volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
IRP Planning Context and Levels of Service
Historically, the cities of Dartmouth and Halifax and Halifax County were responsible for
wastewater collection and treatment within their own service areas. After the 1996
amalgamation, HRM took over the operation of the wastewater system and in 2007
transferred the system to Halifax Water. In the intervening 5 years Halifax Water has
been challenged to bring the system into regulatory compliance and to fully assess the
condition of wastewater system assets.
Wastewater Treatment Facilities (WWTF)
Presently Halifax Water owns and operates 15 wastewater treatment facilities (WWTFs).
These WWTFs provide varying levels of treatment, from primary to tertiary, and have a
broad range of average day flow (ADF) capacities that range from 45 m 3 /d to 133,920
m 3 /d. Nova Scotia Environment regulates the quality and quantity of effluent discharged
from each WWTF through 'Permits to Operate' (PTO) which are specific to each facility.
A summary of 14 of the 15 wastewater treatment facilities operated by Halifax Water is
presented in Table 3.4. The fifteenth WWTF - Belmont WWTF will soon be
decommissioned once the expansion/upgrade of the Eastern Passage WWTF is
completed and has not been included in the summary table.
Five of the WWTFs (six including Belmont) presently discharge to salt water receiving
environments while the remainder discharge to small freshwater lakes or streams. As
noted previously, the freshwater bodies have significant restrictions on assimilative
capacity and hence limit the ability for continued population growth and WWTF
expansion. In future, as treated effluent nutrient requirements for nitrogen and
phosphorus become more stringent, additional limitations on WWTF discharges will
likely result. This is further discussed in Section 4 under the wastewater regulatory
compliance driver and in Section 5, which proposes a new enhanced nutrient reduction
program that was ultimately incorporated into the IRP.
Based on results from fiscal year (FY) 2010-2011, 10 of the 14 WWTFs were noncompliant
with their NSE PTO effluent requirements. 17 Many of the non-compliant
effluents exceeded their suspended solids (TSS) or biological oxygen demand (BOD)
targets. This is likely at least partly the result of excessive wet weather flows stressing
the treatment processes. The widely spread and significant nature of this issue argues
for a comprehensive inflow infiltration (I/I) program across most of the WWTF service
areas. This is further discussed in Section 5 and Volume 1 Appendix F under a new I/I
pilot program as well as in Section 6 in examining the benefits of an I/I program for
wastewater demand reduction.
17 Draft Wastewater Treatment Facilities (WWTF) Compliance Plan, Halifax Water,
August 2011
Revision: 2012-10-29 Integrated Resource Plan 20
October 31 2012 Page 53 of 272