Agriculture and EPA's New Air Quality Standards for Ozone and Particulates

97-670 ENR

CRS Report for Congress

Received through the CRS Web

Agriculture and EPA’s New Air Quality

Standards for Ozone and Particulates

Updated March 24, 1998

(name redacted) and (name redacted)

Senior Analysts in Environmental and Natural Resources Policy

Environment and Natural Resources Policy Division

Congressional Research Service ˜ The Library of Congress

ABSTRACT

This report discusses potential impacts on agriculture of the new air quality standards for

ozone and particulates promulgated by EPA on July 18, 1997. Legislation has been

introduced in both the House and Senate (H.R. 1984 / S. 1084) to block implementation of

the new standards, and the Senate has approved an amendment to the surface transportation

bill, S.Amdt. 1687, to address a limited set of implementation issues. At the request of

agricultural interests, the amendment includes a requirement that EPA report to Congress

on the ability of its sampling and analysis methods to differentiate types of fine particles.

This report will not be updated. For current information on implementation of the clean air

standards and related legislation, see CRS Issue Brief 97007, Clean Air Act Issues.

Agriculture and EPA’s New Air Quality Standards for Ozone

and Particulates

Summary

On July 18, 1997, the Environmental Protection Agency promulgated revisions

of the National Ambient Air Quality Standards for ground-level ozone and

particulates. EPA's action has elevated awareness of possible relationships between

agriculture and air quality in the agricultural community. Many in agriculture,

including the Department of Agriculture's Agricultural Air Quality Task Force, have

questioned the scientific basis for the new standards. The issues raised also have

been aired at congressional oversight hearings. This report summarizes these issues.

In assessing the potential impact of the new standards on agriculture, it is

important to note that EPA has promulgated new or revised standards for three

different pollutants: 1) ozone; 2) the relatively coarse particulate matter already

regulated (PM10); and 3) a new category, fine particulates (PM2.5). The potential

costs and impacts of each of these standards is different.

Agricultural production is adversely affected by ozone in the atmosphere, so

agriculture should benefit from a strengthening of the ozone standard. EPA estimates

these benefits at $1 billion annually. The agricultural community agrees that

lowering ozone concentrations will improve yields, while not necessarily agreeing

with the EPA estimate. The vast majority of the emissions that form ozone (nitrogen

oxides and volatile organic compounds) originate in urban and industrial areas.

Agricultural sources of these emissions would not likely be directly targeted by

measures implementing the new rule, although regulation of fuels and motor vehicles

might have indirect impacts on the agricultural sector.

The second standard being revised -- that for PM10, a category that includes

fugitive dust from construction or tilling the soil -- is effectively relaxed under EPA’s

proposal. The net effect would be that 31 of the 41 counties currently designated

nonattainment (many of them rural) would be reclassified to attainment. This would

benefit agriculture, by eliminating the need for additional controls in those areas.

The third standard, for PM2.5, has been the focus of agriculture’s concerns. EPA

states that fine particulates include five categories of pollutants, two of which can

come from agricultural sources. EPA denies any intention to regulate agricultural

sources of these emissions, which are not well-characterized, and in the Agency’s

view are less significant than emissions from power plants and transportation. But

agricultural interests have not been satisfied by EPA’s response, and, in any event,

regulatory decisions will be made by the states, not EPA.

Legislation has been introduced in both the House and Senate (H.R. 1984 / S.

1084) to block implementation of the new standards. Markup of these bills has not

been scheduled. On March 4, 1998, however, the Senate approved S.Amdt. 1687,

to address a limited set of implementation issues. At the request of agricultural

interests, the amendment includes a requirement that EPA report to Congress on the

ability of its sampling and analysis methods to differentiate types of PM2.5 particles.

Contents

Revisions of the Ozone and Particulate Standards . . . . . . . . . . . . . . . . . . . . 1

Air Quality and the U.S. Department of Agriculture . . . . . . . . . . . . . . . . . . . 4

The Ozone and Particulate Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Scientific Underpinnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Implementation Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Regulatory Impacts Specific to Agriculture . . . . . . . . . . . . . . . . . . . . . . 7

Concluding Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

List of Tables

Table 1. Sources of PM2.5 Emissions, 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Agriculture and EPA’s New Air Quality

Standards for Ozone and Particulates

Revisions of the Ozone and Particulate Standards

On July 18, 1997, the Environmental Protection Agency promulgated revisions

of the National Ambient Air Quality Standards (NAAQS) for ground-level ozone and

particulates. The revisions are the result of a statutory requirement: in Section 109,

the Clean Air Act requires that EPA conduct a thorough review of the NAAQS at

five year intervals and “make such revisions ... as may be appropriate.” In the case

of particulates, the standard had been most recently reviewed in 1987. The American

Lung Association sued EPA over its failure to act within the required time period; in

a consent agreement, EPA has agreed to promulgate standards by July 19, 1997.

The ozone standard was not subject to the court deadline, but was the focus of

an earlier suit which EPA settled by reaffirming existing standards in February 1993

and promising to expedite its next review. The Agency subsequently placed its

review and promulgation of new standards for ozone on the same schedule as that for

particulates, on the grounds that the two standards would require controlling many

of the same sources of emissions.

