Water & Air Quality for Indoor Aquatic Recreation Facilities Prepared by: Franceen Gonzales Great Wolf Resorts Presented by: Douglas C. Sackett Assistant Director NYS Dept. Of Health Bureau of Community Environmental Health and Food Protection

Issue 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.

Overview Indoor aquatic facilities are unique Water chemisty affects air quality Managing air quality through: – Water chemistry – Technological advances – Air handling design – Bather awareness

Indoor Aquatic Facilities are Unique Controlled humidity and temperature Comfortable environment Restricted occupancy Air quality control is necessary 365 day operation is 3 outdoor seasons of wear and tear Corrosion

Indoor Aquatic Facilities are varied

Water Chemistry Review Water (H 2 O) Air

Water exists in equilibrium H 2 O ↔ OH - and H + HH O H O- H+H+

Water molecules bond with other water molecules The average hydrogen bond lasts less than one trillionth of a second!

Now let’s add a sanitizer Sodium Hypochlorite (NaOCl) Calcium Hypochlorite (CaOCl) Chlorine Gas (Cl 2 ) Bromine compounds Water (H 2 O) Air

Sanitizers have much in common Periodic Table of the Elements

Chlorine plus water creates hypochlorous acid NaOCl + H 2 O → HOCl + NaOH Na Cl O HH O H+H+ O NaOH - Substitution Reaction with Bleach (NaOCl)

Ions present in chlorine compounds kill bacteria Cell walls of bacteria are negatively charged HOCl (hypochlorous acid) can penetrate OCl - (hypochlorite) is negative and cannot penetrate as easily BacteriaHOClOCl -

How Chlorine Works to Disinfect Hypochlorous acid is more powerful and exists at lower pH When pH rises, hypochlorite is formed HOCl + H 2 O → H 3 O + + OCl - What pH does traditional pool chemistry target?

How do air and water interact? H 2 O (water) HOCl (hypochlorous acid) OCl - (hypochlorite) Air

Water is hydrophilic The average hydrogen bond lasts less than one trillionth of a second!

If it doesn’t have hydrogen, then water doesn’t like it H 2 O (water) HOCl (hypochlorous acid) OCl - (hypochlorite)

H 2 O (water) HOCl (hypochlorous acid) OCl - and Cl - (chlorine) Chlorine salts Chlorine off-gases into the air Air

Chlorine and salts are deposited

Byproducts in air cause corrosion

Now let’s add people

Urine/ sweat Hair products Lotions, etc. OCl - Chlorine Salts Chloramines Body fluids are the culprit H 2 O HOCl OCl - Plus other byproducts Other disinfection byproducts Trichloramine (NCl 3 )

Did you pee in the pool? 1000 guests Multiplied by % that pee in the pool Multiplied by the avg volume a person pees Equals…..

Typical Organic Urine Compounds Organic CompoundsAmmonium Salts CreatinineTaurineHippurate UropepsinCystineCitrate CreatineCitrullineGlucuronate GlycineAminoisobutyric acidUrate PhenolThreonineLactate HistidineLysineL-Glutamate AndrosteroneIncloxysulfuric acidAsparate 1-MethylhistidineM-Hydroxyhippuric acidFormate ImidazoleInositolPyruvate GlucoseUrobilinOxalate AsparagineTyrosine NASA CR-1802, July 1971 Urea Predominates – 86% Courtesy of Dr. Richard Cavestri

Urea (NH 2 ) 2 CO C H N O H H N H

O Urea + HOCl C H N O HH N H H O Cl H O H N H H N H Urea + 2 Hypochlorous Acid = Monochloramines (Monochloramine is a disinfectant!) CO 2 H2OH2O

Monochloramine + HOCl O H N H Cl Monochloramine + Hypochlorous Acid = Dichloramine Cl H N H H2OH2O

Dichloramine + HOCl O Cl N H H N H2OH2O Dichloramine + Hypochlorous Acid = Trichloramine

Chloramine Formation from Ammonia Monochloramine NH 3 + HOCl→ NH 2 Cl + H 2 O Dichloramine NH 2 Cl + HOCl → NHCl 2 + H 2 O Trichloramine NHCl 2 + HOCl → NCl 3 + H 2 O (plus many other side reactions)

So what happens? Trichloramine Cl N

Trichloramine is volatile Mono- and di- chloramine like to stay in the pool Trichloramine likes to off-gas NCl 3 = trichloramine Trichloramine content in air requires a specialized test

Typical Reaction to Chloramine Exposure in Indoor Swimming Pools Irritated Eyes Nasal and throat irritation Coughing Breathing difficulty – Chest tightness – Wheezing – Congestion

Current Suggested Trichloramine Thresholds in mg/m 3 Levesque -.37 Massin -.5 Gagniere -.5 Hery Bernard -.3 Thickett -.5 (above threshold shows decrease in pulmonary function) WHO provisional value

