RECONSTRUCTION OF WATER SUPPLY SYSTEM OF TOWN MASIS AND NEARBY 4 VILLAGES YEREVAN, REPUBLIC OF ARMENIA ENVIRONMENTAL SCREENING REPORT 2012 Reconstruction of water supply system of town Masis & nearby 4 villages Yerevan, Republic of Armenia Table of Content ENVIRONMENTAL SCREENING .............................................................................................. 3 1.1 Scope of work ................................................................................................................ 3 1.2 Brief description of the operating water supply and wastewater system ................................. 4 1.2.1 External water supply system .................................................................................... 4 1.2.2 Water supply distribution network ............................................................................. 5 1.2.3 Wastewater system .................................................................................................. 6 1.3 Geographical location and climate of the residential areas ................................................... 6 1.4 Environmental screening ................................................................................................. 7 1.5 Environmental impact ..................................................................................................... 8 Reconstruction of water supply system of town Masis & nearby 4 villages Yerevan, Republic of Armenia ENVIRONMENTAL SCREENING 1.1 Scope of work The goal of this project is improvement of drinking water supply to town Masis and villages Ayntap, Marmarashen, Darbnik, Dashtavan, Arbat, Hayanist and Azatashen. To achieve this goal works in two directions are planned under the preliminary design: improvement of external water supply system improvement of the internal networks of the settlements. The external system improvement works include: improvement of sanitary zones of 4 flowing artesian wells, repair of well houses, replacement of technological elements and installation of water meters, repair of the store part of the new Masis PS building and improvement of the area, reconstruction of the sanitary zone of the Kharberd DRRs, replacement of the DRRs’ covers, SAFs and manholes, diking the reservoirs, as well as repair of the dry chamber with replacement of technological elements and construction of water metering node, replacement of about 2.5km long emergency segment of the water main supplying Masis town, lay a new about 1.4km long water pipeline from Kharberd DRRs to village Ayntap, constructing a new 0.9km long polyethylene pipeline to take the inlet line of village Hayanist out of the residential area of village Darbnik, constructing about 0.94km long new inlet line to take the water main supplying village Khachpar out from green houses and privatized lands. The works for renovation of the internal water supply networks of the settlements include: Construction of water lines of distribution network, Construction of water metering nodes of the customers and inlet lines of private houses, Construction of fire hydrants, Construction of buried valve nodes, Construction of water supply chambers. As a result of the project implementation it is planned to provide drinking water supply to the above mentioned settlements and improve water distribution and metering systems. Reconstruction of water supply system of town Masis & nearby 4 villages Yerevan, Republic of Armenia 1.2 Brief description of the operating water supply and wastewater system 1.2.1 External water supply system Water supply to town Masis and 7 villages of the region is carried out from the new pumping station constructed within the area of Araratyan I and II stage pumping station, which in its turn receives water from artesian wells at 6.0km distance (with total discharge of about 500l/s). From the artesian wells water is supplied to a general collecting water main through which water is supplied by gravity to the reservoir constructed nearby the new pumping station, where chlorination takes place. All of the operating 4 artesian wells are in poor condition, buildings are in emergency situation, all valves need replacement, sanitary zones are missing or in a sad condition. Figure 1. Sanitary protection zones of artesian wells Masis I, II stage pump station is newly built, the pumps are new. On each of the water mains emerging from the PS electromagnetic flow meters are installed. Only the PS area needs improvement. Kharberd two DRRs are located at 915.0m altitude, upward village Kharberd. The DRRs cover an area of about 1.5 ha, with its borders stretching at 900.0÷910.0m altitudes. The area is fenced and is in a good condition. The general condition of the DRR structures can be considered satisfactory. Only