The new ozone standard is 0.08 ppm averaged over an 8-hour period, as

opposed to 0.12 ppm averaged over a one-hour period. The particulate standard was

changed in several ways: the previous standard for particles smaller than 10 microns

(PM10) was relaxed as a result of new averaging methods and additional allowed

exceedances; but finer particles, less than 2.5 microns in diameter (referred to as

PM2.5), are to be separately regulated for the first time.

In setting and revising the National Ambient Air Quality Standards, the Clean

Air Act directs the EPA Administrator to protect public health with an adequate

margin of safety. This language has been interpreted, both by the Agency and by the

courts, as requiring standards based on a review of the health impacts, without

consideration of the costs, technological feasibility, or other non-health criteria.1 In

developing these specific proposals, the Agency reviewed more than 270 studies of

health effects over a 3-year period before proposing standards.2

The net impact of both the ozone and PM2.5 standards will be increased

stringency. Analyses by interested parties, as well as EPA, indicate that many areas

1

2

Lead Industries Association v. EPA, 647 F. 2d 1130 (D.C. Cir. 1980).

For a detailed discussion of the studies reviewed, see 61 FR 65641 and 65719, December

13, 1996, or consult EPA’s home page for the standards at

http://ttnwww.rtpnc.epa.gov/naaqspro/index.htm

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considered to be in compliance with the previous NAAQS will not meet the new

standards. Under the PM2.5 standard, EPA estimated that about 170 U.S. counties

would not meet the standard versus 41 under the old PM10 requirement.3 For ozone,

the number of counties out of attainment under the proposed standard was estimated

to nearly triple, from 106 to about 280.4

Such an increase in the number of nonattainment areas and new methods of

measuring air quality could have broad implications for EPA, the states, and affected

industries, including agriculture. But the effects would not be immediate. A number

of steps will be necessary before the new standards can be implemented. In general,

EPA concludes that it will be 5-8 years before any regulatory decisions affecting

industry or other economic sectors are implemented by the states based on the revised

ozone standard, and 10-12 years before regulations are promulgated by states

implementing the PM2.5 standard. Lawsuits challenging the standards or the

measures adopted for implementation could cause further delay. During the interim,

new scientific reviews can be anticipated.

The 5-8 year delay for implementing controls under the ozone standard results

from the steps mandated by law for implementation of a new standard. Under

Section 107 of the Clean Air Act, Governors must submit a list of areas not attaining

a National Ambient Air Quality Standard within one year of its promulgation. EPA

reviews the information submitted and officially designates nonattainment areas

within 2 years of promulgating the standard.

At the time of designation, EPA is required by Section 172(a) of the Act to set

a date by which each area shall achieve attainment. The date may be 5 years or 10

years following the date on which an area is officially designated. The 10-year date

may also be extended for two additional one-year periods. Thus, areas newly

designated as nonattainment under the ozone standard will have 7-14 years after

promulgation of the ozone standard (i.e., July 2004 - July 2011) to attain it.

Actual control measures to be implemented in the states are decided by the

individual states, using guidance provided by EPA. Following the official

designation of nonattainment areas (July 1999), states are given 3 years to develop

a State Implementation Plan (SIP) identifying the control measures that will be

adopted to bring the areas into attainment. Following submission of these plans,

EPA has 6 months to determine whether the submission is complete and an

additional 12 months to approve, conditionally approve, partially approve, or

disapprove a state’s plan. Thus, if all deadlines are met, it would be January 2004

(6 ½ years following promulgation of a new standard) before there is an approved

implementation plan outlining the measures a state will take to attain the standard.

The PM2.5 standard will take 5 years longer to implement than the ozone

standard, for two reasons. First, there is at present no monitoring network in place

3

Due to a lack of monitoring data for the specified pollutant, the estimate is necessarily only

a rough approximation. See http://134.67.104.12/naaqspro/pmlist.htm, for a list of the

counties.

4

For a list of counties, see http://134.67.104.12/naaqspro/o3list.htm.

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to determine which areas are nonattainment. Establishing this network is expected

to take at least 2 years. Second, attainment determinations are based on the results

of 3 years of monitoring. Thus, 5 years need to be added to the front of the process

described for ozone before Governors will submit lists of nonattainment areas to

EPA, and the State Implementation Planning process for PM2.5 begins. Barring

delays, nonattainment areas would be designated by July 2004, with attainment

deadlines in 2009-2016. The statutory deadline for SIPs identifying specific control

measures would be January 2009, if the earlier deadlines outlined here are met.

These dates will be modified if an amendment to the surface transportation bill

(S. 1173), approved by the Senate in March 1998, is enacted. The amendment

(S.Amdt. 1687), sponsored by Senator Inhofe, would give Governors until July 1999

to submit designations of ozone nonattainment areas, with final designation by the

EPA Administrator in July 2000. This would add one year to the ozone

implementation schedule outlined above.

Regarding PM2.5, the legislation sets December 31, 1999, as the deadline for

EPA to establish a monitoring network, requires Governors to submit lists of

nonattainment areas one year after the receipt of three years of monitoring data

(presumably December 31, 2004), and sets a December 31, 2005 deadline for EPA

to designate nonattainment areas. Under this timetable, the statutory deadline for

SIPs outlining control measures would be June 30, 2010, with attainment deadlines

stretching to the end of 2017.

