A demure woman prepares for a cooking demonstration at the Rundle Street Mall in Adelaide, Australia.

Her modest, long-sleeved brown and blue checked dress and her center-parted and feathered hair are picture-perfect late 1970s housewife — which makes sense, since it is 1981. She’s got a microphone to help raise her voice over the cheery mall music, and soon she’s ready to begin the creation of Murray River Punch.

“One of the most wonderful things about this beverage is you don’t have to buy anything much,” she says, as she busies herself over a portable gas burner.  She starts with deoxidized water, and then, using the exact cooking show patois and intonation that recalls Julia Child, calls for the next ingredient.

“A quarter cup of human urine,” she says.

“Just collect a bit of human urine and set it aside. To complement that, you should have some human feces. Here we are. Collect it in the morning…wrap it up to keep it fresh. So in that goes. Right. Now, chop it up…like so. As you know, sewage goes straight into the water so this is really quite an important ingredient to get the full effect, the taste of the punch. Mix it up with the hand blender. You can use an electric blender for doing this, too of course. But for public demonstrations I’ve found it much too noisy.”

And so it goes on, with the woman — actually, the experimental artist Bonita Ely — adding toilet paper  (“you don’t have to shred it or anything like that, as you know, toilet paper is very absorbent”),  fertilizer (“two tablespoons of fertilizer should do it, I should think. It’s an important addition of flavors to the drink”), European carp which were introduced into the river and became invasive, lots of salt, chemicals and insecticide. (“If you want to make this drink even more interesting, add a defoliant, like Agent Orange for instance. But I think we’ll just stick to the insecticide today.”)  And then she’s done.

“Oh, my mouth is just absolutely watering,” she says. “It looks absolutely wonderful.”

I saw stills of this performance in Melbourne last month at the Ian Potter Centre at the National Gallery of Victoria, part of the museum’s permanent collection of contemporary work, much of which had a strong political theme. (If you’re not getting to Melbourne any time soon,  watch and listen to the work here.)  Ely’s been following this troubled  South Australian river since 1977, and released a series of photographs in 2008 and from a time of drought in 2009.

You can talk about river pollution in terms of sediment, run-off, invasive foreign species and other abstractions for hours and hours, but nothing makes you understand the issue quite as well as watching how a particular river got that way — and contemplating the results in a decorative punch bowl, elegantly garnished with rabbit dung.

On Earth Day 2010, this Thursday, have a drink (of something else) to that.