Blackburn Wastewater Treatment Plant Upgrade Study

Section 6.0 -Recommended Option
6.3 EXISTING DOWNTOWN SEWERAGE SYSTEM
Flows transferred from the Blackbum catchment will connect into the existing
sanitary sewer mains at the Regional Correctional Centre that ultimately
discharge into the 600rnrn diameter City trunk sanitary sewermain on Taylor
Drive.
The estimated future peak pump flow rate h m the Mackus Road sewage lift
station is 50 Us (4350 m3/d), based on the ultimate 5,000 population. With
successll implementation of III reduction measures this flow rate could be
reduced to 40 Us. The following upgrades are based on the more conservative
50 L/s and should be reviewed at a detailed design stage. The section of
existing 200mm diameter sewer main from the discharge point of the 200mm
diameter syphon, at MH ~ ~ 2to 3 the a intersection of the 525mm diameter
main at Birch Street, will need to be upgraded to a 300mrn diameter pipe at a
minimum grade of 0.3% to handle the future pumped peak flows of
approximately 0.05 m3/s.
The section of gravity sewer main which requires upgrade totals 430 meters in
length.
The wst for this upgrading work (which requires significant road restoration)
at a unit cost of $250 per lineal metre is 430 x 5250 is approximately $107,500.
This cost includes all associated appurtenances, manholes and restoration
costs. Pipe bursting could be considered during the predesign stage as an
alternative to reduce restoration costs.
Flow capacity of existing mains on the Yellowhead Bridge and within the
subdivision on the west side of the Fraser River are listed in Appendix E.
6.4 UPGRADING PLAN
The City's accelerated 3-4 year implementation plan is to decommission the
existing Blackbum WWTP by 2003, and all flows transferred for treatment at
the Lansdowne Road WWTP via a new forcemain and trunk gravity sewer
from the Mackus Road pumpstation. An accelerated III reduction program is
to be initiated and completed to reduce the volume of wastewater being
transferred during wet weather and snowmelt conditions. The existing Mackus
Road pumpstation is to be upgraded and a new, small pumpstation constructed
at the Blackburn WWTP site to transfer flows generated in the area adjacent to
the plant to the Mackus Road pumpstation.