Merrill Mest remains convinced that man, not nature, caused the purple pigs.

The northern Montgomery County farmer believes that fluoride emissions from the nearby chemical plant, Cabot Performance Materials, made his cows sick and turned some nearby fields and pigs purple in the 1990s.

The courts have yet to agree. In April, a federal judge ruled that Mest and his neighbor can’t pin their earliest claims of crop and livestock damage on the company.

Mest is determined to keep up the fight through appeals, although he knows it won’t be easy.

“It’s depressing,” Mest said as he leaned on his canes at his farm one recent morning. “The whole thing is depressing.”

Mest is 61, a farmer, he said, since he began driving a tractor when he was 5.

He and his family farm between 220 and 240 acres in Upper Frederick Township, off Route 73 between Schwenksville and Gilbertsville.

In the mid-1990s, Mest noticed that his dairy cows “don’t grow right.”

The cows “couldn’t live, couldn’t die,” he told a reporter in 1999. “Kind of in between.”

Neighbor Tom Yarnall, a pig farmer near Gilbertsville, said in a separate interview at the time that “in the spring of ’92, it all went downhill.”

“We had whole litters die when they were born.”

More than 200 pigs were dead within a two-month stretch in 1993, Yarnall said. All displayed a similar symptom: They had turned purple.

Up Congo Road from Yarnall, dairy farmer Wayne Hallowell said three deformed calves had been born within a year and a half at his place in the mid-’90s.

There had been nothing like that there in the last 50 years, he said in a 1999 interview.

And, as at Yarnall’s farm, some of Hallowell’s hay had turned purple.

The farmers banded together to bring their complaints, which they said were caused by Cabot in Boyertown, to the U.S. Environmental Protection Agency in 1998.

Hallowell’s farm lies about a mile east of the Cabot property while Mest’s is about four miles east.

In a preliminary assessment completed in May 1999, the agency reported that test samples at the farms suggested that the drinking water, stream water and soil on their land were not contaminated.

The EPA report noted that the University of Pennsylvania School of Veterinary Medicine, had identified some nutrient deficiencies and bacterial disease after Yarnall reported the pig deaths in 1993.

And, according to the EPA report, state agriculture officials concluded that the purple-colored plants could have been caused by several factors: drought stress, aging, soil problems, herbicides or insects.

At the time, Cabot was using hydrofluoric acid to produce electronics. As a result, a form of fluoride was emitted into the atmosphere, a company spokeswoman said.

But high levels of four chemicals – arsenic, boron, fluoride and uranium – were found only on Hallowell’s farm, the EPA said.

The EPA concluded its report in March 2000, focusing on Hallowell’s farm. The agency said that his herd’s ills and purple coloring came from disease and a lack of exercise instead of nearby chemicals.

Yarnall, who no longer keeps pigs, has since bowed out of the suit.

But in an interview last week, he said the problem still existed, evidenced by a purplish blue tinge he said he finds in the hay that he harvests.

“You don’t find it until things dry,” he said.

And, he said, it’s not benign.

After Yarnall has been out in fields that have produced purple hay, his feet burn, he said.

“It’s something that makes you so awful tired sometime,” he said. “It’s in the ground.”

Hallowell and Mest pressed on with their fight. They filed a federal suit in August 2001, accusing Cabot of harming their farms for at least 20 years.

But in April, U.S. District Judge Cynthia M. Rufe dismissed the claims made against Cabot before the farmers contacted the EPA in 1998, noting that Hallowell was aware that his cows were injured as early as 1972.

Similarly, “Mest has admitted that he has been aware of the alleged injuries to his herd since 1980” but didn’t adequately investigate until 1998, Rufe wrote in the April 29 ruling.

Attorneys for Mest are appealing.

Cabot will not comment on the pending litigation, the company’s attorney, Neil S. Witkes, said.

In a field at the Mest farm recently, the only break in the late-morning quiet was the rustle of cornstalks.

His crops are mostly hay and field corn to feed his small herd of 45 dairy cows, with a few rows of sweet corn and tomatoes for his family table.

Mest can still drive a tractor, but otherwise he seems limited to watching and wondering.

“I love farming,” he said, standing in a barn where the occasional plop of cow manure mixed with the hum of a cooling fan at an open door.

“I like living out in the open,” he said. “I can hear the fox, crying at night.”