HRM Houston Regional Monitoring 1 Hazardous Air Pollutants Ambient Air Monitoring Data Review Air Toxics: What We Know, What We Don’t Know, and What We Need to Know October 17-18, 2005 University of Houston Hilton – Houston, Texas

HRM Houston Regional Monitoring 2 Houston Regional Monitoring Network u Houston Regional Monitoring (HRM) A voluntary industry consortium Operates an ambient air quality-monitoring network in the Houston ship channel area Continuous criteria pollutant data collected for past 24 years, Periodic (24 hour composite samples, every 6 th day) VOC data collected for past 18 years u Data gathered and reported to date are effective in assessing long-term trends for specific pollutants

HRM Houston Regional Monitoring 3 Houston Area Air Monitors u Houston ranks #1 in the number of air monitors in the nation u There are 48 ozone monitors in the Houston- Galveston-Brazoria (HGB) area operated by the TCEQ, City, Harris County, HRM, and other independent sources u There are 32 monitors that measure hazardous air pollutants (HAPs) in HGB

HRM Houston Regional Monitoring 4 Sampling and Analytical Methodology u HRM routinely samples for 157 VOCs at seven sites in Houston Ship Channel u 24-hour time averaged canister VOC samples are collected once every 6th day u Samples are analyzed by EPA TO-15 u Samples are analyzed by gas chromatography/mass spectroscopy u To date over 9,000 samples have been collected and reported

HRM Houston Regional Monitoring 5 HGB HAP Monitors Legend TCEQ & EISM sites HRM sites

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HRM Houston Regional Monitoring 7 * ESL Based on Odor Benzene marginally exceeds the annual ESL at a single site in the HRM Network

HRM Houston Regional Monitoring 8 How does Houston’s air compare to that of other cities for selected compounds?

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HRM Houston Regional Monitoring 13 How Are 1,3-Butadiene Levels Trending in the Houston Ship Channel?

HRM Houston Regional Monitoring 14 Annual Median 1,3-Butadiene Concentration at HRM Sites Annual Medians have declined below 1 ppb-V since 2002

HRM Houston Regional Monitoring 15 Annualized 1,3 Butadiene Reduction Trend Over 10-Year Period ( )* * Annualized trend based on linear regression model

HRM Houston Regional Monitoring 16 Comparison of HRM and TCEQ Annual Mean 1,3-Butadiene Concentrations in Houston Compared to Trends from Other US Cities ( through ) EPA AIRData

HRM Houston Regional Monitoring 17 Observations and Conclusions u Houston industry working in concert with the TCEQ has been active in collecting long-term (high quality) measurements to assess community exposure u There are over 30 HAP monitors currently operating in the Greater Houston Metropolitan area making this area the most heavily monitored area for hazardous air pollutants in the US u It is expected that emissions of HRVOC and associated HAPs will continue to decline in Houston as new rules are phased in to meet the 8-hour Ozone standard u Long-term measurements of air toxics are expected to continue in order to address questions with regard to community health u HRM will continue to do its part to provide high quality data to better understand air quality issues in the region u Houston’s air quality has dramatically improved and will continue to improve

HRM Houston Regional Monitoring 18 Our Commitment to Air Quality With more than 40 air monitors, Houston has the most extensive monitoring network in the U.S. The Houston Regional Monitoring Network is an important part of Houston's air monitoring system. HRM is committed to the scientific understanding of air quality in the Houston area. Our efforts focus on demonstrating attainment of all air quality standards.