American Journal of Water Resources

ISSN (Print): 2333-4797

ISSN (Online): 2333-4819

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Analysis of Groundwater in Puerto Rico

1Atmospheric Sciences Laboratory, University of Puerto Rico at Carolina, PO Box 4800, Carolina, PR 00984

2School of Natural Science and Technology, Universidad del Turabo, Gurabo, Puerto Rico, PO Box 3030, Gurabo, PR 00725

3School of Science and Technology, Universidad del Este, Carolina, Puerto Rico Carr. #190 km 1.8 Carolina, PR 00983

American Journal of Water Resources. 2016, 4(3), 68-76
doi: 10.12691/ajwr-4-3-3
Copyright © 2016 Science and Education Publishing

Cite this paper:
Méndez Tejeda Rafael, Richards Ronald T., Emiliano Anastacio. Analysis of Groundwater in Puerto Rico. American Journal of Water Resources. 2016; 4(3):68-76. doi: 10.12691/ajwr-4-3-3.

Correspondence to: Méndez  Tejeda Rafael, Atmospheric Sciences Laboratory, University of Puerto Rico at Carolina, PO Box 4800, Carolina, PR 00984. Email:


During rainfall events, the aquifers in Puerto Rico capture a small fraction of the rainfall and sometimes can store it for years. Organic pollutants are degraded over time by microbial and chemical processes. The shorter the travel time between raindrop and aquifer recharge the greater is the risk of contamination. Existing data from non-pumping observation wells have been used to identify three areas at risk from superficial contamination. High-risk areas have a high correlation between depth-to-water and temperature or respond quickly to rainfall events. The high-risk areas are in Florida and in the adjoining municipality of Quebradrillas/Camuy and Manatí/Vega Baja. It is proposed that production wells in the high-risk areas be instrumented to measure the rainfall and the temperature and specific conductance of the pumped water and the rainwater. The hypothesis of this proposed experiment is that in the high-risk areas the water pumped from the production well will show a reduction of temperature and specific conductance within 24 hours of a heavy rainfall event. In this manner the travel time from rain drop to aquifer recharge can be measured. The proposed paper will provide concrete data to improve the management of groundwater resources in Puerto Rico.



