Stormwater and Sewer Services | City of Peterborough

Sanitary Sewage System

The Sanitary Sewage System is made up of a series of pipes, maintenance holes and pumping stations that collect wastewater from the plumbing system of all buildings in our community. The system carries wastewater to the Peterborough Wastewater Treatment Plant, where we treat it and return it to the Otonabee River.

Inflow and Infiltration refers to rainwater and groundwater that enters the sanitary sewer through a variety of defects. Learn more about Inflow and Infiltration to the Sanitary System and help us fix this problem. Funding is available to help cover the costs.

We're taking action to manage flows into our sanitary sewer system based on an environmental assessment, which is a detailed review and analysis master plan.

Storm Sewer System

The Storm Sewer System includes a series of pipes and maintenance holes, as well as catch-basins, stormwater management ponds, oil and grit treatment devices and storm pipe outfalls (where stormwater goes into a water-body). All stormwater that is collected in this system goes directly to a creek or the Otonabee River without going to the Wastewater Treatment Plant. Approximately 25% of the City's stormwater receives some treatment in a stormwater management pond or oil and grit treatment device before going into a creek or the Otonabee River.

Rethink the Rain

London Street foot bridge and Otonabee River

Rethink the Rain video

Inflow and infiltration reduction

Inflow and Infiltration refers to rainwater and groundwater that enters the sanitary sewer through a variety of defects.

Inflow sources allow rainwater to enter the sanitary sewer directly from the surface through improper plumbing and cross connections. Some examples include downspout and roof drain connections, and catchbasin cross connections.

Infiltration sources allows the groundwater to seep into the sanitary sewer through cracks or bad joints in sewer pipes and manholes.

A certain amount of inflow and infiltration is unavoidable and is accounted for in routine sewer design. However, when inflow and infiltration exceeds design allowances, sewer capacity is consumed and may result in overflows, risks to health, damage to the environment and increased treatment and disposal costs.

Inflow and infiltration sources allow large volumes of clean water into the sanitary sewer system that generally were not designed to handle such volumes. Most of the sanitary network in Peterborough was designed and constructed in 1960s. Many older pipes simply don't have the capacity to deal with the volume of wastewater that now courses through them. Stormwater entering the sanitary sewers, especially in the older parts of the City, overwhelms the sewers. Sewer overload is a frequent cause of basement flooding, which is very expensive and disruptive for those affected. It may also result in sewage surcharge into the lake and rivers. This is a potential reason for the beach closing, and also causes pollution to fish and wildlife. In addition, climate change has been increasing the magnitude of storms and flooding.

Municipal attempts to prevent flooding and sewer overflows can be enormously expensive. The cost to reduce flooding in a single low-lying area could be hundreds of millions of dollars and take many years to complete. In comparison, inflow and infiltration reduction is cost effective, helps immediately, and even reduces operational and treatment costs at the Wastewater Treatment Plant. The benefits of inflow and infiltration reduction has been proven in practice in various municipalities and is strongly recommended by various private and public parties.

The City of Peterborough initiated the Infiltration and Inflow Reduction Program in April 2014. The project objective is to identify and remediate sources of extraneous flow into the sanitary system (also known as inflow and infiltration sources). Three main steps of the project are:

Source Identification;
Communication; and,
Remediation.

Step 1 is typically performed by the City although the landowner can identify suspected inflow and infiltration sources on their own property and inform the City. Step 2 is performed by the City. Step 3 is performed by the landowners, however funding may be available through the subsidy program.

Phase 1 – Source identification

Sources are identified in the field through various tests and activities. Prior to field testing, local residents and business owners will be notified. Some activities conducted in the field are:

Rain and flow monitoring;
Smoke and dye testing;
CCTV investigation and pipe condition assessment;
Sewer flushing and cleaning;
Sewer joint testing; and
Field survey.

Types of sources identified in the field are:

Defective manhole covers and risers;
Roof downspouts connected to sanitary sewers;
Catchbasins and roof drains cross connected to sanitary sewers;
Overflow structures cross connected between the sanitary and storm systems;
Foundation Drain Collectors and sump pumps connected to the sanitary sewers; and
Cracks and joints in the sanitary sewer mainline or laterals.

Phase 2 - Communication

Confirmed inflow and infiltration sources during phase 1 will be communicated to the respective landowners. In this phase, we will communicate the type and location of inflow and infiltration sources as well as their effect on the sanitary system. Also, we may provide input on owners remediation options. The owner can communicate with us if they have identified an inflow and infiltration source on their property.

Phase 3 - Remediation

It is the landowner's responsibility to remediate and remove any inflow and infiltration source within their property. However, given the importance of inflow and infiltration reduction and its benefit to the public, the City provides financial assistance through the Flood Reduction Subsidy Program. The subsidy program potentially covers up to 100% of the cost of labour and materials used for the remediation. The subsidy limit depends on the cost of remediation and the volume of inflow and infiltration reduced as a result of the reduction.

Naturally, areas with higher inflow and infiltration generation potential and historical flooding will receive higher priority. However, the residents are encouraged to contact the City if they are aware of any inflow and infiltration sources within their property.

Drinking water

Please visit our Water Services pages to learn more about the provision of drinking water in our community.

Sewer surcharge rate

The sewer surcharge rate increased from 107.69% to 109.01% of the water rate for 2026.

For the Draft 2025 Budget staff recommend that the seventh year of the ten-year implementation of the Wastewater-Sanitary Sewer surcharge rate increase be implemented. The sewer surcharge rate is a rate applied to eligible water charges.

Funds collected from this surcharge raise sewer surcharge revenues to be used by the City to pay for operating and capital sanitary sewer works.

All of the Environmental Protection operating expenses, except the Little Lake Fountain, plus Public Works Sanitary Sewer maintenance costs, are funded through Sewer Surcharge Revenues. The revenue from “extra strength” surcharge agreements, and hauled sewage from surrounding counties, will continue to offset operating costs.

All of the Environmental Protection Capital works, plus Wastewater Related Capital works, are funded either through contributions from the Waste Water Reserve Fund or through Development Charges.

Environmental Monitoring Program

The City of Peterborough's Environmental Protection Division Environmental Monitoring Program is responsible for enforcing the City's Sewer Use By-Law through monitoring programs and site inspections at industrial properties. Staff also investigate spills and complaints and provide emergency response to spills to the sewer system and local waterways.

Please contact us about complaints and Sewer Use By-Law questions.

To report a spill to the environment please call the Spills Action Centre 1-800-268-6060.