Photo by katerha on Flickr.

Last week brought a wave of news stories looking back at the first year of the Montgomery County bag fee. Some of them (particularly the Washington Post) concluded the bag fee is ineffective at changing behavior, as shoppers did not appear to be switching from disposable bags to reusable ones as intended.

This conclusion is incorrect. And it’s all because of one number.

Montgomery County appears to have vastly underestimated disposable bag use before the fee took effect and has not provided information on its methodology in developing pre-bag fee estimates on usage. The County says 82.9 million plastic bags were used annually before the fee. In fact, it was likely closer to 300 million.

According to a 2009 report by the US International Trade Commission, Americans used 102,105,637,000 plastic bags in 2008. That works out to about 335 bags per person. This number is used by jurisdictions all over the country in estimating the impact of bag ordinances.

If the pre-fee bag usage was in fact closer to 300 million, then the post-fee numbers actually indicate significant behavior change, in the neighborhood of a 60-70% reduction, which is similar to what DC has observed since putting its bag fee into effect.

The County also reports that it has collected just over $2 million in revenue through November 2012. Some councilmembers have raised concerns that the revenues are too high. But DC collects $1.8 to 2 million per year from its bag fee, and is only two-thirds the size of Montgomery County (and with fewer businesses subject to the bag fee). Thus Montgomery’s revenue numbers seem to be on track.

In fact, Safeway spokesman Craig Muckle says in the Capital Gazette, “In Montgomery County, Safeway saw a 70 percent drop in plastic bag use at the checkouts from 2011 to 2012. There could be other factors, but I am pretty sure the bag fee has a lot to do with it. We saw similar results from the bag fee in the District.”

Likewise, stream protection organizations are seeing fewer bags in cleanups of their waterways. These results are even being reported by Montgomery County Department of Parks and the Washington Suburban Sanitary Commission.

Bob Hoyt, Director of the Montgomery County Department of Environmental Protection, issued this statement:

Montgomery County is committed to reducing litter and is committed to the County’s Bag Law as one of the primary ways of accomplishing this goal. I believe from my own observations when I am shopping, from anecdotal information from others, reports from environmental groups engaged in litter clean ups and reports from retailers about reduced bag use that the Law is working. The Bag Law is changing consumer behavior much in the same way recycling did 20 years ago. We are committed to gathering the appropriate data but are convinced that it will confirm the positive impact the Law is having on Montgomery County’s environment.

Montgomery County is a leader for Maryland and has been effective at reducing plastic litter through its disposable bag fee. It’s a shame that one bad number is calling into question all that good work.

Julie Lawson is director of Trash Free Maryland, a nonprofit creating lasting change to prevent trash pollution. She previously worked for the Anacostia Watershed Society, volunteered with the Surfrider Foundation, and was principal at Communication Visual, a design studio for nonprofit organizations. She lives in Takoma DC with her son Owen.