Dredging and Sediment Remediation in the Kishon River

DREDGING AND SEDIMENT REMEDIATION IN THE /Photo: Alon ben Meir, Kishon River Authority Alon ben Meir, /Photo: KISHON RIVER A three-year NIS 220 million action plan for sediment drainage and remediation will go a long way toward the continued rehabilitation of the Kishon River Kishon River meander Kishon River Something good is happening in the river in the 1960s and 1970s with the approved by Israel’s government in Kishon River. The challenge of restoring discharge of effluents and wastewater November 2001. Most importantly, in the “that ancient stream, the stream of from the chemical fertilizer industry and late 1990s, the Ministry of Environmental Kishon,” (Judges 5:21) to its former glory is from the Haifa wastewater treatment Protection required the polluting being met. The revitalization of the river plant. In parallel, pollutants, including industries and the Haifa wastewater will not only restore life to the river but heavy metals and hydrocarbons, sank treatment plant to apply for waste will provide flood protection and a green to the river bottom, together with discharge permits under the Prevention lung to residents of Israel’s northern runoff from the Jezreel Valley. Sediment of Sea Pollution by Land-Based Sources region. analyses found high concentrations of Law and to comply with the stringent toxic pollutants, due to the indiscriminate conditions stipulated in the permits. The The Kishon River, the second largest discharge of industrial effluents into the requirement was accompanied by an among Israel’s coastal rivers, flows from river for decades. And, to make matters enforcement campaign against seven Jenin in Samaria along some 70 kilometers, worse, dozens of veterans of an elite navy major industrial plants in the environs through the Jezreel Valley, until it empties commando unit filed a legal suit against of the river. The plants could no longer into the sea at Haifa. The perennial river, both industrial and government bodies in discharge their effluents to the Kishon which drains an area of 1,100 square 2000, claiming health damages, including River with impunity. kilometers, traverses the heart of the Haifa cancer, as a result of diver training in the metropolitan area. However, the final polluted river. The results were soon in coming. By seven kilometers downstream have been January of 2002, the pollution plagued by pollution which originated in Something clearly had to be done. load from the industrial plants was both industrial effluents and municipal drastically reduced by as much as wastewater. Contamination transformed 90%, with continuing improvements Revitalizing an Ailing River the once vital river into an open sewage in subsequent years, and the destructive canal which flows to Haifa Bay. Recognition of the dire quality of the acidity (with a pH below 2) which had Kishon River waters led to a number of characterized the river for dozens of years Contamination of the river began long initiatives over the past two decades: a disappeared. The water column improved ago. In the 1930s, the river which had Kishon River Authority was established by and ecological rehabilitation began. Fish, previously boasted a rich biodiversity and the Minister of Environmental Protection birds and soft-shelled turtles along with a served as a source of recreation, sailing in 1994 to restore life to the river’s water, rich variety of vegetation began to return and fishing, was first transformed into a ecological and planning surveys were to the river, including some twenty fish receptacle for the pollutants discharged carried out, and a master plan for the species and dozens of bird species. In by the oil refineries and petrochemical restoration of the river as the green lung fact, in the most recent cormorant count, plants that were established in Haifa Bay. for residents of the Haifa metropolitan some 4,385 cormorants were counted in Additional pollution reached the ailing area and of the country’s north was the downstream section of the Kishon, www.environment.gov.il 21 300 2001 Kishon River Quality Downstream - Histadrut Bridge (ml/liter) 2002 250 2003 2004 200 2005 2006 150 2007 2008 100 2009 2010 50 2011 2012 0 BOD TOC Total Phosphorous Total Nitrogen Ammoniacal Nitrogen constituting the largest roosting site for cubic meters of contaminated sludge today. Clearly, despite the progress in these birds in Israel. from the river bottom throughout the dramatically reducing the pollution load 1990s. The sludge was transferred to to the river, two of the provisions of the sealed temporary pools along the river 2001 master plan for river rehabilitation Sediment Pollution: A bank and later disposed. However two of were yet to be fulfilled: the need to Growing Problem the pools have remained in the area until “dredge, pump, remove and treat the However, the rehabilitation process was not complete. The toxic sediment at the river bottom – the result of its historic contamination – remained, impeding the rehabilitation of the ecosystem and preventing leisure and recreation activities in and around the river. At the same