Elkins did not find any flaws in the carrier-reported data but warned that EPA should establish a way to independently review that data.
EPA uses self-reported data from the 2,900 carriers that participate in SmartWay to calculate the environmental benefits of the program. The data is reviewed on a couple of levels, but there is no direct verification by the agency, Elkins said.
"We believe this lack of direct verification is a potential design weakness in the program, which affects the agency's ability to ensure the overall validity of claimed SmartWay Transport Partnership results," he said.
He noted that EPA is putting a verification system into place, and that this "is a step in the right direction."
The SmartWay program is by all accounts a leading example of how a public-private partnership should work.
It encourages the use of fuel-saving technologies and strategies, and makes it easier for carriers and shippers to adopt the practices of sustainability.
EPA reports that since the program began in 2004, SmartWay partner trucks (there are now about 650,000 of them) have saved more than 50 million barrels of oil.
In his report, Elkins noted reports by outside institutions that have found SmartWay helps accelerate market deployment of fuel-saving technologies. It does this by providing clear, reliable information on technology, spreading the word on efficiency and promoting research and development, he said.
Glenn Kedzie, vice president and environmental counsel at American Trucking Associations and a close follower of the program, described Elkins' report as "rather tame," as such reports go.
"Most inspector general reports are pretty damning," he said. "The worst thing (in this report), which is not a bad thing, is the message that we need to ratchet up the level of oversight of data quality."
After nine years of SmartWay, "it's pretty great to be able to tell the story that we have not come up with any instances where people have grossly misinterpreted or intentionally put information that wasn't accurate into the data system," Kedzie said.
"The best way to address this is to make sure that it doesn't become a problem."
In its response to the report, EPA said it already has begun to build a verification process.
It has identified a sample group of SmartWay shipper, carrier and logistics partners that have demonstrated compliance through use of a quality control program such as ISO certification or Six-Sigma designation.
The agency recently visited these companies to study their compliance methods, and expects by the end of this year to put together a set of best practices.
The document will have to be reviewed, a process that will take eight months. EPA said it plans to publish a best-practices guidance on the SmartWay website by August 31, 2013. After publication, it will reach out to the SmartWay community to explain the guidance and make sure everyone understands the need for data integrity.