Immediate Closures and Violations Identified During Routine Inspections of Public Aquatic Facilities — Network for Aquatic Facility Inspection Surveillance, Five States, 2013

Introduction

Illness and injury associated with aquatic facilities^† in the United States include disease outbreaks of infectious or chemical etiology, drowning, and pool chemical^§–associated health events (e.g., respiratory distress or burns). These conditions affect persons of all ages, particularly young children, and can lead to disability or even death. Construction of public aquatic facilities for swimming, play, and relaxation increased in the United States throughout the 20th century as water treatment technology advanced (1). In 2009, swimming was the fourth most popular sports activity in the United States and the most popular among children aged 7–17 years; an estimated 50,226,000 persons aged ≥7 years swam at least six times in 2009, translating to at least 301,356,000^¶ swimming instances (2). Aquatic sector marketing data indicate that there were an estimated 309,000 public aquatic venues** throughout the United States in 2011 (3). Public aquatic facilities also have increased in size, accommodating tens of thousands of bathers per day, and have moved indoors, making swimming, play, and relaxation in aquatic venues possible year round instead of being limited to the warmer months. Moreover, with design innovations, aquatic venues have simultaneously evolved from being traditional rectangular pools to pools of various designs (e.g., interactive water play venues^††) and to include venues other than pools (e.g., hot tubs/spas).

Water-based physical activity improves physical and mental health throughout life (4) and might be the only physical activity option for those with medical restrictions. However, participants in such activities are at risk for aquatic facility–associated illness and injury. The overriding public health goal is to maximize the health benefits of water-based physical activities while minimizing the risk for illness and injury. Surveillance data are used to characterize the epidemiology of illness and injury at aquatic facilities (i.e., estimate magnitude, document distribution, and track natural history) and inform and evaluate prevention efforts (5). Existing national surveillance systems monitor the following subcategories of aquatic facility–associated illnesses and injuries: aquatic facility–associated outbreaks,^§§ drownings, and pool chemical–associated health events.

Existing National Surveillance Systems Monitoring Aquatic Facility–Associated Illness and Injury

Since 1978, CDC has tracked aquatic facility–associated outbreaks via the Waterborne Disease and Outbreak Surveillance System (WBDOSS) (http://www.cdc.gov/healthywater/surveillance/rec-water-surveillance-reports.html). An aquatic facility–associated outbreak is defined as the occurrence of similar illness in two or more persons, epidemiologically linked by location and time of exposure to recreational water or to recreational water–associated chemicals volatilized or aerosolized into the air surrounding the water. During 1978–2012, a total of 650 aquatic facility–associated outbreaks were reported to CDC (Figure). Although these reported data likely represent only a fraction of outbreaks that occurred,^¶¶ national outbreak data can be used to detect changes in the epidemiology of aquatic facility–associated outbreaks, including novel aquatic venues, emerging infectious pathogens, and the shift to indoor settings. For example, these data indicate that a spike in the incidence of outbreaks of Pseudomonas folliculitis associated with hot tubs/spas occurred in the early 1980s, when hot tubs/spas became popular but before operation and maintenance standards could be established in jurisdictions across the United States. In 1988, the first U.S. aquatic facility–associated outbreak of cryptosporidiosis was detected (6,7). Since then, the annual incidence of such reported outbreaks has increased substantially, and Cryptosporidium, the parasite that causes cryptosporidiosis, has emerged as the leading etiology of reported aquatic facility–associated outbreaks because of its extreme chlorine tolerance (8). Moreover, a focal cryptosporidiosis outbreak associated with one aquatic facility can expand into a community-wide outbreak that is associated with hundreds of aquatic facilities, affects thousands of persons (disproportionately young children), and spreads to other additional settings (e.g., child care facilities) (9). With the proliferation of indoor waterparks in recent years, CDC has increasingly received reports of aquatic facility–associated outbreaks involving indoor settings (8). The largest such outbreak to date, which occurred in Ohio in 2007, affected at least 665 persons and was caused by volatile disinfection by-products called chloramines (10). Dichloramine and trichloramine are created when chlorine oxidizes nitrogenous compounds (e.g., human waste products such as sweat and urine). Unlike monochloramine, which is commonly used to disinfect drinking water, these chloramines can cause ocular and respiratory tract irritation. Limiting the amounts of fresh air introduced and of chloramine-polluted air exhausted, particularly during colder months, increases these health effects.

Mortality data from CDC’s National Vital Statistics System (NVSS) (http://www.cdc.gov/nchs/nvss.htm) for 1999–2010 indicate that approximately 4,000 persons die from drowning each year in the United States (11). Drowning is the leading cause of injury death in children aged 1–4 years; more than half of fatal drownings in this age group occur in a pool. Nonfatal drownings annually lead to an average of approximately 5,800 U.S. emergency department (ED) visits (2005–2009) (12). More than half of the patients are children aged ≤4 years, and nearly two thirds of the nonfatal drownings in this age group occurred in pools. Half of nonfatal drownings require hospitalization and can result in severe brain damage, long-term mental and physical disabilities, and substantial health care costs.

