Primary national ambient air quality standard for sulfur. Currently, only two counties in arkansas fall under this requirement. Epas decision is based on its judgment that the current naaqs protects the public health, with an adequate margin of safety, including the health of atrisk populations with asthma. Epa plans to designate geographic areas as attaining or not attaining the 2006 24hour pm 2. Standard naaqs for sulfur dioxide so2 by establishing a new 1hour standard at a level between 50100 parts per billion ppb. Apart from so2, this letter is significant because it is the first official casac action under the newly appointed chair, anthony cox, and the other new members appointed by this administration. The clean air act requires the epa to set us national ambient air quality standards naaqs for the six caps. Epa publication of so2 naaqs designations starts lawsuit. Epa no longer updates this information, but it may be useful as a reference or resource. This rule establishes the initial air quality designations for certain areas in the united states u. Environmental protection agency epa sets national ambient air quality standards naaqs for criteria pollutants, including sulfur dioxide so2. Epa replaced the 24hour and annual standards with a new shortterm onehour standard of 75 parts per billion ppb. The following documents are agency nonbinding guidance documents relating to the implementation of the 2010 1hour sulfur dioxide so2 primary national ambient air quality standards naaqs. The facts on naaqs national ambient air quality standards.
Designation and naaqs information related to so2 2010. Standards have been drawn up for six criteria pollutants. All4s dan dix presented at the 23rd virginia environmental symposium about 1hour so2 implementation modeling. Dans presentation consisted of a summary of the naaqs, an update on naaqs implementation, naaqs modeling demonstration approach, and a. The naaqs for ozone was reduced from 75 parts per billion ppb to 70 parts per. History of the primary national ambient air quality standards for sulfur dioxide since 1971 115 table 21. National ambient air quality standardssulfur dioxide. National ambient air quality standards ozone naaqs nonattainment consequences so 2 naaqs 2. Green book sulfur dioxide 2010 area information nonattainment. On june 2, 2010, epa revised the so2 standard, establishing a 1hour primary standard of 75 ppb. Environmental protection agency regarding a proposed revision to the national ambient air quality standard naaqs for ozone from dr.
The longview measurements are the highest and exceed the naaqs. Epa promulgated the revised national ambient air quality standard naaqs for sulfur dioxide so 2 on june 2, 2010. It provides an excellent history of the naaqs, and it will become one of the. Updated guidance for area designations for the 2010 primary sulfur dioxide so 2 national ambient air quality standards naaqs. National ambient air quality standards naaqs, pronounced \naks\ are limits on. Overview of ambientozone standards development and benefits. The 8hour ozone 1997 standard was revoked on april 6, 2015 and the 1hour ozone 1979 standard was revoked on june 15, 2005. Sulfur dioxide so2 pollution adeq arizona department of. Sulfur dioxide so2 national ambient air quality standard. What are the national ambient air quality standards naaqs.
These primary standards, which were based on the findings outlined in the original 1969 air quality criteria for sulfur oxides, were set at 0. Sulfur dioxide so2 is a toxic, colorless gas that has a pungent odor, much like that of a. The designations for round 1 covered areas that violated the 1hour so2 naaqs based on certified ambient air quality monitoring data for the years 2009 to 2011. Air interstate rule cair60 will lower the cap on so2 and. Njdepcleanairnjclean air njnj ozone air quality standards. This aspect has motivated experimentation with novel control methods that have. Christopher frey, distinguished university professor at north carolina state university and chair of the epas clean air scientific advisory committee. Naaqs air pollutants and hydrogen sulfide health consultation midlothian, texas april 2016 this brochure provides an overview of the findings and recommendations from one of t he six health consultations prepared for the midlothian site, midlothian, texas. Current and historical monitored so2 levels in arizona. The national ambient air quality standards naaqs are determined by the epa in accordance with the clean air act. The epa designated one nonattainment area in wisconsin in round 1. Federal register air quality designations for the 2010. History of particulate matter pm and total suspended particles tsp.
