How to size your individual sanitation system?
Individual sanitation, also known as non-collective sanitation (NCS), is a key solution for homes not connected to the collective sewer network. In order to guarantee efficient and sustainable wastewater management, it is imperative that your sanitation system is correctly dimensioned. Accurate dimensioning ensures the proper functioning of the system, reduces maintenance costs and preserves the environment. In this article, we will guide you through the sizing process to help you choose the solution that best suits your needs.
Understanding the issues at stake in sizing
The sizing of an individual sanitation system consists of determining the size and type of system necessary to effectively treat the wastewater from your property. This process is influenced by various factors, such as the size of your household, the characteristics of your land and local regulatory requirements. Inappropriate sizing will result in non-compliance of your sanitation system and potentially inefficiencies, malfunctions or even risks to public health and the environment.
Why is proper sizing important?
- Efficiency of treatment: a properly sized system ensures optimal treatment of wastewater, guaranteeing that the effluents are sufficiently purified before being discharged into the natural environment.
- Optimised costs: an oversized system can generate unnecessary costs, while a system that is too small can require costly adjustments or frequent interventions.
- Regulatory compliance: local authorities often require that sanitation systems meet certain sizing standards to ensure safety and efficiency.
- Environmental sustainability: correct sizing contributes to the protection of local water resources and the preservation of ecosystems.
Steps for sizing your sanitation system
Treatment needs assessment
The first step in sizing is to assess your household’s specific wastewater treatment needs. This involves considering:
- The number of population equivalents (PE): the sizing is generally based on the number of PEs which reflects the biological load that the system must treat. One PE is generally equivalent to the consumption and waste production of one person.
- Water consumption: estimate your average daily water consumption. This will depend on the number of inhabitants and their consumption habits (showers, washing machine, etc.).
Site study
An in-depth study of your site will enable you to size your sanitation system correctly. This study includes:
- Topographical analysis: the slope and height of the land influence the type of system and its configuration.
- Soil permeability: a percolation test is often carried out to assess the soil’s capacity to absorb treated water.
- The presence of water tables: the presence of nearby water tables may require the addition of extra components to improve the rate of water removal.
- Geological characteristics: soil types (clay, sand, rock) affect the design of the system.
Choosing the right system
Once you have a clear understanding of the needs and characteristics of your land, you can choose the most appropriate sanitation system. Commonly used options include:
- All-water septic tanks: suitable for well-drained land.
- Micro-treatment plants: effective for limited spaces.
- Planted filters (Sanitation Gardens): take up little space, are attractive and environmentally friendly.
Consult experts
To ensure that your system is correctly dimensioned, it is strongly recommended that you consult professionals. A design office (or Aquatiris) can carry out a sector study, taking into account all the technical and environmental parameters, in order to design the system best suited to your needs.
Conclusion
Correct sizing of your individual sanitation system is a step that guarantees efficient and sustainable wastewater management. By assessing your household’s needs, taking into account the characteristics of the land and choosing the appropriate system, you can ensure optimal operation and compliance with environmental standards.