This paper looks at the question of agricultural impacts from more stringent

ozone and fine particle standards. A subcommittee of USDA’s Agricultural Air

Quality Task Force, created by the 1996 Farm Bill, drafted comments on the

proposed rules during its initial meeting in March, 1997. Excerpts from these

comments were widely circulated in the farm press and in other places. Among other

things, the Task Force questioned the lack of information on incremental benefits and

costs associated with attaining the proposed standard, called for improved monitoring

capability for PM2.5, requested a more complete assessment of precursors to both

ozone and PM2.5, suggested that EPA look at key differences between rural areas and

urban areas where much of the data have been collected, asked EPA to consider the

special needs of smaller and less successful farmers, and recommended that the EPA

analysis be based on a fuller understanding of soil erosion problems and solutions.

Agriculture’s views on possible effects have been discussed at several hearings.

The House Agriculture Committee’s Subcommittee on Forestry, Resource

Conservation and Research held hearings on April 23 and September 16, 1997. The

Senate Agriculture Committee held a hearing July 22, 1997. In addition, at an April

29, 1997 hearing held by the Senate Committee on Environment and Public Works’

Subcommittee on Clean, Air, Wetlands, Private Property and Nuclear Waste, three

panelists addressed agricultural topics; agricultural topics were also discussed at a

July 24, 1997 Environment Committee hearing. The comments offered at these

hearings, comments by USDA’s Agricultural Air Quality Task Force, and

information concerning agriculture provided in EPA’s analysis of the proposals were

the major sources of information used in preparing this report. We begin, however,

with some background concerning the Department of Agriculture and its experience

with air quality issues.

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Air Quality and the U.S. Department of Agriculture

Air quality emerged only recently as a priority environmental topic in

agricultural policy and at USDA. For example, a 1989 national assessment of

resource conditions and concerns on the country’s privately-owned lands published

by USDA included lengthy and detailed discussions of soil and water quality, but

only brief treatment of three air quality issues; atmospheric deposition (more

commonly called acid rain), ozone, and wind erosion. The focus of the acid rain and

ozone discussions was on what is known about relationships between each topic and

agriculture, and centered on research. The wind erosion discussion explained why

air pollution was one of the resulting problems.

Since then, the importance of relationships between air quality and agriculture

has received increased recognition. This recognition culminated in enactment of

provisions in Section 391 of the 1996 Federal Agriculture Improvement and Reform

Act, better known as the 1996 Farm Bill, requiring USDA to create an Agricultural

Air Quality Task Force.5 One finding in the statute states that studies alleging that

agriculture is a source of particulates have been based on erroneous data, and that

USDA should lead efforts to determine accurate measures of agriculture’s role in air

pollution and in the development of cost-effective approaches to reduce pollution.

The Task Force, is an advisor to the Secretary, and focuses on research, with

emphasis on data quality and interagency coordination.

Members of the Task Force, selected in January 1997, are experts who represent

USDA, industry, and basic and applied science. The law specifies that the Chief of

the Natural Resources Conservation Service serves as its chair. At its first meeting

in early March, 1997, the Task Force decided to pursue developing a Memorandum

of Understanding with EPA.6 Topics the Task Force is addressing include

greenhouse gas emissions and climate change, volatile organic compounds and

ammonia associated with livestock waste, and odor and visibility questions that arise

where agriculture is near residential and other land uses.7

For example, a

subcommittee of the Task Force will make recommendations to the whole group on

prescribed burning, to assist EPA as it develops policy proposals on the topic. The

Task Force met three times during its first year.

The Ozone and Particulate Issues

The issues raised by revision of the ozone and particulate standards can be

grouped in at least three categories: the adequacy of the science underpinning the

standards; questions regarding implementation; and regulatory impacts, including the

5

P.L. 104-127, enacted April 4, 1996. Prior to the creation of this Task Force, there was no

official interagency mechanism within USDA to coordinate air quality topics.

6

The goal of the MOU, signed in February 1998, is "to provide a thoughtful process for

involving the agriculture community and the environmental regulation community relative

to agriculture air quality."

7

The minutes of the meeting

http://www.nhq.nrcs.usda.gov.

are

posted

on

the

Internet

at

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costs and benefits of the proposals. Only the last of these has any unique agricultural

component; nevertheless, because of EPA’s mandate under the Clean Air Act, the

costs and benefits to agriculture (or any other sector of the economy) did not play a

central role in shaping the proposals.

Scientific Underpinnings. Questions concerning the scientific underpinnings

of EPA’s proposal have assumed a predominant role in the debate. EPA estimates

that fine particles cause 40,000 deaths per year, and that the proposed standard will

reduce this mortality by 15,000 lives annually. The ozone standards’ projected

effects are less dramatic: EPA estimates that implementation of the ozone proposal

would reduce the risk of significant decrease in children’s lung functions by 1.5

million to 2 million incidences per year, reduce the risk of moderate to severe

respiratory symptoms in children by 200,000 to 400,000 incidences per year, and

prevent 1,600 hospital admissions and 5,000 emergency room visits annually. The

standards will have many additional effects, both positive and negative, but under the

Clean Air Act and its interpretation by the courts, EPA is prohibited from considering

effects other than public health in the setting of air quality standards.

Thus, much of the debate has focused on the quality of the scientific data EPA

used to reach its conclusions. Representative Larry Combest, chair of the House

Agriculture Committee’s Subcommittee on Forestry, Resource Conservation, and

Research, which held a hearing on the standards April 23, 1997, reflected the views

of many in Congress and in the agricultural community in stating:

The science employed in developing this rule is not up to par, and I’m concerned

that farmers could bear the brunt of a bad policy based on equally bad science....

