Grantee Research Project Results
1999 Progress Report: Air Pollutant Concentrations in the Vicinity of Buildings: Model Development and Evaluation
EPA Grant Number: R826156Title: Air Pollutant Concentrations in the Vicinity of Buildings: Model Development and Evaluation
Investigators: Peterson, Holly G. , Lamb, Brian , Stock, David , Schulman, Lloyd
Institution: Montana Tech of the University of Montana
Current Institution: Montana Tech of the University of Montana , Washington State University
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1997 through September 30, 2000
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $360,011
RFA: Exploratory Research - Physics (1997) RFA Text | Recipients Lists
Research Category: Water , Land and Waste Management , Air , Safer Chemicals
Objective:
A better understanding of near-source plume behavior is important for predicting human health risks from acute exposure to toxic air pollutants. In particular, complicated airflow patterns from short stacks or vents in the vicinity of buildings may cause high concentrations of toxic air pollutants near ground level. The Electrical Power Research Institute, in cooperation with the Environmental Protection Agency, recently developed algorithms to predict air pollutant concentrations near buildings. This set of algorithms is known as the Plume Rise Model Enhancement (PRIME), and ISC-PRIME is the corresponding new version of the Industrial Source Complex (ISC) model. The model predicts concentrations downwind of pollutant sources with averaging times of between 1 hour and 1 year, and includes concentrations near buildings in recirculation cavities and downwash regions.The overall goals of this project are to evaluate ISC-PRIME with field data and to improve our fundamental understanding of plume dispersion near buildings. Specific objectives are to: (1) conduct field campaigns to characterize the behavior of trace gases in the vicinity of a building under a range of meteorological conditions; (2) employ advanced numerical finite element modeling to aid field data interpretation; and (3) link results from the field work and numerical studies to test ISC-PRIME.
Progress Summary:
Preliminary fieldwork was performed under afternoon and evening conditions during the summer of 1998 near an industrial-sized building located south of Butte, Montana. Approximately 19 tests, each 1 hour in duration, were conducted under afternoon and evening conditions. In 1999, 33 experiments were conducted during nighttime hours at a rural site outside of Colfax, Washington.In both studies, anemometers were used to monitor approach flows and turbulence within the building cavity. Sulfur hexafluoride (SF6) tracer gas was released through calibrated flowmeters from one of several locations (upwind of the building, within the recirculation cavity near the ground, at the top of the roof, and above roof level). An array of syringe samplers was used to measure time-averaged concentrations within and near the cavity, while fast-response SF6 analyzers monitored concentration fluctuations.
Results to date have addressed concentration fluctuations within the building recirculation cavity and comparison of 1 hour average concentrations to ISC-PRIME predictions. Specifically for a subset of the 1999 data, maximum concentrations with time scales on the order of 1 second exceeded average concentrations by approximately 4?6 times in the building cavity interior, and much greater peak-to-mean ratios were observed at cavity fringes. Also, ISC-PRIME predicted the proper location of the maximum average concentration in the cavity with the modeled value within a factor of 1.4?1.5 of the observed concentration. The model was within a factor of 2.7 for all cavity interior locations; but for points near the cavity borders, larger observed-to-predicted ratios occurred.
Future Activities:
Processing and analysis of the 1999 field data will continue through spring of 2000, and results will be summarized in a paper for publication in a peer-reviewed journal. Additional field experiments will be conducted during the summer of 2000 to fill in the gaps of the 1998/1999 data set. In addition, advanced numerical techniques will be applied to simulate flow about the buildings in both field campaigns.Journal Articles:
No journal articles submitted with this report: View all 9 publications for this projectSupplemental Keywords:
air, ambient air, modeling., Scientific Discipline, Air, Physics, Environmental Chemistry, Atmospheric Sciences, Engineering, Chemistry, & Physics, building vicinity, aerosol particles, air pollution concentrations, building plume downwash models, database development, air pollution, atmospheric stability, plume dispersion model, tracer experimentRelevant Websites:
http://www.mtech.edu/dispersion/
http:// www.ce.wsu.edu/LAR
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.