Tutorial - Siphons
Leach field dosing with Siphon
Siphons are sometimes used for dosing larger systems. The septic tank effluent is collected in a separate chamber or tank. This chamber fills until it activates a siphon. The siphon then empties the chamber rapidly at a high flow rate. The high flow rate is delivered through a network of pipes across the entire leach field. This provides even distribution of wastewater across large leach fields and allows the leach field to rest between doses. Essentially, this process encourages micro-organism "biomat" growth in the soil below the entire leach field and improves filtration. These micro-organisms develop a higher metabolism during the "rest period" to more effectively metabolize (digest) the wastewater.
The dosing process results in better wastewater treatment and prolongs the life of the leach field. Many states require drainfield dosing by siphon or pump system for larger systems. Dosing may also be required for any drainfield placed near sensitve areas like drinking water supplies, surface waters, and wetlands.