Occupational Safety and Health - Case Study Example

of the company: TIPAIMUKH HYDRO-ELECTRIC (MULTI-PURPOSE) PROJECT NORTH EASTERN ELECTRIC POWER CORPORATION LIMITED SHILLONG, MEGHALAYA, INDIA. Introduction: The proposed Tipaimukh H.E. (Multi-Purpose) Project is one of the prestigious projects in North Eastern Region India, (NER) taken up by North Eastern Electric Power Corporation Ltd. (NEEPCO) to uplift the socio-economic status of the people as a whole. The project envisages construction of a 162.8 m high rock fill dam across R. Barak at 500 m down stream of confluence point with R. Tuivai, mainly to generate hydro-power to the tune of 1500 MW (installed capacity). The storage may lead to compulsory acquisition of land and submergence of substantial flora, fauna and hearts of people who are, by and large, economically, socially and otherwise backward and thus extremely vulnerable to dislocation. Also the submergence may lead to loss of homes, means of subsistence like agricultural, horticultural and even forest lands, where tribal have access to minor produces as well as for jhumming, and naturally will have traumatic effect on the affected population. Under such circumstances, it will be proper to take timely steps for planning rehabilitation and resettlement of Project Affected Persons (PAPs) to avoid any further disastrous incidents. Among all the various important aspects of the project we shall be discussing primarily the three important topics of 1. Environmental Protection 2. Occupational Health and Safety 3. Waste Elimination. 1. Environmental Protection Identified Impacts The Principal Geo-environmental Impacts of the Tipaimukh Hydro-Electric Project have been assessed to be: i) Landslides in the catchment /reservoir area, ii) Soil erosion and siltation of reservoir, iii) Declination of forest cover, iv) Seismic risk, v) Gas emission during construction of underground structures, vi) Ground water imbalance in the down stream. Landslides Due to varied geomorphic character, complex tectonics, structure and soft sediment lithostratigraphy, and change in draw down, the impounded water is bound to cause unstable slope condition, especially in reservoir rim, particularly those in the limit of draw down. Thus, in the event of sudden draw down, major slide could develop. Simultaneously, reservoir water would act as the load drive, as is commonly found in the Himalayan Region, which may have a positive stabilizing influence too. It is therefore recommended that about 100 m above the reservoir rim is thoroughly investigated for site specific knowledge on failure mechanism and adequate protection measures, as explained, be planned at the pre-construction stage with tentative provision of shot crating, rock anchoring, carving out of slopes etc. Landslide activity would generate rock boulders, silts and mud, but its effect is again dependent on the distance of occurrence from the project components. If the slide occurs much above the FRL direct impact would be less. However, some slides just at the periphery of the rim would add to the silt load / bed load. This impact on the project could be managed by arresting the potential slide zones through suitable engineering treatment measures, afforestation etc. However, the project shall have a separate provision for engineering geological studies to provide necessary treatment measures. Monitoring Gas Emission During construction / excavation of underground openings in the project site, emission of explosive gas may be encountered as the lithological sequence to be encountered is of tertiary age. Therefore, its adverse effect of damaging environment during construction period could be mitigated through early monitoring of the quantity and quality & concentration of the gas. For this gas detector and protective measures, as per underground construction / mining rule is to be kept and executed strictly. Monitoring of Change in Water Quality Provision for monitoring of change in water quality, both upstream and down stream, should be made. Seismic Risk, Hazard Monitoring and Mitigation Measures Each monitoring station should have one accelerograph and at least 5 seismographs, preferably digital. Monitoring period should be of duration that includes pre-impoundment, during impoundment and post-impoundment of water so that possible RTE can be examined ACTION PLAN FOR TREATMENT OF LANDSLIDE PRONE AREA Factors Causing Landslides A landslide is defined as the downward and outward movement of slope forming material, composed of natural rocks, soils, artificial fills or combination of these materials. Landslides, in a strict sense, do not include creep phenomena or subsidence, but usually these are considered along with landslides, because of their relation to instability of slope. Factors causing landslides have been broadly classified as geological, hydrological and seismic land use. Almost all the landslides involve the failure of earth material under shear stress. Geological Factors Thin beds of clayey lime stones, shale, highly jointed sedimentary beds, ash beds and schist varieties are all pointers of week zones. If along with these, structural deformities like steep dips, folds, faults accompany, the likely danger increases. Further, landslides hazard is indicated if a stronger formation overlies a weaker one and intrusion of one formation into other, causing instability. To locate all these, a careful study of local geology is necessary. Hydrological Factors Water seeping through disturbed slopes, toe cutting by rivers and torrents and pore water pressure in the soil zone are major agents responsible for landslides. Torrents, especially in their early stages, because of excessive velocities of flow and turbulence, carry out quick removal of debris and cutting of sides. The landslides mostly take place after heavy rainfall. The rain water has mainly three effects, via (a) it increases the effective weight of the material due to saturation, (b) lubricates any sliding planes, especially