Investigators from the U.S. Environmental Protection Agency are still baffled by the cause of mysterious abnormalities showing up among animals and cropsraised on some farms in western Montgomery County.

According to an interim report released by the EPA this week, investigators aren’t convinced that elevated levels of fluoride and boron areresponsible for decreased milk production and grotesque physical deformities plaguing livestock in the Gilbertsville area. Nor are they sure where the fluoride and boron are coming from, according to the report.

“EPA will continue to withhold development of any final conclusions until all data and information developed or collected during the assessment period is individually and collectively evaluated,” says the report.

Mike Towle, who is coordinating the investigation for EPA, said the results of tests on several cows conducted at Cornell University should go a long way in answering those questions. The results are due late next month, he said.

In January, Douglass Township dairy farmer Wayne Hallowell and others alerted EPA to what they felt were unusual developments: Normally productive cows stopped producing milk; some failed to gain weight despite massive feedings; some developed sores that wouldn’t heal, others gave birth to deformed calves. Hallowell claimed his herd has been going downhill since 1996. But after taking soil, crop and water samples on five occasions this year, the EPA detected elevated levels of fluoride and boron but couldn’t definitely link it to the abnormalities. “The results … did not suggest a widespread threat to human health or the environment,” said the report.

Investigators did find elevated levels of boron in a limited number of wells around village of the Congo. Residents there have been supplied with bottled water by the EPA.

Elevated levels of fluoride were found in several of Hallowell’s cows but the EPA could not link their health problems to environmental contamination, according to the report.

Towle said letters were sent this month to about 100 property owners north and west of Hallowell’s farm, offering to test their well water for boron and fluoride. So far, about 70 residents have asked for the tests, which should be done during the first week of December, he said. “We’re trying to establish the boundaries of the contamination,” he said.

The EPA did solve one mystery — the unusual purple color of some crops. The report says the coloring is happening naturally because plant pigments are responding to sunlight and other stresses. “Purple coloration appears to be normal and no signs of stress beyond drought or nutrient conditions were noted,” says the report.