July 5, 1999
To:Works Committee
From:Barry H. Gutteridge, Commissioner, Works and Emergency Services
Subject:Dunkers Flow Balancing System Monitoring Program (Ward 13)
Purpose:
To obtain authorization to enter into an agreement with the Ontario Ministry of Environment and the Toronto and Region
Conservation Authority through the Stormwater Assessment and Monitoring Performance II (SWAMP II) Program to
evaluate the performance of the Dunkers Flow Balancing System for treating stormwater runoff from the Brimley Road
Drainage Area.
Funding Sources, Financial Implications and Impact Statement:
Funding in the amount of $160,000.00 has been approved in the 1999 Capital Works Program, Stormwater Management,
under Scarborough Various Locations, Project No. WP953-S25021, "Dunkers Flow Balancing".
Recommendations:
It is recommended that:
- Authority be granted for an expenditure of $160,000.00 to jointly fund, in conjunction with Environment Canada and
the Ontario Ministry of Environment the performance assessment of the Dunkers Flow Balancing System servicing the
Brimley Road Drainage Area over a two year monitoring period, subject to funding of $185,000.00 being provided by
Environment Canada and the Ontario Ministry of Environment and an additional expenditure of about $50,000.00 being
provided by the Ontario Ministry of Environment for chemical analyses.
- Authority be granted to enter into an agreement with the Ontario Ministry of Environment and the Toronto and Region
and Conservation Authority to have this assessment undertaken through the Stormwater Assessment and Monitoring
Performance II (SWAMP II) Program.
- The appropriate City Officials be authorized and directed to take the necessary action to give effect thereto.
Council Reference/Background/History:
The environmental impacts of stormwater runoff and combined sewer overflow discharges on area watercourses and the
waterfront are well documented. The impact of these non-point sources of pollution has contributed to Toronto's
designation as one of forty-two Areas of Concern in the Great Lakes basin by the International Joint Commission.
Environmental impacts attributed to wet weather pollution include: posting of recreational beach areas due to bacterial
contamination; nuisance algal growth as a result of nutrient enrichment; degraded water clarity attributed to algal growth
and suspended solids; elevated contaminant levels in lake sediments; and stressed aquatic communities in areas close to
sewer outfalls. A Remedial Action Plan has been developed to restore beneficial uses within the area. The Remedial Action
Plan has identified and includes recommendations to abate the impacts of these discharges through implementation of
source controls, in-system or conveyance control measures and implementation of downstream storage and/or treatment
systems.
On April 13, 1994, the former City of Scarborough Council, by adoption of Recommendations embodied in Report No. 8
of the Works and Environment Committee, endorsed the Environmental Study Report - Brimley Road Drainage Area
Water Quality Enhancement Strategy. The strategy recommended utilizing source control and other stormwater best
management practices and construction of a Dunkers Flow Balancing System with a wetland cell to treat stormwater runoff
from the above-mentioned drainage area. As part of the strategy, an intensive monitoring program was developed to
evaluate the performance of both the water quality enhancements, their operation and maintenance requirements, as well as
testing the self-sustainability of the wetland ecosystem. The monitoring program will assess the facility's performance to
ensure that it meets the original design expectations and complies with the Certificate of Approval issued for the facility by
the Ontario Ministry of Environment under the Ontario Water Resources Act.
This project was initiated from the outset as a joint venture between the three levels of government and with a common
goal of demonstrating a new, innovative and transferable technology to deal with non-point source discharges of pollution.
Construction of the facility was recently completed and the $2.4M cost was shared by the three levels of government
through the Canada/Ontario Infrastructure Program.
Comments and/or Discussion and/or Justification:
The facility is now fully operational, and the City has a legal obligation to undertake a monitoring program in compliance
with the Certificate of Approval issued by the Ontario Ministry of Environment for the facility. Minimum monitoring
requirements have been identified which involve assessing the effectiveness of the facility in providing water quality
enhancement for the outfall servicing the Brimley Road Drainage Area. This involves assessing the system's hydraulic and
water quality performance. Through the Certificate of Approval, the City must report on the results of the monitoring
program and the system evaluation two years after the system becomes operational.
While the City is obligated to undertake monitoring to satisfy the Certificate of Approval requirements, more extensive
monitoring is required to identify measures to optimize the facility performance, reduce operations and maintenance costs
and assess the facility performance against the original design criteria. These analyses would also be used by the City in
considering the viability and applicability of this technology at other locations through the development of the Wet
Weather Flow Management Master Plan.
Similarly, the Federal Department of Environment and the Ontario Ministry of Environment have an interest in assessing
this new technology. The Dunkers Flow Balancing System is a cost-effective stormwater treatment technology which could
be applied to other sites across the Province and Canada. However, as with most new technologies, the lack of monitoring
data in an Ontario climate precludes acceptance by other jurisdictions. To this end, Environment Canada, the Ontario
Ministries of Environment and Transportation and the Toronto and Region Conservation Authority have established the
Stormwater Assessment Monitoring and Performance (SWAMP) Program in collaboration with municipal agencies. Under
this program, now expanded into a second phase (SWAMP II), staff and financial resources of municipal, provincial and
federal agencies are pooled to support the monitoring activities undertaken through the program. The prime objective of the
program is to evaluate facility performance with respect to design and compliance parameters and to provide technology
transfer and promotion to municipalities, government agencies, consultants and community groups. The pooled resources
serve to address the following objectives for each technology tested:
- Evaluate and document operational and maintenance requirements;
- Demonstrate environmental benefits:
-water quality
-sediment quality
-fisheries and habitat
- Make recommendations for optimizing the facility and evaluate design and operational improvements
- Developing a monitoring and reporting protocol for performance assessment and regulatory compliance purposes
- Develop site selection criteria appropriate to Ontario conditions
- Identify specific technology limitations and applicability
The two year monitoring program for this facility would begin in the fall of 1999 and continue until the fall of 2001. As
noted, the monitoring provides data to support the City's obligation for Certificate of Approval requirements and provides
the detailed analysis required for system optimization. The cost of conducting the monitoring to address the objectives
identified is estimated to be about $395,000. The City's contribution of $160,000 would be matched with a total of
$185,000 contributed by the Ontario Ministry of Environment and Environment Canada and an additional in-kind
contribution for chemical analyses equivalent to $50,000 by the Ontario Ministry of Environment.
Conclusions:
The Dunkers Flow Balancing System is a new cost-effective stormwater management technology. The facility is now fully
operational, and the City has a legal obligation to undertake a monitoring program in compliance with the Certificate of
Approval issued by the Ontario Ministry of Environment for the facility. However, more extensive monitoring is required
to identify measures to optimize the facility performance, reduce operations and maintenance costs and assess the facility
performance against the original design criteria. These analyses would be used by the City in considering the viability and
applicability of this technology at other locations through the development of the Wet Weather Flow Management Master
Plan.
A recommendation is made to cost share the two year monitoring program with Environment Canada and the Ontario
Ministry of Environment through the Stormwater Assessment and Monitoring Performance II Program.
Contact Name:
Mr. M. D'Andrea, P.Eng.
Manager, Infrastructure Asset Management
Quality Control and System Planning
Telephone: (416) 397-4631
Fax: (416) 392-2974
e-mail: michael_d'andrea@metrodesk.metrotor.on.ca
Michael A. Price, P.Eng., FICEBarry H. Gutteridge
General ManagerCommissioner
Water and Wastewater ServicesWorks and Emergency Services
dunkers-wc.wpd
