Ambient Monitoring UpdateNACAA Fall Meeting

Chet Wayland, AQAD Division Director

Office of Air Quality Planning and Standards

1October 3-5, 2011

Cleveland, OH

Ambient Monitoring Revisions Strategic Overview

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• EPA has updated ambient monitoring requirements to support long overdue revisions to the NAAQS

• These revisions directly support key public health related objectives:– Characterizing peak concentrations where people are exposed– Providing support for air quality index notifications– Providing information to inform control measures that lead to

compliance

• EPA has embraced a flexible and efficient monitoring approach that emphasizes multi-pollutant monitoring, extended deployment timelines, adequate equipment funding, and the discontinuation of low-value monitors.

New Monitoring Requirements

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In 2010, EPA strengthened the health-based National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NO2) by adding a new 1-hour standard. The new NO2 standard protects public health by limiting short-term

exposures to NO2 concentrations that could worsen the control of asthma and that have been linked to hospital

admissions and emergency room visits for respiratory illnesses, particularly in at-risk populations such as children, the elderly, and asthmatics.

The revised NAAQS defines the maximum allowable NO2 concentration anywhere in an area. Therefore, the degree

of public health protection envisioned under this revised standard will only be achieved if attainment/non-attainment classifications are based on monitoring of peak 1-hour NO2 concentrations.

In considering the locations where such peak NO2 concentrations are likely to occur, we note that NO2

concentrations in many urban areas are likely to be highest around major roads. Specifically, monitoring studies and modeling efforts indicate that NO2 concentrations in heavy traffic or near major roadways can be twice as high as

concentrations measured away from such roads, increasing exposures to ambient NO2 for people who live, work, or

attend school near major roads and for people who spend time commuting on major roads.

Given the elevated NO2 concentrations near major roads and the potential for peak human exposures to occur on or

near such roads, and given that the public health protection envisioned under the revised NO 2 NAAQS depends on

States monitoring peak 1-hour NO2 concentrations, the final NO2 NAAQS requires monitors near major roadways in

large urban areas. Only with these near-road monitors in place will the revised NO2 NAAQS lead to the degree of

public health protection envisioned in the final rule.

Near-Road Monitoring – Protecting Public Health

NO2 - Near-road Monitoring Plan

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• EPA and NACAA have developed the Build and Hold plan to initially deploy near-road NO2 monitors in areas >1M population (subset of original requirements).– Monitors to be deployed over two years (2013 and 2014)– Section 103 funding to cover establishment costs such as

planning, construction, permits, shelters, monitors, etc.• $5M in FY11 funds to be distributed this fall for phase 1• $5M in FY12 funds requested for phase 2

– Resulting ambient data will inform further network decisions– Detailed siting Technical Assistance Document and Build and

Hold Q&A’s have been developed– Consistent with CASAC advice to deploy in stages

• Near-road network critical aspect of NAAQS revision since level was chosen to represent peak exposure locations

CO - Near-road Monitoring Plan

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• EPA recently finalized revisions to CO monitoring requirements as part of NAAQS review. Near-road CO monitors (total = 52) required at NO2 sites as follows:– CBSA’s of >2.5M population by January 1, 2015– CBSA’s of >1M population by January 1, 2017

• EPA expects existing CO monitors will be relocated to near-road sites, noting:– There are no requirements for other CO monitors except for ~80

NCore stations that are already operating (total of 313 CO monitors in operation during 2011)

– Hundreds of low reading CO monitors are being operated nationally (slide 12)

– EPA regional office experience has demonstrated that CO monitors can be discontinued even if referenced in maintenance plans and SIP’s

Summary:EPA’s Adjustments to NO2/CO Requirements to Address

Burden Concerns

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Downsized NO2 network with Build and Hold plan; staggered deployment as recommended by NACAA and CASAC; paid for by §103 funds Future network build-out based on resulting data

Modest CO network that leverages multi-pollutant concept and acknowledges opportunities for legacy monitor divestment and relocation; extended timelines to 2017

EPA support for review of existing NO2 sites to satisfy area-wide and 40 “Sensitive and Vulnerable population” monitor requirements (next slide)

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Meeting the NO2 Sensitive & VulnerablePopulation Monitoring Requirement

Overview:

40 “additional” monitors are required in areas with sensitive

and vulnerable populations

Using a prototype EPA tool to identify “Areas of Concern”, EPA has identified 128 NO2 monitors being operated in

such areas

We recommend that RA’s work with states

to identify which monitors will be used to meet requirements

Document in Annual Monitoring Network Plans due July 1,

2012

Legacy Monitoring Requirements

Question: What opportunities for divestment exist

across the country?

