volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
Executive Summary
ES 7.
ES 7.1
INTEGRATED RESOURCE PLAN FORMULATION AND EVALUATION
Alternative Resource Plan Formulation and Evaluation
Considering the key drivers - regulatory compliance, asset renewal and growth - an
initial set of 28 alternative resource plans were developed to meet the water,
wastewater, and stormwater service needs of Halifax Water's service areas through to
the year 2043. The initial plans reflected variations on the timing and nature of
wastewater system compliance; levels of asset renewal investment, and the degree of
overflow control.
The initial plans were evaluated in terms of their 30-year net present value (NPV) cost,
their compliance timing, and their potential environmental and public health impacts.
Based on this analysis, 18 intermediate plans worthy of further consideration were
identified. Using a single composite asset renewal strategy, redundant intermediate
plans were eliminated and 10 refined plans were developed. The 30-year NPV at this
stage in the alternative resource plan development and analysis was similar for all
resource plans. Based on environmental and public health impacts the 10 refined plans
were further reduced to 4 short-list plans. A recommended plan was selected from the 4
short-list plans based on the benefits of nutrient control and the enhanced overflow
control program.
ES 7.2
Demand Reduction
One of the key requirements of the IRP Terms of Reference was the examination of
demand reduction strategies for both the water and wastewater systems. The purpose
was to explore the opportunities to incorporate such strategies as the focus of one or
more of the resource plans. Unfortunately, systematic data that would allow a
comprehensive examination of I/I reduction in particular were not available.
Consequently, a high-level analysis of opportunities was carried out with a view to
informing future integrated resource plan evaluation of the potential for incorporating
demand reduction strategies. The focus of the analysis was the Dartmouth WWTF,
which the RWWFP identified as requiring expansion due to growth. Results of the highlevel
analysis of the demand reduction potential in the Dartmouth WWTF sewershed
indicate that it may be possible to reduce anticipated flows sufficiently to defer the
required expansion of the plant beyond the end of the planning period in 2043.
This supports the importance of including a robust treatment of demand reduction
strategies in regional wastewater planning, including the proposed Wet Weather System
Plan and Wastewater Master Plan. The results of such analysis may significantly impact
the recommended plan and should be incorporated when the IRP is updated.
Through a more comprehensive demand reduction analysis, Halifax Water will be able
to assess the effectiveness and affordability of a range of demand reduction solutions
for the wastewater system that may include additional system storage, sewer
Revision: 2012-10-29 Integrated Resource Plan – Executive Summary ES-13
October 31 2012 Page 15 of 272