Environmental impact may be defined as any changes of environmental conditions or creation of a new set of environmental conditions, adverse or beneficial, caused or induced by the action or set of actions under considerations.
Environmental impacts can be of three types as, primary, secondary and tertiary. Primary impacts are the result of direct actions and, secondary and tertiary impacts are indirectly induced and typically include the associated investment and changed patterns of social and economic activities by the proposed action.
All the impacts have been comprehensively assessed or discussed in this section. Many of the impacts were covered in detail in the previous chapters.
7.2 PHYSICAL ENVIRONMENT
a) Granitic terrain of Nakkavagu basin being acidic in nature does not buffer the acidic waters directly released by industries.
b) Joints and fractures in the granites act as conduits for carrying the effluents to far off places.
c) Deep well disposal practice in Nakkavagu basin is not recommendable. As Nakkavagu basin is located over hard rock area (Peninsular granites and gneisses), effluents do not have any chance to penetrate deep into the ground, and get restricted to shallow zones. With the result, groundwater of the area gets polluted.
d) It is possible that some of the pollutants identified in water and soil samples are contributed by the geology of the area. It can be seen that pH of some of the surface water bodies is acidic, which leaches and helps in movement of certain elements. These elements get deposited under favourable conditions.
Slope of the basin is in the north-west direction, while most of the industries are located in the south-eastern quarter of the basin. Consequently, effluents flow all the way across the basin. This increases the residence time for the toxicants. Increase in residence time of effluents leads to spread of pollution in the basin, covering a larger area.
The construction of industries and other ancillary structures has resulted in change in the topography of the area mainly in the south-eastern quadrant of Nakkavagu basin where majority of the industries are located.
a) Black cotton soils are predominantly rich in clay content (up to 50 percent), and are less permeable. They hinder percolation of effluents entering into groundwater.
b) Clay of brick making grade that is available at Patancheru is also a hindrance for the percolation of pollutants. The clay also adsorbs some of the hazardous elements.
c) Industrial pollution had degraded the soil quality, as can be seen in Figure 7.1.
d) The salts dissolved and deposited in the valleys resulted in salt incrustations in the soils adjacent to Nakkavagu. Saline soils lead to relatively poor germination and leads to physiological drought, thereby effecting the growth of the plants.
e) The polluted and non-productive fields are being used for the mining of sand (recent alluvium along the banks of Nakkavagu), and the clay of brick making grade for the construction industry had resulted in loss of top fertile soil and presently these fields are turned into badlands.
f) The mining of sand along Nakkavagu also results in easy movement of pollutants further into new areas along Nakkavagu.
7.2.4 Climate and Meteorology
Temperature conditions and evaporation rates are relatively high in tropical climatic conditions. Such a condition results in concentration of the pollutants in the effluents. Concentrated effluents are more toxic than diluted effluents. Similarly as this area receives just about 80cms of annual rainfall the dilution factor is very less. The problem of formation of salt incrustations increases in areas with high temperature and less rainfall. And also the residence time of pollutants would have been less in case of areas with high rainfall, as the pollutants would be flushed out with the rainwater.
Wind speed and direction is important in understanding the impacts of air pollution. The Pre-monsoon south-eastern winds in the evenings have an impact on the residents of Hyderabad. The winter winds, which move in the eastern and south-eastern direction mostly, are the most hazardous to the residents of Hyderabad. In October (23rd and 24th) and November (15th), 1998, the gas such as methyl mercaptan (it is a heavy gas and it is easily detectable even in miniscule amounts) was released by one of the three industries in Nakkavagu basin, reached as far as Jubilee hills and Panjagutta in Hyderabad. This gas which is easily detectable was the cause of annoyance and protest by the public (Venkateshwarulu, 1998). The hazardous gases released by the industries and which cannot be detected by human beings would have an impact on the health of population residing in north-western part of Hyderabad. The heavy gases would accumulate in the narrow and valley like parts of the city, especially during the winters, as the air would be cool and heavy. This would be part of the usual smog and mist observed during the winters. As the annual wind patterns are rare in the southern and south-western directions the rural people are relatively safer as compared to the larger population residing in Hyderabad to the east and south-east.
