direction from the water, edge of POOL, etc. is to protect people using rescue and service equipment at POOLS, which are typically aluminum.  Clearance in any direction to the diving platform, tower, waterslide or other fixed POOL related structure is to protect a swimmer using these items.  Follow-up procedure for observance of electrical lines within 20 feet (6.1 m) of a swimming POOL during an inspection: o Determine whether the electrical lines are owned by the utility company or by the owner/operator of the swimming POOL/property. o If they are owned by the utility company, the operator should obtain a letter from the utility company stating that these lines are in compliance with NEC 680 STANDARDS. o If the lines are owned by the owner/operator, and there is no waiver or variance, it is a public health hazard.
8.0 MAHC Appendices ANNEX 351 0.5 mg/m 3 was 86% for eye irritation, 61% nose irritation, 29% throat irritation, and 42% dry cough. 514  Airborne TRICHLORAMINE was measured at six indoor swimming facilities and researchers found an elevated prevalence of respiratory symptoms in swimming POOL workers. Mean TRICHLORAMINE concentration of 0.56 mg/m 3 , with the highest concentration reaching 1.34 mg/m 3 . General respiratory symptoms were significantly higher in POOL employees compared to the Dutch population sample (odds ratios ranged from 1.4 to 7.2). 515  Researchers generated TRICHLORAMINES at 0.5 mg/m 3 in a challenge chamber and exposed the participants to a series of 10-minute exposures followed by spirometry. Results showed a decrease in pulmonary function. 516  TRICHLORAMINE is the most volatile and prevalent chloramine compound in the air around swimming POOLS 517 , has low solubility, and decomposes rapidly in sunlight.  The World Health Organization proposes a 0.5 mg/m 3 provisional value although it states that more research is needed to investigate health effects in people who use the POOL for extended periods of time and the role of TRICHLORAMINE in possibly causing or exacerbating asthma. 518  Although proposed STANDARDS and past studies indicate that a comfort level for indoor POOL areas would be to keep TRICHLORAMINE concentrations below 0.5 mg/m 3 , there have been some concerns that this level may not be low enough to prevent symptoms. 519 TRIHALOMETHANE (THM) threshold research reference synopses:
- Animal toxicity studies demonstrate and characterize hepatotoxicty and nephrotoxicity. 520  Investigation of THMs in tap water and swimming POOL water. The concentrations of total THMs in swimming POOL water was higher than those in tap water, particularly, brominated-THMs. This poses a possible cancer risk related to exposure. 521  Environmental and biological MONITORING of THMs was performed in order to assess the uptake of these substances after a defined period in five competitive
Facility Design & Construction ANNEX 181 AQUATIC VENUE. An effective BARRIER shall be one that does not allow BATHERS to walk on the elevated wall.
Small and/or narrow SPAS are examples where the AHJ may allow a relief from the 50% minimum DECK requirements. The rationale is that if a SPA is of a limited size or width then it can be entirely be guarded effectively from one side or one location.
Elevated Spas For example, if an elevated SPA is next to or within 4 feet (1.2 m) of another AQUATIC VENUE, a guard rail or post-and-rope system would be a couple of options as effective BARRIERS which would discourage PATRONS to use this elevated wall to jump into the other AQUATIC VENUE.
Temperature Temperatures above 104 F are essentially inducing a fever in the BATHER'S body as internal temperature rises. It also causes birth defects in fetuses so that pregnant women, particularly in their first trimester, should consult their physician before using. Further research is needed to understand the potential role of SPA use early in pregnancy and associated birth defects. See MAHC Annex 5.7.4.7.2 for further discussion.

# Timers
The "Fifteen Minute Rule" -complies with most state CODES. The timer for the hydrotherapy pump is for the SAFETY of the BATHERS. Longer times can be hazardous to BATHERS and the therapy pump shutting off at least reminds the BATHER to get out and reset the timer.
Emergency Shutoff Emergency shutoffs should be located between 5 feet (1.5 m) and 50 feet (15.2 m) and within sight of the SPA structure.

# Waterslides and Landing Pools
Design and Construction The designs of WATERSLIDES are governed by amusement ride regulations such as ASTM that have appropriate experience. However, the design of the LANDING POOL along with associated water quality and circulation is regulated by this STANDARD.
Exit into Landing Pools Present practices for safe entry into LANDING POOLS include:  A water backup, and  A deceleration distance.
Facility Design & Construction ANNEX 182 4.12.2.9
Drop Slides DROP SLIDES are being highlighted because of one incident that resulted in a fatality in Massachusetts. WATERSLIDES, particularly those that drop BATHERS into the water (versus being delivered to a water entry point), from a height above the water require diligent MONITORING by staff at the top of the slide and the water entry point to ensure there is adequate SPACING between slide users so that people do not land on top of each other. Each slide user must have time to move out of the collision zone before another slide user is allowed down the slide. The incident cited above resulted in the drowning of a slide user and a multi-day period to discover the victim because of the high turbidity of the water.

# Wave Pools
The WAVE POOL will still have side wall ladders for egress purposes (and therefore partial trafficking) and the MAHC still felt that "NO DIVING" signage should still be required for all areas around the WAVE POOL regardless of water depth due to the freeboard. 4.12.4 Therapy Pools 4.12.5 Lazy Rivers 4.12.5.2
Access and Egress

# Means
Since there is moving water in a LAZY RIVER, less frequent means of ingress/egress are acceptable. The moving water propels people around a LAZY RIVER quickly and with less effort to the next means of egress. LAZY RIVERS can be several hundred feet long. They are often constructed with side walls that make it difficult to exit the water. This distance will make it so that a BATHER will never be more than 75 feet (22.9 m) from an exit. The distance to the nearest exit for a large regular POOL can be as much as 50 feet (15.2 m). This distance can be farther for a LAZY RIVER because of the current. If water is flowing at 1 to 4 feet/second around the river, then a person floating around a river will never be more than 2.5 minutes from a means of egress.
Deck LAZY RIVERS are of necessity closed (or mostly closed) loops. The wall for the inside of a LAZY RIVER loop is an ISLAND which may be designed for people but is most often not. Therefore, a PERIMETER DECK is only needed for the outside of the river loop, or only on one side of the river.
Bridges Seven feet (2.1 m) minimum clearance overhead is required since it is consistent with requirements of building code minimum ceiling clearances.
Most LAZY RIVERS are closer to 3.5 feet (1.1 m) deep making the clearance 7.5 feet (2.3 m) if you adhere to the 4 foot (1.2 m) clear requirement above the water surface. The
Facility Design & Construction ANNEX 183 MAHC chose 7 feet (2.1 m) because it is the typical building code minimum height requirement for ceilings whereas the 6 foot 8 inches (2 m) minimum clearance is usually only applicable to doorways.
4.12.6 Moveable Floors 4.12.6.3 Safety 4.12.6.3.1 Not Continuous Examples of adequate SAFETY precautions for entering the other area of the AQUATIC VENUE include but are not limited to the following:  A moveable BULKHEAD, located at least at the water surface, to enclose the area of the MOVEABLE FLOOR;  A highly visible floating line installed over the MOVEABLE FLOOR surface, two feet (61.0 cm) in front of the end of the MOVEABLE FLOOR. A four inch (10.2 cm) wide contrasting marking shall be provided at this leading edge; and  A railing system that shall be anchored into the MOVEABLE FLOOR.
Underside When the MOVEABLE FLOOR is not continuous over the entire surface area of the POOL, access to the underside of the MOVEABLE FLOOR shall be denied when it is not flush with the POOL floor. Examples of adequate measures to prevent access under the MOVEABLE FLOOR include but are not limited to the following:  Position a BULKHEAD at the end of the MOVEABLE FLOOR;  Have a trailing ramp that hinges to the MOVEABLE FLOOR and extends to the POOL floor.
4.12.6.4 Movement There are no U.S. regulations on MOVEABLE FLOORS. This velocity was obtained from European design STANDARDS.
- European Standard EN 13451-11:2004. 4.12.7 Bulkheads 4.12.7.2 Entrapment All BULKHEAD parking positions should be designed such that QUALIFIED LIFEGUARDS can see under 100% of the BULKHEAD from their station on the POOL DECK.
Gap BULKHEADS designed with greater gaps may result in BULKHEADS veering off its intended path.
Facility Design & Construction ANNEX 184 4.12.7.6 Handhold During FINA sanctioned events, full height touchpads will be on most BULKHEADS. But the majority of BULKHEADS in the U.S. allow for wide holes at the waterline for handholds and USS / NFSHSA / NCAA touchpads which are hung from these holes and are below the waterline. Touchpads aren't normally installed during normal operating hours. End wall concrete parapets that cantilever over the gutter that require full height FINA touchpads for those level of competitions do not negate the requirement for handholds (though behind) in these locations.
Width Any BULKHEAD that is intended for foot traffic for use by officials shall be at least one meter (3 ft and 3 in) wide which is the current minimum width provided by commercial manufacturers.
Starting Platforms Any BULKHEAD that dictates starting platforms shall be installed shall be at least three feet and nine inches (1.1 m) wide in order to allow for sufficient trafficking space for officials and athletes behind the starting platforms.
4.12.8 Interactive Water Play Venues 4.12.8.3 Sloped An example for an acceptable design solution would be a diverter valve installation.
Hazard While consistent with many state CODES, the MAHC has determined that this topic needs more research regarding water velocity and eye safety 304 .
Signage Since there is no standing water on INTERACTIVE WATER PLAY VENUES, depth markers and "NO DIVING" warning signs are not required.
This was included because it deviates from the regular marking and warning signage requirements for typical AQUATIC VENUES as stated in this code. Other signage requirements such as diaper changing reminders and "Do Not Drink" would likely be appropriate. 4.12.9 Wading Pools 4.12.9.2 Barrier A more stringent requirement is stipulated for separating WADING POOLS from other bodies of water (compared with the spacing between other aquatic venues) is due to the fact that the predominant users of WADING POOLS are small toddlers, most of whom
Backwashing Frequency Backwashing frequency is important for multiple reasons. First, solids attach more strongly to the filter media over time and can be more difficult to remove following infrequent backwashing. Secondly, the organic particles (e.g., skin cells) held in the filter in contact with FREE CHLORINE can break down over time and produce DISINFECTION BY PRODUCTS and/or combined CHLORINE. The potential to form "mudballs" also increases with solids loading inside of a filter and can cause filter failures. The preceding items are the rationale for requiring backwashes at manufacturer prescribed pressure losses through the filter. Some data suggests tainted backwash water remains inside of the filter at the conclusion of the backwash procedure and therefore should be wasted to drain for at least the first two minutes after restarting.

