Pool Reflections …
A day in the life of a Florida public pool inspector
By Lauren Broom Why are proper disinfectant levels important to a pool tech?
Disinfection is the process that kills recreational water illnesses and algae in the water. Disinfection is not instantaneous and needs time to work in the pool water. The higher the amount of disinfectant in the water the more quickly it can sanitize the water. The majority of recreational water illnesses are killed within one minute with recommended minimum levels of disinfectant. The only exception to this rule is Cryptosporidium. The oocysts of this protozoan parasite can survive at disinfectant levels that most health agencies require daily in a public pool. A pool operator needs to follow the CDC fecal guidelines for diarrheal accidents in the water when it is known that a person diagnosed with Crypto, or an animal was in the pool.
Proper disinfection of pool water is a very important responsibility of a pool tech. A pool that is properly disinfected maintains conditions that minimize algae growth and recreational water illness outbreaks. Pools without disinfectant can appear clear to the pool tech if not enough time has elapsed for algae growth. The pool tech needs to remember that recreational water illnesses cannot be seen by the human eye and regardless of the amount of time without disinfectant in the water they can be present and survive. The disinfectant level should be checked and recorded on each visit. There are many things that can reduce chlorine levels in the water. These can include sunlight, dirt, debris, skin, animal contamination and fecal matter from swimmers.
Specifically for chlorine disinfection, pH level is as important as the disinfectant level. pH levels have a direct affect on how active the chlorine is in the water.
Higher pH levels lower the activity of the chlorine making it not effective at killing germs or algae. Lower pH levels create a satisfactory environment for chlorine to disinfect, but swimmers will complain about eye and skin irritation. The pool tech must maintain a good balance with pH levels in the water in order to optimize the activity of the chlorine in the water.
Bromine disinfection is not affected by changes in pH level like chlorine disinfection. Therefore, many pool techs use bromine on commercial public spas and hot tubs because pH levels do not change as quickly with use.
Florida Disinfectant Levels
Florida Department of Health requires disinfectant levels be maintained within
Lauren Broom is a Certified Pool Operator Course, CPO ® , instructor and a former health inspector for the Florida Department of Health. Lauren has a Bachelor of Science Degree in Biology and is a registered sanitarian.
She has 16-years of experience in commercial pool inspections and waterborne disease outbreak investigations.
Lauren lives in Palm Bay, Florida with her husband of 17 years and their 3 children. Lauren can be reached at [email protected]
Lauren Broom the levels specified in Chapter 64E-9, Florida Administrative Code. If these levels cannot be maintained with an automatic disinfection feeder, then the pool must be closed by the pool tech until this violation can be corrected.
The Florida public pool code enforces the disinfectant level and requires a facility be closed immediately by the pool inspector if the disinfectant levels do not follow the above parameters. A missing or inoperable disinfection feeder would also require immediate closure by the inspector.
Legionella Outbreak in Public Spa
During my time with the Florida Department of Health (FLDOH) as a pool inspector, one of the most memorable inspections involved a commercial spa at a 55 plus community. The spa was possibly the source of a Legionella pneumophila outbreak among 2 residents who lived in the community. These two residents were active with pneumonia-like symptoms and tested positive with an urine antigen test. Upon an epidemiological investigation, it was determined that the only commonality between the Legionella cases was the spa in the community that both had used.
After the residents’ Legionella cases were interviewed, an inspection was conducted by the FLDOH within 2 days. The inspector found no disinfectant in the spa, and high pH levels. The ORP controller was also inoperable. The inspector immediately closed the spa. Eventually there was a lawsuit against the licensed pool service contractor and the property owner. The contributing factors which could have triggered this Legionella outbreak were lack of disinfection, inoperable ORP controller and high pH level. High pH levels inactivated any chlorine that may have been present. The inoperable ORP controller caused the disinfection feeder to also be inoperable.
Chemical Overdosing in Public Spas
Another dangerous condition that occurred a couple times in my career was disinfectant chemical overdosing.
The first example was a spa that was inspected early in the morning, possibly after the pool tech had just hand fed sodium hypochlorite to the water.
The chlorine level in this spa was at 58 ppm. The liquid disinfection feeder was inoperable and most likely the pool tech was hand feeding the spa with sodium hypochlorite.
