Delaware County 'Mystery Odor' Still Eludes Officials

DELAWARE COUNTY, PA — Months after it was first reported, residents and officials in Delaware County are still experiencing the elusive "mystery odor."

The odor was first detected back in 2019.

In October, county officials said there were 25 separate reports from 25 separate locations, mostly in western Delaware County. Some residents were reporting headaches.

Various businesses closed and the Chester Charter School had an early dismissal due to the odor.

Then a short time later in November, the smell emerged in the areas around Interstate 95 and Chester Pike.

But it turns out a Sunoco pipeline valve malfunctioned, causing a flammable petroleum-based product to leak.

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After Delco crews secured the leak, the air quality was monitored until there were dangerous levels of Volatile Organic Compounds, the county's emergency services said.

Now, in early March, residents are still smelling the odor.

One resident in the Media area said he has notice a "really bad smell," saying it was similar to raw sewage.

Another in Haverford said she smells gas all the time outside her home. "PECO has been here many times but say it’s all ok," she said.

A woman in Newtown Square said she smelled something like gas or oil recently.

In December, the county established a task force to probe the smells.

Delaware County Emergency Services are urging residents to report the smell whenever its crops up. Use the form online here to report the smell.

"The Community is our best source of information for the investigation of odors across the region," county officials said. "Smell something? Report something!"

In early February, county officials were briefed on the odors.

The investigation into the cause is now a multi-state effort with Delaware County assets partnering with Delaware and New Jersey environmental responders to identify the source.

The Delaware County District Attorney's Office Environmental Prosecutor has also joined the odor task force, as well as resources from the EAP and United State Coast Guard.

State officials have been deploying a mobile air monitoring lab at select areas around the Delaware County for analyzing.