A discrepancy between a Maryland state law and a Prince George's County zoning ordinance is jeopardizing a Riverdale woman's at-home day care business and, potentially, hundreds of other similar day care facilities in the county.

Evelyn Larsen, who takes care of six children, in addition to four of her own, at her Queensbury Road home, has been told she must close down her business by Oct. 28.

Although she is duly licensed for that many children by the state Department of Human Resources, she is in violation of a county zoning law that prohibits providing day care for more than five children -- including her own -- in a home, according to her attorney, Linda Spevack.

That would, in effect, close down Larsen's business because it allows her to care for only one child, other than her own.

"I never dreamed I was in violation," said Larsen, 37, who has taken in children at her home for eight years and says she has a degree in early childhood education.

Although day care facilities are inspected at least yearly by the county social services department, this is the first time the zoning ordinance has been enforced, according to Frank Sullivan, director of day care for the Maryland Department of Human Resources.

County zoning officials familiar with her case could not be reached yesterday for comment.

Sherry Polvinale, who runs the Prince George's County Family Day Care Association, said that as many as 400 of the more than 600 at-home, or "family," day care providers in the county could be affected by the zoning ordinance.

Their state-issued licenses, she said, "aren't worth the paper they're written on."

"It's potentially devastating because we already have a problem having enough day care providers," Polvinale said.

"Every one of us should now be in fear of losing our business," she said.

Larsen has taken her case to County Councilman James Herl, and an aide said Herl would raise the issue in the council this week or next.

Larsen's troubles began Sept. 27, when she returned from a trip to the zoo with nine children.

What she found was a citation attached to the front door of her old, stucco-covered home.

The citation, issued by county zoning officials in response to a complaint, informed her that she was violating the longtime zoning ordinance.

She could apply for a "special exception" to the zoning law, but Spevack said that process is costly and arduous.

And the special exception still wouldn't guarantee Larsen's right to bring in six children.

Spevack, who has placed her own children with Larsen, said the first step would be to request a stay so the business can remain in operation while they work to get the law changed.

"It doesn't seem to make sense to have to do this case-by-case for every day-care center in the county," Spevack said.

Sullivan, the state day care official, said he knew of only one similar case, in Carroll County, where a day care provider was eventually given an exemption to avoid having to comply with a local ordinance.

"It's a law they've chosen not to enforce. All of a sudden, somebody has decided to enforce this law," said Larsen, who does not know who filed the complaint against her.

"I have no intention of closing down," she said, adding that she would not consider switching to a larger commerical day care facility outside her home.

"I feel little children need the warmth and security of a home, instead of strictly a learning environment," she said.