According to much of the testimony we heard today, it appears the EPA’s

proposed standards do not reflect the science that is available.8

While witnesses at this hearing (including scientific witnesses) offered

information to support this conclusion, proponents of the standards have disagreed

in other forums. Dr. Morton Lippmann, of New York University’s Nelson Institute

of Environmental Medicine, a member of every scientific panel that has conducted

EPA reviews of the ozone and particulate NAAQS since 1980, concludes that there

has never been a proposed standard better supported by the science. He and others

note that the particulate panel of the Clean Air Scientific Advisory Committee

(CASAC) agreed by a vote of 19-2 that fine particles should be regulated, and that

a separate CASAC panel that reviewed the ozone documents reached consensus that

“although our understanding of the health effects of ozone is far from complete, the

document [EPA’s staff paper outlining potential primary standards] provides an

adequate scientific basis for making regulatory decisions concerning a primary ozone

standard.”9

There is, however, a consensus among both proponents and opponents that there

is a need for additional research, which might lead EPA to further revision of the

8

9

House Committee on Agriculture News Release, April 23, 1997.

Closure letter from Dr. George T. Wolff, Chairman, Clean Air Scientific Advisory

Committee, to EPA Administrator Carol Browner, November 30, 1995, p. 1.

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standards, especially regarding fine particles. There is virtually no monitoring data

for PM2.5. Little is known about the biological mechanisms that lead from inhalation

of PM2.5 to disease or death. And there is controversy concerning whether PM2.5 (a

broad category that includes many different types of particles) or some specific

particle type within the broad category is the appropriate pollutant to regulate.

Ultimately, the issue of the adequacy of the science base for EPA’s proposed

standards could affect agriculture in two ways. First, there is the question of whether

EPA has the scientific data to assess correctly the effects of the pollutants. If the

standards are too stringent, unnecessary costs of control will be incurred, possibly

affecting agriculture adversely. Conversely, if the standards are insufficiently

stringent, unnecessary harm from air pollution may result, which for ozone could

include adverse effects on agricultural productivity.

Second, there is the question of whether further research would implicate

agriculture as a source of air pollutants subject to regulation — for example, as

discussed below, whether agricultural sources of ammonia contribute to adverse

effects attributed to PM2.5 and might be subject to regulation.

The requirement of the Clean Air Act that EPA regularly review the NAAQS

makes it clear that EPA must make a decision on the science base available. What

is at issue is the level at which the standards should be set given the available

science.

Implementation Issues. A number of issues have been raised concerning the

consistency of the proposed standards with current provisions of the Clean Air Act

and the pace at which air quality improvements would occur under the proposed

standards.

The Clean Air Act, as written, specifically references the existing 1-hour, 0.12

ppm ozone standard (Section 181) and the PM10 standard (Section 188) in

categorizing nonattainment areas: areas with ozone readings of 0.121 to 0.138 are

defined as Marginal and given a 3-year deadline to reach attainment; 0.138 to 0.160

as Moderate, with a 6-year deadline; 0.160 to 0.180 as Serious, with a 9-year

deadline; etc. Section 182 spells out requirements for each of the five ozone

noncompliance categories, and Section 185 contains specific enforcement

requirements for the two worst categories (Severe and Extreme) if they fail to attain

the standard within the deadlines. Similarly, Section 189 spells out requirements for

the PM10 noncompliance areas.

When the ozone standard changed from 0.12 ppm to 0.08 ppm, the statutory

definition of the 5 nonattainment categories became an anomaly, requiring measured

progress toward a standard that no longer exists -- even though virtually all parties

concede that the ozone control measures required under the law are the same types

of controls one would use to meet the new standard.

Since EPA is proposing to retain the existing PM10 standard, the question of

references in the CAA specifically to PM10 as the PM standard poses less of a

problem. Nevertheless, the measures outlined in Sections 188-190 do not address

compliance with the PM2.5 standard.

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EPA has set forth an implementation plan for dealing with the transition to new

ozone and PM standards, but the implementation plan itself raises questions. The

issue is not whether EPA can implement new ozone and PM standards: the Act

provides EPA general authorities to implement air quality standards. The issue is

whether EPA can disregard specific statutory requirements relating to the existing

standards, as implied by the implementation plan.

A related set of questions concerns what all acknowledge is likely to be a

lengthy process for implementing the new standards. As noted earlier, after

promulgation of the standards, it is 5-8 years before any regulatory decisions

affecting industry or other economic sectors are required to be implemented by the

states based on the revised ozone standard, and 10-12 years before any regulations

are likely to be promulgated implementing the PM2.5 standard. Lawsuits challenging

the standards may cause further delay.

With regard to fine particulates, the lengthy schedule for implementation leads

some to conclude that conducting further research to obtain greater certainty before

regulating would have little impact on public health, particularly as several existing

clean air programs, such as Title IV (concerning acid precipitation), will reduce PM2.5

in the interim. The same set of facts prompts others to suggest that the standard

needed to be promulgated as soon as possible to shorten what is certain to be a

lengthy implementation process. There is general agreement that EPA will still have

time to revisit the PM2.5 standard in 5 years, as required by the Act, before any

measures are taken to control emissions.

