The discussion was driven by an incident on May 22 during which staff at the city's wastewater treatment plant observed oil in the water.

The condition of the MV Wakashio was worsening early on Saturday and it split by the afternoon, the Mauritius National Crisis Committee said.

The Japanese ship, MV Wakashio, ran aground on a coral reef on July 25, cracked two weeks later and spilled an estimated 1,000 tons of oil into the Indian Ocean.

The company says water sampling during well flowback operations showed an "exceedance" on the produced water discharge.

The refinery has made arrangements to have the vanadium-concentrated water hauled off-site for specialized treatment, says the City of Regina.

The Water Security Agency says treatment centre operators diverted thousands of litres of wastewater following an oil spill at the Co-op Refinery.

The pipeline remained shut down Sunday, amid cleanup operations after an oil spill at the Sumas Pump Station in Abbotsford.

While there is no threat to the community, the pipeline remains shut and an investigation into the cause of the spill is ongoing, Trans Mountain said.

A full investigation is ongoing to track the costs associated with the clean up, which the City of Regina will recoup from the Co-op Refinery Complex.

The union is not only calling for more transparency but for the Ministry of Environment to conduct a full investigation into the oil spill.