A worker at Israel's Shafdan
The plant, known to Israelis as Shafdan, was included on the list
thanks to its unique method of using the natural filtration qualities of
sand in order to improve the quality of sewage. After wastewater is
purified in an ordinary facility, it is recharged into the ground, where
it undergoes an additional, natural filtration in the sands of Rishon
Letzion and Yavne.
This improves the quality of the water such that it
can ultimately be used safely for all forms of irrigation.
The list of projects was published in a special report of the UN
Environment Programme and ICLEI, an international association of local
governments that have made a commitment to sustainable development.
The report, which deals with the environmental challenges facing
cities, was published last week, ahead of the UN Conference on
Sustainable Development that was held in Rio de Janeiro.
Urban areas comprise only 1-2 percent of the area of the earth's
surface, but they cause the emission of almost 80 percent of greenhouse
gases. Today about half of the world's population lives in urban areas,
and the forecast is that this figure will increase to over 60 percent
within a decade.
According to the authors of the UN report, local authorities have the
ability to get organized and to deal with a variety of environmental
problems without being dependent on federal assistance. The 30 examples
they provide are from from all over the world, including developing and
poor countries.
The Shafdan plant that was named on the list belongs to the local
authorities in the Dan region, but Mekorot, the national water company,
is responsible for administering and carrying out the purification
process.
Recently the company began to develop even more advanced methods of
purifying the sewage before recharging it into the sand. This is
necessary because despite the benefits of the current purification
process, it was discovered that when the wastewater is recharged into
the ground after undergoing only primary purification, it damages the
soil that it reaches before it hits the sand.
As a result of that damage, experts have been forced to seek new areas
where they can purify the wastewater, which are not easy to find in such
a densely populated area.
The new method is designed to enable more efficient use of areas where
the purified sewage is already being recharged into the soil. Today
Mekorot pumps 130 million cubic meters of purified sewage water into the
area of the sands. The water is almost equal in quality to drinking
water, and is used for irrigation in the Negev.
The company points out that the new method of purification and
filtration will also make it possible to remove polluters such as
remnants of medicines, that until now were not removed in the
purification process.
Among other notable projects in the report were: Water Smart Parks in
the city of Stirling, Australia, where park planners used advanced
irrigation methods to reduce water consumption by more 80 percent.
In Pangkal Pinang, Indonesia, the municipality and a private firm
created a cooperative venture that turned an area that had been used as a
zinc mine into a botanical garden.
An interesting innovation in the city of Portland, Oregon set an "urban
growth boundary" beyond which building is forbidden. In order to meet
this restriction the municipality developed more efficient methods for
utilizing existing construction areas.
Israel company EMEFCY has developed a revolutionary, innovative and
environmentally sound process to convert waste water into electricy,
while purifying the water. This process convert waste water treatment
plants from energy consumers into energy producers.
Wastewater can be formed by different activities, including washing, bathing, and using the toilet. This water treatment includes screening water to eliminate or to easily easily removed objects, some of which could ruin the treatment plant’s machinery.
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