Due to heavy air pollution, acid rains are possible. However, air pollution from NOx, and SO2 is not a major threat presently to the resident population in the area. But there is another threat from the Volatile Organic Compounds (VOCs) like Benzene, Toluene etc., as these chemicals are being used in large quantities in the industries. Absence of forests and other vegetation coverage, the problem of particulate matter is high especially in Patancheru.
7.3 BIOLOGICAL ENVIRONMENT
The region has a rich bio-diversity of plant species, meeting the needs of the people in different ways for the past several centuries. People are well aware of the use of this invaluable resource. However, pollution in the region had drastically reduced the incidence of natural species. Due to the presence of polluted waters, soil and air, under the new environmental conditions, many plant species are reduced to few numbers and are limited to few pockets. The resistant species such as prosopis juliflora is seen in more numbers in all the highly polluted parts of the basin, in the industrial areas, and all along the polluted Isukavagu, Pamulavagu and Nakkavagu. Industrial pollution also affected the agriculture sector in parts of Nakkavagu basin. This relationship is shown in Figure 7.2.
There is very little wild fauna in the region, as the percentage of forest cover is very less, and presently appears in pockets only. The major threat is to existing fauna, mainly domestic animals, and birds. The impact of pollution on domestic animals such as disease and death lead to direct economic losses to the farmers. Appearance of birds, resident and migratory, is decreasing drastically. In fact, even the sparrows are seen in less numbers in the area. The perennial water tanks located to the south and south-eastern part of the basin, where the majority of Industries are located. The industrial effluents entering into such tanks made the water toxic, has impact on the aquatic life, which in turn affects the aquatic birds.
Manjira wild life sanctuary is located close to this region; majority of the industries in Nakkavagu basin are well within 25 to 30 kms of this sanctuary. As per the environmental guidelines for industries (Singh, 1994), all the polluting industries located well within 25 kms from the ecologically sensitive areas which includes Sanctuaries should be shifted to safer distance. Birds not constrained by geographical barriers, birds visiting this sanctuary would also visit Nakkavagu basin wherein they are likely to be exposed to various kinds of pollutants.
7.3.3 Flora and Fauna of Surface waters
The surface waters include the tanks and streams of Nakkavagu basin. The impacts are mainly due to the pollutants released by industries into the surface water bodies. Isukavagu, Nakkavagu and Manjira River (after the confluence of Nakkavagu) do not support any significant life. Similarly Khazipally cheru, Gandigudem cheru, Krishnareddipet cheru, Mukta kunta, Bollaram cheru, Khazipalli village cheru, Saka cheru, Isnapur cheru and Chitkul cheru are the most polluted and support very little aquatic life. Whereas Nagula cheru, Aminpur cheru, Mutangi cheru and Lakdaram cheru, and Manjira River before confluence with Nakkavagu are less polluted, hence they support good number of aquatic species (Table 3.3).
7.4 Socio-Economic and Cultural Environment
For the socio-economic and cultural environment impact assessments Patancheru, R.C.Puram, Jinnaram and Sangareddy Mandals are considered in which Nakkavagu basin exists.
Because of the proximity to Hyderabad, industrial development and the passing of N.H-9 are the factors responsible for the development of R.C.Puram and Patancheru. One of the reasons for less development of Patancheru in comparison to R.C.Puram is because of water pollution and obnoxious smell. Female ratio per 1000 males is less for Patancheru and other three Mandals as single bachelors immigrated from elsewhere, for working in the industries at the cost of local population.
The population structure of most polluted villages, which are located close to the industrial areas and the polluted streams such as Ismailkhanpet, Arutla, Chidruppa, Bythole, Eardanoor, Indrakaran, Lakdaram, Chinnakanjerla, Peddakanjerla, Sultanpur, Krishnareddipet, Indresham, Inole, Bachuguda, Chitkul, Isnapur, Kardanoor, Muttangi, Pocharam, Khazipalli and Bollaram. The percentage of rural population is around 80% in a number of villages, which means not many people are taken in jobs in spite of industrialisation. Only around 20% of the population is literate that reduces the job opportunities. Around 20% of the population being below 6 years of age are the sensitive to pollution.
