At some egg farms, chickens get the run of hundreds of acres of pasture. They scratch at the ground, foraging for bugs and seeds. They peck at the grass, They engage in what the USDA calls their “natural behaviors.”

These farms can label their eggs “organic.”

At other facilities, tens of thousands of birds are packed into large warehouse like buildings and rarely get outdoors. These eggs, too, are being labelled “organic” because of lax USDA enforcement, according to the Cornucopia Institute, a nonprofit watchdog group.

“There’s just not an interest at USDA in enforcing the law,” Mark Kastel, the cofounder of the group, which is releasing a report today criticizing some of the nation’s largest egg farms and publishing a consumer’s guide to organic eggs.  “Consumers expect that they are protected from fraud. But that’s not what’s happening.”

The group’s new “consumer scorecard” ranks hundreds of egg farms around the country and describes the conditions for the animals. Several of the nation’s largest producers of organic eggs declined to answer the group’s questionnaire.

“You can get great organic eggs,” Kastel said. “You just have to do your own homework.”

The report is the latest skirmish in the debate over whether “organic” standards are being maintained at farms claiming the label. The USDA relies on private certifying companies, hired by the farms, to ensure that organics standards are being met. Critics have complained that the private certifying companies have a financial incentive to approve the operations at the farms that hire them.

In the case of eggs farms, one of the key issues is whether the hens are allowed outdoor access, as required by the organic standards.

Last year, the group filed complaints with the USDA regarding five large organic egg producers: Herbrucks, Krehers, Delta Egg Farm, Chino Valley and Bushman Farms. They were based on high-resolution aerial photographs showing the egg farms. The photographs showed no birds were outside, though some of the buildings have “porches,” covered, screened-in concrete areas that some farms have argued meet the requirement for being “outdoors.”