NCG030433_Letter RE Cooling Water Release_20180711

C R E :_
July 3, 2018
NCDEQ
Division of Stormwater Management
DEMLR
1612 Mail Service Center
Raleigh, NC 27699-1612
RE: Follow-up letter for stormwater release
Dear Sir/Madam;
4600 Silicon Drive
Durham, NC 27703 USA
Main: [phone]
This letter follows our telephone conversation on 7/2/2018 of a closed-loop cooling water release to stormwater.
Cree experienced a release of closed-loop cooling water on Monday, July 2, 2017 at its Durham facility located
at 4600 Silicon Drive. Our investigation revealed that the cooling water flange seal failed, allowing for cooling
water to spray through the resulting gap. Upon discovery at 7:00am on Monday, trained site emergency
personnel were dispatched to the scene to contain any further spill runoff, and the piping was fixed with
urgency.
Approximately 1,000 to 2,000 gallons of cooling water was released over the course of a day, before the issue
was discovered. The released water saturated the ground beneath it, and flowed down the asphalt parking lot to a
storm drain. Subsequent examination of the affected area revealed no observable impact to the surrounding
environment.
The flange, seal, and related piping were permanently replaced on Monday by 12:OOPM. This location, and
analogous systems around the site, will be emphasized on future facilities rounds for closer inspection to prevent
similar failures.
Please let me know if you have any questions or concerns.
Thank you and best regards;
bonna Lazzari /��/ J j
Environmental M er
Cree, Inc.
JUL 112018
DENR-LAND QUALITY
STORMWATER PERMIT 1NG