Can municipal sewage be transported to irrigate the desert?
Management Professor C. K. Prahalad authored a treatise in which he explored new business opportunities that result from the convergence of technologies, a concept based on lateral thinking and one where it is possible to envisage tankers being used to deliver municipal waste to new forms of desert agriculture.
The combination of the carrying capacity of large tanker ships, the location of deserts and the location of cities dumping raw sewage into rivers and the ocean, as well the evolving need to transport water internationally, presents a possible new business opportunity based on simultaneously solving several problems.
Dumping Raw Sewage
Last December environmentalists in Montreal, Canada expressed outrage as a result of the need to dump several million liters of raw sewage into the St. Lawrence River. A similar uproar occurred in Cape Town, South Africa as a result of 50 million liters per day of sewage being released into the ocean. On the west coast of the Americas, cities such as Victoria, Canada and Santiago, Chile dump raw sewage into the ocean. At all such locations, evidence of the sewage can be seen in the form of slicks on the seawater and the hue of waves.
At the present day, a tanker ship carries potable water from Southern France to Israel. In some arid regions, water can actually sell at a higher price than the equivalent volume of combustible liquid fuel. Such a scenario enhances the viability of pipelines, tanker railway trains and tanker ships carrying potable water. Except that, in some nations like Canada, environmentalists and people who adhere to a strong nationalist sentiment vehemently oppose the export of water – even while some of their cities dump raw sewage into the waterways.
Proximity of Deserts
A look at an atlas that shows climatic regions of the world also reveals that many cities that dump sewage into the ocean are located in the same general regions as deserts that extend to the coast. Part of the Namib and Kalahari Deserts extend to the coast to the north of Cape Town. The Atacama Desert stretches along South America’s Pacific Coast in close proximity to Lima, Peru, and Santiago, Chile. California’s drought-stricken agricultural region is located close to the coast and several major coastal cities from Vancouver to San Diego.
Deserts extend to the coast in Australia, the Arabian Peninsula and Northern Africa, with several ports located on the edge of deserts internationally. Oil pipelines cross over the Arabian Desert, suggesting scope to adapt the pipeline technology to carry water from a coastal location to inland desert locations.
At locations where large tanker ships are too deep to berth at a port, an offshore terminal could facilitate the unloading of sewage from ship to pipeline. The size of modern tanker ships would allow them to moor at a port for several days, filling to 85 percent of their volume.
Several innovations have recently occurred in India with regard to desert agriculture and using underground disposal of raw sewage as a means of sustaining the growth of food bearing plants.
Minimal annual rainfall in an arid region prompted a community leader to introduce innovative water collection techniques along with underground storage and distribution of water. The region grows crops that require minimal water and exports produce to other large cities. In another region, water collection, storage and distribution into homes flushes sewage into underground tanks that feed and sustain plants that bear tropical fruit.
In several regions, China uses sewage from cities to sustain agricultural production of food crops. Israel has been a pioneer in desert agriculture as well as underground water storage and distribution to plants.
A range of proven technologies can carry sewage from coastal cities to ports at the edge of deserts. From there, pipelines could carry the sewage inland to be distributed through underground pipes to supply commercial crops. Supersize tanker ships and possibly oceanic tanker trains can carry massive volumes of sewage at low cost from cities to desert ports.
Climate, Energy and Rainfall
A variety of geographic and weather factors result in different climatic regions occurring in close proximity to each other. Very recently, the installation of offshore and coastal wind turbines along the west coast of the U.K. resulted in the production of coastal fog, the result of the wind turbines actually cooling the airstream moving inland off the Irish Sea. That precedent can be applied at many locations internationally where humid winds blow off the sea and up a coastal mountain, where wind turbines could cool the incoming airstream to produce fog at high elevations and possibly increase rainfall.
The future development of technology capable of initiating and sustaining offshore waterspouts could also increase the volume of moisture that winds carry to high elevations along coastal mountains. Communities in some regions have installed fog fences in coastal mountains to harvest water directly from incoming fog and mist.
Large cities located near coastal mountains could benefit from the additional rainfall as their future population expands. They would produce greater future volumes of raw sewage that tanker ships would carry to coastal desert regions where agriculture has been developed, perhaps to grow some of the food that the cities would consume.
The tanker ship segment of the maritime industry could come to play a significant role in the combination of future sewage disposal and future food production. Many proven technologies and ideas can connect municipal sewage disposal to desert agriculture. While the short-term cost to initiate such activity may be high, the long-term cost may be sufficiently competitive to entice private sector interests to investigate future long-term business prospects collecting sewage from cities to sustain agricultural production at a desert location
The Original Posted by By Harry Valentine/The maritime Executive