E533 Vol. 20 ELIECTRICITY OF VIETNAM POWER COIMPANY No. 1 SYSTEM EFFiCIENCY IMPROVEMENT, EQUITIZATION AND RENEWABLE PROJECT ENVIRONMENT IMPACT ASSESSMENT FOR REHABILIATION OF CHIENG NGAM HYDROPOWER PLANT Prepared by: POWER ENGINEERING CONSULTING COMPANY No 1 March, 2002 ENVIRONMENT OF CHIENG NGAM HYDROPOWER PROJECT TABLE OF CONTENTS 1. INTRODUCTION 1.1 General Introduction on the Background of Power Development in the Project Area and Relevant Environment Issues. 1.2 Relevant Management Organization Structure 1.3 Purpose of the Report 1.4 Methodology 2. PROJECT DESCRIPTION 2.1 Project Description 2.2 General Layout of Chieng Ngam Hydropower Plant 2.3 Resettlement Plan. 3. LEGAL BASIS, POLICIES AND ADMINISTRATIVE MANAGEMENT 3.1 Requirement from Investor to Environment Issues 3.2 Feasibility Study Report 3.3 Agreement on Project Site 3.4 Environmental Management System 3.5 Laws on Environment. 4. DATA 4.1 Present Situation of Natural Environment in Lat Commune 4.2 Present Situation of Chieng Ngam Hydropower Plant 4.3 Contents of Plant Rehabilitation and Upgrade. 5. ENVIRONMENTAL ISSUES 5.1 Matters Mentioned During Rehabilitating Design Period 5.2 Environmenltal Issues Mentioned During lIrr-1cmenting the Rchabilitation and Upgrade. 6. MITIGATI7)7 MEASURES FOR NEGATIVE ENVIRONMENTAL. IMPACT 7. EVALUATION OF REPLACING ALTERNATIVES 8. ENVIRONMENTAL MANAGEMENT PLAN 8.1 Mitigation Measures for Negative Impacts 8.2 Environmental monitoring 8.3 Action Plan and Cost Estimation 9. PUBLIC CONSULTATION AND DISCLOSURE 10. RESETTLEMENTi 1 1. CONCL,USION ANNEXES ANNEX 1: Minutes of Meeting on dame safety for Chieng Ngam project with Electricity of Son La ANNEX 2: Opinion of Son La DOSTE on the EIA ANNEX -: Minutes of Consultation Meeting with local communities on EIA Map of the Project 2 I INTRODUCTION 1.1 General liitroductioij on the Background of Power Development in the Project Area and Relevant Environmental Issues Chieng Ngam Hydropower Plant is operating in connection with the regional electric system (in Thuan Chau District). The district has a rather large area consists of 35 communes. Of which, II communes have been supplied with electricity. The three-phase 0.4kV transmission line is mainly supplying for 30% of households in towns and centers along Rcad N°.6. At the present, 35/0.4kV substations have been built in several communes. There are not any low voltage transmission lines in the district. The I 1 communes supplied with electricity have not used with all capacity. Other communes have new substations with three-phase 0.4kV transmission lines transverses along commune centers. Electricity generated from Chieng Ngam Hydropower Plant has been connected to the national grid. There is no special issue about t'he local environment. Water resource, vegetable debris as well as the air in the area are always well-protected. 1.2 Relevant Management Organization Structure The management of Chieng Ngam Hydropower Plant is belonged to Chieng Ngam Hydropower Department with 16 people working in a hydropower team. Electricity of Son La who is one of the members of Power Company 1, Electricity of Vietnam, directly governs the department. 1.3 Purpose of the Report The purpose of the report on environmental impact assessment is to clarify the impact from the rehabilitation and upgrade project to the natural environment, the economy and society on Chieng Ngam commune and the area of Chieng Ngam Hydropower Plant. It also assesses the environmental impact to the life and working condition of the workers. Therefore, it is possible to prevent nega.;ve impacts and develop advantage factors to improve the project capacity in electric energy supplying. 1.4 Methodology The rehabilitation and upgrade project for Chieng Ngam hydropower plant is a small one, so it causes little negative impact to the environment. It is fitted with methods of using analysis in combination with direct observation to prepare the Environmental Impact Assessment Report. 3 2. PROJECT DESCRIPTION 2.1 Background of the project Chieng Ngam Hydropower Plant was designed by Institute of Water Resource Designing. The Plant is now managed by Electricity of Son La. It was completed in 1976 and first commissioned in 1977, using water from Nam Muoi stream (in Chieng Ngam Commune, Thuan Chau District, Son La Province). Salient Features of the Plant are as follows: Chieng Ngam Hydropower Plant has an installed capacity of 1890kW, consisting of 2 units; each has a capacity of 945kW, horizontal Francis type with metal spiral case and an output of 83.3%. The two units were manufactured in Bulgaria in 1969. Generator is of horizontal three-phase synchronous type manufactured in Bulgaria in 1970. Rated capacity of the generator is 1260KVA. All main equipment in the plant is operating in normal condition. Chieng Ngam Hydropower Plant is located in Chao mountainous village, Chieng Ngam commune, Thuan Chau district, Son La province. The plant is 20km far from the center of Thuan Chau district and 8km far from Road No.107 to Quynh Nhai. The location of the plant is at about 21°29' north latitude and 103°46' east longitude. In rainy seasons, access road is sliced, so it is difficult for transportation. The area of dam and diversion canal is not sliced but the only traffic-way to dam and diversion canal is an approach road built by local residents for local use. Chieng Ngam Hydropower Plant is z 2rating by water diverted from Nam