Multiple agencies in the Denver metro area have said there is no need to call 911 for the odor unless a gas leak/hissing sound can be heard.
DENVER — Multiple Denver metro area agencies are investigating reports of widespread natural gas or sewage odors Sunday morning.
Douglas County Sheriff’s Office and South Metro Fire Rescue said that crews have been investigating in Highlands Ranch and Centennial and have been unable to find the source.
Aurora Fire said around 7:15 a.m. that Xcel Energy was aware of the odor prevalent across the Denver metro area, and that the company was working to determine the source and resolve the issue.
The agencies said there is no need to call 911 for the outside odor, unless a gas leak/hissing sound can be heard.
South Metro Fire Rescue said that a temperature inversion caused by the Arctic cold front moving through Colorado could be the reason the smell is lingering outside.
A temperature inversion is when the air temperature of a layer in the atmosphere is cooled by contacting a colder surface, causing the air mass to be colder towards the bottom and warmer towards the top.
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“Sometimes on cold mornings this happens,” the department said. “Natural gas meters are designed to burp small amounts of gas to regulate pressure and usually that vapor dissipates quickly in the atmosphere.”
South Metro said that natural gas is inherently colorless and odorless, so a mercaptan is added so that a “rotten egg” smell can be noticed when there is a leak. When there is a temperature inversion, the mercaptan odor can get trapped near the ground and linger.
As of 7:36 a.m., the department said that calls reporting the odor had slowed down.
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Read More: Reports of natural gas and sewage odor in Denver metro area