Pre-filed testimony in support of the ten persons group by Nathan G. Phillips

Abstract

I have two interrelated technical concerns with the Enbridge Model used by MassDEP to grant the air permit for the proposed Weymouth, which invalidate the air permit. I state these immediately below and elaborate on them thereafter. Rural Designation Ignores Coastal Site. Enbridge mischaracterized the site as “rural” when in fact it is a coastal, shoreline site embedded in an urban coastal community. This means the model cannot assess key meteorological phenomena important for pollution dispersion. Using an incorrect site characterization - even if surface meteorological measurements were made in a reasonably comparable location (Logan Airport compared to 50 Bridge Street, Weymouth) - means that the model cannot represent coastal/shoreline advection and incorrectly assumes that surface winds are uniform across a uniform surface rather than exhibiting sharp spatial gradients in surface energy balance and resulting atmospheric stability, winds, and air mixing associated with the water-land boundary. Shoreline Boundary Layer Development and Thermal Inversions Ignored. Since the Enbridge model is incapable of capturing shoreline effects it cannot assess the potential of pollution trapping through under-developed thermal internal boundary layers that may blanket residential areas. Moreover, MassDEP made no data collection or model validation across seasons, crucially ignoring winter coastal temperature inversions and resulting pollution trapping. Thermal and radiative inversions occur typically over vertical length scales of 150 meters, whereas the paired surface and upper air temperature measurements (from Gray, Maine, 185 miles away) used in the Enbridge Model are intended to and can only capture mesoscale effects, and cannot resolve crucial shoreline inversion events. The applicant’s consultant does not state what altitude it used for “upper air” measurements (www.mass.gov/files/documents/2018/06/11/algonquin-modeling.pdf) but according to EPA guidance these are typically several kilometers. The Enbridge Model mistakenly effectively assumes a fully-developed boundary layer condition and is thus unable to produce conditions that produce shoreline-induced looping or downwelling fumigating plumes that can expose residents to intermittently high concentrations of pollutants.