Proponents of acting now argue that the standards can be revised based on

additional research, but that without a commitment to move forward with regulations,

there will be little impetus to conduct the additional research. Proponents of delay,

on the other hand, argue that huge expenditures of limited resources will be set in

motion by the setting of a standard, and that there should be greater certainty about

the scientific underpinnings before those resources are committed.10

Regulatory Impacts Specific to Agriculture. Even if there were no

controversies over the science or implementation issues, there would still be

questions about how these proposals would impact the economics of agriculture and

other economic sectors. Farmers are less able than many other businesses to pass

increased costs along to those who purchase their products because prices are set in

commodity markets in which individual producers have negligible influence. That

inability, combined with a concern about the potential consequences of these

changes, has galvanized the farm community. Critics of the proposals raise the

specter of especially severe effects on small farmers with limited incomes. Affected

farmers of any size might have any number of controls placed on their actions,

according to these critics, from mandating no till days to requiring that the ground be

10

Bills seeking delay of the standards include H.R. 1984 (Klink) and S. 1084 (Inhofe).

Senator Inhofe's amendment (S.Amdt. 1687), although substantially different from S. 1084,

is considered a substitute for the bill. In discussing the amendment during Senate debate,

March 4, Senator Inhofe announced that if the amendment were enacted, he did not intend

to bring up any other legislation or amendments affecting the NAAQS.

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moistened before it is worked. These concerns in some part reflect a situation of

uncertainty, as EPA has not stated what guidance it might develop affecting

agricultural activities for states to meet the new standards.

Most of the concerns about costs expressed by agricultural stakeholders reflect

potential costs, based on assumptions about the implementation of the proposed

standards. The uncertainties in the science underlying the standards, as previously

noted, and the uncertainties about how the standards would be implemented, since

this is a future phase in the process, give considerable range to such assumptions

about potential costs. However, it is possible to identify factors concerning each

proposed standard that place certain boundaries on potential costs and indicate with

some specificity which decisions are key to those costs. These boundaries indicate

that, to the extent that agricultural stakeholders are concerned about the costs of

EPA’s proposals, their focus should be on the PM2.5 standard, but that key decisions

that could affect those costs will not be made for 10 or more years.

Ozone Issues. Ozone received relatively little attention at any of the

Agriculture committee or subcommittee hearings. Agriculture recognizes that it is

adversely affected by ozone. Testimony from the National Audubon Society

estimated that ozone can be responsible for up to a 10% loss in crop production.

Because the proposed standard would lower ozone concentrations in agricultural

areas of the South, Midwest, and Northeast, EPA has estimated a $1 billion annual

savings for agriculture based on increased crop yields from this proposal.

Agricultural interests challenge the magnitude of these projected savings.

Part of this challenge is based on a concern that ozone measurements are

generally taken in urban areas, and agricultural representatives believe that ozone

levels are much lower in rural areas. If they are lower, the crop losses and the crop

benefits are both likely to be less than the estimates above. If ozone is not as

significant a problem in rural areas, these critics argue that agriculture should not be

required to address it, as the health benefits would be limited. Some of the

characteristics of ozone pollution in rural areas were identified in a recent policy

forum.11 The authors concluded that with new regulations in place, large areas of the

eastern United States would be in non-attainment and require regional control

strategies, with potentially significant costs. The role agriculture might play is

unclear.

Proponents of EPA’s proposal respond in two ways. First, unlike other

pollutants for which there are National Ambient Air Quality Standards, ozone is not

emitted directly into the atmosphere, but forms downwind when sunlight and heat

catalyze a chemical reaction between nitrogen oxides (NOx) and volatile organic

compounds (VOCs). Once formed, ozone can be transported long distances from

urban to rural areas. Thus, rural areas are as likely as urban ones to experience high

ozone levels, provided that they are downwind of the sources of ozone precursors.12

11

Chameides, W.L., et. Al., Ozone Pollution in the Rural United States and the New

NAAQS. Science. Vol. 276, May 9, 1997. P. 916.

12

Maine is a good example. With very few sources of pollution, five counties in Maine

(continued...)

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Second, proponents agree with agricultural interests that farmers do little to

generate the nitrogen oxides and volatile organic compounds that cause ozone to

form in the atmosphere. As a result, they argue, agriculture is unlikely to be a target

of regulation under the ozone proposal. In short, they contend agriculture should

benefit from these changes.

The actual measures to be taken to reach attainment would be determined by

states through what are called State Implementation Plans. All states model air

quality based on current emissions and ambient air quality data, and implement

emission control measures sufficient for the models to demonstrate attainment. As

EPA notes,

There are thousands of sources of these gases [ozone precursors]. Some of the

more common sources are gasoline vapors, chemical solvents, combustion

products of various fuels, and consumer products. These products can be

frequently found in large industrial facilities, gas stations, and small businesses

such as bakeries and auto body repair shops.13

By sector, the major sources of NOx and VOCs include transportation, electric

utilities, petroleum refining and marketing, chemical manufacturing, paints, and

architectural coatings. The impacts on agriculture from regulating these sources are

most likely to be indirect, primarily the result of engine modifications that could be

required of the manufacturers of farm equipment or fuel modifications that might

increase the cost of gasoline or diesel fuel.

