The Environics, Inc. Post

Trace Level Monitoring - Ambient Calibration

Posted by Rachel Stansel on Thu, Nov 30, 2017 @ 11:56 AM

More and more, we are talking about trace level ambient monitoring.  This monitoring is in line with the measurement objectives of NCORE which is part of the Ambient Monitoring Technology Information Center of the US EPA.  According to the EPA website, "NCore is a multi pollutant network that integrates several advanced measurement systems for particles, pollutant gases and meteorology. Most NCore stations have been operating since the formal start of the network on January 1, 2011." The measurement standards, as set it 40 CFR Part 58 Appendix A, are:

NCore standards.jpg

It can be a challenge to reach these levels due to a handful of error sources. These were well outlined in a presentation by Avraham Teitz and Mustafa Mustafa of US EPA Region 2. This presentation can be viewed here.

As they described, using a system that allows total flow to be measured at the mass flow control and not the just system output is a great way to minimize error in your flow measurement. In slide 18 and 19, you can see a drawing of the Series 6100 layout which is plumbed to allow direct measurement.

6103 pid.jpg

 A second source of error is the zero air that is used. It is important to scrub the air of all moisture in addition to using charcoal, purafil and palladium scrubbers. Our ZAG provided all of these features, which are show on page 27 (and below). In addition, a hydrocarbon scrubber can be added for applications that need these to be removed. Proper ZAG maintenance (filters and media) is also important to keep the zero air as clean as possible.

7000 pid.jpgIn addition to these error sources, it is critical to have accurate and repeatable results from the calibrators and analyzers. For ozone and NO2, it is critical to have stable and linear readings for these very low ppb levels. For these measurements, the Series 6100 and 6103 both generate down to 2 ppb in a stable a repeatable manner. 

To learn more, check out the following sites: NCore, the referenced presentation, Ambient Monitoring Calibrators and Zero Air Generators.

Tags: Ambient Air calibration, EPA, NCore, News

In the News : New US Ozone Standard Takes Effect

Posted by Rachel Stansel on Thu, Oct 12, 2017 @ 02:06 PM

epa_logo-resized-600.jpgOn October 1, 2017, a new ozone standard took effect in the US amid widely differing opinions. In late 2014, the EPA had proposed lowering the ozone standard to a between 65 to 70 from the current standard of 75 ppb (set in 2008 under the Bush administration). Public discussion was heated with many groups urging the EPA to maintain the existing standard. On October 1, 2015, under a court-ordered deadline, the EPA finalized the ozone National Ambient Air Quality Standard (NAAQS) standard at 70 ppb.

This was not the end of the discussion however. The U.S. Chamber of Commerce and the American Petroleum Association, who said that the rules would be a huge burden and that the cost to comply could be in the billions, filed for a review to challenge in the U.S. Court of Appeals for the D.C. Circuit.  At the same time, five states filed a lawsuit challenging EPA's new 70 ppb ozone standard, with four additional states later joining them Earlier this year, D.C. Circuit Court of Appeals granted EPA’s motion to indefinitely stay the lawsuit to give them the necessary time to review the data and the standard.

With all of this going on for the part 2 years, the EPA, now under the Trump administration, had initially sought to delay the rule. However, after lawsuits were filed by 16 state attorney generals, the EPA declined to delay the rule, which took effect on October 1, 2017. On July 20th, the House passed HR-806 by a vote of 229 to 199. Also known as the Ozone Standards Implementation Act, the bill would double the time frame under which the EPA reviews the ozone standard (from 5 yrs to 10 yrs) and also gives the EPA the ability to consider factors other than human health. This bill now sits in the Senate.

Why is this important?  Michael Greenhouse,co-author of a report issued by the University of Chicago’s Energy Policy Institute spoke to Forbesabout the importance of these regulations, stating, “Our research shows that efforts to reduce ozone extend lifespans. While previous research had suggested this, the especially novel finding here is that pollution reductions lead to significant reductions in the purchase of medications that protect people from becoming sick or even dying prematurely … The implications for air pollution policy are potentially enormous.”

The new regulations have a large impact on the number of areas in the US that now are noncompliant. According to the EPA, 28 counties were classified as nonattainment areas under the 75 ppm standard and data sugegsts 241 counties violate the 70 ppb standard. 

US 8-Hour Ozone Nonattainment Areas at 70ppb
Projected 8-Hour Ozone Nonattainment Areas in U.S. under 70 ppb Standard

The democrats from House Department on Energy and Commerce share the dissenting views on the HR-806. The National Parks Conservation Association statement claimed, "This legislation would actually systematically weaken the Clean Air Act without a single improvement, undermine Americans’ 46-year right to healthy air based on medical science, and delay life-saving health standards already years overdue."


Clearly, there are strong and widely varying opinions on how best to proceed. It will be interesting to hear the Senate discussions if this comes up for debate.



Tags: Air Pollution, EPA, Emission Standards, USA Emissions, News