Posted by: bootsiedecent | June 9, 2009

Israel gives green light to recycling grey water

grey water recycling processThe Israeli government has given the green light recently for a pilot project to examine grey water recycling in Israel. Grey water has one-third to half the contamination of black water, which is from toilets. If successful, the government would consider permitting systems in the public sector and in businesses to recycle shower water for flushing toilets or watering gardens.

With the proper treatment to reduce bacteria, grey water (water leftover from showers, sinks and washing machines), can be reused in toilets or to water gardens. Initially, the Health Ministry in Israel prohibited grey water recycling because of the unacceptably high bacteria count the water contained, but with grey water recycling becoming a hot topic around the world, and with water-strapped countries like Australia and others installing such systems, the government has finally given it its blessing.

“The pilot project, initiated by the environmental organization Shomera for a Better Environment, would only focus on reusing shower water, as there are additional problems with reusing kitchen-sink and washing-machine water,” said Shomera executive director Miriam Garmaise.

This is Shomera’s second attempt at a grey water recycling project, having collaborated on a similar venture with mikvaot (ritual baths) seven years ago, but having failed to meet the standards of the Health Ministry. This time around, Shomera is looking to create a demonstration site at a mikve, which would exhibit the potential for the public sector.

Also, this time around, Garmaise enlisted the Technion – Israel Institute of Technology’s Dr. Eran Friedler, one of the country’s foremost experts on grey water recycling, has investigated grey water recycling for some time and has compiled reports for the Water Authority on the topic in the past.

Together, the two approached Water Authority Water Conservation Branch deputy department head Amir Shisha with their proposal. Shisha immediately realized the Health Ministry needed to be brought in for the project to have a chance at success, and made the connection. The Water-Arc Company was chosen to implement the project.

“The potential water savings from grey water recycling depends on the penetration level into the population. The savings depend on the penetration rate. We did a study in 2003 that showed that with 20 percent to 30 percent of households [not just public buildings] utilizing such systems, the potential annual savings were between 25 million and 50 million cubic meters of water per year. That’s the equivalent of a small city’s annual water use,” Friedler said.

The project, still in the planning stages, plans to take two different types of technologies – one suitable for household use and one for municipal use – and test them on the showers of a Jerusalem mikve for about a year. The technologies themselves are not new, but has never been ‘real-world’ tested in Israel.

“After the testing phase,” Garmaise said, “the intention was for the mikve to become a demo site to showcase the potential for other buildings like dormitories, country clubs or hotels and other end-users.” Garmaise chose mikvaot because one of Shomera’s goals is to make the connection between Judaism and the environment. However, in this case, each partner brings a different target audience to the project.

“Moreover, inherent to the initiative are additional educational opportunities. The choice of a mikve as the site for a water conservation effort invites the opportunity for dialogue between Jewish precepts and concepts of environmental sustainability. This is a prime example of Shomera’s ongoing attempts to inspire new population groups to join the environmental community by illuminating those places where Judaism and the environment meet,” she said, and added that she was still looking to raise the final necessary funds for the project.

The Health Ministry, meanwhile, got involved with the project because they were afraid that more people would attempt to reuse their grey water on their own because of the water crisis. “We became involved because we were afraid that people didn’t realize how many disease-causing bacteria there are in untreated grey water. People are under the mistaken impression that one can just use grey water without treating it first, and that is not true,” warned David Weinberg, national planning and treated-effluent engineer at the Health Ministry.

“Studies have found that there are millions of pathogenic microorganisms in 100 ml. of grey water. It has to be treated before it can be used.” Weinberg also stressed greatly that the pilot project was not intended to pave the way for private grey water recycling systems.

The Health Ministry has released regulations for municipalities interested in recycling grey water, but, this is the first project to test the systems in real-world conditions, the ministry quickly identified another potential problem with grey water recycling – that is – it might reduce the amount of treated sewage available for agriculture. Israel treats and reuses 75% of its sewage water for agricultural use and maintains, by far the best rate in the world.

“Theoretically,” Weinberg said, “if too much grey water was taken out of the black water, it might be a problem. However, that day was far off, if it arrived at all.”

“The Water Authority has been pushing this idea for awhile,” Shisha said, “as part of long-term efforts to conserve water.” “We’ve invested a lot of money in researching the issue. Eran researched it quite a lot for us since 2000. I don’t see it happening tomorrow morning, but people want it, and it can save water in the long run. In our half-desert country, we should also be doing it,” she said.’s-Water-Recycling-Idea

Accessed: June 07, 2009.

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