As the literates and the educated local population is low in comparison to the large number of educated people in a city like Hyderabad which is located in the suburbs, local people are getting less employment opportunities.
Many of the polluted villages in Nakkavagu basin along polluted streams have no safe drinking water supply. In 1997 High Court passed an interim order in the Public Interest Litigation (Justice Sudershan Reddy (W.P.No. 26336) dated 5.7.97), asking the government to provide and continue water supply to the pollution affected villages in and around Patancheru and Bollaram industrial areas. The villages include Kalabgur, Kandi, Rudraram, Isnapur, Chitkul, Muttangi, Pocharam, Patancheru and Ramachandrapuram. The domestic animals such as cattle and sheep, upon drinking the polluted waters either got effected and some of them died in many instances. Moreover the crops grown in such a polluted environment could be phyto-toxic. Therefore the polluted water, air and food would have an adverse impact on the lives of people and other life in Nakkavagu basin. The present Public Health Centers (PHCs) and veterinary services provided by Government are inadequate.
7.4.4 Land – use
Increase in the fallow lands and less percentage of net sown area in Patancheru, Sangareddy, Jinnaram and R.C.Puram Mandals can be related to the developmental activities and the pollution of environment by industries.
Many farmers have shifted to dryland farming where the surface and groundwater sources are polluted. Some of the farmers are leaving their fields fallow even up to 20% as in case of Pocharam and Bachuguda villages.
The polluted tanks and the wells to the south-eastern and southern part of the basin and the wells along Nakkavagu rendered water unfit for irrigation, either the crop yields would be very low or occassionally the whole crop would wither and die. The pollution of water and soil has an adverse impact on the majority of local population still dependent on agriculture especially would affect the majority of marginal farmers.
Industrialisation did not help the local people in getting alternative employment opportunities because of the more competitive people in Hyderabad. Therefore there is large-scale migration of `skilled’ people into this region. As the residential areas are located towards Hyderabad away from the industrial area because of polluted environment in Patancheru area and other disadvantages of services. As a result the indirect employment opportunities are less therefore the multiplier economic benefits are also less (Figure 7.3).
7.4.7 Cultural Properties
The relicts of cultural and other heritage sites existing in and around Patancheru area were neglected due to industrialisation. Innumerable ancient sculptures, engravings etc., found in the region have been abandoned and are never taken care of nor reported to the Archaeology department.
7.5 WATER ENVIRONMENT
7.5.1 Nakkavagu Basin
126.96.36.199 Drainage System
The drainage system of Nakkavagu was altered through many centuries by the interference of human activities, like the construction of tanks and channels etc., and also with the recent developmental activities especially in the south-eastern quadrant of the basin. The drainage system is altered and obstructed, therefore these kinds of activities will act against the free flow of pollutants, and hence the residence time of pollutants in the basin increases.
The presence of water storage tanks in the south and south-eastern part of the basin are acting as solar evaporation ponds for the pollutants entering them for example Isnapur tank, Peddacheruvu, Saka cheruvu, Krishnareddipet tank etc. As these tanks are located on non-permeable rocky area. The excellent water harvesting and storage facilities constructed in Nakkavagu basin are acting like traps against the free flow of pollutants thereby increasing the residence time of the pollutants in the basin.
7.5.2 Industrial Pollution in Nakkavagu Basin
Majority of the industries located in Nakkavagu basin are the bulk-drug or pharmaceutical industries. Some of the chemical compounds which are used as raw material in the production of drugs are Acetone, Acetyl chloride, Ammonia, Aniline, Benzene, Bromine, Chlorine, Chlorosulphonic acid, Dimethylcaromyl, Dioxane, Ethylene dichloride, Formaldehyde, Hexane, Hydrochloric acid, Maleic anhydride, Methylene chloride, Nitrobenzene, Nitrogen dioxide, Nitrogen oxides, Phenol, Phenyl glycidal ether, Sodium cyanide, Sulphuric acid, Thionyl chloride, Toluene, Triethylamine etc. Tonnes of such chemicals are used in the production are hazardous. In a case study of 10 such industries on an average about 4.3 times of hazardous raw material is utilised for every unit of the product produced (Table 5.1). These industries are using organic and inorganic hazardous chemicals which when released in the process are hazardous to the life in Nakkavagu basin.