# Backwash Scheduling
Backwashing while patrons are in the water is not recommended. First, the MAHC requires that recirculation systems are running at all times that an AQUATIC VENUE is open for BATHER use. Second, with no interlock in place, stopping recirculation while inadvertently continuing chemical feed pumps can cause a build-up of acid and chlorine product in the lines that leads to chlorine gas production. When the recirculation system is turned back on, the risk increases dramatically of a chlorine gas plume being delivered into the AQUATIC VENUE causing injury to bathers and initiating an emergency response 312 . Exceptions to this would be if an AQUATIC VENUE has multiple filters and an individual filter can be taken off line without shutting down the recirculation system and there is no chance of overfeeding chemicals that may lead to outgassing events or other chemical mixing emergencies.

# Filtration Enhancing Products
Coagulants should be used with caution due to potential for filter bed fouling. Maintaining records of clean bed headloss is recommended to help detect problems of filters not being adequately cleaned via backwashing. If a facility decides to use coagulants, they should be used continuously. Not using coagulants when the water is clear to save money will significantly impair the capabilities of the filters to remove pathogens like Cryptosporidium and Giardia.
Precoat Filters

# Return to the Pool
In closed-loop mode, it will be necessary to charge the media slurry to the suction side of the pump or precoat tank, prior to closing down the loop and putting the system into recirculation. Precoating of a filter typically takes 5 to 10 minutes. At the end of the precoat cycle, the discharge out of the filter should be clear and free of filter media. If 312Hlavsa MC, et al. Surveillance for waterborne disease outbreaks and other health events associated with recreational water use -United States, 2007. MMWR Surveill Summ. 201160:1-37.
Facility Operation & Maintenance ANNEX 202 the discharge is not clear, the filter should be opened, inspected, and repaired as necessary.
Operation When flow or pressure is lost in the filter, the precoat layer may become unstable and fall off of the filter septum. To reduce the likelihood of debris and CONTAMINANTS being returned to the POOL, it is recommended that prior to restarting the filter, it should be backwashed and/or cleaned and the precoat re-established with new filter media in a closed loop recirculation mode or with water wasting until the discharge of the filter is clear to minimize the potential of media or debris returning to the POOL. It is important that flow not be interrupted after the precoating process is completed and the flow out of the filter is redirected from the recirculation or waste piping back to the POOL. It is acceptable to open and close valves on the filter effluent stream as long as the closed valves are opened first so that the filter effluent water can flow continuously. Allowing the media to fall off of the filter septum decreases the capability of the filter to remove particles. The critical importance of always cleaning the filter and replacing the media when the flow is interrupted for any reason is related to uneven recoating permitting pathogen passage as well as fouling of the media support layers. 313
Cleaning Septum covers should be properly cleaned and inspected to maintain proper performance of precoat filters. Filters should be backwashed following a significant drop in the flow rate or when the pressure differential across the filter is greater than 10 pounds per square inch (69.90 KPa). Vacuum-type precoat filters should be cleaned when the vacuum gauge reading increases to greater than 8 inches (20.3 cm) of mercury or as recommended by the manufacturer. If after precoating with fresh media, the filter pressure does not return to the normal initial starting pressure noted on filter start-up, it would be advisable to disassemble the filter and clean the elements (septum covers) per the filter manual. Septum covers should be cleaned or replaced when they no longer provide effective filtration or create a friction loss preventing maintenance of the recommended recirculation rate. Water and spent media should be discharged in a manner approved by the appropriate regulatory agency.
Bumping Bumping is the act of intentionally stopping the filter and forcing the precoat media and collected CONTAMINANTS to be removed from the filter septum. Bumping may impair pathogen removal and could facilitate the release of pathogens previously trapped in the filter. Therefore, bumping should be performed in accordance with the manufacturer's recommendations. Prior to restarting a bumped filter, it is recommended that the precoat be re-established in a closed loop recirculation mode or with water wasting until the discharge of the filter is clear to minimize the potential of media or CONTAMINANTS returning to the POOL.
Facility Operation & Maintenance ANNEX 203 Pending future research, bumping is strongly discouraged in any precoat filter application where pathogen removal is a concern. Bumping may impair pathogen removal as pathogens once trapped at the surface of the cake could be positioned close to the septum and penetrate the filter during operation. 314 Cyst-contaminated water used for precoating filters led to much higher cyst concentrations in the filter effluent. 315 Precoat filters have been demonstrated to remove greater than 99% of the OOCYSTS. Using clean precoat media to precoat filters as well as maintaining continuous flow is recommended. 316,317,318
Filter Media Continuous filter media feed (or body-feed) can be used to increase the permeability of the cake, maintain flow, and extend cycle length as it becomes coated with debris. Body-feed is filter media added during the normal filtration mode on a continuous basis. The amount of body-feed used is dependent upon the solids loading in the POOL. Turbidity is the best available method to quantify and estimate solids loading. For filter influent turbidities greater than 1.5 NTU, body-feed may be beneficial with addition rates ranging from 1.0 to 4.0 ounces of DE per square foot of filter area per day dependent on the solids loading in the POOL. The lowest effective concentration of suspension should be used in a body-feed system. The concentration of the suspension may not exceed 5% by weight. The body-feed system head and lines should be flushed once every 15 minutes for at least one minute to assure proper and continuous operation. Water from the discharge side of the recirculation pump may be used. If connection is to a potable water supply line, the supply line should be equipped with an approved BACKFLOW prevention device.
Precoat media should normally be fed into the filter at a concentration not to exceed 5% by weight. Since perlite is approximately half the density of DE, half of the weight of perlite will achieve a similar depth of media inside of the filter as shown in MAHC Annex Table 5.7.2.2.7.1.
Facility Operation & Maintenance ANNEX 204 Drinking water applications typically recommend using DE at application rates of 0.2 pounds per square foot (1 kg/m 2 ). 319 This practice seems to be based on research showing that the removal of 9-micron (Giardia-sized) microspheres increased from greater than 99% to greater than 99.9% as the precoat amount increased from 0.5 to 1 Kg/m 2 . 320 Under the range of conditions tested, Logsdon and coworkers 321 found that the amount of DE had a greater impact on microsphere removal than did the grade of DE.
Alum-coated DE has been shown to significantly improve the removal of turbidity and bacteria not normally removed by DE filters. 322 Logsdon 323 reported that alum could be added at 0.05 gram of alum as Al 2 (SO 4 ) 3 14 H 2 O per 1 gram of DE in a slurry to form a precipitate on the surface to enhance performance.

# Cartridge Filters

# NSF Standards
Cartridge filter elements should be cleaned (or replaced) when the differential pressure across the filter exceeds 10 psi (68.9 KPa). Every cartridge filter should have two sets of cartridges. This will allow for one set to be in use while the other is being cleaned (soaking and drying are recommended).
Filtration Rates The 0.375 gallons per minute per square foot (0.26 L/s/m2) maximum design flow rate is acceptable, but an allowance is necessary to accommodate irreversible fouling of Use of high levels of CHLORINE as a "shock dose" when BATHERS are not present may be part of an overall water quality management strategy. Periodic shock dosing can be an effective tool to maintain microbial quality of water and to minimize build-up of biofilms and inorganic chloramines. For BATHER re-entry, FAC levels shall be consistent with label instructions of the disinfectant.
Salt water (saline) chlorination systems generate and deliver a CHLORINE disinfectant onsite directly into POOL water.
While cell size and configuration of these systems may differ depending on the manufacturer, the principles of their operation remain the same. Sodium chloride is added to balanced POOL water to establish a saline solution, which flows through the electrolytic cell. A low voltage electrical charge is passed through the saline solution and the current breaks the sodium and chloride bonds resulting in the formation of CHLORINE gas, hydrogen gas, and sodium hydroxide:

# Facility Operation & Maintenance ANNEX 231

# Too Low
If total alkalinity is too low: pH changes rapidly when chemicals or impurities enter the water. pH may drop rapidly when using net acidic sources of CHLORINE or other acidic chemicals (e.g. Trichlor (trichloro-s-triazinetrione), Dichlor (sodium dichloro-s triazinetrione), potassium monopersulfate), causing etching and corrosion.

# Raising Total Alkalinity
Total alkalinity can be raised by the addition of bicarbonate of soda (sodium bicarbonate, baking soda). 1.4 lbs. bicarbonate of soda per 10,000 gallons (635.0 g per 37,854.1 L) will raise total alkalinity approximately 10 PPM.

# Too High
If total alkalinity is too high: pH becomes difficult to adjust. High pH often occurs causing other problems such as; cloudy water, decreased disinfectant effectiveness, scale formation, and filter problems. The higher the total alkalinity, the more resistant the water is to large changes in pH in response to changes in the dosage of disinfectant and pH correction chemicals. If the total alkalinity is too high, it can make pH adjustment difficult.

# Lowering Total Alkalinity
Add acid -The acid reacts with bicarbonates in the water and reduces the total alkalinity. Add 1.6 pounds of Dry Acid (Sodium Bisulfate) per 10,000 gallons of water, or 1.3 quarts of Muriatic Acid, to decrease the Total Alkalinity by 10 PPM. Retest and adjust the pH.
High levels of cyanuric acid will cause interference in the total alkalinity test. This interference is magnified at low levels of total alkalinity. To correct for cyanuric acid interference, measure the concentration of cyanuric acid, divide that number by 3, and then subtract that value from the measured total alkalinity value.
Minor deviations from the alkalinity levels stated in the CODE do not in themselves present imminent health threats to the BATHERS. As such, minor deviations in alkalinity levels do not require the immediate closure of the facility. Rather, deviations from permissible alkalinity levels indicate poor management of the water balance and should indicate a need for a thorough inspection of the entire facility.
Combined Chlorine (Chloramines) Combined CHLORINE compounds (chloramines) are formed when FREE AVAILABLE CHLORINE combines with amine-containing compounds such as urea, amino acids, and ammonia from perspiration and urine. Chloramines include inorganic compounds (monochloramine (NH 2 Cl), dichloramine (NHCl 2 ) and trichloramine (NCl 3 )) as well as a variety of organic compounds. Inorganic chloramines are biocides, but are much less effective as quick kill disinfectants than FREE AVAILABLE CHLORINE. If the local water treatment plant uses chloramination for drinking water DISINFECTION, inorganic chloramines (predominantly monochloramine) may be present in the fill water.

