Long term wastewater treatment planning

Our long-term plan outlines ongoing investments at our plant to ensure it's safe, reliable and meets our commitment to preserve river valley parkland by keeping future development within our current site.

Planning wastewater treatment for the long term

On average, over $50 million in capital projects for maintenance and rehabilitation are undertaken during each performance based regulation (PBR) period at Gold Bar Wastewater Treatment Plant (WWTP) in Edmonton. For the 2017-2021 period, City Council approved $235 million in funding for capital projects at Gold Bar WWTP. EPCOR has committed to accommodating future wastewater flows at the plant through 2060 while remaining within our existing footprint and fenceline.

Most investment at Gold Bar WWTP is reliability driven: maintaining/replacing assets to keep the plant running safely and reliably. As assets are repaired or replaced, there are often positive impacts on the plant's ability to treat wastewater.

How we plan

EPCOR plans for the long-term by preparing an Integrated Resource Plan. This planning document takes into consideration input from the community, is regularly updated, outlines the factors taken into consideration in the planning process and describes the budget allocated for specific areas of future investment at Gold Bar WWTP. The IRP focuses on reliability and rehabilitation of current assets while aligning current and future work to help achieve the five shared outcomes between EPCOR and nearby Edmonton communities (quality of life; safety; relationship; environment; reliable, responsible and sustainable.)

EPCOR’s IRP also takes population growth and water conservation into consideration. Total water usage in Edmonton has essentially stayed the same over the last 40 years as added flows from population growth have been offset by a systematic decline in water consumption. This trend in water consumption affects the solids, liquids and nutrients treated at Gold Bar WWTP.

How EPCOR will handle future flows at the Gold Bar WWTP

The Gold Bar WWTP is able to safely handle incoming wastewater flows without expanding beyond the current footprint and fenceline through to 2060 and beyond. We'll have to increase nutrient removal capacity in order to keep pace. To do this, we'll be adding membrane technology to our secondary clarifier tanks. If South Edmonton Sanitary Sewer (SESS) flows are redistributed between Gold Bar WWTP and Alberta Capital Region Wastewater Commission (ACRWC) these additions will be required at a slower pace.

How we will adapt the wastewater treatment facility without community impact

We've reviewed engineering reports and now expect only a modest increase in future wastewater flows because per person water use is declining. Our baseline projections show a less than 1% increase per year in the peak flow rate.

As water volumes decline, the concentration of nutrients in wastewater grows. These nutrients need to be removed before treated water is returned to the river. We plan to do this by retrofitting existing tanks at the plant with membrane technology, which provides microfiltration. These units will be gradually added to existing concrete tanks at the plant as needed.

We expect the first of these membrane filtration systems will be installed around 2027. Over time, more will be added based on treatment needs. By 2061—the last year in our current long-term plan—our forecasts show that up to seven of the 11 tanks may have membrane filtration units installed. These retrofits mean there is no need to expand the plant outside the existing fenceline into the foreseeable future.

Starting in 2027, EPCOR will start upgrading existing secondary clarifier tanks with membrane technology.

Membrane technology that would be added to existing tanks.

Ready for a range of scenarios

The long term plan looks at two main scenarios. The first scenario looks at the possibility of the South Edmonton Sanitary Sewer (SESS) system flows directed toward the Gold Bar WWTP after 2038. The alternative scenario looks at the possibility of future SESS flows diverted towards the Alberta Capital Region plant after 2038 instead.

In both scenarios, ongoing investments will be made at Gold Bar WWTP to ensure safe, reliable operations, and to meet the commitments to the community. The only difference between the scenarios is the number of treatment tanks where membrane technology is installed. The pace of these retrofits will be at a slower pace if a portion of south Edmonton's wastewater is directed to another plant.

Buffer zones from wastewater treatment plants

EPCOR understands the importance of odour reduction and has prioritized plans to continue decreasing odour impacts beyond the fenceline.

Buffer zones or setback distances are design standards for new infrastructure. Setback distances are designed to limit the chances of odours impacting the community. This requirement was first considered as part of provincial design guidelines in 1976, approximately 20 years after the plant was built and about 15 years after residents had moved in closer to the plant. Gold Bar is 100% compliant with provincial environmental standards and guidelines.

We're continuing to invest in odour management and monitoring. New monitoring systems are being installed that will provide real-time reporting on ambient air quality next to the plant, and help ensure Gold Bar remains compliant at all times.