Channel 11 takes a closer look at ‘oil and chip’ as roadwork is set to begin soon

PITTSBURGH — It’s that time of year once again: PennDOT and various municipalities are gearing up to “oil and chip” the roadways.

It’s a maintenance treatment that prompted several viewers to contact Channel 11 with complaints last year. Residents and business owners were upset about the extensive dust and rock left behind.

As PennDOT prepares to resume the maintenance work for this year, Channel 11 is diving deeper into what the method entails and why it’s used.

Lori Musto, PennDOT Assistant District Executive for Maintenance in District 11 told Channel 11 that the department refers to “oil and chip” as “sealcoat” and explains that it essentially “seals the roadway” to fill in cracks and prolong the life of the pavement in between paving cycles.

Musto recognizes that not every community member is thrilled when the work is done.

“It’s nobody’s favorite... you drive over it, you hear the stones chipping up,” she said, adding that drivers should “slow down” if traveling on a road that has sealcoat, especially for the first few days.

Musto, however, insists that the operation is “critical.”

We asked her about alternatives. She said that paving would be another option, but it’s “extremely” costly in comparison.

According to Musto, the average cost to sealcoat one mile of roadway in Pennsylvania is about $16,000. Meanwhile, the cost to mill and pave a mile would be nearly four times as much.

At an estimated cost of $67,000 a mile, paving each roadway would not be “feasible” on the cycle that it would need to be performed, she said.

Currently, PennDOT performs sealcoat operations each year, but crews rotate which communities receive it. State roads that are sealcoated see the treatment about every six years.

This spring, the department is targeting several southern Allegheny County communities, including Bethel Park, Upper St. Clair, Elizabeth and Forward Township.

Work is set to begin on May 15, starting with Franklin Road in Pine Township and Geyer Road in Shaler.

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Last September, residents in Millvale were upset by the work, and felt that it shouldn’t have been performed on residential streets.

Channel 11 revisited the borough in late April. The residual dust that had coated homes and vehicles in the fall had dissipated, but there were still small stones off to the sides of the roads.

One resident told Channel 11 that the dust was around until “the rains and snow” washed it away over the course of many weeks. Josephine Magill told us that it impacted “the sidewalks, with a lot of debris getting kicked up.”

When the work was initially performed, unhappy residents had wondered if their health was at risk from breathing in the debris left behind.

Channel 11 took that question to the American Lung Association.

Kevin Stewart, Director of Environmental Health, told Channel 11 that when it comes to excessively settled dust and loose stones, “those, generally speaking, are not respiratory hazards.”

He said, “the idea is that, if the dust is big enough in the atmosphere to settle out, it’s not likely to be a significant respiratory hazard, however, there could be components of the dust that would be airborne, invisible, and could get into the lungs.”

Stewart said that a potential danger would depend on what particular material is being used by a municipal or a state crew.

And, if unsafe, the risk would be more to the workers performing the maintenance than to the everyday citizen.

“Although there could be some risks to the public in terms of what their exposure might be, generally speaking, that would be likely to be episodic, dependent on a local day’s problem,” he said. “People can often remove themselves from exposure by going elsewhere, staying indoors, that kind of thing.”

Musto told Channel 11 that based on their safety data, PennDOT workers are not required to wear any sort of mask or respirator while sealcoating.

She said they will be monitoring the aftermath of this year’s work, and have added an additional broom following last fall’s complaints.

Sealcoat or “oil and chip” is sometimes referred to as “tar and chip” as well, but Musto said tar isn’t actually a material that PennDOT spreads.

Rather, according to a PennDOT spokesman, state crews use “emulsified asphalt,” which is essentially liquid asphalt mixed with water.

Spokesman Steve Cowan explained “emulsifying the asphalt allows it to be transported and sprayed at a lower temperature than just using virgin asphalt. Once emulsified asphalt is sprayed on the road, the water evaporates out or ‘breaks.’” Then, an “aggregate,” which is limestone, is spread on top. Channel 11 has requested the PennDOT Safety Data Sheets related to the maintenance work.

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