# Facility Operation & Maintenance ANNEX 232

# High Chloramines
A high level of chloramines is undesirable in AQUATIC VENUES. The action level for combined CHLORINE is 0.4 PPM (mg/L). Higher levels indicate that bathing loads or pollution from BATHERS may be too high, or that treatment is inadequate. Higher levels may also pose a health concern to BATHERS, employees, and other PATRONS.
The World Health Organization recommends that combined CHLORINE levels be "as low as possible, ideally below 0.2 mg/L" 378 . However, this "ideal" level would be challenging to implement as a CODE requirement. Since the combined chlorine values reflect the combination of inorganic (well demonstrated health effects) and organic (poorly understood relationship to health effects) chloramines, the MAHC has decided to work with an "action" level until they can be differentiated. Development of tests that can measure the inorganic chloramines separately from the organic chloramines is needed so actionable levels can be set. With such tests, aquatics staff will be able to respond to actionable levels of volatile chloramines so appropriate air quality can be maintained. The separate measurement of organic chloramines, which accumulate in the pool, may be a useful marker for the need to replace water or supplement with a system known to remove these compounds.
Published data are limited, but suggest that combined CHLORINE levels are commonly above 0.2 PPM (mg/L) in swimming POOL water 379,380,381 .

# Inorganic Chloramines
Volatilization of chloramine compounds can lead to strong objectionable odors in AQUATIC VENUE environments, as well as eye, mucous membrane, and skin irritation for BATHERS and PATRONS. Among the inorganic chloramines, NCl 3 has the greatest impact on air quality, owing to its relatively low affinity for water and its irritant properties. NCl 3 has been reported to be an irritant at concentrations in water as low as 0.02 PPM (mg/L).
Odors are unlikely to be present from inorganic chloramines below the following concentrations:
Research to understand the relationship between inorganic chloramine concentrations in water and their impact on air quality is limited, although some research indicates that 5.0 Facility Operation & Maintenance ANNEX 249 AEDs were considered to be included in this list, but due to the requirement for medical direction for AED use by trained rescuers, it was not included as it may not be within the AHJ's authority to mandate such equipment. However, AEDs are widely used and can be used for submersion events and any cardiac incident. If local protocols can be established, it is recommended to have an AED.

# UV Protection for Chairs and Stands
In MAHC Section 4.8.5.3.3, permanently installed chairs and stands are required to be designed with UV protection. In MAHC Section 5.8.5.3.1, chairs and stands are required to have the UV protection present. Regardless of when the chair or stand was constructed, UV protection is required to protect the lifeguard from an occupational exposure.
Spinal Injury Board Spinal injury boards facilitate immobilization of a person with a suspected spinal injury. Because these boards are often used in or around the water, their construction should be of materials that can withstand the environment and be easily SANITIZED/disinfected between uses. Boards must be properly maintained and in good repair. An example is using a wooden backboard that is worn so the wood is exposed and no longer cleanable. In this case, refinishing it with a waterproof finish should again make it cleanable. The head immobilizer and straps are commonly used in lifeguard training programs and these tools assist in the immobilization of a person on the board and should be present during operation. Deciding which straps to be included should consider how to best immobilize the person to the board. Common locations for straps are at the upper torso, the hips, and legs.
The number of spine boards available at the AQUATIC FACILITY should be dependent on the size of the AQUATIC FACILITY. It would be difficult to determine the exact number but a general consideration should be to have a spine board reach the location it is needed within a couple of minutes. There should not be a delay: the person needing to be extricated from the water will need to be held in an immobile position in the water. To extricate without a spine board can cause more damage to the person.
Rescue Tube Immediately Available The 50th percentile adult is at least 64 inches (1.6 m) tall. The rationale is that the average adult BATHER'S head would be above the static water line and they could use the AQUATIC VENUE without difficulty. Due to buoyancy considerations at chest level, a short lifeguard could have difficulty doing a rescue safely without equipment. For this reason, the rescue tube is required unless there is less than 3 feet (0.9 m) of depth in which their chest would likely be above the static water line.
Lifeguard training agencies have determined that the use of a rescue tube makes rescues safer for both the victim and the rescuer. The rescue tube provides a BARRIER between the victim and the rescuer as well as a handhold for both during a rescue.
In very shallow water, the rescue tube may not be as effective so the language in the code is flexible to allow for the rescue tube to be available immediately, but is not required to be worn. However, as stated above, the rescue tube provides protection for the lifeguard so the operator should determine the level of risk and requirement for
Facility Operation & Maintenance ANNEX 251 wearing the rescue tube based on the AQUATIC VENUE depth, activities, and frequency of rescue.
Rescue Tube on Person Being properly prepared to respond to an emergency requires wearing the harness strap attached to the rescue tube and keeping the rescue tube in a position and location where it can be immediately used.
It is important to wear the rescue tube in a rescue ready position. Wearing the strap and sitting with the tube at the lifeguard's feet, or in any other position except held against the body, can lead to situations where a lifeguard is injured or cannot respond because the tube's strap is wrapped around handrails, chair pedestals or other catch points. Management should reinforce through pre-service, in-service, and employment policy that the lifeguards are expected to hold the rescue tube in a manner taught and accepted by the lifeguard training agency.
Identifying Uniform There should be no delay in care because a PATRON is unable to find a member of the AQUATIC FACILITY SAFETY TEAM. Distinct uniforms are a standard in most industries to identify workers and their assigned tasks.
Signal Device The most basic communication method used by lifeguards is a combination of whistle blasts and hand signals to communicate with each other, PATRONS, and management. Whistle signals can communicate when to clear the POOL, get another lifeguard's or supervisor's attention, and communicate emergencies.
The devices and their use can vary depending on the AQUATIC FACILITY and its management. Because of inherent background noise, whistles, hand signals, emergency buttons, radios, and telephone handsets are used to provide more effective communication.
Sun Blocking Methods Protection from direct sun exposure is a necessary part of lifeguarding at AQUATIC FACILITIES. Gone are the days when the objective of the lifeguard was to get as deep a tan as possible. Today, sun exposure, especially when the skin becomes burned, increases significantly the risk of skin cancers.
In a recent study of melanoma, it was noted that the melanoma DNA contained 33,000 mutations, many of which may have come from ultraviolet light exposure 411 .
The best sunscreens available at the present time are broad spectrum or full spectrum and are usually so labeled. More will probably become available as new Food and Drug Personal Protective Equipment Appropriate personal protective equipment (PPE) must be provided to all employees that have possible occupational exposures. Lifeguards should carry or have immediately available basic PPE (disposable gloves and resuscitation mask with oneway valve) for immediate use during initial exposure to feces, vomit, and small amounts of blood until the full facility bloodborne pathogen kit arrives at the treatment scene. This could be in a small pouch to be carried on the lifeguard, a pouch associated with the rescue tube, or at a location near the lifeguard position. The intent is that the lifeguard does not need to leave the immediate area to find PPE nor will it create a delay in response.
OSHA Blood borne Pathogen Regulations 424 , require that the employer shall provide, at no cost to the employee, appropriate personal protective equipment such as, but not limited to, gloves, gowns, laboratory coats, face shields or masks and eye protection, and mouthpieces, resuscitation bags, pocket masks, or other ventilation devices. Personal protective equipment will be considered "appropriate" only if it does not permit blood or other potentially infectious materials to pass through to or reach the employee's work clothes, street clothes, undergarments, skin, eyes, mouth, or other mucous membranes under normal conditions of use and for the duration of time which the protective equipment will be used.
Rescue Throwing Device If the single lifeguard is engaged in a rescue and another person is in distress, the rescue throw device allows for an untrained individual to assist the distressed person.
Reaching Pole If the single lifeguard is engaged in a rescue and another person is in distress, the reaching pole allows for an untrained individual to assist the distressed person.
Safety Equipment and Signage Required at Facilities without Lifeguards
Throwing Device A rescue throwing device is a throw bag, buoyant life ring, torpedo buoy or other easily thrown buoyant device that is designed for a person on the DECK to throw to a person in distress in the AQUATIC VENUE. Fifty feet (15.2 m) minimum of 14 inch (6.4 mm) rope securely attached to the device is required. It has been found that untrained individuals have a reasonable ability to reach 30 feet (9.1 m) with a rescue throw device. A 50 foot (15.2 m) rope would accommodate that distance. The 1.5 times the width of the POOL allows for a SAFETY factor to overthrow the device and pull the rope back toward the person in distress. This also allows for extra rope to hold on to. The device must be kept ready for use, and the rope must be coiled to prevent tangles and to facilitate throwing the device. Additional Signage MAHC Section 6.3.2 outlines the conditions that require a QUALIFIED LIFEGUARD. For AQUATIC FACILITIES that do not have lifeguards, PATRONS should be informed that no lifeguard is provided so they can comply with any requirements and understand the identified risk. For instance, at a hotel POOL that requires key entry, the sign would notify hotel guests that no lifeguard is provided and persons under the age of 14 are not allowed in without adult supervision. The label should explain necessary precautions to take; how to handle, store, and dispose of chemicals; and sometimes indicate hazard potential with a number from 0 to 4. This number indicates the degree of risk, with the number 4 representing the greatest risk, and shows the hazard categories (see NFPA 704: Hazard Identification System).

# Filter/Equipment Room
OSHA and EPA Chemicals should never be pre-mixed with water by hand before adding the chemical to the AQUATIC VENUE unless specified by the manufacturer.
If a dissolution or feed tank is used to dissolve product for feeding into the AQUATIC VENUE, the tank must be equipped with a mechanical mixer, dedicated to a single chemical, and clearly labeled to prevent the introduction of incompatible chemicals to the tank.

# Chemicals should be added to water, water should never be added to chemicals.
Pre-mixing in containers that are not clean can result in the generation of heat and toxic gases and may result in fire or explosion.