Muoi stream, a right tributary of Da River, with an average flow of 6.1 Im31s (via Xang village). Catchment area from Binh Thuan to the dam site (in Chao village) is 298km2. The catchment is situated in a limestone mountainous area, with elevation gradually lowering from West to East. Dain: - Stone Masonry with concrete lined (Ophixerop type). - Height of dam: 5.5m; Crest elevation: 494m. - Crest Length: 24m. The dam is built on Nam Muoi stream, creating a head with an inundated area of 2ha. This area slopes gradually with an inclination from 50 to 15°. The 800m long Diversion canal has a stone masonry structure, plastered with a layer of waterproof cement. The plastered layer has been degraded, causing watcr leakage along canal. The canal goes along the right bank of Nam Muoi in the direction from North to Southi. 4 Pe,istocks: The penstock has a diameter of 1.2m and a length of 360m with an inclination of 15 -.30°. Power House and Machinery Hall occupy an area of Iha in Chao village, Chieng Ngam commune. Motorway from Quynh Nhai - Son La inter-province road to the Power House is 7.6km. Traveling in this area is very difficult. 2.2 General Layout of Chieng Ngam Hydropower Project General Layout of the Chieng Ngam hydropower plant is shown in drawing No. 37.01-OlTH-Ol. 2.3. Resettlement This is a rehabilitation and upgrade project. It is not necessary to occupy lands, so no resettlement plan is proposed. 5 3. LEGAL BASIS, POLICIES AND ADMINISTRATVE MANAGEMENT 3.1 World Bank safeguards policies The following World Bank's safeguards policies are relevant o Environmental Assessment (OP 4.01, BP 4.01, GP 4.01), o Pest Management (OP 4.09), o Safety of dams (OP 4.37) Bank Procedures BP 17.50: Public disclosure of Environmental and Social operation documents * Environmee:ztal Assessmett: This will be addressed in this EIA report * Publicity of Iinformatiotn Informnation about the rehabilitation and upgrade project, forecast on environmental changing caused by implementing the project, and other relevant information have been informed to Electricity of Son La, who is responsible for supervising of the Chieng Ngam HPP; Chieng Ngam Hydropower Department; and People's Committees of Chieng Ngam communes since August 2001. Such information should be updated regularly and made public, so that relevant people can have opinion on it. * Dam Safety The dam is built of masonry stones with h a height of 5.5m and crest length of 24m. The dam has a stable structure and it is safe for the operation of the plant. There is much sedimentation in the upstream of the dam, affecting hydraulic regime of the spillway. The dam was built in 1987. There has not been any incident during operating. At the moment, the dam is still in good condition. By coordinating in field investigating, calculating and evaluating, Power Engineering Consulting Company I and Electricity of Son La had issued a document confirming about the long-term safety of the Chieng Ngam dam (see the minutes of meeting in the annex). * Pest man2agementt: Although the existing equipment is manufactured before 1997, the transformers do not contain PCBs. The safeguard policy on pest management will therefore be not triggered 3.2 Feasibility Study Report 6 Power Engineering Consultant Company I prepared Feasibility Study Report in July 2001. 3.3 Environmental Management System This environmental system in Vietnam is divided into two levels: - Ministry of Science, Techlnology and Environment (MSTE) is generally responsible for the managing of environmental protection at State level in the whole country, organizing and instructing all environmental protection activities and reviewing reports on environmental impact assessment of large projects. - Provincial Department of Science, Technology and Environment is responsible to the provincial People's Committee to carry out the managing of environmental protection at State level in the localities. This project is environmental category 11 and will therefore be supervised by DOSTE. - Power Company I is responsible for selecting of design alternative and suitable method of construction; preparing the operating process for the plant in accordance with requirement on environmental protection with monitoring plan. - The Project Management Board, established by Power Company 1, is responsible for managing and supervising during the implementation of the project (the project belongs to Group B) to maintain quality and construction schedule as approved; directly solving arisen matters within its competence or report to PC1 for instruction; making easy condition for construction team to fulfill their responsibilities; and regularly making environmental monitoring reports on all activities at the project site to Electricity of Lai Chau, PC1, EVN, the World Bank, and Son La DOSTE. 3.4 Laws on Environ-Tent - Law on environmental protection approved on 27th December 1993 by the National Assembly of Socialist Republic of Vietnam in Meeting Session 9d'. - The Government Degree No.175/CP dated October 18'' 1994 on Guideline for implementing the Law on Environmental Protection. - Environmental standards of Vietnam. - Circular No. 490/1998/TT-BKHCNMT dated April 9t' 1998 by the Minister of Science, Technology and Environment on the Guideline 7 for establishing and reviewing reports on environmental impact assessment of invested projects. - \ elevant documents to the process of survey, design, construction organization, and management and operation of Chieng Ngam Hydropower Plant. Law oni Mineral Resources approved on May 20th 1998 by the National Assembly of Socialist Republic of Vietnam. Other relevant documents. 