In 2007, the New York State Department of Health (NYSDOH) asked CDC to monitor health events associated with pool chemicals (Doug Sackett, personal communication, 2007). Since then, CDC’s WBDOSS has received additional reports from New York and from other states of outbreaks caused by exposure to toxic chlorine gas. Toxic chlorine gas can be generated when chlorine and acid, which is typically used to adjust pH, are mixed by aquatics staff or in an aquatic venue’s plumbing when there is inadequate water flow. Data from the U.S. Consumer Product Safety Commission’s National Electronic Injury Surveillance System (NEISS) (http://www.cpsc.gov/en/Research–Statistics/NEISS-Injury-Data) for 2003–2012 indicate that pool chemical–associated health events annually lead to approximately 3,000–5,000 visits to U.S. EDs; almost half of the patients are aged <18 years (13–15). The most frequent diagnosis is poisoning (predominantly stemming from inhalation of vapors, fumes, or gases rather than ingestion) followed by dermatitis or conjunctivitis caused by chemical splashes onto the skin or into the eyes, respectively. In addition, CDC’s Sentinel Event Notification System for Occupational Risk data have been used to examine pool chemical–associated health events from an occupational health perspective (16), and data from ATSDR’s Hazardous Substances Emergency Events Surveillance program*** have been used to examine health events resulting from chemical spills (17).

The Model Aquatic Health Code and the Network for Aquatic Facility Inspection Surveillance

During 2007–2014, CDC and NYSDOH led a national consortium of public health and aquatics sector experts to develop the Model Aquatic Health Code (MAHC), national guidance that can be voluntarily adopted by state and local jurisdictions to minimize the risk for illness and injury at public aquatic facilities. The development of the MAHC is described elsewhere (Appendix B). In August 2014, CDC released the first edition of the MAHC (http://www.cdc.gov/mahc/index.html), which covers a full range of issues pertaining to aquatic facilities, including their design, construction, operation, maintenance, and management. The penultimate draft of the MAHC enabled CDC to launch, in 2013, the Network for Aquatic Facility Inspection Surveillance (NAFIS), which established for the first time an ongoing multijurisdictional surveillance network for aquatic facility inspection data.

Data are needed so public health authorities can evaluate whether adoption of MAHC elements minimizes the risk for illness and injury at public aquatic facilities. However, decreases in the incidence of aquatic facility–associated outbreaks, drowning, and pool chemical–associated health events attributable to adoption of MAHC design and construction elements might not be detected by existing national surveillance systems for decades. Long periods of time are likely to elapse between the writing, enactment, implementation, and enforcement of MAHC elements in a given jurisdiction and across the United States. The time to adoption and the number, if any, of MAHC elements adopted will vary across jurisdictions. Most importantly, many design and operation elements apply only to newly constructed or substantially altered aquatic facilities.

Inspections of public aquatic facilities allow a real-time assessment of their operation and maintenance, and environmental health practitioners document their inspection findings using a standardized form. Analysis of inspection data can be used to examine immediate closures and violations (i.e., inspection-outcome data) to estimate magnitude, document distribution, track natural history, and inform and evaluate prevention efforts (5). Because improper operation and maintenance represent risk for aquatic facility–associated illness and injury, NAFIS data can be used to evaluate whether adoption of MAHC elements minimizes risk for illness and injury at public aquatic facilities more immediately (i.e., within years of the release of the MAHC first edition) than existing national surveillance systems.

Methods

The primary objective of NAFIS is to enable public health authorities to evaluate whether adoption of MAHC elements minimizes the risk for illness and injury at public aquatic facilities. The secondary objective is to demonstrate the utility of inspection data and thus expand their use by state and local environmental health programs to monitor the operation and maintenance of public aquatic facilities and inform program planning, implementation, and evaluation.

Inspection of public aquatic facilities (e.g., forms used, items inspected, and inspection methods) varies across jurisdictions because individual state and local jurisdictions write, enact, implement, and enforce their own unique public health codes. Five states (Arizona, California, Florida, New York, and Texas) with the highest estimated counts of public aquatic venues were selected; 39.6% (122,412) of the estimated 309,000 U.S. public aquatic venues are located in these five states (3). CDC invited local jurisdictions (county or city) from these five states to participate in NAFIS. A total of 25 local jurisdictions agreed to report data annually to CDC, but only 16 reported 2013 data to NAFIS by September 2015.

