How many ways can you test for chlorine in recreational water? (50m Lecture)

Abstract: A lecture to describe, explain, and compare the currently available testing methods for the determination of chlorine in recreational waters which are commonly inspected by environmental health officials. Discussion will also include testing interferences and the advantages and disadvantages of using one method over another. 

Session Description/Teaser: If you only thought there was one way to test for chlorine, come to this lecture to find out how many more there really are!
 
Objective #1: Know the different methods available for testing chlorine Objective #2: Test a water sample for chlorine accurately
Objective #3: Identify interferences when testing water

Hot Tub/Spa Inspections — United States, 2002, 2008, and Beyond (50m Lecture)

State and local health departments routinely inspect public hot tubs/spas to assess compliance with regulatory standards. These inspections are the primary means of protecting public health by ensuring good operation and maintenance. In 2002, two state and four local health departments partnered with CDC to report on an analysis of data from hot tub/spa inspections conducted May 1–September 1, 2002. 

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The six sites were a convenience sample of hot tub/spa inspection programs that maintained electronic databases. Collected data included water chemistry, filtration/recirculation system, and policy/management (e.g., record keeping) inspection items. Code noncompliance was documented by recording the corresponding violation.

The 2002 study revealed 5,378 violations were identified during 5,209 hot tub/spa inspections. The majority of inspections (56.8%) found >1 violation(s) (median: one; range: one to eight); 11.0% of inspections resulted in immediate hot tub/spa closure due to serious violations. Disinfectant residual violations were identified during 17.1% of inspections. The proportion of inspections identifying disinfectant residual violations, by setting, ranged from 9.1% at private clubs/gyms to 21.9% at campgrounds.

The 2002 study highlighted the need for aquatic inspections and garnered intense media attention for environmental health pool programs. Budget cuts threaten pool inspection programs across the U.S. warranting a follow-up study that underscores their importance. Six state and 12 local health departments collaborated with CDC to produce a second snapshot of ~40,000 hot tub/spa inspections conducted in 2008. Hot tub/spa inspection data can be used not only to justify the need for inspection programs but also yield critical information to direct public health–decision making. For example, state and local programs can collect and then analyze inspection data to identify venues with repeated violations that threaten public health and consequently target educational and regulatory enforcement activities towards those venues. CDC is currently piloting a national surveillance system that collects inspection data. The findings of the analysis of these data will be used to direct the development of CDC resources.

Pool and Spa Safety Act Program Implementation and Findings in Seattle and King County (20m Lecture)

The Pool and Spa Safety Act is complicated. The requirements created challenges as well an opportunity to revamp our Water Recreation Program to improve the health and safety of our pools. It takes a team to know if a pool is in compliance with the P&SSA. You cannot rely on the owner, installer, engineer, or pool operator to know if it’s in compliance. You must confirm what is under the cover, are there outlet pipes under the cover or have they been abandoned, what is the distance between the covers, is the SVRS installed properly, does it activates when the drain is covered, what is the flow rate, does the pump meet flow rate and TDH requirements without exceeding piping and cover requirements, cover installation adequate, equalizers, etc. A power point presentation will show the implementation of Seattle and King County’s P&SSA compliance program and the results of nearly 1,000 inspections. It will include a short video demonstrating the testing of a Safety Vacuum Release System (SVRS). Attendees will be encouraged to share their experience and findings in a collaborative effort to promote better awareness of the P&SSA and pool safety.

Rethinking Recreational Water Monitoring: Can predictive modelling increase public health outcomes? (50m Lecture)

 First, we will give an overview of current practices the management of recreational water in Canada, drawn from Health Canada’s Guidelines for Canadian Recreational Water Quality, as well as province- and district-specific standards and protocols from across the country. This description will include identifying the decision makers, a description of the different methods used in employing the geometric mean, and a description of current posting practices. We will put Canadian practices in an international context by comparing them with the guidelines put forth by the U.S. EPA and the WHO. Then, we will describe the challenges of enforcing standards in boundary regions where differing practices are drawn into sharp contrast for the public eye, dominating interactions with the media.

 
Next, we will review on the use of the geometric mean. The research questions include what are the limitations of using bacteriology in general, and the geometric mean of E. coli in particular, as the basis of decision-making with respect to the safety of recreational water, and what are the most appropriate, evidence-based cut-offs for values of the geometric mean for water to be considered safe or unsafe? Peer-reviewed studies of the strategies (comprehensive, geometric mean, etc.) used in the management of recreational water, peer-reviewed epidemiological studies of swimming-related gastroenteritis, as well as case reports and the results of outbreak investigations linked to recreational water use, that include information about geometric mean, and grey literature on recreational water quality criteria such as reports by governments and NGOs are considered within the scope of this review. Next, in light of our findings on the geometric mean, we will discuss the potential benefits of a comprehensive risk assessment strategy, forecasting models, and risk management approaches to posting. We will make recommendations aimed at those charged with making decisions about recreational water safety. The emphasis of the recommendations will be on the actions that can be taken to mitigate the problems that exist with the geometric mean. Possible recommendations include: the development of a forecasting model, the use of standardized posting signs, and the development of a communication plan.

Swimmer Recall on a Recreational Waterborne Illness Outbreak Questionnaire (50m Lecture)

Swimming pool outbreak investigators often rely on swimmers to recall pool-use activities and behaviors by questionnaire, as Recreational Waterborne Illness (RWI) does not occur immediately after exposure. Recall bias is common when questionnaires are used in retrospective data collection, and can alter the validity of associations found during statistical analysis. The purpose of this study was to assess swimmer activity recall on a self-administered questionnaire developed for RWI outbreak investigators in order to identify questions that need improvement. Questions associated with recall bias were identified by issuing the questionnaire once immediately and once one week after study participants swam in pool water. Participants experienced the most difficulty recalling reported water ingestion volumes (28% difference), skill level (25% difference), swimming in the deep end (23% difference), getting water up the nose (22% difference), and diving (22% difference). Activities and behaviors statistically associated with RWI incidence are often used to identify risk factors of disease, and where research and mitigation

strategies should focus. Results from this research suggest pool outbreak investigators should consider and/or disclose response recall uncertainties when reporting statistical associations between RWI and swimmer activities, and that questions with high response rate differences should be adjusted in future exposure assessments.

Chlorine resistant pathogen treatment strategies for recreational water (50m Lecture)

Because chlorine resistant pathogens such as cryptosporidium can survive for extended periods of time in even well maintained swimming pools, multipronged approaches are useful in prevention of disease transmission from these pathogens. This presentation will cover the various approaches that are available for treatment of cryptosporidium, including UV, ozone, filtration, enhanced filtration, and traditional sanitizers such as chlorine. Practical application of these treatment options will be discussed as well as published efficacy data and factors that influence the efficacy of these treatments.