PM10 Issues. The proposed changes in the particulate standards affect both

PM10 , for which the standards would be less stringent, and PM2.5, for which there

would be separate standards for the first time. The numeric standard for PM10 would

remain the same, but EPA would use a different method of calculating attainment

that allows additional days above the standard. The net effect would be that 31 of the

41 counties currently designated nonattainment (many of them rural) would be

reclassified to attainment.14

Agriculture is a major source of PM10, accounting for about 17% of emissions

nationally, according to EPA.15 The mix of emission sources varies in specific air

(...continued)

(several with as few as 30,000 - 40,000 people) exceeded the ozone standard in 1995,

primarily because of pollutants transported downwind from other states.

13

U.S. EPA, Office of Air Quality Planning and Standards, National Air Quality and

Emissions Trends Report, 1995, Report No. EPA 454/R-96-005, Research Triangle Park,

NC, October 1996, p. 21.

14

Twenty-six of the 31 counties expected to be redesignated attainment are located west of

the Mississippi River, including 5 in California, 5 in Montana, 3 in Oregon, and 2 in

Washington..

15

U.S. EPA, Office of Air Quality Planning and Standards, Regulatory Impact Analysis for

Proposed Particulate Matter National Ambient Air Quality Standard, Draft Document,

Research Triangle Park, N.C., December 1996, p. 6-13.

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quality control regions; agriculture may account for a higher or lower percentage of

emissions in specific regions.

Despite being a major source of PM10, agricultural activities have not generally

been regulated under the current standard. Nevertheless, the weakening of the PM10

standard could lower potential costs and regulatory requirements for agriculture in

cases where it is a major source of emissions in current PM nonattainment areas.

PM2.5 Issues. Data are inconclusive concerning agriculture’s role as a source

of fine particles (PM2.5). In large measure, this is because, in the absence of

regulation, there existed fewer than 50 PM2.5 monitors in the entire country. Thus,

most of EPA’s data on the prevalence and sources of PM2.5 are estimates subject to

potentially large revisions.

In formulating its estimates of areas likely to exceed the proposed PM2.5

standard, EPA relied in part on estimated relationships between PM10 and PM2.5 and

in part on monitoring data from representative sites in different regions of the

country. As noted, agricultural activities are major sources of PM10, which is

essentially dust raised from unpaved roads, construction, and tilling, and particles

generated in other mechanical processes; but PM2.5 is thought to represent a different

class of particles, more the products of evaporation and combustion, for which

agriculture is a less likely source, than the result of mechanical processes, such as

tilling.

EPA’s Regulatory Impact Analysis for the proposed rule identified five potential

sources of PM2.5: sulfur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3),

secondary organic aerosols (SOA), and fugitive dust smaller than 2.5 microns. The

sources of these pollutants, as estimated by EPA, are summarized in Table 1.

As shown, emissions of SO2 and NOx are by far the largest: SO2 emissions

totaled 29.1 million tons in 1990, of which coal-fired utilities accounted for more

than half; NOx emissions totaled 25.6 million tons, with fuel combustion and vehicles

accounting for nearly all of the total. Agricultural activities, including farm

machinery operating in connection with producing crops, accounted for less than

0.1% of each of these pollutants, according to EPA’s estimates. Similarly,

agriculture accounted for only 200 tons, less than 0.1% of the total SOA emissions

of 221,000 tons.

Agricultural activities do appear to be major sources of the other two categories.

According to EPA, “Livestock feed lots are the largest source of anthropogenic

ammonia emissions (77 percent), followed by crop production (8 percent).” But the

Agency went on to note that “biogenic emissions of ammonia, decomposition of

plants and animals, forest fires and human breath and perspiration also contribute to

ammonia emissions.” As a result, the Agency concluded, “ammonia emissions are

not considered for control in this analysis given that ammonia sources are not

thoroughly inventoried and ammonia controls are not well developed.”16

16

Ibid., p. 6-8.

CRS-11

Table 1. Sources of PM2.5 Emissions, 1990

(thousand tons)

Source

Category

SO2

NOx

Secondary

Organic

Aerosols

Ammonia

Fugitive

Dust

Total

Coal-Fired

Electric

Utilities

15,222

6,690

0

0

99

22,011

Highway

Vehicles

568

7,446

48

198

291

8,551

Industrial

Fuel

Combustion

3,106

3,224

2

17

177

6,526

Off-road

Vehicles

242

2,836

23

3

293

3,397

Other Fuel

Combustion

incl. oil and

gas-fired

utilities

1,229

1,405

1

13

38

2,686

Chemicals,

Petroleum

and Related

Industries

879

397

7

225

63

1,571

Metals

Processing

910

82

0

6

96

1,094

Agricultural

Production,

Livestock

0

0

0

4,186

192

4,378

Agricultural

Production,

Crops

0

10

0

420

838

1,268

Canada

3,194

2,127

17

233

1,225

6,796

Mexico

3,303

710

7

0

105

4,125

Other

449

656

116

147

3,502

4,870

Total

29,102

25,581

221

5,449

6,920

67,273

Source: U.S. EPA, Particulate Matter Regulatory Impact Analysis, Draft, December 1996, p. 6-7.

According to EPA, fugitive dust is PM2.5 emitted directly as particles. SO2, NOx and ammonia are

precursors that transform in the atmosphere to form secondary particulate matter. Secondary organic

aerosols are the particulate transformation products of reactive VOCs and atmospheric oxidants.

The fugitive dust “Other” category includes dust from roads and natural sources, and emissions from

residential wood combustion, wild fires, and prescribed burning. Prescribed burning, which accounts

for 5% of other fugitive dust or 0.5% of the total emissions that become PM2.5, includes agricultural

burning and prescribed burning for forest and range management.

