dc.description.abstract |
Water is a crucial element that covers two-thirds of the surface area of the earth, and it is one
of the main substances in the body of every living being on the earth. Thus clean, safe, and
adequate freshwater is important for secure good health. The National Water Supply and
Drainage Board (NWS&DB) is the main responsible institution for providing safe drinking
water within Sri Lanka. However, NWS&DB is unable to provide safe water to the country’s
entire population. Therefore, Community Managed Water Supply Schemes (CMWSS) were
implemented as a solution for the existing water scarcity issues in rural areas of Sri Lanka. It
was revealed that most of the CMWSS in Southern Sri Lanka are supplying raw water without
proper treatment. So continuous monitoring, management, and evaluation of water quality in
these schemes are essential to supply safe potable water. There are 172 CMWSS in the Galle
district, and 10,814 families benefit from those schemes. On the other hand, there are 333
schemes in the Matara district, and 26482 families benefit from these CMWSS. In
Hambanthota district, there are 182 CMWSS to provide drinking water for 38157 families. In
this study, the water quality of selected CMWSS (71% out of total schemes) in the southern
province of Sri Lanka was assessed by applying the Canadian Council Minister of
Environment Water Quality Index (CCMEWQI). Altogether, water quality (WQ) of 488
(Galle 172, Matara 172, Hambanthota 144) CMWSS was evaluated under the 14 parameters
such as temperature, turbidity, pH, electrical conductivity, total hardness, nitrate, iron,
fluoride, E. coli, total coliforms, Mn, Pb, As and Cd, using Standards method of American
Public Health Association and compared with the Sri Lankan Standards for drinking water
(SLS 614 2013). Water Quality Index (WQI) was also developed for each source and rated as
Excellent, Good, Medium, Bad, and Very Bad. Developed WQI revealed that none of the
CMWSS in the southern province categorized as “Very Bad” quality (0-25). Among 488
schemes in the province, only (2.3%) 11 schemes belonged to the “Excellent” category (91100)
based
on
this
WQI.
Majority
of
the
schemes
(39.1%)
had
the
WQI
between
26-50
and
rated
as “Bad” and need to have secondary treatment. There were 33.8% of CMWSS that
belonged to the “Medium” category (51-74) of WQI and 24.8% in the “Good” category (7590)
which were not suitable for drinking without preliminary treatment. More than half
(56.3%) of CMWSS in Hambanthota district were in the ‘Bad’ category. Therefore,
Hambanthota district CMWSS were highly contaminated than those in Galle and Matara
districts. It was noted that raw water of (97.7%) 477 CMWSS in the southern province need
to be further treated for E. coli, total coliforms, conductivity, hardness, iron, fluoride, pH, and
turbidity. The questionnaire survey revealed, that 62.6% of consumers used water without any
treatment. It is recommended to educate consumers of CMWSS on basic household treatment
systems so that they can treat the water before consumption. It is also required to introduce
more cost-effective treatment procedures for the consumers as the majority of the household
in the southern province monthly income is less than Rs.25,000. |
en_US |