Extracts and Comments | Discussions
Extracts from:
Swaziland Greenstone Quarry
Environmental Impact Assessment and Comprehensive Mitigation Plan
8.3 Description of Mitigation and compensation Measures
Mitigation measures for all impacts as indicated in 8.2 above are given. Impacts occur throughout the life of the quarry, mitigation measures are indicated the first time they arise.
Access route impacts:
Impact on fauna and flora: Widening of the access track.
Type of impact: Permanent
Mitigation measure: No widening of the track will occur.
Target: Pre-quarry affected area not to increase.
Implementation/monitoring responsibility: Mine manager
Audit: environmental consultant
Impact on amphibians and reptiles crossing the access road:
Type of impact: Continuous sporadic
Mitigation measure: Vehicle movement on the track will be limited to daylight hours between 06h00 and 20h00. All vehicles travelling on the track will maintain a speed restriction of 20 km per hour. If an amphibian or reptile is seen on the track, the vehicle will stop and wait for it to cross before proceeding.
Target: No amphibian or reptile mortalities on the road in the Malolotja Nature Reserve
Implementation/monitoring responsibility: Mine manager
Audit: environmental consultant
Impact on topography and surface water runoff: erosion of track surface
Type of impact: Continuous
Mitigation measure: Vehicle movement on the track will be limited to daylight hours between 06h00 and 20h00. All sharp corners will be capped with concrete paving to reduce the possibility of erosion. Waste rock from the quarry operations will be used as surface cover for areas where erosion occurs. Maintenance of the track will be ongoing and occur on a weekly basis.
Target: No gully or pit erosion on road. All erosion susceptible areas to be covered and free of erosion.
Implementation/monitoring responsibility: Mine manager
Audit: environmental consultant
Impact on Air quality and noise in proximity to Mr. Siwela's homestead:
Type of impact: Sporadic continuous
Mitigation measure: The gravel road will be wetted (minimum distance of 100 meters) both sides of the homestead. Wetting of the road will occur twice daily on operational days. MLE vehicles will maintain a maximum speed limit of 20 km per hour in the vicinity of the homestead.
Targets: Noise at from vehicles at homestead less than 80 dB No visible dust from track as vehicle passes.
Implementation/monitoring responsibility: Mine manager
Monitoring responsibility: environmental consultant
Quarry site impacts
Construction phase:
Potential for hydrocarbon pollution in the soil.
Type of impact: Continuous/Contingencies
Mitigation measures: A bunted concrete slab (apron) will be constructed on the site where the diesel tank is to be constructed. The slab design: The slab will extend at least 0,5 meters around the diesel tank. The concrete slab will be at least 0,2 meters thick. A bunt wall will be constructed of two bricks high around the perimeter of the slab. A layer of wood chips will be placed within the bunted area to soak up any spilt diesel. The bunted area will be cleaned once a month during the dry season and weekly durin gthe rainy season.
Target: No hydrocarbon soil pollution
Implementation/monitoring responsibility: Mine manager
Monitoring responsibility: environmental consultant
Impact on soil due to loss of fertility due to compaction:
Type of impact: Initial/continuous
Mitigation measure: The upper 200 mm of soil (topsoil) will be stripped and stockpiled. The topsoil stockpile will not exceed a height of 2 meters.
Target: Topsoil to have the same fertility during replacement as before quarry.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impact on surface water due to increased silt load from stockpile area:
Type of impact: sporadic
Mitigation measure: A storm water diversion trench will be constructed upslope of the stockpile and loading area to divert runoff around the area. Diversion trench design. This storm water diversion trench will be 0,5 meters wide and at least 300 mm deep. Material excavated from the trench will be placed on the down slope side of the diversion trench to form an earthen perimeter wall. The earthen perimeter wall will have a height of approximately 0,5 meters.
Target: All runoff water upslope of the stockpile area will be diverted.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impacts on fauna due to fires on the lease area:
Type of impact: contingencies
Mitigation measure: All fires on the lease area will be combated immediately and extinguished by MLE personnel. Fire fighting equipment will be kept on site (10 rubber fire swatters, 3 industrial foam extinguishers).
