Rapid assessment of drinking-water quality in the - WHO/UNICEF ...

Table 3.14 Pearson’s r analysis of proxy parameters
Technology
Conductivity
versus
Nitrate
Fluoride
Utility piped water supply 0.13 0.09
3.8 Household water quality compared with mains water quality
The household water supplies met WHO guideline value and national standard for thermotolerant
coliforms (Tables 3.15), even though a comparison of household water samples with water from the
piped utility system showed that all household samples had lower concentrations of free chlorine than
found in the utility piped water system (Table 3.16). This indicated that chlorine levels in household
water supplies were nevertheless adequate to ensure safe water, which was consistent with the fact
that the thermotolerant coliform count was the same for both source and corresponding household
water supplies (Table 3.17). As a result, 77.4% of the household water supplies fell into the very low
risk category for thermotolerant coliform contamination, with the remaining supplies in the low risk
category (Table 3.18).
Table 3.15 Compliance of Jordanian household-piped water supplies with
WHO guideline value and national standard for
thermotolerant coliforms a
Technology
n
Proportion of total
samples in compliance
with WHO guideline
value (%)
Proportion of total
samples in compliance
with national standard
(%)
Household piped water 155 100.0 100.0
a
n = total number of samples assessed.
Table 3.16 Free chlorine concentrations in corresponding source and
household water supplies
Free chlorine concentration in
household water compared with
the source
Range Number of samples Proportion of total (%)
Increased by
10%
0
0
0.0
0.0
Decreased by
10%
155
0
100.0
0.0
25