Two of Montgomery County’s three contract trash haulers are expected to have workers on strike Wednesday, keeping more than 100 drivers and helpers off the job, a spokesperson for Laborers International Union of North America said Tuesday evening.

About 70 workers from Unity Disposal and Recycling in Laurel will be in the second day of a walkout to protest the firing of a worker Monday for union activity.

Patrick Lacefield, a spokesman for County Executive Leggett, said there were no reports of interrupted service Tuesday, and that Unity was apparently able to cover its routes with non-striking and managerial personnel.

About 50 workers from Potomac Disposal of Gaithersburg announced Tuesday that they had rejected a final offer from the company and would also strike. Potomac workers struck for three days last month after alleging that the company threatened immigration enforcement.

Together the companies pick up trash and recycling at about 20,000 homes a day in parts of Bethesda, Chevy Chase, Wheaton and Silver Spring. Unity also services portions of Howard County.

The circumstances are different at each company. Unity workers, attempting to organize, were angered when Vladimir Padilla, 28, of Laurel, was fired Monday for speaking in favor of a union at a compulsory meeting called by the company Friday. Nicole Duarte, a spokesperson for the union, said the official reason given for terminating Padilla, who is from El Salvador, was that his immigration documents were not in order. Duarte said Padilla’s status is legal.

Unity chief executive Cordell Proctor did not return a phone message Tuesday.

Potomac Disposal workers won a union election several months ago and have been negotiating a contract.

There was no answer Tuesday evening at Potomac president Lee Levine’s home.