Makes one think twice about sailing near the airport. From abc.net:
Sydney river given 'open sewer' status
Updated October 24, 2011 09:01:23
Researchers have found Sydney's Cooks River is so contaminated that the waterway is little more than an open sewer. The Water Research Centre at the University of New South Wales ran tests on the river, which flows from the city's inner west into Botany Bay. The tests found quantities of pharmaceutical and industrial chemicals in concentrations similar to those found in untreated sewage.
The contaminants included soaps, insecticides, caffeine and anticonvulsants.
Researcher Stuart Khan says the river will not recover until broken sewerage systems are fixed.
"The sewer systems in that area are leaking continuously. They're very old, some of them are close to 100 years old," Dr Khan said.
"The first objective would be to fix the broken sewers, which continuously release sewage into the river.
"But that's a huge job. It's not something that can be done in a week or a year, it's probably at least a decade's worth of serious dedication."
the real question is: "What's the water quality like where it flows into Botany Bay?"
my tafe teacher said today that sydney water has put24kgs of mercure into the enviro .. 2nd on the list was some mine and it put out lik 0.4kg of merc .. one of many pieces of useless info he blurts out that is totaly of topic.....
This is great news. I'm just now thinking about all the times I stood around in the water for hours, right at the mouth, waiting for the wind gusts to do some speed runs. It looked ugly and felt slimy! 
No wonder all those jelly fish plagues we had few years ago all died off! 
All that dredging recently would have stirred things up too.Not very comforting.
As it happens, I spent about an hour swimming in the estuary of Cooks River today. Broke my mast near the airport side on my third reach, and took some time to get back, even getting my broken gear tangled in the shark nets. I knew that there had been little rain, and it was a flood tide, so water quality was OK, though floating weeds sometimes fouled my fin.
Went back to the launch and rigged a smaller sail and had a good sess in 20-25 knot winds.
Rod
Slimy water = less water resistance = faster speeds. Sorry, what was the issue again?
When was the cooks river not an open sewer? 
I always remember it being disgusting ever since I was a lad (and that was quite some time ago!)
Yes I remember in them early nineties the crowd that sailed at La Pa would always say they would never go near Kyeemah because of the filthy Cooks River.But I've never heard of anyone getting sick.isn't the EPA supposed to monitor these things?
