Environmental Issues - an Overview
There are a number of environmental issues that we have to deal with working in fringe and in rural areas. It is not possible to list them all in an article such as this. Broadly speaking, they cover land degradation and water quality issues. One of the most important aspects is that there have to be the appropriate management regimes put in place to ensure that there is a balance achieved between development and the preservation of the environment.
The environments are both sensitive and diverse. The topography varies from steep sandstone gorges to gently undulating farmland with varying soil types. The uses range from intensive agriculture to large scale industrial to grazing to large areas of significant indigenous vegetation. There is also a diverse range of residential uses - rural residential, farm housing and urban areas.
Development in such areas must address these issues and ensure that it does not lead to an increase in land degradation or have a detrimental impact on the quality of surrounding water ways. Otherwise it will come into conflict with the environmental aspects.
This conflict can take various forms. Land degradation can be caused by inappropriate clearing of steep land which can cause soil erosion and gullying. It can also arise from bad drainage design of access ways to houses. Where houses are built on slopes and require cut and fill the potential for erosion can occur if there is not appropriate attention paid to soil and water management. Similarly, land degradation can occur with agriculture - especially intensive horticulture (market gardening and turf growing). There is a need to pay attention to both the constraints and the total water cycle of the site and introduce proper management structures such as sediment traps, cut off drains and other mechanisms.
One of the causes of water quality problems is on-site effluent disposal. Provided there is an adequate irrigation area and the system is regularly maintained they do not cause water quality problems. One of the major constraints to on-site effluent disposal is the size of the irrigation area which is directly related to the size of the lot.
There are various forms of on-site effluent disposal systems. One misnomer about them is that the effluent discharged is clean water similar to that which comes out of the tap. From a public health aspect, provided the system is installed in accordance with the approved design of the NSW Department of Health and operated to achieve the design parameters of effluent quality, it poses little risk to public health. However, from an overall environmental viewpoint, it can cause problems because it still contains high levels of nutrients - phosphates and nitrates, both of which cause water quality problems in the surrounding water ways.
On large sites where there is sufficient area for irrigation and transpiration, this type of effluent disposal works. A draft guideline published by the State government early this year stated that irrigation areas should be a minimum of 1000 square metres. Minimum Lot sizes for non-reticulated water supply was 2000 square metres and where reticulated water was supplied 1 hectare (it is possible that lesser minimums may be satisfactory subject to appropriate climate, soil and site analysis).
On smaller sites, such as in urban situations, on-site effluent disposal causes problems such as waterlogged back yards and associated health risks. The systems may work well when it is dry but when it is wet, they still discharge the treated effluent (by spraying or absorption). Where there are a number of these systems (in some urban areas it can be in the hundreds), they cause water quality problems in the surrounding waterways. For this reason, on-site effluent disposal is not considered appropriate. The only real answer is to construct sewerage schemes. These are large, expensive and complex systems which cannot be implemented over night - in fact it takes many years. The issue of providing the economic resources must be considered by all levels of Government and the community.
|| Rural Planning Wheel ||
launched March, 1999