People are not clean

Hypochlorous acid (HOCl) kills and breaks apart bacteria resulting in bacterial “carcasses” often less than a few microns in size Bacteria HOCl + These bacterial pieces exist like dust. Need to wash surfaces.

bacteria Bacterial Carcasses (endotoxins) Endotoxins Dead bacteria = Endotoxins H 2 O HOCl OCl - Plus other byproducts

Organochloramines Theory Cell wall of bacteria are proteins Hypochlorous acid kills bacteria, breaks it into smaller pieces There are theories that chlorine could be randomly attached to those small pieces of bacterial “carcass” (proteins) Water chemistry shows combined chlorine to be much higher when tested with DPD. These could be organochloramines (chlorine attached to proteins of bacterial bodies) Larger organochloramines do not have the volatility of nitrogen trichloride (TCA)

Dead bacterial bodies can be deposited in air from sprays Air filtration and wash down can help

How do we control irritants? Water Quality – Limit introduction of chlorine – Secondary technology to break down combined chlorine like UV, ozone – Ultra filtration Air Handling – Keep it clean – Monitor temperature and humidity – Push air high, remove it low People – Public awareness – Loading/occupancy – Enforcement

Water Quality Maintain balance of free chlorine: not too much in the air, not too much to create TCAs – Keep it as close to 1.0 with effective pH and ORP Drop pH to achieve ORP for effective disinfection – Ideal Ultra filtration addresses bacterial bodies Keep combined chlorine low – Introduce fresh water every day – Use secondary technology

Health department criteria for outdoor pools is not always most conducive to the quality of water and air in an indoor environment

Indoor Pools are Unique Breakpoint chlorination is not always feasible – Cannot exhaust the off-gassing fast enough Pools recover at night – Turn on features early to exhaust off-gassing – Keep UV or ozone on Fresh air operation in the morning can help

Secondary Technology - UV Low maintenance, less space required UV is effective at reducing chloramines, not temperature sensitive Breakpoint chlorination not needed Disinfection is effective with exposure time Wavelengths nm associated with disinfection

UV breaks the bonds of trichloramine Cl N

Theorized Photochemical Reaction of Chloramine with UV Monochloramine reduction at λ = 245nm: 2NH 2 Cl + HOCl ↔ N 2 + 3HCl + H 2 O Dichloramine reduction at λ = 297 nm: NHCl 2 + OH ↔ NCl 2 + H 2 O NCl NHCl 2 ↔ Cl 2 -N-NHCl + Cl - Cl 2 -N-NHCl ↔ Cl-N=N-Cl + HCl ↔ N 2 + Cl 2 + HCl Trichloramine reduction at λ = 260 nm and 340 nm: 2NCl 3 + 5OH - + H 2 O + Cl - ↔ N 2 + 4OCl - + 3HCl + 2H 2 O Chloramine turns to nitrogen, which escapes via the water surface.

Other Technologies Ozone – Effective oxidizer and disinfectant – Requires extended contact time – Equipment requires higher maintenance, more space and is costly Monopersulfate – Non-chlorine shock to oxidize contaminants – Specialized test kit needed

Air Handling Principles 30 years of HVAC design for “dry” buildings doesn’t work well for “wet” buildings Need to focus on the worst air Balance air exchange (fresh air and exhaust) with energy efficiency (heat recovery) Selecting the right unit to move the air is as important as designing the distribution and controlling it It’s not a warehouse, it is a microcosm of weather systems Body oils affect filtration

Air introduced from above Chloramines, DBPs, water borne particulates are off- gassing near water surface. Removing air at this level can improve air quality. Worst air exhausted Air Handling

Model North Drawing LayoutModel Layout

Results Temperature Relative Humidity Mean Age Temperature, RH, and LMA Plots North Plot viewed from the East

Results 1 Plot 1: 5 ft above floorPlot 2: 25 ft above floorPlot 3: 60 ft above floor Mean Age 2 3 Water slides not shown

Air Flow Paths Animation View from floor indicated by red arrow above. Courtesy of TDMG

Air Handling Practices Keep the system clean – Fans and blades – Returns and ducts – Filters Air, like pools, recover at night – Keep UV or ozone operating at night – Keep air handlers operating at night Set points for humidity and temperature can be indicators of air quality but do not account for contaminants

Address it at the Source

What They Need to Know TAKE A SHOWER BEFORE YOU ENTER THE POOL and AFTER YOU LEAVE DO NOT PEE IN THE POOL DO NOT POOP IN THE POOL

What Operators Can Do Provide guest awareness Limit time in hot tubs, especially toddlers Monitor occupancy in pools Get parents to – Take children to the bathroom – Teach them not to pee in the pool – Make them shower before they enter the pool

Guest Education

Assisting Employees Observe behavior Keep an open door to sharing issues Talk to employees Experience it for yourself Provide awareness Offer alternatives

Critical Items Water chemistry – Chlorine levels – pH level – Fresh water Correct ventilation scheme – Volume – Control – Distribution Clean Bathers