Rapid Assessment of Drinking-Water Quality in the Republic of Nicaragua
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RAPID ASSESSMENT OF DRINKING-WATER QUALITY IN THE REPUBLIC OF NICARAGUA COUNTRY REPORT ii RAPID ASSESSMENT OF DRINKING-WATER QUALITY IN THE REPUBLIC OF NICARAGUA COUNTRY REPORT OF THE PILOT PROJECT IMPLEMENTATION IN 2004-2005 Prepared by Jorge Mendoza Aldana 2010 iii WHO Library Cataloguing-in-Publication Data Rapid assessment of drinking-water quality in the Republic of Nicaragua: country report of the pilot project implementation in 2004-2005 / by Jorge Mendoza Aldana. 1.Potable water - standards. 2.Water quality - standards. 3.Water - standards. 4.Nicaragua. I.Mendoza Aldana, Jorge. II.World Health Organization. III.UNICEF. ISBN 978 92 4 150058 6 (NLM classification: WA 675) © World Health Organization and UNICEF 2010 All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel: +41 22 791 3264; fax: +41 22 791 4857; email: [email protected]). The World Health Organization and UNICEF welcome requests for permission to reproduce or translate their publications — whether for sale or for noncommercial distribution. Applications and enquiries should be addressed to WHO, Office of Publications, at the above address (fax: +41 22 791 4806; email: [email protected] or to UNICEF, Division of Communication, 3 United Nations Plaza, New York 10017, United States of America (fax: +1 212 303 7985; email: [email protected]). The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization or UNICEF concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. 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Editorial support: Kevin Farrell, Federico Properzi Photo Credit: Jorge Mendoza Aldana iv Table of contents Foreword.............................................................................................................................................viii Acknowledgements ..............................................................................................................................ix Acronyms...............................................................................................................................................x Executive summary..............................................................................................................................xi 1. Introduction...................................................................................................................................1 1.1 From Alma Ata to the Millennium Development Goals.........................................................1 1.2 The WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation ............1 1.3 The WHO/UNICEF Rapid Assessment of Drinking-Water Quality pilot study ....................2 1.4 Country background................................................................................................................3 1.5 State of the water and sanitation sector in Nicaragua .............................................................3 2. Methods..........................................................................................................................................5 2.1 The general design of a RADWQ survey ...............................................................................5 2.2 Definitions...............................................................................................................................5 2.3 The RADWQ survey for Nicaragua........................................................................................7 3. Results ..........................................................................................................................................16 3.1 Physical and chemical parameters ........................................................................................16 3.2 Microbiological parameters..................................................................................................27 3.3 Sanitary inspections ..............................................................................................................27 3.4 Household water samples......................................................................................................34 4. Conclusions..................................................................................................................................38 5. Recommendations.......................................................................................................................40 References .....................................................................................................................................41 Annexes Annex 1 RADWQ personnel for Nicaragua..............................................................................43 Annex 2 RADWQ survey teaching aids (Spanish language version)........................................44 Annex 3 Workplan for the RADWQ survey in Nicaragua........................................................57 Annex 4 Sanitary risk factors used in the RADWQ survey of Nicaraguan water supplies .......................................................................................................................60 List of figures Figure 2.1 General design of a RADWQ survey..............................................................................6 Figure 2.2 Broad areas used in the primary stratification of water sampling points ........................9 Figure 2.3 Location of clusters, by broad area and technology........................................................9 Figure 2.4 Workplan for each broad area, by technology type ......................................................12 Figure 3.1 Distribution of pH values for assessed water samples, by broad area ..........................16 Figure 3.2 Distribution of pH values for assessed water supplies, by technology type .................16 Figure 3.3 Distribution of turbidity values, by broad area .............................................................18 Figure 3.4 Distribution of turbidity values, by technology type ....................................................18 Figure 3.5 Distribution of electrical conductivity values, by broad area........................................19 Figure 3.6 Distribution of electrical conductivity values, by technology type...............................19 v Figure 3.7 Location of municipalities with arsenic concentrations exceeding the WHO guideline value of 0.01 mg/l .........................................................................................................22 Figure 3.8 Location of municipalities where the RADWQ survey detected fluoride in water supplies .........................................................................................................................26 Figure 3.9 Distribution of thermotolerant coliforms, by broad area...............................................28 Figure 3.10 Distribution of thermotolerant coliforms, by technology..............................................28 Figure 3.11 Odds ratios for the presence of thermotolerant coliforms, by sanitary risk level................32 Figure 3.12 Percentage of household samples positive for thermotolerant coliforms and faecal streptococci, by technology...........................................................................................37 List of tables Table 2.1 JMP definitions of water supply and sanitation technologies (2004) ...........................7 Table 2.2 Water-supply coverage for Nicaragua, by technology and broad area .........................8 Table 2.3 Number of assigned water supplies in each broad area, by technology......................10 Table 2.4 Cluster number and size for each broad area, by technology......................................11 Table 2.5 Number of water samples assessed, by department and technology........................... 11 Table 2.6 Number of water samples analysed, by broad area and technology type.................... 14 Table 3.1 Percentage of water supplies with turbidity values greater than 5 NTU, by broad area and technology ..........................................................................................17 Table 3.2 Median turbidity values of Nicaraguan water supplies, by broad area and technology type...........................................................................................................17 Table 3.3 Medians and ranges for pH, electrical conductivity and turbidity, by department .....20 Table 3.4 Medians and ranges for free and total chlorine levels in Nicaraguan water sources, by technology type........................................................................................21