West Edmonton Sanitary Trunk Sewer Rehabilitation
Current Status
Phase 1
151 Street/ 100 Avenue
- Due to higher sewage flows entering the pump station than established during the design stage, the pump station is not operating as originally planned.
- Crews have found a solution to the problem with the pump station and have been working to correct it.
- New activities include constructing flow control devices in the existing collection system that will store sanitary flows upstream, reducing flows and allowing the rehabilitation work to proceed safely. The stored sewage flow will then be released during periods of low flow in the sewer.
- Once the pump station is operational, the plan is to still move ahead and divert two trunk sewers to the pump station and the flow of sewage to the shallow underground bypass also constructed as part of the project last year.
- The air scrubber will remain on 100 Avenue until the pump station issue is resolved which is estimated to be in late July.
- We now estimate the project schedule will be completed in December 2016, weather permitting, compared to the earlier October completion date.
- Until the pump station is operating, the shaft that was capped last year will remain closed.
- The following measures will be taken to reduce the odours coming from the shaft once it is opened: installation of an air scrubber (Air Scrubber 2), chemical injections to reduce the generation of hydrogen sulphide (H2S), and placing a solid cover over the shaft at the end of each shift.
- The project team is still committed to meeting again with the community once the project is back on schedule and the sewer on 99 Avenue and 151 Street has been uncapped to provide updates and receive feedback from the community. This is expected to take place around mid-August.
- During this next portion of work, the 151 Street/99 Avenue intersection will remain closed to thru traffic. Residents on 99 Avenue, between 150 Street and 151 Street, will still have access to their homes from the east.
Temporary Air Scrubber placement east of 153 Street and 100 Avenue
Air Scrubber 2 (the smaller self-contained unit with the built-in silencer) will be set up on 100 Avenue, east of 153 Street on April 18 and start operation on April 20/21. The purpose of the scrubber is to reduce odours when construction crews connect from the pump station into the existing sewer. This is a temporary location, expected to last three weeks and the unit will only operate during the day — 7 a.m. to 7 p.m.
The noise levels of Air Scrubber 2 have been measured in our construction yard (i.e. before it is installed on 100 Avenue) and the measurements show that the scrubber will not exceed the City's noise bylaw. Noise monitoring will also be done once Air Scrubber 2 is installed and starts operation.
Phase 2
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The wet weather conditions caused by rain events have delayed completing connections to the existing sewer structure. Once the pump station on 100 Avenue is operating (estimated for July) we’ll be able to complete all of the connections.
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In the next few weeks, we’ll be installing flow control facilities at 151 Street/99 Avenue and 151 Street/93 Avenue which will require temporary lane restrictions while the work is taking place.
Project Overview
The City has identified that the 1.5 meter diameter sanitary trunk sewer along 151 Street from 100 Avenue to 99 Avenue is in poor structural condition and requires immediate rehabilitation. Most of the work for this project is completed underground, but several shafts are required to access the sewer line.
- The sanitary trunk sewer along 151 Street from 100 Avenue to 99 Avenue requires immediate rehabilitation given its poor structural condition.
- Two shafts are required along 151 Street from 100 Avenue to 99 Avenue to access the deep trunk for rehabilitation. The shaft at 99 Avenue was completed in 2015. The rehabilitation work will be completed underground through these two shafts.
- A sewage bypass pipe will be installed along 151 Street from 100 Avenue to 99 Avenue.
What is involved with this project?
Phase One
The project consists of the installation of two shafts that connect the existing sanitary sewer system to the deep tunnels that run along 151 Street. City crews will install a shaft at the intersection of 151 Street and 99 Avenue and a shaft north of 100 Avenue at 151 Street. The rehabilitation work will be completed underground through these two shafts.
Roadways and any other areas that are disturbed by the construction will be restored to their initial condition at the completion of the projects.