of shale and, (c) causes weakening of strata, e.g. if this is a clay stratum it will swell because of moisture intake. One or all these effects in combination may bring about a landslide in rainy season. Whenever these factors are causing slope failure, improving the drainage of the area is called for. Seismic Factors The intensity and frequency, with which earthquakes are felt in a particular region, will also influence the occurrence of landslides. Sometimes landslides are so great that they themselves initiate earthquakes. Thus, both are complementary to each other. It is also a common observation that generally in mountainous areas of Tertiary age group, rocks are relatively younger where seismic activity is common. In case of fine sand, silt and less deposit, shocks due to earthquake or blasting reduce the shear strength due to liquefaction and initiate sand-mud flow. Geomorphic Features of the Reservoir Rim A Geotechnical Evaluation of Competency of Tipaimukh Reservoir Rim was made by GSI, Shillong, and the following abstract is reproduced from their interpretation on geomorphic features of the reservoir areas. The geographic features depict the physiographic expression of the geological structure of the region. Anticline valleys and synclinal ridges are seen in the northern part of the reservoir area exhibit a higher topographic order, where as in the southern part, anticline ridges and synclinal valleys of lower topographic order, where as in the southern part, anticline ridges and synclinal valleys of lower topographic order occur. The ridges maintain the alignment parallel to the regional strike. Morphogenetically, the land form elements of the reservoir area can be classified into structural, degradational and aggredational ones. Stabilization Measures 1. As the slide material consists of small rock fragments to boulders embedded in grey to dark grey clayey to silty matrix, creation of a vegetative cover over the slided material, by afforestation and turfing, along the slope, should be taken up to check the movement of slided material into the reservoir. 2. Also measures like contour bonding, construction of check dams etc should be taken up on degraded valley flanks, sheet eroded and deforested slopes. 3. Detailed stabilization measures to be planned during construction stage of the project, when systematic geotechnical studies and large scale mapping of the slide affected slope is conducted. 4. In addition of above mentioned slides, there may be few others in the catchment area. But as these will be far away from reservoir or river or their tributaries - sub-tributaries, with vast intermediate forests or grassy lands in between, will not have any affect on reservoir. However, to prevent the entry of rolling debris from such zones, arresting them through rising of barriers across their established or possible routes, may be considered. 5. Landslides from moderately unstable zones and steep slopes can be checked by reducing their gradient or by grouting, bolting with anchor device etc. 6. Due to varied geomorphic character, complex tectonic and litho-stratigraphy, the impounded reservoir is bound to change stability condition of slopes on its rim, particularly those in the limit of drawdowns. Thus, in the event of sudden drawdown, major slide could develop. At the same time, reservoir water could act as a toe load drive, as it is commonly found, which may have positive stabilizing influence too. It is therefore, recommended that the vicinity of the reservoir rim is thoroughly investigated for site specific information on failure mechanism and adequate protection measures be planned at pre-construction stage with tentative provision for afforestation / turfing, carving out slopes, shot creting, rock anchoring or other suitable engineering measures etc. 2. Occupational Health and Safety: Health Impact Assessment Disease Ecology This section concentrates on human health issues associated with power projects only, especially human settlement and shelter around the periphery of the reservoir. Characteristics of diseases endemic to this area, whose transmission potential is a function of ecological parameters affected by impounding of inflow, health risk associated with environmental and socio-economic changes, the preventive and mitigating measures and to promote human health in an integral approach are the main issues. Power projects contribute, substantially to conditions that favor good health, food security, improved infrastructure, allowing better access to health services and economic progress which permits rural households a greater purchasing power for drugs and health services. On the other hand, there can be potential negative impacts on human health. Health sector institutions, thus, should examine and access three categories of parameters related to: (a) community vulnerability, (b) environmental susceptibility, and (c) capacity of health services to deal with the situation. Vector-borne diseases resulting from introduction of water impounded may create new or more favorable habitats for disease vectors, their intricate transmission pattern etc. Two key determinants have general influence, i.e. (1) Vector density (which is upto a saturation level, linearly related with the transmission level) and, (2) Vector longevity (the longer the life span of an individual mosquito, the greater chance it transmits a disease to one or more humans). Malaria is a major vector transmitting disease in this part of the State. Other water borne diseases endemic to this area are: Cholera, Typhoid, Para typhoid, Infective hepatitis, Bacillary dysentery, Amoebic dysentery, Gastroenteritis, Skin sepsis and Ulcers, Scabies and Diarrhoeal diseases. Specific Risks and Counter Measures Hydrology of the area plays an important role on risks and counter measures. A low-flow regime may lead to ponding in river bed providing suitable breeding sites for malaria vectors. Dams and impoundments can create a variety of health risks