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​The same sequence of work activities are followed like the other sanitary trunk sewer work underway across Edmonton, these include: (1) Stabilizing the situation (ensure safety, reduce risks), (2) Assessing the issue (info gathering/inspections, and assessment) (3) Engineering Design and (4) Construction.

 

Project updates

100 Avenue trunk sewer repair

  • Hand tunnel excavation and pipe installation on 100 Avenue bypass tunnel is complete.

  • Crew has also completed work in the 12 ft. shaft on 100 Avenue, building the manhole structure to the ground surface.

  • Flow in the 1950 mm sewer has been diverted to the new bypass tunnel and rehabilitation of the existing 1950 mm sewer has been completed. Manhole construction in the 14 ft. – 8 in. diameter shaft on 100 Avenue is underway.

Traffic accommodations:

Road closures on 100 Avenue will remain in effect until the 14 ft. – 8 in. diameter shaft on 100 Avenue is completed. Manhole construction on 100 Avenue is expected to be completed by early 2018.

100 Avenue pump station

  • Construction of the manhole within the pump station shaft is in progress.
  • Flow is now diverted to the new bypass tunnel. The crew will continue building the manhole to the ground surface.
  • Closure of 151 Street North of 100 Avenue will remain in effect until manhole construction is completed by the end of 2017, at which time 151 Street North of 100 Avenue will be reopened to traffic.

New bypass tunnel on 151 street between 99 avenue and 100 avenue

Construction of the 151 Street bypass tunnel is now complete and the intermediate shaft between 99 Avenue and 100 Avenue has been backfilled and restored to the ground surface.

151 street trunk sewer rehabilitation

Flows to the new bypass tunnel have now been fully diverted, work in the shaft at 151 Street and 99 Avenue has now resumed. This will involve uncapping of the shaft and rehabilitation of the existing sewer along 151 Street. This work is expected to carry over into the middle of the first quarter of 2018.

New shaft near 150 street and 99 avenue  

We are currently planning the construction of a new shaft at the intersection of 150 Street and 99 Avenue to facilitate the rehabilitation of the 99 Avenue sewer. Work is expected to begin in November 2017. A construction notice will be shared with details on traffic accommodation before work commences.

Safety

The construction areas will be fenced and/or marked as restricted areas. We will take every precaution to ensure public safety, and we also need your assistance in keeping children and pets a safe distance from the construction site.

Progress of overall construction can be found on the October update.

Overview
​A 1.5 meter diameter sanitary trunk sewer along 151 Street from 100 Avenue to 99 Avenue has been identified as having 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.
  • 2 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 2 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 2 shafts that connect the existing sanitary sewer system to the deep tunnels that run along 151 Street. The shaft will be installed 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 2 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 aim is to 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 one 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.

H2S & Carbon Monoxide Monitoring

​Hydrogen sulfide (H2S) and carbon monoxide (CO) live stream monitoring

Real-time ambient H2S and carbon monoxide (CO) monitors are in place at the southwest corner of 99 Avenue and 151 Street. These monitors will show H2S and CO levels as they occur at the site in real time. Please note the sensor readings are affected by temperature, humidity, air pressure and wind speed and may affect the accuracy of the readings. The sensors can measure H2S and CO levels to an accuracy of +/- 0.5 parts per million, and they will be adjusted once every 6 months.

All monitoring data, real time and other ambient monitors, will continue to be provided to Alberta Health Services.

The real-time ambient air monitor live stream is online and publicly available. A bin has been placed over the unit to cover it from weather and reduce reflections from the glass. The bin still allows air flow to the sensors and gives a great view. LED lights have also been added inside of the bin so the monitor can also be viewed online, at night.

City-Wide Sewer Gas Composition Study

A summary of work done for Edmonton was completed in Spring 2016 and a brief overview of the findings have been provided for the public. Given the concerns and questions that residents have frequently raised  regarding odour and health, and the length of time that the sewer rehabilitation project has been going on in this community, West Jasper Place (WJP) was selected as 1 of the 3 sites where sewer gases were sampled. 

Open house

​On May 9, 2017, an open house was held for the West Jasper Place/Sherwood community sewer rehabilitation work. The session included a presentation which provided project information and progress.

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, 2 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 being used 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.