Wastewater systems comprise of:

1. The network of pipelines or channels, which conveys the wastewater from its point of generation to a treatment facility. In a household the wastewater is generated in toilets, sinks, bath tubs, showers, washing machines, etc.

2. The wastewater treatment facility, which removes pollutants to limits prescribed by standards and regulations. These should be well developed and detailed in order to protect the surrounding environment from the pollutants remaining in the treated wastewater.

3. A discharge or disposal facility, which allows for the disposal of the treated effluent in the natural environment. Most often it is discharged into a natural water body. It may be spread overland or infiltrated underground, and also, it can be reused for different beneficial purposes.

A schematic representation of a wastewater system is shown on Figure 1.

Pay attention to the division by the property line. Usually, the installation within a property is maintained by the owner; the operation of the rest of the system is responsibility of the local authority (municipality). Depending on the aims and objectives of selected tasks, the boundary of the system can vary, including or not the part behind the property lines. Also, it is possible the part behind the property line to be treated as a separate system on its own.

Different types of wastewater systems are applied in practice. They can be classified and described based on different principles in three main groups:

• Classification based on storm water conveyance

• Classification based on hydraulic principles

• Classification based on scale of magnitude

Figure 1