GLADBROOK – In an update/clarification to a story first published on Dec. 27 about a possible oil leak on a Vienna Wind Farm turbine near Gladbrook, MidAmerican Energy says photographic evidence illustrates ‘lubricant residue’ – a condition the company plans to address later this year.

A photo printed in the Dec. 30, 2024 edition of the T-R that was first posted to the Tama County Against Turbines (TCAT) public group Facebook page on Dec. 13, 2024, appears to show a large black smudge running down the back of the turbine’s support tower toward the foundation.

When first contacted by the newspaper, MidAmerican Energy did not refute the ‘oil leak’ claim but also did not address the leak specifically due to the wording of questions by reporter Ruby McAllister.

The newspaper sent a follow-up email on Friday, Jan. 3, inquiring about the black smudge on the support tower in the photo.

“Wind turbines include large mechanical components, such as a generator and gearboxes, which require lubrication. While it’s not a common occurrence, grease, hydraulic fluid, or oil can leak in a wind turbine, just like a leak can occur in any mechanical equipment,” Geoff Greenwood, MidAmerican media relations manager, said in his Jan. 3 email response. “When lubricant residue appears on a tower, it can darken with dirt and dust deposits – particularly during harvest season. That appears to be what this photo depicts; however, this is a non-hazardous condition due to the types of lubricants that are used in our wind turbines.”

Greenwood said such residue will be removed at a later date.

“When we discover excessive residue on a turbine, we remove it. We intend to do that in this case after we get through the winter.”

The London-based company LAIIER, which bills itself as a specialist in “early stage liquid leak detection for commercial and industrial buildings,” addresses wind turbine oil leaks on its website.

“If oil leaks happen, they can cause a lot of environmental damage,” LAIIER states under the subhead ‘The indirect but costly impacts of wind turbine oil leaks.’

“Oil can contaminate farmlands and forests, and becomes particularly problematic when it spreads into groundwater or worse into the sea from offshore turbines. Once these chemicals enter water sources, they are hard to track and can spiral into other social, health and livestock issues.”

When it comes to wind turbine upkeep, Greenwood said MidAmerican Energy has locally based maintenance teams ready to address issues.

“MidAmerican continually monitors, maintains and inspects turbines and components to identify and address any issues,” Greenwood said. “Our maintenance and operations protocols help reduce the chances of more significant issues occurring and also help reduce downtime. And, when an issue occurs, our locally based maintenance teams address it as quickly as possible, so we can return the turbine to service as soon as it’s safe to do so. A fluid leak alone is very unlikely to cause a fire, particularly if it’s addressed properly.”