Catchment Area

Public aquatic facility codes can vary among states and within states (i.e., counties and cities in the same state might have different codes). Florida and New York have statewide public aquatic facility codes; Arizona and California codes vary by county. CDC invited the five counties with the highest counts of public aquatic venues (as per state public health officials in each of the four respective states) to participate in NAFIS. If a county in a given state could not, the county with the sixth highest count of public aquatic venues in that state was invited. Texas public aquatic facility codes can vary within a county, and CDC invited the five most populous cities as determined by 2013 census data to participate in NAFIS (18). If one of these Texas cities could not, the sixth most populous Texas city was invited. The five counties with the highest counts of public aquatic venues in California and Florida, five of the six counties with the highest counts of public aquatic venues in Arizona and New York, and five of the six most populous Texas cities agreed to annually report data to NAFIS. By September 11, 2015, the publication cut-off date, 16 (64%) jurisdictions reported 2013 data to NAFIS (Table 1). The remaining nine (36%) jurisdictions did not report data because three jurisdictions were unable to access data, three were unable to extract data sets (i.e., all records) by the cut-off date, two did not have electronic data for 2013, and one did not respond.

Data Source and Collection

The launch of NAFIS began with the selection of elements for surveillance. CDC reviewed draft MAHC guidance before it was finalized and released in 2014 and identified approximately 50 MAHC illness and injury risk-minimizing elements that protect public health. Because of the variability in codes and inspection data collected, CDC limited NAFIS’s initial list of MAHC elements for surveillance to the 15 elements deemed critical to minimizing the risk for aquatic facility–associated illness and injury (Table 2) and most likely to be included in inspections in these jurisdictions (Table 1). Identifying violations of inspection items corresponding to these 15 critical elements could result in immediate closure because these violations represent a serious threat to public health.

Inspection of a Public Aquatic Facility

An inspection of a public aquatic facility is an assessment of whether its operation and maintenance meet the standards set in the jurisdiction’s public health code and provides a real-time snapshot of whether the facility is being operated and maintained in a way that minimizes risk for aquatic facility–associated illness and injury. There are three types of inspections: routine, complaint, and follow-up. Routine inspections are conducted one to three times per year (primarily during the warmer months) and typically result in the completion of an entire inspection form to document the findings of a full assessment of the operation and maintenance of a public aquatic facility. Complaint inspections are conducted in response to a specific complaint (e.g., from a bather). Follow-up inspections are conducted to ensure that violations that were identified during previous inspections and that resulted in immediate closure have been corrected before reopening. Environmental health practitioners conduct inspections of an entire public aquatic facility, and a separate inspection report or record documents the assessment of each aquatic venue within the public aquatic facility. If an item is inspected and found not to be in compliance with the code, a violation has been identified; violations represent risk for aquatic facility–associated illness and injury. Ideally, the inspection items with the greatest impact on public health are prioritized and identification of corresponding violations could result in immediate closure. Priority inspection items include measuring free available chlorine and pH to ascertain whether they are within the required range; confirming that the fencing, walls, and self-closing and self-latching gates and doors are in good repair; and checking that the pool chemicals have labels required by either the Occupational Safety and Health Administration or the Environmental Protection Agency and are safely and securely stored.

Data Standardization and Analysis

Initially, jurisdictions sent their inspection forms and public aquatic facility codes to CDC for review. CDC sent back, for discussion, a proposed list of inspection items that corresponded to the 15 critical illness and injury risk-minimizing MAHC elements. A jurisdiction’s list of elements was not considered finalized until it was approved by the jurisdiction. Because codes, and thus, inspection forms, items inspected, and even how the same aspect of public aquatic facility operation and maintenance is inspected vary across jurisdictions, identified violations were specific to each jurisdiction and not to an overall standard.

Reporting jurisdictions submitted an electronic data set with their 2013 aquatic facility inspection data. Only data from routine inspections were analyzed because unlike routine inspections, complaint and follow-up inspections typically focus on a subset of inspection items and do not result in a full assessment of the operation and maintenance of a public aquatic facility (i.e., the entire inspection form would not be completed to document inspection findings). Including data collected during complaint and follow-up inspections, in the analysis, could result in underestimates of the proportions of inspections that resulted in immediate closure or that identified violations.

