REQUEST FOR DIRECTION
DATE: October 13, 2021 Report No. EPW-21-022
TO: Laurie Hurst, Chief Administrative Officer
FROM: Jeff Miller, Director of Engineering and Public Works
SUBJECT:
Title
Inflow and Infiltration Strategy
End
ESSENTIAL QUESTION:
How will the inflow and infiltration activities for the private and public portions of the collection system be funded?
RECOMMENDATION:
Recommendation
That the COTW receive Staff Report No. EPW-21-022 for information, provide any additional direction to staff as the COTW considers advisable, and direct staff to prepare a report for Council's consideration.
Body
BACKGROUND:
The term inflow and infiltration (II) is the term to denote the flow of stormwater or ground water into the sanitary collections system. See Attachment 1 for pipe ownership, allocation of II and definitions. This water does not need to be treated before being returned to a receiving water body. Under the Liquid Waste Master Plan (LWMP), the Township has several obligations. These are:
1. Reduce the maximum average daily wet weather flow (ADWF) to less than 4 times the ADWF by 2030; and
2. Eliminate overflows less than a 5-year return period.
The Capital Region District (CRD) reports to the Province under the LWMP every two years on II flows within the Core Area Communities. 2021 is a reporting year. The report identifies that the Township has an estimated 5-year II rate of 54,896 L/ha/day. This estimate translates to an overall rating of 6.1 x ADWF.
To lower this rating, the Township and CRD developed an inflow and infiltration master plan (IIMP). The IIMP determined that the various catchments range from 5 to 9 x ADWF with an average flow of 5.7 ADWF. See Attachment 2 for catchment map. Through the IIMP it is anticipated that this rating can be lowered to the 4 x ADWF threshold.
The IIMP will see rehabilitation of sewer mains and laterals (private and public). Each catchment would need to experience rehabilitation of the various ...
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