feature
Are foreign public pool standards better than the Australian ones? By Paul Stevenson
There has been discussion from time to time about the potential for including overseas health standards into Australian public pool guidelines and the state-based health codes. But first we must define the health standards across the country, before ascertaining if it is it feasible to adopt foreign standards. Paul Stevenson, one of Australia’s most experienced aquatic engineering consultants, bravely delves into this mammoth topic covering commercial spa and swimming pool plant capacity sizing, and the related health standards both here and overseas.
T
Introduction
here is much debate and controversy over the sizing of water treatment plants for public spas and swimming pools across Australia. This has been going on for many years and it seems that few aquatic engineers actually want to agree with each other. Often, because some want to follow local health standards and others don’t. (Some seem to not want to follow any standard at all.) In an ideal world, Australia would have a single method of plant sizing which is adhered to across the whole country. Sadly, we don’t live in an ideal world. This article explores the differences between plant sizing across Australia and some prominent international health standards.
The basics
The size of a water treatment plant is critical to: • Ensuring there is enough water flow to achieve good water distribution across the whole body of water, especially in the corners; • Ensuring that there is enough filtration area to remove turbidity to achieve acceptable standards of clarity, this being directly proportional to the plant flow rate. Pool turnover time is a common term in the industry. It is the time it takes for the whole volume of the spa water or pool water to pass through the water treatment plant. 66
SPLASH!
October/November 2024
“While DIN standards indeed emphasise public control resulting in smaller pool plant sizes, implementing similar measures in Australia might face challenges due to cultural perceptions and expectations.”
ABOVE: Turnover time is how long it takes for the whole volume of the pool or spa water to pass through the water treatment plant
The shallower the pool, the higher the bathing load, and therefore a quicker turnover is time required. This is reflected in all health standards. A less often reflected aspect is that there is clear evidence that outdoor pools are less problematic than indoor pools due to solar/wind exposure and lower bathing loads. Some health standards recognise this, and others don’t. The other important aspect to plant sizing is the control of bathers and what is the excepted norm. A perfect example of this is what happens in Germany under the DIN standard and what happens here in Australia. Under the DIN standard, bathers are required to shower before using the spa/pool, no outdoor footwear is allowed on the concourses and bathing numbers are strictly controlled. In addition, 30 litres of spa/pool water is dumped as each bather enters the spa/pool area. Spas are required by the DIN standard to be emptied and cleaned every week but that is not the case here in Australia. It’s interesting to consider the balance between stringent health standards and public acceptance. While DIN standards indeed emphasise public control resulting in smaller pool plant sizes, implementing similar measures in Australia might face challenges due to cultural perceptions and expectations. Some Australians might view such rigorous control as incompatible with their national identity and just “not Australian”.