6 IDENTIFICATION AND PREDICTION OF IMPACTS

Transcription

1 6 IDENTIFICATION AND PREDICTION OF IMPACTS 6.1 General The actual and potential environmental impacts due to the proposed development by Mauritius Molasses Company Limited in the setting up of an oil storage tank at Quay D road has been divided into two categories: Positive Impacts Negative Impacts Under each category, both the positive and negative impacts have been examined. A positive impact is indicated by a positive (+) sign and a negative impact by a negative (-) sign. The number next to each sign reflects the relative magnitude of the impact on a scale of 1 to 3, where: 1 is a slight impact 2 is a moderate impact 3 is a significant impact The case of no impact is indicated by (0). Table 6.1 at the end of the section, summarises the environmental impacts due to the proposed development in the event that no mitigating measures are implemented. 6.2 Scoping Scoping identified three key environmental factors, namely: air water quality soil contamination There is potential for significant negative environmental effects on the above environmental factors unless suitable mitigation measures are taken to reduce or eliminate them. These are discussed in chapter Air Quality During the conversion phase, dust will be present with the use of construction machinery. However, the impact is considered to be marginally negative. Over the life of the Project there will not be any potential air emissions. However, because of the hazardous nature of the product to be handled at the site, there is a risk of fire which can give rise to air pollution. Conversion of Tank for Oil Storage EIA Report 6-1

2 6.3.1 Risk of Fire Hazardous conditions depend on several factors such as: Types of products handled Total volume of products handled Total capacity of the tank involved Local conditions Size and configuration of the area and types of other plant and equipment in the vicinity. During the life of the project, in the absence of mitigating measures the risk emanating from fire is of a significant negative impact. 6.4 Water Quality Water pollution could arise from oil contaminated wastewater, which has not been properly treated and disposed. In the event that the tank discharged an effluent into the sea it would be necessary to obtain an industrial effluent discharge permit and to comply with the Standards for Effluent Discharge into the Ocean Construction Stage Construction wastes, without proper supervision, could be a cause of pollution during construction. This is considered to be a moderate negative impact Operation Stage Potential sources of pollution on the marine environment during operation are oil spillage, improper treatment and disposal of wastewater. This is considered to be a significant negative impact Oil Spillage There are many sources through which product spillage can occur namely during routine maintenance, overfilling of tank, failure of components of the valves, etc. Owing to the fact that spillage can be the source of fire and pollution related hazards, fire and environmental requirements dictate that spilled product must be controlled and spread of product following spillage should be prevented. Hence, in the absence of mitigating measures, the impacts would be significantly negative. 6.5 Soil Contamination There is potential for localised land contamination at the site during the operation phase. Spill of product may occur and infiltrate into the ground towards seawater. Conversion of Tank for Oil Storage EIA Report 6-2

3 The impact is considered to be significantly negative during operation phase of the project. 6.6 Socio-Economic Effects The socio-economic effects of the proposed development are as follows 1. A significant increase in the storage capacity of petroleum products in Mauritius, which can be translated into reduced stress on shortage of class B products. 2. Employment for approximately 20 skilled and specialised people over a 8 months period during the construction phase. The impact would be positive though short term. 3. Direct and indirect employment for up to 10 people during the operational phase. This is a positive impact, which would have a beneficial impact on other industries such as the transport sector. These constitute a moderate positive impact during the construction stage and significant positive impact during the life of the project. 6.7 Effects on Traffic The receipt of petroleum products and delivery of same will be through existing pipe network from the oil jetty at Mer Rouge to Shell depot. There will be no road transportation. It is therefore considered to have no impact. 6.8 Effects Related to Solid Waste Disposal The only source of solid waste will be waste generated by the staff as a result of food consumption. As this will constitute a very small volume of material, and given the fact that the site is connected to the sewerage network, this is not considered to be a negative impact. 6.9 Effects on Terrestrial Ecology The Project site and surrounding area being land for industrial and commercial development, have low ecological value. Therefore the proposed development would have no significant impact on local terrestrial ecology. The Terre Rouge Bird Sanctuary is an area of ecological importance, located at a distance of approximately 1.8 km on the north of the site. Being separated by the Conversion of Tank for Oil Storage EIA Report 6-3

4 Total fuel farm,the West Cemetery and the free zone area, it is expected that the bird sanctuary would not suffer from impacts originating from noise, fire and spillage pollutions. As such, there will be no overall impact Effects on Cultural and Historical Heritage The development site being in the Port Master Plan as a storage area has no cultural and historical value Noise It is anticipated that the construction of the proposed development will take approximately 8 months. The main activities will be foundation works and erection of the dyke wall and concrete pavement. Hours of work will be normally restricted to daytime. Night work will only be allowed for activities that cannot be interrupted. The proposed site is contained within an area where surrounding developments provide effective screening as far as noise emissions are concerned. Therefore, the potential impact of construction and operational noise emissions is considered negligible Effects on Landscape and Visual Environment The proposed conversion is within an existing industrial site that is located within the industrial zone of Port Louis Harbour. The structure is an existing tank in the port area. Bulk ship unloading takes place at the new oil jetty at Mer Rouge. Consequently there is no negative visual impact on the surrounding industrial environment Accidents/Occupational Health and Safety The most obvious potential for accidents arises from fire hazard and injury/accidents related to the handling and storage of the petroleum products and product spills. Consequently, in the absence of proper mitigating measures, the overall environmental impacts would be significant and negative. Conversion of Tank for Oil Storage EIA Report 6-4

5 6.14 Summary Table of Impacts Without Mitigation Measures Without Mitigation Measures Environment Construction Life of Project Mitigation required Air Quality -1-3 Water Quality -1-1 Soil Contamination -1-3 Socio-Economic Effects Traffic 0 0 Solid waste 0 0 Terrestrial Ecology 0 0 Cultural and Historical 0 0 Heritage Noise 0 0 Landscape and visual 0 0 environment Accidents/Occupational -1-3 Health and safety Sub-total -2-7 Table 6.1: Summary Table of Impacts without Mitigation Measures Where a negative impact has been predicted, a mitigation measure is required and details are provided in Section 7. Conversion of Tank for Oil Storage EIA Report 6-5