# Hazard Ratings
The SDS will typically contain the hazard ratings according to either the NFPA or HMIS systems. The NFPA system may be found in NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response. In the NFPA system, the chemicals are rated according to their health, flammability, instability, and special hazards. The degree of hazard is indicated by a number from 0 to 4, with 0 being the least hazardous and 4 being the most hazardous. Either HMIS or NFPA ratings are useful to include on product labels. Most fire CODES require these ratings to be posted on chemical STORAGE room doors.
Protected In addition to the requirements listed in MAHC Section 5.9.1.5, the following BEST PRACTICES are recommended:  Place all chemical containers, drums, boxes, and bags on pallets to raise them off the floor.  Containers should not be stacked so that they will easily fall over. A general rule of thumb is that they should not be stored more than three high.  Containers of chemicals shall be closed securely to prevent contamination.
Facility Operation & Maintenance ANNEX 257  Any shelving units used to store chemicals should be sturdy enough to support the weight of the chemicals being stored.
No Mixing Particularly keep chlorinated cyanurates, hydantoin bromine, and calcium hypochlorite away from other chemicals, paper, water, petroleum products, or other organic compounds to avoid possible cross-contamination.
No liquids should be stored above solids.
Chemicals must be stored in the original manufacturers' labeled container. Storage containers that held other chemicals previously are unacceptable. Chemicals may be transferred from the original container to a new container if that container was manufactured for the storage of that chemical and properly labeled.
Aquatics staff should read and consider findings and recommendations developed from investigations related to POOL chemical-related injuries.
- See "CDC Recommendations for Preventing Pool Chemical-Associated Injuries" at:  injuries.html
Ignition Sources National Fire Protection Association (NFPA), Hazardous Material Identification System (HMIS), or equivalent hazard rating systems may be used.
Lighting Horizontal-plane illumination must be adequate for SAFETY and navigation, as well as for reading documents.
The Illuminating Engineering Society of North America (IESNA) recommends a 30 footcandle (323 lux) minimum for Motor & Equipment Observation.

# PPE Common components of PPE for chlorinated AQUATIC VENUE chemicals are as follows:
- Respiratory Protection: Wear a NIOSH approved respirator if levels above the exposure limits are possible.  Respirator Type: A NIOSH approved full-face air purifying respirator equipped with combination chlorine/P100 cartridges. Air purifying respirators should not be used in oxygen deficient or IDLH atmospheres or if exposure concentrations exceed ten times the published limit.  Skin Protection: Wear impervious gloves to avoid skin contact. A full impervious suit is recommended if exposure is possible to a large portion of the body. A safety shower should be provided in the immediate work area.  Although the MAHC is not aware of any work in this particular setting, studies in child care settings, schools, long term care facilities and food service establishments all support the importance of surface cleaning. The MAHC feels that daily cleaning at a minimum in this setting is reasonable for aesthetics as well as health and SAFETY.
Rinse Showers Soap is not needed at RINSE SHOWERS because it can have a negative effect on water chemistry.
Diaper-Changing Stations It is the responsibility of PATRONS to clean diaper changing surfaces after each use. This is consistent with practice in other public settings where diapering takes place. However, staff should keep an eye on stations and clean when necessary.
Non-Plumbing Fixture Requirements Associations between AQUATIC VENUES and disease outbreaks have been well documented in the literature. Though an outbreak has never been connected to the materials used specifically, wood and other porous materials have been shown to have bacterial growth on them that can be hard to remove.
Non-porous materials used as matting at AQUATIC FACILITIES were found to be contaminated with bacteria and biofilm scum layers, although conventional cleaning was documented to remove the contamination 428 .
Policies & Management ANNEX 262 immediate closure because of the seriousness of identified violation(s). In addition, SPA inspection data indicated that the following violations regarding the following issues are frequently identified:  437 .
These analyses underscore the need for inclusion of these topic areas in operator training courses. These essential topics are covered in nationally recognized operator training courses.

# Course Content

# Water Disinfection
Many other DISINFECTION chemicals or systems with varying effectiveness and suitability are being offered in the market to AQUATIC FACILITY operators for water treatment. In general terms, discuss the evaluation steps that should be used by the AQUATIC FACILITY operator, including required AHJ acceptance of the chemicals or systems for public AQUATIC FACILITIES, in their decision process on using these types of supplemental systems or treatments. submerged pumps such as turbine, mixed flow, and others used in waterpark applications. Additionally, the operator needs to have an understanding of the winterizing needs for these types of equipment.  Filter Backwashing/Cleaning -In these days of energy and water conservation, it is increasingly important that water conservation be practiced. Backwash water can be responsible for wasting an unnecessary amount of water if not done properly or too frequently.
If properly treated to meet water quality STANDARDS, AQUATIC FACILITIES can obtain savings with water costs. However, in some cases, it may not be cost effective for an AQUATIC FACILITY to expend funds on retreatment of backwash water. In those cases, it is most important that all water is discharged properly in accordance with the regulations of the local jurisdiction.

# Health and Safety

# Recreational Water Illness
The number of outbreaks associated with recreational water has continued to substantially increase since reporting began in 1978, most notably in 1982, 1987, 2004, and 2007. CDC recommends that public health and the aquatic sector collaborate on educating the swimming public, an important source of recreational water contamination, about RWIs and what swimmers can do to protect themselves and others 438 . The operator should be aware of the need for frequent manual testing, standardization of automatic controllers, and adequately sized chemical feeders.
Note the need for larger feeders for waterpark type attractions as compared to FLAT WATER POOLS. Settings of AQUATIC FACILITIES that are recommended to be discussed include community POOLS, apartment complex/condominium/homeowners' association POOLS, hotel/motel POOLS, and water parks.

# General Requirements for Operator Training Courses

# Course Length
The MAHC intentionally does not prescribe a particular length of time for courses. Instead, the MAHC is more PERFORMANCE-BASED by requiring that all of the essential topics in MAHC Section 6.1.2.1 be covered during the course. Most nationally recognized operator training courses run approximately 16 hours, and the MAHC assesses that it would be unlikely that all essential topics could be effectively taught in a shorter time period.
Instructor Requirements Recognized training on AQUATIC FACILITY operation and maintenance as well as instruction (without work experience) is sufficient to qualify an individual to be an instructor if the requirements in MAHC Section 6.1.3.4 are met. It is, however, ideal to have both work experience and training in operation and instruction.

# Final Exam
The final exam is intended to assess the knowledge and skills of the pool operator. Key components of the exam should include questions on the essential topics outlined in MAHC Section 6.1.2, performing essential calculations, reading meters and electronic equipment.
In the future, it would be ideal if course final exams included more than just knowledge testing and have skills testing. This should include an on-site evaluation of skills such as proper calculations of gallonage and chemicals needed to be added to the AQUATIC FACILITY, how to operate the filtration/RECIRCULATION SYSTEM, including backwashing the filters, and water testing (chemical and physical parameters).
Course Certificates The MAHC recommends that each certificate have a unique identifier to minimize the likelihood of mistaking the identity of QUALIFIED OPERATORS.
At this time, a certification process for QUALIFIED OPERATORS is not established. This may make it advisable for some group to develop a certification program similar to that of the Food Code. Thus, the Food Protection Managers Certification Program Standards, Section 7.7, "Responsibilities to the Public and to Employers of Certified Personnel" reflect the following, "A certification organization shall maintain a registry of individuals certified."
These STANDARDS reference certified food operators; however, the same STANDARD shall apply to operator training certificates. Thus, "any title or credential awarded by the course approved organization shall appropriately reflect the" AQUATIC FACILITY QUALIFIED OPERATOR responsibilities and "shall not be confusing to employers, consumers, related professions, and/or interested parties." 444
Continuing Education It is recommended that a QUALIFIED OPERATOR continue their education by attending seminars or training courses to keep up-to-date in AQUATIC FACILITY operation and SAFETY.
In the long term, there is a need for development of a system for Continuing Education Units. However, it may not be prudent to make the leap to require CEUs all at once, especially since this MAHC 1st edition will require for the first time that all AQUATIC FACILITIES have QUALIFIED OPERATORS. To have new requirements for operators at all AQUATIC FACILITIES and for CEUs may be overly burdensome at this time.
Certificate Renewal Nationally recognized operator training courses require renewal of certificates. However, most professional certifications do not require retaking an entire course to renew certification, just passing an exam.
Most states require these certificates or copies to be readily accessible to the AHJ. Copies of certificates should be kept on file at the site and made available upon request.
Policies & Management ANNEX 268 If photocopies are provided as proof of certificate, or certificate renewal, the original documents should be provided within 72 hours upon request from the AHJ.
Certificate Suspension and Revocation The AHJ is expected to contact course providers with questions about the validity of any certificate or with questions about an operator's performance. In turn, course providers are expected to readily provide verification of certificates and suspensions and revocations of certificates and to notify the AHJ of actions taken in response to its reported concerns.
The Food Protection Managers Certification Program Standards, Section 7.5 reflect the following, "A certification organization shall have formal certification policies and operating procedures including the sanction or revocation of the certificate. These procedures shall incorporate due process." 445
Additional Training or Testing Reasons for requiring such training or testing include but are not limited to operator performance or new developments in technology or operation. Such situations include but are not limited to repeat or serious violations identified on inspection, an investigation implicating operation as a contributing factor to illness or injury, or implementation of substantial rule changes. Training can range from brief dialogue during POOL inspection to full-day seminar for all operators in a jurisdiction. Testing can range from questions during inspection to paper-or computer-based exams.
Certificate Recognition The MAHC aims to delegate authority to the AHJ both to choose to recognize individual certificates and to reverse its decisions if operators with certificates demonstrate inadequate knowledge or poor performance or due cause.
Course Recognition The MAHC aims to delegate authority to the AHJ to choose to recognize operator training courses and to reverse its decisions if operators demonstrate inadequate knowledge or poor performance or due cause.