[1]  Anderson MP. 2005. Heat as a Ground Water Tracer. Ground Water. 43(6): 951-968.
[2]  Bosque A. 2011. Economic valuation of groundwater remediation costs and benefits: Towards a more comprehensive approach. Unpublished doctoral dissertation Universidad del Turabo School of Science and Technology, Gurabo, PR.
[3]  Cherry GA. 2001. Simulation of flow in the upper North Coast Limestone Aquifer, Manatí-Vega Baja area, Puerto Rico. United States Geological Survey Water Resources Investigations Report 00-4266. San Juan, PR.
[4]  Colón-Torres JA. 2009. Climatología de Puerto Rico. La Editorial Universidad de Puerto Rico. San Juan, PR.
[5]  Conde-Costas C, Gómez-Gómez F. 1999, Assessment of nitrate contamination of the upper aquifer in the Manatí-Vega Baja area, Puerto Rico, U.S. Geological Survey Water-Resources Investigations Report 99-4040. San Juan, PR.
Show More References
[6]  Dumas JA. 1999. Limestone soils: Interaction with pesticides and its impact on the north coast aquifer of Puerto Rico. Unpublished doctoral dissertation. Chemistry Department, University of Puerto Rico at Río Piedras. San Juan, PR.
[7]  Ecoeléctrica. 2012. Aumentado la producción de agua en el sur. [Internet] Available on (Cited on 26 November 2012).
[8]  Doerfliger N, Jeannin PY, Zwahlen F. 1999. Water vulnerability assessment in karst environments: a new method of defining protection areas using a multiattribute approach and GIS tools (EPIK method). Environmental Geology. 39(2):165-176.
[9]  Ghasemizadeh R, Hellweger F, Butscher C, Padilla I, Vesper D, Field M, Alshawabkeh A. 2012. Review of ground water flow and transport models of karst aquifers, with particular reference to the North Coast Limestone aquifer systems of Puerto Rico. Hydrogeological Journal. 20(8):1441-1461.
[10]  Gogu RC, Dessargues A. 2000. Current trends and future challenges in groundwater vulnerability assessment using overlay and index methods. Environmental Geology 39(6):549-559.
[11]  Graves RP. 1989. Water resources of the Humacao-Naguabo area, eastern Puerto Rico, U.S. Geological Survey Water-Resources Investigations Report 87-4088. San Juan, PR.
[12]  Hoehn E, Cirpka OA. 2006. Assessing residence times of hyporheic ground water in two alluvial flood plains of the Southern Alps using water temperature and tracers. Hydrology and Earth Systems Science. 10:553-563.
[13]  Hunter JM, Arbona SI. 1995. Paradise lost: an introduction to the geography of water pollution in Puerto Rico. Journal of Society, Science, and Medicine 40(10):1331-1355.
[14]  Janssen H. 2015. Puerto Rico residents face water rationing that lasts up to 48 hours amid historic drought. [Internet] (Accessed on 8 Feb 2016).
[15]  Jones IC, Banner JL. 2003. Estimating recharge thresholds in tropical karst island aquifers: Barbados, Puerto Rico and Guam. Journal of Hydrology. 278:131-143.
[16]  Kuniansky EL, Gómez-Gómez F, Torres-Gonzáles S. 2003. Effects of aquifer development and changes in irrigation practices on ground-water availability in the Santa Isabel area, Puerto Rico. United States Geological Survey Water-Resources Investigative Report 03-4303. San Juan, PR.
[17]  Kuniansky EL, Rodríguez JM. 2010. Effects of Changes in Irrigation Practices and Agricultural Development on Ground Water Discharge to the Jobos Bay National Estuary Research Reserve near Salinas, Puerto Rico. United States Geological Survey Scientific Investigations Report 2010-5022. San Juan, PR.
[18]  Larsen MC. 2000. Analysis of 20th century rainfall and streamflow to characterize drought and water resources in Puerto Rico. Physical Geography. 21(6):494-521.
[19]  Lugo AE, Castro LM, Vale A, del Mar López T, Hernández PE, García Martinó A, Pue2nte Rolón AR, Tossas AG, McFarlane DA, Miller T, Rodríguez A, Lundberg J, Thomlinson J, Colón J, Schellekens JH, Ramos O, Helmer E. 2001. Puerto Rican karst—A vital resource. United States Forest Service General Technical Report WO-65.
[20]  Molina-Giraldo N, Bayer P, Blum P, Cirpka OA. 2011. Propagation of seasonal temperature signals into an aquifer upon bank infiltration. Ground Water 49(4):491-502.
[21]  Molina-Rivera WL. 2014. Estimated water use in Puerto Rico. US Geological Survey Open-File Report 2014-1117 35p.
