American Transmission Co.

Helping to keep the lights on, businesses running and communities strong. ®

Madison substation event

At 7:39 a.m. on Friday, July 19, 2019, an American Transmission Co. transformer caught fire at Madison Gas & Electric’s Blount Street Substation in Madison, Wisconsin. A short time later a second fire occurred at the East Campus Substation. Both fires were extinguished by approximately 9 a.m.

ATC thanks Madison’s Fire and Police departments for the quick response to maintain public safety. We also thank officials from the city of Madison and the community for their patience as we worked with Madison Gas & Electric to restore power as quickly and safely as possible.

Environmental cleanup

Following the fire at the Blount Street Substation, the Wisconsin Department of Natural Resources has been on site working closely with ATC and our environmental contractors to direct all activities relating to the environmental cleanup. Overall, the environmental work at the Blount Street Substation is expected to be complete by mid-August, though the DNR will determine when it’s done. Environmental clean-up at the East Campus Substation was minimal and was completed within one week of the incident.

There are two main areas of focus:

Insulating fluid – ATC’s transformer had approximately 18,000 gallons of dielectric insulating fluid that helps to insulate and cool electrical equipment. Some of the fluid burned in the fire, some was safely pumped from the transformer, and our environmental contractor used a skimming method to separate the dielectric fluid from water used to put out the fire that flowed into the storm sewer. The city installed booms at the outlets to Lake Monona and the Yahara River to ensure no insulating fluid from the transformers made it into those waterways. The insulating fluid does not contain PCBs, and there is no evidence that insulating fluid made its way into the lake or river. Approximately 15,000 gallons of the insulating fluid has been recovered and is stored in tankers at an offsite location.

PFAS – The Madison Fire Department used approximately 120,000 gallons of water and a firefighting foam to extinguish the Blount Street Substation fire. Some form of PFAS, which are manmade chemicals that have properties that allow them to repel both water and oil, was contained in the firefighting foam. ATC’s environmental contractor, North Shore Environmental Construction, has withdrawn approximately 120,000 gallons of water from the storm sewer. The DNR asked us to test the water for PFAS, and test results have confirmed the presence of certain PFAS compounds. ATC is working with the DNR and the City of Madison to treat the 120,000 gallons of recovered water to remove all traces of PFAS before a suitable location for discharge is determined. It is anticipated that this process, which uses carbon filtering, will take approximately 4 to 6 weeks.

Substation restoration

While ATC is working to replace the damaged transformer and other equipment at Blount Street Substation, other transmission infrastructure currently operating in the greater Madison area is sufficient at this time to accommodate anticipated electric load in the region.

ATC has a replacement transformer on hand, which will be moved and installed at the Blount Street Substation. We anticipate that the substation restoration work will be complete by late summer/early fall.

Restoration work at the East Campus Substation should be complete in a few weeks.

Community impact

Road closure — Currently, one block of Main Street between East Blount and East Livingston streets is now open after a temporary closure to accommodate environmental cleanup work. We will communicate any intermittent road closures on Main Street that will be required to accommodate the staging and moving of equipment while the substation is brought back to working order.

We apologize for any inconvenience and appreciate your cooperation in maintaining safety near the substation.

Cause investigation

An investigation of the cause of the fires is underway and ATC commits to sharing information as soon as the review is complete. We anticipate that we will be able to share our findings in the coming weeks.

Contact

ATC Media Relations

mediarelations@atcllc.com
877-506-6117

Last Updated: August 9, 2019