Flat Tanks are flat, low profile plastic tanks made to store liquids - typically water, waste and sewage - in off-grid applications - e.g. a toilet block on a construction site, a shower block at an outdoor event, a glamping pod in field etc. - when you cannot connect them to the mains sewage grid.

Flat Tanks are made in the UK by a process called rotational moulding, using a heated, hollow mould filled with plastic polymer, guaranteeing consistent quality and dimensions. The plastic polymer has specific properties - including UV-filters (i.e. sunscreen) - for a long lifespan in the field.

Flat Tanks come in 160, 500, 750 and 1000 gallon capacities. Our first Flat Tank (2010) was the 500 gallon Flat Tank. In 2016 we added the diminutive 160 gallon (725 litre) Mini Flat Tank and in 2019 the range was further extended to include 750 and 1,000 gallon capacities. With the immense demand for the 500 gallon tanks created during Covid (think of all the pop-up testing centres and Nightingale Hospitals that needed waste tank receivers) we added a further, separate 500 gallon tool.

Yes, very much so, for the most popular 500 gallon tank (140 Kgs) although when moving manually we'd advise four people for Health and Safety reasons. But you'll need a bit of (machinery) help with the larger 750 and 1000 gallon tanks (180 and 220 Kgs). All the Flat Tanks are equipped with four integrated lifting handles and strap guides. And we've also built in forklift slots for powered handling. Once loaded onto a vehicle or when positioned on the ground Flat Tanks can be easily pushed and shuffled, which helps when they are being connected to a toilet block / canteen / shower / glamping pod etc. on site.

Absolutely. They will not corrode over time as steel tanks do. They are made from an impact-resistant, UV-protected, medium-density polyethylene - and if treated and handled correctly will have a much longer lifespan than steel tanks. Guaranteed for plastic process and material defects for two years, they are likely to have an extended life if not abused. Just like steel tanks, Flat Tanks can be damaged if dropped from height or "holed" by a fork-lift. However, damage is readily reparable.

Yes, but only when empty. Flat Tanks can be stacked (empty) for transport and storage. To do otherwise will exceed the product's design parameters and your product warranty will become invalid. Why? When full, the most popular 500 gallon Flat Tank will top the scales at 2,413 Kgs. Hence, to stack several tanks on top of each other would exert overwhelming pressure on the lower tank(s).

We have "designed in" the functionality to allow you to link together tanks(of the same original capacity) meaning that you can increase capacity to suit your needs / application. The result is, you will not need to stock different sizes of tanks to meet the requirements of different customers / applications. One “Linking Kit” works for all tank sizes. There are four inbuilt 2” brass inserts in each tank which are the starting point for the linking process.

Please note however, tanks are only linked horizontally: you cannot stack tanks vertically to collect waste and try to link them. If you need more capacity or have a restricted footprint, we also supply cylindrical Above Ground Storage Tanks.

Well, yes and no. We manufactured Flat Tanks predominately in slate grey until 2020 but a glossy black polymer has been our standard colour since the Covid pandemic disrupted worldwide supply chains and it became a Henry Ford moment from the material suppliers of “You can have any colour you like as long as it’s black.” Since returning to relative supply chain normality post Covid, customer feedback has been favourable and we’ve retained black as our standard colour.

The short answer is that these are static tanks only and they are not designed or warrantied for movement when full. When full (of liquid) they will top the scales at 2143 Kgs (500 gallon tank), 3590 Kgs (750 gallon tank) and4766 Kgs (1000 gallon tank). 

Flat Tanks are not designed for burial. Underground tanks tend to be made as cylinders with external ribs to strengthen the tank and counteract the weight of soil. If you’ve ever covered yourself with sand on the beach, for fun, you’ll remember just how heavy an inch or two of wet sand can be. Imagine replacing that sand with several feet of heavy, waterlogged soil and you’ll appreciate the forces involved…and those forces are best handled with the correct, cylindrical design. 

The plastic polymer we use for the manufacture of Flat Tanks is suitable for water and toilet waste. If you have an alternative application / liquid and would like to use the Flat Tank format, please consult us beforehand so that we can check for material compatibility.

There are many ways to fine-tune Flat Tanks for your application: connect to an existing glamping pod with our WC-Tank Connector; add a tank breather valve which doubles as an odour control device; link tanks together; and monitor high liquid levels.

From 2019 we embossed the tank capacity into the plastic on the vertical planes of the tanks’ short edges. Alternatively, we have a handy guide to recognise your tank type. 

These aren’t really holes: they are actually strengthening columns, which serve to retain tank shape and rigidity. Without them, large plastic flat surfaces would tend to sink over time. 

These are simply covers for the four x 2” brass inserts moulded into the tank (used when linking tanks together). They serve no function other than to keep the brass inserts’ threads clean.

This is generally the point into which you will affix a high level alarm. There will be a sticker highlighting this fact.

Simply to lower friction when positioning the tank underneath glamping pods or site accommodation. They are essentially rubbing strips which reduce the surface area in contact with the ground.

Each 500, 750 and 1000 gallon Flat Tank comes pre-configured with two x 5” and 2 x 12” removable lids positioned in the four top corners. Removing the 5”lid will allow inbound waste access from your 4” waste pipe: use our WC-Connector Kit to create a sealed entry.

The two x 12” removable lids on the tank’s top surface are the points from which waste is extracted, typically by vacuum tanker. The vacuum tanker will generally need to get fairly close to the tank in order to extract the waste. Your local waste haulage company will be able to advise you on how close they will need to be. Some people may opt to use a submersible electric pump to empty tanks.