Community swimming pools use a large quantity of water annually. Optimizing this resource is essential both to preserve the planet and to decrease the financial pressure of these amenities on communities. The private swimming pool sector has already succeeded in decreasing the water use by 45% in 25 years. Many ideas and innovations are also applicable to community swimming! Here is an overview of possible solutions to reduce your water use.
1. Treat water appropriately
There is nothing worse than increasing water use besides allowing algae and microorganisms to proliferate in a pool. When a swimming pool is over-stabilized (when it is treated with stabilized chlorine) or when the water is completely unbalanced, the threat of having to empty the pool hovers… as does that of closing for several days.
In the past years, many innovations that use home automation (like these) have become available so that corrective measures can be taken in real time to prevent any imbalance in relation to the frequenting or the weather. They also make it possible to reduce the quantity of chlorine used or to switch to another method: UV treatment, copper-silver ionization, ozonation, etc.
2. Adjust filtration to fit your needs as closely as possible
Modern filtration equipment can significantly decrease water use in community swimming pools. Countercurrent washing of filters, which is required to eliminate impurities, is one of the highest water-consuming operations: 40 to 50% of the total water use of a swimming pool (2). To provide their users with impeccable water, many water facilities launch more cycles than are actually needed. It is preferable to adjust this frequency to meet the actual needs, and to use efficient filtration systems. Some recent models even enable complete elimination of the countercurrent washing phase!
3. Optimize water renewal
In Europe, it is recommended and even required in some countries to renew the water in pools every day that the establishment is open, with at least 30 liters of un-recycled water per swimmer. It becomes immediately obvious why it is important to count the number of swimmers precisely throughout the day rather than making rough estimates. As much as several thousand euros can be saved annually, which is why investing in a crowd calculation software, access control and/or intelligent sensors is important!
4. Cover your public swimming pool
Did you know that a swimming pool can lose up to 3% of its water content by evaporation? Wind, relative humidity, low atmospheric pressure, water/air temperature difference and the size of your pool are some of the parameters that can accentuate this phenomenon. If the water level falls too low, air can enter the skimmers and draw off the water from the filtration pump.
In addition to increasing water use to maintain the ideal level, other problems for indoor pools can be caused by evaporation. If the relative humidity level is too high, this can lead to an increase in the use of the dehumidification system and even the degradation of the building. To avoid this, covers, bubble tarpaulins, roller shutters and flat lids are your allies.
5. Check for leaks
A leak can make your water bill increase really fast, and the more you wait, the worse the problem becomes. To detect them, there is a well-known method that swimming pool professionals use: the bucket test.
- Fill a bucket to ¾ with water
- Half submerge it on a step
- Mark the level of the water in the bucket and that of the swimming pool
- Wait a few days
- Mark the water levels again
- Measure and compare the difference
If the water level decreased more in the pool, there is probably a leak. Installing one meter per pool also enables detection of any malfunctioning.
6. Optimize water use outside the pool
Other units with substantial consumption such as sanitary hot water which accounts for 18 to 35% of the total amount of water used (2). Showers and toilets are often used excessively, which increases the facility’s bill. That is why solutions such as innovative shower columns with a timer, a flow regulator and/or activation by a sensor are being developed. The same goes for detecting leaks. It is important to install different meters to precisely determine which points to improve.
But this will never totally replace one crucial element: making users aware of how much water they use. Be an educator!
7. Recycle your water
In France, each community swimming pool must be completely emptied at least once annually. Many communities are forced to empty several hundred thousand cubic meters of usable water and would like to recycle this resource.
- Towns like Seclin and Nogent-sur-Marne (France) use this water to clean the sidewalks of their roadways.
- Cities like Saint-Nazaire and Toulouse have chosen to take advantage of this water with little chlorine to water their green spaces and to supply their ornamental pools.
- This water is also a welcome relief during dry summer periods when bylaws prohibit watering. In Châtellerault (France), recycling public swimming pool water saved 4,000 young shoots (3).
Other areas to explore: collecting rainwater and overflow water via dedicated tanks.
Efficiently reducing the water use of community swimming pools is quite feasible through the latest innovations in the sector, and let’s not forget that a little common sense goes a long way. Combine this with the energy use reduction methods and you will save substantially!
(1) Piscine Global: Reducing the environmental impact of public and private pools
(2) Weka: Réduire la consommation d’eau et d’énergie des piscines
(3) France 3: L’eau de piscine pour arroser les arbres de Châtellerault
© Crédit photo : Andrey Armyagov / Adobe Stock