Acceptable ways will have to found of reusing sewage. Mined phosphorus is running out and nitrogen fertiliser made from natural gas will escalate in price. It's a pity that cities weren't designed to create large farming zones between transport corridors. That way the food consumption and production loop could be nearly closed with minimal transport costs either way. However broadacre crops such as wheat grown out in the Wimmera seem likely to remain dependent on the weather and synthetic fertilisers. Calcined sewage sludge or grey water are still too bulky to transport hundreds of kilometres. From now on it's a battle between high food prices and the 'yuck' factor.

The recycling of sewage is really a question of vengeance; getting your own back!

An excellent and timely article Valerie. Taswegian is quite correct. Mined phosphorus is indeed running out, not only physically, but running out to sea thanks to modern sewage systems. Once in the oceans, it's practically unrecoverable.

The human race and indeed, I'd venture, all creatures and plants, cannot exist without phosphorus. The potential problem caused by the rapidly declining natural stores of this element eclipses even the threat of peak oil in many respects. Peak oil simply means that the amount of oil still in underground reservoirs equals the amount used over the past 164 years. There's still plenty left in the ground, it's just the practically of extracting it that is already causing problems.

Unlike oil, phosphorus is actually running out and is another reason, hidden to some, that fertiliser prices are going through the roof. Articles like Valerie's need more news coverage and Governments desperately need to implement some of her ideas. At present, we have a fractured food cycle and this requires urgent attention if billions of lives are to be spared misery.
Aime.

All power to you Valerie for raising the subject so often regarded as taboo. Why, I don't know since we all contribute and there is no likelihood of ever running out. It is an under researched (as far as I know) and we have disposed of it in a most profligate way ever since Alexander Cummings invented the flush toilet in 1775. At the time it would have been an amazing advance but it soon will become a curse should the aspiring billions in developing countries wish to dispose of their waste in the same way as we do. As with power supplies we should be endeavouring to generate and retain everything on site wherever possible or at least locally instead of pumping it miles, processing it and dumping it at sea.

It is a good companion piece to Duncan Brown’s excellent book Feed or Feedback. The cost of returning excreted phosphorus from the cities of the world to the food-growing areas is presently prohibitive, with no solution to that in sight. No doubt that will be addressed – one way or another – eventually, if not harmoniously, within a few generations. Long term prospects for world food production are not good, even if human numbers were not continually increasing as they currently are.

There is much phosphorus in a great deal of the world’s soils, but not in a form readily available to plants. In many, perhaps most soils, phosphorus is readily captured to negate availability for plants. Fungi appropriately associated with vegetation can, in many instances, extend that availability enormously - but there are limits. And that will simply extend the time towards finality.

My formative years were near to an unsewered town, whose “night carter” rejoiced under the name of Ketman. Irreverent schoolchildren unkinkdly inferred enthusiasm for the job, with the insinuation that "Ketman the shetman" threw himself into his work. In those times in that area, the back-yard dunny rightly occupied a place in the remotest corner of the yard. If/When we return to such times, I hope for better organization of the system.

I concur with the other posts. An excellent article about two critical issues: sewage and privatisation.

Of pioneering US geologist Eugene Hilgard of the late 19th century, David R. Montgmomery wrote in "Soil - The Erosion of Civilisations" (2007):

Both geologist and chemist by training, Hilgard argued that the secret to fertile soil lay in retaining soil nutrients. "No land can be permanently fertile unless we restore to it, regularly, the mineral ingredients which our crops have withdrawn." Hilgard admired the Asian practice of returning human waste to the fields to maintain soil fertility by recycling nutrients. He considered America's sewers conduits draining soil fertility to the ocean. Refusing to contribute to the problem, he personally fertilised his own backyard garden. (p189).

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On the related topic of agriculture, I recently put some of my thoughts in my blog article "How to make our agricultural sector sustainable" at http://candobetter.org/node/624

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On another somewhat unrelated matter, I heard the end of Val's excellent talk on simplifying English spelling today (yesterday now) on ABC Radio National's Lingua Franca program.