Jun. 1—LONDONDERRY — A company that prides itself on producing a healthy product while supporting its workers and the environment is expanding as it also celebrates its 40th anniversary.

Stonyfield Organic on Thursday announced a $7 million expansion of its manufacturing plant. The 17,000-square-foot addition will expand the brand's organic yogurt pouch production capabilities by 35 percent, according to company officials.

The project and 40th birthday were honored recently at the Stonyfield facility at 10 Burton Drive, where the iconic company employs close to 400 workers.

"Everyone loves our product," said Gary Hirshberg, Stonyfield co-founder and the company's "Chief Organic Optimist."

Speaking at a gathering and ribbon-cutting on May 24, Hirshberg said the loyalty Stonyfield receives from its employees helps drive the company's success. "And we are in more stores today than we have ever been," Hirshberg added.

Stonyfield CEO Bill Cassidy said as the company continues to grow, it comes down to the "Moms, Dads and kids" who perceive the products as a valuable resource in their daily family lives.

"There's a long-term value in buying organic," Cassidy said. "We're doing what's best for the planet."

The newest expansion is the third at the Burton Drive facility, according to Bridget Pichette, Stonyfield's vice president of manufacturing. The growth will add additional jobs.

Stonyfield has a long history in Londonderry.

Back in 1983, company co-founders Samuel Kaymen and Hirshberg were running a nonprofit organic farming school with a herd of seven cows on a small farm in Wilton, N.H., teaching family-run farms how to flourish and grow while protecting the environment at the same time.

The farm eventually began to produce yogurt to help finance the mission.

In 1988 and with the company continuing to expand, Stonyfield landed in Londonderry with an updated facility on 27 acres of land and a growing line of organic yogurt products.

The Londonderry facility was constructed with safe and healthy practices in mind, utilizing solar power, energy-efficient lighting and recycled materials.

Kaymen eventually retired and Hirshberg stepped down from his position, but remained on the Stonyfield board. Kaymen died last year and Stonyfield will dedicate the new building to him.

In his obituary, Kayman was described as "a giant among us. He was an impassioned visionary, activist, advocate, and educator on behalf of the health of the planet and all of its inhabitants."

The company continues to operate efficiently and with the environment and planet in mind. That includes a strong effort for environmental advocacy, awareness for healthy lifestyles, products, and support for other causes in the community and beyond.

After 40 years in business, Cassidy said the company couldn't be prouder of what has been accomplished, starting with those beginnings on a simple farm in Wilton.

"We've had an incredible journey to this point," he said. "We are excited about the next 40 years."

For Hirshberg, producing healthy products while supporting safe and secure farming and environmental measures continues to be Stonyfield's mission.

"Organic," he said. "It's why we exist. It's why we are growing. We do it because it's the right thing to do."