Seattle Mayor Jenny Durkan signed the long-debated and highly controversial head tax Wednesday evening.

"We must make urgent progress on our affordability and homelessness crisis. Looking ahead, I am focused on acting to move people off the street and into safer places, to clean up the garbage and needles that are in our parks and in our communities, and to provide resources to those people experiencing homelessness, including job training, behavioral health services, and other supportive services," said Durkan.

The head tax will begin on January 1, 2019.

"I've heard Seattle loud and clear: they want basic services delivered and are concerned whether the City of Seattle is using their money wisely, efficiently, and responsibly. As part of the budget process, I will remain focused on accountability and transparency for every department and on how this new revenue is going to be used towards homelessness services and new affordable housing," she continued.

The Seattle City Council passed the head tax on Monday. It charges big businesses $275 per year for each full-time employee.

The tax is expected to raise nearly $48 million for affordable housing and homeless services.

WATCH: Seattle City Council passes revised head tax