Differences in free chlorine requirements: Pools1 |
||
|---|---|---|
| Ontario minimum | Alberta minimum | European DIN |
| 0.5 mg/L | 0.5 mg/L (if oxidation reduction potential [ORP] is more than 700 mV | Minimum of 0.3 mg/L and maximum of 0.6 mg/L |
Differences in free chlorine requirements: Spas |
||
|---|---|---|
| Ontario minimum | Alberta minimum | European DIN |
| 5.0 mg/L (if oxidation reduction potential [ORP] is more than 750 mV | 2.0 mg/L | Minimum of 0.7 parts per million (ppm) and maximum of 1.0 ppm |
Long term health effects
Respect for bathers, especially young children with extremely sensitive upper respiratory systems using public swimming pools and spas, is an exacting science and one that cannot be viewed in isolation without concern for long term health.
Long term contact with CBPs have been well documented and is a subject public swimming pool operators and mangers must make themselves aware to understand the health risks.
Research by Dr. James Amburgey of the University of North Carolina shows that it takes six days for bather waste, deposited by swimmers in the pool’s shallow end, to reach the filters—without aggregation. Most public pool officials worldwide agree that to maintain health pool and spa water, a free chlorine reading of approximately 1 ppm is the right level. However, to achieve this, agglomeration, aggregation, flocculation and coagulation combined with superior filtration (using a deep, multi-layered filter bed and a vertical filter with low flow and pressure) are imperative to improving pool or spa water and the health and safety of patrons.
Properly maintained pool water has no chlorine odours or tastes and does not cause bather’s eyes to burn or skin rashes.
While the modern North American scientific community is finally doing its own research, replicating the European studies in actual swimming pools, they are still several decades behind their European counterparts.
Winds of change
During my 47 years of visiting public pools across Canada, I cannot think of one facility that would pass the DIN requirements; thankfully, that is starting to change, as there are several pools presently being built to DIN standards in Canada.
Conclusion
In North America, billions of gallons of unheated, out-of-balance, expensive taxpayer-treated water is wasted every year. Ever-rising chlorine levels, designed to solve numerous resulting mechanical and circulation problems, have proven costly and potentially hazardous to the users, staff and building lifecycles. With these factors in mind, perhaps it is time for the Canadian aquatic facilities industry to look into these European standards for inspiration. Adopting DIN standards could be one of the most important and impactful steps the North American pool and spa industry could make.
Dennis Ashworth joined the aquatics industry in 1963. An author, lecturer, industry court expert witness, builder and designer, he operates SP&S Swimming Pool & Spa Equipment, a water treatment business based in Newmarket, Ont. He can be reached via e-mail at swimpool@msn.com.
