Document wD1XJZmngE40qDNNj3rVvRKjJ

AR226-2155 Catherine A Barton j | a ^ ' g ^ ^ ^ ' s ^ ' s ^ s ^ ^ a ^ i a ^ s ' ' 06/27/2001 0334 PM To: cc: Subject: Debbie J Mulrooney/AE/DuPont@DuPont, Robert F Pinchot/DEV/AE/DuPont@DuPont Catherine A Barton/AE/DuPontDuPont Recap of our meeting Just so we're on the same page (and so I can remember what we said we'd do a week from now), I've summarized some notes from our meeting today. If any of this looks Incorrect to either of you, please holler. AirFKsk Debbie will run an additional air dispersion modeling .case ("Case 5") to represent the following conditions: Release rate = 0.03 g/s Stack flow rate = 10,000 scfm Stack Velocity = 100 ftte 3o.S Stack Height =85 ft SS.I Building Height =55 ft Temperature = 298 K : We will compare the Case 5 concentration results to the CEG tor air of 0.3 ug/m3 to ensure these design conditions meet our guidelines with a "reasonable level of comfort". Drinking Water Risk Debbie will pass along the input file to Cathie to be run in risk mode at 1 g/s to provide revised input for deposition calculations. Cathie will explore the ulitmate fate of all the emissions leaving the stack (ie, 0.03 g/sec for a year which equals 2086 Ibs/yr by my calculations). Specifically, we would like to be able to create a mass balance of all the compound leaving the stack. Cathie will validate her assumptions about the appropriate annual deposition rates and watershed surface area and finalize hercalculations- We will compare the new water concentration results to the CEG for water of either 1 ug/l or 3 ug/I, depending on results from the air exposure to ensure the design conditions meet our drinking water guidelines with a "reasonable level of comfort". Fish Risk Using the water concentration calculated above, a BCP of 10, and fish consumption rates recommended by the Environmental Factors handbook, Cathie will compare expected doses from fish consumption with our guideline of 730 ug/yr. Final Fayetteville Answer We will provide final verbal answers for air and water risk by July 11, with the report following. Washington Works We will provide a rough scope and estimate for the new work that was discussed by July 9. DJM000275 EID502517