Aurora Water officials are still looking for the source of a mysterious waterborne “sediment” that prompted three local hospitals to postpone surgeries late last week.

Children’s Hospital Colorado Anschutz Medical Campus, UCHealth University of Colorado Hospital, and the Rocky Mountain VA Regional Medical Center each delayed or moved some non-emergency surgeries after staff reported concerns with the water used to sterilize surgical instruments.

UCHealth University of Colorado Hospital spokesperson Kelli Christensen said the hospital’s sterile processing department is back online, and normal surgical operations have resumed.

Non-emergency surgeries at Children’s Hospital Colorado Anschutz Medical Campus will resume on Aug. 30, media relations specialist Blayke Roznowski said.

Aurora Water spokesperson Shonnie Cline said that while no additional complaints have been received from the hospitals or customers, officials are still unsure of the substance’s identity or source.

“Our understanding is a trace amount of sediment was discovered within (the) washers before sterilization and that no similar issues have been identified at any of the hospitals’ domestic water supplies (drinking water, toilets, or sinks),” Cline said.

Aurora Water said it has also stepped up its monitoring since the hospitals first reported the concern on Aug. 23.

“We have added increased sampling around the Anschutz Medical Campus and the VA Medical Center since we were notified about their concerns within their washers prior to their sterilization process,” Cline noted. “The water quality from all sampling conducted to date meets and exceeds state and federal water quality standards.”

“We made the decision to briefly postpone non-emergent surgeries while we responded to a water-related issue that reduced the capacity of our sterile processing department, which cleans and sterilizes the instruments and equipment needed for surgeries and procedures,” Roznowski said. “This decision was made to ensure we had the capacity to sterilize the instruments and equipment needed for urgent and emergent cases.”

This is the second time officials at the Rocky Mountain VA Medical Center in Aurora have had to shuffle surgeries and procedures due to fear of equipment contamination.

In April, residue — described by hospital staffers as “black flecks” — was discovered on medical equipment at the VA Medical Center. This compelled the hospital to reschedule or refer more than 200 procedures, including surgeries and dental appointments.

The Denver Gazette contacted the VA Medical Center for comment but has not received a reply.

Cline said that, to date, nothing has been identified within Aurora’s water system that does not meet the regulatory requirements.

“Aurora’s water is safe for drinking and other daily uses,” she said. “Aurora Water treats water to meet drinking water standards, while the hospitals have additional treatments to meet an industrial standard required for medical and surgical facilities. We are working with them to understand how those standards differ from drinking water standards.”

The Denver Gazette reported last month that the state health department has cited a handful of Colorado hospitals for contaminated equipment over the past three years.

Colorado Department of Public Health and Environment citations since 2021 showed that just four hospitals — Children’s Hospital of Colorado in Aurora, St. Luke’s Medical Center in Denver, Animas Surgical Hospital, and Mercy Hospital in Durango — have had issues with contaminated equipment or with the sterilization process.

Reporter Nico Brambila contributed to this story.