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.
