Construction Phase Impacts
Potential pollution issues during the Shopping Centre’s construction will be those typically associated with building construction, including: site erosion and off-site sedimentation; poor stormwater quality from suspended sediment, oil, grease and other contaminants; the generation of a large volume of spoil requiring off-site disposal; site contamination from spills of fuel and other hazardous materials; noise; dust; and traffic. These impacts have the potential to affect local residents and businesses, but can be adequately managed through the effective implementation of standard mitigation measures, mostly covered by the measures proposed in the ESIA. The sponsor’s EHS Officer, assisted by the Construction Manager, will regularly inspect the site and the Construction Contractor’s activities daily to check compliance against regulations and IFC PSs.
A 24 month construction phase is planned, comprising foundation and car park works, utility connections, construction and outfitting of the centre’s building, installation of road entrances/connections, and site landscaping. Construction works will involve large scale earthmoving and will necessitate the delivery of a large volume of construction materials to the site. RMB Westport will develop a detailed EHS statement of requirements that tenderers will be required to comply with. The tender requirements will include incorporating Municipal, Angolan and IFC requirements.
Storage areas and working space during construction will need to be temporarily fenced. The Construction Contractor is also likely to have its own large depot in Luanda where it will store materials and prefabricate concrete reinforcing. A range of construction activities (e.g. welding, lighting) will primarily use electricity supplied from the Angola National grid, with diesel-powered back-up generator provided to cover outage periods. Emissions from the generators will be minimized by ensuring that the engines are properly tuned and maintained.
Water requirements during construction have not been estimated, but a large volume of water will be required for cement mixing, dust suppression, washing equipment, drinking water, toilet flushing, etc. The Construction Contractor is likely to use mobile fuel storage tanks on site primarily for excavator fueling. The temporary storage of fuel will be subject to site controls, with a spill control plan prepared and implemented as required, incorporating the immediate clean-up of any spills and monitoring of site conditions.
General construction waste will be managed in accordance with the EHS plan that will be developed by the Construction Contractor, setting out waste reuse, recycling and disposal. Non-recyclable solid waste will be disposed of at a regulated Municipality facility. Hazardous waste will be separated, with liquid hazardous waste (oils, fuel, chemicals) appropriately labeled and stored in metal/plastic drums in concrete bunded areas. T
ransportation and disposal of hazardous waste will be undertaken by licensed companies with trained employees equipped with appropriate vehicles and equipment.
A large volume of spoil will be generated from the excavation of the foundations and the end use of this material has yet to be determined. Alternatively, the spoil may be stockpiled at a designated premise until a future use is determined.
The erosion and sedimentation hazard created during construction will need to be properly managed. Dust is likely to be generated during construction; therefore this will be suppressed by regularly watering access ways and disturbed areas, and ensuring that mud is removed from vehicles before they leave the site.
Construction noise has the potential to disturb nearby local residences and businesses. This potential impact will be managed by generally restricting site working hours to between 8 am and 5 pm six days a week and ensuring that machinery and equipment are operated and maintained in accordance with manufacturer’s requirements. The Environmental license issued for the development prohibits night time construction work. Given the close proximity of the main road that carries traffic ranging from passenger vehicles to heavy vehicles, construction noise impacts are not expected to be significant during the day, neither should construction traffic create significant additional traffic disturbance. A traffic management plan will be developed and implemented to ensure that vehicle movements onto and off the site create minimal traffic disruption and safety hazard to local pedestrians, with measures developed in compliance with local regulations.
Operational Phase Impacts
Energy and Energy Efficiency
RMB Westport design for the Viana Shopping Centre indicates a formal commitment to energy/building efficiency measures. Proposed energy saving measures confirmed by IFC Green Building specialist include: Reduced window to wall ratio; Reflective paint/tiles for Roof and external walls– Solar reflectivity of 70%; Insulation of roof surface and external walls; Air Conditioning with Air cooled screw chiller; CO2 sensor/demand-controlled ventilation for fresh air intake; and High-efficient light bulbs for sales area, corridor and common areas and external spaces.
Based on the current design and specification information provided by the RMB Westport and using the IFC EDGE Retail Tool, it is estimated that Viana Shopping mall will have 26% lower Energy consumption than a conventional design mall. This meets IFC’s definition for Green Buildings. The Sponsor is required to provide final confirmation letter stating that the features proposed will be installed or suitable alternatives will be provided.
Prior to placing orders, RMB Westport will confirm that the emissions from the generators will comply with the WBG EHS Guidelines and that the secondary containment for the fuel storage tanks, whether they are above-ground or underground tank
s, is appropriate. Each shop and office will have dual electricity meters to record mains and generator electricity use.
Water and Wastewater
Water
Daily water consumption during the Centre’s operation for domestic use and other purposes is estimated to total 85 m3/day (20,086.5 m3/year). The primary source of water (Domestic & Fire) is the “municipal” supply from the connection point at the south western corner of the Viana mall. A 110mm diameter pipeline will connect to the external 125mm diameter pipeline, and will supply water to an on-site storage tank. The storage tank has a 2 x days storage capacity for domestic water. Adjacent to the storage tank is a Water Treatment facility or Water Treatment Package Plant, installed to further treat the received water to ensure that potable water quality standards are indeed met.
