A trial over groundwater contamination by the 3M Co. in Washington County will be delayed for one week at the company's request, a judge ruled Friday afternoon.

The proceedings were set to begin next Tuesday, but Hennepin County District Judge Kevin Burke agreed to a delay so that 3M's attorneys have more time to review a pivotal study released this week by the Minnesota Department of Health.

In a report that caught legal observers by surprise, the agency said its researchers could find no link between the groundwater contamination and health effects among people living in the affected areas.

The findings go right to the heart of their case, 3M's attorneys said.

The Health Department report is consistent with similar studies it released in 2007 and 2015, but it conflicts with a study prepared by an expert witness hired by Minnesota Attorney General Lori Swanson, who is suing 3M over the contaminated water.

Natural resources economist David Sunding said he found much higher levels of cancer, premature births and low birth-weight babies, reinforcing Swanson's contention that 3M's industrial waste has caused substantial damage to Minnesota's residents and natural resources.

In afternoon arguments before Burke, 3M attorney Michael Olsen said the Health Department issued its report because "as far as we can tell, they saw what was going on [in Sunding's report] and were offended. This was misinformation to the public and they wanted to get the truth out."

In an interview with the Star Tribune on Thursday, Sunding said his research was more detailed and thus more accurate than the Health Department study.

Anthony Herman, an outside lawyer representing the attorney general's office, argued that 3M didn't need extra time to assess the Health Department study.

Herman said the state's earlier conclusions were well known and that 3M's lawyers could have found the latest study on the agency's website.

"It's not a 'game changer' " he said. "It's old news."

Herman also pointed out that, even though it found no broad pattern of aberrant health effects in the Washington County communities, the Health Department did find a higher incident of childhood cancers.

Josephine Marcotty • 612-673-7394