Assessment of Water Quality at Water Supply Plant in Sawathee Sub-district, Khon Kaen Province

Abstract

A research survey was conducted at 13 water supply plants in Sawathee subdistrict, Khon Kaen from June 2011 to March 2012. Twelve plants use surface
water as the raw water source; the remaining plant uses water from a deep well.
The water supply plants were tested about the water quality. Water samples were
collected from the raw water sources, supply pipes and consumer taps. However,
the ground water plant only had samples taken from the supply pipe and consumer
tap. These samples underwent physical, chemical and bacterial examinations
which were compared with the required water standard of the Department of
Health (2010), Ministry of Public Health. The data was analyzed and presented as
average, standard deviation and percentage statistics. The results show that water
from only 10 out of 12 water plants were suitable for consumption before
treatment according to the physical, chemical and bacterial conditions. Generally
the raw water quality was found to be of Class 3. The water quality in the
distribution systems failed a number of tests. Firstly, it did not meet water clarity
index, which is one of the many physical parameters. The turbidity of the water
with an average of 6.38 (range, 23-1=22) was substandard. Secondly, the chemical
properties were tested and it was found that the pH averaged at 6.78 (range, 7.9-
5.5=2.4), Fe averaged 1.02 (range, 3.1-0.1=3.0), Mn averaged 0.50 (range, 2.5-
0.0=2.5), Pb averaged 0.03 (range, 0.08-0.00=0.08) and fluoride averaged 0.82
(range, 1.5-0.7=0.8). All these indices did not comply with the standard. Finally,
coliform bacteria and fecal coliform bacteria were found in the distribution
systems. It is recommended to regularly monitor the quality of water supply
plants. This monitoring should include taking regular water samples and training
of operators of the water treatment system as well as maintain the system
regularly and also test the water quality often