The Canadian Engineer, Volume 30. January 13, 1916. pg. 139
By L. McLaren Hunter, C.E.,
City Engineer’s Department, Ottawa.
In designing the Rideau River intercepting sewer, it was important to adopt such a route and grade as would permit of its convenient incorporation in the main drainage scheme which must be provided eventually for the whole city of Ottawa and its suburbs.
The new interceptor is to serve that part of the city lying between the canal and Rideau River, extending from an upstream limit along the canal, to the vicinity of Hurdman Road and Gladstone Avenue, or rather, to the boundary of the area naturally tributary to the Somerset Street main sewer. The area of this section is 1,060 acres, 36 per cent, of which (380 acres in the Ottawa South and Ottawa East districts) is already sewered on the combined system. Fig. I shows the sewered and unsewered areas. The former are referred to by letters and the latter by Roman numerals.
It will be noted that area “A” includes 180 acres in Ottawa South, with an outlet at Cameron Street. Area “B” includes 45 acres in Ottawa East, with an outlet at Clegg Street, and area “E” includes 155 acres in Ottawa East, with an outlet at Brunswick Street. The unsewered areas are as follows : —
- Area “I” Including 400 acres above the Cameron Street outlet.
- Area “II.” Including 180 acres between Street and Clegg Street outlets.
- Area “III.” Including 20 acres between the Clegg Street and Brunswick Street outlets.
- Area “IV.” Including 80 acres lying along the Rideau River between the Ottawa East district and the area tributary to the Somerset Street main sewer, viz., area “D.”
The present main sewer has its outlet in the Ottawa River at Edwards Mill, at the foot of John Street, and crosses the canal at Templeton Street. Some of the areas tributary to this main sewer within the city are shown in Fig. I, and are as follows: —
- Area “D,” including 235 acres between the Canal and the Rideau River.
- Area “F,” including 940 acres west of the canal.
- Area “E” (not shown on plan), including 290 acres in Rideau Ward.
The greater portion of these areas is already sewered on the combined system and the remainder in all probability will be completed on the same system.
The controlling features in the design of the interceptor were : —
( I ) The standard of cleanliness necessary with respect to the Rideau River.
( 2 ) The system to be adopted for the 680 acres of unsewered territory tributary to this interceptor.
In order to keep the Rideau River clean in its course through the city, the discharge of domestic sewerage into this section of the river has to be practically eliminated, and it is imperative to adopt the separate system for the 680 acres included in the unsewered areas 1, 2, 3 and 4, the storm sewers discharging directly into the Rideau River, and the “sanitary” sewers discharging into the new interceptor.
The costs of the two sets of pipes in these areas will be greater than if sewered on the combined system. However, the immediate cost of the interceptor would be very much greater if the separate system were not adopted.
Another factor in the recommendation of the separate system is the upstream area “I,” which is so low that it would cost too much to drain by gravity.
A relief sewer must also be built, to take care of the 940 acres west of the canal in area “F”, as the Somerset Street main is not large enough to carry the maximum discharge which will eventually take place.
The proposed route for the interceptor is as follows : — Along the low side of the territory, following more or less closely to the west bank of the Rideau River, until it nears the railways at Hurdman Road, where it turns northwards on to Lees .Avenue, along Lees Avenue under the railway tracks to Robinson Avenue, until it reaches the Rideau River again. Then it follows the west bank of the Rideau until it flows into the main sewer on Somerset Street.
In conjunction with the new Rideau River interceptor, the city council has decided to open up a street along the banks of the Rideau River and to have expropriated, where necessary, land to a width of 66 ft. In the near future it is proposed to construct a driveway connecting Rank Street, Ottawa South, with the present driveway system in Strathcona Park, at Somerset Street. A subway will have to be constructed at Lees Avenue to connect with Robinson Avenue.
The 60-inch section of the interceptor will be built of segmental blocks; the 54-inch unit and 48 inch sections, of concrete and brick.
The estimated cost of constructing the interceptor is $315,000. The work will be done by day labor under the supervision of F. C. Askwith, acting city engineer, and W. F. M. Bryce, assistant engineer of sewers. Tenders have already been called for the supply of segmental blocks and necessary equipment.
The writer is indebted for most of the above information to Messrs. R. S. and W. S. Lea, consulting engineers, Montreal, who made the report to the city on the necessity for, and the design of, the interceptor.
Source Link: Internet Archive