Inflow and Infiltration

Dave Blake
Supervisor of Environmental Services
408 James Street South, St. Marys, Ontario, N4X 1B6

T.: 519-284-2340 x 209
F.: 519-284-0902
E-Mail the Supervisor of Environmental Services
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General Overview

In 2013, the Town developed the framework for a comprehensive assessment aimed at reducing inflow and infiltration which enters the waste water collection system. Since that time, the Town has been actively working with homeowners, contractors, etc. to identify, reduce and eliminate sources of inflow and infiltration from the system.

What is Inflow and Infiltration?

Inflow and infiltration is when clear water (groundwater or stormwater) enters the sanitary collection system requiring treatment at the wastewater treatment plant. This is important because the sanitary system is designed to be a separate system from stormwater and is not designed to handle groundwater and surface water.

Public Involvement and Education

Public involvement and understanding the effects inflow and infiltration has is vital to the success of the program. Since the launch of the assessment in 2013, Town staff has been working with numerous property owners whom have come forward to rectify illegal or unknown connections contributing to inflow and infiltration. Continued involvement and cooperation from property owners will be required to ensure the program's continued success.

Area's to be Inspected in 2021

If you live in one of these areas, please contact us to arrange your Free Property Drainage Inspection:

To arrange your FREE Property Drainage Inspection, please contact Dave Blake, Environmental Services Supervisor at 519-284-2340 ext. 209 or dblake@town.stmarys.on.ca.

Why are property drainage inspections needed?

The majority of Inflow and Infiltration (I & I) takes place on private properties. I & I happen when “clean” water such as groundwater, surface water, storm water, etc. enters the wastewater collection system, requiring treatment at the Wastewater Treatment Plant.

What problems can improper drainage connections cause?

Sanitary sewer systems are designed to carry wastewater from toilets, washing machines, sinks or showers in homes or businesses to wastewater treatment locations. When an excess of water enters the system, such as during a major rainstorm, it can cause the system to overload and sewage backups or overflows to occur.

I&I is costly because overflows can back up into basements of homes and businesses, into roads and the natural environment. I&I also puts a strain on the entire wastewater system. Treatment facilities must treat a higher volume of water flow, resulting in increased operating, maintenance and capital expenses. I&I also takes up valuable capacity at facilities –requiring costly system upgrades sooner if the problem continues.

How do I know if I am contributing to sewer system overloads?

Signs that your property may be contributing to sewer system overloads are:

Sump pump in basement discharges into a larger pipe;
Sump pump does not discharge to the side of the house;
Eaves trough down spouts go underground

What may the free property drainage inspection include?

Inspections may include:

Review if the property has a sump pump, and if so where does it discharge to;
Review grading for proper drainage away from houses;
Review eaves trough down spout discharge locations and if proper drainage is present
Camera inspections of drainage systems;
Dye testing of eaves trough drains, sump pumps and foundation drains

What happens if an improper inspection is found?

If an improper connection is found during an inspection, the Town will determine any eligible rebates available to the property owner to help ensure any improper connections are properly removed.

What rebate programs are available to assist with repairs?

Three (3) rebate programs are available totaling up to $3,050 per property to help property owners disconnect properly.

Downspout Disconnection

Downspouts that are embedded in the ground could be draining into the sanitary system. You may be eligible for a $50 rebate per disconnection to a maximum of $200.

Sump Pump Disconnection

A sump pump that doesn't drain out of your property into a grassy area could be draining into the sanitary system. You could qualify for up to $350 in rebates to disconnect.

Foundation Drain Connection

If you don't have a sump pump, or are unsure if your drainage system is functioning properly around your property, it may currently be connected to the Town's sanitary sewer. You may qualify for a rebate of up to $2,500 to disconnect and install a proper drainage system.

Progress to Date

The following depicts the approximate timeline of the Inflow and Infiltration Assessment to date:

Framework for assessment developed - Completed December 2012
Background review of historical documents - Completed January 2013
Sanitary flow monitoring - Completed March 2013
Town wide manhole inspection program - Completed December 2013
Public awareness campaign - Part 1 - Completed July 2014
Manhole rehabilitation program - Completed October 2014
Public awareness Campaign - Part 2 - Completed May 2015
Sanitary smoke testing - 32,000 linear metres - July 2015 [Testing Areas]
Precipitation monitoring - ongoing
Video inspection assessments - ongoing