An all-purpose pit is a pre-treatment facility for "collection, partial liquefaction of pollutants contained in wastewater and retention of solids and floating wastes. It receives all domestic wastewater "(excluding rainwater, pool water, etc.) cf Order of 7 September 2009 Annex 1. A complete purification process consists of an all-pit followed by a treatment system (sand filter, spreading network, etc.). The inter-ministerial decree of 7 September 2009 stipulates that all-pit can be used for non-collective sanitation to treat domestic wastewater from unconnected buildings, dispersed dwellings, hotels, holiday camps, campgrounds, etc. Each case must be the subject of a special study. We therefore advise you to ask the opinion of the competent authorities of the place of installation (town hall, SPANC ...) which will help you in your steps. In order to determine the equipment to be used, account should be taken of the number of visitors to the building (permanent, semi-permanent and intermittent users). The pits all water up to 25000L are equipped with pre lters. Beyond this, a DEC3 / 102 or DEC3 / 103 lamellar decolloid is required depending on the volume of the pit (see options), which will be directly integrated into the tank. If this is not possible, an independent pre-filter must be placed at the outlet of the pit to limit the risk of clogging the network.
All horizontal waters from 10 to 60 000L in PRV
The purification capacities of the F.T.E. SIMOP take into account two criteria: - the sludge storage volume - the permissible flow rate. These criteria have allowed SIMOP to characterize the type of pit adapted to the needs according to the daily flows on the one hand and the peak flows on the other hand. In order to simplify the selection of a Pit All Waters for an autonomous sanitation for pooled habitat, the following table gives the mean volume of the pits according to the connected population. The design basis is 150 L of water per day and per permanent user (circular 97-49 of May 22, 1997). For optimal functioning of the anaerobic treatment (see the section "OPERATION"), around a daily flow rate of 10 m3 / day (other <75 EH to 150 L / EH), the residence time changes from 3 days to 2 days.
The wastewater is collected in the pit all waters. Decantable suspended solids sediment and ferment. Over time, the volume of sludge decreases and stabilizes. On the surface are trapped fats that hydrolyze slowly and constitute the "hat".
IMPORTANT: The larger the pool, the bigger the sludge area, the more efficient the fermentation.
Refer to the PHPRV-NC installation instructions before handling and installing the pit.
An emptying should be carried out when the volume of sludge reaches 50% of the working volume of the pit. After each emptying, immediately return the appliance to water under the drainer's supervision. Do not drain appliances during periods of high rainfall.