T-B10901-00-10 Confidential 2013 Emission Summary and Dispersion Modelling Report FINAL Enbridge Gas Distribution Inc. – Crowland Compressor Station October 2013

WESA

Page i

EXECUTIVE SUMMARY AND EMISSION SUMMARY TABLE Enbridge Gas Distribution Inc. (Enbridge) retained WESA, a division of BluMetric Environmental Inc., to update the Emission Summary and Dispersion Modelling (ESDM) Report for their Crowland Compressor Station (ORTECH Report No. 90645-1-2 (Revision 1), March 7, 2013). The facility is located at 3969 White Road, Port Colborne, Ontario. The report was updated to change the reciprocating engine compressor exhaust parameters to a stack height above grade of 11.8 metres and exhaust diameter of 0.36 metres (14”). The Crowland Compressor Station is used to compress natural gas for storage and distribution purposes. During the warmer months of the year when demand for natural gas is lower, the natural gas received is injected via wells into underground storage pools. During colder months of the year when demand for natural gas is higher, the facility is used to compress and dehydrate the natural gas coming out of storage for transmission and distribution. The NAICS Code applicable to the facility is ‘221210 – Natural Gas Distribution’. Facilities described by this NAICS Code are not listed on Schedules 4 or 5 of Ontario Regulation 419/05 Air Pollution – Local Air Quality (O. Reg. 419/05) and are therefore allowed to demonstrate air compliance using Schedule 2 standards until February 1, 2020. However, Enbridge has requested and been approved for the application of Schedule 3 standards under section 20(4) of O. Reg. 419/05 for this facility in advance of the regulatory timeframe. This ESDM Report follows the requirements of O. Reg. 419/05 and the Ontario Ministry of the Environment (MOE) “Procedure for Preparing an Emission Summary and Dispersion Modelling Report Version 3.0” dated March 2009 (the Procedure), and references the Assessment Protocol for Compressor Stations, ORTECH Report 90645-1 (Revision 1), dated January 17, 2013 (the Protocol). The ESDM report includes the quantification of emission rates for all significant sources of contaminants, specifically oxides of nitrogen (NOX) and determination of the aggregate maximum point-of-impingement (POI) concentrations of NOX. The Emission Summary Table (Table 1) shows all of the significant sources and associated air contaminants, the maximum source or site-wide emission rates and maximum predicted 1-hour, and 24-hour calculated POI concentrations, and the POI limits used to evaluate all significant contaminant concentrations and the maximum percentages of the MOE Schedule 3 POI limits, where available. As shown on Table 1, the predicted maximum POI concentrations of NOX resulting from the maximum emission scenario are all below the MOE POI criteria.

T-B10901-00-10 Confidential 2013 Emission Summary and Dispersion Modelling Report FINAL Enbridge Gas Distribution Inc. – Crowland Compressor Station October 2013

WESA

Page ii

Table 1: Emission Summary Table

Contaminant Name

Contaminant CAS #

Total Facility

Emission Rate

Air Dispersion

Model Used

Maximum Off-Property POI Concentration

(μg/m3)

Averaging Period (hours)

MOE POI Limit

(μg/m3)

Limiting Effect

Regulation Schedule #

Percentage of MOE POI

Limit (%)

Nitrogen Oxides

10102-44-0 0.23 AERMOD 45 1 400 Health 3 11

Nitrogen Oxides

10102-44-0 0.0012 AERMOD 30 24 200 Health 3 15