Upcoming Projects at Trail Waste Facility - Odour Management

Councillor's Comments

Trail Waste Facility Comments

The Trail Waste Facility can be a source of odours and is always striving to minimize its impact on the local community. The two biggest investments we make into odour reduction are in the form of gas collection and final capping systems.

This summer, the Trail Waste Facility is embarking on two significant projects, in those areas. An expansion to the landfill gas collection system is under way, and installation of the final cap a large portion of the landfill will be underway shortly.

Landfill Gas Collection

The landfill has two gas collection systems, the Landfill Gas Perimeter Collection System (LGPCS), and the main Landfill Gas Collection System (LFGCS). The perimeter system was installed in 2018 along the eastern and southern and western boundaries of TWF. Overall landfill gas collection increased by 25% at that time, which represented a significant enhancement in odour control.

Since that time, we have made significant additional improvements to the system, adding a substantial number of addition extraction wells on the waste mound to further increase our collection efficiency capabilities, and are now installing additional temporary horizontal gas collection laterals to manage gas in areas which are not yet capped. Concurrent with this project, various components of the leachate collection system are being retrofitted to reduce the risk of acting as a conduit for landfill gas.

While the Landfill Gas Collection Expansion work is under way, construction will be conducted following these best management practices:

1. Trenches excavated to allow for collection infrastructure installation shall be kept to a minimum. Excavations will be limited to that which can be reasonably utilized in each day.

2. Open areas of trench are to be kept to a minimum at the end of each construction day.

3. All waste that is removed for trenching will be replaced as soon as possible. Any excess waste is to be deposited at the tipping face where it will be covered following best management practices.

4. Trenches shall be covered with a minimum of one metre of cover material.

Operation of the Existing Landfill and the Gas Destruction (Flare) System During Construction:

1. The existing gas collection system will continue to operate throughout the construction period as much as possible. Certain collection lines will not be operational during tie-in work where the new piping systems are connected to the existing infrastructure.

2. Flare downtime is not anticipated during this work but will be kept to a minimum if it is required and will be restarted as soon as it is possible.

Landfill Cap System

As a modern engineered landfill site, TWF caps landfill stages as they are completed with a polyethylene membrane final cover system. These caps are extremely important in reducing landfill gas emissions to the environment. Odours from the landfill are the result of landfill gas escaping from the waste mound. The gas is generated by the anaerobic decomposition of organic waste in the landfill producing methane, carbon dioxide and trace elements, which can be odorous. The bacteria breaking down the waste requires moisture to survive.

To reduce the amount of moisture entering the waste mound the City is required to install a final cover over completed sections of the landfill. Stage 1, which is in closest proximity to Barrhaven was capped in 2015 and 2016 (54 acres). Stage 2 was capped in phases between 2018 and 2021 (totaling 49 acres), Stage 3a was capped in 2021 (19 acres), and this summer we are capping Stage 3b and a portion of Stage 4 (20 acres).

The order of landfilling and capping was deliberately sequenced to progress away from the community over time. Typically, a stage is capped when it is filled to its entirety, however, the City is expediting the capping of a portion of Stage 4 as it gives us an opportunity to reduce the risk of odours migrating outside of the landfill. These capping projects not only reduce odours by removing moisture, but also improve the efficiency of our landfill collection infrastructure.