volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
Integrated Resource Plan Development and Evaluation
IRP Driver
The IRP expenditures by driver for fully A, B and C plans with enhanced overflow control
and the RWWFP (Plans 25-1, 28-1, 22-1 respectively) are presented in Figure 5.3. Asset
renewal expenditures dominate. Total asset renewal program costs range from $1,801
million to $992 million for the thirty-year period. This corresponds to 60% of the
expenditures associated with Level A, 55% for Level B and 49% for Level C.
The growth and compliance related expenditures show less variation in moving from the
A to B to C levels.
Figure 5.3
IRP Expenditure by Driver
RWWFP and Modified RWWFP for WWTF Nutrient Control
Comparison of the plans in Bundles 1 and 3 shows an approximately $19 million
difference in 30-year NPV ($23 million in $2012 as per Table 5.3) associated with the
two nutrient reduction strategies for WWTFs discharging to limited receiving waters
(Modified RWWFP versus RWWFP). The Modified RWWFP (upgrading all 9 WWTFs plus
BLT upgrade already under way) is the less expensive of the two alternatives. It has
however the disadvantage that the discharges, although upgraded, are still maintained
into the Nine Mile River from BLT WWTF and Lisle Lake from Springfield Lake WWTF.
This is a less sustainable alternative. The IRP analysis of the costs of the nutrient
reduction alternatives was carried out at a high level and the cost difference will likely
shrink with a more detailed evaluation. Consequently, for purposes of further plan
evaluation the Modified RWWFP option was abandoned eliminating Plans 1-1 to 14-1
(Bundles 1 and 2) from further consideration and concentrating the analysis on Plans 15-
1 to 28-1 (Bundles 3 and 4).
Revision: 2012-10-29 Integrated Resource Plan 64
October 31 2012 Page 97 of 272