188.8.131.52 Common Effluent Treatment Plants (CETPs)
The two CETPs, which were established in Patancheru and Bollaram, to treat the effluents of member industries, are the major contributors of water pollution in Nakkavagu basin. The effluents released by CETP-Patancheru are toxic and hazardous, as the effluents are only partially treated. The sludge that is derived as waste product in the treatment process of both the CETPs has no place for secure disposal, which is again a potential source for water contamination. Therefore CETPs which are industries by themselves are the major contributors of water pollution in Nakkavagu basin.
7.5.3 Surface water
The ranges of pollutants found in the water environment of Nakkavagu basin are shown in Table 7.1.
184.108.40.206 Flowing waters
In general the quality of effluents in Nakkavagu are deteriorating as observed over a period of time (Table 5.8).
The Nakkavagu and Pamulavagu waters are alkaline. TDS, TH, TSS, COD, BOD, SO4, Pb, Hg, As and Se are found to be high in the samples collected from, Nakkavagu, Pamulavagu and CETP. CETP is releasing the effluents with very high concentration of all the above parameters and including Cd, Zn, Cu, B, Mn, Cr and Fe. These waters are not fit for releasing into the inland surface waters (Table 7.1).
TDS, COD, and BOD of the effluents of Nakkavagu are only partially reduced over a distance of about 22kms. As the chances of dilution in Nakkavagu is less as the rainfall in this region is about 80cms only. Therefore Nakkavagu mainly acts as an influent stream, which contaminates the groundwater on either side of the stream.
In rainy season, the level of pollution in Nakkavagu is supposed to be low, considering the factors of dilution. However, contrary to this belief, the early or first monsoon showers also add to pollution of Nakkavagu. Leachets from solid waste dumps enter into Nakkavagu stream. Salts from salt incrustations in the soil and or other precipitates would directly or indirectly reach Nakkavagu. Some of the pollutants may enter Nakkavagu by accident or illegal release of effluents from `solar evaporation ponds’. They usually overflow, since they remain uncovered and get filled by rainwater, and also there will be little evaporation because of cloud cover during monsoons. In spite of dilution it was observed during the peak of rainy season (1997) a particular paddy field irrigated from Nakkavagu waters at Ismailkhanpet Bridge turned brown and withered. However after heavy rains in the later part of rainy season the levels of pollution in Nakkavagu are less, because of dilution. Therefore nowhere and at no time of the year Nakkavagu is fit for irrigation right from Kardanoor village to the confluence point at Gaudcherla (about 25 kms stretch).
Tanks were built for conserving water and recharging groundwater. But now they have become a hindrance to free flow of pollutants in the basin. As a result the residence time of the pollutants increased, causing damage to the environment and ecology in Nakkavagu basin. Industrial effluents polluted many tanks located in different villages on Pamulavagu tributaries; they are Khazipally cheru, Gandigudem cheru, Krishnareddipet cheru, Mukta kunta, Bollaram cheru and Khazipalli village cheru. Some tanks located on the tributaries of Nakkavagu are also polluted such as Saka cheruvu, Isnapur and Peddacheruvu. The tanks in isolation and away from industrial areas are less polluted and some are best preserved, they are Nagula cheru, Aminpur cheru, Mutangi cheru and Lakdaram cheru. Almost all the major tanks of Nakkavagu basin are located to the south-eastern quadrant of the basin, as the industries are also located in the same region, therefore majority of the tanks are polluted by the industrial effluents released into them. These polluted tanks have become secondary sources of pollution of streams, tanks and the groundwater.
