Abstract:
Monaragala district highly suffers from water related issues due to its
geographical location, natural geochemistry and low annual rainfall that are
common in the Dry Zone of Sri Lanka. According to the information
obtained from the Monaragala Regional Office of Health Services, Chronic
Kidney Disease of Unknown etiology (CKDu) was identified as the major
health issue of the region. Since past studies have revealed that the disease
is highly connected with drinking water quality, this study was carried out
to assess the suitability of water for drinking purpose based on the physicochemical
parameters. Total of 97 samples were collected from different
water sources of 8 divisional secretariats of Monaragala district from
September 2017 to February 2018, and analyzed for major anions (NO3
-,
PO4
3-, SO4
2-, F-, Cl-, CO3
2-, HCO3
-) and cations (Na+, K+, Mg2+, Ca2+).
Chemical analysis showed that Sodium and Calcium are the dominant
cations, while bicarbonate and chloride are the dominant anions in the
region. According to the Sri Lanka Standards 614-2013 for potable water,
the highest desirable levels of total hardness (250 mg/l), total dissolved
solids (500 mg/l) and electrical conductivity (750 μS/cm) were exceeded by
the 39%, 49% and 42% of groundwater samples respectively. Up to 5.65
mg/l of fluoride were noted and 46% of the groundwater samples exceeded
the highest desirable level (1.0 mg/l) while 28 % of samples exceeded the
maximum permissible level (1.5 mg/l). The higher levels of total hardness
and fluoride indicate the relationship between groundwater quality and
natural geochemistry of the region. The groundwater in the area should be
treated before using for drinking purpose.