A sample flow scheme is described below, but remember that in many facilities this is modified significantly to allow for local conditions:
- Collection system enters facility inlet after possibly passing through digesters in other parts of the community.
- Sand is precipitated by flow reduction in a sand trap.
- Inlet flows through grate box where large solids are collected.
- Separate stream of livestock waste goes into a biodigester for mineralization and algae production.
- Wastewater from the inlet and biogas digester/livestock pens flows into the settlement pond, sometimes via pump, for; settlement of solids to sludge, biomass production by algae mineralization by microbiological processes, and purification with sunlight.
- Oxygenation basin flows via canal and macrophyte pond to fish pond(s) for; consumption of nutrients by plankton, consumption of plankton by fish, mineralization by microbiological processes, and purification by sunlight.
- Fish ponds flow to macrophyte ponds for; absorption of nutrients by water plants and snails, filtration by roots, sunlight purification.
- Macrophyte ponds flow to polishing basins or garden areas for; nutrient uptake by root-based plants, sunlight purification, microbiological purification and nutrient absorption by soil.
- Conversion of up to two thirds of total water volume may occur through absorption into pond walls, plant uptake, and evapo-transpiration, rather than flowing out of the facility outlet.
- Garden areas lead to outlet.
- Outlet leads to stream or collection system.
- Additionally, ground and rainwater may flow in a separate pattern around the site via a drainage ditch.
The above flow scheme is only an example. There are many variations. For example on small sites the fish pond may occur closer to the end of the facility or not at all.
A principle goal of daily operations is to keep water flowing through the facility without interruption. Stoppage of water flow interferes with nutrient and purification cycles. Therefore maintenance must be undertaken without stopping the water flow, and the entire flow scheme must be checked daily.