Newsletter #2 - August 2009
Working to reduce basement flooding
in the Lawrie Road sewer catchment area
In this issue:
1
2
3
4
Update on the Region’s
activities
Possible solutions
for the Lawrie Road
neighbourhood
Environmental
Assessment update
What happens next?
Taking action at home
The Region adopts
a new sewer use
by-law
A commitment to
communicate
Questions? Suggestions?
Need information about
this study?
Please get in touch.
Kevin Wilson, P. Eng.
Project Manager (Ajax)
The Regional Municipality of
Durham
905-668-7711 ext. 3565
kevin.wilson@durham.ca
Phil Gray, P. Eng.
Project Manager
XCG Consultants Ltd.
905-829-8880 ext. 232
philg@xcg.com
This is the second in a series of newsletters to update residents, and other
interested parties, about what the Region is doing to reduce the risk of basement
flooding in the Lawrie Road Sewer Catchment Area. This newsletter can be viewed
online at www.durham.ca. Follow the links under Departments > Works > Water
and Sewer. The first newsletter can also be viewed online at this location.
Update on the Region’s activities
The Regional Municipality of Durham has recently carried out a number of steps
to investigate and take action to reduce the risk of basement flooding in the Lawrie
Road sewer catchment area, including:
 Improvements to the site drainage at the Lake Shore Sewage Pumping Station
(SPS) were completed in April.
 Inspection of the Lake Shore SPS to verify station capacity and operation.
 Implementation of a flow monitoring program to measure flow response during
dry and wet weather conditions.
 Information about the Region’s basement flooding loan program was distributed
in May. For more information about the loan program, please contact the Risk
Management Division of the Finance Department of the Region of Durham at
905-668-7711 ext. 2264.
 Letters were delivered to a number of residents, whose downspouts are
connected to the sanitary sewage system, requesting that they disconnect,
wherever possible. This disconnection will remove storm water flows from
the sanitary sewage system. Please note that in some cases disconnection
is not possible. If you have questions about this, please call Kevin Wilson at
905-668-7711 ext. 3565.
 Installation of a second flap gate on the overflow pipe from Lake
Shore SPS to the storm outfall. The flap gate will provide an
added level of protection by ensuring storm water does not flow
backwards into the sanitary sewer system.
 Closed circuit television inspection of sanitary sewer pipes and select service
lateral pipes was completed. Additional inspections may occur once the current
information is reviewed. If problems are found, the Region will take action to
reline or repair the pipes.
The Town of Ajax has also initiated a separate storm water management study in
this area to identify solutions to reduce the risk of basement flooding. For more
information about the town’s actions related to this study, please contact Steve
Brake at 905-619-2529 ext. 4206.
www.durham.ca/works
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Newsletter #2 - August 2009
Possible solutions for the Lawrie Road neighbourhood
Now that most of the background information has been analyzed, and some flow information
has been downloaded from the monitors, the team is starting to identify issues and potential
solutions. For this area, possible issues include:
 Sanitary system capacity issues during wet weather.
 Presence of excessive inflow and infiltration in the sanitary system. In other words,
groundwater (water found below the ground surface) could enter sewer pipes through
cracks, pipe joints and other system leaks (infiltration). Or, surface water could directly
enter the sanitary sewer system through manhole covers, connected downspouts and
foundation drains, uncapped clean outs, and/or illegally cross-connected catchbasins
(inflow).
 The potential of backwater conditions from the storm system at the Lake Shore SPS.
To address these issues, some possible solutions are being considered. It is important
to remember that this information is preliminary, and will be confirmed or discounted with
detailed analysis and public input.
Potential solutions include:
1. Neighbourhood source controls, such as disconnecting downspouts and foundation
drains from the sanitary sewer system to reduce the flows.
2. New storage facilities to keep excess wastewater temporarily during and after a wet
weather event.