the cover, manholes and SAFs need replacement. The DRRs are partially diked; in some of the open segments of walls concrete is destroyed and reinforcement is corroded’ soil-vegetative layer on the DRRs is 15-20cm thick (see Fig. 9). The pipes supplying the DRRS is in a normal condition The dry chamber of the DRRs is in a normal condition; however all the valves and pipes need replacement. The distribution node also needs repair. Norabats DRR is newly built. Within its area there is a new pump station with 3 pumps. Reconstruction of water supply system of town Masis & nearby 4 villages Yerevan, Republic of Armenia Presently almost entire town Masis receives water from Kharberd DRRs , except Kayaran district, water supply to which is implemented from the pressure pipeline from Masis newly built PS to Norabats DRR. The beginning part of the water main supplying town Masis from Kharberd DRRs has been reconstructed; the remaining 2.5km segment of the water main is in emergency condition (see Fig. 13). Water supply to village Ayntap is implemented through the water main from Masis PS to Norabats DRRs (about 15l/s), Kharberd DRRs and a water main belonging to YerevanDjur CJSC. Water supply to villages Arbat and Azatashen is implemented from the pressure pipeline of Norabats DRRs. Water supply to villages Hayanist, Dashtavan and Darbnik is implemented from the gravity pipeline of Norabats DRRs. Water supply to village Marmarashen is implemented from Kharberd DRRs. 1.2.2 Water supply distribution network Water supply distribution network of Masis town is about 25km, implemented from 50-200mm metallic and polyethylene pipes, around 11.0km long segment of which has been replaced with new pipes. The non-repaired part of the network is in a sad condition and it is impossible to provide sufficient pressures. The main reason of the network deterioration is of its being implemented of metal pipes. And since the groundwater table is high throughout the area of town Masis, the corrosive influence of groundwater favors prompt deterioration of metallic pipes. The network of the rural residential areas is mainly implemented from cast iron, steel and polyethylene pipes. Though within the ADB funded “Water and Sanitation Project” some water lines were reconstructed and constructed, inlet lines of private houses were replaced in villages Ayntap, Arbat, Dashtavan and Marmarashen, there are still problems needing solution. The distribution network water lines in villages Hayanist, Azatashen and Darbnik are in a sad condition, which causes frequent breaks and leakage in the network. The distribution network of Arbat village is implemented from steel and polyethylene pipes. As a result of the project implemented in Arbat, the condition of the distribution network has improved, but still there are problems requiring solution. Reconstruction of water supply system of town Masis & nearby 4 villages Yerevan, Republic of Armenia 1.2.3 Wastewater system The operating wastewater system of town Masis is about 34km long, implemented from 150- 800mm cast iron, concrete and asbestos pipes. The wastewater network is in a poor condition The villages have not wastewater systems. 1.3 Geographical location and climate of the residential areas Town Masis and villages Ayntap, Marmarashen, Darbnik, Dashtavan, Arbat, Hayanist and Azatashen are located in north-west part of Ararat marz. Masis town is at 20km distance from Yerevan. The villages are located at 5 to 15km distance from Masis. Town Masis and villages Ayntap, Marmarashen, Darbnik, Dashtavan, Arbat, Hayanist and Azatashen are located at altitudes of 828.0÷895.0m. According to the data received from Masis Municipality and the villages’ administrations the total number of population is about 45978. The region has dry, continental climate with cold winters and hot summers. Absolute maximum air temperature is 40°C. Absolute minimum air temperature is -30°C. Annual precipitation us 306mm, north and north-eastern winds of 3.0m/sec velocity predominate here. During 20 years winds of 28m/sec velocity are possible, Snow cover thickness reaches 450cm, pressure – 70kg/m2. Maximum land freezing depth is 70cm. From geomorphologic point of view the region is located within lacustrine-cumulative Ararat valley, in its central part. The surface is flat, with slight south-east gradient to rivers Araks and Vedi. The main occupation of the population in the region is agriculture. The lands are mainly irrigated, therefore a dense irrigation network is constructed here both through pipelines and mains. According to archive documentation and detailed study of the region, the following layers take part in its geological-lithologic section: – Soil-vegetative layer with clay sand and loamy soil composition, rarely with