The High Plains dairy complex reflects the new scale of the U.S. organic industry: It is big.

Stretching across miles of pastures and feedlots north of Greeley, Colorado, the complex is home to more than 15,000 cows, making it more than a hundred times the size of a typical organic herd. It is the main facility of Aurora Organic Dairy, a company that produces enough milk to supply the house brands of Wal-Mart, Costco and other major retailers.

“We take great pride in our commitment to organic, and in our ability to meet the rigorous criteria of the USDA organic regulations,” Aurora advertises.

But a closer look at Aurora and other large operations highlights critical weaknesses in the unorthodox inspection system that the USDA uses to ensure that “organic” food is really organic.

The U.S. organic market now counts more than $40 billion in annual sales and includes products imported from about 100 countries. To enforce the organic rules across this vast industry, the USDA allows farmers to hire and pay their own inspectors to certify them as “USDA Organic.” Industry defenders say enforcement is robust.

But the problems at an entity like Aurora suggests that even large, prominent players can fall short of standards without detection.

With milk, the critical issue is grazing. Organic dairies are required to allow the cows to graze daily throughout the growing season – that is, the cows are supposed to be grass-fed, not confined to barns and feed lots. This method is considered more natural and alters the constituents of the cows milk in ways that consumers deem beneficial.

But during visits by The Washington Post to Aurora’s High Plains complex across nine days last year, signs of grazing were sparse, at best. Aurora said their animals were out on pasture day and night, but during most Post visits the number of cows seen in pastures numbered in the hundreds. A high-resolution satellite photo taken in mid-July by Digital Globe, a space imagery vendor, shows a typical situation – only a few hundred in pastures. At no point were there any more than 10 percent of the herd out.

In response, Aurora spokeswoman Sonja Tuitele dismissed the Post visits as anomalies and “drive-bys.”

The milk produced also provides evidence that Aurora cows do not graze as required by organic rules. Testing conducted for the Post by Virginia Tech scientists shows that on a key indicator of grass-feeding, the Aurora milk matched conventional milk, not organic.

Finally, the Post contacted the inspectors who visited Aurora’s High Plains dairy and certified it as “USDA Organic.” Did their inspectors have evidence that the Aurora cows met the grazing requirement?

It turned out that they were poorly positioned to know.

ARE CONSUMERS MISLED?

The inspectors conducted the annual audit well after grazing season – in November. That means that during the annual audit, inspectors would not have seen whether the cows were grazing as required, a breach of USDA inspection policy.

“We would expect that inspectors are out there during the grazing season,” said Miles McEvoy, chief of the National Organic Program at USDA. He said that the grazing requirement is “a critical compliance component of an organic livestock operation.”

If organic farms violate organic rules, consumers are being misled and overcharged.

In the case of milk, consumers pay extra – often double – when the carton says “USDA Organic” in the belief they are getting something different. Organic dairy sales amounted to $6 billion last year in the U.S.

The failure to comply with organic standards also harms other farms, many of them small. Following the rules costs extra because grazing requires more land and because cows that dine on grass typically produce less milk.

Whether an organic dairy is grazing its herd is relatively easy to see, especially if roads criss-cross their pastures. It is more difficult, however, for outsiders to judge whether a dairy is following other organic rules – such as those regarding hormones and organic feed.

Ten years ago, after a complaint from a consumer group, Aurora faced USDA allegations that it breached organic rules regarding grazing and other issues. The USDA charged that Aurora was in “willful violation” of organic standards, but a settlement agreement allowed them to continue to operate.

There have been no charges since then.

But some small organic dairy farmers say that the new, large organic dairies that have popped up in the Southwest are violating standards.

On one-day visits to several large organic operations in Texas and New Mexico, a Post reporter saw similarly empty pastures. It was difficult to determine where their milk winds up on retail shelves, however, and so no chemical tests were pursued.

“About half of the organic milk sold in the U.S. is coming from very large factory farms that have no intention of living up to organic principles,” said Mark Kastel of the Cornucopia Institute, a Wisconsin-based nonprofit group representing thousand of organic farmers. “Thousands of small organic farmers across the United States depend on the USDA organic system working. Unfortunately, right now, it’s not working for small farmers, or for consumers.”

WHAT DOES THE LABEL MEAN?

The “USDA Organic” seal that appears on food packaging – essentially a USDA guarantee of quality – was created by federal rules in 2000.

Until then, convincing customers that a product was “organic” could be a murky proposition – everyone relied on informal definitions of “organic” and informal measures of trust.

The “USDA Organic” seal changed that, standardizing concepts and setting rules. It has proven a boon: Organic food sales rose from about $6 billion annually in 2000 to $40 billion in 2015, according to the Organic Trade Association.

The integrity of the new label, however, rested on an unusual system of inspections.

Under organic rules, the USDA typically doesn’t inspect farms. Instead, farmers hire their own inspectors from lists of private companies and other organizations licensed by the USDA. An inspector makes an annual visit that is arranged days or weeks in advance. Only 5 percent of inspections are expected to be done unannounced.

To keep the inspectors honest, the USDA reviews the records of each inspection outfit about every 2½ years.

This inspection system saves the USDA money because it doesn’t have to hire many inspectors. The compliance and enforcement team at the USDA National Organic Program has nine people – one for every $4 billion in sales.

At the other end of the scale from Aurora are many small dairies who have come to rely on the USDA Organic label, investing in the opportunity it represents, believing in its promise.

Several years ago, for example, Bobby Prigel, a fourth-generation dairyman with a 300-acre spread of rolling pastures and white plank fences in northern Maryland, made the switch.

With milk prices declining and feed costs rising, Prigel figured he had to try something different. The herd had been in the barn area for decades, munching feed. One day he shooed them out to pasture.

Here’s the funny thing, he said: His cows seemed confused. Though cows are natural grazers – like the wild aurochs they descended from – the grazing instincts of his cows had been dulled.

“They didn’t really know how to graze at first – they didn’t know how to bend down and get grass with their tongues,” Prigel said one day during a break on his farm. Nor were they accustomed to walking much.

THE COST OF BEING ‘ORGANIC’

Prigel, meanwhile, had to make economic adjustments.

Producing milk according to the “USDA Organic” standard costs more.

To begin with, organic cows cannot be given hormones to stimulate milk production. And any feed or pasture for the cows must be organic – that is, grown without most synthetic pesticides.

Second, to be considered organic, cows must obtain a certain percentage of their diet from grazing. Prigel is a purist and feeds his herd entirely from the pasture, but most organic dairies supplement the pasture with corn, soybeans or other grains, even during the grazing season.

The grazing requirement makes milk more costly to produce because it requires a certain amount of pasture land and because a grazing cow produces less milk than one eating a grain diet optimized for milk production.

With grass-fed cows, “there’s just not nearly as much milk,” Prigel said.

On the upside, a farmer can sell certified organic milk for almost double the price of conventional, and there are other benefits, too: The milk is measurably different, and according to the USDA, it improves cow health and reduces the environmental impacts of agriculture. Moreover, because grazing is natural cow behavior, some believe it is more humane.

“Cows aren’t supposed to stay inside and eat corn,” Prigel said.

The growth of mega-dairies that skimp on grazing and produce cheap milk appears to be crushing many small dairies, some analysts said.

“The mom and pop – the smaller traditional family dairies – who are following the pasture rules are seeing their prices erode,” said Hardin, The Milkweed editor. “It is creating a heck of a mess.”