Water quality testing on the La Perouse Headland conducted by La Perouse Coastcare(LPC)
One of the LPC’s key objectives is to assist in improving water quality in the area. Walking across Happy Valley Bridge in Botany Bay National Park you might see oil slicks or floating rubbish but you cannot really tell how much oxygen or phosphate the river contains or whether it is polluted with faecal matter.
The LPC was formed with local adults and children to conduct cleanups, engage in bush regeneration, nature walks and tours of the National Park and intertidal zone. Since 2002 they have also been watertesting as part of the Sydney Water Streamwatch Program www.streamwatch.org.au.
Where do we test and what have we found?
Volunteers take water samples from the creek below Happy Valley Bridge, Congwong Bay Lagoon, Yarra Bay Lagoon and other sites on a needs basis. You might see us with our bottles and pole dipping into the water to collect a sample. Then it’s back home to our portable laboratory for testing.
We compare our results with Government guidelines [viz. Australian and New Zealand Guidelines for Fresh and Marine Water Quality ANZECC 2000]. For example, the healthy guideline range for dissolved oxygen [expressed as a percentage of the saturated value at a given temperature] is 85-110%. We often get results outside this range. Our faecal coliform values are highly variable and depend partly on weather and sewerage performance. Results frequently exceed secondary human contact levels [ie maximum for boating and fishing 1000 CFU/100ml].
What do we do with the data?
We submit our results to Sydney Water for publication on the Streamwatch website. We also use the data for :
- Preparing trend analyses to identify improvements in water quality at individual sites
- Reporting to Councils
- Notifying pollution events to Councils, DECC and Sydney Water
We participate in annual quality assurance events and in 2004 we were Highly Commended for Environmental Action and in 2007 won an Outstanding Water Monitoring Award.
Are you interested?
If you are interested in joining us to learn how to test the waters or if you want to take a look at our results contact us on the CONTACT PAGE on this website.
If mucking about with the river and playing with chemicals is not your thing, you can still keep an eye out for pollution by becoming a La Perouse Lookout
Keeping a ‘LOOKOUT’ – Report Pollution
If you visit regularly you may notice unusual things – a really bad odour or an oil slick or a large frothy scum or an unusual discharge from a drain or even a dead fish or two. We rely on regular users of the area to keep us up to date with what is happening. For example, in November 2011 we had a plume in Congwong Bay. This was reported to the EPA’s Pollution Line. See details at this link.
You can keep a LOOKOUT by reporting pollution events. We ask you to report your observations first to the relevant agency. EPA’s Environment Line on 131 555 and then to notify us so we can follow up to ensure action has been taken.
What’s in water.
- Tidal seawater, river water, stormwater runoff, rainwater
- Fish, worms, mussels, crabs, microorganisms
- Aquatic plants and algae
- Sediments on the river bed contain heavy metals like lead, zinc and arsenic.
- And after heavy rain or sewer chokes … sewage from sewerage overflows
What does Streamwatch test and why do we test it?
|Temperature||The temperature of the water has a major effect on biological activity and growth of river organisms.|
|pH||This tells us how acidic or alkaline the water is. Freshwater fish and other river life are sensitive to changes in pH. Extremely high or low pH levels will lead to the death of aquatic life.|
|Electrical conductivity||This tells us how much salt and organic acid is in the water. Freshwater organisms cannot live in very salty water.|
|Turbidity||This tells us how cloudy or muddy the water is. Turbid water reduces the amount of light entering the river environment. Plant growth decreases and this impacts on the animals that rely on the plants [for food, shelter, oxygen].|
|Dissolved oxygen||Dissolved oxygen is essential for fish, worms, etc living in the river. Fish die if there is not enough dissolved oxygen in the water and they get environmentally ‘stressed’ if the levels are low. This means they are more susceptible to disease, etc.|
|Available phosphate||Phosphorus [in phosphates] is a nutrient essential to the growth of plants and animals. The available phosphate test tells us how much soluble phosphate there is available to plants. Too much phosphate leads to an abundance of algae and aquatic weeds. And less oxygen for fish.|
|Faecal coliforms & E-coli||These are naturally occurring bacteria found in the intestines of all warm blooded animals including humans.|