Ward 12 Storm Pond Sludge Removal Update

The City’s Water services team has been hard at work getting sludge out of two storm ponds in Ward 12 this winter.

The Stillwater Pond in Copperfield has been completed already. This one had odour issues and a significant amount of sludge to be brought out because of an abundance of biomaterial that had accumulated because of issues such as duckweed overgrowth. Now that the sediment has been removed, this should help to prevent odour and algae issues in the future, and the repeated emptying of this pond during winter months should no longer be necessary!

The second one they are working on is the Prestwick Pond, which is a much larger project. This one is being done in stages as seen in the image below, starting with the furthest west portion. Each numbered section has berms under the water separating them, which allows them to be individually drained to have the sludge removed. Each separated section has its own inlet pipe except the largest portion, section 2. This area is purely for overflow, so it will have the least amount of sediment and will be the fastest to remove the sludge. The current section’s inlet gets its runoff from Deerfoot, with the rest of them primarily getting runoff from the community. The solar-bee in the centre of the pond that has been there to help aerate and prevent odours (along with the weather station on the south side of the pond) will be removed during this process as the odour issues will be addressed with the sludge removal, which is exciting news! They anticipate this project will take until the end of April, weather permitting. The goal is to be out of the area before wildlife returns and to help protect the bird habitats.

Restoration of the ponds will be performed the first week of May 2024, weather permitting. This includes re-grading/replacement of the topsoil materials, pathway repairs (if damaged), and seeding.

The sludge is hauled off by dump trucks to an area by the Bearspaw Water Treatment Plant where it continues to de-water and dry out. This area in Bearspaw is already set up for groundwater testing and for accepting this type of product, which makes it ideal. After it dries out, it is then used in our landfills as cover.

A project of this size can be disruptive to those living close by. Residents may notice water levels beginning to lower and some odour from the ponds as organic material is exposed to the air. This is normal and the odour will dissipate quickly. Trucks will be entering and leaving the pond regularly to remove the material from the site. Traffic control signage will be in place to ensure public safety. Noise from the area, especially generator noise is likely and will comply with the Community Standards Bylaw with respect to hours of operation and noise limits. These inconveniences will only be temporary and won’t need to happen again for many years. Prestwick Pond was built in 1998 and this is its first de-sludging!

The purpose of storm ponds is to filter water before heading to our rivers. During rainfall and snowmelt, water runs over rooftops, driveways, lawns, streets and sidewalks. This stormwater collects dirt, gravel and other pollutants along the way, before entering a storm drain where storm pipes are waiting to direct it to a storm pond. The storm pond collects and holds the stormwater, allowing the dirt and other pollutants to separate and settle to the bottom of the pond, helping return cleaner water to our rivers and streams.

Storm ponds are never safe to be near or on when frozen. Water is consistently flowing in and out of the ponds, making the ice thickness unpredictable. Due to maintenance and access, the most enticing places to approach storm ponds are likely where inlet pipes are, which will have the thinnest ice from the constantly flowing water. The water in these ponds also contains sediment and contaminants, which weakens the ice. Please don’t take any chances on storm ponds in your community, instead enjoy one of Calgary’s many safe outdoor rinks. For a list of locations, visit www.calgary.ca/rinks. Many communities in Ward 12 have community-access monitored skating areas that are checked regularly for safety concerns. We regularly hear of children especially playing on storm ponds, so please tell your children of these safety concerns and encourage them to stay away.

For more information visit calgary.ca/stormponds or watch this video.