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No. 3 March 2001
Background
The Logan, Albert, Pimpama and
Coomera River catchments extend from
the McPherson Ranges on the
Queensland-New South Wales border to
Moreton Bay. Each month since 1996,
the Queensland Environmental
Protection Agency (EPA) monitored
water quality indicators (see What was
Measured ) that show how the water is
impacted by human use of the
surrounding land. These indicators can
be interpreted to provide an overall
impression of the health of a waterway.
Within the catchment area, land is used
for rural, urban, industrial and
recreational (national park) activities.
Each of these landuses affect water
quality, particularly during rainfall when
nutrients, contaminants and other
material are washed into waterways.
These stormwater flows, along with
other direct inputs (eg discharge from
wastewater treatment plants), can
impact on organisms in the freshwater
streams, estuaries and coastal areas of
the catchments. Therefore, it is
essential to monitor the water quality to
identify potential risks to the health of
the ecosystem.
Logan-Nerang Water Quality Study
Important Points
• The northern Broadwater and
southern Moreton bay have
good water quality.
• Upstream, freshwater areas
have good water quality.
• Sites in the estuarine section
of the Logan and Albert Rivers
have poor water quality and
some areas are unsuitable for
swimming after heavy rainfall.
• Wastewater treatment
plants in the region are
being upgraded.
• Specific ‘hot spots’- to be
further investigated.
Funding and services
provided by:
The area has been monitored for four years.
Water quality is good in most upstream areas

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Water Quality Monitoring
Results from monitoring the water quality
indicators listed below (see What was
measured?) were compared with the
Queensland Water Quality Guidelines and
an overall assessment made of each site in
1999. These assessments are shown in
the Map of Results.
Monitoring Recreational
Waters
Water samples were collected at sites
where boating, swimming or other
recreational activities commonly occur.
These samples were taken weekly over
six-week periods, in summer Autumn and
Spring of each year. Concentrations of
certain bacteria in the samples (see
Bacterial Indicators) were compared
with national guidelines to determine if the
sites were suitable for recreational
activities. Compliance with guidelines is
required for primary contact recreation
activities such as swimming, skiing and
surfing. Any sites that comply with these
guidelines are also suitable for boating
and canoeing (see Map of Results).
Indicators Explanation
Dissolved oxygen A measure of the amount of oxygen in the water. Very low or
high concentrations of dissolved oxygen can have detrimental
affects on these organisms and can indicate an unbalanced or
unhealthy waterway.
pH A measure of acidity/alkalinity of the water. Highly acidic or alkaline
waters can be toxic to aquatic organisms.
Turbidity and Turbidity is a measure of the clarity of a waterway. Total suspended
Suspended Solids solids measure the amount of particles suspended in the water.
Small suspended particles of soil and organic matter are naturally
present in all waters. In high concentrations, they reduce the
penetration of light (which is necessary for plants), or the particles
can settle and smother some aquatic organisms.
Nitrogen and These are among the most important nutrients for plant growth.
Phosphorus Concentrations are generally low in natural Australian waterways,
but are dramatically increased by some human activities. Very high
concentrations of nutrients cause excessive plant growth,
proliferation of weeds, and algal blooms.
Chlorophyll-a Chlorophyll-a is a green pigment found in most plants including
algae and is an indicator of microalgal biomass. High concentrations
occur in algal blooms which indicate poor ecosystem health.
What was Measured?
Bacterial Indicators
National guidelines recommend the use of
a group of bacteria called faecal coliforms
to indicate levels of faecal contamination.
These bacteria occur naturally in the
digestive tract of humans and other
animals and are usually harmless.
However, their presence in a waterway
indicates contamination by faecal matter
from sewage, livestock, domestic pets or
wildlife. Contaminants such as these may
have other organisms associated with
them that are harmful to humans.
Therefore, faecal coliforms are used as an
indicator to determine whether sites are
suitable for recreational activities.
Some indicators are measured using
equipment at the site. Others are measured at
a laboratory from samples collected at the site.
Most of the waterways tested comply with
guidelines for recreational activities.
Water clarity depends on the amount of sediments suspended in the water column.

