Grey Water system.
The Grey water system is primarily designed to filter water from the shower, washing machine, sinks and tubs.
The house hold water is drained or pumped to the first holding tank with a swirling action that flows into the second tank which continues the swirling action on out through an inline UV Filter and out to a soak hole or leach field.
For a complete sanitation solution, the grey water can flow through a UV filter on its way out to a soak-age hole or leach field.
Including the grey water system into your Enviro system will give you the best composting option in the wider pacific area.