Retention Tanks in HDPE
A retention tank is a watertight underground tank that receives domestic wastewater — sewage and grey water — and holds it until it is periodically emptied by a tanker. It is the right solution for isolated homes with no access to a public sewer network and no conditions for installing a treatment plant.
The RoTerra and RoCko tanks in HDPE (high-density polyethylene) are ideal for this application: they are watertight, corrosion-resistant, light to transport and easy to install without a crane. Sizing depends on the number of occupants and how often you want it emptied — as a rule of thumb, 150 to 200 litres per person per day.
The table below lists every available model with prices and dimensions. For sizing questions, our technical team is on hand to help.
RoTerra — rectangular underground tank
Horizontal oval shape in HDPE. Low profile, ideal for sites with little excavation depth. RoDrive version available for truck traffic up to 40 t.
17 models · Indicative prices excl. transport · VAT at the rate in force
RoCko — cylindrical tank, underground or above ground
Vertical cylindrical shape in HDPE. No concrete base required. Self-levelling telescopic DN600 access, cover with a latch for loads up to 200 kg.
17 models · Indicative prices excl. transport · VAT at the rate in force
To choose the right tank for your needs
Our technical team is on hand to help with sizing.
Talk to the team