Odour Action Plan

​Future odour reduction

At the Gold Bar WWTP, we're taking steps to ensure odour levels consistently meet current and future standards and are safe for health and recreation. When it comes to monitoring and reporting odours, we are making changes at the facility to achieve the following:

• Additional, continuous air quality monitoring in a place closer to the fenceline;

• Real time results that are available in a format that is useful for stakeholders; and

• New regulatory monitoring and reporting for stakeholders to reference so they can confirm the air quality remains safe for health and recreation. 

Additional odour management projects

We'll be carrying out sever​al projects that will further reduce odour impacts from Gold Bar WWTP, while also meeting current and future odour level standards:

• Diversion Structure: At the headworks, where wasterwater enters the facility, we are designing a system that will capture and treat foul air from this wastewater by diverting it through a treatment system. We anticipate this project will be complete by 2026.​

• Primary Clarifiers: Primary clarifiers are the large tanks where solids from wastewater settle out. Clarifiers can be covered to trap foul air, which can then be extracted and sent to treatment scrubbers. At the facility, we have already covered Clarifiers 9, 10, 11, and 12 and planning is underway to cover Clarifiers 5, 6, 7, and 8.​

• Odour Scrubbers: Wet and dry scrubbers reduce odour by collecting and treating foul air using either a chemical solution or carbon filter. Four wet scrubbers and three dry scrubbers treat foul air from many areas of the facility.​
  

• Air Quality Monitoring: We continuously monitor air quality at the Gold Bar facility and use this information to improve our processes. We have a facility-wide odo​ur monitoring system, including H2S monitors, an electronic nose (e-nose), a weather station and wind sensors. We also continuously measure air quality near the facility through our Gold Bar Park ambient air quality monitoring station.​
  

The safety of the public and our employees is always our number one priority. We are constantly monitoring air quality levels at Gold Bar to confirm our odour-control systems are working properly. 

EPCOR actively measures H₂S levels at the plant. We're also members of the Strathcona Industrial Association (SIA), which does environmental monitoring across the region, including ambient air quality. While there are occasional times that H₂S levels at the plant exceed Alberta Ambient Air Quality Objectives (such as during equipment maintenance), our H₂S levels are much lower than those that can bring health concerns outlined in OH&S legislation.

​Understa​​nding H₂S

Manag​​ement actions

*6-10 PPB odour threshhold ​is when r​​​​otten egg smell may first become noticable.

Health & safety level

​

If the H₂S levels ever exceed the OH&S legislation limits, EPCOR will let you know of any concerns and any precautions you should take. One of the ways we will notify you is our through o​​ur water outages and alerts page. Any alarms you hear at the Gold Bar plant are specific to onsite workers and don't apply to nearby communities.

Previous annual reporting

The chart below shows the average H₂S levels from spot readings recorded annually at each station.

 Regulatory requirements for air monitoring

The Environmental Protection and Enhancement Act (EPEA) is the primary Act in Alberta through which regulatory requirements for air, water, land, and biodiversity are managed.

The Act supports and promotes the protection, enhancement and wise use of the environment by designating proposed activities for which an approval or registration is required.

EPCOR Water Services Inc. has an EPEA approval for operating and maintaining the Gold Bar Wastewater Treatment Plant (GBWWTP). EPEA approval holders are responsible for monitoring and reporting air quality as per the Air Monitoring Directive (AMD).  

The Air Monitoring Directive (AMD)

The AMD sets out the Provincial requirements for monitoring and reporting air quality.  The AMD requires that:

• If an approval holder's monitoring duties are fulfilled by an airshed or monitoring network, the airshed or network would monitor and report on behalf of the facility and must adhere to AMD requirements.
• Airsheds and networks must submit their air data and reporting (on a monthly and annual basis).
• Monthly and annual reporting meets the minimum data, information and content standards.

EPCOR fulfills these requirements through monitoring and reporting completed by the Strathcona Industrial Association (SIA) on our behalf.

Strathcona Industrial Association (SIA) air monitoring network

The Strathcona Industrial Association (SIA) is a multi-stakeholder environmental monitoring network. The SIA conducts air, water, and land monitoring in the Strathcona Industrial area. EPCOR is a member of the SIA since 1999. The Gold Bar Air Monitoring Station is managed by the SIA. It monitors air quality at the Gold Bar Water Treatment Plant, measuring Hydrogen Sulphide, Sulphur Dioxide, Oxides of Nitrogen, along with wind speed, direction, and temperature.  SIA stations are regularly audited by Alberta Environment and Parks. Find out more about the SIA

Air monitoring station locations

Reporting

Since 2011, EPCOR has been tracking average hourly and average daily H2S levels captured by the SIA Beverly Station (1 km NE of the GBWWTP) and the Gold Bar Station (1 km S of the GBWWTP). These levels are compared to the AAAQO of 10 ppb over a one hour period and an average of 3 ppb over a twenty-four hour period.

As shown in the graph below, the number of one hour exceedances over the AAAQO average of 10 ppb had been trending down since 2011 until 2015 when the odour scrubbing equipment at the GBWWTP failed. The odour scrubbers were returned to full working order in January 2016. Since the operational improvements and emissions reduction plan began to be implemented in early 2016, there has been continuous improvement in ambient air quality, with just four confirmed exceedances in 2016, one in 2017 and two in 2018.  There was one exceedance in 2020 at the Gold Bar Station. While our air dispersion/odour model determined the GBWWTP was unlikely to be the source of the exceedance, it was attributed to our site as a result of the current reporting methods used by the SIA.