การหาพื้นที่สำหรับระบบบำบัดน้ำเสียแบบธรรมชาติของเทศบาลเมืองฉะเชิงเทรา / วีระพันธุ์ หมั่นสกุล = The siting for natural wastewater treatment system of Chachoengsao Municipality / Weeraphun Munsakul
The objectives of this study are to understand the structure of natural wastewater treatment facilities; to determine criteria for selecting appropriate sites to construct natural wastewater system; and to propose such site for Chacheangsao Municipality which presently has a problem of inadequate wastewater treatment facility. This study has done by using literature review, comparative case studies, and expert interview as methodologies. This study finds 4 main factors which need to take into consideration in order to find an appropriate site. They are consisting of topography and soil, surface water feature, vegetation cover, and land use. The case studies also indicate that natural wastewater facility can be used for recreation, education, open space protection, and mangrove conservation. Moreover, the treated water can be used for fertilize paddy field. The above mentioned 4 factors are used to set up criteria for site selection of natural wastewater treatment facility. The criteria for site selection are as follows: (1) the slope should not more than 5%; (2) the location should further away from flood prone area at least 1 km.; (3) the soil should has poor drainage capacity with clay or clay-loam type; (4) the distance should be at least 300 m. from surface water features, at least 600 m from natural forest, and at least 50 m. from mangrove area; (5) the existing land use should be abandon paddy field or fresh water farm and undeveloped land; and (6) the site should be situated close to existing wastewater collective pipes. The diagram models to run the Arc/GIS have been formulated from these criteria and Chacheangsao Municipality’s data was then input. As a result of the Arc/GIS application, the 3 highest potential sites are proposed according to their physical qualities. In order to decide the most appropriate site, the land size, ownership and price are brought into consideration. The most suitable site is situated on the east of the Bangpakong River, and can be access from Srisotorn 8 Road. The site covers the area of 68 rai which is appropriated for constructed wastewater stabilization pond and constructed wetland with potential for recreation and education as well The criteria for site selection and diagram models proposed in this study can be applied to perform site selection of natural wastewater treatment in any area, which will minimize an environmental impact while benefit to community.
