Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). CHAPTER 8.0: PROPOSED MITIGATION AND ABATEMENT MEASURES 8.1 Introduction The environmental impacts during the full operational phase such as leachate contamination of the rivers, air and noise pollution generated by increased traffic and biological impacts are identified in this section where the mitigation measures are recommended for each impact. 8.2 Site Investigation Stage Activities inherent in the pre-construction phase are rather localized and are not expected to generate any significant detrimental impacts. Reconnaissance study of the entire Project Site is necessary so as to determine the suitability of the existing terrain at the Project Site and feasibility of the existing landuse with respect to the proposed landfill. The activities anticipated during the investigation stage are the site surveying, engineering and soil investigations and activities related to the present environmental assessment. Any disturbances to the environment is confined within the designated surveying sites only, whose locations are established by the respective land surveyors in order to ascertain the existing conditions of the site. If any, beneficial impacts are created through employment opportunities for those that are involved in the surveying works, associated labourers and analytical laboratories. 8.3 Project Development Stage The main activities identified to generate effects on the environment during site preparation stage are platform development, establishment of temporary access routes, site clearing which involves felling and removal of existing vegetation (oil palm) and internal trimming of slopes for the infrastructure works. The proposed mitigations generated from the impacts discussed in Chapter 8 are given in the following subsections. There is no new access road EUROPASIA ENGINEERING SERVICES SDN. BHD. 8-1 Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). to be constructed since the Proposed Project is the expansion of the existing Jeram Sanitary Landfill. 8.3.1 Access Route within Project Site No specific mitigation measures are required. The established access routes however need to be maintained in good travelling condition to adequately cater for the volume of heavy vehicular movements and thus reduce risks of accidents. Preferably these access routes would follow the established road network by MDKS and thus incur the least disturbance and change unto the existing physical and social receptors. Good on-site practices such as: Establishment of tarred road or at least compacted crusher run roads which can minimize dust dispersion; Fully utilize the existing wash through/washing bay at the entrance/exit gateway of the existing Jeram Sanitary Landfill to cleanse heavy vehicles’ tires and subsequently prevent the public roads from being adversely affected. Preferably, the wash trough to be equipped with water jet in order to ensure better dirt removal; Constant wetting of work tracks and cleaning by lorry sprinklers to minimize dust dispersion; 8.3.2 Site Clearing and Biomass Disposal Site-clearing activities are recommended to be carried out in stages to allow migration of the existing fauna (i.e., small mammals and common birds) from the Project Site to the adjacent areas. Site clearing for this development will be carried out in four (4) phases (Phase 7 to Phase 10) whilst each phase will subdivided into many small landfill cells, i.e., Landfill cell 1 to cell 3 in Phases 7, 8, 9 and 10. Apart from this, the site clearing activities shall inevitably lead to habitat loss whilst increase turbidity of Sg. Sembilang (the main receiving end of discharge from the Project Site). The sedimentation problems of the existing water bodies (i.e., rivers) are temporary and will be minimized by implementation of best management practice on-site (i.e., turfing, temporary earth drains, check dams, sediment pond/detention pond). The commencement of platform development must be immediate after the land clearing. EUROPASIA ENGINEERING SERVICES SDN. BHD. 8-2 Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). The biomass generated from the site clearing and platform developments activities consist mainly of oil palms and small woody plants. The tree stumps should be grubbed in stages to minimize soil disturbance and the branches should be shredded and transported to the designated area for decomposing, i.e., existing Jeram Sanitary Landfill and landfill cell in the proposed expansion site. The undergrowth and small woody plants such as branches and fronds of the oil palms can be mulched on site especially the slope within the site away from receiving waterways as temporary mulching material to reduce soil erosion. All mulched vegetation need to be periodically disturbed to speed up the decomposing process. Existing vegetation at places with no interference with construction such as open areas and buffer zones should be retained. Proper disposal methods for the cleared vegetation are very important to avoid adverse impact from this excessive biomass. The summary of the Biomass Disposal Plan is as shown in Figure 8.1. Undoubtedly, the site clearing and platform developments period are the critical period when erosion and siltation are imminent impacts. Thus, sediment basin must be sited at the down-gradient point of the working site to prohibit siltation and sedimentation of the receiving waterways. The design specification of the sediment basin must be in accordance to “Urban Stormwater Manual for Malaysia, 2nd Edition or MSMA 2 (2012) published by Jabatan Pengairan dan Saliran (JPS) Malaysia”. The water to be discharged from the sediment basin outlet should not contain more than 50 mg/L of silt, the limit set by DOE. EUROPASIA ENGINEERING SERVICES SDN. BHD. 8-3 Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). Figure 8.1: Biomass Disposal Plan Biomass Material Undergrowth, Shrubs and Mature and Old Plantings oil palm fronds (Oil Palm) Mulching Method Oil Palm and its branches is to be shredded Grounded Into Fibrous Material Disposed off to Existing Jeram Sanitary Landfill and landfill cells at the proposed expansion site Left to mulch for erosion control Note: Open burning and disposal into the receiving waterbody is strictly prohibited; Designated disposal area will be placed away from any waterbody EUROPASIA ENGINEERING SERVICES SDN. BHD. 8-4 Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). 8.3.3 Groundwater A proper drainage and line system should be designed in the project area to stabilise the groundwater system after the construction. The increased pressure head in the soil compacted area due to increase of pore water pressure. The drainage system should capable to release pore water pressure within the ground to stabilised the develop area and the surrounding area. Groundwater monitoring is identified as potential mitigation measure. Groundwater monitoring is required for early detection of contaminant movement from the developed area. The Groundwater Monitoring System should be established to monitor the performance of residual soil layer as in situ natural barrier is crucial to gain acceptance of the proposed containment technology and to provide early detection of any flaws or leaks. Therefore, a groundwater monitoring system should be capable of readily detecting leakage from the facility from a very early stage. The monitoring system should comprise Construction of monitoring wells, monitoring wells programme and relevant database. 8.3.3.1 Construction of Monitoring Wells Groundwater quality monitoring wells which comprise vertical and horizontal monitoring wells (in soil layers) shall be constructed in the project area. Current monitoring well locations and designed are suitable. However, the need for additional monitoring points may become apparent during the detailed design, construction and operation. The requirement for the monitoring wells are as follows: i. Monitoring wells and piezometers must define the three-dimensional flow system within the critical stratigraphic section that is the aquifers; ii. Monitoring wells shall be designed to detect leakage from the facility in a very early stage to minimize volume and extend of a plume; iii. Design, construction and development of the monitoring wells must be in accordance to currently accepted international engineering practice to ensure that groundwater samples and head level measurements characterise discrete stratigraphic intervals, and to prevent leakage of groundwater or contaminants along the well annulus. EUROPASIA ENGINEERING SERVICES SDN. BHD. 8-5 Detailed EIA for the Proposed Expansion of 130.55 Acres Sanitary Landfill in Mukim Jeram, District of Kuala Selangor, Selangor Darul Ehsan (Rev.01). 8.3.3.2 Monitoring Wells Programme A suitable monitoring programme shall be implemented for regular monitoring of groundwater quality and groundwater level in all groundwater monitoring wells during operation. Groundwater sampling, parameter analyses, and reporting, etc., shall be conducted in accordance with the requirements of