Questions and Answers - Wastewater treatment

  • How often does the sludge normally need to be removed?

    All small wastewater treatment systems are designed such that their function is normally guaranteed for 12 months if run permanently at full load and if the operator and maintenance obligations are met. This period extends accordingly if they are used less. Alternatively, a tank with a larger sludge reservoir can be selected so that the sludge does not need to be disposed of so frequently.

  • What are the most important things to remember when upgrading?

    The existing concrete pit must be emptied and thoroughly cleaned. The tank must be checked to make sure it is still fully sealed. Not only the entire tank but also the dividing walls between the individual chambers must be watertight. An empty pipe should be laid to the planned site of the control unit or external control cabinet. When fitting a new tank downstream, the supply and discharge levels should be noted.

  • What you must remember when operating a GRAF wastewater treatment at constant underload?

    For the Klaro Easy, in this case we recommend our ZK Plus controller. The system only works optimally when there is an incoming flow of wastewater. When the infeed is very low or the residents are absent for some time, water is moved around the system. This automatically activates and keeps alive the bacteria necessary for the cleaning process.

  • What is the advantage of the holiday setting on GRAF small wastewater treatment system?

    The option of switching GRAF small wastewater treatment systems to an energy-saving holiday mode makes it possible to save money at the appropriate times. With the ZK controller the holiday mode is set manually; with the ZKplus it happens automatically.

  • What happens to the wastewater after it has been cleaned?

    If possible, fully biologically cleaned wastewater should be discharged into a flowing watercourse such as a ditch or stream. If there isn’t a watercourse available, then the ‘clear water’ must be infiltrated into the ground. The soil needs to be of a suitable permeability with sufficient distance from groundwater and in compliance with the local authority’s requirements. 

  • Will there be a problem with smell on my proberty?

    Smell is not normally a problem with small wastewater treatment systems as long as they are properly ventilated. However, it is advisable to maintain an adequate distance from living areas and terraces and to ensure good ventilation of the system.