SAS 9.3 (SAS Institute Inc., Cary, North Carolina) was used to reformat, standardize, and analyze data sets. Data sets were reformatted, as needed. For example, a data set, in which each record was an individual identified violation, was restructured into a data set, in which each record was for an inspection and included data on compliance status of multiple inspection items. If a violation was not documented for a specific inspection item, the inspection item was assumed to have been found to be in compliance (i.e., not in violation). Variable names and their respective values were standardized across data sets. Previous analysis of aquatic facility inspection data (19) indicated that these data sets do not typically include data on aquatic facility setting (e.g., apartment/condominium, hotel/motel, and waterpark). Therefore, CDC developed an algorithm to identify aquatic facility setting, using aquatic facility name. The setting algorithm used the following terms to create the setting variable: 1) “apt,” “apartment,” “condo,” “HOA,” “townhouse,” “townhome,” and “home” for the category apartment/condominium; 2) “campground” and “camp” for the category campground (e.g., campsite)/camp (e.g., summer camp or day camp); 3) “child care,” “day care,” “childcare,” and “daycare” for the category childcare; 4) “hospital,” “rehab,” “outpatient,” “medical,” “nursing,” and “assisted living facility” for the category hospital; 5) “hotel,” “motel,” “inn,” “suites,” “extended stay,” “bed and breakfast,” “hostel,” and the names of large hospitality industry chains for the category hotel/motel; 6) “fitness,” “gym,” “country club,” “athletic,” “swim school,” “YMCA,” and “sports center” for the category membership club; 7) “community” and “municipal” for the category municipal; 8) “university” and “college” for the category school/university; and 9) “waterpark” and “water park” for the category waterpark.

The setting algorithm was coded so that once the setting was classified by SAS, subsequent terms in the algorithm did not trigger a reclassification of the setting. After assigning a setting variable, aquatic facility name was deleted. A summary of findings was reported to each jurisdiction; data were not considered finalized until approved by the jurisdiction. Subsequently, the 16 individual data sets were then concatenated into one final data set.

Analyses included counts of routine inspections; median and range of counts of any violations identified per routine inspection; and proportions of routine inspections that identified at least one violation, resulted in immediate closure, or identified violations when inspecting items corresponding to the 15 critical illness and injury risk-minimizing MAHC elements. Analyses were conducted of the data overall and stratified by aquatic venue type (e.g., pool and hot tub/spa) and pool category (e.g., wading pool and interactive water play venue). The denominators in this report vary because of differences in the number of jurisdictions contributing inspection data (Table 2).

Results

Among the 16 NAFIS jurisdictions that provided data, nine (56%) reported aquatic facility inspection data that included both immediate closure and violation data, five (31%) reported only violation data, and two (13%) reported only immediate closure data. One (6%) jurisdiction included data that identified violation(s) leading to immediate closure. The number of jurisdictions contributing data to examine each critical element varied substantially, with no single jurisdiction contributing data to examine all 15 critical elements (Table 2). Fifteen (94%) of 16 data sets included data on aquatic venue type, and 12 (75%) of 16 included data on pool category However, only one (6%) of 16 included data on aquatic facility setting; almost all pool (99.5% [55,622/55,913]) and hot tub/spa (99.1% [20,259/20,449]) inspection records were missing data on aquatic facility setting. Use of the setting algorithm increased the number of inspection records with setting data; however, after the setting algorithm was run, 75.6% (42,249/55,913) of pool and 84.2% (17,213/20,449) of hot tub/spa inspection records still were missing aquatic facility setting data, thus no analyses stratified by setting were conducted.

During 2013, environmental health practitioners in the 16 NAFIS jurisdictions that reported data to CDC conducted 84,187 routine inspections of 48,632 public aquatic venues (Table 1). This corresponds to 15.7% of the estimated 309,000 venues in the United States. More than three quarters (78.9% [50,974/64,580]) of routine aquatic venue inspections identified at least one violation. The median number of violations identified per inspection was two (range: 0–21). Of the 84,187 routine inspection records, 78.5% (66,098) included data on immediate closure; 12.3% (8,118) of routine inspections resulted in immediate closure (Table 3). The most frequently reported violations representing risk for aquatic facility–associated illness were disinfectant concentration (11.9% [7,662/64,580]), pH (14.9% [9,236/62,141]), and automated chemical feeder (5.2% [3,031/57,967]) violations. The most frequently reported violations representing risk for drowning were enclosure (e.g., fence) (5.1% [3,303/64,580]) and safety equipment (12.7% [7,845/61,648]) violations.

Of the total 84,187 routine inspections, 55,913 (66.4%) were of public pools. Of 43,636 routine pool inspections, 11.8% (5,139) resulted in immediate closure. Disinfectant concentration (9.2% [3,927/42,891]), pH (12.4% [5,017/40,533]), and automated chemical feeder (6.2% [2,378/38,401]) violations were the most frequently reported violations representing risk for aquatic facility–associated illness. Enclosure (5.7% [2,449/42,891]) and safety equipment (16.6% [6,689/40,231]) violations were the most frequently reported violations representing risk for drowning. Violations representing risk for pool chemical–associated health events (i.e., labeling, storage, or security of pool chemicals) were identified during 18.1% (427/2,358) of routine pool inspections.

