pa

ge o

ne

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 StudyImportant 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 servicesprovided by:

The area has been monitored for four years.

Water quality is good in most upstream areas

pag

e tw

o

Water Quality MonitoringResults 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 RecreationalWatersWater 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 IndicatorsNational 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 usingequipment at the site. Others are measured ata laboratory from samples collected at the site.

Most of the waterways tested comply withguidelines for recreational activities.

Water clarity depends on the amount of sediments suspended in the water column.

pa

ge

thre

e

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 ResultsResults 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.

pa

ge

fo

ur

Furtherinformation

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.au\environment\

science\water

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 FutureA 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 fromdisturbance of acid sulphate soils.

Clearing riparian (stream bank) vegetation canlead to greater sedimentation in the waterwaydue to increased runoff and decreased filtration.

Water quality is improved if everybody reducesthe amount of pollutants they release in theirlocal area.

The northern broadwater is a popularrecreation site.