CRS-12

The remaining category, fugitive dust, is also a source of concern to farm

organizations. EPA concludes that agricultural activities account for 837,700 tons

of fugitive dust (12% of total emissions) and that production of livestock accounts

for an additional 3%. Fugitive dust, in total, is a relatively small component of the

PM2.5 problem, and EPA argues that one of the major effects of switching from a

focus on PM10 to PM2.5 is to lessen the need to control dust, which in the Agency’s

view is not as significant a pollutant as emissions from power plants and

transportation sources.17 But agricultural interests have not been completely satisfied

by EPA’s response regarding ammonia or fugitive dust; and both sides note that, in

any event, regulatory decisions will be made by the states, not EPA.

Finally, there are specialized agricultural practices that might be locally

important to PM2.5 attainment. One of these is agricultural burning. EPA identified

agricultural burning as part of a category that also included prescribed burning for

forest and range management. Together, these activities are estimated to generate

379,100 tons of PM2.5 annually, about 5% of the direct PM2.5 emissions, or 0.5% of

emissions including precursors. Prescribed burning is unlike other sources of PM2.5,

because it is not a continuous activity. Rather, it is planned and conducted during

confined periods of time. It is unclear from the data whether prescribed burns are

common in areas that might be designated nonattainment, and the Regulatory Impact

Analysis did not address whether measures controlling agricultural burning might be

necessary. Nevertheless, the planned and limited nature of the activity leave open the

possibility that management strategies may be able to accommodate burning within

the proposed standard, a position the EPA Administrator articulated in a letter to the

Secretary of Agriculture, June 5.18 In addition, as promulgated, the 24-hour PM2.5

standard relaxed the proposed standard from 50 :g/m3 to 65:g/m3. This change is

expected to create additional flexibility for episodic sources of fine particles, such as

prescribed burning of agricultural fields or range land.

Concerns about the quality of the underlying scientific research on particulate

matter are related to the potential agricultural impacts of the standards. As noted

previously, at the core of the science issue is the question of whether more research

would help to better define either the problem or the solution, or conversely, whether

the health threat is such that action is warranted now before better information

becomes available. But many other questions have been raised. Examples of the

many questions that were raised in hearings were the potential errors in calculating

the statistical association between particulate matter and health effects, the inability

17

In a June 16 briefing for staff of the House Agriculture Committee, EPA presented data

comparing the composition of PM10 and PM 2.5 for three areas. In Washington, D.C., typical

of an eastern city, soil represents 31% of PM10, but only 5% of PM2.5. In Phoenix, Arizona,

representative of an arid western city surrounded by desert and agriculture, soil represents

66% of PM10, but only 16% of PM2.5. In the San Joaquin Valley of California, a heavily

agricultural area, soil is 53% of PM10, but only 7% of PM2.5. The Agency also identified

sources of soil in the air, concluding that in both Washington and Phoenix, roads and

construction sites were the overwhelming sources, not agriculture. See U.S. EPA, Office of

Air Quality Planning and Standards, Emissions, Monitoring and Analysis Division, “PM-2.5

Composition and Sources,” June 16, 1997.

18

Letter from EPA Administrator Carol Browner to Secretary of Agriculture Dan Glickman,

June 5, 1997.

CRS-13

to make precise estimates using the agriculture tillage emissions test, basing

estimates of the amount of particulates put into the atmosphere by tillage on limited

bench research with little or no apparent field testing, and the inability to distinguish

the source of the particulates generated by alternative tillage methods. One witness

pointed to a research conclusion that a large portion of the very fine particulate matter

in the eastern United States originates not in this country, but from North Africa, and

a 1996 paper by air quality scientists at the University of California at Davis

exploring this dimension of the problem was submitted for the record.19

Many of the agricultural changes of the past decade are likely to reduce the

volume of airborne particulate matter. The role of the Conservation Reserve Program

(CRP), enacted in 1985, was cited several times by witnesses representing

agricultural interests. The CRP has retired up to 36.4 million acres (about one tenth

of the nation’s cropland) under 10 year contracts. It was given credit for reducing

particulate matter by planting cover crops, usually perennial grasses, on land that had

been cultivated to produce annual crops (air quality benefits may be cited as part of

the justification for reauthorizing and extending the program before it expires in

2002). But this land is only retired for 10 years, and should the program end or the

land be returned to production, it is likely to become a larger source of PM.

Another basic change in agriculture has been the widespread adoption of

conservation tillage techniques, now practiced on about 100 million acres annually.

These techniques leave plant residue from the preceding year’s crop on the ground

to reduce erosion and retain soil moisture. The soil is disturbed less and the farmer

may pass over it less frequently in farm machinery, thus generating less particulate

matter.

There was less talk by witnesses at these hearings about how farming might

change as a result of the requirement to control PM. Examples that were identified,

but not discussed extensively, included sweeping machines for harvesting, spraying

the soil before working it, and using Best Management Practices (erosion control

practices that also provide environmental benefits) for discing.

Aspects of agriculture's concerns will be addressed if an amendment to the

surface transportation bill (S. 1173), adopted in the Senate by voice vote, is enacted.

