An all-water tank is a pre treatment device designed to collect and liquefy partially pollutant matters in untreated water and designed to retain solid matters and floating waste. All domestic wastewater enter in the all-water tank (rainwater, water from swimming-pools excluded). See decree dated May 6th 1996, rider 1.1 § 1.A complete water treatment system includes an all-water tank and a waste disposal system (sand filter, spreading system, ...).In accordance with the inter-ministerial decree dated May 6th 1996, article 13, the all-water tanks can be used in wastewater treatment for the treatment of the domestic wastewater coming from the non-connected buildings, scattered houses, hotels, hospitals, schools, summer camps, camp sites, etc.Each case must be of a particular study. We therefore advise to seek the advice of competent authorities of the installation location (city hall, prefecture,...) to help you in your efforts.To choose the suitable device, you must take into account :- The average water consumption of the installation location- The building occupation (permanents or semi-permanents users, intermittents)A pre filter will be installed at the output of the all-water tank in order to avoid premature clogging. Downstream from the tank, a floating bucket will be also installed.