Performance Evaluation of Water Supply Services in Developing Country: A Case Study of Ahmedabad City

S.M. Yadav,N. P. Singh,Kalpana A. Shah,Jigar H. Gamit 대한토목학회 2014 KSCE Journal of Civil Engineering Vol.18 No.7

Unplanned and rapid growth of urban areas of developing countries poses major threat to service providers. Water supply management becomes critical aspect in the above scenario. The onus of managing its supply and distribution rests on the local government of the concerned area. Ahmedabad being world’s third largest and India’s fastest growing city has been selected for analysis of water supply services. Performance evaluation of water supply services for Ahmedabad city was carried out using nine performance indicators suggested by Ministry of Urban Development (MOUD), Government of India. The nine performance indicators as suggested by MOUD are: coverage of water supply connection, per capita supply of water, extent of metering of water connections, extent of non revenue water, continuity of water supply, quality of water supplied, efficiency in redressal of customer complaints, cost recovery of water supply services and efficiency in collection of water supplied related charges. Required data was collected from Ahmedabad Municipal Corporation. Analysis of the data suggests that among all the indicators of supply of water, cost recovery in water supply services, efficiency in redressal of customer complaints, quality of water supplied and efficiency in collection of water supply related charges showed good performance. However, metering of connection, continuity of water supply and non revenue water needs planned efforts to bring them up to the benchmark.

Geo-microbial and geochemical evidences in the near surface soils of Jamnagar sub-basin, Saurashtra, Gujarat, India: implications to hydrocarbon resource potential

Mohammed A. Rasheed,M. Lakshmi,M.S. Kalpana,P.L.S. Rao,D.J. Patil,V. Sudarshan,A.M. Dayal 한국지질과학협의회 2012 Geosciences Journal Vol.16 No.4

The Jamnagar sub-basin of Saurashtra, Gujarat is considered geologically prospective for hydrocarbons by Directorate General of Hydrocarbons (DGH), India. However the major part of the Jamnagar sub-basin is covered by Deccan Traps, hindering the exploration of Mesozoic hydrocarbon targets. In India, significant hydrocarbon finding in the stratigraphic sequence has not been established, as the major part of the Mesozoic sediments is underlying the Deccan Traps. Detection and mapping of the Mesozoic sediments below the Deccan Trap has been a long-standing complex geophysical problem facing the oil industry. The vast sheet of volcanic cover, which overlies the Mesozoic sediments acts as a geophysical shield and inhibit the effective use of conventional seismic techniques. Surface geochemical techniques based on hydrocarbon microseepage from subsurface accumulations, have potential to evaluate the prospects for petroleum exploration. In view of this, surface geochemical survey for adsorbed soil gas and microbial analysis was conducted in Jamnagar sub-basin, total 150 near surface soil samples were collected for the evaluation of hydrocarbon resource potential of the Basin. Microbial analysis revealed high bacteria counts for methane (1.32×106 cfu/gm), ethane (8.50× 105 cfu/gm), propane (6.86×105 cfu/gm) and butane oxidizing bacteria (5.70×105 cfu/gm) in soil samples of Jamnagar sub-basin. The bacterial concentration distribution maps show three distinct anomalies in the study area, indicating hydrocarbon microseepage at these places. The geochemical investigations in soil samples showed the presence of high adsorbed hydrocarbon gases concentration of methane (C1) 1 to 518 ppb and Ethane plus hydrocarbons (C2+) 1 to 977 ppb respectively. Further, carrying out integrated geo-microbial and geo-chemical studies with adsorbed soil gas showed the anomalous hydrocarbon zones nearby Khandera, Haripur, and Laloi areas which could probably aid to assess the true potential of the Basin. On the basis of microbial prospecting and adsorbed soil gas studies Jamnagar sub-basin study area appears to be a warm zone for hydrocarbon prospects and needs detailed investigation with other geo-scientific methods. Integrated geophysical studies have shown that Jamnagar sub-basin of Saurashtra has significant sediment thickness below the Deccan Traps and can be considered for future hydrocarbon exploration. The corroboration of adsorbed light gaseous hydrocarbons and hydrocarbon oxidizing bacteria suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons.

The microbial activity in development of hydrocarbon microseepage: an indicator for oil and gas exploration

Mohammed A. Rasheed,M. Lakshmi,M.S. Kalpana,A.M. Dayal,D.J. Patil 한국지질과학협의회 2013 Geosciences Journal Vol.17 No.3

Geomicrobial prospecting for hydrocarbons is an exploration method based on the seepage of lighter hydrocarbons from oil/gas reservoirs to the surface and their utilization by hydrocarbon oxidizing bacteria. These bacteria utilize the hydrocarbons as their sole source of food and are found to be enriched in the near surface soils/sediments above the oil and gas reservoirs. The detection of anomalous populations of hydrocarbon utilizing bacteria in the surface soils can help to evaluate the prospects for hydrocarbon exploration. Geomicrobial prospecting studies have been carried out to test the efficacy of surface geochemical methods as regional evaluation tools in the petroliferous region of Mehsana Block, North Cambay Basin, Gujarat and to investigate whether the geomicrobial anomalies can establish an upward migration of hydrocarbons from the deep subsurface. In the present study, bacterial counts for n-pentane utilizing bacteria range between 1.0×102 and 9.80×105 cfu/g and and n-hexane utilizing bacteria range between 1.0×102 and 9.20×105 cfu/g. The bacterial concentration distribution maps show four distinct anomalies in the study area. The possibility of discovering oil or gas reservoirs using the microbiological method is emphasized by the fact that the hydrocarbon oxidizing bacteria range between 103 and 106 cfu/g in soil/sediment receiving hydrocarbon microseepages. In the present study area of the Mehsana Block of Cambay Basin, n-pentane and n-hexane utilizing bacteria show 105 cfu/g of soil sample, which is significant and thereby substantiates the seepage of lighter hydrocarbons from oil and gas reservoirs. Geomicrobial prospecting method has shown good correlation with existing oil/ gas fields of Mehsana, Gujarat.

