Huge operational cost savings with onsite chlorine generation
In 2011, a devastating earthquake struck the city of Christchurch in New Zealand. Redevelopment of the Taiora QEII Recreation and Sport Centre pool complex was a key highlight in the post-quake rebuild. The innovative team installed onsite chlorine generation technology and achieved outstanding operational savings of more than 70%.
Provide a world class swimming experience to the people of Christchurch, New Zealand
Christchurch has a population of 396,000+. Christchurch City Council provide the community with 6 large swimming pool complexes to enjoy, plus an additional 4 summer pools.
Following a major earthquake in 2011, Christchurch city was rebuilt. It is estimated that 60% of the swimming pool capacity in Christchurch was lost due to earthquake damage. Rebuilding a city provides opportunity. The Council were keen to embrace and optimize the benefits of new technology for the Taiora QEII pool complex project.
The installation of onsite chlorine generation was a standout decision made by Council, which led to significant safety improvements, full control of supply, as well as long term OpEx savings.
Key data
- Provide a clean and safe swimming space for children to learn to swim, for injured and elderly to rehabilitate, for people to gain and retain health, and for families to share low-cost fun experiences together
- Embrace technology and the benefits it can deliver, including automation, improved employee safety and cost efficiencies
- Reduce chemical handling
- Work with industry leading partners
Full control of chlorine supply with onsite chlorine generation
Previously, a core part of Taiora QEII’s original water treatment process was the purchase of hazardous liquid chlorine chemicals which had to be freighted to site by chemical companies, and then handled regularly by staff - a traditional method of using chlorine but one which carries health and safety concerns.
Due to the hazardous nature of liquid chlorine, the chemical requires HSNO management and special storage tanks must be used, requiring extra certification and expense for a site.
With all of the city’s pools to disinfect, the ongoing cost of chlorine chemicals took up a significant line in the Council’s pool budget. Council identified potential advantages of using modern technology and decided to make the shift to innovative onsite chlorine generation.
Twin ProMinent CHLORINSITU III Electrolyser Systems were installed. Selected for their German engineered smarts, these electrolyser units use just salt and water to generate high volumes of chlorine directly onsite.
Greater concentration of chlorine, for much less cost
With ProMinent’s CHLORINSITU III, concentration levels of approximately 25 g/l are achieved with minimal entrainment of sodium chloride (85% yield) from the membrane cell into the finished product. The final sodium hypochlorite solution can be metered, as required, by separate metering pumps.
With a moderate pH value of 9.5 - 10, there is significantly less effect on the pH of the treated water than conventional sodium hypochlorite (pH 12 – 13.5), meaning less acid is needed.
Greg Finch, a Facilities Leader at Christchurch City Council says, “The cost savings for us is huge! We were paying nearly twice the cost for 0.8% chlorine, compared to what it now costs us to produce 2.5%. So twice as expensive, for a lower concentration. Since we switched to onsite generation with ProMinent electrolysers, our cost per litre of chlorine has dropped by more than 78%. It’s a massive reduction in costs.”
“The CapEx on a unit like this may be higher, but the OpEx is so much lower and that is an ongoing cost saving you have for a long time,” adds Greg.
- Installation of twin ProMinent CHLORINSITU III Electrolyser Systems
- Reduction in cost per litre of chlorine by more than 70%
- No longer reliant on chlorine providers and not affected by supply chain issues
- Easy to use technology means training new staff is quick and simple