Model Clearinghouse Information Storage and Retrieval System
Record Details

Issue:  

The U.S. Environmental Protection Agency (EPA) Region 1 seeks concurrence 
from the Model Clearinghouse regarding the prospective EPA Region 1 
approval of an alternative model for an Outer Continental Shelf (OCS) 
Prevention of Significant Deterioration (PSD) permitting effort. The 
AERCOARE meteorological data preprocessor program will be used in 
conjunction with AERMOD (AERCOARE/AERMOD) to conduct an air quality 
modeling analysis as part of the PSD permit application for the proposed 
Vineyard Wind LLC’s Park City Wind project to be located off the coast 
of Massachusetts near Martha’s Vineyard. Vineyard Wind LLC has sought 
approval to allow the use of the AERCOARE/AERMOD model for their air 
quality modeling analysis, under 40 CFR Part 51, Appendix W §3.2.2(b), 
Condition (3), for the projects OCS PSD permit application. Under 
Condition (3), an alternative model may be used if the Regional Office 
finds the conditions specified in Appendix W §3.2.2(e) are satisfied.

Vineyard Wind LLC submitted their alternative model request on 
August 9, 2021. The request provided evidence and arguments supporting 
approvability of the modeling approach under Appendix W §3.2.2(b), 
Condition (3). EPA’s prior approvals of the AERCOARE/AERMOD, using 
measured meteorological measurements from buoys, are well documented in 
the Model Clearinghouse’s public database. EPA Region 1 also considered 
additional peer-reviewed scientific literature regarding the 
AERCOARE/AERMOD approach when using WRF-MMIF data, which is the approach 
proposed for the project.

EPA Region 1 has conducted a thorough review of the request and intends 
to approve the use of AERCOARE/AERMOD as an alternative model to 
conduct the air quality modeling analysis as part of the Park City Wind 
OCS PSD permit application. We have found the proposed application of 
the model is satisfactory under the requirements of §3.2.2(e). A technical 
analysis summarizing our review is attached to this memo for your 
consideration and includes the August 2021 alternative model request 
submitted by Vineyard Wind LLC.

C/H Response:  

The Model Clearinghouse fully concurs with EPA Region 1 proposed approval 
of a coupled AERCOARE-AERMOD approach for the compliance demonstration 
analysis required in the Park City Wind project based on the alternative 
model justification package provided by Vineyard Wind LLC and the technical 
review documentation provided by EPA Region 1. Given the possible 
importance of platform downwash and shoreline fumigation, the Model 
Clearinghouse recommends caution and careful review before additional 
alternative model considerations of the coupled AERCOARE-AERMOD approach 
in other projects. As similarly stated in the respective EPA Region 6 and 
EPA Region 10 concurrence responses, this case-specific Model Clearinghouse 
concurrence does not constitute a generic approval of a coupled 
AERCOARE-AERMOD approach for other applications elsewhere. However, the 
scope of the technical assessment submitted with this EPA Region 1 and 
the related EPA Region 6 (reference ID No. 19-VI-01) and EPA Region 10 
(reference ID No. 11-X-01) Model Clearinghouse alternative model 
requests continue to provide a good basis for such considerations.

Memo:  Model Clearinghouse review of an alternative model application of AERCOARE
in conjunction with AERMOD in Support of Outer Continental Shelf PSD air
permitting of the Park City Wind offshore wind power project
        Dated: January 28, 2022
        From:  George Bridgers, Model Clearinghouse Director
                 Air Quality Modeling Group, Air Quality Assessment Division, 
                 Office of Air Quality Planning and Standards
        To:    Jay McAlpine, Regional Air Permit Modeler (on detail)
                 Air Permits, Toxics, and Indoor Programs Branch, Air and Radiation Division
                 EPA Region 1, Boston, Massachusetts
               Lynne Hamjian, Director
                 Air and Radiation Division
                 EPA Region 1, Boston, Massachusetts
                 
Memo:  Concurrence Request for Approval of Alternative Model AERCOARE in
Conjunction with AERMOD, in Support of Outer Continental Shelf PSD air permitting
of the Park City Wind offshore wind power project
        Dated: December 22, 2021
        From:    Jay McAlpine, Regional Air Permit Modeler (on detail)
                 Air Permits, Toxics, and Indoor Programs Branch, Air and Radiation Division
                 EPA Region 1, Boston, Massachusetts
        Thru:  Lynne Hamjian, Director
                 Air and Radiation Division
                 EPA Region 1, Boston, Massachusetts
        To:    George Bridgers, Model Clearinghouse Director
                 Air Quality Modeling Group, Office of Air Quality Planning and Standards

Memo:  Technical Review of the Vineyard Wind Request to Use the AERCOARE Meteorological 
Data Preprocessor Program in conjunction with AERMOD in support of its Outer
Continental Shelf (OCS) Permit Application for the Park City Wind project
        Dated: December 21, 2021