Jerusalem has been waiting for a decade for the light railroad to improve its public transportation system, but meanwhile, the city streets are in a state of congestion and excavation. In Tel-Aviv, such a project hasn't even begun, but on the northern outskirts of Kfar Saba, near a new residential neighborhood, on the borders of historical citrus groves - many of which no longer exist - progress is being made at a completely different and surprising rate. Over the past few days, at a site provided by the municipality, infrastructure for Israel's first bio-filter system is being built, to utilize rainwater collected during the rainy season from the city streets and to recycle it for municipal use.
Yaron Zinger
Just to have a general idea - in an average season the sewage systems of the coastal plain cities in Israel collect about 200 million cubic meters of water, all of which is channeled into the sea and wasted. As built-up areas expand, less and less runoff water seeps into underground reservoirs, but it may just happen that thanks to the persistence of one young Israeli, that picture is about to change. The bio-filter system uses unique strands of plants, bacteria with an appetite for substances that negatively affect water quality and layers of water and soil. It absorbs polluted runoff water from fuel residues, heavy metals and nitrates and produces drinking quality or nearly drinking quality water.
Theoretically and practically, the principle has been known for the last few years, but until a doctoral student by the name of Yaron Zinger came up with a proposal to build the first experimental plant of its kind in Israel, and until KKL-JNF and its friends in Australia met the challenge, nothing moved. By the coming winter, that situation will have changed drastically, when the infrastructure of the bio-filter system next to Kfar Saba's Green Park neighborhood will be completed in an area which will become a large city park.
A drainage pipe that will collect rain-water from roughly a third of Kfar Saba's municipal area already runs along the outer edge of the area, providing the bio-filter plant with between 4000-7000 cubic meters of water in the first stage. When water enters the system, it is checked for the composition and concentration of its pollutants then channeled into storage pools with storage capacities of a few dozen cubic meters, where it penetrates through layers of vegetation, "pollutant hungry" bacteria and sand, into a network of perforated joined pipes that will absorb the water. An additional monitoring system will constantly monitor the quality of the purified water, enabling it to be re-introduced into the groundwater by means of a number of inactive wells located in the area. During the winter, unused surpluses will be channeled by the system into the Nahal Ra'anana streambed which is adjacent to the installation, on its north side. Filtration will begin when the necessary permits are provided by the Water Authority.
These hitherto inactive wells are the second reason for the decision to build the bio-filter plant in this specific location. Yaron Zinger explains: "There are five wells in this area that are no longer in use owing to heavy pollution of the water by nitrates, which caused the Water Authority to stop the pumping of water from these wells. According to all available data, the new bio-filter system will enable these wells to be brought back to life, at least for agricultural use and for gardening. Since the bio-filter system is active only when rainwater is collected from the streets, it will be used during the rest of the year for dialysis of the upgraded wells. A pressure pipe from the wells passes through the area of the bio-filter plant, channeling water from the wells to the bio-filter, where it will pass through the nitrate filtering and purification stages and then channeled back into the wells. In this manner, we hope to be able to purify the recycled well water to a degree that will enable these wells to become reusable."
Yaron Zinger (36), studied bio-technological engineering at Beersheva University, and at first, he wanted to write his doctoral thesis on genetic engineering and the fight against cancer. However, with his desire for a different sort of occupation, he decided to focus specifically on the field of water, because of the combination of fieldwork, laboratory work and bio-technological engineering it entails. He found out that the best place to combine these three fields was in Australia, which is where he went, joining a team of researchers at the Monash University in Melbourne. He needed their knowledge of engineering and they needed his knowledge of biotechnology. Through teamwork, the group achieved amazing results in biological removal of nitrates from water, thereby responding to one of Australia's greatest problems. High concentrations of nitrates in water is the central cause of the proliferation of algae, which feed on the water's oxygen and effectively destroy lakes, rivers and even entire seas throughout the world.
During his stay in Australia, a connection developed between Yaron Zinger and the heads of KKL-JNF Australia, inspiring Yaron to connect KKL-JNF Australia with Monash University. KKL-JNF Australia decided to raise the resources necessary to build a first-of-its-kind project in Israel. From this point, the path to KKL-JNF management in Jerusalem was short. Very soon, it was decided to try and interest local authorities in Israel in installing a bio-filter system in their jurisdictions in order to increase the quantities of water available for use. The proposal immediately appealed to the heads of eight local authorities in Israel, who understood the immense combined value of such a system for the municipality and for city residents. The municipalities of Holon, Bat Yam, Yavne, Rehovot, Modi'in, Hadera, Kfar Saba and Rana'na expressed their readiness to invest in the project, so all that was left for the professionals to determine - based on material considerations - was where the first project would be built. Kfar Saba was the choice, and the heavy machinery began work at the site.
"I am very indebted to KKL-JNF Australia and its officers for giving the project a 'kick-start'. Standing here, I am really moved to see the birth of this project," said Yaron Zinger as he surveyed the earthworks, which were proceeding at an accelerated rate. "We are racing against the seasons, because we want the plant to be working this winter. Within a few weeks, I would like to plant the special vegetation in the installation so that in two or three months, the plants will be ready for their job. You need to remember that physically, this will be an installation with real aesthetic foresight, which will blend in beautifully with the future municipal park that we assume will be built quickly thanks to the bio-filter pilot. Furthermore, we expect that the existence of a new water source in the region may have a positive affect on the biological system and the fauna, since the monitor systems that supervise the water quality at all times ensure a quick response for any problems that might arise."
When similar systems will be installed in other sites along Israel's coastal plain, they will help restore the coastal aquifer, which has become increasingly polluted over the past few decades owing to overuse and lack of natural renewal. Rainwater from the city streets, which are not utilized in any way and which flow into the ocean and pollute it, will be partially absorbed into the aquifer during the winter. During the rest of the year, these natural systems, which do not need energy besides that which is produced by the bacteria, will achieve their other goal - improvement of the groundwater, which is of very low-quality because of the nitrates it contains.
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