The project’s potential environmental impacts and their significance have been assessed using the methodology described in Section 8.2 above. A summary of these impacts and their significance is presented in Table 8.4.
WAPDA
Table 8.4: Significance of Environmental Impacts
Impacts Phase Receptor
Mitigation and Enhancement Measure Residual Significance
Land Acquisition and Land Use Change; preparation of construction facilities
Pre-construction Low Minor Low Adverse • Construction camps and other construction facilities to be established on WAPDA owned land.
• Re-plantation plan to be prepared and implemented.
Negligible
Contractor mobilization Pre-construction Medium Moderate Moderate Adverse • Contractor to prepare and implement a traffic management plan. Temporary by-pass routes.
Community awareness.
Low Adverse
Topography:
• blasting and cutting for powerhouse;
• blasting and cutting at borrow sites;
Medium Major Moderate Adverse • no excessive excavation; and
• use of alternative excavation methods wherever possible.
Negligible
Geology and Seismology:
• risk of seismic activity.
All Phases High Major Major Adverse • foundation design of the powerhouse to consider probability of earthquake at the earliest design stage;
• Method Statements and Risk Assessments with particular attention to blasting material and blasting techniques; and closure of existing Tunnel 4 to join with the new tunnel and for constructing the raised intake will result in the interruption of irrigation releases through tunnel 4; and
• operation – the Tunnel 4 capacity will be reduced by
Construction: Medium Moderate Moderate Adverse • connection tunnels will be carried out during the annual canal closure and periods of low demand; and
• Releases from tunnels 1-3 and 5 will be adjusted to meet the irrigation water demands and power generation.
• the reservoir will continue to be operated to ensure meeting the irrigation water demand.
Negligible
Impacts Phase Receptor
Mitigation and Enhancement Measure Residual Significance around 5%.
Operation: High Moderate Major Adverse Negligible
Surface Water Quality:
• many sources of discharge and effluents.
• Surface Water Monitoring Program;
• Select access roads to avoid run off to river;
• pre-treated sewage prior to discharge;
• Wastewater Treatment Plan;
• Oil and Chemical Spill Response Plan;
• Waste Management Plans;
• Store and handle all hazardous substances in accordance with their MSDS;
• Install oil and water separators and settling ponds; and
• Upon completion of decommissioning, disturbed areas will be contoured and revegetated to minimize the potential for soil erosion and water quality related impacts.
Low adverse
Negligible
Ground Water Quality:
• piling for foundations;
• accidental spills and leakage;
and
• Ground Water Monitoring Program;
• work within the requirements of the management plans contained within the EMMP;
• staff training;
• all sanitary effluent will be treated prior to discharge;
• treatment plant will conform to international standards;
• drainage system will be designed so that all spills will be drained and collected in a sump for further appropriate disposal; and
• Oil and chemical storage and vehicle wash and oil change facilities will be on an impermeable surface to avoid percolation.
Negligible
Wastes:
• large volume of spoil;
• possible risk of erosion into the Indus River;
Construction and
De-commissioning:
Medium Moderate Moderate Adverse • reduce volume of material requiring disposal;
• re-use where possible;
• disposal of spoil at designated depressed area;
• only remove equipment and machinery leaving
Negligible
WAPDA
Mitigation and Enhancement Measure Residual Significance
• leakage, spillage from other wastes (domestic and hazardous); and
• camp wastes
• disposal of demolition material.
Operation:
Low Minor Negligible
infrastructure in place for re-use for other purposes;
• Waste Management Plans; and
• Excavated Material Disposal Plan.
• Demolition material disposal plan
Landslides:
• Risk of landslide resulting from excavation and blasting
• extraction from top down;
• use of pre-designed support systems;
• use cushion blasting in confined areas;
• Method Statements and Risk Assessments with particular attention to blasting material and blasting techniques; and
• include in Emergency Preparedness Plan.
Low Adverse
• fish mortality from river turbidity
• surface disturbance from
• storage and use of hazardous materials;
• re-vegetation, especially of slopes, of fast-growing indigenous species;
• road edge buffer replanting;
• Tree Plantation Plan; and
• decommissioning would be followed by contouring and re-vegetation.
Medium Moderate Moderate Adverse • covering standing material and transported material to prevent dust blows;
• washing of construction vehicles;
• specific and agreed routes for traffic;
• speed limits; and
Medium Major Moderate Adverse Ambient noise:
• restricting / limiting timing of blasting activity;
• fitting applicable construction machinery with mufflers;
Low Adverse
Impacts Phase Receptor
Mitigation and Enhancement Measure Residual Significance
• blasting
• power plant operation
Operation
Low Minor Negligible
• maintaining and powering down all plant items when not in use;
• avoid unnecessary revving of vehicle engines;
• use quietest work methods and plant items where practicable;
• provision of noise barriers at excessive noise producing areas (such as blasting sites); and
• informing the communities of activities taking place such as blasting.
• provision of PPE i.e. ear muffs and plugs;
• provision of vibration absorbing gloves;
• instruction in the proper use of equipment;
• frequent breaks;. 10 minutes per hour; and
• manage and properly design all blasting activities.
Landscape and Visual Intrusion:
− new planting and landscape restoration.
• Landscape Plan. Positive
Beneficial
• transport of construction labor;
Construction and
De-commissioning
Medium Moderate Moderate Adverse • Traffic Management Plan
• Provision of by pass routes
• Minimizing the duration of right bank road closure
Negligible/low adverse
WAPDA
Mitigation and Enhancement Measure Residual Significance
• closure of right bank road
• additional traffic to remove demolished material; and
• transport of decommissioning labor.
Increased activities affecting Fauna / Wildlife / Vegetation:
• disruption to areas that are currently used by wild fauna including birds/migratory birds.
Construction Medium Moderate Moderate Adverse • avoid positioning spoil in areas used by fauna;
• provide corridors for animal movement;
• relocation of species; and
• no illegal hunting or poaching.
Negligible
Flora / Vegetation:
• loss of vegetation leads to soil erosion.
Construction and
De-commissioning
Medium Major Major Adverse • avoid dumping material in vegetated areas;
• re-provide plantations in open spaces and practice watershed management;
• enhance flora environment by planting fruit trees and ornamental shrubs;
• use fast-growing species; and
• use grasses to assist slope and soil stability
Positive
Potentially All Medium Moderate Moderate Adverse • during Monsoon runoff will be diverted to adjacent
depressions and from there to river after settling. Negligible
Bird collision with transmission
cables Construction and
Operation
Medium Moderate Moderate Adverse • attaching markers/balls with the cables Negligible