Ozone and Ozone Monitoring

2015 National Tribal Forum

Glenn Gehring, Technology Specialist IIITribal Air Monitoring Support (TAMS) CenterInstitute for Tribal Environmental Professionals (ITEP)Northern Arizona University

Contact information:glenn.gehring@nau.eduhttp://www4.nau.edu/tams/541-612-0899

This presentation includes:

• Ozone National Ambient Air Quality Standards (NAAQS)• Ozone design values, designations, monitor maps …

• Basic ozone atmospheric chemistry• NO, NO2 and ozone interactions

• Brief overview of basic monitoring requirements for NAAQS• Title 40, Part 58, Appendixes A (QA) and E (siting)

• Ozone analyzer (UV type) basic theory of operation• Basic sample collection systems (probes)• Identifying potential sources for high concentrations

• HYSPLIT trajectories and dispersion modeling

http://www.epa.gov/airquality/greenbook/

2013 Ozone Design Values with less than 3-years of data (red dots)

Monitors can be classified as

“Special Purpose” and even when

NAAQS exceedances seem

likely, they may close the site with

less than 3-years of data avoiding

nonattainment designations.

(Valid 2003 Design Values must include years 2013, 2012 and 2011 – some sites have 3-years of data but don’t include these three years)

Ardmore, Oklahoma ODEQ site

The Design Values for this site (.081 in 2013) are not valid without 3 consecutive years of data

So what if we are nonattainment?Two potential financial impacts are:

Different source permitting rules(NSR vs PSD permitting rules)

Precursor emission offsets(reduce area emissions more than the new source will emit)

Another big impact:SIP must be developed to reduce ozone concentrations in ambient air

Snapshots at time of download

Monitoring Networks & Concentrationshttp://www.epa.gov/airdata/

Very important chemical reactions related to ozone:

+

𝑁𝑂 2+𝑉𝑂𝐶+→𝑂 3

Nitrogen oxide (NO) reacts with ozone ( driving ozone concentrations down and producing nitrogen dioxide ()

Nitrogen dioxide () can react with VOCs in the presence of sunlight and produce ozone The VOCs can be natural, such as a pine forest, or anthropogenic such as a wood pulp facility or gas station.

The 5th and 6th is Saturday, Sunday

Quapaw Site on July 22, 2004 – Site’s highest 8-hr Ozone

93 ppb as an 8-hour average

If monitoring for ozone NAAQS comparison, you need to become very familiar with Title 40, Part 58

Appendix A (quality assurance)

Appendix E (siting requirements)

Cal gas must pass through particulate filer that was in place during sampling

Also need to participate in the National Performance Audit Program (NPAP)

Ozone analyzer basic theory of operation

Ozone is useful in the upper atmosphere because it absorbs harmful UV light. Most ozone analyzers use that characteristic of ozone to measure ozone concentrations in ambient air

[Image from Teledyne API 400e manual]

[From Teledyne API manual]

No selective ozone scrubber

Ozone Transfer Standards use zero air for the reference cycle.

X

Teledyne API T703 Ozone Calibrator

In general, all standards (flow, temperature, pressure, ozone standards …)

must be NIST Traceable

Standard Reference Photometer (SRP)

Level II Transfer Standard (Local Primary)

Level III Transfer Standard or Analyzer

EPA Regional Office (NIST Certified)

Annually certified at SRP

National Institute of Standards Technology (NIST)

All materials in contact with sample air must be FEP Teflon, borosilicate glass, or equivalent

Sample air enters through Teflon rain cap and is drawn to analyzer through ¼ OD FEP tubing

Sample collection

¼-inch OD FEP Teflon tubing is inside the conduit

Conduit is for support and is not part of the sample pathway

Calibration Verification

Cal Gas enters through tee, is drawn to analyzer through ¼ FEP tubing - excess vents through inlet during calibration verifications

Must have positive vent flow at all times to prevent ambient air mixing with cal gas

Note: Care must be taken to assure proper venting and to avoid pressurizing your photometer(s)

Warm moist air can condense in an air conditioned monitoring shelter. A Teflon water trap can reduce the possibility of analyzer damage

Residence time is the time it takes a molecule of air to travel from the sample inlet to the analyzer inlet and must be 20 seconds or less (10 seconds max is highly recommended)

From Here

To Here

Note: Can use smaller ID tubing, manifolds with pumps, pumps on the sample tubing with the analyzer inlet connected to a tee upstream of the pump, or combinations to get the residence time within limits.

Area 8-hr Ozone on July 22, 2004

Saint Louis

Memphis

Quapaw Site

Tulsa

KansasCity

Little Rock

OklahomaCity

Where did it come from? www.arl.noaa.gov/ready.html

Highest Quapaw Concentration – 93 ppb7/22/2004

Muskogee Power Plant 48-hr dispersion(NOAA Air Resource Laboratory HYSPLIT Model)

Quapaw Site

Forward Trajectory from 3 Coal-Fired Power Plants on July 22, 2004(endpoints that are less than 10 meters AGL)

Ambient Air Monitoring Site

Gas Analyzer Rack

Data Logger

Calibrator

Continuous Particulate Monitor Control Units

Zero Air Generator

NOy

NOx

SO2

Ozone

Toxics Flow Controller

Continuous Particulate Sensor Unit

Vertical manifold

Tubing for NOy

EPA Protocol Gas

316 Stainless Steel 1/8 inch tubing connects regulator to calibrator

CGA 660? Fitting must match bottle

Always purge regulator when seal is broken

Questions?