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The Logan River
The Logan River is impacted by a
variety of landuses including dairying,
grazing, crops, aquaculture, rural
residential and urban uses. In addition,
treated wastewater is discharged to
the river at five locations. Each of
these activities can contribute
sediments, nutrients and contaminants
to the Logan River and this is reflected
in water quality ratings that indicate a
moderate to high degree of impact (see
Map of Results). Impacted sites had
high concentrations of nitrogen,
phosphorus and sediments and also
have large algal populations on
occasions. In addition, a few sites
failed to comply with national guidelines
for primary contact recreation. These
sites are not suitable for swimming,
particularly after heavy rainfall
(see red on Map of Results).
Despite the impacted nature of the
Logan River, improvements are
possible. The EPA and all local
government bodies adjoining the river
have been cooperating to upgrade
wastewater treatment plants and to
minimise other sources of pollution.
Water Quality Monitoring Sites
Recreational Monitoring
The Slacks Creek wastewater treatment
plant has recently been decommissioned
and all treatment is now carried out at
the Loganholme waste water treatment
plant. A widespread scientific study of
water quality in the freshwater reaches
is underway. However, another major
source of pollutants damaging the
waterway is stormwater runoff which
can only be prevented if everyone
takes care not to release pollutants in
their own local area (see The Future).
The Albert River
Water quality in the Albert River is
similar to that in the Logan River
because of tidal exchange between the
waterways. Nutrients and sediments
are also introduced from surrounding
landuses and the Beenleigh wastewater
treatment plant. Further, the single
recreational site tested did not comply
with national guidelines. A study
investigating some of the poor water
quality ‘hotspots’ along with planned
improvements in wastewater treatment
will result in improved water quality in
the Albert River.
Map of Results
Results from monthly
water quality monitoring
in 1999 were used to
determine if the overall
water quality of each
site was unimpacted,
moderately impacted
or highly impacted.
The ratings are shown
on the map as coloured
symbols. These ratings
give an idea of the
quality of each of the
sites and thus of the
waterway overall.

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Further
information
Logan, Coomera and South Moreton Bay
Regional Wastewater Management Study:
Environmental Monitoring Program, Annual
Report 1999 Bothwell, A., Fearon, R. and
Semple. P.
Logan, Coomera and South Moreton Bay
Regional Wastewater Management Study:
Environmental Monitoring Program, Annual
Report 1998 Fearon. R and Semple.P.
The Crew Members Guide to the health of
our waterways.1998 Moreton Bay Catchment
Water Quality Management Strategy Team
Copies of these reports are
available from:
Naturally Queensland
Information Centre
Ground Floor, 160 Ann Street,
PO Box 155, BRISBANE ALBERT STREET,
Queensland, 4002
Visit the EPA Environmental and
Technical Services (Water) website at:
www.env.qld.gov.auenvironment
sciencewater
Gold coast City Council:
www.goldcoast.qld.gov.au
Redland Shire Council:
www.redland.net.au
Logan City Council:
www.logan.qld.gov.au
Bp1333 March 2001 • Recycled paper saves energy and resources
Canungra Creek
This freshwater stream originates in the
Lamington National Park and flows through
rural areas before joining the Albert River.
The upstream site has good water quality
and supports platypus and other native
fauna. The site downstream of the
Canungra township is mildly impacted from
domestic wastewater treatment plants,
rural activities and the effluent from the
Canungra wastwater treatment plant.
Northern Broadwater
The northern Broadwater and southern
Moreton Bay are popular recreational
areas and support a wide diversity of
marine organisms including dugongs, fish
and seagrass. Water quality is generally
good and most sites tested complied with
recreational guidelines for primary contact.
The few areas with poorer water quality
and those that did not always comply with
recreational guidelines were usually near
the mouth of rivers or creeks (see Map of
Results). This fact reflects the
importance of the impacts the waterways
have on the Broadwater and the Bay.
Pimpama River
Water quality in Pimpama River ranges from
good in the upstream reaches to highly
impacted in the mid-estuary. Many problems
in the estuary result from acid sulphate
soils being disturbed by landuse in the
catchment, and causing highly acidic waters.
Coomera River
The lower reaches of the Coomera River
are highly developed and include a number
of canal estates. Upstream, landuse
includes crop growing, dairy farming and
cattle grazing. Despite these impacts, the
Coomera River currently has good water
quality but is moderately impacted near
the areas of high development.
As well as changing your own habits, there
are numerous groups you can join if you
are interested in helping the environment
further. Contact the EPA or your local
council for more details.
Monitoring studies will continue in order to
identify water quality problems that may
arise. Specific studies are already being
planned to investigate ‘hotspots’ in the region.
These actions are undertaken cooperatively
among the local governments in the region
and the EPA. The continued health of the
ecosystem has wide reaching effects. We
obtain water for drinking, cleaning, irrigation
and enjoyment and we are only one of
many species of organisms that rely on
healthy waterways to survive.
The Future
A lot can be done to improve the quality of
our waterways. Your own backyard can be
a source of contamination. Anything that
enters a stormwater drain including
rubbish, pesticides, grass clippings or
detergents from washing the car, will
ultimately end up in our waterways.
These contaminants can upset the
delicate balance of the ecosystem.
High acidity in Pimpama River results from
disturbance of acid sulphate soils.
Clearing riparian (stream bank) vegetation can
lead to greater sedimentation in the waterway
due to increased runoff and decreased filtration.
Water quality is improved if everybody reduces
the amount of pollutants they release in their
local area.
The northern broadwater is a popular
recreation site.