A Review of Documented Sites of Concern within
the Blue Lake Capture Zone, Mount Gambier, South Australia
The EPA has engaged environmental consulting company Resource
& Environmental Management Pty Ltd (REM) to undertake a review
of the documented groundwater impacts from point sources within
Mount Gambier to assess the risks to the unconfined aquifer (Mount
Gambier's drinking water supply) and to identify potential management
actions to be considered by the EPA for the sites.
Three sites were selected for the project; the groundwater impacts
at these sites occurred prior to the commencement of the Environment
Protection Act 1993 and are of a historic nature.
The report will provide an assessment of the risk to the environment
and humans by the contaminants of concern. The report will also
provide management options for minimising the risk to the receptors.
Future recommendations for these sites include may include groundwater
monitoring, additional groundwater investigations and developing
Environmental Management Plans for the sites.
This report is currently being finalised and will be available
on the EPA web site by June 2006.
Burial of Livestock in Shallow Pits in the
Lower South East.
The EPA engaged environmental consulting company Gutteridge,
Haskins and Davies (GHD) to undertake an assessment of the impact
on groundwater from the burial of livestock in shallow pits in
the lower South East of South Australia.
During February 1983 the bushfires in South Australia destroyed
300,000 sheep and 10,000 cattle. The livestock were hastily buried
in shallow pits to avoid the spread of diseases and odours. The
Department of Mines and Energy installed groundwater-monitoring
wells at six sites to assess the potential groundwater impacts.
Sampling of these sites occurred between 1984 and 1988. GHD were
engaged to undertake another sampling event on the wells to assess
the current status of these sites and to compare the results with
historic data.
GHD identified that data limitations were imposed by the design
of the well networks and this reduced the certainty with which
they were able to assess the presence of groundwater impacts.
The assessment has indicated that there may be some general evidence
to indicate that limited groundwater impact from the stock burial
may be present at some of the sites. >>
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Assessing and Improving the Sustainability
of Urban Water Resources and Systems. (AISUWRS)
AISUWRS is an urban water research project, which commenced in
late 2002 and was finished in late 2005. The aim of the project
was to develop a decision support system for use by cities that
rely on groundwater for their drinking water. The aim of the study
in Mount Gambier was understand the hydrogeology of the area and
to assess the extent of human influences or the expansion of urban
infrastructure on the urban water balance and on water quality.
The EPA has provided CSIRO with groundwater quality data of the
EPA monitoring network and data from the Blue Lake. This data
will enable CSIRO to develop a number of models to analyse and
understand the urban water infrastructure and the groundwater
systems. The study will provide further information and guidelines
for the sustainable development of urban water systems to ensure
that the effect of future development on groundwater contamination
is addressed.
EPA Guidelines for Stormwater Management
in Mount Gambier
The EPA in conjunction with the City Council of Mount Gambier,
the District Council of Grant, SA Water and the South East Natural
Resource Management Board engaged the University of South Australia
to develop stormwater guidelines for the City of Mount Gambier.
Stormwater in Mount Gambier has traditionally been discharged
directly to the aquifer via a series of drainage wells. The aquifer
beneath Mount Gambier is used as the city's potable water supply.
This guideline is aimed at developers who need to be aware that
stormwater discharged into the aquifer will ultimately find its
way to the Blue Lake.
The guideline outlines principles of stormwater management and
incorporates a selection of disposal options for stormwater for
different types of developments. Many of the design principles
involve Water Sensitive Urban Design techniques with an emphasis
away from direct disposal to the aquifer.
These methods range from retention basins and wetlands to manufactured
units and other options such as permeable paving. This guideline
will give developers an indication of the what the EPA is expecting
in the development application process and should streamline the
current process and educate developers in the principles of stormwater
management.
The guidelines are currently in publication and will be available
on the EPA website once they are finalised.
Dairy Effluent Guidelines
In 1995 the EPA as part of the South East Dairy Effluent Guidelines
Group published the documents: "Guidelines for the Management
of Dairy Shed Effluent in the South East of South Australia".
Although these guidelines were not linked to the (then) Environment
Protection (Milking Shed Effluent Management) Policy, they provided
a useful resource for improving dairy effluent management within
the region.
In light of recent changes to the relevant legislation relating
to this industry, the burgeoning nature of dairying in the South
East region of SA, and the potential for much of the dairy industry's
future growth in SA expected to come from this area, it was considered
that the 1995 guideline documents needed to be updated to reflect
recent legislative changes, industry best practice and modern
technology applicable to larger scale dairy farms. A key component
that the EPA has promoted within the updated guidelines is the
requirement for effluent storage over the winter months. This
is to negate the need to irrigate nutrient-rich effluent during
the winter months when infiltration (and aquifer recharge) rates
are high and nutrient usage by plant is low.
These guidelines will be available in the near future from Dairy
Industry SA website.
Sinkhole Rehabilitation Project
The South East Natural Resource Consultative Committee in conjunction
with the EPA and other agencies and local government undertook
a project to clean out selected sinkholes and caves in the South
East that have historically been used for the indiscriminate disposal
of waste.
The filling up of these sinkholes with waste has the potential
to have an adverse effect on the groundwater beneath the sinkhole
and to impact upon sensitive aquatic ecosystems. Two sinkholes
and two caves have been cleaned out to date with nearly 900 tonnes
of waste removed from the sinkholes alone.
Assessing Water Quality Risks to the Blue
Lake
This research project will define the necessary land management
practices for ensuring the sustainability of the Blue Lake and
the groundwater within the catchment zone of the Blue Lake.
This project will collate and build upon extensive research information
and establish a comprehensive risk assessment model for the semi-quantification
of land use risks on the quality and quantity of water within
the Blue Lake and its surrounding groundwater capture zone.
The extended value of this project will be the inclusion of investigations
into the controlling options to address those risk activities
that provide the greatest economic, social and environmental benefits
to the region and the state. The outcomes of this project will
allow for resource managers to then implement the preferred controlling
outcomes so that the wider vision for the project can be achieved.
The research project will encompass activities that have both
a diffuse and point-source impact upon groundwater within the
Blue Lake Capture Zone, and include broad-acre land management,
wastewater management and disposal, stormwater management and
disposal and urban development.
The wider vision of this project is "to implement within
the Blue Lake Capture Zone by 2013, land management practices
and resource management regimes that will provide for the long-term
protection of the Blue Lake
This project is ongoing and will conclude at the end of 2007,
it is being project managed by CSIRO with the EPA and DWLBC providing
input.
This page was last modified 24-10-2006
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