here in court today but the second sentence of the definition allows an unlimited amount and an unlimited proportion of man made industrial pollution to qualify as part of a natural nine percent what the law and all those agencies brief attempts to gloss over this significant loophole the interpretation is a post hoc interpretation and it cannot be squared with the actual text of the regulation the crux of the problem here lies in the second sentence of the definition when read on its own the first sentence appears to require nature to be the predominant cause of both the event and the emissions that together comprise a natural event but the second sentence in this rates this limitation because it allows virtually any amount so if we just have the first sentence you you think it's permissible that eve even though we're on the natural process they the agency can permit human activity that plays a little role that does not go too far yes that's correct your honor we agree with that interpretation and the second sentence allows a natural event to incorporate virtually any amount and proportion of industrial manmade pollution in the words of  words at the time of rule making and this is that j a m d for this is the case regardless of the now going to have the emissions that are generated by these reasonably controlled anthropogenic sources and regardless of the relative contribution of the sources as written the second sentence thereby creates a significant loophole in the clean air act and it threatens to him cough the narrow exception that congress intended to create  section three nineteen why doesn't the phrase reasonably controlled to the limiting work that you think is necessary yes or not your honor it does not do so because even when sources are reasonably controlled they can still in that vast amounts of pollution to give an example a single coal fired power plant can generate sixteen thousand tons of power tens of pollution software dioxide in a single year and this is a power plant that is subject to we smoke controls and just to put things into perspective that is twenty times the amount of sulfur dioxide that is produced by all of the sources within the entire district of columbia within a certain event if you have power plants that are put that are reasonably controlled that are putting a large amount of industrial pollution into the air and those emissions are swept up by the high winds then they can qualify as part of a natural  so you do need that piece of nature that's part of their that but the admission component can be coming from anthropogenic sources suppose that suppose the regulation were limited to what i he regards as the paradigmatic event which is right when the storm sweeps through the desert and it's kicking up dust all over the place and happens to kick up some dust coming off of interstate ten as of little amount of the overall emissions we don't quarrel with that but if you have the situation where the dust from the desert is ninety eight percent fifty percent but fifty percent of the dust is coming off the interstate than we do you think that's not consistent so it's not it's see that's true then are you saying that the regulation might be overbroad in some of its applications even though the the core of it or at least what  produce and we would think that the majority or many of the applications that are in person this fall would actually be allowed by the actual regulatory tast and i'd like to draw the court's attention to i'm footnote eight lifted off the ground by the wind on the one hand and pollutants that are already airborne at the time that they are in train by high winds so in that latter category we have not only particulates matter that is put into the air by smokestacks and other anthropogenic sources but we also have the large amounts of gashes pollution that come from reasonably controlled sources but that never settle to the ground you've actually gone one step beyond where i was in the analysis and that's why the don't we start with what does the phrase natural event mean when that congress is said a natural event and what what what's the meaning of that yes you and congress has made it very plain by use of that term we're using that the statute does not provide a definition of the word natural and so there doesn't seem to be any dissents that's critical right we start with that congress doesn't define ordinary meaning of the term and natural means of arising from or for me part of the charter and it defies any ordinary meat understanding of the word natural to think that a cloud of power honor i think that goes back to the idea of reasonable controls and the distinction that he draws so if the hurricane i know what i know i think i've focused right what does it mean to say something natural and unnatural event is heard a hurricane that kicks up pollution is not a natural that it is it certainly is your honor and the reason for that is in the e p a s limiting construction which is when it's nature that is putting pollution into the air and air pollution is defined as emissions that are in then that is natural but when you have smokestacks that are putting the pollution into the air then that nature is not the source of those pollutants and congress made this very clear in the congressional  report it said that when you have an ecological process that itself generates pollutants that can be enough for a vent and they examined pools that congress provided were located or ructions and forest fires and in both of those this court house says that has said that the legislative history is appropriate to consider during the first step of the shotgun inquiry and so that informs what congress plainly meant by the term natural that and and it volume is there just swirling more closer with what is your understanding about what we do with your own air we're not talking about that body of pollution so if the let's say a smokestack is putting pollution in the air and that would normally be counted by the monitors right that is not part of the vent that's just the background in the shins so what we're talking about is not the emissions that normally