In their first debate since the June 4 primary, Santa Clara County supervisorial candidates Cindy Chavez and Teresa Alvarado on Wednesday offered few differences in how they would approach challenges facing the county, from health care to the homeless as well as social services, especially for seniors.

At an hourlong morning forum hosted by the Silicon Valley Council of Nonprofits, however, the candidates continued to highlight some already well-known platforms: Labor leader Chavez is running on her experience as a two-term San Jose city councilwoman, former head of the South Bay AFL-CIO Labor Council and current director of its think tank policy arm, Working Partnerships USA.

Alvarado, meanwhile, emphasized her knowledge of the district where she was born and raised, her work in the private and nonprofit sectors, and her current job at the Santa Clara Valley Water District as communications manager.

Because no candidate in the June primary received more than 50 percent of the vote for the District 2 seat, the top two vote-getters head to a July 30 runoff; vote-by-mail ballots will be sent out Monday.

The two women are competing to replace disgraced former Supervisor George Shirakawa Jr., who has pleaded guilty to a series of charges related to his misuse of taxpayer and campaign funds.

While Chavez is emphasizing health care, crime and social services in her campaign, Alvarado is pushing a reform agenda, in the wake of Shirakawa's troubles, to make government more transparent. Through reform, she believes the public will feel confident that their government is using their money effectively. And that, she said, will open up more funding for county services.

Wednesday's 50-member audience included local nonprofit leaders and moderator Garrick Percival, a San Jose State political science professor.

Asked about the key health care decisions the county will face as the Affordable Care Act goes into effect Jan. 1, Chavez said the new plan for the first time will put a premium on customer service at the county's hospital and clinics because "clients can take their insurance and go anywhere ... we have to improve customer service in order to keep people coming back.''

Alvarado said Obamacare will force the county to refocus "how we are providing health care from a preventive standpoint and not as a medical service provider of last resort.''

Both candidates lauded the county's work on the state-mandated realignment program that lets nonviolent offenders serve their time in local jails instead of the state penitentiary. Percival, however, pushed both candidates to address what he called the "800-pound gorilla'' in the room: the county's $1.8 billion unfunded retiree health care liability.

Chavez said the county is preparing an August study on the unfunded liability that will help county officials understand how the liability is being calculated and options that should be considered for resolving it.

But Alvarado stressed that these sorts of fiscal issues should not be viewed as an "800-pound gorilla" but discussed in a "fair, open, transparent and respectful dialogue with our current employees ... Nobody wants to see a series of cuts, but we have to look at employee contributions.''

The county, she said, should ''not be afraid to have these conversations about real financial issues that will affect our lives as individuals and as constituents and as public employees. I'm a public employee myself.''

Asked if they would support raising employee contributions to pay down that retiree health care debt, Alvarado said it would be discussed at the bargaining table.

Chavez pointed out that county employees have already made $75 million of concessions over the past few years, and city employees have had to take cuts in pay and benefits as well.

Audience members said both candidates seemed informed and prepared to take on the job.

"I would just say they were pretty even,'' said Mary Sousa, executive director of the nonprofit Portuguese Community Center. "Both are very passionate about the issues brought forward today.''

Dana Bunnett, director of Kids in Common, a child advocacy program affiliated with Planned Parenthood Mar Monte, said both candidates "are concerned about the community and will place a high priority on people over systems.''

Afterward, Percival said there was no clear winner.

"My general impression of the race is that this doesn't seem to be a race with a lot of big issues that separate the candidates,'' he said. Nevertheless, because Chavez won by 9 points in the primary, it remains Alvarado's challenge to "find some areas in policy where she can make a case that she is a better candidate for the job,'' he added.

"My overall observation is that there needs to be some sort of separation in their candidacies, or she (Alvarado) is not going to turn the tables.''