In the water-scarce world we live in, rainwater storage is always a good idea. However, homes in urban environments face both space and accessibility constraints when it comes to installing a storage tank to capture and harvest rainwater.

Architects and builders are increasingly choosing underground water tanks for this purpose. Underground storage tanks allow homeowners to maximise available space on their property when placed under paved traffic areas, driveways, garden beds or lawns. Underground water tanks are, therefore, an aesthetically pleasing as well as an eco-friendly solution for harvesting rainwater.

Polymaster’s underground storage tanks

Underground water storage tanks from Polymaster are designed and manufactured in Australia, and subject to rigorous health and safety testing; constructed from BPA-free food-grade polyethylene; and certified to AS/NZS 4766 for a rainwater tank, and AS/NZS4020 for drinking water, which is the Australian standard for drinking water.

Polymaster underground water tanks are available in a choice of two sizes – 3300 litres and 5000 litres – which can also be joined together to create more capacity. With the smallest footprint in the industry, these water tanks deliver maximum capacity for the minimum square meterage. 

Polymaster underground water tanks are suitable for high traffic areas; can be safely installed under the driveway, withstanding loads up to 3.5 tonne; have unlimited storage capacity when joined together – interconnecting seals are provided; allow shallow excavation due to smart design; are self-anchoring, eliminating any need for concrete; come with a fully adjustable riser – extension risers available for deeper installations; feature a ‘plug-and-play’ mains changeover system with submersible pump option; incorporate a childproof lockable lid; are lightweight and super strong; and can be easily manoeuvred around building sites with no crane required.

Fully designed and tested to withstand ground and water pressure at depth, Polymaster underground tanks are engineered by geotechnical experts with finite element analysis (FEA) done to suit ground conditions throughout Australia.

Keeping your water clean

Polymaster recommends a vortex filter to keep your tank and stored rainwater clean. The self-cleaning vortex filter will not only remove 95 per cent of sediment and debris during collection and harvesting, but also aerate the water, which keeps the walls of the tank healthy, thereby, reducing the chance of any harmful bacteria growing in the tank.

How does a vortex filter work?

A vortex filter is fitted to a horizontal drainpipe, where it filters and diverts the rainwater to a storage tank. The incoming rainwater flows out of the horizontal drainpipe into the side of the filter and is then led in a vortex to the filter housing below. The aerated rainwater is drawn through the vertically placed fine filter by adhesion and directed through the outlet to the storage area, while the debris is rinsed away with the remaining water. More than 90 per cent of the rainwater flowing into the inlet can be captured for storage.

Installation Guide for Polymaster underground water tanks

A comprehensive and easy to understand Installation Guide is available from Polymaster. For more information, simply call Polymaster on 1800 062 064 or email sales@polymaster.com.au.