The abbreviation (WQI) stands for Water Quality
Index which ranges from 0-very bad to 100-excellent. WQI is found by a
combination of data from nine different tests which are which are all preformed
to determine the over all quality of a water sample. These nine tests are DO,
fecal coliform, PH, BOD, Temperature, total phosphate, Nitrates, turbidity, and
total solids. The way that someone would go about finding the WQI of a water
sample would be to perform each test and find the Q-value by a specific formula
given for each test. After finding the Q-value you would multiply this by the
different weighting factor given already on each test. When each of these tests
are complete and Q-value and weighting factor are multiplied then you would have
the total data of each test which would then be combined to find the actual WQI
on a range of 0-very bad to 100- excellent as shown by the table below.
90-100
= Excellent
70-90
=
Good
50-70
=
Medium
25-50
=
Bad
0-25 = Very Bad