Calpuff modeling analysis of the sulfur dioxide and pm2. The primary standards are designed to protect the health of sensitive populations such as asthmatics, children, and the elderly. Implementation guidance for the national ambient air. 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. Epa no longer updates this information, but it may be useful as a reference or resource. Primary national ambient air quality standard for sulfur.
Several essays and books have been written about the legal, policy, societal. The 8hour ozone 1997 standard was revoked on april 6, 2015 and the 1hour ozone 1979 standard was revoked on june 15, 2005. So 2 primary rea plans presentation for the casac bob hetes, stephen graham, nicole hagan march 21, 2017. This rule establishes the initial air quality designations for certain areas in the united states u.
Updates to the sulfur dioxide so2 national ambient air. Green book sulfur dioxide 2010 area information nonattainment. A history of the federal clean air act can be found here. This includes both primary and secondary standards. The clean air act requires the epa to set us national ambient air quality standards naaqs for the six caps. History of the national ambient air quality standards for oxides of sulfur during the period 19712012. Dans presentation consisted of a summary of the naaqs, an update on naaqs implementation, naaqs modeling demonstration approach, and a. It is very important for all modelers both within and outside of the u. Njdepcleanairnjclean air njnj ozone air quality standards. Assessing the public health implications or the criteria. Christopher frey, distinguished university professor at north carolina state university and chair of the epas clean air scientific advisory committee. The epa designated one nonattainment area in wisconsin in round 1.
As epas proposal follows the recommendations of the clean air scientific advisory. Sulfur dioxide so2 national ambient air quality standard. Epa publication of so2 naaqs designations starts lawsuit. On june 2, 2010, epa revised the so2 standard, establishing a 1hour primary standard of 75 ppb. Currently, only two counties in arkansas fall under this requirement. Epa is also proposing to revoke the existing 24hour and annual primary so2 standards.
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. Standards have been drawn up for six criteria pollutants. Indiana nonattainmentmaintenance status for each county. 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.
Epa science advisors support current so2 naaqs verdant law. Current and historical monitored so2 levels in arizona. History of primary naaqs for ozone and other photochemical oxidants. It provides an excellent history of the naaqs, and it will become one of the. 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. Designation and naaqs information related to so2 2010. Epa replaced the 24hour and annual standards with a new shortterm onehour standard of 75 parts per billion ppb.
Table of historical so2 naaqs sulfur dioxide naaqs us epa. National ambient air quality standardssulfur dioxide. National ambient air quality standards ozone naaqs nonattainment consequences so 2 naaqs 2. All4s dan dix presented at the 23rd virginia environmental symposium about 1hour so2 implementation modeling. Epa promulgated the revised national ambient air quality standard naaqs for sulfur dioxide so 2 on june 2, 2010. What are the national ambient air quality standards naaqs. Under the 1997 ozone naaqs, about 391 counties or parts of counties with a total. This aspect has motivated experimentation with novel control methods that have.
Maximum 1hour so2 measurements in dallas, longview and waco for 20062008 are shown in table 2. The naaqs are health based and the epa sets two types of standards. Environmental protection agency office of air quality planning and standards health and environmental impact division air benefitcost group research triangle park, north carolina. For comparing against the so2 1hour naaqs, background concentrations at a monitoring station are added to the concentrations predicted by the aermod model. Sulfur dioxide so2 is a toxic, colorless gas that has a pungent odor, much like that of a. The longview measurements are the highest and exceed the naaqs. Updated guidance for area designations for the 2010 primary sulfur dioxide so 2 national ambient air quality standards naaqs. Naaqs implementation coalition virtual facilities naaqs study. 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. Table of historical sulfur dioxide national ambient air. Here are answers to some questions about the recent announcement by the u. The paper looks at several periods in the history of the u. Air interstate rule cair60 will lower the cap on so2 and. A history of the us national ambient air quality standards.
The epa is completing area designations for this naaqs in four rounds. See the history of limits to the level of sulfur dioxide so2 in ambient air, set through the. Sulfur dioxide so2 pollution adeq arizona department of. These primary standards, which were based on the findings outlined in the original 1969 air quality criteria for sulfur oxides, were set at 0. National ambient air quality standards naaqs for 1hour so 2, 1hour no 2, and 24hour pm 2.
Ambient air quality standards include primary standards directed at protecting public health and secondary standards aimed at promoting public welfare. History of particulate matter pm and total suspended particles tsp. Standard naaqs for sulfur dioxide so2 by establishing a new 1hour standard at a level between 50100 parts per billion ppb. The national ambient air quality standards naaqs are determined by the epa in accordance with the clean air act.
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. The clean air act, which was last amended in 1990, requires epa to set national ambient air. 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. Federal register primary national ambient air quality. Epa plans to designate geographic areas as attaining or not attaining the 2006 24hour pm 2. 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. Epa guidance on the development of modeled emission rates for precursors merps as a tier i demonstration tool for ozone and pm 2.
Epa alumni association oral history video early implementation of the clean air act of 1970 in california. The facts on naaqs national ambient air quality standards. The naaqs for ozone was reduced from 75 parts per billion ppb to 70 parts per. 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. Environmental protection agency epa sets national ambient air quality standards naaqs for criteria pollutants, including sulfur dioxide so2.
June 2010 epa promulgated the 1hr so 2 primary naaqs as a replacement for the existing annual and 24 hour primary naaqs 75 ppb as the 3 year average of the 99th percentile of the annual distributions of the daily maximum 1hour concentrations. 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. 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. National ambient air quality standardssulfur dioxide page 3 of 8 date. Environmental protection agency regarding a proposed revision to the national ambient air quality standard naaqs for ozone from dr. 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. Established by the united states environmental protection agency epa under authority of the clean air act 42 u. The environmental protection agency epa is designating the areas as either nonattainment. National ambient air quality standards naaqs for 1hour so2, 1hour no2, and 24hour pm2.
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. Primary national ambient air quality standard naaqs for. 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. Originally the council reached out to me to talk about the short term naaqs implementation, modeling and monitoring. The us epa set oxidants standards in 1971, which included ozone.
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