Multipollutant Air Quality Management

Reinventing the WheelCritical Review commentary

Air and Waste Management Association Annual Meeting

June 23, 2010Calgary, Alberta

John BachmannVision Air Consulting, LLC

Ammonium

Overview• Hidy and Pennell’s Critical Review suggests

– Multipollutant AQM is a logical extension of risk-based AQM– A multipollutant perspective with greater emphasis on accountability

provides a useful paradigm for air quality related policy, regulation, legislation, and science

– Full implementation is probably impossible - ever

• Some riffs– Is the recommended MP risk-based paradigm really the best approach for

merging climate, ecosystem effects, and air toxics?• Is the current US CAA program really single pollutant driven?• Multipollutant/accountability technology-based programs deserve equal

consideration• Suggestions for more feasible interim improvements in the near term (<10yr)• Examples of difficult climate and air quality trade-offs based on current

information

Why risk-based multipollutant programs?• Not discussed much in the CR, which cites NRC and NARSTO

– The Holy Grail: optimized control strategies to maximize risk reductions at minimum costs, with tracking to show actual benefits and costs. What’s not to like?

– Effectiveness and efficiency – flexibility vs. simplicity– You want it soon???

• NRC – ideal not possible soon; much of current system is good, transitional recommendations

1) strengthen capacity for assessing risk and tracking progress; 2) expand national and multistate performance oriented programs (technology based)3) move from SIPs to multipollutant AQM plans with tracking 4) integrate criteria and HAP programs5) enhance ecosystem protection

The NARSTO and CR recommendations are generally congruent with the NRC

Alternative Management Approaches• Risk-based

– e.g. Air quality management based on health and environmental goals (NAAQS) or risk estimates

– Emission limits based on residual risk (s. 112 post MACT)– Potentially most optimal, but information intensive, slow, some risk calls vex

decision makers (s 112 before 1990)

• Technology-based– e.g. ‘Best’ technology on all major source categories regardless of risk (MACT, NSPS,

RACT)– Fast, more equitable to sources, may go too far or not enough

• Market approaches– e.g. Cap and trade, emissions taxes/fees (Acid rain, CAIR)– Least cost solution for regional pollutants, hard to adjust cap

• NRC recommends them all for multipollutant approaches

The Clean Air Act Success Story

Cumulative benefits 1970-90 $6 to $50 trillionCumulative costs - $ 520 billion

NOx Trends

VOC Trends

Major CAA reductions in NOx, VOC, and CO, lead (not shown) from multipollutant tail-pipe and fuel standards.

Multipollutant power plant NSPS (SOx, NOx, PM) in 1979, CAIR (SOx, NOx, Hg caps) 2004 (remanded by court); acid rain (SOx, NOx) in 1990’s.

Technology-based source standards played a major role in CAA benefits

What’s wrong with current AQM?

Heavy emphasis on modeling forecasts, regional control strategies depend on multiple states

Determine Emissions

Reductions

Track and Evaluate Results

Implement and Enforce Strategies

Develop Programs to

achieve

Establish Goals

NAAQS revision timelines push single pollutant SIPs

The SIP process is inefficient, time consuming

Tracking focuses on air quality, attainment, 5 -10 years; no provisions for mid-course corrections or tracking; failure restarts the entire process

Federal role complicates state options, EPA not accountable for success of national rules

“Consider this…”*

*REM: Losing my Religion

PM and O3NAAQS: multipollutants and sources

Pollutants contributing to PM2.5 and OzoneSO2 – Sulfate particlesNOx – Nitrate PM, acid gases, formation of ozone and organic PM (toxics)VOC – formation of ozone and organic PM (toxics)C6+unsat. – secondary organic PM (toxics)NH3 – AmmoniumDirect PM of carbonaceous PM, crustal materials, metals (toxics – e.g. POM, Hg, Ni, V)CO, CH4 - background ozone formation

Sulfate

Esti Ammonium

Nitrate

Carbonaceous

Crustal

NRC: major AQM challenge, risk

Provides an obvious OPPORTUNITY for transition to multipollutant AQM, tracking, streamlined approaches

Multiple sources of multiple pollutantsHNO3

SO2

NO2

CH4

Organics

NH3

CO

Initial improvements to AQM

Less emphasis on modeling, more on inventories and tracking. EPA facilitates regional control strategies.

Determine Emissions

Reductions

Track and Evaluate Results

Implement and Enforce Strategies

Develop Programs to

achieve

Establish Goals

SIP replaced by Comprehensive AQM plan, streamlined process for developing rules. Provisions for S/L/T actions on existing mobile sources.

Tracking includes air quality, attainment; but adds interim benchmarks to permit mid-course corrections. Failure leads directly to implementing additional measures.

Maintain Federal enforceability; EPA commits to reductions under national rules

Coordinate PM/O3 implementation dates, multi-pollutant NAAQS (SOx/NOx, extinction)

• How multipollutant consideration might make a difference to today’s AQM– Climate and air quality (asymmetrical risks)– PM and the seven dwarves– Body counts, benefits, and equity

• The limits of accountability

Making it real – some examples

Climate and air quality links – the multi-pollutant PM and ozone NAAQS

Accumulating health effects evidence leading to tighter fine particle and ozone standards

PM2.5 Nonattainment

• Black carbon sources contribute a significant fraction of fine particles

• Evidence that traffic emissions (e.g. diesels) are particularly important to health

• Lower ozone NAAQS levels increase the importance of addressing global background

• Black carbon, other fine particles and ozone are significant ‘short-lived climate forcers’

Potential O3 Nonattainment

How might NAAQS implementation strategies change if climate effects are considered?

