rapid assessment of drinking-water quality in the republic of tajikistan

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Table 3.1 Compliance with the Tajikistan national standard and WHO guideline value for thermotolerant coliforms Broad area a Utility piped supplies Protected springs Total No. of samples Compliance (%) No. of samples Compliance (%) No. of samples Compliance (%) RRS & Dushanbe 506 93.3 108 86.1 614 92.0 Khatlon 346 85.5 103 94.2 449 87.5 Sughd 410 86.6 60 58.3 470 83.0 GBAO 24 66.7 63 77.8 87 74.7 National 1 286 88.6 334 82.0 1 620 87.2 a GBAO = Gorno-Badakhshan Autonomous Oblast. RRS = rayons under direct republican subordination. Table 3.2 Cumulative frequencies for thermotolerant coliforms a Count category (cfu/100 ml) a Utility piped supplies Protected springs Total Proportion (%) Cumulative frequency (%) Proportion (%) Cumulative frequency (%) Proportion (%) Cumulative frequency (%) 100 0.0 100.0 0.9 100.0 0.2 100.0 Total no. of samples 1 286 334 1 620 cfu = colony forming unit. Table 3.3 Compliance Comparison of sampling rounds for utility piped supplies Proportion (%) Compliance with WHO guideline value and national standard in 1st sampling round 89.5 Compliance with WHO guideline value and national standard in 2nd sampling round 88.1 Compliance with WHO guideline value and national standard in 1st and 2nd sampling round 84.2 Thermotolerant coliform counts Proportion (%) Thermotolerant coliform count higher in 1st sampling round 6.2 Thermotolerant coliform count equal in 1st and 2nd sampling rounds 89.0 Thermotolerant coliform count lower in 1st sampling round 4.8 For protected springs, compliance was lowest in Sughd (58.3%) and highest in Khatlon (94.2%). It is suspected that source protection measures are not adequately maintained, particularly in Sughd, but this would need to be confirmed by an in-depth analysis of the sanitary risk factors identified by individual site inspections. The results of the RADWQ survey suggest that approximately 44.3% of the springs included in the survey were not adequately protected and could not be described as “protected” (Table 3.13). 18
Faecal streptococci Faecal streptococci may also be used as indicators of the microbiological quality of water. Compared to E. coli, these bacteria have a stronger relationship to diarrhoeal disease and to bacterial indicators of known human faecal origin. They are generally more environmentally resistant than E. coli or thermotolerant coliforms and it has therefore been recommended that the levels of these bacteria be tested in groundwater receiving contaminated recharge water and in chlorinated distribution systems. A variety of techniques can be used for analysis and although some are simple, they are timeconsuming and results cannot be obtained within 48 hours. This may limit their usefulness in routine monitoring, but would have limited impact on their value in assessments. The assessment results showed that 151 of 154 (98.1%) water samples tested for faecal streptococci from utility piped supplies and protected springs met both the national standard and the WHO guideline value (Table 3.4). For utility piped supplies, only 2 of 34 samples (5.9%) in Sughd did not meet the requirements. Both came from the same supply scheme and also tested positive for thermotolerant coliforms (the positive findings were not confirmed in the second sampling round, 3.5 months later). For springs, only one sample of 11 tested (9.1%) in RRS and Dushanbe was not in compliance with the national standard, and again the sample had a high thermotolerant coliform count. Table 3.4 Broad area a Compliance with the Tajikistan national standard and WHO guideline value for faecal streptococci Utility piped supplies Protected springs Total No. of samples Compliance (%) No. of samples Compliance (%) No. of samples Compliance (%) RRS & Dushanbe 49 100.0 11 90.9 60 98.3 Khatlon 35 100.0 11 100.0 46 100.0 Sughd 34 94.1 7 100.0 41 95.1 GBAO 2 100.0 5 100.0 7 100.0 a National 120 98.3 34 97.1 154 98.1 GBAO = Gorno-Badakhshan Autonomous Oblast. RRS = rayons under direct republican subordination. Table 3.5 Cumulative frequencies for faecal streptococci Count category (cfu/100 ml) a Utility piped supplies Protected springs Total Proportion (%) Cumulative frequency (%) Proportion (%) Cumulative frequency (%) Proportion (%) Cumulative frequency (%) 100 0.0 100.0 0.0 100.0 0.0 100.0 Total no. of samples 120 34 154 a cfu = colony forming unit. 3.2 Chemical parameters Many chemical substances that are found in water affect public health, the acceptability of the water (aesthetics), and the operational performance of supplies. In the third edition of the WHO Guidelines for drinking-water quality, for example, guidelines values are given for 98 such substances (WHO, 2004). However, it is expensive, difficult and largely unnecessary to test for all these parameters, 19
Page 1: RAPID ASSESSMENT OF DRINKING-WATER
Page 4 and 5: WHO Library Cataloguing-in-Publicat
Page 6 and 7: Annexes Annex 1. Rayon database of
Page 8 and 9: Foreword Among the infectious disea
Page 10 and 11: Acronyms GBAO Gorno-Badakhshan Auto
Page 13 and 14: 1 Introduction 1.1 The WHO/UNICEF J
Page 15 and 16: Measuring gender disparities. Data
Page 17 and 18: Microbial parameters. This involves
Page 19 and 20: 2 Methods 2.1 Survey design The met
Page 21 and 22: Figure 2.2 Steps in the design of t
Page 23 and 24: Cluster size. Cluster sizes ranged
Page 25 and 26: Table 2.2 Country-specific survey d
Page 27 and 28: Throughout the field visits, field
Page 29: 3 Results 3.1 Microbiological param
Page 33 and 34: Water sources were tested for fluor
Page 35 and 36: Table 3.8 Compliance with the Tajik
Page 37 and 38: Table 3.11 Compliance with WHO sugg
Page 39 and 40: Table 3.13 Results of sanitary insp
Page 41 and 42: Faecal contamination (thermotoleran
Page 43 and 44: comparison was possible, 42.5% show
Page 45 and 46: Table 3.23 Compliance of household
Page 47 and 48: protecting the spring (37.7%). Sani
Page 49 and 50: quality. The Republican SES hopes t
Page 51 and 52: Annex 1. Rayon database of utility
Page 53 and 54: Rayon Water supply Working conditio
Page 63 and 64: Annex 4. Primary stratification a S
Page 65 and 66: Rayons included in the RADWQ survey
Page 67 and 68: Annex 6. Example of a sampling plan
Page 69 and 70: Annex 7. Initial fieldwork plan Fie
Page 71 and 72: Annex 8. Example of a monthly progr
Page 73 and 74: Table 3. # Total number of analyses
Page 75 and 76: The following analyses are planned
Page 77 and 78: Remarks: The Sughd team is continui
Page 79 and 80: No. Description of expense Expense
Page 81 and 82:
RADWQ Daily Report Sheet Chemical d
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