Storm & Sanitary Sewers

The Town of Midland maintains a vital network of storm and sanitary sewer infrastructure to support public health and environmental protection. Ongoing maintenance and system upgrades help ensure wastewater is safely managed and stormwater is effectively controlled throughout the community.

Storm Sewer System

The municipal storm sewer system carries the rain and snow melt water that reaches the towns catch basins. These basins are typically found along the side of roadways or in parking lots. Water that enters a storm drain is NOT treated to remove pollutants. It is important to not dispose of any waste materials into any storm water collection point. Catch basins are never an option to dispose of hazardous materials such as paints, oil, grout wash water or drywall mud.

Sanitary Sewer System

The municipal sanitary sewer system is a system of underground pipes that transport wastewater from the privately owned buildings to the Wastewater Treatment Centre (WWTC). Manholes are used at designated intervals in a sewer line as a means of access for inspection or cleaning. Sewage is treated at the WWTC and treated water is discharged in the bay. Disposing of certain items can upset the process of treating sewage.

An underground pipe outside of your home, called a sanitary lateral, carries wastewater from your sinks, toilets, laundry, showers, etc. to the town’s sanitary sewer mains. If not cared for properly it can lead to a sewage blockage in your home.

Sewer Overflows

A sewer overflow occurs when untreated sewage from the sanitary or combined sewer systems is discharged into the environment, such as streets, waterways, or basements. In the Town of Midland, most overflows are caused by combined sewers systems that carry both sewage and stormwater. During heavy rainfall or snowmelt, these systems can become overwhelmed, leading to overflows. 

The Town's Water and Wastewater Department monitors and manages sewage systems and overflows. In the event of an overflow, we post a community advisory to report the time, location, and estimated volume of discharge.

Inflow & Infiltration (I&I)

Excess water entering the wastewater system is known as inflow and infiltration (I&I), one of the leading causes of system strain, treatment challenges, and overflow events in municipalities across Ontario. Reducing I&I helps protect our environment, improve system reliability, and avoid costly infrastructure upgrades. Property owners can help reduce inflow and infiltration.

Inflow is stormwater that enters the sanitary sewer system through direct connections. These connections send large volumes of clean rainwater directly into a system designed only for wastewater. Examples: sump pumps connected to sanitary drains, roof downspouts flowing into sewer pipes, foundation drains tied into the sanitary system, and stormwater entering through leaky or poorly sealed manhole covers.

Infiltration occurs when groundwater seeps into the sanitary sewer system through cracked or aging sewer pipes, deteriorated pipe joints, faulty service laterals, and/or defects in maintenance holes or underground connections. Over time, pipes naturally degrade and become more susceptible to infiltration.

I&I is a problem because it:

Sanitary systems are designed to collect and treat sewage—not stormwater. During heavy rain or rapid snowmelt, I&I can increase flows dramatically, pushing infrastructure beyond its intended capacity.

When the system becomes overloaded, partially treated or untreated wastewater may bypass normal processes and be released into the environment.

Every litre of stormwater entering the wastewater system must be pumped, screened, and treated—driving up operational costs that are ultimately funded through user rates.

Higher flows create increased wear on pumps, pipes, and treatment equipment, accelerating the need for maintenance and capital rehabilitation.

 

Property Owner's Responsibilities

Disposing of these items can upset the process of treating sewage:

  • Cooking oils, fats, grease, bacon drippings, butter
  • Baby wipes, “flushable” wipes, paper towels, tissues, and napkins
  • Feminine hygiene products, cotton swabs, cotton balls, and dental floss
  • Medications, vitamins, and supplements
  • Paint, solvents, cleaners, pesticides, fertilizers, and other household chemicals
  • Motor oil, antifreeze, gasoline, and automotive fluids
  • Coffee grounds, tea leaves, eggshells, food scraps, and kitchen waste
  • Hair, pet fur, kitty litter, disposable masks, and gloves

Visit idontflush.ca to learn more.

Small steps at home can make a big difference in reducing I&I:

  • Disconnect sump pumps from the sanitary sewer. Sump pumps must discharge to the yard, a drainage ditch, or the storm system (where permitted).

  • Ensure downspouts drain onto your property. Downspouts should not be connected to the sewer and should direct water at least two metres away from the foundation.

  • Maintain your private sewer lateral. The pipe connecting your home to the Town’s system is your responsibility. Cracks or leaks can allow groundwater into the sewer.

