De-Centralizing

(Originally posted on waterefficiency.net)

By Elizabeth Cutright
Editor
Water Efficiency

Whether you like it or not, we are in the middle of a water crisis. You can blame it on climate change or aging infrastructure or green-lawn addicts, but whichever devil you choose the outcome is still the same: a diminishing supply struggling to meet an ever-growing demand.
Decentralized water systems (both treatment and delivery) can attack the problem of a shrinking water supply in two ways. First, advances in water reuse now allow for pristine, potable-quality water to be discharged back into the water supply, thereby curtailing the amount of water “lost” to pollution. Secondly, when onsite water treatment is combined with water reuse, we can insure that valuable drinking water is not squandered on green lawns in the desert or urban carwashes.
While municipal water treatment and delivery systems are most often associated with centralized systems (like city sewers or water utilities), the refinement of treatment technologies, ever-grander land development, and the push to “green” public and private industry is sure to change all that: one day onsite water treatment will go beyond the backyard septic system and bleed into the municipal market where it can reach its full potential and vastly improve the management and conservation of our water resources.
In Europe, that day has already come…
The public sewer systems in Germany are over 100 years old and rapidly deteriorating. Experts warn it could take years and several billion dollars to rehabilitate the centralized systems currently in place. The high cost associated with maintaining the existing centralized systems has prompted the exploration of alternative treatment systems. “As with an old car,” explains Dr. Harald Hiesll of the Fraunhofer Institute for Systems and Innovation Research ISI (Fraunhofer-ISI), “if the costs for repairs and renovations start to increase, you should think about whether to make further investments in the old system or whether a new system would be more sensible in the long term"
In April of 2003, the Fraunhofer-ISI initiated the AKWA 2100 project in order to “investigated alternative water infrastructure systems.” The study concluded that although rehabilitating the current centralized system was the least expensive option, abandoning a centralized system altogether in favor of a combination of decentralized water treatment and water reuse was the better option. According to Dr. Hiessl, the sustainable aspects of combining onsite water treatment with water recycling far outweighed the 5-15% increase in cost.
Although this study was conducted in Europe, it has international implications. The conclusion drawn by the study – that decentralized systems in an urban environment are “technologically and economically feasible”– should serve as a clarion call to municipalities around the world.
There are several reasons for a municipality to encourage onsite water treatment. A decentralized system allows for greater flexibility when it comes to growth and development. Onsite water treatment facilities also allow for the development of previously inaccessible areas, opening up development opportunities for communities bursting at the seams. Of course, as cities expand, the strain on water resources increases. What better way to mitigate increased water demand than to combine water treatment with water recycling?