The International Union of Operating Engineers Local 49 on Monday filed an intent-to-strike notice on behalf of 176 operators at the Metropolitan Council’s nine wastewater treatment plants.

The notice comes after members overwhelmingly rejected a contract offer that union officials said would have “failed to match the compensation paid even by some small cities,” according to a news release. The notice legally triggers a 10-day cooling-off period before workers would strike. Negotiations with the Met Council will continue during that time.

“These workers kept the water flowing and the toilets flushing for the entire Twin Cities metro area during a pandemic, at great risk to themselves and their families. They never worked from home — they stayed on the job like they always do. The Met Council spends lots of taxpayer money on many things. It’s time it focused on fairly compensating critical employees who make the entire water infrastructure of the Twin Cities operate,” said Jason George, Local 40 business manager.

About 2.7 million people in 111 cities in the Twin Cities metro area rely on the wastewater treatment plants to clean the water that drains from toilets, showers, washing machines and more, the union said.