[22]  Olcott PG. 1999. Groundwater atlas of the United States: Alaska, Hawaii, Puerto Rico and the United States Virgin Islands. HA 730 N. Puerto Rico and the United States Virgin Islands North Coast Limestone aquifer system. Available on (Accessed on 5 March 2016).
[23]  Osborne, ED. 1986. Acid rain in Puerto Rico. Final technical report to U.S. Department of the Interior. Project #G930-02. Grant Agreement #14-08-0001-G930. Engineering Research Center. University of Puerto Rico in Mayagüez.
[24]  Pérez-Blair F. 1996. Ground Water Resources of Alluvial Valleys in Northeastern Puerto Rico—Río Espíritu Santo to Río Demajaua Area. United States Geological Survey Water Resources Investigations Report 96-4201. San Juan, PR.
[25]  Puerto Rico Department of Health. 2005. Public Health Assessment—Pesticide Warehouse III, Palo Alto, Manati County, Puerto Rico EPA Facility ID: PRD987367299. U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry 52 p.
[26]  Puerto Rico Electric Power Authority (PREPA). 2013. [Internet] Available on (Cited on 20 August 2013).
[27]  Renken RA, Ward WC, Gill IP, Gómez-Gómez F, Rodríguez-Martínez J. 2002. Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands: U.S. Geological Survey Professional Paper 1419. Reston, VA.
[28]  Richards RT. 2003. The barometric efficiency of observation wells in Puerto Rico and the U.S. Virgin Islands. Unpublished Masters Thesis, Physics Department, University of Puerto Rico at Río Piedras. San Juan, PR.
[29]  Rodríguez JM. 1996. Characterization of stormwater discharges at the San Isidro Industrial Park, Canóvanas, Puerto Rico. U.S. Geological Survey Open-File Report 96-348. San Juan, PR.
[30]  Rodríguez JM. 1999. Characterization of stormwater discharges at the Guanajibo Industrial Park, Mayagüez, Puerto Rico, 1997-98. U.S. Geological Survey Water-Resources Investigations Report. San Juan, PR.
[31]  Rodríguez JM. 2001. Characterization of stormwater discharges from Las Flores Industrial Park, Río Grande, Puerto Rico, 1998-99. U.S. Geological Survey Open-File Report. San Juan, PR.
[32]  Rodríguez JM. 2012, Evaluation of groundwater quality and selected hydrologic conditions in the South Coast Aquifer, Santa Isabel area, Puerto Rico, 2008-09: U.S. Geological Survey Scientific Investigations Report 2012-5254. San Juan, PR.
[33]  Rodríguez-Martínez J. 1997. Characterization of springflow in the North Coast Limestone of Puerto Rico using physical, chemical, and stable isotopic methods. U.S. Geological Survey Water-Resources Investigations Report 97-4122. San Juan, PR.
[34]  Ryan M, Meiman J. 1996. An Examination of Short-Term Variations in Water Quality at a Spring in Kentucky. Ground Water 34(1): 23-30.
[35]  Sampat P. 2000. Deep trouble: The hidden threat of ground water pollution. Worldwatch Paper 154, Worldwatch Institute, Washington DC.
[36]  Torres-González A. 1985. Simulation of ground-water flow in the water table aquifer near Barceloneta, Puerto Rico. United States Geological Survey Water-Resources Investigations Report 844113. San Juan, PR.
[37]  Torres-González S, Planert M, Rodríguez JM. 1996. Hydrogeological and simulation of the ground-water flow in the upper aquifer of the Río Camuy to Río Grande de Manatí, Puerto Rico. United States Geological Survey Water Resources Investigations Report 95-4286. San Juan, PR.
[38]  Troester JW. 1999. Geochemistry and hydrogeologic framework of the saline-freshwater interface and the calculation of net recharge in the Dorado area, north-central Puerto Rico, U.S. Geological Survey Water-Resources Investigations Report 98-4030. San Juan, PR.
[39]  Tucci P, Martínez MI. 1995. Hydrology and simulation of ground-water flow in the Aguadilla to Río Camuy area, Puerto Rico. U.S. Geological Survey Water Resources Investigations Report 95-4028. San Juan, PR.
[40]  United States Census Bureau (USCB). 2014. [Internet] Available on (cited 21 March 2016).
[41]  United States Geological Survey (USGS). 2015. Groundwater Levels for Puerto Rico [Internet] Available on (Cited on 11 October 2015).
[42]  Verter V, Kara BY. 2001. A GIS-based framework for hazardous materials transport risk assessment. Risk Analysis 21(6):1109-1120.
Show Less References