Target: Veldt fires to be extinguished within 2 hours after discovery. Site fires to be extinguished within 1 hour.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impacts on fauna due to feeding and trapping
Type of impact: continuous/contingencies
Mitigation measure: All domestic waste will be collected in 44 gallon drums and removed from the Malolotja nature reserve on a daily basis. Personnel will not be permitted to feed or trap animals. Where it is found that a member of MLE sets traps or trapped an animal he will be dismissed immediately.
Target: No domestic waste on site except on designated holder. No domestic waste on site after work hours. No snares on lease area.
Implementation responsibility: Mine manager
Monitoring responsibility: Environmental consultant
Impacts on air quality due to drilling dust:
Type of impact: Continuous sporadic
Mitigation measure: Water drippers will be installed and used on the drills. All drilling personnel will be supplied with dust masks.
Target: less than 200 ppm dust in air at a 5 meter distance from drill.
Implementation responsibility: Mine manager
Monitoring responsibility: Environmental consultant
Operation phase:
Impact on geology due to the potential reduction in chert value:
Type of impact: contingency
Mitigation measure: Care will be exercised during drilling operations to ensure that the extraction process does not detrimentally affect the value of the green chert. If necessary drill patterns will be modified to ensure the best extraction.
Target: Waste production 40% or less.
Implementation responsibility: Mine manager
Impact on topography due to height of stockpile:
Type of impact: continuous The product stockpile will not exceed a height of three meters.
Target: Stockpile height less than 3 meters.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impact on soil on lease area due to gully erosion:
Type of impact: continuous
Mitigation measure: The gully erosion on the lease area will be combated by the placement of wate rock filled gabian structures at intervals of 10 meters within the gully. Gabian structures will be 4 meters wide and 0,5 meters high. The gabian walls will be progressively lifted during the life of the quarry.
Target: 50 running meters of gabian structures per year.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impacts on surface water from the quarrying area
Type of impact: continuous sporadic
Mitigation measure: A 1 meter wide and 300 mm high rock wall will be constructed upslope of the quarry area to divert storm water runoff around the work site. This wall will be extended progressively at least 10 meters in front of the work area.
Target: All upslope runoff water diverted around affected quarry area.
Implementation responsibility: Mine manager
Monitoring responsibility: Environmental consultant
Impacts on fauna during breeding season:
Type of impact: continuous sporadic
Mitigation measure: No quarrying will occur during the months of October to February.
Target: Knysna lourie, Brown robin, Orange thrush and Bush blackcap still occur in Mgwayiza forest during breeding seasons.
Implementation responsibilty: Mine manager
Monitoring responsibility: Environmental consultant - ornithologist to be appointed.
Decommissioning phase:
Impact on topography due to the removal of stockpile and infrastructure:
Type of impact: Positive continuous
Mitigation measure: All infrastructure and concrete bases will be removed. All material from the stockpile area will be removed. The stockpiled topsoil will be used to cover the loading and stockpile area. No holes will be left on site.
Target: No foreign material to be left on stockpiling or infrastructure site.
Implementation responsibility: Mine manager
Audit responsibility: Environmental consultant
Impacts on soil and surface water at the stockpiling and loading area: sheet erosion.
Type of impact: sporadic continuous
Mitigation measure: The stockpiled topsoil will be spread 200 mm thick over the product stockpile and loading areas. 100 mm deep velocity break furrows will be constructed perpendicular to the natural slope at intervals of 30 meters. The storm water diversion trench around the upslope side of the stockpiling and loading area will be left intact. The rehabilitated stockpiling and loading area will be seeded with natural flora seeds from the immediate area.
Target: rehabilitated area to be free of erosion and have 50-70 vegetation cover within 2 years after commencement of rehabilitation.
Implementation responsibility: Mine manager
Monitoring responsibility: Environmental consultant
Socio-economic impact due to decrease in work force.
Type of impact: continuous
Mitigation measure: Everything possible will be conducted to accommodate the excess labour force on other projects. If it is not possible to accommodate any employee on another project (for whatever reason) MLE will enter into negotiations with that employee or his appointed representative to determine an amicable retrenchment package. This retrenchment package will include the option of being funded for training in an alternative field of his choice. Funding for training will be provided for from the Trust Fund. Individual funding will equate to 10% of the employees final annual wage multiplied by the years of employment.
Target: To accommodate all retrenched personnel
Implementation responsibility: Project proponent