'Zero discharge irrigation system, where apartment building owners want to avoid the cost of connecting to the central grid.'
Size of facilities varies from a few square meters to several square kilometers. The world is urbanizing but up to half of its communities still have less than 50,000 inhabitants. Many are surrounded by unused, underutilized or poor quality land. This is ideal for recycling wastewater.
These models were developed for such communities:
- The dilution model; where a wastewater collection system exists but is infiltrated by groundwater, rain and sand.
- The digester-dyke-pond model for concentrated effluent; to rebuild or construct a collection system which separates wastewater from rainwater, then pass concentrated effluent through a digester into an integrated farm.
- The soil filter model, where large water surfaces are undesirable for social reasons such as houses located very close to the treatment area.
The zero-discharge models
- Dry compost toilets & graywater systems to eliminate water in the flushing system. Useful in areas where severe water shortages occur. It is necessary to combine compost toilets with graywater recycling systems. Practical examples are described in the publication 'Building an Oasis' by Art Ludwig, available at: Oasis Design.
- Zero discharge irrigation system, where apartment building owners want to avoid the cost of connecting to the central grid. These use biodigester, landscaping and controlled irrigation. Further data is available from Hamburger Umweltinstitut e.V.