The Bay area's largest school district returned to class today as summer vacation came to an end for Hillsborough County's 200,000-plus students.  

And there are plenty of changes this year for the district, which is the eighth largest in the nation.

Most notably, under the first phase of a new security plan, the district is employing 20 new community service officers at elementary schools. The officers work for the district and oversee four to six schools each. The officers do not have arrest powers like school resource officers.  

District officials said they will decide on hiring more security officers during the next three years.  

"They are here as a community builder," said Bailey Elementary principal Russell Wallace. "They are here to get to know the students, the families and work to keep our whole community safe. That's the only thing we intend on using them for: an added measure of safety and security."

Also, more than 1,000 bus drivers are running routes across the county today, after a summer in which district mechanics worked overtime to repair hundreds of buses.

There are now 200 extra buses on the roads after a school year last year that saw problems arise with buses that were broken down or out of service. School officials also created a new bus stop near Middleton High in Tampa, after two students were hit by a vehicle near the school crossing busy Hillsborough Avenue.

Those buses are delivering students to 12 schools with new principals and one new school altogether - J. Vince Thompson Elementary in Ruskin.

There are also new standards in the classroom. New language arts and math standards are being instituted this year with the Florida Standards Assessment, replacing the FCAT in the spring.