A CWMS is a system designed to collect, treat, re-use and/or dispose of primary treated effluent from septic tanks on individual properties.
The collection system is a network of pipes and pumping stations which transport the effluent from the septic tanks to the treatment site. In some cases (generally rare) no pumping stations are required where the collection system operates by gravity.
The treatment system can be by either:
- facultative (oxidation) lagoons where effluent is stored and treated by aerobic action. Mechanical aeration is sometimes installed to speed up the process and/or reduce the size of the lagoon system; or
- mechanical treatment plants where aerobic action is undertaken in a series of aerated tanks.
The disposal system can be by either:
- evaporation ponds; or
- irrigation systems or other re-use (eg, wetlands).
Generally many of the older systems are lagoon systems (facultative lagoon and evaporation pond) whilst the newer systems tend to comprise mechanical treatment plants, a storage pond and an irrigation system onto parklands, golf courses or crops.