Assessment of Sedimentation Status of Ruiru Reservoir, Central Kenya

1Department of Soil Water and Environmental Engineering (SWEE), Jomo Kenyatta University of Agriculture and Technology (JKUAT) Kenya

2Agricultural and Bio-system Engineering Department (ABE), Jomo Kenyatta University of Agriculture and Technology (JKUAT), Kenya

3Water Research and Resources Centre (WARREC), Jomo Kenyatta University of Agriculture and Technology (JKUAT), Kenya

4Agricultural Engineering Department, Egerton University, Kenya

American Journal of Water Resources. 2016, 4(4), 77-82
doi: 10.12691/ajwr-4-4-1
Copyright © 2016 Science and Education Publishing

Cite this paper:
Stanley K. Maloi, Joseph K. Sang, James M. Raude, Urbanus N. Mutwiwa, Bancy M. Mati, Caroline W. Maina. Assessment of Sedimentation Status of Ruiru Reservoir, Central Kenya. American Journal of Water Resources. 2016; 4(4):77-82. doi: 10.12691/ajwr-4-4-1.

Correspondence to: Stanley  K. Maloi, Department of Soil Water and Environmental Engineering (SWEE), Jomo Kenyatta University of Agriculture and Technology (JKUAT) Kenya. Email:


Reservoir sedimentation can adversely affect the storage capacity of water bodies; reduce flood attenuation, change water quality, damage valves and conduits amongst others. This study investigated sedimentation rate in Ruiru reservoir as a measure for monitoring water resource management using capacity survey method. Water depth was measured using a transducer fitted on the side of the boat which also recorded corresponding geographic positions with an inbuilt GPS receiver. About 5000 points covering approximately 36 hectare of the water surface were surveyed. A total of eleven sediment sampling points were identified in the reservoir in which five were strategically selected at location near entry from respective streams. The depth of sediments, which relate to the quantity of sediment deposition from the streams ranged between 600 mm and 2100 mm. Ruiru stream demonstrated the highest level of sediment influx into the dam while Ngeteti stream had the least. The reservoir volume was calculated to be 2,632,347m3 and estimate volume of the sediments 389,245 m3, which is a 13.1% storage capacity loss. A related recent study noted storage capacity loss of 11%, which shows that the reservoir has lost about 11-14% of its storage capacity in 65 years. Results further showed that the Area Specific Sediment Yield (ASY) was 38.84 Mg ha-1 y-1, which is higher than the tolerable soil loss of 2 to 18 Mg ha-1 y-1 for the tropics, but is within the range of 10 - 200 Mg ha-1 y-1 typical of savanna ecosystems. These findings are useful to water resource managers because they can help in computing the useful life of a reservoir.



