Cole Engineering

Welcome to the Inflow and Infiltration (I/I) Reduction study website. The purpose of this website is to provide information about the I/I Reduction study that is occurring in the City of Vaughan. This website contains background information, weekly status updates of on-going testing, and the contacts of this study.

Introduction to the Project

The City of Vaughan is working with Cole Engineering Group Ltd. on an Inflow and Infiltration (I/I) Reduction study. The study’s objectives are to identify sources of I/I entering the sanitary sewers and develop a plan to reduce these “extraneous” flows.

The sanitary sewer system is an underground pipe network that collects wastewater produced by houses, businesses, and institutions. The purpose of the pipe network is to direct the wastewater to a treatment plant where the water is treated before being discharged into Lake Ontario.

The storm sewer system is an underground pipe network that collects rainwater runoff. During storm events, rain water infiltrates into pervious areas, such as grassed lawns and gardens. Any rain water that does not infiltrate will turn into runoff that will flow down impervious areas, such as roads and parking lots. Catch basins and other inlets are designed to collect the rainwater runoff and convey the water through a storm sewer system. Rain water, unlike wastewater, does not need to be treated by a plant and can be treated by on-site controls such as a stormwater management pond or an oil and grit separator. Therefore the purpose of having a storm and sanitary sewer system is to separate these flows prior to treatment and discharge to the environment.

Inflow and infiltration (I/I) occurs when rain water or groundwater enters the sanitary sewer instead of the storm sewer network. This can be through cracks or holes in the pipe network or through inappropriate connections such as catch basins or roof downspouts. I/I increases the flow and volume in the sanitary sewer and reduces the capacity of the pipe and the treatment plant. The result is a higher risk of overloading the pipe network leading to potential basement flooding and increased flows and volumes that must be treated at the plant.

The City of Vaughan and Cole Engineering are conducting this program to identify and reduce sources of I/I entering the sanitary sewers. A flow monitoring program will identify areas within the City of Vaughan that have high I/I flows and field testing will identify specific sources of I/I. The field testing includes smoke and dye testing and CCTV inspection.

What is fog testing?

The fog testing consists of blowing a harmless coloured fog into manholes and pipes and observing where the fog exits from the system. The fog is expected to exit primarily out of manholes on the street and plumbing vents stack at the top of buildings. It is also possible for fog to exit stormwater catch basins and roof downspouts at the side of a house, where inappropriate connections were made to the sanitary sewer.

The fog used in the test has no odour and is not harmful to your health, and will disappear after a few minutes. For more information on fog testing (also known as smoke testing), please visit www.smoketesting.com

Notices will be distributed to residents in areas where fog testing will be occurring. On the day of testing, Cole Engineering staff will visit each building to notify that testing will be occurring. Please note that there is no need to be home during testing and that there is no need to enter the building to conduct the test. A second notice will be distributed when testing is completed at your residence. Cole Engineering staff, identified with a company and name tag, will be on site during the entire process of the testing.

What you need to do Prior to Scheduled Fog Testing

Pour one (1) pail of water into any infrequently used sink and in your basement floor drain before the fog testing begins in your area (Refer to the notice in your mail or to the Fog Testing Status on this website for testing dates).

Call Cole Engineering [Drew Corbett at (905)940-6161 ext. 438 ] if you have a health condition you think may be affected by the testing.

Related Links

www.smoketesting.com– For further information on fog/smoke testing.

What is dye testing and why is it conducted?

Dye testing is a method used to locate rain or ground water entry points into the sanitary sewer system. During this process, non-toxic, biodegradable dyed water is introduced into roof leaders, driveway drains, or catch basins. After introducing the dyed water, the downstream sanitary sewer manhole is checked. Dye testing with a non-toxic, biodegradable dye is one way of determining where a pipe or structure drains to if it is not obvious by observation or on existing plans or records. By conducting dye testing, inappropriate connections can be identified. For instance, if a dye is introduced to a catch basin and the dye is then observed in the sanitary sewer downstream from that point, this would indicate that the catch basin is directly connected to the sanitary sewer system.

Dye testing is used to identify direct sources of I/I. The process consists of pouring harmless dye/ water mixture into potential illegal connections. These connections form part of the storm sewer system and can consist of roof drain leaders, driveway drains, manholes, catch basins, etc. After introducing the dyed water, the downstream sanitary sewer manhole is checked for dyed mixture. By conducting dye testing, inappropriate connections from the storm to the sanitary systems can be identified.

How safe is the dye used?

The dye is non-toxic, biodegradable and poses no harmful effects to humans, wildlife or the environment. The dye does not permanently stain and washes away with water. The dye is fluorescent GREEN in color. The dyed water is pour directly into the sanitary system or roof drain leaders; therefore it is unlikely that any person will come into contact with the dye. Signs will be displayed along outfalls of the storm sewer system such as rivers and creeks. Do not be alarmed if you observe a GREEN liquid entering a waterway in your area or if your waterway is GREEN during testing periods.

What do you need to know?

The resident of each property will be informed 1 week before testing by posted notice and on the day of testing by a Cole Engineering representative with and ID badge. On the day of testing, our field crews will require access to the exterior of your property i.e. roof leaders, area drains and will NOT require access to your home. There are no other measures needed to be taken by the resident before dye testing.

Call Cole Engineering [Drew Corbett at (905)940-6161 ext. 438 ] if you have a health condition you think may be affected by the testing.