Of the total 84,187 routine inspections, 20,449 (24.3%) were of public hot tubs/spas. Of 14,637 routine hot tub/spa inspections, 15.1% (2,217) resulted in immediate closure. The most frequently reported violations identified during inspections of hot tubs/spas were disinfectant concentration (19.2% [2,663/13,864]), pH (27.5% [3,789/13,783]), pool chemical safety (9.9% [8/81]), and water temperature (7.5% [1,037/13,783]).

By pool category, >95% (95.8% [53,537/55,913]) of inspections were of pools, 2.9% (1,606) of wading pools, 0.1% (69) of interactive water play venues, and 1.3% (701) of other (Table 4). Because >95% of pool inspections were of “pools,” their inspection findings and those of “pools,” when the data are analyzed by aquatic venue type (e.g., pool and hot tub/spa), were nearly identical (Table 3). Of 948 routine inspections of wading pools, 21.6% (205) resulted in immediate closure (Table 4). The most frequently reported violations all represented risk for aquatic facility–associated illness: disinfectant concentration (19.2% [303/1,581]), pH (26.0% [411/1,581]), and automated chemical feeder (6.1% [94/1,539]). Of 66 routine inspections of interactive water play venues, 12.1% (eight) resulted in immediate closure. As with wading pools, the most frequently reported violations were all related to prevention of aquatic facility–associated illness: disinfectant concentration (10.1% [7/69]), pH (6.1% [4/66]), or automated chemical feeder (5.8% [4/69]).

Discussion

This report is the first to summarize data from NAFIS; 15.7% of the estimated 309,000 U.S. public aquatic venues are located in the 16 reporting jurisdictions. The findings of this report underscore the need to improve the operation and maintenance of U.S. public aquatic facilities to prevent illness and injury, as more than three quarters (78.9%) of routine inspections of public aquatic venues identified at least one violation. Multiple reports have previously examined data collected during inspections of U.S. public aquatic facilities with similar results, including analyses of 1961–1963 data from DuPage County, Illinois (20), 1999–2007 data from Plano, Texas (21), and 2005–2006 data from Nebraska (22). Three additional reports examined data collected during routine inspections of public aquatic facilities conducted in 2002 and 2008 in multiple jurisdictions across the United States (Table 5) (19,23,24). All of these reports also found that violations of public health codes are identified frequently and immediate closures of public aquatic venues frequently occur.

Of note, 12.3% of routine inspections (11.8% of pools and 15.1% of hot tubs/spas) resulted in immediate closure and violations of inspection items that corresponded to the 15 critical illness and injury risk-minimizing MAHC elements were identified frequently (Table 3) (Table 4). These findings underscore the public health function that code enforcement, conducted by environmental health practitioners, plays in preventing illness and injury at public aquatic facilities. During inspections, environmental health practitioners can serve as illness-and-injury-prevention advisors to aquatic facility operators. Immediate closures and identified violations offer an opportunity to educate operators about how to properly operate and maintain aquatic facilities and why these measures are necessary, to prevent repeated violations of a given operation or maintenance standard in public aquatic facility codes. Currently, only 68% of U.S. local public health agencies regulate, inspect, or license public aquatic facilities (25).

Minimizing Risk for Aquatic Facility–Associated Outbreaks of Infectious Etiology

In aquatic facilities, halogenation (e.g., chlorination or bromination) is the primary barrier to the transmission of infectious pathogens; proper pH ensures that the more active form of the halogen is available to inactivate infectious pathogens, and the automated chemical feeder delivers the halogen and pH-adjusting chemical. ^††† Outbreaks of acute gastrointestinal illness caused by halogen-susceptible pathogens do not occur unless the disinfectant concentration is inadequate; pH is improper; the automated chemical feeder is in poor condition or inoperable; or an operator error has occurred. Environmental health practitioners in the 16 reporting NAFIS jurisdictions identified disinfectant concentration, pH, and automated chemical feeder violations during 11.9%, 14.9%, and 5.2% of all inspections, respectively. These findings are corroborated by national data on outbreaks of infectious etiology; during 2003–2012, halogen-susceptible pathogens caused 15.2–20.2% of aquatic facility–associated outbreaks of acute gastrointestinal illness.^§§§ Transmission of halogen-susceptible infectious pathogens (e.g., E. coli O157:H7 or Shigella spp.) can be prevented at MAHC-recommended disinfectant concentrations (1 ppm minimum free available chlorine [MAHC 5.7.3.1.1.2^¶¶¶] or 3 ppm minimum free available bromine [MAHC 5.7.3.1.2.2]) at pH 7.2–7.8 (MAHC 5.7.3.4.1). To minimize the incidence of disinfectant concentration and pH violations, aquatic facility operators (MAHC 6.3.1.1) should complete a training course (MAHC 6.1.1.1) (22,26) that covers water disinfection and chemistry, mechanical systems (including automated chemical feeders), and other risk management strategies (MAHC 6.1.2).

