Assistant Commissioner Herndon interviews the Air Staff to get the Scoop on Ozone
– Part 2 (August 2014)
I am continuing my “ozone season” interviews with the Department’s air quality experts to learn more about ozone. Last month, Charlie Pietarinen explained some fundamentals about ozone. This month, Sharon Davis, head of the Bureau of Air Quality Planning, explains why reducing the ground-level ozone level in New Jersey is such a complex job, and what New Jersey is doing to lower our ozone levels.
JH: First, tell me some good news about ozone in New Jersey!
SD: New Jersey has seen tremendous reductions in ozone levels over the past 25 years. In 2002, New Jersey had 45 days that exceeded the old ozone standard of 85 parts per billion (ppb) – this year so far we have only had 2 days that exceeded the lower, current 75 ppb standard. According to New Jersey’s ozone monitoring data, ozone levels have decreased across the state by 30-40% since 1986.
JH: Sharon, last month Charlie mentioned that ozone is transported into New Jersey from our upwind neighboring states. Can you elaborate on that?
SD: As Charlie mentioned, weather – including wind directions -- plays a big role in the formation of ground-level ozone (not to be confused with stratospheric ozone – the earth’s protective layer against UV radiation). The pollutants that form ozone (oxides of nitrogen (NOx) and volatile organic compounds (VOCs)) are not contained within state borders. Wind carries these pollutants far from the sources that emit them into New Jersey and from New Jersey into downwind states. On the way to New Jersey and other downwind states, these pollutants react with heat and sunlight to form ozone.
JH: How much of our ozone problem comes from these out-of-state, upwind sources?
SD: Approximately one-third to one-half of the ozone in New Jersey is blown by the prevailing winds into our state from upwind states. At some locations, depending on the day and the wind direction, 85 to 90 percent of the man-made ozone in New Jersey’s air could be caused by emissions from out of state. Unfortunately, many of these upwind states are not as protective of their air quality as New Jersey. In fact, some of New Jersey’s neighboring states have seen increases of NOx emissions during hot summer months. This is allowed under their states’ air regulations.
JH: I was surprised to learn that some power plants in upwind states from New Jersey actually stop running the equipment that lowers their emissions of NOx. How can they do that?
SD: It is true that some power plants in upwind states have not been running their air pollution controls during the hot summer months. Air pollution control is used to reduce emissions to comply with permit limits. However, in certain states, these plants are allowed to buy “NOx allowances” to meet their limits instead of running their controls. These NOx allowances are part of an emissions trading program established by USEPA rules, where reductions from one facility can be sold (“traded”) to another facility or “banked” from one year to another. The intent of the rule was to provide flexibility for facilities to comply with their emissions obligations. However, it turns out that it is cheaper to buy NOx allowances than operate emission controls. So, those facilities save money, but emit more NOx. And that impacts New Jersey’s air quality. New Jersey power plants are required to run their air pollution control equipment all of the time. So, while USEPA’s emissions trading program has helped to lower New Jersey’s ozone levels, it is no longer delivering the real emissions cuts it did at one time.
JH: How does New Jersey keep track of how much of our ozone is from upwind sources and how much is from within New Jersey?
SD: New Jersey has monitors across the state that measure actual ozone levels. These monitors tell us the ozone levels in New Jersey, but not the source of those emissions. To determine how much of that is due to sources inside or outside our state borders we use complex, atmospheric modeling tools. These tools use a lot of data from the source and location of emissions that contribute to ozone formation in the region, as well as meteorological data that influences when and where ozone occurs. New Jersey has the ability to perform these model runs in-house and often coordinates with other regional states with similar modeling centers to help determine the contributors to the ozone problem in the Northeast.
JH: So, what can be done to reduce ozone transport?
SD: That’s a challenge because ozone is a multi-state issue in the Eastern United States. New Jersey is a member of the Ozone Transport Commission (OTC), an organization created under the Clean Air Act that consists of states from Maine to Washington, D.C. (including Northern Virginia). The OTC coordinates regional solutions for ozone in the Northeast and Mid-Atlantic states. The OTC has been successful in reducing emissions of NOx and VOCs from within the OTC member states, and it is focusing its work on reducing ozone transport from the upwind states that are outside the OTC. Cooperation among states is crucial in solving ozone transport.
New Jersey has regulated the emissions from power plants and major sources, and shown that the emissions standards that New Jersey has used for many years are feasible in upwind states.
The USEPA’s efforts to reduce the transport of ozone between states, while initially successful, have failed recently, as noted in an earlier question where sources are turning off existing emissions controls.
USEPA is also looking to propose a revision the current 75 ppb ozone standard this Fall and may lower it to an even more protective level. With this in mind, the states and USEPA will need to find a solution to transport that not only addresses the impact of upwind sources to provide clean healthy air as expeditiously as possible.
JH: What challenges do we face from sources of emissions within our own borders?
SD: The primary challenge with regard to emissions that come from within New Jersey’s borders is the mobile sector – our cars and trucks. Cars and trucks are large contributors to ozone air pollution in New Jersey (and across the country). About 45% of our NOx emissions are from on-road mobile sources. New Jersey already has the most stringent car and truck standards allowed by federal law, and we ensure that our cars and trucks meet their emissions standards through our vehicle Inspection and Maintenance program. Peg Hanna, who heads up our Mobile Source Program, will explain how emissions from our cars and trucks are controlled in next month’s interview.
Another challenge we face is reducing emissions from what we call “area sources” – things like, consumer products, paints, industrial surface coating and gasoline stations. Not a single one of them emits much air pollution, but put together, the emissions add up. For example, 50% of in-state VOC emissions are from area sources. Not a small number. New Jersey has adopted several rules to reduce the amount of VOCs from autobody refinishing operations, solvent cleaning operations, insecticides, household cleaners, hair products, paints, stains and primers.
The Department issues permits to stationary sources (industries, power plants, etc.) of emissions, and those permits include limits on emissions of NOx and VOCs. Check out our air permitting website for more information about how these permits work. New Jersey’s emissions limits in our rules and in our permits have been very successful in reducing the pollutants that lead to ozone formation.
Next month I will interview Peg Hanna about the mobile sector and the challenges with reducing emissions from mobile sources.
Follow this link to review the Ozone Interview - Part 1 (July 2014)