Using SO2, NO2, and CO as examples to compare actual network size to current

federal requirements

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SO2 Monitors – Active in 2011

SO2 by the Numbers:

Active = 424

Required by CFR = 129

Excess in CBSA areas = 112

Additional excess = 183

A few of these monitors are for

the NCore network

Objectives for remaining

monitors should be reviewed

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NO2 Monitors – Active in 2011

NO2 by the Numbers:

Active = 364

Required by CFR = 52

Excess in CBSA areas = 126

Additional excess = 186

Objectives for remaining should be reviewed

Some monitors can be used to meet “RA 40”

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CO Monitors – Active in 2011

CO by the Numbers:

Active = 313

Required by CFRNCore = 81

near-road = 52 (2015/2017)

Excess = 180

Objectives for excess monitors

should be reviewed

Recommendations

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States are running far more SO2, NO2, and CO monitors than required by current federal requirements

These networks, along with PM10, should be closely reviewed for redundancy and value on a monitor-by-monitor basis

Work with your EPA Regional Office to develop plans for monitor divestment and/or relocation

Resulting burden reduction in monitor operations, quality assurance, and data validation and reporting can partially offset new requirements such as near-road and lead monitoring

Additional Monitoring Burden Reductions

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• Status of ozone monitoring final rule under review– No new monitors– Ozone monitoring seasons may be expanded as appropriate to

support NAAQS if rule goes forward• Proposed secondary NOx/SOx monitoring framework

will not require new state/local operated monitors– Plan is to leverage existing CASTNET framework in 3-5

sensitive eco-regions• EPA not currently envisioning network expansion for

PM2.5 or to support characterization of urban visibility• Final lead monitoring plan eliminated separate non-

source network and reduced airport monitoring from ~70 locations with > 0.5 TPY emissions to only 15 airports with higher NAAQS risk (next slide)

Lead Monitoring Requirements

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• Section 105 funding for ½ TPY lead sources distributed last spring– Additional sites to be operational by December 27, 2011

– Network size smaller than anticipated due to waiver provisions and reduced emissions in updated NEI

• Section 103 funding for 15 airport sites was distributed to affected regions in August– All sites are on schedule to commence their 1-year of

monitoring by December 27, 2011

– Monitors readings > 50% of NAAQS will become permanent

Key Monitoring Issues For Your StaffNetwork Investments

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• Build and Hold (NO2) states should be reviewing near-road Technical Assistance Document and starting dialogue with Regions regarding funding and siting– http://www.epa.gov/ttnamti1/nearroad.html

• States should be reviewing existing NO2 and SO2 monitors to assess compliance with NO2 area-wide requirement (CBSA’s > 1M), EJ requirement, and PWEI minimums (SO2)– EPA supports use of existing monitors to meet requirements where

appropriate

• Fully implement NCore multi-pollutant sites and focus on data quality and reporting issues for newer measurements such as high-sensitivity gases and PM10-2.5 mass.

Key Monitoring Issues For Your StaffNetwork Efficiencies

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• States should be implementing 2010 network assessment recommendations and discontinue legacy CO, SO2, NO2, and PM10 monitors not needed for federal requirements, overarching state/local needs, or national heath studies– Commence discussions with regions to prioritize and discontinue these

monitors utilizing annual network monitoring plan process– Determine necessary steps for revising maintenance plans that reference

monitors• Review continuous PM2.5 FEM operating procedures and conduct

data quality comparisons with FRM’s to evaluate method performance and identify areas for improvement– Supports potential divestment of some manual FRM’s

• Consider replacing archaic state data systems with newer data management products that support automated control of monitor calibrations, monitor diagnostics, and data screening, flagging, and reporting actions– http://www.epa.gov/networkg/

• Issue– Continuous FEMs do not achieve the same performance in the

field, and generate data that are biased high (compared to FRM) in areas with high humidity, high nitrates, and urban aerosol.

– Positive bias of continuous FEMs is an issue for areas near the NAAQS as possible risk of non-attainment

• What is EPA doing to enable State/local Monitoring agencies to be successful with PM2.5 continuous FEMs?

– Technical note on PM2.5 FEM data reporting provides for use of FEM for up to 24 months as an SPM without comparison to NAAQS.

– Developed consensus SOP’s for the most widely used continuous PM methods

– Working closely with multiple stakeholders such as the NACAA monitoring steering committee, ORD, and the instrument companies.

– Implementing recommendations from NACAA monitoring steering committee:

• Tool for monitoring agencies to quickly assess their continuous FEM data quality• Providing flexibility for monitoring agencies to determine if their continuous FEM provides data

of sufficient comparability to collocated FRM for comparison to the NAAQS - planned for inclusion in PM NAAQS/monitoring proposal.

• Troubleshooting/Best practices document for each of the major deployed continuous FEMs to assist monitoring agencies with improving data quality

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PM2.5 FEM Data Quality Issues

Questions?

U.S. Environmental Protection Agency 19