volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
IRP Planning Context and Levels of Service
The results presented in Table 3.6 show that under current baseline conditions
approximately 7.8 million m 3 /yr is discharged through the 28 outfalls addressed in the
RWWFP with an additional 1.6 million m 3 /yr. discharged through the remaining 31
active overflows. It is noteworthy that 49% of the non-growth baseline volume is made
to B or C risk level receiving waters while about 12% of the growth impacted volume is
discharged to B and C risk level receiving waters. The impact of growth with no
additional controls is evident with an over 100% increase in overflow volumes between
the baseline and growth with no controls cases. The preferred RWWFP strategy
however reduces the average annual overflow volume for the 28 outfalls by 16% for the
total system outfalls thus already achieving a substantial improvement.
It is for these reasons that an Enhanced Overflow Control Program was developed and is
proposed for implementation through the IRP. The Enhanced Program would control
the 28 B and C risk level growth (9) and non-growth (19) overflows to a uniform 10
overflows per average year. It would be in addition to the overflow control provided by
the RWWFP. Ideally, these two programs would be integrated under the Wet Weather
System Plan, discussed above, to achieve optimal receiving water benefit for the overall
investment. The Enhanced Overflow Control Program is discussed under new programs
in Volume 1 Appendix F.
Presently, regulatory compliance requirements for overflows include monitoring and
reporting. Halifax Water complies with these requirements and through its Five-Year
Capital Budget, discussed later in this Section, has a variety of programs and projects
aimed at overflow mitigation (e.g. overflow screening) and reduction (e.g. Stormwater
Inflow Reduction (SIR) Program).
The location of the combined and separate sewer areas as well as the overflow locations
and major trunk sewers are presented in Volume 1 Appendix D, which contains the maps
for Volume 1.
Wastewater System Summary
The wastewater system assets are summarized in Table 3.7.
Table 3.7
Summary of Wastewater Infrastructure
Asset Category
Number of Assets
Forcemains
90 km
WWTF 15 facilities (1)
Trunk
Sewers
Wastewater Pumping Stations
Notes:
1. This includes the Belmont WWTF, which will be soon decommissioned.
145 km
1193 km
172 stations
Revision: 2012-10-29 Integrated Resource Plan 27
October 31 2012 Page 60 of 272