Water Treatment Technologies and Their Costs - Global Drinking Water Management and Conservation - page 45

Table 3.7 Examples of estimated average cost functions for BC small systems in 2008 CDN
dollars for three capacity levels
Water treatment classi cation Average cost function Predicted cost per cubic meter

based on plant with daily
capacity
100 m 3 200 m 3 500 m 3

y = 19.343x − 0.6428 Class 1 1.00 0.64 0.36

y = 25.537x − 0.5998 Class 2 1.61 1.06 0.61

y = 375.873x − 1.000 Class 4 3.76 1.88 0.75

Details of the NLLS estimation are shown in Appendix C . Costs shown above
for Class 1 are operating costs for treatment only. Class 1 plants with a daily ow

rate of 100 m 3 can produce drinking water at an average cost of $1.00, while the
cost is almost quadrupled for a similar sized plant producing Class 4 drinking water
on an island off the coast of British Columbia.

3.7 Summing up and Tentative Conclusions

We can now show, in Figs. 3.3 and 3.4 , that with the estimated cost functions, we
can reproduce an actual set of cost functions that can then be compared to the
hypothetical Fig. 3.1 . Figure 3.3 shows the estimated cost curves based on man-
ufacturers

rated costs, while Fig. 3.4 shows the estimated cost curves based on a
sample of small systems in BC.
Figure 3.3 indicates that ozone technology, a Class 4 water treatment, is more
expensive than the Class 3 (UV and MF-UF) and Class 2 (HRC) treatment types.

'

Fig. 3.4 Estimated cost curves: Classes 1, 2 and 4 for BC Small Systems