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Current Status of 100 Avenue Trunk Sewer Repair

The following image shows the location of work being done at the new development on 100 Avenue.

Current Status of 100 Avenue Trunk Sewer Repair Image

The City will follow the same work activities as the other sanitary trunk sewer work underway in West Jasper Place:

  1. Stabilizing the situation (ensure safety, reduce risks)
  2. Assessing the issue (info gathering/inspections, root cause assessment)
  3. Engineering Design
  4. Construction

Progress of overall construction can be found on the  January 27 Update

Progess of construction on 151 Street can be found on the February 15 Notice

Odour Mitigation

The air scrubber plays a major role in odour mitigation for the 100 Avenue shaft repair. In addition, there are also chemical injections (hydrogen peroxide injections and nitrate injections), into sewers of nearby pump stations. Hydrogen peroxide and nitrate will reduce the effects of hydrogen sulphide, a chemical created in sewer systems. This will help reduce odours and make the environment safer for our workers.

Live Stream

The real-time ambient air monitor live stream is now online

Open House

Utilities Infrastructure held an open house on October 3, 2016 for residents of West Jasper Place and Sherwood. Todd Wyman, Executive Director, Utilities Infrastructure and Clem Yong, Director, Project Delivery, Utilities Infrastructure, presented information on the  condition of local sewers, an update on the new development at 100 Avenue as well as steps taken and planned to reduce odour and noise. The Utilities Infrastructure team and a representative from the City’s traffic operations area were available to answer questions. There was also an opportunity for residents to provide comments via a feedback survey and ask questions at conversation stations set up around the hall.

The presentation and minutes from the open house, that also include a synopsis of the questions and feedback, are available for your viewing. Much of the discussion at the open house focused on odour, noise, construction activity and the impact on traffic..

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.

100 Avenue Trunk Sewer Repair Image

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.

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 six 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 The City of 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 with the City's drainage group 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 one of the three sites where sewer gases were sampled. 



Odour Control


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

Scrubber tank (there are three) for air scrubber 1

Filter for air scrubber 1

Filter for air scrubber 1

Manifold for air scrubber 1

Manifold for air scrubber 1

Air scrubber 2 (the whole unit)  

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 




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