3. Improvements to the Lake Shore SPS.
4. Modifications to the existing sanitary sewer system.
www.durham.ca/works
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Newsletter #2 - August 2009
Environmental Assessment update
In the spring, the Region started an engineering study, under the province’s Class Environmental
Assessment (EA) process (Schedule B), to identify remaining sanitary sewer system issues in the
neighbourhood and develop plans about how best to reduce the risk of basement flooding. During the
course of the EA, the study team has or will:
 Collect and review all available information. Studies conducted in the past are valuable data sources,
along with additional information collected from residents, the town and the Region.
 Understand the interaction between the sanitary and storm water systems, and identify primary
causes of flooding.
 Identify any additional early action control measures.
 Evaluate alternative control strategies to reduce the risk of basement flooding.
 Recommend solutions that will minimize the risk of basement flooding that are also environmentally
sound and cost effective.
The study team, led by XCG Consultants Limited, has placed a number of flow monitors at various locations
in the neighbourhood. Between April and October, the monitors will provide information about where water
is entering the system, the direction of the flows, and the reaction of the system. Information is being
downloaded at regular intervals. This information will be analyzed and used to support the development
of a system hydraulic model to evaluate the system under a variety of conditions and “what-if” scenarios.
What happens next?
The next step will be to use computer models as an information tool. First, the computer model will be
set up to show the existing sanitary sewer system, including the type of pipes and flows. Then, the model
will be tested to make sure it shows results that are like the ones experienced in the real world. Finally,
the potential solutions can be introduced into the model to show the effects it would have on the sanitary
sewer system.
Each solution will also be reviewed against a number of factors, such as:
 How it affects the neighbourhood.
 How it affects the natural environment.
 Performance.
 Cost.
 How easy it is to build and maintain.
These are called evaluation criteria, and they are an important and required part of any EA process.
If you have any comments or ideas about these potential solutions, or how they will be evaluated, please get
in touch with a member of the study team. Preliminary recommendations will be presented for community
feedback at a public information centre this fall.
www.durham.ca/works
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Newsletter #2 - August 2009
Taking action at home
While the Region does its work, homeowners can
also take a number of steps to reduce the amount of
water entering the sewer systems.
Use water efficiently to reduce flows to sanitary
sewer system:
 When replacing toilets
and washing machines,
choose low-flow, waterefficient models.
 Turn off the tap when
brushing one’s teeth.
 Water your lawn wisely
in the summer. It takes
only 2.5 centimetres
(one inch) of water,
per week to maintain a
healthy lawn.
 Wherever possible, disconnect downspouts from
the sewer system.
Manage your storm water at home:
 Consider soft-surface landscaping that allows
storm water to soak into the ground.
 Plant a tree or rain garden to absorb storm water.
 If your downspouts are disconnected, consider
using a rain barrel to capture water for use
around your property.
The Region adopts
a new sewer use by-law
In June 2009, revisions to the Region’s sewer
use by-law were approved. These revisions
mean that when building new homes, or
additions to existing homes, connecting private
and/or foundation drains to the sanitary sewer
system is now prohibited. Removing these
storm water flows from the sanitary sewer
system ensures that more sewage treatment
capacity is available, especially during heavy
rain and snow melt. It also means that the
sewage treatment plants and pumping stations
can operate more efficiently and reduces
the likelihood of causing sewage backups to
basements and the environment.
The revisions to the Sewer Use By-Law also
permit the Region to disconnect existing
foundation drains from the sanitary sewer if the
associated flows adversely affect the operation
of the sanitary sewer system.
Although
connecting downspouts, foundation and
private drains to the sanitary sewer system was
common practice prior to the 1980s, current
best practices are to manage storm water on
site by using sump pumps, or to connect to the
storm sewer.
A copy of the Region’s Homeowner Guide to
Foundation Drain Connections is attached to
this newsletter.
A commitment to communicate
Through the course of this study, residents
can expect to receive updates as information
becomes available. You can expect:
 A second public information centre to be held
in the fall, to present and gain feedback on
the study recommendations.
 A follow-up newsletter in the fall.
 Updates on the Region’s website at www.
durham.ca
 Responses to your inquiries, questions and
concerns throughout this study. If a response
isn’t available right away, it will be provided
as the information becomes available.
www.durham.ca/works
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