3.5 Correspondences of Duty Assignment and Contents of the Regulation on Upgrade and Rehabilitation activities of Hydropower Plant. - Letter No.1490EVN/KH-QHQT approved on April 1 g,h 2001 by Electricity Vietnam to assign the work duty for Power Company 1, 2, 3 and Power Engineering Consulting Company 1 on establishing feasibility study report of projects which planed to get the loan from World Bank financial results for the year 2002-2003. - Agreement on the contents of the rehabilitation and upgrade of the Chieng Ngam Hydropower Plant signed by Electricity of Son La and the Investigation Team of Power Engineering Consulting Company l(PECCI) dated 2001. 4 DATA Basis data for assessment of the environmental impact of Chieng Ngam Hlydropower Rehabilitation and Upgrade Project consists of: - Design and rehabilitation document of the plant - The Master Plan for socio-economy of Thuan Chau district, Son La province to the year 2005. - Natural, economic and social condition in the project area (Chieng Ngam commune, Thuan Chau district, Son La province). - Present situation of Chieng Ngam hydropower plant. - Contents of the rehabilitation and upgrade that has been agreed in an agreemient signed by designing party and Electricity of Son La. - Insitu-survey documents of relevant areas and hydropower plant prepared by PECC I in June 2001 and other related documents. 4.1 Natural and Economic Con(lition of Chieng Ngam Commune in General 4.1.1 Geographty 8 Chieng Ngam is a moun,tainous communLe in Thuan Chau District, Son La province, 350km in the northwest of Hanoi Capital City (along national highway N°.6 to Thuan Clati). Geological coordinator: at 21°29' northern latitude and 103°46' eastern longitude. 4.1.2 Topographty: The regional topography is mainly mountainous and hilly, inclined from northwest to southeast, situated at elevation 700 - 750m in compared to sea level. Inclination of streams is rather big. 4.1.3 Climate Chieng Ngam HPP is situated in the monsoon tropical climate with dry cold winters and humid hot summers. - The average annual rainfall in the Nam Muoi catchment is 1,400mm (according to isohyetal map). Rainy season is from May to October and dry season is from November to April of the following year. - Air temperatures vary very much, from 14.3°C to 25°C. Annual average temperature is 21°C. - Air humidity varies from 69% to 89%. Annual average humidity is 83%. - Annual average evaporation is 936mm by Pitch at Son La gauging station. - Monthly average wind speed varies from 0.9 - 1.5m/s. Annual average speed is 1.2m1s 4.1.4 Hydrology On the Nam Muoi stream and other tributaries from it, there is only Chieng Ngam HPP with a dam site in Xang village and Power House in Chao village. From upstream along the Nam Muoi stream, there are stoplogs made by local residents for irrigating purposes, mainly used in dry season and when the flow velocity is small. The catchment is divided into two areas: the first one is from Taten mountain to Binh Thuan (with an area of 100km2), the second one is from Binh Thuan to Power House (with an area of 298km2) as an surface flow. Hydrology characteristics are shown in the table below: Hydrology Characteristics of the Catchment TABLE 1 No River - Site Catch. Length Length of Width of River Area of river catchment catchment (kmn2) (km) (kin) (km) Spillway (Xang village) 297 29.2 22 13.5 0.0085 Nam Muoi river.___ 2 Power House (Chao 298 30.2 22 13.5 0.012 village) Nam Muoi river. 4.1.5 Minerals In general, Chieng Ngam is poor in mineral resources. The locality only has limestone and clay. Other resources are not enough for industrial purposes. The project area does not affect the exploitation of minerals. 4.2 Present Situation of Socio-economy and Pop;;lation in Chieng Ngam Chieng Ngam Commune has a natural area of 4889ha, of which there is 55ha cultivating water rice. It has a population of 3350 people with 511 households, occupying 3% of the district population. There are three ethnic groups living in the commune. They are Thai, Kho mu, and H'mong, allocating in 12 villages. Of which 10 villages are of economic region 2 and the other two are of economic region 3. There are 902 people in working ages. Thanks to the population propagating work, birthrate in the commune has been reduced to 1.5%. Lifetime expectation of people here is from 52 to 55 years old. The regional population is mainly living on agriculture. In the future, a land area of the commune will be used for litchi cultivating center. Chieng Ngam has not invested for any industrial sectors or services. There are only some spontaneous services. Average income per capita (in rice) is 240kg. Initially, living standard of population in Chieng Ngam has been increased, but poverty still exists. The percentage of tile-roofed houses is 70%. lIealthl rare service: The whole commune has a clinic center with 5 staff (1 doctor, I physician, 1 nurse, I medical orderly, and I midwife). Equipment for hospital treatment has not been supplied well. However, death rate in the commune has been reduced since the population has been treated in time to have right diagnoses and sent patients to provincial hospital if necessary. 