During construction, the intersection of 151 Street and 99 Avenue will be closed and only local traffic access allowed. North of 100 Avenue, 151 Street will be closed to traffic. During non-rush hour traffic, there will be minor disruptions to east-west bound traffic at the intersection of 100 Avenue and 151 Street. The City will minimize traffic disruptions as much as possible.
Phase Two
Several condition assessments are being completed for sanitary trunk sewers in the area of 151 Street and 99 Avenue. The assessment of the trunk sewer along 99 Avenue from 151 Street to 142 Street has now been completed and the first 50 m (165 ft) has been identified to be in critical condition. The trunk sewer is a critical piece of infrastructure as it services a large portion of west Edmonton, and this sewer will need to be rehabilitated.
While the design for the rehabilitation of the 99 Avenue trunk sewer proceeds, a bypass tunnel will be constructed (as a precautionary measure) to allow flow to bypass the portion of the existing trunk sewer that is in the worst condition. This new tunnel will also help with Phase I construction by allowing work to continue if it rains, and it will form a part of the ultimate rehabilitation solution of the existing sewer.
The bypass tunnel will require a second shaft about 50 m (165 ft) east of the current work site at 151 Street and 99 Avenue.
Public Engagement / Information Updates
Task Force
West Jasper Place Sherwood Drainage Task Force Meeting #1, November 25, 2015
West Jasper Place Sherwood Drainage Task Force Meeting #2, January 21, 2016
West Jasper Place Sherwood Drainage Task Force Meeting #3, March 10, 2016
Members
- Johnothan Cruz
- Sherina Dhala
- Peter Doell
- Karl Holba
- Sandro Marrocco
- Mary-Ann McLennan
- Hanna Nash
- Shirley Thompson
- Wendy Woodruff
- Andrew Knack, Councillor Ward 1
- Clem Yong, Director, Project Delivery
- Todd Wyman, Director, Drainage Planning
- Godfrey Huybregts, Task Force Coordinator
H2S & Carbon Monoxide Monitoring
Hydrogen Sulfide (H2S) and Carbon Monoxide (CO) monitoring
Before construction and as part of the City's commitment at the public meeting held on September 15, 2015, an ambient H2S monitor will be installed north of 100 Avenue at 151 Street. Although CO is not a sewer gas, a monitor has been installed due to community concerns. The monitor will measure if ambient CO is detected at 100 Avenue and 99 Avenue.
All monitoring data is and will continue to be provided to Alberta Health Services. The City is working to develop real-time, online access to the data. Until then, the data will be shared with Task Force members.
Odour Control
Bioxide
Bioxide — a non-toxic chemical way to prevent hydrogen sulphide from forming — will be continuously injected into the system. After working hours, the shafts will be covered to minimize any odours.
Mobile Carbon Filters (Air Scrubbers)
The shaft at 151 Street and 99 Avenue is still capped. Before the cap will be removed, two larger capacity air scrubbers will be placed at the intersections of 151 Street and 99 Avenue, and 151 Street and 100 Avenue:
- air scrubber 1 — 13.4 m (44 feet) long X 6 m (20 feet) wide*
- air scrubber 2 — 9.3 m (31 feet) long X 3 m (10 feet) wide
*The dimensions for air scrubber 1 are different from when first communicated as it can be put together differently due to the modular design of the unit. The configuration the City is using is smaller than the one the manufacturer sent.
The gentleman in the following photos is 5'8" (1.77 m) for reference.
Scrubber tank (there are three) for air scrubber 1
Filter for air scrubber 1
Manifold for air scrubber 1
Air scrubber 2 (the whole unit)
Liquid Treatment of Waste Water With Chemical Injections at Pumping Stations
As an added measure of odour mitigation, and to ensure worker safety, chemical treatment of waste water will be used to reduce the amount of hydrogen sulfide in the waste water. The rate of chemical injections can be adjusted to meet changes in the condition of the waste water and the air scrubbers’ performance.
For More Information
Utilities Infrastructure
General Information
| Telephone | 311 |
|---|---|
| drainageprojects@edmonton.ca |