# Length of Certificate Validity
Policies & Management ANNEX 271 emergency response. Training agencies should develop appropriate skills to address the variety of water depths in which a victim may be found. These skills should be trained not only for the technical aspects of the skill, but also how the skill is incorporated into a venue's EMERGENCY ACTION PLAN. Lifeguards should be trained to respond within the scope of, at a minimum, Basic First Aid skills to provide care for illness or injury that may occur on land within the AQUATIC FACILITY until EMS arrives.
Resuscitation Skills Lifeguards should be competent in CPR/AED at the professional rescuer level. The predominant body for the research of such skills is the International Liaison Commission on Resuscitation (ILCOR; www.ilcor.org). ILCOR currently reviews available research every five years and is composed of physicians and medical researchers from across the globe. One organization from each country/region of the world is assigned to interpret the science-based evidence and prepare guidelines for voluntary use by training agencies in that country/region. In the United States, this designated agency is the American Heart Association. The AHA collaborates with host groups, training agencies, as well as leaders in the field from nonprofit, educational, and commercial organizations to create the "Guidelines for CPR and ECC". 463 These recommendations are also commonly known as "AHA Guidelines". Emergency Cardiovascular Care Update (ECCU; www.citizencpr.org) conferences are held biennially to present research and recommendations for guidelines. Detailed Information about the process and current research is available on the ILCOR and ECCU websites.
First Aid The evidence-based application of first aid skills is currently reviewed through the National First Aid Science Advisory Board and recommendations published as a separate section of the AHA CPR and ECC Guidelines and are available at the website identified in MAHC Section 6.2.1.1.3.
Legal Issues Lifeguards are part of the pre-hospital chain of response and should have basic understandings of critical legal concepts such as consent, refusal of care, and negligence. Legal topics to be covered are not limited to these listed topics. Training agencies are strongly recommended to add topics based on the typical environment in which the trained lifeguard will be employed.
Lifeguard Training Delivery

# Standardized and Comprehensive
A standardized method of training with comprehensive materials is essential to the implementation of a consistently-delivered lifeguard training program.
A specific method is not being recommended by the MAHC.
463 American Heart Association Guidelines available at : /.
Policies & Management ANNEX 272
Skills Practice While much of the necessary cognitive knowledge may be obtained through selfdirected study, especially in an interactive online format, physical skills practice is necessary to develop an understanding of how to apply knowledge and identify the various needs in an emergency situation. During skills practice an instructor can provide individualized learning approaches, corrective feedback, and lead simulations and scenarios.

# Shallow Water Training
It is important that the student lifeguard be able to practice and be tested in the deepest water specified in their certification.

# Deep Water Training
It is important that the student lifeguard be able to practice and be tested in at least the minimum water depth specified in their certification.
Sufficient Time This CODE does not prescribe a particular length of time for courses. Instead, this CODE is more performance based by requiring that all of the essential topics in MAHC Section 6.
Certified Instructors The instruction of a course by an individual not directly authorized by the training agency is extremely problematic and risks the quality controls established by the training agency. This also places public SAFETY at risk, in that the unauthorized instructor may not be fully qualified to teach the materials as intended. It also affects the training agency in that there is no direct recourse against an unauthorized, and unqualified, instructor. Lifeguard certifications, obtained from a lifeguard training course taught by an instructor who is not currently certified or authorized by the training agency to teach lifeguarding courses, will not be recognized as certified or trained by the AHJ per MAHC Section 6.2.1.3.

# Minimum Prerequisites
The creation of minimum instructor prerequisites is a crucial piece to create quality and consistency for the training agency. Instructors who lack such experiences may not fully understand the requirements and demands of a lifeguarding position and may not provide an experienced instructor's insight to students on how to apply the skills and knowledge found in the training agency curriculum.
It is necessary that lifeguard instructors have a firm understanding of the course they will be teaching. While it may be possible for an individual to pass a lifeguard instructor course without first taking a basic course, such an instructor would lack a firm understanding of the skills required by the training agency. It should be noted however, that training agencies should have the ability to create curriculum that would allow an individual from another training agency, or an individual who chooses to take an alternative to a full basic level course, to become instructors.
A Lifeguard Instructor Training Course must also provide information to the instructor candidates on how to safely and effectively conduct a course including:  Knowledge of how to provide for the health and SAFETY of the students. (example knowing how to disinfect manikins for use);  Ability to maintain adequate supervision at all times during in water skills and have a lifeguard on duty;  Knowledge of how to effectively use program materials and training equipment as listed in MAHC Section 6.2.1.2.7;  Ability to supervise student skill practice and provide timely, positive and corrective feedback; and  Knowledge and ability to evaluate students as to meeting the criteria set forth by the training agency for which they are an instructor.

# Instructor Renewal/Recertification Process
The training agency must have a process in place for renewal/recertification of instructors. The process should identify the criteria when reauthorization is required such as an instructor must teach a certain number of lifeguard courses in a certain time period (years) and/or do in-person or on-line updates as needed (e.g., when course materials or content have been revised).

# Quality Control
Quality instruction is crucial to the survival of a training agency and, in the case of lifeguard training, crucial to the SAFETY and well-being of millions of swimmers every year. Training agencies must have procedures that allow for the correction, remediation and, if necessary, the revocation of instructor credentials.
Training Equipment These pieces of equipment are required to accomplish the objectives of lifeguard training as outlined in the code. It is educationally sound to provide enough equipment based on the number of students who will be using it at the same time. Below is a listing  o Four triangular bandages, o One 3-inch roller bandage, o A blanket or pillow, and o a rigid splint such as a magazine, cardboard, or long and short boards;  Spinal immobilization materials;  Backboards, each equipped with 3 straps and head immobilizers (one backboard for every three participants is recommended); if fewer backboards are available, additional time may be required.

# Competency and Certification

# Requirements
The readiness of lifeguard candidates to respond to aquatic-based emergencies should be assessed thoroughly for skill mastery, knowledge, and practical application prior to being issued a certificate. In regards to a written exam, all nationally recognized training agencies currently require an 80% correct answer rate as the minimum threshold for passing.
Policies & Management ANNEX 275
Instructor Physically Present The physical presence of the instructor of record assures that students are evaluated accordingly in both cognitive and physical testing. This also significantly reduces the risk of individuals becoming certified who lack the basic skills and knowledge necessary through either acts of omission caused by the substitution of another individual to provide testing, or by student fraud.
Certifications A certification issued at the end of a lifeguard course indicates that the individual successfully met the training requirements on the day of assessment. A completion certificate does not imply future performance or suitability in all circumstances. It is the responsibility of the employer to verify skills and ongoing competency suitable for the environment in which the lifeguard will be assigned through pre-service and in-service training.

# Number of Years
The United States Lifeguarding Standards Coalition (USLSC) final report 464 , the scientific review by the American Red Cross (ARC) 465 , and the MAHC agree that lifeguarding skills need to be refreshed as often as possible. The ARC reviewed 12 peer-reviewed publications on CPR skill retention in healthcare providers (retraining intervals of 6 weeks to 24 months) and 28 papers focused on non-healthcare providers (retraining interval of 3 to 48 months). 466 The data from these 40 studies (all measured manikin skills, none measured patient outcomes) showed significant CPR skill degradation within the first year after training in both job categories and the majority of skill degradation occurred in the first year. None of the 40 studies documented adequate skill retention after two years but several showed improved retention if a brief refresher was given at 6-12 months. As a result of this review and the low probability that lifeguards use the skill often enough in their job to retain the skill, the MAHC felt that the skills needed to be refreshed every year through re-certification. They did not think that the convenience of aligning the length of valid certifications for lifeguarding and first aid at two years overrode the strong data showing CPR skill degradation over two years that could put BATHER health at risk. The time periods listed in the MAHC are acceptable only if ongoing in-service and pre-service STANDARDS are followed.

# Documentation
In order to verify compliance with MAHC Section 6.2.1.3.5, requiring the expiration date of the certification allows employers and the AHJ to identify that the lifeguard has a current certification.
Policies & Management ANNEX 287 When first hired, lifeguarding skills should be assessed during pre-service training prior to the first duty assignment. In-service training should assess skills on a regular basis to determine ability for ongoing duty assignments. Training agencies require that employees have training, knowledge and the proper equipment to protect the employee and the PATRON against disease transmission. This level of awareness must be in place before active PATRON surveillance takes place.
All lifeguard training agencies require lifeguards to be able to perform a combined rescue skill with equipment to receive completion certification. All lifeguard training agencies train their lifeguards that they must be able and ready to recognize, respond, rescue, and resuscitate a victim as quickly as possible. The employer should verify that the lifeguard maintains these skills in the workplace.
Documentation of Pre-Service Training Documentation provides a method for the AHJ to verify compliance. An example of the type of documentation required is a skills check-off form with a participant attendance sheet.
In-Service Training

# Documentation of In-Service Training
All lifeguard training agencies support the need for ongoing in-service training. Both ANSI/APSP -1 and -9 state that certain topics be covered in this training. These inservice trainings should include all the SAFETY PLANS and in and out of water rescue skills for lifeguards.
The United States Lifeguarding Standards Coalition final report 473 , the scientific review by the American Red Cross 474 and the MAHC agree that lifeguarding skills need to be refreshed as often as possible. The Texas state POOL code requires at least 4 hours of in-service a month. Other states require that in-service training be documented and signed. The MAHC agrees that all AQUATIC FACILITIES should have an ongoing in-service program for their SAFETY TEAM members.
The term "periodic" is to offer flexibility to the QUALIFIED OPERATOR based on their seasonality, staff scheduling, and the training agency requirements.
In-Service Documentation Documentation is maintained at the AQUATIC FACILITY to provide a method for the AHJ to verify compliance during an inspection. Documentation is crucial to prove that the inservice training took place, and this documentation should include a list of the topics covered, who was in attendance, and the date and time of the training.
Policies & Management ANNEX 289
Competency Demonstration The point of this section is to have the skills performed consecutively and not individually as they may be done in some training classes. If all of these skills cannot be done consecutively, it is difficult to expect a successful rescue. This is not intended to preclude scenario-based activities that accomplish the same.
AHJ Authority to Approve Safety Plan Some jurisdictions will have the resources to review the SAFETY PLAN and others may not. These line items allow for that flexibility but as a matter of enforcement, the submittal of the SAFETY PLAN is required in either scenario. Should an incident occur in which the jurisdiction is investigating, the SAFETY PLAN on file would be a good point of reference. The MAHC agreed that there needs to be an SAFETY PLAN that is retained and available for review by the AHJ as a point of reference detailing the intended operation to compare to the operation observed in the field.