[1]  Verstraeten, G. and Poesen. J. “Estimating trap efficiency of small reservoirs and ponds: methods and implications for the assessment of sediment yield”, Prog. Phys. Geogr, vol. 24, no. 2, pp. 19-51, 2000.
[2]  Corbeels, M., Graaff J., Ndah, T., Penot, E., Baudron, F., Naudin, K., Andrieu, N., Chirat, G., Schuler, J., Nyagumbo, I., Rusinamhodzi, L., Traore, K., Mzoba, H., and Adolwa, S. “Understanding the impact and adoption of conservation agriculture in Africa: A multi-scale analysis”, Agric. Ecosyst. Environ., vol. 187, pp. 155-170, (2014).
[3]  Edward, B. R., Thomas D. and John, M. M. “Impacts of climate variability and land use alterations\non frequency distributions of terrestrial runoff\nloading to coastal waters in southern california1,” J. Am. Water Resour. Assoc., vol. 44, no. 1, pp. 62-74, 2008.
[4]  Small, I. F., Rowan, J. S. and Duck, R. W. “Long-term sediment yield in Crombie Reservoir catchment, Angus; and its regional significance within the Midland Valley of Scotland,” Hydrol. Sci. Journal-Journal Des Sci. Hydrol., vol. 48, no. 2003, pp. 619-635, August 2003..
[5]  Walling, D. E. “The response of sediment yields to environmental change,” IAHS Publ., vol. 245, no. 245, pp. 77-89, 1997.
Show More References
[6]  Walling, D. E. “The changing sediment loads of the world’s rivers,” Ann. Warsaw Univ. Life Sci, vol. Landa Recla, no. 39, pp. 3-20, 2008.
[7]  Verstraeten, G. and Poesen, J. “Factors controlling sediment yield from small intensively cultivated catchments in a temperate humid climate,” Geomorphology, vol. 40, no. 1-2, pp. 123-144, 2001
[8]  Fu, B. J., Zhao, W. W., Chen, L. D., Zhang, Q. J., Lü, Y. H., Gulinck, H. and Poesen, J. “Assessment of soil erosion at large watershed scale using RUSLE and GIS: a case study in the Loess Plateau of China,” L. Degrad. Dev., vol. 16, no. 1, pp. 73-85, 2005.
[9]  De Araújo, J. C. and Knight, D. W. “A review of the measurement of sediment yield in different scales,” Rev. Esc. Minas, vol. 58, no. 3, pp. 257-265, 2005
[10]  Berg, M. D., Marcantonio, F., Allison, M. A., McAlister, J., Wilcox, B. P., and Fox, W. E. “Contrasting watershed-scale trends in runoff and sediment yield complicate rangeland water resources planning,” Hydrol. Earth Syst. Sci. Discuss., no. January, pp. 1-31, 2016.
[11]  Levi, B., Chuck, H,. Ronda, D., Jennifer, A., Samantha, Z., and John, W. (2016, February). Sedimentation: Filling up a resevoir in less than a lifetime, Reclamation – Managing Water in the West. The Knowledge Stream, Resevoir Sedimentation and Sustainability Issue, pp 1-44.
[12]  Adwubi, A., Amegashie, B. K., Agyare, W. A., Tamene, L., Odai, S. N., Quansah, C., and Vlek, P., “Assessing sediment inputs to small reservoirs in Upper East Region, Ghana,” Lakes Reserv. Res. Manag., vol. 14, no. 4, pp. 279-287, 2009.
[13]  Verstraeten, G. and Poesen, J. “Using sediment deposits in small ponds to quantify sediment yield from small catchments: possibilities and limitations,” Geomorphology, vol. 1439, pp. 1425-1439, 2002.
[14]  Constantine, J. A., Dunne, T., Ahmed, J., Legleiter, C., and Eli, D. “Sediment supply as a driver of river evolution in the Amazon Basin,” Nat. Geosci., vol. 7, no. December, pp. 899-903, 2014.
[15]  Tamene, L., Abegaz, A., Aynekulu, E., Woldearegay, K., and Vlek, P. G. “Estimating sediment yield risk of reservoirs in northern Ethiopia using expert knowledge and semi-quantitative approaches,” Lakes Reserv. Res. Manag., vol. 16, no. 4, pp. 293-305, 2011.
[16]  Lu, X. and Higgitt, D. L. “Recent changes of sediment yield in the Upper Yangtze, China,” Environ. Manage., vol. 22, no. 5, pp. 697-709, 1998
[17]  Tesfahunegn, G. B., and Vlek, P. G. “Assessing Sediment-Nutrient Export Rate and Soil Degradation in Mai-Negus Catchment , Northern Ethiopia,” Hindawi Publ. Corp. ISRN Soil Sci., vol. 2013, 2013.
[18]  Verstraeten, G., Van, K., VanRompaeyA., Poesen, J., and Govers, G. “Evaluating an integrated approach to catchment management to reduce soil loss and sediment pollution through modelling,” Soil Use Manag., vol. 18, no. 4, pp. 386-394, 2002.
[19]  Wambua, R. M., B. M. Mutua, and J. M. Raude, “Prediction of Missing Hydro-Meteorological Data Series Using Artificial Neural Networks ( ANN ) for Upper Tana River Basin , Kenya,” vol. 4, no. 2, pp. 35-43, 2016.
[20]  Ralph J., Helmut S., Berthold, H., Chris, S. Farm management handbook of Kenya, VOL. II, 2nd Edition, Part B, Central Kenya, Ministry of Agriculture, Kenya, in Cooperation with the German Agency for Technical Cooperation (GTZ), Printed in Nairobi, pp. 222-230, 2006.
[21]  Dunbar, J. A., P. Allen, and P. D. Higley, “Multi-frequency acoustic profiling for water reservoir sedimentation studies”, Journal of Sediment Research. v. 69, p. 521-527, 1999.
[22]  Dost, R. J. and Mannaerts, C. M. “Generation of lake bathymetry using Sonar, Satellite Imagery and GIS,” 2008 Esri Int. User Conf. Proc., no. 1, pp. 1-5, 2008.
[23]  Sang, J. K., Raude, J. M., Mutwiwa, U. N., and Ochieng, F. “Dual Echo Sounder Bathymetric Survey for Enhanced Management of Ruiru Reservoir Kenya,” pp. 1-8.
[24]  Odhiambo, B. K., and Boss, S. K. “Integrated Echo Sounder , GPS , and GIS for Reservoir Sedimentation Studies: Examples From Two Arkansas Lakes 1,” J. Am. Water Resour. Assoc., vol. 40, no. 4, pp. 981-997, 2004.
[25]  Powell, D. M., Reid, I., Laronne, J. B., and Frostick, L. E. “Bed load as a component of sediment yield from a semiarid watershed of the northern Negev,” Eros. Sediment Yield Glob. Reg. Perspect, no. 236, pp. 389-397, 1996.
[26]  Mulu, A., and Dwarakish, G. S. “Different Approach for Using Trap Efficiency for Estimation of Reservoir Sedimentation. An Overview,” Aquat. Procedia, vol. 4, no. Icwrcoe, pp. 847-852, 2015.
[27]  Verstraeten, G., and Poesen, J. “Variability of dry sediment bulk density between and within retention ponds and its impact on the calculation of sediment yields,” Earth Surf. Process. Landforms, vol. 26, no. 4, pp. 375-394, 2001.
[28]  Jain, S. K., Singh, P., and Seth, S. M. “Assessment of sedimentation in Bhakra Reservoir in the western Himalayan region using remotely sensed data,” Hydrol. Sci. J., vol. 47, no. April, pp. 203-212, 2002.
[29]  Kouhpeima, A., Hashemi, S. A., Feiznia, S., and Ahmadi, H. “Using Sediment Deposited in Small Reservoirs to Quantify Sediment Yield in Two Small Catchments of Iran,” J. Sustain. Dev., vol. 3, no. 3, p. P133, 2010.
[30]  Lal, R. “Soil erosion and sediment transport research in tropical Africa,” Hydrol. Sci., vol. 30, p. 1985, 1985.
[31]  Rashleigh, B., Razinkovas, A., and Pilkaityte, R. “Ecosystem services assessment of the nemunas river delta,” Transitional Waters Bull., vol. 5, no. 2, pp. 75-84, 2011.
Show Less References