  • Seal foundation cracks. Reducing groundwater around your home decreases the chance of infiltration into private drains.

  • Keep surface water away from your home. Grading your yard to slope away from the foundation and keeping gutters clear helps reduce inflow impacts.

Town’s responsibilities

The Town maintains Town‑owned sewer pipes located under streets and public rights‑of‑way.

From May through August annually, the Town undertakes its Sewer Line Assessment Program as part of our ongoing commitment to proactive sewer system maintenance and service reliability, using the Sewer Line Rapid Assessment Tool (SL-RAT), a handheld tool that uses sound to identify potential blockages between manholes. In just a few minutes per segment, we can screen large sections of pipe, so we can direct cleaning resources more efficiently and cost effectively.

This non-invasive technology allows crews to assess sewer pipes from the surface, reducing the need for confined space entry while helping staff identify areas that may require cleaning or further inspection. By using sound-based screening to prioritize work, the Town can focus maintenance efforts where they are most needed, minimizing service disruptions and supporting the long-term performance of Midland’s sewer infrastructure.

Based on assessment results, the Town may carry out targeted sewer cleaning, closed‑circuit television (CCTV) inspections, or localized repairs as required.

Residents may see municipal crews accessing manholes in various neighbourhoods while SL-RAT assessments are underway. No interruption to water or wastewater service is expected during this work.

The Town of Midland is responsible for the portion of the sewer lateral extending from the municipal sewer main to the property line only when work is undertaken as part of a road reconstruction and/or sewer main replacement project.

The Town may also offer sewer lateral inspections to assist property owners in troubleshooting issues or in determining potential solutions where a blockage is suspected.

The Town will repair damage to a sewer lateral at no cost to the owner if:

  • the cause of the blockage or failure is located on Town property, and
  • the issue is the result of poor workmanship, negligence, or failure of the pipe material on the Town‑owned portion of the lateral.

Please note:

  • The Town assumes no responsibility for defects located within the private portion of the sewer lateral.
  • The Town is not responsible for cleanup related to sewage or water backups in basements or other areas of private property.
  • The Town assumes no responsibility for the maintenance or repair of the private sewer lateral, including (but not limited to) equipment rental, contractor costs, routine rodding, or cleaning, regardless of the cause or location of a blockage or failure.

The Town actively monitors and manages inflow and infiltration through:

  • sewer condition assessments and inspections
  • smoke testing and flow monitoring
  • targeted repairs and lining of aging sewer pipes
  • replacement of deteriorated maintenance holes
  • upgrades to the Wastewater Treatment Centre and other key assets
  • public education and enforcement around prohibited connections

The Town’s Wastewater Master Plan (2021) identified peak-flow capacity challenges at the Wastewater Treatment Centre and outlined the need for system upgrades. This work is underway through projects like the Headworks Upgrade Project, which will improve reliability and help manage higher wet-weather flows.

Frequently Asked Questions

Wastewater system operators do not have control over when overflows happen.

The Wastewater Treatment Centre is built to safely handle large amounts of water. When flows become higher than normal, the extra water is directed to a storm tank for temporary storage. If the storm tank fills up during extreme weather, an overflow may occur. Even in this situation, the water still receives partial treatment to protect the environment as much as possible.

This prevents damage to the facilities bacteriological processes and equipment.

The Town completed an I&I study and a Wastewater Master Plan to better understand where system challenges exist and how to reduce excess flows. These studies provided a clearer picture of aging infrastructure, areas with elevated I&I, and capacity pressures during peak flow conditions. Their findings continue to shape the Town’s approach to source control measures, long term capital planning, and overflow reduction strategies.

Sewer gas smell within a home is normally due to an issue within the private plumbing of a home. Call a plumber to investigate.

If a back-up from a sanitary sewer enters the home, please call 705-526-4275 to arrange for a Wastewater Operator to come and verify the blockage is not on the main line.

Once the Operator verifies that it is not that main line, the property owner is responsible for determining the cause of the back up and to call a plumber to investigate.  The qualified plumber will determine the cause of the blockage and where it is located.

Yes, RVs can empty their tanks at the Wastewater Treatment Centre (200 Bay St.) from Monday to Fridays, 7:30am–11:45am and 12:45pm–3pm. Please buzz at the front gate and speak with a Town employee prior to entering the property even if the gate is open.