wouldn't be picked up by those monitors because they're being blown in by from further away so on a normal when day let's say that the pollution would only be dispersed within a fifty mile radius but on a day when the winds are at twenty five mph above we have pollution coming in from beyond the twenty five mile radius so it's that body of pollution that we're talking about here matters here is that it's also registering for these monitors where it normally wouldn't reach and the clean air act has provisions that deal with this kind of interstate transportation of pollution there's section one ten which makes it very clear that a jurisdiction is responsible for making sure that it's pollutants are contributing to exceed and says in other jurisdictions and so this is part of the scheme that congress intended and  large definition of natural event threatens to undermine that scheme and regardless have power reasonable the limiting interpretation that e p a has put forth in its brief is the problem is that there's no support for that narrow interpretation in the actual text of the regulation so someone who is just reading regulation would have no basis to think that the regulation can be applied only in the very the courts both this court and the supreme court have made it very clear that in agencies interpretation of its own regulation is not entitled to any deference where it is contradictory and plainly and consistent with the actual  for the rule that says that there's nothing in the preamble or other documents that say that and but most importantly it's not in the text of the regulation itself your honor and this court and the supreme court have made it very clear construe we try to construe text to make it lawful rather than unlawful so if if that limiting construction of the regulation were necessary to make it a reasonable interpretation of the statute  chevron signs why wouldn't we impose it rather than just throw the whole thing out your honor the court has addressed situations like this before i'm so for example in the cuomo versus clearinghouse case you have a regulation that's very broad and then you have an agency interpretation that is narrower and perhaps reasonable and that narrower interpretation could fit within that broader interpretation harvard the court found there that when you're just looking at broad regulation it's inconsistent with the narrow one being advanced by the agency because someone reading that broader actual language would not have any idea that you could actually that what they didn't seem that was of limiting construction and so this is i mean you have a problem there turning to explain how the definition it works and then briefly addressing petitioner's argument that you piece interpretation isn't how post hoc rationalization as he explained a j eight thirty and want to one  emissions nene's aerodynamic and train it so in plain english to him it means to put into the air to make something airborne so for example when sweeping up darts from the ground is generating emissions and those emissions are said result from the wind a factory that releases pollutants into the air through it's no sap or have is generating emissions and those emissions are sets result from the factory and that's true even if later on when comes by and transports those emissions elsewhere because that does not change the fact that it was the factory not the wind that generated the emissions that it was the factory not the wind that released the pollutants into the air read them both and you have to read them in the order in which they appear so let's start with the first sentence which says natural event means an event and it's resulting emissions which may recur at the same location in which human activity plays little or no direct causal role there are two basic elements required for a natural event you need an event and you need its resulting emissions think of these two elements as a door to the universe of potential natural events so that if you don't have an event you can't get in the door if the emissions that you're talking about do not result from we're not generated by the event you can't get in the door either and this is where petitioners tripped up they completely ignore that requirement the routine industrial emissions their worried about cannot get past the door and why is that because routine industrial emissions are not an event and event is a deviation from normal conditions and routine industrial missions are routine they are the emissions generated of by industrial sources operating as a matter of course so there is no event here and for the same reason routine industrial emissions do not result from an event and so routine industry missions get shut out of the definition you don't even proceed to the second sentence petitioners see it straight ahead  really they read it to say that routine industrial missions are a natural event or can be part of a natural event and they're wrong for two reasons the first is that their interpretation ignores the first threshold requirement that you need an event and its resulting emissions nothing in a second sentence exempts you from that requirement and as it explained routine industrial emissions not satisfy that requirement so for this court to accept petitioners interpretation you would have to strike out the words an event and its resulting emissions from the first sentence the other reason that they're wrong in their interpretation is that the second sentence does not actually talk about routine industrial emissions the second sentence for purposes of the definition of a national event anthropogenic sources that are reasonably controlled shall be considered to not play a direct role in and these emissions refers back to the events resulting emissions in the first sentence because that is the only other place in the entire definition that talks about emissions now under the first sentence the emissions have to resolve and not just any of it because if you read on you'll see that the event has to be one in which human activity place little or no direct causal role in other words and event that's predominantly