22-28 Blasts/Explosions

How will the Spectra compressor station and pipeline be protected from an event potentially triggering a larger scale accident at the Spectra site? Has this potential been calculated into the scope of the impact area proximate to the site?

Invenergy cannot speak for Spectra or to the details of the Spectra site.  However, please see Invenergy’s response to Town’s Request No. 17-1 and Spectra Letter, attached to Invenergy’s response to Town Request No. 17-1.

To repeat, here is Invenergy’s Response to No. 17-1 (exhibit not re-attached):

Invenergy Thermal Development LLC (“Invenergy”) does not believe there is a possibility that an explosion at Spectra’s Burrillville Compressor Station (“BCS”) could cause an explosion at Clear River Energy Center (“CREC”).  As discussed in our response to questions 17-2, 3 and 17-4 Invenergy engaged Exponent as an expert consultant who has ample experience in evaluating the types of events that are being postulated in the question. Exponent estimated the area that could be impacted by an event at either location is really a function of the size of the enclosed area (e.g. building) where gas could accumulate and given that the powerhouse building at CREC is larger and has more volume than the building at Spectra’s site, an event at CREC would be governing. Please refer to the response to question 17-2 for the results of this event.

As it relates to the potential of an explosion at the Spectra/Algonquin compressor station which could cause damage at CREC, Invenergy contacted Spectra with regard to this question, and Spectra provided the attached letter that highlights the diligence associated with safe operation and maintenance of natural gas compressor facilities and outlines the federal standards they use for the design and maintenance of their facilities. In the attached response Spectra indicates that their Integrity Management Program has determined the Potential Impact Radius (“PIR”) of a possible event, and the PIR is limited to their site and more specifically the fenced area of their site (as it relates to an event at the BCS itself).     

The physical separation of the Algonquin compressor station and the CREC minimizes the possibility of direct impacts to the CREC in the remotely possible event of a fire or explosion.