10 Elucationi: 95% of the children at the ages from 6 to 10 attend primary classes. Chieng Ngam has maintained their education at state standard and applied compulsory education and anti-literacy in the whole commune. However, there is no kindergarten and secondary school. Schools are mainly made of bamboo trees. Commnll1icittioni system in the commune has been improved with telephone lines stretches to center of the commune. So information from district and province can be transmitted quickly to the commune. Infrastruicture: out of 12 villages, there are 6 villages have temporary motorways to the center of each vi'lage. It is still necessary to have support from upper authorized levels to be upgraded. Thanks to the program of pure water supported by the United State, 30 six-cubic-meter water tanks and 11 three-cubic-meter tanks have been provided for the commune. In addition, in remote villages, people have used water in wells and from mountains. Irrigation system: With the support from 925 Program, several irrigating channels and 330m of steel traps were made in combination with other existing works to supply water for 55/55 ha of rice of the commune. The commune has a head office to govern all activities in the area. 4.3 Present situation of project site. 4.3.1 Present Coniditiont of Hydro-engineering Work Chieng NIgam hydropower project consists of following items: Dam, canal intake, diversion canal, surge tank, penstock and powerhouse. The plant was first come into operation in 1991. Up to now, many items have been degraded, causing unsafe condition for the operating. By investigating and evaluating the present situation of the plant, the needed rehabilitated and upgraded items are as follows: 4.3.1.1 Dam The dam is built of masonry stones with h a height of 5.5m and crest length of 24m. The dam has a stable structure and it is safe for the operation of the plant. There is much sedimentation in the upstream of the dam, affecting hydraulic regime of the spillway. Both of the dam slopes are not strengthened so they have been sliced. In the future, the dam can be sliced more, leading to the unsafe condition of itself. 4.3.1.2 Initakes, Diversionz Canal, Masoniiy Stone Siurge Tank In general, the stability of Intakes, Diversion Canal, and Masonry Stone Surge Tank ensurc tile nor-mal operation of the plant. The waterproof cement mortar layer of the above-mentioned works has been damaged, causing instability in many places along the canal as well as losses in capacity, head, etc. This situation has caused the reduction of power generating capacity. 4.3.1.3 Canal Inilet Valve Hotuse an1d Peis lock Inlet Valve House - Inlet Valve House and Penstock Inlet Valve House have been degraded; and cement mortar layers of both inside and outside walls have been damaged. Windows, doors of the valve house have been degraded and damaged, too. 4.3.1.4 Penstock - The steel penstock has a diameter of D = 1,2m; length of 360m. There are supporting anchors and poles arranged along the penstock. Steel structure, anchors and supporting poles are still stable; there is no sign of instability (subsidence; slice; etc,). - Penstock foundation is built of stones, cement mortar connecting stones with each other has been damaged; surface water can absorb through the stone layer, creating erosion inside the foundation. That is in. danger and can cause deformation and sliding and unsafe condition for the plant. - Rehabilitating alternative: cement mortar lines connecting the paving stones should be lined tightly and casted with a 10cm thichness of D100 concrete along the penstock foundation. 4.3.1.5 Power House - The open-air part cr the powerhouse has a concrete structure, with reinforced concrete roofs and brick built surrounding walls. Cement mortar layers of both inside and outside walls have been damaged. Windows, doors of the valve house have been degraded and damaged, too. - The powerhouse has no heatproof or waterproof material, so this condition affects much to the health of operating workers and the stability as well as appearance of the plant. 12 4.3.1.6 Administration anid Acconinmodlation of the Plant 's staff - The administration and accommodation area is on the riglht side of the powerhouse, including one office, two family houses and one collective house. - The plan of the area is narrow and not good in environmental and appearance terms. These houses and offices were built in previous construction period and have been repaired many times. They are now in bad condition so that the living and working conditions here are affected much. 4.3.1. 7 Infrastructutre - Access Road System: Access road system of the station is 7640m long, from the T-junction with Son La - Quynh Nhai inter-provincial road to the ground yard of the plant. - Structures of the road surfaces have been degraded; many drainage trenches have been damaged and water spills over the road surface; therefore, it is difficult for pedestrians and vehicles to travel along such road. * Water Supplying System There is no water supplying system in the area of administration and accommodation. Water for living purpose is taken from river and stream so that it is not disinfected and not sanitized; therefore it is not good for the health of the plant's staff. 