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Mr. igor Zahynacz, P.Eng. Page Two
City of Por: Coquitlam Saptember 4, 1990

Thr ayntindle erals ih 19%, Pro a Manning's friction coefficient of a 0,012, 4 200
mm ¢ pipe is capable of conveying 0.92 IMGD at 2 FPS for full pipe flaw. A 250 mm
6 is capable of conveying 0.68 IMGD at 1.9 FPS for full pipe flow. This compares with
a present PWWF of 0.82 IMGD and a future PWWF of 0.86 IMGD into the Handley
Pump Station as projected in our November 15, 1989 pre-design letter report. A 300
Dimi & pipe io rscommondod.

The proposed 300 mm o gravity sewer profile is illustrated in the attached Page 1 of 2
sketches. Excavation of between 4% m to 5+ m is anticipated.

The north half of the proposed alignment for the 300 mm o sewer would be along the
centreiine of Freemont Street due to existing services on either side of the road. The
south half of the sewer line pass Handley Crescent would be located to the west side
of Freemont since all the services are located on the east side.

Upgrading of Freemont Pump Station

The design PWWF provided by the City for Freemont Pump Station are:

Present 12.5 M/s (200 USgpm)
Future 26.1 Va (400 USgpm)

The duplex pumps in the Freemont Pump Station are Flygt submersibles, C-3162 with
454 impellers. Each pump is designed for a peak flow of 900 USgpm at 50 ft. TDH.

The proposed Handley Crescent pumps are for a future PWWF of 45 i/s (715 USgpm).
If the sewage tributary to the Handley Crescent Pump Station is diverted to Freemont,
the increase flows are:

Present Future

Handley 686 USgpm 716 USgpm
Freemont 200 USgpm 400 USgpin .

Total 886 USgpm 1116 USgpm

The Freemont Pump Station system head curves are illustrated on page 2. of 2 of the
encicsures. The existing pumps are capable of conveying the combined present PWWI
but not the future combined PWWF.

By chenging the existing 464 impellers to 432 impellers, the pump capacity i increasec
by about 10% to between 1025 to 1100 USgpm which is slightly less than the combine
design future PWWF.

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