Rosedale Sanitary Sewer Feasibility Review

Introduction

The City of Chilliwack retained Wedler Engineering to review sanitary servicing options for the Rosedale area in July 2013. This review is based on a high level sanitary sewage servicing investigation completed by Kerr Wood Leidal (KWL) for the communities of Yarrow, Greendale and Rosedale in 2008. The City has requested further review on the two options, R1 and R2 presented in the KWL study and any feasible alternative options for expansion or extension of the system for potential additional cost sharing benefits.

Scope of Works

Wedler has reviewed the original report and costs and provide the following information:

• Analysis of alternative alignment options
• Potential of additional servicing options/cost sharing benefits to Popkum (FVRD)
• Analysis of the servicing integration of option R1 into the current Eastern Hillsides Servicing Plan
• Other potential cost sharing benefits

Background

The 2008 KWL report provides core and optional servicing areas for the Rosedale community along with benefitting land parcels. Substantial work was completed in conjunction with the City to establish
service areas, land use, equivalent population, water consumption (for wastewater loading) and design flows. Number of lots and equivalent design populations were provided for the Rosedale area, broken
down by the “core” area and the “optional” areas for development. The design peak wet weather flow was calculated to be 37 liters per second based on both the core and optional areas with an equivalent
population of 1824 over 367 lots. We have utilized this data in this analysis for the trunk forcemain and major pump station.

Rosedale Community Sewer System

In review of overall costs, Welder reviewed the proposed servicing strategy within the community. While the concepts are high level at this time, there are some basic constraints which govern the potential servicing. Service areas on the North side of the slough require individual pump stations to cross to the south or a stand‐alone gravity system with a local pump station. Figure 1 shows the catchment boundary proposed for the community. We have developed two options for servicing the Rosedale Community further detailed in this report.