A Division scientist is a member of the Air Subcommittee, a working subcommittee of the
Chesapeake Bay Program. Previously this Subcommittee was an advisory group to the
Implementation Committee. The subcommittee has responsibility for advice and leadership on
issues of atmospheric deposition to the watershed and the Bay, on overseeing application of the
Extended Regional Acid Deposition Model (Extended RADM) to link atmospheric deposition
with watershed models, and in dealing with the potential role of atmospheric deposition on Bay
restoration efforts.
The Air Subcommittee also works with other Chesapeake Bay committees to
define the top priority air quality scenarios to be simulated by the Extended RADM.
The Division scientist is also a member of the Modeling Subcommittee of the
Implementation Committee. This Subcommittee has responsibility for overseeing the application
of water quality models and coordinating the linkage of Extended RADM with those models and
the interpretation of the findings.
Work with the Extended RADM focused on a re-evaluation of
the potential magnitude of reductions in oxidized nitrogen deposition
stemming from the Clean Air Act Amendments (CAAA) and possible
additional reductions from point sources beyond requirements of the CAAA.
The CAAA reductions were associated with the new heavy duty diesel rule
being promulgated by EPA for 2020 and the additional point source
reductions were those being examined by the EPA Office of Air Programs,
Clean Air Markets Division. The Extended RADM was also used to estimate
the relative contribution each of the six Bay states’ (Maryland,
Pennsylvania, Virginia, New York, Delaware, and West Virginia) nitrogen
oxide emissions make to the oxidized nitrogen deposition to the
Chesapeake Bay major tributaries.
