2022 05-17 CC PACKET - Laserfiche WebLink

Home

Appendix B - 2009-2018 TCE in Air Maps DEPARTMENT will OF HEALTH Water Gremlin HEALTH ASSESSMENT SERIES 12009-2018 TCE IN AIR MAPS Maps of estimates of TCE in air from the Water G. rem lia facility from 2009-2018, based on.MPCA air dispersion modeling data, are how available. The maps were created to provide:a better understanding of estimated annual average TCE concentrations over time. The 2018 map is very similar to the map distributed in February 2019. To see the original map and for information about TCE and health, go to the TCE Air Emissions and Health document found at www.health.state: mn.us/commu nities/environment/hazardous/dots/sites/ramsey/wgtceairerni sum.ndf. What do the maps show? The. maps show the range of.estimated annual average amounts of TCE in outdoor air at.different locations. These locations were predicted by air quality dispersion modeling to be above the M.DH inhalation Health -Based Value. (HBV) of-2 ggfm3 (micrograms per cubic meter). The HBV. is anamount, or concentration, of a contaminant in air that is unI!kely to. lead to health effects even if sensitive members of the population are exposed to it 24 hours a day, 7 days a week,. for .a.Iifetime. The .highest TCE amounts were. predicted to beon the Water Grem linproperty. The.. highest annual average concentration at a residential property was estimated and noted on each MP p: What is air quality dispersion modeling? Air quality dispersion modeling uses computer simulation to predict the amount of a pollutant in air at different locations and distances from a source. MPCA used the AERMO❑ dispersion model; developed and recommended. by the U.S. EPA, -to estimate the concentrations of air pollutants emitted from Water Gremlin. AERMOD simul.atio.n typ'i.cally considers the emis.s.ion rate,:stack height, stack diameter., and stack. gas temperature and velocity, as well as the effect of nearby buildings and terrain. AERMOD also uses meteorological data.such as temperature, wind. direction, and. wind speed. Why is the shape of the 2018 map slightly different on earlier versions? Meteorological data,. such as tern perature, wind direction, and Wind speed, are used in the model to calculate TCE concentrations at v..arious locations.. Most meteorological data comes from surface weather observation stations Atairports,.The meteorological data used to model.Water Gremlin emissions earlier this year was from the Minneapolis/St. Paul International Airport. The updated map shows results when meteorological data from the Crystal, MN airport were used. The Crystal airport data are thought to represent conditions. near Water Gremlin better. Each 'map year uses meteorological data from the year of the map; with the exception that the 2417 and 2018.maps use 2016 data, which was the latest meteorological data. available at the time the modeling was conducted.,,