Development of a quantitative approach for Environmental Impact Assessment of a desalination plan: Shavei-Zion case study
Gili Noi Harpaz and Yohay Carmel.
Desalination is a technology that involves several processes that remove salts and minerals from the water and produce potable drinking water. The total annual production of desalinated water in Israel increases constantly. Seawater desalination plant is planned to be constructed at the Western Galilee in 2018, near Shavei-Zion. By the year 2020, the plant is expected to increase its water supply, so it may require the construction of a small power plant on-site. Desalination plants are, in most cases, associated with high energy consumption, potential damage to marine life as a result of brine discharge to the marine environment, and use of land along the coast.
An Environmental Impact Assessment (EIA) is a procedure conducted in order to
evaluate potential effects that are likely to arise as a result of a major project or action. Different methods for EIA are applied for different projects. Yet, in general, the methods applied today have several disadvantages. First, current EIA methods are mainly qualitative rather than quantitative, creating an assessment which is based on qualitative rather than quantitative data. Second, decision makers often lack the necessary knowledge required to achieve the best environmental decision, since they are exposed to unclear indices and inconclusive information. Presenting the EIA results in a quantitative way could help dealing with the problem.
The main goal of this work is to develop a new and better method for assessing the
impacts of desalination plants on the environment. This research will focus on the two major environmental effects of desalination activities: air pollution and brine discharge to the marine environment. The marine ecology impact assessment method is based on three main ecosystem parameters: primary production, species diversity and decomposition. For each parameter a degree of impact scale was designed. The estimation of the cost resulted from the effect on air pollution and public health in this work followed a fixed pathway adopted from the European Commission project, the ExternE project, and was improved, using the Impact Pathway Approach (IPA), to enable applying it in other areas. The method is illustrated for assessing the impact of on-site and off-site power production for the desalination plant, and accounts for either local or national air pollution related health effects. We demonstrated the method for estimating the effects of PM2.5 emissions due to the facility power requirements and cardiopulmonary mortality in Nahariya and Akko.
The results of the above methods were demonstrated for the proposed Shavei Zion desalination plant. We found that the degree of ecological impact on the three parameters that were studied is expected to be minimal based on Palmachim desalination plant monitoring data. Regarding air pollution and public health impact assessment, at the national scale, describing all health outcome resulted from the increased PM2.5 concentration (with health related monetary value of 1,896,800 NIS), and the local scale, describing mortality from cardiopulmonary diseases in Akko and Nahariya in people older than 45 as a result of increased PM2.5 concentration (with health related monetary values in the range of 74,500-1,585,500 NIS).
Since there are no concrete construction plans for the Shavei-Zion desalination
plant at this point, the expected accuracy of the current impact assessment is not high. Nevertheless, important concepts were set on the way for EIA to gain more popularity and possibly broaden their use.
The research did not suggest an integration between these two assessments. Two possible paths for integration are suggested, and the idea of examine the benefits and weaknesses of the integration in every impact assessment study.
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