Evidence for a relationship between hydrocarbon microseepage and trace metal anomalies: an implication for petroleum exploration

Todupunuri Madhavi,Munnuru S. Kalpana,Dattatray J. Patil,Anurodh M. Dayal 한국지질과학협의회 2011 Geosciences Journal Vol.15 No.2

The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/gas fields of Mehsana block, North Cambay basin, India. The ranges of adsorbed soil gas concentrations of Methane, Ethane, Propane, i-Butane and n-Butane are found to vary from 1–402 ppb, 1–135 ppb, 1–70 ppb, 1–9 ppb, 1–18 ppb respectively, suggesting the presence of hydrocarbons and microseepage associated with the study area. The carbon isotopic signature of methane ranged from –29.5 to –43.0‰ (PDB) and ethane from –19.1 to –20.9‰ (PDB), indicating a thermogenic source of hydrocarbons. The absence of any significant correlation of Total Organic Carbon (TOC) and Total Inorganic Carbon (TIC) (r = 0.1 and 0.5 respectively) content with hydrocarbons in soil samples demonstrates the catagenetic origin of the desorbed gases. The Trace metal concentrations varied in the following manner: Ni: 49–155 ppm, V: 67–158 ppm, Cu: 29–82 ppm, Zn: 64–327 ppm, Ba: 241–554 ppm and Sr: 118–892 ppm. These high concentrations of trace metals which are more than their respective average concentrations generally found in soils are indicative of hydrocarbon induced alterations in the area. The low Eh values observed in anomalous hydrocarbon bearing soil samples compared to non anomalous samples in the area, could be attributed to the reducing conditions created by the hydrocarbon seepage from subsurface and might have influenced the trace metal solubilities which is reflected in their increased concentrations. Trace metal anomalies are seen haloed to adsorbed soil gas anomalies (∑C_(2+)) indicating that the major generative depressions of oil and /or gas fields of Sobhasan / Linch in the study area promoted vertical migration of hydrocarbon microbubbles which in turn facilitated trace metal deposition in the surface soils. By using integrated method approach, the weak signal of oil and gas reservoirs could be amplified in the frontier areas and the uncertainity of the vertical correlation of surface anomalies could be reduced

Multiscale Modeling of Swelling Clays: A Computational and Experimental Approach

Dinesh R. Katti,Mohamed I. Matar,Kalpana S. Katti,Priyanthi M. Amarasinghe 대한토목학회 2009 KSCE Journal of Civil Engineering Vol.13 No.4

Expansive clays such as montmorillonite cause severe distress to infrastructure due to swelling. The swelling of montmorillonite clay is also the basis for its use in many commercial applications such as drilling muds in petroleum engineering, as landfill liners in environmental engineering and in making polymer clay nanocomposites. The focus of this work is to carry out a systematic experimental and numerical study to understand and model behavior of Na-montmorillonite at molecular and particulate level to find mechanism of swelling in the Na-montmorillonite interlayer. Experimental results show breakdown of particles with an increase in swelling of the clay. This phenomenon was numerically studied by developing a modified Discrete Element Method (DEM) model that incorporates the latest developments in both clay and computer science, and can simulate particle subdivision. DEM results show the role of particle subdivision on swelling and swelling pressure. In understanding the true mechanism of swelling, it is essential to incorporate the interactions between clay molecular structure and the interlayer water molecules. For bridging the length scales, we have also evaluated the stress deformation response of the clay molecular structure using Molecular Dynamic (MD) simulations. Simulation results show that the deformation in the clay molecular structure due to external stress is mostly due to deformation of the water molecules in the clay interlayer. A new experimental technique which enables us to capture the molecular changes in the clay molecular structure upon hydration is also developed. This work provides a foundation for multiscale modeling of swelling clays. Expansive clays such as montmorillonite cause severe distress to infrastructure due to swelling. The swelling of montmorillonite clay is also the basis for its use in many commercial applications such as drilling muds in petroleum engineering, as landfill liners in environmental engineering and in making polymer clay nanocomposites. The focus of this work is to carry out a systematic experimental and numerical study to understand and model behavior of Na-montmorillonite at molecular and particulate level to find mechanism of swelling in the Na-montmorillonite interlayer. Experimental results show breakdown of particles with an increase in swelling of the clay. This phenomenon was numerically studied by developing a modified Discrete Element Method (DEM) model that incorporates the latest developments in both clay and computer science, and can simulate particle subdivision. DEM results show the role of particle subdivision on swelling and swelling pressure. In understanding the true mechanism of swelling, it is essential to incorporate the interactions between clay molecular structure and the interlayer water molecules. For bridging the length scales, we have also evaluated the stress deformation response of the clay molecular structure using Molecular Dynamic (MD) simulations. Simulation results show that the deformation in the clay molecular structure due to external stress is mostly due to deformation of the water molecules in the clay interlayer. A new experimental technique which enables us to capture the molecular changes in the clay molecular structure upon hydration is also developed. This work provides a foundation for multiscale modeling of swelling clays.