Air Pollution:

Reliability and Adequacy of Air Quality Dispersion Models

RCED-88-192: Published: Aug 24, 1988. Publicly Released: Sep 27, 1988.

Additional Materials:

Contact:

Office of Public Affairs
(202) 512-4800
youngc1@gao.gov

Pursuant to a congressional request, GAO reviewed the status and results of the Environmental Protection Agency's (EPA): (1) testing of its air quality dispersion models to determine their reliability; and (2) efforts to develop additional models to meet identified needs.

GAO found that: (1) EPA evaluated 29 of its 48 air quality dispersion models using the recommended uniform statistical approach; (2) EPA evaluated two of the models before it adopted the uniform approach; (3) other organizations evaluated nine of the models, but did not use the uniform approach; (4) the models' reliability ranged from underestimating pollution concentrations by 50 percent to overestimating concentrations by 1,720 percent; (5) some models gave substantially different results when tested at different sites; (6) EPA is studying the use of simulated conditions to obtain more reliable estimates of model reliability; and (7) EPA believes that the model estimates are still useful as regulatory and research tools as long as users recognize their limitations. GAO also found that EPA: (1) in 1985, identified 65 of 241 modelling needs as high priority; (2) has not identified the actual number of models or amount of funding it requires to meet all of its modelling needs; and (3) estimated that it would cost $97 million to develop and evaluate models to address 6 urgent and 70 high-priority modelling needs.

Oct 18, 2017

Oct 16, 2017

Oct 12, 2017

Oct 2, 2017

Sep 18, 2017

Sep 6, 2017

Aug 16, 2017

Aug 3, 2017

Jun 20, 2017

Jun 15, 2017

Looking for more? Browse all our products here