Disinfectant concentration and pH violations were frequently documented at wading pools and interactive water play venues. Both of these aquatic venue types have features that make it more difficult to maintain halogen levels: wading pools are typically shallow, which facilitates halogen depletion by the sun’s ultraviolet light, and interactive water play venues typically aerosolize the water, which depletes halogens. Wading pools and interactive water play venues are designed and intended for young children. Young children are more likely to experience acute gastrointestinal illnesses, such as cryptosporidiosis (caused by the extremely halogen-tolerant Cryptosporidium) (27–29), and are more likely to contaminate the water because they either are incontinent or have inadequate toileting and hygiene skills. Contamination can occur via direct release of formed or diarrheal feces (30), or as much as 10 grams of fecal material can rinse off a young child’s perianal surface and into the water (31). Furthermore, swim diapers do not prevent feces, urine, or infectious pathogens from contaminating the water (32); and oxidation of organic or nitrogenous compounds (e.g., feces and urine) released or rinsed into the water deplete the halogen. In addition, young children typically ingest more recreational water than adults (33), putting them at increased risk for infection if pathogens are present. Consequently, maintaining proper disinfectant concentration and pH, combined with effective control of the automated chemical feeder, is particularly critical in these aquatic venues. The MAHC classifies wading pools and interactive water play venues as “increased-risk aquatic venues” and recommends all such newly constructed or substantially altered aquatic venues include secondary disinfection systems (e.g., ultraviolet light or ozone [MAHC 4.7.3.3]) to achieve at least 3-log₁₀ (99.9%) inactivation of Cryptosporidium.

Disinfectant concentration and pH violations were also frequently documented at hot tubs/spas. Maintaining adequate disinfectant concentration in hot tubs/spas can be particularly difficult, because the halogen can be depleted by both the higher water temperatures and aerosolization of water by jets. Moreover, thermophilic infectious pathogens, such as Pseudomonas aeruginosa and Legionella spp., can colonize and amplify in hot tubs/spas in which the disinfectant concentration is inadequately maintained (34,35), leading to biofilm build-up that can protect these pathogens from disinfectants, even when adequate disinfectant concentration is maintained (36). During 2003–2012, Pseudomonas aeruginosa and Legionella spp. were confirmed or suspected to have caused 77 hot tub–/spa-associated outbreaks (8,15,37–39). To increase the likelihood that adequate disinfectant concentration is maintained, facility operators should ensure that hot tubs/spas have higher minimum disinfectant concentrations (3 ppm minimum free available chlorine [MAHC 5.7.3.1.1.2.3] or 4 ppm minimum free available bromine [MAHC 5.7.3.1.2.2]) than other aquatic venues. In addition, because cyanuric acid (which prevents halogen depletion by the sun’s ultraviolet light) increases inactivation times of infectious pathogens (40–43), cyanuric acid should not be used in hot tubs/spas (MAHC 5.7.3.1.3.1). Debris and organic materials (which deplete halogens) and biofilm should be removed from the water and accessible surfaces of hot tubs/spas (MAHC 5.6.10.6.1) and there should be more frequent draining and cleaning of hot tubs/spas than other aquatic venues (MAHC 5.12.7.2). Finally, aquatic facility operators or responsible supervisors should conduct routine checks, in part to ensure biofilm has been removed from accessible surfaces, prior to facility opening (MAHC 6.4.1.3.1).

Minimizing Risk for Drowning, Pool Chemical–Associated Health Events, and Other Injuries

Maintaining enclosures (e.g., fencing, walls, and self-closing and self-latching gates and doors) (44) and safety equipment (e.g., hook or ring) at aquatic facilities minimizes the risk for drowning. Violations of these safety measures were documented by environmental health practitioners during 5.7% and 16.6%, respectively, of routine pool inspections. Enclosures should be maintained at all times (MAHC 5.6.10.5.1) and newly constructed or substantially altered aquatic facilities should have 6-foot fences (MAHC 4.8.6.2.4.2) and fencing mesh with no greater than a 1.75-inch opening to minimize scalability by young children (MAHC 4.8.6.2.1.2). Routine checks to ensure safety equipment is in place and in good repair should be conducted prior to facility opening (MAHC 6.4.1.3.1); if all required equipment is not present, the venue should be immediately closed (MAHC 6.6.3.1). Bather surveillance by trained lifeguards is another strategy to minimize the risk for drowning, but drowning can occur even in the presence of lifeguards (45). Lifeguard staffing should include clear and unobstructed zones of surveillance, and lifeguard staffing numbers should be based on the number of zones needed to have 100% unobstructed vision of the entire aquatic venue (MAHC 6.3.3.1.1, 6.3.3.1.2, and 6.3.3.1.3). To help minimize the risk for main drain–associated entrapment,**** aquatic facility operator training should include the requirements of the Virginia Graeme Baker Pool and Spa Safety Act (MAHC 6.1.2.1.4.7).

