The BC Zero Discharge Lagoon System
The BC zero discharge lagoon is a system unique to BC. The lagoon disperses effluent by infiltration into the
soil and by evaporation from the pond surface, similar in concept to an evapotranspiration absorption (ETA)
bed.
A BC zero discharge lagoon system consists of one or more large excavated cells surrounded by a berm.
Sewage is fed directly or from a septic tank by gravity - if topography allows – otherwise a septic tank is used
and effluent is discharged to the lagoon by pump, siphon or other dosing device. Excavated clay material is
placed and compacted in an elevated berm intended to prevent surface water from entering the lagoon and
to provide reserve capacity.
Fencing is installed on the berm, or immediately adjacent to the berm to prevent entry of animals and to
provide security/safety.
Preventing problems associated with odour, mosquito breeding, disease transmission by insects and
exposure to animals are key considerations. Managing the long term growth of vegetation is important,
particularly as trees can cause leakage.
