Environmental Monitoring at MGP Remediation Sites

Coal tar contaminants include total volatile organic compounds (TVOC) and semi-volatile organic compounds (SVOCs). The TVOC compounds of concern (CoC) often include benzene; the SVOC CoCs include naphthalene. Coal tar vapors have an odor threshold of around 10 ppb (very low, comparatively speaking). Real-time air monitoring solutions for TVOCs can indicate the presence of coal tar contaminant—but not identify CoCs such as benzene. 

Triumvirate Environmental has provided both fixed and mobile air monitoring stations at many manufactured gas plant (MGP) remediation sites. These stations typically have particulate monitors that measure dust at a variety of particle sizes—and Photoionization Detectors (PIDs) that measure TVOC concentrations in real time. We designed these monitoring stations to support remote monitoring and to operate automatically. 

Attached to the PID is the Greenlight™ Benzene Monitor, which automatically screens the TVOC vapor for benzene when levels exceed a preset threshold (sometimes as low as 10 ppb). As part of this monitoring system, a TO-15 air sample can be initiated to collect vapors. After collection, our staff can analyze the sample for benzene and other VOCs, as well as naphthalene.  

The system connects to the Greenlight™ Environmental Monitoring System, which typically networks with one full weather station. The system also includes up to two wind speed and direction sensors—these accurately measure the varying wind flow site impacts. 

The system takes in data from the weather station and the wind speed and direction sensors, and integrates it with monitoring stations. Additionally, the solution streams live results to project personnel and other stakeholders, while the air monitoring system sends out alerts and notifications. The collected Greenlight™ System data can demonstrate if any given MGP project is safe—and not contaminating the surrounding community.