Indicator: Discharges to waters

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What the results tell us for Tumut

See also: | Surface water quality |

Effluent generated in the major towns in Tumut Shire is treated at Sewage Treatment Plants at Adelong, Batlow, Brungle, Talbingo and Tumut (Table 1) Treated effluent is discharged into streams with the exception of Talbingo, where it is discharged into Jounama Pondage.

In rural areas, septic systems are used to treat sewage. NSW Government initiatives have introduced a scheme of inspecting and risk rating On Site Sewage Management (OSSM) which has resulted in some 1300 OSSM units being checked within the Shire. With associated follow-up work by staff, locally the initiative has resulted in a significant reduction in pollution caused by the operation of OSSM units.

Tumut Shire Council is currently implementing a trade waste policy which had a July 2000 deadline for compliance. Notice has been sent to all non-domestic sites that prepare greasy food (restaurants, cafes etc.) or sites that discharge oil (service stations, motor mechanics etc). Some 85% of local businesses are now having grease and oil wastes removed from sewage wastes before entering the network, resulting in much improved effluent discharges from Councils sewage treatment plants.

*Types of discharge can include sewage, stormwater, agricultural chemicals, oil, and etc.
The volume of materials discharged illegally or accidentally were not estimated.

About the data

Council maintains records on the amount and quality of waters discharged from the sewage treatment works.

Description: What does 'discharges to waters' measure?

Which data are collected?

• volume, number, type and mass loads of licensed and other (unlicensed/illegal/accidental) discharges into groundwater, streams, estuaries and the sea
• number of discharge licenses exceeded, by type and volume
• estimated volume of diffuse discharges from different landuses, calculated from runoff rates and annual rainfall

Why do we report this indicator?

Human occupation not only removes water from surface water and groundwaters for consumption, but it also changes the amount and quality of water flowing into our lakes, rivers and estuaries. The impact on streamflow, groundwater levels, groundwater quality, surface water quality and aquatic biota can be significant at the point of discharge and further downstream or out to sea. Where the quality of discharged water does not meet guidelines then the potential for adverse impacts is much increased.

Many discharges are "point discharges", in that they flow from a single point (usually a pipe) into a river, lake, estuary or the sea. A pipe discharging sewage effluent into a river or the sea is a good example of a point discharge. Many others are "diffuse" because they flow into the waterways at no particular point. Runoff from farms and forests into streams is a good example of a diffuse discharge.

The amount of runoff from urban areas is higher than would occur in a vegetated catchment due to the large amount of impervious surface such as roads, car parks and building roofs. Additional sources of wastewater include sewage and runoff from building, industrial and mining sites. All discharges are generally collected and treated to remove contaminants before discharge into streams, although the same high standard of treatment does not always apply to waters discharged into estuaries and the sea.

Effective disposal of human waste and stormwater is a necessity for the health of human systems as much as natural ones. However a well designed and managed stormwater and wastewater collection and treatment system ensures that the impacts, particularly of extra nitrogen and phosphorus are minimal.