The amendment (S.Amdt. 1687), sponsored by Senator Inhofe, sets aspects of EPA's

implementation plan in law, providing until December 31, 2005 to designate PM2.5

nonattainment areas, and requiring a report to Congress within 2 years of enactment

regarding the ability of the Agency's sampling and analysis methods to differentiate

types of PM2.5 particles. The latter provision, according to Senator Inhofe, was

added to accommodate the agricultural community. The Administration has agreed

to this amendment. In the immediate aftermath of passage, there has been little

public reaction to the amendment by agricultural groups or in the farm press.

19

Article attached to the testimony submitted by Mr. Bob Vice, representing the California

and American Farm Bureau Federation.

CRS-14

Concluding Observations

Testimony from agricultural interests has focused on questions about data and

analysis, including the assessment and characterization of problems and the impacts

of taking action. Based on these questions, these interests have sought a delay before

EPA acts, so that any action will be based on better information and result in

responses by individual farm operators that more precisely resolve problems

addressed in the regulatory regime. In seeking delay, many comments were offered

about the degree to which current farm practices could be threatened as a result of

these new regulations. The accuracy of these predictions can not be verified for the

most part, but they have generated attention and headlines, especially in the farm

press.

At the heart of this issue are a question and a clash of perspectives. The

question is how much does agriculture contribute to the problems that these

regulations will address (and how much can it contribute to the solutions). This

question has several components, including the diversity of natural conditions and

agricultural practices, the quality and age of the available information, the replication

of actual and current agricultural practices in the data and analysis, and whether all

agriculture should be treated the same in all airsheds. One witness commented that

agriculture is not like the large stationary sources that EPA traditionally regulates,

and the structure of the environmental regulatory regime is far more difficult to apply

to many smaller sources than to few large ones.

The difference of perspectives reflects the different milieus in which the two

agencies operate. Some examples help to characterize this clash. First, EPA science

centers on human health effects, while USDA science centers on effects on

agriculture. At times, scientists with such different foci reportedly encounter

difficulty when trying to communicate with each other. Implementing the

Memorandum of Understanding between the two agencies may help ameliorate these

kinds of problems.

Second, EPA’s statutory mandates are segmented by media. Air quality is

addressed by a separate entity in EPA from water and land issues. In agriculture, the

media are considered together in efforts to help farmers conserve and enhance their

resources. This segmentation has been an effective approach for many problems, but

it may limit both an understanding of the problems agriculture might face and the

range of possible solutions.

Third, the EPA regulatory environment is based on setting national standards

that are applied by state agencies in all airsheds. EPA does not have a program

delivery system at the local level. USDA, by contrast, works almost exclusively at

the local level through direct contact with individual landowners. This approach is

based on voluntary participation, and local flexibility and solutions. One source of

the strenuous objections from agriculture may be a concern over the EPA regulatory

approach as much as the different views on the seriousness of the problem, especially

agriculture’s role. In part, this concern may reflect a misunderstanding of EPA’s

regulatory approach (which does allow states and local air quality control regions

substantial flexibility in designing control strategies) or the time-frame within which

regulations will be implemented, which is likely to be prolonged. Nevertheless, the

CRS-15

different backgrounds or world views that EPA and agriculture bring to the

discussion are a major source of potential misunderstandings.

Fourth, EPA views soil as a potential source of pollutants, and is concerned with

particle sizes and the ways that soil is transported by air in the case of PM.

Agriculture views soil as a basic and valued component for commodity production.

Both EPA and agriculture see major benefits in keeping soil in place on the farm.

Agriculture measures erosion using a tolerance rate that is based on the gross volume

of soil that can be lost while maintaining the long-term production capability. EPA

is concerned with particle size that is transported by the processes of erosion.

Agriculture believes that appropriate soil conservation measures, properly designed

and implemented, should go a long way to solving its definition of the problem, that

is, loss of an asset, while the EPA is basically concerned with solving the particulate

matter problem. While both strive to keep as much soil in place as possible, the

different objectives and possible solutions make common ground on the most

appropriate erosion control measures more difficult to find.

A June 5, 1997 letter from Carol Browner to Dan Glickman stated that EPA did

not plan to focus on agricultural sources as it implemented the proposed standards.

The letter states that agriculture would benefit from the change in the ozone standard,

by reducing crop damage. Regarding the PM proposal, EPA states that it plans to

issue guidance to states that would direct their control strategies away from farming

and tilling activities. The letter also states that burning is a recognized agricultural

practice, and that strategies that can accommodate burning will be sought.

The hearings before congressional committees reflect a call to Congress by

agricultural interests (and others who might be adversely affected) to hear their

concerns and explore these issues, and to consider acting on their behalf. They also

represented an attempt to influence EPA’s decision-making process.

Continued congressional oversight of these issues is certain. EPA will need a

continuing flow of resources to review monitoring data submitted by the states,

categorize areas as nonattainment, review new State Implementation Plans, and

promulgate regulations affecting specific sources of pollution. The conferees on

EPA’s FY 1997 appropriation expressed their concerns about the new PM standard

even before its proposal. The appropriations committees will continue to monitor

these regulations. More broadly, some have suggested free-standing legislation (such

as H.R. 1984 / S. 1084) to impose a moratorium on implementation of the new

standards. While enactment of such legislation appears less likely as time goes on,

the Senate's adoption of S.Amdt. 1687 to the surface transportation bill in early

March indicates a continued search for legislative language that can reassure affected

interests and narrow Agency discretion in implementing the new standards. (For a

discussion of recent congressional actions on clean air issues, see CRS Issue Brief

97007, Clean Air Act Issues.)

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