The Iowa Utilities Board voted Friday to split the 3-1-9 area code in eastern Iowa into two. Board spokesman Chuck Seel says the I-380/Highway 218 corridor that runs from Waterloo to Cedar Rapids and south to Keokuk, will stay with 3-1-9. Cities to the east will get a new area code.Callers would start using the new code in March and it will become mandatory in September of next year. Seel says the new area code number probably won’t be know until January.Seel says they needed to split the 3-1-9 area code to meet the growing demand for new telephone numbers.This is the second Iowa area code to undergo a split. The 5-1-5 area code in central Iowa was split up earlier this year.