While hand-feeding is allowed under normal conditions within FLDOH rules, a chemical disinfection feeder must be operable to feed disinfectant in small increments over long periods of time. This rule exists to reduce the likelihood of chemical overdosing.
The second example started with an anonymously phoned in complaint. The complaint stated that after using the community’s public spa, the “hair on their legs had burned off.”
Upon inspection the chlorine level was found to be at 30 ppm, and the ORP controller was not operating correctly. The feeder had somehow overfed the spa with sodium hypochlorite.
Insurance & Disinfection Levels
I spoke with Ray Arouesty at HUB International about common claims concerning disinfection issues including
ORP controller Low ORP, high pH levels on public spa
overdosing of chemicals, especially in hot tubs or spas with a smaller amount of water. Arouesty stated he had a large case involving a liquid chemical feeder that failed and was in a constant running position. An 800 gallon spa was fed by a liquid disinfection feeder from a 5 gallon storage container. The failed chemical feeder put in over 750 ppm of chlorine in a few hours. During this time, two people had used the spa for a couple hours. The high disinfectant levels resulted in extreme burns from the neck down along with loss of hair and damaged skin. The ensuing litigation involved the pool tech and the property owner, as well as the chemical feeder manufacturer for product liability. Arouesty also said that he hasn’t had any claims involving pools or spas that used Oxidation Reductions Potential (ORP) controllers.
Waterborne disease insurance claims are infrequent but are the second most significant in terms of claims payouts. Arouesty said “I don’t get a lot of them, but the ones that I do get are pretty high valued in terms of dollar signs.” The claims are usually a result of lack of disinfection in the water that leads to outbreaks or infections of Pseudomonas aerginosa, E. coli or especially Legionella pneomophila. Arouesty noted that as little as 0.6 ppm of chlorine disinfectant will kill RWI’s with the exception being Cryptosporidium. This means that 0.6 ppm is enough chlorine to maintain safe water. “It does not take that much disinfectant to keep pool water safe. The most important task for a pool tech is to keep pool water safe.”
Biofilm in the plumbing lines can protect germs by allowing them to hide in the biofilm. What is biofilm? It is made up of “human slough off”, such as skin, grease, oil and lotions from pool users. Biofilm is especially an issue in commercial spas and hot tubs where it can help hide the bacteria. It can help contribute to outbreaks of Legionella. A combination of biofilm in the plumbing lines, hot water temperatures and lack of adequate disinfection of 0.6 ppm can lead to outbreaks of Legionella. Other issues that can contribute to Legionella outbreaks are high cyanuric acid levels, high pH levels, inoperable or damaged chemical controllers and inoperable or damaged disinfections feeders.
Ray stated that he has had insurance claims over the years for Pseudomonas outbreaks. Pseudomonas infections will affect the pool user’s skin causing infections. According to Ray, “Pseudomonas and E. coli claims are not huge dollar amounts due to good use of antibiotics. But, Legionalla is a different kind of animal.” Legionella is transmitted completely differently that the other two organsims. Legionella is transmitted through the aerosolized water droplets, usually from a commercial spa or hot tub. The contributing factors to outbreaks are hot water temperature, biofilm buildup, low disinfection levels and aerosolized water droplets from the spa jets. “Spas are the perfect environment for Legionella”, notes Ray.
Outbreaks and insurance claims due to Legionella are becoming more frequent. Ray told me about one Legionella insurance claim in a Florida public spa in a 55+ community which sickened 18 people. He stated “this was one of the biggest claims I had regarding recreational water illnesses traced back to the spa water.” The contributing factors were lack of disinfectant, high bather load and green water. “It is hard to defend a pool tech when their number one job is to disinfect the water to maintain safe water.”
Liquid disinfection feeder electrical interlock is another item that is sometimes overlooked by pool techs. This item can become very dangerous if overlooked. Ray had one claim regarding lack of electrical interlock at an indoor pool facility resulting in a gas cloud from the mixture of sodium hypochlorite and muriatic acid.
Pool equipment to assist the pool tech
ORP is an excellent choice of equipment to assist a pool tech in gaining more information on how well their disinfectant is working in the pool water. Local health authorities often require ORP on commercial public spas or hot tubs to maintain disinfection and pH levels on a constant basis.