4.3.2 Present Con(lition of the Plant Surface - The surface of the accommodation and office areas are narrow and do not meet the looking demand with shortage of equipment. - Infrastructure: The access road to powerhouse is 7.64km. Structure of road surface has been degraded; it is difficult for traffic. There has not been any water supply system. On the other hand, drainage system has been degraded and damaged. In some areas, wastewater flows over road surfaces; and drainage trenches are filled with soil and sand. 4.3.3 Present Condition of th.e-35kVtranismission linle - The 35kV transmission line from. Son La to the Plant has a length of 47km. Type of cable is AC35, which has been degraded. Foundations of 13 many towers are not stable C )ugh, so it is dangcroLus for local residents who live near the transmnissi line and such towers. 4.3.4 Hydraulic Mechaniical Equipiment All the equipment, such as turbine, turbine valve, dewatering pump system and auxiliary equipment systeni are too old and backward; there are stained and rusty parts, that can not b, suitable with the design. Only generator is working in normal condition. 4.3.5 Hydro-eiigineering Equtipuiient Canal Inlet, Penstock, Machinery Crane, Joints, and Lifters have been stained. However, they are still working in normal condition. The Crane cannot operate because the pulley drive is stuck. 4.3.6 Electric Eq. p>ment Electric system in the Plant consists of two Units Gl and G2, Transforner, 6.3kV voltage equipment, Control and Protection Cubicles, and AC and DC auxiliary electric power supplying cubicles. Equipment was installed asynchronously and they were all first brought into operation in 1987. Such equipment has been old and backward, cannot meet the demand on the stability, sensibility, accuracy, safety and reliability. They should be replaced with the new ones. 4.4 Activities to Rehabilitate and Upgrade Chieng Ngam Hydropower Plant. - Strengthen degraded hydro-engineering items (diversion canal, penstock foundation and outlet canal). - Rehabilitate and upgrade the plan of the powerhouse area, office and accommodation areas. - Upgrade the plant's infrastructure: Rehabilitate the 7.6km long access road. Construct water supply systern for operating and managing office area. - Replace all broken and degraded hydraulic, hydro-engineering, and electrical equipmenit witli new ones. - Rehabilitate the 47km long 35kV transmission line. Details are sliown in Table I 14 Table 1 No Work item I Equipment ........... ....................... . ... ....... ..... 1........ ... .... .. .I ..- ...... .-... .............. . ................ ....... ........... ..... ....... .. .. ... ..-.. . ............. .... .... . .. .... .... ...... .......... - - .............. . ... . . ..... ... . ............ .... Hydro-nmechanical equipnienl: Replacement of two completed sets of turbine (excluding governors and turbinie inlet valve); overhauling of 02 generators. Hydro-mnechlanical eqtuipmjient: Design one more coarse trash rack in the Intake; repairing of the whole pulley drive to operate the canal inlet gate and penstock inlet gate. Electrical equipment: Rehabilitatinig of voltage electrical equipment for generators, distributing equipment, control, automatic, signal, protection, measuring systems; and cable, lighting, ventilation, and communication systems; Rehabilitating of the 47km long 35kV transmission line. 2 Construction - Strengthening of upper slope of the spillway, strengthening and waterproofing for diversion canal, strengthening of penstock foundation and downstream outlet canal. - Canal Inlet Valve House and Penstock Inlet Valve House: removal of the old cemert mortar layers and plastering with new ones. Replacement of all doors and windows. - Powerhouse: Paving inside and outside of walls with white baked-clay bricks; paving floors with granite. Replacement of all doors and windows with timber and glass framed panel ones. Heat-proofing and water-proofing by covering the roofs with iron sheets and steel beams. Making new wall between control room and machinery hall with glass and aluminum frames. Rehabilitating of the ground yard of the plant. - Administration and accommodation area: Rehabilitating of accommodation area and constructing of new administration houses. 3 Infrastructure - Constructing of a new water supplying system. - Access road: Constructing of 6 drainage trenches; and rehabilitating of road surfaces with 12cm asphalt and macadam layer. 15 MAIN QUANTIT Y OF THE REHABILITATION AND UPGRADE WORK Table 2 No Items Unit Quantity I Excavation, soil m3 8558.0 2 Filling, soil m3 4500.0 ............ .... .............................. .. ....... ... ...... .... ........ ....... . . ............ ....... I ........ . ... .......... . ............... ......... . ....... ..... .. ........ ... ..... .... ............. 3 Construction, stone m3 1590.0 4 Plastering, cement mortar m2 6550.0 5 Concrete m3 422.2 6 Doors and windows m2 191.0 7 Paving floor, bricks m2 490.0 .................... ........ ........ ... ............... ............. ....... ....... -....... ... . ........................ -..... ....... . . .......... ... .... ... .... . ............ . ........ .. . .. .... ... ....... .... . .... ...... -- - 8 Roofing, AUSTNAM iron sheets m2 480.0 9 Replacement of conductors; km 47.0 supplementation of steel poles ... ........ .. .... ... . .......... ......... . .. .... ............... .............. .. .... . ... .. ...... . .. _.... ........ . ... . . ................... .... ... .. .... 