volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
Recommended IRP and Analysis
Figure 6.6
King County I/I Reduction Costs
The capital and operating cost reduction with both water demand and I/I reduction is
about a NPV of $21.2 million to 2043. Using I/I reduction alone corresponds to about
$10 million NPV in cost reduction by 2043.
The flow reduction of 30% in the existing I/I flow would cost about $8.4 million using
King County data. This would provide a potential savings in NPV of $1.6 million ($10
million in savings - $8.4 million I/I program cost) for a future I/I reduction program. This
of course must be tempered with the recognition that local conditions and costs may
prove to be very different than King County and highlights the need for a comprehensive
Halifax I/I program.
The case study findings support 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 IRP 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
separation, sewer twinning, installation of deep storm sewers, and a range of solutions
on the private portion of the network. The formal wet weather planning and I/I
reduction pilot programs proposed in the current IRP will build on the preliminary
Revision: 2012-10-29 Integrated Resource Plan 84
October 31 2012 Page 117 of 272