Pool Culvert Remediation – Cumberland Council
- Client Cumberland Council
- Location Wentworthville Memorial Swimming Centre
- Duration 6 months
by Daniel Green
Revered around the globe as one of the absolute best, an Australian summer is legendary. And even though the weather through this last one was less surface-of-the-sun and more Amazonian rainforest, the good people of Cumberland Shire at least had a refurbished pool to swim in. Two days before Christmas no doubt!
First opened in 1965, the Wentworthville Memorial Swimming Centre has given an extraordinary service life. So when the Dunmore street dip was in need of some work they called on Perfect Group’s remedial arm: Perfect Remediation and Refurbishment. And with a SoW as wide and as deep as an Olympic swimming pool, PRR GM Tom Matanovic and site supervisor Nathan Hill began pre-planning in readiness for a mid-August start date.
The Cumberland Council outlined two major works in our scope:
- Pool balance tank remediation.
- Pool Reticulation Culvert Upgrade & Remediation.
Balance tanks are utilised to control large volumes of water that remain in constant flux. Much like a radiator overflow bottle in a car, they store water in reserve for the main ‘tank’, which in this case was the pool itself. Because their role is so critical their structural integrity is paramount. Over it’s 50+ year life the tank lid become structurally unsound and was in need of extensive reworks. Originally, just the integrity of the concrete lid had been called into question. But once it was removed the council soon learned that the tank walls and structural corbel were also questionable. Concrete cancer had been at work for many years. There was also extensive cracking of the tank walls due to the shifting sub base. The steel access ladder was rusted, rendering it unsafe. It was also likely any waterproofing was compromised.
As for the culvert it was a necessary part of the pool circulation system. Its main purpose is to circulate and distribute filtered water via the main pump. Showing signs of ageing, the original concrete culvert was in need of crucial remediation and upgrade works. This scope being the replacing the aging concrete lid, concrete repair in the culvert and the replacing of the water outlets.
With summer just around the corner and the council eager to get things moving, Tom and Nathan established on site on 16th August 2021. And as primary works centred around concrete repair, waterproofing, steel cathodic protection, concrete repairs, new concrete installation and tiling works – Tom and Nathan rolled up their remedial sleeves and got down to getting busy. The balance tank 200mm thick slab was removed while intricately maintaining some of the existing main steel reinforcement bars. A structural catch deck was installed and the concrete was removed in manageable pieces from the site. As the remaining walls and the floor of the tank were in fair condition crack injection was carried out, while the structural corbel was in need of some major concrete repairs.
The new suspended concrete slab was formed up, reinforcement installed, while the existing steel reinforcement bars were cleaned, treated and Cathodic protection installed. Cathodic protection runs were chased in, anodes installed and wired up. For the uninitiated, cathodic protection is corrosion future-proofing. It utilises LV power strung through a web of cabling to anodes anchored directly into the concrete. The difference in voltage between it and the earth ensures corrosion is stopped or at the very least, significantly slowed.
Once all the required repairs were completed the walls and the floor of the tank were coated with a waterproof membrane, surprising the original tank lacked any membranes.
The centre culvert would prove equally challenging. This was essentially a 450 wide x 350 deep channel that ran the length of the pool serving as a water circulation vessel. Its primary role was to aid in the funnelling of clean water back into the pool once it had been filtered and chlorinated. While it was still mostly functional, the design was antiquated and now was a great opportunity to upgrade it. Engineering deemed a reticulation water outlet system would be the best improvement while replacing the concrete lid of the entire culvert. This called for the existing concrete lid to be removed, major repairs to all the pool control joints and waterproof bandage installed. A new culvert lid was formed, new stainless steel support angles to main control joints installed, stainless steel reinforcement fixed to the lid and all new priority PVC water outlets installed. Finishing works consisted of tiling and caulking.
The project spanned over a 6 month period with weather disruptions and covid challenges that the team had to navigate through. Needless to say Cumberland Shire Council was pretty dang happy with the outcome. Just in time for the annual Aussie heatwave.
Wentworthville pool may not be the most historical pool in Sydney or the most expensive – what it is though is a significant landmark for the families of Cumberland Shire. For teaching their little ones how to swim. For cooling off in summer. For eating ice blocks after a dip. For making memories.
Here’s to another fifty-five years.