Risk for pool chemical–associated health events can be minimized through proper pool chemical labeling, storage, and security. Violations of this critical element were documented by environmental health practitioners during 18.1% and 9.9% of routine inspections of pools and hot tubs/spas, respectively. Data reported elsewhere indicate that 87% (27/31) of reported pool chemical–associated health events resulted from mixing incompatible chemicals, and 69% (25/36) of pool chemical–associated health events were caused by poor chemical storage or handling practices (14). Aquatic facility operator training should include pool chemical safety (e.g., how to read pool chemical labels required by the Occupational Safety and Health Administration or the Environmental Protection Agency [MAHC 5.9.2.1.1] to identify incompatible chemical[s] and personal protective equipment needed for safe handling) (MAHC 6.1.2.1.4.6). Safe chemical storage practices include preventing access by unauthorized persons, such as children (MAHC 5.9.1.4); safe chemical handling practices include adding a concentrated pool chemical to water when diluting and not vice versa to prevent splashing of the concentrated chemical, potentially explosive reactions, and release of toxic chlorine gas (MAHC 5.9.2.4.2.1). Exposure to chemical vapors, fumes, or gases should be minimized by ensuring there is no air movement from the chemical storage area into any other interior space of a building intended for occupation (MAHC 4.9.2.6.1). Finally, when the recirculation pump shuts down or fails to generate adequate flow but the automated chemical feeder pumps continue to inject concentrated chlorine and acid into the water, the mixing of concentrated chemicals produces toxic chlorine gas. Restarting the recirculation pump then vents the toxic chlorine gas from the venue plumbing and into the aquatic venue. To prevent this from happening, an electrical interlock should be installed between the automated chemical feeders, the recirculation pumps, and water flow meter/flow switch to shut down automated chemical feeder pumps if the recirculation pumps shut down or there is inadequate water flow in the venue plumbing (MAHC 4.7.3.2.1.3).

Violations related to water temperature were documented during 7.5% of routine inspections of hot tubs/spas. Sitting in high temperature water for a prolonged time essentially mimics fever and poses a risk for hyperthermia in vulnerable persons. For example, young children are still developing the ability to regulate body temperature, and body temperature regulation is especially difficult for infants given their small body mass relative to their body surface area. In addition, data suggest that hot tub/spa use by pregnant women, particularly in the first trimester, might be associated with birth defects (46,47). To minimize the risk for injury related to water temperature, the water temperature should not exceed 104° F (40° C) (MAHC 5.7.4.7.2). Hot tub/spa signage should include text indicating that children aged <5 years are prohibited from using hot tubs/spas, pregnant women should not use the hot tub/spa without prior consultation with a health care provider, and the water temperature should not exceed 104º F (40º C) (MAHC 6.4.2.2.3.7). Aquatic facility operators might consider providing accurate thermometers that allow bathers to easily check the hot tub/spa water temperature before entering.

Improving the Collection and Storage of Aquatic Facility Inspection Data

The process of submitting, reformatting, standardizing, and analyzing 2013 NAFIS data highlighted several areas where the collection and storage of aquatic facility inspection data could be improved. First, data on aquatic facility setting (e.g., apartment/condominium, hotel/motel, and waterpark) were not included in most submitted data sets and pool category (e.g., wading pool and interactive water play venue) for almost all inspected pools was designated as “pool” instead of a specific type of pool. This precluded the characterization of the distribution of immediate closures and violations by aquatic facility setting and limited characterization by pool category. Collecting aquatic facility setting, aquatic venue type, and pool category data enable identification of increased-risk settings, aquatic venue types, and pool categories. Second, data on quantitative results of water quality testing conducted during inspections were not collected or submitted, limiting the interpretation of disinfectant concentration and pH violation data. Quantitative results of water quality testing are particularly useful when there are different public health implications related to upper and lower limits of mandated water quality parameters. For example, as pH decreases below 7.2, disinfection effectiveness increases because more of the active form of the halogen (e.g., hypochlorous acid) is formed; however, as pH decreases below 7.2, bathers are increasingly likely to experience skin and eye irritation and the aquatic venue plumbing is more likely to corrode. Alternatively, as pH increases above 7.8, disinfection effectiveness decreases (because less of the active form of the halogen is available for disinfection), and bathers are again increasingly likely to experience skin and eye irritation. Third, data for which specific inspection items resulted in immediate closures were submitted by only one jurisdiction; these data enable more in-depth characterization of immediate closures and identification of operator training needs. The structure of inspection forms and design of the electronic databases can also be optimized to facilitate analysis. For 10 (67%) of 15 critical illness and injury risk-minimizing MAHC elements (Table 2), at least one NAFIS jurisdiction combined data on multiple inspection items. While this practice expedites data collection and entry and limits data storage needs, it precludes analysis of individual inspection items and leads to an underestimate of the total number of identified violations. Assessing and documenting findings for individual inspection items enables a more comprehensive picture of the operation and maintenance of public aquatic venues. Additionally, structuring databases to efficiently document whether each individual inspection item was in compliance, in violation, or not inspected, could allow for the inclusion of complaint and follow-up inspection data in analyses. Finally, nine (36%) NAFIS jurisdictions could not participate in this report. Not all NAFIS jurisdictions had electronic data, and among those that did have electronic data, not all could readily access or retrieve their data in time to collaborate on this report. CDC has developed two resources to help optimize the collection and analysis of aquatic facility inspection data: a draft model inspection form (http://www.cdc.gov/mahc/tools-forms.html), which includes approximately 50 MAHC illness and injury risk-minimizing elements that protect public health, and a set of recommendations to improve data collection and database construction (http://www.cdc.gov/healthywater/swimming/pools/regulation/recommendations-pool-inspection-data-collection.html).

