Garbage rates are going up in the county starting this month.

A 96-cent increase in ratepayers’ monthly bills for the first quarter of 2015 is tied to changes in the consumer price index calculated by the federal government and built into the county’s contract with Waste Management. Changes affect about 6,500 customers outside Vicksburg city limits.

“We had an allowance in there on the contract that allows them to adjust the price to the consumer price index,” Board President Bill Lauderdale said Monday as Warren County supervisors OK’d information in a letter from the garbage hauler detailing the rate hike. In 2013, the county put garbage service out for bid after decades of permitting family-run operations to collect household and commercial waste alongside larger outfits. Waste Management submitted the least expensive quarterly rates of two bids received.

A table in the company’s letter showed the index for the Department of Labor’s index for all urban wage workers and clerical workers showed a 1.96 percent increase in July 2014 compared to the same time in 2013. The rate will move to about $53.43 each quarter, up from about $52.47. It includes a $1.25 monthly surcharge that funds the county’s environmental and building permit field officers. The two positions track the number of paying customers to satisfy disposal laws enforced the Mississippi Department of Environmental Quality.

Waste Management’s letter was dated Dec. 3 and addressed to the attention of environmental officer Katie Strong. The increase is noted on customers’ bills that will cover January, February and March, though customers received no advance notice of the hike. Supervisors directed County Administrator John Smith to ask company officials in Mississippi to notify customers sooner about future rate increases.

“It would be only the right thing to do,” District 5 Supervisor Richard George said.

Twice-weekly pickup is mandated in the county’s contract with the company, as are guarantees built in that assure the company will be paid for delinquent accounts after 90 days.

Waste Management has handled residential and commercial pickup inside the city since 2001.