50% of the potable water storage tank (hereto referred as Water Tank A) will be used to store water prior to further treatment, and the remaining 50% (hereto referred as Water Tank B) will be used as a balancing tank, housing treated water which is basically ready for use/consumption. As sometimes the case in Angola, there may be problems encountered with the delivery of piped municipal water. In such cases, “Water Tank A” will be used to store water delivered to site with any other means, e.g. Truck delivered water. This will then accommodate the day to day water management processes of receiving water and storing it in “Water Tank A”, treating the water and then discharging the treated water into “Water Tank B” for use/consumption. Fire outlet pipes are fitted to the bottom end of the water storage tanks, allowing for full usage of Fire water when the need arises.
Adopting the above philosophy basically ensures that there is constantly sufficient treated water available for a one day demand for the Centre. The mall’s Facility Management team, would be required to monitor the availability of piped municipal water to ensure that water truck deliveries are arranged for, on time in the event of there being water shortages from the primary source – municipality. Stormwater from Centre will be discharged into broader precinct stormwater system, which will in turn be discharged into the municipality watercourse.
Wastewater
The wastewater yielded on site will be conveyed to the external sewer pipeline at the east of the Viana shopping centre site. This external sewer pipeline gravitates north easterly towards the traffic circle, where a sewer pump station then pumps the wastewater to the overall precinct’s Waste Water Treatment Works (WWTW). The sewer infrastructure on the Centre includes a septic tank, complete with a sewer pump station/lift station. The septic tank has a 3 x day storage capacity, and is incorporated to serve the following functions:
• Provide an on-site storage facility of wastewater, should there be maintenance requirement on either the external sewer pump station and/or the external WWTW.
• Provide an on-site storage facility of wastewater, should there be a power failure in Viana, which may affect the external sewer pump station and/or the external WWTW.
• Accommodate wastewater pre-treatment to some degree, as per Parkgest’s requests to have pre-treatment incorporated on all sites. The main objectives achieved with this pre-treatment \are mainly a 60% to possibly 80% reduction in solids that are discharged into the external sewer infrastructure, but also limited primary anaerobic treatment. This thus requires the mall’s Facility Management team to periodically manage the extraction of solids in the Septic tank. The frequency of this extraction of solids will be determined by, amongst others, the type/composition of wastewater yielded on site.
Based on the fact that the Centre is located on a naturally lower laying portion of land in relation to the rest of the precinct, the on-site sewer pump station serves the following functions:
• Allows for a functional sewer system that discharges wastewater into the external sewer infrastructure.
• Enables the Centre sewer system to discharge wastewater into the external sewer infrastructure, at a high enough level, to alleviate the potential risk of the overall precinct’s wastewater back-flowing into the shopping centre sewer system, given the general site level of the Centre in relation to the rest of the precinct.
The wastewater yielded on site would thus flow via gravity from the building, into the septic tank at the north eastern corner of the site, then gravitate into the on-site pump station, and then further be discharged into the external sewer infrastructure.
No provision has been made for re-use of treated effluent.
Stormwater
The stormwater infrastructure on the shopping centre consists mainly of a piped system, but also has a short section of open channel along the western site boundary. The stormwater generated site will be conveyed to the external stormwater pipeline (East of the Centre’s site). The access roads and parking area are designed to (i) minimize the ingress of stormwater from external roads and (ii) allow for the surface water to flow away from the building, thus preventing ponding of water around the building.
Provision has been made for stormwater escape routes in the parking area on site, via the design of the road and parking area levels, although not achieved thought the entire extent of the site due to levels of the surrounding sites.
No provision has been made for an on-site stormwater detention pond, as a result of lack of usable space.
Waste and Hazardous Materials
During the Centre’s operation, the primary solid waste streams will be office and domestic solid waste (e.g. paper, plastic, glass bottles, food waste). Solid waste will be collected and segregated on site, most likely by third party operators who will be granted the right by RMB Westport to do this and sell salvaged materials. During the construction stage, th
e appointed contractor will be responsible for the Centre’s waste management practices. The main contractor is expected to implement a waste management plan (WMP), retain waste records and issue quarterly reports to the building owner. In addition to this, RMP Westport is to ensure that EHS officer implements the waste management plan approved for the ESIA.
Hazardous materials required during mall operation (such as cleaning agents, water and sewage treatment chemicals, oils, lubricants) will be stored in a dedicated, locked areas with bounded epoxy coated floors to contain spillages. Diesel for the back-up generators will be stored in the fuel tanks of each generator, with bulk storage being considered. Fuel tanks will need to be stored in bonded areas.
Other Issues
Restaurant and food court kitchens will use liquefied petroleum gas (LPG) for cooking. Gas will be delivered to the Centre by truck and stored in fenced LPG tanks on site. The sponsor will go through a selection process to select the LPG supplier who will in turn have a service level agreement (SLA) in place with the end-user tenant. Fire safety measures for the LPG use have been considered in Life and Fire Safety (LFS) design of the shopping centre. The LFS plans and designs were developed by the consulting engineering company for the proposed development. The LFS rationale and design has been reviewed by IFC’s LFS specialist and this was considered satisfactory with few recommendations made. LFS considerations are further discussed in the PS4 section