Excerpted from Galena-Park-Monitoring-Report-FINAL.pdf
Are the current TCEQ PM2.5 Monitors representative of the Galena Park Community?
by Laura Campos Rice University Department of Statistics 6100 Main Street June 2014
OBJECTIVES: The primary objective of this study was to determine if PM2.5 concentrations measured at current Texas Commission on Environmental Quality (TCEQ) fixed site monitors in the Galena Park area are representative of those within the Galena Park community by comparing the PM2.5 concentrations from TCEQ area fixed site monitors to the Air Alliance Houston (AAH) Monitors located in the community.
METHODS: Concentrations of PM2.5 at TCEQ fixed site monitors and at the AAH monitors were statistically compared. Because there are no TCEQ monitors within the Galena Park community, the TCEQ concentrations were obtained from surrounding TCEQ monitors. A comparison was made with the AAH monitor concentrations and the nearest TCEQ monitor concentrations. In addition, a similar comparison was made with the AAH monitor concentrations and a concentration within the Galena Park community derived from inverse distance weighting of several surrounding TCEQ fixed site monitor concentrations.
RESULTS AND CONCLUSIONS: The nearest TCEQ monitoring is located between 1 and 1.5 miles from the AAH monitoring locations on Clinton Drive. No statistically significant difference was found between the concentrations at this site and the AAH concentrations. Because both the Clinton Drive location and Galena Park community are proximate to similar particulate emission sources (i.e., heavy diesel traffic and other Port of Houston activities), and the Clinton Drive monitor location is much nearer than the next closest TCEQ monitors, comparison with Clinton Drive concentrations is most appropriate.
In addition, no statistically significant difference was found between the PM2.5 concentration from surrounding TCEQ fixed site monitor estimated from inverse distance weighting and the AAH concentrations. This result is consistent with the direct comparison to Clinton Drive, and anticipated because the distance to other monitors is much greater than that of Clinton Drive (i.e., Clinton Drive concentrations heavily influence the inverse distance weighting estimate).
While this analysis did not find a statistically significant difference between concentrations measured at AAH locations compared with TCEQ locations, care should be taken in drawing a decisive conclusion based on these analyses because AAH and TCEQ use different sampling and analysis methods. Differences introduced by using different sampling and analysis techniques should be better understood possibly through co-location of an AAH monitor at the Clinton Drive location.