The Lowdown: When guests at a new Great Wolf Lodge began complaining of health issues,

operators knew they had to do something. The problem was chloramines, and one part of the  solution was to lower airflow vents to make them closer to the water level. This helps evacuate more of the worst air, while directly replacing it with the freshest air.
The Lowdown: When guests at a new Great Wolf Lodge began complaining of health issues, operators knew they had to do something. The problem was chloramines, and one part of the  solution was to lower airflow vents to make them closer to the water level. This helps evacuate more of the worst air, while directly replacing it with the freshest air.

In December 2006 Great Wolf Lodge in Mason, Ohio, opened as the ninth indoor waterpark resort for the brand. Opening an 84-degree indoor waterpark in the middle of winter in Ohio was expected to be a draw to the region. What wasn’t expected were issues with indoor air quality. 

After a successful grand opening, the property was in full swing by the time flu season heated up. Perhaps that’s why a number of guests reported flu-like symptoms, such as coughing. A logical conclusion, but the fact that some guests reported skin irritation (which can result from prolonged exposure to a chlorinated environment, especially during a dry, cold winter) meant perhaps the culprit was something else: chloramines.

Found wherever there are swimming pools, these chemical compounds are produced when organic agents such as sweat or urine mix with the chlorine in the water.

But how could that be a problem at our brand-new facility? Our air and water quality tested safe and normal. The waterpark was in compliance with all the state Health Department and Agriculture Department regulations, and we exceeded compliance with the Ohio Basic Building Code for our ventilation system. Still, this information proved contrary to the unfavorable effects that some guests were experiencing.

The local health department, Warren County Combined Boards of Health, was made aware of these conditions and asked for the assistance of the National Institute of Occupational Safety and Health. As a result, an investigation was launched in March 2007.

Up until this point, indoor air quality was determined by engineering meant for natatoriums. At the time, this was thought to be sufficient, but maybe there was a better way for our waterpark. I began reading every bit of research I could get my hands on. In addition to NIOSH’s investigation, which we actively participated in, we brought in a nationally recognized ventilation expert and worked with our design/engineering firm to find solutions.

After 15 months of ongoing investigation, the NIOSH report was issued. The findings attributed the short-term discomfort in less than 1 percent of the total bathers to elevated levels of chloramines during high bather load periods. The results of NIOSH’s testing showed our chloramine levels were in the range of other indoor swimming pool environments where irritation could occur. This information was beneficial because there isn’t an exposure standard for chloramines, and we finally had scientific research on which to base our design and operations.

In the end, we made operational changes that defied traditional waterpark operations and HVAC philosophies. I am proud to say that we proactively completed the vast majority of NIOSH’s recommendations well before the report was released. In fact, many of the recommendations were changes we suggested and were implemented immediately.

First, while our chlorine levels have always been in the safe and normal range for disinfection, we recognized that some more sensitive guests can have a reaction even to approved levels for chlorinated water, especially in cases of prolonged exposure. The levels suggested by health departments often are meant for outdoor pools that experience UV and high user loads that peak suddenly. But we have indoor pools with a limited occupancy, so, with permission from the Ohio Agriculture Department and the Ohio Health Department, we voluntarily reduced chlorine levels. This allowed us to maintain chlorine near 1 ppm, and a lower pH near 7.2 – 7.4 because we had excellent control and UV for disinfection.

Second, we’ve always met or exceeded state ventilation requirements, but we took our ventilation system a step further and increased our waterpark’s air flow by 10 percent. We also lowered our return vents so we would collecting the worst air near the pool surfaces. To help further improve air flow near the pool surfaces, we also dropped our supply vents and decreased our chlorine levels to close to 1.2 ppm and our pH to 7.3. Less chlorine means we were making fewer chloramines. We have to keep pH low to make sure we were reaching optimum disinfection. These practices were very different from traditional water chemistry for high bather load facilities. 

While all of the recommendations from the NIOSH report were implemented, it is important to note that in a cold weather climate, it is hard for anyone to guarantee that someone won’t feel skin irritation if they have dry skin, are sensitive to chlorine and stay in a chlorinated environment for prolonged periods of time. It’s also difficult to predict how many people will have flu-like symptoms during flu season, as well as to discern the cause of their symptoms.

For that reason, we also focused on education. We expanded our employee education and reporting process to be able to identify and resolve any health concerns immediately.

To ensure that all guests have the best possible visit, we increased education at all points, including check-in, in guest rooms, and in the waterpark. This included a recommendation that guests take soap showers before and after using the waterpark. Additionally, we recommend limiting hot tub usage to 15 minutes at a time.

As an industry leader, Great Wolf Resorts is determined to lead the nation in the development of waterpark technology and safety standards. That's why we’ve  also used the research we gathered over the past two years to educate others. I lead the subcommittee on ventilation for the Model Aquatic Health Code project, which is being championed by the Centers for Disease Control and Prevention. Along with that, I’ve presented seminars to operators, designers and sanitarians at the World Waterpark Association annual symposium, the Ohio Indoor Air Quality summit, and the American Industrial Hygienists Association annual convention.

After the NIOSH air quality report was released, we also worked diligently to regain trust. We wanted previous guests and prospective guests to know  that the indoor waterpark at Great Wolf Lodge in Mason is safe. Since it opened, nearly 1 million guests have experienced our indoor waterpark.

In the end, I’m proud to say our improvements have become a part of our regular operations and as a result of our hard work, Warren County Combined Boards of Health has not received any additional complaints since the original cases nearly three years ago.