Groundwater is polluted on either side of the Nakkavagu and the waters are not useful for drinking. TDS, COD, BOD, Cl, and Hg are found to be high in the groundwater samples collected at Pocharam, Ganapathiguda and Bachuguda villages. Openwells, which are close to Nakkavagu, are highly contaminated in comparison to the borewells.
The pollutants also contaminated the drinking water sources of the following villages: Baithole, Baithole Tanda, Lakdaram, Sultanpur, Inole, Chitkul, Arutla, Chidruppa, Ismailkhanpet, Peddakanjerla, Kardanoor, Eardanoor and Eardanoor Tanda. Some of the pollutants such as F, Mn could have been partially entered into borewells through deep fractures and also the pollutants such as NO2 and NO3 could have been the result of use of nitrogen fertilisers by farmers. Overall the groundwater is contaminated, up to a distance of 500 to 1000 meters on either side of Nakkavagu, from Kardanoor to Ismailkhanpet.
7.6 ASSESSMENT OF ENVIRONMENTAL IMPACTS ON NAKKAVAGU BASIN WITH AND WITHOUT INDUSTRIES
This is an exercise to quantify the impacts based on the checklist developed by the Environmental Evaluation System (EES) at the Batelle Columbus Laboratories, USA (Dee et al, 1973) is used with some modifications, for final evaluation of impacts with and without industries. In this assessment 36 parameters are selected (Figure 1.5). Parameter Importance Weights (PIW) represent the value of importance of each environmental parameter. The weights have been given to the 36 environmental parameters based on the degree of impact caused by the establishment of industries and associated developmental activities over the last 40 years (industrialisation started in Nakkavagu basin about 40 years back). Similarly the weights were given assessing the degree of alteration of environmental parameters that would have happened over the last 40 years, even without industries in Nakkavagu basin.
Impact assessment is a comparative exercise. In the absence of industries too there ought to be changes in the environment, mainly because of four factors:
a) The growing population in Nakkavagu basin and associated developmental activities like housing, road networks and other services.
b) The modernisation of agriculture (increasing use of chemical pesticides and fertilisers)
c) Influence of growing Hyderabad City and the expansion of the city along NH-9 axis
d) Impact of NH-9, pollution by vehicles, increase in number of vehicles etc.
The resultant weights were given to all parameters (Tables 7.2 (a), (b), (c), (d) and (e)). The difference and the total weights are also presented in the tables. The quantification of the impacts is through personal judgement after going through all methods of assessment of impacts.
The reasons for impacts without industries are comprehensively discussed below. Patancheru was traditionally an intensive agricultural zone. In comparison, there is enormous water potential in the area. Further, being nearer to Hyderabad, market plays a vital role in defining the orientation of agricultural practices. Thus, there should be a decreasing preference among the farmers to leave the lands fallow. There would have been slight change in cropping pattern from traditional crops like paddy to commercial crops. In such a situation, there would have been a corresponding increase in the consumption of pesticides and fertilisers to maximise yields. The residual chemicals lead to agricultural pollution from inorganic and organic chemicals. Natural growth of population in the region will increase pressure on the natural resources like, construction material for housing, etc. Energy consumption also increases. People dependent on firewood would deplete the existing flora in the common lands. Water, health and sanitation are also of prime concern. In the absence of industries, the community structure and participation in social and cultural activities would be strong. As it is close to Hyderabad City, some people would prefer to shift to the city for residential purpose. Vehicular traffic on the highway passing through Patancheru increase the incidence of air and noise pollution leading to adverse environmental impacts. NH-9 is one of the busiest highways.
The impact assessment studies of this area indicate that there is a considerable adverse impact on the environment. There is a two-fold increase when compared to the ratios to ‘No industries’. When viewed for ‘No industries’ it would have retained 80% of the environment unaffected. Whereas with industries, it is observed that the loss to the environment is to the extent of 60%. Overall the differences show that there is a limited advantage for human interest such as generation of jobs but the value of losses to the environment, ecology and aesthetics cannot be accounted due to the industries. The results should be viewed seriously otherwise the basin would further becomes unsuitable for any kind of activities.