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.