In the "Spillage Prevention and Control" section of the Kittitas Valley (Washington) Wind Power Project Application (available here), the expected maximum quantities are described for each of the 1.5-MW turbines planned:
- cooling fluid (glycol & water) for the generator, 50 gallons
- lubricating oil for the gears, 105 gallons
- hydraulic oil for the blade control systems, 85 gallons
- mineral oil to cool the transformer at the base of each turbine, 500 gallons
Planners in Valencia, Spain, admit the likelihood of spills as well as the dripping and flinging off of these and other fluids (see here). Older transformers may also contain PCBs.