In the northeast and southwest quadrants, sweeping will be conducted on the third Wednesday of each month on odd-numbered sides of streets and on the fourth Wednesday on even-numbered sides.

Streets without curbs and those that can't be accessed by the sweepers, either because they are too narrow or are dead ends, won't be swept.

As the program moves forward, sweepers will establish regular schedules and residents should be able to determine a narrow window of time when their neighborhood will be affected on sweeping days, officials said.

Rawlings-Blake and other officials said the expanded street sweeping will help the city meet new U.S. Environmental Protection Agency standards aimed at protecting waterways by removing pollutants at the street level before they seep into sewers and storm drains.

In 2010, the city's vacuum-powered sweepers collected nearly 7,000 tons of dirt, debris, trash and pollutants, according to city data. That amount has risen each year since, with the city sweeping up nearly 10,200 tons in 2013.

The mayor said the program will extend a valued service beyond the city's central districts, into neighborhoods where taxpayers deserve clean streets.

A cleaner Baltimore will keep residents here, she said, and will help attract new residents — a long-term goal of her administration.

"This is about making sure that we look for ways, innovative ways, to keep our waterways clean and our city streets clean," Rawlings-Blake said, "and everything we can do toward that effort makes us better."