Industrial activities including infrastructure and other associated developmental activities, which are concentrated in certain zones especially to the south-eastern quadrant of Nakkavagu basin. Consequently, physical, chemical and biological nature of surface environment was altered. In this work it has been tried to assess the impacts of such developmental activities on physical, biological, socio-economic and cultural, and water environments in Nakkavagu basin. Mainly based on the principles of Environmental Impact Assessment (EIA) and broadly on Strategic Environmental Assessment (SEA).
The Patancheru township and the main industrial area lies around 78 0 15’ East longitude and 17 0 32’ North latitude in Medak District of Andhra Pradesh. Patancheru industrial area in this context implies Patancheru, Bollaram, Pashamylaram, Khazipalli, Gaddapotharam, Bonthapalli and Chitkul industrial clusters, which are located in Nakkavagu basin. Nakkavagu basin extending over 734 sq. kms, lies between the longitudes 78 0 05‘ and 78 0 25‘ East and the latitudes 17 0 25‘ and 17 0 45‘ North. Nakkavagu (a stream) and its tributaries drain Nakkavagu basin. Nakkavagu basin is the sub-basin of Manjira River basin, which in turn is the sub-basin of Godavari River basin. Industrialisation in Patancheru area has devastated the environment of Nakkavagu basin, which has about 300 industries. The present work is an integrated and multidisciplinary approach towards assessing the impact of water pollution and to some extent other kinds of pollution on Nakkavagu basin.
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 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.
In the physical environment geology, topography, soils, climate and meteorology, and air of a region influences the mobility, dispersion and concentration of pollutants.
Granitic terrain of Nakkavagu basin being acidic in nature does not buffer the acidic waters directly released by industries. Joints and fractures in the granites act as conduits for wider dispersion. 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. It is possible that some of the pollutants identified in water and soil samples are contributed by the geology of the area.
Effluents flow all the way across the basin, which increases the residence time for the toxicants; therefore residence time of pollutants is more in the basin. Slope of the basin is in the NW direction, while most of the industries are located in the south-east quarter of the basin. The establishment of industries and other ancillary structures have also resulted in change in the topography of Nakkavagu basin.
The black cotton soils are polluted as they adsorb large amounts of hazardous elements. Salt incrustations in the soils adjacent to Nakkavagu are common which effect the growth of flora. The mining of sand along Nakkavagu also results in easy movement of pollutants further into new areas along Nakkavagu.
The high temperature conditions and evaporation rates resulted in increase of concentration of the pollutants in the effluents. 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.
The gases such as methyl mercaptan released from industries in Nakkavagu basin was detected recently in the heart of the city. This indicates that other harmful gases also do reach the City, which would add up to the existing air pollution problems. The use of several tonnes of volatile organic compounds (VOCs) such as like Benzene, Toluene etc. are also hazardous to the people.
Pollution in the region had drastically reduced the incidence of natural species and are restricted to few pockets. The species such as prosopis juliflora is seen in more numbers in all the highly polluted parts of the basin. Pollution also affected the agricultural sector in parts of Nakkavagu basin.
There is no appreciable wild fauna in the region, as the percentage of forest cover is very less. Many domestic animals were effected by diseases and many died this led to direct economic losses to the farmers. Appearance of birds, resident and migratory, is decreasing drastically. Aerial fauna got effected the most due to pollution of water bodies such as streams and tanks. Manjira wild life sanctuary an ecologically sensitive area is well within 25 to 30 kms of the industrial area.
The socio-economic and cultural environment of Nakkavagu basin would get effected, covered in Patancheru, R.C.Puram, Jinnaram and Sangareddy Mandals. Patancheru is less developed in comparison to R.C.Puram because of water pollution and obnoxious smell. Female ratio per 1000 males is less for Patancheru and other three Mandals as bachelors immigrated from elsewhere, for working in the industries at the cost of local population.
The villages considered as highly affected are located close to the industrial areas and the polluted streams, are 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 most of these 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 sensitive to pollution. As literacy and the educated local population is small 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 have no safe drinking water and in some villages inadequate water supply is available. The domestic animals such as cattle and sheep, upon drinking the polluted waters either got effected or died. 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.
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.
In the south-east and southern part of the basin the irrigated crops are yielding low and or the whole crop dyeing due to pollution of tanks and wells. 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 a 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.
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.
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 tanks such as Isnapur tank, Peddacheruvu, Saka cheruvu, Krishnareddipet tank etc., in the south and south-eastern part of the basin which receives highly polluted water are acting as solar evaporation ponds thereby increasing the residence time of the pollutants in the 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. The use of tonnes of such chemicals in the production is 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. These industries are using organic and inorganic hazardous chemicals, release of such chemicals during the process are hazardous to the life in Nakkavagu basin.
The two CETPs, which were established in Patancheru and Bollaram, to treat the effluents of member industries, are in fact became major contributors for 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.
In general the quality of effluents in Nakkavagu are deteriorating as observed over a period of time. 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 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.
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.
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’. 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).
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 entering into 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.
Evaluation of the impacts with and without industries is done finally choosing 36 parameters. Parameter importance weights (PIW) were given were given to represent the value of importance of each environmental parameter. In the absence of industries too there ought to be changes in the environment, mainly because of four factors: The growing population in Nakkavagu basin and associated developmental activities like housing, road networks and other services. The modernisation of agriculture (increasing use of chemical pesticides and fertilisers). Influence of growing Hyderabad City and the expansion of the city along NH-9 axis. Affect of NH-9, pollution by vehicles, increase in number of vehicles, etc.
The impact assessment studies of this area indicate that there is 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%. The differences show that there is a limited advantage for human interest. Finally the results produced using this modified methodology is an exercise to quantify the environmental degradation. The results should be viewed seriously otherwise the basin would further becomes unsuitable for any kind of activities.