Future Directions

To optimize the analysis and collection of aquatic facility inspection data, and thus the application of findings, a collaboration of federal, state, and local partners from different disciplines is needed and should include environmental health practitioners with technical knowledge about the operation and maintenance of public aquatic facilities and with inspection experience, epidemiologists skilled in conducting surveillance and data analysis, and information technology specialists with expertise in database construction. This collaboration could provide input on identifying public aquatic facility code elements deemed critical to protecting public health and on the creation of needed resources (e.g., standard inspection forms, training for inspectors, criteria for the construction of databases, and tools to analyze data).

The Council for the Model Aquatic Health Code (CMAHC; http://www.cmahc.org), a national clearinghouse for MAHC change requests that are relayed back to CDC (Appendix B), could facilitate this collaboration and development of resources. This collaboration could, to some degree, standardize data across jurisdictions, including jurisdictions participating in NAFIS. This would enable cross-jurisdictional comparisons, further elucidating the epidemiology of immediate closures and violations of public aquatic facility codes and enabling sharing of environmental health aquatic inspection program lessons learned. Additionally, analysis of NAFIS data can also be used to prioritize revisions or updates to the MAHC itself.

The CMAHC-facilitated collaboration could also serve as a model for the creation of multidisciplinary teams within state or local jurisdictions. These teams could adapt resources as needed for their individual state or local jurisdictions. This team-based approach would increase state and local capacity to use data to inform environmental health aquatic inspection program planning, implementation, and evaluation. Beyond optimizing aquatic facility inspection data for surveillance at the local, state, and multijurisdictional level, these principles can be applied to data collected by other state and local environmental health inspection programs, including those focused on food service establishments and childcare settings.

Limitations

The findings in this report are subject to at least three limitations. First, these data are not generalizable to U.S. public aquatic facilities and venues nationwide. Second, the number of public aquatic venues inspected and the frequency of routine inspections differs by jurisdiction; thus, some jurisdictions (e.g., Maricopa County in Arizona and Orange County in California) contributed a higher proportion of inspection records to this analysis than other jurisdictions. Finally, the variability in public health codes, and thus in inspection forms, items inspected, and how the same aspect of public aquatic facility operation and maintenance is inspected across jurisdictions limited data analysis (i.e., violations were specific to each jurisdiction and not to an overall standard).

Conclusion

With an estimated 15.7% of U.S. public aquatic venues under surveillance, NAFIS is the first ongoing multijurisdictional surveillance network to use aquatic facility inspection data to monitor the operation and maintenance of public aquatic facilities in the United States. The findings of this report and others (19,23,24), while not directly comparable, are similar: operation and maintenance violations and consequent immediate closures of U.S. public aquatic venues frequently occur. The findings of this report also demonstrate the utility of aquatic facility inspection data; highlight the potential of these data to inform state and local environmental health aquatic inspection program planning, implementation, and evaluation; and underscore the public health function that code enforcement, conducted by environmental health practitioners, plays in preventing illness and injury at public aquatic facilities.

For the aquatics sector and public health to continue to minimize the risk for illness and injury at public aquatic facilities, the following measures are recommended: 1) expanded use of inspection data to inform state and local environmental health aquatic inspection program planning, implementation, and evaluation and 2) broad participation in CMAHC to keep the MAHC current and up to date. Adoption, implementation, and enforcement of the MAHC elements in jurisdictions across the United States could help minimize illness and injury at public aquatic facilities. Collaboration among environmental health practitioners, epidemiologists, and IT specialists nationally and within individual state and local jurisdictions is essential to optimizing aquatic facility inspection data collection and evaluating whether the adoption of MAHC elements minimizes illness and injury at public aquatic facilities.