Rainwater Harvesting

Water reservoir. A large plastic barrel that collects rainwater.

Rain flowing down from the roof house in rainy season
Composting Toilets
Their are also hybrid systems that use normal flushing toilets followed by solids separation by centrifuge. The solids are then composted in a separate digester, while the liquids are disinfected and discharged with the grey water system.
Wetland Ecological Treatment
For larger development we would need to put treatment plants into the design of the eco village. This would vary depending on the codes and restrictions. Their are different types of treatments that could be employed. Constructed wetlands are built as a surface flow or a sub-surface flow. The former uses plants growing in soil over an impermeable liner. Both systems use plants to filter the water.

Pond with green banks, overgrown with reeds for water catchment.
Biogas digestors
This is similar to a septic tank except that the main chamber is domed to capture and siphon off the methane gas.
Tank Based Systems
This takes waste into a single or series of tasks. This process is more highly engineered, are of smaller size and use larger amounts of energy.