Spatial Analysis of the Quality of Groundwater Supply: Evidence from Abia State

1Department of Geography and Planning, Abia State University, Uturu, Nigeria

2Department of Architecture, Abia State University, Uturu, Nigeria

American Journal of Water Resources. 2016, 4(4), 83-90
doi: 10.12691/ajwr-4-4-2
Copyright © 2016 Science and Education Publishing

Cite this paper:
V. U. Nkemdirim, G. C. Alozie, Ike Felix. Spatial Analysis of the Quality of Groundwater Supply: Evidence from Abia State. American Journal of Water Resources. 2016; 4(4):83-90. doi: 10.12691/ajwr-4-4-2.

Correspondence to: V.  U. Nkemdirim, Department of Geography and Planning, Abia State University, Uturu, Nigeria. Email:


The importance of potable water has been documented by many researchers. However, one major challenge in Nigeria is the ability for both rural and urban areas to access a clean water supply. This study examined the spatial analysis of the quality of groundwater supply in selected urban centres of Abia State. To achieve this, 13 borehole water samples were collected using purposive sampling technique. The parameters tested include; Temperature (°C), pH value, Electrical conductivity (µs), Total suspended solids (mg/l), Biological Oxygen demand (BOD),Turbidity (NTU), Sulphate (So4), Chloride (Cl), Nitrate (No3), Potassium (K), Sodium (Na), Calcium (Ca), Magnesium (Mg), Zinc (Zn), Iron (Fe) Copper (Cu) and Lead (Pb). The results of the water samples were compared with the WHO quality standards. The analyses revealed that the quality of water supply is inadequate. For instance, temperature in all the sampled sites ranged from 27.1°C - 29.7°C which is above the WHO value of 26.6°C, while the pH values (5.79 - 6.81) were lower than the WHO value of 7 – 8.5, indicating mildly acidic. Similarly, electrical conductivity, total suspended solids, biological oxygen demand, sulphate, nitrate, and chloride values were all below the WHO values. All the hypotheses were tested using analysis of variance. It was observed that significant variations exist between Ohafia and Umuahia, Ohafia and Aba, but no significant difference exists between Umuahia and Aba. Thus, the null hypothesis (H0) was accepted in all, that “there are no significant variations in the physicochemical content as regards the sampling points in the zones. The study recommends amongst others that water should be boiled before use, or through the use of alum, water guard, or through disinfection with the use of chlorine.



