Tertiary wastewater treatment systems provide additional treatment to the effluent emitted from secondary treatment systems. Essentially, an additional or tertiary treatment stage is added to a standard wastewater treatment system which raises the effluent quality before it is discharged to the receiving environment.
These systems can be designed to reduce the concentration of organics, settled solids, nutrients and micro-organisms discharged from secondary systems. The treatment standards to be achieved by these systems are often dependent on the sensitivity of the receiving environment.
They are often deployed to mitigate against adverse environmental impacts or to overcome planning or site restrictions. In many cases, the extra expense associated with a tertiary treatment system is offset by overcoming the frustration of planning refusals thus helping people to realise the full potential of the site.