ROCKVILLE, Md. (AP) — A five-cent tax on plastic bags isn’t changing the behavior of Montgomery County shoppers as much as officials had hoped.

A year after the fee went into effect, it’s generating twice the revenue officials expected. County data shows the bag tax is on pace to exceed $2 million in revenue. The county had estimated it would generate $1 million.

READ MORE: 'The School Shouldn't Be Open Right Now': Parents React To COVID-19 Outbreak At Cherry Hill Elementary Middle School

The tax was meant to discourage use of plastic, disposable bags to make up for litter found in streams and ponds. It’s meant to encourage use of reusable bags.

READ MORE: Almost 9,000 Vaccinated Marylanders Get Additional Shots Since Approval of Pfizer Booster

The District of Columbia created the region’s first bag fee in 2010. The city claimed an 80 percent drop in bag usage the first year.

But officials now acknowledge they’re not sure how many bags were used before the taxes.

MORE NEWS: 'We're The Cure To This Situation': 9 Killed, 13 Wounded In Baltimore Over The Past Week

(Copyright 2013 by The Associated Press. All Rights Reserved.)