10 Paving wall m2 1570.0 16 5 ENVIRONMENTAL ISSUES 5.1 Matters msenitioned (luriing rehabilitatinig desigin period 5.1.1 Land conisumzptiont issue The rehabilitation and upgrade project will not occupy more regional land. However, if the project is not implemented, annually, sedimentation will continue to rise and it will affect 1.5ha of water rice in the upstream. 5.1.2 Eco-Systein The rehabilitation and upgrade project will be implemented in a modest area (only carried out inside the old plant). No land will be occupied for the project, so there will be no negative impact on the eco-system. Inside the project area there are no valuable animals living. 5.1.3 Climate The implementation of project doesn't cause any negative impacts to the meteorology, but it will improve the biological system in the area after the project being implemented. 5.1.4 WYater Supply Substances that can pollute water are: waste water from the staff areas, water used for maintenance and periodical reparation of machines, water from rain and solid wastes such as oil cleaning dusts, rubbish, papers and nylon bags etc...This quantity of waste is inconsiderable to Chieng Ngam hydropower plant as it is collected and treated to prevent the pollution of the water. 5.1.5 Agricultutre The implement of project doesn't cause any negative impacts to the agriculture. On the other hand, when the production of electricity is stable the demand on electricity for agriculture will be more ensured. 5.1.6 Irrigationi As well as in agriculture, irrigation activities shall be ran more effectively when electricity to be stably supplied. 5.1. 7 Eniergy 17 Energy of the hydlopower plant is cican without waste gas and pollution. The purpose of implementing the rehabilitation and upgrade project is to have a plant with stable production capacity. Chieng Ngam is equipped with two horizontal units; each has a capacity of 950kW with a net head of 82.82m. At present, annual average energy production of the plant is 10*106kWh. After being rehabilitated and upgraded, the number will increase to 13.96*106kWh.Using this energy resource can reduce a considerable quantity of waste to the environment in comparison with using coal. This is typical characteristic of hydropower plants. However, stop operating every three month according to design for periodical rehabilitation and upgrade shall loss a certain quantity of energy, therefore it is necessary to reasonably arranged time of stop operating for the plant. 5.1.8 Minierals, Ildustry and Small Scale Indutstry Industries always require stable electric supplying. Every electric fault will cause the serious loss. Rehabilitation and upgrade of the plant is an important factor to improve the quality of electric supplying. This project completely does not obstruct to these industries. On the other hand, it is a positive factor for speeding up the regional development. 5.2 Issues Mentioned During Implementing the Rehabilitation and Upgrade Project 5.2.1 Construction Materials and Solidl Waste Discharging Construction materials and solid waste are collected to the waste yard in forest, brushes far from the people resident and treated to keep the hygiene of the environment. 5.2.2 Noise Since the volume of work, number of machines and equipment is not much, and the capacity is small and in addition the site is far from the residential area, noise impacts to the regional inhabitants is inconsiderable. 5.2.3 Imipactfronm Worker's campintg Number of worker for the rehabilitation is about 30 - 40 people. In this time plant is temporary closed so plan of the plant shall be used for the camp to reduce the tree cutting down, and the negative impact to the vegetation debris in area. 18 5.2.4 Labour Safety In order to ensure the labour safety, all units participating in the project construction shouild be well prepared in safety condition, with safety working clothes and tools. Labour safety activities of each worker should be regularly checked. It is necessary to work in conform to the labour safety regulation. 5.2.5 PCBs lisposal anid m(antageentt Althoughi the existing cquipment is manufactured before 1977, it has been found that the transformers do not contain PCBs and therefore no specific management or disposal plan for PCBs will be required 19 6 MITIGATION MEASURES FOR NEGATIVE ENVIRONMENTAL IMPACT FROM TIIE PROJECT - Power Company I is responsible for selecting of design alternative and suitable method of construction; preparing the operating process for the plant in accordance with requirement on environmental protection with monitoring plan. - Construction Schedule should be set so reasonably that the plant can stop operating for rehabilitating and upgrading in dry seasons so that electric energy loss is minimized. - While the plant stops operating for rehabilitating and upgrading, the loss of electric energy is about 1.8 million kWh, therefore it should be informed in advance to Electricity of Son La to prepare electric supplying for daily consumption. - Arrange replacing jobs for workers during the stop working time to ensure the their life and for their family. - Arrange camps reasonably to limit the negative impact to the vegetation debris in area. - Waste discharged from the construction work should be collected to waste yard and treated well to keep environmental hygiene. 