The suits are being filed on behalf of consumers in 27 states in US federal courts in St Louis and Denver.
They come after a two-year investigation by the US Department of Agriculture (USDA), which found that Aurora violated 14 provisions of the Organic Food Production Act.
According to outspoken organic watchdog Cornucopia Institute, "one of the most egregious of the findings was that from December 5, 2003, to April 16, 2007, the Aurora Dairy 'labeled and represented milk as organically produced, when such milk was not produced and handled in accordance with the National Organic Program regulations'".
As a result of its investigation, USDA entered into a consent agreement with the firm directing Aurora to stop organic production at one facility and make numerous changes in its operations.
The complaint filed today alleges that the illegal activities identified by USDA at Aurora's facilities should not have allowed the company to label its milk as 'organic' and that such labeling resulted in extensive consumer deception The suit seeks to recoup damages for consumers who purchased the organic milk and other sanctions seeking limits on Aurora's ability to market organic products.
For its part, Aurora has categorically dismissed the grounds of the lawsuits filed today.
"There is absolutely no basis for claims we defrauded consumers by selling milk that isn't organic - none whatsoever," said Marc Peperzak, Aurora Organic chairman and chief executive officer.
"Aurora Organic Dairy has maintained continuous organic certifications for all of our farms and facilities.
Our milk is and always has been organic."
Consumer groups do not agree, with health advocate Center for Food Safety (CFS) announcing its support of the lawsuits.
"The action filed today will ensure that there are the teeth in the organic law.
It is needed in order to ensure that American consumers can trust the USDA Organic label.
It will send a powerful message that organic standards must be maintained, ensuring that those consumers who choose to buy organic are not deceived," said Joseph Mendelson, CFS legal director.
The Organic Consumers Association (OCA) also expressed its support: "We are pleased to see this legal action.
We will do what we can to ensure that organic continues to mean organic and that consumers get exactly that when they are paying premium prices for organic food".
Aurora had previously been singled out by the OCA as one of a number of national organic dairy companies allegedly breaching organic standards.
In June this year, the organization told FoodNavigator-USA.com sister site DairyReporter.com that certain dairy groups have exploited failings in the USDA's organic certification.
But exploiting these loopholes could damage the reputation of US organic dairy products both domestically and abroad, it said.
In August this year, Aurora signed an agreement with USDA's Agricultural Marketing Service (AMS) after it was found to have breeched some of the standards outlined under the National Organic Program (NOP) regulations.
The agreement, which gave Aurora a year-long probationary period to address these concerns, required the firm to ensure cattle at its Platteville site in Colorado have daily access to pasture during the growing season.
The company will also have to reduce its herd size to meet maximum levels allowed for the size of its grazing areas at the facility.
Of these cows, those that do not comply with the organic regulation must be removed from the herd.
Aurora will be unable to sell their milk as an organic product.
Aurora has also agreed not to renew its organic certification for its site at Woodward, Colorado.
The company is also filing new organic systems plans for its Platteville, Colorado and Dublin ,Texas operations.
The group must also begin signing contracts with animal suppliers for its Texas plant to verify the organic status of animals bought to the site.
Aurora CEO Peperzak yesterday said: "our USDA consent agreement makes clear that all of our organic certifications are valid."
The firm blamed consumer groups for spreading "misinformation" that has led to the lawsuits it now faces.
"It's ironic we've been falsely accused of misleading consumers.
The principal sources of misinformation and consumer confusion are the activist groups that are attacking our company and encouraging the filing of misguided lawsuits.
Their agenda is clear: they want to limit the supply of organic milk and drive up the price paid by American families.
This would harm consumers and slow the spread of organic agriculture," said Peperzak.
"If they win, consumers lose.
But we're prepared to fight, and confident we will prevail based on the facts."