# Safety Plan on File
The SAFETY PLAN itself should be a tool for facility staff to utilize and as such should be present at the AQUATIC FACILITY and not merely a book sitting on a shelf in an administrative office.
Safety Plan Implemented These MAHC Sections are written to be performance-based and since each AQUATIC FACILITY is different, each SAFETY PLAN may be different. The SAFETY PLAN is developed to be a written document that establishes the processes the AQUATIC FACILITY will employ to be compliant with the code. It is important to also put in the code that those processes, although written, are also practiced and in evidence for the AHJ to see and compare the operation to what is written in the SAFETY PLAN and therefore compliant with the code. During routine inspections, the AHJ may want to see the SAFETY PLAN for the AQUATIC FACILITY as a point of reference but also to enforce a requirement of the code to have a plan.
Staff Management

# Lifeguard Staff

# Minimum Number of Lifeguards
Parts of POOLS or additional POOLS within the same AQUATIC FACILITY may not be open at all times during any given day. For example, only three lanes of a large POOL may be open during early morning lap swim. All zones of PATRON surveillance must be staffed unless the AQUATIC FACILITY can effectively limit access to only the lap lanes. A potential problem arises though, when the entire POOL is not under surveillance because a PATRON in the open section may move to a section/zone not intended to be open. Without surveillance, it may go unnoticed. So, the ability to restrict access and monitor or otherwise assure that no one enters the un-opened section/zone must be able to be effectively addressed and those details must be included in the SAFETY PLAN.
Policies & Management ANNEX 290
Lifeguard Responsibilities QUALIFIED LIFEGUARDS are the front line personnel at an AQUATIC FACILITY to witness most of the situations in which an AQUATIC FACILITY or AQUATIC VENUE should be closed. The QUALIFIED LIFEGUARD must be aware of these emergency closure issues in order to enforce them -examples include an inability to see the bottom or main drains, fecal accidents, severe weather, and others developed by the MAHC.
The MAHC agreed that since there is no established guideline for vision needed for the job of a QUALIFIED LIFEGUARD that if the individual QUALIFIED LIFEGUARD has corrected vision via lenses that they should wear them while conducting PATRON surveillance. Further research needs to be done in this area. Some professions require a minimum vision STANDARD non-corrected while others accept corrected vision to a certain level.

# Shallow Water Certified Lifeguards
If a training agency issues a shallow water certification, the shallow water lifeguard is not qualified to be stationed in a zone that has a water depth greater than that identified for the certification. If any part of the zone has a depth of water greater than that depth, the shallow water lifeguard is not qualified to be assigned to that zone.
Direct Surveillance The factors of recognition, intrusion, and distraction have been identified as major contributor to drowning in guarded venues. Nothing should be allowed to interfere with a lifeguard's duty to perform PATRON surveillance. The MAHC agreed that QUALIFIED LIFEGUARDS performing PATRON surveillance should not be doing other tasks that could distract them.
When on duty, a QUALIFIED LIFEGUARD should scan and supervise the AQUATIC VENUE with no other distracting activities such as cleaning, water testing, and minimize unnecessary conversing with PATRONS.
Distractions When QUALIFIED LIFEGUARDS are engaged in conversations while performing PATRON surveillance activities, their attention is distracted from surveillance. As a parallel, research has shown that even hands-free cell phone conversations can cause drivers to be distracted. 480
Supervisor Staff

# Lifeguard Supervisor Required
The LIFEGUARD SUPERVISOR fulfills the role of making QUALIFIED LIFEGUARDS accountable for performing well and making sure the rotations are conducted properly. It is critical that QUALIFIED LIFEGUARDS perform their duties as trained and that the risk factors that affect the QUALIFIED LIFEGUARD'S ability to perform have been mitigated. In addition, Low or absent disinfectant levels lead to reduced inactivation of pathogens and these conditions have been associated with infectious disease outbreaks. 487 Low pH has been associated with loss of dental enamel 488,489,490 . Dental erosion begins to occur below pH 6.0 and rapidly accelerates as the pH drops. High pH reduces the efficacy of CHLORINEbased DISINFECTION by reducing the amount of molecular hypochlorous acid (HOCl), the active form that is available for DISINFECTION. At pH 7.0, about 70% of the hypochlorous acid is molecular, at pH 7.5 about 50% is molecular, at pH 8.0 about 20% is molecular, and at pH 8.5 only 10% is molecular. As a result, the MAHC decided to set upper and lower limits for pH as an IMMINENT HEALTH HAZARD.

# Operations

# Operations Manual

# Develop
The facility design consultant can provide valuable assistance with preparation of a manual based on their knowledge of the physical system. The facility owner/operator must provide their preferences for operation and maintenance activities, based on location, climate, programs, budget, etc.
Include A manual for the operation of AQUATIC FACILITIES should be kept at the facility, in both printed and digital formats. The manual should include basic information, chemical data, and operation and maintenance instructions about each POOL, SPA and spray ground feature at the facility. The manual should be updated on a regular basis to include added features, renovation work, and new code requirements.

# Chemical Data
The operations manual should also provide chemical data for each chemical system in the facility. This includes but is not necessarily limited to the following:  Description of chemicals provided for primary disinfectant, pH adjustment, alkalinity adjustment, stabilizer, SUPERCHLORINATION, coagulant, filter aid, etc.;  SECONDARY DISINFECTION SYSTEM description, if provided (UV, ozone, other);  Type of chemical feed equipment and rated capacities;  Discussion of water treatment goals and range of chemical targets;  Description of chemical testing equipment;  Testing frequency and location for each test;  Chemical controller information, probe cleaning, and calibration procedures;  Water testing log forms for chemical results; and  Chemical supplies (STORAGE quantity, providers, safety procedures).

# Facility Operation Info
The operations manual should also provide instructions for AQUATIC FACILITY operations. These instructions should include, but not necessarily be limited to the following:  Filter backwash or cleaning schedule and procedure;  Periodic vacuuming and cleaning schedule and procedures;  Seasonal cleaning procedures;  SUPERCHLORINATION basis and procedure;  Controller sensor maintenance (if applicable);  Preventive maintenance tasks and schedule;  Winterizing procedures; and  Start-up and closing procedures.

# Maintenance Instructions
The operations manual should provide instruction for proper maintenance for the facility. Both daily and seasonal or periodic maintenance will be required for the AQUATIC FACILITY. Available time and budget must always be balanced with the maintenance need. Regardless of whether the facility is large or small, frequent maintenance is more effective and more efficient than waiting until a larger problem occurs.
- Provide an inventory of available maintenance equipment and materials;  Develop a daily maintenance schedule;  Develop a schedule for periodic or seasonal maintenance; and  Create a maintenance log with date and activity for future planning and budgeting.

# Policies & Management ANNEX 298

# Office Management
The operations manual also provides office management information for the facility. This manual should include, but not be limited to following:  Active and inactive records and general file information;  Forms for water test results and filter cleaning frequency;  Forms for inventory of chemicals, equipment, cleaning supplies, etc.;  Maintenance inspection forms for facility, equipment, and structures;  Maintenance work forms;  Requisition forms for purchasing based on facility policies;  Staff evaluation forms log;  POOL operation log (water quality, attendance, weather, open hours, injuries, complaints, equipment issues, etc.); and  Security (opening and closing, underwater lighting, overhead lighting, doors, windows, alarms, bank deposits, etc.).

# Personnel Records
Accurate records should be maintained for all personnel.
The options for this category are varied and numerous. The following list of personnel items is offered as an outline and a starting point for developing an operations manual including, but not limited to the following: Illness and Injury Incident Reports Aquatic injuries and illnesses can occur after normal office working hours; therefore, a 24/7 system for reporting and responding to injury and illnesses at AQUATIC VENUES must be maintained. Early reporting and intervention could reduce the spread of illness or prevent additional injury.
Notify the AHJ The POOL owner/operator should immediately report to the permit issuing official any injuries resulting in death or that require emergency medical response, resuscitation or transport to medical facility, or any illness suspected of being associated with bathing water quality or use of the AQUATIC FACILITY. The POOL owner/operator will have posted and available for use the routine phone numbers and after hours phone numbers necessary for reporting to the permit issuing official. This will facilitate a rapid investigation of the incident and could result in limiting further spread of disease and additional injuries.
Most jurisdictions have some reporting requirements. This section is more comprehensive than the existing reporting requirements of many jurisdictions. Prompt reporting of significant injuries or waterborne illness allows for the permit issuing agency to immediately assess the conditions at the AQUATIC VENUE to determine if it can continue to operate safely or must be closed. Prompt reporting and investigation also allows for more accurate investigations to determine the causes of injury and illness. This information can be used to prevent future injuries or illness.

# Contamination Incidents
The Body Fluid Contamination Response Log is an important part of the administrative procedures for the venue and will document, in the case of a subsequent fecal, vomit, or blood contamination incident, that an appropriate response was conducted. A sample Body Fluid Contamination Response Log is provided below:
Policies & Management ANNEX 302
Patron-Related Management Aspects

# Signage
The purpose of this is to limit injuries and the spread of communicable disease spread by direct contact with objects. Healthy swimming messages can also be put on posters to be hung in bathroom stalls, at the AQUATIC FACILITY entrance, on the back of ticket stubs, and in group-event contracts. Ideally, signage should be provided to encourage BATHERS to take a second shower after using the toilet before reentering the AQUATIC VENUE. While this requirement may be difficult to enforce, the posting of such signs may encourage compliance. Consider the needs of clients and provide effective communication which could include signs in more than one language, Braille, etc.
Sign Messages Suggested content for WATERSLIDES should also include content on their signs to comply with the manufactures recommendations. Minimum content should include:  Rider position,  Number of riders allowed at a time,  Dispatch instructions,  Water depth at slide exit, and  Height requirement if specified by manufacturer.

# Spa Signs
See discussion on temperature and relevant data pertaining to SPA temperatures in MAHC Section 5.7.4.7.2. These data have been used to support wording for SPA venue signs.

# Suggested Spa Sign Content
- Post signs with suggested time limits (15 minutes);  It is recommended that all SPAS have the following statement included on the signage. "Depth of spa is variable. Enter with caution;"  Other suggested SPA and SAFETY equipment;  Place time clocks with numbers large enough to read from a distance on a nearby wall in clear view of all users;  Place a thermometer on the wall with numbers large enough to read from a distance or place the thermometer in the SPA itself;  Place a 15-minute timer on the water jets. The reset button should be placed at least 10 feet (3 m) from the tub so users must physically leave the tub to turn the water jets on again.

