Model Clearinghouse Information Storage and Retrieval System
Record Details

Issue:

Vineyard Northeast, LLC has proposed developing an offshore wind energy 
project (VNE 1 Project) in a federal lease area on the Outer Continental 
Shelf (OCS) off the coast of Massachusetts, south of Nantucket Island. 
The VNE 1 Project will include up to 99 wind turbine generators and 1 
electrical service platform within the lease area. The VNE 1 Project is 
subject to Prevention of Significant Deterioration (PSD) permitting and 
is required to submit an OCS Air Permit application that includes a 
dispersion modeling demonstration that air emissions from the project will 
not cause or contribute to an exceedance of the National Ambient Air 
Quality Standards (NAAQS) or PSD increments.

Vineyard Northeast, LLC has requested to use an alternative model, as 
provided in Section 3.2 of the Guideline on Air Quality Models (40 CFR 
Part 51, Appendix W) , to conduct its PSD air quality modeling analysis 
of the VNE 1 Project. Specifically, Vineyard Northeast, LLC has submitted 
a justification  for the use of the Coupled Ocean-Atmosphere Response 
Experiment (COARE) bulk flux algorithm, as implemented in the AERCOARE 
meteorological data preprocessor program, to prepare meteorological data 
for use in the American Meteorological Society/Environmental Protection 
Agency Regulatory Model (AERMOD) dispersion program in lieu of the preferred 
Offshore and Coastal Dispersion (OCD) model to assess ambient impacts in a 
marine environment. 

EPA Region 1 has conducted a thorough review of Vineyard Northeast, LLC’s 
request and has found the proposed application of the alternative model to 
be satisfactory and addresses the requirements of the Guideline, 
Section 3.2.2(b), Condition (3), including the subsequent five elements 
contained in Section 3.2.2(e). As such, pursuant to the Guideline, 
Sections 3.0(b) and 3.2.2(a), Region 1 currently intends to approve the use 
of proposed coupled AERCOARE-AERMOD alternative model approach for the 
VNE 1 Project air permit application.

C/H Response:

The Model Clearinghouse concurs with EPA Region 1’s proposed approval of a 
coupled AERCOARE-AERMOD alternative modeling approach for the air quality 
modeling analysis required in the VNE 1 Project based on the alternative 
model request package provided by Vineyard Northeast, LLC and the review 
documentation in the alternative model concurrence request memorandum 
provided by EPA Region 1. The Model Clearinghouse encourages EPA Region 1 
to respond to Vineyard Northeast, LLC and to the docket for federal 
permitting actions related to the VNE 1 Project with a letter of alternative 
model approval, as appropriate. The information associated with the EPA 
Region 1 alternative model approval and the Model Clearinghouse concurrence 
should be available for comment during the appropriate public comment period(s).

Given the possible importance of platform downwash and shoreline fumigation, 
the Model Clearinghouse continues to recommend caution and careful review 
before additional alternative model considerations of the coupled 
AERCOARE-AERMOD model methodology in other projects. 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 here and with similar AERCOARE-AERMOD 
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 VNE 1 Project
        Dated: June 14, 2024
        From:  George Bridgers, Model Clearinghouse Director
                 Air Quality Modeling Group, Air Quality Assessment Division, 
                 Office of Air Quality Planning and Standards
        To:    Patrick Bird, Manager
                 Air Permits, Toxics, and Indoor Programs Branch, Air and Radiation Division
                 EPA Region 1
        Thru:  Lynne Hamjian, Director
                 Air and Radiation Division
                 EPA Region 1
                 
Memo:  Concurrence Request for Approval of Alternative Model AERCOARE in Conjunction 
with AERMOD, in Support of Outer Continental Shelf PSD air permitting of the 
VNE 1 Project
        Dated: June 3, 2024
        From:  Patrick Bird, Manager
                 Air Permits, Toxics, and Indoor Programs Branch, Air and Radiation Division
                 EPA Region 1
        Thru:  Lynne Hamjian, Director
                 Air and Radiation Division
                 EPA Region 1
        To:    George Bridgers, Model Clearinghouse Director
                 Air Quality Modeling Group, Air Quality Assessment Division, 
                 Office of Air Quality Planning and Standards

Memo:  VNE 1 Request for Approval to use COARE Bulk Flux Algorithm to Generate Hourly
Meteorological Data for use with AERMOD
        Dated: May 9, 2024