20 7 EVALUAT'ION OF THIE IREPLACING ALTERNATIVES The purpose of the project is to rehabilitate and upgrade stable electricity together with national grid so that it can supply for regions far from the load center. The feasibility replacing alternatives in this situation shall be as follows: - Replace with a diesel power supply Alternative to replace with a local diesel power supply: this alternative can be quickly but it has some disadvantages: high cost and pollution of the surrounding environment. - Supplement with electric power generated from the national grid. Alternative to supplement with electric power generated from the national grid can be implemented since we already have the electric power grid. However, there is still no supplemented power supply since the electricity generated to the nation grid is limited to the increasing load demand. This alternative would not have major environmental impacts. Some very minor impacts could be as tree cutting and construction of tower pads leading to an increased soil erosion. - Construction some new small hydropower station in the area. To construct some new small hydropower stations in the area will take long time and may occupy land or may resettle residents in the project area, etc. with high costs. Hence, it is feasible to carry out the rehabilitation and upgrade project in this period. Time of implementing this project is short, investment cost for it is limit and the project does not cause environmental pollution. (Details are shown in Table 1). 21 8 ENVIRONMENTAL MANAGEMENT PLAN 2.1 Mitigation Measures for Negative Impacts Construction work in the rehabilitation and upgrade includes soil and rock excavation, concrete casting, rock built, brick paving, plastering, roofing, installing and dissembling of equipment; and renewing road surfaces, etc,... - Soil and rock excavation, plastering, rock built, brick paving, roofing will be carried out by executing. - Concrete casting is carried out by machine in combination with manual ways. - Installing and dissembling of electrical and hydro-mechanical equipment is carried out by manual ways in combination with using winch and crane in the plant. The construction site and local material exploitation area (for sand, stone and gravel) is in Chieng Ngam commune, Thuan Chau district. Concrete, steel, timber, etc, are supplied from Thuan Chau town, 20km far from the site. According to Table 1, we can see that quantity of material to be transported is not much: about 330m2 of cement and dozens of tons of other materials. Transporting distance is short, only 20km, so it is possible to transport the above-mentioned materials in weekends or in the time transportation density is little. Therefore, it will reduce traffic jam. Negative impacts from the transportation of material from Thuan Chau to the construction site are inconsiderable. Quantity of exploiting material (sand, stone, gravel) is not much: 4,000m3 of stones and gravel; other 8,500m3 will be exploited in the site area, so there are no impacts to local environment and eco-system. The transportation of material is carried out in a small area where there are not many residents living in, so it does not affects people's health. Installation work in the project is: dissembling of needed replacing equipment and installing new equipment. Material and equipment are easy to dissemble so arranging and collecting such material and equipment is easy, too. Collecting oil and grease when dissembling eq uipment, such as governor and turbine, so that it can limit the environmental pollution. 22 Electricity of Son La is responsible to arrange work and support in finance for labour force of the plant while irmplernenting the project. Labour force of the plant is supposed to arrange as follows: - Participating in the Project management board. - Participating in some other work of the project. - Having siuitable work in offices of the electricity of Son La. - Stop working and having allowance (as agreed) Making a list of the affected households, planning suitable electricity supplying plan to maintain quantity and quality of electricity supplying so as not to affect households who are using electricity supplied by Chieng Ngam HPP. Taking seriously the labour safety supervision, especially to workers who are carrying out complicated workL so as to reduce working accidents. Special measures to ensure the dam stability will be applied, based on the available technical design data and additional checking of the technical features 8.2 Environmental Monitoring - The Environmental monitoring and management should be carried out regularly. The project has a small reservoir and modest site area, affects to the environment is not much, so it is not necessary to have specialized officials to supervise and manage this kind of work. The environmental monitoring and management of the mitigation measures can be carried out regularly by the existing staff of the Plant to improve their experience and to have treatment timely (Such staff should be trained in specialization). - Contents of the monitoring and supervising work during the rehabilitation and operation are specified in Table 3 and 4 in the annex part. - Dam safety will be monitored 8.3 Action Plan and Cost Estimation 8.3.1 Rehabilitation and Upgrade Plan Time for implementing the project is 01 year. Total Cost for the project is VND 22,242,319 thousand (Details are shown in "Feasibility Study Report"). 