STUDY AREA
4.2 PHYSICAL RESOURCE
4.1 Introduction:
CHAPTER-4
Probable Discharge Point From N. Gonj to downstream Laklya, Tejgaon to Balu Turag khal to up stream Balu.
Ghorasal to Lakhya
N. Gonj to down stream Lakhya, Tejgaon to Balu, Tongi to up-steam Balu Tejgaon to Balu Tongi to Balu Type of Pollutants
Oil, grease, chlorinated Hydrocarbons acids, alkalis, HZs. CN, Cr, Cd, Ni, Cu, Zn, Ag
Acid mists, vapourts Metal and lime sludges.
Cr, Pb, Cu, Cd, organic, solvents, Cyanides Organic solvents, Packing materials (rejected paint cans)
Alkali, CI. Dyes, organic matter, detergents, N,P,SS
SMP, yam, cloth, packing Materials, ink waste
Organic matter, 55, NH], color, Zn, Hg, Sox, particulate matters, Wastewater sludge, ash, bark wood waste, paper etc.
H2S04, H)P04, HF, fluorides, phosphates, NH, NH4- , salts, Amins, CH3-0H, HZs, SPM, fluorides, CH3, HZ, S, Ash, gypsum
Wastewater Gaseous emission Solid waste Wastewater Gaseous emission Solid waste Type of Emission Wastewater Gaseous emission Solid waste Wastewater Gaseous emission
Solid waste Wastewater Gaseous emission Solid waste Industries
Electroplating Industries
Paint Industries
4.2.1 Surface Water Quality:
Fertilizer Industries
ENVIRONMENTAL IMPACT ASSESSMENT
Paper and Pulp Industry Textile Industries (Dying &Printing)
Table 4.1: Examples of some Polluting Industries around Balu and Lakhya River Surface run-off include the pollution load run-off due to all human and other related concerns such as domestic, industrial, agricultural and other related activities. The river Sitalakhya is mainly used for navigation purposes. Regarding pollution load concern, Sitalakhya River receives discharges from all the industries situated up and down stream (Table 4.1) which include Textile, Jute Mills, Soap Industries, Pulp and Paper Mills's etc.
A few of them have some effective treatment plant. Besides the industrial pollution, the domestic effluent is also discharged into the Lakhya. Engine boat and shipping activities are also added considerable source of pollution to the river in terms of oil and grease.
Tongi to Balu
Wastewater
Gaseous emission Solid waste
Jan Feb Nbr Pfx Nby June July AJg
Month
12 10 8 6 4 2
o
::::
C)E c:
c o
m
Fig 4.1: Variation of BOD of Sitalakhya River with time (Source: DOE, 1985)
Pesticides and Insecticides Industries
Acids, organic solvents, Cn,
CI, phenolic compounds, Pb, Cu, As, Hg, C12. Organic solvents, acid Vapours Package materials, filter dust sludge
(Source: DWASA (2000); Fourth Dhaka Water Supply Project, EIA interim report.)
A vast disposal site also exists in the Matuail mouza. The disposal usually has done in the khals. The uncontrolled dumping of solid wastes at Matuail could severely affect both surface water and ground water in the project area. The input of high strength organic leachate and inorganic solutions of metals in a reduced state of oxidation into a water course can deplete the oxygen content of the water and ultimately will result in extinction of all oxygen dependent life. The over all surface water quality is not up to the mark
because of industrial pollution, which is due to the urbanization. The degree of impact due to the urbanization has been considered -5.
4.2.2 Ground water Quality:
The quantity and quality of water are the most important consideration in selecting any source of supply. Cost considerations involving the development and operation of water supply are also significant. The quantity of water obtainable from any source should be sufficient to cater to the needs of the towns or city, regarding domestic service, industrial demands, fire-extinguishing requirements and other public uses. The water quality should be wholesome, safe and free from all sources of pollution and contamination. The quality of ground water in DND area is comparatively better. This is due to the fact that the water gets stained during its passage through the pOrous underground strata. The bacterial content of deep tube wells is generally low due to the straining action involved. In a wide term, ground water is good in quantity but may require some treatments to improve its chemical characteristics. The analysis of water supplies is the prime criteria for determining the quality of ground water of a particular area. Water in DND area of Dhaka City were collected (1992) for analysis. Twenty-six parameters were determined to find out suitability for drinking pUrPose and contamination. The results indicated that the water samples were free from any contamination in terms of chemical point of view.
