More and more separate sewerage systems are being installed in Flanders. An incorrect connection to this sewerage system has a considerably greater impact than with a mixed system. Monitoring this therefore becomes more important. But you can also see it as an extra check on the work supplied by your contractor.
When is an inspection mandatory?
Since 1 July 2011, the inspection of the private drainage system has been mandatory:
» Before the first commissioning
» In the event of major changes (ie: changes that may threaten the proper functioning of the public remediation network)
» After finding a breach of conformity (the legal requirements), at the request of the operator
» When constructing a separate sewer system on the public domain, with the obligation to disconnect on private domain
What does an inspector do?
During the inspection, it is checked on private property whether on the one hand the separation of waste and rain water and on the other hand the connection of both water flows to the public sewer system is in accordance with the legal and technical regulations. The way in which this happens depends on the situation on site: the inspector can use various techniques and aids such as smoke machines, harmless dyes, sound sources and camera inspection. On the basis of the investigation, the inspector can assess the drainage situation.
If the private water drainage is not in accordance with the legal and technical regulations, the public sewer network operator must take measures to ensure that the individual makes the necessary adjustments . For example, the operator can refuse or limit the connection to the sewage system as long as the water drainage does not comply with the regulations.
If the private water drainage is approved, the inspector issues an inspection certificate to the customer or holder.
During an inspection, we check, among other things, the following:
» The correct separation of the private waste water and rainwater circuit
» The correct connection of devices (toilet, bath, ...) to the circuits
» Rainwater drainage from paved surfaces
» The possible infiltration and drainage facilities.
Why a separate system?
A separate sewer system is a system consisting of two pipes: a pipe for transporting waste water (waste water from toilets, from the bathroom and kitchen, ...) and a pipe for transporting rainwater.
All new public sewers are installed separately and existing mixed systems are systematically replaced by separate systems (only in predetermined areas).
To improve the quality of the water in streams, rivers and canals, it is important it is of great importance to drain rainwater directly to watercourses as much as possible, to allow it to penetrate into the ground or to buffer it. For example, only the waste water is discharged to the treatment stations, resulting in better treatment.
» Only 1 connection from buildings to sewer system, and therefore cheaper to install than a separate system
» Less complex sewer system, both on private and public land
» In the event of sudden and heavy rain showers, the sewer system cannot process the inflow: overflows come into operation whereby waste water ends up in the watercourses. Sewer pits and gullies overflow with possible flooding as a result.
» Reduced efficiency of the treatment plants due to the supply of highly diluted waste water.
» Fewer overflows and therefore reduced polluted waste water in watercourses, streams, canals, ...
» Better functioning of sewage treatment plants because of less diluted waste water (higher efficiency with concentrated waste water).
» Fewer flood risks
» Addition of the groundwater table
» Danger of incorrect connections with possible direct emission of dirt to the environment
» Rainwater running off can be contaminated
» Accidental discharges end up in the environment faster (does not pass through treatment plants)
» More expensive in construction due to double the number of pipes