natural what we call an act nature so the emissions have to result from have to be generated by an act of nature and you put all this together and what the second sentence as and all that the second sentence says is that re controlled sources do not play a direct causal role in the emissions generated by an act of nature it does not say anything about nineteen industrial emissions and it certainly does not say anything about routine industrial nations or any other human activity being a natural event as we explain in our brief the purpose of the second sentence is to clarify this unique situation where you have emissions by the wind suppose you have a different example you have a and a natural event causing emissions very very substantial emissions whose source was human made so i don't know of a bolt of lightning hits a reasonably controlled container of toxic gas and as a result the the only emissions resulting from out of that the toxic gas stored in the container that seems a little different from the the wind in the desert case so in that situation i am not sure if it would be considered a natural event or it whether it would be considered an event caused by human activity unlikely to occur this is a very fact and since analogy with your your regulation would classify that one as natural he even though it seems like it's a much closer question that would i think depends on the facts but i think you get your question maybe another maybe another hypothetical that's less problematic with which would better illustrate the point you're concerned about just  so in our dirt road example let's say all the dust but by the wind came from the dirt road in that case provided the dirt road was reason we controlled that would be a natural event yeah it's just that's hypothetical seems unlikely to me and the more realistic hypothetical with a dirt road most of the dust will come from the desert and that's part of the intuitive appeal of the regulation but the regulation isn't limited to that kind of case natural natural you're you're paradigmatic cases a natural event when emissions are natural right but the dust from the desert disposed of the dust from the road right but in your example i up it's not it could be the case that because the human sewers well in your case with the it would still be the case that without the natural event there wouldn't you wouldn't have all that pollutants in the air in the first place and remember the context that we're talking about here is the clean air act and wo and that event then cause pollutants to get in the air so you would have it's resulting emissions and i under the second sentence if and that makes sense because it was the it was the act of nature you would still say you would still say the emissions were caused by strike because it was if that is the lightning strike was what and if i'm sorry the police are already in the area no then that would be counted as the initials generated from the factory and would not be part of the natural analysis so the question really is what but the pollutants in the air guidance at j a two to two or three recognized that national bank can include human contribution only on only under very limited and narrow circumstances in his two thousand and seven definition  similarly explained that a natural event is an event in which human activity place little or no direct causal role and in its response to comments in this room making at j one forty seven e p a address natural and definition and it said under this definition repeated a long term human activity would preclude the event from being natural so even his definition and its interpretation that definition articulate the agency's longstanding and considered judgment about the permissible relationship between natural bands and human activities i like to leave the court with one final thought which is what you have heard here today are two starkly different readings of the natural bent definition petitioner's reading ignores he parts of the regulatory tax and produces this absurd result that human activities are natural events e d s reading in contrast addresses every w any further questions thank you there's there are just three points i'd like to make the first that is that if it's just edwards said just the court believes that eat peas interpretation is reasonable we think thought that would address the problem but we would ask the court to memorialize that in a written opinion because we don't think that the actual text of the regulation conveys that unlimited interpretation and that we would wish that the agency is held to that narrow interpretation the second is that and related to the first is the actual text of the regulation does not say what he is now saying that it says he's counseled mention j eight zero eight and the quote talking about routine emissions generated by and transported from anthropogenic sources are not exceptional events but again that's just talking about normal emissions on days without a natural that it's talking about the smokestack emissions on days we don't have high winds and the universe of the events that we're concerned about are the high wind days when you have the pollution that's being blown over and that's being considered part of from natural event and the agenc sentence was not in the two thousand and seven regulation and all that the two thousand and seven regulations that was something very similar to the first sentence of e p a its current definition which is that nature must play the pretty dominant role in the natural event i'm sorry how is your broader reading consistent with the word resulting in the first sentence natural of that means an event and its resulting in missions so if you have the smallest the smokestack that is emitting pollution regardless and then you have the very high wind day i would think the those emissions will not be resulting from the event your honor that is certainly one plausible reading of thought word and again if the court were to accept that we were just asked about it memory i think but we believe that as written when you're reading the phrase resulting from that the way that the