Table 4.2: Analytical results of water samples from Deep Tube wells around project area
Chemical. Unit Jatrabari Derma
Parameter
TDS mgll 121 196
pH at 20 degree 6.4 6.5
EC mSlcm 190 300
Calcium mgll 18.0 28.5
Magnesium mgll 3.7 8.7
Sodium mg/l 25.0 40.5
Potassium mg II 1.3 1.8
Iron mg/l 0.11 0.11
Lead mg II 0.12 0.13
Zinc mg II 0.12 0.10
Manganese mg/l 0.15 0.12
Cadmium mg/l Nil Nil
Nichel mg/l Nil Nil
Copper mg!1 Nil Nil
Chromium mg!1 Nil Nil
Aluminium mg!l Nil Nil
Boron mg!1 0.20 0.26
Bicarbonate mg!1 20.5 29.8
Carbonate mg!1 Nil Nil
Nitrate mg!l 15.5 12.8
Chloride mgt! 16.1 34.2
Sulphate mg!l 15.1 30.5 .
Fluoride mg!1 Nil Nil
Phosphate mg!1 0.01 0.02
Permanganate 1.8 2.21
Index
Ammonia-Nitrogen mg!1 0.20 0.26
(Source: Journal of the Asiatic society of Bangladesh Vol: 24, No-I, June 1998; Test period: 1992-94 (March-May))
The degree of impact has been considered as +3.
4.2.3 Air &Noise Pollution
Air Pollution:
Air quality data around the project site is not available, as there is no provision for monitoring air quality in the area. But during site visit it was observed that the ambient air quality in regards to SPM of the area is very dusty near the industrial locations. The roadside area always receives dust due to vehicular uses. The low lying and other areas found to be non-hazard in this regard. People of Matuail area always receiving fowl smell from the DCC dumping station at Matuai!' Several gases are generated within the landfill.
The principal gases are Carbon Dioxide, Methane, Nitrogen etc and occasionally Hydrogen Sulfide. Concentration of Methane in the atmosphere between 5% and 15% are explosive. The continuing source of complaints is the additional traffic generated by the landfill, heavy truck and oversized waste disposal vehicles give rise to nuisance from noise, vibration, exhaust emission, dust, dirt and visual intrusion. Objectionable odors are coming out near the working face from the normal incoming refuse. Since soil cover is not provided, strong odors are dissipating around the area and intolerable nuisance and
environmental havoc to passer and local community. The degree of impact has been considered as -2.
Noise Pollution:
According to the survey (RAJUK, 2001) it is found that 37.1 percent people of Matuail;
27.4 percent of Jatrabari have complained about sound pollution within the mauza. The degree of impact has been considered as -2.
4.2.4 Soil Quality:
Annual flooding in the rainy season in the low land areas brings with them fertile soil made up of organic matters and they benefit crops in the dry season. Farmers will be encouraged to grow HYV because there will be no flooding in the farmland any more. It will lead to more use of chemical fertilizer since the growth of HYV and the use of fertilizers are inseparable. This situation may contribute to the deterioration of soil quality. However, this effect is expected to be insignificant in consideration to the reduced agricultural land use in future due to the urbanization. The degree of impact has been considered as + I.
4.2.5 Climate: The climate of the area is that of Dhaka which lies in the subtropical, high rainfall, humid belt with three distinct reasons: pre"monsoon, monsoon and post monsoon. The monsoon season is normally from May to October. Average temperature varies from about 20.C in December-January to about 30.C in March. The mean annual rainfall is 2037mm. A small portion of this area is evaporated and the infiltration rate is very low due to over consolidation of the less permeable Madhupur Clay on the top of underlying aquifer Dhupi Tila sand bed. Evaporation is the lowest in November and highest in August and most of the rainwater drains out to the surrounding rivers.
Impact measurement is considered as zero.
4.2.6 Hydrology: The project area is affected by internal and external flood. External floods are caused in the low area by over flow of surrounding river and khal, while internal floods are caused by storm water due to rainfall and insufficient drainage facilities.
Hydrology of the project area greatly influenced by Balu River located outside the project area and their tributaries. Water levels of these rivers/khals are lowest in January- February and highest in August-September. Normally the low area of the project is submerged by over flowing of Balu River during August-September.
Excessive local rainfall sometimes causes flood in the low area damaging properties. The annual average rainfall in the project area is about 2037mm. High area of the project was flood free during 1988 flood. Low area of the project remains under water in most of the time of the year.
Storm water from the high area discharges into the low lying area through over flow and natural drain and drainage of the low lying area normally occurs through Balu and Sitalakhya river. Dholai khal also plays role in the drainage system of the project area.
The natural drainage system of the project area is being obstructed due to land filling activities for housing development.
In the project area ground water is met at depth 5 meter to 9 meter below the surface and the seasonal fluctuation of the ground water table ranges from 0.5 meter to 2.50 meter.
Measurement of impact is considered as zero.