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

Update: July 18, 1997

CONTENTS

Summary
Revisions of the Ozone and Particulate Standards
Air Quality and the U.S. Department of Agriculture
The Ozone and Particulate Issues

Scientific Underpinnings
Implementation Issues
Regulatory Impacts Specific to Agriculture

Concluding Observations
List of Tables

Table 1. Sources of PM2.5 Emissions, 1990

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 fliels and motor vehicles might have indirect impacts on the agricultural sector.

The second standard being revised -- that for PM10, a category that includes fligitive 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 nonattailanent (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 PM25, 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 Rouse 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 PM25 particles.

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. Ths 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 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 flirther 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 detennme 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 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 successfbl farmers, and recommended that the EPA analysis be based on a fliller 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.

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 reaearch. 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.

Endnotes

1 Lead Industries Associatin V. EPA, 647 F. 2d 1130 (D.C. Cir. 1980).

2 For a detailed discussion ofthe studies reeiewed, 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

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.l2lnaaqsprolpmlist.htm for a list of the counties.

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

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 l998, is "to provide a thoughtful process for involing the agriculture community and the environmental regulation community relative to agriculture air quality."

7 The minutes of the meeting are posted on the Internet at http://www.nhq.nrcs.usda.gov.