Video drone footage over Aurora Organic Dairy in Greeley, Colo. last year indicated that the dairy was not allowing most of its herd to graze. (Jorge Ribas/The Washington Post)

The USDA has closed an investigation into Aurora Organic Dairy, a mega-dairy highlighted in a Post story earlier this year, finding no violations of organic standards.

But the agency did not say whether the investigation disproved the potential violations The Post uncovered last year, saying only that Aurora is currently operating in compliance with organic rules.

“We determined that Aurora’s livestock and pasture management practices comply with existing USDA organic regulations and NOP policies,” Betsy Rakola, the director of enforcement for the National Organic Program at USDA wrote in a letter to Aurora. “Therefore, the case is hereby closed.”

The closure of the case was blasted by the watchdog group that filed the official complaint. The Cornucopia Institute has long criticized the USDA for lax enforcement of organic standards.

“Federal regulators believe Aurora, and other large members of the industry lobby group Organic Trade Association, are 'too big to fail,'" said Mark Kastel of the Cornucopia Institute, which filed the official complaint that set off the investigation after the Post report.

The Post reported in May that on repeated visits to the dairy last year, most of the cows were not grazing as required by organic rules. In addition, chemical analysis of the milk showed that it was more like conventional than other organic brands.

The Post also reported that inspectors who certify Aurora's dairy as “USDA Organic” conducted their annual audit last year in November, well after grazing season — a breach of USDA inspection policy. As a result, those inspectors would not have seen whether the cows were grazing as required.

Officials from Aurora Organic Dairy, which has supplied organic milk for brands sold at Walmart, Costco and Target, touted the closure of the investigation as vindication of its practices.

“The NOP confirmed what we have known all along: that Aurora Organic Dairy is a 100 percent organic company,” said Marc Peperzak, founder and CEO of the company. “We’ve confronted false criticism with facts by fully and transparently cooperating with this enforcement process, and this outcome clearly validates our organic certifications.”

Beginning this spring, following the Post story, Aurora started to graze much more of its 15,000-cow herd, according to a person who lives in the area who spoke on the condition of anonymity for fear of angering the company. When a Dallas Morning News crew approached an Aurora farm several years ago, a worker put a hand over their video camera, according to the reporters, while other Aurora personnel shooed the herd out of the feed lot and into the previously empty pastures, Kastel recalled.

The extent of the USDA investigation is not known other than that it included a visit to the farm and a review of “grazing” records including some from last year. Also unknown is whether the USDA's visit to Aurora was announced in advance.

On Wednesday, The Post asked Aurora and the USDA for records that would prove that Aurora had complied with regulations last year. Aurora has declined to say whether the USDA checked records from last year or to forward records that might have proved to the USDA that they were in compliance last year. The USDA said it reviewed grazing records from last year but has not shared the contents of those records or how they might have shown that Aurora was meeting grazing requirements.

The Post story reported that during visits to Aurora’s High Plains complex across eight days last year, signs of grazing were sparse, at best. Aurora said its animals were out on pasture day and night, but at no point during those visits was any more than 10 percent of the 15,000 cow herd out on pasture. A high-resolution satellite photo taken in mid-July by DigitalGlobe, a space imagery vendor, showed a typical situation — only a few hundred on pasture. Drone footage taken by the Post similarly showed few cows on pasture.

The USDA's Rakola said the Post photographs, visits and chemical testing did not prove violations.

“The photographs and observations referenced in the news article, while reviewed as supporting information, did not provide sufficient evidence to substantiate such violations,” Rakola said in the letter.

The USDA also confirmed that the required annual inspection of Aurora, which was conducted by the Colorado Department of Agriculture, occurred after grazing season, contrary to policy. But it announced no sanctions against the agency for the breach.

Consumers pay roughly twice the price for “USDA Organic” milk believing, among other things, that the cows that produce it are allowed to graze during grazing season.

But many organic farmers and industry observers say that USDA enforcement of those standards leave consumers far too vulnerable to fraud and small family farms to unfair competition.

The USDA typically does not inspect a farm to see whether it meets USDA organic standards. Instead, an “organic” farm hires its own inspection agency, or certifier, to judge whether it meets USDA organic standards and can feature the “USDA Organic” label. Most inspections are announced days or weeks in advance.

It was not the first time that Aurora and its inspectors at the Colorado Department of Agriculture have been under fire. In April 2007, the USDA said it had identified “willful violations” of organic rules by the dairy. Aurora had, among other things, for three years “failed to provide a total feed ration that included pasture.”

The USDA proposed revoking Aurora’s organic status and suspending the Colorado Department of Agriculture from certifying organic livestock “due to the nature and extent of these violations.”

After Aurora agreed to what the USDA called “major changes,” the USDA dropped the matter, however.

Bruce Scholten, a geographer at Durham University who has written extensively on U.S. organic dairy operations and family, compared Aurora's operations to “what crappy magicians do. They divert your attention from the essentials. And through crimes of omission or commission the USDA has been complicit.”