Alameda County will have to step up efforts to assist Chinese and Spanish-speaking voters with limited English ability during elections as the result of a settlement announced Tuesday.

The Department of Justice accused the county in a lawsuit of failing to train an adequate pool of Mandarin, Cantonese and Spanish speakers to serve as poll workers and assist voters on Election Day.

The agency also alleged the county did not translate or properly distribute ballots and other election-related material in Chinese and Spanish, a violation of the federal Voting Rights Act.

The settlement worked out between the county and the Department of Justice still must be approved by the federal district court.

"It's a very good first step," said Christopher Punongbayan, an attorney with the Asian Law Caucus. His group gauged the county's performance at the polls in 2010.

The group rated Alameda County the worst among four counties, including Santa Clara, San Mateo and San Francisco, in its support of non-English speakers. The presence of federal poll monitors led to the lawsuit, Pun- ongbayan said.

Under the settlement, the county would have to distribute election-related materials and information in Spanish and Chinese. The county also would have to provide bilingual election officials at polling places and make sure signs in Spanish and Chinese are as visible to voters as signs in English at polling places. The decree would force the county to develop an advisory group made up of community advocates and members of organizations to assist in effectively providing election materials, information and assistance to Spanish- and Chinese-speaking voters.

The county has improved efforts since 1995, when advocacy groups began pushing for the changes.

The settlement determines how many workers are needed by putting the number in proportion to the number of Spanish- and Chinese-sounding surnames on the voter rolls.

"We'll have to step it up," District 5 Supervisor Keith Carson said.

There has been no formal opposition to the existing or proposed enhanced voting rights. But the county has to find a way to comply with the Department of Justice requirements despite a $138 million budget deficit during the 2011-12 fiscal year.

The cost of the changes has not been determined but could come from the county general fund and cities, Carson said.

District 3 Supervisor Wilma Chan said the county will have to call on the community to volunteer as poll workers to meet the settlement's demands. "We want to comply and we will comply," she said.

The federal Voting Rights Act requires that alternative-language ballots and other assistance be provided if either 5 percent of a county's adult citizen population, or at least 10,000 adult citizens, belong to a language minority -- in other words, a large group of people who speak the same language but have limited proficiency in English.

In California, the bar that triggers the required assistance is lower. If 3 percent of the population is monolingual in a language other than English, assistance must be provided to that group.

In Alameda County, Latino residents numbered 339,889 in the 2010 U.S. Census. That means they make up 22.5 percent of the county's 1.5 million residents. Nearly 10 percent are Chinese.

Those numbers are up from 2000, when Latinos counted for 19 percent of residents and Chinese 8 percent.

"We want to make sure they exercise their rights," Chan said.

Bay Area News Group Reporter Matt O'Brien contributed to this report.