volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
Appendices
• Review of system models and other tools such as asset inventories and GIS data and
identification and/confirmation of gaps.
• Review of the characteristics of waters receiving wet weather discharges.
• Data and information collection designed to fill vital gaps.
• System model update and refinement.
• Development and analysis of alternative system-wide wet weather management
strategies in consideration of receiving water characteristics. The alternatives would
incorporate the new information and data developed during the Wet Weather
System Plan as well as the previous studies. Demand reduction strategies would be
assessed as part of this activity.
• Recommendation of a preferred Wet Weather System Plan. This would be
incorporated into the overall Wastewater Master Plan.
A total of $14.3 million has been budgeted for Wet Weather System Plan development
for the 30-year period including initial plan development and updates every five years.
This total also includes funds for ongoing monitoring for wastewater system model
calibration and the further expansion and refinement of the model. The details of the
costs are presented in Volume 1 Appendix H.
Two specific programs that would be additional inputs to the Wet Weather System Plan
are discussed below. The additional costs above and beyond the Wet Weather System
Plan preparation are presented for the two components. Cost details and distribution by
year are presented in Volume 1 Appendix H.
An Enhanced Overflow Control Program is recommended to address a comprehensive
strategy for control of all active overflows. This goes beyond the good starting point
provided by the RWWFP. The discussion below provides a high-level presentation of the
program basis and the potential costs of additional overflow control (beyond RWWFP).
It will need to be refined through the development of the Wet Weather System Plan.
An I/I pilot program is also recommended to provide the necessary data to establish the
benefits and costs of extraneous flow (i.e. wastewater demand) reduction.
2.2.1 Enhanced Overflow Control
Based on data collected by Halifax Water there are presently a total of 216 known
potential overflow locations within the wastewater system approximately 105 of which
are known to have been active at any time. Twenty-nine (29) of the 105 active overflows
locations are associated with the combined sewer system.
The RWWFP modelled a total of 96 of the potential overflow locations and determined
based on the modeled results, 59 overflows are active during a year with average rainfall.
The RWWFP modeling further determined that 28 of the 59 overflows active during an
average rainfall year would be impacted by future growth. The RWWFP includes measures
Revision: 2012-10-29 Integrated Resource Plan –Appendices F-22
October 31 2012 Page 201 of 272