# Infants and Toddlers
Infants and toddlers are not recommended in a SPA. Small children are still developing internal temperature regulations, and infants in particular have a small body mass compared to body surface area. HOT WATER also could cause hyperthermia, and a SPA seat is not designed for a small child to sit properly to keep their head above water.
Swimmer Empowerment Methods

# Public Information and Health Messaging
The MAHC felt strongly that public education and health communication with users should be required at any INDOOR AQUATIC FACILITY. This messaging should make clear the responsibility of the user to shower before entering the POOL and that they should not urinate in the POOL. It is known that urine and sweat contribute nitrogen to the POOL resulting in chloramines. By actively limiting the introduction of urine and sweat, the result should be fewer chloramines in the POOL and the air. A summary of health and exposure data can be found in MAHC Appendix 1: Summary of Health and Exposure Data for Chemical and Biological Contaminants.

# Post Inspection Results
There are only a relatively small number of municipal organizations that require public or web-based disclosure of inspection reports. However, as inspection activity is tax payer supported, there is a growing trend toward requiring public disclosure. One recent example is the Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000, a Federal Act that requires public disclosure of coastal beach closings. Additionally, DeKalb County, Georgia requires the public posting of inspection results for AQUATIC FACILITIES as well as posting them on the internet, which is similar to the ever expanding requirement for posting inspection results at food service establishments. The posting of inspections at AQUATIC FACILITIES will increase public awareness of aquatic SAFETY and health and encourage aquatic operators to comply with all code requirements.
Most jurisdictions require the permit to be conspicuously posted. This is to inform the public that the facility has met the minimum SAFETY STANDARDS required by law.

# Fecal/Vomit/Blood Contamination Response
The following discussion gives the rationale behind the remediation recommendations. Fecal contamination of recreational water is an increasing problem in the United States and other countries. Since the mid 1980s, the number of outbreaks of diarrheal illness 491 American Academy Of Pediatrics, et al. (2002). Caring for Our Children: National Health and Safety Performance Standards; Guidelines for Out-of-Home Child Care Programs, 2nd edition. Elk Grove Village, IL: American Academy of Pediatrics and Washington, DC: American Public Health Association. Available at .
Policies & Management ANNEX 304 associated with recreational water has been increasing in the United States. 492 Of these outbreaks, disinfected, man-made swimming venues, the target of the MAHC, have had the greatest increase. These outbreaks are usually a result of people swimming while they have infectious, pathogen-containing diarrhea caused by pathogens such as Cryptosporidium, Giardia, Shigella, Salmonella, or E. coli O157:H7. Contamination of swimming water by infected persons and subsequent swallowing of contaminated water by other swimmers continues the spread of diarrheal illness.
Diarrheal illness is common in the United States with surveys indicating that 7.2-9.3% of the general public have had diarrhea in the previous month. 493 Additional studies demonstrated that people routinely have a mean of 0.14 grams (range = 0.1 to 10 grams) of fecal contamination on their buttocks and peri-anal surface. 494 The increase in outbreaks, the high prevalence of diarrheal illness in the public, and likelihood of frequent fecal contamination of POOLS by BATHERS raised the question of how to respond to overt fecal releases, particularly formed stools that were more visible, in POOLS. The need to develop a response plan was amplified by the emergence of the CHLORINEtolerant parasite Cryptosporidium as the leading cause of disinfected venue-associated outbreaks of diarrheal illness. First, formed stools were thought to be a significantly lower risk for spreading illness compared to diarrhea, since most pathogens are shed in the greatest numbers in diarrhea. As the highest risk material, diarrhea was considered the worst case contamination scenario that could potentially contain Cryptosporidium. As a result, a response should require the extreme treatment conditions needed to inactivate Cryptosporidium. Formed stool was assessed as a lower risk than diarrhea but several questions remained. Should formed stools be treated as potentially infectious materials? If so, then should the stool be treated as a potential Cryptosporidium contamination event like diarrhea (i.e., longer inactivation time) or could it be treated to inactivate all other pathogens other than Cryptosporidium (i.e., shorter inactivation time).
To collect data relevant to answering the questions above, a study to collect fecal releases from POOLS in the United States was conducted in 1999. POOL staff volunteers from across the United States collected almost 300 samples from fecal incidents that occurred at water parks and POOLS. 495 The Centers for Disease Control and Prevention then tested these samples for Cryptosporidium and Giardia. Giardia was chosen as a representative surrogate for moderately-CHLORINE resistant pathogens like hepatitis A virus and norovirus. Using conditions to inactivate Giardia would inactivate most pathogens other than Cryptosporidium. None of the sampled feces tested positive for Cryptosporidium, but Giardia was found in 4.4% of the samples collected. These results suggested that formed fecal incidents posed only a very small Cryptosporidium threat but should be treated as a risk for spreading other pathogens such as Giardia. As a
Policies & Management ANNEX 305 result of these data and the discussion above, it was decided to treat formed stools as potential Giardia contamination events, and liquid stool as potential Cryptosporidium contamination events.
It was thought that norovirus contamination posed the greatest threat from vomit contamination and that the virus would be inactivated by a formed stool response using Giardia inactivation times as discussed above. Further assessment also suggested that blood contamination of POOL water posed little health risk due to the sensitivity of bloodborne pathogens (e.g., viruses, bacteria) to environmental exposure, dilution in the water, and chlorination. In addition, POOL water exposures would lack the requisite bloodborne exposure routes needed to spread the pathogens to other people.

# Contamination Response Plan
The Fecal/Vomit/Blood CONTAMINATION RESPONSE PLAN is a vital part of the administrative procedures for the venue. All staff associated with the operation of the POOL should be aware of the response plan and trained in implementation procedures. At least one responder should be available on-site during all hours of operation.

# Contamination Training

# Minimum
A staff member trained in fecal/vomit/blood contamination response should be on site during all operational hours. OSHA discusses occupational issues related to potential bloodborne pathogen exposure in the Bloodborne Pathogens Standard, 29 CFR 1910.1030 with further discussion under General Guidance 497 and the OSHA Fact Sheet: OSHA's Bloodborne Pathogens Standard 498 .
Aquatic Venue Water Contamination Response 6.5.2.2 Physical Removal

