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

Table 2.1
RADWQ parameters and inspections
Microbiological and related
parameters
Thermotolerant coliforms
Faecal streptococci
Turbidity
pH
Residual chlorine
Physical and chemical
parameters
Appearance
Conductivity
Nitrate
Iron
Arsenic
Fluoride
Copper
Inspections
Sanitary inspection
Database. Data on water supply coverage and technology were available at three administrative
levels (i.e. national, regional and district level), as required by the methodology (see alsoTable
1.2). Additionally, a detailed rayon inventory of individual utility piped supplies was available,
which included information about the serving capacity and working condition of individual water
supplies (Annex 2). The database allowed an exact calculation of supply zones.
Criteria for including a water supply in the survey. The cut-off size for supplies to be included in
the survey was set at a serving capacity of 500 people. Also, even though the utility piped
supplies in Tajikistan are subdivided into four categories, only three of the categories were
included in the survey. The fourth supply category was judged not to be a primary source of
drinking-water and therefore was not relevant for the RADWQ project. The included categories
of water supply were: municipal/communal supplies; kolkhoz supplies, which serve the rural
population; and supplies serving individual hospitals, kindergartens or schools. The fourth
category, supplies serving workers at individual combines or industries, was not included.
Primary stratification. At the national level, utility piped supplies and springs serve more than
5% of the population 1 (Table 1.2). Other improved technologies (according to JMP definitions)
serve less than 5% of the population. In contrast, it is estimated that ca. 42% of the total
population uses water from open sources (i.e. rivers, channels, irrigation canals) for domestic
purposes (see also Section 1.2). It was decided to include in the survey only water supplies that
served more than 5% of the national population. The option of applying the 5% criterion to the
oblast, rather than national, level was discussed but rejected. Following that option would have
meant that transported water would have be included in the oblast of GBAO, and dug wells
included in the oblast of Khatlon. The data would therefore have better represented the primary
source of drinking-water of the rural population in these regions.
Secondary stratification. The oblast administrative level was selected as the broad area category.
It is the most accepted broad division within the country, and the oblasts divide the country into
geographical categories (e.g. mountainous and flatland areas). An overview of the broad areas
selected is given in Figure 2.3.
Sampling units. Rayons were chosen as the sampling unit category from which the clusters were
to be selected, because rayon data on the served population were available. Towns that
represented an independent administrative unit were annexed to the overlying rayons, with the
exception of the city of Dushanbe, which was treated as an independent sampling unit. The
selection of sampling units or rayons to be included in the survey used proportional weighting
tables, as suggested by the RADWQ methodology (see Annex 4 for a list of selected rayons).
1 Even though national figures for springs do not differentiate between protected and non-protected sources, all
springs were included in this study as a way to verify their level of protection.
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