Blackburn Wastewater Treatment Plant Upgrade Study

Section 4.0 - Blackbum Treatment Options
descriptions to assist with the decision making process. These seven basic
wastewater treatment andor transfer options and the two sub-options will be
evaluated against both economic and non-economic criteria.
The non-economic analysis is described in Section 5.0, and was completed at
the Decision Workshop held with City staff on October 19, 1999.
The economic analysis is based on preliminary capital cost estimates and
ongoing operating and maintenance (O&M) cost estimates for the above nine
options. Estimates were also made of the approximate timing of the required
capital expenditures. These values were used to generate 25-year life cycle
wst estimates for the nine options using a net present value (NPV) analysis at
a discount rate of 6 percent. :
In all nine options, it was assumed that the major capital expenditure would
occur in 200612007, so that the upgrades would be fully operational when the
existing sewage lagoons at the Blackbum WWTP are at capacity. The existing
lagoons will be operated until that time. Implicit in this assumption is that the
L'I mitigation measures will be successhlly completed in the next five years.
In all options involving the transfer of wastewater from the Blackburn
colIection area to the Lansdowne Road W P , which are Options 1 to 5, a
small incremental O&M cost allowance was made for treating the additional
wastewater at the Lansdowne Road WWTP. However, no allowance was
made for the fact that this transfer may require & earlier upgrade at
Landsdowe Road WWTP as the Blackburn sewage flows are less that 4
percent of the existing capacity at Lansdowne Road WWTP, and the effect of
such a small incremental increase is outside the accuracy of this analysis.
The estimated capital and 25-year life cycle costs for the nine wastewater
treatment options are presentd in Appendix B, and are summarized in Table
4.1 below.
TabIe 4.1: 25-year Life Cycle Costs