Modular Precast Onsite Detention System Solution Range


Every now and then we launch a new product that is so fundamentally simple and effective that we can't help but ask ourselves "why hasn’t this been done before?"

With this particular treatment tank, we had one thing in mind: Narrowing the price difference for a quality product that fills a market void for the challenging space that sits between shallow and deep sites.

And that's precisely what our new 9.5kl tank does, we’ve created a heavy-duty concrete tank with the perfect mid-level height, at a price point that keeps well within Australian Tanks renowned cost efficiency.

Simply put, this is an unrivalled solution when considering time and cost efficiencies, and an OSD solution that gets the job done simply and safely the first time – This tank comes from Australian Tanks - the original innovators and the best in clever, heavy duty rectangle, modular OSD solutions. 

As with our entire range of tried and tested water and waste water civil solutions, we’re confident the 9.5kl treatment tanks are the ultimate fit-for-purpose product and when you do the comparisons on real costs and real benefits, offers the ideal combination of success factors for any project that needs an internal height of between 1.5 - 1.6 metres:

  • 9,500 litre volume; easily interconnected in multiples to create any volume quickly and cost effectively
  • Anti-Floatation and trafficable for mid to large scale infrastructure projects
  • Installed and ready to be backfilled and complete in 1- 3 days on average
  • Backup and commercial warranty
  • Certified – engineer approved build with clear heavy duty load ratings

Fast and Easy Installation

Cost Effective

Design Services For Increased Capacities 

10 Year Warranty
50 Year Design Life

Our Solutions

Over the past five years Australian Tanks has developed and refined 
an EASY, FAST & COST EFFECTIVE solution to On Site Detention

7000 Litre

Internal height of ??

With a lower internal height, the ATQ7000 tank is perfect for shallow requirements of many small On Site Detention systems.


9500 Litre

Internal height of 1.5 - 1.6 metres

12000 Litre

Internal height of ??

a larger and more robust modular tank that can achieve even more substantial and deeper detention solutions


The Australian Tanks heavy duty trafficable detention systems now consist of 7,000 litre, 9,500 litre and 12,000 litre rectangular tanks which are easily interconnected in multiples to create any volume quickly and very cost effectively.

Every system is certifiable, with increasing numbers of engineers incorporating our systems into their designs due to the structural integrity and multiple efficiencies the Australian Tanks solutions offer.

Every modular system can arrive on site with weir walls, filtration, penetrations, trash screens, ladders, risers, manholes, drainage holes and orifice plates in place, ready for immediate install in the prepared site excavation. Importantly, all AT systems are pre-cured with no further waterproofing required, ready for the site install to be completed in hours, not weeks , and can connected ready for backfill within the same day.

These systems are designed for small, medium, or large capacities and compete extremely favourably with alternative precast or built-on-site systems.  Additionally, the lifecycle costs measure extremely well against alternatives as they are very easy to access, clean and maintain.

Why Choose Pre Cast Over 'Block and Slab'

Traditionally, OSD installers have heavily relied on ‘block and slab’ solutions to build On Site Detention tanks and systems.

As the necessity for On Site Detention systems has increased, so too has the reliance on those traditional labour and time-intensive block and slab detention tanks. 

And, as with all demand increases, the costs have increased for slab work, block walls, suspended roofing and waterproofing.

More importantly the on site occupational health and safety requirements have made it more onerous for builders and contractors – this has also lead to increasing costs as well as the need for considerably more manpower and paperwork for Project Managers on site.

Builders and contractors are fast becoming busier in the ever-growing markets of Sydney, Melbourne, Brisbane and the Gold Coast – time becomes a major asset and lost time costs big money. Open excavations, delayed contractors, bad weather Australia regularly experiences, and the need to find additional components for block and slab systems can all combine to negatively impact building costs and efficiencies.

Australian Tanks modular systems can be installed with all On Site Detention requirements in place, delivered to site pre-cured and with no waterproofing needed, and ready for an install that takes hours, not weeks or months. 

Our heavy duty trafficable detention system consists of one, or multiple, anti-floatation rectangular tanks that are easily interconnected to create any volume quickly and cost effectively.

Every module system can be engineer certified, with increasing numbers of engineers incorporating our system into their On Site Detention designs. The systems can arrive with weir walls, filtration, penetrations, trash screens, ladders, risers, manholes, drainage holes and orifice plates in place and can be installed and connected ready for backfill within the same day.

These systems are designed for small to medium capacities and compete extremely favorably with alternative precast or built-on-site systems. Additionally, the lifecycle costs measure well against alternatives as they are very easy to access, clean and maintain.

If you are interested in finding out more about our range of modular systems, please call one of our civil design and business development specialists so they can assist you to develop a CAD driven design for your On Site Detention system.


Australian Tanks also manufacture larger systems consisting of 15,000 – 20,000 – 25,000 and 45,000 litre inter-connectable tanks. These systems are designed specifically for large capacities and to compete with in-situ head to head; achieve a substantial detention system in 1–3 days instead of weeks.

As with all of our products, this comes with heavy duty traffic load ratings in accordance with Australian Standards design codes (AS5100.2) and can be backfilled and bear traffic immediately. No downtime while curing.

Thanks to the team at Australian Tanks for getting this key piece of site infrastructure in place in such a short space of time despite rain and allowing the site access back in use quickly. Well done to our BUILDUS team for getting on with the job.

Bruce Rob

Group General Manager HWB GROUP

On Site Stormwater Detention Systems Projects

DEQ Consulting Engineers

Storm water Detention

stormwater-detention-deq-consult-engineers5 (1)

Hutchinsons Builders

Precast Transfer Station


Dean Ash Construction

Storm water Detention



Storm water Detention


Contact us today to find out how we can be of service to you.