Document MMgwkGMxxLKdd0JVrakB1b90x

AR226-2316 / Charles J Zarzecki 03/20/2003 08:08 AM To: cc: Subjecfc Catherine A Barton/AE/DuPont Re: lookee what I found Q Cathie, The uncertainty is about 2X. That goes either way. The numbers can be half what we got, or twice what we got. Unless these papers specifically address averaging time periods, I don't know how they will help our position. Also, even though they can underpredict, the ISC model is inherently conservative, as we have discussed. I'll take a look, though. Charlie Z. Catherine A Barton y Catherine A Barton 03/19/2003 04:25 PM To: cc: Subject: Charles J Zarzecki/AE/DuPont@DuPont lookee what I found Charlie, Dam it,- There are a few papers on the web that discuss uncertaintly around Gaussian models. I'm reading through them to see if they could be used to say the answers we've gotten could be x times lower, or something of that nature. If you don't mind, take a look and see if they make a case or if they're full of hot air. here are three references: htlp://www.chemalliance.org/Columns/lndustry/lnd9908l 6.asp#(1) http://www.air-dispersion.com/feature.ntml http://www.epa.gov/epaoswer/hazwaste/combust/chg-air.pdf EID747641