Implications of considering climate

• Implementing fine particle and ozone standards– Current PM2.5 and O3 NAAQS implementation relies heavily

on regional SO2 and NOx reductions (least cost)– The downside for climate – Consider strategies, guidance for more balanced programs

that consider health, exposure, and climate implications

• Slow arctic melting, near-term- Reduce black carbon

- Retrofit diesels, I/M; biodiesel fuels

- Shift springtime agricultural burning

- Reduce methane, ozone

‘Unmasking’ committed warming

• IPCC modeling shows masking of about 1 degree C from all sulfates. Increase in temperature is immediate with assumed SO2 reduction.

• SO2 emissions forecast to continue decline under current programs

• A crash CO2 reduction program could not curb the projected unmasking for decades.

Eliminate anth. SOx

CO2 stays at 2000 levels

• Cooling by sulfate, nitrates, and organic particles masks some of warming expected from greenhouse gases and black carbon

• Reductions in SO2 – needed to reduce health and acid rain impacts - are ‘unmasking’ the warming already built into the system.

• Selective BC and O3 controls could partially counter the SO2 unmasking

• Implications for PM2.5 Air Quality Management Plans:

•Climate, health and exposure case for providing more balanced reductions in all PM components than provided by current least cost approach that emphasizes regional SOx

• This increases costs, but also both climate and health benefits.

Rethinking Ozone Implementation Strategy (again) • Ozone strategy – regional NOx control, VOC/NOx

in urban areas.

• EPA RIA – more regional NOx control needed to attain tighter standards.• See Chart: Net ‘forcing’ compared for multiple pollutants. More NOx reductions will warm by increasing lifespan of methane, reducing nitrate particles.

• At lower O3 NAAQS levels, hemispheric transport becomes more significant. Methane and CO reductions effective on that scale.

• NOx reductions still needed for health, but a long-term strategy to reduce methane and CO in the northern hemisphere could offset NOx warming - and also help attain and maintain ozone standards in US and other nations.

Ozone produced by methane

Shindell et al., 2009

Current tools: Relative PM Benefits

Average effectiveness ($benefit/ton) of alternative PM control options

Assuming equal potency, reducing primary PM emissions in populated areas is most effective – importance of population exposure in “body-count” riskAdding O3, toxics benefits would not change relative rankings significantly

812 Estimates* - fraction of total air pollution damages

*first prospective study, draft second study has larger numbers

Effect Pollutant Mean %Baseline

MortalityAges 30 or older

PM 23,000 1%

Chronic bronchitis PM 20,000 3Chronic asthma O3 7,200 4%HospitializationRespiratory admissions PM, CO, NO2,

SO2, O3

22,000 0.6%

Cardiovascular admissions PM, CO, NO2, SO2, O3

42,000 0.9%

Emergency room visits for asthma PM, O3 3,800 0.6%Minor IllnessAcute bronchitis PM 47,000 5%Upper respiratory symptoms PM 950,000 0.9%Lower respiratory symptoms PM 520,000 4%Respiratory illness NO2 330,000 10%Moderate or worse asthma PM 400,000 0.2%Asthma attacks O3, PM 1,700,000 1%Chest tightness, shortness of breath, or wheeze

SO2 520,000 0.0003%

Shortness of breath PM 01,000 2%Work loss days PM 4,100,000 1%Minor respiratory restricted activity days

O3, PM 31,000 2%

Restricted activity days PM 12,000,000 1%

Change in Incidence of Adverse Health Effects Associated with Criteria Pollutants in 2010 (Pre-CAAA minus Post-CAAA) – 48 State U.S. (avoided cases per year) 2010

Mortality risk in ‘Six Cities’ v. PM declines

Accountability is hard• Even with high ‘body count’ risk, air pollution is

typically a small contribution to non-specific effects– It takes large concentration changes and populations to

see effects i.e., low signal to noise– HEI, CDC/EPA pilot tracking – air change x CR functions– Routine level 4 not

realistic for foreseeable future, need better specific indicators

– Look for major interventions, reductions retrospective and prospective (CR – LA)

Parting shots• Multipollutant perspectives, accountability have

already informed AQM, technology-based programs on national, regional, and local scales – Conceptualizing more comprehensive programs is useful, but

more focus on how to include in policy now– PM, ozone epidemiology studies generally reflect

contribution of multipollutant mixtures, not single pollutants.

– Priority research on PM, VOC components• Highly toxic low mass contributors and higher than average potency

mass fractions – chemical classes and/ or source specific• Harder to identify interactions, enabling agents

– CR - Maximum risk = body count; CAA continues concerns for equity, sensitive individuals

Parting shots (cont’d)• EPA should be encouraged to continue comprehensive AQM

experiments, innovative NAAQS specification– SOx/NOx combination standards for deposition– Multipollutant indicator for secondary PM and visibility

NAAQS = aSO4 + bOrg + cEC + dNO3 + edust– But why can’t PM, O3 designation be coordinated?

• Legislative initiatives – Multipollutant legislation – (e.g. Carper power sector act) should include

requirements, funding for accountability research, measurements with periodic reports

– Post energy/climate legislation likely to consider revisions to the CAA. An opportunity to identify modest changes that authorize or promote improved AQM approaches