The City of Lethbridge is investigating the presence of a yellow, oily substance that was released into the Oldman River through the stormwater system.

Crews worked with local spill response specialists to contain the substance Tuesday and will continue to remove it from the river until it has passed through.

Testing is being done to determine what the substance is but preliminary results suggest it could be cooking oil.

Anything that enters street storm drains goes directly into the Oldman River untreated.

Residents are being reminded that only clean water or naturally occuring stormwater should enter the drainage system.

Examples of harmful materials include:

  • cooking oils and grease
  • industrial waste
  • pesticides, herbicides or fertilizers
  • trash, soil, leaves, and grass clippings
  • gasoline, motor oil, transmission fluid and antifreeze
  • solvents and paints
  • water from pools and hot tubs
  • soaps or detergents (including biodegradable products)
  • cement/concrete waste
  • sawdust and construction materials
  • any substance that gives off an odour