Now, you might be wondering, what is ORP? Oxidation-reduction potential, or ORP, is a measure of the oxidizing capacity in water. The simpler definition for the pool tech is that ORP measures the cleanliness of the water and its ability to break down contaminants.
The World Health Organization has adopted ORP as the standard test for drinking water treatment. ORP does not measure how much disinfectant is present in the water, but actually measures the potential the disinfectant has to oxidize the water. This concept was then duplicated to be used in the pool industry to assist pool techs in
Photo Credit: www.molecularhydrogeninstitute. com/oxidation-reduction-potential-orp-explained successfully being able to monitor how well the disinfectant is working in the water.
ORP measures the water using probes that detect voltage in the water between two probes and gives the readings back to the controller in millivolts (mV). The sensors will detect a positive millivolt charge for oxidizers and negative charge for reducers. Reducers are contaminants from pool users and the environment. ORP measures the quantity of an oxidizer that is needed to maintain the water at the programmed ORP level. The pool tech can program into the controller that they want the millivolt level to be maintained in the water.
The World Health Organization and CDC have determined that a minimum of 650 mV are required for instant inactivation of most pathogens. Thus, this value has become the industry standard for a minimum acceptable ORP value. The Florida public pool code requirement for ORP levels to be maintained by the pool tech is 700850mV. Secondary Disinfection Systems
These systems can pair with chemicals to give microorganisms a double punch Ozone Secondary Disinfection
Ozone is a great choice for disinfection for pool techs as long as they understand it should only be used as a secondary disinfection system. Ozone is a very powerful oxidizer. The term “Oxidizer”, as used by the pool and spa industry, usually means to destroy everything in the water by adding a large dose of chlorine or non-chlorine shock. This shock treatment rids the water of ammonia, perspiration and other organic matter including swimmer wastes. Ozone will oxidize most of them very quickly, including iron and manganese, as well as the bonds of many odor producing contaminants like decaying leaves and grass. Ozone provides better water quality and oxidizes many contaminants that chlorine cannot.
With an ozone system performing the primary oxidizing work in your pool, you will be able to cut way back on the level of chlorine needed. The technology will inject ozone into the pool water as it passes through the equipment for filtration. The FLDOH pool rule only allows ozone disinfection to be used as a secondary disinfectant. This means it has to be used as a back-up, but that chlorine or bromine still has to be the main disinfection system.
Ozone is pH neutral and with less chlorine in the water, there is less fluctuations in pH levels. Ozone excels in killing micro-organisms such as Cryptosporidium and Giardia. If the pool tech is only using chlorine as the primary oxidizer/sanitizer, then these waterborne parasites are more resistant. Due to ozone being very unstable and having a short life, chlorine is still needed as the main sanitizer. The small amounts of chlorine also help combat algae growth.
Ultraviolet(UV) Secondary Disinfection
UV secondary disinfection is a another choice the pool tech has to assist the primary disinfection system. UV is a secondary disinfection system to assist the main disinfection system in combating recreational water illnesses such as cryptosporidium and Giadia. Ultraviolet (UV-C) water treatment technology is one technique that has seen increased popularity thanks to its ease of use, reduced chemical consumption, health advantages and environmentally friendly benefits.
UV-C light can improve water and air quality in pool areas. UV-C is an invisible light with a wavelength shorter than that of visible light but longer than X-rays. UV sanitation systems can eliminate chlorine-resistant microorganisms. These systems reproduce UV radiation inside light chambers via powerful lamps, which emit germicidal light that is used to disinfect pool and spa water. Facilities equipped with these systems consume fewer chemicals and allow sanitizers to be more effective. UV-C causes permanent damage to a number of microorganisms almost instantly by disrupting the microorganism’s DNA. Protozoans, viruses and bacteria are then unable to replicate and remain inert. This light, however, works only on water that flows through the chamber. Water in dead zones isn’t treated by the light and the light does not act as a residual, thus the need for the presence of a primary disinfection system. Finally, cloudy water will not allow the germicidal light to disinfect the water, thus another reason why a primary disinfection system is needed that leaves a residual in the water.
Residential UV disinfection system