Another bad air day and more on air quality

Today, September 23, 2016, is an official Code Orange bad air day in Delaware. A(n) Action Day has been declared for Delaware, on Friday, Sep 23A(n) Action Day has been declared for Delaware, on Friday, Sep 23   The forecast is Code Orange for ozone and Code Yellow for particles.   In simple terms, Code Yellow means the level is expected to be above one-half of the ambient air quality standard.  Code Orange means the level is expected to be above the air quality standard.  From Green Delaware’s view, when two pollutants are elevated we would bump the status to Code Red.  This air is unhealthy and we urge you to take care.

The good news is that this is expected to be only a one-day bad air episode, and allergen (pollen) counts are in the low-medium range.  Temperatures are high but not extreme.

In a recent post (“Bad Air in Delaware–an intractable but not hopeless problem“) we reported that “Delaware is officially in ‘non-attainment’ of two major National Ambient Air Quality Standards.–ozone and fine particles.

This is not entirely correct.  At Delaware’s request, EPA officially redesignated New Castle County, Delaware, as “in attainment,” of the fine particle standard, effective September 4, 2014.

“The Environmental Protection Agency (EPA) is approving the State of Delaware’s requests to redesignate to attainment the Delaware portion of the Philadelphia-Wilmington, PA-NJ-DE nonattainment are…”

Federal Register Volume 79, Number 150 (Tuesday, August 5, 2014)

This was two years ago and we should have known about it.  However, nobody should think this means the air has magically been cleaned of particle pollution.  It hasn’t.  Rather, the levels have dropped from slightly above the federal standard to slightly below.  Delaware remains in “non-attainment” for Ozone.

The whole subject is complex and confusing.

Some numbers:

The National Ambient Air Quality Standard (annual standard)  for PM2.5 was 15.0 micrograms per cubic meter.   On Dec. 14, 2012 the EPA lowered it to 12.

In 2004 Delaware DNREC reported these numbers to the EPA:

3 year annual average PM2.5 concentrations for 2000, 2001, and 2002:

(In parenthesis are the numbers for 2004/2005/2006)

Bellefonte     15.0  (13.5)

Wilmington            16.4  (14.8)

Newark                   15.2 (13.9)

Lums Pond             13.9 (12.8)

Dover                      13.1 (12.5)

Killens Pond          12.9 (12.6)

Seaford                  14.0 (13.5)

For For the more recent three-year period 2012 – 2014, the highest average occurred in New Castle and was 9.9.

What’s to notice here?

Only two New Castle County monitoring sites showed levels higher than the federal standard.  The levels all over the state are really not that different.  Do you think your body really cares about the difference between 15.2 and 14?

Levels have dropped noticeably.  This is due, in large part, to emission reduction measures taken in Delaware and upwind states.  We can see that regulatory efforts have some beneficial effect.

But this is the annual standard.  There is also a “24 hour” standard and this was lowered from 65 to 35 micrograms per cubic meter in 2007 after the usual political contest between polluters and health/environmental interests.  Delaware levels in 2004 were higher than 35 but lower than 65.  So attention shifted to the 24 hour standard.

Note that these time intervals are very important because a blast of pollutants that could trigger health problems may not show up if averaged into long periods of time.  Consider, for example, the clouds of Diesel particulate around Rodney Square in Wilmington when DART buses are gathered.

The picture for ozone is confusing.  For instance, Sussex County is (sort of) in non-attainment for ozone, whereas Kent County is (sort of) in attainment.  Much of our bad-air emissions come from “mobile sources”–cars, trucks, and ships.   Yet the tailpipe inspection requirements are apparently less strict in Sussex County.  Why?

The Delaware Department of Transportation is looking at reducing testing for gas tank vapor leaks.  Of course, this can be a nuisance, especially for those of us with older vehicles, but would likely be a serious mistake from a health and environmental point of view.

Not long ago Delaware backed off on gasoline vapor control requirements for gas stations, partly under pressure from state senator Gerald Hocker, who owns gas stations See Green Delaware’s comments here.



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