PORTABLE PM10 MONITORING FOR A LARGE ROADWAY TUNNEL PROJECT
Y.J. Lin, Bechtel Power Corporation
Alex Kasprak, Bechtel/Parsons Brinckerhoff

Presented at the AWMA 90th Annual Meeting & Exhibition, June 8-13, 1997

Abstract
INTRODUCTION
The Massachusetts Highway Department's Central Artery/Tunnel (CA/T) Project in Boston, Massachusetts, is one of the largest ongoing public works projects in the country today. When completed, the CA/T Project will consist of a new third harbor tunnel (named the Ted Williams Tunnel) which will link downtown Boston to Logan Airport in East Boston and a new 3 mile underground artery which will replace Boston's current elevated north-south expressway. The results of the Final Supplemental Environmental Impact Statement/Report for the CA/T Project concluded that the Project, when completed, should meet all applicable National and State Ambient Air Quality Standards (AAQS), and will result in beneficial long-term air quality impacts for the Boston area. However, during the peak construction period of the Project, fine particulate matter with a diameter of less than 10 microns (i.e., PM10) generated from CA/T construction activities, may result in potential exceedances of the 24-hour PM10 standard. In order to mitigate and minimize potential dust impacts, the CA/T Project has implemented PM10 monitoring to evaluate construction related fugitive particulate emissions. The objectives of the monitoring programs have been to 1) characterize background and construction phase PM10 levels along the Project's alignment; 2) verify design-phase dispersion modeling analyses; 3) assess the need for construction-related dust control measures. PM10 data collection for these programs have been obtained using a continuous real-time PM10 monitor approved by the Environmental Protection Agency (EPA) along with portable PM10 saturation samplers originally developed by the Lane Regional Air Pollution Authority (EPA Region 10). In addition, the equipment used to assess ambient PM10 impacts from construction related activities, have also been used to assess PM10 emissions from the ventilation system of completed sections of the CA/T's Ted Williams Tunnel.
This paper provides a comparison of ambient PM10 data that have been collected during the summer of 1994 using portable saturation samplers and comparing the data to coincident data collected by the Project's continuous reference PM10 air monitor (EPA approved). The comparison is used to justify the use of portable air samplers to record in-tunnel PM10 concentrations which are also presented to assess vehicle emissions rates from the CA/T's ventilation system.

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