23 8.3.2 ELiiviro,imienital Maniagemiientt Plani As stated above, an engineer who is responsible for operatinig will be employed to supervise the environment management plan during implementing the project as well as in long term. Details are shown in Table 3 and 4 Total cost for the whole environmental management plan is MVND 187; details as foliows: I . Cost for training management and operation staff: VND 10,000,000 2,000,000 VND/person x 5 persons 2. Cost for supervision, checking and implementation for VND 60,000,000 environment protection measures during construction phase ': 3. Annual Cost for supervision, checking and VND 100,000,000 implementation for environment protection measures2 4,000,000 VND/y x 25 years Subtotal VND170,000,000 4. Contingency: 10% (1 +2+3) VND 17,000,000 Total VND 187,000,000 Total (by USD, Ex.rate: USD1 = 15000 VND) USD 12,467 1 Environment costs during construction consist of: - Salary of 4 officers in 12 months will be used to pay for supervisors who do extra work (apa.' from working in their specialized aspects): 1,000,000 x x 12 = 48,000,000 VND - Cost for taking and having water samples analyzed: VND2,000,000 - Costs for travel, stationary, equipment: VND 10,000,000 (MVND 0O) 2 Environment costs during operation: - Annual mnonitoring of environment and water measuring and analyzing over 25 years is: VND 50,000,000 (MVND 50). - Cost for officers of the plant to work as environment supervisors to monitor environmental issues over 25 years is: VND 50,000,000 (MVND 50) 24 The Environment Impact Assessment Report on the Rehabilitation and Upgrade Project of Chieng Ngam Hydropower Project in Son La Province has been reviewed by the Department of Science, Technology and Environment of Son La Province. The Review report concluded that the project does not have any negative impacts on the natural environment and local socio-economy, and the project is supported to be implemented (see the report in the annex part). 25 A - MITIGATING PLAN TABLE 3 Cost Institutional Responsibility Phase Issue Mitigating Measure Installation Operating Installation Operi Suitable construction plan, included in tender document of Included in the cost Contractor for Electricity of Flow obstruction INone construction an-d SnL construction and installation parts for construction installation Son La Construction Suitable construction plan, tight construction supervision; Included in the cost None Contractor for Electricity of material, waste suitable tanks for waste collecting. for construction .. construction and Son La Noise No influence, far from residential areas None None affected vegetable Tight monitoring, supplying sufficient woodltimber for None Itcluded in Contractor ior Electricity of O cover construction. construction installation Son la coveContractor for --- Included in the cost Cotatrfr Electricity of D Camps Suitably arranged with WC area as regulated. for i None construction and Sni La F ~~~~~~~~~~~~~~~ ~ ~ ~~~~~ ~~for constr-uctlo ntalton Son La _ _._ _ _.__ _ _ _ _ _ _ _ _ _ _.._ _ _______.____..__ _ _ _ _ _ . . . . . . _ _ _ _ . . . .. _ _ _ _ _.. ...._._...._ _ _ _ . . . . in stallatio n.........i. . Z .. ...Included --in.Contractor. .fo. O Labo Safe Instruction about labour safety, supplying sufficient labour Included in the cost Included in construction and Electricity of UT LabourSafety safety tools and equipment for construction t ti nstlti Son la Resettlement No influence because there is no residential inundated area None None Deforestation There are only hills with grass and bushes in the project None None construction o Electricity of area. Tight management of tree cutting . installation on a I Included in the Electricity of~~~~~~~~~~nstllaio Dam safety Safety measure to ensure the stability of the dam onstructlon cost None Constructor Electricity of 26 TABLE 3 (continue) Cost Institutional Responsibility Phase Issue Mitigating Measure. Phase Iss_e Mitigating Measure Installation / Operating Installation / Operating Inconsiderable because the weir is low with a height of 4m. None None NA Electricity of Flow obstruction Son La Waste (oil, grease) Check, collect and treat timely Included in Included in Electcity of ectcty of from Construction the operation the operation Son La Eetiiyo material ~~~~ ~ ~~~~~~~~~~~~~~cost cost Son La rnaterial ... .. ....s _ _ _. Noise No influence, far from residential area None None NA Tree cutting, None None Included in NA Electricity of O affected vegetable the operation Son La E cover ____ cost nok ~ + \ ~ + ~' 9 \ //' | G EN ERA L LAYO U T ' , . / // Scale: A / / | 0 9 2 % 3 c n \ \ - ////// // 00 tz~~~~~~~~~~~~~/ / , 9 9 v s / * Road to Ban,, Song- ± - ~ 7 d0t \ < _ tf - + F ' _ => ' < / 4 ' ; y~~~~~~~~~/ j 4/ 7 0 /~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i- 11\nprovlng va 4 Q / /veh moprovou adm ai e 73500+ + \ t\ ±'V x + + +~ v1 -+ I 75500 7S000 I 77500 LEGENDE: NOTE: i (' Powerhouse oCanl 1.Thisdrawingisestablistedbasingoncontructiondrawing Scale A 0.0 '0 100 150 200m Penstock '9 Surface water drain of Chieng Ngam hydropower and factual situation.I ®t Basin $> Spillway 2. DimensIons are in cm, elevations are in m. (1OutLet iQi Intake ?OWER ENGrNEESNGCOL¶JII1NGCOMPANY N01 CHIENG NSAM HYDROPOWER STATION (, 35Kv substation *IRi Masonry dam IMPrOovEMENT R Administrationhouse @ Reservoir CHEN nGAM 1IJv GENERAL LAYOUT X ma. rrx2nager NgLuy&5 rdh Son | 3Checkeby HoMritHbo F/S |6/2f1 |37 - 01 - 01TH - 01 - _esigned by NQ. Trpng cu_ng W j~~~~~~~N ' ^ ' w~~~~~~~~~~~~' id osw-- * -, . ;- *-, -~a II' ~ , Chiengngam.Hydropower plan Chiengngam Hydropower plan