time, flooding during major winter rainstorms has continued to plague residents downstream due to the inability of the river channel to transport the required peak flow to the sea as a result of the sediment buildup. In fact, in an effort to increase the flow rates in the wake of devastating flooding events in the winter of 1991-92, the Kishon Drainage Authority dredged tens of thousands of Cormorants in the Kishon/Photo: Gil Gutman, Kishon River Authority 22 ISRAEL ENVIRONMENT BULLETIN | vol.32vol.39 Kishon riverside park/Photo: Gil Gutman, Kishon River Authority contaminated sludge in the riverbed” and to “remove the existing sludge ponds along the riverbanks.” To fulfill these provisions and find solutions, an expert committee was established in 2004, including representatives of academia, the Chief Scientist of the Ministry of Environmental Protection, and professionals from the Kishon River Authority and the Kishon Drainage and Rivers Authority. In accordance with the guidelines of the committee, the Kishon River Authority would carry out the project and that a › Diverting the Kishon channel into a initiated a survey of the riverbed in 2006, joint administration would manage and new meander in its course just south which confirmed the polluted state of oversee the project at every stage. of the petrochemical plants and seven kilometers downstream by Total creating dry open land to serve as the Petroleum Hydrocarbons (TPH) and At the end of the day, says Alon Zask, remediation site for the contaminated heavy metals, especially cadmium and head of the Water and Streams Division at sediment; chromium. The contaminated layer, some the Ministry of Environmental Protection, 2.5 meters deep, generally correlated › Dredging and removing the sediment it was decided to “kill two birds with one with the hydraulic profile needed for from some seven kilometers in the stone” by integrating the solutions to two river regulation and flood protection. downstream section of the Kishon problems. On the one hand, a solution According to the calculations, some had to be found to the problem of the riverbed; 400,000 cubic meters of material had contaminated sediment which had › Mechanically dewatering the dredged to be removed from the river bottom. accumulated on the riverbed, along with sediment slurry; the clean sediment from the Jezreel Valley, › Treating the supernatant produced The Preferred Solution in order to protect the river’s ecosystem by the dewatering process prior to and to promote leisure and recreation by With the findings in hand, it was time to residents and visitors. On the other hand, discharge back to the river; decide on the optimal method of treating a solution had to be found to the problem › Mixing the dewatered sediment cake the dredged material along with the of the accumulated sediment, which with the dried material from the old 150,000 cubic meters of contaminated blocked the channel, in order to prevent ponds and with clean, inert bulking sludge which were still stored in the old floods and their attendant damages to agents to achieve sufficient porosity sludge ponds on the riverbank. The expert both human life and property. to allow the required aeration; committee set out to assess different › alternatives: disposal, incineration, The solution, which is expected to bring Biologically treating the sediment in chemical stabilization, thermal treatment an end both to the drainage problem the aerated bio-piles to the required and biological treatment. The preferred and to the environmental-ecological threshold levels; solution was bioremediation. In order problem, is based on a master plan for › Piling the treated sediment into to verify the feasibility of the solution, a the lower portion of the Kishon River landscaped hills in preparation for professional study tour to a number of which was proposed by the Kishon their incorporation into a public European countries was organized in Drainage and Rivers Authority. In 2009, park, based on the guidelines of a October 2010 with the participation of the Authority published a tender aimed landscape architect. all stakeholders. The tour confirmed the at better understanding the problem and feasibility of the proposed bioremediation developing an effective plan for flood Every aspect of the complex process – solution and the project got a go-ahead. mitigation. The solution, developed by from laboratory analyses to tenders, from It was agreed that an international Yodfat Engineers, called for a number of budgetary allocations to education and company with extensive experience steps: information - was carefully discussed www.environment.gov.il 23 Kishon new meander/Photo: Kishon River Authority Main Components of the Government Decision 1 The Ministry of Environmental Protection will coordinate the activities necessary for implementation of the action plan by the different stakeholders including government ministries (Agriculture, Interior, Water and Energy and Finance), the Water Authority, the Kishon Drainage Authority, the Kishon River Authority, local authorities and industries.

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