The 800 workers were called into work Tuesday to finish processing beef carcasses as part of a Canadian Food Inspection Agency assessment of the XL Foods plant in Brooks.
"The workers completed the job. They are now laid off again. We are waiting on the CFIA to decide when the plant can reopen," Doug O'Halloran, president of the United Food and Commercial Workers union said Wednesday.
"I think the earliest we are looking at now is Friday or maybe Monday."
The agency said it expects to complete a report and make a recommendation to the federal government about the plant before the beginning of next week.
The CFIA said its review in the coming days will include how well the XL Foods is handling E. coli controls, meat hygiene, sampling techniques and overall sanitation.
The agency said it will also analyze the results of tests done on the meat by XL Foods and CFIA inspectors.
"Based on these observations and test results, the CFIA will prepare a report of its assessment and make a recommendation on next steps," the agency said in a release.
The CFIA does not spell out what those next steps could be or how soon the plant might be able to resume slaughtering cattle or sending beef products to market.
On Tuesday night, the food agency announced yet another recall of beef from the plant, this time involving brands sold under different product names in British Columbia and Alberta. The recall of more than 1,800 products now involves 33 retail chains across Canada.
XL Foods officials could not immediately be reached for comment.
The company announced Saturday it was laying off more than 2,000 workers at the plant, which has been idle since Sept. 27. The meat packer, the second-largest in Canada, has not been allowed to export beef products into the United States since Sept. 13.
Fifteen people in four provinces have become ill from a strain of E. coli linked to the XL plant.
O'Halloran said the union planned to hold a news conference later this week about the need to bolster food safety at meat plants.
XL Foods could learn some lessons from the Cargill beef operation down the highway in High River, Alta., the union leader added.
"I think that the management at Cargill are more able to deal with all situations and they are more qualified to do the job," he said.
The United Food and Commercial Workers union also represents workers at Cargill.
"Cargill management tends to work with the workers, as opposed to XL management trying to bully the workers." O'Halloran said.
Since the XL Foods plant shut down, the Cargill facility has added a Saturday shift and has been operating six days a week.
Also on HuffPost