[1]  Aimiuwu, D. O. (2008). Impact of Socio- Environmental Characteristics on Quality of Potable Water Development and Sustainability: A Case Study of Benin-City. 50th Annual Conference, Association of Nigerian Geographers (ANG); August 25th-28th, University of Calabar.
[2]  Akaninyene, M. and Atser, J. (2000). “Demand and supply relationship and quality of public water supply system in Makurdi, A sub-humid tropical city of central Nigeria” in Adinna, E.N.; Ekpo, O.B. and Attah, V.I. (eds.), Environmental Pollution and Management in the Tropics, Enugu: Snaap Press Ltd, 350-356.
[3]  Alayande, A.W. (2005). Water Demand Management: Paper presented at a workshop titled “Urban water supply facilities maintenance course.” held at National Water Resource Institute, Kaduna, November 7-18, 2005.
[4]  Chima, G.N., Nkemdirim, V.U. and Iroegbu, A.N. (2009). Water Demand and Supply in Umuahia Urban-Abia State: Critical study. Knowledge Review 18 (1) 9-15.
[5]  Clasen, T; Schmidt, W.P; Rabie, T; Roberts, I. & Cairncross, S. (2007). Interventions to improve water quality for preventing diarrhea: a systematic review and Meta-analysis. British Medical Journal 334: 782-785.
Show More References
[6]  Ekop, O.B. (1994). “Spatial variations in quality and quantity of Public Water Supply in Calabar Municipality, Nigeria” Nigeria Journal of Technical Education 11:107-125.
[7]  Ekop, O.B. (2003). Pollution Assessment of Public Water Supply in Calabar urban Nigeria. In Adinna, E.N.; Ekpo, O.B. & Attah, V.I.(eds.).Environmental Pollution and Management in the Tropic. 337 -349. nugu: Snaap Press Ltd.
[8]  Emoabino, I.U. and Alayande, A.W. (2006). “Water Demand Management:Problems and Prospects of Implementation in Nigeria”. Proceedings of International Congress on River Basin Management, 154-159.
[9]  Haller, L; Hutton G; and Bartram, J. (2007). Estimating the costs and benefits of water and sanitation improvements at global level. J Water Health 5:467-480.
[10]  Holden, M.J. and Green, J. (1960). The hydrology and plankton of river Sokoto, journal of animal ecology; 29: 65-84.
[11]  Hutton, G. and Bartram, J. (2008). Global costs of attaining the millennium Development Goal for water supply and sanitation. Bull World Health Organ 86:13-19.
[12]  Ijioma, M.A. and Ogwuegbu, M.O.C. (1999). Policy-Oriented Water Pollution Impact Assessment: Illustrations from Aba River, Abia State; in A.I. Kalu(ed), A Journal on the Environment 3(1): 23-28.
[13]  Ijioma, M.A. (2000). Nigeria: Giant in the Tropics: Survey of states in Mamman, A.B; Oyebanji, J.O. and Petters, S.W. (eds), Abuja, 2:3-13.
[14]  Nwadiaro, C.S., Oranusi, N.A. and Umeham, S.N. (1982). Preliminary survey of the drinking water quality of some areas in Imo and Rivers States. Proceeding of the 3rd National conference on water pollution held at the Nigerian Agip Oil Co. Hq., Port-harcourt, 15-22.
[15]  Ocheri, M. I. Mile, Y. and Oklo, A. (2008). Nitrate Contamination of Shallow Wells in Makurdi Urban area of Benue State. 50th Annual Conference Book of Proceedings; association of Nigerian Geographers (ANG); 25th-28th August, 2008.
[16]  Obgeibu, A. E. and Victor, R. (1995). Hydrological studies of water bodies in the Okomu forest reserves (Santuary) in Southern Nigeria. 2 physico-chemical hydrology. Tropical Freshwater Biology, 4: 83-100.
[17]  Petr, T. (1983). The Purari- tropical Environment of a High Rainfall River Basin. W. junk. The Hague.
[18]  Standards Organization of Nigeria (2007). Nigeria standard for drinking water quality, ICS 13.060.20: Nigeria Industrial Standard Manual, NIS 554: 2007.
[19]  Seeling, B; Derickson, R and Bergsrud, F (1992) Treatment systems for household water supplies: Iron and manganese removal,”1992 [Online]. Available: Accessed January 1, 2004.
[20]  Ubogu, A. E. and Rimomson, A. M. (2008). An Overview of Access to Potable Water Supply in Jema’a L.G.A. of Kaduna State, Nigeria. 50th Annual Conference, Association of Nigerian Geographers (ANG) 25th-28th August, 2008.
[21]  Umeham, S.N and Elekwa, I. (2005). “The Hydro-Biological status of Ngwui, Ikwu and Eme streams in Umuahia North LGA, Abia State, Nigeria”. In E.I.C. Agwu, M.A. Ijioma and I.U. Kalu (2005) (eds) Journal of the Environment. 1(1) Dec.2005, ISSN Heritage Projects Publishers, Owerri, Nigeria. 31-36.
[22]  UN-Habitat (2003). The Challenge of the slums: Global Report on Human settlements. London.
[23]  UN (2005). World Urbanization Prospects: The 2005 Revision. Department of Economics and Social Affairs. Population Division.
[24]  WHO (2006a). Health and the MDGs: background. Accessed May 21, 2010
[25]  WHO (2006b). Typhoid and Paratyphoid enteric fevers. sanitation health/disease/typhoid. Accessed August, 2012.
Show Less References