2016-07-12 - Item 14 - Att 1 - Effluent Disposal Planning Study

3. About On-site Wastewater Treatment
3.1      Overview
Figure 2 (courtesy Building Codes Queensland) is a simple representation of the main elements of on-site
wastewater treatment.

Figure 2 - On-site wastewater treatment




The following overview is an extract from a Discussion Paper to support a review of the Plumbing
and Drainage Act 2002 prepared by Building Codes Queensland and released in June 2014.

        The non-sewered areas of Queensland are most commonly serviced by septic tanks or on-
        site sewage treatment plants. The resulting effluent is either treated and diverted for re-use
        (greywater only) or applied to land application areas.

        The function of an on-site sewage treatment plant is to receive and to treat domestic
        sewage by means of aerobic and/or anaerobic processes and, where required, disinfection
        so as to produce an effluent appropriate to the land application area.

        An on-site sewage treatment plant must protect public health by minimising the risks
        associated with the treatment of sewage and its ultimate discharge to the environment.
        On-site sewage facilities that are appropriately designed, sited and maintained can provide
        satisfactory waste management solutions. However, anecdotal reports suggest that many
        systems are underperforming (60 – 80%) and, as a result, pose an increased risk to public
        and environmental health.

        Environmental impacts caused by the discharge of poorly treated sewage may include
        pollution of groundwater, streams and waterways along with degradation of soil and
        vegetation. Apart from the environmental effects caused by poorly or untreated wastewater,
        failing systems also pose a health risk through direct human contact. This can not only lead
        to upset stomachs, they can also lead to more serious conditions caused by bacteria and
        viruses. Children are particularly at risk when they play in areas that are polluted by the
        discharge from poorly serviced or maintained on-site sewerage [sic] treatment plants.
        Failing on-site sewerage systems can have the following adverse impacts to both the
        occupants of the property and public in general:
                  spread of infectious bacteria, viruses and other organisms in the wastewater
                  cause odours

On-Site Effluent Disposal in Noosa Shire 2016                                                       Page 6