The dismantling of Sonoma County’s 25-year-old Department of Fire and Emergency Services continued this week as the Board of Supervisors shifted two of its key roles — hazardous materials programs and fire prevention — to a different county agency. Next month, another major division — emergency management — will be broken away from the department and moved more directly under the control of the county administrator. The moves stem from long-running discontent within the fire services community over a county agency that had little more than an administrative role, overseeing volunteer companies across the region. Its annual budget was $10 million — $2.4 million which went to firefighting oversight with more than half the money going to department salaries, with many positions filled by retired firefighters already getting a pension .