# No Vacuum Cleaners
Questions are often received concerning the MAHC recommendation to NOT VACUUM fecal material from the POOL. When the material is drawn through the vacuum, the vacuum itself is then contaminated and must be disinfected. At the present time, the MAHC is not aware of any manufacturer that has a decontamination protocol for disinfecting fecal-, vomit-, or blood-contaminated POOL vacuum units.
Treated Many conventional test kits cannot measure FREE AVAILABLE CHLORINE levels up to 20 mg/L. Operators should use, in order of preference, a FAS-DPD titration test kit with or 496 OSHA. Bloodborne pathogens and needlestick prevention standards. Available at: . Accessed: 5/1/2013. 497 OSHA. Bloodborne pathogens and needlestick prevention. Available at: . Accessed: 5/1/2013. 498 OSHA. Fact Sheet: OSHA's bloodborne pathogen standards. Available at: . Accessed: 5/1/2013.
Policies & Management ANNEX 306 without dilutions using CHLORINE-free water, or use test strips that measure FREE AVAILABLE CHLORINE in a range that includes 20 mg/L. The inactivation time should only be started once testing indicates that the intended FREE CHLORINE  FAS-DPD should be used instead of a color comparator DPD test.
It is important that the operator use a non-stabilized CHLORINE product when raising the FREE CHLORINE RESIDUAL particularly when raising to high levels such as 40 mg/L. If a stabilized product such as dichlor or trichlor were used, a high level of cyanuric acid would remain in the POOL after the HYPERCHLORINATION process. The cyanuric acid level in POOL water can only be lowered by dilution of POOL water with make-up water. Since CHLORINE products degrade over time, it is not recommended that non-stabilized CHLORINE products be stored in case of a fecal incident. The operator could either purchase a non-stabilized product at a POOL supply store or buy unscented household bleach (sodium hypochlorite) product that has a label indicating it is EPA-REGISTERED for use as a drinking water disinfectant.
Aquatic Venue Water Contamination Disinfection 6.5.3.1 Formed-Stool Contamination For formed-stool contamination, a free CHLORINE value of 2 mg/L was selected to keep the POOL closure time to approximately 30 minutes. Other CHLORINE concentrations or closure times can be used as long as the CT inactivation value is kept constant. The CT VALUE is the concentration (C) of FREE AVAILABLE CHLORINE in mg/L multiplied by time (T) in minutes: (CT Value = C x T).
For formed-stool contaminated water the CT VALUE for Giardia ( 45) is used as a basis for calculations:
Policies & Management ANNEX 307 6.5.
Pools Containing Chlorine Stabilizers CHLORINE stabilizers such as cyanuric acid slow DISINFECTION; therefore, higher CHLORINE levels are likely necessary to reach the CT VALUE for Giardia inactivation in POOLS using CHLORINE stabilizers. However, at this time there is no standardized protocol to compensate for CHLORINE stabilizers and no data determining how the inactivation of Giardia is affected by CHLORINE stabilizers under POOL conditions. A SAFETY value of 2 has been incorporated until these data can be gathered.
Diarrheal-Stool Contamination For diarrheal-stool contamination, inactivation times are based on Cryptosporidium inactivation times. The CT VALUE for Cryptosporidium is 15,300. If a different CHLORINE concentration or inactivation time is used, an operator must ensure that the CT VALUES remain the same.
For example, to determine the length of time needed to disinfect a POOL at 20 mg/L after a diarrheal accident, use the following formula: C x T = 15,300.
Solve for time: T= 15,300  20 mg/L = 12.75 hours.
Therefore, it would take 12.75 hours to inactivate Cryptosporidium at 20 mg/L. See table below:
The CT 3log used is for a 3-log inactivation to achieve a decrease in the concentration of oocysts below one infectious dose per volume of water swallowed (1 oocyst/100 mL). Similar to the assumptions made for secondary disinfection (See MAHC Section 4.7.3.3.2.5), this calculation assumes a single contamination event (e.g. diarrheal incident) of ~100 mL could introduce 10 8 Cryptosporidium OOCYSTS into the water 499,500 . This allows for a safety factor to include smaller volume venues and still achieve the required concentration. An additional safety factor not included is the impact of the filtration system since filter oocyst removal efficacy varies widely. This may be more quantifiable in the future so that it could be included in the calculation. Volume calculations indicate that small volume AQUATIC VENUES like splash pads should be able to achieve this goal by using the CT VALUE cited:
Policies & Management ANNEX 308 10 8 oocysts / 10,000 gallons = 10 8 oocysts / (10,000 gallons X 3785.4 mL/gallon) = 2.64 OOCYSTS/mL = 264 OOCYSTS / 100 mL With the 3-log inactivation, this volume will contain 0.264 OOCYSTS per 100 mL which is below the required one OOCYST/100 mL and larger volume facilities will exceed this requirement.
Pools Containing Chlorine Stabilizers CHLORINE stabilizers such as cyanuric acid slow DISINFECTION; therefore, higher CHLORINE levels may be necessary to reach the CT VALUE for Cryptosporidium inactivation in POOLS using CHLORINE stabilizers. Limited data suggest that a 3-log inactivation of Cryptosporidium is possible in more extreme conditions when 50 PPM cyanuric acid was present in the water (pH of 6.5, FREE CHLORINE RESIDUAL of 40 mg/L). 501 The level of cyanurate mentioned above (i.e., 50 PPM) was the concentration used in the experiment and should not be construed with suggested operating conditions; POOL operators should not add additional cyanurate to a POOL to reach 50 PPM. Higher levels of stabilization (i.e., over 50 PPM) may or may not decrease DISINFECTION efficacy further so more data are needed to address the issue.
Along with the pH level and FREE CHLORINE RESIDUAL, the cyanuric acid level should be checked and adjusted if necessary prior to reopening the POOL. Data are not currently available for remediation procedures with POOLS that contain stabilized CHLORINE or cyanuric acid. CDC has extrapolated current data and has the following suggestions for remediation.
In POOL water that contains CHLORINE stabilizer such as cyanuric acid under 50 mg/L, the pH should either be lowered to 6.5 and the FREE CHLORINE RESIDUAL shall be raised to 40 mg/L using a non-stabilized CHLORINE product and maintained for at least 30 hours or an equivalent time to reach the same CT VALUE as shown in the MAHC Annex 6.5.3.2. Further data are being collected by CDC to better address the issue of HYPERCHLORINATION of Cryptosporidium in POOLS using stabilizers in POOL water that contains CHLORINE stabilizer such as cyanuric acid under 50 mg/L.
Another method for remediation could be reached by dilution, draining the POOL of enough water to reach 50 mg/L stabilizer and then following the procedure above. If that cannot be accomplished, the POOL could be drained completely and scrubbed. Vomit-Contamination For vomit contamination, the CT VALUE for norovirus is thought to be in the same range as Giardia, so the same CT VALUES are used as for a formed stool contamination. 502
Blood-Contamination If the CHLORINE or bromine residual and pH are in a satisfactory range, there is no public health reason to recommend closing a POOL due to blood contamination. Data suggest that the risk posed by potential bloodborne pathogens is greatly diminished by dilution and normal FREE CHLORINE RESIDUAL levels. However, the operator may wish to temporarily close the POOL for aesthetic reasons or to satisfy PATRON concerns.
Procedures for Brominated Pools There are no inactivation data for Giardia or Cryptosporidium for bromine or any developed protocols for how to hyperbrominate a swimming POOL and inactivate pathogens that may be present in fecal matter or vomit. Therefore, POOL operators should use CHLORINE in their DISINFECTION procedures. It should also be noted that DPD test kits cannot differentiate between CHLORINE and bromine. This is because DPD undergoes the same chemical reaction with both CHLORINE and bromine. Therefore, it is important that the POOL'S bromine residual be measured before CHLORINE is added to the POOL. This bromine residual should be taken into consideration when determining that the FREE CHLORINE RESIDUAL necessary for the type of contamination has been met (i.e., the FREE CHLORINE RESIDUAL measured minus the bromine residual should be equal to or greater than the intended FREE CHLORINE RESIDUAL). If a DPD test kit with a CHLORINE comparator is used; the total bromine residual can be determined by multiplying the FREE CHLORINE RESIDUAL by a factor of 2.2.
Policies & Management ANNEX 310
Surface Contamination Cleaning and Disinfection 6.5.4.1 Limit Access Body fluids, including blood, feces, and vomit are all considered potentially contaminated with pathogens. Therefore, spills of these fluids on the POOL DECK should be cleaned up immediately. Visible contamination should be removed first, followed by DISINFECTION of the contaminated surfaces.
Clean Surface The CDC protocol for cleaning body fluid spills from POOL DECKS entitled "Cleaning up Body Fluid Spills on Pool Surfaces" can be found on the CDC Healthy Swimming/Recreational Water website at:   .
These procedures are based on hospital infection control guidelines. 503
Contaminant Removal and Disposal Currently, there are no standardized procedures for removing CONTAMINANTS, particularly those found in biofilms/slime layers, in piping, or AQUATIC FEATURES that spray or dump water. All water features should be well drained and disinfected per manufacturer's instructions. Development of appropriate guidelines deserves further investigation and data gathering.
Disinfect Surface The efficacy of disinfectants is greatly impacted by the organic load on the surface to be disinfected. Reducing the organic load as much as possible through cleaning and removal of all visible contamination BEFORE adding disinfectant is critical to successful DISINFECTION. Contact times apply only if all visible organic material has been removed before DISINFECTION.

# AHJ Inspections

# Inspection Process
The AHJ has the authority to enter the facility for both routine inspections and to investigate reports of illness and injury. At the time of investigation, all records and facility personnel required for interviews must be available.
Policies & Management ANNEX 312 o This requirement does not apply to wiring inside walls/ceilings, etc. at an indoor POOL.

# Enforcement

# Enforcement Penalties
This is meant to apply to an AQUATIC FACILITY not making a good faith effort to correct the problem. This is not meant to apply to a closed AQUATIC FACILITY that is working on correcting an imminent health hazard or other violation (e.g., parts on order, maintenance scheduled).
7.0 MAHC Resources ANNEX 313

# MAHC Resources

# A Note about Resources:
The resources used in all MAHC modules come from peer-reviewed journals and government publications. No company-endorsed publications have been permitted to be used as a basis for writing code or annex materials.
Codes Cited within the MAHC

# MAHC
Appendices ANNEX 354
Appendix 2: Air Quality Formula NOTE: Significant numbers of public comments were received regarding the proposed increase, above ASHRAE 62 STANDARDS of required outdoor air. The commenters noted that the requirements will result in increased costs for equipment and operation while lacking adequate data to support the increase. Based on the potential negative impact and the need for additional research and data to differentiate the causes and sources of indoor air quality problems on design criteria (e.g., design, inappropriate operation, inadequate maintenance), the MAHC Committee decided to defer to ASHRAE outdoor air requirements in this version of the MAHC. The Committee thought it important to preserve the work done by the Technical Committee, so the proposed code language for additional outdoor air has been moved to Appendix 2  The following outlines the discussion by the MAHC Committee. One of the goals was to establish a more comprehensive formula than is currently published in the ASHRAE 62 ventilation document (e.g., adding additional air requirements to the minimum ASHRAE standards). The formula should include consideration for the type of feature as well as what type of water treatment is being utilized to maintain the water chemistry. The Committee realized early on that there is very little research in the off-gassing of chemicals for INDOOR AQUATIC FACILITIES. ASHRAE completed a preliminary research project 539 but did not perform detailed research on various AQUATIC VENUES and treatment methods. The Committee had to use the experience of its members on what was working in the real world and what was not working to modify the formula used in ASHRAE 62. In other words, the Committee had the final answer and developed a modified formula that yielded the desired results. This formula calculated the minimum air required in ASHRAE 62 and then added additional air TURNOVER requirements depending on the type and area of AQUATIC FEATURE or DECK/spectator area.
The matrix was set up with three types of AQUATIC VENUES: FLAT WATER, AGITATED WATER, and HOT WATER as each type of AQUATIC VENUE differs in how it affects air quality. One of the key drivers that the Committee identified that made these AQUATIC VENUES different was the expected THEORETICAL PEAK OCCUPANCY density. With increased BATHERS per unit volume of water, there is an increase in the organic contamination from the POOL users and thus the presence of combined CHLORINE or combined bromine. The second factor was how much surface area of the AQUATIC VENUE water would come in contact with the air to increase the expected off-gassing of chemicals. Design professionals experience factored into the final cfm/ft 2 . Design professionals knew from experience where the final number needed to be, added in reasonable density factors and then addressed the individual characteristics of the AQUATIC VENUES to include splashing at the surface and the temperature of the water.
To calculate the minimum cfm of fresh air required:

# Appendix 3: Dye Test Procedure
Dye testing should be performed to determine and adjust the performance of the RECIRCULATION SYSTEM. Dye studies tend to be qualitative in nature. 540 Some judgment is generally required to determine whether a dye study should be classified as passing or a failing. In general, dead zones (or areas of poor circulation) would indicate a failure that could be fixed by adjusting the INLETS or other system hydraulics. If the POOL does not reach a uniform color within 15 minutes, then adjustments are required. MAHC Appendices ANNEX 362 react with the dye. Come back the following day to make sure there is no CHLORINE, and likewise on the day of the dye study. 5. Prepare the pump by attaching the tubing to the existing piping and calibrate the flow rate to 700 mL/min. At this flow rate, the stock solution of dye will be injected into the POOL over a 16 minute period. Tube clamps may be used to secure the connection between the tubing and the connectors. 6. Prepare the filter room by laying down a trash bag (or similar item) as protection from a potential chemical spill/leak. Then place the pump and containers containing the dye stock solution and sodium hypochlorite solution on the plastic cover. 7. Prepare a location in the pipe network (preferably after the filter) to inject the chemicals. If a location does not already exist (e.g., an existing CHLORINE feed or acid feed point) then one will need to be made by tapping the pipe and inserting the proper fitting. 8. Attach the tubing from the pump to the existing or newly created injection point.

# Materials
Depending on what fitting is present you might need an adapter for the tubing.
The other end of the tubing should be placed in the chemical container holding the dye. 9. Make sure all assistants are in place to record video, take pictures, collect data, and time injection to 15 minute pass/fail observation point. 10. When ready to start, turn on the pump. The dye should begin to flow into the POOL. Start the timer at the same time as the pump is turned on (pump on, time (t) = 0 min). The stock dye solution should be depleted in 16 minutes. After 16 minutes, turn the pump off so that air will not be introduced into the system. 11. Record the time when the dye is first observed coming into the POOL. 12. Record the time when the POOL water is completely dyed (having uniform color