Air quality designations for the 2010 sulfur dioxide so 2 primary naaqs round 2 july 12, 2016 see 81 fr 45039 contact us to ask a question, provide feedback, or report a problem. National ambient air quality standards naaqs for 1hour so 2, 1hour no 2, and 24hour pm 2. As a part of the continuing implementation of the air quality management system, on october 3, 2016 ministers announced new canadian ambient air quality standards caaqs for sulphur dioxide that will drive the improvement of air quality across the country. Naaqs based on the form ofthe standard, including significant contribution analyses using the interim significant impact level sil established in the june 29, 2010 memo, 1. Naaqs implementation coalition virtual facilities naaqs study. It is very important for all modelers both within and outside of the u. Here are answers to some questions about the recent announcement by the u. National ambient air quality standards naaqs for 1hour so2, 1hour no2, and 24hour pm2. The naaqs are health based and the epa sets two types of standards. National ambient air quality standardssulfur dioxide page 3 of 8 date. For more information about so2, naaqs and areas in arizona that do not meet standards, visit.
Primary national ambient air quality standard naaqs for. Under the 1997 ozone naaqs, about 391 counties or parts of counties with a total. History of the national ambient air quality standards for oxides of sulfur during the period 19712012. The paper looks at several periods in the history of the u. Epa alumni association oral history video early implementation of the clean air act of 1970 in california. Maximum 1hour so2 measurements in dallas, longview and waco for 20062008 are shown in table 2.
National ambient air quality standards naaqs, pronounced \naks\ are limits on atmospheric concentration of six pollutants that cause smog, acid rain, and other health hazards. The primary standards are designed to protect the health of sensitive populations such as asthmatics, children, and the elderly. Epa is also proposing to revoke the existing 24hour and annual primary so2 standards. However, given epas recent shift in how they see, or dont see the 1hr so2 implementation process happening, we agreed that it was more important to focus on how the process has played out so far and what to expect next. History of the 2010 so2 1hr naaqs june 2, 2010, epa issued the revised primary naaqs to improve public health protection first revision since the initial so2 naaqs was issued in 1971 the 2010 revision was compelled by a judicial consent decree and legal challenge to. Table of historical so2 naaqs sulfur dioxide naaqs us epa. A history of the us national ambient air quality standards. The environmental protection agency epa is designating the areas as either nonattainment.
Environmental protection agency office of air quality planning and standards health and environmental impact division air benefitcost group research triangle park, north carolina. See the history of limits to the level of sulfur dioxide so2 in ambient air, set through the. This includes both primary and secondary standards. Table of historical sulfur dioxide national ambient air. Ambient air quality standards include primary standards directed at protecting public health and secondary standards aimed at promoting public welfare. As part of the implementation of the new 1hour so2 naaqs, epa has begun requiring, in addition to monitoring data, the use of dispersion modeling for areas with facilities emitting large quantities of so2 as a means of determining compliance with the new standard. Epa guidance on the development of modeled emission rates for precursors merps as a tier i demonstration tool for ozone and pm 2.
History of primary naaqs for ozone and other photochemical oxidants. The clean air act, which was last amended in 1990, requires epa to set national ambient air. The bill would delay enforcement of the new 2015 ozone naaqs by postponing final epa designation of nonattainment areas under the new standard from 2017 until october 26, 2025. Assessing the public health implications or the criteria. Epa science advisors support current so2 naaqs verdant law. Updates to the sulfur dioxide so2 national ambient air. Established by the united states environmental protection agency epa under authority of the clean air act 42 u. Review of the national ambient air quality standards. National ambient air quality standards naaqs the clean air act, which was last amended in 1990, requires epa to set national ambient air quality standards 40 cfr part 50 for pollutants considered harmful to public health and the environment.
Implementation guidance for the national ambient air. Originally the council reached out to me to talk about the short term naaqs implementation, modeling and monitoring. A history of the federal clean air act can be found here. The green book so2 nonattainment areas 2010 standard.
Indiana nonattainmentmaintenance status for each county. The us epa set oxidants standards in 1971, which included ozone. So 2 primary rea plans presentation for the casac bob hetes, stephen graham, nicole hagan march 21, 2017. Federal register primary national ambient air quality. Calpuff modeling analysis of the sulfur dioxide and pm2. As epas proposal follows the recommendations of the clean air scientific advisory. History of ozone naaqs same as previous 18 final rule date indicator averaging time level ppm. Several essays and books have been written about the legal, policy, societal.
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