If you live on Capitol Hill, you may find parking more difficult than ever - at least one day a week. But it's only because the city wants to do a better job cleaning your streets.

On May 15, alternate side of the street parking started on five streets on Capital Hill as part of the city program to clean arterial streets, or major thoroughfares, in the city. Unlike the streets in the Capitol Hill area, most city thoroughfares are in commercial or other non-residential neighborhoods.

The affected areas on Capitol Hill are C Street NE, East Capitol Street NE and SE, Maryland Avenue NE, Massachusetts Avenue NE and SE and Independence Avenue SE. One morning a week, residents on those streets must clear their cars from one side of the street to allow the sanitation departmant's mechanical sweeper to clean near the curbs. The job had been done by six-man crews, who swept sidewalks and the street area between cars.

Even though the program may have come as a surprise to some Hill residents, flyers were distributed May 1 notifying the residents of the parking restrictions. The restrictions are in effect from 9 a.m. to 11 a.m. On Mondays parking is limited on C Street; Mondays and Tuesdays, Massachusetts and Independence avenues; Wednesdays and Thursdays, East Capitol Street and Maryland Avenue.

Violators' cars may be ticketed or towed away.

Ann Witt, special assistant to the solid waste and management administration, said neighborhoods in Upper Northwest have had similar parking restrictions since 1973, and that the Capitol Hill thoroughfares are the last to be included in the arterial street sweeping program. Now that the arterial street program has been completed, she said, the use of the mechanical sweepers will be expanded to include more residential streets.

Whenever possible, the sanitation department has made use of existing rush hour restrictions, Witt said. But in communities like Capitol Hill, she said, the deparment sought the cooperation of residents and allowed area parking patterns to stabilize - through efforts such as permit parking - before attempting to enforce more parking restrictions.

"The willingness to move the cars must come from the citizens," said Witt. "We aren't proposing this for every neighborhood. It's the areas where we (lack) access to 50 to 100 percent of the curb that we're concerned about." She estimates that more than 50 percent of the city could have limited parking restrictions so streets can be cleaned with mechanical sweepers.

Witt said the five Capitol Hill streets were selected because of sanitation problems and the willingness of the area's residents, civic groups and grassroot politicans to help enforce the program.

She said the department has found that mechanical sweepers are more efficient and economical than the six-men crews. Witt said the mechanical sweeper costs about $2.73 a curb mile to operate; cleaning with a manual crew costs $67 a curb mile. She added that streets previously swept once every five weeks are now cleaned weekly. The manual crew are now able to devote more time to sidewalk work and there are also more men available to clean frequently dirtied streets.

Now that the city is moving into its residential cleaning program, communities with severe sanitation problems have already begun to request mechanical cleaning, said Witt. Of the areas asking for mechanical cleaning the Trinidad area is prime candidate, she said. Mount Pleasant and Dupont Circle are among numerous other neighbourhoods also requesting the mechanical sweeper, she said.

Services for the city's mechanical cleaning program were expanded in 1975, said Witt, when Congress added $1.2 million to the District sanitation budget through a federally funded sanitation program. The city hired more sanitation workers, bought 12 new mechanical sweepers and started more trainee programs, she said.