Barnard's early research addressed severe eutrophication and water scarcity challenges. His four-stage nitrogen removal process and development of enhanced biological phosphorus removal became the basis for the world’s first full-scale biological nutrient removal plant in Johannesburg, South Africa. What began as a regional breakthrough ultimately reshaped wastewater treatment practices worldwide, according to Black & Veatch.

He went on to guide the design of more than 100 global nutrient removal facilities, including milestone projects on five continents. His leadership and technical insights supported large and complex treatment systems in New York City, Hong Kong and other locations, the company notes.

Born in Cape Town, South Africa, Barnard studied civil engineering at Stellenbosch University, located in the town of that name in the country before further studies at the University of Texas-Austin. After completing his Ph.D. in water resources and environmental health engineering at Vanderbilt University in 1971, Barnard returned to Cape Town, a highly populated area suffering from a water shortage and deficient water quality and where water treatment standards did not include nitrogen and phosphorus removal, causing severe eutrophication.

“When observing the green pea-soup overflowing one of these reservoirs, I decided to pursue biological means of removing these nutrients," Barnard said before his retirement. "At the time, practices like chemical treatment and stripping and ammonia were the standard. Biological treatment was still only lab scale.” 

Convincing Johannesburg to apply the process Barnard developed to its Goudkopples wastewater treatment plant—now one of the largest activated sludge biological nutrient removal facilities in southern Africa—was a career highlight, Barnard said. It now treats about 120 to 150 megaliters of wastewater per day. 

Barnard supervised the design, construction and activation of the first nutrient removal system in the U.S. at the Palmetto wastewater treatment plant in Florida in 1978. Another key achievement was the improved performance of the Sacramento regional wastewater treatment plant.

“It was such a tight design with everything working so well. The facilities have all but eliminated ammonia and significantly reduced nitrogen in the discharge,” he said.

At Black & Veatch, Barnard "expanded innovation, elevated the firm’s technical standing and mentored generations of engineers whose work continues to influence wastewater treatment practices and biological nutrient removal design worldwide,” says Leon Downing, company director of water solutions research.

Downing notes that Barnard’s “professional reputation, scientific achievements and deeply personal mentorship have left an enduring legacy on the global water profession and on Black & Veatch’s culture and technical excellence," adding that his "design of facilities to achieve biological nutrient removal with a focus on operations and maintenance will be a lasting legacy in the industry."

One thing "that made James absolutely unique was his unwavering focus on operations, listening to how the operations staff approached control at the plant, and figuring out what was causing the results they were seeing,” says Chris deBarbadillo, company plant optimization practice leader. “His ability to do that helped lead to the many process improvements he made over the decades and that the industry adopted. Operators just loved him.”

Among numerous career recognitions, Barnard received the Water Environment Federation Camp Award, International Water Association Medal, American Society of Civil Engineers OPAL Award, Singapore’s International Water Week Lee Kuan Yew Water Prize, honorary doctorates from three universities and election to the U.S. National Academy of Engineering.

Barnard’s advice for young engineers was to “be curious and question everything. Don’t just accept that what’s in the box is final.”