State air quality stations measure pollution improvement over time

  • Above: Kendall Perkins, program manager of the air monitoring program for the DES Air Resources Division, describes how the station works on top of Pack Monadnock. Left: Below the fire tower sits the air monitoring station. Staff photoS by Ben Conant

Monadnock Ledger-Transcript
Monday, July 31, 2017 11:41PM

A state scientist said he was standing at the top of Pack Monadnock years ago when something dawned on him.

“I thought, ‘this is the perfect location to measure air pollution transport,’” said Jeff Underhill, chief scientist of atmospheric science & analysis at the state’s Department of Environmental Services Air Resources Division.

He said measuring air pollution transport is ideal at 2,000 to 3,000 feet in elevation. Pack Monadnock is 2,290 feet above sea level.

Soon after Underhill submitted a recommendation to the U.S. Environmental Protection Agency, and an initiative at the University of New Hampshire. The consensus was that the site would work.

“We moved forward with it,” Underhill said in reference to an air quality monitoring station that was built on the top of the mountain.

Underhill said the small unit, which now sits adjacent to the fire tower, was completed in the early 2000s. It’s now one of 13 other air monitoring stations across the state, he said. The station on Pack Monadnock is one of two super stations, meaning it completes more air quality tests than others in the state. The other super station is located in Londonderry.

Inside the station on the mountain, a complex array of machines tests for ozone, particulates, sulfur dioxide, mercury, and carbon monoxide. Today, the station has tracked more than a decade worth of information that has helped map out air-quality trends across the state.

“What the trends have told us is that air quality in New Hampshire is improving,” Underhill said.

Kendall Perkins, program manager of the air monitoring program for the DES Air Resources Division, said improved air quality is largely a result of federal initiatives like the establishment of the 1970s Clean Air Act. The law increased the number of catalytic converters in automobiles, tightened rules on power plants, and lead to retrofitting gas stations.

And while air quality may be improving, Underhill said New Hampshire is still paying close attention to its ozone readings.

“We’re still wrestling with ozone standards,” he said. “We’re meeting the requirements, but not by a lot.”

EPA has set the ozone standard at 70 ppb (parts per billion).

The ozone reading Friday on Pack Monadnock came in at 29 ppb, according to the state’s website.

Perkins said ozone is a secondary pollutant, occurring when auto emissions and coal-fired power plants are released into the atmosphere and then heated up by the sun. On hot days, ozone can concentrate and can become an issue. Hazardous ozone levels can lead to health problems including wheezing and shortness of breath. High concentrations are most dangerous for young kids, older adults, and those who are active.

Perkins said in the winter the department monitors particulates closely, as wood burning stove releases can suspend in valleys. He said it’s been a recurring problem in Keene over the years. The station at Pack Monadnock doesn’t typically catch the readings in the valley because of the elevation difference.

Underhill said each of the readings for the various pollutants changes “all of the time.”

That’s in part due to air currents, which pick up pollution readings from along the coast, big cities like Boston and New York City, southwest states, and the midwest.

“In the past everyone thought the air pollution problems were from right nearby, but we now know it’s can come from hundreds or even thousands of miles away,” Underhill said.

The finding has led to state, multi-state, and federal work that Underhill says has driven down pollution on a whole.

Underhill said the department used to issue 10 to 15 air quality alerts per year for various polluters. These days, that number is closer to five.

He thinks that has a lot to do with air monitoring stations, like the one on Pack Monadnock.

“By having information that we can use it in our discussions with EPA and upland states,” Underhill said. “It gives you something more than a good word.”

Abby Kessler can be reached at 924-7172, ext. 234 or akessler@ledgertranscript.com.