because of ecological change, i.e. mosquito and snail propagation along shallow shorelines, associated with aquatic weeds and black fly breeding on spillways. A rise in the water table resulting in water logging creates conditions in which many mosquito vector species thrive. Provision for Health Care For carrying out regular health surveillance and health care facilities of the population of the affected villages as well as of the adjoining areas, it has been proposed to establish six Primary Health Centers with two mobile ambulatory clinics to provide better health care facility. Population Pressure It is envisaged that total number of persons, including officers and staff (both technical and non-technical) and labor force, during the peak construction period will be around 1840. Thereafter, the number will be reduced to about 759, who are needed for operation and maintenance of the project. This workforce will need fuel wood and other means of energy sources for their camp as well as for domestic purposes. The fuel wood and fodder plantation, planned under Forestry and Silvi-Pasture Management Programme will take care of these requirements. Also, the labor force will be provided with alternate energy sources, like Kerosene / electric power, at a subsidized rate. 3. Waste elimination: Usable and Un-usable Quantity As per the in-situ and laboratory tests conducted core samples and on the drift at right flank, it is found that certain quantity of excavated materials could be used as construction materials like fine aggregate, coarse aggregate and rock fill in casings. Selection of Dumping Site There will be a great demand for working space due to topographical constraint. As such, it is felt that all the usable materials could better be used within a short span of time, after due processing, which will minimize the dumping spaces for usable materials and consequently will provide more working space. Further, any dumping of un-usable material towards the upstream of reservoir rim and inside the divide ridge line, will affect the storage capacity, thereby life of the project. Similarly, any dumping towards down stream of river course will pollute the water for down stream inhabitants. Usable quantity from Power House and Switch Yard excavations can be dumped near to their premises to minimize lead. Also rock masses to be used as Fine Aggregate and Coarse Aggregate can be dumped near to the Crushing and Screening plant and stone crushers. Recommended Dumping Sites As the excavation and use of construction materials from approved borrow and quarry areas will cause depressions, bowls, cavities, pits etc., it would be advisable to fill these up by un-usable excavated materials from different components of structures, so that these depressions, bowls, cavities, pits etc. could be restored simultaneously to avoid any pollution hazard. Protection and Design of Dumping Yard Sipikawn Saddle Borrow Area is on a flat land (terrace) in between R. Tuivai and Ronglui Nala. The periphery of this area will need adequate protection so that silt inflow into the reservoir through R. Tuivai and Ronglui Nala could be entirely checked. Keeping this in view, a line of defense will be created by providing vegetative barriers (Green Belt) around the periphery, with sufficient width by means of Intensive Afforestation and Reforestation, with selected plant species. Based on examination of this area from topographic, climatic and soil cover angle, the following species are recommended. RESTORATION PLAN FOR BORROW AND QUARRY AREAS Approach for Restoration Out of above mentioned five sites, the depressions, bowls, cavities, pits etc. of three sites that will be formed consequent upon removal of materials, will be filled up considerably by the un-usable excavated materials from different structural components. Thus, these three sites will get the benefit of having a thick top layer of mixed materials to act as a top soil for germination of plant species and ultimately to act as a vegetative cover in near future. For the other two quarries, the top soil layer is to be created by transporting such materials from nearby areas. Preferably, areas having sandy clay or loam type of soil may be selected for transfer. Such soil will enhance the process of germination of plant species. However, in both cases, i.e. during extraction as well as during dumping process, a suitable gradient, without disturbing hill slope profile or masses, is to be maintained. Thickness of top soil layer may be kept around 2.0 m. Plant species, as suggested for providing barrier around the borrow area can also be grown for restoration of these sites. Conclusion For an organization, other than maintaining its regular activities in order to meet its primary goal, it has to regulate other secondary factors too. Environmental protection, Waste elimination and safety are three such examples that have been discussed here. Though for a power corporation, need for environmental measure is tremendous but it's not limited to that only. Each and everyone should be aware of their safety and healthy atmosphere. In simple words, if we want a green world for our living then, ourselves will only be responsible to bring it and we have to take necessary action. References: 1) No. 29 OF 1986. "THE ENVIRONMENT (PROTECTION) ACT, 1986". < http://envfor.nic.in/legis/env/env1.html> 2) Canadian Environmental Protection Act. 1999. < www.ec.gc.ca/CEPARegistry/the_act/Download/CEPA_Full_EN.pdf> 3) Environmental Auditing: Good Business and Environmental Protection Converge. < http://www.p2pays.org/ref/15/14004.pdf> 4) Safety and Health Topics. Occupational Safety and Health. US Department of Labor Administration. < http://www.vic-ikp.info/vic_new/pdf/Safety%20and%20Health%20Topics.pdf> 5) Organizing for Health and Safety. A TUC Resource for use in the workplace. 6) Elimination of Organic Solvent at Dynamic Manufacturing. < http://www.wmrc.uiuc.edu/main_sections/info_services/library_docs/TN/tn06-083.pdf> Read More