GZA GeoEnvironmental, Inc.

Scope Of Work

GZA was retained by one of the largest Cogeneration facilities in the world to evaluate planned changes to the combined cycle natural gas fired turbines with respect to the federal New Source Review (NSR) program requirements as well as State-specific requirements.  GZA concluded that the changes would require review under the federal NSR/PSD program and prepared a permit application which included developing the appropriate best available control technology (BACT) review as well as an ambient impact analysis demonstrating that air quality would not be significantly impacted by the proposed changes.  A netting analysis was also conducted to demonstrate that there was not a significant net increase of particulate matter or volatile organic compounds associated with the planned changes.  A PSD permit application was submitted to the Michigan Department of Environmental Quality (MDEQ) and the BACT and ambient air impact analyses were accepted by the MDEQ.  GZA provided review and comment on the draft permit-to-install (PTI) which was followed by issuance of a PTI allowing construction to proceed within the facility’s timeframe. 

The BACT analysis considered the technical feasibility of multiple control technologies and strategies for the significant criteria pollutants (NOX, CO and SO2) and also included appropriate costs analyses based in part upon USEPA’s OAQPS Control Cost Manual and CostAIR spreadsheets.  The application demonstrated that the facility’s existing air emissions control system and strategies would constitute BACT. 

The modeling efforts included: Creation of base maps utilizing internet or other sources;  Locating and importing terrain data as needed from sources such as webMet or equivalent;  Obtaining and importing meteorological data;  Importing site plans and process layouts in AutoCAD format and adjusting to ensure true north was identified;  Manual input of additional stack and building parameters and importing of stack parameters and chemical specific emission rates including data from off-site sources for NAAQS impact and increment analyses;  Development of AERMOD modeling runs including running BPIP for building downwash and establishment of  appropriate receptor grids.  Modeling output was evaluated to demonstrate that facility criteria and air toxics emissions met the applicable ambient impact standards.

Upon issuance of the PTI, the facility retained GZA to prepare a Title V Operating Permit amendment package for submittal to the MDEQ addressing the amended NSR permits.  In addition, the facility’s NOX Budget Permit was included in the Title V amendment package pursuant to the State regulations.

Subsequently, GZA permitted the installation of six – 370MMBtu/Hr natural gas fired boilers for the site.  A PSD permit application was submitted to the State air quality agency and included a BACT review and ambient impact analyses.  The BACT and ambient impact analyses were accepted followed by issuance of a permit allowing construction to proceed in a timely manner.